Bitcoin Core 28.99.0
P2P Digital Currency
validation.cpp
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1// Copyright (c) 2009-2010 Satoshi Nakamoto
2// Copyright (c) 2009-present The Bitcoin Core developers
3// Distributed under the MIT software license, see the accompanying
4// file COPYING or http://www.opensource.org/licenses/mit-license.php.
5
6#include <bitcoin-build-config.h> // IWYU pragma: keep
7
8#include <validation.h>
9
10#include <arith_uint256.h>
11#include <chain.h>
12#include <checkqueue.h>
13#include <clientversion.h>
14#include <consensus/amount.h>
15#include <consensus/consensus.h>
16#include <consensus/merkle.h>
17#include <consensus/tx_check.h>
18#include <consensus/tx_verify.h>
20#include <cuckoocache.h>
21#include <flatfile.h>
22#include <hash.h>
23#include <kernel/chain.h>
24#include <kernel/chainparams.h>
25#include <kernel/coinstats.h>
30#include <kernel/warning.h>
31#include <logging.h>
32#include <logging/timer.h>
33#include <node/blockstorage.h>
34#include <node/utxo_snapshot.h>
36#include <policy/policy.h>
37#include <policy/rbf.h>
38#include <policy/settings.h>
39#include <policy/truc_policy.h>
40#include <pow.h>
41#include <primitives/block.h>
43#include <random.h>
44#include <script/script.h>
45#include <script/sigcache.h>
46#include <signet.h>
47#include <tinyformat.h>
48#include <txdb.h>
49#include <txmempool.h>
50#include <uint256.h>
51#include <undo.h>
52#include <util/check.h>
53#include <util/fs.h>
54#include <util/fs_helpers.h>
55#include <util/hasher.h>
56#include <util/moneystr.h>
57#include <util/rbf.h>
58#include <util/result.h>
60#include <util/strencodings.h>
61#include <util/string.h>
62#include <util/time.h>
63#include <util/trace.h>
64#include <util/translation.h>
65#include <validationinterface.h>
66
67#include <algorithm>
68#include <cassert>
69#include <chrono>
70#include <deque>
71#include <numeric>
72#include <optional>
73#include <ranges>
74#include <span>
75#include <string>
76#include <tuple>
77#include <utility>
78
83
86using node::BlockMap;
90
92static constexpr size_t WARN_FLUSH_COINS_SIZE = 1 << 30; // 1 GiB
94static constexpr std::chrono::hours DATABASE_WRITE_INTERVAL{1};
96static constexpr std::chrono::hours DATABASE_FLUSH_INTERVAL{24};
98static constexpr std::chrono::hours MAX_FEE_ESTIMATION_TIP_AGE{3};
99const std::vector<std::string> CHECKLEVEL_DOC {
100 "level 0 reads the blocks from disk",
101 "level 1 verifies block validity",
102 "level 2 verifies undo data",
103 "level 3 checks disconnection of tip blocks",
104 "level 4 tries to reconnect the blocks",
105 "each level includes the checks of the previous levels",
106};
112static constexpr int PRUNE_LOCK_BUFFER{10};
113
114TRACEPOINT_SEMAPHORE(validation, block_connected);
115TRACEPOINT_SEMAPHORE(utxocache, flush);
116TRACEPOINT_SEMAPHORE(mempool, replaced);
117TRACEPOINT_SEMAPHORE(mempool, rejected);
118
120{
122
123 // Find the latest block common to locator and chain - we expect that
124 // locator.vHave is sorted descending by height.
125 for (const uint256& hash : locator.vHave) {
126 const CBlockIndex* pindex{m_blockman.LookupBlockIndex(hash)};
127 if (pindex) {
128 if (m_chain.Contains(pindex)) {
129 return pindex;
130 }
131 if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) {
132 return m_chain.Tip();
133 }
134 }
135 }
136 return m_chain.Genesis();
137}
138
140 const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore,
141 bool cacheFullScriptStore, PrecomputedTransactionData& txdata,
142 ValidationCache& validation_cache,
143 std::vector<CScriptCheck>* pvChecks = nullptr)
145
146bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx)
147{
149
150 // CheckFinalTxAtTip() uses active_chain_tip.Height()+1 to evaluate
151 // nLockTime because when IsFinalTx() is called within
152 // AcceptBlock(), the height of the block *being*
153 // evaluated is what is used. Thus if we want to know if a
154 // transaction can be part of the *next* block, we need to call
155 // IsFinalTx() with one more than active_chain_tip.Height().
