}
macro_rules! handle_monitor_update_completion {
- ($self: ident, $update_id: expr, $peer_state_lock: expr, $peer_state: expr, $chan: expr) => { {
+ ($self: ident, $update_id: expr, $peer_state_lock: expr, $peer_state: expr, $per_peer_state_lock: expr, $chan: expr) => { {
let mut updates = $chan.monitor_updating_restored(&$self.logger,
&$self.node_signer, $self.genesis_hash, &$self.default_configuration,
$self.best_block.read().unwrap().height());
let channel_id = $chan.channel_id();
core::mem::drop($peer_state_lock);
+ core::mem::drop($per_peer_state_lock);
$self.handle_monitor_update_completion_actions(update_actions);
}
macro_rules! handle_new_monitor_update {
- ($self: ident, $update_res: expr, $update_id: expr, $peer_state_lock: expr, $peer_state: expr, $chan: expr, MANUALLY_REMOVING, $remove: expr) => { {
+ ($self: ident, $update_res: expr, $update_id: expr, $peer_state_lock: expr, $peer_state: expr, $per_peer_state_lock: expr, $chan: expr, MANUALLY_REMOVING, $remove: expr) => { {
// update_maps_on_chan_removal needs to be able to take id_to_peer, so make sure we can in
// any case so that it won't deadlock.
debug_assert!($self.id_to_peer.try_lock().is_ok());
.update_id == $update_id) &&
$chan.get_latest_monitor_update_id() == $update_id
{
- handle_monitor_update_completion!($self, $update_id, $peer_state_lock, $peer_state, $chan);
+ handle_monitor_update_completion!($self, $update_id, $peer_state_lock, $peer_state, $per_peer_state_lock, $chan);
}
Ok(())
},
}
} };
- ($self: ident, $update_res: expr, $update_id: expr, $peer_state_lock: expr, $peer_state: expr, $chan_entry: expr) => {
- handle_new_monitor_update!($self, $update_res, $update_id, $peer_state_lock, $peer_state, $chan_entry.get_mut(), MANUALLY_REMOVING, $chan_entry.remove_entry())
+ ($self: ident, $update_res: expr, $update_id: expr, $peer_state_lock: expr, $peer_state: expr, $per_peer_state_lock: expr, $chan_entry: expr) => {
+ handle_new_monitor_update!($self, $update_res, $update_id, $peer_state_lock, $peer_state, $per_peer_state_lock, $chan_entry.get_mut(), MANUALLY_REMOVING, $chan_entry.remove_entry())
}
}
if let Some(monitor_update) = monitor_update_opt.take() {
let update_id = monitor_update.update_id;
let update_res = self.chain_monitor.update_channel(funding_txo_opt.unwrap(), monitor_update);
- break handle_new_monitor_update!(self, update_res, update_id, peer_state_lock, peer_state, chan_entry);
+ break handle_new_monitor_update!(self, update_res, update_id, peer_state_lock, peer_state, per_peer_state, chan_entry);
}
if chan_entry.get().is_shutdown() {
})
}
- // Only public for testing, this should otherwise never be called direcly
- pub(crate) fn send_payment_along_path(&self, path: &Vec<RouteHop>, payment_params: &Option<PaymentParameters>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
+ #[cfg(test)]
+ pub(crate) fn test_send_payment_along_path(&self, path: &Vec<RouteHop>, payment_params: &Option<PaymentParameters>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
+ let _lck = self.total_consistency_lock.read().unwrap();
+ self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv_bytes)
+ }
+
+ fn send_payment_along_path(&self, path: &Vec<RouteHop>, payment_params: &Option<PaymentParameters>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32, payment_id: PaymentId, keysend_preimage: &Option<PaymentPreimage>, session_priv_bytes: [u8; 32]) -> Result<(), APIError> {
+ // The top-level caller should hold the total_consistency_lock read lock.
