- 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;
- }
-
- // 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)));
- }
- 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)));
- }
-
- // 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)));
- }
-
- 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;
- }
-
- 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 };
-
- 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 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
- };
-
- self.context.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters {
- selected_contest_delay: msg.to_self_delay,
- pubkeys: counterparty_pubkeys,
- });
-
- self.context.counterparty_cur_commitment_point = Some(msg.first_per_commitment_point);
- self.context.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey;
-
- 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.
-
- Ok(())
- }
-
- fn funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<(Txid, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
- let funding_script = self.get_funding_redeemscript();
-
- let keys = self.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.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.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
- }
-
- let counterparty_keys = self.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();
- 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 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;
-
- // 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))
- }
-
- fn counterparty_funding_pubkey(&self) -> &PublicKey {
- &self.context.get_counterparty_pubkeys().funding_pubkey
- }
-
- pub fn funding_created<SP: Deref, L: Deref>(
- &mut self, msg: &msgs::FundingCreated, best_block: BestBlock, signer_provider: &SP, logger: &L
- ) -> Result<(msgs::FundingSigned, ChannelMonitor<Signer>), ChannelError>
- where
- SP::Target: SignerProvider<Signer = Signer>,
- 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.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");
- }
-
- 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 (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);
- }
- };
-