Generate shutdown script at channel close
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index 42c3e13a34feeff236a1b19712470808f0b19f69..6c11703d3158fc86567a49b2c81d771a1b8517b0 100644 (file)
@@ -53,9 +53,9 @@ use util::events::Event;
 
 use prelude::*;
 use core::{cmp, mem};
-use std::io::Error;
+use io::{self, Error};
 use core::ops::Deref;
-use std::sync::Mutex;
+use sync::Mutex;
 
 /// An update generated by the underlying Channel itself which contains some new information the
 /// ChannelMonitor should be made aware of.
@@ -88,7 +88,7 @@ pub struct ChannelMonitorUpdate {
 pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
 
 impl Writeable for ChannelMonitorUpdate {
-       fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                write_ver_prefix!(w, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
                self.update_id.write(w)?;
                (self.updates.len() as u64).write(w)?;
@@ -100,7 +100,7 @@ impl Writeable for ChannelMonitorUpdate {
        }
 }
 impl Readable for ChannelMonitorUpdate {
-       fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+       fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
                let _ver = read_ver_prefix!(r, SERIALIZATION_VERSION);
                let update_id: u64 = Readable::read(r)?;
                let len: u64 = Readable::read(r)?;
@@ -199,10 +199,12 @@ pub enum MonitorEvent {
 pub struct HTLCUpdate {
        pub(crate) payment_hash: PaymentHash,
        pub(crate) payment_preimage: Option<PaymentPreimage>,
-       pub(crate) source: HTLCSource
+       pub(crate) source: HTLCSource,
+       pub(crate) onchain_value_satoshis: Option<u64>,
 }
 impl_writeable_tlv_based!(HTLCUpdate, {
        (0, payment_hash, required),
+       (1, onchain_value_satoshis, option),
        (2, source, required),
        (4, payment_preimage, option),
 });
@@ -293,7 +295,7 @@ struct CounterpartyCommitmentTransaction {
 }
 
 impl Writeable for CounterpartyCommitmentTransaction {
-       fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                w.write_all(&byte_utils::be64_to_array(self.per_htlc.len() as u64))?;
                for (ref txid, ref htlcs) in self.per_htlc.iter() {
                        w.write_all(&txid[..])?;
@@ -311,7 +313,7 @@ impl Writeable for CounterpartyCommitmentTransaction {
        }
 }
 impl Readable for CounterpartyCommitmentTransaction {
-       fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+       fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
                let counterparty_commitment_transaction = {
                        let per_htlc_len: u64 = Readable::read(r)?;
                        let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
@@ -385,6 +387,7 @@ enum OnchainEvent {
        HTLCUpdate {
                source: HTLCSource,
                payment_hash: PaymentHash,
+               onchain_value_satoshis: Option<u64>,
        },
        MaturingOutput {
                descriptor: SpendableOutputDescriptor,
@@ -400,6 +403,7 @@ impl_writeable_tlv_based!(OnchainEventEntry, {
 impl_writeable_tlv_based_enum!(OnchainEvent,
        (0, HTLCUpdate) => {
                (0, source, required),
+               (1, onchain_value_satoshis, option),
                (2, payment_hash, required),
        },
        (1, MaturingOutput) => {
@@ -434,6 +438,9 @@ pub(crate) enum ChannelMonitorUpdateStep {
                /// think we've fallen behind!
                should_broadcast: bool,
        },
+       ShutdownScript {
+               scriptpubkey: Script,
+       },
 }
 
 impl_writeable_tlv_based_enum!(ChannelMonitorUpdateStep,
@@ -457,6 +464,9 @@ impl_writeable_tlv_based_enum!(ChannelMonitorUpdateStep,
        (4, ChannelForceClosed) => {
                (0, should_broadcast, required),
        },
+       (5, ShutdownScript) => {
+               (0, scriptpubkey, required),
+       },
 ;);
 
