From: Duncan Dean Date: Wed, 7 Jun 2023 14:17:18 +0000 (+0200) Subject: Move inbound channel constructor into `InboundV1Channel` impl X-Git-Tag: v0.0.116-alpha1~10^2~7 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=baadeb73746980f684a0f2fff1a3c8f39350f9d0;p=rust-lightning Move inbound channel constructor into `InboundV1Channel` impl --- diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 131b9b40..7e983fa7 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -2018,2136 +2018,2093 @@ impl Channel { Ok(()) } - /// Creates a new channel from a remote sides' request for one. - /// Assumes chain_hash has already been checked and corresponds with what we expect! - pub fn new_from_req( - fee_estimator: &LowerBoundedFeeEstimator, entropy_source: &ES, signer_provider: &SP, - counterparty_node_id: PublicKey, our_supported_features: &ChannelTypeFeatures, - their_features: &InitFeatures, msg: &msgs::OpenChannel, user_id: u128, config: &UserConfig, - current_chain_height: u32, logger: &L, outbound_scid_alias: u64 - ) -> Result, ChannelError> - where ES::Target: EntropySource, - SP::Target: SignerProvider, - F::Target: FeeEstimator, - L::Target: Logger, - { - let announced_channel = if (msg.channel_flags & 1) == 1 { true } else { false }; + #[inline] + fn get_closing_scriptpubkey(&self) -> Script { + // The shutdown scriptpubkey is set on channel opening when option_upfront_shutdown_script + // is signaled. Otherwise, it is set when sending a shutdown message. Calling this method + // outside of those situations will fail. + self.context.shutdown_scriptpubkey.clone().unwrap().into_inner() + } - // First check the channel type is known, failing before we do anything else if we don't - // support this channel type. - let channel_type = if let Some(channel_type) = &msg.channel_type { - if channel_type.supports_any_optional_bits() { - return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned())); - } + #[inline] + fn get_closing_transaction_weight(&self, a_scriptpubkey: Option<&Script>, b_scriptpubkey: Option<&Script>) -> u64 { + let mut ret = + (4 + // version + 1 + // input count + 36 + // prevout + 1 + // script length (0) + 4 + // sequence + 1 + // output count + 4 // lock time + )*4 + // * 4 for non-witness parts + 2 + // witness marker and flag + 1 + // witness element count + 4 + // 4 element lengths (2 sigs, multisig dummy, and witness script) + self.context.get_funding_redeemscript().len() as u64 + // funding witness script + 2*(1 + 71); // two signatures + sighash type flags + if let Some(spk) = a_scriptpubkey { + ret += ((8+1) + // output values and script length + spk.len() as u64) * 4; // scriptpubkey and witness multiplier + } + if let Some(spk) = b_scriptpubkey { + ret += ((8+1) + // output values and script length + spk.len() as u64) * 4; // scriptpubkey and witness multiplier + } + ret + } - // We only support the channel types defined by the `ChannelManager` in - // `provided_channel_type_features`. The channel type must always support - // `static_remote_key`. - if !channel_type.requires_static_remote_key() { - return Err(ChannelError::Close("Channel Type was not understood - we require static remote key".to_owned())); - } - // Make sure we support all of the features behind the channel type. - if !channel_type.is_subset(our_supported_features) { - return Err(ChannelError::Close("Channel Type contains unsupported features".to_owned())); - } - if channel_type.requires_scid_privacy() && announced_channel { - return Err(ChannelError::Close("SCID Alias/Privacy Channel Type cannot be set on a public channel".to_owned())); - } - channel_type.clone() - } else { - let channel_type = ChannelTypeFeatures::from_init(&their_features); - if channel_type != ChannelTypeFeatures::only_static_remote_key() { - return Err(ChannelError::Close("Only static_remote_key is supported for non-negotiated channel types".to_owned())); - } - channel_type - }; - let opt_anchors = channel_type.supports_anchors_zero_fee_htlc_tx(); + #[inline] + fn build_closing_transaction(&self, proposed_total_fee_satoshis: u64, skip_remote_output: bool) -> (ClosingTransaction, u64) { + assert!(self.context.pending_inbound_htlcs.is_empty()); + assert!(self.context.pending_outbound_htlcs.is_empty()); + assert!(self.context.pending_update_fee.is_none()); - let channel_keys_id = signer_provider.generate_channel_keys_id(true, msg.funding_satoshis, user_id); - let holder_signer = signer_provider.derive_channel_signer(msg.funding_satoshis, channel_keys_id); - let pubkeys = holder_signer.pubkeys().clone(); - let counterparty_pubkeys = ChannelPublicKeys { - funding_pubkey: msg.funding_pubkey, - revocation_basepoint: msg.revocation_basepoint, - payment_point: msg.payment_point, - delayed_payment_basepoint: msg.delayed_payment_basepoint, - htlc_basepoint: msg.htlc_basepoint - }; + let mut total_fee_satoshis = proposed_total_fee_satoshis; + let mut value_to_holder: i64 = (self.context.value_to_self_msat as i64) / 1000 - if self.context.is_outbound() { total_fee_satoshis as i64 } else { 0 }; + let mut value_to_counterparty: i64 = ((self.context.channel_value_satoshis * 1000 - self.context.value_to_self_msat) as i64 / 1000) - if self.context.is_outbound() { 0 } else { total_fee_satoshis as i64 }; - if config.channel_handshake_config.our_to_self_delay < BREAKDOWN_TIMEOUT { - return Err(ChannelError::Close(format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks. It must be greater than {}", config.channel_handshake_config.our_to_self_delay, BREAKDOWN_TIMEOUT))); + if value_to_holder < 0 { + assert!(self.context.is_outbound()); + total_fee_satoshis += (-value_to_holder) as u64; + } else if value_to_counterparty < 0 { + assert!(!self.context.is_outbound()); + total_fee_satoshis += (-value_to_counterparty) as u64; } - // Check sanity of message fields: - if msg.funding_satoshis > config.channel_handshake_limits.max_funding_satoshis { - return Err(ChannelError::Close(format!("Per our config, funding must be at most {}. It was {}", config.channel_handshake_limits.max_funding_satoshis, msg.funding_satoshis))); - } - if msg.funding_satoshis >= TOTAL_BITCOIN_SUPPLY_SATOSHIS { - return Err(ChannelError::Close(format!("Funding must be smaller than the total bitcoin supply. It was {}", msg.funding_satoshis))); - } - if msg.channel_reserve_satoshis > msg.funding_satoshis { - return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must be not greater than funding_satoshis: {}", msg.channel_reserve_satoshis, msg.funding_satoshis))); - } - let full_channel_value_msat = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000; - if msg.push_msat > full_channel_value_msat { - return Err(ChannelError::Close(format!("push_msat {} was larger than channel amount minus reserve ({})", msg.push_msat, full_channel_value_msat))); - } - if msg.dust_limit_satoshis > msg.funding_satoshis { - return Err(ChannelError::Close(format!("dust_limit_satoshis {} was larger than funding_satoshis {}. Peer never wants payout outputs?", msg.dust_limit_satoshis, msg.funding_satoshis))); - } - if msg.htlc_minimum_msat >= full_channel_value_msat { - return Err(ChannelError::Close(format!("Minimum htlc value ({}) was larger than full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat))); + if skip_remote_output || value_to_counterparty as u64 <= self.context.holder_dust_limit_satoshis { + value_to_counterparty = 0; } - Channel::::check_remote_fee(fee_estimator, msg.feerate_per_kw, None, logger)?; - let max_counterparty_selected_contest_delay = u16::min(config.channel_handshake_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT); - if msg.to_self_delay > max_counterparty_selected_contest_delay { - return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_counterparty_selected_contest_delay, msg.to_self_delay))); - } - if msg.max_accepted_htlcs < 1 { - return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned())); - } - if msg.max_accepted_htlcs > MAX_HTLCS { - return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS))); + if value_to_holder as u64 <= self.context.holder_dust_limit_satoshis { + value_to_holder = 0; } - // Now check against optional parameters as set by config... - if msg.funding_satoshis < config.channel_handshake_limits.min_funding_satoshis { - return Err(ChannelError::Close(format!("Funding satoshis ({}) is less than the user specified limit ({})", msg.funding_satoshis, config.channel_handshake_limits.min_funding_satoshis))); - } - if msg.htlc_minimum_msat > config.channel_handshake_limits.max_htlc_minimum_msat { - return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, config.channel_handshake_limits.max_htlc_minimum_msat))); - } - if msg.max_htlc_value_in_flight_msat < config.channel_handshake_limits.min_max_htlc_value_in_flight_msat { - return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.channel_handshake_limits.min_max_htlc_value_in_flight_msat))); - } - if msg.channel_reserve_satoshis > config.channel_handshake_limits.max_channel_reserve_satoshis { - return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.channel_handshake_limits.max_channel_reserve_satoshis))); - } - if msg.max_accepted_htlcs < config.channel_handshake_limits.min_max_accepted_htlcs { - return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.channel_handshake_limits.min_max_accepted_htlcs))); - } - if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { - return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); - } - if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS { - return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS))); - } + assert!(self.context.shutdown_scriptpubkey.is_some()); + let holder_shutdown_script = self.get_closing_scriptpubkey(); + let counterparty_shutdown_script = self.context.counterparty_shutdown_scriptpubkey.clone().unwrap(); + let funding_outpoint = self.funding_outpoint().into_bitcoin_outpoint(); - // Convert things into internal flags and prep our state: + let closing_transaction = ClosingTransaction::new(value_to_holder as u64, value_to_counterparty as u64, holder_shutdown_script, counterparty_shutdown_script, funding_outpoint); + (closing_transaction, total_fee_satoshis) + } - if config.channel_handshake_limits.force_announced_channel_preference { - if config.channel_handshake_config.announced_channel != announced_channel { - return Err(ChannelError::Close("Peer tried to open channel but their announcement preference is different from ours".to_owned())); - } - } + fn funding_outpoint(&self) -> OutPoint { + self.context.channel_transaction_parameters.funding_outpoint.unwrap() + } - let holder_selected_channel_reserve_satoshis = get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis, config); - if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { - // Protocol level safety check in place, although it should never happen because - // of `MIN_THEIR_CHAN_RESERVE_SATOSHIS` - return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). dust_limit_satoshis is ({}).", holder_selected_channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); - } - if holder_selected_channel_reserve_satoshis * 1000 >= full_channel_value_msat { - return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({})msats. Channel value is ({} - {})msats.", holder_selected_channel_reserve_satoshis * 1000, full_channel_value_msat, msg.push_msat))); - } - if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { - log_debug!(logger, "channel_reserve_satoshis ({}) is smaller than our dust limit ({}). We can broadcast stale states without any risk, implying this channel is very insecure for our counterparty.", - msg.channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS); - } - if holder_selected_channel_reserve_satoshis < msg.dust_limit_satoshis { - return Err(ChannelError::Close(format!("Dust limit ({}) too high for the channel reserve we require the remote to keep ({})", msg.dust_limit_satoshis, holder_selected_channel_reserve_satoshis))); + /// Claims an HTLC while we're disconnected from a peer, dropping the [`ChannelMonitorUpdate`] + /// entirely. + /// + /// The [`ChannelMonitor`] for this channel MUST be updated out-of-band with the preimage + /// provided (i.e. without calling [`crate::chain::Watch::update_channel`]). + /// + /// The HTLC claim will end up in the holding cell (because the caller must ensure the peer is + /// disconnected). + pub fn claim_htlc_while_disconnected_dropping_mon_update + (&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L) + where L::Target: Logger { + // Assert that we'll add the HTLC claim to the holding cell in `get_update_fulfill_htlc` + // (see equivalent if condition there). + assert!(self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32) != 0); + let mon_update_id = self.context.latest_monitor_update_id; // Forget the ChannelMonitor update + let fulfill_resp = self.get_update_fulfill_htlc(htlc_id_arg, payment_preimage_arg, logger); + self.context.latest_monitor_update_id = mon_update_id; + if let UpdateFulfillFetch::NewClaim { msg, .. } = fulfill_resp { + assert!(msg.is_none()); // The HTLC must have ended up in the holding cell. } + } - // check if the funder's amount for the initial commitment tx is sufficient - // for full fee payment plus a few HTLCs to ensure the channel will be useful. - let funders_amount_msat = msg.funding_satoshis * 1000 - msg.push_msat; - let commitment_tx_fee = commit_tx_fee_msat(msg.feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT, opt_anchors) / 1000; - if funders_amount_msat / 1000 < commitment_tx_fee { - return Err(ChannelError::Close(format!("Funding amount ({} sats) can't even pay fee for initial commitment transaction fee of {} sats.", funders_amount_msat / 1000, commitment_tx_fee))); + fn get_update_fulfill_htlc(&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L) -> UpdateFulfillFetch where L::Target: Logger { + // Either ChannelReady got set (which means it won't be unset) or there is no way any + // caller thought we could have something claimed (cause we wouldn't have accepted in an + // incoming HTLC anyway). If we got to ShutdownComplete, callers aren't allowed to call us, + // either. + if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { + panic!("Was asked to fulfill an HTLC when channel was not in an operational state"); } + assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); - let to_remote_satoshis = funders_amount_msat / 1000 - commitment_tx_fee; - // While it's reasonable for us to not meet the channel reserve initially (if they don't - // want to push much to us), our counterparty should always have more than our reserve. - if to_remote_satoshis < holder_selected_channel_reserve_satoshis { - return Err(ChannelError::Close("Insufficient funding amount for initial reserve".to_owned())); - } + let payment_hash_calc = PaymentHash(Sha256::hash(&payment_preimage_arg.0[..]).into_inner()); - let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() { - match &msg.shutdown_scriptpubkey { - &Some(ref script) => { - // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything - if script.len() == 0 { - None - } else { - if !script::is_bolt2_compliant(&script, their_features) { - return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))) - } - Some(script.clone()) - } - }, - // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel - &None => { - return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned())); - } - } - } else { None }; + // ChannelManager may generate duplicate claims/fails due to HTLC update events from + // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop + // these, but for now we just have to treat them as normal. - let shutdown_scriptpubkey = if config.channel_handshake_config.commit_upfront_shutdown_pubkey { - match signer_provider.get_shutdown_scriptpubkey() { - Ok(scriptpubkey) => Some(scriptpubkey), - Err(_) => return Err(ChannelError::Close("Failed to get upfront shutdown scriptpubkey".to_owned())), - } - } else { None }; - - if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey { - if !shutdown_scriptpubkey.is_compatible(&their_features) { - return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey))); + let mut pending_idx = core::usize::MAX; + let mut htlc_value_msat = 0; + for (idx, htlc) in self.context.pending_inbound_htlcs.iter().enumerate() { + if htlc.htlc_id == htlc_id_arg { + assert_eq!(htlc.payment_hash, payment_hash_calc); + match htlc.state { + InboundHTLCState::Committed => {}, + InboundHTLCState::LocalRemoved(ref reason) => { + if let &InboundHTLCRemovalReason::Fulfill(_) = reason { + } else { + log_warn!(logger, "Have preimage and want to fulfill HTLC with payment hash {} we already failed against channel {}", log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id())); + debug_assert!(false, "Tried to fulfill an HTLC that was already failed"); + } + return UpdateFulfillFetch::DuplicateClaim {}; + }, + _ => { + debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); + // Don't return in release mode here so that we can update channel_monitor + } + } + pending_idx = idx; + htlc_value_msat = htlc.amount_msat; + break; } } + if pending_idx == core::usize::MAX { + #[cfg(any(test, fuzzing))] + // If we failed to find an HTLC to fulfill, make sure it was previously fulfilled and + // this is simply a duplicate claim, not previously failed and we lost funds. + debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); + return UpdateFulfillFetch::DuplicateClaim {}; + } - let destination_script = match signer_provider.get_destination_script() { - Ok(script) => script, - Err(_) => return Err(ChannelError::Close("Failed to get destination script".to_owned())), + // Now update local state: + // + // We have to put the payment_preimage in the channel_monitor right away here to ensure we + // can claim it even if the channel hits the chain before we see their next commitment. + self.context.latest_monitor_update_id += 1; + let monitor_update = ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::PaymentPreimage { + payment_preimage: payment_preimage_arg.clone(), + }], }; - let mut secp_ctx = Secp256k1::new(); - secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes()); - - let chan = Channel { - context: ChannelContext { - user_id, - - config: LegacyChannelConfig { - options: config.channel_config.clone(), - announced_channel, - commit_upfront_shutdown_pubkey: config.channel_handshake_config.commit_upfront_shutdown_pubkey, - }, + if (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0 { + // Note that this condition is the same as the assertion in + // `claim_htlc_while_disconnected_dropping_mon_update` and must match exactly - + // `claim_htlc_while_disconnected_dropping_mon_update` would not work correctly if we + // do not not get into this branch. + for pending_update in self.context.holding_cell_htlc_updates.iter() { + match pending_update { + &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { + // Make sure we don't leave latest_monitor_update_id incremented here: + self.context.latest_monitor_update_id -= 1; + #[cfg(any(test, fuzzing))] + debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); + return UpdateFulfillFetch::DuplicateClaim {}; + } + }, + &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { + log_warn!(logger, "Have preimage and want to fulfill HTLC with pending failure against channel {}", log_bytes!(self.context.channel_id())); + // TODO: We may actually be able to switch to a fulfill here, though its + // rare enough it may not be worth the complexity burden. + debug_assert!(false, "Tried to fulfill an HTLC that was already failed"); + return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; + } + }, + _ => {} + } + } + log_trace!(logger, "Adding HTLC claim to holding_cell in channel {}! Current state: {}", log_bytes!(self.context.channel_id()), self.context.channel_state); + self.context.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::ClaimHTLC { + payment_preimage: payment_preimage_arg, htlc_id: htlc_id_arg, + }); + #[cfg(any(test, fuzzing))] + self.context.historical_inbound_htlc_fulfills.insert(htlc_id_arg); + return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; + } + #[cfg(any(test, fuzzing))] + self.context.historical_inbound_htlc_fulfills.insert(htlc_id_arg); - prev_config: None, + { + let htlc = &mut self.context.pending_inbound_htlcs[pending_idx]; + if let InboundHTLCState::Committed = htlc.state { + } else { + debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); + return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; + } + log_trace!(logger, "Upgrading HTLC {} to LocalRemoved with a Fulfill in channel {}!", log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id)); + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(payment_preimage_arg.clone())); + } - inbound_handshake_limits_override: None, + UpdateFulfillFetch::NewClaim { + monitor_update, + htlc_value_msat, + msg: Some(msgs::UpdateFulfillHTLC { + channel_id: self.context.channel_id(), + htlc_id: htlc_id_arg, + payment_preimage: payment_preimage_arg, + }), + } + } - temporary_channel_id: Some(msg.temporary_channel_id), - channel_id: msg.temporary_channel_id, - channel_state: (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32), - announcement_sigs_state: AnnouncementSigsState::NotSent, - secp_ctx, + pub fn get_update_fulfill_htlc_and_commit(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage, logger: &L) -> UpdateFulfillCommitFetch where L::Target: Logger { + let release_cs_monitor = self.context.pending_monitor_updates.iter().all(|upd| !upd.blocked); + match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger) { + UpdateFulfillFetch::NewClaim { mut monitor_update, htlc_value_msat, msg } => { + // Even if we aren't supposed to let new monitor updates with commitment state + // updates run, we still need to push the preimage ChannelMonitorUpdateStep no + // matter what. Sadly, to push a new monitor update which flies before others + // already queued, we have to insert it into the pending queue and update the + // update_ids of all the following monitors. + let unblocked_update_pos = if release_cs_monitor && msg.is_some() { + let mut additional_update = self.build_commitment_no_status_check(logger); + // build_commitment_no_status_check may bump latest_monitor_id but we want them + // to be strictly increasing by one, so decrement it here. + self.context.latest_monitor_update_id = monitor_update.update_id; + monitor_update.updates.append(&mut additional_update.updates); + self.context.pending_monitor_updates.push(PendingChannelMonitorUpdate { + update: monitor_update, blocked: false, + }); + self.context.pending_monitor_updates.len() - 1 + } else { + let insert_pos = self.context.pending_monitor_updates.iter().position(|upd| upd.blocked) + .unwrap_or(self.context.pending_monitor_updates.len()); + let new_mon_id = self.context.pending_monitor_updates.get(insert_pos) + .map(|upd| upd.update.update_id).unwrap_or(monitor_update.update_id); + monitor_update.update_id = new_mon_id; + self.context.pending_monitor_updates.insert(insert_pos, PendingChannelMonitorUpdate { + update: monitor_update, blocked: false, + }); + for held_update in self.context.pending_monitor_updates.iter_mut().skip(insert_pos + 1) { + held_update.update.update_id += 1; + } + if msg.is_some() { + debug_assert!(false, "If there is a pending blocked monitor we should have MonitorUpdateInProgress set"); + let update = self.build_commitment_no_status_check(logger); + self.context.pending_monitor_updates.push(PendingChannelMonitorUpdate { + update, blocked: true, + }); + } + insert_pos + }; + self.monitor_updating_paused(false, msg.is_some(), false, Vec::new(), Vec::new(), Vec::new()); + UpdateFulfillCommitFetch::NewClaim { + monitor_update: &self.context.pending_monitor_updates.get(unblocked_update_pos) + .expect("We just pushed the monitor update").update, + htlc_value_msat, + } + }, + UpdateFulfillFetch::DuplicateClaim {} => UpdateFulfillCommitFetch::DuplicateClaim {}, + } + } - latest_monitor_update_id: 0, + /// We can only have one resolution per HTLC. In some cases around reconnect, we may fulfill + /// an HTLC more than once or fulfill once and then attempt to fail after reconnect. We cannot, + /// however, fail more than once as we wait for an upstream failure to be irrevocably committed + /// before we fail backwards. + /// + /// If we do fail twice, we `debug_assert!(false)` and return `Ok(None)`. Thus, this will always + /// return `Ok(_)` if preconditions are met. In any case, `Err`s will only be + /// [`ChannelError::Ignore`]. + pub fn queue_fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket, logger: &L) + -> Result<(), ChannelError> where L::Target: Logger { + self.fail_htlc(htlc_id_arg, err_packet, true, logger) + .map(|msg_opt| assert!(msg_opt.is_none(), "We forced holding cell?")) + } - holder_signer, - shutdown_scriptpubkey, - destination_script, + /// We can only have one resolution per HTLC. In some cases around reconnect, we may fulfill + /// an HTLC more than once or fulfill once and then attempt to fail after reconnect. We cannot, + /// however, fail more than once as we wait for an upstream failure to be irrevocably committed + /// before we fail backwards. + /// + /// If we do fail twice, we `debug_assert!(false)` and return `Ok(None)`. Thus, this will always + /// return `Ok(_)` if preconditions are met. In any case, `Err`s will only be + /// [`ChannelError::Ignore`]. + fn fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket, mut force_holding_cell: bool, logger: &L) + -> Result, ChannelError> where L::Target: Logger { + if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { + panic!("Was asked to fail an HTLC when channel was not in an operational state"); + } + assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); - cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, - cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, - value_to_self_msat: msg.push_msat, + // ChannelManager may generate duplicate claims/fails due to HTLC update events from + // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop + // these, but for now we just have to treat them as normal. - pending_inbound_htlcs: Vec::new(), - pending_outbound_htlcs: Vec::new(), - holding_cell_htlc_updates: Vec::new(), - pending_update_fee: None, - holding_cell_update_fee: None, - next_holder_htlc_id: 0, - next_counterparty_htlc_id: 0, - update_time_counter: 1, + let mut pending_idx = core::usize::MAX; + for (idx, htlc) in self.context.pending_inbound_htlcs.iter().enumerate() { + if htlc.htlc_id == htlc_id_arg { + match htlc.state { + InboundHTLCState::Committed => {}, + InboundHTLCState::LocalRemoved(ref reason) => { + if let &InboundHTLCRemovalReason::Fulfill(_) = reason { + } else { + debug_assert!(false, "Tried to fail an HTLC that was already failed"); + } + return Ok(None); + }, + _ => { + debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); + return Err(ChannelError::Ignore(format!("Unable to find a pending HTLC which matched the given HTLC ID ({})", htlc.htlc_id))); + } + } + pending_idx = idx; + } + } + if pending_idx == core::usize::MAX { + #[cfg(any(test, fuzzing))] + // If we failed to find an HTLC to fail, make sure it was previously fulfilled and this + // is simply a duplicate fail, not previously failed and we failed-back too early. + debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); + return Ok(None); + } - resend_order: RAACommitmentOrder::CommitmentFirst, + if (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0 { + debug_assert!(force_holding_cell, "!force_holding_cell is only called when emptying the holding cell, so we shouldn't end up back in it!"); + force_holding_cell = true; + } - monitor_pending_channel_ready: false, - monitor_pending_revoke_and_ack: false, - monitor_pending_commitment_signed: false, - monitor_pending_forwards: Vec::new(), - monitor_pending_failures: Vec::new(), - monitor_pending_finalized_fulfills: Vec::new(), + // Now update local state: + if force_holding_cell { + for pending_update in self.context.holding_cell_htlc_updates.iter() { + match pending_update { + &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { + #[cfg(any(test, fuzzing))] + debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); + return Ok(None); + } + }, + &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { + debug_assert!(false, "Tried to fail an HTLC that was already failed"); + return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned())); + } + }, + _ => {} + } + } + log_trace!(logger, "Placing failure for HTLC ID {} in holding cell in channel {}.", htlc_id_arg, log_bytes!(self.context.channel_id())); + self.context.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::FailHTLC { + htlc_id: htlc_id_arg, + err_packet, + }); + return Ok(None); + } - #[cfg(debug_assertions)] - holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)), - #[cfg(debug_assertions)] - counterparty_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)), + log_trace!(logger, "Failing HTLC ID {} back with a update_fail_htlc message in channel {}.", htlc_id_arg, log_bytes!(self.context.channel_id())); + { + let htlc = &mut self.context.pending_inbound_htlcs[pending_idx]; + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(err_packet.clone())); + } - last_sent_closing_fee: None, - pending_counterparty_closing_signed: None, - closing_fee_limits: None, - target_closing_feerate_sats_per_kw: None, + Ok(Some(msgs::UpdateFailHTLC { + channel_id: self.context.channel_id(), + htlc_id: htlc_id_arg, + reason: err_packet + })) + } - inbound_awaiting_accept: true, + // Message handlers: - funding_tx_confirmed_in: None, - funding_tx_confirmation_height: 0, - short_channel_id: None, - channel_creation_height: current_chain_height, + pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, default_limits: &ChannelHandshakeLimits, their_features: &InitFeatures) -> Result<(), ChannelError> { + let peer_limits = if let Some(ref limits) = self.context.inbound_handshake_limits_override { limits } else { default_limits }; - feerate_per_kw: msg.feerate_per_kw, - channel_value_satoshis: msg.funding_satoshis, - counterparty_dust_limit_satoshis: msg.dust_limit_satoshis, - holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS, - counterparty_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000), - holder_max_htlc_value_in_flight_msat: get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis, &config.channel_handshake_config), - counterparty_selected_channel_reserve_satoshis: Some(msg.channel_reserve_satoshis), - holder_selected_channel_reserve_satoshis, - counterparty_htlc_minimum_msat: msg.htlc_minimum_msat, - holder_htlc_minimum_msat: if config.channel_handshake_config.our_htlc_minimum_msat == 0 { 1 } else { config.channel_handshake_config.our_htlc_minimum_msat }, - counterparty_max_accepted_htlcs: msg.max_accepted_htlcs, - holder_max_accepted_htlcs: cmp::min(config.channel_handshake_config.our_max_accepted_htlcs, MAX_HTLCS), - minimum_depth: Some(cmp::max(config.channel_handshake_config.minimum_depth, 1)), + // Check sanity of message fields: + if !self.context.is_outbound() { + return Err(ChannelError::Close("Got an accept_channel message from an inbound peer".to_owned())); + } + if self.context.channel_state != ChannelState::OurInitSent as u32 { + return Err(ChannelError::Close("Got an accept_channel message at a strange time".to_owned())); + } + if msg.dust_limit_satoshis > 21000000 * 100000000 { + return Err(ChannelError::Close(format!("Peer never wants payout outputs? dust_limit_satoshis was {}", msg.dust_limit_satoshis))); + } + if msg.channel_reserve_satoshis > self.context.channel_value_satoshis { + return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than ({})", msg.channel_reserve_satoshis, self.context.channel_value_satoshis))); + } + if msg.dust_limit_satoshis > self.context.holder_selected_channel_reserve_satoshis { + return Err(ChannelError::Close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.dust_limit_satoshis, self.context.holder_selected_channel_reserve_satoshis))); + } + if msg.channel_reserve_satoshis > self.context.channel_value_satoshis - self.context.holder_selected_channel_reserve_satoshis { + return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than channel value minus our reserve ({})", + msg.channel_reserve_satoshis, self.context.channel_value_satoshis - self.context.holder_selected_channel_reserve_satoshis))); + } + let full_channel_value_msat = (self.context.channel_value_satoshis - msg.channel_reserve_satoshis) * 1000; + if msg.htlc_minimum_msat >= full_channel_value_msat { + return Err(ChannelError::Close(format!("Minimum htlc value ({}) is full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat))); + } + let max_delay_acceptable = u16::min(peer_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT); + if msg.to_self_delay > max_delay_acceptable { + return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_delay_acceptable, msg.to_self_delay))); + } + if msg.max_accepted_htlcs < 1 { + return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned())); + } + if msg.max_accepted_htlcs > MAX_HTLCS { + return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS))); + } - counterparty_forwarding_info: None, + // Now check against optional parameters as set by config... + if msg.htlc_minimum_msat > peer_limits.max_htlc_minimum_msat { + return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, peer_limits.max_htlc_minimum_msat))); + } + if msg.max_htlc_value_in_flight_msat < peer_limits.min_max_htlc_value_in_flight_msat { + return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, peer_limits.min_max_htlc_value_in_flight_msat))); + } + if msg.channel_reserve_satoshis > peer_limits.max_channel_reserve_satoshis { + return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, peer_limits.max_channel_reserve_satoshis))); + } + if msg.max_accepted_htlcs < peer_limits.min_max_accepted_htlcs { + return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, peer_limits.min_max_accepted_htlcs))); + } + if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { + return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); + } + if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS { + return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS))); + } + if msg.minimum_depth > peer_limits.max_minimum_depth { + return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", peer_limits.max_minimum_depth, msg.minimum_depth))); + } - channel_transaction_parameters: ChannelTransactionParameters { - holder_pubkeys: pubkeys, - holder_selected_contest_delay: config.channel_handshake_config.our_to_self_delay, - is_outbound_from_holder: false, - counterparty_parameters: Some(CounterpartyChannelTransactionParameters { - selected_contest_delay: msg.to_self_delay, - pubkeys: counterparty_pubkeys, - }), - funding_outpoint: None, - opt_anchors: if opt_anchors { Some(()) } else { None }, - opt_non_zero_fee_anchors: None - }, - funding_transaction: None, + if let Some(ty) = &msg.channel_type { + if *ty != self.context.channel_type { + return Err(ChannelError::Close("Channel Type in accept_channel didn't match the one sent in open_channel.".to_owned())); + } + } else if their_features.supports_channel_type() { + // Assume they've accepted the channel type as they said they understand it. + } else { + let channel_type = ChannelTypeFeatures::from_init(&their_features); + if channel_type != ChannelTypeFeatures::only_static_remote_key() { + return Err(ChannelError::Close("Only static_remote_key is supported for non-negotiated channel types".to_owned())); + } + self.context.channel_type = channel_type; + } - counterparty_cur_commitment_point: Some(msg.first_per_commitment_point), - counterparty_prev_commitment_point: None, - counterparty_node_id, + let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() { + match &msg.shutdown_scriptpubkey { + &Some(ref script) => { + // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything + if script.len() == 0 { + None + } else { + if !script::is_bolt2_compliant(&script, their_features) { + return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))); + } + Some(script.clone()) + } + }, + // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel + &None => { + return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned())); + } + } + } else { None }; - counterparty_shutdown_scriptpubkey, + self.context.counterparty_dust_limit_satoshis = msg.dust_limit_satoshis; + self.context.counterparty_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.context.channel_value_satoshis * 1000); + self.context.counterparty_selected_channel_reserve_satoshis = Some(msg.channel_reserve_satoshis); + self.context.counterparty_htlc_minimum_msat = msg.htlc_minimum_msat; + self.context.counterparty_max_accepted_htlcs = msg.max_accepted_htlcs; - commitment_secrets: CounterpartyCommitmentSecrets::new(), + if peer_limits.trust_own_funding_0conf { + self.context.minimum_depth = Some(msg.minimum_depth); + } else { + self.context.minimum_depth = Some(cmp::max(1, msg.minimum_depth)); + } - channel_update_status: ChannelUpdateStatus::Enabled, - closing_signed_in_flight: false, + let counterparty_pubkeys = ChannelPublicKeys { + funding_pubkey: msg.funding_pubkey, + revocation_basepoint: msg.revocation_basepoint, + payment_point: msg.payment_point, + delayed_payment_basepoint: msg.delayed_payment_basepoint, + htlc_basepoint: msg.htlc_basepoint + }; - announcement_sigs: None, + self.context.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters { + selected_contest_delay: msg.to_self_delay, + pubkeys: counterparty_pubkeys, + }); - #[cfg(any(test, fuzzing))] - next_local_commitment_tx_fee_info_cached: Mutex::new(None), - #[cfg(any(test, fuzzing))] - next_remote_commitment_tx_fee_info_cached: Mutex::new(None), + self.context.counterparty_cur_commitment_point = Some(msg.first_per_commitment_point); + self.context.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey; - workaround_lnd_bug_4006: None, - sent_message_awaiting_response: None, + self.context.channel_state = ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32; + self.context.inbound_handshake_limits_override = None; // We're done enforcing limits on our peer's handshake now. - latest_inbound_scid_alias: None, - outbound_scid_alias, + Ok(()) + } - channel_pending_event_emitted: false, - channel_ready_event_emitted: false, + fn funding_created_signature(&mut self, sig: &Signature, logger: &L) -> Result<(Txid, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger { + let funding_script = self.context.get_funding_redeemscript(); - #[cfg(any(test, fuzzing))] - historical_inbound_htlc_fulfills: HashSet::new(), + let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); + let initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx; + { + let trusted_tx = initial_commitment_tx.trust(); + let initial_commitment_bitcoin_tx = trusted_tx.built_transaction(); + let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis); + // They sign the holder commitment transaction... + log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.", + log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.context.counterparty_funding_pubkey().serialize()), + encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]), + encode::serialize_hex(&funding_script), log_bytes!(self.context.channel_id())); + secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &sig, self.context.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned()); + } - channel_type, - channel_keys_id, + let counterparty_keys = self.context.build_remote_transaction_keys(); + let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx; - pending_monitor_updates: Vec::new(), - } - }; + let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust(); + let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction(); + log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}", + log_bytes!(self.context.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction)); - Ok(chan) - } + let counterparty_signature = self.context.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx) + .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0; - #[inline] - fn get_closing_scriptpubkey(&self) -> Script { - // The shutdown scriptpubkey is set on channel opening when option_upfront_shutdown_script - // is signaled. Otherwise, it is set when sending a shutdown message. Calling this method - // outside of those situations will fail. - self.context.shutdown_scriptpubkey.clone().unwrap().into_inner() + // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish. + Ok((counterparty_initial_bitcoin_tx.txid, initial_commitment_tx, counterparty_signature)) } - #[inline] - fn get_closing_transaction_weight(&self, a_scriptpubkey: Option<&Script>, b_scriptpubkey: Option<&Script>) -> u64 { - let mut ret = - (4 + // version - 1 + // input count - 36 + // prevout - 1 + // script length (0) - 4 + // sequence - 1 + // output count - 4 // lock time - )*4 + // * 4 for non-witness parts - 2 + // witness marker and flag - 1 + // witness element count - 4 + // 4 element lengths (2 sigs, multisig dummy, and witness script) - self.context.get_funding_redeemscript().len() as u64 + // funding witness script - 2*(1 + 71); // two signatures + sighash type flags - if let Some(spk) = a_scriptpubkey { - ret += ((8+1) + // output values and script length - spk.len() as u64) * 4; // scriptpubkey and witness multiplier + pub fn funding_created( + &mut self, msg: &msgs::FundingCreated, best_block: BestBlock, signer_provider: &SP, logger: &L + ) -> Result<(msgs::FundingSigned, ChannelMonitor), ChannelError> + where + SP::Target: SignerProvider, + L::Target: Logger + { + if self.context.is_outbound() { + return Err(ChannelError::Close("Received funding_created for an outbound channel?".to_owned())); } - if let Some(spk) = b_scriptpubkey { - ret += ((8+1) + // output values and script length - spk.len() as u64) * 4; // scriptpubkey and witness multiplier + if self.context.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) { + // BOLT 2 says that if we disconnect before we send funding_signed we SHOULD NOT + // remember the channel, so it's safe to just send an error_message here and drop the + // channel. + return Err(ChannelError::Close("Received funding_created after we got the channel!".to_owned())); + } + if self.context.inbound_awaiting_accept { + return Err(ChannelError::Close("FundingCreated message received before the channel was accepted".to_owned())); + } + if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) || + self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER || + self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { + panic!("Should not have advanced channel commitment tx numbers prior to funding_created"); } - ret - } - #[inline] - fn build_closing_transaction(&self, proposed_total_fee_satoshis: u64, skip_remote_output: bool) -> (ClosingTransaction, u64) { - assert!(self.context.pending_inbound_htlcs.is_empty()); - assert!(self.context.pending_outbound_htlcs.is_empty()); - assert!(self.context.pending_update_fee.is_none()); + let funding_txo = OutPoint { txid: msg.funding_txid, index: msg.funding_output_index }; + self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo); + // This is an externally observable change before we finish all our checks. In particular + // funding_created_signature may fail. + self.context.holder_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); - let mut total_fee_satoshis = proposed_total_fee_satoshis; - let mut value_to_holder: i64 = (self.context.value_to_self_msat as i64) / 1000 - if self.context.is_outbound() { total_fee_satoshis as i64 } else { 0 }; - let mut value_to_counterparty: i64 = ((self.context.channel_value_satoshis * 1000 - self.context.value_to_self_msat) as i64 / 1000) - if self.context.is_outbound() { 0 } else { total_fee_satoshis as i64 }; + let (counterparty_initial_commitment_txid, initial_commitment_tx, signature) = match self.funding_created_signature(&msg.signature, logger) { + Ok(res) => res, + Err(ChannelError::Close(e)) => { + self.context.channel_transaction_parameters.funding_outpoint = None; + return Err(ChannelError::Close(e)); + }, + Err(e) => { + // The only error we know how to handle is ChannelError::Close, so we fall over here + // to make sure we don't continue with an inconsistent state. + panic!("unexpected error type from funding_created_signature {:?}", e); + } + }; - if value_to_holder < 0 { - assert!(self.context.is_outbound()); - total_fee_satoshis += (-value_to_holder) as u64; - } else if value_to_counterparty < 0 { - assert!(!self.context.is_outbound()); - total_fee_satoshis += (-value_to_counterparty) as u64; - } + let holder_commitment_tx = HolderCommitmentTransaction::new( + initial_commitment_tx, + msg.signature, + Vec::new(), + &self.context.get_holder_pubkeys().funding_pubkey, + self.context.counterparty_funding_pubkey() + ); - if skip_remote_output || value_to_counterparty as u64 <= self.context.holder_dust_limit_satoshis { - value_to_counterparty = 0; - } + self.context.holder_signer.validate_holder_commitment(&holder_commitment_tx, Vec::new()) + .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?; - if value_to_holder as u64 <= self.context.holder_dust_limit_satoshis { - value_to_holder = 0; - } + // Now that we're past error-generating stuff, update our local state: - assert!(self.context.shutdown_scriptpubkey.is_some()); - let holder_shutdown_script = self.get_closing_scriptpubkey(); - let counterparty_shutdown_script = self.context.counterparty_shutdown_scriptpubkey.clone().unwrap(); - let funding_outpoint = self.funding_outpoint().into_bitcoin_outpoint(); + let funding_redeemscript = self.context.get_funding_redeemscript(); + let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); + let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.context.get_holder_pubkeys().payment_point, &self.context.get_counterparty_pubkeys().payment_point, self.context.is_outbound()); + let shutdown_script = self.context.shutdown_scriptpubkey.clone().map(|script| script.into_inner()); + let mut monitor_signer = signer_provider.derive_channel_signer(self.context.channel_value_satoshis, self.context.channel_keys_id); + monitor_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); + let channel_monitor = ChannelMonitor::new(self.context.secp_ctx.clone(), monitor_signer, + shutdown_script, self.context.get_holder_selected_contest_delay(), + &self.context.destination_script, (funding_txo, funding_txo_script.clone()), + &self.context.channel_transaction_parameters, + funding_redeemscript.clone(), self.context.channel_value_satoshis, + obscure_factor, + holder_commitment_tx, best_block, self.context.counterparty_node_id); - let closing_transaction = ClosingTransaction::new(value_to_holder as u64, value_to_counterparty as u64, holder_shutdown_script, counterparty_shutdown_script, funding_outpoint); - (closing_transaction, total_fee_satoshis) - } + channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_commitment_txid, Vec::new(), self.context.cur_counterparty_commitment_transaction_number, self.context.counterparty_cur_commitment_point.unwrap(), logger); - fn funding_outpoint(&self) -> OutPoint { - self.context.channel_transaction_parameters.funding_outpoint.unwrap() - } + self.context.channel_state = ChannelState::FundingSent as u32; + self.context.channel_id = funding_txo.to_channel_id(); + self.context.cur_counterparty_commitment_transaction_number -= 1; + self.context.cur_holder_commitment_transaction_number -= 1; - /// Claims an HTLC while we're disconnected from a peer, dropping the [`ChannelMonitorUpdate`] - /// entirely. - /// - /// The [`ChannelMonitor`] for this channel MUST be updated out-of-band with the preimage - /// provided (i.e. without calling [`crate::chain::Watch::update_channel`]). - /// - /// The HTLC claim will end up in the holding cell (because the caller must ensure the peer is - /// disconnected). - pub fn claim_htlc_while_disconnected_dropping_mon_update - (&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L) - where L::Target: Logger { - // Assert that we'll add the HTLC claim to the holding cell in `get_update_fulfill_htlc` - // (see equivalent if condition there). - assert!