Check if funding transaction is final for propagation

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

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 3fa136e9af862403f5957dd245c53d6951ccf3b1..b9971d8148cbf356dca7688abc5ea59c0955e78b 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -2783,6 +2783,9 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        /// Returns an [`APIError::APIMisuseError`] if the funding_transaction spent non-SegWit outputs
        /// or if no output was found which matches the parameters in [`Event::FundingGenerationReady`].
        ///
+       /// Returns [`APIError::APIMisuseError`] if the funding transaction is not final for propagation
+       /// across the p2p network.
+       ///
        /// Returns [`APIError::ChannelUnavailable`] if a funding transaction has already been provided
        /// for the channel or if the channel has been closed as indicated by [`Event::ChannelClosed`].
        ///
@@ -2810,6 +2813,18 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                });
                        }
                }
+               {
+                       let height = self.best_block.read().unwrap().height();
+                       // Transactions are evaluated as final by network mempools at the next block. However, the modules
+                       // constituting our Lightning node might not have perfect sync about their blockchain views. Thus, if
+                       // the wallet module is in advance on the LDK view, allow one more block of headroom.
+                       // TODO: updated if/when https://github.com/rust-bitcoin/rust-bitcoin/pull/994 landed and rust-bitcoin bumped.
+                       if !funding_transaction.input.iter().all(|input| input.sequence == 0xffffffff) && funding_transaction.lock_time < 500_000_000 && funding_transaction.lock_time > height + 2 {
+                               return Err(APIError::APIMisuseError {
+                                       err: "Funding transaction absolute timelock is non-final".to_owned()
+                               });
+                       }
+               }
                self.funding_transaction_generated_intern(temporary_channel_id, counterparty_node_id, funding_transaction, |chan, tx| {
                        let mut output_index = None;
                        let expected_spk = chan.get_funding_redeemscript().to_v0_p2wsh();