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[rust-lightning] / lightning / src / chain / onchaintx.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
8 // licenses.
9
10 //! The logic to build claims and bump in-flight transactions until confirmations.
11 //!
12 //! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all
13 //! building, tracking, bumping and notifications functions.
14
15 use bitcoin::blockdata::locktime::absolute::LockTime;
16 use bitcoin::blockdata::transaction::Transaction;
17 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
18 use bitcoin::blockdata::script::{Script, ScriptBuf};
19 use bitcoin::hashes::{Hash, HashEngine};
20 use bitcoin::hashes::sha256::Hash as Sha256;
21 use bitcoin::hash_types::{Txid, BlockHash};
22 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
23 use bitcoin::secp256k1;
24
25 use crate::chain::chaininterface::compute_feerate_sat_per_1000_weight;
26 use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, ChannelSigner, EntropySource, SignerProvider, ecdsa::WriteableEcdsaChannelSigner};
27 use crate::ln::msgs::DecodeError;
28 use crate::ln::PaymentPreimage;
29 use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment, HolderCommitmentTransaction};
30 use crate::chain::ClaimId;
31 use crate::chain::chaininterface::{ConfirmationTarget, FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
32 use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
33 use crate::chain::package::{PackageSolvingData, PackageTemplate};
34 use crate::chain::transaction::MaybeSignedTransaction;
35 use crate::util::logger::Logger;
36 use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter};
37
38 use crate::io;
39 use crate::prelude::*;
40 use alloc::collections::BTreeMap;
41 use core::cmp;
42 use core::ops::Deref;
43 use core::mem::replace;
44 use core::mem::swap;
45 use crate::ln::features::ChannelTypeFeatures;
46
47 const MAX_ALLOC_SIZE: usize = 64*1024;
48
49 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
50 /// transaction causing it.
51 ///
52 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
53 #[derive(Clone, PartialEq, Eq)]
54 struct OnchainEventEntry {
55         txid: Txid,
56         height: u32,
57         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
58         event: OnchainEvent,
59 }
60
61 impl OnchainEventEntry {
62         fn confirmation_threshold(&self) -> u32 {
63                 self.height + ANTI_REORG_DELAY - 1
64         }
65
66         fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
67                 height >= self.confirmation_threshold()
68         }
69 }
70
71 /// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe
72 /// from a chain reorg, the [`OnchainTxHandler`] will act accordingly.
73 #[derive(Clone, PartialEq, Eq)]
74 enum OnchainEvent {
75         /// A pending request has been claimed by a transaction spending the exact same set of outpoints
76         /// as the request. This claim can either be ours or from the counterparty. Once the claiming
77         /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the
78         /// pending request.
79         Claim {
80                 claim_id: ClaimId,
81         },
82         /// The counterparty has claimed an outpoint from one of our pending requests through a
83         /// different transaction than ours. If our transaction was attempting to claim multiple
84         /// outputs, we need to drop the outpoint claimed by the counterparty and regenerate a new claim
85         /// transaction for ourselves. We keep tracking, separately, the outpoint claimed by the
86         /// counterparty up to [`ANTI_REORG_DELAY`] confirmations to ensure we attempt to re-claim it
87         /// if the counterparty's claim is reorged from the chain.
88         ContentiousOutpoint {
89                 package: PackageTemplate,
90         }
91 }
92
93 impl Writeable for OnchainEventEntry {
94         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
95                 write_tlv_fields!(writer, {
96                         (0, self.txid, required),
97                         (1, self.block_hash, option),
98                         (2, self.height, required),
99                         (4, self.event, required),
100                 });
101                 Ok(())
102         }
103 }
104
105 impl MaybeReadable for OnchainEventEntry {
106         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
107                 let mut txid = Txid::all_zeros();
108                 let mut height = 0;
109                 let mut block_hash = None;
110                 let mut event = UpgradableRequired(None);
111                 read_tlv_fields!(reader, {
112                         (0, txid, required),
113                         (1, block_hash, option),
114                         (2, height, required),
115                         (4, event, upgradable_required),
116                 });
117                 Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
118         }
119 }
120
121 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
122         (0, Claim) => {
123                 (0, claim_id, required),
124         },
125         (1, ContentiousOutpoint) => {
126                 (0, package, required),
127         },
128 );
129
130 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
131         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
132                 match Readable::read(reader)? {
133                         0u8 => Ok(None),
134                         1u8 => {
135                                 let vlen: u64 = Readable::read(reader)?;
136                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
137                                 for _ in 0..vlen {
138                                         ret.push(match Readable::read(reader)? {
139                                                 0u8 => None,
140                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
141                                                 _ => return Err(DecodeError::InvalidValue)
142                                         });
143                                 }
144                                 Ok(Some(ret))
145                         },
146                         _ => Err(DecodeError::InvalidValue),
147                 }
148         }
149 }
150
151 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
152         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
153                 match self {
154                         &Some(ref vec) => {
155                                 1u8.write(writer)?;
156                                 (vec.len() as u64).write(writer)?;
157                                 for opt in vec.iter() {
158                                         match opt {
159                                                 &Some((ref idx, ref sig)) => {
160                                                         1u8.write(writer)?;
161                                                         (*idx as u64).write(writer)?;
162                                                         sig.write(writer)?;
163                                                 },
164                                                 &None => 0u8.write(writer)?,
165                                         }
166                                 }
167                         },
168                         &None => 0u8.write(writer)?,
169                 }
170                 Ok(())
171         }
172 }
173
174 /// The claim commonly referred to as the pre-signed second-stage HTLC transaction.
