Track claimed outbound HTLCs in ChannelMonitors

[rust-lightning] / lightning / src / ln / channel.rs

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 2b9920aa2bae50879764b632f6f071588a14f89d..842c91180868c3d21a95feff20b303aba7c5288d 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -27,7 +27,7 @@ use crate::ln::features::{ChannelTypeFeatures, InitFeatures};
 use crate::ln::msgs;
 use crate::ln::msgs::{DecodeError, OptionalField, DataLossProtect};
 use crate::ln::script::{self, ShutdownScript};
-use crate::ln::channelmanager::{self, CounterpartyForwardingInfo, PendingHTLCStatus, HTLCSource, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+use crate::ln::channelmanager::{self, CounterpartyForwardingInfo, PendingHTLCStatus, HTLCSource, SentHTLCId, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
 use crate::ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, htlc_success_tx_weight, htlc_timeout_tx_weight, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor, ClosingTransaction};
 use crate::ln::chan_utils;
 use crate::ln::onion_utils::HTLCFailReason;
@@ -192,6 +192,7 @@ enum OutboundHTLCState {
 
 #[derive(Clone)]
 enum OutboundHTLCOutcome {
+       /// LDK version 0.0.105+ will always fill in the preimage here.
        Success(Option<PaymentPreimage>),
        Failure(HTLCFailReason),
 }
@@ -3159,15 +3160,6 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                        }
                }
 
-               self.latest_monitor_update_id += 1;
-               let mut monitor_update = ChannelMonitorUpdate {
-                       update_id: self.latest_monitor_update_id,
-                       updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
-                               commitment_tx: holder_commitment_tx,
-                               htlc_outputs: htlcs_and_sigs
-                       }]
-               };
-
                for htlc in self.pending_inbound_htlcs.iter_mut() {
                        let new_forward = if let &InboundHTLCState::RemoteAnnounced(ref forward_info) = &htlc.state {
                                Some(forward_info.clone())
@@ -3179,6 +3171,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                                need_commitment = true;
                        }
                }
+               let mut claimed_htlcs = Vec::new();
                for htlc in self.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 {}.",
@@ -3186,11 +3179,30 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                                // 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;
                        }
                }
 
+               self.latest_monitor_update_id += 1;
+               let mut monitor_update = ChannelMonitorUpdate {
+                       update_id: self.latest_monitor_update_id,
+                       updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
+                               commitment_tx: holder_commitment_tx,
+                               htlc_outputs: htlcs_and_sigs,
+                               claimed_htlcs,
+                       }]
+               };
+
                self.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.