--- /dev/null
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+//! The logic to build claims and bump in-flight transactions until confirmations.
+//!
+//! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all
+//! building, tracking, bumping and notifications functions.
+
+use bitcoin::blockdata::transaction::Transaction;
+use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
+use bitcoin::blockdata::script::Script;
+
+use bitcoin::hash_types::Txid;
+
+use bitcoin::secp256k1::{Secp256k1, Signature};
+use bitcoin::secp256k1;
+
+use ln::msgs::DecodeError;
+use ln::PaymentPreimage;
+use ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction};
+use chain::chaininterface::{FeeEstimator, BroadcasterInterface};
+use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
+use chain::keysinterface::{Sign, KeysInterface};
+use chain::package::PackageTemplate;
+use chain::package;
+use util::logger::Logger;
+use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
+use util::byte_utils;
+
+use std::collections::HashMap;
+use core::cmp;
+use core::ops::Deref;
+use core::mem::replace;
+
+const MAX_ALLOC_SIZE: usize = 64*1024;
+
+/// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
+/// transaction causing it.
+///
+/// Used to determine when the on-chain event can be considered safe from a chain reorganization.
+#[derive(PartialEq)]
+struct OnchainEventEntry {
+ txid: Txid,
+ height: u32,
+ event: OnchainEvent,
+}
+
+impl OnchainEventEntry {
+ fn confirmation_threshold(&self) -> u32 {
+ self.height + ANTI_REORG_DELAY - 1
+ }
+
+ fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
+ height >= self.confirmation_threshold()
+ }
+}
+
+/// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
+/// once they mature to enough confirmations (ANTI_REORG_DELAY)
+#[derive(PartialEq)]
+enum OnchainEvent {
+ /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
+ /// bump-txn candidate buffer.
+ Claim {
+ claim_request: Txid,
+ },
+ /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
+ /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
+ /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
+ ContentiousOutpoint {
+ package: PackageTemplate,
+ }
+}
+
+impl Readable for Option<Vec<Option<(usize, Signature)>>> {
+ fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+ match Readable::read(reader)? {
+ 0u8 => Ok(None),
+ 1u8 => {
+ let vlen: u64 = Readable::read(reader)?;
+ let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
+ for _ in 0..vlen {
+ ret.push(match Readable::read(reader)? {
+ 0u8 => None,
+ 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
+ _ => return Err(DecodeError::InvalidValue)
+ });
+ }
+ Ok(Some(ret))
+ },
+ _ => Err(DecodeError::InvalidValue),
+ }
+ }
+}
+
+impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ match self {
+ &Some(ref vec) => {
+ 1u8.write(writer)?;
+ (vec.len() as u64).write(writer)?;
+ for opt in vec.iter() {
+ match opt {
+ &Some((ref idx, ref sig)) => {
+ 1u8.write(writer)?;
+ (*idx as u64).write(writer)?;
+ sig.write(writer)?;
+ },
+ &None => 0u8.write(writer)?,
+ }
+ }
+ },
+ &None => 0u8.write(writer)?,
+ }
+ Ok(())
+ }
+}
+
+
+/// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
+/// do RBF bumping if possible.
+pub struct OnchainTxHandler<ChannelSigner: Sign> {
+ destination_script: Script,
+ holder_commitment: HolderCommitmentTransaction,
+ // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
+ // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
+ // the set of HTLCs in the HolderCommitmentTransaction.
+ holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
+ prev_holder_commitment: Option<HolderCommitmentTransaction>,
+ prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
+
+ pub(super) signer: ChannelSigner,
+ pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
+
+ // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
+ // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
+ // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
+ // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
+ // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
+ // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
+ // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
+ // we need to regenerate new claim request with reduced set of still-claimable outpoints.
+ // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
+ // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
+ // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
+ #[cfg(test)] // Used in functional_test to verify sanitization
+ pub(crate) pending_claim_requests: HashMap<Txid, PackageTemplate>,
+ #[cfg(not(test))]
+ pending_claim_requests: HashMap<Txid, PackageTemplate>,
+
+ // Used to link outpoints claimed in a connected block to a pending claim request.
+ // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
+ // Value is (pending claim request identifier, confirmation_block), identifier
+ // is txid of the initial claiming transaction and is immutable until outpoint is
+ // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
+ // block with output gets disconnected.