175 #[derive(Clone, PartialEq, Eq)]
176 pub(crate) struct ExternalHTLCClaim {
177         pub(crate) commitment_txid: Txid,
178         pub(crate) per_commitment_number: u64,
179         pub(crate) htlc: HTLCOutputInCommitment,
180         pub(crate) preimage: Option<PaymentPreimage>,
181         pub(crate) counterparty_sig: Signature,
182 }
183
184 // Represents the different types of claims for which events are yielded externally to satisfy said
185 // claims.
186 #[derive(Clone, PartialEq, Eq)]
187 pub(crate) enum ClaimEvent {
188         /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
189         /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
190         BumpCommitment {
191                 package_target_feerate_sat_per_1000_weight: u32,
192                 commitment_tx: Transaction,
193                 anchor_output_idx: u32,
194         },
195         /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
196         /// resolved by broadcasting a transaction with sufficient fee to claim them.
197         BumpHTLC {
198                 target_feerate_sat_per_1000_weight: u32,
199                 htlcs: Vec<ExternalHTLCClaim>,
200                 tx_lock_time: LockTime,
201         },
202 }
203
204 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
205 /// control) onchain.
206 pub(crate) enum OnchainClaim {
207         /// A finalized transaction pending confirmation spending the output to claim.
208         Tx(MaybeSignedTransaction),
209         /// An event yielded externally to signal additional inputs must be added to a transaction
210         /// pending confirmation spending the output to claim.
211         Event(ClaimEvent),
212 }
213
214 /// Represents the different feerate strategies a pending request can use when generating a claim.
215 pub(crate) enum FeerateStrategy {
216         /// We must reuse the most recently used feerate, if any.
217         RetryPrevious,
218         /// We must pick the highest between the most recently used and the current feerate estimate.
219         HighestOfPreviousOrNew,
220         /// We must force a bump of the most recently used feerate, either by using the current feerate
221         /// estimate if it's higher, or manually bumping.
222         ForceBump,
223 }
224
225 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
226 /// do RBF bumping if possible.
227 #[derive(Clone)]
228 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
229         channel_value_satoshis: u64,
230         channel_keys_id: [u8; 32],
231         destination_script: ScriptBuf,
232         holder_commitment: HolderCommitmentTransaction,
233         prev_holder_commitment: Option<HolderCommitmentTransaction>,
234
235         pub(super) signer: ChannelSigner,
236         pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
237
238         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
239         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
240         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
241         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
242         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
243         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
244         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
245         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
246         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
247         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
248         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
249         #[cfg(test)] // Used in functional_test to verify sanitization
250         pub(crate) pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
251         #[cfg(not(test))]
252         pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
253
254         // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec`
255         // essentially acts as an insertion-ordered `HashMap` â€“ there should only ever be one occurrence
256         // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and
257         // a new block has been connected, resulting in a new claim, the previous will be replaced with
258         // the new.
259         //
260         // These external events may be generated in the following cases:
261         //      - A channel has been force closed by broadcasting the holder's latest commitment transaction
262         //      - A block being connected/disconnected
263         //      - Learning the preimage for an HTLC we can claim onchain
264         pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
265
266         // Used to link outpoints claimed in a connected block to a pending claim request. The keys
267         // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
268         // claim. The values track the pending claim request identifier and the initial confirmation
269         // block height, and are immutable until the outpoint has enough confirmations to meet our
270         // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
271         // the block gets disconnected.
272         #[cfg(test)] // Used in functional_test to verify sanitization
273         pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
274         #[cfg(not(test))]
275         claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
276
277         locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
278
279         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
280
281         pub(super) secp_ctx: Secp256k1<secp256k1::All>,
282 }
283
284 impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
285         fn eq(&self, other: &Self) -> bool {
286                 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
287                 self.channel_value_satoshis == other.channel_value_satoshis &&
288                         self.channel_keys_id == other.channel_keys_id &&
289                         self.destination_script == other.destination_script &&
290                         self.holder_commitment == other.holder_commitment &&
291                         self.prev_holder_commitment == other.prev_holder_commitment &&
292                         self.channel_transaction_parameters == other.channel_transaction_parameters &&
293                         self.pending_claim_requests == other.pending_claim_requests &&
294                         self.claimable_outpoints == other.claimable_outpoints &&
295                         self.locktimed_packages == other.locktimed_packages &&
296                         self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
297         }
298 }
299
300 const SERIALIZATION_VERSION: u8 = 1;
301 const MIN_SERIALIZATION_VERSION: u8 = 1;
302
303 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
304         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
305                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
306
307                 self.destination_script.write(writer)?;
308                 self.holder_commitment.write(writer)?;
309                 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // holder_htlc_sigs
310                 self.prev_holder_commitment.write(writer)?;
311                 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // prev_holder_htlc_sigs
312
313                 self.channel_transaction_parameters.write(writer)?;
314
315                 let mut key_data = VecWriter(Vec::new());
316                 self.signer.write(&mut key_data)?;
317                 assert!(key_data.0.len() < core::usize::MAX);
318                 assert!(key_data.0.len() < core::u32::MAX as usize);
319                 (key_data.0.len() as u32).write(writer)?;
320                 writer.write_all(&key_data.0[..])?;
321
322                 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
323                 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
324                         ancestor_claim_txid.write(writer)?;
325                         request.write(writer)?;
326                 }
327
328                 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
329                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
330                         outp.write(writer)?;
331                         claim_and_height.0.write(writer)?;
332                         claim_and_height.1.write(writer)?;
333                 }
334
335                 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
336                 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
337                         locktime.write(writer)?;
338                         writer.write_all(&(packages.len() as u64).to_be_bytes())?;
339                         for ref package in packages.iter() {
340                                 package.write(writer)?;
341                         }
342                 }
343
344                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
345                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
346                         entry.write(writer)?;
347                 }
348
349                 write_tlv_fields!(writer, {});
350                 Ok(())
351         }
352 }
353
354 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::EcdsaSigner> {
355         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
356                 let entropy_source = args.0;
357                 let signer_provider = args.1;
358                 let channel_value_satoshis = args.2;
359                 let channel_keys_id = args.3;
360
361                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
362
363                 let destination_script = Readable::read(reader)?;
364
365                 let holder_commitment = Readable::read(reader)?;
366                 let _holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
367                 let prev_holder_commitment = Readable::read(reader)?;
368                 let _prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
369
370                 let channel_parameters = Readable::read(reader)?;
371
372                 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
373                 // by re-deriving the private key material.
