Merge pull request #325 from TheBlueMatt/2019-03-322-cleanup
[rust-lightning] / src / ln / channel.rs
index a14cc06b2520a42b3ed66b5a6d89c0c5c04b165d..b67468b3859ecd5e1a50c951ce02d6670f39d05d 100644 (file)
@@ -2,13 +2,14 @@ use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::blockdata::script::{Script,Builder};
 use bitcoin::blockdata::transaction::{TxIn, TxOut, Transaction, SigHashType};
 use bitcoin::blockdata::opcodes;
-use bitcoin::util::hash::{BitcoinHash, Sha256dHash};
+use bitcoin::util::hash::BitcoinHash;
 use bitcoin::util::bip143;
 use bitcoin::consensus::encode::{self, Encodable, Decodable};
 
 use bitcoin_hashes::{Hash, HashEngine};
 use bitcoin_hashes::sha256::Hash as Sha256;
 use bitcoin_hashes::hash160::Hash as Hash160;
+use bitcoin_hashes::sha256d::Hash as Sha256dHash;
 
 use secp256k1::key::{PublicKey,SecretKey};
 use secp256k1::{Secp256k1,Signature};
@@ -880,9 +881,14 @@ impl Channel {
                        }
                }
 
-
                let value_to_self_msat: i64 = (self.value_to_self_msat - local_htlc_total_msat) as i64 + value_to_self_msat_offset;
-               let value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000 - self.value_to_self_msat - remote_htlc_total_msat) as i64 - value_to_self_msat_offset;
+               assert!(value_to_self_msat >= 0);
+               // Note that in case they have several just-awaiting-last-RAA fulfills in-progress (ie
+               // AwaitingRemoteRevokeToRemove or AwaitingRemovedRemoteRevoke) we may have allowed them to
+               // "violate" their reserve value by couting those against it. Thus, we have to convert
+               // everything to i64 before subtracting as otherwise we can overflow.
+               let value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000) as i64 - (self.value_to_self_msat as i64) - (remote_htlc_total_msat as i64) - value_to_self_msat_offset;
+               assert!(value_to_remote_msat >= 0);
 
                #[cfg(debug_assertions)]
                {
@@ -929,7 +935,19 @@ impl Channel {
                        }, None));
                }
 
-               transaction_utils::sort_outputs(&mut txouts);
+               transaction_utils::sort_outputs(&mut txouts, |a, b| {
+                       if let &Some(ref a_htlc) = a {
+                               if let &Some(ref b_htlc) = b {
+                                       a_htlc.0.cltv_expiry.cmp(&b_htlc.0.cltv_expiry)
+                                               // Note that due to hash collisions, we have to have a fallback comparison
+                                               // here for fuzztarget mode (otherwise at least chanmon_fail_consistency
+                                               // may fail)!
+                                               .then(a_htlc.0.payment_hash.0.cmp(&b_htlc.0.payment_hash.0))
+                               // For non-HTLC outputs, if they're copying our SPK we don't really care if we
+                               // close the channel due to mismatches - they're doing something dumb:
+                               } else { cmp::Ordering::Equal }
+                       } else { cmp::Ordering::Equal }
+               });
 
                let mut outputs: Vec<TxOut> = Vec::with_capacity(txouts.len());
                let mut htlcs_included: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::with_capacity(txouts.len() + included_dust_htlcs.len());
@@ -1005,7 +1023,7 @@ impl Channel {
                        }, ()));
                }
 
-               transaction_utils::sort_outputs(&mut txouts);
+               transaction_utils::sort_outputs(&mut txouts, |_, _| { cmp::Ordering::Equal }); // Ordering doesnt matter if they used our pubkey...
 
