From b3689412df1511a1196cad4aba532463057d2fa9 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Viktor=20Tigerstr=C3=B6m?= <11711198+ViktorTigerstrom@users.noreply.github.com> Date: Fri, 19 Aug 2022 01:07:15 +0200 Subject: [PATCH] Make `process_pending_htlc_forwards` more readable Refactor `process_pending_htlc_forwards` to ensure that both branches that fails `pending_forwards` are placed next to eachother for improved readability. --- lightning/src/ln/channelmanager.rs | 239 +++++++++++++++-------------- 1 file changed, 121 insertions(+), 118 deletions(-) diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index 1dfddf940..465256d21 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -3242,134 +3242,137 @@ impl ChannelManager { - log_trace!(self.logger, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", prev_short_channel_id, log_bytes!(payment_hash.0), short_chan_id); - let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData { - short_channel_id: prev_short_channel_id, - outpoint: prev_funding_outpoint, - htlc_id: prev_htlc_id, - incoming_packet_shared_secret: incoming_shared_secret, - // Phantom payments are only PendingHTLCRouting::Receive. - phantom_shared_secret: None, - }); - match chan.get_mut().send_htlc(amt_to_forward, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet, &self.logger) { - Err(e) => { - if let ChannelError::Ignore(msg) = e { - log_trace!(self.logger, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(payment_hash.0), msg); - } else { - panic!("Stated return value requirements in send_htlc() were not met"); - } - let (failure_code, data) = self.get_htlc_temp_fail_err_and_data(0x1000|7, short_chan_id, chan.get()); - failed_forwards.push((htlc_source, payment_hash, - HTLCFailReason::Reason { failure_code, data }, - HTLCDestination::NextHopChannel { node_id: Some(chan.get().get_counterparty_node_id()), channel_id: forward_chan_id } - )); - continue; - }, - Ok(update_add) => { - match update_add { - Some(msg) => { add_htlc_msgs.push(msg); }, - None => { - // Nothing to do here...we're waiting on a remote - // revoke_and_ack before we can add anymore HTLCs. The Channel - // will automatically handle building the update_add_htlc and - // commitment_signed messages when we can. - // TODO: Do some kind of timer to set the channel as !is_live() - // as we don't really want others relying on us relaying through - // this channel currently :/. + match channel_state.by_id.entry(forward_chan_id) { + hash_map::Entry::Vacant(_) => { + forwarding_channel_not_found!(); + continue; + }, + hash_map::Entry::Occupied(mut chan) => { + let mut add_htlc_msgs = Vec::new(); + let mut fail_htlc_msgs = Vec::new(); + for forward_info in pending_forwards.drain(..) { + match forward_info { + HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo { + routing: PendingHTLCRouting::Forward { + onion_packet, .. + }, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value }, + prev_funding_outpoint } => { + log_trace!(self.logger, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", prev_short_channel_id, log_bytes!(payment_hash.0), short_chan_id); + let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData { + short_channel_id: prev_short_channel_id, + outpoint: prev_funding_outpoint, + htlc_id: prev_htlc_id, + incoming_packet_shared_secret: incoming_shared_secret, + // Phantom payments are only PendingHTLCRouting::Receive. + phantom_shared_secret: None, + }); + match chan.get_mut().send_htlc(amt_to_forward, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet, &self.logger) { + Err(e) => { + if let ChannelError::Ignore(msg) = e { + log_trace!(self.logger, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(payment_hash.0), msg); + } else { + panic!("Stated return value requirements in send_htlc() were not met"); + } + let (failure_code, data) = self.get_htlc_temp_fail_err_and_data(0x1000|7, short_chan_id, chan.get()); + failed_forwards.push((htlc_source, payment_hash, + HTLCFailReason::Reason { failure_code, data }, + HTLCDestination::NextHopChannel { node_id: Some(chan.get().get_counterparty_node_id()), channel_id: forward_chan_id } + )); + continue; + }, + Ok(update_add) => { + match update_add { + Some(msg) => { add_htlc_msgs.push(msg); }, + None => { + // Nothing to do here...we're waiting on a remote + // revoke_and_ack before we can add anymore HTLCs. The Channel + // will automatically handle building the update_add_htlc and + // commitment_signed messages when we can. + // TODO: Do some kind of timer to set the channel as !is_live() + // as we don't really want others relying on us relaying through + // this channel currently :/. + } } } } - } - }, - HTLCForwardInfo::AddHTLC { .. } => { - panic!("short_channel_id != 0 should imply any pending_forward entries are of type Forward"); - }, - HTLCForwardInfo::FailHTLC { htlc_id, err_packet } => { - log_trace!(self.logger, "Failing HTLC back to channel with short id {} (backward HTLC ID {}) after delay", short_chan_id, htlc_id); - match chan.get_mut().get_update_fail_htlc(htlc_id, err_packet, &self.logger) { - Err(e) => { - if let ChannelError::Ignore(msg) = e { - log_trace!(self.logger, "Failed to fail HTLC with ID {} backwards to short_id {}: {}", htlc_id, short_chan_id, msg); - } else { - panic!("Stated return value requirements in get_update_fail_htlc() were not met"); + }, + HTLCForwardInfo::AddHTLC { .. } => { + panic!("short_channel_id != 0 should imply any pending_forward entries are of type Forward"); + }, + HTLCForwardInfo::FailHTLC { htlc_id, err_packet } => { + log_trace!(self.logger, "Failing HTLC back to channel with short id {} (backward HTLC ID {}) after delay", short_chan_id, htlc_id); + match chan.get_mut().get_update_fail_htlc(htlc_id, err_packet, &self.logger) { + Err(e) => { + if let ChannelError::Ignore(msg) = e { + log_trace!