374                 let keys_len: u32 = Readable::read(reader)?;
375                 let mut bytes_read = 0;
376                 while bytes_read != keys_len as usize {
377                         // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
378                         let mut data = [0; 1024];
379                         let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
380                         let read_slice = &mut data[0..bytes_to_read];
381                         reader.read_exact(read_slice)?;
382                         bytes_read += bytes_to_read;
383                 }
384
385                 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
386                 signer.provide_channel_parameters(&channel_parameters);
387
388                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
389                 let mut pending_claim_requests = hash_map_with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
390                 for _ in 0..pending_claim_requests_len {
391                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
392                 }
393
394                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
395                 let mut claimable_outpoints = hash_map_with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
396                 for _ in 0..claimable_outpoints_len {
397                         let outpoint = Readable::read(reader)?;
398                         let ancestor_claim_txid = Readable::read(reader)?;
399                         let height = Readable::read(reader)?;
400                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
401                 }
402
403                 let locktimed_packages_len: u64 = Readable::read(reader)?;
404                 let mut locktimed_packages = BTreeMap::new();
405                 for _ in 0..locktimed_packages_len {
406                         let locktime = Readable::read(reader)?;
407                         let packages_len: u64 = Readable::read(reader)?;
408                         let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
409                         for _ in 0..packages_len {
410                                 packages.push(Readable::read(reader)?);
411                         }
412                         locktimed_packages.insert(locktime, packages);
413                 }
414
415                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
416                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
417                 for _ in 0..waiting_threshold_conf_len {
418                         if let Some(val) = MaybeReadable::read(reader)? {
419                                 onchain_events_awaiting_threshold_conf.push(val);
420                         }
421                 }
422
423                 read_tlv_fields!(reader, {});
424
425                 let mut secp_ctx = Secp256k1::new();
426                 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
427
428                 Ok(OnchainTxHandler {
429                         channel_value_satoshis,
430                         channel_keys_id,
431                         destination_script,
432                         holder_commitment,
433                         prev_holder_commitment,
434                         signer,
435                         channel_transaction_parameters: channel_parameters,
436                         claimable_outpoints,
437                         locktimed_packages,
438                         pending_claim_requests,
439                         onchain_events_awaiting_threshold_conf,
440                         pending_claim_events: Vec::new(),
441                         secp_ctx,
442                 })
443         }
444 }
445
446 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
447         pub(crate) fn new(
448                 channel_value_satoshis: u64, channel_keys_id: [u8; 32], destination_script: ScriptBuf,
449                 signer: ChannelSigner, channel_parameters: ChannelTransactionParameters,
450                 holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>
451         ) -> Self {
452                 OnchainTxHandler {
453                         channel_value_satoshis,
454                         channel_keys_id,
455                         destination_script,
456                         holder_commitment,
457                         prev_holder_commitment: None,
458                         signer,
459                         channel_transaction_parameters: channel_parameters,
460                         pending_claim_requests: new_hash_map(),
461                         claimable_outpoints: new_hash_map(),
462                         locktimed_packages: BTreeMap::new(),
463                         onchain_events_awaiting_threshold_conf: Vec::new(),
464                         pending_claim_events: Vec::new(),
465                         secp_ctx,
466                 }
467         }
468
469         pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
470                 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
471         }
472
473         pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
474                 self.holder_commitment.to_broadcaster_value_sat()
475         }
476
477         pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
478                 let mut events = Vec::new();
479                 swap(&mut events, &mut self.pending_claim_events);
480                 events
481         }
482
483         /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
484         /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
485         /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
486         /// invoking this every 30 seconds, or lower if running in an environment with spotty
487         /// connections, like on mobile.
488         pub(super) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Logger>(
489                 &mut self, current_height: u32, feerate_strategy: FeerateStrategy, broadcaster: &B,
490                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
491         )
492         where
493                 B::Target: BroadcasterInterface,
494                 F::Target: FeeEstimator,
495         {
496                 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
497                 for (claim_id, request) in self.pending_claim_requests.iter() {
498                         let inputs = request.outpoints();
499                         log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
500                         bump_requests.push((*claim_id, request.clone()));
501                 }
502                 for (claim_id, request) in bump_requests {
503                         self.generate_claim(current_height, &request, &feerate_strategy, fee_estimator, logger)
504                                 .map(|(_, new_feerate, claim)| {
505                                         let mut bumped_feerate = false;
506                                         if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
507                                                 bumped_feerate = request.previous_feerate() > new_feerate;
508                                                 mut_request.set_feerate(new_feerate);
509                                         }
510                                         match claim {
511                                                 OnchainClaim::Tx(tx) => {
512                                                         if tx.is_fully_signed() {
513                                                                 let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
514                                                                 log_info!(logger, "{} onchain {}", log_start, log_tx!(tx.0));
515                                                                 broadcaster.broadcast_transactions(&[&tx.0]);
516                                                         } else {
517                                                                 log_info!(logger, "Waiting for signature of unsigned onchain transaction {}", tx.0.txid());
518                                                         }
519                                                 },
520                                                 OnchainClaim::Event(event) => {
521                                                         let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
522                                                         log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
523                                                                 request.outpoints());
524                                                         #[cfg(debug_assertions)] {
525                                                                 debug_assert!(request.requires_external_funding());
526                                                                 let num_existing = self.pending_claim_events.iter()
527                                                                         .filter(|entry| entry.0 == claim_id).count();
528                                                                 assert!(num_existing == 0 || num_existing == 1);
529                                                         }
530                                                         self.pending_claim_events.retain(|event| event.0 != claim_id);
531                                                         self.pending_claim_events.push((claim_id, event));
532                                                 }
533                                         }
534                                 });
535                 }
536         }
537
538         /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
539         /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
540         /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
541         /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
542         /// Child-Pay-For-Parent.
