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Merged
merged 1 commit into from
Jun 7, 2023
+148 −7
Merged

Support atomic partial updates to ChannelConfig #2330

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100 changes: 93 additions & 7 deletions lightning/src/ln/channelmanager.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@ use crate::ln::outbound_payment;
use crate::ln::outbound_payment::{OutboundPayments, PaymentAttempts, PendingOutboundPayment};
use crate::ln::wire::Encode;
use crate::sign::{EntropySource, KeysManager, NodeSigner, Recipient, SignerProvider, ChannelSigner, WriteableEcdsaChannelSigner};
use crate::util::config::{UserConfig, ChannelConfig};
use crate::util::config::{UserConfig, ChannelConfig, ChannelConfigUpdate};
use crate::util::wakers::{Future, Notifier};
use crate::util::scid_utils::fake_scid;
use crate::util::string::UntrustedString;
Expand Down Expand Up @@ -3228,7 +3228,7 @@ where
})
}

/// Atomically updates the [`ChannelConfig`] for the given channels.
/// Atomically applies partial updates to the [`ChannelConfig`] of the given channels.
///
/// Once the updates are applied, each eligible channel (advertised with a known short channel
/// ID and a change in [`forwarding_fee_proportional_millionths`], [`forwarding_fee_base_msat`],
Expand All @@ -3250,10 +3250,10 @@ where
/// [`ChannelUpdate`]: msgs::ChannelUpdate
/// [`ChannelUnavailable`]: APIError::ChannelUnavailable
/// [`APIMisuseError`]: APIError::APIMisuseError
pub fn update_channel_config(
&self, counterparty_node_id: &PublicKey, channel_ids: &[[u8; 32]], config: &ChannelConfig,
pub fn update_partial_channel_config(
&self, counterparty_node_id: &PublicKey, channel_ids: &[[u8; 32]], config_update: &ChannelConfigUpdate,
) -> Result<(), APIError> {
if config.cltv_expiry_delta < MIN_CLTV_EXPIRY_DELTA {
if config_update.cltv_expiry_delta.map(|delta| delta < MIN_CLTV_EXPIRY_DELTA).unwrap_or(false) {
return Err(APIError::APIMisuseError {
err: format!("The chosen CLTV expiry delta is below the minimum of {}", MIN_CLTV_EXPIRY_DELTA),
});
Expand All @@ -3274,7 +3274,9 @@ where
}
for channel_id in channel_ids {
let channel = peer_state.channel_by_id.get_mut(channel_id).unwrap();
if !channel.update_config(config) {
let mut config = channel.config();
config.apply(config_update);
if !channel.update_config(&config) {
continue;
}
if let Ok(msg) = self.get_channel_update_for_broadcast(channel) {
Expand All @@ -3289,6 +3291,34 @@ where
Ok(())
}

/// Atomically updates the [`ChannelConfig`] for the given channels.
///
/// Once the updates are applied, each eligible channel (advertised with a known short channel
/// ID and a change in [`forwarding_fee_proportional_millionths`], [`forwarding_fee_base_msat`],
/// or [`cltv_expiry_delta`]) has a [`BroadcastChannelUpdate`] event message generated
/// containing the new [`ChannelUpdate`] message which should be broadcast to the network.
///
/// Returns [`ChannelUnavailable`] when a channel is not found or an incorrect
/// `counterparty_node_id` is provided.
///
/// Returns [`APIMisuseError`] when a [`cltv_expiry_delta`] update is to be applied with a value
/// below [`MIN_CLTV_EXPIRY_DELTA`].
///
/// If an error is returned, none of the updates should be considered applied.
///
/// [`forwarding_fee_proportional_millionths`]: ChannelConfig::forwarding_fee_proportional_millionths
/// [`forwarding_fee_base_msat`]: ChannelConfig::forwarding_fee_base_msat
/// [`cltv_expiry_delta`]: ChannelConfig::cltv_expiry_delta
/// [`BroadcastChannelUpdate`]: events::MessageSendEvent::BroadcastChannelUpdate
/// [`ChannelUpdate`]: msgs::ChannelUpdate
/// [`ChannelUnavailable`]: APIError::ChannelUnavailable
/// [`APIMisuseError`]: APIError::APIMisuseError
pub fn update_channel_config(
&self, counterparty_node_id: &PublicKey, channel_ids: &[[u8; 32]], config: &ChannelConfig,
) -> Result<(), APIError> {
return self.update_partial_channel_config(counterparty_node_id, channel_ids, &(*config).into());
}

