Merge pull request #949 from TheBlueMatt/2021-06-send-priv-update
authorMatt Corallo <649246+TheBlueMatt@users.noreply.github.com>
Wed, 7 Jul 2021 20:17:10 +0000 (20:17 +0000)
committerGitHub <noreply@github.com>
Wed, 7 Jul 2021 20:17:10 +0000 (20:17 +0000)
Send channel_update messages to direct peers on private channels

1  2 
fuzz/src/chanmon_consistency.rs
lightning-background-processor/src/lib.rs
lightning/src/ln/channelmanager.rs
lightning/src/ln/functional_test_utils.rs
lightning/src/ln/functional_tests.rs

index 38e12b8496bcc1c5ac0d6fe269acc38aeb8959a2,158d87149a5ef2eff4b45d83cb953057fc48c74b..4aa641d1fa4144275764a9b205ca87ea2b8921c5
@@@ -30,13 -30,13 +30,13 @@@ use bitcoin::hashes::sha256::Hash as Sh
  use bitcoin::hash_types::{BlockHash, WPubkeyHash};
  
  use lightning::chain;
 -use lightning::chain::{chainmonitor, channelmonitor, Confirm, Watch};
 +use lightning::chain::{BestBlock, chainmonitor, channelmonitor, Confirm, Watch};
  use lightning::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, MonitorEvent};
  use lightning::chain::transaction::OutPoint;
  use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
  use lightning::chain::keysinterface::{KeysInterface, InMemorySigner};
  use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 -use lightning::ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, PaymentSendFailure, ChannelManagerReadArgs};
 +use lightning::ln::channelmanager::{ChainParameters, ChannelManager, PaymentSendFailure, ChannelManagerReadArgs};
  use lightning::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
  use lightning::ln::msgs::{CommitmentUpdate, ChannelMessageHandler, DecodeError, UpdateAddHTLC, Init};
  use lightning::util::enforcing_trait_impls::{EnforcingSigner, INITIAL_REVOKED_COMMITMENT_NUMBER};
@@@ -571,7 -571,12 +571,12 @@@ pub fn do_test<Out: test_logger::Output
                                                events::MessageSendEvent::SendFundingLocked { .. } => continue,
                                                events::MessageSendEvent::SendAnnouncementSignatures { .. } => continue,
                                                events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => continue,
-                                               _ => panic!("Unhandled message event"),
+                                               events::MessageSendEvent::SendChannelUpdate { ref node_id, ref msg } => {
+                                                       assert_eq!(msg.contents.flags & 2, 0); // The disable bit must never be set!
+                                                       if Some(*node_id) == expect_drop_id { panic!("peer_disconnected should drop msgs bound for the disconnected peer"); }
+                                                       *node_id == a_id
+                                               },
+                                               _ => panic!("Unhandled message event {:?}", event),
                                        };
                                        if push_a { ba_events.push(event); } else { bc_events.push(event); }
                                }
                                                        // Can be generated due to a payment forward being rejected due to a
                                                        // channel having previously failed a monitor update
                                                },
-                                               _ => panic!("Unhandled message event"),
+                                               events::MessageSendEvent::SendChannelUpdate { ref msg, .. } => {
+                                                       // When we reconnect we will resend a channel_update to make sure our
+                                                       // counterparty has the latest parameters for receiving payments
+                                                       // through us. We do, however, check that the message does not include
+                                                       // the "disabled" bit, as we should never ever have a channel which is
+                                                       // disabled when we send such an update (or it may indicate channel
+                                                       // force-close which we should detect as an error).
+                                                       assert_eq!(msg.contents.flags & 2, 0);
+                                               },
+                                               _ => panic!("Unhandled message event {:?}", event),
                                        }
                                        if $limit_events != ProcessMessages::AllMessages {
                                                break;
                                                        events::MessageSendEvent::SendFundingLocked { .. } => {},
                                                        events::MessageSendEvent::SendAnnouncementSignatures { .. } => {},
                                                        events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => {},
+                                                       events::MessageSendEvent::SendChannelUpdate { ref msg, .. } => {
+                                                               assert_eq!(msg.contents.flags & 2, 0); // The disable bit must never be set!
+                                                       },
                                                        _ => panic!("Unhandled message event"),
                                                }
                                        }
                                                        events::MessageSendEvent::SendFundingLocked { .. } => {},
                                                        events::MessageSendEvent::SendAnnouncementSignatures { .. } => {},
                                                        events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => {},
+                                                       events::MessageSendEvent::SendChannelUpdate { ref msg, .. } => {
+                                                               assert_eq!(msg.contents.flags & 2, 0); // The disable bit must never be set!
+                                                       },
                                                        _ => panic!("Unhandled message event"),
                                                }
                                        }
index 197eff45ab5c101d3d29a41b5b1fdf8bc21aba54,8c90532d1ea1491db56d8f90db3f0fedbf9bc01f..3a36bb5625eab033b05c5aec3cfa183eb2d67a7d
@@@ -174,12 -174,13 +174,12 @@@ mod tests 
        use bitcoin::blockdata::constants::genesis_block;
        use bitcoin::blockdata::transaction::{Transaction, TxOut};
        use bitcoin::network::constants::Network;
 -      use lightning::chain::Confirm;
 -      use lightning::chain::chainmonitor;
 +      use lightning::chain::{BestBlock, Confirm, chainmonitor};
        use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
        use lightning::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager};
        use lightning::chain::transaction::OutPoint;
        use lightning::get_event_msg;
 -      use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, BestBlock, ChainParameters, ChannelManager, SimpleArcChannelManager};
 +      use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, ChannelManager, SimpleArcChannelManager};
        use lightning::ln::features::InitFeatures;
        use lightning::ln::msgs::ChannelMessageHandler;
        use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor};
  
