X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fonchaintx.rs;h=039fb5ff13a04eb1fd843d061bbd992a0f394935;hb=9f41bd7f6492ca146a852c779f072d5b87581fed;hp=8f62c43c44e5a41b7229e004c13a4d7840cdf1ff;hpb=4005724ae6719594e42d11718ce9b83fa0641f3b;p=rust-lightning diff --git a/lightning/src/chain/onchaintx.rs b/lightning/src/chain/onchaintx.rs index 8f62c43c..039fb5ff 100644 --- a/lightning/src/chain/onchaintx.rs +++ b/lightning/src/chain/onchaintx.rs @@ -16,28 +16,36 @@ use bitcoin::blockdata::transaction::Transaction; use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint; use bitcoin::blockdata::script::Script; -use bitcoin::hash_types::Txid; +use bitcoin::hash_types::{Txid, BlockHash}; use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature}; use bitcoin::secp256k1; -use ln::msgs::DecodeError; -use ln::PaymentPreimage; -use ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction}; -use chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator}; -use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER}; -use chain::keysinterface::{Sign, KeysInterface}; -use chain::package::PackageTemplate; -use util::logger::Logger; -use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter}; -use util::byte_utils; - -use io; -use prelude::*; +use crate::chain::keysinterface::{ChannelSigner, EntropySource, SignerProvider}; +use crate::ln::msgs::DecodeError; +use crate::ln::PaymentPreimage; +#[cfg(anchors)] +use crate::ln::chan_utils::{self, HTLCOutputInCommitment}; +use crate::ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction}; +#[cfg(anchors)] +use crate::chain::chaininterface::ConfirmationTarget; +use crate::chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator}; +use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER}; +use crate::chain::keysinterface::WriteableEcdsaChannelSigner; +#[cfg(anchors)] +use crate::chain::package::PackageSolvingData; +use crate::chain::package::PackageTemplate; +use crate::util::logger::Logger; +use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter}; + +use crate::io; +use crate::prelude::*; use alloc::collections::BTreeMap; use core::cmp; use core::ops::Deref; use core::mem::replace; +#[cfg(anchors)] +use core::mem::swap; use bitcoin::hashes::Hash; const MAX_ALLOC_SIZE: usize = 64*1024; @@ -46,10 +54,11 @@ const MAX_ALLOC_SIZE: usize = 64*1024; /// transaction causing it. /// /// Used to determine when the on-chain event can be considered safe from a chain reorganization. -#[derive(PartialEq)] +#[derive(PartialEq, Eq)] struct OnchainEventEntry { txid: Txid, height: u32, + block_hash: Option, // Added as optional, will be filled in for any entry generated on 0.0.113 or after event: OnchainEvent, } @@ -65,12 +74,12 @@ impl OnchainEventEntry { /// 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)] +#[derive(PartialEq, Eq)] 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, + package_id: PackageID, }, /// 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 @@ -84,6 +93,7 @@ impl Writeable for OnchainEventEntry { fn write(&self, writer: &mut W) -> Result<(), io::Error> { write_tlv_fields!(writer, { (0, self.txid, required), + (1, self.block_hash, option), (2, self.height, required), (4, self.event, required), }); @@ -95,14 +105,16 @@ impl MaybeReadable for OnchainEventEntry { fn read(reader: &mut R) -> Result, DecodeError> { let mut txid = Txid::all_zeros(); let mut height = 0; + let mut block_hash = None; let mut event = None; read_tlv_fields!(reader, { (0, txid, required), + (1, block_hash, option), (2, height, required), (4, event, ignorable), }); if let Some(ev) = event { - Ok(Some(Self { txid, height, event: ev })) + Ok(Some(Self { txid, height, block_hash, event: ev })) } else { Ok(None) } @@ -111,7 +123,7 @@ impl MaybeReadable for OnchainEventEntry { impl_writeable_tlv_based_enum_upgradable!(OnchainEvent, (0, Claim) => { - (0, claim_request, required), + (0, package_id, required), }, (1, ContentiousOutpoint) => { (0, package, required), @@ -162,10 +174,53 @@ impl Writeable for Option>> { } } +#[cfg(anchors)] +/// The claim commonly referred to as the pre-signed second-stage HTLC transaction. +pub(crate) struct ExternalHTLCClaim { + pub(crate) commitment_txid: Txid, + pub(crate) per_commitment_number: u64, + pub(crate) htlc: HTLCOutputInCommitment, + pub(crate) preimage: Option, + pub(crate) counterparty_sig: Signature, +} + +// Represents the different types of claims for which events are yielded externally to satisfy said +// claims. +#[cfg(anchors)] +pub(crate) enum