Merge pull request #407 from TheBlueMatt/2019-11-396-english

[rust-lightning] / lightning / src / ln / channelmanager.rs

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 33f9441cf6c17e80edadbc12060ef3b851618ede..21eab0c48df447e5a2df0eab7947737043db697c 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -318,6 +318,12 @@ const ERR: () = "You need at least 32 bit pointers (well, usize, but we'll assum
 /// the "reorg path" (ie call block_disconnected() until you get to a common block and then call
 /// block_connected() to step towards your best block) upon deserialization before using the
 /// object!
+///
+/// Note that ChannelManager is responsible for tracking liveness of its channels and generating
+/// ChannelUpdate messages informing peers that the channel is temporarily disabled. To avoid
+/// spam due to quick disconnection/reconnection, updates are not sent until the channel has been
+/// offline for a full minute. In order to track this, you must call
+/// timer_chan_freshness_every_min roughly once per minute, though it doesn't have to be perfec.
 pub struct ChannelManager<'a> {
        default_configuration: UserConfig,
        genesis_hash: Sha256dHash,
@@ -1488,6 +1494,31 @@ impl<'a> ChannelManager<'a> {
                events.append(&mut new_events);
        }
 
+       /// If a peer is disconnected we mark any channels with that peer as 'disabled'.
+       /// After some time, if channels are still disabled we need to broadcast a ChannelUpdate
+       /// to inform the network about the uselessness of these channels.
+       ///
+       /// This method handles all the details, and must be called roughly once per minute.
+       pub fn timer_chan_freshness_every_min(&self) {
+               let _ = self.total_consistency_lock.read().unwrap();
+               let mut channel_state_lock = self.channel_state.lock().unwrap();
+               let channel_state = channel_state_lock.borrow_parts();
+               for (_, chan) in channel_state.by_id {
+                       if chan.is_disabled_staged() && !chan.is_live() {
+                               if let Ok(update) = self.get_channel_update(&chan) {
+                                       channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
+                                               msg: update
+                                       });
+                               }
+                               chan.to_fresh();
+                       } else if chan.is_disabled_staged() && chan.is_live() {
+                               chan.to_fresh();
+                       } else if chan.is_disabled_marked() {
+                               chan.to_disabled_staged();
+                       }
+               }
+       }
+
        /// Indicates that the preimage for payment_hash is unknown or the received amount is incorrect
        /// after a PaymentReceived event, failing the HTLC back to its origin and freeing resources
        /// along the path (including in our own channel on which we received it).
@@ -2797,8 +2828,8 @@ impl<'a> ChannelMessageHandler for ChannelManager<'a> {
                                log_debug!(self, "Marking channels with {} disconnected and generating channel_updates", log_pubkey!(their_node_id));
                                channel_state.by_id.retain(|_, chan| {
                                        if chan.get_their_node_id() == *their_node_id {
-                                               //TODO: mark channel disabled (and maybe announce such after a timeout).
                                                let failed_adds = chan.remove_uncommitted_htlcs_and_mark_paused();
+                                               chan.to_disabled_marked();
                                                if !failed_adds.is_empty() {
                                                        let chan_update = self.get_channel_update(&chan).map(|u| u.encode_with_len()).unwrap(); // Cannot add/recv HTLCs before we have a short_id so unwrap is safe
                                                        failed_payments.push((chan_update, failed_adds));