RemoteOffered,
}
+/// An enum gathering stats on pending HTLCs, either inbound or outbound side.
+struct HTLCStats {
+ pending_htlcs: u32,
+ pending_htlcs_value_msat: u64,
+ on_counterparty_tx_dust_exposure_msat: u64,
+ on_holder_tx_dust_exposure_msat: u64,
+}
+
/// Used when calculating whether we or the remote can afford an additional HTLC.
struct HTLCCandidate {
amount_msat: u64,
enum UpdateFulfillFetch {
NewClaim {
monitor_update: ChannelMonitorUpdate,
+ htlc_value_msat: u64,
msg: Option<msgs::UpdateFulfillHTLC>,
},
DuplicateClaim {},
NewClaim {
/// The ChannelMonitorUpdate which places the new payment preimage in the channel monitor
monitor_update: ChannelMonitorUpdate,
+ /// The value of the HTLC which was claimed, in msat.
+ htlc_value_msat: u64,
/// The update_fulfill message and commitment_signed message (if the claim was not placed
/// in the holding cell).
msgs: Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>,
// Holder designates channel data owned for the benefice of the user client.
// Counterparty designates channel data owned by the another channel participant entity.
pub(super) struct Channel<Signer: Sign> {
+ #[cfg(any(test, feature = "_test_utils"))]
+ pub(crate) config: ChannelConfig,
+ #[cfg(not(any(test, feature = "_test_utils")))]
config: ChannelConfig,
user_id: u64,
// these, but for now we just have to treat them as normal.
let mut pending_idx = core::usize::MAX;
+ let mut htlc_value_msat = 0;
for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() {
if htlc.htlc_id == htlc_id_arg {
assert_eq!(htlc.payment_hash, payment_hash_calc);
}
}
pending_idx = idx;
+ htlc_value_msat = htlc.amount_msat;
break;
}
}
// TODO: We may actually be able to switch to a fulfill here, though its
// rare enough it may not be worth the complexity burden.
debug_assert!(false, "Tried to fulfill an HTLC that was already failed");
- return UpdateFulfillFetch::NewClaim { monitor_update, msg: None };
+ return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
}
},
_ => {}
});
#[cfg(any(test, feature = "fuzztarget"))]
self.historical_inbound_htlc_fulfills.insert(htlc_id_arg);
- return UpdateFulfillFetch::NewClaim { monitor_update, msg: None };
+ return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
}
#[cfg(any(test, feature = "fuzztarget"))]
self.historical_inbound_htlc_fulfills.insert(htlc_id_arg);
if let InboundHTLCState::Committed = htlc.state {
} else {
debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
- return UpdateFulfillFetch::NewClaim { monitor_update, msg: None };
+ return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
}
log_trace!(logger, "Upgrading HTLC {} to LocalRemoved with a Fulfill in channel {}!", log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id));
htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(payment_preimage_arg.clone()));
UpdateFulfillFetch::NewClaim {
monitor_update,
+ htlc_value_msat,
msg: Some(msgs::UpdateFulfillHTLC {
channel_id: self.channel_id(),
htlc_id: htlc_id_arg,
pub fn get_update_fulfill_htlc_and_commit<L: Deref>(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage, logger: &L) -> Result<UpdateFulfillCommitFetch, (ChannelError, ChannelMonitorUpdate)> where L::Target: Logger {
match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger) {
- UpdateFulfillFetch::NewClaim { mut monitor_update, msg: Some(update_fulfill_htlc) } => {
+ UpdateFulfillFetch::NewClaim { mut monitor_update, htlc_value_msat, msg: Some(update_fulfill_htlc) } => {
let (commitment, mut additional_update) = match self.send_commitment_no_status_check(logger) {
Err(e) => return Err((e, monitor_update)),
Ok(res) => res
// strictly increasing by one, so decrement it here.
self.latest_monitor_update_id = monitor_update.update_id;
monitor_update.updates.append(&mut additional_update.updates);
- Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, msgs: Some((update_fulfill_htlc, commitment)) })
+ Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: Some((update_fulfill_htlc, commitment)) })
},
- UpdateFulfillFetch::NewClaim { monitor_update, msg: None } => Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, msgs: None }),
+ UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None } =>
+ Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: None }),
UpdateFulfillFetch::DuplicateClaim {} => Ok(UpdateFulfillCommitFetch::DuplicateClaim {}),
}
}
Ok(())
}
- /// Returns (inbound_htlc_count, htlc_inbound_value_msat)
- fn get_inbound_pending_htlc_stats(&self) -> (u32, u64) {
- let mut htlc_inbound_value_msat = 0;
+ /// Returns a HTLCStats about inbound pending htlcs
+ fn get_inbound_pending_htlc_stats(&self) -> HTLCStats {
+ let mut stats = HTLCStats {
+ pending_htlcs: self.pending_inbound_htlcs.len() as u32,
+ pending_htlcs_value_msat: 0,
+ on_counterparty_tx_dust_exposure_msat: 0,
+ on_holder_tx_dust_exposure_msat: 0,
+ };
+
+ let counterparty_dust_limit_timeout_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
+ let holder_dust_limit_success_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
for ref htlc in self.pending_inbound_htlcs.iter() {
- htlc_inbound_value_msat += htlc.amount_msat;
+ stats.pending_htlcs_value_msat += htlc.amount_msat;
+ if htlc.amount_msat / 1000 < counterparty_dust_limit_timeout_sat {
+ stats.on_counterparty_tx_dust_exposure_msat += htlc.amount_msat;
+ }
+ if htlc.amount_msat / 1000 < holder_dust_limit_success_sat {
+ stats.on_holder_tx_dust_exposure_msat += htlc.amount_msat;
+ }
}
- (self.pending_inbound_htlcs.len() as u32, htlc_inbound_value_msat)
+ stats
}
- /// Returns (outbound_htlc_count, htlc_outbound_value_msat) *including* pending adds in our
- /// holding cell.