ClaimEvent { + /// Event yielded to signal that the commitment transaction fee must be bumped to claim any + /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist. + BumpCommitment { + package_target_feerate_sat_per_1000_weight: u32, + commitment_tx: Transaction, + anchor_output_idx: u32, + }, + /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be + /// resolved by broadcasting a transaction with sufficient fee to claim them. + BumpHTLC { + target_feerate_sat_per_1000_weight: u32, + htlcs: Vec, + }, +} + +/// Represents the different ways an output can be claimed (i.e., spent to an address under our +/// control) onchain. +pub(crate) enum OnchainClaim { + /// A finalized transaction pending confirmation spending the output to claim. + Tx(Transaction), + #[cfg(anchors)] + /// An event yielded externally to signal additional inputs must be added to a transaction + /// pending confirmation spending the output to claim. + Event(ClaimEvent), +} + +/// An internal identifier to track pending package claims within the `OnchainTxHandler`. +type PackageID = [u8; 32]; /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and /// do RBF bumping if possible. -pub struct OnchainTxHandler { +#[derive(PartialEq)] +pub struct OnchainTxHandler { destination_script: Script, holder_commitment: HolderCommitmentTransaction, // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment @@ -190,9 +245,11 @@ pub struct OnchainTxHandler { // 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, + pub(crate) pending_claim_requests: HashMap, #[cfg(not(test))] - pending_claim_requests: HashMap, + pending_claim_requests: HashMap, + #[cfg(anchors)] + pending_claim_events: HashMap, // 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 @@ -201,9 +258,9 @@ pub struct OnchainTxHandler { // 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, + pub claimable_outpoints: HashMap, #[cfg(not(test))] - claimable_outpoints: HashMap, + claimable_outpoints: HashMap, locktimed_packages: BTreeMap>, @@ -215,7 +272,7 @@ pub struct OnchainTxHandler { const SERIALIZATION_VERSION: u8 = 1; const MIN_SERIALIZATION_VERSION: u8 = 1; -impl OnchainTxHandler { +impl OnchainTxHandler { pub(crate) fn write(&self, writer: &mut W) -> Result<(), io::Error> { write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION); @@ -234,29 +291,29 @@ impl OnchainTxHandler { (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))?; + writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?; 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))?; + writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?; 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.locktimed_packages.len() as u64))?; + writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?; for (ref locktime, ref packages) in self.locktimed_packages.iter() { locktime.write(writer)?; - writer.write_all(&byte_utils::be64_to_array(packages.len() as u64))?; + writer.write_all(&(packages.len() as u64).to_be_bytes())?; for ref package in packages.iter() { package.write(writer)?; } } - writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?; + writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?; for ref entry in self.onchain_events_awaiting_threshold_conf.iter() { entry.write(writer)?; } @@ -266,8 +323,13 @@ impl OnchainTxHandler { } } -impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler { - fn read(reader: &mut R, keys_manager: &'a K) -> Result { +impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler { + fn read(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result { + let entropy_source = args.0; + let signer_provider = args.1; + let channel_value_satoshis = args.2; + let channel_keys_id = args.3; + let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION); let destination_script = Readable::read(reader)?; @@ -279,16 +341,21 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler { let channel_parameters = Readable::read(reader)?; + // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer + // by re-deriving the private key material. 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 { + let mut bytes_read = 0; + while bytes_read != 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())]; + let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read); + let read_slice = &mut data[0..bytes_to_read]; reader.read_exact(read_slice)?; - keys_data.extend_from_slice(read_slice); + bytes_read += bytes_to_read; } - let signer = keys_manager.read_chan_signer(&keys_data)?; + + let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id); + signer.provide_channel_parameters(&channel_parameters); 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)); @@ -328,7 +395,7 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler { read_tlv_fields!