X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fln%2Fchannel.rs;h=a8550932d5ad597e4e16bef4cfdfe7ae68f8df3f;hb=b9a155d75f723f0e99f7bf7faf0abe5c7b492dfd;hp=83698f1172632ffc8903e4ee7cdb1091867e429f;hpb=b58bab0700e93e093a77731eb7bf33204a4902fc;p=rust-lightning diff --git a/src/ln/channel.rs b/src/ln/channel.rs index 83698f11..a8550932 100644 --- a/src/ln/channel.rs +++ b/src/ln/channel.rs @@ -285,6 +285,24 @@ pub(super) struct Channel { pending_inbound_htlcs: Vec, pending_outbound_htlcs: Vec, holding_cell_htlc_updates: Vec, + + // pending_update_fee is filled when sending and receiving update_fee + // For outbound channel, feerate_per_kw is updated with the value from + // pending_update_fee when revoke_and_ack is received + // + // For inbound channel, feerate_per_kw is updated when it receives + // commitment_signed and revoke_and_ack is generated + // The pending value is kept when another pair of update_fee and commitment_signed + // is received during AwaitingRemoteRevoke and relieved when the expected + // revoke_and_ack is received and new commitment_signed is generated to be + // sent to the funder. Otherwise, the pending value is removed when receiving + // commitment_signed. + pending_update_fee: Option, + // update_fee() during ChannelState::AwaitingRemoteRevoke is hold in + // holdina_cell_update_fee then moved to pending_udpate_fee when revoke_and_ack + // is received. holding_cell_update_fee is updated when there are additional + // update_fee() during ChannelState::AwaitingRemoteRevoke. + holding_cell_update_fee: Option, next_local_htlc_id: u64, next_remote_htlc_id: u64, channel_update_count: u32, @@ -445,6 +463,8 @@ impl Channel { pending_inbound_htlcs: Vec::new(), pending_outbound_htlcs: Vec::new(), holding_cell_htlc_updates: Vec::new(), + pending_update_fee: None, + holding_cell_update_fee: None, next_local_htlc_id: 0, next_remote_htlc_id: 0, channel_update_count: 1, @@ -603,6 +623,8 @@ impl Channel { pending_inbound_htlcs: Vec::new(), pending_outbound_htlcs: Vec::new(), holding_cell_htlc_updates: Vec::new(), + pending_update_fee: None, + holding_cell_update_fee: None, next_local_htlc_id: 0, next_remote_htlc_id: 0, channel_update_count: 1, @@ -695,7 +717,7 @@ impl Channel { /// generated by the peer which proposed adding the HTLCs, and thus we need to understand both /// which peer generated this transaction and "to whom" this transaction flows. #[inline] - fn build_commitment_transaction(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool) -> (Transaction, Vec) { + fn build_commitment_transaction(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, feerate_per_kw: u64) -> (Transaction, Vec) { let obscured_commitment_transaction_number = self.get_commitment_transaction_number_obscure_factor() ^ (INITIAL_COMMITMENT_NUMBER - commitment_number); let txins = { @@ -719,7 +741,7 @@ impl Channel { macro_rules! add_htlc_output { ($htlc: expr, $outbound: expr) => { if $outbound == local { // "offered HTLC output" - if $htlc.amount_msat / 1000 >= dust_limit_satoshis + (self.feerate_per_kw * HTLC_TIMEOUT_TX_WEIGHT / 1000) { + if $htlc.amount_msat / 1000 >= dust_limit_satoshis + (feerate_per_kw * HTLC_TIMEOUT_TX_WEIGHT / 1000) { let htlc_in_tx = get_htlc_in_commitment!($htlc, true); txouts.push((TxOut { script_pubkey: chan_utils::get_htlc_redeemscript(&htlc_in_tx, &keys).to_v0_p2wsh(), @@ -727,7 +749,7 @@ impl Channel { }, Some(htlc_in_tx))); } } else { - if $htlc.amount_msat / 1000 >= dust_limit_satoshis + (self.feerate_per_kw * HTLC_SUCCESS_TX_WEIGHT / 1000) { + if $htlc.amount_msat / 1000 >= dust_limit_satoshis + (feerate_per_kw * HTLC_SUCCESS_TX_WEIGHT / 1000) { let htlc_in_tx = get_htlc_in_commitment!