Update Channel::funding_signed to use ChannelMonitorUpdate
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 2a7c0949da0a3ce3d7a1b23aceddff3ab4ba1497..311cf2e4901425f96a163a93bf6931c675c9ba0b 100644 (file)
@@ -57,15 +57,19 @@ use std::ops::Deref;
 // forward the HTLC with information it will give back to us when it does so, or if it should Fail
 // the HTLC with the relevant message for the Channel to handle giving to the remote peer.
 //
-// When a Channel forwards an HTLC to its peer, it will give us back the PendingForwardHTLCInfo
-// which we will use to construct an outbound HTLC, with a relevant HTLCSource::PreviousHopData
-// filled in to indicate where it came from (which we can use to either fail-backwards or fulfill
-// the HTLC backwards along the relevant path).
+// Once said HTLC is committed in the Channel, if the PendingHTLCStatus indicated Forward, the
+// Channel will return the PendingHTLCInfo back to us, and we will create an HTLCForwardInfo
+// with it to track where it came from (in case of onwards-forward error), waiting a random delay
+// before we forward it.
+//
+// We will then use HTLCForwardInfo's PendingHTLCInfo to construct an outbound HTLC, with a
+// relevant HTLCSource::PreviousHopData filled in to indicate where it came from (which we can use
+// to either fail-backwards or fulfill the HTLC backwards along the relevant path).
 // Alternatively, we can fill an outbound HTLC with a HTLCSource::OutboundRoute indicating this is
 // our payment, which we can use to decode errors or inform the user that the payment was sent.
-/// Stores the info we will need to send when we want to forward an HTLC onwards
+
 #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
-pub(super) struct PendingForwardHTLCInfo {
+pub(super) struct PendingHTLCInfo {
        onion_packet: Option<msgs::OnionPacket>,
        incoming_shared_secret: [u8; 32],
        payment_hash: PaymentHash,
@@ -83,10 +87,22 @@ pub(super) enum HTLCFailureMsg {
 /// Stores whether we can't forward an HTLC or relevant forwarding info
 #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
 pub(super) enum PendingHTLCStatus {
-       Forward(PendingForwardHTLCInfo),
+       Forward(PendingHTLCInfo),
        Fail(HTLCFailureMsg),
 }
 
+pub(super) enum HTLCForwardInfo {
+       AddHTLC {
+               prev_short_channel_id: u64,
+               prev_htlc_id: u64,
+               forward_info: PendingHTLCInfo,
+       },
+       FailHTLC {
+               htlc_id: u64,
+               err_packet: msgs::OnionErrorPacket,
+       },
+}
+
 /// Tracks the inbound corresponding to an outbound HTLC
 #[derive(Clone, PartialEq)]
 pub(super) struct HTLCPreviousHopData {
@@ -231,18 +247,6 @@ impl MsgHandleErrInternal {
 /// second to 30 seconds, but people expect lightning to be, you know, kinda fast, sadly.
 const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u64 = 100;
 