543         ///
544         /// Panics if there are signing errors, because signing operations in reaction to on-chain
545         /// events are not expected to fail, and if they do, we may lose funds.
546         fn generate_claim<F: Deref, L: Logger>(
547                 &mut self, cur_height: u32, cached_request: &PackageTemplate, feerate_strategy: &FeerateStrategy,
548                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
549         ) -> Option<(u32, u64, OnchainClaim)>
550         where F::Target: FeeEstimator,
551         {
552                 let request_outpoints = cached_request.outpoints();
553                 if request_outpoints.is_empty() {
554                         // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
555                         // packages cannot be aggregated and will never be split, so we cannot end up with an
556                         // empty claim.
557                         debug_assert!(cached_request.is_malleable());
558                         return None;
559                 }
560                 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
561                 // don't need to continue generating more claims. We'll keep tracking the request to fully
562                 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
563                 // transaction is reorged out.
564                 let mut all_inputs_have_confirmed_spend = true;
565                 for outpoint in request_outpoints.iter() {
566                         if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
567                                 // We check for outpoint spends within claims individually rather than as a set
568                                 // since requests can have outpoints split off.
569                                 if !self.onchain_events_awaiting_threshold_conf.iter()
570                                         .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
571                                                 *request_claim_id == claim_id
572                                         } else {
573                                                 // The onchain event is not a claim, keep seeking until we find one.
574                                                 false
575                                         })
576                                 {
577                                         // Either we had no `OnchainEvent::Claim`, or we did but none matched the
578                                         // outpoint's registered spend.
579                                         all_inputs_have_confirmed_spend = false;
580                                 }
581                         } else {
582                                 // The request's outpoint spend does not exist yet.
583                                 all_inputs_have_confirmed_spend = false;
584                         }
585                 }
586                 if all_inputs_have_confirmed_spend {
587                         return None;
588                 }
589
590                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
591                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
592                 let new_timer = cached_request.get_height_timer(cur_height);
593                 if cached_request.is_malleable() {
594                         if cached_request.requires_external_funding() {
595                                 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
596                                         fee_estimator, ConfirmationTarget::OnChainSweep, feerate_strategy,
597                                 );
598                                 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
599                                         return Some((
600                                                 new_timer,
601                                                 target_feerate_sat_per_1000_weight as u64,
602                                                 OnchainClaim::Event(ClaimEvent::BumpHTLC {
603                                                         target_feerate_sat_per_1000_weight,
604                                                         htlcs,
605                                                         tx_lock_time: LockTime::from_consensus(cached_request.package_locktime(cur_height)),
606                                                 }),
607                                         ));
608                                 } else {
609                                         return None;
610                                 }
611                         }
612
613                         let predicted_weight = cached_request.package_weight(&self.destination_script);
614                         if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
615                                 predicted_weight, self.destination_script.dust_value().to_sat(),
616                                 feerate_strategy, fee_estimator, logger,
617                         ) {
618                                 assert!(new_feerate != 0);
619
620                                 let transaction = cached_request.maybe_finalize_malleable_package(
621                                         cur_height, self, output_value, self.destination_script.clone(), logger
622                                 ).unwrap();
623                                 assert!(predicted_weight >= transaction.0.weight().to_wu());
624                                 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
625                         }
626                 } else {
627                         // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
628                         // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
629                         // which require external funding.
630                         let mut inputs = cached_request.inputs();
631                         debug_assert_eq!(inputs.len(), 1);
632                         let tx = match cached_request.maybe_finalize_untractable_package(self, logger) {
633                                 Some(tx) => tx,
634                                 None => return None,
635                         };
636                         if !cached_request.requires_external_funding() {
637                                 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
638                         }
639                         return inputs.find_map(|input| match input {
640                                 // Commitment inputs with anchors support are the only untractable inputs supported
641                                 // thus far that require external funding.
642                                 PackageSolvingData::HolderFundingOutput(output) => {
643                                         debug_assert_eq!(tx.0.txid(), self.holder_commitment.trust().txid(),
644                                                 "Holder commitment transaction mismatch");
645
646                                         let conf_target = ConfirmationTarget::OnChainSweep;
647                                         let package_target_feerate_sat_per_1000_weight = cached_request
648                                                 .compute_package_feerate(fee_estimator, conf_target, feerate_strategy);
649                                         if let Some(input_amount_sat) = output.funding_amount {
650                                                 let fee_sat = input_amount_sat - tx.0.output.iter().map(|output| output.value).sum::<u64>();
651                                                 let commitment_tx_feerate_sat_per_1000_weight =
652                                                         compute_feerate_sat_per_1000_weight(fee_sat, tx.0.weight().to_wu());
653                                                 if commitment_tx_feerate_sat_per_1000_weight >= package_target_feerate_sat_per_1000_weight {
654                                                         log_debug!(logger, "Pre-signed commitment {} already has feerate {} sat/kW above required {} sat/kW",
655                                                                 tx.0.txid(), commitment_tx_feerate_sat_per_1000_weight,
656                                                                 package_target_feerate_sat_per_1000_weight);
657                                                         return Some((new_timer, 0, OnchainClaim::Tx(tx.clone())));
658                                                 }
659                                         }
660
661                                         // We'll locate an anchor output we can spend within the commitment transaction.