(self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32) != 0); - let mon_update_id = self.context.latest_monitor_update_id; // Forget the ChannelMonitor update - let fulfill_resp = self.get_update_fulfill_htlc(htlc_id_arg, payment_preimage_arg, logger); - self.context.latest_monitor_update_id = mon_update_id; - if let UpdateFulfillFetch::NewClaim { msg, .. } = fulfill_resp { - assert!(msg.is_none()); // The HTLC must have ended up in the holding cell. - } + log_info!(logger, "Generated funding_signed for peer for channel {}", log_bytes!(self.context.channel_id())); + + let need_channel_ready = self.check_get_channel_ready(0).is_some(); + self.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new()); + + Ok((msgs::FundingSigned { + channel_id: self.context.channel_id, + signature, + #[cfg(taproot)] + partial_signature_with_nonce: None, + }, channel_monitor)) } - fn get_update_fulfill_htlc(&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L) -> UpdateFulfillFetch where L::Target: Logger { - // Either ChannelReady got set (which means it won't be unset) or there is no way any - // caller thought we could have something claimed (cause we wouldn't have accepted in an - // incoming HTLC anyway). If we got to ShutdownComplete, callers aren't allowed to call us, - // either. - if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { - panic!("Was asked to fulfill an HTLC when channel was not in an operational state"); + /// Handles a funding_signed message from the remote end. + /// If this call is successful, broadcast the funding transaction (and not before!) + pub fn funding_signed( + &mut self, msg: &msgs::FundingSigned, best_block: BestBlock, signer_provider: &SP, logger: &L + ) -> Result, ChannelError> + where + SP::Target: SignerProvider, + L::Target: Logger + { + if !self.context.is_outbound() { + return Err(ChannelError::Close("Received funding_signed for an inbound channel?".to_owned())); + } + if self.context.channel_state & !(ChannelState::MonitorUpdateInProgress as u32) != ChannelState::FundingCreated as u32 { + return Err(ChannelError::Close("Received funding_signed in strange state!".to_owned())); + } + if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) || + self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER || + self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { + panic!("Should not have advanced channel commitment tx numbers prior to funding_created"); } - assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); - let payment_hash_calc = PaymentHash(Sha256::hash(&payment_preimage_arg.0[..]).into_inner()); + let funding_script = self.context.get_funding_redeemscript(); - // ChannelManager may generate duplicate claims/fails due to HTLC update events from - // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop - // these, but for now we just have to treat them as normal. + let counterparty_keys = self.context.build_remote_transaction_keys(); + let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx; + let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust(); + let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction(); - let mut pending_idx = core::usize::MAX; - let mut htlc_value_msat = 0; - for (idx, htlc) in self.context.pending_inbound_htlcs.iter().enumerate() { - if htlc.htlc_id == htlc_id_arg { - assert_eq!(htlc.payment_hash, payment_hash_calc); - match htlc.state { - InboundHTLCState::Committed => {}, - InboundHTLCState::LocalRemoved(ref reason) => { - if let &InboundHTLCRemovalReason::Fulfill(_) = reason { - } else { - log_warn!(logger, "Have preimage and want to fulfill HTLC with payment hash {} we already failed against channel {}", log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id())); - debug_assert!(false, "Tried to fulfill an HTLC that was already failed"); - } - return UpdateFulfillFetch::DuplicateClaim {}; - }, - _ => { - debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); - // Don't return in release mode here so that we can update channel_monitor - } - } - pending_idx = idx; - htlc_value_msat = htlc.amount_msat; - break; + log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}", + log_bytes!(self.context.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction)); + + let holder_signer = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); + let initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &holder_signer, true, false, logger).tx; + { + let trusted_tx = initial_commitment_tx.trust(); + let initial_commitment_bitcoin_tx = trusted_tx.built_transaction(); + let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis); + // They sign our commitment transaction, allowing us to broadcast the tx if we wish. + if let Err(_) = self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.context.get_counterparty_pubkeys().funding_pubkey) { + return Err(ChannelError::Close("Invalid funding_signed signature from peer".to_owned())); } } - if pending_idx == core::usize::MAX { - #[cfg(any(test, fuzzing))] - // If we failed to find an HTLC to fulfill, make sure it was previously fulfilled and - // this is simply a duplicate claim, not previously failed and we lost funds. - debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); - return UpdateFulfillFetch::DuplicateClaim {}; - } - // Now update local state: - // - // We have to put the payment_preimage in the channel_monitor right away here to ensure we - // can claim it even if the channel hits the chain before we see their next commitment. - self.context.latest_monitor_update_id += 1; - let monitor_update = ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::PaymentPreimage { - payment_preimage: payment_preimage_arg.clone(), - }], - }; + let holder_commitment_tx = HolderCommitmentTransaction::new( + initial_commitment_tx, + msg.signature, + Vec::new(), + &self.context.get_holder_pubkeys().funding_pubkey, + self.context.counterparty_funding_pubkey() + ); - if (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0 { - // Note that this condition is the same as the assertion in - // `claim_htlc_while_disconnected_dropping_mon_update` and must match exactly - - // `claim_htlc_while_disconnected_dropping_mon_update` would not work correctly if we - // do not not get into this branch. - for pending_update in self.context.holding_cell_htlc_updates.iter() { - match pending_update { - &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => { - if htlc_id_arg == htlc_id { - // Make sure we don't leave latest_monitor_update_id incremented here: - self.context.latest_monitor_update_id -= 1; - #[cfg(any(test, fuzzing))] - debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); - return UpdateFulfillFetch::DuplicateClaim {}; - } - }, - &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => { - if htlc_id_arg == htlc_id { - log_warn!(logger, "Have preimage and want to fulfill HTLC with pending failure against channel {}", log_bytes!(self.context.channel_id())); - // TODO: We may actually be able to switch to a fulfill here, though its - // rare enough it may not be worth the complexity burden. - debug_assert!(false, "Tried to fulfill an HTLC that was already failed"); - return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; - } - }, - _ => {} - } - } - log_trace!(logger, "Adding HTLC claim to holding_cell in channel {}! Current state: {}", log_bytes!(self.context.channel_id()), self.context.channel_state); - self.context.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::ClaimHTLC { - payment_preimage: payment_preimage_arg, htlc_id: htlc_id_arg, - }); - #[cfg(any(test, fuzzing))] - self.context.historical_inbound_htlc_fulfills.insert(htlc_id_arg); - return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; + self.context.holder_signer.validate_holder_commitment(&holder_commitment_tx, Vec::new()) + .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?; + + + let funding_redeemscript = self.context.get_funding_redeemscript(); + let funding_txo = self.context.get_funding_txo().unwrap(); + let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); + let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.context.get_holder_pubkeys().payment_point, &self.context.get_counterparty_pubkeys().payment_point, self.context.is_outbound()); + let shutdown_script = self.context.shutdown_scriptpubkey.clone().map(|script| script.into_inner()); + let mut monitor_signer = signer_provider.derive_channel_signer(self.context.channel_value_satoshis, self.context.channel_keys_id); + monitor_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); + let channel_monitor = ChannelMonitor::new(self.context.secp_ctx.clone(), monitor_signer, + shutdown_script, self.context.get_holder_selected_contest_delay(), + &self.context.destination_script, (funding_txo, funding_txo_script), + &self.context.channel_transaction_parameters, + funding_redeemscript.clone(), self.context.channel_value_satoshis, + obscure_factor, + holder_commitment_tx, best_block, self.context.counterparty_node_id); + + channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_bitcoin_tx.txid, Vec::new(), self.context.cur_counterparty_commitment_transaction_number, self.context.counterparty_cur_commitment_point.unwrap(), logger); + + assert_eq!(self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32), 0); // We have no had any monitor(s) yet to fail update! + self.context.channel_state = ChannelState::FundingSent as u32; + self.context.cur_holder_commitment_transaction_number -= 1; + self.context.cur_counterparty_commitment_transaction_number -= 1; + + log_info!(logger, "Received funding_signed from peer for channel {}", log_bytes!(self.context.channel_id())); + + let need_channel_ready = self.check_get_channel_ready(0).is_some(); + self.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new()); + Ok(channel_monitor) + } + + /// Handles a channel_ready message from our peer. If we've already sent our channel_ready + /// and the channel is now usable (and public), this may generate an announcement_signatures to + /// reply with. + pub fn channel_ready( + &mut self, msg: &msgs::ChannelReady, node_signer: &NS, genesis_block_hash: BlockHash, + user_config: &UserConfig, best_block: &BestBlock, logger: &L + ) -> Result, ChannelError> + where + NS::Target: NodeSigner, + L::Target: Logger + { + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + self.context.workaround_lnd_bug_4006 = Some(msg.clone()); + return Err(ChannelError::Ignore("Peer sent channel_ready when we needed a channel_reestablish. The peer is likely lnd, see https://github.com/lightningnetwork/lnd/issues/4006".to_owned())); } - #[cfg(any(test, fuzzing))] - self.context.historical_inbound_htlc_fulfills.insert(htlc_id_arg); - { - let htlc = &mut self.context.pending_inbound_htlcs[pending_idx]; - if let InboundHTLCState::Committed = htlc.state { - } else { - debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); - return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None }; + if let Some(scid_alias) = msg.short_channel_id_alias { + if Some(scid_alias) != self.context.short_channel_id { + // The scid alias provided can be used to route payments *from* our counterparty, + // i.e. can be used for inbound payments and provided in invoices, but is not used + // when routing outbound payments. + self.context.latest_inbound_scid_alias = Some(scid_alias); } - log_trace!(logger, "Upgrading HTLC {} to LocalRemoved with a Fulfill in channel {}!", log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id)); - htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(payment_preimage_arg.clone())); } - UpdateFulfillFetch::NewClaim { - monitor_update, - htlc_value_msat, - msg: Some(msgs::UpdateFulfillHTLC { - channel_id: self.context.channel_id(), - htlc_id: htlc_id_arg, - payment_preimage: payment_preimage_arg, - }), - } - } + let non_shutdown_state = self.context.channel_state & (!MULTI_STATE_FLAGS); - pub fn get_update_fulfill_htlc_and_commit(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage, logger: &L) -> UpdateFulfillCommitFetch where L::Target: Logger { - let release_cs_monitor = self.context.pending_monitor_updates.iter().all(|upd| !upd.blocked); - match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger) { - UpdateFulfillFetch::NewClaim { mut monitor_update, htlc_value_msat, msg } => { - // Even if we aren't supposed to let new monitor updates with commitment state - // updates run, we still need to push the preimage ChannelMonitorUpdateStep no - // matter what. Sadly, to push a new monitor update which flies before others - // already queued, we have to insert it into the pending queue and update the - // update_ids of all the following monitors. - let unblocked_update_pos = if release_cs_monitor && msg.is_some() { - let mut additional_update = self.build_commitment_no_status_check(logger); - // build_commitment_no_status_check may bump latest_monitor_id but we want them - // to be strictly increasing by one, so decrement it here. - self.context.latest_monitor_update_id = monitor_update.update_id; - monitor_update.updates.append(&mut additional_update.updates); - self.context.pending_monitor_updates.push(PendingChannelMonitorUpdate { - update: monitor_update, blocked: false, - }); - self.context.pending_monitor_updates.len() - 1 + if non_shutdown_state == ChannelState::FundingSent as u32 { + self.context.channel_state |= ChannelState::TheirChannelReady as u32; + } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurChannelReady as u32) { + self.context.channel_state = ChannelState::ChannelReady as u32 | (self.context.channel_state & MULTI_STATE_FLAGS); + self.context.update_time_counter += 1; + } else if self.context.channel_state & (ChannelState::ChannelReady as u32) != 0 || + // If we reconnected before sending our `channel_ready` they may still resend theirs: + (self.context.channel_state & (ChannelState::FundingSent as u32 | ChannelState::TheirChannelReady as u32) == + (ChannelState::FundingSent as u32 | ChannelState::TheirChannelReady as u32)) + { + // They probably disconnected/reconnected and re-sent the channel_ready, which is + // required, or they're sending a fresh SCID alias. + let expected_point = + if self.context.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 { + // If they haven't ever sent an updated point, the point they send should match + // the current one. + self.context.counterparty_cur_commitment_point + } else if self.context.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 2 { + // If we've advanced the commitment number once, the second commitment point is + // at `counterparty_prev_commitment_point`, which is not yet revoked. + debug_assert!(self.context.counterparty_prev_commitment_point.is_some()); + self.context.counterparty_prev_commitment_point } else { - let insert_pos = self.context.pending_monitor_updates.iter().position(|upd| upd.blocked) - .unwrap_or(self.context.pending_monitor_updates.len()); - let new_mon_id = self.context.pending_monitor_updates.get(insert_pos) - .map(|upd| upd.update.update_id).unwrap_or(monitor_update.update_id); - monitor_update.update_id = new_mon_id; - self.context.pending_monitor_updates.insert(insert_pos, PendingChannelMonitorUpdate { - update: monitor_update, blocked: false, - }); - for held_update in self.context.pending_monitor_updates.iter_mut().skip(insert_pos + 1) { - held_update.update.update_id += 1; - } - if msg.is_some() { - debug_assert!(false, "If there is a pending blocked monitor we should have MonitorUpdateInProgress set"); - let update = self.build_commitment_no_status_check(logger); - self.context.pending_monitor_updates.push(PendingChannelMonitorUpdate { - update, blocked: true, - }); - } - insert_pos + // If they have sent updated points, channel_ready is always supposed to match + // their "first" point, which we re-derive here. + Some(PublicKey::from_secret_key(&self.context.secp_ctx, &SecretKey::from_slice( + &self.context.commitment_secrets.get_secret(INITIAL_COMMITMENT_NUMBER - 1).expect("We should have all prev secrets available") + ).expect("We already advanced, so previous secret keys should have been validated already"))) }; - self.monitor_updating_paused(false, msg.is_some(), false, Vec::new(), Vec::new(), Vec::new()); - UpdateFulfillCommitFetch::NewClaim { - monitor_update: &self.context.pending_monitor_updates.get(unblocked_update_pos) - .expect("We just pushed the monitor update").update, - htlc_value_msat, - } - }, - UpdateFulfillFetch::DuplicateClaim {} => UpdateFulfillCommitFetch::DuplicateClaim {}, + if expected_point != Some(msg.next_per_commitment_point) { + return Err(ChannelError::Close("Peer sent a reconnect channel_ready with a different point".to_owned())); + } + return Ok(None); + } else { + return Err(ChannelError::Close("Peer sent a channel_ready at a strange time".to_owned())); } - } - /// We can only have one resolution per HTLC. In some cases around reconnect, we may fulfill - /// an HTLC more than once or fulfill once and then attempt to fail after reconnect. We cannot, - /// however, fail more than once as we wait for an upstream failure to be irrevocably committed - /// before we fail backwards. - /// - /// If we do fail twice, we `debug_assert!(false)` and return `Ok(None)`. Thus, this will always - /// return `Ok(_)` if preconditions are met. In any case, `Err`s will only be - /// [`ChannelError::Ignore`]. - pub fn queue_fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket, logger: &L) - -> Result<(), ChannelError> where L::Target: Logger { - self.fail_htlc(htlc_id_arg, err_packet, true, logger) - .map(|msg_opt| assert!(msg_opt.is_none(), "We forced holding cell?")) - } + self.context.counterparty_prev_commitment_point = self.context.counterparty_cur_commitment_point; + self.context.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point); - /// We can only have one resolution per HTLC. In some cases around reconnect, we may fulfill - /// an HTLC more than once or fulfill once and then attempt to fail after reconnect. We cannot, - /// however, fail more than once as we wait for an upstream failure to be irrevocably committed - /// before we fail backwards. - /// - /// If we do fail twice, we `debug_assert!(false)` and return `Ok(None)`. Thus, this will always - /// return `Ok(_)` if preconditions are met. In any case, `Err`s will only be - /// [`ChannelError::Ignore`]. - fn fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket, mut force_holding_cell: bool, logger: &L) - -> Result, ChannelError> where L::Target: Logger { - if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { - panic!("Was asked to fail an HTLC when channel was not in an operational state"); - } - assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); + log_info!(logger, "Received channel_ready from peer for channel {}", log_bytes!(self.context.channel_id())); - // ChannelManager may generate duplicate claims/fails due to HTLC update events from - // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop - // these, but for now we just have to treat them as normal. + Ok(self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger)) + } - let mut pending_idx = core::usize::MAX; - for (idx, htlc) in self.context.pending_inbound_htlcs.iter().enumerate() { - if htlc.htlc_id == htlc_id_arg { - match htlc.state { - InboundHTLCState::Committed => {}, - InboundHTLCState::LocalRemoved(ref reason) => { - if let &InboundHTLCRemovalReason::Fulfill(_) = reason { - } else { - debug_assert!(false, "Tried to fail an HTLC that was already failed"); - } - return Ok(None); - }, - _ => { - debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); - return Err(ChannelError::Ignore(format!("Unable to find a pending HTLC which matched the given HTLC ID ({})", htlc.htlc_id))); - } - } - pending_idx = idx; - } - } - if pending_idx == core::usize::MAX { - #[cfg(any(test, fuzzing))] - // If we failed to find an HTLC to fail, make sure it was previously fulfilled and this - // is simply a duplicate fail, not previously failed and we failed-back too early. - debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); - return Ok(None); + pub fn update_add_htlc(&mut self, msg: &msgs::UpdateAddHTLC, mut pending_forward_status: PendingHTLCStatus, create_pending_htlc_status: F, logger: &L) -> Result<(), ChannelError> + where F: for<'a> Fn(&'a Self, PendingHTLCStatus, u16) -> PendingHTLCStatus, L::Target: Logger { + // We can't accept HTLCs sent after we've sent a shutdown. + let local_sent_shutdown = (self.context.channel_state & (ChannelState::ChannelReady as u32 | ChannelState::LocalShutdownSent as u32)) != (ChannelState::ChannelReady as u32); + if local_sent_shutdown { + pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x4000|8); } - - if (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0 { - debug_assert!(force_holding_cell, "!force_holding_cell is only called when emptying the holding cell, so we shouldn't end up back in it!"); - force_holding_cell = true; + // If the remote has sent a shutdown prior to adding this HTLC, then they are in violation of the spec. + let remote_sent_shutdown = (self.context.channel_state & (ChannelState::ChannelReady as u32 | ChannelState::RemoteShutdownSent as u32)) != (ChannelState::ChannelReady as u32); + if remote_sent_shutdown { + return Err(ChannelError::Close("Got add HTLC message when channel was not in an operational state".to_owned())); } - - // Now update local state: - if force_holding_cell { - for pending_update in self.context.holding_cell_htlc_updates.iter() { - match pending_update { - &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => { - if htlc_id_arg == htlc_id { - #[cfg(any(test, fuzzing))] - debug_assert!(self.context.historical_inbound_htlc_fulfills.contains(&htlc_id_arg)); - return Ok(None); - } - }, - &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => { - if htlc_id_arg == htlc_id { - debug_assert!(false, "Tried to fail an HTLC that was already failed"); - return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned())); - } - }, - _ => {} - } - } - log_trace!(logger, "Placing failure for HTLC ID {} in holding cell in channel {}.", htlc_id_arg, log_bytes!(self.context.channel_id())); - self.context.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::FailHTLC { - htlc_id: htlc_id_arg, - err_packet, - }); - return Ok(None); - } - - log_trace!(logger, "Failing HTLC ID {} back with a update_fail_htlc message in channel {}.", htlc_id_arg, log_bytes!(self.context.channel_id())); - { - let htlc = &mut self.context.pending_inbound_htlcs[pending_idx]; - htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(err_packet.clone())); - } - - Ok(Some(msgs::UpdateFailHTLC { - channel_id: self.context.channel_id(), - htlc_id: htlc_id_arg, - reason: err_packet - })) - } - - // Message handlers: - - pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, default_limits: &ChannelHandshakeLimits, their_features: &InitFeatures) -> Result<(), ChannelError> { - let peer_limits = if let Some(ref limits) = self.context.inbound_handshake_limits_override { limits } else { default_limits }; - - // Check sanity of message fields: - if !self.context.is_outbound() { - return Err(ChannelError::Close("Got an accept_channel message from an inbound peer".to_owned())); - } - if self.context.channel_state != ChannelState::OurInitSent as u32 { - return Err(ChannelError::Close("Got an accept_channel message at a strange time".to_owned())); - } - if msg.dust_limit_satoshis > 21000000 * 100000000 { - return Err(ChannelError::Close(format!("Peer never wants payout outputs? dust_limit_satoshis was {}", msg.dust_limit_satoshis))); - } - if msg.channel_reserve_satoshis > self.context.channel_value_satoshis { - return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than ({})", msg.channel_reserve_satoshis, self.context.channel_value_satoshis))); - } - if msg.dust_limit_satoshis > self.context.holder_selected_channel_reserve_satoshis { - return Err(ChannelError::Close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.dust_limit_satoshis, self.context.holder_selected_channel_reserve_satoshis))); - } - if msg.channel_reserve_satoshis > self.context.channel_value_satoshis - self.context.holder_selected_channel_reserve_satoshis { - return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than channel value minus our reserve ({})", - msg.channel_reserve_satoshis, self.context.channel_value_satoshis - self.context.holder_selected_channel_reserve_satoshis))); - } - let full_channel_value_msat = (self.context.channel_value_satoshis - msg.channel_reserve_satoshis) * 1000; - if msg.htlc_minimum_msat >= full_channel_value_msat { - return Err(ChannelError::Close(format!("Minimum htlc value ({}) is full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat))); + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + return Err(ChannelError::Close("Peer sent update_add_htlc when we needed a channel_reestablish".to_owned())); } - let max_delay_acceptable = u16::min(peer_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT); - if msg.to_self_delay > max_delay_acceptable { - return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_delay_acceptable, msg.to_self_delay))); + if msg.amount_msat > self.context.channel_value_satoshis * 1000 { + return Err(ChannelError::Close("Remote side tried to send more than the total value of the channel".to_owned())); } - if msg.max_accepted_htlcs < 1 { - return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned())); + if msg.amount_msat == 0 { + return Err(ChannelError::Close("Remote side tried to send a 0-msat HTLC".to_owned())); } - if msg.max_accepted_htlcs > MAX_HTLCS { - return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS))); + if msg.amount_msat < self.context.holder_htlc_minimum_msat { + return Err(ChannelError::Close(format!("Remote side tried to send less than our minimum HTLC value. Lower limit: ({}). Actual: ({})", self.context.holder_htlc_minimum_msat, msg.amount_msat))); } - // Now check against optional parameters as set by config... - if msg.htlc_minimum_msat > peer_limits.max_htlc_minimum_msat { - return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, peer_limits.max_htlc_minimum_msat))); - } - if msg.max_htlc_value_in_flight_msat < peer_limits.min_max_htlc_value_in_flight_msat { - return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, peer_limits.min_max_htlc_value_in_flight_msat))); - } - if msg.channel_reserve_satoshis > peer_limits.max_channel_reserve_satoshis { - return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, peer_limits.max_channel_reserve_satoshis))); - } - if msg.max_accepted_htlcs < peer_limits.min_max_accepted_htlcs { - return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, peer_limits.min_max_accepted_htlcs))); - } - if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { - return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); + let inbound_stats = self.context.get_inbound_pending_htlc_stats(None); + let outbound_stats = self.context.get_outbound_pending_htlc_stats(None); + if inbound_stats.pending_htlcs + 1 > self.context.holder_max_accepted_htlcs as u32 { + return Err(ChannelError::Close(format!("Remote tried to push more than our max accepted HTLCs ({})", self.context.holder_max_accepted_htlcs))); } - if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS { - return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS))); + if inbound_stats.pending_htlcs_value_msat + msg.amount_msat > self.context.holder_max_htlc_value_in_flight_msat { + return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", self.context.holder_max_htlc_value_in_flight_msat))); } - if msg.minimum_depth > peer_limits.max_minimum_depth { - return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", peer_limits.max_minimum_depth, msg.minimum_depth))); + // Check holder_selected_channel_reserve_satoshis (we're getting paid, so they have to at least meet + // the reserve_satoshis we told them to always have as direct payment so that they lose + // something if we punish them for broadcasting an old state). + // Note that we don't really care about having a small/no to_remote output in our local + // commitment transactions, as the purpose of the channel reserve is to ensure we can + // punish *them* if they misbehave, so we discount any outbound HTLCs which will not be + // present in the next commitment transaction we send them (at least for fulfilled ones, + // failed ones won't modify value_to_self). + // Note that we will send HTLCs which another instance of rust-lightning would think + // violate the reserve value if we do not do this (as we forget inbound HTLCs from the + // Channel state once they will not be present in the next received commitment + // transaction). + let mut removed_outbound_total_msat = 0; + for ref htlc in self.context.pending_outbound_htlcs.iter() { + if let OutboundHTLCState::AwaitingRemoteRevokeToRemove(OutboundHTLCOutcome::Success(_)) = htlc.state { + removed_outbound_total_msat += htlc.amount_msat; + } else if let OutboundHTLCState::AwaitingRemovedRemoteRevoke(OutboundHTLCOutcome::Success(_)) = htlc.state { + removed_outbound_total_msat += htlc.amount_msat; + } } - if let Some(ty) = &msg.channel_type { - if *ty != self.context.channel_type { - return Err(ChannelError::Close("Channel Type in accept_channel didn't match the one sent in open_channel.".to_owned())); - } - } else if their_features.supports_channel_type() { - // Assume they've accepted the channel type as they said they understand it. + let (htlc_timeout_dust_limit, htlc_success_dust_limit) = if self.context.opt_anchors() { + (0, 0) } else { - let channel_type = ChannelTypeFeatures::from_init(&their_features); - if channel_type != ChannelTypeFeatures::only_static_remote_key() { - return Err(ChannelError::Close("Only static_remote_key is supported for non-negotiated channel types".to_owned())); + let dust_buffer_feerate = self.context.get_dust_buffer_feerate(None) as u64; + (dust_buffer_feerate * htlc_timeout_tx_weight(false) / 1000, + dust_buffer_feerate * htlc_success_tx_weight(false) / 1000) + }; + let exposure_dust_limit_timeout_sats = htlc_timeout_dust_limit + self.context.counterparty_dust_limit_satoshis; + if msg.amount_msat / 1000 < exposure_dust_limit_timeout_sats { + let on_counterparty_tx_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat + msg.amount_msat; + if on_counterparty_tx_dust_htlc_exposure_msat > self.context.get_max_dust_htlc_exposure_msat() { + log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on counterparty commitment tx", + on_counterparty_tx_dust_htlc_exposure_msat, self.context.get_max_dust_htlc_exposure_msat()); + pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7); } - self.context.channel_type = channel_type; } - let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() { - match &msg.shutdown_scriptpubkey { - &Some(ref script) => { - // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything - if script.len() == 0 { - None - } else { - if !script::is_bolt2_compliant(&script, their_features) { - return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))); - } - Some(script.clone()) - } - }, - // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel - &None => { - return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned())); - } + let exposure_dust_limit_success_sats = htlc_success_dust_limit + self.context.holder_dust_limit_satoshis; + if msg.amount_msat / 1000 < exposure_dust_limit_success_sats { + let on_holder_tx_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat + msg.amount_msat; + if on_holder_tx_dust_htlc_exposure_msat > self.context.get_max_dust_htlc_exposure_msat() { + log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on holder commitment tx", + on_holder_tx_dust_htlc_exposure_msat, self.context.get_max_dust_htlc_exposure_msat()); + pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7); } - } else { None }; - - self.context.counterparty_dust_limit_satoshis = msg.dust_limit_satoshis; - self.context.counterparty_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.context.channel_value_satoshis * 1000); - self.context.counterparty_selected_channel_reserve_satoshis = Some(msg.channel_reserve_satoshis); - self.context.counterparty_htlc_minimum_msat = msg.htlc_minimum_msat; - self.context.counterparty_max_accepted_htlcs = msg.max_accepted_htlcs; + } - if peer_limits.trust_own_funding_0conf { - self.context.minimum_depth = Some(msg.minimum_depth); - } else { - self.context.minimum_depth = Some(cmp::max(1, msg.minimum_depth)); + let pending_value_to_self_msat = + self.context.value_to_self_msat + inbound_stats.pending_htlcs_value_msat - removed_outbound_total_msat; + let pending_remote_value_msat = + self.context.channel_value_satoshis * 1000 - pending_value_to_self_msat; + if pending_remote_value_msat < msg.amount_msat { + return Err(ChannelError::Close("Remote HTLC add would overdraw remaining funds".to_owned())); } - let counterparty_pubkeys = ChannelPublicKeys { - funding_pubkey: msg.funding_pubkey, - revocation_basepoint: msg.revocation_basepoint, - payment_point: msg.payment_point, - delayed_payment_basepoint: msg.delayed_payment_basepoint, - htlc_basepoint: msg.htlc_basepoint + // Check that the remote can afford to pay for this HTLC on-chain at the current + // feerate_per_kw, while maintaining their channel reserve (as required by the spec). + let remote_commit_tx_fee_msat = if self.context.is_outbound() { 0 } else { + let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered); + self.context.next_remote_commit_tx_fee_msat(htlc_candidate, None) // Don't include the extra fee spike buffer HTLC in calculations + }; + if pending_remote_value_msat - msg.amount_msat < remote_commit_tx_fee_msat { + return Err(ChannelError::Close("Remote HTLC add would not leave enough to pay for fees".to_owned())); }; - self.context.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters { - selected_contest_delay: msg.to_self_delay, - pubkeys: counterparty_pubkeys, - }); + if pending_remote_value_msat - msg.amount_msat - remote_commit_tx_fee_msat < self.context.holder_selected_channel_reserve_satoshis * 1000 { + return Err(ChannelError::Close("Remote HTLC add would put them under remote reserve value".to_owned())); + } - self.context.counterparty_cur_commitment_point = Some(msg.first_per_commitment_point); - self.context.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey; + if !self.context.is_outbound() { + // `2 *` and `Some(())` is for the fee spike buffer we keep for the remote. This deviates from + // the spec because in the spec, the fee spike buffer requirement doesn't exist on the + // receiver's side, only on the sender's. + // Note that when we eventually remove support for fee updates and switch to anchor output + // fees, we will drop the `2 *`, since we no longer be as sensitive to fee spikes. But, keep + // the extra htlc when calculating the next remote commitment transaction fee as we should + // still be able to afford adding this HTLC plus one more future HTLC, regardless of being + // sensitive to fee spikes. + let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered); + let remote_fee_cost_incl_stuck_buffer_msat = 2 * self.context.next_remote_commit_tx_fee_msat(htlc_candidate, Some(())); + if pending_remote_value_msat - msg.amount_msat - self.context.holder_selected_channel_reserve_satoshis * 1000 < remote_fee_cost_incl_stuck_buffer_msat { + // Note that if the pending_forward_status is not updated here, then it's because we're already failing + // the HTLC, i.e. its status is already set to failing. + log_info!(logger, "Attempting to fail HTLC due to fee spike buffer violation in channel {}. Rebalancing is required.", log_bytes!(self.context.channel_id())); + pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7); + } + } else { + // Check that they won't violate our local required channel reserve by adding this HTLC. + let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered); + let local_commit_tx_fee_msat = self.context.next_local_commit_tx_fee_msat(htlc_candidate, None); + if self.context.value_to_self_msat < self.context.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 + local_commit_tx_fee_msat { + return Err(ChannelError::Close("Cannot accept HTLC that would put our balance under counterparty-announced channel reserve value".to_owned())); + } + } + if self.context.next_counterparty_htlc_id != msg.htlc_id { + return Err(ChannelError::Close(format!("Remote skipped HTLC ID (skipped ID: {})", self.context.next_counterparty_htlc_id))); + } + if msg.cltv_expiry >= 500000000 { + return Err(ChannelError::Close("Remote provided CLTV expiry in seconds instead of block height".to_owned())); + } - self.context.channel_state = ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32; - self.context.inbound_handshake_limits_override = None; // We're done enforcing limits on our peer's handshake now. + if self.context.channel_state & ChannelState::LocalShutdownSent as u32 != 0 { + if let PendingHTLCStatus::Forward(_) = pending_forward_status { + panic!("ChannelManager shouldn't be trying to add a forwardable HTLC after we've started closing"); + } + } - Ok(()) + // Now update local state: + self.context.next_counterparty_htlc_id += 1; + self.context.pending_inbound_htlcs.push(InboundHTLCOutput { + htlc_id: msg.htlc_id, + amount_msat: msg.amount_msat, + payment_hash: msg.payment_hash, + cltv_expiry: msg.cltv_expiry, + state: InboundHTLCState::RemoteAnnounced(pending_forward_status), + }); + Ok(()) } - fn funding_created_signature(&mut self, sig: &Signature, logger: &L) -> Result<(Txid, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger { - let funding_script = self.context.get_funding_redeemscript(); + /// Marks an outbound HTLC which we have received update_fail/fulfill/malformed + #[inline] + fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option, fail_reason: Option) -> Result<&OutboundHTLCOutput, ChannelError> { + assert!(!(check_preimage.is_some() && fail_reason.is_some()), "cannot fail while we have a preimage"); + for htlc in self.context.pending_outbound_htlcs.iter_mut() { + if htlc.htlc_id == htlc_id { + let outcome = match check_preimage { + None => fail_reason.into(), + Some(payment_preimage) => { + let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()); + if payment_hash != htlc.payment_hash { + return Err(ChannelError::Close(format!("Remote tried to fulfill HTLC ({}) with an incorrect preimage", htlc_id))); + } + OutboundHTLCOutcome::Success(Some(payment_preimage)) + } + }; + match htlc.state { + OutboundHTLCState::LocalAnnounced(_) => + return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) before it had been committed", htlc_id))), + OutboundHTLCState::Committed => { + htlc.state = OutboundHTLCState::RemoteRemoved(outcome); + }, + OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) | OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) | OutboundHTLCState::RemoteRemoved(_) => + return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) that they'd already fulfilled/failed", htlc_id))), + } + return Ok(htlc); + } + } + Err(ChannelError::Close("Remote tried to fulfill/fail an HTLC we couldn't find".to_owned())) + } - let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); - let initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx; - { - let trusted_tx = initial_commitment_tx.trust(); - let initial_commitment_bitcoin_tx = trusted_tx.built_transaction(); - let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis); - // They sign the holder commitment transaction... - log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.", - log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.context.counterparty_funding_pubkey().serialize()), - encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]), - encode::serialize_hex(&funding_script), log_bytes!(self.context.channel_id())); - secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &sig, self.context.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned()); + pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(HTLCSource, u64), ChannelError> { + if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { + return Err(ChannelError::Close("Got fulfill HTLC message when channel was not in an operational state".to_owned())); + } + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + return Err(ChannelError::Close("Peer sent update_fulfill_htlc when we needed a channel_reestablish".to_owned())); } - let counterparty_keys = self.context.build_remote_transaction_keys(); - let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx; + self.mark_outbound_htlc_removed(msg.htlc_id, Some(msg.payment_preimage), None).map(|htlc| (htlc.source.clone(), htlc.amount_msat)) + } - let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust(); - let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction(); - log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}", - log_bytes!(self.context.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction)); + pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> { + if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { + return Err(ChannelError::Close("Got fail HTLC message when channel was not in an operational state".to_owned())); + } + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + return Err(ChannelError::Close("Peer sent update_fail_htlc when we needed a channel_reestablish".to_owned())); + } - let counterparty_signature = self.context.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx) - .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0; + self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?; + Ok(()) + } - // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish. - Ok((counterparty_initial_bitcoin_tx.txid, initial_commitment_tx, counterparty_signature)) + pub fn update_fail_malformed_htlc(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> { + if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { + return Err(ChannelError::Close("Got fail malformed HTLC message when channel was not in an operational state".to_owned())); + } + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + return Err(ChannelError::Close("Peer sent update_fail_malformed_htlc when we needed a channel_reestablish".to_owned())); + } + + self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?; + Ok(()) } - pub fn funding_created( - &mut self, msg: &msgs::FundingCreated, best_block: BestBlock, signer_provider: &SP, logger: &L - ) -> Result<(msgs::FundingSigned, ChannelMonitor), ChannelError> - where - SP::Target: SignerProvider, - L::Target: Logger + pub fn commitment_signed(&mut self, msg: &msgs::CommitmentSigned, logger: &L) -> Result, ChannelError> + where L::Target: Logger { - if self.context.is_outbound() { - return Err(ChannelError::Close("Received funding_created for an outbound channel?".to_owned())); - } - if self.context.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) { - // BOLT 2 says that if we disconnect before we send funding_signed we SHOULD NOT - // remember the channel, so it's safe to just send an error_message here and drop the - // channel. - return Err(ChannelError::Close("Received funding_created after we got the channel!".to_owned())); + if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { + return Err(ChannelError::Close("Got commitment signed message when channel was not in an operational state".to_owned())); } - if self.context.inbound_awaiting_accept { - return Err(ChannelError::Close("FundingCreated message received before the channel was accepted".to_owned())); + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + return Err(ChannelError::Close("Peer sent commitment_signed when we needed a channel_reestablish".to_owned())); } - if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) || - self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER || - self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { - panic!("Should not have advanced channel commitment tx numbers prior to funding_created"); + if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.context.last_sent_closing_fee.is_some() { + return Err(ChannelError::Close("Peer sent commitment_signed after we'd started exchanging closing_signeds".to_owned())); } - let funding_txo = OutPoint { txid: msg.funding_txid, index: msg.funding_output_index }; - self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo); - // This is an externally observable change before we finish all our checks. In particular - // funding_created_signature may fail. - self.context.holder_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); + let funding_script = self.context.get_funding_redeemscript(); - let (counterparty_initial_commitment_txid, initial_commitment_tx, signature) = match self.funding_created_signature(&msg.signature, logger) { - Ok(res) => res, - Err(ChannelError::Close(e)) => { - self.context.channel_transaction_parameters.funding_outpoint = None; - return Err(ChannelError::Close(e)); - }, - Err(e) => { - // The only error we know how to handle is ChannelError::Close, so we fall over here - // to make sure we don't continue with an inconsistent state. - panic!("unexpected error type from funding_created_signature {:?}", e); + let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); + + let commitment_stats = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger); + let commitment_txid = { + let trusted_tx = commitment_stats.tx.trust(); + let bitcoin_tx = trusted_tx.built_transaction(); + let sighash = bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis); + + log_trace!(logger, "Checking commitment tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}", + log_bytes!(msg.signature.serialize_compact()[..]), + log_bytes!(self.context.counterparty_funding_pubkey().serialize()), encode::serialize_hex(&bitcoin_tx.transaction), + log_bytes!(sighash[..]), encode::serialize_hex(&funding_script), log_bytes!(self.context.channel_id())); + if let Err(_) = self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.context.counterparty_funding_pubkey()) { + return Err(ChannelError::Close("Invalid commitment tx signature from peer".to_owned())); } + bitcoin_tx.txid }; + let mut htlcs_cloned: Vec<_> = commitment_stats.htlcs_included.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect(); + + // If our counterparty updated the channel fee in this commitment transaction, check that + // they can actually afford the new fee now. + let update_fee = if let Some((_, update_state)) = self.context.pending_update_fee { + update_state == FeeUpdateState::RemoteAnnounced + } else { false }; + if update_fee { + debug_assert!(!self.context.is_outbound()); + let counterparty_reserve_we_require_msat = self.context.holder_selected_channel_reserve_satoshis * 1000; + if commitment_stats.remote_balance_msat < commitment_stats.total_fee_sat * 1000 + counterparty_reserve_we_require_msat { + return Err(ChannelError::Close("Funding remote cannot afford proposed new fee".to_owned())); + } + } + #[cfg(any(test, fuzzing))] + { + if self.context.is_outbound() { + let projected_commit_tx_info = self.context.next_local_commitment_tx_fee_info_cached.lock().unwrap().take(); + *self.context.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None; + if let Some(info) = projected_commit_tx_info { + let total_pending_htlcs = self.context.pending_inbound_htlcs.len() + self.context.pending_outbound_htlcs.len() + + self.context.holding_cell_htlc_updates.len(); + if info.total_pending_htlcs == total_pending_htlcs + && info.next_holder_htlc_id == self.context.next_holder_htlc_id + && info.next_counterparty_htlc_id == self.context.next_counterparty_htlc_id + && info.feerate == self.context.feerate_per_kw { + assert_eq!