-pub(super) enum HTLCForwardInfo {
-       AddHTLC {
-               prev_short_channel_id: u64,
-               prev_htlc_id: u64,
-               forward_info: PendingForwardHTLCInfo,
-       },
-       FailHTLC {
-               htlc_id: u64,
-               err_packet: msgs::OnionErrorPacket,
-       },
-}
-
 /// For events which result in both a RevokeAndACK and a CommitmentUpdate, by default they should
 /// be sent in the order they appear in the return value, however sometimes the order needs to be
 /// variable at runtime (eg Channel::channel_reestablish needs to re-send messages in the order
@@ -262,7 +266,7 @@ pub(super) struct ChannelHolder<ChanSigner: ChannelKeys> {
        /// short channel id -> forward infos. Key of 0 means payments received
        /// Note that while this is held in the same mutex as the channels themselves, no consistency
        /// guarantees are made about the existence of a channel with the short id here, nor the short
-       /// ids in the PendingForwardHTLCInfo!
+       /// ids in the PendingHTLCInfo!
        pub(super) forward_htlcs: HashMap<u64, Vec<HTLCForwardInfo>>,
        /// payment_hash -> Vec<(amount_received, htlc_source)> for tracking things that were to us and
        /// can be failed/claimed by the user
@@ -574,7 +578,7 @@ macro_rules! handle_monitor_err {
                                                        } else if $resend_commitment { "commitment" }
                                                        else if $resend_raa { "RAA" }
                                                        else { "nothing" },
-                                               (&$failed_forwards as &Vec<(PendingForwardHTLCInfo, u64)>).len(),
+                                               (&$failed_forwards as &Vec<(PendingHTLCInfo, u64)>).len(),
                                                (&$failed_fails as &Vec<(HTLCSource, PaymentHash, HTLCFailReason)>).len());
                                if !$resend_commitment {
                                        debug_assert!($action_type == RAACommitmentOrder::RevokeAndACKFirst || !$resend_raa);
@@ -969,7 +973,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref> ChannelManager<ChanSigner, M,
                                // instead we stay symmetric with the forwarding case, only responding (after a
                                // delay) once they've send us a commitment_signed!
 
-                               PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
+                               PendingHTLCStatus::Forward(PendingHTLCInfo {
                                        onion_packet: None,
                                        payment_hash: msg.payment_hash.clone(),
                                        short_channel_id: 0,
@@ -1021,7 +1025,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref> ChannelManager<ChanSigner, M,
                                        },
                                };
 
-                               PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
+                               PendingHTLCStatus::Forward(PendingHTLCInfo {
                                        onion_packet: Some(outgoing_packet),
                                        payment_hash: msg.payment_hash.clone(),
                                        short_channel_id: short_channel_id,
@@ -1032,7 +1036,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref> ChannelManager<ChanSigner, M,
                        };
 
                channel_state = Some(self.channel_state.lock().unwrap());
-               if let &PendingHTLCStatus::Forward(PendingForwardHTLCInfo { ref onion_packet, ref short_channel_id, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
+               if let &PendingHTLCStatus::Forward(PendingHTLCInfo { ref onion_packet, ref short_channel_id, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
                        if onion_packet.is_some() { // If short_channel_id is 0 here, we'll reject them in the body here
                                let id_option = channel_state.as_ref().unwrap().short_to_id.get(&short_channel_id).cloned();
                                let forwarding_id = match id_option {
@@ -1777,6 +1781,112 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref> ChannelManager<ChanSigner, M,
                PublicKey::from_secret_key(&self.secp_ctx, &self.our_network_key)
        }
 