(reader, {}); let mut secp_ctx = Secp256k1::new(); - secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes()); + secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes()); Ok(OnchainTxHandler { destination_script, @@ -342,12 +409,14 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler { locktimed_packages, pending_claim_requests, onchain_events_awaiting_threshold_conf, + #[cfg(anchors)] + pending_claim_events: HashMap::new(), secp_ctx, }) } } -impl OnchainTxHandler { +impl OnchainTxHandler { pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1) -> Self { OnchainTxHandler { destination_script, @@ -361,6 +430,8 @@ impl OnchainTxHandler { claimable_outpoints: HashMap::new(), locktimed_packages: BTreeMap::new(), onchain_events_awaiting_threshold_conf: Vec::new(), + #[cfg(anchors)] + pending_claim_events: HashMap::new(), secp_ctx, } @@ -374,54 +445,175 @@ impl OnchainTxHandler { self.holder_commitment.to_broadcaster_value_sat() } - /// 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(&mut self, cur_height: u32, cached_request: &PackageTemplate, fee_estimator: &LowerBoundedFeeEstimator, logger: &L) -> Option<(Option, u64, Transaction)> + #[cfg(anchors)] + pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec { + let mut ret = HashMap::new(); + swap(&mut ret, &mut self.pending_claim_events); + ret.into_iter().map(|(_, event)| event).collect::>() + } + + /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty + /// 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 get 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(&mut self, cur_height: u32, cached_request: &PackageTemplate, fee_estimator: &LowerBoundedFeeEstimator, logger: &L) -> Option<(Option, u64, OnchainClaim)> 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 + let request_outpoints = cached_request.outpoints(); + if request_outpoints.is_empty() { + // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable + // packages cannot be aggregated and will never be split, so we cannot end up with an + // empty claim. + debug_assert!(cached_request.is_malleable()); + return None; + } + // If we've seen transaction inclusion in the chain for all outpoints in our request, we + // don't need to continue generating more claims. We'll keep tracking the request to fully + // remove it once it reaches the confirmation threshold, or to generate a new claim if the + // transaction is reorged out. + let mut all_inputs_have_confirmed_spend = true; + for outpoint in request_outpoints.iter() { + if let Some(first_claim_txid_height) = self.claimable_outpoints.get(*outpoint) { + // We check for outpoint spends within claims individually rather than as a set + // since requests can have outpoints split off. + if !self.onchain_events_awaiting_threshold_conf.iter() + .any(|event_entry| if let OnchainEvent::Claim { package_id } = event_entry.event { + first_claim_txid_height.0 == package_id + } else { + // The onchain event is not a claim, keep seeking until we find one. + false + }) + { + // Either we had no `OnchainEvent::Claim`, or we did but none matched the + // outpoint's registered spend. + all_inputs_have_confirmed_spend = false; + } + } else { + // The request's outpoint spend does not exist yet. + all_inputs_have_confirmed_spend = false; + } + } + if all_inputs_have_confirmed_spend { + return None; + } // 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(cached_request.get_height_timer(cur_height)); if cached_request.is_malleable() { - let predicted_weight = cached_request.package_weight(&self.destination_script, self.channel_transaction_parameters.opt_anchors.is_some()); - if let Some((output_value, new_feerate)) = - cached_request.compute_package_output(predicted_weight, self.destination_script.dust_value().to_sat(), fee_estimator, logger) { + #[cfg(anchors)] + { // Attributes are not allowed on if expressions on our current MSRV of 1.41. + if cached_request.requires_external_funding() { + let target_feerate_sat_per_1000_weight = cached_request + .compute_package_feerate(fee_estimator, ConfirmationTarget::HighPriority); + if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) { + return Some(( + new_timer, + target_feerate_sat_per_1000_weight as u64, + OnchainClaim::Event(ClaimEvent::BumpHTLC { + target_feerate_sat_per_1000_weight, + htlcs, + }), + )); + } else { + return None; + } + } + } + + let predicted_weight = cached_request.package_weight(&self.destination_script); + if let Some((output_value, new_feerate)) = cached_request.compute_package_output( + predicted_weight, self.destination_script.dust_value().to_sat(), fee_estimator, logger, + ) { assert!