(commitment_stats.total_fee_sat, info.fee / 1000); + } + } + } + } + + if msg.htlc_signatures.len() != commitment_stats.num_nondust_htlcs { + return Err(ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_stats.num_nondust_htlcs))); + } + + // Up to LDK 0.0.115, HTLC information was required to be duplicated in the + // `htlcs_and_sigs` vec and in the `holder_commitment_tx` itself, both of which were passed + // in the `ChannelMonitorUpdate`. In 0.0.115, support for having a separate set of + // outbound-non-dust-HTLCSources in the `ChannelMonitorUpdate` was added, however for + // backwards compatibility, we never use it in production. To provide test coverage, here, + // we randomly decide (in test/fuzzing builds) to use the new vec sometimes. + #[allow(unused_assignments, unused_mut)] + let mut separate_nondust_htlc_sources = false; + #[cfg(all(feature = "std", any(test, fuzzing)))] { + use core::hash::{BuildHasher, Hasher}; + // Get a random value using the only std API to do so - the DefaultHasher + let rand_val = std::collections::hash_map::RandomState::new().build_hasher().finish(); + separate_nondust_htlc_sources = rand_val % 2 == 0; + } + + let mut nondust_htlc_sources = Vec::with_capacity(htlcs_cloned.len()); + let mut htlcs_and_sigs = Vec::with_capacity(htlcs_cloned.len()); + for (idx, (htlc, mut source_opt)) in htlcs_cloned.drain(..).enumerate() { + if let Some(_) = htlc.transaction_output_index { + let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.feerate_per_kw, + self.context.get_counterparty_selected_contest_delay().unwrap(), &htlc, self.context.opt_anchors(), + false, &keys.broadcaster_delayed_payment_key, &keys.revocation_key); + + let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.context.opt_anchors(), &keys); + let htlc_sighashtype = if self.context.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All }; + let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]); + log_trace!(logger, "Checking HTLC tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}.", + log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(keys.countersignatory_htlc_key.serialize()), + encode::serialize_hex(&htlc_tx), log_bytes!(htlc_sighash[..]), encode::serialize_hex(&htlc_redeemscript), log_bytes!(self.context.channel_id())); + if let Err(_) = self.context.secp_ctx.verify_ecdsa(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key) { + return Err(ChannelError::Close("Invalid HTLC tx signature from peer".to_owned())); + } + if !separate_nondust_htlc_sources { + htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source_opt.take())); + } + } else { + htlcs_and_sigs.push((htlc, None, source_opt.take())); + } + if separate_nondust_htlc_sources { + if let Some(source) = source_opt.take() { + nondust_htlc_sources.push(source); + } + } + debug_assert!(source_opt.is_none(), "HTLCSource should have been put somewhere"); + } let holder_commitment_tx = HolderCommitmentTransaction::new( - initial_commitment_tx, + commitment_stats.tx, msg.signature, - Vec::new(), + msg.htlc_signatures.clone(), &self.context.get_holder_pubkeys().funding_pubkey, self.context.counterparty_funding_pubkey() ); - self.context.holder_signer.validate_holder_commitment(&holder_commitment_tx, Vec::new()) + self.context.holder_signer.validate_holder_commitment(&holder_commitment_tx, commitment_stats.preimages) .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?; - // Now that we're past error-generating stuff, update our local state: + // Update state now that we've passed all the can-fail calls... + let mut need_commitment = false; + if let &mut Some((_, ref mut update_state)) = &mut self.context.pending_update_fee { + if *update_state == FeeUpdateState::RemoteAnnounced { + *update_state = FeeUpdateState::AwaitingRemoteRevokeToAnnounce; + need_commitment = true; + } + } - let funding_redeemscript = self.context.get_funding_redeemscript(); - let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); - let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.context.get_holder_pubkeys().payment_point, &self.context.get_counterparty_pubkeys().payment_point, self.context.is_outbound()); - let shutdown_script = self.context.shutdown_scriptpubkey.clone().map(|script| script.into_inner()); - let mut monitor_signer = signer_provider.derive_channel_signer(self.context.channel_value_satoshis, self.context.channel_keys_id); - monitor_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); - let channel_monitor = ChannelMonitor::new(self.context.secp_ctx.clone(), monitor_signer, - shutdown_script, self.context.get_holder_selected_contest_delay(), - &self.context.destination_script, (funding_txo, funding_txo_script.clone()), - &self.context.channel_transaction_parameters, - funding_redeemscript.clone(), self.context.channel_value_satoshis, - obscure_factor, - holder_commitment_tx, best_block, self.context.counterparty_node_id); + for htlc in self.context.pending_inbound_htlcs.iter_mut() { + let new_forward = if let &InboundHTLCState::RemoteAnnounced(ref forward_info) = &htlc.state { + Some(forward_info.clone()) + } else { None }; + if let Some(forward_info) = new_forward { + log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToAnnounce due to commitment_signed in channel {}.", + log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id)); + htlc.state = InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info); + need_commitment = true; + } + } + let mut claimed_htlcs = Vec::new(); + for htlc in self.context.pending_outbound_htlcs.iter_mut() { + if let &mut OutboundHTLCState::RemoteRemoved(ref mut outcome) = &mut htlc.state { + log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToRemove due to commitment_signed in channel {}.", + log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id)); + // Grab the preimage, if it exists, instead of cloning + let mut reason = OutboundHTLCOutcome::Success(None); + mem::swap(outcome, &mut reason); + if let OutboundHTLCOutcome::Success(Some(preimage)) = reason { + // If a user (a) receives an HTLC claim using LDK 0.0.104 or before, then (b) + // upgrades to LDK 0.0.114 or later before the HTLC is fully resolved, we could + // have a `Success(None)` reason. In this case we could forget some HTLC + // claims, but such an upgrade is unlikely and including claimed HTLCs here + // fixes a bug which the user was exposed to on 0.0.104 when they started the + // claim anyway. + claimed_htlcs.push((SentHTLCId::from_source(&htlc.source), preimage)); + } + htlc.state = OutboundHTLCState::AwaitingRemoteRevokeToRemove(reason); + need_commitment = true; + } + } - channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_commitment_txid, Vec::new(), self.context.cur_counterparty_commitment_transaction_number, self.context.counterparty_cur_commitment_point.unwrap(), logger); + self.context.latest_monitor_update_id += 1; + let mut monitor_update = ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { + commitment_tx: holder_commitment_tx, + htlc_outputs: htlcs_and_sigs, + claimed_htlcs, + nondust_htlc_sources, + }] + }; - self.context.channel_state = ChannelState::FundingSent as u32; - self.context.channel_id = funding_txo.to_channel_id(); - self.context.cur_counterparty_commitment_transaction_number -= 1; self.context.cur_holder_commitment_transaction_number -= 1; + // Note that if we need_commitment & !AwaitingRemoteRevoke we'll call + // build_commitment_no_status_check() next which will reset this to RAAFirst. + self.context.resend_order = RAACommitmentOrder::CommitmentFirst; - log_info!(logger, "Generated funding_signed for peer for channel {}", log_bytes!(self.context.channel_id())); + if (self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32) != 0 { + // In case we initially failed monitor updating without requiring a response, we need + // to make sure the RAA gets sent first. + self.context.monitor_pending_revoke_and_ack = true; + if need_commitment && (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 { + // If we were going to send a commitment_signed after the RAA, go ahead and do all + // the corresponding HTLC status updates so that get_last_commitment_update + // includes the right HTLCs. + self.context.monitor_pending_commitment_signed = true; + let mut additional_update = self.build_commitment_no_status_check(logger); + // build_commitment_no_status_check may bump latest_monitor_id but we want them to be + // strictly increasing by one, so decrement it here. + self.context.latest_monitor_update_id = monitor_update.update_id; + monitor_update.updates.append(&mut additional_update.updates); + } + log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updated HTLC state but awaiting a monitor update resolution to reply.", + log_bytes!(self.context.channel_id)); + return Ok(self.push_ret_blockable_mon_update(monitor_update)); + } - let need_channel_ready = self.check_get_channel_ready(0).is_some(); - self.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new()); + let need_commitment_signed = if need_commitment && (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 { + // If we're AwaitingRemoteRevoke we can't send a new commitment here, but that's ok - + // we'll send one right away when we get the revoke_and_ack when we + // free_holding_cell_htlcs(). + let mut additional_update = self.build_commitment_no_status_check(logger); + // build_commitment_no_status_check may bump latest_monitor_id but we want them to be + // strictly increasing by one, so decrement it here. + self.context.latest_monitor_update_id = monitor_update.update_id; + monitor_update.updates.append(&mut additional_update.updates); + true + } else { false }; - Ok((msgs::FundingSigned { - channel_id: self.context.channel_id, - signature, - #[cfg(taproot)] - partial_signature_with_nonce: None, - }, channel_monitor)) + log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updating HTLC state and responding with{} a revoke_and_ack.", + log_bytes!(self.context.channel_id()), if need_commitment_signed { " our own commitment_signed and" } else { "" }); + self.monitor_updating_paused(true, need_commitment_signed, false, Vec::new(), Vec::new(), Vec::new()); + return Ok(self.push_ret_blockable_mon_update(monitor_update)); } - /// Handles a funding_signed message from the remote end. - /// If this call is successful, broadcast the funding transaction (and not before!) - pub fn funding_signed( - &mut self, msg: &msgs::FundingSigned, best_block: BestBlock, signer_provider: &SP, logger: &L - ) -> Result, ChannelError> - where - SP::Target: SignerProvider, - L::Target: Logger - { - if !self.context.is_outbound() { - return Err(ChannelError::Close("Received funding_signed for an inbound channel?".to_owned())); - } - if self.context.channel_state & !(ChannelState::MonitorUpdateInProgress as u32) != ChannelState::FundingCreated as u32 { - return Err(ChannelError::Close("Received funding_signed in strange state!".to_owned())); - } - if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) || - self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER || - self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { - panic!("Should not have advanced channel commitment tx numbers prior to funding_created"); - } - - let funding_script = self.context.get_funding_redeemscript(); + /// Public version of the below, checking relevant preconditions first. + /// If we're not in a state where freeing the holding cell makes sense, this is a no-op and + /// returns `(None, Vec::new())`. + pub fn maybe_free_holding_cell_htlcs(&mut self, logger: &L) -> (Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger { + if self.context.channel_state >= ChannelState::ChannelReady as u32 && + (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32)) == 0 { + self.free_holding_cell_htlcs(logger) + } else { (None, Vec::new()) } + } - let counterparty_keys = self.context.build_remote_transaction_keys(); - let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx; - let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust(); - let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction(); + /// Frees any pending commitment updates in the holding cell, generating the relevant messages + /// for our counterparty. + fn free_holding_cell_htlcs(&mut self, logger: &L) -> (Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger { + assert_eq!(self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32, 0); + if self.context.holding_cell_htlc_updates.len() != 0 || self.context.holding_cell_update_fee.is_some() { + log_trace!(logger, "Freeing holding cell with {} HTLC updates{} in channel {}", self.context.holding_cell_htlc_updates.len(), + if self.context.holding_cell_update_fee.is_some() { " and a fee update" } else { "" }, log_bytes!(self.context.channel_id())); - log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}", - log_bytes!(self.context.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction)); + let mut monitor_update = ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id + 1, // We don't increment this yet! + updates: Vec::new(), + }; - let holder_signer = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); - let initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &holder_signer, true, false, logger).tx; - { - let trusted_tx = initial_commitment_tx.trust(); - let initial_commitment_bitcoin_tx = trusted_tx.built_transaction(); - let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis); - // They sign our commitment transaction, allowing us to broadcast the tx if we wish. - if let Err(_) = self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.context.get_counterparty_pubkeys().funding_pubkey) { - return Err(ChannelError::Close("Invalid funding_signed signature from peer".to_owned())); + let mut htlc_updates = Vec::new(); + mem::swap(&mut htlc_updates, &mut self.context.holding_cell_htlc_updates); + let mut update_add_htlcs = Vec::with_capacity(htlc_updates.len()); + let mut update_fulfill_htlcs = Vec::with_capacity(htlc_updates.len()); + let mut update_fail_htlcs = Vec::with_capacity(htlc_updates.len()); + let mut htlcs_to_fail = Vec::new(); + for htlc_update in htlc_updates.drain(..) { + // Note that this *can* fail, though it should be due to rather-rare conditions on + // fee races with adding too many outputs which push our total payments just over + // the limit. In case it's less rare than I anticipate, we may want to revisit + // handling this case better and maybe fulfilling some of the HTLCs while attempting + // to rebalance channels. + match &htlc_update { + &HTLCUpdateAwaitingACK::AddHTLC {amount_msat, cltv_expiry, ref payment_hash, ref source, ref onion_routing_packet, ..} => { + match self.send_htlc(amount_msat, *payment_hash, cltv_expiry, source.clone(), onion_routing_packet.clone(), false, logger) { + Ok(update_add_msg_option) => update_add_htlcs.push(update_add_msg_option.unwrap()), + Err(e) => { + match e { + ChannelError::Ignore(ref msg) => { + log_info!(logger, "Failed to send HTLC with payment_hash {} due to {} in channel {}", + log_bytes!(payment_hash.0), msg, log_bytes!(self.context.channel_id())); + // If we fail to send here, then this HTLC should + // be failed backwards. Failing to send here + // indicates that this HTLC may keep being put back + // into the holding cell without ever being + // successfully forwarded/failed/fulfilled, causing + // our counterparty to eventually close on us. + htlcs_to_fail.push((source.clone(), *payment_hash)); + }, + _ => { + panic!("Got a non-IgnoreError action trying to send holding cell HTLC"); + }, + } + } + } + }, + &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, htlc_id, .. } => { + // If an HTLC claim was previously added to the holding cell (via + // `get_update_fulfill_htlc`, then generating the claim message itself must + // not fail - any in between attempts to claim the HTLC will have resulted + // in it hitting the holding cell again and we cannot change the state of a + // holding cell HTLC from fulfill to anything else. + let (update_fulfill_msg_option, mut additional_monitor_update) = + if let UpdateFulfillFetch::NewClaim { msg, monitor_update, .. } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) { + (msg, monitor_update) + } else { unreachable!() }; + update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap()); + monitor_update.updates.append(&mut additional_monitor_update.updates); + }, + &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, ref err_packet } => { + match self.fail_htlc(htlc_id, err_packet.clone(), false, logger) { + Ok(update_fail_msg_option) => { + // If an HTLC failure was previously added to the holding cell (via + // `queue_fail_htlc`) then generating the fail message itself must + // not fail - we should never end up in a state where we double-fail + // an HTLC or fail-then-claim an HTLC as it indicates we didn't wait + // for a full revocation before failing. + update_fail_htlcs.push(update_fail_msg_option.unwrap()) + }, + Err(e) => { + if let ChannelError::Ignore(_) = e {} + else { + panic!("Got a non-IgnoreError action trying to fail holding cell HTLC"); + } + } + } + }, + } } - } + if update_add_htlcs.is_empty() && update_fulfill_htlcs.is_empty() && update_fail_htlcs.is_empty() && self.context.holding_cell_update_fee.is_none() { + return (None, htlcs_to_fail); + } + let update_fee = if let Some(feerate) = self.context.holding_cell_update_fee.take() { + self.send_update_fee(feerate, false, logger) + } else { + None + }; - let holder_commitment_tx = HolderCommitmentTransaction::new( - initial_commitment_tx, - msg.signature, - Vec::new(), - &self.context.get_holder_pubkeys().funding_pubkey, - self.context.counterparty_funding_pubkey() - ); + let mut additional_update = self.build_commitment_no_status_check(logger); + // build_commitment_no_status_check and get_update_fulfill_htlc may bump latest_monitor_id + // but we want them to be strictly increasing by one, so reset it here. + self.context.latest_monitor_update_id = monitor_update.update_id; + monitor_update.updates.append(&mut additional_update.updates); - self.context.holder_signer.validate_holder_commitment(&holder_commitment_tx, Vec::new()) - .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?; + log_debug!(logger, "Freeing holding cell in channel {} resulted in {}{} HTLCs added, {} HTLCs fulfilled, and {} HTLCs failed.", + log_bytes!(self.context.channel_id()), if update_fee.is_some() { "a fee update, " } else { "" }, + update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len()); + self.monitor_updating_paused(false, true, false, Vec::new(), Vec::new(), Vec::new()); + (self.push_ret_blockable_mon_update(monitor_update), htlcs_to_fail) + } else { + (None, Vec::new()) + } + } - let funding_redeemscript = self.context.get_funding_redeemscript(); - let funding_txo = self.context.get_funding_txo().unwrap(); - let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); - let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.context.get_holder_pubkeys().payment_point, &self.context.get_counterparty_pubkeys().payment_point, self.context.is_outbound()); - let shutdown_script = self.context.shutdown_scriptpubkey.clone().map(|script| script.into_inner()); - let mut monitor_signer = signer_provider.derive_channel_signer(self.context.channel_value_satoshis, self.context.channel_keys_id); - monitor_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); - let channel_monitor = ChannelMonitor::new(self.context.secp_ctx.clone(), monitor_signer, - shutdown_script, self.context.get_holder_selected_contest_delay(), - &self.context.destination_script, (funding_txo, funding_txo_script), - &self.context.channel_transaction_parameters, - funding_redeemscript.clone(), self.context.channel_value_satoshis, - obscure_factor, - holder_commitment_tx, best_block, self.context.counterparty_node_id); - - channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_bitcoin_tx.txid, Vec::new(), self.context.cur_counterparty_commitment_transaction_number, self.context.counterparty_cur_commitment_point.unwrap(), logger); - - assert_eq!(self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32), 0); // We have no had any monitor(s) yet to fail update! - self.context.channel_state = ChannelState::FundingSent as u32; - self.context.cur_holder_commitment_transaction_number -= 1; - self.context.cur_counterparty_commitment_transaction_number -= 1; - - log_info!(logger, "Received funding_signed from peer for channel {}", log_bytes!(self.context.channel_id())); - - let need_channel_ready = self.check_get_channel_ready(0).is_some(); - self.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new()); - Ok(channel_monitor) - } - - /// Handles a channel_ready message from our peer. If we've already sent our channel_ready - /// and the channel is now usable (and public), this may generate an announcement_signatures to - /// reply with. - pub fn channel_ready( - &mut self, msg: &msgs::ChannelReady, node_signer: &NS, genesis_block_hash: BlockHash, - user_config: &UserConfig, best_block: &BestBlock, logger: &L - ) -> Result, ChannelError> - where - NS::Target: NodeSigner, - L::Target: Logger + /// Handles receiving a remote's revoke_and_ack. Note that we may return a new + /// commitment_signed message here in case we had pending outbound HTLCs to add which were + /// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail, + /// generating an appropriate error *after* the channel state has been updated based on the + /// revoke_and_ack message. + pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK, logger: &L) -> Result<(Vec<(HTLCSource, PaymentHash)>, Option<&ChannelMonitorUpdate>), ChannelError> + where L::Target: Logger, { + if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { + return Err(ChannelError::Close("Got revoke/ACK message when channel was not in an operational state".to_owned())); + } if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - self.context.workaround_lnd_bug_4006 = Some(msg.clone()); - return Err(ChannelError::Ignore("Peer sent channel_ready when we needed a channel_reestablish. The peer is likely lnd, see https://github.com/lightningnetwork/lnd/issues/4006".to_owned())); + return Err(ChannelError::Close("Peer sent revoke_and_ack when we needed a channel_reestablish".to_owned())); } - - if let Some(scid_alias) = msg.short_channel_id_alias { - if Some(scid_alias) != self.context.short_channel_id { - // The scid alias provided can be used to route payments *from* our counterparty, - // i.e. can be used for inbound payments and provided in invoices, but is not used - // when routing outbound payments. - self.context.latest_inbound_scid_alias = Some(scid_alias); - } + if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.context.last_sent_closing_fee.is_some() { + return Err(ChannelError::Close("Peer sent revoke_and_ack after we'd started exchanging closing_signeds".to_owned())); } - let non_shutdown_state = self.context.channel_state & (!MULTI_STATE_FLAGS); + let secret = secp_check!(SecretKey::from_slice(&msg.per_commitment_secret), "Peer provided an invalid per_commitment_secret".to_owned()); - if non_shutdown_state == ChannelState::FundingSent as u32 { - self.context.channel_state |= ChannelState::TheirChannelReady as u32; - } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurChannelReady as u32) { - self.context.channel_state = ChannelState::ChannelReady as u32 | (self.context.channel_state & MULTI_STATE_FLAGS); - self.context.update_time_counter += 1; - } else if self.context.channel_state & (ChannelState::ChannelReady as u32) != 0 || - // If we reconnected before sending our `channel_ready` they may still resend theirs: - (self.context.channel_state & (ChannelState::FundingSent as u32 | ChannelState::TheirChannelReady as u32) == - (ChannelState::FundingSent as u32 | ChannelState::TheirChannelReady as u32)) - { - // They probably disconnected/reconnected and re-sent the channel_ready, which is - // required, or they're sending a fresh SCID alias. - let expected_point = - if self.context.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 { - // If they haven't ever sent an updated point, the point they send should match - // the current one. - self.context.counterparty_cur_commitment_point - } else if self.context.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 2 { - // If we've advanced the commitment number once, the second commitment point is - // at `counterparty_prev_commitment_point`, which is not yet revoked. - debug_assert!(self.context.counterparty_prev_commitment_point.is_some()); - self.context.counterparty_prev_commitment_point - } else { - // If they have sent updated points, channel_ready is always supposed to match - // their "first" point, which we re-derive here. - Some(PublicKey::from_secret_key(&self.context.secp_ctx, &SecretKey::from_slice( - &self.context.commitment_secrets.get_secret(INITIAL_COMMITMENT_NUMBER - 1).expect("We should have all prev secrets available") - ).expect("We already advanced, so previous secret keys should have been validated already"))) - }; - if expected_point != Some(msg.next_per_commitment_point) { - return Err(ChannelError::Close("Peer sent a reconnect channel_ready with a different point".to_owned())); + if let Some(counterparty_prev_commitment_point) = self.context.counterparty_prev_commitment_point { + if PublicKey::from_secret_key(&self.context.secp_ctx, &secret) != counterparty_prev_commitment_point { + return Err(ChannelError::Close("Got a revoke commitment secret which didn't correspond to their current pubkey".to_owned())); } - return Ok(None); - } else { - return Err(ChannelError::Close("Peer sent a channel_ready at a strange time".to_owned())); } - self.context.counterparty_prev_commitment_point = self.context.counterparty_cur_commitment_point; - self.context.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point); - - log_info!(logger, "Received channel_ready from peer for channel {}", log_bytes!(self.context.channel_id())); - - Ok(self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger)) - } - - pub fn update_add_htlc(&mut self, msg: &msgs::UpdateAddHTLC, mut pending_forward_status: PendingHTLCStatus, create_pending_htlc_status: F, logger: &L) -> Result<(), ChannelError> - where F: for<'a> Fn(&'a Self, PendingHTLCStatus, u16) -> PendingHTLCStatus, L::Target: Logger { - // We can't accept HTLCs sent after we've sent a shutdown. - let local_sent_shutdown = (self.context.channel_state & (ChannelState::ChannelReady as u32 | ChannelState::LocalShutdownSent as u32)) != (ChannelState::ChannelReady as u32); - if local_sent_shutdown { - pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x4000|8); - } - // If the remote has sent a shutdown prior to adding this HTLC, then they are in violation of the spec. - let remote_sent_shutdown = (self.context.channel_state & (ChannelState::ChannelReady as u32 | ChannelState::RemoteShutdownSent as u32)) != (ChannelState::ChannelReady as u32); - if remote_sent_shutdown { - return Err(ChannelError::Close("Got add HTLC message when channel was not in an operational state".to_owned())); - } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent update_add_htlc when we needed a channel_reestablish".to_owned())); - } - if msg.amount_msat > self.context.channel_value_satoshis * 1000 { - return Err(ChannelError::Close("Remote side tried to send more than the total value of the channel".to_owned())); - } - if msg.amount_msat == 0 { - return Err(ChannelError::Close("Remote side tried to send a 0-msat HTLC".to_owned())); - } - if msg.amount_msat < self.context.holder_htlc_minimum_msat { - return Err(ChannelError::Close(format!("Remote side tried to send less than our minimum HTLC value. Lower limit: ({}). Actual: ({})", self.context.holder_htlc_minimum_msat, msg.amount_msat))); + if self.context.channel_state & ChannelState::AwaitingRemoteRevoke as u32 == 0 { + // Our counterparty seems to have burned their coins to us (by revoking a state when we + // haven't given them a new commitment transaction to broadcast). We should probably + // take advantage of this by updating our channel monitor, sending them an error, and + // waiting for them to broadcast their latest (now-revoked claim). But, that would be a + // lot of work, and there's some chance this is all a misunderstanding anyway. + // We have to do *something*, though, since our signer may get mad at us for otherwise + // jumping a remote commitment number, so best to just force-close and move on. + return Err(ChannelError::Close("Received an unexpected revoke_and_ack".to_owned())); } - let inbound_stats = self.context.get_inbound_pending_htlc_stats(None); - let outbound_stats = self.context.get_outbound_pending_htlc_stats(None); - if inbound_stats.pending_htlcs + 1 > self.context.holder_max_accepted_htlcs as u32 { - return Err(ChannelError::Close(format!("Remote tried to push more than our max accepted HTLCs ({})", self.context.holder_max_accepted_htlcs))); - } - if inbound_stats.pending_htlcs_value_msat + msg.amount_msat > self.context.holder_max_htlc_value_in_flight_msat { - return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", self.context.holder_max_htlc_value_in_flight_msat))); - } - // Check holder_selected_channel_reserve_satoshis (we're getting paid, so they have to at least meet - // the reserve_satoshis we told them to always have as direct payment so that they lose - // something if we punish them for broadcasting an old state). - // Note that we don't really care about having a small/no to_remote output in our local - // commitment transactions, as the purpose of the channel reserve is to ensure we can - // punish *them* if they misbehave, so we discount any outbound HTLCs which will not be - // present in the next commitment transaction we send them (at least for fulfilled ones, - // failed ones won't modify value_to_self). - // Note that we will send HTLCs which another instance of rust-lightning would think - // violate the reserve value if we do not do this (as we forget inbound HTLCs from the - // Channel state once they will not be present in the next received commitment - // transaction). - let mut removed_outbound_total_msat = 0; - for ref htlc in self.context.pending_outbound_htlcs.iter() { - if let OutboundHTLCState::AwaitingRemoteRevokeToRemove(OutboundHTLCOutcome::Success(_)) = htlc.state { - removed_outbound_total_msat += htlc.amount_msat; - } else if let OutboundHTLCState::AwaitingRemovedRemoteRevoke(OutboundHTLCOutcome::Success(_)) = htlc.state { - removed_outbound_total_msat += htlc.amount_msat; - } + #[cfg(any(test, fuzzing))] + { + *self.context.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None; + *self.context.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None; } - let (htlc_timeout_dust_limit, htlc_success_dust_limit) = if self.context.opt_anchors() { - (0, 0) - } else { - let dust_buffer_feerate = self.context.get_dust_buffer_feerate(None) as u64; - (dust_buffer_feerate * htlc_timeout_tx_weight(false) / 1000, - dust_buffer_feerate * htlc_success_tx_weight(false) / 1000) + self.context.holder_signer.validate_counterparty_revocation( + self.context.cur_counterparty_commitment_transaction_number + 1, + &secret + ).map_err(|_| ChannelError::Close("Failed to validate revocation from peer".to_owned()))?; + + self.context.commitment_secrets.provide_secret(self.context.cur_counterparty_commitment_transaction_number + 1, msg.per_commitment_secret) + .map_err(|_| ChannelError::Close("Previous secrets did not match new one".to_owned()))?; + self.context.latest_monitor_update_id += 1; + let mut monitor_update = ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::CommitmentSecret { + idx: self.context.cur_counterparty_commitment_transaction_number + 1, + secret: msg.per_commitment_secret, + }], }; - let exposure_dust_limit_timeout_sats = htlc_timeout_dust_limit + self.context.counterparty_dust_limit_satoshis; - if msg.amount_msat / 1000 < exposure_dust_limit_timeout_sats { - let on_counterparty_tx_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat + msg.amount_msat; - if on_counterparty_tx_dust_htlc_exposure_msat > self.context.get_max_dust_htlc_exposure_msat() { - log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on counterparty commitment tx", - on_counterparty_tx_dust_htlc_exposure_msat, self.context.get_max_dust_htlc_exposure_msat()); - pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7); - } - } - let exposure_dust_limit_success_sats = htlc_success_dust_limit + self.context.holder_dust_limit_satoshis; - if msg.amount_msat / 1000 < exposure_dust_limit_success_sats { - let on_holder_tx_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat + msg.amount_msat; - if on_holder_tx_dust_htlc_exposure_msat > self.context.get_max_dust_htlc_exposure_msat() { - log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on holder commitment tx", - on_holder_tx_dust_htlc_exposure_msat, self.context.get_max_dust_htlc_exposure_msat()); - pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7); - } - } + // Update state now that we've passed all the can-fail calls... + // (note that we may still fail to generate the new commitment_signed message, but that's + // OK, we step the channel here and *then* if the new generation fails we can fail the + // channel based on that, but stepping stuff here should be safe either way. + self.context.channel_state &= !(ChannelState::AwaitingRemoteRevoke as u32); + self.context.sent_message_awaiting_response = None; + self.context.counterparty_prev_commitment_point = self.context.counterparty_cur_commitment_point; + self.context.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point); + self.context.cur_counterparty_commitment_transaction_number -= 1; - let pending_value_to_self_msat = - self.context.value_to_self_msat + inbound_stats.pending_htlcs_value_msat - removed_outbound_total_msat; - let pending_remote_value_msat = - self.context.channel_value_satoshis * 1000 - pending_value_to_self_msat; - if pending_remote_value_msat < msg.amount_msat { - return Err(ChannelError::Close("Remote HTLC add would overdraw remaining funds".to_owned())); + if self.context.announcement_sigs_state == AnnouncementSigsState::Committed { + self.context.announcement_sigs_state = AnnouncementSigsState::PeerReceived; } - // Check that the remote can afford to pay for this HTLC on-chain at the current - // feerate_per_kw, while maintaining their channel reserve (as required by the spec). - let remote_commit_tx_fee_msat = if self.context.is_outbound() { 0 } else { - let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered); - self.context.next_remote_commit_tx_fee_msat(htlc_candidate, None) // Don't include the extra fee spike buffer HTLC in calculations - }; - if pending_remote_value_msat - msg.amount_msat < remote_commit_tx_fee_msat { - return Err(ChannelError::Close("Remote HTLC add would not leave enough to pay for fees".to_owned())); - }; + log_trace!(logger, "Updating HTLCs on receipt of RAA in channel {}...", log_bytes!(self.context.channel_id())); + let mut to_forward_infos = Vec::new(); + let mut revoked_htlcs = Vec::new(); + let mut finalized_claimed_htlcs = Vec::new(); + let mut update_fail_htlcs = Vec::new(); + let mut update_fail_malformed_htlcs = Vec::new(); + let mut require_commitment = false; + let mut value_to_self_msat_diff: i64 = 0; - if pending_remote_value_msat - msg.amount_msat - remote_commit_tx_fee_msat < self.context.holder_selected_channel_reserve_satoshis * 1000 { - return Err(ChannelError::Close("Remote HTLC add would put them under remote reserve value".to_owned())); - } + { + // Take references explicitly so that we can hold multiple references to self.context. + let pending_inbound_htlcs: &mut Vec<_> = &mut self.context.pending_inbound_htlcs; + let pending_outbound_htlcs: &mut Vec<_> = &mut self.context.pending_outbound_htlcs; - if !self.context.is_outbound() { - // `2 *` and `Some(())` is for the fee spike buffer we keep for the remote. This deviates from - // the spec because in the spec, the fee spike buffer requirement doesn't exist on the - // receiver's side, only on the sender's. - // Note that when we eventually remove support for fee updates and switch to anchor output - // fees, we will drop the `2 *`, since we no longer be as sensitive to fee spikes. But, keep - // the extra htlc when calculating the next remote commitment transaction fee as we should - // still be able to afford adding this HTLC plus one more future HTLC, regardless of being - // sensitive to fee spikes. - let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered); - let remote_fee_cost_incl_stuck_buffer_msat = 2 * self.context.next_remote_commit_tx_fee_msat(htlc_candidate, Some(())); - if pending_remote_value_msat - msg.amount_msat - self.context.holder_selected_channel_reserve_satoshis * 1000 < remote_fee_cost_incl_stuck_buffer_msat { - // Note that if the pending_forward_status is not updated here, then it's because we're already failing - // the HTLC, i.e. its status is already set to failing. - log_info!(logger, "Attempting to fail HTLC due to fee spike buffer violation in channel {}. Rebalancing is required.", log_bytes!(self.context.channel_id())); - pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7); + // We really shouldnt have two passes here, but retain gives a non-mutable ref (Rust bug) + pending_inbound_htlcs.retain(|htlc| { + if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state { + log_trace!(logger, " ...removing inbound LocalRemoved {}", log_bytes!(htlc.payment_hash.0)); + if let &InboundHTLCRemovalReason::Fulfill(_) = reason { + value_to_self_msat_diff += htlc.amount_msat as i64; + } + false + } else { true } + }); + pending_outbound_htlcs.retain(|htlc| { + if let &OutboundHTLCState::AwaitingRemovedRemoteRevoke(ref outcome) = &htlc.state { + log_trace!(logger, " ...removing outbound AwaitingRemovedRemoteRevoke {}", log_bytes!(htlc.payment_hash.0)); + if let OutboundHTLCOutcome::Failure(reason) = outcome.clone() { // We really want take() here, but, again, non-mut ref :( + revoked_htlcs.push((htlc.source.clone(), htlc.payment_hash, reason)); + } else { + finalized_claimed_htlcs.push(htlc.source.clone()); + // They fulfilled, so we sent them money + value_to_self_msat_diff -= htlc.amount_msat as i64; + } + false + } else { true } + }); + for htlc in pending_inbound_htlcs.iter_mut() { + let swap = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) = &htlc.state { + true + } else if let &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) = &htlc.state { + true + } else { false }; + if swap { + let mut state = InboundHTLCState::Committed; + mem::swap(&mut state, &mut htlc.state); + + if let InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info) = state { + log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); + htlc.state = InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info); + require_commitment = true; + } else if let InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info) = state { + match forward_info { + PendingHTLCStatus::Fail(fail_msg) => { + log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to LocalRemoved due to PendingHTLCStatus indicating failure", log_bytes!(htlc.payment_hash.0)); + require_commitment = true; + match fail_msg { + HTLCFailureMsg::Relay(msg) => { + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(msg.reason.clone())); + update_fail_htlcs.push(msg) + }, + HTLCFailureMsg::Malformed(msg) => { + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailMalformed((msg.sha256_of_onion, msg.failure_code))); + update_fail_malformed_htlcs.push(msg) + }, + } + }, + PendingHTLCStatus::Forward(forward_info) => { + log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to Committed", log_bytes!(htlc.payment_hash.0)); + to_forward_infos.push((forward_info, htlc.htlc_id)); + htlc.state = InboundHTLCState::Committed; + } + } + } + } } - } else { - // Check that they won't violate our local required channel reserve by adding this HTLC. - let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered); - let local_commit_tx_fee_msat = self.context.next_local_commit_tx_fee_msat(htlc_candidate, None); - if self.context.value_to_self_msat < self.context.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 + local_commit_tx_fee_msat { - return Err(ChannelError::Close("Cannot accept HTLC that would put our balance under counterparty-announced channel reserve value".to_owned())); + for htlc in pending_outbound_htlcs.iter_mut() { + if let OutboundHTLCState::LocalAnnounced(_) = htlc.state { + log_trace!(logger, " ...promoting outbound LocalAnnounced {} to Committed", log_bytes!(htlc.payment_hash.0)); + htlc.state = OutboundHTLCState::Committed; + } + if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut outcome) = &mut htlc.state { + log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); + // Grab the preimage, if it exists, instead of cloning + let mut reason = OutboundHTLCOutcome::Success(None); + mem::swap(outcome, &mut reason); + htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(reason); + require_commitment = true; + } } } - if self.context.next_counterparty_htlc_id != msg.htlc_id { - return Err(ChannelError::Close(format!("Remote skipped HTLC ID (skipped ID: {})", self.context.next_counterparty_htlc_id))); - } - if msg.cltv_expiry >= 500000000 { - return Err(ChannelError::Close("Remote provided CLTV expiry in seconds instead of block height".to_owned())); + self.context.value_to_self_msat = (self.context.value_to_self_msat as i64 + value_to_self_msat_diff) as u64; + + if let Some((feerate, update_state)) = self.context.pending_update_fee { + match update_state { + FeeUpdateState::Outbound => { + debug_assert!(self.context.is_outbound()); + log_trace!(logger, " ...promoting outbound fee update {} to Committed", feerate); + self.context.feerate_per_kw = feerate; + self.context.pending_update_fee = None; + }, + FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.context.is_outbound()); }, + FeeUpdateState::AwaitingRemoteRevokeToAnnounce => { + debug_assert!(!self.context.is_outbound()); + log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate); + require_commitment = true; + self.context.feerate_per_kw = feerate; + self.context.pending_update_fee = None; + }, + } } - if self.context.channel_state & ChannelState::LocalShutdownSent as u32 != 0 { - if let PendingHTLCStatus::Forward(_) = pending_forward_status { - panic!("ChannelManager shouldn't be trying to add a forwardable HTLC after we've started closing"); + if (self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32) == ChannelState::MonitorUpdateInProgress as u32 { + // We can't actually generate a new commitment transaction (incl by freeing holding + // cells) while we can't update the monitor, so we just return what we have. + if require_commitment { + self.context.monitor_pending_commitment_signed = true; + // When the monitor updating is restored we'll call get_last_commitment_update(), + // which does not update state, but we're definitely now awaiting a remote revoke + // before we can step forward any more, so set it here. + let mut additional_update = self.build_commitment_no_status_check(logger); + // build_commitment_no_status_check may bump latest_monitor_id but we want them to be + // strictly increasing by one, so decrement it here. + self.context.latest_monitor_update_id = monitor_update.update_id; + monitor_update.updates.append(&mut additional_update.updates); } + self.context.monitor_pending_forwards.append(&mut to_forward_infos); + self.context.monitor_pending_failures.append(&mut revoked_htlcs); + self.context.monitor_pending_finalized_fulfills.append(&mut finalized_claimed_htlcs); + log_debug!(logger, "Received a valid revoke_and_ack for channel {} but awaiting a monitor update resolution to reply.", log_bytes!(self.context.channel_id())); + return Ok((Vec::new(), self.push_ret_blockable_mon_update(monitor_update))); } - // Now update local state: - self.context.next_counterparty_htlc_id += 1; - self.context.pending_inbound_htlcs.push(InboundHTLCOutput { - htlc_id: msg.htlc_id, - amount_msat: msg.amount_msat, - payment_hash: msg.payment_hash, - cltv_expiry: msg.cltv_expiry, - state: InboundHTLCState::RemoteAnnounced(pending_forward_status), - }); - Ok(()) - } + match self.free_holding_cell_htlcs(logger) { + (Some(_), htlcs_to_fail) => { + let mut additional_update = self.context.pending_monitor_updates.pop().unwrap().update; + // free_holding_cell_htlcs may bump latest_monitor_id multiple times but we want them to be + // strictly increasing by one, so decrement it here. + self.context.latest_monitor_update_id = monitor_update.update_id; + monitor_update.updates.append(&mut additional_update.updates); - /// Marks an outbound HTLC which we have received update_fail/fulfill/malformed - #[inline] - fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option, fail_reason: Option) -> Result<&OutboundHTLCOutput, ChannelError> { - assert!(!(check_preimage.is_some() && fail_reason.is_some()), "cannot fail while we have a preimage"); - for htlc in self.context.pending_outbound_htlcs.iter_mut() { - if htlc.htlc_id == htlc_id { - let outcome = match check_preimage { - None => fail_reason.into(), - Some(payment_preimage) => { - let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()); - if payment_hash != htlc.payment_hash { - return Err(ChannelError::Close(format!("Remote tried to fulfill HTLC ({}) with an incorrect preimage", htlc_id))); - } - OutboundHTLCOutcome::Success(Some(payment_preimage)) - } - }; - match htlc.state { - OutboundHTLCState::LocalAnnounced(_) => - return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) before it had been committed", htlc_id))), - OutboundHTLCState::Committed => { - htlc.state = OutboundHTLCState::RemoteRemoved(outcome); - }, - OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) | OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) | OutboundHTLCState::RemoteRemoved(_) => - return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) that they'd already fulfilled/failed", htlc_id))), + self.monitor_updating_paused(false, true, false, to_forward_infos, revoked_htlcs, finalized_claimed_htlcs); + Ok((htlcs_to_fail, self.push_ret_blockable_mon_update(monitor_update))) + }, + (None, htlcs_to_fail) => { + if require_commitment { + let mut additional_update = self.build_commitment_no_status_check(logger); + + // build_commitment_no_status_check may bump latest_monitor_id but we want them to be + // strictly increasing by one, so decrement it here. + self.context.latest_monitor_update_id = monitor_update.update_id; + monitor_update.updates.append(&mut additional_update.updates); + + log_debug!(logger, "Received a valid revoke_and_ack for channel {}. Responding with a commitment update with {} HTLCs failed.", + log_bytes!(self.context.channel_id()), update_fail_htlcs.len() + update_fail_malformed_htlcs.len()); + self.monitor_updating_paused(false, true, false, to_forward_infos, revoked_htlcs, finalized_claimed_htlcs); + Ok((htlcs_to_fail, self.push_ret_blockable_mon_update(monitor_update))) + } else { + log_debug!(logger, "Received a valid revoke_and_ack for channel {} with no reply necessary.", log_bytes!