+ debug_assert!(self.total_consistency_lock.try_write().is_err());
+
log_trace!(self.logger, "Attempting to send payment for path with next hop {}", path.first().unwrap().short_channel_id);
let prng_seed = self.entropy_source.get_secure_random_bytes();
let session_priv = SecretKey::from_slice(&session_priv_bytes[..]).expect("RNG is busted");
}
let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, prng_seed, payment_hash);
- let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
-
let err: Result<(), _> = loop {
let (counterparty_node_id, id) = match self.short_to_chan_info.read().unwrap().get(&path.first().unwrap().short_channel_id) {
None => return Err(APIError::ChannelUnavailable{err: "No channel available with first hop!".to_owned()}),
Some(monitor_update) => {
let update_id = monitor_update.update_id;
let update_res = self.chain_monitor.update_channel(funding_txo, monitor_update);
- if let Err(e) = handle_new_monitor_update!(self, update_res, update_id, peer_state_lock, peer_state, chan) {
+ if let Err(e) = handle_new_monitor_update!(self, update_res, update_id, peer_state_lock, peer_state, per_peer_state, chan) {
break Err(e);
}
if update_res == ChannelMonitorUpdateStatus::InProgress {
/// [`ChannelMonitorUpdateStatus::InProgress`]: crate::chain::ChannelMonitorUpdateStatus::InProgress
pub fn send_payment(&self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, payment_id: PaymentId) -> Result<(), PaymentSendFailure> {
let best_block_height = self.best_block.read().unwrap().height();
+ let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
self.pending_outbound_payments
.send_payment_with_route(route, payment_hash, payment_secret, payment_id, &self.entropy_source, &self.node_signer, best_block_height,
|path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
/// `route_params` and retry failed payment paths based on `retry_strategy`.
pub fn send_payment_with_retry(&self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<(), RetryableSendFailure> {
let best_block_height = self.best_block.read().unwrap().height();
+ let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
self.pending_outbound_payments
.send_payment(payment_hash, payment_secret, payment_id, retry_strategy, route_params,
&self.router, self.list_usable_channels(), || self.compute_inflight_htlcs(),
#[cfg(test)]
fn test_send_payment_internal(&self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>, onion_session_privs: Vec<[u8; 32]>) -> Result<(), PaymentSendFailure> {
let best_block_height = self.best_block.read().unwrap().height();
+ let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
self.pending_outbound_payments.test_send_payment_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id, recv_value_msat, onion_session_privs, &self.node_signer, best_block_height,
|path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
/// [`send_payment`]: Self::send_payment
pub fn send_spontaneous_payment(&self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId) -> Result<PaymentHash, PaymentSendFailure> {
let best_block_height = self.best_block.read().unwrap().height();
+ let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
self.pending_outbound_payments.send_spontaneous_payment_with_route(
route, payment_preimage, payment_id, &self.entropy_source, &self.node_signer,
best_block_height,
/// [`PaymentParameters::for_keysend`]: crate::routing::router::PaymentParameters::for_keysend
pub fn send_spontaneous_payment_with_retry(&self, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<PaymentHash, RetryableSendFailure> {
let best_block_height = self.best_block.read().unwrap().height();
+ let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
self.pending_outbound_payments.send_spontaneous_payment(payment_preimage, payment_id,
retry_strategy, route_params, &self.router, self.list_usable_channels(),
|| self.compute_inflight_htlcs(), &self.entropy_source, &self.node_signer, best_block_height,
/// us to easily discern them from real payments.
pub fn send_probe(&self, hops: Vec<RouteHop>) -> Result<(PaymentHash, PaymentId), PaymentSendFailure> {
let best_block_height = self.best_block.read().unwrap().height();
+ let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
self.pending_outbound_payments.send_probe(hops, self.probing_cookie_secret, &self.entropy_source, &self.node_signer, best_block_height,
|path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
self.send_payment_along_path(path, payment_params, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
)
).unwrap_or(None);
- if let Some(mut peer_state_lock) = peer_state_opt.take() {
+ if peer_state_opt.is_some() {
+ let mut peer_state_lock = peer_state_opt.unwrap();
let peer_state = &mut *peer_state_lock;
if let hash_map::Entry::Occupied(mut chan) = peer_state.channel_by_id.entry(chan_id) {
let counterparty_node_id = chan.get().get_counterparty_node_id();
let update_id = monitor_update.update_id;
let update_res = self.chain_monitor.update_channel(prev_hop.outpoint, monitor_update);
let res = handle_new_monitor_update!(self, update_res, update_id, peer_state_lock,
- peer_state, chan);
+ peer_state, per_peer_state, chan);
if let Err(e) = res {
// TODO: This is a *critical* error - we probably updated the outbound edge
// of the HTLC's monitor with a preimage. We should retry this monitor
}
fn channel_monitor_updated(&self, funding_txo: &OutPoint, highest_applied_update_id: u64, counterparty_node_id: Option<&PublicKey>) {
- let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
+ debug_assert!(self.total_consistency_lock.try_write().is_err()); // Caller holds read lock
let counterparty_node_id = match counterparty_node_id {
Some(cp_id) => cp_id.clone(),
if !channel.get().is_awaiting_monitor_update() || channel.get().get_latest_monitor_update_id() != highest_applied_update_id {
return;
}
- handle_monitor_update_completion!(self, highest_applied_update_id, peer_state_lock, peer_state, channel.get_mut());
+ handle_monitor_update_completion!(self, highest_applied_update_id, peer_state_lock, peer_state, per_peer_state, channel.get_mut());
}
/// Accepts a request to open a channel after a [`Event::OpenChannelRequest`].