                // Confirm the funding transaction.
                confirm_transaction(&mut nodes[0], &funding_tx);
+               let as_funding = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
                confirm_transaction(&mut nodes[1], &funding_tx);
-               nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id()));
-               nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id()));
+               let bs_funding = get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id());
+               nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &bs_funding);
+               let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
+               nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &as_funding);
+               let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
  
                assert!(bg_processor.stop().is_ok());
  
index 21d13eaefc2d350c81c32ad3c246c4f3823e4c15,47ea356442398d461e68f4656b81e0d35ffe1b79..bbd32994e875138ff5574cbb6e45f381e43ebb2a
@@@ -36,7 -36,8 +36,7 @@@ use bitcoin::secp256k1::ecdh::SharedSec
  use bitcoin::secp256k1;
  
  use chain;
 -use chain::Confirm;
 -use chain::Watch;
 +use chain::{Confirm, Watch, BestBlock};
  use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
  use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, ChannelMonitorUpdateErr, HTLC_FAIL_BACK_BUFFER, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY, MonitorEvent, CLOSED_CHANNEL_UPDATE_ID};
  use chain::transaction::{OutPoint, TransactionData};
@@@ -507,6 -508,34 +507,6 @@@ pub struct ChainParameters 
        pub best_block: BestBlock,
  }
  