+       /// Restores a single, given channel to normal operation after a
+       /// ChannelMonitorUpdateErr::TemporaryFailure was returned from a channel monitor update
+       /// operation.
+       ///
+       /// All ChannelMonitor updates up to and including highest_applied_update_id must have been
+       /// fully committed in every copy of the given channels' ChannelMonitors.
+       ///
+       /// Note that there is no effect to calling with a highest_applied_update_id other than the
+       /// current latest ChannelMonitorUpdate and one call to this function after multiple
+       /// ChannelMonitorUpdateErr::TemporaryFailures is fine. The highest_applied_update_id field
+       /// exists largely only to prevent races between this and concurrent update_monitor calls.
+       ///
+       /// Thus, the anticipated use is, at a high level:
+       ///  1) You register a ManyChannelMonitor with this ChannelManager,
+       ///  2) it stores each update to disk, and begins updating any remote (eg watchtower) copies of
+       ///     said ChannelMonitors as it can, returning ChannelMonitorUpdateErr::TemporaryFailures
+       ///     any time it cannot do so instantly,
+       ///  3) update(s) are applied to each remote copy of a ChannelMonitor,
+       ///  4) once all remote copies are updated, you call this function with the update_id that
+       ///     completed, and once it is the latest the Channel will be re-enabled.
+       pub fn channel_monitor_updated(&self, funding_txo: &OutPoint, highest_applied_update_id: u64) {
+               let _ = self.total_consistency_lock.read().unwrap();
+
+               let mut close_results = Vec::new();
+               let mut htlc_forwards = Vec::new();
+               let mut htlc_failures = Vec::new();
+               let mut pending_events = Vec::new();
+
+               {
+                       let mut channel_lock = self.channel_state.lock().unwrap();
+                       let channel_state = &mut *channel_lock;
+                       let short_to_id = &mut channel_state.short_to_id;
+                       let pending_msg_events = &mut channel_state.pending_msg_events;
+                       let channel = match channel_state.by_id.get_mut(&funding_txo.to_channel_id()) {
+                               Some(chan) => chan,
+                               None => return,
+                       };
+                       if !channel.is_awaiting_monitor_update() || channel.get_latest_monitor_update_id() != highest_applied_update_id {
+                               return;
+                       }
+
+                       let (raa, commitment_update, order, pending_forwards, mut pending_failures, needs_broadcast_safe, funding_locked) = channel.monitor_updating_restored();
+                       if !pending_forwards.is_empty() {
+                               htlc_forwards.push((channel.get_short_channel_id().expect("We can't have pending forwards before funding confirmation"), pending_forwards));
+                       }
+                       htlc_failures.append(&mut pending_failures);
+
+                       macro_rules! handle_cs { () => {
+                               if let Some(update) = commitment_update {
+                                       pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
+                                               node_id: channel.get_their_node_id(),
+                                               updates: update,
+                                       });
+                               }
+                       } }
+                       macro_rules! handle_raa { () => {
+                               if let Some(revoke_and_ack) = raa {
+                                       pending_msg_events.push(events::MessageSendEvent::SendRevokeAndACK {
+                                               node_id: channel.get_their_node_id(),
+                                               msg: revoke_and_ack,
+                                       });
+                               }
+                       } }
+                       match order {
+                               RAACommitmentOrder::CommitmentFirst => {
+                                       handle_cs!();
+                                       handle_raa!();
+                               },
+                               RAACommitmentOrder::RevokeAndACKFirst => {
+                                       handle_raa!();
+                                       handle_cs!();
+                               },
+                       }
+                       if needs_broadcast_safe {
+                               pending_events.push(events::Event::FundingBroadcastSafe {
+                                       funding_txo: channel.get_funding_txo().unwrap(),
+                                       user_channel_id: channel.get_user_id(),
+                               });
+                       }
+                       if let Some(msg) = funding_locked {
+                               pending_msg_events.push(events::MessageSendEvent::SendFundingLocked {
+                                       node_id: channel.get_their_node_id(),
+                                       msg,
+                               });
+                               if let Some(announcement_sigs) = self.get_announcement_sigs(channel) {
+                                       pending_msg_events.push(events::MessageSendEvent::SendAnnouncementSignatures {
+                                               node_id: channel.get_their_node_id(),
+                                               msg: announcement_sigs,
+                                       });
+                               }
+                               short_to_id.insert(channel.get_short_channel_id().unwrap(), channel.channel_id());
+                       }
+               }
+
+               self.pending_events.lock().unwrap().append(&mut pending_events);
+
+               for failure in htlc_failures.drain(..) {
+                       self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), failure.0, &failure.1, failure.2);
+               }
+               self.forward_htlcs(&mut htlc_forwards[..]);
+
+               for res in close_results.drain(..) {
+                       self.finish_force_close_channel(res);
+               }
+       }
+
        /// Used to restore channels to normal operation after a
        /// ChannelMonitorUpdateErr::TemporaryFailure was returned from a channel monitor update
        /// operation.
@@ -1995,8 +2105,8 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref> ChannelManager<ChanSigner, M,
                                        if chan.get().get_their_node_id() != *their_node_id {
                                                return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.channel_id));
                                        }
-                                       let chan_monitor = try_chan_entry!(self, chan.get_mut().funding_signed(&msg), channel_state, chan);
-                                       if let Err(e) = self.monitor.add_update_monitor(chan_monitor.get_funding_txo().unwrap(), chan_monitor) {
+                                       let monitor_update = try_chan_entry!(self, chan.get_mut().funding_signed(&msg), channel_state, chan);
+                                       if let Err(e) = self.monitor.update_monitor(chan.get().get_funding_txo().unwrap(), monitor_update) {
                                                return_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::RevokeAndACKFirst, false, false);
                                        }
                                        (chan.get().get_funding_txo().unwrap(), chan.get().get_user_id())
@@ -2158,7 +2268,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref> ChannelManager<ChanSigner, M,
                                        // 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 {
+                                       if let PendingHTLCStatus::Forward(PendingHTLCInfo { incoming_shared_secret, .. }) = pending_forward_info {
                                                let chan_update = self.get_channel_update(chan.get());
                                                pending_forward_info = PendingHTLCStatus::Fail(HTLCFailureMsg::Relay(msgs::UpdateFailHTLC {
                                                        channel_id: msg.channel_id,
@@ -2289,7 +2399,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref> ChannelManager<ChanSigner, M,
        }
 
