-
- 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 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(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 destination_script = match signer_provider.get_destination_script() {
- Ok(script) => script,
- Err(_) => return Err(ChannelError::Close("Failed to get destination script".to_owned())),
- };
-
- 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,
- },
-
- prev_config: None,
-
- inbound_handshake_limits_override: None,
-
- 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,
-
- latest_monitor_update_id: 0,
-
- holder_signer,
- shutdown_scriptpubkey,
- destination_script,
-
- cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
- cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
- value_to_self_msat: msg.push_msat,
-
- 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,
-
- resend_order: RAACommitmentOrder::CommitmentFirst,
-
- 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(),
-
- #[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)),
-
- last_sent_closing_fee: None,
- pending_counterparty_closing_signed: None,
- closing_fee_limits: None,
- target_closing_feerate_sats_per_kw: None,
-
- 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: 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)),
-
- 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: 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,
-
- counterparty_cur_commitment_point: Some(msg.first_per_commitment_point),
- counterparty_prev_commitment_point: None,
- counterparty_node_id,
-
- counterparty_shutdown_scriptpubkey,
-
- commitment_secrets: CounterpartyCommitmentSecrets::new(),
-
- channel_update_status: ChannelUpdateStatus::Enabled,
- closing_signed_in_flight: false,
-
- announcement_sigs: None,
-
- #[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),
-
- workaround_lnd_bug_4006: None,
- sent_message_awaiting_response: None,
-
- latest_inbound_scid_alias: None,
- outbound_scid_alias,
-
- channel_pending_event_emitted: false,
- channel_ready_event_emitted: false,
-
- #[cfg(any(test, fuzzing))]
- historical_inbound_htlc_fulfills: HashSet::new(),
-
- channel_type,
- channel_keys_id,
-
- pending_monitor_updates: Vec::new(),
- }
- };
-
- Ok(chan)
- }
-
- #[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()
- }
-
- #[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
- }
-
- #[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 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 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;
- }
-
- if skip_remote_output || value_to_counterparty as u64 <= self.context.holder_dust_limit_satoshis {
- value_to_counterparty = 0;
- }
-
- if value_to_holder as u64 <= self.context.holder_dust_limit_satoshis {
- value_to_holder = 0;
- }
-
- 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 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)
- }
-
- fn funding_outpoint(&self) -> OutPoint {
- self.context.channel_transaction_parameters.funding_outpoint.unwrap()
- }
-
- /// 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<L: Deref>
- (&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.
- }
- }
-
- fn get_update_fulfill_htlc<L: Deref>(&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 payment_hash_calc = PaymentHash(Sha256::hash(&payment_preimage_arg.0[..]).into_inner());