156 const int nBlockHeight = active_chain_tip.nHeight + 1;
157
158 // BIP113 requires that time-locked transactions have nLockTime set to
159 // less than the median time of the previous block they're contained in.
160 // When the next block is created its previous block will be the current
161 // chain tip, so we use that to calculate the median time passed to
162 // IsFinalTx().
163 const int64_t nBlockTime{active_chain_tip.GetMedianTimePast()};
164
165 return IsFinalTx(tx, nBlockHeight, nBlockTime);
166}
167
168namespace {
179std::optional<std::vector<int>> CalculatePrevHeights(
180 const CBlockIndex& tip,
181 const CCoinsView& coins,
182 const CTransaction& tx)
183{
184 std::vector<int> prev_heights;
185 prev_heights.resize(tx.vin.size());
186 for (size_t i = 0; i < tx.vin.size(); ++i) {
187 if (auto coin{coins.GetCoin(tx.vin[i].prevout)}) {
188 prev_heights[i] = coin->nHeight == MEMPOOL_HEIGHT
189 ? tip.nHeight + 1 // Assume all mempool transaction confirm in the next block.
190 : coin->nHeight;
191 } else {
192 LogPrintf("ERROR: %s: Missing input %d in transaction \'%s\'\n", __func__, i, tx.GetHash().GetHex());
193 return std::nullopt;
194 }
195 }
196 return prev_heights;
197}
198} // namespace
199
200std::optional<LockPoints> CalculateLockPointsAtTip(
201 CBlockIndex* tip,
202 const CCoinsView& coins_view,
203 const CTransaction& tx)
204{
205 assert(tip);
206
207 auto prev_heights{CalculatePrevHeights(*tip, coins_view, tx)};
208 if (!prev_heights.has_value()) return std::nullopt;
209
210 CBlockIndex next_tip;
211 next_tip.pprev = tip;
212 // When SequenceLocks() is called within ConnectBlock(), the height
213 // of the block *being* evaluated is what is used.
214 // Thus if we want to know if a transaction can be part of the
215 // *next* block, we need to use one more than active_chainstate.m_chain.Height()
216 next_tip.nHeight = tip->nHeight + 1;
217 const auto [min_height, min_time] = CalculateSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS, prev_heights.value(), next_tip);
218
219 // Also store the hash of the block with the highest height of
220 // all the blocks which have sequence locked prevouts.
221 // This hash needs to still be on the chain
222 // for these LockPoint calculations to be valid
223 // Note: It is impossible to correctly calculate a maxInputBlock
224 // if any of the sequence locked inputs depend on unconfirmed txs,
225 // except in the special case where the relative lock time/height
226 // is 0, which is equivalent to no sequence lock. Since we assume
227 // input height of tip+1 for mempool txs and test the resulting
228 // min_height and min_time from CalculateSequenceLocks against tip+1.
229 int max_input_height{0};
230 for (const int height : prev_heights.value()) {
231 // Can ignore mempool inputs since we'll fail if they had non-zero locks
232 if (height != next_tip.nHeight) {
233 max_input_height = std::max(max_input_height, height);
234 }
235 }
236
237 // tip->GetAncestor(max_input_height) should never return a nullptr
238 // because max_input_height is always less than the tip height.
239 // It would, however, be a bad bug to continue execution, since a
240 // LockPoints object with the maxInputBlock member set to nullptr
241 // signifies no relative lock time.
242 return LockPoints{min_height, min_time, Assert(tip->GetAncestor(max_input_height))};
243}
244
246 const LockPoints& lock_points)
247{
248 assert(tip != nullptr);
249
250 CBlockIndex index;
251 index.pprev = tip;
252 // CheckSequenceLocksAtTip() uses active_chainstate.m_chain.Height()+1 to evaluate
253 // height based locks because when SequenceLocks() is called within
254 // ConnectBlock(), the height of the block *being*
255 // evaluated is what is used.
