}
balance_msat -= outbound_stats.pending_htlcs_value_msat;
- let outbound_capacity_msat = cmp::max(self.value_to_self_msat as i64
- - outbound_stats.pending_htlcs_value_msat as i64
- - self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0) as i64 * 1000,
- 0) as u64;
+ let outbound_capacity_msat = self.value_to_self_msat
+ .saturating_sub(outbound_stats.pending_htlcs_value_msat)
+ .saturating_sub(
+ self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0) * 1000);
+
+ let mut available_capacity_msat = outbound_capacity_msat;
+
+ if self.is_outbound() {
+ // We should mind channel commit tx fee when computing how much of the available capacity
+ // can be used in the next htlc. Mirrors the logic in send_htlc.
+ //
+ // The fee depends on whether the amount we will be sending is above dust or not,
+ // and the answer will in turn change the amount itself — making it a circular
+ // dependency.
+ // This complicates the computation around dust-values, up to the one-htlc-value.
+ let mut real_dust_limit_timeout_sat = self.holder_dust_limit_satoshis;
+ if !self.opt_anchors() {
+ real_dust_limit_timeout_sat += self.feerate_per_kw as u64 * htlc_timeout_tx_weight(false) / 1000;
+ }
+
+ let htlc_above_dust = HTLCCandidate::new(real_dust_limit_timeout_sat * 1000, HTLCInitiator::LocalOffered);
+ let max_reserved_commit_tx_fee_msat = FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE * self.next_local_commit_tx_fee_msat(htlc_above_dust, Some(()));
+ let htlc_dust = HTLCCandidate::new(real_dust_limit_timeout_sat * 1000 - 1, HTLCInitiator::LocalOffered);
+ let min_reserved_commit_tx_fee_msat = FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE * self.next_local_commit_tx_fee_msat(htlc_dust, Some(()));
+
+ // We will first subtract the fee as if we were above-dust. Then, if the resulting
+ // value ends up being below dust, we have this fee available again. In that case,
+ // match the value to right-below-dust.
+ let mut capacity_minus_commitment_fee_msat: i64 = (available_capacity_msat as i64) - (max_reserved_commit_tx_fee_msat as i64);
+ if capacity_minus_commitment_fee_msat < (real_dust_limit_timeout_sat as i64) * 1000 {
+ let one_htlc_difference_msat = max_reserved_commit_tx_fee_msat - min_reserved_commit_tx_fee_msat;
+ debug_assert!(one_htlc_difference_msat != 0);
+ capacity_minus_commitment_fee_msat += one_htlc_difference_msat as i64;
+ capacity_minus_commitment_fee_msat = cmp::min(real_dust_limit_timeout_sat as i64 * 1000 - 1, capacity_minus_commitment_fee_msat);
+ available_capacity_msat = cmp::max(0, cmp::min(capacity_minus_commitment_fee_msat, available_capacity_msat as i64)) as u64;
+ } else {
+ available_capacity_msat = capacity_minus_commitment_fee_msat as u64;
+ }
+ }
AvailableBalances {
inbound_capacity_msat: cmp::max(self.channel_value_satoshis as i64 * 1000
- self.value_to_self_msat as i64
- self.holder_selected_channel_reserve_satoshis as i64 * 1000,
0) as u64,
outbound_capacity_msat,
- next_outbound_htlc_limit_msat: cmp::max(cmp::min(outbound_capacity_msat as i64,
+ next_outbound_htlc_limit_msat: cmp::max(cmp::min(available_capacity_msat as i64,
self.counterparty_max_htlc_value_in_flight_msat as i64
- outbound_stats.pending_htlcs_value_msat as i64),
0) as u64,
let holder_balance_msat = self.value_to_self_msat
.saturating_sub(outbound_stats.pending_htlcs_value_msat);
if holder_balance_msat < amount_msat {
+ debug_assert!(amount_msat > self.get_available_balances().next_outbound_htlc_limit_msat);
return Err(ChannelError::Ignore(format!("Cannot send value that would overdraw remaining funds. Amount: {}, pending value to self {}", amount_msat, holder_balance_msat)));
}
FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE * self.next_local_commit_tx_fee_msat(htlc_candidate, Some(()))
} else { 0 };
if holder_balance_msat - amount_msat < commit_tx_fee_msat {
+ debug_assert!(amount_msat > self.get_available_balances().next_outbound_htlc_limit_msat);
return Err(ChannelError::Ignore(format!("Cannot send value that would not leave enough to pay for fees. Pending value to self: {}. local_commit_tx_fee {}", holder_balance_msat, commit_tx_fee_msat)));
}
// reserve for the remote to have something to claim if we misbehave)
let chan_reserve_msat = self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000;
if holder_balance_msat - amount_msat - commit_tx_fee_msat < chan_reserve_msat {
+ debug_assert!(amount_msat > self.get_available_balances().next_outbound_htlc_limit_msat);
return Err(ChannelError::Ignore(format!("Cannot send value that would put our balance under counterparty-announced channel reserve value ({})", chan_reserve_msat)));
}
// The 2* and +1 are for the fee spike reserve.
