X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fonchaintx.rs;h=f690d3664273b94e8ee9fe8d6d4c9f16d44ece0e;hb=ee9afd315d22151e314aff2ca826561569ac4d03;hp=18679f0aacd5cd34fead7952fc91be997ad4e57b;hpb=a257906743d528c32c862b053b652d4b728aa990;p=rust-lightning diff --git a/lightning/src/chain/onchaintx.rs b/lightning/src/chain/onchaintx.rs index 18679f0a..f690d366 100644 --- a/lightning/src/chain/onchaintx.rs +++ b/lightning/src/chain/onchaintx.rs @@ -12,31 +12,33 @@ //! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all //! building, tracking, bumping and notifications functions. +#[cfg(anchors)] +use bitcoin::PackedLockTime; 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 crate::chain::keysinterface::{ChannelSigner, EntropySource, SignerProvider}; use crate::ln::msgs::DecodeError; use crate::ln::PaymentPreimage; #[cfg(anchors)] -use crate::ln::chan_utils; +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::{Sign, KeysInterface}; +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::util::byte_utils; +use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter}; use crate::io; use crate::prelude::*; @@ -58,6 +60,7 @@ const MAX_ALLOC_SIZE: usize = 64*1024; 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, } @@ -71,18 +74,23 @@ 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) +/// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe +/// from a chain reorg, the [`OnchainTxHandler`] will act accordingly. #[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. + /// A pending request has been claimed by a transaction spending the exact same set of outpoints + /// as the request. This claim can either be ours or from the counterparty. Once the claiming + /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the + /// pending request. 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 - /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen. + /// The counterparty has claimed an outpoint from one of our pending requests through a + /// different transaction than ours. If our transaction was attempting to claim multiple + /// outputs, we need to drop the outpoint claimed by the counterparty and regenerate a new claim + /// transaction for ourselves. We keep tracking, separately, the outpoint claimed by the + /// counterparty up to [`ANTI_REORG_DELAY`] confirmations to ensure we attempt to re-claim it + /// if the counterparty's claim is reorged from the chain. ContentiousOutpoint { package: PackageTemplate, } @@ -92,6 +100,7 @@ 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), }); @@ -103,23 +112,21 @@ impl MaybeReadable for OnchainEventEntry { fn read(reader: &mut R) -> Result, DecodeError> { let mut txid = Txid::all_zeros(); let mut height = 0; - let mut event = None; + let mut block_hash = None; + let mut event = UpgradableRequired(None); read_tlv_fields!(reader, { (0, txid, required), + (1, block_hash, option), (2, height, required), - (4, event, ignorable), + (4, event, upgradable_required), }); - if let Some(ev) = event { - Ok(Some(Self { txid, height, event: ev })) - } else { - Ok(None) - } + Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) })) } } impl_writeable_tlv_based_enum_upgradable!(OnchainEvent, (0, Claim) => { - (0, claim_request, required), + (0, package_id, required), }, (1, ContentiousOutpoint) => { (0, package, required), @@ -170,6 +177,16 @@ 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)] @@ -181,6 +198,13 @@ pub(crate) enum ClaimEvent { 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, + tx_lock_time: PackedLockTime, + }, } /// Represents the different ways an output can be claimed (i.e., spent to an address under our @@ -194,9 +218,12 @@ pub(crate) enum OnchainClaim { 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 { +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 @@ -221,22 +248,33 @@ 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, + + // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec` + // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence + // of a `PackageID`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and + // a new block has been connected, resulting in a new claim, the previous will be replaced with + // the new. + // + // These external events may be generated in the following cases: + // - A channel has been force closed by broadcasting the holder's latest commitment transaction + // - A block being connected/disconnected + // - Learning the preimage for an HTLC we can claim onchain #[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 - // 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. + pending_claim_events: Vec<(PackageID, ClaimEvent)>, + + // Used to link outpoints claimed in a connected block to a pending claim request. The keys + // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to + // claim. The values track the pending claim request identifier and the initial