(self.context.channel_id())); + self.monitor_updating_paused(false, false, false, to_forward_infos, revoked_htlcs, finalized_claimed_htlcs); + Ok((htlcs_to_fail, self.push_ret_blockable_mon_update(monitor_update))) } - return Ok(htlc); } } - Err(ChannelError::Close("Remote tried to fulfill/fail an HTLC we couldn't find".to_owned())) } - pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(HTLCSource, u64), ChannelError> { - if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { - return Err(ChannelError::Close("Got fulfill HTLC message when channel was not in an operational state".to_owned())); - } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent update_fulfill_htlc when we needed a channel_reestablish".to_owned())); - } - - self.mark_outbound_htlc_removed(msg.htlc_id, Some(msg.payment_preimage), None).map(|htlc| (htlc.source.clone(), htlc.amount_msat)) + /// Queues up an outbound update fee by placing it in the holding cell. You should call + /// [`Self::maybe_free_holding_cell_htlcs`] in order to actually generate and send the + /// commitment update. + pub fn queue_update_fee(&mut self, feerate_per_kw: u32, logger: &L) where L::Target: Logger { + let msg_opt = self.send_update_fee(feerate_per_kw, true, logger); + assert!(msg_opt.is_none(), "We forced holding cell?"); } - pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> { - if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { - return Err(ChannelError::Close("Got fail HTLC message when channel was not in an operational state".to_owned())); + /// Adds a pending update to this channel. See the doc for send_htlc for + /// further details on the optionness of the return value. + /// If our balance is too low to cover the cost of the next commitment transaction at the + /// new feerate, the update is cancelled. + /// + /// You MUST call [`Self::send_commitment_no_state_update`] prior to any other calls on this + /// [`Channel`] if `force_holding_cell` is false. + fn send_update_fee(&mut self, feerate_per_kw: u32, mut force_holding_cell: bool, logger: &L) -> Option where L::Target: Logger { + if !self.context.is_outbound() { + panic!("Cannot send fee from inbound channel"); } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent update_fail_htlc when we needed a channel_reestablish".to_owned())); + if !self.context.is_usable() { + panic!("Cannot update fee until channel is fully established and we haven't started shutting down"); } - - self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?; - Ok(()) - } - - pub fn update_fail_malformed_htlc(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> { - if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { - return Err(ChannelError::Close("Got fail malformed HTLC message when channel was not in an operational state".to_owned())); + if !self.context.is_live() { + panic!("Cannot update fee while peer is disconnected/we're awaiting a monitor update (ChannelManager should have caught this)"); } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent update_fail_malformed_htlc when we needed a channel_reestablish".to_owned())); + + // Before proposing a feerate update, check that we can actually afford the new fee. + let inbound_stats = self.context.get_inbound_pending_htlc_stats(Some(feerate_per_kw)); + let outbound_stats = self.context.get_outbound_pending_htlc_stats(Some(feerate_per_kw)); + let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); + let commitment_stats = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, true, logger); + let buffer_fee_msat = commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + outbound_stats.on_holder_tx_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize, self.context.opt_anchors()) * 1000; + let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat; + if holder_balance_msat < buffer_fee_msat + self.context.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 { + //TODO: auto-close after a number of failures? + log_debug!(logger, "Cannot afford to send new feerate at {}", feerate_per_kw); + return None; } - self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?; - Ok(()) - } - - pub fn commitment_signed(&mut self, msg: &msgs::CommitmentSigned, logger: &L) -> Result, ChannelError> - where L::Target: Logger - { - if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { - return Err(ChannelError::Close("Got commitment signed message when channel was not in an operational state".to_owned())); - } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent commitment_signed when we needed a channel_reestablish".to_owned())); + // Note, we evaluate pending htlc "preemptive" trimmed-to-dust threshold at the proposed `feerate_per_kw`. + let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat; + let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat; + if holder_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { + log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw); + return None; } - if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.context.last_sent_closing_fee.is_some() { - return Err(ChannelError::Close("Peer sent commitment_signed after we'd started exchanging closing_signeds".to_owned())); + if counterparty_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { + log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw); + return None; } - let funding_script = self.context.get_funding_redeemscript(); + if (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0 { + force_holding_cell = true; + } - let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); + if force_holding_cell { + self.context.holding_cell_update_fee = Some(feerate_per_kw); + return None; + } - let commitment_stats = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger); - let commitment_txid = { - let trusted_tx = commitment_stats.tx.trust(); - let bitcoin_tx = trusted_tx.built_transaction(); - let sighash = bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis); + debug_assert!(self.context.pending_update_fee.is_none()); + self.context.pending_update_fee = Some((feerate_per_kw, FeeUpdateState::Outbound)); - log_trace!(logger, "Checking commitment tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}", - log_bytes!(msg.signature.serialize_compact()[..]), - log_bytes!(self.context.counterparty_funding_pubkey().serialize()), encode::serialize_hex(&bitcoin_tx.transaction), - log_bytes!(sighash[..]), encode::serialize_hex(&funding_script), log_bytes!(self.context.channel_id())); - if let Err(_) = self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.context.counterparty_funding_pubkey()) { - return Err(ChannelError::Close("Invalid commitment tx signature from peer".to_owned())); - } - bitcoin_tx.txid - }; - let mut htlcs_cloned: Vec<_> = commitment_stats.htlcs_included.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect(); + Some(msgs::UpdateFee { + channel_id: self.context.channel_id, + feerate_per_kw, + }) + } - // If our counterparty updated the channel fee in this commitment transaction, check that - // they can actually afford the new fee now. - let update_fee = if let Some((_, update_state)) = self.context.pending_update_fee { - update_state == FeeUpdateState::RemoteAnnounced - } else { false }; - if update_fee { - debug_assert!(!self.context.is_outbound()); - let counterparty_reserve_we_require_msat = self.context.holder_selected_channel_reserve_satoshis * 1000; - if commitment_stats.remote_balance_msat < commitment_stats.total_fee_sat * 1000 + counterparty_reserve_we_require_msat { - return Err(ChannelError::Close("Funding remote cannot afford proposed new fee".to_owned())); - } - } - #[cfg(any(test, fuzzing))] - { - if self.context.is_outbound() { - let projected_commit_tx_info = self.context.next_local_commitment_tx_fee_info_cached.lock().unwrap().take(); - *self.context.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None; - if let Some(info) = projected_commit_tx_info { - let total_pending_htlcs = self.context.pending_inbound_htlcs.len() + self.context.pending_outbound_htlcs.len() - + self.context.holding_cell_htlc_updates.len(); - if info.total_pending_htlcs == total_pending_htlcs - && info.next_holder_htlc_id == self.context.next_holder_htlc_id - && info.next_counterparty_htlc_id == self.context.next_counterparty_htlc_id - && info.feerate == self.context.feerate_per_kw { - assert_eq!(commitment_stats.total_fee_sat, info.fee / 1000); - } - } - } + /// Removes any uncommitted inbound HTLCs and resets the state of uncommitted outbound HTLC + /// updates, to be used on peer disconnection. After this, update_*_htlc messages need to be + /// resent. + /// No further message handling calls may be made until a channel_reestablish dance has + /// completed. + pub fn remove_uncommitted_htlcs_and_mark_paused(&mut self, logger: &L) where L::Target: Logger { + assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); + if self.context.channel_state < ChannelState::FundingSent as u32 { + self.context.channel_state = ChannelState::ShutdownComplete as u32; + return; } - if msg.htlc_signatures.len() != commitment_stats.num_nondust_htlcs { - return Err(ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_stats.num_nondust_htlcs))); + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == (ChannelState::PeerDisconnected as u32) { + // While the below code should be idempotent, it's simpler to just return early, as + // redundant disconnect events can fire, though they should be rare. + return; } - // Up to LDK 0.0.115, HTLC information was required to be duplicated in the - // `htlcs_and_sigs` vec and in the `holder_commitment_tx` itself, both of which were passed - // in the `ChannelMonitorUpdate`. In 0.0.115, support for having a separate set of - // outbound-non-dust-HTLCSources in the `ChannelMonitorUpdate` was added, however for - // backwards compatibility, we never use it in production. To provide test coverage, here, - // we randomly decide (in test/fuzzing builds) to use the new vec sometimes. - #[allow(unused_assignments, unused_mut)] - let mut separate_nondust_htlc_sources = false; - #[cfg(all(feature = "std", any(test, fuzzing)))] { - use core::hash::{BuildHasher, Hasher}; - // Get a random value using the only std API to do so - the DefaultHasher - let rand_val = std::collections::hash_map::RandomState::new().build_hasher().finish(); - separate_nondust_htlc_sources = rand_val % 2 == 0; + if self.context.announcement_sigs_state == AnnouncementSigsState::MessageSent || self.context.announcement_sigs_state == AnnouncementSigsState::Committed { + self.context.announcement_sigs_state = AnnouncementSigsState::NotSent; } - let mut nondust_htlc_sources = Vec::with_capacity(htlcs_cloned.len()); - let mut htlcs_and_sigs = Vec::with_capacity(htlcs_cloned.len()); - for (idx, (htlc, mut source_opt)) in htlcs_cloned.drain(..).enumerate() { - if let Some(_) = htlc.transaction_output_index { - let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.feerate_per_kw, - self.context.get_counterparty_selected_contest_delay().unwrap(), &htlc, self.context.opt_anchors(), - false, &keys.broadcaster_delayed_payment_key, &keys.revocation_key); + // Upon reconnect we have to start the closing_signed dance over, but shutdown messages + // will be retransmitted. + self.context.last_sent_closing_fee = None; + self.context.pending_counterparty_closing_signed = None; + self.context.closing_fee_limits = None; - let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.context.opt_anchors(), &keys); - let htlc_sighashtype = if self.context.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All }; - let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]); - log_trace!(logger, "Checking HTLC tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}.", - log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(keys.countersignatory_htlc_key.serialize()), - encode::serialize_hex(&htlc_tx), log_bytes!(htlc_sighash[..]), encode::serialize_hex(&htlc_redeemscript), log_bytes!(self.context.channel_id())); - if let Err(_) = self.context.secp_ctx.verify_ecdsa(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key) { - return Err(ChannelError::Close("Invalid HTLC tx signature from peer".to_owned())); - } - if !separate_nondust_htlc_sources { - htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source_opt.take())); - } - } else { - htlcs_and_sigs.push((htlc, None, source_opt.take())); - } - if separate_nondust_htlc_sources { - if let Some(source) = source_opt.take() { - nondust_htlc_sources.push(source); - } + let mut inbound_drop_count = 0; + self.context.pending_inbound_htlcs.retain(|htlc| { + match htlc.state { + InboundHTLCState::RemoteAnnounced(_) => { + // They sent us an update_add_htlc but we never got the commitment_signed. + // We'll tell them what commitment_signed we're expecting next and they'll drop + // this HTLC accordingly + inbound_drop_count += 1; + false + }, + InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_)|InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => { + // We received a commitment_signed updating this HTLC and (at least hopefully) + // sent a revoke_and_ack (which we can re-transmit) and have heard nothing + // in response to it yet, so don't touch it. + true + }, + InboundHTLCState::Committed => true, + InboundHTLCState::LocalRemoved(_) => { + // We (hopefully) sent a commitment_signed updating this HTLC (which we can + // re-transmit if needed) and they may have even sent a revoke_and_ack back + // (that we missed). Keep this around for now and if they tell us they missed + // the commitment_signed we can re-transmit the update then. + true + }, } - debug_assert!(source_opt.is_none(), "HTLCSource should have been put somewhere"); - } - - let holder_commitment_tx = HolderCommitmentTransaction::new( - commitment_stats.tx, - msg.signature, - msg.htlc_signatures.clone(), - &self.context.get_holder_pubkeys().funding_pubkey, - self.context.counterparty_funding_pubkey() - ); - - self.context.holder_signer.validate_holder_commitment(&holder_commitment_tx, commitment_stats.preimages) - .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?; + }); + self.context.next_counterparty_htlc_id -= inbound_drop_count; - // Update state now that we've passed all the can-fail calls... - let mut need_commitment = false; - if let &mut Some((_, ref mut update_state)) = &mut self.context.pending_update_fee { - if *update_state == FeeUpdateState::RemoteAnnounced { - *update_state = FeeUpdateState::AwaitingRemoteRevokeToAnnounce; - need_commitment = true; + if let Some((_, update_state)) = self.context.pending_update_fee { + if update_state == FeeUpdateState::RemoteAnnounced { + debug_assert!(!self.context.is_outbound()); + self.context.pending_update_fee = None; } } - for htlc in self.context.pending_inbound_htlcs.iter_mut() { - let new_forward = if let &InboundHTLCState::RemoteAnnounced(ref forward_info) = &htlc.state { - Some(forward_info.clone()) - } else { None }; - if let Some(forward_info) = new_forward { - log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToAnnounce due to commitment_signed in channel {}.", - log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id)); - htlc.state = InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info); - need_commitment = true; - } - } - let mut claimed_htlcs = Vec::new(); for htlc in self.context.pending_outbound_htlcs.iter_mut() { - if let &mut OutboundHTLCState::RemoteRemoved(ref mut outcome) = &mut htlc.state { - log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToRemove due to commitment_signed in channel {}.", - log_bytes!(htlc.payment_hash.0), log_bytes!(self.context.channel_id)); - // Grab the preimage, if it exists, instead of cloning - let mut reason = OutboundHTLCOutcome::Success(None); - mem::swap(outcome, &mut reason); - if let OutboundHTLCOutcome::Success(Some(preimage)) = reason { - // If a user (a) receives an HTLC claim using LDK 0.0.104 or before, then (b) - // upgrades to LDK 0.0.114 or later before the HTLC is fully resolved, we could - // have a `Success(None)` reason. In this case we could forget some HTLC - // claims, but such an upgrade is unlikely and including claimed HTLCs here - // fixes a bug which the user was exposed to on 0.0.104 when they started the - // claim anyway. - claimed_htlcs.push((SentHTLCId::from_source(&htlc.source), preimage)); - } - htlc.state = OutboundHTLCState::AwaitingRemoteRevokeToRemove(reason); - need_commitment = true; + if let OutboundHTLCState::RemoteRemoved(_) = htlc.state { + // They sent us an update to remove this but haven't yet sent the corresponding + // commitment_signed, we need to move it back to Committed and they can re-send + // the update upon reconnection. + htlc.state = OutboundHTLCState::Committed; } } - self.context.latest_monitor_update_id += 1; - let mut monitor_update = ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo { - commitment_tx: holder_commitment_tx, - htlc_outputs: htlcs_and_sigs, - claimed_htlcs, - nondust_htlc_sources, - }] - }; + self.context.sent_message_awaiting_response = None; - self.context.cur_holder_commitment_transaction_number -= 1; - // Note that if we need_commitment & !AwaitingRemoteRevoke we'll call - // build_commitment_no_status_check() next which will reset this to RAAFirst. - self.context.resend_order = RAACommitmentOrder::CommitmentFirst; + self.context.channel_state |= ChannelState::PeerDisconnected as u32; + log_trace!(logger, "Peer disconnection resulted in {} remote-announced HTLC drops on channel {}", inbound_drop_count, log_bytes!(self.context.channel_id())); + } - if (self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32) != 0 { - // In case we initially failed monitor updating without requiring a response, we need - // to make sure the RAA gets sent first. - self.context.monitor_pending_revoke_and_ack = true; - if need_commitment && (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 { - // If we were going to send a commitment_signed after the RAA, go ahead and do all - // the corresponding HTLC status updates so that get_last_commitment_update - // includes the right HTLCs. - self.context.monitor_pending_commitment_signed = true; - let mut additional_update = self.build_commitment_no_status_check(logger); - // build_commitment_no_status_check may bump latest_monitor_id but we want them to be - // strictly increasing by one, so decrement it here. - self.context.latest_monitor_update_id = monitor_update.update_id; - monitor_update.updates.append(&mut additional_update.updates); - } - log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updated HTLC state but awaiting a monitor update resolution to reply.", - log_bytes!(self.context.channel_id)); - return Ok(self.push_ret_blockable_mon_update(monitor_update)); - } + /// Indicates that a ChannelMonitor update is in progress and has not yet been fully persisted. + /// This must be called before we return the [`ChannelMonitorUpdate`] back to the + /// [`ChannelManager`], which will call [`Self::monitor_updating_restored`] once the monitor + /// update completes (potentially immediately). + /// The messages which were generated with the monitor update must *not* have been sent to the + /// remote end, and must instead have been dropped. They will be regenerated when + /// [`Self::monitor_updating_restored`] is called. + /// + /// [`ChannelManager`]: super::channelmanager::ChannelManager + /// [`chain::Watch`]: crate::chain::Watch + /// [`ChannelMonitorUpdateStatus::InProgress`]: crate::chain::ChannelMonitorUpdateStatus::InProgress + fn monitor_updating_paused(&mut self, resend_raa: bool, resend_commitment: bool, + resend_channel_ready: bool, mut pending_forwards: Vec<(PendingHTLCInfo, u64)>, + mut pending_fails: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, + mut pending_finalized_claimed_htlcs: Vec + ) { + self.context.monitor_pending_revoke_and_ack |= resend_raa; + self.context.monitor_pending_commitment_signed |= resend_commitment; + self.context.monitor_pending_channel_ready |= resend_channel_ready; + self.context.monitor_pending_forwards.append(&mut pending_forwards); + self.context.monitor_pending_failures.append(&mut pending_fails); + self.context.monitor_pending_finalized_fulfills.append(&mut pending_finalized_claimed_htlcs); + self.context.channel_state |= ChannelState::MonitorUpdateInProgress as u32; + } - let need_commitment_signed = if need_commitment && (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 { - // If we're AwaitingRemoteRevoke we can't send a new commitment here, but that's ok - - // we'll send one right away when we get the revoke_and_ack when we - // free_holding_cell_htlcs(). - let mut additional_update = self.build_commitment_no_status_check(logger); - // build_commitment_no_status_check may bump latest_monitor_id but we want them to be - // strictly increasing by one, so decrement it here. - self.context.latest_monitor_update_id = monitor_update.update_id; - monitor_update.updates.append(&mut additional_update.updates); - true - } else { false }; + /// Indicates that the latest ChannelMonitor update has been committed by the client + /// successfully and we should restore normal operation. Returns messages which should be sent + /// to the remote side. + pub fn monitor_updating_restored( + &mut self, logger: &L, node_signer: &NS, genesis_block_hash: BlockHash, + user_config: &UserConfig, best_block_height: u32 + ) -> MonitorRestoreUpdates + where + L::Target: Logger, + NS::Target: NodeSigner + { + assert_eq!(self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32, ChannelState::MonitorUpdateInProgress as u32); + self.context.channel_state &= !(ChannelState::MonitorUpdateInProgress as u32); + let mut found_blocked = false; + self.context.pending_monitor_updates.retain(|upd| { + if found_blocked { debug_assert!(upd.blocked, "No mons may be unblocked after a blocked one"); } + if upd.blocked { found_blocked = true; } + upd.blocked + }); - log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updating HTLC state and responding with{} a revoke_and_ack.", - log_bytes!(self.context.channel_id()), if need_commitment_signed { " our own commitment_signed and" } else { "" }); - self.monitor_updating_paused(true, need_commitment_signed, false, Vec::new(), Vec::new(), Vec::new()); - return Ok(self.push_ret_blockable_mon_update(monitor_update)); - } + // If we're past (or at) the FundingSent stage on an outbound channel, try to + // (re-)broadcast the funding transaction as we may have declined to broadcast it when we + // first received the funding_signed. + let mut funding_broadcastable = + if self.context.is_outbound() && self.context.channel_state & !MULTI_STATE_FLAGS >= ChannelState::FundingSent as u32 { + self.context.funding_transaction.take() + } else { None }; + // That said, if the funding transaction is already confirmed (ie we're active with a + // minimum_depth over 0) don't bother re-broadcasting the confirmed funding tx. + if self.context.channel_state & !MULTI_STATE_FLAGS >= ChannelState::ChannelReady as u32 && self.context.minimum_depth != Some(0) { + funding_broadcastable = None; + } - /// Public version of the below, checking relevant preconditions first. - /// If we're not in a state where freeing the holding cell makes sense, this is a no-op and - /// returns `(None, Vec::new())`. - pub fn maybe_free_holding_cell_htlcs(&mut self, logger: &L) -> (Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger { - if self.context.channel_state >= ChannelState::ChannelReady as u32 && - (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32)) == 0 { - self.free_holding_cell_htlcs(logger) - } else { (None, Vec::new()) } - } + // We will never broadcast the funding transaction when we're in MonitorUpdateInProgress + // (and we assume the user never directly broadcasts the funding transaction and waits for + // us to do it). Thus, we can only ever hit monitor_pending_channel_ready when we're + // * an inbound channel that failed to persist the monitor on funding_created and we got + // the funding transaction confirmed before the monitor was persisted, or + // * a 0-conf channel and intended to send the channel_ready before any broadcast at all. + let channel_ready = if self.context.monitor_pending_channel_ready { + assert!(!self.context.is_outbound() || self.context.minimum_depth == Some(0), + "Funding transaction broadcast by the local client before it should have - LDK didn't do it!"); + self.context.monitor_pending_channel_ready = false; + let next_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); + Some(msgs::ChannelReady { + channel_id: self.context.channel_id(), + next_per_commitment_point, + short_channel_id_alias: Some(self.context.outbound_scid_alias), + }) + } else { None }; - /// Frees any pending commitment updates in the holding cell, generating the relevant messages - /// for our counterparty. - fn free_holding_cell_htlcs(&mut self, logger: &L) -> (Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger { - assert_eq!(self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32, 0); - if self.context.holding_cell_htlc_updates.len() != 0 || self.context.holding_cell_update_fee.is_some() { - log_trace!(logger, "Freeing holding cell with {} HTLC updates{} in channel {}", self.context.holding_cell_htlc_updates.len(), - if self.context.holding_cell_update_fee.is_some() { " and a fee update" } else { "" }, log_bytes!(self.context.channel_id())); + let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block_height, logger); - let mut monitor_update = ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id + 1, // We don't increment this yet! - updates: Vec::new(), - }; + let mut accepted_htlcs = Vec::new(); + mem::swap(&mut accepted_htlcs, &mut self.context.monitor_pending_forwards); + let mut failed_htlcs = Vec::new(); + mem::swap(&mut failed_htlcs, &mut self.context.monitor_pending_failures); + let mut finalized_claimed_htlcs = Vec::new(); + mem::swap(&mut finalized_claimed_htlcs, &mut self.context.monitor_pending_finalized_fulfills); - let mut htlc_updates = Vec::new(); - mem::swap(&mut htlc_updates, &mut self.context.holding_cell_htlc_updates); - let mut update_add_htlcs = Vec::with_capacity(htlc_updates.len()); - let mut update_fulfill_htlcs = Vec::with_capacity(htlc_updates.len()); - let mut update_fail_htlcs = Vec::with_capacity(htlc_updates.len()); - let mut htlcs_to_fail = Vec::new(); - for htlc_update in htlc_updates.drain(..) { - // Note that this *can* fail, though it should be due to rather-rare conditions on - // fee races with adding too many outputs which push our total payments just over - // the limit. In case it's less rare than I anticipate, we may want to revisit - // handling this case better and maybe fulfilling some of the HTLCs while attempting - // to rebalance channels. - match &htlc_update { - &HTLCUpdateAwaitingACK::AddHTLC {amount_msat, cltv_expiry, ref payment_hash, ref source, ref onion_routing_packet, ..} => { - match self.send_htlc(amount_msat, *payment_hash, cltv_expiry, source.clone(), onion_routing_packet.clone(), false, logger) { - Ok(update_add_msg_option) => update_add_htlcs.push(update_add_msg_option.unwrap()), - Err(e) => { - match e { - ChannelError::Ignore(ref msg) => { - log_info!(logger, "Failed to send HTLC with payment_hash {} due to {} in channel {}", - log_bytes!(payment_hash.0), msg, log_bytes!(self.context.channel_id())); - // If we fail to send here, then this HTLC should - // be failed backwards. Failing to send here - // indicates that this HTLC may keep being put back - // into the holding cell without ever being - // successfully forwarded/failed/fulfilled, causing - // our counterparty to eventually close on us. - htlcs_to_fail.push((source.clone(), *payment_hash)); - }, - _ => { - panic!("Got a non-IgnoreError action trying to send holding cell HTLC"); - }, - } - } - } - }, - &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, htlc_id, .. } => { - // If an HTLC claim was previously added to the holding cell (via - // `get_update_fulfill_htlc`, then generating the claim message itself must - // not fail - any in between attempts to claim the HTLC will have resulted - // in it hitting the holding cell again and we cannot change the state of a - // holding cell HTLC from fulfill to anything else. - let (update_fulfill_msg_option, mut additional_monitor_update) = - if let UpdateFulfillFetch::NewClaim { msg, monitor_update, .. } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) { - (msg, monitor_update) - } else { unreachable!() }; - update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap()); - monitor_update.updates.append(&mut additional_monitor_update.updates); - }, - &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, ref err_packet } => { - match self.fail_htlc(htlc_id, err_packet.clone(), false, logger) { - Ok(update_fail_msg_option) => { - // If an HTLC failure was previously added to the holding cell (via - // `queue_fail_htlc`) then generating the fail message itself must - // not fail - we should never end up in a state where we double-fail - // an HTLC or fail-then-claim an HTLC as it indicates we didn't wait - // for a full revocation before failing. - update_fail_htlcs.push(update_fail_msg_option.unwrap()) - }, - Err(e) => { - if let ChannelError::Ignore(_) = e {} - else { - panic!("Got a non-IgnoreError action trying to fail holding cell HTLC"); - } - } - } - }, - } - } - if update_add_htlcs.is_empty() && update_fulfill_htlcs.is_empty() && update_fail_htlcs.is_empty() && self.context.holding_cell_update_fee.is_none() { - return (None, htlcs_to_fail); - } - let update_fee = if let Some(feerate) = self.context.holding_cell_update_fee.take() { - self.send_update_fee(feerate, false, logger) - } else { - None + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) != 0 { + self.context.monitor_pending_revoke_and_ack = false; + self.context.monitor_pending_commitment_signed = false; + return MonitorRestoreUpdates { + raa: None, commitment_update: None, order: RAACommitmentOrder::RevokeAndACKFirst, + accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, channel_ready, announcement_sigs }; + } - let mut additional_update = self.build_commitment_no_status_check(logger); - // build_commitment_no_status_check and get_update_fulfill_htlc may bump latest_monitor_id - // but we want them to be strictly increasing by one, so reset it here. - self.context.latest_monitor_update_id = monitor_update.update_id; - monitor_update.updates.append(&mut additional_update.updates); - - log_debug!(logger, "Freeing holding cell in channel {} resulted in {}{} HTLCs added, {} HTLCs fulfilled, and {} HTLCs failed.", - log_bytes!(self.context.channel_id()), if update_fee.is_some() { "a fee update, " } else { "" }, - update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len()); + let raa = if self.context.monitor_pending_revoke_and_ack { + Some(self.get_last_revoke_and_ack()) + } else { None }; + let commitment_update = if self.context.monitor_pending_commitment_signed { + self.mark_awaiting_response(); + Some(self.get_last_commitment_update(logger)) + } else { None }; - self.monitor_updating_paused(false, true, false, Vec::new(), Vec::new(), Vec::new()); - (self.push_ret_blockable_mon_update(monitor_update), htlcs_to_fail) - } else { - (None, Vec::new()) + self.context.monitor_pending_revoke_and_ack = false; + self.context.monitor_pending_commitment_signed = false; + let order = self.context.resend_order.clone(); + log_debug!(logger, "Restored monitor updating in channel {} resulting in {}{} commitment update and {} RAA, with {} first", + log_bytes!(self.context.channel_id()), if funding_broadcastable.is_some() { "a funding broadcastable, " } else { "" }, + if commitment_update.is_some() { "a" } else { "no" }, if raa.is_some() { "an" } else { "no" }, + match order { RAACommitmentOrder::CommitmentFirst => "commitment", RAACommitmentOrder::RevokeAndACKFirst => "RAA"}); + MonitorRestoreUpdates { + raa, commitment_update, order, accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, channel_ready, announcement_sigs } } - /// Handles receiving a remote's revoke_and_ack. Note that we may return a new - /// commitment_signed message here in case we had pending outbound HTLCs to add which were - /// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail, - /// generating an appropriate error *after* the channel state has been updated based on the - /// revoke_and_ack message. - pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK, logger: &L) -> Result<(Vec<(HTLCSource, PaymentHash)>, Option<&ChannelMonitorUpdate>), ChannelError> - where L::Target: Logger, + pub fn update_fee(&mut self, fee_estimator: &LowerBoundedFeeEstimator, msg: &msgs::UpdateFee, logger: &L) -> Result<(), ChannelError> + where F::Target: FeeEstimator, L::Target: Logger { - if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) { - return Err(ChannelError::Close("Got revoke/ACK message when channel was not in an operational state".to_owned())); + if self.context.is_outbound() { + return Err(ChannelError::Close("Non-funding remote tried to update channel fee".to_owned())); } if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent revoke_and_ack when we needed a channel_reestablish".to_owned())); - } - if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.context.last_sent_closing_fee.is_some() { - return Err(ChannelError::Close("Peer sent revoke_and_ack after we'd started exchanging closing_signeds".to_owned())); + return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned())); } + Channel::::check_remote_fee(fee_estimator, msg.feerate_per_kw, Some(self.context.feerate_per_kw), logger)?; + let feerate_over_dust_buffer = msg.feerate_per_kw > self.context.get_dust_buffer_feerate(None); - let secret = secp_check!(SecretKey::from_slice(&msg.per_commitment_secret), "Peer provided an invalid per_commitment_secret".to_owned()); - - if let Some(counterparty_prev_commitment_point) = self.context.counterparty_prev_commitment_point { - if PublicKey::from_secret_key(&self.context.secp_ctx, &secret) != counterparty_prev_commitment_point { - return Err(ChannelError::Close("Got a revoke commitment secret which didn't correspond to their current pubkey".to_owned())); + self.context.pending_update_fee = Some((msg.feerate_per_kw, FeeUpdateState::RemoteAnnounced)); + self.context.update_time_counter += 1; + // If the feerate has increased over the previous dust buffer (note that + // `get_dust_buffer_feerate` considers the `pending_update_fee` status), check that we + // won't be pushed over our dust exposure limit by the feerate increase. + if feerate_over_dust_buffer { + let inbound_stats = self.context.get_inbound_pending_htlc_stats(None); + let outbound_stats = self.context.get_outbound_pending_htlc_stats(None); + let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat; + let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat; + if holder_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { + return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our own transactions (totaling {} msat)", + msg.feerate_per_kw, holder_tx_dust_exposure))); + } + if counterparty_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { + return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our counterparty's transactions (totaling {} msat)", + msg.feerate_per_kw, counterparty_tx_dust_exposure))); } } + Ok(()) + } - if self.context.channel_state & ChannelState::AwaitingRemoteRevoke as u32 == 0 { - // Our counterparty seems to have burned their coins to us (by revoking a state when we - // haven't given them a new commitment transaction to broadcast). We should probably - // take advantage of this by updating our channel monitor, sending them an error, and - // waiting for them to broadcast their latest (now-revoked claim). But, that would be a - // lot of work, and there's some chance this is all a misunderstanding anyway. - // We have to do *something*, though, since our signer may get mad at us for otherwise - // jumping a remote commitment number, so best to just force-close and move on. - return Err(ChannelError::Close("Received an unexpected revoke_and_ack".to_owned())); - } - - #[cfg(any(test, fuzzing))] - { - *self.context.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None; - *self.context.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None; - } - - self.context.holder_signer.validate_counterparty_revocation( - self.context.cur_counterparty_commitment_transaction_number + 1, - &secret - ).map_err(|_| ChannelError::Close("Failed to validate revocation from peer".to_owned()))?; - - self.context.commitment_secrets.provide_secret(self.context.cur_counterparty_commitment_transaction_number + 1, msg.per_commitment_secret) - .map_err(|_| ChannelError::Close("Previous secrets did not match new one".to_owned()))?; - self.context.latest_monitor_update_id += 1; - let mut monitor_update = ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::CommitmentSecret { - idx: self.context.cur_counterparty_commitment_transaction_number + 1, - secret: msg.per_commitment_secret, - }], - }; - - // Update state now that we've passed all the can-fail calls... - // (note that we may still fail to generate the new commitment_signed message, but that's - // OK, we step the channel here and *then* if the new generation fails we can fail the - // channel based on that, but stepping stuff here should be safe either way. - self.context.channel_state &= !(ChannelState::AwaitingRemoteRevoke as u32); - self.context.sent_message_awaiting_response = None; - self.context.counterparty_prev_commitment_point = self.context.counterparty_cur_commitment_point; - self.context.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point); - self.context.cur_counterparty_commitment_transaction_number -= 1; - - if self.context.announcement_sigs_state == AnnouncementSigsState::Committed { - self.context.announcement_sigs_state = AnnouncementSigsState::PeerReceived; + fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK { + let next_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); + let per_commitment_secret = self.context.holder_signer.release_commitment_secret(self.context.cur_holder_commitment_transaction_number + 2); + msgs::RevokeAndACK { + channel_id: self.context.channel_id, + per_commitment_secret, + next_per_commitment_point, + #[cfg(taproot)] + next_local_nonce: None, } + } - log_trace!(logger, "Updating HTLCs on receipt of RAA in channel {}...", log_bytes!(self.context.channel_id())); - let mut to_forward_infos = Vec::new(); - let mut revoked_htlcs = Vec::new(); - let mut finalized_claimed_htlcs = Vec::new(); + fn get_last_commitment_update(&self, logger: &L) -> msgs::CommitmentUpdate where L::Target: Logger { + let mut update_add_htlcs = Vec::new(); + let mut update_fulfill_htlcs = Vec::new(); let mut update_fail_htlcs = Vec::new(); let mut update_fail_malformed_htlcs = Vec::new(); - let mut require_commitment = false; - let mut value_to_self_msat_diff: i64 = 0; - - { - // Take references explicitly so that we can hold multiple references to self.context. - let pending_inbound_htlcs: &mut Vec<_> = &mut self.context.pending_inbound_htlcs; - let pending_outbound_htlcs: &mut Vec<_> = &mut self.context.pending_outbound_htlcs; - - // We really shouldnt have two passes here, but retain gives a non-mutable ref (Rust bug) - pending_inbound_htlcs.retain(|htlc| { - if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state { - log_trace!(logger, " ...removing inbound LocalRemoved {}", log_bytes!(htlc.payment_hash.0)); - if let &InboundHTLCRemovalReason::Fulfill(_) = reason { - value_to_self_msat_diff += htlc.amount_msat as i64; - } - false - } else { true } - }); - pending_outbound_htlcs.retain(|htlc| { - if let &OutboundHTLCState::AwaitingRemovedRemoteRevoke(ref outcome) = &htlc.state { - log_trace!(logger, " ...removing outbound AwaitingRemovedRemoteRevoke {}", log_bytes!(htlc.payment_hash.0)); - if let OutboundHTLCOutcome::Failure(reason) = outcome.clone() { // We really want take() here, but, again, non-mut ref :( - revoked_htlcs.push((htlc.source.clone(), htlc.payment_hash, reason)); - } else { - finalized_claimed_htlcs.push(htlc.source.clone()); - // They fulfilled, so we sent them money - value_to_self_msat_diff -= htlc.amount_msat as i64; - } - false - } else { true } - }); - for htlc in pending_inbound_htlcs.iter_mut() { - let swap = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) = &htlc.state { - true - } else if let &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) = &htlc.state { - true - } else { false }; - if swap { - let mut state = InboundHTLCState::Committed; - mem::swap(&mut state, &mut htlc.state); - if let InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info) = state { - log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); - htlc.state = InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info); - require_commitment = true; - } else if let InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info) = state { - match forward_info { - PendingHTLCStatus::Fail(fail_msg) => { - log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to LocalRemoved due to PendingHTLCStatus indicating failure", log_bytes!(htlc.payment_hash.0)); - require_commitment = true; - match fail_msg { - HTLCFailureMsg::Relay(msg) => { - htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(msg.reason.clone())); - update_fail_htlcs.push(msg) - }, - HTLCFailureMsg::Malformed(msg) => { - htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailMalformed((msg.sha256_of_onion, msg.failure_code))); - update_fail_malformed_htlcs.push(msg) - }, - } - }, - PendingHTLCStatus::Forward(forward_info) => { - log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to Committed", log_bytes!(htlc.payment_hash.0)); - to_forward_infos.push((forward_info, htlc.htlc_id)); - htlc.state = InboundHTLCState::Committed; - } - } - } - } - } - for htlc in pending_outbound_htlcs.iter_mut() { - if let OutboundHTLCState::LocalAnnounced(_) = htlc.state { - log_trace!(logger, " ...promoting outbound LocalAnnounced {} to Committed", log_bytes!(htlc.payment_hash.0)); - htlc.state = OutboundHTLCState::Committed; - } - if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut outcome) = &mut htlc.state { - log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); - // Grab the preimage, if it exists, instead of cloning - let mut reason = OutboundHTLCOutcome::Success(None); - mem::swap(outcome, &mut reason); - htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(reason); - require_commitment = true; - } + for htlc in self.context.pending_outbound_htlcs.iter() { + if let &OutboundHTLCState::LocalAnnounced(ref onion_packet) = &htlc.state { + update_add_htlcs.push(msgs::UpdateAddHTLC { + channel_id: self.context.channel_id(), + htlc_id: htlc.htlc_id, + amount_msat: htlc.amount_msat, + payment_hash: htlc.payment_hash, + cltv_expiry: htlc.cltv_expiry, + onion_routing_packet: (**onion_packet).clone(), + }); } } - self.context.value_to_self_msat = (self.context.value_to_self_msat as i64 + value_to_self_msat_diff) as u64; - if let Some((feerate, update_state)) = self.context.pending_update_fee { - match update_state { - FeeUpdateState::Outbound => { - debug_assert!(self.context.is_outbound()); - log_trace!(logger, " ...promoting outbound fee update {} to Committed", feerate); - self.context.feerate_per_kw = feerate; - self.context.pending_update_fee = None; - }, - FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.context.is_outbound()); }, - FeeUpdateState::AwaitingRemoteRevokeToAnnounce => { - debug_assert!(!self.context.is_outbound()); - log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate); - require_commitment = true; - self.context.feerate_per_kw = feerate; - self.context.pending_update_fee = None; - }, + for htlc in self.context.pending_inbound_htlcs.iter() { + if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state { + match reason { + &InboundHTLCRemovalReason::FailRelay(ref err_packet) => { + update_fail_htlcs.push(msgs::UpdateFailHTLC { + channel_id: self.context.channel_id(), + htlc_id: htlc.htlc_id, + reason: err_packet.clone() + }); + }, + &InboundHTLCRemovalReason::FailMalformed((ref sha256_of_onion, ref failure_code)) => { + update_fail_malformed_htlcs.push(msgs::UpdateFailMalformedHTLC { + channel_id: self.context.channel_id(), + htlc_id: htlc.htlc_id, + sha256_of_onion: sha256_of_onion.clone(), + failure_code: failure_code.clone(), + }); + }, + &InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => { + update_fulfill_htlcs.push(msgs::UpdateFulfillHTLC { + channel_id: self.context.channel_id(), + htlc_id: htlc.htlc_id, + payment_preimage: payment_preimage.clone(), + }); + }, + } } } - if (self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32) == ChannelState::MonitorUpdateInProgress as u32 { - // We can't actually generate a new commitment transaction (incl by freeing holding - // cells) while we can't update the monitor, so we just return what we have. - if require_commitment { - self.context.monitor_pending_commitment_signed = true; - // When the monitor updating is restored we'll call get_last_commitment_update(), - // which does not update state, but we're definitely now awaiting a remote revoke - // before we can step forward any more, so set it here. - let mut additional_update = self.build_commitment_no_status_check(logger); - // build_commitment_no_status_check may bump latest_monitor_id but we want them to be - // strictly increasing by one, so decrement it here. - self.context.latest_monitor_update_id = monitor_update.update_id; - monitor_update.updates.append(&mut additional_update.updates); - } - self.context.monitor_pending_forwards.append(&mut to_forward_infos); - self.context.monitor_pending_failures.append(&mut revoked_htlcs); - self.context.monitor_pending_finalized_fulfills.append(&mut finalized_claimed_htlcs); - log_debug!(logger, "Received a valid revoke_and_ack for channel {} but awaiting a monitor update resolution to reply.", log_bytes!(self.context.channel_id())); - return Ok((Vec::new(), self.push_ret_blockable_mon_update(monitor_update))); + let update_fee = if self.context.is_outbound() && self.context.pending_update_fee.is_some() { + Some(msgs::UpdateFee { + channel_id: self.context.channel_id(), + feerate_per_kw: self.context.pending_update_fee.unwrap().0, + }) + } else { None }; + + log_trace!(logger, "Regenerated latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds", + log_bytes!(self.context.channel_id()), if update_fee.is_some() { " update_fee," } else { "" }, + update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len(), update_fail_malformed_htlcs.len()); + msgs::CommitmentUpdate { + update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs, update_fee, + commitment_signed: self.send_commitment_no_state_update(logger).expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0, } + } - match self.free_holding_cell_htlcs(logger) { - (Some(_), htlcs_to_fail) => { - let mut additional_update = self.context.pending_monitor_updates.pop().unwrap().update; - // free_holding_cell_htlcs may bump latest_monitor_id multiple times but we want them to be - // strictly increasing by one, so decrement it here. - self.context.latest_monitor_update_id = monitor_update.update_id; - monitor_update.updates.append(&mut additional_update.updates); - - self.monitor_updating_paused(false, true, false, to_forward_infos, revoked_htlcs, finalized_claimed_htlcs); - Ok((htlcs_to_fail, self.push_ret_blockable_mon_update(monitor_update))) - }, - (None, htlcs_to_fail) => { - if require_commitment { - let mut additional_update = self.build_commitment_no_status_check(logger); - - // build_commitment_no_status_check may bump latest_monitor_id but we want them to be - // strictly increasing by one, so decrement it here. - self.context.latest_monitor_update_id = monitor_update.update_id; - monitor_update.updates.append(&mut additional_update.updates); - - log_debug!(logger, "Received a valid revoke_and_ack for channel {}. Responding with a commitment update with {} HTLCs failed.", - log_bytes!(self.context.channel_id()), update_fail_htlcs.len() + update_fail_malformed_htlcs.len()); - self.monitor_updating_paused(false, true, false, to_forward_infos, revoked_htlcs, finalized_claimed_htlcs); - Ok((htlcs_to_fail, self.push_ret_blockable_mon_update(monitor_update))) - } else { - log_debug!