 -/// The best known block as identified by its hash and height.
 -#[derive(Clone, Copy, PartialEq)]
 -pub struct BestBlock {
 -      block_hash: BlockHash,
 -      height: u32,
 -}
 -
 -impl BestBlock {
 -      /// Returns the best block from the genesis of the given network.
 -      pub fn from_genesis(network: Network) -> Self {
 -              BestBlock {
 -                      block_hash: genesis_block(network).header.block_hash(),
 -                      height: 0,
 -              }
 -      }
 -
 -      /// Returns the best block as identified by the given block hash and height.
 -      pub fn new(block_hash: BlockHash, height: u32) -> Self {
 -              BestBlock { block_hash, height }
 -      }
 -
 -      /// Returns the best block hash.
 -      pub fn block_hash(&self) -> BlockHash { self.block_hash }
 -
 -      /// Returns the best block height.
 -      pub fn height(&self) -> u32 { self.height }
 -}
 -
  #[derive(Copy, Clone, PartialEq)]
  enum NotifyOption {
        DoPersist,
@@@ -627,74 -656,25 +627,74 @@@ pub struct ChannelDetails 
        pub counterparty_features: InitFeatures,
        /// The value, in satoshis, of this channel as appears in the funding output
        pub channel_value_satoshis: u64,
 +      /// The value, in satoshis, that must always be held in the channel for us. This value ensures
 +      /// that if we broadcast a revoked state, our counterparty can punish us by claiming at least
 +      /// this value on chain.
 +      ///
 +      /// This value is not included in [`outbound_capacity_msat`] as it can never be spent.
 +      ///
 +      /// This value will be `None` for outbound channels until the counterparty accepts the channel.
 +      ///
 +      /// [`outbound_capacity_msat`]: ChannelDetails::outbound_capacity_msat
 +      pub to_self_reserve_satoshis: Option<u64>,
 +      /// The value, in satoshis, that must always be held in the channel for our counterparty. This
 +      /// value ensures that if our counterparty broadcasts a revoked state, we can punish them by
 +      /// claiming at least this value on chain.
 +      ///
 +      /// This value is not included in [`inbound_capacity_msat`] as it can never be spent.
 +      ///
 +      /// [`inbound_capacity_msat`]: ChannelDetails::inbound_capacity_msat
 +      pub to_remote_reserve_satoshis: u64,
        /// The user_id passed in to create_channel, or 0 if the channel was inbound.
        pub user_id: u64,
        /// The available outbound capacity for sending HTLCs to the remote peer. This does not include
        /// any pending HTLCs which are not yet fully resolved (and, thus, who's balance is not
        /// available for inclusion in new outbound HTLCs). This further does not include any pending
        /// outgoing HTLCs which are awaiting some other resolution to be sent.
 +      ///
 +      /// This value is not exact. Due to various in-flight changes, feerate changes, and our
 +      /// conflict-avoidance policy, exactly this amount is not likely to be spendable. However, we
 +      /// should be able to spend nearly this amount.
        pub outbound_capacity_msat: u64,
        /// The available inbound capacity for the remote peer to send HTLCs to us. This does not
        /// include any pending HTLCs which are not yet fully resolved (and, thus, who's balance is not
        /// available for inclusion in new inbound HTLCs).
        /// Note that there are some corner cases not fully handled here, so the actual available
        /// inbound capacity may be slightly higher than this.
 +      ///
 +      /// This value is not exact. Due to various in-flight changes, feerate changes, and our
 +      /// counterparty's conflict-avoidance policy, exactly this amount is not likely to be spendable.
 +      /// However, our counterparty should be able to spend nearly this amount.
        pub inbound_capacity_msat: u64,
 +      /// The number of required confirmations on the funding transaction before the funding will be
 +      /// considered "locked". This number is selected by the channel fundee (i.e. us if
 +      /// [`is_outbound`] is *not* set), and can be selected for inbound channels with
 +      /// [`ChannelHandshakeConfig::minimum_depth`] or limited for outbound channels with
 +      /// [`ChannelHandshakeLimits::max_minimum_depth`].
 +      ///
 +      /// This value will be `None` for outbound channels until the counterparty accepts the channel.
 +      ///
 +      /// [`is_outbound`]: ChannelDetails::is_outbound
 +      /// [`ChannelHandshakeConfig::minimum_depth`]: crate::util::config::ChannelHandshakeConfig::minimum_depth
 +      /// [`ChannelHandshakeLimits::max_minimum_depth`]: crate::util::config::ChannelHandshakeLimits::max_minimum_depth
 +      pub confirmations_required: Option<u32>,
 +      /// The number of blocks (after our commitment transaction confirms) that we will need to wait
 +      /// until we can claim our funds after we force-close the channel. During this time our
 +      /// counterparty is allowed to punish us if we broadcasted a stale state. If our counterparty
 +      /// force-closes the channel and broadcasts a commitment transaction we do not have to wait any
 +      /// time to claim our non-HTLC-encumbered funds.
 +      ///
 +      /// This value will be `None` for outbound channels until the counterparty accepts the channel.
 +      pub spend_csv_on_our_commitment_funds: Option<u16>,
        /// True if the channel was initiated (and thus funded) by us.
        pub is_outbound: bool,
        /// True if the channel is confirmed, funding_locked messages have been exchanged, and the
        /// channel is not currently being shut down. `funding_locked` message exchange implies the
        /// required confirmation count has been reached (and we were connected to the peer at some
 -      /// point after the funding transaction received enough confirmations).
 +      /// point after the funding transaction received enough confirmations). The required
 +      /// confirmation count is provided in [`confirmations_required`].
 +      ///
 +      /// [`confirmations_required`]: ChannelDetails::confirmations_required
        pub is_funding_locked: bool,
        /// True if the channel is (a) confirmed and funding_locked messages have been exchanged, (b)
        /// the peer is connected, and (c) the channel is not currently negotiating a shutdown.
@@@ -800,7 -780,7 +800,7 @@@ macro_rules! convert_chan_err 
                                        $short_to_id.remove(&short_id);
                                }
                                let shutdown_res = $channel.force_shutdown(true);
-                               (true, MsgHandleErrInternal::from_finish_shutdown(msg, *$channel_id, shutdown_res, $self.get_channel_update(&$channel).ok()))
+                               (true, MsgHandleErrInternal::from_finish_shutdown(msg, *$channel_id, shutdown_res, $self.get_channel_update_for_broadcast(&$channel).ok()))
                        },
                        ChannelError::CloseDelayBroadcast(msg) => {
                                log_error!($self.logger, "Channel {} need to be shutdown but closing transactions not broadcast due to {}", log_bytes!($channel_id[..]), msg);
                                        $short_to_id.remove(&short_id);
                                }
                                let shutdown_res = $channel.force_shutdown(false);
-                               (true, MsgHandleErrInternal::from_finish_shutdown(msg, *$channel_id, shutdown_res, $self.get_channel_update(&$channel).ok()))
+                               (true, MsgHandleErrInternal::from_finish_shutdown(msg, *$channel_id, shutdown_res, $self.get_channel_update_for_broadcast(&$channel).ok()))
                        }
                }
        }
@@@ -864,7 -844,8 +864,8 @@@ macro_rules! handle_monitor_err 
                                // splitting hairs we'd prefer to claim payments that were to us, but we haven't
                                // given up the preimage yet, so might as well just wait until the payment is
                                // retried, avoiding the on-chain fees.
-                               let res: Result<(), _> = Err(MsgHandleErrInternal::from_finish_shutdown("ChannelMonitor storage failure".to_owned(), *$chan_id, $chan.force_shutdown(true), $self.get_channel_update(&$chan).ok()));
+                               let res: Result<(), _> = Err(MsgHandleErrInternal::from_finish_shutdown("ChannelMonitor storage failure".to_owned(), *$chan_id,
+                                               $chan.force_shutdown(true), $self.get_channel_update_for_broadcast(&$chan).ok() ));
                                (res, true)
                        },
                        ChannelMonitorUpdateErr::TemporaryFailure => {
@@@ -1166,8 -1147,6 +1167,8 @@@ impl<Signer: Sign, M: Deref, T: Deref, 
                        res.reserve(channel_state.by_id.len());
                        for (channel_id, channel) in channel_state.by_id.iter().filter(f) {
                                let (inbound_capacity_msat, outbound_capacity_msat) = channel.get_inbound_outbound_available_balance_msat();
 +                              let (to_remote_reserve_satoshis, to_self_reserve_satoshis) =
 +                                      channel.get_holder_counterparty_selected_channel_reserve_satoshis();
                                res.push(ChannelDetails {
                                        channel_id: (*channel_id).clone(),
                                        funding_txo: channel.get_funding_txo(),
                                        remote_network_id: channel.get_counterparty_node_id(),
                                        counterparty_features: InitFeatures::empty(),
                                        channel_value_satoshis: channel.get_value_satoshis(),
 +                                      to_self_reserve_satoshis,
 +                                      to_remote_reserve_satoshis,
                                        inbound_capacity_msat,
                                        outbound_capacity_msat,
                                        user_id: channel.get_user_id(),
 +                                      confirmations_required: channel.minimum_depth(),
 +                                      spend_csv_on_our_commitment_funds: channel.get_counterparty_selected_contest_delay(),
                                        is_outbound: channel.is_outbound(),
                                        is_funding_locked: channel.is_usable(),
                                        is_usable: channel.is_live(),
                        self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
                }
                let chan_update = if let Some(chan) = chan_option {
-                       if let Ok(update) = self.get_channel_update(&chan) {
-                               Some(update)
-                       } else { None }
+                       self.get_channel_update_for_broadcast(&chan).ok()
                } else { None };
  
