Merge pull request #2367 from wpaulino/remove-anchors-flag
[rust-lightning] / lightning / src / ln / channel.rs
index ba9fd5eb03f07401707d668062fe05ac95723b50..4d6e02ccf69e4bdfa3e4fc3136991bae3fe1cdba 100644 (file)
@@ -488,13 +488,13 @@ enum UpdateFulfillFetch {
 }
 
 /// The return type of get_update_fulfill_htlc_and_commit.
-pub enum UpdateFulfillCommitFetch<'a> {
+pub enum UpdateFulfillCommitFetch {
        /// Indicates the HTLC fulfill is new, and either generated an update_fulfill message, placed
        /// it in the holding cell, or re-generated the update_fulfill message after the same claim was
        /// previously placed in the holding cell (and has since been removed).
        NewClaim {
                /// The ChannelMonitorUpdate which places the new payment preimage in the channel monitor
-               monitor_update: &'a ChannelMonitorUpdate,
+               monitor_update: ChannelMonitorUpdate,
                /// The value of the HTLC which was claimed, in msat.
                htlc_value_msat: u64,
        },
@@ -588,17 +588,10 @@ pub(crate) const DISCONNECT_PEER_AWAITING_RESPONSE_TICKS: usize = 2;
 
 struct PendingChannelMonitorUpdate {
        update: ChannelMonitorUpdate,
-       /// In some cases we need to delay letting the [`ChannelMonitorUpdate`] go until after an
-       /// `Event` is processed by the user. This bool indicates the [`ChannelMonitorUpdate`] is
-       /// blocked on some external event and the [`ChannelManager`] will update us when we're ready.
-       ///
-       /// [`ChannelManager`]: super::channelmanager::ChannelManager
-       blocked: bool,
 }
 
 impl_writeable_tlv_based!(PendingChannelMonitorUpdate, {
        (0, update, required),
-       (2, blocked, required),
 });
 
 /// Contains everything about the channel including state, and various flags.
@@ -869,11 +862,9 @@ pub(super) struct ChannelContext<Signer: ChannelSigner> {
        /// [`SignerProvider::derive_channel_signer`].
        channel_keys_id: [u8; 32],
 
-       /// When we generate [`ChannelMonitorUpdate`]s to persist, they may not be persisted immediately.
-       /// If we then persist the [`channelmanager::ChannelManager`] and crash before the persistence
-       /// completes we still need to be able to complete the persistence. Thus, we have to keep a
-       /// copy of the [`ChannelMonitorUpdate`] here until it is complete.
-       pending_monitor_updates: Vec<PendingChannelMonitorUpdate>,
+       /// If we can't release a [`ChannelMonitorUpdate`] until some external action completes, we
+       /// store it here and only release it to the `ChannelManager` once it asks for it.
+       blocked_monitor_updates: Vec<PendingChannelMonitorUpdate>,
 }
 
 impl<Signer: ChannelSigner> ChannelContext<Signer> {
@@ -2259,7 +2250,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
        }
 
