Handle monitor update failure during funding on the fundee side
[rust-lightning] / src / ln / channel.rs
index 6dd7e8c82ddb285748586635e424d6a01f6016df..bcc91508f9bfc6f444bec5e94594ccee671d7e1c 100644 (file)
@@ -181,9 +181,9 @@ enum ChannelState {
        /// "disconnected" and no updates are allowed until after we've done a channel_reestablish
        /// dance.
        PeerDisconnected = (1 << 7),
-       /// Flag which is set on ChannelFunded and FundingSent indicating the user has told us they
-       /// failed to update our ChannelMonitor somewhere and we should pause sending any outbound
-       /// messages until they've managed to do so.
+       /// Flag which is set on ChannelFunded, FundingCreated, and FundingSent indicating the user has
+       /// told us they failed to update our ChannelMonitor somewhere and we should pause sending any
+       /// outbound messages until they've managed to do so.
        MonitorUpdateFailed = (1 << 8),
        /// Flag which implies that we have sent a commitment_signed but are awaiting the responding
        /// revoke_and_ack message. During this time period, we can't generate new commitment_signed
@@ -248,6 +248,7 @@ pub(super) struct Channel {
        /// send it first.
        resend_order: RAACommitmentOrder,
 
+       monitor_pending_funding_locked: bool,
        monitor_pending_revoke_and_ack: bool,
        monitor_pending_commitment_signed: bool,
        monitor_pending_forwards: Vec<(PendingForwardHTLCInfo, u64)>,
@@ -457,6 +458,7 @@ impl Channel {
 
                        resend_order: RAACommitmentOrder::CommitmentFirst,
 
+                       monitor_pending_funding_locked: false,
                        monitor_pending_revoke_and_ack: false,
                        monitor_pending_commitment_signed: false,
                        monitor_pending_forwards: Vec::new(),
@@ -672,6 +674,7 @@ impl Channel {
 
                        resend_order: RAACommitmentOrder::CommitmentFirst,
 
+                       monitor_pending_funding_locked: false,
                        monitor_pending_revoke_and_ack: false,
                        monitor_pending_commitment_signed: false,
                        monitor_pending_forwards: Vec::new(),
@@ -2352,11 +2355,29 @@ impl Channel {
        /// Indicates that the latest ChannelMonitor update has been committed by the client
        /// successfully and we should restore normal operation. Returns messages which should be sent
        /// to the remote side.
-       pub fn monitor_updating_restored(&mut self) -> (Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, RAACommitmentOrder, Vec<(PendingForwardHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, bool) {
+       pub fn monitor_updating_restored(&mut self) -> (Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, RAACommitmentOrder, Vec<(PendingForwardHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, bool, Option<msgs::FundingLocked>) {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, ChannelState::MonitorUpdateFailed as u32);
                self.channel_state &= !(ChannelState::MonitorUpdateFailed as u32);
+
                let needs_broadcast_safe = self.channel_state & (ChannelState::FundingSent as u32) != 0 && self.channel_outbound;
 
+               // Because we will never generate a FundingBroadcastSafe event when we're in
+               // MonitorUpdateFailed, if we assume the user only broadcast the funding transaction when
+               // they received the FundingBroadcastSafe event, we can only ever hit
+               // monitor_pending_funding_locked when we're an inbound channel which failed to persist the
+               // monitor on funding_created, and we even got the funding transaction confirmed before the
+               // monitor was persisted.
+               let funding_locked = if self.monitor_pending_funding_locked {
+                       assert!(!self.channel_outbound, "Funding transaction broadcast without FundingBroadcastSafe!");
+                       self.monitor_pending_funding_locked = false;
+                       let next_per_commitment_secret = self.build_local_commitment_secret(self.cur_local_commitment_transaction_number);
+                       let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &next_per_commitment_secret);
+                       Some(msgs::FundingLocked {
+                               channel_id: self.channel_id(),
+                               next_per_commitment_point: next_per_commitment_point,
+                       })
+               } else { None };
+
                let mut forwards = Vec::new();
                mem::swap(&mut forwards, &mut self.monitor_pending_forwards);
                let mut failures = Vec::new();
@@ -2365,7 +2386,7 @@ impl Channel {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) != 0 {
                        self.monitor_pending_revoke_and_ack = false;
                        self.monitor_pending_commitment_signed = false;
-                       return (None, None, RAACommitmentOrder::RevokeAndACKFirst, forwards, failures, needs_broadcast_safe);
+                       return (None, None, RAACommitmentOrder::RevokeAndACKFirst, forwards, failures, needs_broadcast_safe, funding_locked);
                }
 