(new_feerate != 0); - let transaction = cached_request.finalize_package(self, output_value, self.destination_script.clone(), logger).unwrap(); + let transaction = cached_request.finalize_malleable_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.weight()); - return Some((new_timer, new_feerate, transaction)) + return Some((new_timer, new_feerate, OnchainClaim::Tx(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. - if let Some(transaction) = cached_request.finalize_package(self, 0, self.destination_script.clone(), logger) { - return Some((None, 0, transaction)); + // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some + // packages may support fee bumping through Child-Pays-For-Parent, indicated by those + // which require external funding. + #[cfg(not(anchors))] + let inputs = cached_request.inputs(); + #[cfg(anchors)] + let mut inputs = cached_request.inputs(); + debug_assert_eq!(inputs.len(), 1); + let tx = match cached_request.finalize_untractable_package(self, logger) { + Some(tx) => tx, + None => return None, + }; + if !cached_request.requires_external_funding() { + return Some((None, 0, OnchainClaim::Tx(tx))); } + #[cfg(anchors)] + return inputs.find_map(|input| match input { + // Commitment inputs with anchors support are the only untractable inputs supported + // thus far that require external funding. + PackageSolvingData::HolderFundingOutput(..) => { + debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(), + "Holder commitment transaction mismatch"); + // We'll locate an anchor output we can spend within the commitment transaction. + let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey; + match chan_utils::get_anchor_output(&tx, funding_pubkey) { + // An anchor output was found, so we should yield a funding event externally. + Some((idx, _)) => { + // TODO: Use a lower confirmation target when both our and the + // counterparty's latest commitment don't have any HTLCs present. + let conf_target = ConfirmationTarget::HighPriority; + let package_target_feerate_sat_per_1000_weight = cached_request + .compute_package_feerate(fee_estimator, conf_target); + Some(( + new_timer, + package_target_feerate_sat_per_1000_weight as u64, + OnchainClaim::Event(ClaimEvent::BumpCommitment { + package_target_feerate_sat_per_1000_weight, + commitment_tx: tx.clone(), + anchor_output_idx: idx, + }), + )) + }, + // An anchor output was not found. There's nothing we can do other than + // attempt to broadcast the transaction with its current fee rate and hope + // it confirms. This is essentially the same behavior as a commitment + // transaction without anchor outputs. + None => Some((None, 0, OnchainClaim::Tx(tx.clone()))), + } + }, + _ => { + debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding"); + None + }, + }) } 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. - /// `conf_height` represents the height at which the transactions in `txn_matched` were - /// confirmed. This does not need to equal the current blockchain tip height, which should be - /// provided via `cur_height`, however it must never be higher than `cur_height`. - pub(crate) fn update_claims_view(&mut self, txn_matched: &[&Transaction], requests: Vec, conf_height: u32, cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator, logger: &L) - where B::Target: BroadcasterInterface, - F::Target: FeeEstimator, - L::Target: Logger, + /// Together with `update_claims_view_from_matched_txn` this used to be named + /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a + /// preimage after force-close. + /// + /// `conf_height` represents the height at which the request was generated. This + /// does not need to equal the current blockchain tip height, which should be provided via + /// `cur_height`, however it must never be higher than `cur_height`. + pub(crate) fn update_claims_view_from_requests( + &mut self, requests: Vec, conf_height: u32, cur_height: u32, + broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator, logger: &L + ) where + B::Target: BroadcasterInterface, + F::Target: FeeEstimator, + L::Target: Logger, { - log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {} and {} claim requests", cur_height, txn_matched.len(), conf_height, requests.len()); + log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len()); let mut preprocessed_requests = Vec::with_capacity(requests.len()); let mut aggregated_request = None; @@ -475,20 +667,62 @@ impl OnchainTxHandler { // 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(cur_height, &req, &*fee_estimator, &*logger) { + if let Some((new_timer, new_feerate, claim)) = self.generate_claim(cur_height, &req, &*fee_estimator, &*logger) { req.set_timer(new_timer); req.set_feerate(new_feerate); - let txid = tx.txid(); + let package_id = match claim { + OnchainClaim::Tx(tx) => { + log_info!