(self.logger, "Failed to fail HTLC with ID {} backwards to short_id {}: {}", htlc_id, short_chan_id, msg); + } else { + panic!("Stated return value requirements in get_update_fail_htlc() were not met"); + } + // fail-backs are best-effort, we probably already have one + // pending, and if not that's OK, if not, the channel is on + // the chain and sending the HTLC-Timeout is their problem. + continue; + }, + Ok(Some(msg)) => { fail_htlc_msgs.push(msg); }, + Ok(None) => { + // Nothing to do here...we're waiting on a remote + // revoke_and_ack before we can update the commitment + // transaction. The Channel will automatically handle + // building the update_fail_htlc and commitment_signed + // messages when we can. + // We don't need any kind of timer here as they should fail + // the channel onto the chain if they can't get our + // update_fail_htlc in time, it's not our problem. } - // fail-backs are best-effort, we probably already have one - // pending, and if not that's OK, if not, the channel is on - // the chain and sending the HTLC-Timeout is their problem. - continue; - }, - Ok(Some(msg)) => { fail_htlc_msgs.push(msg); }, - Ok(None) => { - // Nothing to do here...we're waiting on a remote - // revoke_and_ack before we can update the commitment - // transaction. The Channel will automatically handle - // building the update_fail_htlc and commitment_signed - // messages when we can. - // We don't need any kind of timer here as they should fail - // the channel onto the chain if they can't get our - // update_fail_htlc in time, it's not our problem. } - } - }, + }, + } } - } - if !add_htlc_msgs.is_empty() || !fail_htlc_msgs.is_empty() { - let (commitment_msg, monitor_update) = match chan.get_mut().send_commitment(&self.logger) { - Ok(res) => res, - Err(e) => { - // We surely failed send_commitment due to bad keys, in that case - // close channel and then send error message to peer. - let counterparty_node_id = chan.get().get_counterparty_node_id(); - let err: Result<(), _> = match e { - ChannelError::Ignore(_) | ChannelError::Warn(_) => { - panic!("Stated return value requirements in send_commitment() were not met"); - } - ChannelError::Close(msg) => { - log_trace!(self.logger, "Closing channel {} due to Close-required error: {}", log_bytes!(chan.key()[..]), msg); - let mut channel = remove_channel!(self, chan); - // ChannelClosed event is generated by handle_error for us. - Err(MsgHandleErrInternal::from_finish_shutdown(msg, channel.channel_id(), channel.get_user_id(), channel.force_shutdown(true), self.get_channel_update_for_broadcast(&channel).ok())) - }, - }; - handle_errors.push((counterparty_node_id, err)); - continue; - } - }; - match self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) { - ChannelMonitorUpdateStatus::Completed => {}, - e => { - handle_errors.push((chan.get().get_counterparty_node_id(), handle_monitor_update_res!(self, e, chan, RAACommitmentOrder::CommitmentFirst, false, true))); - continue; + if !add_htlc_msgs.is_empty() || !fail_htlc_msgs.is_empty() { + let (commitment_msg, monitor_update) = match chan.get_mut().send_commitment(&self.logger) { + Ok(res) => res, + Err(e) => { + // We surely failed send_commitment due to bad keys, in that case + // close channel and then send error message to peer. + let counterparty_node_id = chan.get().get_counterparty_node_id(); + let err: Result<(), _> = match e { + ChannelError::Ignore(_) | ChannelError::Warn(_) => { + panic!("Stated return value requirements in send_commitment() were not met"); + } + ChannelError::Close(msg) => { + log_trace!(self.logger, "Closing channel {} due to Close-required error: {}", log_bytes!(chan.key()[..]), msg); + let mut channel = remove_channel!(self, chan); + // ChannelClosed event is generated by handle_error for us. + Err(MsgHandleErrInternal::from_finish_shutdown(msg, channel.channel_id(), channel.get_user_id(), channel.force_shutdown(true), self.get_channel_update_for_broadcast(&channel).ok())) + }, + }; + handle_errors.push((counterparty_node_id, err)); + continue; + } + }; + match self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) { + ChannelMonitorUpdateStatus::Completed => {}, + e => { + handle_errors.push((chan.get().get_counterparty_node_id(), handle_monitor_update_res!(self, e, chan, RAACommitmentOrder::CommitmentFirst, false, true))); + continue; + } } + log_debug!(self.logger, "Forwarding HTLCs resulted in a commitment update with {} HTLCs added and {} HTLCs failed for channel {}", + add_htlc_msgs.len(), fail_htlc_msgs.len(), log_bytes!(chan.get().channel_id())); + channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs { + node_id: chan.get().get_counterparty_node_id(), + updates: msgs::CommitmentUpdate { + update_add_htlcs: add_htlc_msgs, + update_fulfill_htlcs: Vec::new(), + update_fail_htlcs: fail_htlc_msgs, + update_fail_malformed_htlcs: Vec::new(), + update_fee: None, + commitment_signed: commitment_msg, + }, + }); } - log_debug!(self.logger, "Forwarding HTLCs resulted in a commitment update with {} HTLCs added and {} HTLCs failed for channel {}", - add_htlc_msgs.len(), fail_htlc_msgs.len(), log_bytes!(chan.get().channel_id())); - channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs { - node_id: chan.get().get_counterparty_node_id(), - updates: msgs::CommitmentUpdate { - update_add_htlcs: add_htlc_msgs, - update_fulfill_htlcs: Vec::new(), - update_fail_htlcs: fail_htlc_msgs, - update_fail_malformed_htlcs: Vec::new(), - update_fee: None, - commitment_signed: commitment_msg, - }, - }); } - } else { - forwarding_channel_not_found!(); - continue; } } else { for forward_info in pending_forwards.drain(..) { -- 2.39.5