confirmation + // block height, and are immutable until the outpoint has enough confirmations to meet our + // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if + // the block 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>, @@ -245,10 +283,26 @@ pub struct OnchainTxHandler { pub(super) secp_ctx: Secp256k1, } +impl PartialEq for OnchainTxHandler { + fn eq(&self, other: &Self) -> bool { + // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose. + self.destination_script == other.destination_script && + self.holder_commitment == other.holder_commitment && + self.holder_htlc_sigs == other.holder_htlc_sigs && + self.prev_holder_commitment == other.prev_holder_commitment && + self.prev_holder_htlc_sigs == other.prev_holder_htlc_sigs && + self.channel_transaction_parameters == other.channel_transaction_parameters && + self.pending_claim_requests == other.pending_claim_requests && + self.claimable_outpoints == other.claimable_outpoints && + self.locktimed_packages == other.locktimed_packages && + self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf + } +} + 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); @@ -267,29 +321,29 @@ 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)?; } @@ -299,8 +353,13 @@ 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)?; @@ -312,16 +371,21 @@ 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)); @@ -361,7 +425,7 @@ 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, @@ -376,13 +440,13 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler { pending_claim_requests, onchain_events_awaiting_threshold_conf, #[cfg(anchors)] - pending_claim_events: HashMap::new(), + pending_claim_events: Vec::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, @@ -397,8 +461,7 @@ impl OnchainTxHandler { locktimed_packages: BTreeMap::new(), onchain_events_awaiting_threshold_conf: Vec::new(), #[cfg(anchors)] - pending_claim_events: HashMap::new(), - + pending_claim_events: Vec::new(), secp_ctx, } } @@ -413,9 +476,9 @@ impl OnchainTxHandler { #[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::>() + let mut events = Vec::new(); + swap(&mut events, &mut self.pending_claim_events); + events.into_iter().map(|(_, event)| event).collect() } /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty @@ -430,21 +493,81 @@ impl OnchainTxHandler { 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((request_package_id, _)) = 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 { + *request_package_id == 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() { + #[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, + tx_lock_time: PackedLockTime(cached_request.package_locktime(cur_height)), + }), + )); + } 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) { + 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_malleable_package(self, output_value, self.destination_script.clone(), logger).unwrap(); + let transaction = cached_request.finalize_malleable_package( + cur_height, 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, OnchainClaim::Tx(transaction))) + return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction))); } } else { // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some @@ -500,24 +623,29 @@ impl OnchainTxHandler { 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; @@ -532,16 +660,17 @@ impl OnchainTxHandler { .find(|locked_package| locked_package.outpoints() == req.outpoints()); if let Some(package) = timelocked_equivalent_package { log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.", - req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_timelock()); + req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height)); continue; } - if req.package_timelock() > cur_height + 1 { - log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", req.package_timelock(), cur_height); + let package_locktime = req.package_locktime(cur_height); + if package_locktime > cur_height + 1 { + log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height); for outpoint in req.outpoints() { log_info!(logger, " Outpoint {}", outpoint); } - self.locktimed_packages.entry(req.package_timelock()).or_insert(Vec::new()).push(req); + self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req); continue; } @@ -574,49 +703,78 @@ impl OnchainTxHandler { 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 = match claim { + let package_id = match claim { OnchainClaim::Tx(tx) => { log_info!(logger, "Broadcasting onchain {}", log_tx!