(logger, "Received a valid revoke_and_ack for channel {} with no reply necessary.", log_bytes!(self.context.channel_id())); - self.monitor_updating_paused(false, false, false, to_forward_infos, revoked_htlcs, finalized_claimed_htlcs); - Ok((htlcs_to_fail, self.push_ret_blockable_mon_update(monitor_update))) - } - } - } - } - - /// Queues up an outbound update fee by placing it in the holding cell. You should call - /// [`Self::maybe_free_holding_cell_htlcs`] in order to actually generate and send the - /// commitment update. - pub fn queue_update_fee(&mut self, feerate_per_kw: u32, logger: &L) where L::Target: Logger { - let msg_opt = self.send_update_fee(feerate_per_kw, true, logger); - assert!(msg_opt.is_none(), "We forced holding cell?"); - } - - /// Adds a pending update to this channel. See the doc for send_htlc for - /// further details on the optionness of the return value. - /// If our balance is too low to cover the cost of the next commitment transaction at the - /// new feerate, the update is cancelled. + /// May panic if some calls other than message-handling calls (which will all Err immediately) + /// have been called between remove_uncommitted_htlcs_and_mark_paused and this call. /// - /// You MUST call [`Self::send_commitment_no_state_update`] prior to any other calls on this - /// [`Channel`] if `force_holding_cell` is false. - fn send_update_fee(&mut self, feerate_per_kw: u32, mut force_holding_cell: bool, logger: &L) -> Option where L::Target: Logger { - if !self.context.is_outbound() { - panic!("Cannot send fee from inbound channel"); - } - if !self.context.is_usable() { - panic!("Cannot update fee until channel is fully established and we haven't started shutting down"); - } - if !self.context.is_live() { - panic!("Cannot update fee while peer is disconnected/we're awaiting a monitor update (ChannelManager should have caught this)"); - } - - // Before proposing a feerate update, check that we can actually afford the new fee. - let inbound_stats = self.context.get_inbound_pending_htlc_stats(Some(feerate_per_kw)); - let outbound_stats = self.context.get_outbound_pending_htlc_stats(Some(feerate_per_kw)); - let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number); - let commitment_stats = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, true, logger); - let buffer_fee_msat = commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + outbound_stats.on_holder_tx_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize, self.context.opt_anchors()) * 1000; - let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat; - if holder_balance_msat < buffer_fee_msat + self.context.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 { - //TODO: auto-close after a number of failures? - log_debug!(logger, "Cannot afford to send new feerate at {}", feerate_per_kw); - return None; + /// Some links printed in log lines are included here to check them during build (when run with + /// `cargo doc --document-private-items`): + /// [`super::channelmanager::ChannelManager::force_close_without_broadcasting_txn`] and + /// [`super::channelmanager::ChannelManager::force_close_all_channels_without_broadcasting_txn`]. + pub fn channel_reestablish( + &mut self, msg: &msgs::ChannelReestablish, logger: &L, node_signer: &NS, + genesis_block_hash: BlockHash, user_config: &UserConfig, best_block: &BestBlock + ) -> Result + where + L::Target: Logger, + NS::Target: NodeSigner + { + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == 0 { + // While BOLT 2 doesn't indicate explicitly we should error this channel here, it + // almost certainly indicates we are going to end up out-of-sync in some way, so we + // just close here instead of trying to recover. + return Err(ChannelError::Close("Peer sent a loose channel_reestablish not after reconnect".to_owned())); } - // Note, we evaluate pending htlc "preemptive" trimmed-to-dust threshold at the proposed `feerate_per_kw`. - let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat; - let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat; - if holder_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { - log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw); - return None; - } - if counterparty_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { - log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw); - return None; + if msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER || + msg.next_local_commitment_number == 0 { + return Err(ChannelError::Close("Peer sent a garbage channel_reestablish (usually an lnd node with lost state asking us to force-close for them)".to_owned())); } - if (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0 { - force_holding_cell = true; + if msg.next_remote_commitment_number > 0 { + let expected_point = self.context.holder_signer.get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - msg.next_remote_commitment_number + 1, &self.context.secp_ctx); + let given_secret = SecretKey::from_slice(&msg.your_last_per_commitment_secret) + .map_err(|_| ChannelError::Close("Peer sent a garbage channel_reestablish with unparseable secret key".to_owned()))?; + if expected_point != PublicKey::from_secret_key(&self.context.secp_ctx, &given_secret) { + return Err(ChannelError::Close("Peer sent a garbage channel_reestablish with secret key not matching the commitment height provided".to_owned())); + } + if msg.next_remote_commitment_number > INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number { + macro_rules! log_and_panic { + ($err_msg: expr) => { + log_error!(logger, $err_msg, log_bytes!(self.context.channel_id), log_pubkey!(self.context.counterparty_node_id)); + panic!($err_msg, log_bytes!(self.context.channel_id), log_pubkey!(self.context.counterparty_node_id)); + } + } + log_and_panic!("We have fallen behind - we have received proof that if we broadcast our counterparty is going to claim all our funds.\n\ + This implies you have restarted with lost ChannelMonitor and ChannelManager state, the first of which is a violation of the LDK chain::Watch requirements.\n\ + More specifically, this means you have a bug in your implementation that can cause loss of funds, or you are running with an old backup, which is unsafe.\n\ + If you have restored from an old backup and wish to force-close channels and return to operation, you should start up, call\n\ + ChannelManager::force_close_without_broadcasting_txn on channel {} with counterparty {} or\n\ + ChannelManager::force_close_all_channels_without_broadcasting_txn, then reconnect to peer(s).\n\ + Note that due to a long-standing bug in lnd you may have to reach out to peers running lnd-based nodes to ask them to manually force-close channels\n\ + See https://github.com/lightningdevkit/rust-lightning/issues/1565 for more info."); + } } - if force_holding_cell { - self.context.holding_cell_update_fee = Some(feerate_per_kw); - return None; + // Before we change the state of the channel, we check if the peer is sending a very old + // commitment transaction number, if yes we send a warning message. + let our_commitment_transaction = INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number - 1; + if msg.next_remote_commitment_number + 1 < our_commitment_transaction { + return Err( + ChannelError::Warn(format!("Peer attempted to reestablish channel with a very old local commitment transaction: {} (received) vs {} (expected)", msg.next_remote_commitment_number, our_commitment_transaction)) + ); } - debug_assert!(self.context.pending_update_fee.is_none()); - self.context.pending_update_fee = Some((feerate_per_kw, FeeUpdateState::Outbound)); + // Go ahead and unmark PeerDisconnected as various calls we may make check for it (and all + // remaining cases either succeed or ErrorMessage-fail). + self.context.channel_state &= !(ChannelState::PeerDisconnected as u32); + self.context.sent_message_awaiting_response = None; - Some(msgs::UpdateFee { - channel_id: self.context.channel_id, - feerate_per_kw, - }) - } + let shutdown_msg = if self.context.channel_state & (ChannelState::LocalShutdownSent as u32) != 0 { + assert!(self.context.shutdown_scriptpubkey.is_some()); + Some(msgs::Shutdown { + channel_id: self.context.channel_id, + scriptpubkey: self.get_closing_scriptpubkey(), + }) + } else { None }; - /// Removes any uncommitted inbound HTLCs and resets the state of uncommitted outbound HTLC - /// updates, to be used on peer disconnection. After this, update_*_htlc messages need to be - /// resent. - /// No further message handling calls may be made until a channel_reestablish dance has - /// completed. - pub fn remove_uncommitted_htlcs_and_mark_paused(&mut self, logger: &L) where L::Target: Logger { - assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); - if self.context.channel_state < ChannelState::FundingSent as u32 { - self.context.channel_state = ChannelState::ShutdownComplete as u32; - return; - } + let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger); - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == (ChannelState::PeerDisconnected as u32) { - // While the below code should be idempotent, it's simpler to just return early, as - // redundant disconnect events can fire, though they should be rare. - return; - } + if self.context.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 { + // If we're waiting on a monitor update, we shouldn't re-send any channel_ready's. + if self.context.channel_state & (ChannelState::OurChannelReady as u32) == 0 || + self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32) != 0 { + if msg.next_remote_commitment_number != 0 { + return Err(ChannelError::Close("Peer claimed they saw a revoke_and_ack but we haven't sent channel_ready yet".to_owned())); + } + // Short circuit the whole handler as there is nothing we can resend them + return Ok(ReestablishResponses { + channel_ready: None, + raa: None, commitment_update: None, + order: RAACommitmentOrder::CommitmentFirst, + shutdown_msg, announcement_sigs, + }); + } - if self.context.announcement_sigs_state == AnnouncementSigsState::MessageSent || self.context.announcement_sigs_state == AnnouncementSigsState::Committed { - self.context.announcement_sigs_state = AnnouncementSigsState::NotSent; + // We have OurChannelReady set! + let next_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); + return Ok(ReestablishResponses { + channel_ready: Some(msgs::ChannelReady { + channel_id: self.context.channel_id(), + next_per_commitment_point, + short_channel_id_alias: Some(self.context.outbound_scid_alias), + }), + raa: None, commitment_update: None, + order: RAACommitmentOrder::CommitmentFirst, + shutdown_msg, announcement_sigs, + }); } - // Upon reconnect we have to start the closing_signed dance over, but shutdown messages - // will be retransmitted. - self.context.last_sent_closing_fee = None; - self.context.pending_counterparty_closing_signed = None; - self.context.closing_fee_limits = None; - - let mut inbound_drop_count = 0; - self.context.pending_inbound_htlcs.retain(|htlc| { - match htlc.state { - InboundHTLCState::RemoteAnnounced(_) => { - // They sent us an update_add_htlc but we never got the commitment_signed. - // We'll tell them what commitment_signed we're expecting next and they'll drop - // this HTLC accordingly - inbound_drop_count += 1; - false - }, - InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_)|InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => { - // We received a commitment_signed updating this HTLC and (at least hopefully) - // sent a revoke_and_ack (which we can re-transmit) and have heard nothing - // in response to it yet, so don't touch it. - true - }, - InboundHTLCState::Committed => true, - InboundHTLCState::LocalRemoved(_) => { - // We (hopefully) sent a commitment_signed updating this HTLC (which we can - // re-transmit if needed) and they may have even sent a revoke_and_ack back - // (that we missed). Keep this around for now and if they tell us they missed - // the commitment_signed we can re-transmit the update then. - true - }, + let required_revoke = if msg.next_remote_commitment_number + 1 == INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number { + // Remote isn't waiting on any RevokeAndACK from us! + // Note that if we need to repeat our ChannelReady we'll do that in the next if block. + None + } else if msg.next_remote_commitment_number + 1 == (INITIAL_COMMITMENT_NUMBER - 1) - self.context.cur_holder_commitment_transaction_number { + if self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32) != 0 { + self.context.monitor_pending_revoke_and_ack = true; + None + } else { + Some(self.get_last_revoke_and_ack()) } - }); - self.context.next_counterparty_htlc_id -= inbound_drop_count; + } else { + return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old local commitment transaction".to_owned())); + }; - if let Some((_, update_state)) = self.context.pending_update_fee { - if update_state == FeeUpdateState::RemoteAnnounced { - debug_assert!(!self.context.is_outbound()); - self.context.pending_update_fee = None; - } + // We increment cur_counterparty_commitment_transaction_number only upon receipt of + // revoke_and_ack, not on sending commitment_signed, so we add one if have + // AwaitingRemoteRevoke set, which indicates we sent a commitment_signed but haven't gotten + // the corresponding revoke_and_ack back yet. + let is_awaiting_remote_revoke = self.context.channel_state & ChannelState::AwaitingRemoteRevoke as u32 != 0; + if is_awaiting_remote_revoke && !self.is_awaiting_monitor_update() { + self.mark_awaiting_response(); } + let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.cur_counterparty_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 }; - for htlc in self.context.pending_outbound_htlcs.iter_mut() { - if let OutboundHTLCState::RemoteRemoved(_) = htlc.state { - // They sent us an update to remove this but haven't yet sent the corresponding - // commitment_signed, we need to move it back to Committed and they can re-send - // the update upon reconnection. - htlc.state = OutboundHTLCState::Committed; - } - } - - self.context.sent_message_awaiting_response = None; - - self.context.channel_state |= ChannelState::PeerDisconnected as u32; - log_trace!(logger, "Peer disconnection resulted in {} remote-announced HTLC drops on channel {}", inbound_drop_count, log_bytes!(self.context.channel_id())); - } - - /// Indicates that a ChannelMonitor update is in progress and has not yet been fully persisted. - /// This must be called before we return the [`ChannelMonitorUpdate`] back to the - /// [`ChannelManager`], which will call [`Self::monitor_updating_restored`] once the monitor - /// update completes (potentially immediately). - /// The messages which were generated with the monitor update must *not* have been sent to the - /// remote end, and must instead have been dropped. They will be regenerated when - /// [`Self::monitor_updating_restored`] is called. - /// - /// [`ChannelManager`]: super::channelmanager::ChannelManager - /// [`chain::Watch`]: crate::chain::Watch - /// [`ChannelMonitorUpdateStatus::InProgress`]: crate::chain::ChannelMonitorUpdateStatus::InProgress - fn monitor_updating_paused(&mut self, resend_raa: bool, resend_commitment: bool, - resend_channel_ready: bool, mut pending_forwards: Vec<(PendingHTLCInfo, u64)>, - mut pending_fails: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, - mut pending_finalized_claimed_htlcs: Vec - ) { - self.context.monitor_pending_revoke_and_ack |= resend_raa; - self.context.monitor_pending_commitment_signed |= resend_commitment; - self.context.monitor_pending_channel_ready |= resend_channel_ready; - self.context.monitor_pending_forwards.append(&mut pending_forwards); - self.context.monitor_pending_failures.append(&mut pending_fails); - self.context.monitor_pending_finalized_fulfills.append(&mut pending_finalized_claimed_htlcs); - self.context.channel_state |= ChannelState::MonitorUpdateInProgress as u32; - } - - /// Indicates that the latest ChannelMonitor update has been committed by the client - /// successfully and we should restore normal operation. Returns messages which should be sent - /// to the remote side. - pub fn monitor_updating_restored( - &mut self, logger: &L, node_signer: &NS, genesis_block_hash: BlockHash, - user_config: &UserConfig, best_block_height: u32 - ) -> MonitorRestoreUpdates - where - L::Target: Logger, - NS::Target: NodeSigner - { - assert_eq!(self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32, ChannelState::MonitorUpdateInProgress as u32); - self.context.channel_state &= !(ChannelState::MonitorUpdateInProgress as u32); - let mut found_blocked = false; - self.context.pending_monitor_updates.retain(|upd| { - if found_blocked { debug_assert!(upd.blocked, "No mons may be unblocked after a blocked one"); } - if upd.blocked { found_blocked = true; } - upd.blocked - }); - - // If we're past (or at) the FundingSent stage on an outbound channel, try to - // (re-)broadcast the funding transaction as we may have declined to broadcast it when we - // first received the funding_signed. - let mut funding_broadcastable = - if self.context.is_outbound() && self.context.channel_state & !MULTI_STATE_FLAGS >= ChannelState::FundingSent as u32 { - self.context.funding_transaction.take() - } else { None }; - // That said, if the funding transaction is already confirmed (ie we're active with a - // minimum_depth over 0) don't bother re-broadcasting the confirmed funding tx. - if self.context.channel_state & !MULTI_STATE_FLAGS >= ChannelState::ChannelReady as u32 && self.context.minimum_depth != Some(0) { - funding_broadcastable = None; - } - - // We will never broadcast the funding transaction when we're in MonitorUpdateInProgress - // (and we assume the user never directly broadcasts the funding transaction and waits for - // us to do it). Thus, we can only ever hit monitor_pending_channel_ready when we're - // * an inbound channel that failed to persist the monitor on funding_created and we got - // the funding transaction confirmed before the monitor was persisted, or - // * a 0-conf channel and intended to send the channel_ready before any broadcast at all. - let channel_ready = if self.context.monitor_pending_channel_ready { - assert!(!self.context.is_outbound() || self.context.minimum_depth == Some(0), - "Funding transaction broadcast by the local client before it should have - LDK didn't do it!"); - self.context.monitor_pending_channel_ready = false; + let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number == 1 { + // We should never have to worry about MonitorUpdateInProgress resending ChannelReady let next_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); Some(msgs::ChannelReady { channel_id: self.context.channel_id(), @@ -4156,671 +4113,382 @@ impl Channel { }) } else { None }; - let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block_height, logger); + if msg.next_local_commitment_number == next_counterparty_commitment_number { + if required_revoke.is_some() { + log_debug!(logger, "Reconnected channel {} with only lost outbound RAA", log_bytes!(self.context.channel_id())); + } else { + log_debug!(logger, "Reconnected channel {} with no loss", log_bytes!(self.context.channel_id())); + } - let mut accepted_htlcs = Vec::new(); - mem::swap(&mut accepted_htlcs, &mut self.context.monitor_pending_forwards); - let mut failed_htlcs = Vec::new(); - mem::swap(&mut failed_htlcs, &mut self.context.monitor_pending_failures); - let mut finalized_claimed_htlcs = Vec::new(); - mem::swap(&mut finalized_claimed_htlcs, &mut self.context.monitor_pending_finalized_fulfills); + Ok(ReestablishResponses { + channel_ready, shutdown_msg, announcement_sigs, + raa: required_revoke, + commitment_update: None, + order: self.context.resend_order.clone(), + }) + } else if msg.next_local_commitment_number == next_counterparty_commitment_number - 1 { + if required_revoke.is_some() { + log_debug!(logger, "Reconnected channel {} with lost outbound RAA and lost remote commitment tx", log_bytes!(self.context.channel_id())); + } else { + log_debug!(logger, "Reconnected channel {} with only lost remote commitment tx", log_bytes!(self.context.channel_id())); + } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) != 0 { - self.context.monitor_pending_revoke_and_ack = false; - self.context.monitor_pending_commitment_signed = false; - return MonitorRestoreUpdates { - raa: None, commitment_update: None, order: RAACommitmentOrder::RevokeAndACKFirst, - accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, channel_ready, announcement_sigs - }; + if self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32) != 0 { + self.context.monitor_pending_commitment_signed = true; + Ok(ReestablishResponses { + channel_ready, shutdown_msg, announcement_sigs, + commitment_update: None, raa: None, + order: self.context.resend_order.clone(), + }) + } else { + Ok(ReestablishResponses { + channel_ready, shutdown_msg, announcement_sigs, + raa: required_revoke, + commitment_update: Some(self.get_last_commitment_update(logger)), + order: self.context.resend_order.clone(), + }) + } + } else { + Err(ChannelError::Close("Peer attempted to reestablish channel with a very old remote commitment transaction".to_owned())) } + } - let raa = if self.context.monitor_pending_revoke_and_ack { - Some(self.get_last_revoke_and_ack()) - } else { None }; - let commitment_update = if self.context.monitor_pending_commitment_signed { - self.mark_awaiting_response(); - Some(self.get_last_commitment_update(logger)) - } else { None }; + /// Calculates and returns our minimum and maximum closing transaction fee amounts, in whole + /// satoshis. The amounts remain consistent unless a peer disconnects/reconnects or we restart, + /// at which point they will be recalculated. + fn calculate_closing_fee_limits(&mut self, fee_estimator: &LowerBoundedFeeEstimator) + -> (u64, u64) + where F::Target: FeeEstimator + { + if let Some((min, max)) = self.context.closing_fee_limits { return (min, max); } - self.context.monitor_pending_revoke_and_ack = false; - self.context.monitor_pending_commitment_signed = false; - let order = self.context.resend_order.clone(); - log_debug!(logger, "Restored monitor updating in channel {} resulting in {}{} commitment update and {} RAA, with {} first", - log_bytes!(self.context.channel_id()), if funding_broadcastable.is_some() { "a funding broadcastable, " } else { "" }, - if commitment_update.is_some() { "a" } else { "no" }, if raa.is_some() { "an" } else { "no" }, - match order { RAACommitmentOrder::CommitmentFirst => "commitment", RAACommitmentOrder::RevokeAndACKFirst => "RAA"}); - MonitorRestoreUpdates { - raa, commitment_update, order, accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, channel_ready, announcement_sigs + // Propose a range from our current Background feerate to our Normal feerate plus our + // force_close_avoidance_max_fee_satoshis. + // If we fail to come to consensus, we'll have to force-close. + let mut proposed_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background); + let normal_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal); + let mut proposed_max_feerate = if self.context.is_outbound() { normal_feerate } else { u32::max_value() }; + + // The spec requires that (when the channel does not have anchors) we only send absolute + // channel fees no greater than the absolute channel fee on the current commitment + // transaction. It's unclear *which* commitment transaction this refers to, and there isn't + // very good reason to apply such a limit in any case. We don't bother doing so, risking + // some force-closure by old nodes, but we wanted to close the channel anyway. + + if let Some(target_feerate) = self.context.target_closing_feerate_sats_per_kw { + let min_feerate = if self.context.is_outbound() { target_feerate } else { cmp::min(self.context.feerate_per_kw, target_feerate) }; + proposed_feerate = cmp::max(proposed_feerate, min_feerate); + proposed_max_feerate = cmp::max(proposed_max_feerate, min_feerate); } + + // Note that technically we could end up with a lower minimum fee if one sides' balance is + // below our dust limit, causing the output to disappear. We don't bother handling this + // case, however, as this should only happen if a channel is closed before any (material) + // payments have been made on it. This may cause slight fee overpayment and/or failure to + // come to consensus with our counterparty on appropriate fees, however it should be a + // relatively rare case. We can revisit this later, though note that in order to determine + // if the funders' output is dust we have to know the absolute fee we're going to use. + let tx_weight = self.get_closing_transaction_weight(Some(&self.get_closing_scriptpubkey()), Some(self.context.counterparty_shutdown_scriptpubkey.as_ref().unwrap())); + let proposed_total_fee_satoshis = proposed_feerate as u64 * tx_weight / 1000; + let proposed_max_total_fee_satoshis = if self.context.is_outbound() { + // We always add force_close_avoidance_max_fee_satoshis to our normal + // feerate-calculated fee, but allow the max to be overridden if we're using a + // target feerate-calculated fee. + cmp::max(normal_feerate as u64 * tx_weight / 1000 + self.context.config.options.force_close_avoidance_max_fee_satoshis, + proposed_max_feerate as u64 * tx_weight / 1000) + } else { + self.context.channel_value_satoshis - (self.context.value_to_self_msat + 999) / 1000 + }; + + self.context.closing_fee_limits = Some((proposed_total_fee_satoshis, proposed_max_total_fee_satoshis)); + self.context.closing_fee_limits.clone().unwrap() } - pub fn update_fee(&mut self, fee_estimator: &LowerBoundedFeeEstimator, msg: &msgs::UpdateFee, logger: &L) -> Result<(), ChannelError> - where F::Target: FeeEstimator, L::Target: Logger - { - if self.context.is_outbound() { - return Err(ChannelError::Close("Non-funding remote tried to update channel fee".to_owned())); - } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned())); - } - Channel::::check_remote_fee(fee_estimator, msg.feerate_per_kw, Some(self.context.feerate_per_kw), logger)?; - let feerate_over_dust_buffer = msg.feerate_per_kw > self.context.get_dust_buffer_feerate(None); + /// Returns true if we're ready to commence the closing_signed negotiation phase. This is true + /// after both sides have exchanged a `shutdown` message and all HTLCs have been drained. At + /// this point if we're the funder we should send the initial closing_signed, and in any case + /// shutdown should complete within a reasonable timeframe. + fn closing_negotiation_ready(&self) -> bool { + self.context.pending_inbound_htlcs.is_empty() && self.context.pending_outbound_htlcs.is_empty() && + self.context.channel_state & + (BOTH_SIDES_SHUTDOWN_MASK | ChannelState::AwaitingRemoteRevoke as u32 | + ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32) + == BOTH_SIDES_SHUTDOWN_MASK && + self.context.pending_update_fee.is_none() + } - self.context.pending_update_fee = Some((msg.feerate_per_kw, FeeUpdateState::RemoteAnnounced)); - self.context.update_time_counter += 1; - // If the feerate has increased over the previous dust buffer (note that - // `get_dust_buffer_feerate` considers the `pending_update_fee` status), check that we - // won't be pushed over our dust exposure limit by the feerate increase. - if feerate_over_dust_buffer { - let inbound_stats = self.context.get_inbound_pending_htlc_stats(None); - let outbound_stats = self.context.get_outbound_pending_htlc_stats(None); - let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat; - let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat; - if holder_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { - return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our own transactions (totaling {} msat)", - msg.feerate_per_kw, holder_tx_dust_exposure))); - } - if counterparty_tx_dust_exposure > self.context.get_max_dust_htlc_exposure_msat() { - return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our counterparty's transactions (totaling {} msat)", - msg.feerate_per_kw, counterparty_tx_dust_exposure))); + /// Checks if the closing_signed negotiation is making appropriate progress, possibly returning + /// an Err if no progress is being made and the channel should be force-closed instead. + /// Should be called on a one-minute timer. + pub fn timer_check_closing_negotiation_progress(&mut self) -> Result<(), ChannelError> { + if self.closing_negotiation_ready() { + if self.context.closing_signed_in_flight { + return Err(ChannelError::Close("closing_signed negotiation failed to finish within two timer ticks".to_owned())); + } else { + self.context.closing_signed_in_flight = true; } } Ok(()) } - fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK { - let next_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); - let per_commitment_secret = self.context.holder_signer.release_commitment_secret(self.context.cur_holder_commitment_transaction_number + 2); - msgs::RevokeAndACK { - channel_id: self.context.channel_id, - per_commitment_secret, - next_per_commitment_point, - #[cfg(taproot)] - next_local_nonce: None, - } - } - - fn get_last_commitment_update(&self, logger: &L) -> msgs::CommitmentUpdate where L::Target: Logger { - let mut update_add_htlcs = Vec::new(); - let mut update_fulfill_htlcs = Vec::new(); - let mut update_fail_htlcs = Vec::new(); - let mut update_fail_malformed_htlcs = Vec::new(); - - for htlc in self.context.pending_outbound_htlcs.iter() { - if let &OutboundHTLCState::LocalAnnounced(ref onion_packet) = &htlc.state { - update_add_htlcs.push(msgs::UpdateAddHTLC { - channel_id: self.context.channel_id(), - htlc_id: htlc.htlc_id, - amount_msat: htlc.amount_msat, - payment_hash: htlc.payment_hash, - cltv_expiry: htlc.cltv_expiry, - onion_routing_packet: (**onion_packet).clone(), - }); - } + pub fn maybe_propose_closing_signed( + &mut self, fee_estimator: &LowerBoundedFeeEstimator, logger: &L) + -> Result<(Option, Option), ChannelError> + where F::Target: FeeEstimator, L::Target: Logger + { + if self.context.last_sent_closing_fee.is_some() || !self.closing_negotiation_ready() { + return Ok((None, None)); } - for htlc in self.context.pending_inbound_htlcs.iter() { - if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state { - match reason { - &InboundHTLCRemovalReason::FailRelay(ref err_packet) => { - update_fail_htlcs.push(msgs::UpdateFailHTLC { - channel_id: self.context.channel_id(), - htlc_id: htlc.htlc_id, - reason: err_packet.clone() - }); - }, - &InboundHTLCRemovalReason::FailMalformed((ref sha256_of_onion, ref failure_code)) => { - update_fail_malformed_htlcs.push(msgs::UpdateFailMalformedHTLC { - channel_id: self.context.channel_id(), - htlc_id: htlc.htlc_id, - sha256_of_onion: sha256_of_onion.clone(), - failure_code: failure_code.clone(), - }); - }, - &InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => { - update_fulfill_htlcs.push(msgs::UpdateFulfillHTLC { - channel_id: self.context.channel_id(), - htlc_id: htlc.htlc_id, - payment_preimage: payment_preimage.clone(), - }); - }, - } + if !self.context.is_outbound() { + if let Some(msg) = &self.context.pending_counterparty_closing_signed.take() { + return self.closing_signed(fee_estimator, &msg); } + return Ok((None, None)); } - let update_fee = if self.context.is_outbound() && self.context.pending_update_fee.is_some() { - Some(msgs::UpdateFee { - channel_id: self.context.channel_id(), - feerate_per_kw: self.context.pending_update_fee.unwrap().0, - }) - } else { None }; + let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator); - log_trace!(logger, "Regenerated latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds", - log_bytes!(self.context.channel_id()), if update_fee.is_some() { " update_fee," } else { "" }, - update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len(), update_fail_malformed_htlcs.len()); - msgs::CommitmentUpdate { - update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs, update_fee, - commitment_signed: self.send_commitment_no_state_update(logger).expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0, - } + assert!(self.context.shutdown_scriptpubkey.is_some()); + let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(our_min_fee, false); + log_trace!(logger, "Proposing initial closing_signed for our counterparty with a fee range of {}-{} sat (with initial proposal {} sats)", + our_min_fee, our_max_fee, total_fee_satoshis); + + let sig = self.context.holder_signer + .sign_closing_transaction(&closing_tx, &self.context.secp_ctx) + .map_err(|()| ChannelError::Close("Failed to get signature for closing transaction.".to_owned()))?; + + self.context.last_sent_closing_fee = Some((total_fee_satoshis, sig.clone())); + Ok((Some(msgs::ClosingSigned { + channel_id: self.context.channel_id, + fee_satoshis: total_fee_satoshis, + signature: sig, + fee_range: Some(msgs::ClosingSignedFeeRange { + min_fee_satoshis: our_min_fee, + max_fee_satoshis: our_max_fee, + }), + }), None)) } - /// May panic if some calls other than message-handling calls (which will all Err immediately) - /// have been called between remove_uncommitted_htlcs_and_mark_paused and this call. + // Marks a channel as waiting for a response from the counterparty. If it's not received + // [`DISCONNECT_PEER_AWAITING_RESPONSE_TICKS`] after sending our own to them, then we'll attempt + // a reconnection. + fn mark_awaiting_response(&mut self) { + self.context.sent_message_awaiting_response = Some(0); + } + + /// Determines whether we should disconnect the counterparty due to not receiving a response + /// within our expected timeframe. /// - /// Some links printed in log lines are included here to check them during build (when run with - /// `cargo doc --document-private-items`): - /// [`super::channelmanager::ChannelManager::force_close_without_broadcasting_txn`] and - /// [`super::channelmanager::ChannelManager::force_close_all_channels_without_broadcasting_txn`]. - pub fn channel_reestablish( - &mut self, msg: &msgs::ChannelReestablish, logger: &L, node_signer: &NS, - genesis_block_hash: BlockHash, user_config: &UserConfig, best_block: &BestBlock - ) -> Result - where - L::Target: Logger, - NS::Target: NodeSigner + /// This should be called on every [`super::channelmanager::ChannelManager::timer_tick_occurred`]. + pub fn should_disconnect_peer_awaiting_response(&mut self) -> bool { + let ticks_elapsed = if let Some(ticks_elapsed) = self.context.sent_message_awaiting_response.as_mut() { + ticks_elapsed + } else { + // Don't disconnect when we're not waiting on a response. + return false; + }; + *ticks_elapsed += 1; + *ticks_elapsed >= DISCONNECT_PEER_AWAITING_RESPONSE_TICKS + } + + pub fn shutdown( + &mut self, signer_provider: &SP, their_features: &InitFeatures, msg: &msgs::Shutdown + ) -> Result<(Option, Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), ChannelError> + where SP::Target: SignerProvider { - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == 0 { - // While BOLT 2 doesn't indicate explicitly we should error this channel here, it - // almost certainly indicates we are going to end up out-of-sync in some way, so we - // just close here instead of trying to recover. - return Err(ChannelError::Close("Peer sent a loose channel_reestablish not after reconnect".to_owned())); + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + return Err(ChannelError::Close("Peer sent shutdown when we needed a channel_reestablish".to_owned())); + } + if self.context.channel_state < ChannelState::FundingSent as u32 { + // Spec says we should fail the connection, not the channel, but that's nonsense, there + // are plenty of reasons you may want to fail a channel pre-funding, and spec says you + // can do that via error message without getting a connection fail anyway... + return Err(ChannelError::Close("Peer sent shutdown pre-funding generation".to_owned())); + } + for htlc in self.context.pending_inbound_htlcs.iter() { + if let InboundHTLCState::RemoteAnnounced(_) = htlc.state { + return Err(ChannelError::Close("Got shutdown with remote pending HTLCs".to_owned())); + } } + assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); - if msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER || - msg.next_local_commitment_number == 0 { - return Err(ChannelError::Close("Peer sent a garbage channel_reestablish (usually an lnd node with lost state asking us to force-close for them)".to_owned())); + if !script::is_bolt2_compliant(&msg.scriptpubkey, their_features) { + return Err(ChannelError::Warn(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex()))); } - if msg.next_remote_commitment_number > 0 { - let expected_point = self.context.holder_signer.get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - msg.next_remote_commitment_number + 1, &self.context.secp_ctx); - let given_secret = SecretKey::from_slice(&msg.your_last_per_commitment_secret) - .map_err(|_| ChannelError::Close("Peer sent a garbage channel_reestablish with unparseable secret key".to_owned()))?; - if expected_point != PublicKey::from_secret_key(&self.context.secp_ctx, &given_secret) { - return Err(ChannelError::Close("Peer sent a garbage channel_reestablish with secret key not matching the commitment height provided".to_owned())); - } - if msg.next_remote_commitment_number > INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number { - macro_rules! log_and_panic { - ($err_msg: expr) => { - log_error!(logger, $err_msg, log_bytes!(self.context.channel_id), log_pubkey!(self.context.counterparty_node_id)); - panic!($err_msg, log_bytes!(self.context.channel_id), log_pubkey!(self.context.counterparty_node_id)); - } - } - log_and_panic!("We have fallen behind - we have received proof that if we broadcast our counterparty is going to claim all our funds.\n\ - This implies you have restarted with lost ChannelMonitor and ChannelManager state, the first of which is a violation of the LDK chain::Watch requirements.\n\ - More specifically, this means you have a bug in your implementation that can cause loss of funds, or you are running with an old backup, which is unsafe.\n\ - If you have restored from an old backup and wish to force-close channels and return to operation, you should start up, call\n\ - ChannelManager::force_close_without_broadcasting_txn on channel {} with counterparty {} or\n\ - ChannelManager::force_close_all_channels_without_broadcasting_txn, then reconnect to peer(s).\n\ - Note that due to a long-standing bug in lnd you may have to reach out to peers running lnd-based nodes to ask them to manually force-close channels\n\ - See https://github.com/lightningdevkit/rust-lightning/issues/1565 for more info."); + if self.context.counterparty_shutdown_scriptpubkey.is_some() { + if Some(&msg.scriptpubkey) != self.context.counterparty_shutdown_scriptpubkey.as_ref() { + return Err(ChannelError::Warn(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_bytes().to_hex()))); } + } else { + self.context.counterparty_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone()); } - // Before we change the state of the channel, we check if the peer is sending a very old - // commitment transaction number, if yes we send a warning message. - let our_commitment_transaction = INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number - 1; - if msg.next_remote_commitment_number + 1 < our_commitment_transaction { - return Err( - ChannelError::Warn(format!("Peer attempted to reestablish channel with a very old local commitment transaction: {} (received) vs {} (expected)", msg.next_remote_commitment_number, our_commitment_transaction)) - ); - } + // If we have any LocalAnnounced updates we'll probably just get back an update_fail_htlc + // immediately after the commitment dance, but we can send a Shutdown because we won't send + // any further commitment updates after we set LocalShutdownSent. + let send_shutdown = (self.context.channel_state & ChannelState::LocalShutdownSent as u32) != ChannelState::LocalShutdownSent as u32; - // Go ahead and unmark PeerDisconnected as various calls we may make check for it (and all - // remaining cases either succeed or ErrorMessage-fail). - self.context.channel_state &= !(ChannelState::PeerDisconnected as u32); - self.context.sent_message_awaiting_response = None; + let update_shutdown_script = match self.context.shutdown_scriptpubkey { + Some(_) => false, + None => { + assert!(send_shutdown); + let shutdown_scriptpubkey = match signer_provider.get_shutdown_scriptpubkey() { + Ok(scriptpubkey) => scriptpubkey, + Err(_) => return Err(ChannelError::Close("Failed to get shutdown scriptpubkey".to_owned())), + }; + if !shutdown_scriptpubkey.is_compatible(their_features) { + return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey))); + } + self.context.shutdown_scriptpubkey = Some(shutdown_scriptpubkey); + true + }, + }; - let shutdown_msg = if self.context.channel_state & (ChannelState::LocalShutdownSent as u32) != 0 { - assert!(self.context.shutdown_scriptpubkey.is_some()); + // From here on out, we may not fail! + + self.context.channel_state |= ChannelState::RemoteShutdownSent as u32; + self.context.update_time_counter += 1; + + let monitor_update = if update_shutdown_script { + self.context.latest_monitor_update_id += 1; + let monitor_update = ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::ShutdownScript { + scriptpubkey: self.get_closing_scriptpubkey(), + }], + }; + self.monitor_updating_paused(false, false, false, Vec::new(), Vec::new(), Vec::new()); + if self.push_blockable_mon_update(monitor_update) { + self.context.pending_monitor_updates.last().map(|upd| &upd.update) + } else { None } + } else { None }; + let shutdown = if send_shutdown { Some(msgs::Shutdown { channel_id: self.context.channel_id, scriptpubkey: self.get_closing_scriptpubkey(), }) } else { None }; - let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger); - - if self.context.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 { - // If we're waiting on a monitor update, we shouldn't re-send any channel_ready's. - if self.context.channel_state & (ChannelState::OurChannelReady as u32) == 0 || - self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32) != 0 { - if msg.next_remote_commitment_number != 0 { - return Err(ChannelError::Close("Peer claimed they saw a revoke_and_ack but we haven't sent channel_ready yet".to_owned())); - } - // Short circuit the whole handler as there is nothing we can resend them - return Ok(ReestablishResponses { - channel_ready: None, - raa: None, commitment_update: None, - order: RAACommitmentOrder::CommitmentFirst, - shutdown_msg, announcement_sigs, - }); + // We can't send our shutdown until we've committed all of our pending HTLCs, but the + // remote side is unlikely to accept any new HTLCs, so we go ahead and "free" any holding + // cell HTLCs and return them to fail the payment. + self.context.holding_cell_update_fee = None; + let mut dropped_outbound_htlcs = Vec::with_capacity(self.context.holding_cell_htlc_updates.len()); + self.context.holding_cell_htlc_updates.retain(|htlc_update| { + match htlc_update { + &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => { + dropped_outbound_htlcs.push((source.clone(), payment_hash.clone())); + false + }, + _ => true } + }); - // We have OurChannelReady set! - let next_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); - return Ok(ReestablishResponses { - channel_ready: Some(msgs::ChannelReady { - channel_id: self.context.channel_id(), - next_per_commitment_point, - short_channel_id_alias: Some(self.context.outbound_scid_alias), - }), - raa: None, commitment_update: None, - order: RAACommitmentOrder::CommitmentFirst, - shutdown_msg, announcement_sigs, - }); - } - - let required_revoke = if msg.next_remote_commitment_number + 1 == INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number { - // Remote isn't waiting on any RevokeAndACK from us! - // Note that if we need to repeat our ChannelReady we'll do that in the next if block. - None - } else if msg.next_remote_commitment_number + 1 == (INITIAL_COMMITMENT_NUMBER - 1) - self.context.cur_holder_commitment_transaction_number { - if self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32) != 0 { - self.context.monitor_pending_revoke_and_ack = true; - None - } else { - Some(self.get_last_revoke_and_ack()) - } - } else { - return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old local commitment transaction".to_owned())); - }; - - // We increment cur_counterparty_commitment_transaction_number only upon receipt of - // revoke_and_ack, not on sending commitment_signed, so we add one if have - // AwaitingRemoteRevoke set, which indicates we sent a commitment_signed but haven't gotten - // the corresponding revoke_and_ack back yet. - let is_awaiting_remote_revoke = self.context.channel_state & ChannelState::AwaitingRemoteRevoke as u32 != 0; - if is_awaiting_remote_revoke && !self.is_awaiting_monitor_update() { - self.mark_awaiting_response(); - } - let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.cur_counterparty_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 }; + self.context.channel_state |= ChannelState::LocalShutdownSent as u32; + self.context.update_time_counter += 1; - let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number == 1 { - // We should never have to worry about MonitorUpdateInProgress resending ChannelReady - let next_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); - Some(msgs::ChannelReady { - channel_id: self.context.channel_id(), - next_per_commitment_point, - short_channel_id_alias: Some(self.context.outbound_scid_alias), - }) - } else { None }; + Ok((shutdown, monitor_update, dropped_outbound_htlcs)) + } - if msg.next_local_commitment_number == next_counterparty_commitment_number { - if required_revoke.is_some() { - log_debug!(logger, "Reconnected channel {} with only lost outbound RAA", log_bytes!(self.context.channel_id())); - } else { - log_debug!(logger, "Reconnected channel {} with no loss", log_bytes!(self.context.channel_id())); - } + fn build_signed_closing_transaction(&self, closing_tx: &ClosingTransaction, counterparty_sig: &Signature, sig: &Signature) -> Transaction { + let mut tx = closing_tx.trust().built_transaction().clone(); - Ok(ReestablishResponses { - channel_ready, shutdown_msg, announcement_sigs, - raa: required_revoke, - commitment_update: None, - order: self.context.resend_order.clone(), - }) - } else if msg.next_local_commitment_number == next_counterparty_commitment_number - 1 { - if required_revoke.is_some() { - log_debug!(logger, "Reconnected channel {} with lost outbound RAA and lost remote commitment tx", log_bytes!(self.context.channel_id())); - } else { - log_debug!(logger, "Reconnected channel {} with only lost remote commitment tx", log_bytes!