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Allow configuring different max fee rate from peer
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@benthecarman
benthecarman committed Oct 11, 2023
1 parent 989304e commit 07c7a67
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Showing 2 changed files with 44 additions and 9 deletions.
19 changes: 10 additions & 9 deletions lightning/src/ln/channel.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2144,19 +2144,20 @@ impl<SP: Deref> Channel<SP> where
<SP::Target as SignerProvider>::Signer: WriteableEcdsaChannelSigner
{
fn check_remote_fee<F: Deref, L: Deref>(
channel_type: &ChannelTypeFeatures, fee_estimator: &LowerBoundedFeeEstimator<F>,
feerate_per_kw: u32, cur_feerate_per_kw: Option<u32>, logger: &L
channel_type: &ChannelTypeFeatures, config: &ChannelConfig,
fee_estimator: &LowerBoundedFeeEstimator<F>, feerate_per_kw: u32,
cur_feerate_per_kw: Option<u32>, logger: &L
) -> Result<(), ChannelError> where F::Target: FeeEstimator, L::Target: Logger,
{
// We only bound the fee updates on the upper side to prevent completely absurd feerates,
// always accepting up to 25 sat/vByte or 10x our fee estimator's "High Priority" fee.
// by default accepting up to 25 sat/vByte or 10x our fee estimator's "High Priority" fee.
// We generally don't care too much if they set the feerate to something very high, but it
// could result in the channel being useless due to everything being dust. This doesn't
// apply to channels supporting anchor outputs since HTLC transactions are pre-signed with a
// zero fee, so their fee is no longer considered to determine dust limits.
if !channel_type.supports_anchors_zero_fee_htlc_tx() {
let upper_limit = cmp::max(250 * 25,
fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64 * 10);
let upper_limit = cmp::max(config.base_max_accepted_fee_rate as u64,
fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64 * config.max_accepted_fee_rate_multiplier as u64);
if feerate_per_kw as u64 > upper_limit {
return Err(ChannelError::Close(format!("Peer's feerate much too high. Actual: {}. Our expected upper limit: {}", feerate_per_kw, upper_limit)));
}
Expand Down Expand Up @@ -3854,7 +3855,7 @@ impl<SP: Deref> Channel<SP> where
if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned()));
}
Channel::<SP>::check_remote_fee(&self.context.channel_type, fee_estimator, msg.feerate_per_kw, Some(self.context.feerate_per_kw), logger)?;
Channel::<SP>::check_remote_fee(&self.context.channel_type, &self.context.config(), fee_estimator, msg.feerate_per_kw, Some(self.context.feerate_per_kw), logger)?;
let feerate_over_dust_buffer = msg.feerate_per_kw > self.context.get_dust_buffer_feerate(None);

self.context.pending_update_fee = Some((msg.feerate_per_kw, FeeUpdateState::RemoteAnnounced));
Expand Down Expand Up @@ -6289,7 +6290,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
if msg.htlc_minimum_msat >= full_channel_value_msat {
return Err(ChannelError::Close(format!("Minimum htlc value ({}) was larger than full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
}
Channel::<SP>::check_remote_fee(&channel_type, fee_estimator, msg.feerate_per_kw, None, logger)?;
Channel::<SP>::check_remote_fee(&channel_type, &config.channel_config, fee_estimator, msg.feerate_per_kw, None, logger)?;

let max_counterparty_selected_contest_delay = u16::min(config.channel_handshake_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
if msg.to_self_delay > max_counterparty_selected_contest_delay {
Expand Down Expand Up @@ -7642,7 +7643,7 @@ mod tests {
use crate::ln::PaymentHash;
use crate::ln::channelmanager::{self, HTLCSource, PaymentId};
use crate::ln::channel::InitFeatures;
use crate::ln::channel::{Channel, ChannelState, InboundHTLCOutput, OutboundV1Channel, InboundV1Channel, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator, commit_tx_fee_msat};
use crate::ln::channel::{Channel, ChannelConfig, ChannelState, InboundHTLCOutput, OutboundV1Channel, InboundV1Channel, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator, commit_tx_fee_msat};
use crate::ln::channel::{MAX_FUNDING_SATOSHIS_NO_WUMBO, TOTAL_BITCOIN_SUPPLY_SATOSHIS, MIN_THEIR_CHAN_RESERVE_SATOSHIS};
use crate::ln::features::ChannelTypeFeatures;
use crate::ln::msgs::{ChannelUpdate, DecodeError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
Expand Down Expand Up @@ -7691,7 +7692,7 @@ mod tests {
let fee_est = TestFeeEstimator { fee_est: 42 };
let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_est);
assert!(Channel::<&TestKeysInterface>::check_remote_fee(
&ChannelTypeFeatures::only_static_remote_key(), &bounded_fee_estimator,
&ChannelTypeFeatures::only_static_remote_key(), &ChannelConfig::default(), &bounded_fee_estimator,
u32::max_value(), None, &&test_utils::TestLogger::new()).is_err());
}