(logger, "Broadcasting onchain {}", log_tx!(tx)); + broadcaster.broadcast_transaction(&tx); + tx.txid().into_inner() + }, + #[cfg(anchors)] + OnchainClaim::Event(claim_event) => { + log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints()); + let package_id = match claim_event { + ClaimEvent::BumpCommitment { ref commitment_tx, .. } => commitment_tx.txid().into_inner(), + ClaimEvent::BumpHTLC { ref htlcs, .. } => { + // Use the same construction as a lightning channel id to generate + // the package id for this request based on the first HTLC. It + // doesn't matter what we use as long as it's unique per request. + let mut package_id = [0; 32]; + package_id[..].copy_from_slice(&htlcs[0].commitment_txid[..]); + let htlc_output_index = htlcs[0].htlc.transaction_output_index.unwrap(); + package_id[30] ^= ((htlc_output_index >> 8) & 0xff) as u8; + package_id[31] ^= ((htlc_output_index >> 0) & 0xff) as u8; + package_id + }, + }; + self.pending_claim_events.insert(package_id, claim_event); + package_id + }, + }; for k in req.outpoints() { log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout); - self.claimable_outpoints.insert(k.clone(), (txid, conf_height)); + self.claimable_outpoints.insert(k.clone(), (package_id, conf_height)); } - self.pending_claim_requests.insert(txid, req); - log_info!(logger, "Broadcasting onchain {}", log_tx!(tx)); - broadcaster.broadcast_transaction(&tx); + self.pending_claim_requests.insert(package_id, req); } } + } + /// 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. + /// Together with `update_claims_view_from_requests` this used to be named `block_connected`, + /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close. + /// + /// `conf_height` represents the height at which the transactions in `txn_matched` were + /// confirmed. This does not need to equal the current blockchain tip height, which should be + /// provided via `cur_height`, however it must never be higher than `cur_height`. + pub(crate) fn update_claims_view_from_matched_txn( + &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash, + cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator, logger: &L + ) where + B::Target: BroadcasterInterface, + F::Target: FeeEstimator, + L::Target: Logger, + { + log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height); 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 @@ -500,14 +734,13 @@ impl OnchainTxHandler { //... 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; - } + let mut are_sets_equal = true; + let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::>(); + tx_inputs.sort_unstable(); + for request_input in request.outpoints() { + if tx_inputs.binary_search(&request_input).is_err() { + are_sets_equal = false; + break; } } @@ -516,7 +749,8 @@ impl OnchainTxHandler { let entry = OnchainEventEntry { txid: tx.txid(), height: conf_height, - event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() } + block_hash: Some(conf_hash), + event: OnchainEvent::Claim { package_id: first_claim_txid_height.0 } }; if !self.onchain_events_awaiting_threshold_conf.contains(&entry) { self.onchain_events_awaiting_threshold_conf.push(entry); @@ -527,7 +761,7 @@ impl OnchainTxHandler { // 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 { + if are_sets_equal { clean_claim_request_after_safety_delay!(); } else { // If false, generate new claim request with update outpoint set let mut at_least_one_drop = false; @@ -556,6 +790,7 @@ impl OnchainTxHandler { let entry = OnchainEventEntry { txid: tx.txid(), height: conf_height, + block_hash: Some(conf_hash), event: OnchainEvent::ContentiousOutpoint { package }, }; if !self.onchain_events_awaiting_threshold_conf.contains(&entry) { @@ -570,20 +805,23 @@ impl OnchainTxHandler { for entry in onchain_events_awaiting_threshold_conf { if entry.has_reached_confirmation_threshold(cur_height) { match entry.event { - OnchainEvent::Claim { claim_request } => { + OnchainEvent::Claim { package_id } => { // 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) { + if let Some(request) = self.pending_claim_requests.remove(&package_id) { for outpoint in request.outpoints() { - log_debug!