use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
use bitcoin::secp256k1;
-use crate::chain::keysinterface::{BaseSign, EntropySource, SignerProvider};
+use crate::chain::keysinterface::{ChannelSigner, EntropySource, SignerProvider};
use crate::ln::msgs::DecodeError;
use crate::ln::PaymentPreimage;
#[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;
+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::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter};
use crate::io;
use crate::prelude::*;
}
}
-/// 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 {
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,
}
let mut txid = Txid::all_zeros();
let mut height = 0;
let mut block_hash = None;
- let mut event = 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, block_hash, event: ev }))
- } else {
- Ok(None)
- }
+ Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
}
}
/// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
/// do RBF bumping if possible.
-pub struct OnchainTxHandler<ChannelSigner: Sign> {
+pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
destination_script: Script,
holder_commitment: HolderCommitmentTransaction,
// holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
pub(crate) pending_claim_requests: HashMap<PackageID, PackageTemplate>,
#[cfg(not(test))]
pending_claim_requests: HashMap<PackageID, PackageTemplate>,
+
+ // 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<PackageID, ClaimEvent>,
-
- // 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<BitcoinOutPoint, (PackageID, u32)>,
#[cfg(not(test))]
pub(super) secp_ctx: Secp256k1<secp256k1::All>,
}
+impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
+ 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<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
+impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
}
}
-impl<'a, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'a SP, u64, [u8; 32])> for OnchainTxHandler<SP::Signer> {
- fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'a SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
+impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::Signer> {
+ fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
let entropy_source = args.0;
let signer_provider = args.1;
let channel_value_satoshis = args.2;
pending_claim_requests,
onchain_events_awaiting_threshold_conf,
#[cfg(anchors)]
- pending_claim_events: HashMap::new(),
+ pending_claim_events: Vec::new(),
secp_ctx,
})
}
}
-impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
+impl<ChannelSigner: WriteableEcdsaChannelSigner> 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,
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,
}
}
#[cfg(anchors)]
pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<ClaimEvent> {
- let mut ret = HashMap::new();
- swap(&mut ret, &mut self.pending_claim_events);
- ret.into_iter().map(|(_, event)| event).collect::<Vec<_>>()
+ 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
// 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) {
+ 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 {
- first_claim_txid_height.0 == package_id
+ *request_package_id == package_id
} else {
// The onchain event is not a claim, keep seeking until we find one.
false
package_id
},
};
- self.pending_claim_events.insert(package_id, claim_event);
+ 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
},
};
// 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.
txid: tx.txid(),
height: conf_height,
block_hash: Some(conf_hash),
- event: OnchainEvent::Claim { package_id: first_claim_txid_height.0 }
+ event: OnchainEvent::Claim { package_id: *package_id }
};
if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
self.onchain_events_awaiting_threshold_conf.push(entry);
}
//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
for outpoint in request.outpoints() {
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);
+ 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 {
}
// 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) => {
#[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);
}
//- 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());
}
}
},
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);
#[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));
},
}
}
projects / rust-lightning / blobdiff