X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fonchaintx.rs;h=9cfa9d288ce3590a585a3e7e708e0bcb54911b30;hb=790d26f63f1ed6fff8742bd0df58bf010a11b567;hp=765a9c091815379104b42c05578bda5b9622f7a5;hpb=ba50dd57868a78d00ed1a3c7a9089cf39d3ca235;p=rust-lightning diff --git a/lightning/src/chain/onchaintx.rs b/lightning/src/chain/onchaintx.rs index 765a9c09..9cfa9d28 100644 --- a/lightning/src/chain/onchaintx.rs +++ b/lightning/src/chain/onchaintx.rs @@ -18,26 +18,35 @@ use bitcoin::blockdata::script::Script; use bitcoin::hash_types::Txid; -use bitcoin::secp256k1::{Secp256k1, Signature}; +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}; -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::ln::msgs::DecodeError; +use crate::ln::PaymentPreimage; +#[cfg(anchors)] +use crate::ln::chan_utils; +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}; +#[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::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; @@ -45,7 +54,7 @@ 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, @@ -64,7 +73,7 @@ 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. @@ -92,7 +101,7 @@ impl Writeable for OnchainEventEntry { impl MaybeReadable for OnchainEventEntry { fn read(reader: &mut R) -> Result, DecodeError> { - let mut txid = Default::default(); + let mut txid = Txid::all_zeros(); let mut height = 0; let mut event = None; read_tlv_fields!(reader, { @@ -161,6 +170,29 @@ impl Writeable for Option>> { } } +// 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, + }, +} + +/// 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), +} /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and /// do RBF bumping if possible. @@ -192,6 +224,8 @@ pub struct OnchainTxHandler { pub(crate) pending_claim_requests: HashMap, #[cfg(not(test))] 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 @@ -341,6 +375,8 @@ 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, }) } @@ -360,6 +396,8 @@ 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, } @@ -373,15 +411,62 @@ 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: &F, 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 { + 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 { claim_request } = event_entry.event { + first_claim_txid_height.0 == claim_request + } 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). @@ -389,21 +474,69 @@ impl OnchainTxHandler { if cached_request.is_malleable() { 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().as_sat(), fee_estimator, logger) { + 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.get_weight()); - return Some((new_timer, new_feerate, transaction)) + assert!(predicted_weight >= transaction.weight()); + 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 } @@ -415,7 +548,7 @@ impl OnchainTxHandler { /// `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: &F, logger: &L) + 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, @@ -474,17 +607,30 @@ 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 txid = match claim { + OnchainClaim::Tx(tx) => { + log_info!(logger, "Broadcasting onchain {}", log_tx!(tx)); + broadcaster.broadcast_transaction(&tx); + tx.txid() + }, + #[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(), + }; + self.pending_claim_events.insert(txid, claim_event); + txid + }, + }; 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.pending_claim_requests.insert(txid, req); - log_info!(logger, "Broadcasting onchain {}", log_tx!(tx)); - broadcaster.broadcast_transaction(&tx); } } @@ -576,6 +722,8 @@ impl OnchainTxHandler { 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); } } }, @@ -602,9 +750,18 @@ 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); @@ -617,7 +774,7 @@ impl OnchainTxHandler { &mut self, txid: &Txid, broadcaster: B, - fee_estimator: F, + fee_estimator: &LowerBoundedFeeEstimator, logger: L, ) where B::Target: BroadcasterInterface, @@ -637,7 +794,7 @@ impl OnchainTxHandler { } } - pub(crate) fn block_disconnected(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L) + pub(crate) fn block_disconnected(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator, logger: L) where B::Target: BroadcasterInterface, F::Target: FeeEstimator, L::Target: Logger, @@ -666,12 +823,21 @@ 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() { @@ -690,6 +856,10 @@ impl OnchainTxHandler { } } + 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 { let mut txids: Vec = self.onchain_events_awaiting_threshold_conf .iter() @@ -786,6 +956,10 @@ impl OnchainTxHandler { htlc_tx } + pub(crate) fn opt_anchors(&self) -> bool { + self.channel_transaction_parameters.opt_anchors.is_some() + } + #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option) -> Option { let latest_had_sigs = self.holder_htlc_sigs.is_some();