256 // Thus if we want to know if a transaction can be part of the
257 // *next* block, we need to use one more than active_chainstate.m_chain.Height()
258 index.nHeight = tip->nHeight + 1;
259
260 return EvaluateSequenceLocks(index, {lock_points.height, lock_points.time});
261}
262
263// Returns the script flags which should be checked for a given block
264static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman);
265
266static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache)
268{
270 AssertLockHeld(pool.cs);
271 int expired = pool.Expire(GetTime<std::chrono::seconds>() - pool.m_opts.expiry);
272 if (expired != 0) {
273 LogDebug(BCLog::MEMPOOL, "Expired %i transactions from the memory pool\n", expired);
274 }
275
276 std::vector<COutPoint> vNoSpendsRemaining;
277 pool.TrimToSize(pool.m_opts.max_size_bytes, &vNoSpendsRemaining);
278 for (const COutPoint& removed : vNoSpendsRemaining)
279 coins_cache.Uncache(removed);
280}
281
283{
285 if (active_chainstate.m_chainman.IsInitialBlockDownload()) {
286 return false;
287 }
288 if (active_chainstate.m_chain.Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE))
289 return false;
290 if (active_chainstate.m_chain.Height() < active_chainstate.m_chainman.m_best_header->nHeight - 1) {
291 return false;
292 }
293 return true;
294}
295
297 DisconnectedBlockTransactions& disconnectpool,
298 bool fAddToMempool)
299{
300 if (!m_mempool) return;
301
304 std::vector<uint256> vHashUpdate;
305 {
306 // disconnectpool is ordered so that the front is the most recently-confirmed
307 // transaction (the last tx of the block at the tip) in the disconnected chain.
308 // Iterate disconnectpool in reverse, so that we add transactions
309 // back to the mempool starting with the earliest transaction that had
310 // been previously seen in a block.
311 const auto queuedTx = disconnectpool.take();
312 auto it = queuedTx.rbegin();
313 while (it != queuedTx.rend()) {
314 // ignore validation errors in resurrected transactions
315 if (!fAddToMempool || (*it)->IsCoinBase() ||
316 AcceptToMemoryPool(*this, *it, GetTime(),
317 /*bypass_limits=*/true, /*test_accept=*/false).m_result_type !=
319 // If the transaction doesn't make it in to the mempool, remove any
320 // transactions that depend on it (which would now be orphans).
322 } else if (m_mempool->exists(GenTxid::Txid((*it)->GetHash()))) {
323 vHashUpdate.push_back((*it)->GetHash());
324 }
325 ++it;
326 }
327 }
328
329 // AcceptToMemoryPool/addNewTransaction all assume that new mempool entries have
330 // no in-mempool children, which is generally not true when adding
331 // previously-confirmed transactions back to the mempool.
332 // UpdateTransactionsFromBlock finds descendants of any transactions in
333 // the disconnectpool that were added back and cleans up the mempool state.
335
336 // Predicate to use for filtering transactions in removeForReorg.
337 // Checks whether the transaction is still final and, if it spends a coinbase output, mature.
338 // Also updates valid entries' cached LockPoints if needed.
339 // If false, the tx is still valid and its lockpoints are updated.
340 // If true, the tx would be invalid in the next block; remove this entry and all of its descendants.
341 // Note that TRUC rules are not applied here, so reorgs may cause violations of TRUC inheritance or
342 // topology restrictions.
343 const auto filter_final_and_mature = [&](CTxMemPool::txiter it)
347 const CTransaction& tx = it->GetTx();
348
349 // The transaction must be final.
350 if (!CheckFinalTxAtTip(*Assert(m_chain.Tip()), tx)) return true;
351
352 const LockPoints& lp = it->GetLockPoints();
353 // CheckSequenceLocksAtTip checks if the transaction will be final in the next block to be
354 // created on top of the new chain.
357 return true;
358 }
359 } else {
360 const CCoinsViewMemPool view_mempool{&CoinsTip(), *m_mempool};
361 const std::optional<LockPoints> new_lock_points{CalculateLockPointsAtTip(m_chain.Tip(), view_mempool, tx)};
362 if (new_lock_points.has_value() && CheckSequenceLocksAtTip(m_chain.Tip(), *new_lock_points)) {
363 // Now update the mempool entry lockpoints as well.