        pub fn get_update_fulfill_htlc_and_commit<L: Deref>(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage, logger: &L) -> UpdateFulfillCommitFetch where L::Target: Logger {
-               let release_cs_monitor = self.context.pending_monitor_updates.iter().all(|upd| !upd.blocked);
+               let release_cs_monitor = self.context.blocked_monitor_updates.is_empty();
                match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger) {
                        UpdateFulfillFetch::NewClaim { mut monitor_update, htlc_value_msat, msg } => {
                                // Even if we aren't supposed to let new monitor updates with commitment state
@@ -2267,43 +2258,30 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                                // matter what. Sadly, to push a new monitor update which flies before others
                                // already queued, we have to insert it into the pending queue and update the
                                // update_ids of all the following monitors.
-                               let unblocked_update_pos = if release_cs_monitor && msg.is_some() {
+                               if release_cs_monitor && msg.is_some() {
                                        let mut additional_update = self.build_commitment_no_status_check(logger);
                                        // build_commitment_no_status_check may bump latest_monitor_id but we want them
                                        // to be strictly increasing by one, so decrement it here.
                                        self.context.latest_monitor_update_id = monitor_update.update_id;
                                        monitor_update.updates.append(&mut additional_update.updates);
-                                       self.context.pending_monitor_updates.push(PendingChannelMonitorUpdate {
-                                               update: monitor_update, blocked: false,
-                                       });
-                                       self.context.pending_monitor_updates.len() - 1
                                } else {
-                                       let insert_pos = self.context.pending_monitor_updates.iter().position(|upd| upd.blocked)
-                                               .unwrap_or(self.context.pending_monitor_updates.len());
-                                       let new_mon_id = self.context.pending_monitor_updates.get(insert_pos)
+                                       let new_mon_id = self.context.blocked_monitor_updates.get(0)
                                                .map(|upd| upd.update.update_id).unwrap_or(monitor_update.update_id);
                                        monitor_update.update_id = new_mon_id;
-                                       self.context.pending_monitor_updates.insert(insert_pos, PendingChannelMonitorUpdate {
-                                               update: monitor_update, blocked: false,
-                                       });
-                                       for held_update in self.context.pending_monitor_updates.iter_mut().skip(insert_pos + 1) {
+                                       for held_update in self.context.blocked_monitor_updates.iter_mut() {
                                                held_update.update.update_id += 1;
                                        }
                                        if msg.is_some() {
                                                debug_assert!(false, "If there is a pending blocked monitor we should have MonitorUpdateInProgress set");
                                                let update = self.build_commitment_no_status_check(logger);
-                                               self.context.pending_monitor_updates.push(PendingChannelMonitorUpdate {
-                                                       update, blocked: true,
+                                               self.context.blocked_monitor_updates.push(PendingChannelMonitorUpdate {
+                                                       update,
                                                });
                                        }
-                                       insert_pos
-                               };
-                               self.monitor_updating_paused(false, msg.is_some(), false, Vec::new(), Vec::new(), Vec::new());
-                               UpdateFulfillCommitFetch::NewClaim {
-                                       monitor_update: &self.context.pending_monitor_updates.get(unblocked_update_pos)
-                                               .expect("We just pushed the monitor update").update,
-                                       htlc_value_msat,
                                }
+
+                               self.monitor_updating_paused(false, msg.is_some(), false, Vec::new(), Vec::new(), Vec::new());
+                               UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, }
                        },
                        UpdateFulfillFetch::DuplicateClaim {} => UpdateFulfillCommitFetch::DuplicateClaim {},
                }
@@ -2793,7 +2771,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                Ok(())
        }
 
-       pub fn commitment_signed<L: Deref>(&mut self, msg: &msgs::CommitmentSigned, logger: &L) -> Result<Option<&ChannelMonitorUpdate>, ChannelError>
+       pub fn commitment_signed<L: Deref>(&mut self, msg: &msgs::CommitmentSigned, logger: &L) -> Result<Option<ChannelMonitorUpdate>, ChannelError>
                where L::Target: Logger
        {
                if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) {
@@ -3017,7 +2995,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
        /// Public version of the below, checking relevant preconditions first.
        /// If we're not in a state where freeing the holding cell makes sense, this is a no-op and
        /// returns `(None, Vec::new())`.
-       pub fn maybe_free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> (Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger {
+       pub fn maybe_free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> (Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger {
                if self.context.channel_state >= ChannelState::ChannelReady as u32 &&
                   (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateInProgress as u32)) == 0 {
                        self.free_holding_cell_htlcs(logger)
@@ -3026,7 +3004,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 
        /// Frees any pending commitment updates in the holding cell, generating the relevant messages
        /// for our counterparty.
-       fn free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> (Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger {
+       fn free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> (Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>) where L::Target: Logger {
                assert_eq!(self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32, 0);
                if self.context.holding_cell_htlc_updates.len() != 0 || self.context.holding_cell_update_fee.is_some() {
                        log_trace!(logger, "Freeing holding cell with {} HTLC updates{} in channel {}", self.context.holding_cell_htlc_updates.len(),
@@ -3142,7 +3120,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
        /// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail,
        /// generating an appropriate error *after* the channel state has been updated based on the
        /// revoke_and_ack message.
-       pub fn revoke_and_ack<L: Deref>(&mut self, msg: &msgs::RevokeAndACK, logger: &L) -> Result<(Vec<(HTLCSource, PaymentHash)>, Option<&ChannelMonitorUpdate>), ChannelError>
+       pub fn revoke_and_ack<L: Deref>(&mut self, msg: &msgs::RevokeAndACK, logger: &L) -> Result<(Vec<(HTLCSource, PaymentHash)>, Option<ChannelMonitorUpdate>), ChannelError>
                where L::Target: Logger,
        {
                if (self.context.channel_state & (ChannelState::ChannelReady as u32)) != (ChannelState::ChannelReady as u32) {
@@ -3344,8 +3322,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                }
 