                let mut outputs: Vec<TxOut> = Vec::new();
                for out in txouts.drain(..) {
@@ -1594,7 +1612,24 @@ impl Channel {
                // Check our_channel_reserve_satoshis (we're getting paid, so they have to at least meet
                // the reserve_satoshis we told them to always have as direct payment so that they lose
                // something if we punish them for broadcasting an old state).
-               if htlc_inbound_value_msat + msg.amount_msat + self.value_to_self_msat > (self.channel_value_satoshis - Channel::get_our_channel_reserve_satoshis(self.channel_value_satoshis)) * 1000 {
+               // Note that we don't really care about having a small/no to_remote output in our local
+               // commitment transactions, as the purpose of the channel reserve is to ensure we can
+               // punish *them* if they misbehave, so we discount any outbound HTLCs which will not be
+               // present in the next commitment transaction we send them (at least for fulfilled ones,
+               // failed ones won't modify value_to_self).
+               // Note that we will send HTLCs which another instance of rust-lightning would think
+               // violate the reserve value if we do not do this (as we forget inbound HTLCs from the
+               // Channel state once they will not be present in the next received commitment
+               // transaction).
+               let mut removed_outbound_total_msat = 0;
+               for ref htlc in self.pending_outbound_htlcs.iter() {
+                       if let OutboundHTLCState::AwaitingRemoteRevokeToRemove(None) = htlc.state {
+                               removed_outbound_total_msat += htlc.amount_msat;
+                       } else if let OutboundHTLCState::AwaitingRemovedRemoteRevoke(None) = htlc.state {
+                               removed_outbound_total_msat += htlc.amount_msat;
+                       }
+               }
+               if htlc_inbound_value_msat + msg.amount_msat + self.value_to_self_msat > (self.channel_value_satoshis - Channel::get_our_channel_reserve_satoshis(self.channel_value_satoshis)) * 1000 + removed_outbound_total_msat {
                        return Err(ChannelError::Close("Remote HTLC add would put them over their reserve value"));
                }
                if self.next_remote_htlc_id != msg.htlc_id {
@@ -1851,6 +1886,8 @@ impl Channel {
        fn free_holding_cell_htlcs(&mut self) -> Result<Option<(msgs::CommitmentUpdate, ChannelMonitor)>, ChannelError> {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, 0);
                if self.holding_cell_htlc_updates.len() != 0 || self.holding_cell_update_fee.is_some() {
+                       log_trace!(self, "Freeing holding cell with {} HTLC updates{}", self.holding_cell_htlc_updates.len(), if self.holding_cell_update_fee.is_some() { " and a fee update" } else { "" });
+
                        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());
@@ -3143,7 +3180,7 @@ impl Channel {
                        excess_data: Vec::new(),
                };
 
-               let msghash = hash_to_message!(&Sha256dHash::from_data(&msg.encode()[..])[..]);
+               let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
                let sig = self.secp_ctx.sign(&msghash, &self.local_keys.funding_key);
 
                Ok((msg, sig))
@@ -3956,12 +3993,12 @@ impl<R : ::std::io::Read> ReadableArgs<R, Arc<Logger>> for Channel {
 
 #[cfg(test)]
 mod tests {
-       use bitcoin::util::hash::{Sha256dHash, Hash160};
        use bitcoin::util::bip143;
        use bitcoin::consensus::encode::serialize;
        use bitcoin::blockdata::script::{Script, Builder};
        use bitcoin::blockdata::transaction::Transaction;
        use bitcoin::blockdata::opcodes;
+       use bitcoin_hashes::hex::FromHex;
        use hex;
        use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
        use ln::channel::{Channel,ChannelKeys,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,TxCreationKeys};
@@ -3976,6 +4013,8 @@ mod tests {
        use secp256k1::{Secp256k1,Message,Signature};
        use secp256k1::key::{SecretKey,PublicKey};
        use bitcoin_hashes::sha256::Hash as Sha256;
+       use bitcoin_hashes::sha256d::Hash as Sha256dHash;
+       use bitcoin_hashes::hash160::Hash as Hash160;
        use bitcoin_hashes::Hash;
        use std::sync::Arc;
 
@@ -4002,7 +4041,7 @@ mod tests {
                fn get_destination_script(&self) -> Script {
                        let secp_ctx = Secp256k1::signing_only();
                        let channel_monitor_claim_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
-                       let our_channel_monitor_claim_key_hash = Hash160::from_data(&PublicKey::from_secret_key(&secp_ctx, &channel_monitor_claim_key).serialize());
+                       let our_channel_monitor_claim_key_hash = Hash160::hash(&PublicKey::from_secret_key(&secp_ctx, &channel_monitor_claim_key).serialize());
                        Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_monitor_claim_key_hash[..]).into_script()
                }