($htlc, false); txouts.push((TxOut { // "received HTLC output" script_pubkey: chan_utils::get_htlc_redeemscript(&htlc_in_tx, &keys).to_v0_p2wsh(), @@ -791,7 +813,8 @@ impl Channel { } } - let total_fee: u64 = self.feerate_per_kw * (COMMITMENT_TX_BASE_WEIGHT + (txouts.len() as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000; + + 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: i64 = ((self.value_to_self_msat - local_htlc_total_msat) as i64 + value_to_self_msat_offset) / 1000 - if self.channel_outbound { total_fee as i64 } else { 0 }; let value_to_remote: i64 = (((self.channel_value_satoshis * 1000 - self.value_to_self_msat - remote_htlc_total_msat) as i64 - value_to_self_msat_offset) / 1000) - if self.channel_outbound { 0 } else { total_fee as i64 }; @@ -983,8 +1006,8 @@ impl Channel { /// Builds the htlc-success or htlc-timeout transaction which spends a given HTLC output /// @local is used only to convert relevant internal structures which refer to remote vs local /// to decide value of outputs and direction of HTLCs. - fn build_htlc_transaction(&self, prev_hash: &Sha256dHash, htlc: &HTLCOutputInCommitment, local: bool, keys: &TxCreationKeys) -> Transaction { - chan_utils::build_htlc_transaction(prev_hash, self.feerate_per_kw, if local { self.their_to_self_delay } else { BREAKDOWN_TIMEOUT }, htlc, &keys.a_delayed_payment_key, &keys.revocation_key) + fn build_htlc_transaction(&self, prev_hash: &Sha256dHash, htlc: &HTLCOutputInCommitment, local: bool, keys: &TxCreationKeys, feerate_per_kw: u64) -> Transaction { + chan_utils::build_htlc_transaction(prev_hash, feerate_per_kw, if local { self.their_to_self_delay } else { BREAKDOWN_TIMEOUT }, htlc, &keys.a_delayed_payment_key, &keys.revocation_key) } fn create_htlc_tx_signature(&self, tx: &Transaction, htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Result<(Script, Signature, bool), HandleError> { @@ -1282,14 +1305,14 @@ impl Channel { let funding_script = self.get_funding_redeemscript(); let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?; - let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false).0; + let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0; let local_sighash = Message::from_slice(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap(); // They sign the "local" commitment transaction, allowing us to broadcast the tx if we wish. secp_call!(self.secp_ctx.verify(&local_sighash, &sig, &self.their_funding_pubkey.unwrap()), "Invalid funding_created signature from peer", self.channel_id()); let remote_keys = self.build_remote_transaction_keys()?; - let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false).0; + let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw).0; let remote_sighash = Message::from_slice(&bip143::SighashComponents::new(&remote_initial_commitment_tx).sighash_all(&remote_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap(); // We sign the "remote" commitment transaction, allowing them to broadcast the tx if they wish. @@ -1356,7 +1379,7 @@ impl Channel { let funding_script = self.get_funding_redeemscript(); let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?; - let mut local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false).0; + let mut local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0; let local_sighash = Message::from_slice(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap(); // They sign the "local" commitment transaction, allowing us to broadcast the tx if we wish. @@ -1567,7 +1590,14 @@ impl Channel { let funding_script = self.get_funding_redeemscript(); let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?; - let mut local_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false); + + let feerate_per_kw = if !self.channel_outbound && self.pending_update_fee.is_some() { + self.pending_update_fee.unwrap() + } else { + self.feerate_per_kw + }; + + let mut local_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, feerate_per_kw); let local_commitment_txid = local_commitment_tx.0.txid(); let local_sighash = Message::from_slice(&bip143::SighashComponents::new(&local_commitment_tx.0).sighash_all(&local_commitment_tx.0.