                match self.free_holding_cell_htlcs(logger) {
-                       (Some(_), htlcs_to_fail) => {
-                               let mut additional_update = self.context.pending_monitor_updates.pop().unwrap().update;
+                       (Some(mut additional_update), htlcs_to_fail) => {
                                // free_holding_cell_htlcs may bump latest_monitor_id multiple times but we want them to be
                                // strictly increasing by one, so decrement it here.
                                self.context.latest_monitor_update_id = monitor_update.update_id;
@@ -3561,12 +3538,6 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
        {
                assert_eq!(self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32, ChannelState::MonitorUpdateInProgress as u32);
                self.context.channel_state &= !(ChannelState::MonitorUpdateInProgress as u32);
-               let mut found_blocked = false;
-               self.context.pending_monitor_updates.retain(|upd| {
-                       if found_blocked { debug_assert!(upd.blocked, "No mons may be unblocked after a blocked one"); }
-                       if upd.blocked { found_blocked = true; }
-                       upd.blocked
-               });
 
                // If we're past (or at) the FundingSent stage on an outbound channel, try to
                // (re-)broadcast the funding transaction as we may have declined to broadcast it when we
@@ -4070,7 +4041,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 
        pub fn shutdown<SP: Deref>(
                &mut self, signer_provider: &SP, their_features: &InitFeatures, msg: &msgs::Shutdown
-       ) -> Result<(Option<msgs::Shutdown>, Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), ChannelError>
+       ) -> Result<(Option<msgs::Shutdown>, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), ChannelError>
        where SP::Target: SignerProvider
        {
                if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
@@ -4136,9 +4107,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                                }],
                        };
                        self.monitor_updating_paused(false, false, false, Vec::new(), Vec::new(), Vec::new());
-                       if self.push_blockable_mon_update(monitor_update) {
-                               self.context.pending_monitor_updates.last().map(|upd| &upd.update)
-                       } else { None }
+                       self.push_ret_blockable_mon_update(monitor_update)
                } else { None };
                let shutdown = if send_shutdown {
                        Some(msgs::Shutdown {
@@ -4428,64 +4397,37 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                (self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32) != 0
        }
 
-       pub fn get_latest_complete_monitor_update_id(&self) -> u64 {
-               if self.context.pending_monitor_updates.is_empty() { return self.context.get_latest_monitor_update_id(); }
-               self.context.pending_monitor_updates[0].update.update_id - 1
+       /// Gets the latest [`ChannelMonitorUpdate`] ID which has been released and is in-flight.
+       pub fn get_latest_unblocked_monitor_update_id(&self) -> u64 {
+               if self.context.blocked_monitor_updates.is_empty() { return self.context.get_latest_monitor_update_id(); }
+               self.context.blocked_monitor_updates[0].update.update_id - 1
        }
 