(self.context.channel_id())); - } + tx.input[0].witness.push(Vec::new()); // First is the multisig dummy - if self.context.channel_state & (ChannelState::MonitorUpdateInProgress as u32) != 0 { - self.context.monitor_pending_commitment_signed = true; - Ok(ReestablishResponses { - channel_ready, shutdown_msg, announcement_sigs, - commitment_update: None, raa: None, - order: self.context.resend_order.clone(), - }) - } else { - Ok(ReestablishResponses { - channel_ready, shutdown_msg, announcement_sigs, - raa: required_revoke, - commitment_update: Some(self.get_last_commitment_update(logger)), - order: self.context.resend_order.clone(), - }) - } + let funding_key = self.context.get_holder_pubkeys().funding_pubkey.serialize(); + let counterparty_funding_key = self.context.counterparty_funding_pubkey().serialize(); + let mut holder_sig = sig.serialize_der().to_vec(); + holder_sig.push(EcdsaSighashType::All as u8); + let mut cp_sig = counterparty_sig.serialize_der().to_vec(); + cp_sig.push(EcdsaSighashType::All as u8); + if funding_key[..] < counterparty_funding_key[..] { + tx.input[0].witness.push(holder_sig); + tx.input[0].witness.push(cp_sig); } else { - Err(ChannelError::Close("Peer attempted to reestablish channel with a very old remote commitment transaction".to_owned())) + tx.input[0].witness.push(cp_sig); + tx.input[0].witness.push(holder_sig); } + + tx.input[0].witness.push(self.context.get_funding_redeemscript().into_bytes()); + tx } - /// Calculates and returns our minimum and maximum closing transaction fee amounts, in whole - /// satoshis. The amounts remain consistent unless a peer disconnects/reconnects or we restart, - /// at which point they will be recalculated. - fn calculate_closing_fee_limits(&mut self, fee_estimator: &LowerBoundedFeeEstimator) - -> (u64, u64) + pub fn closing_signed( + &mut self, fee_estimator: &LowerBoundedFeeEstimator, msg: &msgs::ClosingSigned) + -> Result<(Option, Option), ChannelError> where F::Target: FeeEstimator { - if let Some((min, max)) = self.context.closing_fee_limits { return (min, max); } - - // Propose a range from our current Background feerate to our Normal feerate plus our - // force_close_avoidance_max_fee_satoshis. - // If we fail to come to consensus, we'll have to force-close. - let mut proposed_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background); - let normal_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal); - let mut proposed_max_feerate = if self.context.is_outbound() { normal_feerate } else { u32::max_value() }; - - // The spec requires that (when the channel does not have anchors) we only send absolute - // channel fees no greater than the absolute channel fee on the current commitment - // transaction. It's unclear *which* commitment transaction this refers to, and there isn't - // very good reason to apply such a limit in any case. We don't bother doing so, risking - // some force-closure by old nodes, but we wanted to close the channel anyway. + if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK != BOTH_SIDES_SHUTDOWN_MASK { + return Err(ChannelError::Close("Remote end sent us a closing_signed before both sides provided a shutdown".to_owned())); + } + if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { + return Err(ChannelError::Close("Peer sent closing_signed when we needed a channel_reestablish".to_owned())); + } + if !self.context.pending_inbound_htlcs.is_empty() || !self.context.pending_outbound_htlcs.is_empty() { + return Err(ChannelError::Close("Remote end sent us a closing_signed while there were still pending HTLCs".to_owned())); + } + if msg.fee_satoshis > TOTAL_BITCOIN_SUPPLY_SATOSHIS { // this is required to stop potential overflow in build_closing_transaction + return Err(ChannelError::Close("Remote tried to send us a closing tx with > 21 million BTC fee".to_owned())); + } - if let Some(target_feerate) = self.context.target_closing_feerate_sats_per_kw { - let min_feerate = if self.context.is_outbound() { target_feerate } else { cmp::min(self.context.feerate_per_kw, target_feerate) }; - proposed_feerate = cmp::max(proposed_feerate, min_feerate); - proposed_max_feerate = cmp::max(proposed_max_feerate, min_feerate); + if self.context.is_outbound() && self.context.last_sent_closing_fee.is_none() { + return Err(ChannelError::Close("Remote tried to send a closing_signed when we were supposed to propose the first one".to_owned())); } - // Note that technically we could end up with a lower minimum fee if one sides' balance is - // below our dust limit, causing the output to disappear. We don't bother handling this - // case, however, as this should only happen if a channel is closed before any (material) - // payments have been made on it. This may cause slight fee overpayment and/or failure to - // come to consensus with our counterparty on appropriate fees, however it should be a - // relatively rare case. We can revisit this later, though note that in order to determine - // if the funders' output is dust we have to know the absolute fee we're going to use. - let tx_weight = self.get_closing_transaction_weight(Some(&self.get_closing_scriptpubkey()), Some(self.context.counterparty_shutdown_scriptpubkey.as_ref().unwrap())); - let proposed_total_fee_satoshis = proposed_feerate as u64 * tx_weight / 1000; - let proposed_max_total_fee_satoshis = if self.context.is_outbound() { - // We always add force_close_avoidance_max_fee_satoshis to our normal - // feerate-calculated fee, but allow the max to be overridden if we're using a - // target feerate-calculated fee. - cmp::max(normal_feerate as u64 * tx_weight / 1000 + self.context.config.options.force_close_avoidance_max_fee_satoshis, - proposed_max_feerate as u64 * tx_weight / 1000) - } else { - self.context.channel_value_satoshis - (self.context.value_to_self_msat + 999) / 1000 - }; + if self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32 != 0 { + self.context.pending_counterparty_closing_signed = Some(msg.clone()); + return Ok((None, None)); + } - self.context.closing_fee_limits = Some((proposed_total_fee_satoshis, proposed_max_total_fee_satoshis)); - self.context.closing_fee_limits.clone().unwrap() - } + let funding_redeemscript = self.context.get_funding_redeemscript(); + let (mut closing_tx, used_total_fee) = self.build_closing_transaction(msg.fee_satoshis, false); + if used_total_fee != msg.fee_satoshis { + return Err(ChannelError::Close(format!("Remote sent us a closing_signed with a fee other than the value they can claim. Fee in message: {}. Actual closing tx fee: {}", msg.fee_satoshis, used_total_fee))); + } + let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.context.channel_value_satoshis); - /// Returns true if we're ready to commence the closing_signed negotiation phase. This is true - /// after both sides have exchanged a `shutdown` message and all HTLCs have been drained. At - /// this point if we're the funder we should send the initial closing_signed, and in any case - /// shutdown should complete within a reasonable timeframe. - fn closing_negotiation_ready(&self) -> bool { - self.context.pending_inbound_htlcs.is_empty() && self.context.pending_outbound_htlcs.is_empty() && - self.context.channel_state & - (BOTH_SIDES_SHUTDOWN_MASK | ChannelState::AwaitingRemoteRevoke as u32 | - ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32) - == BOTH_SIDES_SHUTDOWN_MASK && - self.context.pending_update_fee.is_none() - } + match self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.context.get_counterparty_pubkeys().funding_pubkey) { + Ok(_) => {}, + Err(_e) => { + // The remote end may have decided to revoke their output due to inconsistent dust + // limits, so check for that case by re-checking the signature here. + closing_tx = self.build_closing_transaction(msg.fee_satoshis, true).0; + let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.context.channel_value_satoshis); + secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, self.context.counterparty_funding_pubkey()), "Invalid closing tx signature from peer".to_owned()); + }, + }; - /// Checks if the closing_signed negotiation is making appropriate progress, possibly returning - /// an Err if no progress is being made and the channel should be force-closed instead. - /// Should be called on a one-minute timer. - pub fn timer_check_closing_negotiation_progress(&mut self) -> Result<(), ChannelError> { - if self.closing_negotiation_ready() { - if self.context.closing_signed_in_flight { - return Err(ChannelError::Close("closing_signed negotiation failed to finish within two timer ticks".to_owned())); - } else { - self.context.closing_signed_in_flight = true; + for outp in closing_tx.trust().built_transaction().output.iter() { + if !outp.script_pubkey.is_witness_program() && outp.value < MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS { + return Err(ChannelError::Close("Remote sent us a closing_signed with a dust output. Always use segwit closing scripts!".to_owned())); } } - Ok(()) - } - - pub fn maybe_propose_closing_signed( - &mut self, fee_estimator: &LowerBoundedFeeEstimator, logger: &L) - -> Result<(Option, Option), ChannelError> - where F::Target: FeeEstimator, L::Target: Logger - { - if self.context.last_sent_closing_fee.is_some() || !self.closing_negotiation_ready() { - return Ok((None, None)); - } - if !self.context.is_outbound() { - if let Some(msg) = &self.context.pending_counterparty_closing_signed.take() { - return self.closing_signed(fee_estimator, &msg); + assert!(self.context.shutdown_scriptpubkey.is_some()); + if let Some((last_fee, sig)) = self.context.last_sent_closing_fee { + if last_fee == msg.fee_satoshis { + let tx = self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig); + self.context.channel_state = ChannelState::ShutdownComplete as u32; + self.context.update_time_counter += 1; + return Ok((None, Some(tx))); } - return Ok((None, None)); } let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator); - assert!(self.context.shutdown_scriptpubkey.is_some()); - let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(our_min_fee, false); - log_trace!(logger, "Proposing initial closing_signed for our counterparty with a fee range of {}-{} sat (with initial proposal {} sats)", - our_min_fee, our_max_fee, total_fee_satoshis); + macro_rules! propose_fee { + ($new_fee: expr) => { + let (closing_tx, used_fee) = if $new_fee == msg.fee_satoshis { + (closing_tx, $new_fee) + } else { + self.build_closing_transaction($new_fee, false) + }; - let sig = self.context.holder_signer - .sign_closing_transaction(&closing_tx, &self.context.secp_ctx) - .map_err(|()| ChannelError::Close("Failed to get signature for closing transaction.".to_owned()))?; - - self.context.last_sent_closing_fee = Some((total_fee_satoshis, sig.clone())); - Ok((Some(msgs::ClosingSigned { - channel_id: self.context.channel_id, - fee_satoshis: total_fee_satoshis, - signature: sig, - fee_range: Some(msgs::ClosingSignedFeeRange { - min_fee_satoshis: our_min_fee, - max_fee_satoshis: our_max_fee, - }), - }), None)) - } - - // Marks a channel as waiting for a response from the counterparty. If it's not received - // [`DISCONNECT_PEER_AWAITING_RESPONSE_TICKS`] after sending our own to them, then we'll attempt - // a reconnection. - fn mark_awaiting_response(&mut self) { - self.context.sent_message_awaiting_response = Some(0); - } - - /// Determines whether we should disconnect the counterparty due to not receiving a response - /// within our expected timeframe. - /// - /// This should be called on every [`super::channelmanager::ChannelManager::timer_tick_occurred`]. - pub fn should_disconnect_peer_awaiting_response(&mut self) -> bool { - let ticks_elapsed = if let Some(ticks_elapsed) = self.context.sent_message_awaiting_response.as_mut() { - ticks_elapsed - } else { - // Don't disconnect when we're not waiting on a response. - return false; - }; - *ticks_elapsed += 1; - *ticks_elapsed >= DISCONNECT_PEER_AWAITING_RESPONSE_TICKS - } - - pub fn shutdown( - &mut self, signer_provider: &SP, their_features: &InitFeatures, msg: &msgs::Shutdown - ) -> Result<(Option, Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), ChannelError> - where SP::Target: SignerProvider - { - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent shutdown when we needed a channel_reestablish".to_owned())); - } - if self.context.channel_state < ChannelState::FundingSent as u32 { - // Spec says we should fail the connection, not the channel, but that's nonsense, there - // are plenty of reasons you may want to fail a channel pre-funding, and spec says you - // can do that via error message without getting a connection fail anyway... - return Err(ChannelError::Close("Peer sent shutdown pre-funding generation".to_owned())); - } - for htlc in self.context.pending_inbound_htlcs.iter() { - if let InboundHTLCState::RemoteAnnounced(_) = htlc.state { - return Err(ChannelError::Close("Got shutdown with remote pending HTLCs".to_owned())); - } - } - assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); - - if !script::is_bolt2_compliant(&msg.scriptpubkey, their_features) { - return Err(ChannelError::Warn(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex()))); - } - - if self.context.counterparty_shutdown_scriptpubkey.is_some() { - if Some(&msg.scriptpubkey) != self.context.counterparty_shutdown_scriptpubkey.as_ref() { - return Err(ChannelError::Warn(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_bytes().to_hex()))); - } - } else { - self.context.counterparty_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone()); - } - - // If we have any LocalAnnounced updates we'll probably just get back an update_fail_htlc - // immediately after the commitment dance, but we can send a Shutdown because we won't send - // any further commitment updates after we set LocalShutdownSent. - let send_shutdown = (self.context.channel_state & ChannelState::LocalShutdownSent as u32) != ChannelState::LocalShutdownSent as u32; - - let update_shutdown_script = match self.context.shutdown_scriptpubkey { - Some(_) => false, - None => { - assert!(send_shutdown); - let shutdown_scriptpubkey = match signer_provider.get_shutdown_scriptpubkey() { - Ok(scriptpubkey) => scriptpubkey, - Err(_) => return Err(ChannelError::Close("Failed to get shutdown scriptpubkey".to_owned())), - }; - if !shutdown_scriptpubkey.is_compatible(their_features) { - return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey))); - } - self.context.shutdown_scriptpubkey = Some(shutdown_scriptpubkey); - true - }, - }; - - // From here on out, we may not fail! - - self.context.channel_state |= ChannelState::RemoteShutdownSent as u32; - self.context.update_time_counter += 1; - - let monitor_update = if update_shutdown_script { - self.context.latest_monitor_update_id += 1; - let monitor_update = ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::ShutdownScript { - scriptpubkey: self.get_closing_scriptpubkey(), - }], - }; - self.monitor_updating_paused(false, false, false, Vec::new(), Vec::new(), Vec::new()); - if self.push_blockable_mon_update(monitor_update) { - self.context.pending_monitor_updates.last().map(|upd| &upd.update) - } else { None } - } else { None }; - let shutdown = if send_shutdown { - Some(msgs::Shutdown { - channel_id: self.context.channel_id, - scriptpubkey: self.get_closing_scriptpubkey(), - }) - } else { None }; - - // We can't send our shutdown until we've committed all of our pending HTLCs, but the - // remote side is unlikely to accept any new HTLCs, so we go ahead and "free" any holding - // cell HTLCs and return them to fail the payment. - self.context.holding_cell_update_fee = None; - let mut dropped_outbound_htlcs = Vec::with_capacity(self.context.holding_cell_htlc_updates.len()); - self.context.holding_cell_htlc_updates.retain(|htlc_update| { - match htlc_update { - &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => { - dropped_outbound_htlcs.push((source.clone(), payment_hash.clone())); - false - }, - _ => true - } - }); - - self.context.channel_state |= ChannelState::LocalShutdownSent as u32; - self.context.update_time_counter += 1; - - Ok((shutdown, monitor_update, dropped_outbound_htlcs)) - } - - fn build_signed_closing_transaction(&self, closing_tx: &ClosingTransaction, counterparty_sig: &Signature, sig: &Signature) -> Transaction { - let mut tx = closing_tx.trust().built_transaction().clone(); - - tx.input[0].witness.push(Vec::new()); // First is the multisig dummy - - let funding_key = self.context.get_holder_pubkeys().funding_pubkey.serialize(); - let counterparty_funding_key = self.context.counterparty_funding_pubkey().serialize(); - let mut holder_sig = sig.serialize_der().to_vec(); - holder_sig.push(EcdsaSighashType::All as u8); - let mut cp_sig = counterparty_sig.serialize_der().to_vec(); - cp_sig.push(EcdsaSighashType::All as u8); - if funding_key[..] < counterparty_funding_key[..] { - tx.input[0].witness.push(holder_sig); - tx.input[0].witness.push(cp_sig); - } else { - tx.input[0].witness.push(cp_sig); - tx.input[0].witness.push(holder_sig); - } - - tx.input[0].witness.push(self.context.get_funding_redeemscript().into_bytes()); - tx - } - - pub fn closing_signed( - &mut self, fee_estimator: &LowerBoundedFeeEstimator, msg: &msgs::ClosingSigned) - -> Result<(Option, Option), ChannelError> - where F::Target: FeeEstimator - { - if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK != BOTH_SIDES_SHUTDOWN_MASK { - return Err(ChannelError::Close("Remote end sent us a closing_signed before both sides provided a shutdown".to_owned())); - } - if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 { - return Err(ChannelError::Close("Peer sent closing_signed when we needed a channel_reestablish".to_owned())); - } - if !self.context.pending_inbound_htlcs.is_empty() || !self.context.pending_outbound_htlcs.is_empty() { - return Err(ChannelError::Close("Remote end sent us a closing_signed while there were still pending HTLCs".to_owned())); - } - if msg.fee_satoshis > TOTAL_BITCOIN_SUPPLY_SATOSHIS { // this is required to stop potential overflow in build_closing_transaction - return Err(ChannelError::Close("Remote tried to send us a closing tx with > 21 million BTC fee".to_owned())); - } - - if self.context.is_outbound() && self.context.last_sent_closing_fee.is_none() { - return Err(ChannelError::Close("Remote tried to send a closing_signed when we were supposed to propose the first one".to_owned())); - } - - if self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32 != 0 { - self.context.pending_counterparty_closing_signed = Some(msg.clone()); - return Ok((None, None)); - } - - let funding_redeemscript = self.context.get_funding_redeemscript(); - let (mut closing_tx, used_total_fee) = self.build_closing_transaction(msg.fee_satoshis, false); - if used_total_fee != msg.fee_satoshis { - return Err(ChannelError::Close(format!("Remote sent us a closing_signed with a fee other than the value they can claim. Fee in message: {}. Actual closing tx fee: {}", msg.fee_satoshis, used_total_fee))); - } - let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.context.channel_value_satoshis); - - match self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.context.get_counterparty_pubkeys().funding_pubkey) { - Ok(_) => {}, - Err(_e) => { - // The remote end may have decided to revoke their output due to inconsistent dust - // limits, so check for that case by re-checking the signature here. - closing_tx = self.build_closing_transaction(msg.fee_satoshis, true).0; - let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.context.channel_value_satoshis); - secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &msg.signature, self.context.counterparty_funding_pubkey()), "Invalid closing tx signature from peer".to_owned()); - }, - }; - - for outp in closing_tx.trust().built_transaction().output.iter() { - if !outp.script_pubkey.is_witness_program() && outp.value < MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS { - return Err(ChannelError::Close("Remote sent us a closing_signed with a dust output. Always use segwit closing scripts!".to_owned())); - } - } - - assert!(self.context.shutdown_scriptpubkey.is_some()); - if let Some((last_fee, sig)) = self.context.last_sent_closing_fee { - if last_fee == msg.fee_satoshis { - let tx = self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig); - self.context.channel_state = ChannelState::ShutdownComplete as u32; - self.context.update_time_counter += 1; - return Ok((None, Some(tx))); - } - } - - let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator); - - macro_rules! propose_fee { - ($new_fee: expr) => { - let (closing_tx, used_fee) = if $new_fee == msg.fee_satoshis { - (closing_tx, $new_fee) - } else { - self.build_closing_transaction($new_fee, false) - }; - - let sig = self.context.holder_signer - .sign_closing_transaction(&closing_tx, &self.context.secp_ctx) - .map_err(|_| ChannelError::Close("External signer refused to sign closing transaction".to_owned()))?; + let sig = self.context.holder_signer + .sign_closing_transaction(&closing_tx, &self.context.secp_ctx) + .map_err(|_| ChannelError::Close("External signer refused to sign closing transaction".to_owned()))?; let signed_tx = if $new_fee == msg.fee_satoshis { self.context.channel_state = ChannelState::ShutdownComplete as u32; @@ -5368,972 +5036,1305 @@ impl Channel { // We never learned about the funding confirmation anyway, just ignore Ok(()) } - } + } + + // Methods to get unprompted messages to send to the remote end (or where we already returned + // something in the handler for the message that prompted this message): + + pub fn get_open_channel(&self, chain_hash: BlockHash) -> msgs::OpenChannel { + if !self.context.is_outbound() { + panic!("Tried to open a channel for an inbound channel?"); + } + if self.context.channel_state != ChannelState::OurInitSent as u32 { + panic!("Cannot generate an open_channel after we've moved forward"); + } + + if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { + panic!("Tried to send an open_channel for a channel that has already advanced"); + } + + let first_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); + let keys = self.context.get_holder_pubkeys(); + + msgs::OpenChannel { + chain_hash, + temporary_channel_id: self.context.channel_id, + funding_satoshis: self.context.channel_value_satoshis, + push_msat: self.context.channel_value_satoshis * 1000 - self.context.value_to_self_msat, + dust_limit_satoshis: self.context.holder_dust_limit_satoshis, + max_htlc_value_in_flight_msat: self.context.holder_max_htlc_value_in_flight_msat, + channel_reserve_satoshis: self.context.holder_selected_channel_reserve_satoshis, + htlc_minimum_msat: self.context.holder_htlc_minimum_msat, + feerate_per_kw: self.context.feerate_per_kw as u32, + to_self_delay: self.context.get_holder_selected_contest_delay(), + max_accepted_htlcs: self.context.holder_max_accepted_htlcs, + funding_pubkey: keys.funding_pubkey, + revocation_basepoint: keys.revocation_basepoint, + payment_point: keys.payment_point, + delayed_payment_basepoint: keys.delayed_payment_basepoint, + htlc_basepoint: keys.htlc_basepoint, + first_per_commitment_point, + channel_flags: if self.context.config.announced_channel {1} else {0}, + shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey { + Some(script) => script.clone().into_inner(), + None => Builder::new().into_script(), + }), + channel_type: Some(self.context.channel_type.clone()), + } + } + + pub fn inbound_is_awaiting_accept(&self) -> bool { + self.context.inbound_awaiting_accept + } + + /// Sets this channel to accepting 0conf, must be done before `get_accept_channel` + pub fn set_0conf(&mut self) { + assert!(self.context.inbound_awaiting_accept); + self.context.minimum_depth = Some(0); + } + + /// Marks an inbound channel as accepted and generates a [`msgs::AcceptChannel`] message which + /// should be sent back to the counterparty node. + /// + /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel + pub fn accept_inbound_channel(&mut self, user_id: u128) -> msgs::AcceptChannel { + if self.context.is_outbound() { + panic!("Tried to send accept_channel for an outbound channel?"); + } + if self.context.channel_state != (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32) { + panic!("Tried to send accept_channel after channel had moved forward"); + } + if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { + panic!("Tried to send an accept_channel for a channel that has already advanced"); + } + if !self.context.inbound_awaiting_accept { + panic!("The inbound channel has already been accepted"); + } + + self.context.user_id = user_id; + self.context.inbound_awaiting_accept = false; + + self.generate_accept_channel_message() + } + + /// This function is used to explicitly generate a [`msgs::AcceptChannel`] message for an + /// inbound channel. If the intention is to accept an inbound channel, use + /// [`Channel::accept_inbound_channel`] instead. + /// + /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel + fn generate_accept_channel_message(&self) -> msgs::AcceptChannel { + let first_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); + let keys = self.context.get_holder_pubkeys(); + + msgs::AcceptChannel { + temporary_channel_id: self.context.channel_id, + dust_limit_satoshis: self.context.holder_dust_limit_satoshis, + max_htlc_value_in_flight_msat: self.context.holder_max_htlc_value_in_flight_msat, + channel_reserve_satoshis: self.context.holder_selected_channel_reserve_satoshis, + htlc_minimum_msat: self.context.holder_htlc_minimum_msat, + minimum_depth: self.context.minimum_depth.unwrap(), + to_self_delay: self.context.get_holder_selected_contest_delay(), + max_accepted_htlcs: self.context.holder_max_accepted_htlcs, + funding_pubkey: keys.funding_pubkey, + revocation_basepoint: keys.revocation_basepoint, + payment_point: keys.payment_point, + delayed_payment_basepoint: keys.delayed_payment_basepoint, + htlc_basepoint: keys.htlc_basepoint, + first_per_commitment_point, + shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey { + Some(script) => script.clone().into_inner(), + None => Builder::new().into_script(), + }), + channel_type: Some(self.context.channel_type.clone()), + #[cfg(taproot)] + next_local_nonce: None, + } + } + + /// Enables the possibility for tests to extract a [`msgs::AcceptChannel`] message for an + /// inbound channel without accepting it. + /// + /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel + #[cfg(test)] + pub fn get_accept_channel_message(&self) -> msgs::AcceptChannel { + self.generate_accept_channel_message() + } + + /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created) + fn get_outbound_funding_created_signature(&mut self, logger: &L) -> Result where L::Target: Logger { + let counterparty_keys = self.context.build_remote_transaction_keys(); + let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx; + Ok(self.context.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx) + .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0) + } + + /// Updates channel state with knowledge of the funding transaction's txid/index, and generates + /// a funding_created message for the remote peer. + /// Panics if called at some time other than immediately after initial handshake, if called twice, + /// or if called on an inbound channel. + /// Note that channel_id changes during this call! + /// Do NOT broadcast the funding transaction until after a successful funding_signed call! + /// If an Err is returned, it is a ChannelError::Close. + pub fn get_outbound_funding_created(&mut self, funding_transaction: Transaction, funding_txo: OutPoint, logger: &L) -> Result where L::Target: Logger { + if !self.context.is_outbound() { + panic!("Tried to create outbound funding_created message on an inbound channel!"); + } + if self.context.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) { + panic!("Tried to get a funding_created messsage at a time other than immediately after initial handshake completion (or tried to get funding_created twice)"); + } + if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) || + self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER || + self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { + panic!("Should not have advanced channel commitment tx numbers prior to funding_created"); + } + + self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo); + self.context.holder_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); + + let signature = match self.get_outbound_funding_created_signature(logger) { + Ok(res) => res, + Err(e) => { + log_error!(logger, "Got bad signatures: {:?}!", e); + self.context.channel_transaction_parameters.funding_outpoint = None; + return Err(e); + } + }; + + let temporary_channel_id = self.context.channel_id; + + // Now that we're past error-generating stuff, update our local state: + + self.context.channel_state = ChannelState::FundingCreated as u32; + self.context.channel_id = funding_txo.to_channel_id(); + self.context.funding_transaction = Some(funding_transaction); + + Ok(msgs::FundingCreated { + temporary_channel_id, + funding_txid: funding_txo.txid, + funding_output_index: funding_txo.index, + signature, + #[cfg(taproot)] + partial_signature_with_nonce: None, + #[cfg(taproot)] + next_local_nonce: None, + }) + } + + /// Gets an UnsignedChannelAnnouncement for this channel. The channel must be publicly + /// announceable and available for use (have exchanged ChannelReady messages in both + /// directions). Should be used for both broadcasted announcements and in response to an + /// AnnouncementSignatures message from the remote peer. + /// + /// Will only fail if we're not in a state where channel_announcement may be sent (including + /// closing). + /// + /// This will only return ChannelError::Ignore upon failure. + fn get_channel_announcement( + &self, node_signer: &NS, chain_hash: BlockHash, user_config: &UserConfig, + ) -> Result where NS::Target: NodeSigner { + if !self.context.config.announced_channel { + return Err(ChannelError::Ignore("Channel is not available for public announcements".to_owned())); + } + if !self.context.is_usable() { + return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement if the channel is not currently usable".to_owned())); + } + + let node_id = NodeId::from_pubkey(&node_signer.get_node_id(Recipient::Node) + .map_err(|_| ChannelError::Ignore("Failed to retrieve own public key".to_owned()))?); + let counterparty_node_id = NodeId::from_pubkey(&self.context.get_counterparty_node_id()); + let were_node_one = node_id.as_slice() < counterparty_node_id.as_slice(); + + let msg = msgs::UnsignedChannelAnnouncement { + features: channelmanager::provided_channel_features(&user_config), + chain_hash, + short_channel_id: self.context.get_short_channel_id().unwrap(), + node_id_1: if were_node_one { node_id } else { counterparty_node_id }, + node_id_2: if were_node_one { counterparty_node_id } else { node_id }, + bitcoin_key_1: NodeId::from_pubkey(if were_node_one { &self.context.get_holder_pubkeys().funding_pubkey } else { self.context.counterparty_funding_pubkey() }), + bitcoin_key_2: NodeId::from_pubkey(if were_node_one { self.context.counterparty_funding_pubkey() } else { &self.context.get_holder_pubkeys().funding_pubkey }), + excess_data: Vec::new(), + }; + + Ok(msg) + } + + fn get_announcement_sigs( + &mut self, node_signer: &NS, genesis_block_hash: BlockHash, user_config: &UserConfig, + best_block_height: u32, logger: &L + ) -> Option + where + NS::Target: NodeSigner, + L::Target: Logger + { + if self.context.funding_tx_confirmation_height == 0 || self.context.funding_tx_confirmation_height + 5 > best_block_height { + return None; + } + + if !self.context.is_usable() { + return None; + } + + if self.context.channel_state & ChannelState::PeerDisconnected as u32 != 0 { + log_trace!(logger, "Cannot create an announcement_signatures as our peer is disconnected"); + return None; + } + + if self.context.announcement_sigs_state != AnnouncementSigsState::NotSent { + return None; + } + + log_trace!(logger, "Creating an announcement_signatures message for channel {}", log_bytes!(self.context.channel_id())); + let announcement = match self.get_channel_announcement(node_signer, genesis_block_hash, user_config) { + Ok(a) => a, + Err(e) => { + log_trace!(logger, "{:?}", e); + return None; + } + }; + let our_node_sig = match node_signer.sign_gossip_message(msgs::UnsignedGossipMessage::ChannelAnnouncement(&announcement)) { + Err(_) => { + log_error!(logger, "Failed to generate node signature for channel_announcement. Channel will not be announced!"); + return None; + }, + Ok(v) => v + }; + let our_bitcoin_sig = match self.context.holder_signer.sign_channel_announcement_with_funding_key(&announcement, &self.context.secp_ctx) { + Err(_) => { + log_error!(logger, "Signer rejected channel_announcement signing. Channel will not be announced!"); + return None; + }, + Ok(v) => v + }; + self.context.announcement_sigs_state = AnnouncementSigsState::MessageSent; + + Some(msgs::AnnouncementSignatures { + channel_id: self.context.channel_id(), + short_channel_id: self.context.get_short_channel_id().unwrap(), + node_signature: our_node_sig, + bitcoin_signature: our_bitcoin_sig, + }) + } + + /// Signs the given channel announcement, returning a ChannelError::Ignore if no keys are + /// available. + fn sign_channel_announcement( + &self, node_signer: &NS, announcement: msgs::UnsignedChannelAnnouncement + ) -> Result where NS::Target: NodeSigner { + if let Some((their_node_sig, their_bitcoin_sig)) = self.context.announcement_sigs { + let our_node_key = NodeId::from_pubkey(&node_signer.get_node_id(Recipient::Node) + .map_err(|_| ChannelError::Ignore("Signer failed to retrieve own public key".to_owned()))?); + let were_node_one = announcement.node_id_1 == our_node_key; + + let our_node_sig = node_signer.sign_gossip_message(msgs::UnsignedGossipMessage::ChannelAnnouncement(&announcement)) + .map_err(|_| ChannelError::Ignore("Failed to generate node signature for channel_announcement".to_owned()))?; + let our_bitcoin_sig = self.context.holder_signer.sign_channel_announcement_with_funding_key(&announcement, &self.context.secp_ctx) + .map_err(|_| ChannelError::Ignore("Signer rejected channel_announcement".to_owned()))?; + Ok(msgs::ChannelAnnouncement { + node_signature_1: if were_node_one { our_node_sig } else { their_node_sig }, + node_signature_2: if were_node_one { their_node_sig } else { our_node_sig }, + bitcoin_signature_1: if were_node_one { our_bitcoin_sig } else { their_bitcoin_sig }, + bitcoin_signature_2: if were_node_one { their_bitcoin_sig } else { our_bitcoin_sig }, + contents: announcement, + }) + } else { + Err(ChannelError::Ignore("Attempted to sign channel announcement before we'd received announcement_signatures".to_string())) + } + } + + /// Processes an incoming announcement_signatures message, providing a fully-signed + /// channel_announcement message which we can broadcast and storing our counterparty's + /// signatures for later reconstruction/rebroadcast of the channel_announcement. + pub fn announcement_signatures( + &mut self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32, + msg: &msgs::AnnouncementSignatures, user_config: &UserConfig + ) -> Result where NS::Target: NodeSigner { + let announcement = self.get_channel_announcement(node_signer, chain_hash, user_config)?; + + let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]); + + if self.context.secp_ctx.verify_ecdsa(&msghash, &msg.node_signature, &self.context.get_counterparty_node_id()).is_err() { + return Err(ChannelError::Close(format!( + "Bad announcement_signatures. Failed to verify node_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_node_key is {:?}", + &announcement, self.context.get_counterparty_node_id()))); + } + if self.context.secp_ctx.verify_ecdsa(&msghash, &msg.bitcoin_signature, self.context.counterparty_funding_pubkey()).is_err() { + return Err(ChannelError::Close(format!( + "Bad announcement_signatures. Failed to verify bitcoin_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_bitcoin_key is ({:?})", + &announcement, self.context.counterparty_funding_pubkey()))); + } + + self.context.announcement_sigs = Some((msg.node_signature, msg.bitcoin_signature)); + if self.context.funding_tx_confirmation_height == 0 || self.context.funding_tx_confirmation_height + 5 > best_block_height { + return Err(ChannelError::Ignore( + "Got announcement_signatures prior to the required six confirmations - we may not have received a block yet that our peer has".to_owned())); + } + + self.sign_channel_announcement(node_signer, announcement) + } + + /// Gets a signed channel_announcement for this channel, if we previously received an + /// announcement_signatures from our counterparty. + pub fn get_signed_channel_announcement( + &self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32, user_config: &UserConfig + ) -> Option where NS::Target: NodeSigner { + if self.context.funding_tx_confirmation_height == 0 || self.context.funding_tx_confirmation_height + 5 > best_block_height { + return None; + } + let announcement = match self.get_channel_announcement(node_signer, chain_hash, user_config) { + Ok(res) => res, + Err(_) => return None, + }; + match self.sign_channel_announcement(node_signer, announcement) { + Ok(res) => Some(res), + Err(_) => None, + } + } + + /// May panic if called on a channel that wasn't immediately-previously + /// self.remove_uncommitted_htlcs_and_mark_paused()'d + pub fn get_channel_reestablish(&mut self, logger: &L) -> msgs::ChannelReestablish where L::Target: Logger { + assert_eq!(self.context.channel_state & ChannelState::PeerDisconnected as u32, ChannelState::PeerDisconnected as u32); + assert_ne!(self.context.cur_counterparty_commitment_transaction_number, INITIAL_COMMITMENT_NUMBER); + // Prior to static_remotekey, my_current_per_commitment_point was critical to claiming + // current to_remote balances. However, it no longer has any use, and thus is now simply + // set to a dummy (but valid, as required by the spec) public key. + // fuzzing mode marks a subset of pubkeys as invalid so that we can hit "invalid pubkey" + // branches, but we unwrap it below, so we arbitrarily select a dummy pubkey which is both + // valid, and valid in fuzzing mode's arbitrary validity criteria: + let mut pk = [2; 33]; pk[1] = 0xff; + let dummy_pubkey = PublicKey::from_slice(&pk).unwrap(); + let remote_last_secret = if self.context.cur_counterparty_commitment_transaction_number + 1 < INITIAL_COMMITMENT_NUMBER { + let remote_last_secret = self.context.commitment_secrets.get_secret(self.context.cur_counterparty_commitment_transaction_number + 2).unwrap(); + log_trace!(logger, "Enough info to generate a Data Loss Protect with per_commitment_secret {} for channel {}", log_bytes!(remote_last_secret), log_bytes!(self.context.channel_id())); + remote_last_secret + } else { + log_info!(logger, "Sending a data_loss_protect with no previous remote per_commitment_secret for channel {}", log_bytes!(self.context.channel_id())); + [0;32] + }; + self.mark_awaiting_response(); + msgs::ChannelReestablish { + channel_id: self.context.channel_id(), + // The protocol has two different commitment number concepts - the "commitment + // transaction number", which starts from 0 and counts up, and the "revocation key + // index" which starts at INITIAL_COMMITMENT_NUMBER and counts down. We track + // commitment transaction numbers by the index which will be used to reveal the + // revocation key for that commitment transaction, which means we have to convert them + // to protocol-level commitment numbers here... + + // next_local_commitment_number is the next commitment_signed number we expect to + // receive (indicating if they need to resend one that we missed). + next_local_commitment_number: INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number, + // We have to set next_remote_commitment_number to the next revoke_and_ack we expect to + // receive, however we track it by the next commitment number for a remote transaction + // (which is one further, as they always revoke previous commitment transaction, not + // the one we send) so we have to decrement by 1. Note that if + // cur_counterparty_commitment_transaction_number is INITIAL_COMMITMENT_NUMBER we will have + // dropped this channel on disconnect as it hasn't yet reached FundingSent so we can't + // overflow here. + next_remote_commitment_number: INITIAL_COMMITMENT_NUMBER - self.context.cur_counterparty_commitment_transaction_number - 1, + your_last_per_commitment_secret: remote_last_secret, + my_current_per_commitment_point: dummy_pubkey, + // TODO(dual_funding): If we've sent `commtiment_signed` for an interactive transaction + // construction but have not received `tx_signatures` we MUST set `next_funding_txid` to the + // txid of that interactive transaction, else we MUST NOT set it. + next_funding_txid: None, + } + } + + + // Send stuff to our remote peers: + + /// Queues up an outbound HTLC to send by placing it in the holding cell. You should call + /// [`Self::maybe_free_holding_cell_htlcs`] in order to actually generate and send the + /// commitment update. + /// + /// `Err`s will only be [`ChannelError::Ignore`]. + pub fn queue_add_htlc(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, + onion_routing_packet: msgs::OnionPacket, logger: &L) + -> Result<(), ChannelError> where L::Target: Logger { + self + .send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet, true, logger) + .map(|msg_opt| assert!(msg_opt.is_none(), "We forced holding cell?")) + .map_err(|err| { + if let ChannelError::Ignore(_) = err { /* fine */ } + else { debug_assert!(false, "Queueing cannot trigger channel failure"); } + err + }) + } + + /// Adds a pending outbound HTLC to this channel, note that you probably want + /// [`Self::send_htlc_and_commit`] instead cause you'll want both messages at once. + /// + /// This returns an optional UpdateAddHTLC as we may be in a state where we cannot add HTLCs on + /// the wire: + /// * In cases where we're waiting on the remote peer to send us a revoke_and_ack, we + /// wouldn't be able to determine what they actually ACK'ed if we have two sets of updates + /// awaiting ACK. + /// * In cases where we're marked MonitorUpdateInProgress, we cannot commit to a new state as + /// we may not yet have sent the previous commitment update messages and will need to + /// regenerate them. + /// + /// You MUST call [`Self::send_commitment_no_state_update`] prior to calling any other methods + /// on this [`Channel`] if `force_holding_cell` is false. + /// + /// `Err`s will only be [`ChannelError::Ignore`]. + fn send_htlc(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, + onion_routing_packet: msgs::OnionPacket, mut force_holding_cell: bool, logger: &L) + -> Result, ChannelError> where L::Target: Logger { + if (self.context.channel_state & (ChannelState::ChannelReady as u32 | BOTH_SIDES_SHUTDOWN_MASK)) != (ChannelState::ChannelReady as u32) { + return Err(ChannelError::Ignore("Cannot send HTLC until channel is fully established and we haven't started shutting down".to_owned())); + } + let channel_total_msat = self.context.channel_value_satoshis * 1000; + if amount_msat > channel_total_msat { + return Err(ChannelError::Ignore(format!("Cannot send amount {}, because it is more than the total value of the channel {}", amount_msat, channel_total_msat))); + } - // Methods to get unprompted messages to send to the remote end (or where we already returned - // something in the handler for the message that prompted this message): + if amount_msat == 0 { + return Err(ChannelError::Ignore("Cannot send 0-msat HTLC".to_owned())); + } - pub fn get_open_channel(&self, chain_hash: BlockHash) -> msgs::OpenChannel { - if !self.context.is_outbound() { - panic!("Tried to open a channel for an inbound channel?"); + let available_balances = self.context.get_available_balances(); + if amount_msat < available_balances.next_outbound_htlc_minimum_msat { + return Err(ChannelError::Ignore(format!("Cannot send less than our next-HTLC minimum - {} msat", + available_balances.next_outbound_htlc_minimum_msat))); } - if self.context.channel_state != ChannelState::OurInitSent as u32 { - panic!("Cannot generate an open_channel after we've moved forward"); + + if amount_msat > available_balances.next_outbound_htlc_limit_msat { + return Err(ChannelError::Ignore(format!("Cannot send more than our next-HTLC maximum - {} msat", + available_balances.next_outbound_htlc_limit_msat))); } - if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { - panic!("Tried to send an open_channel for a channel that has already advanced"); + if (self.context.channel_state & (ChannelState::PeerDisconnected as u32)) != 0 { + // Note that this should never really happen, if we're !is_live() on receipt of an + // incoming HTLC for relay will result in us rejecting the HTLC and we won't allow + // the user to send directly into a !is_live() channel. However, if we + // disconnected during the time the previous hop was doing the commitment dance we may + // end up getting here after the forwarding delay. In any case, returning an + // IgnoreError will get ChannelManager to do the right thing and fail backwards now. + return Err(ChannelError::Ignore("Cannot send an HTLC while disconnected from channel counterparty".to_owned())); } - let first_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); - let keys = self.context.get_holder_pubkeys(); + let need_holding_cell = (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0; + log_debug!(logger, "Pushing new outbound HTLC for {} msat {}", amount_msat, + if force_holding_cell { "into holding cell" } + else if need_holding_cell { "into holding cell as we're awaiting an RAA or monitor" } + else { "to peer" }); - msgs::OpenChannel { - chain_hash, - temporary_channel_id: self.context.channel_id, - funding_satoshis: self.context.channel_value_satoshis, - push_msat: self.context.channel_value_satoshis * 1000 - self.context.value_to_self_msat, - dust_limit_satoshis: self.context.holder_dust_limit_satoshis, - max_htlc_value_in_flight_msat: self.context.holder_max_htlc_value_in_flight_msat, - channel_reserve_satoshis: self.context.holder_selected_channel_reserve_satoshis, - htlc_minimum_msat: self.context.holder_htlc_minimum_msat, - feerate_per_kw: self.context.feerate_per_kw as u32, - to_self_delay: self.context.get_holder_selected_contest_delay(), - max_accepted_htlcs: self.context.holder_max_accepted_htlcs, - funding_pubkey: keys.funding_pubkey, - revocation_basepoint: keys.revocation_basepoint, - payment_point: keys.payment_point, - delayed_payment_basepoint: keys.delayed_payment_basepoint, - htlc_basepoint: keys.htlc_basepoint, - first_per_commitment_point, - channel_flags: if self.context.config.announced_channel {1} else {0}, - shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey { - Some(script) => script.clone().into_inner(), - None => Builder::new().into_script(), - }), - channel_type: Some(self.context.channel_type.clone()), + if need_holding_cell { + force_holding_cell = true; } - } - pub fn inbound_is_awaiting_accept(&self) -> bool { - self.context.inbound_awaiting_accept - } + // Now update local state: + if force_holding_cell { + self.context.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::AddHTLC { + amount_msat, + payment_hash, + cltv_expiry, + source, + onion_routing_packet, + }); + return Ok(None); + } - /// Sets this channel to accepting 0conf, must be done before `get_accept_channel` - pub fn set_0conf(&mut self) { - assert!(self.context.inbound_awaiting_accept); - self.context.minimum_depth = Some(0); + self.context.pending_outbound_htlcs.push(OutboundHTLCOutput { + htlc_id: self.context.next_holder_htlc_id, + amount_msat, + payment_hash: payment_hash.clone(), + cltv_expiry, + state: OutboundHTLCState::LocalAnnounced(Box::new(onion_routing_packet.clone())), + source, + }); + + let res = msgs::UpdateAddHTLC { + channel_id: self.context.channel_id, + htlc_id: self.context.next_holder_htlc_id, + amount_msat, + payment_hash, + cltv_expiry, + onion_routing_packet, + }; + self.context.next_holder_htlc_id += 1; + + Ok(Some(res)) } - /// Marks an inbound channel as accepted and generates a [`msgs::AcceptChannel`] message which - /// should be sent back to the counterparty node. - /// - /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel - pub fn accept_inbound_channel(&mut self, user_id: u128) -> msgs::AcceptChannel { - if self.context.is_outbound() { - panic!("Tried to send accept_channel for an outbound channel?"); - } - if self.context.channel_state != (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32) { - panic!("Tried to send accept_channel after channel had moved forward"); + fn build_commitment_no_status_check(&mut self, logger: &L) -> ChannelMonitorUpdate where L::Target: Logger { + log_trace!