Additional asserts to include in fuzztesting (though may get hit?)
[rust-lightning] / lightning / src / ln / channel.rs
index 02b1ae4ed2f58b413e8e4375716d490b6e0552e3..d3767eb987f469e5e9bf2fe48c9325fd0a1f15a3 100644 (file)
@@ -19,7 +19,7 @@ use ln::features::{ChannelFeatures, InitFeatures};
 use ln::msgs;
 use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
 use ln::channelmonitor::ChannelMonitor;
-use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingForwardHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
 use ln::chan_utils::{LocalCommitmentTransaction, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys};
 use ln::chan_utils;
 use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
@@ -36,6 +36,9 @@ use std::default::Default;
 use std::{cmp,mem,fmt};
 use std::sync::{Arc};
 
+#[cfg(all(test, feature = "mutation_testing"))]
+use mutagen::mutate;
+
 #[cfg(test)]
 pub struct ChannelValueStat {
        pub value_to_self_msat: u64,
@@ -240,7 +243,10 @@ pub(super) struct Channel<ChanSigner: ChannelKeys> {
        secp_ctx: Secp256k1<secp256k1::All>,
        channel_value_satoshis: u64,
 
+       #[cfg(not(test))]
        local_keys: ChanSigner,
+       #[cfg(test)]
+       pub(super) local_keys: ChanSigner,
        shutdown_pubkey: PublicKey,
 
        // Our commitment numbers start at 2^48-1 and count down, whereas the ones used in transaction
@@ -266,7 +272,7 @@ pub(super) struct Channel<ChanSigner: ChannelKeys> {
        monitor_pending_funding_locked: bool,
        monitor_pending_revoke_and_ack: bool,
        monitor_pending_commitment_signed: bool,
-       monitor_pending_forwards: Vec<(PendingForwardHTLCInfo, u64)>,
+       monitor_pending_forwards: Vec<(PendingHTLCInfo, u64)>,
        monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
 
        // pending_update_fee is filled when sending and receiving update_fee
@@ -356,11 +362,18 @@ pub const OUR_MAX_HTLCS: u16 = 50; //TODO
 /// on ice until the funding transaction gets more confirmations, but the LN protocol doesn't
 /// really allow for this, so instead we're stuck closing it out at that point.
 const UNCONF_THRESHOLD: u32 = 6;
-/// Exposing these two constants for use in test in ChannelMonitor
-pub const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
-pub const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
 const SPENDING_INPUT_FOR_A_OUTPUT_WEIGHT: u64 = 79; // prevout: 36, nSequence: 4, script len: 1, witness lengths: (3+1)/4, sig: 73/4, if-selector: 1, redeemScript: (6 ops + 2*33 pubkeys + 1*2 delay)/4
 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;
+#[cfg(test)]
+pub const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
+#[cfg(not(test))]
+const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
+#[cfg(test)]
+pub const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
+
 /// Maximmum `funding_satoshis` value, according to the BOLT #2 specification
 /// it's 2^24.
 pub const MAX_FUNDING_SATOSHIS: u64 = (1 << 24);
@@ -420,7 +433,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
        // Constructors:
        pub fn new_outbound(fee_estimator: &FeeEstimator, keys_provider: &Arc<KeysInterface<ChanKeySigner = ChanSigner>>, their_node_id: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_id: u64, logger: Arc<Logger>, config: &UserConfig) -> Result<Channel<ChanSigner>, APIError> {
-               let chan_keys = keys_provider.get_channel_keys(false);
+               let chan_keys = keys_provider.get_channel_keys(false, channel_value_satoshis);
 