let commit_tx_fee = 2 * commit_tx_fee_msat(get_feerate!(nodes[0], nodes[1], chan.2), 1 + 1, get_opt_anchors!(nodes[0], nodes[1], chan.2));
let max_can_send = 5000000 - channel_reserve - commit_tx_fee;
- let (route, our_payment_hash, _, our_payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[1], max_can_send + 1);
+ let (mut route, our_payment_hash, _, our_payment_secret) =
+ get_route_and_payment_hash!(nodes[0], nodes[1], max_can_send);
+ route.paths[0].hops.last_mut().unwrap().fee_msat += 1;
let err = nodes[0].node.send_payment_with_route(&route, our_payment_hash,
RecipientOnionFields::secret_only(our_payment_secret), PaymentId(our_payment_hash.0)).err().unwrap();
match err {
let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
- let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[1], 3460001);
+ let (mut route, payment_hash, _, payment_secret) =
+ get_route_and_payment_hash!(nodes[0], nodes[1], 3460000);
+ route.paths[0].hops[0].fee_msat += 1;
// Need to manually create the update_add_htlc message to go around the channel reserve check in send_htlc()
let secp_ctx = Secp256k1::new();
let session_priv = SecretKey::from_slice(&[42; 32]).expect("RNG is bad!");
let commit_tx_fee_2_htlcs = commit_tx_fee_msat(feerate, 2, opt_anchors);
let recv_value_2 = chan_stat.value_to_self_msat - amt_msat_1 - chan_stat.channel_reserve_msat - total_routing_fee_msat - commit_tx_fee_2_htlcs + 1;
let amt_msat_2 = recv_value_2 + total_routing_fee_msat;
- let (route_2, _, _, _) = get_route_and_payment_hash!(nodes[0], nodes[2], amt_msat_2);
+ let mut route_2 = route_1.clone();
+ route_2.paths[0].hops.last_mut().unwrap().fee_msat = amt_msat_2;
// Need to manually create the update_add_htlc message to go around the channel reserve check in send_htlc()
let secp_ctx = Secp256k1::new();
// channel reserve test with htlc pending output > 0
let recv_value_2 = stat01.value_to_self_msat - amt_msat_1 - stat01.channel_reserve_msat - total_fee_msat - commit_tx_fee_2_htlcs;
{
- let (route, our_payment_hash, _, our_payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[2], recv_value_2 + 1);
+ let mut route = route_1.clone();
+ route.paths[0].hops.last_mut().unwrap().fee_msat = recv_value_2 + 1;
+ let (_, our_payment_hash, our_payment_secret) = get_payment_preimage_hash!(nodes[2]);
unwrap_send_err!(nodes[0].node.send_payment_with_route(&route, our_payment_hash,
RecipientOnionFields::secret_only(our_payment_secret), PaymentId(our_payment_hash.0)
), true, APIError::ChannelUnavailable { ref err },
// test with outbound holding cell amount > 0
{
- let (route, our_payment_hash, _, our_payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[2], recv_value_22+1);
+ let (mut route, our_payment_hash, _, our_payment_secret) =
+ get_route_and_payment_hash!(nodes[0], nodes[2], recv_value_22);
+ route.paths[0].hops.last_mut().unwrap().fee_msat += 1;
unwrap_send_err!(nodes[0].node.send_payment_with_route(&route, our_payment_hash,
RecipientOnionFields::secret_only(our_payment_secret), PaymentId(our_payment_hash.0)
), true, APIError::ChannelUnavailable { ref err },
let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
- let (route, our_payment_hash, _, our_payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[1], 3999999);
+ let send_amt = 3999999;
+ let (mut route, our_payment_hash, _, our_payment_secret) =
+ get_route_and_payment_hash!(nodes[0], nodes[1], 1000);
+ route.paths[0].hops[0].fee_msat = send_amt;
let session_priv = SecretKey::from_slice(&[42; 32]).unwrap();
let cur_height = nodes[0].node.best_block.read().unwrap().height() + 1;
let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::signing_only(), &route.paths[0], &session_priv).unwrap();
let (onion_payloads, _htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(
- &route.paths[0], 3999999, RecipientOnionFields::secret_only(our_payment_secret), cur_height, &None).unwrap();
+ &route.paths[0], send_amt, RecipientOnionFields::secret_only(our_payment_secret), cur_height, &None).unwrap();
let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, [0; 32], &our_payment_hash).unwrap();
let mut msg = msgs::UpdateAddHTLC {
projects / rust-lightning / commitdiff