        #[inline]
-       fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, Vec<(PendingForwardHTLCInfo, u64)>)]) {
+       fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, Vec<(PendingHTLCInfo, u64)>)]) {
                for &mut (prev_short_channel_id, ref mut pending_forwards) in per_source_pending_forwards {
                        let mut forward_event = None;
                        if !pending_forwards.is_empty() {
@@ -3016,7 +3126,7 @@ impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send, T: Deref + Sync + Send> Ch
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
-impl Writeable for PendingForwardHTLCInfo {
+impl Writeable for PendingHTLCInfo {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
                self.onion_packet.write(writer)?;
                self.incoming_shared_secret.write(writer)?;
@@ -3028,9 +3138,9 @@ impl Writeable for PendingForwardHTLCInfo {
        }
 }
 
-impl<R: ::std::io::Read> Readable<R> for PendingForwardHTLCInfo {
-       fn read(reader: &mut R) -> Result<PendingForwardHTLCInfo, DecodeError> {
-               Ok(PendingForwardHTLCInfo {
+impl<R: ::std::io::Read> Readable<R> for PendingHTLCInfo {
+       fn read(reader: &mut R) -> Result<PendingHTLCInfo, DecodeError> {
+               Ok(PendingHTLCInfo {
                        onion_packet: Readable::read(reader)?,
                        incoming_shared_secret: Readable::read(reader)?,
                        payment_hash: Readable::read(reader)?,
@@ -3342,12 +3452,13 @@ impl<'a, R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>, M: Deref, T
                                return Err(DecodeError::InvalidValue);
                        }
 
-                       let funding_txo = channel.channel_monitor().get_funding_txo().ok_or(DecodeError::InvalidValue)?;
+                       let funding_txo = channel.get_funding_txo().ok_or(DecodeError::InvalidValue)?;
                        funding_txo_set.insert(funding_txo.clone());
                        if let Some(ref mut monitor) = args.channel_monitors.get_mut(&funding_txo) {
                                if channel.get_cur_local_commitment_transaction_number() != monitor.get_cur_local_commitment_number() ||
                                                channel.get_revoked_remote_commitment_transaction_number() != monitor.get_min_seen_secret() ||
-                                               channel.get_cur_remote_commitment_transaction_number() != monitor.get_cur_remote_commitment_number() {
+                                               channel.get_cur_remote_commitment_transaction_number() != monitor.get_cur_remote_commitment_number() ||
+                                               channel.get_latest_monitor_update_id() != monitor.get_latest_update_id() {
                                        let mut force_close_res = channel.force_shutdown();
                                        force_close_res.0 = monitor.get_latest_local_commitment_txn();
                                        closed_channels.push(force_close_res);