                if channel_value_satoshis >= MAX_FUNDING_SATOSHIS {
                        return Err(APIError::APIMisuseError{err: "funding value > 2^24"});
@@ -532,7 +545,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
        /// Creates a new channel from a remote sides' request for one.
        /// Assumes chain_hash has already been checked and corresponds with what we expect!
        pub fn new_from_req(fee_estimator: &FeeEstimator, keys_provider: &Arc<KeysInterface<ChanKeySigner = ChanSigner>>, their_node_id: PublicKey, their_features: InitFeatures, msg: &msgs::OpenChannel, user_id: u64, logger: Arc<Logger>, config: &UserConfig) -> Result<Channel<ChanSigner>, ChannelError> {
-               let mut chan_keys = keys_provider.get_channel_keys(true);
+               let mut chan_keys = keys_provider.get_channel_keys(true, msg.funding_satoshis);
                let their_pubkeys = ChannelPublicKeys {
                        funding_pubkey: msg.funding_pubkey,
                        revocation_basepoint: msg.revocation_basepoint,
@@ -1418,7 +1431,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
                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, self.feerate_per_kw).0;
-               let remote_signature = self.local_keys.sign_remote_commitment(self.channel_value_satoshis, self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
+               let remote_signature = self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
                                .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?.0;
 
                // We sign the "remote" commitment transaction, allowing them to broadcast the tx if they wish.
@@ -1619,6 +1632,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                let mut removed_outbound_total_msat = 0;
                for ref htlc in self.pending_outbound_htlcs.iter() {
                        if let OutboundHTLCState::AwaitingRemoteRevokeToRemove(None) = htlc.state {
+debug_assert!(false, "This should be triggerable, and we should add a test case that does so!");
                                removed_outbound_total_msat += htlc.amount_msat;
                        } else if let OutboundHTLCState::AwaitingRemovedRemoteRevoke(None) = htlc.state {
                                removed_outbound_total_msat += htlc.amount_msat;
@@ -1974,7 +1988,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
        /// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail,
        /// generating an appropriate error *after* the channel state has been updated based on the
        /// revoke_and_ack message.
-       pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK, fee_estimator: &FeeEstimator) -> Result<(Option<msgs::CommitmentUpdate>, Vec<(PendingForwardHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, Option<msgs::ClosingSigned>, ChannelMonitor), ChannelError> {
+       pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK, fee_estimator: &FeeEstimator) -> Result<(Option<msgs::CommitmentUpdate>, Vec<(PendingHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, Option<msgs::ClosingSigned>, ChannelMonitor), ChannelError> {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        return Err(ChannelError::Close("Got revoke/ACK message when channel was not in an operational state"));
                }
@@ -1993,6 +2007,17 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                self.channel_monitor.provide_secret(self.cur_remote_commitment_transaction_number + 1, msg.per_commitment_secret)
                        .map_err(|e| ChannelError::Close(e.0))?;
 
+               if self.channel_state & ChannelState::AwaitingRemoteRevoke as u32 == 0 {
+                       // Our counterparty seems to have burned their coins to us (by revoking a state when we
+                       // haven't given them a new commitment transaction to broadcast). We should probably
+                       // take advantage of this by updating our channel monitor, sending them an error, and
+                       // waiting for them to broadcast their latest (now-revoked claim). But, that would be a
+                       // lot of work, and there's some chance this is all a misunderstanding anyway.
+                       // We have to do *something*, though, since our signer may get mad at us for otherwise
+                       // jumping a remote commitment number, so best to just force-close and move on.
+                       return Err(ChannelError::Close("Got a revoke when we weren't expecting one"));
+               }
+
                // Update state now that we've passed all the can-fail calls...
                // (note that we may still fail to generate the new commitment_signed message, but that's
                // OK, we step the channel here and *then* if the new generation fails we can fail the
@@ -2194,6 +2219,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                }
        }
 