662                                         let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
663                                         match chan_utils::get_anchor_output(&tx.0, funding_pubkey) {
664                                                 // An anchor output was found, so we should yield a funding event externally.
665                                                 Some((idx, _)) => {
666                                                         // TODO: Use a lower confirmation target when both our and the
667                                                         // counterparty's latest commitment don't have any HTLCs present.
668                                                         Some((
669                                                                 new_timer,
670                                                                 package_target_feerate_sat_per_1000_weight as u64,
671                                                                 OnchainClaim::Event(ClaimEvent::BumpCommitment {
672                                                                         package_target_feerate_sat_per_1000_weight,
673                                                                         commitment_tx: tx.0.clone(),
674                                                                         anchor_output_idx: idx,
675                                                                 }),
676                                                         ))
677                                                 },
678                                                 // An anchor output was not found. There's nothing we can do other than
679                                                 // attempt to broadcast the transaction with its current fee rate and hope
680                                                 // it confirms. This is essentially the same behavior as a commitment
681                                                 // transaction without anchor outputs.
682                                                 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
683                                         }
684                                 },
685                                 _ => {
686                                         debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
687                                         None
688                                 },
689                         })
690                 }
691                 None
692         }
693
694         pub fn abandon_claim(&mut self, outpoint: &BitcoinOutPoint) {
695                 let claim_id = self.claimable_outpoints.get(outpoint).map(|(claim_id, _)| *claim_id)
696                         .or_else(|| {
697                                 self.pending_claim_requests.iter()
698                                         .find(|(_, claim)| claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint))
699                                         .map(|(claim_id, _)| *claim_id)
700                         });
701                 if let Some(claim_id) = claim_id {
702                         if let Some(claim) = self.pending_claim_requests.remove(&claim_id) {
703                                 for outpoint in claim.outpoints() {
704                                         self.claimable_outpoints.remove(outpoint);
705                                 }
706                         }
707                 } else {
708                         self.locktimed_packages.values_mut().for_each(|claims|
709                                 claims.retain(|claim| !claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint)));
710                 }
711         }
712
713         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
714         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
715         /// Together with `update_claims_view_from_matched_txn` this used to be named
716         /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
717         /// preimage after force-close.
718         ///
719         /// `conf_height` represents the height at which the request was generated. This
720         /// does not need to equal the current blockchain tip height, which should be provided via
721         /// `cur_height`, however it must never be higher than `cur_height`.
722         pub(super) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Logger>(
723                 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
724                 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
725         ) where
726                 B::Target: BroadcasterInterface,
727                 F::Target: FeeEstimator,
728         {
729                 if !requests.is_empty() {
730                         log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
731                 }
732
733                 let mut preprocessed_requests = Vec::with_capacity(requests.len());
734                 let mut aggregated_request = None;
735
736                 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
737                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
738                 for req in requests {
739                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
740                         if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
741                                 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
742                         } else {
743                                 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
744                                         .find(|locked_package| locked_package.outpoints() == req.outpoints());
745                                 if let Some(package) = timelocked_equivalent_package {
746                                         log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
747                                                 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
748                                         continue;
749                                 }
750
751                                 let package_locktime = req.package_locktime(cur_height);
752                                 if package_locktime > cur_height + 1 {
753                                         log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
754                                         for outpoint in req.outpoints() {
755                                                 log_info!(logger, "  Outpoint {}", outpoint);
756                                         }
757                                         self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
758                                         continue;
759                                 }
760
761                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
762                                 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
763                                         // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
764                                         preprocessed_requests.push(req);
765                                 } else if aggregated_request.is_none() {
766                                         aggregated_request = Some(req);
767                                 } else {
768                                         aggregated_request.as_mut().unwrap().merge_package(req);
769                                 }
770                         }
771                 }
772                 if let Some(req) = aggregated_request {
773                         preprocessed_requests.push(req);
774                 }
775
776                 // Claim everything up to and including `cur_height`
777                 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
778                 if !self.locktimed_packages.is_empty() {
779                         log_debug!(logger,
780                                 "Updating claims view at height {} with {} locked packages available for claim",
781                                 cur_height,
782                                 self.locktimed_packages.len());
783                 }
784                 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
785                         log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
786                         preprocessed_requests.append(&mut entry);
787                 }
788                 self.locktimed_packages = remaining_locked_packages;
789
790                 // Generate claim transactions and track them to bump if necessary at
791                 // height timer expiration (i.e in how many blocks we're going to take action).
792                 for mut req in preprocessed_requests {
793                         if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
794                                 cur_height, &req, &FeerateStrategy::ForceBump, &*fee_estimator, &*logger,
795                         ) {
796                                 req.set_timer(new_timer);
797                                 req.set_feerate(new_feerate);
798                                 // Once a pending claim has an id assigned, it remains fixed until the claim is
799                                 // satisfied, regardless of whether the claim switches between different variants of
800                                 // `OnchainClaim`.
801                                 let claim_id = match claim {
802                                         OnchainClaim::Tx(tx) => {
803                                                 if tx.is_fully_signed() {
804                                                         log_info!(logger, "Broadcasting onchain {}", log_tx!(tx.0));
805                                                         broadcaster.broadcast_transactions(&[&tx.0]);
806                                                 } else {
807                                                         log_info!(logger, "Waiting for signature of unsigned onchain transaction {}", tx.0.txid());
808                                                 }
809                                                 ClaimId(tx.0.txid().to_byte_array())
810                                         },
811                                         OnchainClaim::Event(claim_event) => {
812                                                 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
813                                                 let claim_id = match claim_event {
814                                                         ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
815                                                                 // For commitment claims, we can just use their txid as it should
816                                                                 // already be unique.