/// Attempts to forward an intercepted HTLC over the provided channel id and with the provided
/// amount to forward. Should only be called in response to an [`HTLCIntercepted`] event.
///
Expand Down Expand Up @@ -8578,7 +8608,7 @@ mod tests {
use crate::routing::router::{PaymentParameters, RouteParameters, find_route};
use crate::util::errors::APIError;
use crate::util::test_utils;
use crate::util::config::ChannelConfig;
use crate::util::config::{ChannelConfig, ChannelConfigUpdate};
use crate::sign::EntropySource;

#[test]
Expand Down Expand Up @@ -9489,6 +9519,62 @@ mod tests {

check_closed_event!(nodes[1], 1, ClosureReason::HolderForceClosed);
}

#[test]
fn test_update_channel_config() {
let chanmon_cfg = create_chanmon_cfgs(2);
let node_cfg = create_node_cfgs(2, &chanmon_cfg);
let mut user_config = test_default_channel_config();
let node_chanmgr = create_node_chanmgrs(2, &node_cfg, &[Some(user_config), Some(user_config)]);
let nodes = create_network(2, &node_cfg, &node_chanmgr);
let _ = create_announced_chan_between_nodes(&nodes, 0, 1);
let channel = &nodes[0].node.list_channels()[0];

nodes[0].node.update_channel_config(&channel.counterparty.node_id, &[channel.channel_id], &user_config.channel_config).unwrap();
let events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 0);

user_config.channel_config.forwarding_fee_base_msat += 10;
nodes[0].node.update_channel_config(&channel.counterparty.node_id, &[channel.channel_id], &user_config.channel_config).unwrap();
assert_eq!(nodes[0].node.list_channels()[0].config.unwrap().forwarding_fee_base_msat, user_config.channel_config.forwarding_fee_base_msat);
let events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 1);
match &events[0] {
MessageSendEvent::BroadcastChannelUpdate { .. } => {},
_ => panic!("expected BroadcastChannelUpdate event"),
}

nodes[0].node.update_partial_channel_config(&channel.counterparty.node_id, &[channel.channel_id], &ChannelConfigUpdate::default()).unwrap();
let events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 0);

let new_cltv_expiry_delta = user_config.channel_config.cltv_expiry_delta + 6;
nodes[0].node.update_partial_channel_config(&channel.counterparty.node_id, &[channel.channel_id], &ChannelConfigUpdate {
cltv_expiry_delta: Some(new_cltv_expiry_delta),
..Default::default()
}).unwrap();
assert_eq!(nodes[0].node.list_channels()[0].config.unwrap().cltv_expiry_delta, new_cltv_expiry_delta);
let events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 1);
match &events[0] {
MessageSendEvent::BroadcastChannelUpdate { .. } => {},
_ => panic!("expected BroadcastChannelUpdate event"),
}

let new_fee = user_config.channel_config.forwarding_fee_proportional_millionths + 100;
nodes[0].node.update_partial_channel_config(&channel.counterparty.node_id, &[channel.channel_id], &ChannelConfigUpdate {
forwarding_fee_proportional_millionths: Some(new_fee),
..Default::default()
}).unwrap();
assert_eq!(nodes[0].node.list_channels()[0].config.unwrap().cltv_expiry_delta, new_cltv_expiry_delta);
assert_eq!(nodes[0].node.list_channels()[0].config.unwrap().forwarding_fee_proportional_millionths, new_fee);
let events = nodes[0].node.get_and_clear_pending_msg_events();
assert_eq!(events.len(), 1);
match &events[0] {
MessageSendEvent::BroadcastChannelUpdate { .. } => {},
_ => panic!("expected BroadcastChannelUpdate event"),
}
}
}