                let raa = if self.monitor_pending_revoke_and_ack {
@@ -2383,7 +2404,7 @@ impl Channel {
                        if commitment_update.is_some() { "a" } else { "no" },
                        if raa.is_some() { "an" } else { "no" },
                        match order { RAACommitmentOrder::CommitmentFirst => "commitment", RAACommitmentOrder::RevokeAndACKFirst => "RAA"});
-               (raa, commitment_update, order, forwards, failures, needs_broadcast_safe)
+               (raa, commitment_update, order, forwards, failures, needs_broadcast_safe, funding_locked)
        }
 
        pub fn update_fee(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::UpdateFee) -> Result<(), ChannelError> {
@@ -2493,7 +2514,9 @@ impl Channel {
                } else { None };
 
                if self.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 {
-                       if self.channel_state & ChannelState::OurFundingLocked as u32 == 0 {
+                       // If we're waiting on a monitor update, we shouldn't re-send any funding_locked's.
+                       if self.channel_state & (ChannelState::OurFundingLocked as u32) == 0 ||
+                                       self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
                                if msg.next_remote_commitment_number != 0 {
                                        return Err(ChannelError::Close("Peer claimed they saw a revoke_and_ack but we haven't sent funding_locked yet"));
                                }
@@ -2984,12 +3007,17 @@ impl Channel {
                                        //they can by sending two revoke_and_acks back-to-back, but not really). This appears to be
                                        //a protocol oversight, but I assume I'm just missing something.
                                        if need_commitment_update {
-                                               let next_per_commitment_secret = self.build_local_commitment_secret(self.cur_local_commitment_transaction_number);
-                                               let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &next_per_commitment_secret);
-                                               return Ok(Some(msgs::FundingLocked {
-                                                       channel_id: self.channel_id,
-                                                       next_per_commitment_point: next_per_commitment_point,
-                                               }));
+                                               if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 {
+                                                       let next_per_commitment_secret = self.build_local_commitment_secret(self.cur_local_commitment_transaction_number);
+                                                       let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &next_per_commitment_secret);
+                                                       return Ok(Some(msgs::FundingLocked {
+                                                               channel_id: self.channel_id,
+                                                               next_per_commitment_point: next_per_commitment_point,
+                                                       }));
+                                               } else {
+                                                       self.monitor_pending_funding_locked = true;
+                                                       return Ok(None);
+                                               }
                                        }
                                }
                        }
@@ -3708,6 +3736,7 @@ impl Writeable for Channel {
                        RAACommitmentOrder::RevokeAndACKFirst => 1u8.write(writer)?,
                }
 
+               self.monitor_pending_funding_locked.write(writer)?;
                self.monitor_pending_revoke_and_ack.write(writer)?;
                self.monitor_pending_commitment_signed.write(writer)?;
 
@@ -3875,6 +3904,7 @@ impl<R : ::std::io::Read> ReadableArgs<R, Arc<Logger>> for Channel {
                        _ => return Err(DecodeError::InvalidValue),
                };
 
+               let monitor_pending_funding_locked = Readable::read(reader)?;
                let monitor_pending_revoke_and_ack = Readable::read(reader)?;
                let monitor_pending_commitment_signed = Readable::read(reader)?;
 
@@ -3971,6 +4001,7 @@ impl<R : ::std::io::Read> ReadableArgs<R, Arc<Logger>> for Channel {
 
                        resend_order,
 
+                       monitor_pending_funding_locked,
                        monitor_pending_revoke_and_ack,
                        monitor_pending_commitment_signed,
                        monitor_pending_forwards,