From 4b231d5e6d0dc70b2c2ec8ba0ebd444d2cb9084e Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Mon, 15 Oct 2018 14:38:19 -0400 Subject: [PATCH] Store per-state HTLC data in the state enum itself (and store more) --- src/ln/channel.rs | 134 ++++++++++++++++++++++++++-------------------- 1 file changed, 75 insertions(+), 59 deletions(-) diff --git a/src/ln/channel.rs b/src/ln/channel.rs index 1d736d41d..db0b0475a 100644 --- a/src/ln/channel.rs +++ b/src/ln/channel.rs @@ -98,22 +98,27 @@ impl ChannelKeys { } } -#[derive(PartialEq)] +enum InboundHTLCRemovalReason { + FailRelay(msgs::OnionErrorPacket), + FailMalformed(([u8; 32], u16)), + Fulfill([u8; 32]), +} + enum InboundHTLCState { /// Added by remote, to be included in next local commitment tx. - RemoteAnnounced, + RemoteAnnounced(PendingHTLCStatus), /// Included in a received commitment_signed message (implying we've revoke_and_ack'ed it), but /// the remote side hasn't yet revoked their previous state, which we need them to do before we /// accept this HTLC. Implies AwaitingRemoteRevoke. /// We also have not yet included this HTLC in a commitment_signed message, and are waiting on /// a remote revoke_and_ack on a previous state before we can do so. - AwaitingRemoteRevokeToAnnounce, + AwaitingRemoteRevokeToAnnounce(PendingHTLCStatus), /// Included in a received commitment_signed message (implying we've revoke_and_ack'ed it), but /// the remote side hasn't yet revoked their previous state, which we need them to do before we /// accept this HTLC. Implies AwaitingRemoteRevoke. /// We have included this HTLC in our latest commitment_signed and are now just waiting on a /// revoke_and_ack. - AwaitingAnnouncedRemoteRevoke, + AwaitingAnnouncedRemoteRevoke(PendingHTLCStatus), Committed, /// Removed by us and a new commitment_signed was sent (if we were AwaitingRemoteRevoke when we /// created it we would have put it in the holding cell instead). When they next revoke_and_ack @@ -125,7 +130,7 @@ enum InboundHTLCState { /// ChannelMonitor::would_broadcast_at_height) so we actually remove the HTLC from our own /// local state before then, once we're sure that the next commitment_signed and /// ChannelMonitor::provide_latest_local_commitment_tx_info will not include this HTLC. - LocalRemoved, + LocalRemoved(InboundHTLCRemovalReason), } struct InboundHTLCOutput { @@ -134,10 +139,6 @@ struct InboundHTLCOutput { cltv_expiry: u32, payment_hash: [u8; 32], state: InboundHTLCState, - /// If we're in LocalRemoved, set to true if we fulfilled the HTLC, and can claim money - local_removed_fulfilled: bool, - /// state pre-Committed implies pending_forward_state, otherwise it must be None - pending_forward_state: Option, } #[derive(PartialEq)] @@ -791,21 +792,23 @@ impl Channel { for ref htlc in self.pending_inbound_htlcs.iter() { let include = match htlc.state { - InboundHTLCState::RemoteAnnounced => !generated_by_local, - InboundHTLCState::AwaitingRemoteRevokeToAnnounce => !generated_by_local, - InboundHTLCState::AwaitingAnnouncedRemoteRevoke => true, + InboundHTLCState::RemoteAnnounced(_) => !generated_by_local, + InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) => !generated_by_local, + InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => true, InboundHTLCState::Committed => true, - InboundHTLCState::LocalRemoved => !generated_by_local, + InboundHTLCState::LocalRemoved(_) => !generated_by_local, }; if include { add_htlc_output!(htlc, false); remote_htlc_total_msat += htlc.amount_msat; } else { - match htlc.state { - InboundHTLCState::LocalRemoved => { - if generated_by_local && htlc.local_removed_fulfilled { - value_to_self_msat_offset += htlc.amount_msat as i64; + match &htlc.state { + &InboundHTLCState::LocalRemoved(ref reason) => { + if generated_by_local { + if let &InboundHTLCRemovalReason::Fulfill(_) = reason { + value_to_self_msat_offset += htlc.amount_msat as i64; + } } }, _ => {}, @@ -1131,7 +1134,8 @@ impl Channel { 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); - if htlc.state != InboundHTLCState::Committed { + if let