 /// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
@@ -489,7 +499,7 @@ pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
        destination_script: Script,
        broadcasted_holder_revokable_script: Option<(Script, PublicKey, PublicKey)>,
        counterparty_payment_script: Script,
-       shutdown_script: Script,
+       shutdown_script: Option<Script>,
 
        channel_keys_id: [u8; 32],
        holder_revocation_basepoint: PublicKey,
@@ -665,7 +675,10 @@ impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
                }
 
                self.counterparty_payment_script.write(writer)?;
-               self.shutdown_script.write(writer)?;
+               match &self.shutdown_script {
+                       Some(script) => script.write(writer)?,
+                       None => Script::new().write(writer)?,
+               }
 
                self.channel_keys_id.write(writer)?;
                self.holder_revocation_basepoint.write(writer)?;
@@ -795,7 +808,7 @@ impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
 }
 
 impl<Signer: Sign> ChannelMonitor<Signer> {
-       pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_pubkey: &PublicKey,
+       pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
                          on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
                          channel_parameters: &ChannelTransactionParameters,
                          funding_redeemscript: Script, channel_value_satoshis: u64,
@@ -804,8 +817,6 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                          best_block: BestBlock) -> ChannelMonitor<Signer> {
 
                assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
-               let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
-               let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
                let payment_key_hash = WPubkeyHash::hash(&keys.pubkeys().payment_point.serialize());
                let counterparty_payment_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_key_hash[..]).into_script();
 
@@ -1432,7 +1443,13 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                // shouldn't print the scary warning above.
                                                log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
                                        }
-                               }
+                               },
+                               ChannelMonitorUpdateStep::ShutdownScript { scriptpubkey } => {
+                                       log_trace!(logger, "Updating ChannelMonitor with shutdown script");
+                                       if let Some(shutdown_script) = self.shutdown_script.replace(scriptpubkey.clone()) {
+                                               panic!("Attempted to replace shutdown script {} with {}", shutdown_script, scriptpubkey);
+                                       }
+                               },
                        }
                }
                self.latest_update_id = updates.update_id;
@@ -1574,6 +1591,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                                                event: OnchainEvent::HTLCUpdate {
                                                                                        source: (**source).clone(),
                                                                                        payment_hash: htlc.payment_hash.clone(),
+                                                                                       onchain_value_satoshis: Some(htlc.amount_msat / 1000),
                                                                                },
                                                                        };
                                                                        log_info!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of revoked counterparty commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, entry.confirmation_threshold());
@@ -1641,6 +1659,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                                        event: OnchainEvent::HTLCUpdate {
                                                                                source: (**source).clone(),
                                                                                payment_hash: htlc.payment_hash.clone(),
+                                                                               onchain_value_satoshis: Some(htlc.amount_msat / 1000),
                                                                        },
                                                                });
                                                        }
@@ -1779,27 +1798,6 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                let mut claim_requests = Vec::new();
                let mut watch_outputs = Vec::new();
 
-               macro_rules! wait_threshold_conf {
-                       ($source: expr, $commitment_tx: expr, $payment_hash: expr) => {
-                               self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
-                                       if entry.height != height { return true; }
-                                       match entry.event {
-                                               OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
-                                                       *update_source != $source
-                                               },
-                                               _ => true,
-                                       }
-                               });
-                               let entry = OnchainEventEntry {
-                                       txid: commitment_txid,
-                                       height,
-                                       event: OnchainEvent::HTLCUpdate { source: $source, payment_hash: $payment_hash },
-                               };
-                               log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, entry.confirmation_threshold());
-                               self.onchain_events_awaiting_threshold_conf.push(entry);
-                       }
-               }
-
                macro_rules! append_onchain_update {
                        ($updates: expr, $to_watch: expr) => {
                                claim_requests = $updates.0;
@@ -1828,11 +1826,30 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                }
 