Expand Down
34 changes: 34 additions & 0 deletions lightning/src/util/config.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -485,6 +485,24 @@ pub struct ChannelConfig {
/// [`PaymentClaimable::counterparty_skimmed_fee_msat`]: crate::events::Event::PaymentClaimable::counterparty_skimmed_fee_msat
// TODO: link to bLIP when it's merged
pub accept_underpaying_htlcs: bool,

/// When checking our channel counterparty's fee rate, we will allow any value that is either at least
/// [`ChannelConfig::base_max_accepted_fee_rate`] or at least [`ChannelConfig::max_accepted_fee_rate_multiplier`]
/// times our [`HighPriority`] estimated feerate.
///
/// Default value: 25 sat/vbyte.
///
/// [`HighPriority`]: crate::chain::chaininterface::ConfirmationTarget::HighPriority
pub base_max_accepted_fee_rate: u32,

/// When checking our channel counterparty's fee rate, we will allow any value that is either at least
/// [`ChannelConfig::base_max_accepted_fee_rate`] or at least [`ChannelConfig::max_accepted_fee_rate_multiplier`]
/// times our [`HighPriority`] estimated feerate.
///
/// Default value: 10.
///
/// [`HighPriority`]: crate::chain::chaininterface::ConfirmationTarget::HighPriority
pub max_accepted_fee_rate_multiplier: u32,
}

impl ChannelConfig {
Expand Down Expand Up @@ -518,6 +536,8 @@ impl Default for ChannelConfig {
max_dust_htlc_exposure: MaxDustHTLCExposure::FeeRateMultiplier(5000),
force_close_avoidance_max_fee_satoshis: 1000,
accept_underpaying_htlcs: false,
base_max_accepted_fee_rate: 25 * 250, // 25 sat/vbyte
max_accepted_fee_rate_multiplier: 10,
}
}
}
Expand All @@ -539,6 +559,8 @@ impl crate::util::ser::Writeable for ChannelConfig {
// LegacyChannelConfig. To make sure that serialization is not compatible with this one, we use
// the next required type of 10, which if seen by the old serialization will always fail.
(10, self.force_close_avoidance_max_fee_satoshis, required),
(12, self.base_max_accepted_fee_rate, required),
(14, self.max_accepted_fee_rate_multiplier, required),
});
Ok(())
}
Expand All @@ -553,6 +575,8 @@ impl crate::util::ser::Readable for ChannelConfig {
let mut max_dust_htlc_exposure_msat = None;
let mut max_dust_htlc_exposure_enum = None;
let mut force_close_avoidance_max_fee_satoshis = 1000;
let mut base_max_accepted_fee_rate = 25 * 250;
let mut max_accepted_fee_rate_multiplier = 10;
read_tlv_fields!(reader, {
(0, forwarding_fee_proportional_millionths, required),
(1, accept_underpaying_htlcs, (default_value, false)),
Expand All @@ -562,6 +586,8 @@ impl crate::util::ser::Readable for ChannelConfig {
// Has always been written, but became optionally read in 0.0.116
(6, max_dust_htlc_exposure_msat, option),
(10, force_close_avoidance_max_fee_satoshis, required),
(12, base_max_accepted_fee_rate, required),
(14, max_accepted_fee_rate_multiplier, required),
});
let max_dust_htlc_fixed_limit = max_dust_htlc_exposure_msat.unwrap_or(5_000_000);
let max_dust_htlc_exposure_msat = max_dust_htlc_exposure_enum
Expand All @@ -573,6 +599,8 @@ impl crate::util::ser::Readable for ChannelConfig {
cltv_expiry_delta,
max_dust_htlc_exposure: max_dust_htlc_exposure_msat,
force_close_avoidance_max_fee_satoshis,
base_max_accepted_fee_rate,
max_accepted_fee_rate_multiplier,
})
}
}
Expand Down Expand Up @@ -666,6 +694,8 @@ impl crate::util::ser::Readable for LegacyChannelConfig {
let mut commit_upfront_shutdown_pubkey = false;
let mut forwarding_fee_base_msat = 0;
let mut max_dust_htlc_exposure_enum = None;
let mut base_max_accepted_fee_rate = 25 * 250;
let mut max_accepted_fee_rate_multiplier = 10;
read_tlv_fields!(reader, {
(0, forwarding_fee_proportional_millionths, required),
// Has always been written, but became optionally read in 0.0.116
Expand All @@ -676,6 +706,8 @@ impl crate::util::ser::Readable for LegacyChannelConfig {
(5, max_dust_htlc_exposure_enum, option),
(6, commit_upfront_shutdown_pubkey, required),
(8, forwarding_fee_base_msat, required),
(12, base_max_accepted_fee_rate, required),
(14, max_accepted_fee_rate_multiplier, required),
});
let max_dust_htlc_exposure_msat_fixed_limit =
max_dust_htlc_exposure_msat_fixed_limit.unwrap_or(5_000_000);
Expand All @@ -689,6 +721,8 @@ impl crate::util::ser::Readable for LegacyChannelConfig {
force_close_avoidance_max_fee_satoshis,
forwarding_fee_base_msat,
accept_underpaying_htlcs: false,
base_max_accepted_fee_rate,
max_accepted_fee_rate_multiplier,
},
announced_channel,
commit_upfront_shutdown_pubkey,
Expand Down

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