let monitor_res = self.chain_monitor.watch_channel(monitor.get_funding_txo().0, monitor);
let chan = e.insert(chan);
- let mut res = handle_new_monitor_update!(self, monitor_res, 0, peer_state_lock, peer_state, chan, MANUALLY_REMOVING, { peer_state.channel_by_id.remove(&new_channel_id) });
+ let mut res = handle_new_monitor_update!(self, monitor_res, 0, peer_state_lock, peer_state,
+ per_peer_state, chan, MANUALLY_REMOVING, { peer_state.channel_by_id.remove(&new_channel_id) });
// Note that we reply with the new channel_id in error messages if we gave up on the
// channel, not the temporary_channel_id. This is compatible with ourselves, but the
let monitor = try_chan_entry!(self,
chan.get_mut().funding_signed(&msg, best_block, &self.signer_provider, &self.logger), chan);
let update_res = self.chain_monitor.watch_channel(chan.get().get_funding_txo().unwrap(), monitor);
- let mut res = handle_new_monitor_update!(self, update_res, 0, peer_state_lock, peer_state, chan);
+ let mut res = handle_new_monitor_update!(self, update_res, 0, peer_state_lock, peer_state, per_peer_state, chan);
if let Err(MsgHandleErrInternal { ref mut shutdown_finish, .. }) = res {
// We weren't able to watch the channel to begin with, so no updates should be made on
// it. Previously, full_stack_target found an (unreachable) panic when the
if let Some(monitor_update) = monitor_update_opt {
let update_id = monitor_update.update_id;
let update_res = self.chain_monitor.update_channel(funding_txo_opt.unwrap(), monitor_update);
- break handle_new_monitor_update!(self, update_res, update_id, peer_state_lock, peer_state, chan_entry);
+ break handle_new_monitor_update!(self, update_res, update_id, peer_state_lock, peer_state, per_peer_state, chan_entry);
}
break Ok(());
},
let update_res = self.chain_monitor.update_channel(funding_txo.unwrap(), monitor_update);
let update_id = monitor_update.update_id;
handle_new_monitor_update!(self, update_res, update_id, peer_state_lock,
- peer_state, chan)
+ peer_state, per_peer_state, chan)
},
hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
}
fn internal_revoke_and_ack(&self, counterparty_node_id: &PublicKey, msg: &msgs::RevokeAndACK) -> Result<(), MsgHandleErrInternal> {
let (htlcs_to_fail, res) = {
let per_peer_state = self.per_peer_state.read().unwrap();
- let peer_state_mutex = per_peer_state.get(counterparty_node_id)
+ let mut peer_state_lock = per_peer_state.get(counterparty_node_id)
.ok_or_else(|| {
debug_assert!(false);
MsgHandleErrInternal::send_err_msg_no_close(format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id), msg.channel_id)
- })?;
- let mut peer_state_lock = peer_state_mutex.lock().unwrap();
+ }).map(|mtx| mtx.lock().unwrap())?;
let peer_state = &mut *peer_state_lock;
match peer_state.channel_by_id.entry(msg.channel_id) {
hash_map::Entry::Occupied(mut chan) => {
let (htlcs_to_fail, monitor_update) = try_chan_entry!(self, chan.get_mut().revoke_and_ack(&msg, &self.logger), chan);
let update_res = self.chain_monitor.update_channel(funding_txo.unwrap(), monitor_update);
let update_id = monitor_update.update_id;
- let res = handle_new_monitor_update!(self, update_res, update_id, peer_state_lock,
- peer_state, chan);
+ let res = handle_new_monitor_update!(self, update_res, update_id,
+ peer_state_lock, peer_state, per_peer_state, chan);
(htlcs_to_fail, res)
},
hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
/// Process pending events from the `chain::Watch`, returning whether any events were processed.