                if let Some(update) = chan_update {
                };
                log_error!(self.logger, "Force-closing channel {}", log_bytes!(channel_id[..]));
                self.finish_force_close_channel(chan.force_shutdown(true));
-               if let Ok(update) = self.get_channel_update(&chan) {
+               if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                        let mut channel_state = self.channel_state.lock().unwrap();
                        channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                msg: update
                                        // hopefully an attacker trying to path-trace payments cannot make this occur
                                        // on a small/per-node/per-channel scale.
                                        if !chan.is_live() { // channel_disabled
-                                               break Some(("Forwarding channel is not in a ready state.", 0x1000 | 20, Some(self.get_channel_update(chan).unwrap())));
+                                               break Some(("Forwarding channel is not in a ready state.", 0x1000 | 20, Some(self.get_channel_update_for_unicast(chan).unwrap())));
                                        }
                                        if *amt_to_forward < chan.get_counterparty_htlc_minimum_msat() { // amount_below_minimum
-                                               break Some(("HTLC amount was below the htlc_minimum_msat", 0x1000 | 11, Some(self.get_channel_update(chan).unwrap())));
+                                               break Some(("HTLC amount was below the htlc_minimum_msat", 0x1000 | 11, Some(self.get_channel_update_for_unicast(chan).unwrap())));
                                        }
                                        let fee = amt_to_forward.checked_mul(chan.get_fee_proportional_millionths() as u64).and_then(|prop_fee| { (prop_fee / 1000000).checked_add(chan.get_holder_fee_base_msat(&self.fee_estimator) as u64) });
                                        if fee.is_none() || msg.amount_msat < fee.unwrap() || (msg.amount_msat - fee.unwrap()) < *amt_to_forward { // fee_insufficient
-                                               break Some(("Prior hop has deviated from specified fees parameters or origin node has obsolete ones", 0x1000 | 12, Some(self.get_channel_update(chan).unwrap())));
+                                               break Some(("Prior hop has deviated from specified fees parameters or origin node has obsolete ones", 0x1000 | 12, Some(self.get_channel_update_for_unicast(chan).unwrap())));
                                        }
                                        if (msg.cltv_expiry as u64) < (*outgoing_cltv_value) as u64 + chan.get_cltv_expiry_delta() as u64 { // incorrect_cltv_expiry
-                                               break Some(("Forwarding node has tampered with the intended HTLC values or origin node has an obsolete cltv_expiry_delta", 0x1000 | 13, Some(self.get_channel_update(chan).unwrap())));
+                                               break Some(("Forwarding node has tampered with the intended HTLC values or origin node has an obsolete cltv_expiry_delta", 0x1000 | 13, Some(self.get_channel_update_for_unicast(chan).unwrap())));
                                        }
                                        let cur_height = self.best_block.read().unwrap().height() + 1;
                                        // Theoretically, channel counterparty shouldn't send us a HTLC expiring now, but we want to be robust wrt to counterparty
                                        // packet sanitization (see HTLC_FAIL_BACK_BUFFER rational)
                                        if msg.cltv_expiry <= cur_height + HTLC_FAIL_BACK_BUFFER as u32 { // expiry_too_soon
-                                               break Some(("CLTV expiry is too close", 0x1000 | 14, Some(self.get_channel_update(chan).unwrap())));
+                                               break Some(("CLTV expiry is too close", 0x1000 | 14, Some(self.get_channel_update_for_unicast(chan).unwrap())));
                                        }
                                        if msg.cltv_expiry > cur_height + CLTV_FAR_FAR_AWAY as u32 { // expiry_too_far
                                                break Some(("CLTV expiry is too far in the future", 21, None));
                                        }
-                                       // In theory, we would be safe against unitentional channel-closure, if we only required a margin of LATENCY_GRACE_PERIOD_BLOCKS.
-                                       // But, to be safe against policy reception, we use a longuer delay.
+                                       // In theory, we would be safe against unintentional channel-closure, if we only required a margin of LATENCY_GRACE_PERIOD_BLOCKS.
+                                       // But, to be safe against policy reception, we use a longer delay.
                                        if (*outgoing_cltv_value) as u64 <= (cur_height + HTLC_FAIL_BACK_BUFFER) as u64 {
-                                               break Some(("Outgoing CLTV value is too soon", 0x1000 | 14, Some(self.get_channel_update(chan).unwrap())));
+                                               break Some(("Outgoing CLTV value is too soon", 0x1000 | 14, Some(self.get_channel_update_for_unicast(chan).unwrap())));
                                        }
  
                                        break None;
                (pending_forward_info, channel_state.unwrap())
        }
  