+ #[cfg(test)] // Used in functional_test to verify sanitization
+ pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
+ #[cfg(not(test))]
+ claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
+
+ onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
+
+ latest_height: u32,
+
+ pub(super) secp_ctx: Secp256k1<secp256k1::All>,
+}
+
+const SERIALIZATION_VERSION: u8 = 1;
+const MIN_SERIALIZATION_VERSION: u8 = 1;
+
+impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
+ pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
+
+ self.destination_script.write(writer)?;
+ self.holder_commitment.write(writer)?;
+ self.holder_htlc_sigs.write(writer)?;
+ self.prev_holder_commitment.write(writer)?;
+ self.prev_holder_htlc_sigs.write(writer)?;
+
+ self.channel_transaction_parameters.write(writer)?;
+
+ let mut key_data = VecWriter(Vec::new());
+ self.signer.write(&mut key_data)?;
+ assert!(key_data.0.len() < core::usize::MAX);
+ assert!(key_data.0.len() < core::u32::MAX as usize);
+ (key_data.0.len() as u32).write(writer)?;
+ writer.write_all(&key_data.0[..])?;
+
+ writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
+ for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
+ ancestor_claim_txid.write(writer)?;
+ request.write(writer)?;
+ }
+
+ writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
+ for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
+ outp.write(writer)?;
+ claim_and_height.0.write(writer)?;
+ claim_and_height.1.write(writer)?;
+ }
+
+ writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
+ for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
+ entry.txid.write(writer)?;
+ writer.write_all(&byte_utils::be32_to_array(entry.height))?;
+ match entry.event {
+ OnchainEvent::Claim { ref claim_request } => {
+ writer.write_all(&[0; 1])?;
+ claim_request.write(writer)?;
+ },
+ OnchainEvent::ContentiousOutpoint { ref package } => {
+ writer.write_all(&[1; 1])?;
+ package.write(writer)?;
+ }
+ }
+ }
+ self.latest_height.write(writer)?;
+
+ write_tlv_fields!(writer, {}, {});
+ Ok(())
+ }
+}
+
+impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
+ fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
+ let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
+
+ let destination_script = Readable::read(reader)?;
+
+ let holder_commitment = Readable::read(reader)?;
+ let holder_htlc_sigs = Readable::read(reader)?;
+ let prev_holder_commitment = Readable::read(reader)?;
+ let prev_holder_htlc_sigs = Readable::read(reader)?;
+
+ let channel_parameters = Readable::read(reader)?;
+
+ let keys_len: u32 = Readable::read(reader)?;
+ let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
+ while keys_data.len() != keys_len as usize {
+ // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
+ let mut data = [0; 1024];
+ let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
+ reader.read_exact(read_slice)?;
+ keys_data.extend_from_slice(read_slice);
+ }
+ let signer = keys_manager.read_chan_signer(&keys_data)?;
+
+ let pending_claim_requests_len: u64 = Readable::read(reader)?;
+ let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
+ for _ in 0..pending_claim_requests_len {
+ pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
+ }
+
+ let claimable_outpoints_len: u64 = Readable::read(reader)?;
+ let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
+ for _ in 0..claimable_outpoints_len {
+ let outpoint = Readable::read(reader)?;
+ let ancestor_claim_txid = Readable::read(reader)?;
+ let height = Readable::read(reader)?;
+ claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
+ }
+ let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
+ let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
+ for _ in 0..waiting_threshold_conf_len {
+ let txid = Readable::read(reader)?;
+ let height = Readable::read(reader)?;
+ let event = match <u8 as Readable>::read(reader)? {
+ 0 => {
+ let claim_request = Readable::read(reader)?;
+ OnchainEvent::Claim {
+ claim_request
+ }
+ },
+ 1 => {
+ let package = Readable::read(reader)?;
+ OnchainEvent::ContentiousOutpoint {
+ package
+ }
+ }
+ _ => return Err(DecodeError::InvalidValue),
+ };
+ onchain_events_awaiting_threshold_conf.push(OnchainEventEntry { txid, height, event });
+ }
+ let latest_height = Readable::read(reader)?;
+
+ read_tlv_fields!(reader, {}, {});
+
+ let mut secp_ctx = Secp256k1::new();
+ secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
+
+ Ok(OnchainTxHandler {
+ destination_script,
+ holder_commitment,
+ holder_htlc_sigs,
+ prev_holder_commitment,
+ prev_holder_htlc_sigs,
+ signer,
+ channel_transaction_parameters: channel_parameters,
+ claimable_outpoints,
+ pending_claim_requests,
+ onchain_events_awaiting_threshold_conf,
+ latest_height,
+ secp_ctx,
+ })
+ }
+}
+
+impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
+ pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
+ OnchainTxHandler {
+ destination_script,
+ holder_commitment,
+ holder_htlc_sigs: None,
+ prev_holder_commitment: None,
+ prev_holder_htlc_sigs: None,
+ signer,
+ channel_transaction_parameters: channel_parameters,
+ pending_claim_requests: HashMap::new(),
+ claimable_outpoints: HashMap::new(),
+ onchain_events_awaiting_threshold_conf: Vec::new(),
+ latest_height: 0,
+
+ secp_ctx,
+ }
+ }
+
+ /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
+ /// output detection, we generate a first version of a claim tx and associate to it a height timer. A height timer is an absolute block
+ /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
+ /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
+ /// frequency of the bump and so increase our bets of success.
+ fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
+ if timelock_expiration <= current_height + 3 {
+ return current_height + 1
+ } else if timelock_expiration - current_height <= 15 {
+ return current_height + 3
+ }
+ current_height + 15
+ }
+
+ /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
+ /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
+ /// Panics if there are signing errors, because signing operations in reaction to on-chain events
+ /// are not expected to fail, and if they do, we may lose funds.
+ fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_request: &PackageTemplate, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u64, Transaction)>
+ where F::Target: FeeEstimator,
+ L::Target: Logger,
+ {
+ if cached_request.outpoints().len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
+
+ // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
+ // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
+ let new_timer = Some(Self::get_height_timer(height, cached_request.timelock()));
+ let amt = cached_request.package_amount();
+ if cached_request.is_malleable() {
+ let predicted_weight = cached_request.package_weight(&self.destination_script);
+ if let Some((output_value, new_feerate)) = package::compute_output_value(predicted_weight, amt, cached_request.feerate(), fee_estimator, logger) {
+ assert!(new_feerate != 0);
+
+ let transaction = cached_request.finalize_package(self, output_value, self.destination_script.clone(), logger).unwrap();
+ log_trace!(logger, "...with timer {} and feerate {}", new_timer.unwrap(), new_feerate);
+ assert!(predicted_weight >= transaction.get_weight());
+ return Some((new_timer, new_feerate, transaction))
+ }
+ } else {
+ // Note: Currently, amounts of holder outputs spending witnesses aren't used
+ // as we can't malleate spending package to increase their feerate. This
+ // should change with the remaining anchor output patchset.
+ debug_assert!(amt == 0);
+ if let Some(transaction) = cached_request.finalize_package(self, amt, self.destination_script.clone(), logger) {
+ return Some((None, 0, transaction));
+ }
+ }
+ None
+ }
+
+ /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
+ /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
+ /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
+ /// if we receive a preimage after force-close.
+ pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], requests: Vec<PackageTemplate>, latest_height: Option<u32>, broadcaster: &B, fee_estimator: &F, logger: &L)
+ where B::Target: BroadcasterInterface,
+ F::Target: FeeEstimator,
+ L::Target: Logger,
+ {
+ let height = match latest_height {
+ Some(h) => h,
+ None => self.latest_height,
+ };
+ log_trace!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), requests.len());
+ let mut preprocessed_requests = Vec::with_capacity(requests.len());
+ let mut aggregated_request = None;
+
+ // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
+ // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
+ for req in requests {
+ // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
+ if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) { log_trace!(logger, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout); } else {
+ log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), height + CLTV_SHARED_CLAIM_BUFFER);
+ if req.timelock() <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
+ // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
+ preprocessed_requests.push(req);
+ } else if aggregated_request.is_none() {
+ aggregated_request = Some(req);
+ } else {
+ aggregated_request.as_mut().unwrap().merge_package(req);
+ }
+ }
+ }
+ if let Some(req) = aggregated_request {
+ preprocessed_requests.push(req);
+ }
+
+ // Generate claim transactions and track them to bump if necessary at
+ // height timer expiration (i.e in how many blocks we're going to take action).
+ for mut req in preprocessed_requests {
+ if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &req, &*fee_estimator, &*logger) {
+ req.set_timer(new_timer);
+ req.set_feerate(new_feerate);
+ let txid = tx.txid();
+ for k in req.outpoints() {
+ log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
+ self.claimable_outpoints.insert(k.clone(), (txid, height));
+ }
+ self.pending_claim_requests.insert(txid, req);
+ log_trace!(logger, "Broadcasting onchain {}", log_tx!(tx));
+ broadcaster.broadcast_transaction(&tx);
+ }
+ }
+
+ let mut bump_candidates = HashMap::new();
+ for tx in txn_matched {
+ // Scan all input to verify is one of the outpoint spent is of interest for us
+ let mut claimed_outputs_material = Vec::new();
+ for inp in &tx.input {
+ if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
+ // If outpoint has claim request pending on it...