#[cfg(ldk_bench)]
Expand Down
55 changes: 55 additions & 0 deletions lightning/src/util/config.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -399,6 +399,27 @@ pub struct ChannelConfig {
pub force_close_avoidance_max_fee_satoshis: u64,
}

impl ChannelConfig {
/// Applies the given [`ChannelConfigUpdate`] as a partial update to the [`ChannelConfig`].
pub fn apply(&mut self, update: &ChannelConfigUpdate) {
if let Some(forwarding_fee_proportional_millionths) = update.forwarding_fee_proportional_millionths {
self.forwarding_fee_proportional_millionths = forwarding_fee_proportional_millionths;
}
if let Some(forwarding_fee_base_msat) = update.forwarding_fee_base_msat {
self.forwarding_fee_base_msat = forwarding_fee_base_msat;
}
if let Some(cltv_expiry_delta) = update.cltv_expiry_delta {
self.cltv_expiry_delta = cltv_expiry_delta;
}
if let Some(max_dust_htlc_exposure_msat) = update.max_dust_htlc_exposure_msat {
self.max_dust_htlc_exposure_msat = max_dust_htlc_exposure_msat;
}
if let Some(force_close_avoidance_max_fee_satoshis) = update.force_close_avoidance_max_fee_satoshis {
self.force_close_avoidance_max_fee_satoshis = force_close_avoidance_max_fee_satoshis;
}
}
}

impl Default for ChannelConfig {
/// Provides sane defaults for most configurations (but with zero relay fees!).
fn default() -> Self {
Expand All @@ -423,6 +444,40 @@ impl_writeable_tlv_based!(ChannelConfig, {
(10, force_close_avoidance_max_fee_satoshis, required),
});

/// A parallel struct to [`ChannelConfig`] to define partial updates.
#[allow(missing_docs)]
pub struct ChannelConfigUpdate {
pub forwarding_fee_proportional_millionths: Option<u32>,
pub forwarding_fee_base_msat: Option<u32>,
pub cltv_expiry_delta: Option<u16>,
pub max_dust_htlc_exposure_msat: Option<u64>,
pub force_close_avoidance_max_fee_satoshis: Option<u64>,
}

impl Default for ChannelConfigUpdate {
fn default() -> ChannelConfigUpdate {
ChannelConfigUpdate {
forwarding_fee_proportional_millionths: None,
forwarding_fee_base_msat: None,
cltv_expiry_delta: None,
max_dust_htlc_exposure_msat: None,
force_close_avoidance_max_fee_satoshis: None,
}
}
}

impl From<ChannelConfig> for ChannelConfigUpdate {
fn from(config: ChannelConfig) -> ChannelConfigUpdate {
ChannelConfigUpdate {
forwarding_fee_proportional_millionths: Some(config.forwarding_fee_proportional_millionths),
forwarding_fee_base_msat: Some(config.forwarding_fee_base_msat),
cltv_expiry_delta: Some(config.cltv_expiry_delta),
max_dust_htlc_exposure_msat: Some(config.max_dust_htlc_exposure_msat),
force_close_avoidance_max_fee_satoshis: Some(config.force_close_avoidance_max_fee_satoshis),
}
}
}

/// Legacy version of [`ChannelConfig`] that stored the static
/// [`ChannelHandshakeConfig::announced_channel`] and
/// [`ChannelHandshakeConfig::commit_upfront_shutdown_pubkey`] fields.
Expand Down