fn process_pending_monitor_events(&self) -> bool {
+ debug_assert!(self.total_consistency_lock.try_write().is_err()); // Caller holds read lock
+
let mut failed_channels = Vec::new();
let mut pending_monitor_events = self.chain_monitor.release_pending_monitor_events();
let has_pending_monitor_events = !pending_monitor_events.is_empty();
/// update events as a separate process method here.
#[cfg(fuzzing)]
pub fn process_monitor_events(&self) {
- self.process_pending_monitor_events();
+ PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
+ if self.process_pending_monitor_events() {
+ NotifyOption::DoPersist
+ } else {
+ NotifyOption::SkipPersist
+ }
+ });
}
/// Check the holding cell in each channel and free any pending HTLCs in them if possible.
let mut has_monitor_update = false;
let mut failed_htlcs = Vec::new();
let mut handle_errors = Vec::new();
- let per_peer_state = self.per_peer_state.read().unwrap();
- for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
- 'chan_loop: loop {
- let mut peer_state_lock = peer_state_mutex.lock().unwrap();
- let peer_state: &mut PeerState<_> = &mut *peer_state_lock;
- for (channel_id, chan) in peer_state.channel_by_id.iter_mut() {
- let counterparty_node_id = chan.get_counterparty_node_id();
- let funding_txo = chan.get_funding_txo();
- let (monitor_opt, holding_cell_failed_htlcs) =
- chan.maybe_free_holding_cell_htlcs(&self.logger);
- if !holding_cell_failed_htlcs.is_empty() {
- failed_htlcs.push((holding_cell_failed_htlcs, *channel_id, counterparty_node_id));
- }
- if let Some(monitor_update) = monitor_opt {
- has_monitor_update = true;
-
- let update_res = self.chain_monitor.update_channel(
- funding_txo.expect("channel is live"), monitor_update);
- let update_id = monitor_update.update_id;
- let channel_id: [u8; 32] = *channel_id;
- let res = handle_new_monitor_update!(self, update_res, update_id,
- peer_state_lock, peer_state, chan, MANUALLY_REMOVING,
- peer_state.channel_by_id.remove(&channel_id));
- if res.is_err() {
- handle_errors.push((counterparty_node_id, res));
+ // Walk our list of channels and find any that need to update. Note that when we do find an
+ // update, if it includes actions that must be taken afterwards, we have to drop the
+ // per-peer state lock as well as the top level per_peer_state lock. Thus, we loop until we
+ // manage to go through all our peers without finding a single channel to update.
+ 'peer_loop: loop {
+ let per_peer_state = self.per_peer_state.read().unwrap();
+ for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
+ 'chan_loop: loop {
+ let mut peer_state_lock = peer_state_mutex.lock().unwrap();
+ let peer_state: &mut PeerState<_> = &mut *peer_state_lock;
+ for (channel_id, chan) in peer_state.channel_by_id.iter_mut() {
+ let counterparty_node_id = chan.get_counterparty_node_id();
+ let funding_txo = chan.get_funding_txo();
+ let (monitor_opt, holding_cell_failed_htlcs) =
+ chan.maybe_free_holding_cell_htlcs(&self.logger);
+ if !holding_cell_failed_htlcs.is_empty() {
+ failed_htlcs.push((holding_cell_failed_htlcs, *channel_id, counterparty_node_id));
+ }
+ if let Some(monitor_update) = monitor_opt {
+ has_monitor_update = true;
+
+ let update_res = self.chain_monitor.update_channel(
+ funding_txo.expect("channel is live"), monitor_update);
+ let update_id = monitor_update.update_id;
+ let channel_id: [u8; 32] = *channel_id;
+ let res = handle_new_monitor_update!(self, update_res, update_id,
+ peer_state_lock, peer_state, per_peer_state, chan, MANUALLY_REMOVING,
+ peer_state.channel_by_id.remove(&channel_id));
+ if res.is_err() {
+ handle_errors.push((counterparty_node_id, res));
+ }
+ continue 'peer_loop;
}
- continue 'chan_loop;
}
+ break 'chan_loop;
}
- break 'chan_loop;
}
+ break 'peer_loop;
}
let has_update = has_monitor_update || !failed_htlcs.is_empty() || !handle_errors.is_empty();
let mut monitor_update_blocked_actions_per_peer = None;
let mut peer_states = Vec::new();
for (_, peer_state_mutex) in per_peer_state.iter() {
- peer_states.push(peer_state_mutex.lock().unwrap());
+ // Because we're holding the owning `per_peer_state` write lock here there's no chance
+ // of a lockorder violation deadlock - no other thread can be holding any
+ // per_peer_state lock at all.