(logger, "Updating HTLC state for a newly-sent commitment_signed..."); + // We can upgrade the status of some HTLCs that are waiting on a commitment, even if we + // fail to generate this, we still are at least at a position where upgrading their status + // is acceptable. + for htlc in self.context.pending_inbound_htlcs.iter_mut() { + let new_state = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(ref forward_info) = &htlc.state { + Some(InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info.clone())) + } else { None }; + if let Some(state) = new_state { + log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); + htlc.state = state; + } } - if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { - panic!("Tried to send an accept_channel for a channel that has already advanced"); + for htlc in self.context.pending_outbound_htlcs.iter_mut() { + if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut outcome) = &mut htlc.state { + log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); + // Grab the preimage, if it exists, instead of cloning + let mut reason = OutboundHTLCOutcome::Success(None); + mem::swap(outcome, &mut reason); + htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(reason); + } } - if !self.context.inbound_awaiting_accept { - panic!("The inbound channel has already been accepted"); + if let Some((feerate, update_state)) = self.context.pending_update_fee { + if update_state == FeeUpdateState::AwaitingRemoteRevokeToAnnounce { + debug_assert!(!self.context.is_outbound()); + log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate); + self.context.feerate_per_kw = feerate; + self.context.pending_update_fee = None; + } } + self.context.resend_order = RAACommitmentOrder::RevokeAndACKFirst; - self.context.user_id = user_id; - self.context.inbound_awaiting_accept = false; - - self.generate_accept_channel_message() - } - - /// This function is used to explicitly generate a [`msgs::AcceptChannel`] message for an - /// inbound channel. If the intention is to accept an inbound channel, use - /// [`Channel::accept_inbound_channel`] instead. - /// - /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel - fn generate_accept_channel_message(&self) -> msgs::AcceptChannel { - let first_per_commitment_point = self.context.holder_signer.get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); - let keys = self.context.get_holder_pubkeys(); + let (counterparty_commitment_txid, mut htlcs_ref) = self.build_commitment_no_state_update(logger); + let htlcs: Vec<(HTLCOutputInCommitment, Option>)> = + htlcs_ref.drain(..).map(|(htlc, htlc_source)| (htlc, htlc_source.map(|source_ref| Box::new(source_ref.clone())))).collect(); - msgs::AcceptChannel { - temporary_channel_id: self.context.channel_id, - dust_limit_satoshis: self.context.holder_dust_limit_satoshis, - max_htlc_value_in_flight_msat: self.context.holder_max_htlc_value_in_flight_msat, - channel_reserve_satoshis: self.context.holder_selected_channel_reserve_satoshis, - htlc_minimum_msat: self.context.holder_htlc_minimum_msat, - minimum_depth: self.context.minimum_depth.unwrap(), - to_self_delay: self.context.get_holder_selected_contest_delay(), - max_accepted_htlcs: self.context.holder_max_accepted_htlcs, - funding_pubkey: keys.funding_pubkey, - revocation_basepoint: keys.revocation_basepoint, - payment_point: keys.payment_point, - delayed_payment_basepoint: keys.delayed_payment_basepoint, - htlc_basepoint: keys.htlc_basepoint, - first_per_commitment_point, - shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey { - Some(script) => script.clone().into_inner(), - None => Builder::new().into_script(), - }), - channel_type: Some(self.context.channel_type.clone()), - #[cfg(taproot)] - next_local_nonce: None, + if self.context.announcement_sigs_state == AnnouncementSigsState::MessageSent { + self.context.announcement_sigs_state = AnnouncementSigsState::Committed; } - } - /// Enables the possibility for tests to extract a [`msgs::AcceptChannel`] message for an - /// inbound channel without accepting it. - /// - /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel - #[cfg(test)] - pub fn get_accept_channel_message(&self) -> msgs::AcceptChannel { - self.generate_accept_channel_message() + self.context.latest_monitor_update_id += 1; + let monitor_update = ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { + commitment_txid: counterparty_commitment_txid, + htlc_outputs: htlcs.clone(), + commitment_number: self.context.cur_counterparty_commitment_transaction_number, + their_per_commitment_point: self.context.counterparty_cur_commitment_point.unwrap() + }] + }; + self.context.channel_state |= ChannelState::AwaitingRemoteRevoke as u32; + monitor_update } - /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created) - fn get_outbound_funding_created_signature(&mut self, logger: &L) -> Result where L::Target: Logger { + fn build_commitment_no_state_update(&self, logger: &L) -> (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>) where L::Target: Logger { let counterparty_keys = self.context.build_remote_transaction_keys(); - let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx; - Ok(self.context.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx) - .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0) - } + let commitment_stats = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger); + let counterparty_commitment_txid = commitment_stats.tx.trust().txid(); - /// Updates channel state with knowledge of the funding transaction's txid/index, and generates - /// a funding_created message for the remote peer. - /// Panics if called at some time other than immediately after initial handshake, if called twice, - /// or if called on an inbound channel. - /// Note that channel_id changes during this call! - /// Do NOT broadcast the funding transaction until after a successful funding_signed call! - /// If an Err is returned, it is a ChannelError::Close. - pub fn get_outbound_funding_created(&mut self, funding_transaction: Transaction, funding_txo: OutPoint, logger: &L) -> Result where L::Target: Logger { - if !self.context.is_outbound() { - panic!("Tried to create outbound funding_created message on an inbound channel!"); - } - if self.context.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) { - panic!("Tried to get a funding_created messsage at a time other than immediately after initial handshake completion (or tried to get funding_created twice)"); - } - if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) || - self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER || - self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { - panic!("Should not have advanced channel commitment tx numbers prior to funding_created"); + #[cfg(any(test, fuzzing))] + { + if !self.context.is_outbound() { + let projected_commit_tx_info = self.context.next_remote_commitment_tx_fee_info_cached.lock().unwrap().take(); + *self.context.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None; + if let Some(info) = projected_commit_tx_info { + let total_pending_htlcs = self.context.pending_inbound_htlcs.len() + self.context.pending_outbound_htlcs.len(); + if info.total_pending_htlcs == total_pending_htlcs + && info.next_holder_htlc_id == self.context.next_holder_htlc_id + && info.next_counterparty_htlc_id == self.context.next_counterparty_htlc_id + && info.feerate == self.context.feerate_per_kw { + let actual_fee = commit_tx_fee_msat(self.context.feerate_per_kw, commitment_stats.num_nondust_htlcs, self.context.opt_anchors()); + assert_eq!(actual_fee, info.fee); + } + } + } } - self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo); - self.context.holder_signer.provide_channel_parameters(&self.context.channel_transaction_parameters); + (counterparty_commitment_txid, commitment_stats.htlcs_included) + } + + /// Only fails in case of signer rejection. Used for channel_reestablish commitment_signed + /// generation when we shouldn't change HTLC/channel state. + fn send_commitment_no_state_update(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger { + // Get the fee tests from `build_commitment_no_state_update` + #[cfg(any(test, fuzzing))] + self.build_commitment_no_state_update(logger); + + let counterparty_keys = self.context.build_remote_transaction_keys(); + let commitment_stats = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger); + let counterparty_commitment_txid = commitment_stats.tx.trust().txid(); + let (signature, htlc_signatures); - let signature = match self.get_outbound_funding_created_signature(logger) { - Ok(res) => res, - Err(e) => { - log_error!(logger, "Got bad signatures: {:?}!", e); - self.context.channel_transaction_parameters.funding_outpoint = None; - return Err(e); + { + let mut htlcs = Vec::with_capacity(commitment_stats.htlcs_included.len()); + for &(ref htlc, _) in commitment_stats.htlcs_included.iter() { + htlcs.push(htlc); } - }; - let temporary_channel_id = self.context.channel_id; + let res = self.context.holder_signer.sign_counterparty_commitment(&commitment_stats.tx, commitment_stats.preimages, &self.context.secp_ctx) + .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?; + signature = res.0; + htlc_signatures = res.1; - // Now that we're past error-generating stuff, update our local state: + log_trace!(logger, "Signed remote commitment tx {} (txid {}) with redeemscript {} -> {} in channel {}", + encode::serialize_hex(&commitment_stats.tx.trust().built_transaction().transaction), + &counterparty_commitment_txid, encode::serialize_hex(&self.context.get_funding_redeemscript()), + log_bytes!(signature.serialize_compact()[..]), log_bytes!(self.context.channel_id())); - self.context.channel_state = ChannelState::FundingCreated as u32; - self.context.channel_id = funding_txo.to_channel_id(); - self.context.funding_transaction = Some(funding_transaction); + for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(htlcs) { + log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}", + encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.context.get_holder_selected_contest_delay(), htlc, self.context.opt_anchors(), false, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)), + encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, self.context.opt_anchors(), &counterparty_keys)), + log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()), + log_bytes!(htlc_sig.serialize_compact()[..]), log_bytes!(self.context.channel_id())); + } + } - Ok(msgs::FundingCreated { - temporary_channel_id, - funding_txid: funding_txo.txid, - funding_output_index: funding_txo.index, + Ok((msgs::CommitmentSigned { + channel_id: self.context.channel_id, signature, + htlc_signatures, #[cfg(taproot)] partial_signature_with_nonce: None, - #[cfg(taproot)] - next_local_nonce: None, - }) + }, (counterparty_commitment_txid, commitment_stats.htlcs_included))) } - /// Gets an UnsignedChannelAnnouncement for this channel. The channel must be publicly - /// announceable and available for use (have exchanged ChannelReady messages in both - /// directions). Should be used for both broadcasted announcements and in response to an - /// AnnouncementSignatures message from the remote peer. - /// - /// Will only fail if we're not in a state where channel_announcement may be sent (including - /// closing). + /// Adds a pending outbound HTLC to this channel, and builds a new remote commitment + /// transaction and generates the corresponding [`ChannelMonitorUpdate`] in one go. /// - /// This will only return ChannelError::Ignore upon failure. - fn get_channel_announcement( - &self, node_signer: &NS, chain_hash: BlockHash, user_config: &UserConfig, - ) -> Result where NS::Target: NodeSigner { - if !self.context.config.announced_channel { - return Err(ChannelError::Ignore("Channel is not available for public announcements".to_owned())); - } - if !self.context.is_usable() { - return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement if the channel is not currently usable".to_owned())); + /// Shorthand for calling [`Self::send_htlc`] followed by a commitment update, see docs on + /// [`Self::send_htlc`] and [`Self::build_commitment_no_state_update`] for more info. + pub fn send_htlc_and_commit(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket, logger: &L) -> Result, ChannelError> where L::Target: Logger { + let send_res = self.send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet, false, logger); + if let Err(e) = &send_res { if let ChannelError::Ignore(_) = e {} else { debug_assert!(false, "Sending cannot trigger channel failure"); } } + match send_res? { + Some(_) => { + let monitor_update = self.build_commitment_no_status_check(logger); + self.monitor_updating_paused(false, true, false, Vec::new(), Vec::new(), Vec::new()); + Ok(self.push_ret_blockable_mon_update(monitor_update)) + }, + None => Ok(None) } + } - let node_id = NodeId::from_pubkey(&node_signer.get_node_id(Recipient::Node) - .map_err(|_| ChannelError::Ignore("Failed to retrieve own public key".to_owned()))?); - let counterparty_node_id = NodeId::from_pubkey(&self.context.get_counterparty_node_id()); - let were_node_one = node_id.as_slice() < counterparty_node_id.as_slice(); - - let msg = msgs::UnsignedChannelAnnouncement { - features: channelmanager::provided_channel_features(&user_config), - chain_hash, - short_channel_id: self.context.get_short_channel_id().unwrap(), - node_id_1: if were_node_one { node_id } else { counterparty_node_id }, - node_id_2: if were_node_one { counterparty_node_id } else { node_id }, - bitcoin_key_1: NodeId::from_pubkey(if were_node_one { &self.context.get_holder_pubkeys().funding_pubkey } else { self.context.counterparty_funding_pubkey() }), - bitcoin_key_2: NodeId::from_pubkey(if were_node_one { self.context.counterparty_funding_pubkey() } else { &self.context.get_holder_pubkeys().funding_pubkey }), - excess_data: Vec::new(), - }; + pub fn channel_update(&mut self, msg: &msgs::ChannelUpdate) -> Result<(), ChannelError> { + if msg.contents.htlc_minimum_msat >= self.context.channel_value_satoshis * 1000 { + return Err(ChannelError::Close("Minimum htlc value is greater than channel value".to_string())); + } + self.context.counterparty_forwarding_info = Some(CounterpartyForwardingInfo { + fee_base_msat: msg.contents.fee_base_msat, + fee_proportional_millionths: msg.contents.fee_proportional_millionths, + cltv_expiry_delta: msg.contents.cltv_expiry_delta + }); - Ok(msg) + Ok(()) } - fn get_announcement_sigs( - &mut self, node_signer: &NS, genesis_block_hash: BlockHash, user_config: &UserConfig, - best_block_height: u32, logger: &L - ) -> Option - where - NS::Target: NodeSigner, - L::Target: Logger - { - if self.context.funding_tx_confirmation_height == 0 || self.context.funding_tx_confirmation_height + 5 > best_block_height { - return None; + /// Begins the shutdown process, getting a message for the remote peer and returning all + /// holding cell HTLCs for payment failure. + /// + /// May jump to the channel being fully shutdown (see [`Self::is_shutdown`]) in which case no + /// [`ChannelMonitorUpdate`] will be returned). + pub fn get_shutdown(&mut self, signer_provider: &SP, their_features: &InitFeatures, + target_feerate_sats_per_kw: Option, override_shutdown_script: Option) + -> Result<(msgs::Shutdown, Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError> + where SP::Target: SignerProvider { + for htlc in self.context.pending_outbound_htlcs.iter() { + if let OutboundHTLCState::LocalAnnounced(_) = htlc.state { + return Err(APIError::APIMisuseError{err: "Cannot begin shutdown with pending HTLCs. Process pending events first".to_owned()}); + } } - - if !self.context.is_usable() { - return None; + if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK != 0 { + if (self.context.channel_state & ChannelState::LocalShutdownSent as u32) == ChannelState::LocalShutdownSent as u32 { + return Err(APIError::APIMisuseError{err: "Shutdown already in progress".to_owned()}); + } + else if (self.context.channel_state & ChannelState::RemoteShutdownSent as u32) == ChannelState::RemoteShutdownSent as u32 { + return Err(APIError::ChannelUnavailable{err: "Shutdown already in progress by remote".to_owned()}); + } } - - if self.context.channel_state & ChannelState::PeerDisconnected as u32 != 0 { - log_trace!(logger, "Cannot create an announcement_signatures as our peer is disconnected"); - return None; + if self.context.shutdown_scriptpubkey.is_some() && override_shutdown_script.is_some() { + return Err(APIError::APIMisuseError{err: "Cannot override shutdown script for a channel with one already set".to_owned()}); + } + assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); + if self.context.channel_state & (ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32) != 0 { + return Err(APIError::ChannelUnavailable{err: "Cannot begin shutdown while peer is disconnected or we're waiting on a monitor update, maybe force-close instead?".to_owned()}); } - if self.context.announcement_sigs_state != AnnouncementSigsState::NotSent { - return None; + // If we haven't funded the channel yet, we don't need to bother ensuring the shutdown + // script is set, we just force-close and call it a day. + let mut chan_closed = false; + if self.context.channel_state < ChannelState::FundingSent as u32 { + chan_closed = true; } - log_trace!(logger, "Creating an announcement_signatures message for channel {}", log_bytes!(self.context.channel_id())); - let announcement = match self.get_channel_announcement(node_signer, genesis_block_hash, user_config) { - Ok(a) => a, - Err(e) => { - log_trace!(logger, "{:?}", e); - return None; - } - }; - let our_node_sig = match node_signer.sign_gossip_message(msgs::UnsignedGossipMessage::ChannelAnnouncement(&announcement)) { - Err(_) => { - log_error!(logger, "Failed to generate node signature for channel_announcement. Channel will not be announced!"); - return None; - }, - Ok(v) => v - }; - let our_bitcoin_sig = match self.context.holder_signer.sign_channel_announcement_with_funding_key(&announcement, &self.context.secp_ctx) { - Err(_) => { - log_error!(logger, "Signer rejected channel_announcement signing. Channel will not be announced!"); - return None; + let update_shutdown_script = match self.context.shutdown_scriptpubkey { + Some(_) => false, + None if !chan_closed => { + // use override shutdown script if provided + let shutdown_scriptpubkey = match override_shutdown_script { + Some(script) => script, + None => { + // otherwise, use the shutdown scriptpubkey provided by the signer + match signer_provider.get_shutdown_scriptpubkey() { + Ok(scriptpubkey) => scriptpubkey, + Err(_) => return Err(APIError::ChannelUnavailable{err: "Failed to get shutdown scriptpubkey".to_owned()}), + } + }, + }; + if !shutdown_scriptpubkey.is_compatible(their_features) { + return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() }); + } + self.context.shutdown_scriptpubkey = Some(shutdown_scriptpubkey); + true }, - Ok(v) => v + None => false, }; - self.context.announcement_sigs_state = AnnouncementSigsState::MessageSent; - - Some(msgs::AnnouncementSignatures { - channel_id: self.context.channel_id(), - short_channel_id: self.context.get_short_channel_id().unwrap(), - node_signature: our_node_sig, - bitcoin_signature: our_bitcoin_sig, - }) - } - - /// Signs the given channel announcement, returning a ChannelError::Ignore if no keys are - /// available. - fn sign_channel_announcement( - &self, node_signer: &NS, announcement: msgs::UnsignedChannelAnnouncement - ) -> Result where NS::Target: NodeSigner { - if let Some((their_node_sig, their_bitcoin_sig)) = self.context.announcement_sigs { - let our_node_key = NodeId::from_pubkey(&node_signer.get_node_id(Recipient::Node) - .map_err(|_| ChannelError::Ignore("Signer failed to retrieve own public key".to_owned()))?); - let were_node_one = announcement.node_id_1 == our_node_key; - let our_node_sig = node_signer.sign_gossip_message(msgs::UnsignedGossipMessage::ChannelAnnouncement(&announcement)) - .map_err(|_| ChannelError::Ignore("Failed to generate node signature for channel_announcement".to_owned()))?; - let our_bitcoin_sig = self.context.holder_signer.sign_channel_announcement_with_funding_key(&announcement, &self.context.secp_ctx) - .map_err(|_| ChannelError::Ignore("Signer rejected channel_announcement".to_owned()))?; - Ok(msgs::ChannelAnnouncement { - node_signature_1: if were_node_one { our_node_sig } else { their_node_sig }, - node_signature_2: if were_node_one { their_node_sig } else { our_node_sig }, - bitcoin_signature_1: if were_node_one { our_bitcoin_sig } else { their_bitcoin_sig }, - bitcoin_signature_2: if were_node_one { their_bitcoin_sig } else { our_bitcoin_sig }, - contents: announcement, - }) + // From here on out, we may not fail! + self.context.target_closing_feerate_sats_per_kw = target_feerate_sats_per_kw; + if self.context.channel_state < ChannelState::FundingSent as u32 { + self.context.channel_state = ChannelState::ShutdownComplete as u32; } else { - Err(ChannelError::Ignore("Attempted to sign channel announcement before we'd received announcement_signatures".to_string())) + self.context.channel_state |= ChannelState::LocalShutdownSent as u32; } - } + self.context.update_time_counter += 1; + + let monitor_update = if update_shutdown_script { + self.context.latest_monitor_update_id += 1; + let monitor_update = ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::ShutdownScript { + scriptpubkey: self.get_closing_scriptpubkey(), + }], + }; + self.monitor_updating_paused(false, false, false, Vec::new(), Vec::new(), Vec::new()); + if self.push_blockable_mon_update(monitor_update) { + self.context.pending_monitor_updates.last().map(|upd| &upd.update) + } else { None } + } else { None }; + let shutdown = msgs::Shutdown { + channel_id: self.context.channel_id, + scriptpubkey: self.get_closing_scriptpubkey(), + }; - /// Processes an incoming announcement_signatures message, providing a fully-signed - /// channel_announcement message which we can broadcast and storing our counterparty's - /// signatures for later reconstruction/rebroadcast of the channel_announcement. - pub fn announcement_signatures( - &mut self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32, - msg: &msgs::AnnouncementSignatures, user_config: &UserConfig - ) -> Result where NS::Target: NodeSigner { - let announcement = self.get_channel_announcement(node_signer, chain_hash, user_config)?; + // Go ahead and drop holding cell updates as we'd rather fail payments than wait to send + // our shutdown until we've committed all of the pending changes. + self.context.holding_cell_update_fee = None; + let mut dropped_outbound_htlcs = Vec::with_capacity(self.context.holding_cell_htlc_updates.len()); + self.context.holding_cell_htlc_updates.retain(|htlc_update| { + match htlc_update { + &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => { + dropped_outbound_htlcs.push((source.clone(), payment_hash.clone())); + false + }, + _ => true + } + }); - let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]); + debug_assert!(!self.is_shutdown() || monitor_update.is_none(), + "we can't both complete shutdown and return a monitor update"); - if self.context.secp_ctx.verify_ecdsa(&msghash, &msg.node_signature, &self.context.get_counterparty_node_id()).is_err() { - return Err(ChannelError::Close(format!( - "Bad announcement_signatures. Failed to verify node_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_node_key is {:?}", - &announcement, self.context.get_counterparty_node_id()))); - } - if self.context.secp_ctx.verify_ecdsa(&msghash, &msg.bitcoin_signature, self.context.counterparty_funding_pubkey()).is_err() { - return Err(ChannelError::Close(format!( - "Bad announcement_signatures. Failed to verify bitcoin_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_bitcoin_key is ({:?})", - &announcement, self.context.counterparty_funding_pubkey()))); - } + Ok((shutdown, monitor_update, dropped_outbound_htlcs)) + } - self.context.announcement_sigs = Some((msg.node_signature, msg.bitcoin_signature)); - if self.context.funding_tx_confirmation_height == 0 || self.context.funding_tx_confirmation_height + 5 > best_block_height { - return Err(ChannelError::Ignore( - "Got announcement_signatures prior to the required six confirmations - we may not have received a block yet that our peer has".to_owned())); + /// Gets the latest commitment transaction and any dependent transactions for relay (forcing + /// shutdown of this channel - no more calls into this Channel may be made afterwards except + /// those explicitly stated to be allowed after shutdown completes, eg some simple getters). + /// Also returns the list of payment_hashes for channels which we can safely fail backwards + /// immediately (others we will have to allow to time out). + pub fn force_shutdown(&mut self, should_broadcast: bool) -> ShutdownResult { + // Note that we MUST only generate a monitor update that indicates force-closure - we're + // called during initialization prior to the chain_monitor in the encompassing ChannelManager + // being fully configured in some cases. Thus, its likely any monitor events we generate will + // be delayed in being processed! See the docs for `ChannelManagerReadArgs` for more. + assert!(self.context.channel_state != ChannelState::ShutdownComplete as u32); + + // We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and + // return them to fail the payment. + let mut dropped_outbound_htlcs = Vec::with_capacity(self.context.holding_cell_htlc_updates.len()); + let counterparty_node_id = self.context.get_counterparty_node_id(); + for htlc_update in self.context.holding_cell_htlc_updates.drain(..) { + match htlc_update { + HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } => { + dropped_outbound_htlcs.push((source, payment_hash, counterparty_node_id, self.context.channel_id)); + }, + _ => {} + } } + let monitor_update = if let Some(funding_txo) = self.context.get_funding_txo() { + // If we haven't yet exchanged funding signatures (ie channel_state < FundingSent), + // returning a channel monitor update here would imply a channel monitor update before + // we even registered the channel monitor to begin with, which is invalid. + // Thus, if we aren't actually at a point where we could conceivably broadcast the + // funding transaction, don't return a funding txo (which prevents providing the + // monitor update to the user, even if we return one). + // See test_duplicate_chan_id and test_pre_lockin_no_chan_closed_update for more. + if self.context.channel_state & (ChannelState::FundingSent as u32 | ChannelState::ChannelReady as u32 | ChannelState::ShutdownComplete as u32) != 0 { + self.context.latest_monitor_update_id = CLOSED_CHANNEL_UPDATE_ID; + Some((self.context.get_counterparty_node_id(), funding_txo, ChannelMonitorUpdate { + update_id: self.context.latest_monitor_update_id, + updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast }], + })) + } else { None } + } else { None }; - self.sign_channel_announcement(node_signer, announcement) + self.context.channel_state = ChannelState::ShutdownComplete as u32; + self.context.update_time_counter += 1; + (monitor_update, dropped_outbound_htlcs) } - /// Gets a signed channel_announcement for this channel, if we previously received an - /// announcement_signatures from our counterparty. - pub fn get_signed_channel_announcement( - &self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32, user_config: &UserConfig - ) -> Option where NS::Target: NodeSigner { - if self.context.funding_tx_confirmation_height == 0 || self.context.funding_tx_confirmation_height + 5 > best_block_height { - return None; - } - let announcement = match self.get_channel_announcement(node_signer, chain_hash, user_config) { - Ok(res) => res, - Err(_) => return None, - }; - match self.sign_channel_announcement(node_signer, announcement) { - Ok(res) => Some(res), - Err(_) => None, - } + pub fn inflight_htlc_sources(&self) -> impl Iterator { + self.context.holding_cell_htlc_updates.iter() + .flat_map(|htlc_update| { + match htlc_update { + HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } + => Some((source, payment_hash)), + _ => None, + } + }) + .chain(self.context.pending_outbound_htlcs.iter().map(|htlc| (&htlc.source, &htlc.payment_hash))) } +} - /// May panic if called on a channel that wasn't immediately-previously - /// self.remove_uncommitted_htlcs_and_mark_paused()'d - pub fn get_channel_reestablish(&mut self, logger: &L) -> msgs::ChannelReestablish where L::Target: Logger { - assert_eq!(self.context.channel_state & ChannelState::PeerDisconnected as u32, ChannelState::PeerDisconnected as u32); - assert_ne!(self.context.cur_counterparty_commitment_transaction_number, INITIAL_COMMITMENT_NUMBER); - // Prior to static_remotekey, my_current_per_commitment_point was critical to claiming - // current to_remote balances. However, it no longer has any use, and thus is now simply - // set to a dummy (but valid, as required by the spec) public key. - // fuzzing mode marks a subset of pubkeys as invalid so that we can hit "invalid pubkey" - // branches, but we unwrap it below, so we arbitrarily select a dummy pubkey which is both - // valid, and valid in fuzzing mode's arbitrary validity criteria: - let mut pk = [2; 33]; pk[1] = 0xff; - let dummy_pubkey = PublicKey::from_slice(&pk).unwrap(); - let remote_last_secret = if self.context.cur_counterparty_commitment_transaction_number + 1 < INITIAL_COMMITMENT_NUMBER { - let remote_last_secret = self.context.commitment_secrets.get_secret(self.context.cur_counterparty_commitment_transaction_number + 2).unwrap(); - log_trace!(logger, "Enough info to generate a Data Loss Protect with per_commitment_secret {} for channel {}", log_bytes!(remote_last_secret), log_bytes!(self.context.channel_id())); - remote_last_secret - } else { - log_info!(logger, "Sending a data_loss_protect with no previous remote per_commitment_secret for channel {}", log_bytes!(self.context.channel_id())); - [0;32] - }; - self.mark_awaiting_response(); - msgs::ChannelReestablish { - channel_id: self.context.channel_id(), - // The protocol has two different commitment number concepts - the "commitment - // transaction number", which starts from 0 and counts up, and the "revocation key - // index" which starts at INITIAL_COMMITMENT_NUMBER and counts down. We track - // commitment transaction numbers by the index which will be used to reveal the - // revocation key for that commitment transaction, which means we have to convert them - // to protocol-level commitment numbers here... +/// A not-yet-funded outbound (from holder) channel using V1 channel establishment. +pub(super) struct OutboundV1Channel { + pub context: ChannelContext, +} - // next_local_commitment_number is the next commitment_signed number we expect to - // receive (indicating if they need to resend one that we missed). - next_local_commitment_number: INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number, - // We have to set next_remote_commitment_number to the next revoke_and_ack we expect to - // receive, however we track it by the next commitment number for a remote transaction - // (which is one further, as they always revoke previous commitment transaction, not - // the one we send) so we have to decrement by 1. Note that if - // cur_counterparty_commitment_transaction_number is INITIAL_COMMITMENT_NUMBER we will have - // dropped this channel on disconnect as it hasn't yet reached FundingSent so we can't - // overflow here. - next_remote_commitment_number: INITIAL_COMMITMENT_NUMBER - self.context.cur_counterparty_commitment_transaction_number - 1, - your_last_per_commitment_secret: remote_last_secret, - my_current_per_commitment_point: dummy_pubkey, - // TODO(dual_funding): If we've sent `commtiment_signed` for an interactive transaction - // construction but have not received `tx_signatures` we MUST set `next_funding_txid` to the - // txid of that interactive transaction, else we MUST NOT set it. - next_funding_txid: None, +impl OutboundV1Channel { + fn get_initial_channel_type(config: &UserConfig, their_features: &InitFeatures) -> ChannelTypeFeatures { + // The default channel type (ie the first one we try) depends on whether the channel is + // public - if it is, we just go with `only_static_remotekey` as it's the only option + // available. If it's private, we first try `scid_privacy` as it provides better privacy + // with no other changes, and fall back to `only_static_remotekey`. + let mut ret = ChannelTypeFeatures::only_static_remote_key(); + if !config.channel_handshake_config.announced_channel && + config.channel_handshake_config.negotiate_scid_privacy && + their_features.supports_scid_privacy() { + ret.set_scid_privacy_required(); } - } - - // Send stuff to our remote peers: + // Optionally, if the user would like to negotiate the `anchors_zero_fee_htlc_tx` option, we + // set it now. If they don't understand it, we'll fall back to our default of + // `only_static_remotekey`. + #[cfg(anchors)] + { // Attributes are not allowed on if expressions on our current MSRV of 1.41. + if config.channel_handshake_config.negotiate_anchors_zero_fee_htlc_tx && + their_features.supports_anchors_zero_fee_htlc_tx() { + ret.set_anchors_zero_fee_htlc_tx_required(); + } + } - /// Queues up an outbound HTLC to send by placing it in the holding cell. You should call - /// [`Self::maybe_free_holding_cell_htlcs`] in order to actually generate and send the - /// commitment update. - /// - /// `Err`s will only be [`ChannelError::Ignore`]. - pub fn queue_add_htlc(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, - onion_routing_packet: msgs::OnionPacket, logger: &L) - -> Result<(), ChannelError> where L::Target: Logger { - self - .send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet, true, logger) - .map(|msg_opt| assert!(msg_opt.is_none(), "We forced holding cell?")) - .map_err(|err| { - if let ChannelError::Ignore(_) = err { /* fine */ } - else { debug_assert!(false, "Queueing cannot trigger channel failure"); } - err - }) + ret } - /// Adds a pending outbound HTLC to this channel, note that you probably want - /// [`Self::send_htlc_and_commit`] instead cause you'll want both messages at once. - /// - /// This returns an optional UpdateAddHTLC as we may be in a state where we cannot add HTLCs on - /// the wire: - /// * In cases where we're waiting on the remote peer to send us a revoke_and_ack, we - /// wouldn't be able to determine what they actually ACK'ed if we have two sets of updates - /// awaiting ACK. - /// * In cases where we're marked MonitorUpdateInProgress, we cannot commit to a new state as - /// we may not yet have sent the previous commitment update messages and will need to - /// regenerate them. - /// - /// You MUST call [`Self::send_commitment_no_state_update`] prior to calling any other methods - /// on this [`Channel`] if `force_holding_cell` is false. - /// - /// `Err`s will only be [`ChannelError::Ignore`]. - fn send_htlc(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, - onion_routing_packet: msgs::OnionPacket, mut force_holding_cell: bool, logger: &L) - -> Result, ChannelError> where L::Target: Logger { - if (self.context.channel_state & (ChannelState::ChannelReady as u32 | BOTH_SIDES_SHUTDOWN_MASK)) != (ChannelState::ChannelReady as u32) { - return Err(ChannelError::Ignore("Cannot send HTLC until channel is fully established and we haven't started shutting down".to_owned())); + pub fn new_outbound( + fee_estimator: &LowerBoundedFeeEstimator, entropy_source: &ES, signer_provider: &SP, counterparty_node_id: PublicKey, their_features: &InitFeatures, + channel_value_satoshis: u64, push_msat: u64, user_id: u128, config: &UserConfig, current_chain_height: u32, + outbound_scid_alias: u64 + ) -> Result, APIError> + where ES::Target: EntropySource, + SP::Target: SignerProvider, + F::Target: FeeEstimator, + { + let holder_selected_contest_delay = config.channel_handshake_config.our_to_self_delay; + let channel_keys_id = signer_provider.generate_channel_keys_id(false, channel_value_satoshis, user_id); + let holder_signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id); + let pubkeys = holder_signer.pubkeys().clone(); + + if !their_features.supports_wumbo() && channel_value_satoshis > MAX_FUNDING_SATOSHIS_NO_WUMBO { + return Err(APIError::APIMisuseError{err: format!("funding_value must not exceed {}, it was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, channel_value_satoshis)}); } - let channel_total_msat = self.context.channel_value_satoshis * 1000; - if amount_msat > channel_total_msat { - return Err(ChannelError::Ignore(format!("Cannot send amount {}, because it is more than the total value of the channel {}", amount_msat, channel_total_msat))); + if channel_value_satoshis >= TOTAL_BITCOIN_SUPPLY_SATOSHIS { + return Err(APIError::APIMisuseError{err: format!("funding_value must be smaller than the total bitcoin supply, it was {}", channel_value_satoshis)}); + } + let channel_value_msat = channel_value_satoshis * 1000; + if push_msat > channel_value_msat { + return Err(APIError::APIMisuseError { err: format!("Push value ({}) was larger than channel_value ({})", push_msat, channel_value_msat) }); + } + if holder_selected_contest_delay < BREAKDOWN_TIMEOUT { + return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", holder_selected_contest_delay)}); + } + let holder_selected_channel_reserve_satoshis = get_holder_selected_channel_reserve_satoshis(channel_value_satoshis, config); + if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { + // Protocol level safety check in place, although it should never happen because + // of `MIN_THEIR_CHAN_RESERVE_SATOSHIS` + return Err(APIError::APIMisuseError { err: format!("Holder selected channel reserve below implemention limit dust_limit_satoshis {}", holder_selected_channel_reserve_satoshis) }); } - if amount_msat == 0 { - return Err(ChannelError::Ignore("Cannot send 0-msat HTLC".to_owned())); - } + let channel_type = Self::get_initial_channel_type(&config, their_features); + debug_assert!(channel_type.is_subset(&channelmanager::provided_channel_type_features(&config))); - let available_balances = self.context.get_available_balances(); - if amount_msat < available_balances.next_outbound_htlc_minimum_msat { - return Err(ChannelError::Ignore(format!("Cannot send less than our next-HTLC minimum - {} msat", - available_balances.next_outbound_htlc_minimum_msat))); - } + let feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal); - if amount_msat > available_balances.next_outbound_htlc_limit_msat { - return Err(ChannelError::Ignore(format!("Cannot send more than our next-HTLC maximum - {} msat", - available_balances.next_outbound_htlc_limit_msat))); + let value_to_self_msat = channel_value_satoshis * 1000 - push_msat; + let commitment_tx_fee = commit_tx_fee_msat(feerate, MIN_AFFORDABLE_HTLC_COUNT, channel_type.requires_anchors_zero_fee_htlc_tx()); + if value_to_self_msat < commitment_tx_fee { + return Err(APIError::APIMisuseError{ err: format!("Funding amount ({}) can't even pay fee for initial commitment transaction fee of {}.", value_to_self_msat / 1000, commitment_tx_fee / 1000) }); } - if (self.context.channel_state & (ChannelState::PeerDisconnected as u32)) != 0 { - // Note that this should never really happen, if we're !is_live() on receipt of an - // incoming HTLC for relay will result in us rejecting the HTLC and we won't allow - // the user to send directly into a !is_live() channel. However, if we - // disconnected during the time the previous hop was doing the commitment dance we may - // end up getting here after the forwarding delay. In any case, returning an - // IgnoreError will get ChannelManager to do the right thing and fail backwards now. - return Err(ChannelError::Ignore("Cannot send an HTLC while disconnected from channel counterparty".to_owned())); - } + let mut secp_ctx = Secp256k1::new(); + secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes()); - let need_holding_cell = (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateInProgress as u32)) != 0; - log_debug!(logger, "Pushing new outbound HTLC for {} msat {}", amount_msat, - if force_holding_cell { "into holding cell" } - else if need_holding_cell { "into holding cell as we're awaiting an RAA or monitor" } - else { "to peer" }); + let shutdown_scriptpubkey = if config.channel_handshake_config.commit_upfront_shutdown_pubkey { + match signer_provider.get_shutdown_scriptpubkey() { + Ok(scriptpubkey) => Some(scriptpubkey), + Err(_) => return Err(APIError::ChannelUnavailable { err: "Failed to get shutdown scriptpubkey".to_owned()}), + } + } else { None }; - if need_holding_cell { - force_holding_cell = true; + if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey { + if !shutdown_scriptpubkey.is_compatible(&their_features) { + return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() }); + } } - // Now update local state: - if force_holding_cell { - self.context.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::AddHTLC { - amount_msat, - payment_hash, - cltv_expiry, - source, - onion_routing_packet, - }); - return Ok(None); - } + let destination_script = match signer_provider.get_destination_script() { + Ok(script) => script, + Err(_) => return Err(APIError::ChannelUnavailable { err: "Failed to get destination script".to_owned()}), + }; - self.context.pending_outbound_htlcs.push(OutboundHTLCOutput { - htlc_id: self.context.next_holder_htlc_id, - amount_msat, - payment_hash: payment_hash.clone(), - cltv_expiry, - state: OutboundHTLCState::LocalAnnounced(Box::new(onion_routing_packet.clone())), - source, - }); + let temporary_channel_id = entropy_source.get_secure_random_bytes(); - let res = msgs::UpdateAddHTLC { - channel_id: self.context.channel_id, - htlc_id: self.context.next_holder_htlc_id, - amount_msat, - payment_hash, - cltv_expiry, - onion_routing_packet, - }; - self.context.next_holder_htlc_id += 1; + Ok(Channel { + context: ChannelContext { + user_id, - Ok(Some(res)) - } + config: LegacyChannelConfig { + options: config.channel_config.clone(), + announced_channel: config.channel_handshake_config.announced_channel, + commit_upfront_shutdown_pubkey: config.channel_handshake_config.commit_upfront_shutdown_pubkey, + }, - fn build_commitment_no_status_check(&mut self, logger: &L) -> ChannelMonitorUpdate where L::Target: Logger { - log_trace!(logger, "Updating HTLC state for a newly-sent commitment_signed..."); - // We can upgrade the status of some HTLCs that are waiting on a commitment, even if we - // fail to generate this, we still are at least at a position where upgrading their status - // is acceptable. - for htlc in self.context.pending_inbound_htlcs.iter_mut() { - let new_state = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(ref forward_info) = &htlc.state { - Some(InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info.clone())) - } else { None }; - if let Some(state) = new_state { - log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); - htlc.state = state; - } - } - for htlc in self.context.pending_outbound_htlcs.iter_mut() { - if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut outcome) = &mut htlc.state { - log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0)); - // Grab the preimage, if it exists, instead of cloning - let mut reason = OutboundHTLCOutcome::Success(None); - mem::swap(outcome, &mut reason); - htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(reason); - } - } - if let Some((feerate, update_state)) = self.context.pending_update_fee { - if update_state == FeeUpdateState::AwaitingRemoteRevokeToAnnounce { - debug_assert!(!self.context.is_outbound()); - log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate); - self.context.feerate_per_kw = feerate; - self.context.pending_update_fee = None; - } - } - self.context.resend_order = RAACommitmentOrder::RevokeAndACKFirst; + prev_config: None, - let (counterparty_commitment_txid, mut htlcs_ref) = self.build_commitment_no_state_update(logger); - let htlcs: Vec<(HTLCOutputInCommitment, Option>)> = - htlcs_ref.drain(..).map(|(htlc, htlc_source)| (htlc, htlc_source.map(|source_ref| Box::new(source_ref.clone())))).collect(); + inbound_handshake_limits_override: Some(config.channel_handshake_limits.clone()), - if self.context.announcement_sigs_state == AnnouncementSigsState::MessageSent { - self.context.announcement_sigs_state = AnnouncementSigsState::Committed; - } + channel_id: temporary_channel_id, + temporary_channel_id: Some(temporary_channel_id), + channel_state: ChannelState::OurInitSent as u32, + announcement_sigs_state: AnnouncementSigsState::NotSent, + secp_ctx, + channel_value_satoshis, - self.context.latest_monitor_update_id += 1; - let monitor_update = ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { - commitment_txid: counterparty_commitment_txid, - htlc_outputs: htlcs.clone(), - commitment_number: self.context.cur_counterparty_commitment_transaction_number, - their_per_commitment_point: self.context.counterparty_cur_commitment_point.unwrap() - }] - }; - self.context.channel_state |= ChannelState::AwaitingRemoteRevoke as u32; - monitor_update - } + latest_monitor_update_id: 0, - fn build_commitment_no_state_update(&self, logger: &L) -> (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>) where L::Target: Logger { - let counterparty_keys = self.context.build_remote_transaction_keys(); - let commitment_stats = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger); - let counterparty_commitment_txid = commitment_stats.tx.trust().txid(); + holder_signer, + shutdown_scriptpubkey, + destination_script, - #[cfg(any(test, fuzzing))] - { - if !self.context.is_outbound() { - let projected_commit_tx_info = self.context.next_remote_commitment_tx_fee_info_cached.lock().unwrap().take(); - *self.context.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None; - if let Some(info) = projected_commit_tx_info { - let total_pending_htlcs = self.context.pending_inbound_htlcs.len() + self.context.pending_outbound_htlcs.len(); - if info.total_pending_htlcs == total_pending_htlcs - && info.next_holder_htlc_id == self.context.next_holder_htlc_id - && info.next_counterparty_htlc_id == self.context.next_counterparty_htlc_id - && info.feerate == self.context.feerate_per_kw { - let actual_fee = commit_tx_fee_msat(self.context.feerate_per_kw, commitment_stats.num_nondust_htlcs, self.context.opt_anchors()); - assert_eq!(actual_fee, info.fee); - } - } - } - } + cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, + cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, + value_to_self_msat, - (counterparty_commitment_txid, commitment_stats.htlcs_included) - } + pending_inbound_htlcs: Vec::new(), + pending_outbound_htlcs: Vec::new(), + holding_cell_htlc_updates: Vec::new(), + pending_update_fee: None, + holding_cell_update_fee: None, + next_holder_htlc_id: 0, + next_counterparty_htlc_id: 0, + update_time_counter: 1, - /// Only fails in case of signer rejection. Used for channel_reestablish commitment_signed - /// generation when we shouldn't change HTLC/channel state. - fn send_commitment_no_state_update(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger { - // Get the fee tests from `build_commitment_no_state_update` - #[cfg(any(test, fuzzing))] - self.build_commitment_no_state_update(logger); + resend_order: RAACommitmentOrder::CommitmentFirst, - let counterparty_keys = self.context.build_remote_transaction_keys(); - let commitment_stats = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger); - let counterparty_commitment_txid = commitment_stats.tx.trust().txid(); - let (signature, htlc_signatures); + monitor_pending_channel_ready: false, + monitor_pending_revoke_and_ack: false, + monitor_pending_commitment_signed: false, + monitor_pending_forwards: Vec::new(), + monitor_pending_failures: Vec::new(), + monitor_pending_finalized_fulfills: Vec::new(), - { - let mut htlcs = Vec::with_capacity(commitment_stats.htlcs_included.len()); - for &(ref htlc, _) in commitment_stats.htlcs_included.iter() { - htlcs.push(htlc); - } + #[cfg(debug_assertions)] + holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)), + #[cfg(debug_assertions)] + counterparty_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)), - let res = self.context.holder_signer.sign_counterparty_commitment(&commitment_stats.tx, commitment_stats.preimages, &self.context.secp_ctx) - .