-       /// only fails if the channel does not yet have an assigned short_id
+       /// Gets the current channel_update for the given channel. This first checks if the channel is
+       /// public, and thus should be called whenever the result is going to be passed out in a
+       /// [`MessageSendEvent::BroadcastChannelUpdate`] event.
+       ///
+       /// May be called with channel_state already locked!
+       fn get_channel_update_for_broadcast(&self, chan: &Channel<Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
+               if !chan.should_announce() {
+                       return Err(LightningError {
+                               err: "Cannot broadcast a channel_update for a private channel".to_owned(),
+                               action: msgs::ErrorAction::IgnoreError
+                       });
+               }
+               log_trace!(self.logger, "Attempting to generate broadcast channel update for channel {}", log_bytes!(chan.channel_id()));
+               self.get_channel_update_for_unicast(chan)
+       }
+       /// Gets the current channel_update for the given channel. This does not check if the channel
+       /// is public (only returning an Err if the channel does not yet have an assigned short_id),
+       /// and thus MUST NOT be called unless the recipient of the resulting message has already
+       /// provided evidence that they know about the existence of the channel.
        /// May be called with channel_state already locked!
-       fn get_channel_update(&self, chan: &Channel<Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
+       fn get_channel_update_for_unicast(&self, chan: &Channel<Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
+               log_trace!(self.logger, "Attempting to generate channel update for channel {}", log_bytes!(chan.channel_id()));
                let short_channel_id = match chan.get_short_channel_id() {
                        None => return Err(LightningError{err: "Channel not yet established".to_owned(), action: msgs::ErrorAction::IgnoreError}),
                        Some(id) => id,
                        if let Some(msg) = chan.get_signed_channel_announcement(&self.our_network_key, self.get_our_node_id(), self.genesis_hash.clone()) {
                                channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelAnnouncement {
                                        msg,
-                                       update_msg: match self.get_channel_update(chan) {
+                                       update_msg: match self.get_channel_update_for_broadcast(chan) {
                                                Ok(msg) => msg,
                                                Err(_) => continue,
                                        },
                                                                                        } else {
                                                                                                panic!("Stated return value requirements in send_htlc() were not met");
                                                                                        }
-                                                                                       let chan_update = self.get_channel_update(chan.get()).unwrap();
+                                                                                       let chan_update = self.get_channel_update_for_unicast(chan.get()).unwrap();
                                                                                        failed_forwards.push((htlc_source, payment_hash,
                                                                                                HTLCFailReason::Reason { failure_code: 0x1000 | 7, data: chan_update.encode_with_len() }
                                                                                        ));
                                                                                        if let Some(short_id) = channel.get_short_channel_id() {
                                                                                                channel_state.short_to_id.remove(&short_id);
                                                                                        }
-                                                                                       Err(MsgHandleErrInternal::from_finish_shutdown(msg, channel_id, channel.force_shutdown(true), self.get_channel_update(&channel).ok()))
+                                                                                       Err(MsgHandleErrInternal::from_finish_shutdown(msg, channel_id, channel.force_shutdown(true), self.get_channel_update_for_broadcast(&channel).ok()))
                                                                                },
                                                                                ChannelError::CloseDelayBroadcast(_) => { panic!("Wait is only generated on receipt of channel_reestablish, which is handled by try_chan_entry, we don't bother to support it here"); }
                                                                        };
                                        ChannelUpdateStatus::DisabledStaged if chan.is_live() => chan.set_channel_update_status(ChannelUpdateStatus::Enabled),
                                        ChannelUpdateStatus::EnabledStaged if !chan.is_live() => chan.set_channel_update_status(ChannelUpdateStatus::Disabled),
                                        ChannelUpdateStatus::DisabledStaged if !chan.is_live() => {
-                                               if let Ok(update) = self.get_channel_update(&chan) {
+                                               if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                                                        channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                                                msg: update
                                                        });
                                                chan.set_channel_update_status(ChannelUpdateStatus::Disabled);
                                        },
                                        ChannelUpdateStatus::EnabledStaged if chan.is_live() => {
-                                               if let Ok(update) = self.get_channel_update(&chan) {
+                                               if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                                                        channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                                                msg: update
                                                        });
                                        let (failure_code, onion_failure_data) =
                                                match self.channel_state.lock().unwrap().by_id.entry(channel_id) {
                                                        hash_map::Entry::Occupied(chan_entry) => {
-                                                               if let Ok(upd) = self.get_channel_update(&chan_entry.get()) {
+                                                               if let Ok(upd) = self.get_channel_update_for_unicast(&chan_entry.get()) {
                                                                        (0x1000|7, upd.encode_with_len())
                                                                } else {
                                                                        (0x4000|10, Vec::new())
        pub fn channel_monitor_updated(&self, funding_txo: &OutPoint, highest_applied_update_id: u64) {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
  
-               let (mut pending_failures, chan_restoration_res) = {
+               let chan_restoration_res;
+               let mut pending_failures = {
                        let mut channel_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_lock;
                        let mut channel = match channel_state.by_id.entry(funding_txo.to_channel_id()) {
                        }
  