InboundHTLCState::Committed = htlc.state { + } else { debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to"); // Don't return in release mode here so that we can update channel_monitor } @@ -1176,12 +1180,12 @@ impl Channel { { let htlc = &mut self.pending_inbound_htlcs[pending_idx]; - if htlc.state != InboundHTLCState::Committed { + 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 Ok((None, Some(self.channel_monitor.clone()))); } - htlc.state = InboundHTLCState::LocalRemoved; - htlc.local_removed_fulfilled = true; + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(payment_preimage_arg.clone())); } Ok((Some(msgs::UpdateFulfillHTLC { @@ -1213,7 +1217,8 @@ impl Channel { let mut pending_idx = std::usize::MAX; for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() { if htlc.htlc_id == htlc_id_arg { - if htlc.state != InboundHTLCState::Committed { + if let InboundHTLCState::Committed = htlc.state { + } else { debug_assert!(false, "Have an inbound HTLC we tried to fail before it was fully committed to"); return Err(HandleError{err: "Unable to find a pending HTLC which matched the given HTLC ID", action: Some(msgs::ErrorAction::IgnoreError)}); } @@ -1253,8 +1258,7 @@ impl Channel { { let htlc = &mut self.pending_inbound_htlcs[pending_idx]; - htlc.state = InboundHTLCState::LocalRemoved; - htlc.local_removed_fulfilled = false; + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(err_packet.clone())); } Ok(Some(msgs::UpdateFailHTLC { @@ -1533,9 +1537,7 @@ impl Channel { amount_msat: msg.amount_msat, payment_hash: msg.payment_hash, cltv_expiry: msg.cltv_expiry, - state: InboundHTLCState::RemoteAnnounced, - local_removed_fulfilled: false, - pending_forward_state: Some(pending_forward_state), + state: InboundHTLCState::RemoteAnnounced(pending_forward_state), }); Ok(()) @@ -1675,8 +1677,11 @@ impl Channel { self.channel_monitor.provide_latest_local_commitment_tx_info(local_commitment_tx.0, local_keys, self.feerate_per_kw, htlcs_and_sigs); for htlc in self.pending_inbound_htlcs.iter_mut() { - if htlc.state == InboundHTLCState::RemoteAnnounced { - htlc.state = InboundHTLCState::AwaitingRemoteRevokeToAnnounce; + let new_forward = if let &InboundHTLCState::RemoteAnnounced(ref forward_info) = &htlc.state { + Some(forward_info.clone()) + } else { None }; + if let Some(forward_info) = new_forward { + htlc.state = InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info); need_our_commitment = true; } } @@ -1833,8 +1838,8 @@ impl Channel { let mut value_to_self_msat_diff: i64 = 0; // We really shouldnt have two passes here, but retain gives a non-mutable ref (Rust bug) self.pending_inbound_htlcs.retain(|htlc| { - if htlc.state == InboundHTLCState::LocalRemoved { - if htlc.local_removed_fulfilled { + if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state { + if let &InboundHTLCRemovalReason::Fulfill(_) = reason { value_to_self_msat_diff += htlc.amount_msat as i64; } false @@ -1852,22 +1857,37 @@ impl Channel { } else { true } }); for htlc in self.pending_inbound_htlcs.iter_mut() { - if htlc.state == InboundHTLCState::AwaitingRemoteRevokeToAnnounce { - htlc.state = InboundHTLCState::AwaitingAnnouncedRemoteRevoke; - require_commitment = true; - } else if htlc.state == InboundHTLCState::AwaitingAnnouncedRemoteRevoke { - match htlc.pending_forward_state.take().unwrap() { - PendingHTLCStatus::Fail(fail_msg) => { - htlc.state = InboundHTLCState::LocalRemoved; - require_commitment = true; - match fail_msg { - HTLCFailureMsg::Relay(msg) => update_fail_htlcs.push(msg), - HTLCFailureMsg::Malformed(msg) => update_fail_malformed_htlcs.push(msg), + let swap = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) = &htlc.state { + true + } else if let &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) = &htlc.state { + true + } else { false }; + if swap { + let mut state = InboundHTLCState::Committed; + mem::swap(&mut state, &mut htlc.state); + + if let InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info) = state { + htlc.state = InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info); + require_commitment = true; + } else if let InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info) = state { + match forward_info { + PendingHTLCStatus::Fail(fail_msg) => { + require_commitment = true; + match fail_msg { + HTLCFailureMsg::Relay(msg) => { + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(msg.reason.clone())); + update_fail_htlcs.push(msg) + }, + HTLCFailureMsg::Malformed(msg) => { + htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailMalformed((msg.sha256_of_onion, msg.failure_code))); + update_fail_malformed_htlcs.push(msg) + }, + } + }, + PendingHTLCStatus::Forward(forward_info) => { + to_forward_infos.push((forward_info, htlc.htlc_id)); + htlc.state = InboundHTLCState::Committed; } - }, - PendingHTLCStatus::Forward(forward_info) => { - to_forward_infos.push((forward_info, htlc.htlc_id)); - htlc.state = InboundHTLCState::Committed; } } } @@ -1985,22 +2005,21 @@ impl Channel { let mut inbound_drop_count = 0; self.pending_inbound_htlcs.retain(|htlc| { match htlc.state { - InboundHTLCState::RemoteAnnounced => { + InboundHTLCState::RemoteAnnounced(_) => { // They sent us an update_add_htlc but we never got the commitment_signed. // We'll tell them what commitment_signed we're expecting next and they'll drop // this HTLC accordingly inbound_drop_count += 1; false }, - InboundHTLCState::AwaitingRemoteRevokeToAnnounce|InboundHTLCState::AwaitingAnnouncedRemoteRevoke => { - // Same goes for AwaitingRemoteRevokeToRemove and AwaitingRemovedRemoteRevoke + InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_)|InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => { // We received a commitment_signed updating this HTLC and (at least hopefully) // sent a revoke_and_ack (which we can re-transmit) and have heard nothing // in response to it yet, so don't touch it. true }, InboundHTLCState::Committed => true, - InboundHTLCState::LocalRemoved => { // Same goes for LocalAnnounced + InboundHTLCState::LocalRemoved(_) => { // We (hopefully) sent a commitment_signed updating this HTLC (which we can // re-transmit if needed) and they may have even sent a revoke_and_ack back // (that we missed). Keep this around for now and if they tell us they missed @@ -2141,7 +2160,7 @@ impl Channel { return Ok((None, None, Vec::new())); } for htlc in self.pending_inbound_htlcs.iter() { - if htlc.state == InboundHTLCState::RemoteAnnounced { + if let InboundHTLCState::RemoteAnnounced(_) = htlc.state { return Err(HandleError{err: "Got shutdown with remote pending HTLCs", action: None}); } } @@ -2878,8 +2897,11 @@ impl Channel { // fail to generate this, we still are at least at a position where upgrading their status // is acceptable. for htlc in self.pending_inbound_htlcs.iter_mut() { - if htlc.state == InboundHTLCState::AwaitingRemoteRevokeToAnnounce { - htlc.state = InboundHTLCState::AwaitingAnnouncedRemoteRevoke; + let new_state = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(ref forward_info) = &htlc.state { + Some(InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info.clone())) + } else { None }; + if let Some(state) = new_state { + htlc.state = state; } } for htlc in self.pending_outbound_htlcs.iter_mut() { @@ -3188,8 +3210,6 @@ mod tests { cltv_expiry: 500, payment_hash: [0; 32], state: InboundHTLCState::Committed, - local_removed_fulfilled: false, - pending_forward_state: None, }; let mut sha = Sha256::new(); sha.input(&hex::decode("0000000000000000000000000000000000000000000000000000000000000000").unwrap()); @@ -3203,8 +3223,6 @@ mod tests { cltv_expiry: 501, payment_hash: [0; 32], state: InboundHTLCState::Committed, - local_removed_fulfilled: false, - pending_forward_state: None, }; let mut sha = Sha256::new(); sha.input(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()); @@ -3248,8 +3266,6 @@ mod tests { cltv_expiry: 504, payment_hash: [0; 32], state: InboundHTLCState::Committed, - local_removed_fulfilled: false, - pending_forward_state: None, }; let mut sha = Sha256::new(); sha.input(&hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()); -- 2.39.5