(logger, "Removing claim tracking for {} due to maturation of claim tx {}.", outpoint, claim_request); - self.claimable_outpoints.remove(&outpoint); + log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.", + outpoint, log_bytes!(package_id)); + self.claimable_outpoints.remove(outpoint); + #[cfg(anchors)] + self.pending_claim_events.remove(&package_id); } } }, OnchainEvent::ContentiousOutpoint { package } => { log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:"); log_debug!(logger, " {:?}", package.outpoints()); - self.claimable_outpoints.remove(&package.outpoints()[0]); + self.claimable_outpoints.remove(package.outpoints()[0]); } } } else { @@ -603,9 +841,18 @@ impl OnchainTxHandler { // 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(cur_height, &request, &*fee_estimator, &*logger) { - log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx)); - broadcaster.broadcast_transaction(&bump_tx); + if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(cur_height, &request, &*fee_estimator, &*logger) { + match bump_claim { + OnchainClaim::Tx(bump_tx) => { + log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx)); + broadcaster.broadcast_transaction(&bump_tx); + }, + #[cfg(anchors)] + OnchainClaim::Event(claim_event) => { + log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints()); + self.pending_claim_events.insert(*first_claim_txid, claim_event); + }, + } if let Some(request) = self.pending_claim_requests.get_mut(first_claim_txid) { request.set_timer(new_timer); request.set_feerate(new_feerate); @@ -652,7 +899,7 @@ impl OnchainTxHandler { //- 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(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 @@ -667,12 +914,21 @@ impl OnchainTxHandler { 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) { + for (_first_claim_txid_height, request) in bump_candidates.iter_mut() { + if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(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); + match bump_claim { + OnchainClaim::Tx(bump_tx) => { + log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx)); + broadcaster.broadcast_transaction(&bump_tx); + }, + #[cfg(anchors)] + OnchainClaim::Event(claim_event) => { + log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints()); + self.pending_claim_events.insert(_first_claim_txid_height.0, claim_event); + }, + } } } for (ancestor_claim_txid, request) in bump_candidates.drain() { @@ -691,12 +947,16 @@ impl OnchainTxHandler { } } - pub(crate) fn get_relevant_txids(&self) -> Vec { - let mut txids: Vec = self.onchain_events_awaiting_threshold_conf + pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool { + self.claimable_outpoints.get(outpoint).is_some() + } + + pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, Option)> { + let mut txids: Vec<(Txid, Option)> = self.onchain_events_awaiting_threshold_conf .iter() - .map(|entry| entry.txid) + .map(|entry| (entry.txid, entry.block_hash)) .collect(); - txids.sort_unstable(); + txids.sort_unstable_by_key(|(txid, _)| *txid); txids.dedup(); txids } @@ -787,6 +1047,37 @@ impl OnchainTxHandler { htlc_tx } + #[cfg(anchors)] + pub(crate) fn generate_external_htlc_claim( + &self, outp: &::bitcoin::OutPoint, preimage: &Option + ) -> Option { + let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option { + let trusted_tx = holder_commitment.trust(); + if outp.txid != trusted_tx.txid() { + return None; + } + trusted_tx.htlcs().iter().enumerate() + .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index { + output_index == outp.vout + } else { + false + }) + .map(|(htlc_idx, htlc)| { + let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx]; + ExternalHTLCClaim { + commitment_txid: trusted_tx.txid(), + per_commitment_number: trusted_tx.commitment_number(), + htlc: htlc.clone(), + preimage: *preimage, + counterparty_sig: counterparty_htlc_sig, + } + }) + }; + // Check if the HTLC spends from the current holder commitment or the previous one otherwise. + find_htlc(&self.holder_commitment) + .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten()) + } + pub(crate) fn opt_anchors(&self) -> bool { self.channel_transaction_parameters.opt_anchors.is_some() }