+       #[cfg_attr(all(test, feature = "mutation_testing"), mutate)]
        /// Removes any uncommitted HTLCs, to be used on peer disconnection, including any pending
        /// HTLCs that we intended to add but haven't as we were waiting on a remote revoke.
        /// Returns the set of PendingHTLCStatuses from remote uncommitted HTLCs (which we're
@@ -2269,7 +2295,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
        /// which failed. The messages which were generated from that call which generated the
        /// monitor update failure must *not* have been sent to the remote end, and must instead
        /// have been dropped. They will be regenerated when monitor_updating_restored is called.
-       pub fn monitor_update_failed(&mut self, resend_raa: bool, resend_commitment: bool, mut pending_forwards: Vec<(PendingForwardHTLCInfo, u64)>, mut pending_fails: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>) {
+       pub fn monitor_update_failed(&mut self, resend_raa: bool, resend_commitment: bool, mut pending_forwards: Vec<(PendingHTLCInfo, u64)>, mut pending_fails: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>) {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, 0);
                self.monitor_pending_revoke_and_ack = resend_raa;
                self.monitor_pending_commitment_signed = resend_commitment;
@@ -2280,10 +2306,11 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                self.channel_state |= ChannelState::MonitorUpdateFailed as u32;
        }
 
+       #[cfg_attr(all(test, feature = "mutation_testing"), mutate)]
        /// Indicates that the latest ChannelMonitor update has been committed by the client
        /// successfully and we should restore normal operation. Returns messages which should be sent
        /// to the remote side.
-       pub fn monitor_updating_restored(&mut self) -> (Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, RAACommitmentOrder, Vec<(PendingForwardHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, bool, Option<msgs::FundingLocked>) {
+       pub fn monitor_updating_restored(&mut self) -> (Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, RAACommitmentOrder, Vec<(PendingHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, bool, Option<msgs::FundingLocked>) {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, ChannelState::MonitorUpdateFailed as u32);
                self.channel_state &= !(ChannelState::MonitorUpdateFailed as u32);
 
@@ -2348,6 +2375,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                Ok(())
        }
 
+       #[cfg_attr(all(test, feature = "mutation_testing"), mutate)]
        fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK {
                let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &self.build_local_commitment_secret(self.cur_local_commitment_transaction_number));
                let per_commitment_secret = chan_utils::build_commitment_secret(self.local_keys.commitment_seed(), self.cur_local_commitment_transaction_number + 2);
@@ -2563,7 +2591,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
                let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(proposed_total_fee_satoshis, false);
                let our_sig = self.local_keys
-                       .sign_closing_transaction(self.channel_value_satoshis, &self.get_funding_redeemscript(), &closing_tx, &self.secp_ctx)
+                       .sign_closing_transaction(&closing_tx, &self.secp_ctx)
                        .ok();
                if our_sig.is_none() { return None; }
 
@@ -2719,7 +2747,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                                let closing_tx_max_weight = Self::get_closing_transaction_weight(&self.get_closing_scriptpubkey(), self.their_shutdown_scriptpubkey.as_ref().unwrap());
                                let (closing_tx, used_total_fee) = self.build_closing_transaction($new_feerate * closing_tx_max_weight / 1000, false);
                                let our_sig = self.local_keys
-                                       .sign_closing_transaction(self.channel_value_satoshis, &funding_redeemscript, &closing_tx, &self.secp_ctx)
+                                       .sign_closing_transaction(&closing_tx, &self.secp_ctx)
                                        .map_err(|_| ChannelError::Close("External signer refused to sign closing transaction"))?;
                                self.last_sent_closing_fee = Some(($new_feerate, used_total_fee, our_sig.clone()));
                                return Ok((Some(msgs::ClosingSigned {
@@ -2754,7 +2782,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                }
 
                let our_sig = self.local_keys
-                       .sign_closing_transaction(self.channel_value_satoshis, &funding_redeemscript, &closing_tx, &self.secp_ctx)
+                       .sign_closing_transaction(&closing_tx, &self.secp_ctx)
                        .map_err(|_| ChannelError::Close("External signer refused to sign closing transaction"))?;
                self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &our_sig);
 
@@ -2964,12 +2992,24 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
        }
 