817                                                                 ClaimId(commitment_tx.txid().to_byte_array()),
818                                                         ClaimEvent::BumpHTLC { ref htlcs, .. } => {
819                                                                 // For HTLC claims, commit to the entire set of HTLC outputs to
820                                                                 // claim, which will always be unique per request. Once a claim ID
821                                                                 // is generated, it is assigned and remains unchanged, even if the
822                                                                 // underlying set of HTLCs changes.
823                                                                 let mut engine = Sha256::engine();
824                                                                 for htlc in htlcs {
825                                                                         engine.input(&htlc.commitment_txid.to_byte_array());
826                                                                         engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
827                                                                 }
828                                                                 ClaimId(Sha256::from_engine(engine).to_byte_array())
829                                                         },
830                                                 };
831                                                 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
832                                                 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
833                                                 self.pending_claim_events.push((claim_id, claim_event));
834                                                 claim_id
835                                         },
836                                 };
837                                 // Because fuzzing can cause hash collisions, we can end up with conflicting claim
838                                 // ids here, so we only assert when not fuzzing.
839                                 debug_assert!(cfg!(fuzzing) || self.pending_claim_requests.get(&claim_id).is_none());
840                                 for k in req.outpoints() {
841                                         log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
842                                         self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
843                                 }
844                                 self.pending_claim_requests.insert(claim_id, req);
845                         }
846                 }
847         }
848
849         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
850         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
851         /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
852         /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
853         ///
854         /// `conf_height` represents the height at which the transactions in `txn_matched` were
855         /// confirmed. This does not need to equal the current blockchain tip height, which should be
856         /// provided via `cur_height`, however it must never be higher than `cur_height`.
857         pub(super) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Logger>(
858                 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
859                 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
860         ) where
861                 B::Target: BroadcasterInterface,
862                 F::Target: FeeEstimator,
863         {
864                 let mut have_logged_intro = false;
865                 let mut maybe_log_intro = || {
866                         if !have_logged_intro {
867                                 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
868                                 have_logged_intro = true;
869                         }
870                 };
871                 let mut bump_candidates = new_hash_map();
872                 if !txn_matched.is_empty() { maybe_log_intro(); }
873                 for tx in txn_matched {
874                         // Scan all input to verify is one of the outpoint spent is of interest for us
875                         let mut claimed_outputs_material = Vec::new();
876                         for inp in &tx.input {
877                                 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
878                                         // If outpoint has claim request pending on it...
879                                         if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
880                                                 //... we need to verify equality between transaction outpoints and claim request
881                                                 // outpoints to know if transaction is the original claim or a bumped one issued
882                                                 // by us.
883                                                 let mut are_sets_equal = true;
884                                                 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
885                                                 tx_inputs.sort_unstable();
886                                                 for request_input in request.outpoints() {
887                                                         if tx_inputs.binary_search(&request_input).is_err() {
888                                                                 are_sets_equal = false;
889                                                                 break;
890                                                         }
891                                                 }
892
893                                                 macro_rules! clean_claim_request_after_safety_delay {
894                                                         () => {
895                                                                 let entry = OnchainEventEntry {
896                                                                         txid: tx.txid(),
897                                                                         height: conf_height,
898                                                                         block_hash: Some(conf_hash),
899                                                                         event: OnchainEvent::Claim { claim_id: *claim_id }
900                                                                 };
901                                                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
902                                                                         self.onchain_events_awaiting_threshold_conf.push(entry);
903                                                                 }
904                                                         }
905                                                 }
906
907                                                 // If this is our transaction (or our counterparty spent all the outputs
908                                                 // before we could anyway with same inputs order than us), wait for
909                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
910                                                 if are_sets_equal {
911                                                         clean_claim_request_after_safety_delay!();
912                                                 } else { // If false, generate new claim request with update outpoint set
913                                                         let mut at_least_one_drop = false;
914                                                         for input in tx.input.iter() {
915                                                                 if let Some(package) = request.split_package(&input.previous_output) {
916                                                                         claimed_outputs_material.push(package);
917                                                                         at_least_one_drop = true;
918                                                                 }
919                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
920                                                                 if request.outpoints().is_empty() {
921                                                                         clean_claim_request_after_safety_delay!();
922                                                                 }
923                                                         }
924                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
925                                                         if at_least_one_drop {
926                                                                 bump_candidates.insert(*claim_id, request.clone());
927                                                                 // If we have any pending claim events for the request being updated
928                                                                 // that have yet to be consumed, we'll remove them since they will
929                                                                 // end up producing an invalid transaction by double spending
930                                                                 // input(s) that already have a confirmed spend. If such spend is
931                                                                 // reorged out of the chain, then we'll attempt to re-spend the
932                                                                 // inputs once we see it.
