From: Duncan Dean <git@dunxen.dev>
Date: Fri, 14 Jul 2023 14:59:29 +0000 (+0200)
Subject: Close and remove unfunded inbound/outbound channels that are older than an hour
X-Git-Tag: v0.0.116~5^2
X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=50a6d41d265941b7d394750ba3e3ff11f18defec;p=rust-lightning
Close and remove unfunded inbound/outbound channels that are older than an hour
We introduce a `UnfundedChannelContext` which contains a counter for the
current age of an unfunded channel in timer ticks. This age is incremented
for every `ChannelManager::timer_tick_ocurred` and the unfunded channel
is removed if it exceeds `UNFUNDED_CHANNEL_AGE_LIMIT_TICKS`.
The value will not be persisted as unfunded channels themselves are not
persisted.
---
diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 31aecf68e..e74f659fb 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -590,6 +590,11 @@ pub(crate) const EXPIRE_PREV_CONFIG_TICKS: usize = 5;
/// See [`ChannelContext::sent_message_awaiting_response`] for more information.
pub(crate) const DISCONNECT_PEER_AWAITING_RESPONSE_TICKS: usize = 2;
+/// The number of ticks that may elapse while we're waiting for an unfunded outbound/inbound channel
+/// to be promoted to a [`Channel`] since the unfunded channel was created. An unfunded channel
+/// exceeding this age limit will be force-closed and purged from memory.
+pub(crate) const UNFUNDED_CHANNEL_AGE_LIMIT_TICKS: usize = 60;
+
struct PendingChannelMonitorUpdate {
update: ChannelMonitorUpdate,
}
@@ -598,6 +603,28 @@ impl_writeable_tlv_based!(PendingChannelMonitorUpdate, {
(0, update, required),
});
+/// Contains all state common to unfunded inbound/outbound channels.
+pub(super) struct UnfundedChannelContext {
+ /// A counter tracking how many ticks have elapsed since this unfunded channel was
+ /// created. If this unfunded channel reaches peer has yet to respond after reaching
+ /// `UNFUNDED_CHANNEL_AGE_LIMIT_TICKS`, it will be force-closed and purged from memory.
+ ///
+ /// This is so that we don't keep channels around that haven't progressed to a funded state
+ /// in a timely manner.
+ unfunded_channel_age_ticks: usize,
+}
+
+impl UnfundedChannelContext {
+ /// Determines whether we should force-close and purge this unfunded channel from memory due to it
+ /// having reached the unfunded channel age limit.
+ ///
+ /// This should be called on every [`super::channelmanager::ChannelManager::timer_tick_occurred`].
+ pub fn should_expire_unfunded_channel(&mut self) -> bool {
+ self.unfunded_channel_age_ticks += 1;
+ self.unfunded_channel_age_ticks >= UNFUNDED_CHANNEL_AGE_LIMIT_TICKS
+ }
+}
+
/// Contains everything about the channel including state, and various flags.
pub(super) struct ChannelContext<Signer: ChannelSigner> {
config: LegacyChannelConfig,
@@ -5477,6 +5504,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
/// A not-yet-funded outbound (from holder) channel using V1 channel establishment.
pub(super) struct OutboundV1Channel<Signer: ChannelSigner> {
pub context: ChannelContext<Signer>,
+ pub unfunded_context: UnfundedChannelContext,
}
impl<Signer: WriteableEcdsaChannelSigner> OutboundV1Channel<Signer> {
@@ -5678,7 +5706,8 @@ impl<Signer: WriteableEcdsaChannelSigner> OutboundV1Channel<Signer> {
channel_keys_id,
blocked_monitor_updates: Vec::new(),
- }
+ },
+ unfunded_context: UnfundedChannelContext { unfunded_channel_age_ticks: 0 }
})
}
@@ -5983,6 +6012,7 @@ impl<Signer: WriteableEcdsaChannelSigner> OutboundV1Channel<Signer> {
/// A not-yet-funded inbound (from counterparty) channel using V1 channel establishment.