        /// Called by channelmanager based on chain blocks being connected.
-       /// Note that we only need to use this to detect funding_signed, anything else is handled by
-       /// the channel_monitor.
+       /// We need to use this to detect funding_signed and outgoing HTLC timed out before we were able 
+       /// to commit them on remote commitment tx, anything else is handled by the channel_monitor.
        /// In case of Err, the channel may have been closed, at which point the standard requirements
        /// apply - no calls may be made except those explicitly stated to be allowed post-shutdown.
        /// Only returns an ErrorAction of DisconnectPeer, if Err.
-       pub fn block_connected(&mut self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) -> Result<Option<msgs::FundingLocked>, msgs::ErrorMessage> {
+       pub fn block_connected(&mut self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash, u64)>), msgs::ErrorMessage> {
+               let mut timed_out_htlcs = Vec::new();
+               self.holding_cell_htlc_updates.retain(|htlc_update| {
+                       match htlc_update {
+                               &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, ref cltv_expiry, ref amount_msat, .. } => {
+                                       if cltv_expiry <= &height { // XXX follow 0a4821b
+                                               timed_out_htlcs.push((source.clone(), payment_hash.clone(), *amount_msat));
+                                               false
+                                       } else { true }
+                               },
+                               _ => true
+                       }
+               });
                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
                if header.bitcoin_hash() != self.last_block_connected {
                        self.last_block_connected = header.bitcoin_hash();
@@ -3005,13 +3045,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                                                if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 {
                                                        let next_per_commitment_secret = self.build_local_commitment_secret(self.cur_local_commitment_transaction_number);
                                                        let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &next_per_commitment_secret);
-                                                       return Ok(Some(msgs::FundingLocked {
+                                                       return Ok((Some(msgs::FundingLocked {
                                                                channel_id: self.channel_id,
                                                                next_per_commitment_point: next_per_commitment_point,
-                                                       }));
+                                                       }), timed_out_htlcs));
                                                } else {
                                                        self.monitor_pending_funding_locked = true;
-                                                       return Ok(None);
+                                                       return Ok((None, timed_out_htlcs));
                                                }
                                        }
                                }
@@ -3057,7 +3097,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                                }
                        }
                }
-               Ok(None)
+               Ok((None, timed_out_htlcs))
        }
 
        /// Called by channelmanager based on chain blocks being disconnected.
@@ -3154,7 +3194,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
        fn get_outbound_funding_created_signature(&mut self) -> Result<(Signature, Transaction), ChannelError> {
                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, self.feerate_per_kw).0;
-               Ok((self.local_keys.sign_remote_commitment(self.channel_value_satoshis, self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
+               Ok((self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx)
                                .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?.0, remote_initial_commitment_tx))
        }
 
@@ -3462,7 +3502,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
                                htlcs.push(htlc);
                        }
 
-                       let res = self.local_keys.sign_remote_commitment(self.channel_value_satoshis, feerate_per_kw, &remote_commitment_tx.0, &remote_keys, &htlcs, self.our_to_self_delay, &self.secp_ctx)
+                       let res = self.local_keys.sign_remote_commitment(feerate_per_kw, &remote_commitment_tx.0, &remote_keys, &htlcs, self.our_to_self_delay, &self.secp_ctx)
                                .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?;
                        signature = res.0;
                        htlc_signatures = res.1;
@@ -4101,7 +4141,9 @@ mod tests {
                        PublicKey::from_secret_key(&secp_ctx, &channel_close_key)
                }
 
-               fn get_channel_keys(&self, _inbound: bool) -> InMemoryChannelKeys { self.chan_keys.clone() }
+               fn get_channel_keys(&self, _inbound: bool, _channel_value_satoshis: u64) -> InMemoryChannelKeys {
+                       self.chan_keys.clone()
+               }
                fn get_onion_rand(&self) -> (SecretKey, [u8; 32]) { panic!(); }
                fn get_channel_id(&self) -> [u8; 32] { [0; 32] }
        }
@@ -4127,6 +4169,7 @@ mod tests {
                        revocation_base_key: SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
                        commitment_seed: [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff],
                        remote_channel_pubkeys: None,
+                       channel_value_satoshis: 7000000000,
                };
                assert_eq!(PublicKey::from_secret_key(&secp_ctx, chan_keys.funding_key()).serialize()[..],
                                hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);