+ peer_states.push(peer_state_mutex.unsafe_well_ordered_double_lock_self());
}
(serializable_peer_count).write(writer)?;
}
}
- let pending_outbounds = OutboundPayments { pending_outbound_payments: Mutex::new(pending_outbound_payments.unwrap()), retry_lock: Mutex::new(()) };
+ let pending_outbounds = OutboundPayments {
+ pending_outbound_payments: Mutex::new(pending_outbound_payments.unwrap()),
+ retry_lock: Mutex::new(())
+ };
if !forward_htlcs.is_empty() || pending_outbounds.needs_abandon() {
// If we have pending HTLCs to forward, assume we either dropped a
// `PendingHTLCsForwardable` or the user received it but never processed it as they
// indicates there are more HTLCs coming.
let cur_height = CHAN_CONFIRM_DEPTH + 1; // route_payment calls send_payment, which adds 1 to the current height. So we do the same here to match.
let session_privs = nodes[0].node.test_add_new_pending_payment(our_payment_hash, Some(payment_secret), payment_id, &mpp_route).unwrap();
- nodes[0].node.send_payment_along_path(&mpp_route.paths[0], &route.payment_params, &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[0]).unwrap();
+ nodes[0].node.test_send_payment_along_path(&mpp_route.paths[0], &route.payment_params, &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[0]).unwrap();
check_added_monitors!(nodes[0], 1);
let mut events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 1);
expect_payment_failed!(nodes[0], our_payment_hash, true);
// Send the second half of the original MPP payment.
- nodes[0].node.send_payment_along_path(&mpp_route.paths[1], &route.payment_params, &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[1]).unwrap();
+ nodes[0].node.test_send_payment_along_path(&mpp_route.paths[1], &route.payment_params, &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None, session_privs[1]).unwrap();
check_added_monitors!(nodes[0], 1);
let mut events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 1);
let nodes_0_lock = nodes[0].node.id_to_peer.lock().unwrap();
assert_eq!(nodes_0_lock.len(), 1);
assert!(nodes_0_lock.contains_key(channel_id));
-
- assert_eq!(nodes[1].node.id_to_peer.lock().unwrap().len(), 0);
}
+ assert_eq!(nodes[1].node.id_to_peer.lock().unwrap().len(), 0);
+
let funding_created_msg = get_event_msg!(nodes[0], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id());
nodes[1].node.handle_funding_created(&nodes[0].node.get_our_node_id(), &funding_created_msg);
let nodes_0_lock = nodes[0].node.id_to_peer.lock().unwrap();
assert_eq!(nodes_0_lock.len(), 1);
assert!(nodes_0_lock.contains_key(channel_id));
+ }
+ {
// Assert that `nodes[1]`'s `id_to_peer` map is populated with the channel as soon as
// as it has the funding transaction.
let nodes_1_lock = nodes[1].node.id_to_peer.lock().unwrap();
let nodes_0_lock = nodes[0].node.id_to_peer.lock().unwrap();
assert_eq!(nodes_0_lock.len(), 1);
assert!(nodes_0_lock.contains_key(channel_id));
+ }
+ {
// At this stage, `nodes[1]` has proposed a fee for the closing transaction in the
// `handle_closing_signed` call above. As `nodes[1]` has not yet received the signature
// from `nodes[0]` for the closing transaction with the proposed fee, the channel is