Fix EnforcingChannelKeys panic when our counterparty burns their $.

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

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index b50a701f17c1c3c016085ab98131403a491e21f1..07ad171aa20eb394ee8dbbab0201628348c6703c 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -1993,6 +1993,17 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                self.channel_monitor.provide_secret(self.cur_remote_commitment_transaction_number + 1, msg.per_commitment_secret)
                        .map_err(|e| ChannelError::Close(e.0))?;
 
+               if self.channel_state & ChannelState::AwaitingRemoteRevoke as u32 == 0 {
+                       // Our counterparty seems to have burned their coins to us (by revoking a state when we
+                       // haven't given them a new commitment transaction to broadcast). We should probably
+                       // take advantage of this by updating our channel monitor, sending them an error, and
+                       // waiting for them to broadcast their latest (now-revoked claim). But, that would be a
+                       // lot of work, and there's some chance this is all a misunderstanding anyway.
+                       // We have to do *something*, though, since our signer may get mad at us for otherwise
+                       // jumping a remote commitment number, so best to just force-close and move on.
+                       return Err(ChannelError::Close("Got a revoke when we weren't expecting one"));
+               }
+
                // Update state now that we've passed all the can-fail calls...
                // (note that we may still fail to generate the new commitment_signed message, but that's
                // OK, we step the channel here and *then* if the new generation fails we can fail the