Fail incoming HTLCs sent after we start shutdown, not the chan

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index 9d58caf9a1450aff9847be6946c073b96bee0cb4..e0768e37cc1a67553ed94d3b3740dc42ab96e36a 100644 (file)
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -1553,6 +1553,12 @@ impl Channel {
 
                //TODO: Check msg.cltv_expiry further? Do this in channel manager?
 
+               if self.channel_state & ChannelState::LocalShutdownSent as u32 != 0 {
+                       if let PendingHTLCStatus::Forward(_) = pending_forward_state {
+                               panic!("ChannelManager shouldn't be trying to add a forwardable HTLC after we've started closing");
+                       }
+               }
+
                // Now update local state:
                self.next_remote_htlc_id += 1;
                self.pending_inbound_htlcs.push(InboundHTLCOutput {

diff --git a/src/ln/channelmanager.rs b/src/ln/channelmanager.rs
index 28444d75ae683a45adc8393d5a4ff2300b057710..80f0d9635040951b8f5069c5e9a8122ba9500050 100644 (file)
--- a/src/ln/channelmanager.rs
+++ b/src/ln/channelmanager.rs
@@ -1929,7 +1929,7 @@ impl ChannelManager {
                //encrypted with the same key. Its not immediately obvious how to usefully exploit that,
                //but we should prevent it anyway.
 
-               let (pending_forward_info, mut channel_state_lock) = self.decode_update_add_htlc_onion(msg);
+               let (mut pending_forward_info, mut channel_state_lock) = self.decode_update_add_htlc_onion(msg);
                let channel_state = channel_state_lock.borrow_parts();
 
                match channel_state.by_id.get_mut(&msg.channel_id) {
@@ -1939,7 +1939,16 @@ impl ChannelManager {
                                        return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.channel_id));
                                }
                                if !chan.is_usable() {
-                                       return Err(MsgHandleErrInternal::from_no_close(HandleError{err: "Channel not yet available for receiving HTLCs", action: Some(msgs::ErrorAction::IgnoreError)}));
+                                       // If the update_add is completely bogus, the call will Err and we will close,
+                                       // but if we've sent a shutdown and they haven't acknowledged it yet, we just
+                                       // want to reject the new HTLC and fail it backwards instead of forwarding.
+                                       if let PendingHTLCStatus::Forward(PendingForwardHTLCInfo { incoming_shared_secret, .. }) = pending_forward_info {
+                                               pending_forward_info = PendingHTLCStatus::Fail(HTLCFailureMsg::Relay(msgs::UpdateFailHTLC {
+                                                       channel_id: msg.channel_id,
+                                                       htlc_id: msg.htlc_id,
+                                                       reason: ChannelManager::build_first_hop_failure_packet(&incoming_shared_secret, 0x1000|20, &self.get_channel_update(chan).unwrap().encode_with_len()[..]),
+                                               }));
+                                       }
                                }
                                chan.update_add_htlc(&msg, pending_forward_info).map_err(|e| MsgHandleErrInternal::from_maybe_close(e))
                        },