const B_OUTPUT_PLUS_SPENDING_INPUT_WEIGHT: u64 = 104; // prevout: 40, nSequence: 4, script len: 1, witness lengths: 3/4, sig: 73/4, pubkey: 33/4, output: 31 (TODO: Wrong? Useless?)
#[cfg(not(test))]
-const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
+const COMMITMENT_TX_BASE_WEIGHT: u64 = 896;
#[cfg(test)]
-pub const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
+pub const COMMITMENT_TX_BASE_WEIGHT: u64 = 896;
#[cfg(not(test))]
const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
#[cfg(test)]
pub const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
+const ANCHOR_VALUE_SATOSHIS: u64 = 330;
+
/// Maximmum `funding_satoshis` value, according to the BOLT #2 specification
/// it's 2^24.
pub const MAX_FUNDING_SATOSHIS: u64 = 1 << 24;
// check if the funder's amount for the initial commitment tx is sufficient
// for full fee payment
let funders_amount_msat = msg.funding_satoshis * 1000 - msg.push_msat;
- if funders_amount_msat < background_feerate * COMMITMENT_TX_BASE_WEIGHT {
+ if funders_amount_msat < background_feerate * COMMITMENT_TX_BASE_WEIGHT + ANCHOR_VALUE_SATOSHIS * 1000 {
return Err(ChannelError::Close("Insufficient funding amount for initial commitment"));
}
- let to_local_msat = msg.push_msat;
- let to_remote_msat = funders_amount_msat - background_feerate * COMMITMENT_TX_BASE_WEIGHT;
- if to_local_msat <= msg.channel_reserve_satoshis * 1000 && to_remote_msat <= remote_channel_reserve_satoshis * 1000 {
+ let to_remote_msat = funders_amount_msat - background_feerate * COMMITMENT_TX_BASE_WEIGHT - ANCHOR_VALUE_SATOSHIS * 1000;
+ // While its reasonable for us to not meet the channel reserve initially (if they don't
+ // want to push much to us), our counterparty should always have more than the reserve.
+ if to_remote_msat <= remote_channel_reserve_satoshis * 1000 {
return Err(ChannelError::Close("Insufficient funding amount for initial commitment"));
}
let total_fee: u64 = feerate_per_kw * (COMMITMENT_TX_BASE_WEIGHT + (txouts.len() as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000;
let (value_to_self, value_to_remote) = if self.channel_outbound {
- (value_to_self_msat / 1000 - total_fee as i64, value_to_remote_msat / 1000)
+ (value_to_self_msat / 1000 - total_fee as i64 - ANCHOR_VALUE_SATOSHIS as i64, value_to_remote_msat / 1000)
} else {
- (value_to_self_msat / 1000, value_to_remote_msat / 1000 - total_fee as i64)
+ (value_to_self_msat / 1000, value_to_remote_msat / 1000 - total_fee as i64 - ANCHOR_VALUE_SATOSHIS as i64)
};
+ debug_assert!(value_to_self >= 0);
+ debug_assert!(value_to_remote >= 0);
let value_to_a = if local { value_to_self } else { value_to_remote };
let value_to_b = if local { value_to_remote } else { value_to_self };
+ if value_to_a >= (dust_limit_satoshis as i64) || !txouts.is_empty() {
+ // Always push the anchor output so that local can get the transaction confirmed.
+ txouts.push((TxOut {
+ script_pubkey: Script::new(), //XXX
+ value: ANCHOR_VALUE_SATOSHIS
+ }, None));
+ }
+
if value_to_a >= (dust_limit_satoshis as i64) {
log_trace!(logger, " ...including {} output with value {}", if local { "to_local" } else { "to_remote" }, value_to_a);
txouts.push((TxOut {
}, None));
}
+
transaction_utils::sort_outputs(&mut txouts, |a, b| {
if let &Some(ref a_htlc) = a {
if let &Some(ref b_htlc) = b {
//If channel fee was updated by funder confirm funder can afford the new fee rate when applied to the current local commitment transaction
if update_fee {
let num_htlcs = local_commitment_tx.1;
- let total_fee: u64 = feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + (num_htlcs as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000;
+ let total_fee: u64 = feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + (num_htlcs as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000 + ANCHOR_VALUE_SATOSHIS;
let remote_reserve_we_require = Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis);
if self.channel_value_satoshis - self.value_to_self_msat / 1000 < total_fee + remote_reserve_we_require {