364 it->UpdateLockPoints(*new_lock_points);
365 } else {
366 return true;
367 }
368 }
369
370 // If the transaction spends any coinbase outputs, it must be mature.
371 if (it->GetSpendsCoinbase()) {
372 for (const CTxIn& txin : tx.vin) {
373 if (m_mempool->exists(GenTxid::Txid(txin.prevout.hash))) continue;
374 const Coin& coin{CoinsTip().AccessCoin(txin.prevout)};
375 assert(!coin.IsSpent());
376 const auto mempool_spend_height{m_chain.Tip()->nHeight + 1};
377 if (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY) {
378 return true;
379 }
380 }
381 }
382 // Transaction is still valid and cached LockPoints are updated.
383 return false;
384 };
385
386 // We also need to remove any now-immature transactions
387 m_mempool->removeForReorg(m_chain, filter_final_and_mature);
388 // Re-limit mempool size, in case we added any transactions
390}
391
398 const CCoinsViewCache& view, const CTxMemPool& pool,
399 unsigned int flags, PrecomputedTransactionData& txdata, CCoinsViewCache& coins_tip,
400 ValidationCache& validation_cache)
402{
405
407 for (const CTxIn& txin : tx.vin) {
408 const Coin& coin = view.AccessCoin(txin.prevout);
409
410 // This coin was checked in PreChecks and MemPoolAccept
411 // has been holding cs_main since then.
412 Assume(!coin.IsSpent());
413 if (coin.IsSpent()) return false;
414
415 // If the Coin is available, there are 2 possibilities:
416 // it is available in our current ChainstateActive UTXO set,
417 // or it's a UTXO provided by a transaction in our mempool.
418 // Ensure the scriptPubKeys in Coins from CoinsView are correct.
419 const CTransactionRef& txFrom = pool.get(txin.prevout.hash);
420 if (txFrom) {
421 assert(txFrom->GetHash() == txin.prevout.hash);
422 assert(txFrom->vout.size() > txin.prevout.n);
423 assert(txFrom->vout[txin.prevout.n] == coin.out);
424 } else {
425 const Coin& coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout);
426 assert(!coinFromUTXOSet.IsSpent());
427 assert(coinFromUTXOSet.out == coin.out);
428 }
429 }
430
431 // Call CheckInputScripts() to cache signature and script validity against current tip consensus rules.
432 return CheckInputScripts(tx, state, view, flags, /* cacheSigStore= */ true, /* cacheFullScriptStore= */ true, txdata, validation_cache);
433}
434
435namespace {
436
437class MemPoolAccept
438{
439public:
440 explicit MemPoolAccept(CTxMemPool& mempool, Chainstate& active_chainstate) :
441 m_pool(mempool),
442 m_view(&m_dummy),
443 m_viewmempool(&active_chainstate.CoinsTip(), m_pool),
444 m_active_chainstate(active_chainstate)
445 {
446 }
447
448 // We put the arguments we're handed into a struct, so we can pass them
449 // around easier.
450 struct ATMPArgs {
451 const CChainParams& m_chainparams;
452 const int64_t m_accept_time;
453 const bool m_bypass_limits;
454 /*
455 * Return any outpoints which were not previously present in the coins
456 * cache, but were added as a result of validating the tx for mempool
457 * acceptance. This allows the caller to optionally remove the cache
458 * additions if the associated transaction ends up being rejected by
459 * the mempool.