933                                                                 #[cfg(debug_assertions)] {
934                                                                         let existing = self.pending_claim_events.iter()
935                                                                                 .filter(|entry| entry.0 == *claim_id).count();
936                                                                         assert!(existing == 0 || existing == 1);
937                                                                 }
938                                                                 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
939                                                         }
940                                                 }
941                                                 break; //No need to iterate further, either tx is our or their
942                                         } else {
943                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
944                                         }
945                                 }
946                         }
947                         for package in claimed_outputs_material.drain(..) {
948                                 let entry = OnchainEventEntry {
949                                         txid: tx.txid(),
950                                         height: conf_height,
951                                         block_hash: Some(conf_hash),
952                                         event: OnchainEvent::ContentiousOutpoint { package },
953                                 };
954                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
955                                         self.onchain_events_awaiting_threshold_conf.push(entry);
956                                 }
957                         }
958                 }
959
960                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
961                 let onchain_events_awaiting_threshold_conf =
962                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
963                 for entry in onchain_events_awaiting_threshold_conf {
964                         if entry.has_reached_confirmation_threshold(cur_height) {
965                                 maybe_log_intro();
966                                 match entry.event {
967                                         OnchainEvent::Claim { claim_id } => {
968                                                 // We may remove a whole set of claim outpoints here, as these one may have
969                                                 // been aggregated in a single tx and claimed so atomically
970                                                 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
971                                                         for outpoint in request.outpoints() {
972                                                                 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
973                                                                         outpoint, log_bytes!(claim_id.0));
974                                                                 self.claimable_outpoints.remove(outpoint);
975                                                         }
976                                                         #[cfg(debug_assertions)] {
977                                                                 let num_existing = self.pending_claim_events.iter()
978                                                                         .filter(|entry| entry.0 == claim_id).count();
979                                                                 assert!(num_existing == 0 || num_existing == 1);
980                                                         }
981                                                         self.pending_claim_events.retain(|(id, _)| *id != claim_id);
982                                                 }
983                                         },
984                                         OnchainEvent::ContentiousOutpoint { package } => {
985                                                 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
986                                                 log_debug!(logger, " {:?}", package.outpoints());
987                                                 self.claimable_outpoints.remove(package.outpoints()[0]);
988                                         }
989                                 }
990                         } else {
991                                 self.onchain_events_awaiting_threshold_conf.push(entry);
992                         }
993                 }
994
995                 // Check if any pending claim request must be rescheduled
996                 for (claim_id, request) in self.pending_claim_requests.iter() {
997                         if cur_height >= request.timer() {
998                                 bump_candidates.insert(*claim_id, request.clone());
999                         }
1000                 }
1001
1002                 // Build, bump and rebroadcast tx accordingly
1003                 if !bump_candidates.is_empty() {
1004                         maybe_log_intro();
1005                         log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
1006                 }
1007
1008                 for (claim_id, request) in bump_candidates.iter() {
1009                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1010                                 cur_height, &request, &FeerateStrategy::ForceBump, &*fee_estimator, &*logger,
1011                         ) {
1012                                 match bump_claim {
1013                                         OnchainClaim::Tx(bump_tx) => {
1014                                                 if bump_tx.is_fully_signed() {
1015                                                         log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx.0));
1016                                                         broadcaster.broadcast_transactions(&[&bump_tx.0]);
1017                                                 } else {
1018                                                         log_info!(logger, "Waiting for signature of RBF-bumped unsigned onchain transaction {}",
1019                                                                 bump_tx.0.txid());
1020                                                 }
1021                                         },
1022                                         OnchainClaim::Event(claim_event) => {
1023                                                 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
1024                                                 #[cfg(debug_assertions)] {
1025                                                         let num_existing = self.pending_claim_events.iter().
1026                                                                 filter(|entry| entry.0 == *claim_id).count();
1027                                                         assert!(num_existing == 0 || num_existing == 1);
1028                                                 }
1029                                                 self.pending_claim_events.retain(|event| event.0 != *claim_id);
1030                                                 self.pending_claim_events.push((*claim_id, claim_event));
1031                                         },
1032                                 }
1033                                 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
1034                                         request.set_timer(new_timer);
1035                                         request.set_feerate(new_feerate);
1036                                 }
1037                         }
1038                 }
1039         }
1040
1041         pub(super) fn transaction_unconfirmed<B: Deref, F: Deref, L: Logger>(
1042                 &mut self,
1043                 txid: &Txid,
1044                 broadcaster: B,
1045                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1046                 logger: &L,
1047         ) where
1048                 B::Target: BroadcasterInterface,
1049                 F::Target: FeeEstimator,
1050         {
1051                 let mut height = None;
1052                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
1053                         if entry.txid == *txid {
1054                                 height = Some(entry.height);
1055                                 break;
1056                         }
1057                 }
1058
1059                 if let Some(height) = height {
1060                         self.block_disconnected(height, broadcaster, fee_estimator, logger);
1061                 }
1062         }
1063
1064         pub(super) fn block_disconnected<B: Deref, F: Deref, L: Logger>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
1065                 where B::Target: BroadcasterInterface,
1066                         F::Target: FeeEstimator,
1067         {
1068                 let mut bump_candidates = new_hash_map();
1069                 let onchain_events_awaiting_threshold_conf =
1070                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1071                 for entry in onchain_events_awaiting_threshold_conf {
1072                         if entry.height >= height {
1073                                 //- our claim tx on a commitment tx output
1074                                 //- resurect outpoint back in its claimable set and regenerate tx
1075                                 match entry.event {
1076                                         OnchainEvent::ContentiousOutpoint { package } => {
1077                                                 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1078                                                         if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1079                                                                 request.merge_package(package);
1080                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
1081                                                                 // resurrected only one bump claim tx is going to be broadcast
1082                                                                 bump_candidates.insert(pending_claim.clone(), request.clone());
1083                                                         }
1084                                                 }
1085                                         },
1086                                         _ => {},
1087                                 }
1088                         } else {
1089                                 self.onchain_events_awaiting_threshold_conf.push(entry);
1090                         }
1091                 }
1092                 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1093                         // `height` is the height being disconnected, so our `current_height` is 1 lower.
