Merge pull request #413 from TheBlueMatt/2019-12-381-nits

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

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 33f9441cf6c17e80edadbc12060ef3b851618ede..5a59d0c45af798aa22f0291b88eeb1b242dff52e 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,
@@ -890,6 +896,21 @@ impl<'a> ChannelManager<'a> {
                };
 
                let pending_forward_info = if next_hop_data.hmac == [0; 32] {
+                               #[cfg(test)]
+                               {
+                                       // In tests, make sure that the initial onion pcket data is, at least, non-0.
+                                       // We could do some fancy randomness test here, but, ehh, whatever.
+                                       // This checks for the issue where you can calculate the path length given the
+                                       // onion data as all the path entries that the originator sent will be here
+                                       // as-is (and were originally 0s).
+                                       // Of course reverse path calculation is still pretty easy given naive routing
+                                       // algorithms, but this fixes the most-obvious case.
+                                       let mut new_packet_data = [0; 19*65];
+                                       chacha.process(&msg.onion_routing_packet.hop_data[65..], &mut new_packet_data[0..19*65]);
+                                       assert_ne!(new_packet_data[0..65], [0; 65][..]);
+                                       assert_ne!(new_packet_data[..], [0; 19*65][..]);
+                               }
+
                                // OUR PAYMENT!
                                // final_expiry_too_soon
                                if (msg.cltv_expiry as u64) < self.latest_block_height.load(Ordering::Acquire) as u64 + (CLTV_CLAIM_BUFFER + LATENCY_GRACE_PERIOD_BLOCKS) as u64 {
@@ -1083,14 +1104,14 @@ impl<'a> ChannelManager<'a> {
                        }
                }
 
-               let session_priv = self.keys_manager.get_session_key();
+               let (session_priv, prng_seed) = self.keys_manager.get_onion_rand();
 
                let cur_height = self.latest_block_height.load(Ordering::Acquire) as u32 + 1;
 
                let onion_keys = secp_call!(onion_utils::construct_onion_keys(&self.secp_ctx, &route, &session_priv),
                                APIError::RouteError{err: "Pubkey along hop was maliciously selected"});
                let (onion_payloads, htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(&route, cur_height)?;
-               let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, &payment_hash);
+               let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, prng_seed, &payment_hash);
 
                let _ = self.total_consistency_lock.read().unwrap();
 
@@ -1488,6 +1509,31 @@ 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 +2843,8 @@ 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));