- fn get_outbound_pending_htlc_stats(&self) -> (u32, u64) {
- let mut htlc_outbound_value_msat = 0;
+ /// Returns a HTLCStats about pending outbound htlcs, *including* pending adds in our holding cell.
+ fn get_outbound_pending_htlc_stats(&self) -> HTLCStats {
+ let mut stats = HTLCStats {
+ pending_htlcs: self.pending_outbound_htlcs.len() as u32,
+ pending_htlcs_value_msat: 0,
+ on_counterparty_tx_dust_exposure_msat: 0,
+ on_holder_tx_dust_exposure_msat: 0,
+ };
+
+ let counterparty_dust_limit_success_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
+ let holder_dust_limit_timeout_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
for ref htlc in self.pending_outbound_htlcs.iter() {
- htlc_outbound_value_msat += htlc.amount_msat;
+ stats.pending_htlcs_value_msat += htlc.amount_msat;
+ if htlc.amount_msat / 1000 < counterparty_dust_limit_success_sat {
+ stats.on_counterparty_tx_dust_exposure_msat += htlc.amount_msat;
+ }
+ if htlc.amount_msat / 1000 < holder_dust_limit_timeout_sat {
+ stats.on_holder_tx_dust_exposure_msat += htlc.amount_msat;
+ }
}
- let mut htlc_outbound_count = self.pending_outbound_htlcs.len();
for update in self.holding_cell_htlc_updates.iter() {
if let &HTLCUpdateAwaitingACK::AddHTLC { ref amount_msat, .. } = update {
- htlc_outbound_count += 1;
- htlc_outbound_value_msat += amount_msat;
+ stats.pending_htlcs += 1;
+ stats.pending_htlcs_value_msat += amount_msat;
+ if *amount_msat / 1000 < counterparty_dust_limit_success_sat {
+ stats.on_counterparty_tx_dust_exposure_msat += amount_msat;
+ }
+ if *amount_msat / 1000 < holder_dust_limit_timeout_sat {
+ stats.on_holder_tx_dust_exposure_msat += amount_msat;
+ }
}
}
-
- (htlc_outbound_count as u32, htlc_outbound_value_msat)
+ stats
}
/// Get the available (ie not including pending HTLCs) inbound and outbound balance in msat.
(
cmp::max(self.channel_value_satoshis as i64 * 1000
- self.value_to_self_msat as i64
- - self.get_inbound_pending_htlc_stats().1 as i64
+ - self.get_inbound_pending_htlc_stats().pending_htlcs_value_msat as i64
- Self::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis) as i64 * 1000,
0) as u64,
cmp::max(self.value_to_self_msat as i64
- - self.get_outbound_pending_htlc_stats().1 as i64
+ - self.get_outbound_pending_htlc_stats().pending_htlcs_value_msat as i64
- self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0) as i64 * 1000,
0) as u64
)
return Err(ChannelError::Close(format!("Remote side tried to send less than our minimum HTLC value. Lower limit: ({}). Actual: ({})", self.holder_htlc_minimum_msat, msg.amount_msat)));
}
- let (inbound_htlc_count, htlc_inbound_value_msat) = self.get_inbound_pending_htlc_stats();
- if inbound_htlc_count + 1 > OUR_MAX_HTLCS as u32 {
+ let inbound_stats = self.get_inbound_pending_htlc_stats();
+ let outbound_stats = self.get_outbound_pending_htlc_stats();
+ if inbound_stats.pending_htlcs + 1 > OUR_MAX_HTLCS as u32 {
return Err(ChannelError::Close(format!("Remote tried to push more than our max accepted HTLCs ({})", OUR_MAX_HTLCS)));
}
let holder_max_htlc_value_in_flight_msat = Channel::<Signer>::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis);
- if htlc_inbound_value_msat + msg.amount_msat > holder_max_htlc_value_in_flight_msat {
+ if inbound_stats.pending_htlcs_value_msat + msg.amount_msat > holder_max_htlc_value_in_flight_msat {
return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", holder_max_htlc_value_in_flight_msat)));
}
// Check holder_selected_channel_reserve_satoshis (we're getting paid, so they have to at least meet
}
let pending_value_to_self_msat =
- self.value_to_self_msat + htlc_inbound_value_msat - removed_outbound_total_msat;
+ self.value_to_self_msat + inbound_stats.pending_htlcs_value_msat - removed_outbound_total_msat;
let pending_remote_value_msat =
self.channel_value_satoshis * 1000 - pending_value_to_self_msat;
if pending_remote_value_msat < msg.amount_msat {
/// Marks an outbound HTLC which we have received update_fail/fulfill/malformed
#[inline]
- fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<PaymentHash>, fail_reason: Option<HTLCFailReason>) -> Result<&HTLCSource, ChannelError> {
+ fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<PaymentHash>, fail_reason: Option<HTLCFailReason>) -> Result<&OutboundHTLCOutput, ChannelError> {
