X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannel.rs;h=89b1fd191deb830d7ce11217c19ad3fe31281fdb;hb=ba1349982ba28657c9e2d03a5b02c3ecc054b5cc;hp=ce68e4273b28b774ae9c6655fd87e4b11b59adb6;hpb=8fcbe641286831c3678b073f9fd2a914829d8cd5;p=rust-lightning

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index ce68e427..89b1fd19 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -3134,9 +3134,24 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 			return Err(ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_stats.num_nondust_htlcs)));
 		}
 
-		// TODO: Sadly, we pass HTLCs twice to ChannelMonitor: once via the HolderCommitmentTransaction and once via the update
+		// Up to LDK 0.0.115, HTLC information was required to be duplicated in the
+		// `htlcs_and_sigs` vec and in the `holder_commitment_tx` itself, both of which were passed
+		// in the `ChannelMonitorUpdate`. In 0.0.115, support for having a separate set of
+		// outbound-non-dust-HTLCSources in the `ChannelMonitorUpdate` was added, however for
+		// backwards compatibility, we never use it in production. To provide test coverage, here,
+		// we randomly decide (in test/fuzzing builds) to use the new vec sometimes.
+		#[allow(unused_assignments, unused_mut)]
+		let mut separate_nondust_htlc_sources = false;
+		#[cfg(all(feature = "std", any(test, fuzzing)))] {
+			use core::hash::{BuildHasher, Hasher};
+			// Get a random value using the only std API to do so - the DefaultHasher
+			let rand_val = std::collections::hash_map::RandomState::new().build_hasher().finish();
+			separate_nondust_htlc_sources = rand_val % 2 == 0;
+		}
+
+		let mut nondust_htlc_sources = Vec::with_capacity(htlcs_cloned.len());
 		let mut htlcs_and_sigs = Vec::with_capacity(htlcs_cloned.len());
-		for (idx, (htlc, source)) in htlcs_cloned.drain(..).enumerate() {
+		for (idx, (htlc, mut source_opt)) in htlcs_cloned.drain(..).enumerate() {
 			if let Some(_) = htlc.transaction_output_index {
 				let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.feerate_per_kw,
 					self.get_counterparty_selected_contest_delay().unwrap(), &htlc, self.opt_anchors(),
@@ -3151,10 +3166,18 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 				if let Err(_) = self.secp_ctx.verify_ecdsa(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key) {
 					return Err(ChannelError::Close("Invalid HTLC tx signature from peer".to_owned()));
 				}
-				htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source));
+				if !separate_nondust_htlc_sources {
+					htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source_opt.take()));
+				}
 			} else {
-				htlcs_and_sigs.push((htlc, None, source));
+				htlcs_and_sigs.push((htlc, None, source_opt.take()));
+			}
+			if separate_nondust_htlc_sources {
+				if let Some(source) = source_opt.take() {
+					nondust_htlc_sources.push(source);
+				}
 			}
+			debug_assert!(source_opt.is_none(), "HTLCSource should have been put somewhere");
 		}
 
 		let holder_commitment_tx = HolderCommitmentTransaction::new(
@@ -3217,6 +3240,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 				commitment_tx: holder_commitment_tx,
 				htlc_outputs: htlcs_and_sigs,
 				claimed_htlcs,
+				nondust_htlc_sources,
 			}]
 		};