Consistently clean up when failing in `internal_funding_created` 2023-11-robuster-chan-to-peer
authorMatt Corallo <git@bluematt.me>
Thu, 30 Nov 2023 00:04:09 +0000 (00:04 +0000)
committerMatt Corallo <git@bluematt.me>
Fri, 15 Dec 2023 21:08:14 +0000 (21:08 +0000)
When we fail to accept a counterparty's funding for various
reasons, we should ensure we call the correct cleanup methods in
`internal_funding_created` to remove the temporary data for the
channel in our various internal structs (primarily the SCID alias
map).

This adds the missing cleanup, using `convert_chan_phase_err`
consistently in all the error paths.

This also ensures we get a `ChannelClosed` event when relevant.

lightning/src/ln/channel.rs
lightning/src/ln/channelmanager.rs
lightning/src/ln/functional_test_utils.rs
lightning/src/ln/functional_tests.rs

index c5f2e0c7d43f423ad30ad4a5a58800a8ff522586..28842b1bf79d2b0f21d2367291338c898c76226f 100644 (file)
@@ -2920,6 +2920,20 @@ impl<SP: Deref> Channel<SP> where
                self.context.channel_state.clear_waiting_for_batch();
        }
 
+       /// Unsets the existing funding information.
+       ///
+       /// This must only be used if the channel has not yet completed funding and has not been used.
+       ///
+       /// Further, the channel must be immediately shut down after this with a call to
+       /// [`ChannelContext::force_shutdown`].
+       pub fn unset_funding_info(&mut self, temporary_channel_id: ChannelId) {
+               debug_assert!(matches!(
+                       self.context.channel_state, ChannelState::AwaitingChannelReady(_)
+               ));
+               self.context.channel_transaction_parameters.funding_outpoint = None;
+               self.context.channel_id = temporary_channel_id;
+       }
+
        /// Handles a channel_ready message from our peer. If we've already sent our channel_ready
        /// and the channel is now usable (and public), this may generate an announcement_signatures to
        /// reply with.
index 9d5cf7e903ea088da51dac9fc951115f8aab49b3..08296c4346d834fbcdd7878e938565a6fa4334d6 100644 (file)
@@ -1251,7 +1251,10 @@ where
        /// required to access the channel with the `counterparty_node_id`.
        ///
        /// See `ChannelManager` struct-level documentation for lock order requirements.
+       #[cfg(not(test))]
        outpoint_to_peer: Mutex<HashMap<OutPoint, PublicKey>>,
+       #[cfg(test)]
+       pub(crate) outpoint_to_peer: Mutex<HashMap<OutPoint, PublicKey>>,
 
        /// SCIDs (and outbound SCID aliases) -> `counterparty_node_id`s and `channel_id`s.
        ///
@@ -6205,44 +6208,55 @@ where
 
                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
                let peer_state = &mut *peer_state_lock;
-               let (chan, funding_msg_opt, monitor) =
+               let (mut chan, funding_msg_opt, monitor) =
                        match peer_state.channel_by_id.remove(&msg.temporary_channel_id) {
                                Some(ChannelPhase::UnfundedInboundV1(inbound_chan)) => {
                                        let logger = WithChannelContext::from(&self.logger, &inbound_chan.context);
                                        match inbound_chan.funding_created(msg, best_block, &self.signer_provider, &&logger) {
                                                Ok(res) => res,
-                                               Err((mut inbound_chan, err)) => {
+                                               Err((inbound_chan, err)) => {
                                                        // We've already removed this inbound channel from the map in `PeerState`
                                                        // above so at this point we just need to clean up any lingering entries
                                                        // concerning this channel as it is safe to do so.
-                                                       update_maps_on_chan_removal!(self, &inbound_chan.context);
-                                                       let user_id = inbound_chan.context.get_user_id();
-                                                       let shutdown_res = inbound_chan.context.force_shutdown(false);
-                                                       return Err(MsgHandleErrInternal::from_finish_shutdown(format!("{}", err),
-                                                               msg.temporary_channel_id, user_id, shutdown_res, None, inbound_chan.context.get_value_satoshis()));
+                                                       debug_assert!(matches!(err, ChannelError::Close(_)));
+                                                       // Really we should be returning the channel_id the peer expects based
+                                                       // on their funding info here, but they're horribly confused anyway, so
+                                                       // there's not a lot we can do to save them.
+                                                       return Err(convert_chan_phase_err!(self, err, &mut ChannelPhase::UnfundedInboundV1(inbound_chan), &msg.temporary_channel_id).1);
                                                },
                                        }
                                },
-                               Some(ChannelPhase::Funded(_)) | Some(ChannelPhase::UnfundedOutboundV1(_)) => {
-                                       return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got an unexpected funding_created message from peer with counterparty_node_id {}", counterparty_node_id), msg.temporary_channel_id));
+                               Some(mut phase) => {
+                                       let err_msg = format!("Got an unexpected funding_created message from peer with counterparty_node_id {}", counterparty_node_id);
+                                       let err = ChannelError::Close(err_msg);
+                                       return Err(convert_chan_phase_err!(self, err, &mut phase, &msg.temporary_channel_id).1);
                                },
                                None => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.temporary_channel_id))
                        };
 