(tx)); broadcaster.broadcast_transaction(&tx); - tx.txid() + tx.txid().into_inner() }, #[cfg(anchors)] OnchainClaim::Event(claim_event) => { log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints()); - let txid = match claim_event { - ClaimEvent::BumpCommitment { ref commitment_tx, .. } => commitment_tx.txid(), + 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(txid, claim_event); - txid + debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == package_id).count(), 0); + self.pending_claim_events.push((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); + 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 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 let Some((package_id, _)) = 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) { + if let Some(request) = self.pending_claim_requests.get_mut(package_id) { //... 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; } } @@ -625,7 +783,8 @@ 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: *package_id } }; if !self.onchain_events_awaiting_threshold_conf.contains(&entry) { self.onchain_events_awaiting_threshold_conf.push(entry); @@ -636,7 +795,7 @@ 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; @@ -652,7 +811,21 @@ impl OnchainTxHandler { } //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()); + bump_candidates.insert(*package_id, request.clone()); + // If we have any pending claim events for the request being updated + // that have yet to be consumed, we'll remove them since they will + // end up producing an invalid transaction by double spending + // input(s) that already have a confirmed spend. If such spend is + // reorged out of the chain, then we'll attempt to re-spend the + // inputs once we see it. + #[cfg(anchors)] { + #[cfg(debug_assertions)] { + let existing = self.pending_claim_events.iter() + .filter(|entry| entry.0 == *package_id).count(); + assert!(existing == 0 || existing == 1); + } + self.pending_claim_events.retain(|entry| entry.0 != *package_id); + } } } break; //No need to iterate further, either tx is our or their @@ -665,6 +838,7 @@ 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) { @@ -679,22 +853,29 @@ 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); - #[cfg(anchors)] - self.pending_claim_events.remove(&claim_request); + 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)] { + #[cfg(debug_assertions)] { + let num_existing = self.pending_claim_events.iter() + .filter(|entry| entry.0 == package_id).count(); + assert!(num_existing == 0 || num_existing == 1); + } + self.pending_claim_events.retain(|(id, _)| *id != 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 { @@ -703,17 +884,17 @@ impl OnchainTxHandler { } // Check if any pending claim request must be rescheduled - for (first_claim_txid, ref request) in self.pending_claim_requests.iter() { + for (package_id, request) in self.pending_claim_requests.iter() { if let Some(h) = request.timer() { if cur_height >= h { - bump_candidates.insert(*first_claim_txid, (*request).clone()); + bump_candidates.insert(*package_id, 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() { + for (package_id, request) in bump_candidates.iter() { 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) => { @@ -723,10 +904,16 @@ impl OnchainTxHandler { #[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); + #[cfg(debug_assertions)] { + let num_existing = self.pending_claim_events.iter(). + filter(|entry| entry.0 == *package_id).count(); + assert!(num_existing == 0 || num_existing == 1); + } + self.pending_claim_events.retain(|event| event.0 != *package_id); + self.pending_claim_events.push((*package_id, claim_event)); }, } - if let Some(request) = self.pending_claim_requests.get_mut(first_claim_txid) { + if let Some(request) = self.pending_claim_requests.get_mut(package_id) { request.set_timer(new_timer); request.set_feerate(new_feerate); } @@ -772,12 +959,12 @@ 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(request) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) { + if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) { + if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.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()); + bump_candidates.insert(pending_claim.clone(), request.clone()); } } }, @@ -787,7 +974,7 @@ impl OnchainTxHandler { self.onchain_events_awaiting_threshold_conf.push(entry); } } - for (_first_claim_txid_height, request) in bump_candidates.iter_mut() { + for ((_package_id, _), ref mut 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); @@ -799,7 +986,13 @@ impl OnchainTxHandler { #[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); + #[cfg(debug_assertions)] { + let num_existing = self.pending_claim_events.iter() + .filter(|entry| entry.0 == *_package_id).count(); + assert!(num_existing == 0 || num_existing == 1); + } + self.pending_claim_events.retain(|event| event.0 != *_package_id); + self.pending_claim_events.push((*_package_id, claim_event)); }, } } @@ -824,12 +1017,12 @@ impl OnchainTxHandler { self.claimable_outpoints.get(outpoint).is_some() } - pub(crate) fn get_relevant_txids(&self) -> Vec { - let mut txids: Vec = self.onchain_events_awaiting_threshold_conf + 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 } @@ -920,6 +1113,37 @@ 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() }