        /// Returns the next blocked monitor update, if one exists, and a bool which indicates a
        /// further blocked monitor update exists after the next.
-       pub fn unblock_next_blocked_monitor_update(&mut self) -> Option<(&ChannelMonitorUpdate, bool)> {
-               for i in 0..self.context.pending_monitor_updates.len() {
-                       if self.context.pending_monitor_updates[i].blocked {
-                               self.context.pending_monitor_updates[i].blocked = false;
-                               return Some((&self.context.pending_monitor_updates[i].update,
-                                       self.context.pending_monitor_updates.len() > i + 1));
-                       }
-               }
-               None
+       pub fn unblock_next_blocked_monitor_update(&mut self) -> Option<(ChannelMonitorUpdate, bool)> {
+               if self.context.blocked_monitor_updates.is_empty() { return None; }
+               Some((self.context.blocked_monitor_updates.remove(0).update,
+                       !self.context.blocked_monitor_updates.is_empty()))
        }
 
-       /// Pushes a new monitor update into our monitor update queue, returning whether it should be
-       /// immediately given to the user for persisting or if it should be held as blocked.
-       fn push_blockable_mon_update(&mut self, update: ChannelMonitorUpdate) -> bool {
-               let release_monitor = self.context.pending_monitor_updates.iter().all(|upd| !upd.blocked);
-               self.context.pending_monitor_updates.push(PendingChannelMonitorUpdate {
-                       update, blocked: !release_monitor
-               });
-               release_monitor
-       }
-
-       /// Pushes a new monitor update into our monitor update queue, returning a reference to it if
-       /// it should be immediately given to the user for persisting or `None` if it should be held as
-       /// blocked.
+       /// Pushes a new monitor update into our monitor update queue, returning it if it should be
+       /// immediately given to the user for persisting or `None` if it should be held as blocked.
        fn push_ret_blockable_mon_update(&mut self, update: ChannelMonitorUpdate)
-       -> Option<&ChannelMonitorUpdate> {
-               let release_monitor = self.push_blockable_mon_update(update);
-               if release_monitor { self.context.pending_monitor_updates.last().map(|upd| &upd.update) } else { None }
-       }
-
-       pub fn no_monitor_updates_pending(&self) -> bool {
-               self.context.pending_monitor_updates.is_empty()
-       }
-
-       pub fn complete_all_mon_updates_through(&mut self, update_id: u64) {
-               self.context.pending_monitor_updates.retain(|upd| {
-                       if upd.update.update_id <= update_id {
-                               assert!(!upd.blocked, "Completed update must have flown");
-                               false
-                       } else { true }
-               });
-       }
-
-       pub fn complete_one_mon_update(&mut self, update_id: u64) {
-               self.context.pending_monitor_updates.retain(|upd| upd.update.update_id != update_id);
+       -> Option<ChannelMonitorUpdate> {
+               let release_monitor = self.context.blocked_monitor_updates.is_empty();
+               if !release_monitor {
+                       self.context.blocked_monitor_updates.push(PendingChannelMonitorUpdate {
+                               update,
+                       });
+                       None
+               } else {
+                       Some(update)
+               }
        }
 
-       /// Returns an iterator over all unblocked monitor updates which have not yet completed.
-       pub fn uncompleted_unblocked_mon_updates(&self) -> impl Iterator<Item=&ChannelMonitorUpdate> {
-               self.context.pending_monitor_updates.iter()
-                       .filter_map(|upd| if upd.blocked { None } else { Some(&upd.update) })
+       pub fn blocked_monitor_updates_pending(&self) -> usize {
+               self.context.blocked_monitor_updates.len()
        }
 