                macro_rules! fail_dust_htlcs_after_threshold_conf {
-                       ($holder_tx: expr) => {
+                       ($holder_tx: expr, $commitment_tx: expr) => {
                                for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
                                        if htlc.transaction_output_index.is_none() {
                                                if let &Some(ref source) = source {
-                                                       wait_threshold_conf!(source.clone(), "lastest", htlc.payment_hash.clone());
+                                                       self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
+                                                               if entry.height != height { return true; }
+                                                               match entry.event {
+                                                                       OnchainEvent::HTLCUpdate { source: ref update_source, .. } => {
+                                                                               update_source != source
+                                                                       },
+                                                                       _ => true,
+                                                               }
+                                                       });
+                                                       let entry = OnchainEventEntry {
+                                                               txid: commitment_txid,
+                                                               height,
+                                                               event: OnchainEvent::HTLCUpdate {
+                                                                       source: source.clone(), payment_hash: htlc.payment_hash,
+                                                                       onchain_value_satoshis: Some(htlc.amount_msat / 1000)
+                                                               },
+                                                       };
+                                                       log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})",
+                                                               log_bytes!(htlc.payment_hash.0), $commitment_tx, entry.confirmation_threshold());
+                                                       self.onchain_events_awaiting_threshold_conf.push(entry);
                                                }
                                        }
                                }
@@ -1840,9 +1857,9 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                }
 
                if is_holder_tx {
-                       fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx);
+                       fail_dust_htlcs_after_threshold_conf!(self.current_holder_commitment_tx, "latest");
                        if let &Some(ref holder_tx) = &self.prev_holder_signed_commitment_tx {
-                               fail_dust_htlcs_after_threshold_conf!(holder_tx);
+                               fail_dust_htlcs_after_threshold_conf!(holder_tx, "previous");
                        }
                }
 
@@ -2090,7 +2107,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                // Produce actionable events from on-chain events having reached their threshold.
                for entry in onchain_events_reaching_threshold_conf.drain(..) {
                        match entry.event {
-                               OnchainEvent::HTLCUpdate { ref source, payment_hash } => {
+                               OnchainEvent::HTLCUpdate { ref source, payment_hash, onchain_value_satoshis } => {
                                        // Check for duplicate HTLC resolutions.
                                        #[cfg(debug_assertions)]
                                        {
@@ -2109,9 +2126,10 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
 
                                        log_debug!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!(payment_hash.0));
                                        self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
-                                               payment_hash: payment_hash,
+                                               payment_hash,
                                                payment_preimage: None,
                                                source: source.clone(),
+                                               onchain_value_satoshis,
                                        }));
                                },
                                OnchainEvent::MaturingOutput { descriptor } => {
@@ -2328,7 +2346,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                        if pending_htlc.payment_hash == $htlc_output.payment_hash && pending_htlc.amount_msat == $htlc_output.amount_msat {
                                                                if let &Some(ref source) = pending_source {
                                                                        log_claim!("revoked counterparty commitment tx", false, pending_htlc, true);
-                                                                       payment_data = Some(((**source).clone(), $htlc_output.payment_hash));
+                                                                       payment_data = Some(((**source).clone(), $htlc_output.payment_hash, $htlc_output.amount_msat));
                                                                        break;
                                                                }
                                                        }
@@ -2348,7 +2366,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                                // transaction. This implies we either learned a preimage, the HTLC
                                                                // has timed out, or we screwed up. In any case, we should now
                                                                // resolve the source HTLC with the original sender.
-                                                               payment_data = Some(((*source).clone(), htlc_output.payment_hash));
+                                                               payment_data = Some(((*source).clone(), htlc_output.payment_hash, htlc_output.amount_msat));
                                                        } else if !$holder_tx {
                                                                        check_htlc_valid_counterparty!(self.current_counterparty_commitment_txid, htlc_output);
                                                                if payment_data.is_none() {
@@ -2381,7 +2399,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
 