                        let (raa, commitment_update, order, pending_forwards, pending_failures, funding_broadcastable, funding_locked) = channel.get_mut().monitor_updating_restored(&self.logger);
-                       (pending_failures, handle_chan_restoration_locked!(self, channel_lock, channel_state, channel, raa, commitment_update, order, None, pending_forwards, funding_broadcastable, funding_locked))
+                       let channel_update = if funding_locked.is_some() && channel.get().is_usable() && !channel.get().should_announce() {
+                               // We only send a channel_update in the case where we are just now sending a
+                               // funding_locked and the channel is in a usable state. Further, we rely on the
+                               // normal announcement_signatures process to send a channel_update for public
+                               // channels, only generating a unicast channel_update if this is a private channel.
+                               Some(events::MessageSendEvent::SendChannelUpdate {
+                                       node_id: channel.get().get_counterparty_node_id(),
+                                       msg: self.get_channel_update_for_unicast(channel.get()).unwrap(),
+                               })
+                       } else { None };
+                       chan_restoration_res = handle_chan_restoration_locked!(self, channel_lock, channel_state, channel, raa, commitment_update, order, None, pending_forwards, funding_broadcastable, funding_locked);
+                       if let Some(upd) = channel_update {
+                               channel_state.pending_msg_events.push(upd);
+                       }
+                       pending_failures
                };
                post_handle_chan_restoration!(self, chan_restoration_res);
                for failure in pending_failures.drain(..) {
                                                node_id: counterparty_node_id.clone(),
                                                msg: announcement_sigs,
                                        });
+                               } else if chan.get().is_usable() {
+                                       channel_state.pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
+                                               node_id: counterparty_node_id.clone(),
+                                               msg: self.get_channel_update_for_unicast(chan.get()).unwrap(),
+                                       });
                                }
                                Ok(())
                        },
                        self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
                }
                if let Some(chan) = chan_option {
-                       if let Ok(update) = self.get_channel_update(&chan) {
+                       if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                                let mut channel_state = self.channel_state.lock().unwrap();
                                channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                        msg: update
                        self.tx_broadcaster.broadcast_transaction(&broadcast_tx);
                }
                if let Some(chan) = chan_option {
-                       if let Ok(update) = self.get_channel_update(&chan) {
+                       if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                                let mut channel_state = self.channel_state.lock().unwrap();
                                channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                        msg: update
                                        // want to reject the new HTLC and fail it backwards instead of forwarding.
                                        match pending_forward_info {
                                                PendingHTLCStatus::Forward(PendingHTLCInfo { ref incoming_shared_secret, .. }) => {
-                                                       let reason = if let Ok(upd) = self.get_channel_update(chan) {
+                                                       let reason = if let Ok(upd) = self.get_channel_update_for_unicast(chan) {
                                                                onion_utils::build_first_hop_failure_packet(incoming_shared_secret, error_code, &{
                                                                        let mut res = Vec::with_capacity(8 + 128);
                                                                        // TODO: underspecified, follow https://github.com/lightningnetwork/lightning-rfc/issues/791
  
                                channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelAnnouncement {
                                        msg: try_chan_entry!(self, chan.get_mut().announcement_signatures(&self.our_network_key, self.get_our_node_id(), self.genesis_hash.clone(), msg), channel_state, chan),
-                                       update_msg: self.get_channel_update(chan.get()).unwrap(), // can only fail if we're not in a ready state
+                                       // Note that announcement_signatures fails if the channel cannot be announced,
+                                       // so get_channel_update_for_broadcast will never fail by the time we get here.
+                                       update_msg: self.get_channel_update_for_broadcast(chan.get()).unwrap(),
                                });
                        },
                        hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
                                        }
                                        return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a channel_update for a channel from the wrong node - it shouldn't know about our private channels!".to_owned(), chan_id));
                                }
-                               try_chan_entry!(self, chan.get_mut().channel_update(&msg), channel_state, chan);
+                               let were_node_one = self.get_our_node_id().serialize()[..] < chan.get().get_counterparty_node_id().serialize()[..];
+                               let msg_from_node_one = msg.contents.flags & 1 == 0;
+                               if were_node_one == msg_from_node_one {
+                                       return Ok(NotifyOption::SkipPersist);
+                               } else {
+                                       try_chan_entry!(self, chan.get_mut().channel_update(&msg), channel_state, chan);
+                               }
                        },
                        hash_map::Entry::Vacant(_) => unreachable!()
                }
        }
  
        fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<(), MsgHandleErrInternal> {
-               let (htlcs_failed_forward, need_lnd_workaround, chan_restoration_res) = {
+               let chan_restoration_res;
+               let (htlcs_failed_forward, need_lnd_workaround) = {
                        let mut channel_state_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_state_lock;
  