        /// Returns true if the channel is awaiting the persistence of the initial ChannelMonitor.
@@ -5297,7 +5239,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
        pub fn send_htlc_and_commit<L: Deref>(
                &mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource,
                onion_routing_packet: msgs::OnionPacket, skimmed_fee_msat: Option<u64>, logger: &L
-       ) -> Result<Option<&ChannelMonitorUpdate>, ChannelError> where L::Target: Logger {
+       ) -> Result<Option<ChannelMonitorUpdate>, ChannelError> where L::Target: Logger {
                let send_res = self.send_htlc(amount_msat, payment_hash, cltv_expiry, source,
                        onion_routing_packet, false, skimmed_fee_msat, logger);
                if let Err(e) = &send_res { if let ChannelError::Ignore(_) = e {} else { debug_assert!(false, "Sending cannot trigger channel failure"); } }
@@ -5331,7 +5273,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
        /// [`ChannelMonitorUpdate`] will be returned).
        pub fn get_shutdown<SP: Deref>(&mut self, signer_provider: &SP, their_features: &InitFeatures,
                target_feerate_sats_per_kw: Option<u32>, override_shutdown_script: Option<ShutdownScript>)
-       -> Result<(msgs::Shutdown, Option<&ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError>
+       -> Result<(msgs::Shutdown, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError>
        where SP::Target: SignerProvider {
                for htlc in self.context.pending_outbound_htlcs.iter() {
                        if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
@@ -5402,9 +5344,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
                                }],
                        };
                        self.monitor_updating_paused(false, false, false, Vec::new(), Vec::new(), Vec::new());
-                       if self.push_blockable_mon_update(monitor_update) {
-                               self.context.pending_monitor_updates.last().map(|upd| &upd.update)
-                       } else { None }
+                       self.push_ret_blockable_mon_update(monitor_update)
                } else { None };
                let shutdown = msgs::Shutdown {
                        channel_id: self.context.channel_id,
@@ -5642,7 +5582,7 @@ impl<Signer: WriteableEcdsaChannelSigner> OutboundV1Channel<Signer> {
                                channel_type,
                                channel_keys_id,
 
-                               pending_monitor_updates: Vec::new(),
+                               blocked_monitor_updates: Vec::new(),
                        }
                })
        }
@@ -6268,7 +6208,7 @@ impl<Signer: WriteableEcdsaChannelSigner> InboundV1Channel<Signer> {
                                channel_type,
                                channel_keys_id,
 
-                               pending_monitor_updates: Vec::new(),
+                               blocked_monitor_updates: Vec::new(),
                        }
                };
 
@@ -6854,7 +6794,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Writeable for Channel<Signer> {
                        (28, holder_max_accepted_htlcs, option),
                        (29, self.context.temporary_channel_id, option),
                        (31, channel_pending_event_emitted, option),
-                       (33, self.context.pending_monitor_updates, vec_type),
+                       (33, self.context.blocked_monitor_updates, vec_type),
                        (35, pending_outbound_skimmed_fees, optional_vec),
                        (37, holding_cell_skimmed_fees, optional_vec),
                });
@@ -7135,7 +7075,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
                let mut temporary_channel_id: Option<[u8; 32]> = None;
                let mut holder_max_accepted_htlcs: Option<u16> = None;
 
-               let mut pending_monitor_updates = Some(Vec::new());
+               let mut blocked_monitor_updates = Some(Vec::new());
 
                let mut pending_outbound_skimmed_fees_opt: Option<Vec<Option<u64>>> = None;
                let mut holding_cell_skimmed_fees_opt: Option<Vec<Option<u64>>> = None;
@@ -7162,7 +7102,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
                        (28, holder_max_accepted_htlcs, option),
                        (29, temporary_channel_id, option),
                        (31, channel_pending_event_emitted, option),
-                       (33, pending_monitor_updates, vec_type),
+                       (33, blocked_monitor_updates, vec_type),
                        (35, pending_outbound_skimmed_fees_opt, optional_vec),
                        (37, holding_cell_skimmed_fees_opt, optional_vec),
                });
@@ -7359,7 +7299,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
                                channel_type: channel_type.unwrap(),
                                channel_keys_id,
 
-                               pending_monitor_updates: pending_monitor_updates.unwrap(),
+                               blocked_monitor_updates: blocked_monitor_updates.unwrap(),
                        }
                })
        }