for htlc in self.pending_outbound_htlcs.iter_mut() {
if htlc.htlc_id == htlc_id {
match check_preimage {
OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) | OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) | OutboundHTLCState::RemoteRemoved(_) =>
return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) that they'd already fulfilled/failed", htlc_id))),
}
- return Ok(&htlc.source);
+ return Ok(htlc);
}
}
Err(ChannelError::Close("Remote tried to fulfill/fail an HTLC we couldn't find".to_owned()))
}
- pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<HTLCSource, ChannelError> {
+ pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(HTLCSource, u64), ChannelError> {
if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
return Err(ChannelError::Close("Got fulfill HTLC message when channel was not in an operational state".to_owned()));
}
}
let payment_hash = PaymentHash(Sha256::hash(&msg.payment_preimage.0[..]).into_inner());
- self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None).map(|source| source.clone())
+ self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None).map(|htlc| (htlc.source.clone(), htlc.amount_msat))
}
pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> {
// in it hitting the holding cell again and we cannot change the state of a
// holding cell HTLC from fulfill to anything else.
let (update_fulfill_msg_option, mut additional_monitor_update) =
- if let UpdateFulfillFetch::NewClaim { msg, monitor_update } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) {
+ if let UpdateFulfillFetch::NewClaim { msg, monitor_update, .. } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) {
(msg, monitor_update)
} else { unreachable!() };
update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap());
cmp::max(self.config.cltv_expiry_delta, MIN_CLTV_EXPIRY_DELTA)
}
+ pub fn get_max_dust_htlc_exposure_msat(&self) -> u64 {
+ self.config.max_dust_htlc_exposure_msat
+ }
+
#[cfg(test)]
pub fn get_feerate(&self) -> u32 {
self.feerate_per_kw
}
+ pub fn get_dust_buffer_feerate(&self) -> u32 {
+ // When calculating our exposure to dust HTLCs, we assume that the channel feerate
+ // may, at any point, increase by at least 10 sat/vB (i.e 2530 sat/kWU) or 25%,
+ // whichever is higher. This ensures that we aren't suddenly exposed to significantly
+ // more dust balance if the feerate increases when we have several HTLCs pending
+ // which are near the dust limit.
+ cmp::max(2530, self.feerate_per_kw * 1250 / 1000)
+ }
+
pub fn get_cur_holder_commitment_transaction_number(&self) -> u64 {
self.cur_holder_commitment_transaction_number + 1
}
return Err(ChannelError::Ignore("Cannot send an HTLC while disconnected from channel counterparty".to_owned()));
}
- let (outbound_htlc_count, htlc_outbound_value_msat) = self.get_outbound_pending_htlc_stats();
- if outbound_htlc_count + 1 > self.counterparty_max_accepted_htlcs as u32 {
+ let inbound_stats = self.get_inbound_pending_htlc_stats();
+ let outbound_stats = self.get_outbound_pending_htlc_stats();
+ if outbound_stats.pending_htlcs + 1 > self.counterparty_max_accepted_htlcs as u32 {
return Err(ChannelError::Ignore(format!("Cannot push more than their max accepted HTLCs ({})", self.counterparty_max_accepted_htlcs)));
}
// Check their_max_htlc_value_in_flight_msat
- if htlc_outbound_value_msat + amount_msat > self.counterparty_max_htlc_value_in_flight_msat {
+ if outbound_stats.pending_htlcs_value_msat + amount_msat > self.counterparty_max_htlc_value_in_flight_msat {
return Err(ChannelError::Ignore(format!("Cannot send value that would put us over the max HTLC value in flight our peer will accept ({})", self.counterparty_max_htlc_value_in_flight_msat)));
}
}
}
- let pending_value_to_self_msat = self.value_to_self_msat - htlc_outbound_value_msat;
+ let pending_value_to_self_msat = self.value_to_self_msat - outbound_stats.pending_htlcs_value_msat;
if pending_value_to_self_msat < amount_msat {
return Err(ChannelError::Ignore(format!("Cannot send value that would overdraw remaining funds. Amount: {}, pending value to self {}", amount_msat, pending_value_to_self_msat)));
}
projects / rust-lightning / blobdiff