pub(super) struct InboundV1Channel<Signer: ChannelSigner> {
pub context: ChannelContext<Signer>,
+ pub unfunded_context: UnfundedChannelContext,
}
impl<Signer: WriteableEcdsaChannelSigner> InboundV1Channel<Signer> {
@@ -6310,7 +6340,8 @@ impl<Signer: WriteableEcdsaChannelSigner> InboundV1Channel<Signer> {
channel_keys_id,
blocked_monitor_updates: Vec::new(),
- }
+ },
+ unfunded_context: UnfundedChannelContext { unfunded_channel_age_ticks: 0 }
};
Ok(chan)
diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 31e719cd4..b22c3716c 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -40,7 +40,7 @@ use crate::events::{Event, EventHandler, EventsProvider, MessageSendEvent, Messa
// Since this struct is returned in `list_channels` methods, expose it here in case users want to
// construct one themselves.
use crate::ln::{inbound_payment, PaymentHash, PaymentPreimage, PaymentSecret};
-use crate::ln::channel::{Channel, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UpdateFulfillCommitFetch, OutboundV1Channel, InboundV1Channel};
+use crate::ln::channel::{Channel, ChannelContext, ChannelError, ChannelUpdateStatus, ShutdownResult, UnfundedChannelContext, UpdateFulfillCommitFetch, OutboundV1Channel, InboundV1Channel};
use crate::ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
#[cfg(any(feature = "_test_utils", test))]
use crate::ln::features::Bolt11InvoiceFeatures;
@@ -4326,6 +4326,7 @@ where
/// * Expiring a channel's previous [`ChannelConfig`] if necessary to only allow forwarding HTLCs
/// with the current [`ChannelConfig`].
/// * Removing peers which have disconnected but and no longer have any channels.
+ /// * Force-closing and removing channels which have not completed establishment in a timely manner.
///
/// Note that this may cause reentrancy through [`chain::Watch::update_channel`] calls or feerate
/// estimate fetches.
@@ -4420,6 +4421,26 @@ where
true
});
+
+ let process_unfunded_channel_tick = |
+ chan_id: &[u8; 32],
+ chan_context: &mut ChannelContext<<SP::Target as SignerProvider>::Signer>,
+ unfunded_chan_context: &mut UnfundedChannelContext,
+ | {
+ chan_context.maybe_expire_prev_config();
+ if unfunded_chan_context.should_expire_unfunded_channel() {
+ log_error!(self.logger, "Force-closing pending outbound channel {} for not establishing in a timely manner", log_bytes!(&chan_id[..]));
+ update_maps_on_chan_removal!(self, &chan_context);
+ self.issue_channel_close_events(&chan_context, ClosureReason::HolderForceClosed);
+ self.finish_force_close_channel(chan_context.force_shutdown(false));
+ false
+ } else {
+ true
+ }
+ };
+ peer_state.outbound_v1_channel_by_id.retain(|chan_id, chan| process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context));
+ peer_state.inbound_v1_channel_by_id.retain(|chan_id, chan| process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context));
+
if peer_state.ok_to_remove(true) {
pending_peers_awaiting_removal.push(counterparty_node_id);
}
diff --git a/lightning/src/ln/functional_tests.rs b/lightning/src/ln/functional_tests.rs
index 0e35f35f0..8de2e9f63 100644
--- a/lightning/src/ln/functional_tests.rs
+++ b/lightning/src/ln/functional_tests.rs
@@ -61,6 +61,8 @@ use crate::sync::{Arc, Mutex};
use crate::ln::functional_test_utils::*;
use crate::ln::chan_utils::CommitmentTransaction;
+use super::channel::UNFUNDED_CHANNEL_AGE_LIMIT_TICKS;
+
#[test]
fn test_insane_channel_opens() {
// Stand up a network of 2 nodes
@@ -10017,3 +10019,89 @@ fn test_disconnects_peer_awaiting_response_ticks() {
}
}
}
+
+#[test]
+fn test_remove_expired_outbound_unfunded_channels() {
+ let chanmon_cfgs = create_chanmon_cfgs(2);
+ let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+ let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+ let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+ let temp_channel_id = nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, 0, 42, None).unwrap();
+ let open_channel_message = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
+ nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_message);
+ let accept_channel_message = get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, nodes[0].node.get_our_node_id());
+ nodes[0].node.handle_accept_channel(&nodes[1].node.get_our_node_id(), &accept_channel_message);
+
+ let events = nodes[0].node.get_and_clear_pending_events();
+ assert_eq!(events.len(), 1);
+ match events[0] {
+ Event::FundingGenerationReady { .. } => (),
+ _ => panic!("Unexpected event"),
+ };
+
+ // Asserts the outbound channel has been removed from a nodes[0]'s peer state map.