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?; - signature = res.0; - htlc_signatures = res.1; + last_sent_closing_fee: None, + pending_counterparty_closing_signed: None, + closing_fee_limits: None, + target_closing_feerate_sats_per_kw: None, - log_trace!(logger, "Signed remote commitment tx {} (txid {}) with redeemscript {} -> {} in channel {}", - encode::serialize_hex(&commitment_stats.tx.trust().built_transaction().transaction), - &counterparty_commitment_txid, encode::serialize_hex(&self.context.get_funding_redeemscript()), - log_bytes!(signature.serialize_compact()[..]), log_bytes!(self.context.channel_id())); + inbound_awaiting_accept: false, - for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(htlcs) { - log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}", - encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.context.get_holder_selected_contest_delay(), htlc, self.context.opt_anchors(), false, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)), - encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, self.context.opt_anchors(), &counterparty_keys)), - log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()), - log_bytes!(htlc_sig.serialize_compact()[..]), log_bytes!(self.context.channel_id())); - } - } + funding_tx_confirmed_in: None, + funding_tx_confirmation_height: 0, + short_channel_id: None, + channel_creation_height: current_chain_height, - Ok((msgs::CommitmentSigned { - channel_id: self.context.channel_id, - signature, - htlc_signatures, - #[cfg(taproot)] - partial_signature_with_nonce: None, - }, (counterparty_commitment_txid, commitment_stats.htlcs_included))) - } + feerate_per_kw: feerate, + counterparty_dust_limit_satoshis: 0, + holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS, + counterparty_max_htlc_value_in_flight_msat: 0, + holder_max_htlc_value_in_flight_msat: get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis, &config.channel_handshake_config), + counterparty_selected_channel_reserve_satoshis: None, // Filled in in accept_channel + holder_selected_channel_reserve_satoshis, + counterparty_htlc_minimum_msat: 0, + holder_htlc_minimum_msat: if config.channel_handshake_config.our_htlc_minimum_msat == 0 { 1 } else { config.channel_handshake_config.our_htlc_minimum_msat }, + counterparty_max_accepted_htlcs: 0, + holder_max_accepted_htlcs: cmp::min(config.channel_handshake_config.our_max_accepted_htlcs, MAX_HTLCS), + minimum_depth: None, // Filled in in accept_channel - /// Adds a pending outbound HTLC to this channel, and builds a new remote commitment - /// transaction and generates the corresponding [`ChannelMonitorUpdate`] in one go. - /// - /// Shorthand for calling [`Self::send_htlc`] followed by a commitment update, see docs on - /// [`Self::send_htlc`] and [`Self::build_commitment_no_state_update`] for more info. - pub fn send_htlc_and_commit(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket, logger: &L) -> Result, ChannelError> where L::Target: Logger { - let send_res = self.send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet, false, logger); - if let Err(e) = &send_res { if let ChannelError::Ignore(_) = e {} else { debug_assert!(false, "Sending cannot trigger channel failure"); } } - match send_res? { - Some(_) => { - let monitor_update = self.build_commitment_no_status_check(logger); - self.monitor_updating_paused(false, true, false, Vec::new(), Vec::new(), Vec::new()); - Ok(self.push_ret_blockable_mon_update(monitor_update)) - }, - None => Ok(None) - } - } + counterparty_forwarding_info: None, - pub fn channel_update(&mut self, msg: &msgs::ChannelUpdate) -> Result<(), ChannelError> { - if msg.contents.htlc_minimum_msat >= self.context.channel_value_satoshis * 1000 { - return Err(ChannelError::Close("Minimum htlc value is greater than channel value".to_string())); - } - self.context.counterparty_forwarding_info = Some(CounterpartyForwardingInfo { - fee_base_msat: msg.contents.fee_base_msat, - fee_proportional_millionths: msg.contents.fee_proportional_millionths, - cltv_expiry_delta: msg.contents.cltv_expiry_delta - }); + channel_transaction_parameters: ChannelTransactionParameters { + holder_pubkeys: pubkeys, + holder_selected_contest_delay: config.channel_handshake_config.our_to_self_delay, + is_outbound_from_holder: true, + counterparty_parameters: None, + funding_outpoint: None, + opt_anchors: if channel_type.requires_anchors_zero_fee_htlc_tx() { Some(()) } else { None }, + opt_non_zero_fee_anchors: None + }, + funding_transaction: None, - Ok(()) - } + counterparty_cur_commitment_point: None, + counterparty_prev_commitment_point: None, + counterparty_node_id, - /// Begins the shutdown process, getting a message for the remote peer and returning all - /// holding cell HTLCs for payment failure. - /// - /// May jump to the channel being fully shutdown (see [`Self::is_shutdown`]) in which case no - /// [`ChannelMonitorUpdate`] will be returned). - pub fn get_shutdown(&mut self, signer_provider: &SP, their_features: &InitFeatures, - target_feerate_sats_per_kw: Option, override_shutdown_script: Option) - -> Result<(msgs::Shutdown, Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError> - where SP::Target: SignerProvider { - for htlc in self.context.pending_outbound_htlcs.iter() { - if let OutboundHTLCState::LocalAnnounced(_) = htlc.state { - return Err(APIError::APIMisuseError{err: "Cannot begin shutdown with pending HTLCs. Process pending events first".to_owned()}); - } - } - if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK != 0 { - if (self.context.channel_state & ChannelState::LocalShutdownSent as u32) == ChannelState::LocalShutdownSent as u32 { - return Err(APIError::APIMisuseError{err: "Shutdown already in progress".to_owned()}); - } - else if (self.context.channel_state & ChannelState::RemoteShutdownSent as u32) == ChannelState::RemoteShutdownSent as u32 { - return Err(APIError::ChannelUnavailable{err: "Shutdown already in progress by remote".to_owned()}); - } - } - if self.context.shutdown_scriptpubkey.is_some() && override_shutdown_script.is_some() { - return Err(APIError::APIMisuseError{err: "Cannot override shutdown script for a channel with one already set".to_owned()}); - } - assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0); - if self.context.channel_state & (ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32) != 0 { - return Err(APIError::ChannelUnavailable{err: "Cannot begin shutdown while peer is disconnected or we're waiting on a monitor update, maybe force-close instead?".to_owned()}); - } + counterparty_shutdown_scriptpubkey: None, - // If we haven't funded the channel yet, we don't need to bother ensuring the shutdown - // script is set, we just force-close and call it a day. - let mut chan_closed = false; - if self.context.channel_state < ChannelState::FundingSent as u32 { - chan_closed = true; - } + commitment_secrets: CounterpartyCommitmentSecrets::new(), - let update_shutdown_script = match self.context.shutdown_scriptpubkey { - Some(_) => false, - None if !chan_closed => { - // use override shutdown script if provided - let shutdown_scriptpubkey = match override_shutdown_script { - Some(script) => script, - None => { - // otherwise, use the shutdown scriptpubkey provided by the signer - match signer_provider.get_shutdown_scriptpubkey() { - Ok(scriptpubkey) => scriptpubkey, - Err(_) => return Err(APIError::ChannelUnavailable{err: "Failed to get shutdown scriptpubkey".to_owned()}), - } - }, - }; - if !shutdown_scriptpubkey.is_compatible(their_features) { - return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() }); - } - self.context.shutdown_scriptpubkey = Some(shutdown_scriptpubkey); - true - }, - None => false, - }; + channel_update_status: ChannelUpdateStatus::Enabled, + closing_signed_in_flight: false, - // From here on out, we may not fail! - self.context.target_closing_feerate_sats_per_kw = target_feerate_sats_per_kw; - if self.context.channel_state < ChannelState::FundingSent as u32 { - self.context.channel_state = ChannelState::ShutdownComplete as u32; - } else { - self.context.channel_state |= ChannelState::LocalShutdownSent as u32; - } - self.context.update_time_counter += 1; + announcement_sigs: None, - let monitor_update = if update_shutdown_script { - self.context.latest_monitor_update_id += 1; - let monitor_update = ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::ShutdownScript { - scriptpubkey: self.get_closing_scriptpubkey(), - }], - }; - self.monitor_updating_paused(false, false, false, Vec::new(), Vec::new(), Vec::new()); - if self.push_blockable_mon_update(monitor_update) { - self.context.pending_monitor_updates.last().map(|upd| &upd.update) - } else { None } - } else { None }; - let shutdown = msgs::Shutdown { - channel_id: self.context.channel_id, - scriptpubkey: self.get_closing_scriptpubkey(), - }; + #[cfg(any(test, fuzzing))] + next_local_commitment_tx_fee_info_cached: Mutex::new(None), + #[cfg(any(test, fuzzing))] + next_remote_commitment_tx_fee_info_cached: Mutex::new(None), - // Go ahead and drop holding cell updates as we'd rather fail payments than wait to send - // our shutdown until we've committed all of the pending changes. - self.context.holding_cell_update_fee = None; - let mut dropped_outbound_htlcs = Vec::with_capacity(self.context.holding_cell_htlc_updates.len()); - self.context.holding_cell_htlc_updates.retain(|htlc_update| { - match htlc_update { - &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => { - dropped_outbound_htlcs.push((source.clone(), payment_hash.clone())); - false - }, - _ => true - } - }); + workaround_lnd_bug_4006: None, + sent_message_awaiting_response: None, - debug_assert!(!self.is_shutdown() || monitor_update.is_none(), - "we can't both complete shutdown and return a monitor update"); + latest_inbound_scid_alias: None, + outbound_scid_alias, - Ok((shutdown, monitor_update, dropped_outbound_htlcs)) - } + channel_pending_event_emitted: false, + channel_ready_event_emitted: false, - /// Gets the latest commitment transaction and any dependent transactions for relay (forcing - /// shutdown of this channel - no more calls into this Channel may be made afterwards except - /// those explicitly stated to be allowed after shutdown completes, eg some simple getters). - /// Also returns the list of payment_hashes for channels which we can safely fail backwards - /// immediately (others we will have to allow to time out). - pub fn force_shutdown(&mut self, should_broadcast: bool) -> ShutdownResult { - // Note that we MUST only generate a monitor update that indicates force-closure - we're - // called during initialization prior to the chain_monitor in the encompassing ChannelManager - // being fully configured in some cases. Thus, its likely any monitor events we generate will - // be delayed in being processed! See the docs for `ChannelManagerReadArgs` for more. - assert!(self.context.channel_state != ChannelState::ShutdownComplete as u32); + #[cfg(any(test, fuzzing))] + historical_inbound_htlc_fulfills: HashSet::new(), - // We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and - // return them to fail the payment. - let mut dropped_outbound_htlcs = Vec::with_capacity(self.context.holding_cell_htlc_updates.len()); - let counterparty_node_id = self.context.get_counterparty_node_id(); - for htlc_update in self.context.holding_cell_htlc_updates.drain(..) { - match htlc_update { - HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } => { - dropped_outbound_htlcs.push((source, payment_hash, counterparty_node_id, self.context.channel_id)); - }, - _ => {} - } - } - let monitor_update = if let Some(funding_txo) = self.context.get_funding_txo() { - // If we haven't yet exchanged funding signatures (ie channel_state < FundingSent), - // returning a channel monitor update here would imply a channel monitor update before - // we even registered the channel monitor to begin with, which is invalid. - // Thus, if we aren't actually at a point where we could conceivably broadcast the - // funding transaction, don't return a funding txo (which prevents providing the - // monitor update to the user, even if we return one). - // See test_duplicate_chan_id and test_pre_lockin_no_chan_closed_update for more. - if self.context.channel_state & (ChannelState::FundingSent as u32 | ChannelState::ChannelReady as u32 | ChannelState::ShutdownComplete as u32) != 0 { - self.context.latest_monitor_update_id = CLOSED_CHANNEL_UPDATE_ID; - Some((self.context.get_counterparty_node_id(), funding_txo, ChannelMonitorUpdate { - update_id: self.context.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast }], - })) - } else { None } - } else { None }; + channel_type, + channel_keys_id, - self.context.channel_state = ChannelState::ShutdownComplete as u32; - self.context.update_time_counter += 1; - (monitor_update, dropped_outbound_htlcs) + pending_monitor_updates: Vec::new(), + } + }) } +} - pub fn inflight_htlc_sources(&self) -> impl Iterator { - self.context.holding_cell_htlc_updates.iter() - .flat_map(|htlc_update| { - match htlc_update { - HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } - => Some((source, payment_hash)), - _ => None, - } - }) - .chain(self.context.pending_outbound_htlcs.iter().map(|htlc| (&htlc.source, &htlc.payment_hash))) - } +/// A not-yet-funded inbound (from counterparty) channel using V1 channel establishment. +pub(super) struct InboundV1Channel { + pub context: ChannelContext, } -/// A not-yet-funded outbound (from holder) channel using V1 channel establishment. -pub(super) struct OutboundV1Channel { - pub context: ChannelContext, -} +impl InboundV1Channel { + /// Creates a new channel from a remote sides' request for one. + /// Assumes chain_hash has already been checked and corresponds with what we expect! + pub fn new_from_req( + fee_estimator: &LowerBoundedFeeEstimator, entropy_source: &ES, signer_provider: &SP, + counterparty_node_id: PublicKey, our_supported_features: &ChannelTypeFeatures, + their_features: &InitFeatures, msg: &msgs::OpenChannel, user_id: u128, config: &UserConfig, + current_chain_height: u32, logger: &L, outbound_scid_alias: u64 + ) -> Result, ChannelError> + where ES::Target: EntropySource, + SP::Target: SignerProvider, + F::Target: FeeEstimator, + L::Target: Logger, + { + let announced_channel = if (msg.channel_flags & 1) == 1 { true } else { false }; + + // First check the channel type is known, failing before we do anything else if we don't + // support this channel type. + let channel_type = if let Some(channel_type) = &msg.channel_type { + if channel_type.supports_any_optional_bits() { + return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned())); + } + + // We only support the channel types defined by the `ChannelManager` in + // `provided_channel_type_features`. The channel type must always support + // `static_remote_key`. + if !channel_type.requires_static_remote_key() { + return Err(ChannelError::Close("Channel Type was not understood - we require static remote key".to_owned())); + } + // Make sure we support all of the features behind the channel type. + if !channel_type.is_subset(our_supported_features) { + return Err(ChannelError::Close("Channel Type contains unsupported features".to_owned())); + } + if channel_type.requires_scid_privacy() && announced_channel { + return Err(ChannelError::Close("SCID Alias/Privacy Channel Type cannot be set on a public channel".to_owned())); + } + channel_type.clone() + } else { + let channel_type = ChannelTypeFeatures::from_init(&their_features); + if channel_type != ChannelTypeFeatures::only_static_remote_key() { + return Err(ChannelError::Close("Only static_remote_key is supported for non-negotiated channel types".to_owned())); + } + channel_type + }; + let opt_anchors = channel_type.supports_anchors_zero_fee_htlc_tx(); + + let channel_keys_id = signer_provider.generate_channel_keys_id(true, msg.funding_satoshis, user_id); + let holder_signer = signer_provider.derive_channel_signer(msg.funding_satoshis, channel_keys_id); + let pubkeys = holder_signer.pubkeys().clone(); + let counterparty_pubkeys = ChannelPublicKeys { + funding_pubkey: msg.funding_pubkey, + revocation_basepoint: msg.revocation_basepoint, + payment_point: msg.payment_point, + delayed_payment_basepoint: msg.delayed_payment_basepoint, + htlc_basepoint: msg.htlc_basepoint + }; -impl OutboundV1Channel { - fn get_initial_channel_type(config: &UserConfig, their_features: &InitFeatures) -> ChannelTypeFeatures { - // The default channel type (ie the first one we try) depends on whether the channel is - // public - if it is, we just go with `only_static_remotekey` as it's the only option - // available. If it's private, we first try `scid_privacy` as it provides better privacy - // with no other changes, and fall back to `only_static_remotekey`. - let mut ret = ChannelTypeFeatures::only_static_remote_key(); - if !config.channel_handshake_config.announced_channel && - config.channel_handshake_config.negotiate_scid_privacy && - their_features.supports_scid_privacy() { - ret.set_scid_privacy_required(); + if config.channel_handshake_config.our_to_self_delay < BREAKDOWN_TIMEOUT { + return Err(ChannelError::Close(format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks. It must be greater than {}", config.channel_handshake_config.our_to_self_delay, BREAKDOWN_TIMEOUT))); } - // Optionally, if the user would like to negotiate the `anchors_zero_fee_htlc_tx` option, we - // set it now. If they don't understand it, we'll fall back to our default of - // `only_static_remotekey`. - #[cfg(anchors)] - { // Attributes are not allowed on if expressions on our current MSRV of 1.41. - if config.channel_handshake_config.negotiate_anchors_zero_fee_htlc_tx && - their_features.supports_anchors_zero_fee_htlc_tx() { - ret.set_anchors_zero_fee_htlc_tx_required(); - } + // Check sanity of message fields: + if msg.funding_satoshis > config.channel_handshake_limits.max_funding_satoshis { + return Err(ChannelError::Close(format!("Per our config, funding must be at most {}. It was {}", config.channel_handshake_limits.max_funding_satoshis, msg.funding_satoshis))); } + if msg.funding_satoshis >= TOTAL_BITCOIN_SUPPLY_SATOSHIS { + return Err(ChannelError::Close(format!("Funding must be smaller than the total bitcoin supply. It was {}", msg.funding_satoshis))); + } + if msg.channel_reserve_satoshis > msg.funding_satoshis { + return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must be not greater than funding_satoshis: {}", msg.channel_reserve_satoshis, msg.funding_satoshis))); + } + let full_channel_value_msat = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000; + if msg.push_msat > full_channel_value_msat { + return Err(ChannelError::Close(format!("push_msat {} was larger than channel amount minus reserve ({})", msg.push_msat, full_channel_value_msat))); + } + if msg.dust_limit_satoshis > msg.funding_satoshis { + return Err(ChannelError::Close(format!("dust_limit_satoshis {} was larger than funding_satoshis {}. Peer never wants payout outputs?", msg.dust_limit_satoshis, msg.funding_satoshis))); + } + if msg.htlc_minimum_msat >= full_channel_value_msat { + return Err(ChannelError::Close(format!("Minimum htlc value ({}) was larger than full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat))); + } + Channel::::check_remote_fee(fee_estimator, msg.feerate_per_kw, None, logger)?; - ret - } - - pub fn new_outbound( - fee_estimator: &LowerBoundedFeeEstimator, entropy_source: &ES, signer_provider: &SP, counterparty_node_id: PublicKey, their_features: &InitFeatures, - channel_value_satoshis: u64, push_msat: u64, user_id: u128, config: &UserConfig, current_chain_height: u32, - outbound_scid_alias: u64 - ) -> Result, APIError> - where ES::Target: EntropySource, - SP::Target: SignerProvider, - F::Target: FeeEstimator, - { - let holder_selected_contest_delay = config.channel_handshake_config.our_to_self_delay; - let channel_keys_id = signer_provider.generate_channel_keys_id(false, channel_value_satoshis, user_id); - let holder_signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id); - let pubkeys = holder_signer.pubkeys().clone(); + let max_counterparty_selected_contest_delay = u16::min(config.channel_handshake_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT); + if msg.to_self_delay > max_counterparty_selected_contest_delay { + return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_counterparty_selected_contest_delay, msg.to_self_delay))); + } + if msg.max_accepted_htlcs < 1 { + return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned())); + } + if msg.max_accepted_htlcs > MAX_HTLCS { + return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS))); + } - if !their_features.supports_wumbo() && channel_value_satoshis > MAX_FUNDING_SATOSHIS_NO_WUMBO { - return Err(APIError::APIMisuseError{err: format!("funding_value must not exceed {}, it was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, channel_value_satoshis)}); + // Now check against optional parameters as set by config... + if msg.funding_satoshis < config.channel_handshake_limits.min_funding_satoshis { + return Err(ChannelError::Close(format!("Funding satoshis ({}) is less than the user specified limit ({})", msg.funding_satoshis, config.channel_handshake_limits.min_funding_satoshis))); } - if channel_value_satoshis >= TOTAL_BITCOIN_SUPPLY_SATOSHIS { - return Err(APIError::APIMisuseError{err: format!("funding_value must be smaller than the total bitcoin supply, it was {}", channel_value_satoshis)}); + if msg.htlc_minimum_msat > config.channel_handshake_limits.max_htlc_minimum_msat { + return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, config.channel_handshake_limits.max_htlc_minimum_msat))); } - let channel_value_msat = channel_value_satoshis * 1000; - if push_msat > channel_value_msat { - return Err(APIError::APIMisuseError { err: format!("Push value ({}) was larger than channel_value ({})", push_msat, channel_value_msat) }); + if msg.max_htlc_value_in_flight_msat < config.channel_handshake_limits.min_max_htlc_value_in_flight_msat { + return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.channel_handshake_limits.min_max_htlc_value_in_flight_msat))); } - if holder_selected_contest_delay < BREAKDOWN_TIMEOUT { - return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", holder_selected_contest_delay)}); + if msg.channel_reserve_satoshis > config.channel_handshake_limits.max_channel_reserve_satoshis { + return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.channel_handshake_limits.max_channel_reserve_satoshis))); } - let holder_selected_channel_reserve_satoshis = get_holder_selected_channel_reserve_satoshis(channel_value_satoshis, config); + if msg.max_accepted_htlcs < config.channel_handshake_limits.min_max_accepted_htlcs { + return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.channel_handshake_limits.min_max_accepted_htlcs))); + } + if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { + return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); + } + if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS { + return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS))); + } + + // Convert things into internal flags and prep our state: + + if config.channel_handshake_limits.force_announced_channel_preference { + if config.channel_handshake_config.announced_channel != announced_channel { + return Err(ChannelError::Close("Peer tried to open channel but their announcement preference is different from ours".to_owned())); + } + } + + let holder_selected_channel_reserve_satoshis = get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis, config); if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { // Protocol level safety check in place, although it should never happen because // of `MIN_THEIR_CHAN_RESERVE_SATOSHIS` - return Err(APIError::APIMisuseError { err: format!("Holder selected channel reserve below implemention limit dust_limit_satoshis {}", holder_selected_channel_reserve_satoshis) }); + return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). dust_limit_satoshis is ({}).", holder_selected_channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS))); + } + if holder_selected_channel_reserve_satoshis * 1000 >= full_channel_value_msat { + return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({})msats. Channel value is ({} - {})msats.", holder_selected_channel_reserve_satoshis * 1000, full_channel_value_msat, msg.push_msat))); + } + if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS { + log_debug!(logger, "channel_reserve_satoshis ({}) is smaller than our dust limit ({}). We can broadcast stale states without any risk, implying this channel is very insecure for our counterparty.", + msg.channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS); + } + if holder_selected_channel_reserve_satoshis < msg.dust_limit_satoshis { + return Err(ChannelError::Close(format!("Dust limit ({}) too high for the channel reserve we require the remote to keep ({})", msg.dust_limit_satoshis, holder_selected_channel_reserve_satoshis))); } - let channel_type = Self::get_initial_channel_type(&config, their_features); - debug_assert!(channel_type.is_subset(&channelmanager::provided_channel_type_features(&config))); - - let feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal); + // check if the funder's amount for the initial commitment tx is sufficient + // for full fee payment plus a few HTLCs to ensure the channel will be useful. + let funders_amount_msat = msg.funding_satoshis * 1000 - msg.push_msat; + let commitment_tx_fee = commit_tx_fee_msat(msg.feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT, opt_anchors) / 1000; + if funders_amount_msat / 1000 < commitment_tx_fee { + return Err(ChannelError::Close(format!("Funding amount ({} sats) can't even pay fee for initial commitment transaction fee of {} sats.", funders_amount_msat / 1000, commitment_tx_fee))); + } - let value_to_self_msat = channel_value_satoshis * 1000 - push_msat; - let commitment_tx_fee = commit_tx_fee_msat(feerate, MIN_AFFORDABLE_HTLC_COUNT, channel_type.requires_anchors_zero_fee_htlc_tx()); - if value_to_self_msat < commitment_tx_fee { - return Err(APIError::APIMisuseError{ err: format!("Funding amount ({}) can't even pay fee for initial commitment transaction fee of {}.", value_to_self_msat / 1000, commitment_tx_fee / 1000) }); + let to_remote_satoshis = funders_amount_msat / 1000 - commitment_tx_fee; + // While it's reasonable for us to not meet the channel reserve initially (if they don't + // want to push much to us), our counterparty should always have more than our reserve. + if to_remote_satoshis < holder_selected_channel_reserve_satoshis { + return Err(ChannelError::Close("Insufficient funding amount for initial reserve".to_owned())); } - let mut secp_ctx = Secp256k1::new(); - secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes()); + let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() { + match &msg.shutdown_scriptpubkey { + &Some(ref script) => { + // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything + if script.len() == 0 { + None + } else { + if !script::is_bolt2_compliant(&script, their_features) { + return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))) + } + Some(script.clone()) + } + }, + // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel + &None => { + return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned())); + } + } + } else { None }; let shutdown_scriptpubkey = if config.channel_handshake_config.commit_upfront_shutdown_pubkey { match signer_provider.get_shutdown_scriptpubkey() { Ok(scriptpubkey) => Some(scriptpubkey), - Err(_) => return Err(APIError::ChannelUnavailable { err: "Failed to get shutdown scriptpubkey".to_owned()}), + Err(_) => return Err(ChannelError::Close("Failed to get upfront shutdown scriptpubkey".to_owned())), } } else { None }; if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey { if !shutdown_scriptpubkey.is_compatible(&their_features) { - return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() }); + return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey))); } } let destination_script = match signer_provider.get_destination_script() { Ok(script) => script, - Err(_) => return Err(APIError::ChannelUnavailable { err: "Failed to get destination script".to_owned()}), + Err(_) => return Err(ChannelError::Close("Failed to get destination script".to_owned())), }; - let temporary_channel_id = entropy_source.get_secure_random_bytes(); + let mut secp_ctx = Secp256k1::new(); + secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes()); - Ok(Channel { + let chan = Channel { context: ChannelContext { user_id, config: LegacyChannelConfig { options: config.channel_config.clone(), - announced_channel: config.channel_handshake_config.announced_channel, + announced_channel, commit_upfront_shutdown_pubkey: config.channel_handshake_config.commit_upfront_shutdown_pubkey, }, prev_config: None, - inbound_handshake_limits_override: Some(config.channel_handshake_limits.clone()), + inbound_handshake_limits_override: None, - channel_id: temporary_channel_id, - temporary_channel_id: Some(temporary_channel_id), - channel_state: ChannelState::OurInitSent as u32, + temporary_channel_id: Some(msg.temporary_channel_id), + channel_id: msg.temporary_channel_id, + channel_state: (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32), announcement_sigs_state: AnnouncementSigsState::NotSent, secp_ctx, - channel_value_satoshis, latest_monitor_update_id: 0, @@ -6343,7 +6344,7 @@ impl OutboundV1Channel { cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER, - value_to_self_msat, + value_to_self_msat: msg.push_msat, pending_inbound_htlcs: Vec::new(), pending_outbound_htlcs: Vec::new(), @@ -6364,53 +6365,57 @@ impl OutboundV1Channel { monitor_pending_finalized_fulfills: Vec::new(), #[cfg(debug_assertions)] - holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)), + holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)), #[cfg(debug_assertions)] - counterparty_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)), + counterparty_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)), last_sent_closing_fee: None, pending_counterparty_closing_signed: None, closing_fee_limits: None, target_closing_feerate_sats_per_kw: None, - inbound_awaiting_accept: false, + inbound_awaiting_accept: true, funding_tx_confirmed_in: None, funding_tx_confirmation_height: 0, short_channel_id: None, channel_creation_height: current_chain_height, - feerate_per_kw: feerate, - counterparty_dust_limit_satoshis: 0, + feerate_per_kw: msg.feerate_per_kw, + channel_value_satoshis: msg.funding_satoshis, + counterparty_dust_limit_satoshis: msg.dust_limit_satoshis, holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS, - counterparty_max_htlc_value_in_flight_msat: 0, - holder_max_htlc_value_in_flight_msat: get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis, &config.channel_handshake_config), - counterparty_selected_channel_reserve_satoshis: None, // Filled in in accept_channel + counterparty_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000), + holder_max_htlc_value_in_flight_msat: get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis, &config.channel_handshake_config), + counterparty_selected_channel_reserve_satoshis: Some(msg.channel_reserve_satoshis), holder_selected_channel_reserve_satoshis, - counterparty_htlc_minimum_msat: 0, + counterparty_htlc_minimum_msat: msg.htlc_minimum_msat, holder_htlc_minimum_msat: if config.channel_handshake_config.our_htlc_minimum_msat == 0 { 1 } else { config.channel_handshake_config.our_htlc_minimum_msat }, - counterparty_max_accepted_htlcs: 0, + counterparty_max_accepted_htlcs: msg.max_accepted_htlcs, holder_max_accepted_htlcs: cmp::min(config.channel_handshake_config.our_max_accepted_htlcs, MAX_HTLCS), - minimum_depth: None, // Filled in in accept_channel + minimum_depth: Some(cmp::max(config.channel_handshake_config.minimum_depth, 1)), counterparty_forwarding_info: None, channel_transaction_parameters: ChannelTransactionParameters { holder_pubkeys: pubkeys, holder_selected_contest_delay: config.channel_handshake_config.our_to_self_delay, - is_outbound_from_holder: true, - counterparty_parameters: None, + is_outbound_from_holder: false, + counterparty_parameters: Some(CounterpartyChannelTransactionParameters { + selected_contest_delay: msg.to_self_delay, + pubkeys: counterparty_pubkeys, + }), funding_outpoint: None, - opt_anchors: if channel_type.requires_anchors_zero_fee_htlc_tx() { Some(()) } else { None }, + opt_anchors: if opt_anchors { Some(()) } else { None }, opt_non_zero_fee_anchors: None }, funding_transaction: None, - counterparty_cur_commitment_point: None, + counterparty_cur_commitment_point: Some(msg.first_per_commitment_point), counterparty_prev_commitment_point: None, counterparty_node_id, - counterparty_shutdown_scriptpubkey: None, + counterparty_shutdown_scriptpubkey, commitment_secrets: CounterpartyCommitmentSecrets::new(), @@ -6441,17 +6446,12 @@ impl OutboundV1Channel { pending_monitor_updates: Vec::new(), } - }) - } -} + }; -/// A not-yet-funded inbound (from counterparty) channel using V1 channel establishment. -pub(super) struct InboundV1Channel { - pub context: ChannelContext, + Ok(chan) + } } -impl InboundV1Channel {} - const SERIALIZATION_VERSION: u8 = 3; const MIN_SERIALIZATION_VERSION: u8 = 2; @@ -7295,7 +7295,7 @@ mod tests { use crate::ln::channelmanager::{self, HTLCSource, PaymentId}; #[cfg(anchors)] use crate::ln::channel::InitFeatures; - use crate::ln::channel::{Channel, InboundHTLCOutput, OutboundV1Channel, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator, commit_tx_fee_msat}; + use crate::ln::channel::{Channel, InboundHTLCOutput, OutboundV1Channel, InboundV1Channel, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator, commit_tx_fee_msat}; use crate::ln::channel::{MAX_FUNDING_SATOSHIS_NO_WUMBO, TOTAL_BITCOIN_SUPPLY_SATOSHIS, MIN_THEIR_CHAN_RESERVE_SATOSHIS}; use crate::ln::features::ChannelTypeFeatures; use crate::ln::msgs::{ChannelUpdate, DecodeError, UnsignedChannelUpdate, MAX_VALUE_MSAT}; @@ -7459,7 +7459,7 @@ mod tests { // Make sure A's dust limit is as we expect. let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash()); let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap()); - let mut node_b_chan = Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap(); + let mut node_b_chan = InboundV1Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap(); // Node B --> Node A: accept channel, explicitly setting B's dust limit. let mut accept_channel_msg = node_b_chan.accept_inbound_channel(0); @@ -7575,7 +7575,7 @@ mod tests { // Create Node B's channel by receiving Node A's open_channel message let open_channel_msg = node_a_chan.get_open_channel(chain_hash); let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap()); - let mut node_b_chan = Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap(); + let mut node_b_chan = InboundV1Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap(); // Node B --> Node A: accept channel let accept_channel_msg = node_b_chan.accept_inbound_channel(0); @@ -7647,12 +7647,12 @@ mod tests { // Test that `new_from_req` creates a channel with the correct value for // `holder_max_htlc_value_in_flight_msat`, when configured with a valid percentage value, // which is set to the lower bound - 1 (2%) of the `channel_value`. - let chan_3 = Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_2_percent), &channelmanager::provided_init_features(&config_2_percent), &chan_1_open_channel_msg, 7, &config_2_percent, 0, &&logger, 42).unwrap(); + let chan_3 = InboundV1Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_2_percent), &channelmanager::provided_init_features(&config_2_percent), &chan_1_open_channel_msg, 7, &config_2_percent, 0, &&logger, 42).unwrap(); let chan_3_value_msat = chan_3.context.channel_value_satoshis * 1000; assert_eq!(chan_3.context.holder_max_htlc_value_in_flight_msat, (chan_3_value_msat as f64 * 0.02) as u64); // Test with the upper bound - 1 of valid values (99%). - let chan_4 = Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_99_percent), &channelmanager::provided_init_features(&config_99_percent), &chan_1_open_channel_msg, 7, &config_99_percent, 0, &&logger, 42).unwrap(); + let chan_4 = InboundV1Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_99_percent), &channelmanager::provided_init_features(&config_99_percent), &chan_1_open_channel_msg, 7, &config_99_percent, 0, &&logger, 42).unwrap(); let chan_4_value_msat = chan_4.context.channel_value_satoshis * 1000; assert_eq!(chan_4.context.holder_max_htlc_value_in_flight_msat, (chan_4_value_msat as f64 * 0.99) as u64); @@ -7671,14 +7671,14 @@ mod tests { // Test that `new_from_req` uses the lower bound of the configurable percentage values (1%) // if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a value less than 1. - let chan_7 = Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_0_percent), &channelmanager::provided_init_features(&config_0_percent), &chan_1_open_channel_msg, 7, &config_0_percent, 0, &&logger, 42).unwrap(); + let chan_7 = InboundV1Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_0_percent), &channelmanager::provided_init_features(&config_0_percent), &chan_1_open_channel_msg, 7, &config_0_percent, 0, &&logger, 42).unwrap(); let chan_7_value_msat = chan_7.context.channel_value_satoshis * 1000; assert_eq!(chan_7.context.holder_max_htlc_value_in_flight_msat, (chan_7_value_msat as f64 * 0.01) as u64); // Test that `new_from_req` uses the upper bound of the configurable percentage values // (100%) if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a larger value // than 100. - let chan_8 = Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_101_percent), &channelmanager::provided_init_features(&config_101_percent), &chan_1_open_channel_msg, 7, &config_101_percent, 0, &&logger, 42).unwrap(); + let chan_8 = InboundV1Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&config_101_percent), &channelmanager::provided_init_features(&config_101_percent), &chan_1_open_channel_msg, 7, &config_101_percent, 0, &&logger, 42).unwrap(); let chan_8_value_msat = chan_8.context.channel_value_satoshis * 1000; assert_eq!(chan_8.context.holder_max_htlc_value_in_flight_msat, chan_8_value_msat); } @@ -7728,7 +7728,7 @@ mod tests { inbound_node_config.channel_handshake_config.their_channel_reserve_proportional_millionths = (inbound_selected_channel_reserve_perc * 1_000_000.0) as u32; if outbound_selected_channel_reserve_perc + inbound_selected_channel_reserve_perc < 1.0 { - let chan_inbound_node = Channel::::new_from_req(&&fee_est, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&inbound_node_config), &channelmanager::provided_init_features(&outbound_node_config), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42).unwrap(); + let chan_inbound_node = InboundV1Channel::::new_from_req(&&fee_est, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&inbound_node_config), &channelmanager::provided_init_features(&outbound_node_config), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42).unwrap(); let expected_inbound_selected_chan_reserve = cmp::max(MIN_THEIR_CHAN_RESERVE_SATOSHIS, (chan.context.channel_value_satoshis as f64 * inbound_selected_channel_reserve_perc) as u64); @@ -7736,7 +7736,7 @@ mod tests { assert_eq!(chan_inbound_node.context.counterparty_selected_channel_reserve_satoshis.unwrap(), expected_outbound_selected_chan_reserve); } else { // Channel Negotiations failed - let result = Channel::::new_from_req(&&fee_est, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&inbound_node_config), &channelmanager::provided_init_features(&outbound_node_config), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42); + let result = InboundV1Channel::::new_from_req(&&fee_est, &&keys_provider, &&keys_provider, inbound_node_id, &channelmanager::provided_channel_type_features(&inbound_node_config), &channelmanager::provided_init_features(&outbound_node_config), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42); assert!(result.is_err()); } } @@ -8560,7 +8560,7 @@ mod tests { let mut open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash()); open_channel_msg.channel_type = Some(channel_type_features); let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap()); - let res = Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, + let res = InboundV1Channel::::new_from_req(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, 42); assert!(res.is_ok()); @@ -8602,7 +8602,7 @@ mod tests { ).unwrap(); let open_channel_msg = channel_a.get_open_channel(genesis_block(network).header.block_hash()); - let channel_b = Channel::::new_from_req( + let channel_b = InboundV1Channel::::new_from_req( &fee_estimator, &&keys_provider, &&keys_provider, node_id_a, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, 42 @@ -8645,7 +8645,7 @@ mod tests { // Since A supports both `static_remote_key` and `option_anchors`, but B only accepts // `static_remote_key`, it will fail the channel. - let channel_b = Channel::::new_from_req( + let channel_b = InboundV1Channel::::new_from_req( &fee_estimator, &&keys_provider, &&keys_provider, node_id_a, &channelmanager::provided_channel_type_features(&config), &init_features_with_simple_anchors, &open_channel_msg, 7, &config, 0, &&logger, 42 @@ -8689,7 +8689,7 @@ mod tests { let mut open_channel_msg = channel_a.get_open_channel(genesis_block(network).header.block_hash()); open_channel_msg.channel_type = Some(simple_anchors_channel_type.clone()); - let res = Channel::::new_from_req( + let res = InboundV1Channel::::new_from_req( &fee_estimator, &&keys_provider, &&keys_provider, node_id_a, &channelmanager::provided_channel_type_features(&config), &simple_anchors_init, &open_channel_msg, 7, &config, 0, &&logger, 42 @@ -8707,7 +8707,7 @@ mod tests { let open_channel_msg = channel_a.get_open_channel(genesis_block(network).header.block_hash()); - let channel_b = Channel::::new_from_req( + let channel_b = InboundV1Channel::::new_from_req( &fee_estimator, &&keys_provider, &&keys_provider, node_id_a, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, 42 diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index 78265a0b..e8c76720 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -40,7 +40,7 @@ use crate::events::{Event, EventHandler, EventsProvider, MessageSendEvent, Messa // Since this struct is returned in `list_channels` methods, expose it here in case users want to // construct one themselves. use crate::ln::{inbound_payment, PaymentHash, PaymentPreimage, PaymentSecret}; -use crate::ln::channel::{Channel, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UpdateFulfillCommitFetch, OutboundV1Channel}; +use crate::ln::channel::{Channel, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UpdateFulfillCommitFetch, OutboundV1Channel, InboundV1Channel}; use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures}; #[cfg(any(feature = "_test_utils", test))] use crate::ln::features::InvoiceFeatures; @@ -4901,7 +4901,7 @@ where msg.temporary_channel_id.clone())); } - let mut channel = match Channel::new_from_req(&self.fee_estimator, &self.entropy_source, &self.signer_provider, + let mut channel = match InboundV1Channel::new_from_req(&self.fee_estimator, &self.entropy_source, &self.signer_provider, counterparty_node_id.clone(), &self.channel_type_features(), &peer_state.latest_features, msg, user_channel_id, &self.default_configuration, best_block_height, &self.logger, outbound_scid_alias) { diff --git a/lightning/src/ln/functional_tests.rs b/lightning/src/ln/functional_tests.rs index 6af81108..bfab15f3 100644 --- a/lightning/src/ln/functional_tests.rs +++ b/lightning/src/ln/functional_tests.rs @@ -20,9 +20,9 @@ use crate::chain::transaction::OutPoint; use crate::sign::{ChannelSigner, EcdsaChannelSigner, EntropySource}; use crate::events::{Event, MessageSendEvent, MessageSendEventsProvider, PathFailure, PaymentPurpose, ClosureReason, HTLCDestination, PaymentFailureReason}; use crate::ln::{PaymentPreimage, PaymentSecret, PaymentHash}; -use crate::ln::channel::{commitment_tx_base_weight, COMMITMENT_TX_WEIGHT_PER_HTLC, CONCURRENT_INBOUND_HTLC_FEE_BUFFER, FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE, MIN_AFFORDABLE_HTLC_COUNT, get_holder_selected_channel_reserve_satoshis, OutboundV1Channel}; +use crate::ln::channel::{commitment_tx_base_weight, COMMITMENT_TX_WEIGHT_PER_HTLC, CONCURRENT_INBOUND_HTLC_FEE_BUFFER, FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE, MIN_AFFORDABLE_HTLC_COUNT, get_holder_selected_channel_reserve_satoshis, OutboundV1Channel, InboundV1Channel}; use crate::ln::channelmanager::{self, PaymentId, RAACommitmentOrder, PaymentSendFailure, RecipientOnionFields, BREAKDOWN_TIMEOUT, ENABLE_GOSSIP_TICKS, DISABLE_GOSSIP_TICKS, MIN_CLTV_EXPIRY_DELTA}; -use crate::ln::channel::{DISCONNECT_PEER_AWAITING_RESPONSE_TICKS, Channel, ChannelError}; +use crate::ln::channel::{DISCONNECT_PEER_AWAITING_RESPONSE_TICKS, ChannelError}; use crate::ln::{chan_utils, onion_utils}; use crate::ln::chan_utils::{OFFERED_HTLC_SCRIPT_WEIGHT, htlc_success_tx_weight, htlc_timeout_tx_weight, HTLCOutputInCommitment}; use crate::routing::gossip::{NetworkGraph, NetworkUpdate}; @@ -6961,11 +6961,11 @@ fn test_user_configurable_csv_delay() { } } else { assert!(false) } - // We test config.our_to_self > BREAKDOWN_TIMEOUT is enforced in Channel::new_from_req() + // We test config.our_to_self > BREAKDOWN_TIMEOUT is enforced in InboundV1Channel::new_from_req() nodes[1].node.create_channel(nodes[0].node.get_our_node_id(), 1000000, 1000000, 42, None).unwrap(); let mut open_channel = get_event_msg!(nodes[1], MessageSendEvent::SendOpenChannel, nodes[0].node.get_our_node_id()); open_channel.to_self_delay = 200; - if let Err(error) = Channel::new_from_req(&LowerBoundedFeeEstimator::new(&test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) }), + if let Err(error) = InboundV1Channel::new_from_req(&LowerBoundedFeeEstimator::new(&test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) }), &nodes[0].keys_manager, &nodes[0].keys_manager, nodes[1].node.get_our_node_id(), &nodes[0].node.channel_type_features(), &nodes[1].node.init_features(), &open_channel, 0, &low_our_to_self_config, 0, &nodes[0].logger, 42) { @@ -6993,11 +6993,11 @@ fn test_user_configurable_csv_delay() { } else { panic!(); } check_closed_event!(nodes[0], 1, ClosureReason::ProcessingError { err: reason_msg }); - // We test msg.to_self_delay <= config.their_to_self_delay is enforced in Channel::new_from_req() + // We test msg.to_self_delay <= config.their_to_self_delay is enforced in InboundV1Channel::new_from_req() nodes[1].node.create_channel(nodes[0].node.get_our_node_id(), 1000000, 1000000, 42, None).unwrap(); let mut open_channel = get_event_msg!(nodes[1], MessageSendEvent::SendOpenChannel, nodes[0].node.get_our_node_id()); open_channel.to_self_delay = 200; - if let Err(error) = Channel::new_from_req(&LowerBoundedFeeEstimator::new(&test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) }), + if let Err(error) = InboundV1Channel::new_from_req(&LowerBoundedFeeEstimator::new(&test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) }), &nodes[0].keys_manager, &nodes[0].keys_manager, nodes[1].node.get_our_node_id(), &nodes[0].node.channel_type_features(), &nodes[1].node.init_features(), &open_channel, 0, &high_their_to_self_config, 0, &nodes[0].logger, 42) {