                                        // add-HTLCs on disconnect, we may be handed HTLCs to fail backwards here.
                                        let (funding_locked, revoke_and_ack, commitment_update, monitor_update_opt, order, htlcs_failed_forward, shutdown) =
                                                try_chan_entry!(self, chan.get_mut().channel_reestablish(msg, &self.logger), channel_state, chan);
+                                       let mut channel_update = None;
                                        if let Some(msg) = shutdown {
                                                channel_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
                                                        node_id: counterparty_node_id.clone(),
                                                        msg,
                                                });
+                                       } else if chan.get().is_usable() {
+                                               // If the channel is in a usable state (ie the channel is not being shut
+                                               // down), send a unicast channel_update to our counterparty to make sure
+                                               // they have the latest channel parameters.
+                                               channel_update = Some(events::MessageSendEvent::SendChannelUpdate {
+                                                       node_id: chan.get().get_counterparty_node_id(),
+                                                       msg: self.get_channel_update_for_unicast(chan.get()).unwrap(),
+                                               });
                                        }
                                        let need_lnd_workaround = chan.get_mut().workaround_lnd_bug_4006.take();
-                                       (htlcs_failed_forward, need_lnd_workaround,
-                                               handle_chan_restoration_locked!(self, channel_state_lock, channel_state, chan, revoke_and_ack, commitment_update, order, monitor_update_opt, Vec::new(), None, funding_locked))
+                                       chan_restoration_res = handle_chan_restoration_locked!(self, channel_state_lock, channel_state, chan, revoke_and_ack, commitment_update, order, monitor_update_opt, Vec::new(), None, funding_locked);
+                                       if let Some(upd) = channel_update {
+                                               channel_state.pending_msg_events.push(upd);
+                                       }
+                                       (htlcs_failed_forward, need_lnd_workaround)
                                },
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
                        }
                                                        short_to_id.remove(&short_id);
                                                }
                                                failed_channels.push(chan.force_shutdown(false));
-                                               if let Ok(update) = self.get_channel_update(&chan) {
+                                               if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                                                        pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                                                msg: update
                                                        });
@@@ -3960,7 -3994,7 +4020,7 @@@ wher
                                let res = f(channel);
                                if let Ok((chan_res, mut timed_out_pending_htlcs)) = res {
                                        for (source, payment_hash) in timed_out_pending_htlcs.drain(..) {
-                                               let chan_update = self.get_channel_update(&channel).map(|u| u.encode_with_len()).unwrap(); // Cannot add/recv HTLCs before we have a short_id so unwrap is safe
+                                               let chan_update = self.get_channel_update_for_unicast(&channel).map(|u| u.encode_with_len()).unwrap(); // Cannot add/recv HTLCs before we have a short_id so unwrap is safe
                                                timed_out_htlcs.push((source, payment_hash,  HTLCFailReason::Reason {
                                                        failure_code: 0x1000 | 14, // expiry_too_soon, or at least it is now
                                                        data: chan_update,
                                                                node_id: channel.get_counterparty_node_id(),
                                                                msg: announcement_sigs,
                                                        });
+                                               } else if channel.is_usable() {
+                                                       log_trace!(self.logger, "Sending funding_locked WITHOUT announcement_signatures but with private channel_update for our counterparty on channel {}", log_bytes!(channel.channel_id()));
+                                                       pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
+                                                               node_id: channel.get_counterparty_node_id(),
+                                                               msg: self.get_channel_update_for_unicast(channel).unwrap(),
+                                                       });
                                                } else {
                                                        log_trace!(self.logger, "Sending funding_locked WITHOUT announcement_signatures for {}", log_bytes!(channel.channel_id()));
                                                }
                                        // It looks like our counterparty went on-chain or funding transaction was
                                        // reorged out of the main chain. Close the channel.
                                        failed_channels.push(channel.force_shutdown(true));
-                                       if let Ok(update) = self.get_channel_update(&channel) {
+                                       if let Ok(update) = self.get_channel_update_for_broadcast(&channel) {
                                                pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                                        msg: update
                                                });
                let guard = mtx.lock().unwrap();
                *guard
        }
 +
 +      /// Gets the latest best block which was connected either via the [`chain::Listen`] or
 +      /// [`chain::Confirm`] interfaces.
 +      pub fn current_best_block(&self) -> BestBlock {
 +              self.best_block.read().unwrap().clone()
 +      }
  }
  
  impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
                                                        short_to_id.remove(&short_id);
                                                }
                                                failed_channels.push(chan.force_shutdown(true));
-                                               if let Ok(update) = self.get_channel_update(&chan) {
+                                               if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
                                                        pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                                                msg: update
                                                        });
                                        &events::MessageSendEvent::BroadcastChannelAnnouncement { .. } => true,
                                        &events::MessageSendEvent::BroadcastNodeAnnouncement { .. } => true,
                                        &events::MessageSendEvent::BroadcastChannelUpdate { .. } => true,
+                                       &events::MessageSendEvent::SendChannelUpdate { ref node_id, .. } => node_id != counterparty_node_id,
                                        &events::MessageSendEvent::HandleError { ref node_id, .. } => node_id != counterparty_node_id,
                                        &events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => true,
                                        &events::MessageSendEvent::SendChannelRangeQuery { .. } => false,
@@@ -4955,6 -4990,31 +5022,31 @@@ mod tests 
                // At this point the channel info given by peers should still be the same.
                assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
                assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);
+               // An earlier version of handle_channel_update didn't check the directionality of the
+               // update message and would always update the local fee info, even if our peer was
+               // (spuriously) forwarding us our own channel_update.
+               let as_node_one = nodes[0].node.get_our_node_id().serialize()[..] < nodes[1].node.get_our_node_id().serialize()[..];
+               let as_update = if as_node_one == (chan.0.contents.flags & 1 == 0 /* chan.0 is from node one */) { &chan.0 } else { &chan.1 };
+               let bs_update = if as_node_one == (chan.0.contents.flags & 1 == 0 /* chan.0 is from node one */) { &chan.1 } else { &chan.0 };
+               // First deliver each peers' own message, checking that the node doesn't need to be
+               // persisted and that its channel info remains the same.
+               nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &as_update);
+               nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &bs_update);
+               assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
+               assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);
+               // Finally, deliver the other peers' message, ensuring each node needs to be persisted and
+               // the channel info has updated.
+               nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &bs_update);
+               nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &as_update);
+               assert!(nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert!(nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
+               assert_ne!(nodes[0].node.list_channels()[0], node_a_chan_info);
+               assert_ne!(nodes[1].node.list_channels()[0], node_b_chan_info);
        }
  }
  
@@@ -5055,7 -5115,19 +5147,19 @@@ pub mod bench 
                Listen::block_connected(&node_b, &block, 1);
  
                node_a.handle_funding_locked(&node_b.get_our_node_id(), &get_event_msg!(node_b_holder, MessageSendEvent::SendFundingLocked, node_a.get_our_node_id()));
-               node_b.handle_funding_locked(&node_a.get_our_node_id(), &get_event_msg!(node_a_holder, MessageSendEvent::SendFundingLocked, node_b.get_our_node_id()));
+               let msg_events = node_a.get_and_clear_pending_msg_events();
+               assert_eq!(msg_events.len(), 2);
+               match msg_events[0] {
+                       MessageSendEvent::SendFundingLocked { ref msg, .. } => {
+                               node_b.handle_funding_locked(&node_a.get_our_node_id(), msg);
+                               get_event_msg!(node_b_holder, MessageSendEvent::SendChannelUpdate, node_a.get_our_node_id());
+                       },
+                       _ => panic!(),
+               }
+               match msg_events[1] {
+                       MessageSendEvent::SendChannelUpdate { .. } => {},
+                       _ => panic!(),
+               }
  
                let dummy_graph = NetworkGraph::new(genesis_hash);
  
index c9dcb8517c323569d975c3bb9240c6c7eb7eae6d,e9fae460dd6e9605345c68d3134a0be0e7ab8b55..2e9439916df7b8c64760813d94685621183dba01
  //! A bunch of useful utilities for building networks of nodes and exchanging messages between
  //! nodes for functional tests.
  