+ if let Some(request) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
+ //... we need to verify equality between transaction outpoints and claim request
+ // outpoints to know if transaction is the original claim or a bumped one issued
+ // by us.
+ let mut set_equality = true;
+ if request.outpoints().len() != tx.input.len() {
+ set_equality = false;
+ } else {
+ for (claim_inp, tx_inp) in request.outpoints().iter().zip(tx.input.iter()) {
+ if **claim_inp != tx_inp.previous_output {
+ set_equality = false;
+ }
+ }
+ }
+
+ macro_rules! clean_claim_request_after_safety_delay {
+ () => {
+ let entry = OnchainEventEntry {
+ txid: tx.txid(),
+ height,
+ event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() }
+ };
+ if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
+ self.onchain_events_awaiting_threshold_conf.push(entry);
+ }
+ }
+ }
+
+ // If this is our transaction (or our counterparty spent all the outputs
+ // before we could anyway with same inputs order than us), wait for
+ // ANTI_REORG_DELAY and clean the RBF tracking map.
+ if set_equality {
+ clean_claim_request_after_safety_delay!();
+ } else { // If false, generate new claim request with update outpoint set
+ let mut at_least_one_drop = false;
+ for input in tx.input.iter() {
+ if let Some(package) = request.split_package(&input.previous_output) {
+ claimed_outputs_material.push(package);
+ at_least_one_drop = true;
+ }
+ // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
+ if request.outpoints().is_empty() {
+ clean_claim_request_after_safety_delay!();
+ }
+ }
+ //TODO: recompute soonest_timelock to avoid wasting a bit on fees
+ if at_least_one_drop {
+ bump_candidates.insert(first_claim_txid_height.0.clone(), request.clone());
+ }
+ }
+ break; //No need to iterate further, either tx is our or their
+ } else {
+ panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
+ }
+ }
+ }
+ for package in claimed_outputs_material.drain(..) {
+ let entry = OnchainEventEntry {
+ txid: tx.txid(),
+ height,
+ event: OnchainEvent::ContentiousOutpoint { package },
+ };
+ if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
+ self.onchain_events_awaiting_threshold_conf.push(entry);
+ }
+ }
+ }
+
+ // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
+ let onchain_events_awaiting_threshold_conf =
+ self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
+ for entry in onchain_events_awaiting_threshold_conf {
+ if entry.has_reached_confirmation_threshold(height) {
+ match entry.event {
+ OnchainEvent::Claim { claim_request } => {
+ // We may remove a whole set of claim outpoints here, as these one may have
+ // been aggregated in a single tx and claimed so atomically
+ if let Some(request) = self.pending_claim_requests.remove(&claim_request) {
+ for outpoint in request.outpoints() {
+ self.claimable_outpoints.remove(&outpoint);
+ }
+ }
+ },
+ OnchainEvent::ContentiousOutpoint { package } => {
+ self.claimable_outpoints.remove(&package.outpoints()[0]);
+ }
+ }
+ } else {
+ self.onchain_events_awaiting_threshold_conf.push(entry);
+ }
+ }
+
+ // Check if any pending claim request must be rescheduled
+ for (first_claim_txid, ref request) in self.pending_claim_requests.iter() {
+ if let Some(h) = request.timer() {
+ if height >= h {
+ bump_candidates.insert(*first_claim_txid, (*request).clone());
+ }
+ }
+ }
+
+ // Build, bump and rebroadcast tx accordingly
+ log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
+ for (first_claim_txid, request) in bump_candidates.iter() {
+ if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &request, &*fee_estimator, &*logger) {
+ log_trace!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
+ broadcaster.broadcast_transaction(&bump_tx);
+ if let Some(request) = self.pending_claim_requests.get_mut(first_claim_txid) {
+ request.set_timer(new_timer);
+ request.set_feerate(new_feerate);
+ }
+ }
+ }
+ }
+
+ pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
+ &mut self,
+ txid: &Txid,
+ broadcaster: B,
+ fee_estimator: F,
+ logger: L,
+ ) where
+ B::Target: BroadcasterInterface,
+ F::Target: FeeEstimator,
+ L::Target: Logger,
+ {
+ let mut height = None;
+ for entry in self.onchain_events_awaiting_threshold_conf.iter() {
+ if entry.txid == *txid {
+ height = Some(entry.height);
+ break;
+ }
+ }
+
+ if let Some(height) = height {
+ self.block_disconnected(height, broadcaster, fee_estimator, logger);
+ }
+ }
+
+ pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
+ where B::Target: BroadcasterInterface,
+ F::Target: FeeEstimator,
+ L::Target: Logger,
+ {
+ let mut bump_candidates = HashMap::new();
+ let onchain_events_awaiting_threshold_conf =
+ self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
+ for entry in onchain_events_awaiting_threshold_conf {
+ if entry.height >= height {
+ //- our claim tx on a commitment tx output
+ //- resurect outpoint back in its claimable set and regenerate tx
+ match entry.event {
+ OnchainEvent::ContentiousOutpoint { package } => {
+ if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&package.outpoints()[0]) {
+ if let Some(request) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
+ request.merge_package(package);
+ // Using a HashMap guarantee us than if we have multiple outpoints getting