-               match peer_state.channel_by_id.entry(chan.context.channel_id()) {
+               let funded_channel_id = chan.context.channel_id();
+
+               macro_rules! fail_chan { ($err: expr) => { {
+                       // Note that at this point we've filled in the funding outpoint on our
+                       // channel, but its actually in conflict with another channel. Thus, if
+                       // we call `convert_chan_phase_err` immediately (thus calling
+                       // `update_maps_on_chan_removal`), we'll remove the existing channel
+                       // from `outpoint_to_peer`. Thus, we must first unset the funding outpoint
+                       // on the channel.
+                       let err = ChannelError::Close($err.to_owned());
+                       chan.unset_funding_info(msg.temporary_channel_id);
+                       return Err(convert_chan_phase_err!(self, err, chan, &funded_channel_id, UNFUNDED_CHANNEL).1);
+               } } }
+
+               match peer_state.channel_by_id.entry(funded_channel_id) {
                        hash_map::Entry::Occupied(_) => {
-                               Err(MsgHandleErrInternal::send_err_msg_no_close(
-                                       "Already had channel with the new channel_id".to_owned(),
-                                       chan.context.channel_id()
-                               ))
+                               fail_chan!("Already had channel with the new channel_id");
                        },
                        hash_map::Entry::Vacant(e) => {
                                let mut outpoint_to_peer_lock = self.outpoint_to_peer.lock().unwrap();
                                match outpoint_to_peer_lock.entry(monitor.get_funding_txo().0) {
                                        hash_map::Entry::Occupied(_) => {
-                                               return Err(MsgHandleErrInternal::send_err_msg_no_close(
-                                                       "The funding_created message had the same funding_txid as an existing channel - funding is not possible".to_owned(),
-                                                       chan.context.channel_id()))
+                                               fail_chan!("The funding_created message had the same funding_txid as an existing channel - funding is not possible");
                                        },
                                        hash_map::Entry::Vacant(i_e) => {
                                                let monitor_res = self.chain_monitor.watch_channel(monitor.get_funding_txo().0, monitor);
@@ -6271,13 +6285,7 @@ where
                                                } else {
                                                        let logger = WithChannelContext::from(&self.logger, &chan.context);
                                                        log_error!(logger, "Persisting initial ChannelMonitor failed, implying the funding outpoint was duplicated");
-                                                       let channel_id = match funding_msg_opt {
-                                                               Some(msg) => msg.channel_id,
-                                                               None => chan.context.channel_id(),
-                                                       };
-                                                       return Err(MsgHandleErrInternal::send_err_msg_no_close(
-                                                               "The funding_created message had the same funding_txid as an existing channel - funding is not possible".to_owned(),
-                                                               channel_id));
+                                                       fail_chan!("Duplicate funding outpoint");
                                                }
                                        }
                                }
index d3d2e3322cafb79f58573d6e18aa7deb84672709..eba30404f4d38ea73b73599fc769e18c93aca974 100644 (file)
@@ -1536,6 +1536,18 @@ pub struct ExpectedCloseEvent {
        pub reason: Option<ClosureReason>,
 }
 