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap(); secp_call!(self.secp_ctx.verify(&local_sighash, &msg.signature, &self.their_funding_pubkey.unwrap()), "Invalid commitment tx signature from peer", self.channel_id()); @@ -1582,7 +1612,7 @@ impl Channel { let mut htlcs_and_sigs = Vec::with_capacity(local_commitment_tx.1.len()); for (idx, ref htlc) in local_commitment_tx.1.iter().enumerate() { - let mut htlc_tx = self.build_htlc_transaction(&local_commitment_txid, htlc, true, &local_keys); + let mut htlc_tx = self.build_htlc_transaction(&local_commitment_txid, htlc, true, &local_keys, feerate_per_kw); let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &local_keys); let htlc_sighash = Message::from_slice(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]).unwrap(); secp_call!(self.secp_ctx.verify(&htlc_sighash, &msg.htlc_signatures[idx], &local_keys.b_htlc_key), "Invalid HTLC tx siganture from peer", self.channel_id()); @@ -1600,9 +1630,22 @@ impl Channel { let per_commitment_secret = chan_utils::build_commitment_secret(self.local_keys.commitment_seed, self.cur_local_commitment_transaction_number + 1); // Update state now that we've passed all the can-fail calls... + let mut need_our_commitment = false; + if !self.channel_outbound { + if let Some(fee_update) = self.pending_update_fee { + self.feerate_per_kw = fee_update; + // We later use the presence of pending_update_fee to indicate we should generate a + // commitment_signed upon receipt of revoke_and_ack, so we can only set it to None + // if we're not awaiting a revoke (ie will send a commitment_signed now). + if (self.channel_state & ChannelState::AwaitingRemoteRevoke as u32) == 0 { + need_our_commitment = true; + self.pending_update_fee = None; + } + } + } + self.channel_monitor.provide_latest_local_commitment_tx_info(local_commitment_tx.0, local_keys, self.feerate_per_kw, htlcs_and_sigs); - let mut need_our_commitment = false; for htlc in self.pending_inbound_htlcs.iter_mut() { if htlc.state == InboundHTLCState::RemoteAnnounced { htlc.state = InboundHTLCState::AwaitingRemoteRevokeToAnnounce; @@ -1637,7 +1680,7 @@ impl Channel { /// Used to fulfill holding_cell_htlcs when we get a remote ack (or implicitly get it by them /// fulfilling or failing the last pending HTLC) fn free_holding_cell_htlcs(&mut self) -> Result, HandleError> { - if self.holding_cell_htlc_updates.len() != 0 { + if self.holding_cell_htlc_updates.len() != 0 || self.holding_cell_update_fee.is_some() { let mut htlc_updates = Vec::new(); mem::swap(&mut htlc_updates, &mut self.holding_cell_htlc_updates); let mut update_add_htlcs = Vec::with_capacity(htlc_updates.len()); @@ -1694,18 +1737,28 @@ impl Channel { //fail it back the route, if its a temporary issue we can ignore it... match err { None => { - if update_add_htlcs.is_empty() && update_fulfill_htlcs.is_empty() && update_fail_htlcs.is_empty() { + if update_add_htlcs.is_empty() && update_fulfill_htlcs.is_empty() && update_fail_htlcs.is_empty() && self.holding_cell_update_fee.is_none() { // This should never actually happen and indicates we got some Errs back // from update_fulfill_htlc/update_fail_htlc, but we handle it anyway in // case there is some strange way to hit duplicate HTLC removes. return Ok(None); } + let update_fee = if let Some(feerate) = self.holding_cell_update_fee { + self.pending_update_fee = self.holding_cell_update_fee.take(); + Some(msgs::UpdateFee { + channel_id: self.channel_id, + feerate_per_kw: feerate as u32, + }) + } else { + None + }; let (commitment_signed, monitor_update) = self.send_commitment_no_status_check()?; Ok(Some((msgs::CommitmentUpdate { update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs: Vec::new(), + update_fee: update_fee, commitment_signed, }, monitor_update))) }, @@ -1801,6 +1854,24 @@ impl Channel { } self.value_to_self_msat = (self.value_to_self_msat as i64 + value_to_self_msat_diff) as u64; + if self.channel_outbound { + if