+ let check_outbound_channel_existence = |should_exist: bool| {
+ let per_peer_state = nodes[0].node.per_peer_state.read().unwrap();
+ let chan_lock = per_peer_state.get(&nodes[1].node.get_our_node_id()).unwrap().lock().unwrap();
+ assert_eq!(chan_lock.outbound_v1_channel_by_id.contains_key(&temp_channel_id), should_exist);
+ };
+
+ // Channel should exist without any timer ticks.
+ check_outbound_channel_existence(true);
+
+ // Channel should exist with 1 timer tick less than required.
+ for _ in 0..UNFUNDED_CHANNEL_AGE_LIMIT_TICKS - 1 {
+ nodes[0].node.timer_tick_occurred();
+ check_outbound_channel_existence(true)
+ }
+
+ // Remove channel after reaching the required ticks.
+ nodes[0].node.timer_tick_occurred();
+ check_outbound_channel_existence(false);
+
+ check_closed_event!(nodes[0], 1, ClosureReason::HolderForceClosed);
+}
+
+#[test]
+fn test_remove_expired_inbound_unfunded_channels() {
+ let chanmon_cfgs = create_chanmon_cfgs(2);
+ let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+ let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+ let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+ let temp_channel_id = nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, 0, 42, None).unwrap();
+ let open_channel_message = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
+ nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_message);
+ let accept_channel_message = get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, nodes[0].node.get_our_node_id());
+ nodes[0].node.handle_accept_channel(&nodes[1].node.get_our_node_id(), &accept_channel_message);
+
+ let events = nodes[0].node.get_and_clear_pending_events();
+ assert_eq!(events.len(), 1);
+ match events[0] {
+ Event::FundingGenerationReady { .. } => (),
+ _ => panic!("Unexpected event"),
+ };
+
+ // Asserts the inbound channel has been removed from a nodes[1]'s peer state map.
+ let check_inbound_channel_existence = |should_exist: bool| {
+ let per_peer_state = nodes[1].node.per_peer_state.read().unwrap();
+ let chan_lock = per_peer_state.get(&nodes[0].node.get_our_node_id()).unwrap().lock().unwrap();
+ assert_eq!(chan_lock.inbound_v1_channel_by_id.contains_key(&temp_channel_id), should_exist);
+ };
+
+ // Channel should exist without any timer ticks.
+ check_inbound_channel_existence(true);
+
+ // Channel should exist with 1 timer tick less than required.
+ for _ in 0..UNFUNDED_CHANNEL_AGE_LIMIT_TICKS - 1 {
+ nodes[1].node.timer_tick_occurred();
+ check_inbound_channel_existence(true)
+ }
+
+ // Remove channel after reaching the required ticks.
+ nodes[1].node.timer_tick_occurred();
+ check_inbound_channel_existence(false);
+
+ check_closed_event!(nodes[1], 1, ClosureReason::HolderForceClosed);
+}