+ // resurrected only one bump claim tx is going to be broadcast
+ bump_candidates.insert(ancestor_claimable_txid.clone(), request.clone());
+ }
+ }
+ },
+ _ => {},
+ }
+ } else {
+ self.onchain_events_awaiting_threshold_conf.push(entry);
+ }
+ }
+ for (_, request) in bump_candidates.iter_mut() {
+ if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &request, &&*fee_estimator, &&*logger) {
+ request.set_timer(new_timer);
+ request.set_feerate(new_feerate);
+ log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
+ broadcaster.broadcast_transaction(&bump_tx);
+ }
+ }
+ for (ancestor_claim_txid, request) in bump_candidates.drain() {
+ self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
+ }
+ //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
+ // right now if one of the outpoint get disconnected, just erase whole pending claim request.
+ let mut remove_request = Vec::new();
+ self.claimable_outpoints.retain(|_, ref v|
+ if v.1 >= height {
+ remove_request.push(v.0.clone());
+ false
+ } else { true });
+ for req in remove_request {
+ self.pending_claim_requests.remove(&req);
+ }
+ }
+
+ pub(crate) fn get_relevant_txids(&self) -> Vec<Txid> {
+ let mut txids: Vec<Txid> = self.onchain_events_awaiting_threshold_conf
+ .iter()
+ .map(|entry| entry.txid)
+ .collect();
+ txids.sort_unstable();
+ txids.dedup();
+ txids
+ }
+
+ pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
+ self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
+ self.holder_htlc_sigs = None;
+ }
+
+ // Normally holder HTLCs are signed at the same time as the holder commitment tx. However,
+ // in some configurations, the holder commitment tx has been signed and broadcast by a
+ // ChannelMonitor replica, so we handle that case here.
+ fn sign_latest_holder_htlcs(&mut self) {
+ if self.holder_htlc_sigs.is_none() {
+ let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
+ self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
+ }
+ }
+
+ // Normally only the latest commitment tx and HTLCs need to be signed. However, in some
+ // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
+ // broadcast the previous one before we sync with it. We handle that case here.
+ fn sign_prev_holder_htlcs(&mut self) {
+ if self.prev_holder_htlc_sigs.is_none() {
+ if let Some(ref holder_commitment) = self.prev_holder_commitment {
+ let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
+ self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
+ }
+ }
+ }
+
+ fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
+ let mut ret = Vec::new();
+ for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
+ let tx_idx = htlc.transaction_output_index.unwrap();
+ if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
+ ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
+ }
+ ret
+ }
+
+ //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
+ // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
+ // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
+ // to monitor before.
+ pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
+ let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
+ self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
+ self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
+ }
+
+ #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
+ pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
+ let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
+ self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
+ self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
+ }
+
+ pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
+ let mut htlc_tx = None;
+ let commitment_txid = self.holder_commitment.trust().txid();
+ // Check if the HTLC spends from the current holder commitment
+ if commitment_txid == outp.txid {
+ self.sign_latest_holder_htlcs();
+ if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
+ let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
+ let trusted_tx = self.holder_commitment.trust();
+ let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
+ htlc_tx = Some(trusted_tx
+ .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
+ }
+ }
+ // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
+ if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
+ let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
+ if commitment_txid == outp.txid {
+ self.sign_prev_holder_htlcs();
+ if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
+ let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
+ let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
+ let trusted_tx = holder_commitment.trust();
+ let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
+ htlc_tx = Some(trusted_tx
+ .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
+ }
+ }
+ }
+ htlc_tx
+ }
+
+ #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
+ pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
+ let latest_had_sigs = self.holder_htlc_sigs.is_some();
+ let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
+ let ret = self.get_fully_signed_htlc_tx(outp, preimage);
+ if !latest_had_sigs {
+ self.holder_htlc_sigs = None;
+ }
+ if !prev_had_sigs {
+ self.prev_holder_htlc_sigs = None;
+ }
+ ret
+ }
+}
projects / rust-lightning / blobdiff