1094                         let current_height = height - 1;
1095                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1096                                 current_height, &request, &FeerateStrategy::ForceBump, fee_estimator, logger
1097                         ) {
1098                                 request.set_timer(new_timer);
1099                                 request.set_feerate(new_feerate);
1100                                 match bump_claim {
1101                                         OnchainClaim::Tx(bump_tx) => {
1102                                                 if bump_tx.is_fully_signed() {
1103                                                         log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx.0));
1104                                                         broadcaster.broadcast_transactions(&[&bump_tx.0]);
1105                                                 } else {
1106                                                         log_info!(logger, "Waiting for signature of unsigned onchain transaction {}", bump_tx.0.txid());
1107                                                 }
1108                                         },
1109                                         OnchainClaim::Event(claim_event) => {
1110                                                 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1111                                                 #[cfg(debug_assertions)] {
1112                                                         let num_existing = self.pending_claim_events.iter()
1113                                                                 .filter(|entry| entry.0 == *_claim_id).count();
1114                                                         assert!(num_existing == 0 || num_existing == 1);
1115                                                 }
1116                                                 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1117                                                 self.pending_claim_events.push((*_claim_id, claim_event));
1118                                         },
1119                                 }
1120                         }
1121                 }
1122                 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1123                         self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1124                 }
1125                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1126                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1127                 let mut remove_request = Vec::new();
1128                 self.claimable_outpoints.retain(|_, ref v|
1129                         if v.1 >= height {
1130                         remove_request.push(v.0.clone());
1131                         false
1132                         } else { true });
1133                 for req in remove_request {
1134                         self.pending_claim_requests.remove(&req);
1135                 }
1136         }
1137
1138         pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1139                 self.claimable_outpoints.get(outpoint).is_some()
1140         }
1141
1142         pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, u32, Option<BlockHash>)> {
1143                 let mut txids: Vec<(Txid, u32, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1144                         .iter()
1145                         .map(|entry| (entry.txid, entry.height, entry.block_hash))
1146                         .collect();
1147                 txids.sort_unstable_by(|a, b| a.0.cmp(&b.0).then(b.1.cmp(&a.1)));
1148                 txids.dedup_by_key(|(txid, _, _)| *txid);
1149                 txids
1150         }
1151
1152         pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1153                 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1154         }
1155
1156         pub(crate) fn get_unsigned_holder_commitment_tx(&self) -> &Transaction {
1157                 &self.holder_commitment.trust().built_transaction().transaction
1158         }
1159
1160         pub(crate) fn get_maybe_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> MaybeSignedTransaction {
1161                 let tx = self.signer.sign_holder_commitment(&self.holder_commitment, &self.secp_ctx)
1162                         .map(|sig| self.holder_commitment.add_holder_sig(funding_redeemscript, sig))
1163                         .unwrap_or_else(|_| self.get_unsigned_holder_commitment_tx().clone());
1164                 MaybeSignedTransaction(tx)
1165         }
1166
1167         #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1168         pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1169                 let sig = self.signer.unsafe_sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1170                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1171         }
1172
1173         pub(crate) fn get_maybe_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<MaybeSignedTransaction> {
1174                 let get_signed_htlc_tx = |holder_commitment: &HolderCommitmentTransaction| {
1175                         let trusted_tx = holder_commitment.trust();
1176                         if trusted_tx.txid() != outp.txid {
1177                                 return None;
1178                         }
1179                         let (htlc_idx, htlc) = trusted_tx.htlcs().iter().enumerate()
1180                                 .find(|(_, htlc)| htlc.transaction_output_index.unwrap() == outp.vout)
1181                                 .unwrap();
1182                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1183                         let mut htlc_tx = trusted_tx.build_unsigned_htlc_tx(
1184                                 &self.channel_transaction_parameters.as_holder_broadcastable(), htlc_idx, preimage,
1185                         );
1186
1187                         let htlc_descriptor = HTLCDescriptor {
1188                                 channel_derivation_parameters: ChannelDerivationParameters {
1189                                         value_satoshis: self.channel_value_satoshis,
1190                                         keys_id: self.channel_keys_id,
1191                                         transaction_parameters: self.channel_transaction_parameters.clone(),
1192                                 },
1193                                 commitment_txid: trusted_tx.txid(),
1194                                 per_commitment_number: trusted_tx.commitment_number(),
1195                                 per_commitment_point: trusted_tx.per_commitment_point(),
1196                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1197                                 htlc: htlc.clone(),
1198                                 preimage: preimage.clone(),
1199                                 counterparty_sig: counterparty_htlc_sig.clone(),
1200                         };
1201                         if let Ok(htlc_sig) = self.signer.sign_holder_htlc_transaction(&htlc_tx, 0, &htlc_descriptor, &self.secp_ctx) {
1202                                 htlc_tx.input[0].witness = trusted_tx.build_htlc_input_witness(
1203                                         htlc_idx, &counterparty_htlc_sig, &htlc_sig, preimage,
1204                                 );
1205                         }
1206                         Some(MaybeSignedTransaction(htlc_tx))
1207                 };
1208
1209                 // Check if the HTLC spends from the current holder commitment first, or the previous.
1210                 get_signed_htlc_tx(&self.holder_commitment)
1211                         .or_else(|| self.prev_holder_commitment.as_ref().and_then(|prev_holder_commitment| get_signed_htlc_tx(prev_holder_commitment)))
1212         }
1213
1214         pub(crate) fn generate_external_htlc_claim(
1215                 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1216         ) -> Option<ExternalHTLCClaim> {
1217                 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1218                         let trusted_tx = holder_commitment.trust();
1219                         if outp.txid != trusted_tx.txid() {
1220                                 return None;
1221                         }
1222                         trusted_tx.htlcs().iter().enumerate()
1223                                 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1224                                         output_index == outp.vout
1225                                 } else {
1226                                         false
1227                                 })
1228                                 .map(|(htlc_idx, htlc)| {
1229                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1230                                         ExternalHTLCClaim {
1231                                                 commitment_txid: trusted_tx.txid(),
1232                                                 per_commitment_number: trusted_tx.commitment_number(),
1233                                                 htlc: htlc.clone(),
1234                                                 preimage: *preimage,
1235                                                 counterparty_sig: counterparty_htlc_sig,
1236                                         }
1237                                 })
1238                 };
1239                 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1240                 find_htlc(&self.holder_commitment)
1241                         .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1242         }
1243
1244         pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1245                 &self.channel_transaction_parameters.channel_type_features
1246         }
1247 }