let Some(feerate) = self.pending_update_fee.take() { + self.feerate_per_kw = feerate; + } + } else { + if let Some(feerate) = self.pending_update_fee { + // Because a node cannot send two commitment_signed's in a row without getting a + // revoke_and_ack from us (as it would otherwise not know the per_commitment_point + // it should use to create keys with) and because a node can't send a + // commitment_signed without changes, checking if the feerate is equal to the + // pending feerate update is sufficient to detect require_commitment. + if feerate == self.feerate_per_kw { + require_commitment = true; + self.pending_update_fee = None; + } + } + } + match self.free_holding_cell_htlcs()? { Some(mut commitment_update) => { commitment_update.0.update_fail_htlcs.reserve(update_fail_htlcs.len()); @@ -1821,6 +1892,7 @@ impl Channel { update_fulfill_htlcs: Vec::new(), update_fail_htlcs, update_fail_malformed_htlcs, + update_fee: None, commitment_signed }), to_forward_infos, revoked_htlcs, monitor_update)) } else { @@ -1828,6 +1900,43 @@ impl Channel { } } } + + } + + /// Adds a pending update to this channel. See the doc for send_htlc for + /// further details on the optionness of the return value. + /// You MUST call send_commitment prior to any other calls on this Channel + fn send_update_fee(&mut self, feerate_per_kw: u64) -> Option { + if !self.channel_outbound { + panic!("Cannot send fee from inbound channel"); + } + + if !self.is_usable() { + panic!("Cannot update fee until channel is fully established and we haven't started shutting down"); + } + + if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) { + self.holding_cell_update_fee = Some(feerate_per_kw); + return None; + } + + debug_assert!(self.pending_update_fee.is_none()); + self.pending_update_fee = Some(feerate_per_kw); + + Some(msgs::UpdateFee { + channel_id: self.channel_id, + feerate_per_kw: feerate_per_kw as u32, + }) + } + + pub fn send_update_fee_and_commit(&mut self, feerate_per_kw: u64) -> Result, HandleError> { + match self.send_update_fee(feerate_per_kw) { + Some(update_fee) => { + let (commitment_signed, monitor_update) = self.send_commitment_no_status_check()?; + Ok(Some((update_fee, commitment_signed, monitor_update))) + }, + None => Ok(None) + } } /// Removes any uncommitted HTLCs, to be used on peer disconnection, including any pending @@ -1904,8 +2013,9 @@ impl Channel { return Err(HandleError{err: "Peer sent update_fee when we needed a channel_reestablish", action: Some(msgs::ErrorAction::SendErrorMessage{msg: msgs::ErrorMessage{data: "Peer sent update_fee when we needed a channel_reestablish".to_string(), channel_id: msg.channel_id}})}); } Channel::check_remote_fee(fee_estimator, msg.feerate_per_kw)?; + + self.pending_update_fee = Some(msg.feerate_per_kw as u64); self.channel_update_count += 1; - self.feerate_per_kw = msg.feerate_per_kw as u64; Ok(()) } @@ -1981,6 +2091,7 @@ impl Channel { update_fulfill_htlcs: Vec::new(), update_fail_htlcs: Vec::new(), update_fail_malformed_htlcs: Vec::new(), + update_fee: None, commitment_signed: self.send_commitment_no_state_update().expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0, }), None)); } else { @@ -2230,6 +2341,11 @@ impl Channel { self.channel_value_satoshis } + #[cfg(test)] + pub fn get_feerate(&self) -> u64 { + self.feerate_per_kw + } + //TODO: Testing purpose only, should be changed in another way after #81 #[cfg(test)] pub fn get_local_keys(&self) -> &ChannelKeys { @@ -2245,6 +2361,10 @@ impl Channel { self.announce_publicly } + pub fn is_outbound(&self) -> bool { + self.channel_outbound + } + /// Gets the fee we'd want to charge for adding an HTLC output to this Channel /// Allowed in any state (including after shutdown) pub fn get_our_fee_base_msat(&self, fee_estimator: &FeeEstimator) -> u32 { @@ -2469,7 +2589,7 @@ impl Channel { let funding_script = self.get_funding_redeemscript(); let remote_keys = self.build_remote_transaction_keys()?; - let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false).0; + let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw).0; let remote_sighash = Message::from_slice(&bip143::SighashComponents::new(&remote_initial_commitment_tx).sighash_all(&remote_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap(); // We sign the "remote" commitment transaction, allowing them to broadcast the tx if they wish. @@ -2672,7 +2792,7 @@ impl Channel { if (self.channel_state & (ChannelState::PeerDisconnected as u32)) == (ChannelState::PeerDisconnected as u32) { panic!("Cannot create commitment tx while disconnected, as send_htlc will have returned an Err so a send_commitment precondition has been violated"); } - let mut have_updates = false; // TODO initialize with "have we sent a fee update?" + let mut have_updates = self.pending_update_fee.is_some(); for htlc in self.pending_outbound_htlcs.iter() { if htlc.state == OutboundHTLCState::LocalAnnounced { have_updates = true; @@ -2716,8 +2836,15 @@ impl Channel { fn send_commitment_no_state_update(&self) -> Result<(msgs::CommitmentSigned, (Transaction, Vec)), HandleError> { let funding_script = self.get_funding_redeemscript(); + let mut feerate_per_kw = self.feerate_per_kw; + if let Some(feerate) = self.pending_update_fee { + if self.channel_outbound { + feerate_per_kw = feerate; + } + } + let remote_keys = self.build_remote_transaction_keys()?; - let remote_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, true); + let remote_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, true, feerate_per_kw); let remote_commitment_txid = remote_commitment_tx.0.txid(); let remote_sighash = Message::from_slice(&bip143::SighashComponents::new(&remote_commitment_tx.0).sighash_all(&remote_commitment_tx.0.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap(); let our_sig = self.secp_ctx.sign(&remote_sighash, &self.local_keys.funding_key); @@ -2725,7 +2852,7 @@ impl Channel { let mut htlc_sigs = Vec::new(); for ref htlc in remote_commitment_tx.1.iter() { - let htlc_tx = self.build_htlc_transaction(&remote_commitment_txid, htlc, false, &remote_keys); + let htlc_tx = self.build_htlc_transaction(&remote_commitment_txid, htlc, false, &remote_keys, feerate_per_kw); let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &remote_keys); let htlc_sighash = Message::from_slice(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]).unwrap(); let our_htlc_key = secp_derived_key!(chan_utils::derive_private_key(&self.secp_ctx, &remote_keys.per_commitment_point, &self.local_keys.htlc_base_key), self.channel_id()); @@ -2927,7 +3054,7 @@ mod tests { macro_rules! test_commitment { ( $their_sig_hex: expr, $our_sig_hex: expr, $tx_hex: expr) => { - unsigned_tx = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false); + unsigned_tx = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, chan.feerate_per_kw); let their_signature = Signature::from_der(&secp_ctx, &hex::decode($their_sig_hex).unwrap()[..]).unwrap(); let sighash = Message::from_slice(&bip143::SighashComponents::new(&unsigned_tx.0).sighash_all(&unsigned_tx.0.input[0], &chan.get_funding_redeemscript(), chan.channel_value_satoshis)[..]).unwrap(); secp_ctx.verify(&sighash, &their_signature, &chan.their_funding_pubkey.unwrap()).unwrap(); @@ -2944,7 +3071,7 @@ mod tests { let remote_signature = Signature::from_der(&secp_ctx, &hex::decode($their_sig_hex).unwrap()[..]).unwrap(); let ref htlc = unsigned_tx.1[$htlc_idx]; - let mut htlc_tx = chan.build_htlc_transaction(&unsigned_tx.0.txid(), &htlc, true, &keys); + let mut htlc_tx = chan.build_htlc_transaction(&unsigned_tx.0.txid(), &htlc, true, &keys, chan.feerate_per_kw); let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys); let htlc_sighash = Message::from_slice(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]).unwrap(); secp_ctx.verify(&htlc_sighash, &remote_signature, &keys.b_htlc_key).unwrap();