460 */
461 std::vector<COutPoint>& m_coins_to_uncache;
463 const bool m_test_accept;
467 const bool m_allow_replacement;
469 const bool m_allow_sibling_eviction;
474 const bool m_package_submission;
478 const bool m_package_feerates;
483 const std::optional<CFeeRate> m_client_maxfeerate;
484
486 const bool m_allow_carveouts;
487
489 static ATMPArgs SingleAccept(const CChainParams& chainparams, int64_t accept_time,
490 bool bypass_limits, std::vector<COutPoint>& coins_to_uncache,
491 bool test_accept) {
492 return ATMPArgs{/* m_chainparams */ chainparams,
493 /* m_accept_time */ accept_time,
494 /* m_bypass_limits */ bypass_limits,
495 /* m_coins_to_uncache */ coins_to_uncache,
496 /* m_test_accept */ test_accept,
497 /* m_allow_replacement */ true,
498 /* m_allow_sibling_eviction */ true,
499 /* m_package_submission */ false,
500 /* m_package_feerates */ false,
501 /* m_client_maxfeerate */ {}, // checked by caller
502 /* m_allow_carveouts */ true,
503 };
504 }
505
507 static ATMPArgs PackageTestAccept(const CChainParams& chainparams, int64_t accept_time,
508 std::vector<COutPoint>& coins_to_uncache) {
509 return ATMPArgs{/* m_chainparams */ chainparams,
510 /* m_accept_time */ accept_time,
511 /* m_bypass_limits */ false,
512 /* m_coins_to_uncache */ coins_to_uncache,
513 /* m_test_accept */ true,
514 /* m_allow_replacement */ false,
515 /* m_allow_sibling_eviction */ false,
516 /* m_package_submission */ false, // not submitting to mempool
517 /* m_package_feerates */ false,
518 /* m_client_maxfeerate */ {}, // checked by caller
519 /* m_allow_carveouts */ false,
520 };
521 }
522
524 static ATMPArgs PackageChildWithParents(const CChainParams& chainparams, int64_t accept_time,
525 std::vector<COutPoint>& coins_to_uncache, const std::optional<CFeeRate>& client_maxfeerate) {
526 return ATMPArgs{/* m_chainparams */ chainparams,
527 /* m_accept_time */ accept_time,
528 /* m_bypass_limits */ false,
529 /* m_coins_to_uncache */ coins_to_uncache,
530 /* m_test_accept */ false,
531 /* m_allow_replacement */ true,
532 /* m_allow_sibling_eviction */ false,
533 /* m_package_submission */ true,
534 /* m_package_feerates */ true,
535 /* m_client_maxfeerate */ client_maxfeerate,
536 /* m_allow_carveouts */ false,
537 };
538 }
539
541 static ATMPArgs SingleInPackageAccept(const ATMPArgs& package_args) {
542 return ATMPArgs{/* m_chainparams */ package_args.m_chainparams,
543 /* m_accept_time */ package_args.m_accept_time,
544 /* m_bypass_limits */ false,
545 /* m_coins_to_uncache */ package_args.m_coins_to_uncache,
546 /* m_test_accept */ package_args.m_test_accept,
547 /* m_allow_replacement */ true,
548 /* m_allow_sibling_eviction */ true,
549 /* m_package_submission */ true, // do not LimitMempoolSize in Finalize()
550 /* m_package_feerates */ false, // only 1 transaction
551 /* m_client_maxfeerate */ package_args.m_client_maxfeerate,
552 /* m_allow_carveouts */ false,
553 };
554 }
555
556 private:
557 // Private ctor to avoid exposing details to clients and allowing the possibility of
558 // mixing up the order of the arguments. Use static functions above instead.
559 ATMPArgs(const CChainParams& chainparams,
560 int64_t accept_time,
561 bool bypass_limits,
562 std::vector<COutPoint>& coins_to_uncache,
563 bool test_accept,
564 bool allow_replacement,
565 bool allow_sibling_eviction,
566 bool package_submission,
567 bool package_feerates,
568 std::optional<CFeeRate> client_maxfeerate,
569 bool allow_carveouts)
570 : m_chainparams{chainparams},
571 m_accept_time{accept_time},
572 m_bypass_limits{bypass_limits},
573 m_coins_to_uncache{coins_to_uncache},
574 m_test_accept{test_accept},
575 m_allow_replacement{allow_replacement},
576 m_allow_sibling_eviction{allow_sibling_eviction},
577 m_package_submission{package_submission},
578 m_package_feerates{package_feerates},
579 m_client_maxfeerate{client_maxfeerate},
580 m_allow_carveouts{allow_carveouts}
581 {
582 // If we are using package feerates, we must be doing package submission.
583 // It also means carveouts and sibling eviction are not permitted.