                        // Check that scan_commitment, above, decided there is some source worth relaying an
                        // HTLC resolution backwards to and figure out whether we learned a preimage from it.
-                       if let Some((source, payment_hash)) = payment_data {
+                       if let Some((source, payment_hash, amount_msat)) = payment_data {
                                let mut payment_preimage = PaymentPreimage([0; 32]);
                                if accepted_preimage_claim {
                                        if !self.pending_monitor_events.iter().any(
@@ -2390,7 +2408,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
                                                        source,
                                                        payment_preimage: Some(payment_preimage),
-                                                       payment_hash
+                                                       payment_hash,
+                                                       onchain_value_satoshis: Some(amount_msat / 1000),
                                                }));
                                        }
                                } else if offered_preimage_claim {
@@ -2402,7 +2421,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
                                                        source,
                                                        payment_preimage: Some(payment_preimage),
-                                                       payment_hash
+                                                       payment_hash,
+                                                       onchain_value_satoshis: Some(amount_msat / 1000),
                                                }));
                                        }
                                } else {
@@ -2418,7 +2438,10 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        let entry = OnchainEventEntry {
                                                txid: tx.txid(),
                                                height,
-                                               event: OnchainEvent::HTLCUpdate { source: source, payment_hash: payment_hash },
+                                               event: OnchainEvent::HTLCUpdate {
+                                                       source, payment_hash,
+                                                       onchain_value_satoshis: Some(amount_msat / 1000),
+                                               },
                                        };
                                        log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height {})", log_bytes!(payment_hash.0), entry.confirmation_threshold());
                                        self.onchain_events_awaiting_threshold_conf.push(entry);
@@ -2451,7 +2474,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        output: outp.clone(),
                                });
                                break;
-                       } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
+                       }
+                       if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
                                if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
                                        spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
                                                outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
@@ -2464,7 +2488,8 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        }));
                                        break;
                                }
-                       } else if self.counterparty_payment_script == outp.script_pubkey {
+                       }
+                       if self.counterparty_payment_script == outp.script_pubkey {
                                spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
                                        outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
                                        output: outp.clone(),
@@ -2472,11 +2497,13 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        channel_value_satoshis: self.channel_value_satoshis,
                                }));
                                break;
-                       } else if outp.script_pubkey == self.shutdown_script {
+                       }
+                       if self.shutdown_script.as_ref() == Some(&outp.script_pubkey) {
                                spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
                                        outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
                                        output: outp.clone(),
                                });
+                               break;
                        }
                }
                if let Some(spendable_output) = spendable_output {
@@ -2581,7 +2608,7 @@ const MAX_ALLOC_SIZE: usize = 64*1024;
 
 impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
                for (BlockHash, ChannelMonitor<Signer>) {
-       fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
+       fn read<R: io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
                macro_rules! unwrap_obj {
                        ($key: expr) => {
                                match $key {
@@ -2608,7 +2635,10 @@ impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
                        _ => return Err(DecodeError::InvalidValue),
                };
                let counterparty_payment_script = Readable::read(reader)?;
-               let shutdown_script = Readable::read(reader)?;
+               let shutdown_script = {
+                       let script = <Script as Readable>::read(reader)?;
+                       if script.is_empty() { None } else { Some(script) }
+               };
 
                let channel_keys_id = Readable::read(reader)?;
                let holder_revocation_basepoint = Readable::read(reader)?;
@@ -2840,10 +2870,11 @@ mod tests {
        use ln::{PaymentPreimage, PaymentHash};
        use ln::chan_utils;
        use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
+       use ln::script::ShutdownScript;
        use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};
        use bitcoin::secp256k1::key::{SecretKey,PublicKey};
        use bitcoin::secp256k1::Secp256k1;
-       use std::sync::{Arc, Mutex};
+       use sync::{Arc, Mutex};
        use chain::keysinterface::InMemorySigner;
        use prelude::*;
 
@@ -2852,7 +2883,7 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let logger = Arc::new(TestLogger::new());
                let broadcaster = Arc::new(TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
-               let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: 253 });
+               let fee_estimator = Arc::new(TestFeeEstimator { sat_per_kw: Mutex::new(253) });
 
                let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let dummy_tx = Transaction { version: 0, lock_time: 0, input: Vec::new(), output: Vec::new() };
@@ -2933,9 +2964,10 @@ mod tests {
                };
                // Prune with one old state and a holder commitment tx holding a few overlaps with the
                // old state.
+               let shutdown_pubkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let best_block = BestBlock::from_genesis(Network::Testnet);
                let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
-                                                 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
+                                                 Some(ShutdownScript::new_p2wpkh_from_pubkey(shutdown_pubkey).into_inner()), 0, &Script::new(),
                                                  (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
                                                  &channel_parameters,
                                                  Script::new(), 46, 0,