 -use chain::{Confirm, Listen, Watch};
 +use chain::{BestBlock, Confirm, Listen, Watch};
  use chain::channelmonitor::ChannelMonitor;
  use chain::transaction::OutPoint;
  use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
 -use ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, ChannelManagerReadArgs, RAACommitmentOrder, PaymentSendFailure};
 +use ln::channelmanager::{ChainParameters, ChannelManager, ChannelManagerReadArgs, RAACommitmentOrder, PaymentSendFailure};
  use routing::router::{Route, get_route};
  use routing::network_graph::{NetGraphMsgHandler, NetworkGraph};
  use ln::features::{InitFeatures, InvoiceFeatures};
@@@ -1583,18 -1583,20 +1583,20 @@@ macro_rules! handle_chan_reestablish_ms
                        let mut revoke_and_ack = None;
                        let mut commitment_update = None;
                        let order = if let Some(ev) = msg_events.get(idx) {
-                               idx += 1;
                                match ev {
                                        &MessageSendEvent::SendRevokeAndACK { ref node_id, ref msg } => {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                revoke_and_ack = Some(msg.clone());
+                                               idx += 1;
                                                RAACommitmentOrder::RevokeAndACKFirst
                                        },
                                        &MessageSendEvent::UpdateHTLCs { ref node_id, ref updates } => {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                commitment_update = Some(updates.clone());
+                                               idx += 1;
                                                RAACommitmentOrder::CommitmentFirst
                                        },
+                                       &MessageSendEvent::SendChannelUpdate { .. } => RAACommitmentOrder::CommitmentFirst,
                                        _ => panic!("Unexpected event"),
                                }
                        } else {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                assert!(revoke_and_ack.is_none());
                                                revoke_and_ack = Some(msg.clone());
+                                               idx += 1;
                                        },
                                        &MessageSendEvent::UpdateHTLCs { ref node_id, ref updates } => {
                                                assert_eq!(*node_id, $dst_node.node.get_our_node_id());
                                                assert!(commitment_update.is_none());
                                                commitment_update = Some(updates.clone());
+                                               idx += 1;
                                        },
+                                       &MessageSendEvent::SendChannelUpdate { .. } => {},
                                        _ => panic!("Unexpected event"),
                                }
                        }
  
+                       if let Some(&MessageSendEvent::SendChannelUpdate { ref node_id, ref msg }) = msg_events.get(idx) {
+                               assert_eq!(*node_id, $dst_node.node.get_our_node_id());
+                               assert_eq!(msg.contents.flags & 2, 0); // "disabled" flag must not be set as we just reconnected.
+                       }
                        (funding_locked, revoke_and_ack, commitment_update, order)
                }
        }
index 4e51f6b4bf5fe9dcdd08d393e31461b05aa5ff9b,d6c4716b19d737b12283678f6c345e0b5dc01de9..073f3578de60b4419ed196d4b39ae5758942d0fe
@@@ -1039,7 -1039,8 +1039,8 @@@ fn do_test_shutdown_rebroadcast(recv_co
                nodes[0].node.handle_shutdown(&nodes[1].node.get_our_node_id(), &InitFeatures::known(), &node_1_2nd_shutdown);
                node_0_2nd_shutdown
        } else {
-               assert!(nodes[0].node.get_and_clear_pending_msg_events().is_empty());
+               let node_0_chan_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
+               assert_eq!(node_0_chan_update.contents.flags & 2, 0); // "disabled" flag must not be set as we just reconnected.
                nodes[0].node.handle_shutdown(&nodes[1].node.get_our_node_id(), &InitFeatures::known(), &node_1_2nd_shutdown);
                get_event_msg!(nodes[0], MessageSendEvent::SendShutdown, nodes[1].node.get_our_node_id())
        };
@@@ -1878,12 -1879,11 +1879,12 @@@ fn test_inbound_outbound_capacity_is_no
        assert_eq!(channels0.len(), 1);
        assert_eq!(channels1.len(), 1);
  
 -      assert_eq!(channels0[0].inbound_capacity_msat, 95000000);
 -      assert_eq!(channels1[0].outbound_capacity_msat, 95000000);
 +      let reserve = Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100000);
 +      assert_eq!(channels0[0].inbound_capacity_msat, 95000000 - reserve*1000);
 +      assert_eq!(channels1[0].outbound_capacity_msat, 95000000 - reserve*1000);
  
 -      assert_eq!(channels0[0].outbound_capacity_msat, 100000 * 1000 - 95000000);
 -      assert_eq!(channels1[0].inbound_capacity_msat, 100000 * 1000 - 95000000);
 +      assert_eq!(channels0[0].outbound_capacity_msat, 100000 * 1000 - 95000000 - reserve*1000);
 +      assert_eq!(channels1[0].inbound_capacity_msat, 100000 * 1000 - 95000000 - reserve*1000);
  }
  
  fn commit_tx_fee_msat(feerate: u32, num_htlcs: u64) -> u64 {