+impl ExpectedCloseEvent {
+       pub fn from_id_reason(channel_id: ChannelId, discard_funding: bool, reason: ClosureReason) -> Self {
+               Self {
+                       channel_capacity_sats: None,
+                       channel_id: Some(channel_id),
+                       counterparty_node_id: None,
+                       discard_funding,
+                       reason: Some(reason),
+               }
+       }
+}
+
 /// Check that multiple channel closing events have been issued.
 pub fn check_closed_events(node: &Node, expected_close_events: &[ExpectedCloseEvent]) {
        let closed_events_count = expected_close_events.len();
index fee3a3b399475d885ee1ac7996f9f246c771eb81..fca6abb35969ef25b3a929a6eed34a45db448784 100644 (file)
@@ -8970,6 +8970,54 @@ fn test_duplicate_temporary_channel_id_from_different_peers() {
        }
 }
 
+#[test]
+fn test_duplicate_funding_err_in_funding() {
+       // Test that if we have a live channel with one peer, then another peer comes along and tries
+       // to create a second channel with the same txid we'll fail and not overwrite the
+       // outpoint_to_peer map in `ChannelManager`.
+       //
+       // This was previously broken.
+       let chanmon_cfgs = create_chanmon_cfgs(3);
+       let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
+       let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
+
+       let (_, _, _, real_channel_id, funding_tx) = create_chan_between_nodes(&nodes[0], &nodes[1]);
+       let real_chan_funding_txo = chain::transaction::OutPoint { txid: funding_tx.txid(), index: 0 };
+       assert_eq!(real_chan_funding_txo.to_channel_id(), real_channel_id);
+
+       nodes[2].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, 0, 42, None, None).unwrap();
+       let mut open_chan_msg = get_event_msg!(nodes[2], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
+       let node_c_temp_chan_id = open_chan_msg.temporary_channel_id;
+       open_chan_msg.temporary_channel_id = real_channel_id;
+       nodes[1].node.handle_open_channel(&nodes[2].node.get_our_node_id(), &open_chan_msg);
+       let mut accept_chan_msg = get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, nodes[2].node.get_our_node_id());
+       accept_chan_msg.temporary_channel_id = node_c_temp_chan_id;
+       nodes[2].node.handle_accept_channel(&nodes[1].node.get_our_node_id(), &accept_chan_msg);
+
+       // Now that we have a second channel with the same funding txo, send a bogus funding message
+       // and let nodes[1] remove the inbound channel.
+       let (_, funding_tx, _) = create_funding_transaction(&nodes[2], &nodes[1].node.get_our_node_id(), 100_000, 42);
+
+       nodes[2].node.funding_transaction_generated(&node_c_temp_chan_id, &nodes[1].node.get_our_node_id(), funding_tx).unwrap();
+
+       let mut funding_created_msg = get_event_msg!(nodes[2], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id());
+       funding_created_msg.temporary_channel_id = real_channel_id;
+       // Make the signature invalid by changing the funding output
+       funding_created_msg.funding_output_index += 10;
+       nodes[1].node.handle_funding_created(&nodes[2].node.get_our_node_id(), &funding_created_msg);
+       get_err_msg(&nodes[1], &nodes[2].node.get_our_node_id());
+       let err = "Invalid funding_created signature from peer".to_owned();
+       let reason = ClosureReason::ProcessingError { err };
+       let expected_closing = ExpectedCloseEvent::from_id_reason(real_channel_id, false, reason);
+       check_closed_events(&nodes[1], &[expected_closing]);
+
+       assert_eq!(
+               *nodes[1].node.outpoint_to_peer.lock().unwrap().get(&real_chan_funding_txo).unwrap(),
+               nodes[0].node.get_our_node_id()
+       );
+}
+
 #[test]
 fn test_duplicate_chan_id() {
        // Test that if a given peer tries to open a channel with the same channel_id as one that is
@@ -9080,6 +9128,12 @@ fn test_duplicate_chan_id() {
        // without trying to persist the `ChannelMonitor`.
        check_added_monitors!(nodes[1], 0);
 
+       check_closed_events(&nodes[1], &[
+               ExpectedCloseEvent::from_id_reason(channel_id, false, ClosureReason::ProcessingError {
+                       err: "Already had channel with the new channel_id".to_owned()
+               })
+       ]);
+
        // ...still, nodes[1] will reject the duplicate channel.
        {
                let events = nodes[1].node.get_and_clear_pending_msg_events();