From: Matt Corallo Date: Tue, 5 Sep 2023 20:46:28 +0000 (+0000) Subject: Handling for sign_counterparty_commitment failing during normal op X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;ds=sidebyside;h=65737c6eab46a12b8abd04454c5396d643025e65;p=rust-lightning Handling for sign_counterparty_commitment failing during normal op If sign_counterparty_commitment fails (i.e. because the signer is temporarily disconnected), this really indicates that we should retry the message sending later, rather than force-closing the channel (which probably won't even work if the signer is missing). Here we add initial handling of sign_counterparty_commitment failing during normal channel operation, setting a new flag in `ChannelContext` which indicates we should retry sending the commitment update later. We don't yet add any ability to do that retry. --- diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 022767e6f..b0c318a91 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -700,6 +700,14 @@ pub(super) struct ChannelContext where SP::Target: SignerProvider { monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, monitor_pending_finalized_fulfills: Vec, + /// If we went to send a commitment update (ie some messages then [`msgs::CommitmentSigned`]) + /// but our signer (initially) refused to give us a signature, we should retry at some point in + /// the future when the signer indicates it may have a signature for us. + /// + /// This flag is set in such a case. Note that we don't need to persist this as we'll end up + /// setting it again as a side-effect of [`Channel::channel_reestablish`]. + signer_pending_commitment_update: bool, + // pending_update_fee is filled when sending and receiving update_fee. // // Because it follows the same commitment flow as HTLCs, `FeeUpdateState` is either `Outbound` @@ -3047,8 +3055,8 @@ impl Channel where 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. + // the corresponding HTLC status updates so that + // get_last_commitment_update_for_send 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 @@ -3422,9 +3430,10 @@ impl Channel where // 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. + // When the monitor updating is restored we'll call + // get_last_commitment_update_for_send(), 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. @@ -3726,9 +3735,11 @@ impl Channel where 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)) + self.get_last_commitment_update_for_send(logger).ok() } else { None }; + if commitment_update.is_some() { + self.mark_awaiting_response(); + } self.context.monitor_pending_revoke_and_ack = false; self.context.monitor_pending_commitment_signed = false; @@ -3789,7 +3800,8 @@ impl Channel where } } - fn get_last_commitment_update(&self, logger: &L) -> msgs::CommitmentUpdate where L::Target: Logger { + /// Gets the last commitment update for immediate sending to our peer. + fn get_last_commitment_update_for_send(&mut self, logger: &L) -> Result 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(); @@ -3848,10 +3860,17 @@ impl Channel where log_trace!(logger, "Regenerated latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds", &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 { + let commitment_signed = if let Ok(update) = self.send_commitment_no_state_update(logger).map(|(cu, _)| cu) { + self.context.signer_pending_commitment_update = false; + update + } else { + self.context.signer_pending_commitment_update = true; + return Err(()); + }; + Ok(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, - } + commitment_signed, + }) } /// Gets the `Shutdown` message we should send our peer on reconnect, if any. @@ -4031,7 +4050,7 @@ impl Channel where Ok(ReestablishResponses { channel_ready, shutdown_msg, announcement_sigs, raa: required_revoke, - commitment_update: Some(self.get_last_commitment_update(logger)), + commitment_update: self.get_last_commitment_update_for_send(logger).ok(), order: self.context.resend_order.clone(), }) } @@ -5389,7 +5408,7 @@ impl Channel where } let res = ecdsa.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()))?; + .map_err(|_| ChannelError::Ignore("Failed to get signatures for new commitment_signed".to_owned()))?; signature = res.0; htlc_signatures = res.1; @@ -5702,6 +5721,8 @@ impl OutboundV1Channel where SP::Target: SignerProvider { monitor_pending_failures: Vec::new(), monitor_pending_finalized_fulfills: Vec::new(), + signer_pending_commitment_update: false, + #[cfg(debug_assertions)] holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)), #[cfg(debug_assertions)] @@ -6349,6 +6370,8 @@ impl InboundV1Channel where SP::Target: SignerProvider { monitor_pending_failures: Vec::new(), monitor_pending_finalized_fulfills: Vec::new(), + signer_pending_commitment_update: false, + #[cfg(debug_assertions)] holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)), #[cfg(debug_assertions)] @@ -7435,6 +7458,8 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch monitor_pending_failures, monitor_pending_finalized_fulfills: monitor_pending_finalized_fulfills.unwrap(), + signer_pending_commitment_update: false, + pending_update_fee, holding_cell_update_fee, next_holder_htlc_id,