584 if (m_package_feerates) {
585 Assume(m_package_submission);
586 Assume(!m_allow_carveouts);
587 Assume(!m_allow_sibling_eviction);
588 }
589 if (m_allow_sibling_eviction) Assume(m_allow_replacement);
590 }
591 };
592
594 void CleanupTemporaryCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
595
596 // Single transaction acceptance
597 MempoolAcceptResult AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
598
604 PackageMempoolAcceptResult AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
605
616 PackageMempoolAcceptResult AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args)
618
623 PackageMempoolAcceptResult AcceptPackage(const Package& package, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
624
625private:
626 // All the intermediate state that gets passed between the various levels
627 // of checking a given transaction.
628 struct Workspace {
629 explicit Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {}
632 std::set<Txid> m_conflicts;
635 CTxMemPool::setEntries m_iters_conflicting;
637 CTxMemPool::setEntries m_ancestors;
638 /* Handle to the tx in the changeset */
642 bool m_sibling_eviction{false};
643
646 int64_t m_vsize;
648 CAmount m_base_fees;
650 CAmount m_modified_fees;
651
655 CFeeRate m_package_feerate{0};
656
657 const CTransactionRef& m_ptx;
659 const Txid& m_hash;
660 TxValidationState m_state;
663 PrecomputedTransactionData m_precomputed_txdata;
664 };
665
666 // Run the policy checks on a given transaction, excluding any script checks.
667 // Looks up inputs, calculates feerate, considers replacement, evaluates
668 // package limits, etc. As this function can be invoked for "free" by a peer,
669 // only tests that are fast should be done here (to avoid CPU DoS).
670 bool PreChecks(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
671
672 // Run checks for mempool replace-by-fee, only used in AcceptSingleTransaction.
673 bool ReplacementChecks(Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
674
675 // Enforce package mempool ancestor/descendant limits (distinct from individual
676 // ancestor/descendant limits done in PreChecks) and run Package RBF checks.
677 bool PackageMempoolChecks(const std::vector<CTransactionRef>& txns,
678 std::vector<Workspace>& workspaces,
679 int64_t total_vsize,
680 PackageValidationState& package_state) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
681
682 // Run the script checks using our policy flags. As this can be slow, we should
683 // only invoke this on transactions that have otherwise passed policy checks.
684 bool PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
685
686 // Re-run the script checks, using consensus flags, and try to cache the
687 // result in the scriptcache. This should be done after
688 // PolicyScriptChecks(). This requires that all inputs either be in our
689 // utxo set or in the mempool.
690 bool ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
691
692 // Try to add the transaction to the mempool, removing any conflicts first.
693 void FinalizeSubpackage(const ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
694
695 // Submit all transactions to the mempool and call ConsensusScriptChecks to add to the script
696 // cache - should only be called after successful validation of all transactions in the package.
697 // Does not call LimitMempoolSize(), so mempool max_size_bytes may be temporarily exceeded.
698 bool SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, PackageValidationState& package_state,
699 std::map<uint256, MempoolAcceptResult>& results)
701
702 // Compare a package's feerate against minimum allowed.
703 bool CheckFeeRate(size_t package_size, CAmount package_fee, TxValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs)
704 {
706 AssertLockHeld(m_pool.cs);
707 CAmount mempoolRejectFee = m_pool.GetMinFee().GetFee(package_size);
708 if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) {
709 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee));
710 }
711
712 if (package_fee < m_pool.m_opts.min_relay_feerate.GetFee(package_size)) {
713 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "min relay fee not met",
714 strprintf("%d < %d", package_fee, m_pool.m_opts.min_relay_feerate.GetFee(package_size)));
715 }
716 return true;
717 }
718
719 ValidationCache& GetValidationCache()
720 {
721 return m_active_chainstate.m_chainman.m_validation_cache;
722 }
723
724private:
725 CTxMemPool& m_pool;
726 CCoinsViewCache m_view;
727 CCoinsViewMemPool m_viewmempool;
728 CCoinsView m_dummy;
729
730 Chainstate& m_active_chainstate;
731
732 // Fields below are per *sub*package state and must be reset prior to subsequent
733 // AcceptSingleTransaction and AcceptMultipleTransactions invocations
734 struct SubPackageState {
736 CAmount m_total_modified_fees{0};
738 int64_t m_total_vsize{0};
739
740 // RBF-related members
743 bool m_rbf{false};
745 std::list<CTransactionRef> m_replaced_transactions;
746 /* Changeset representing adding transactions and removing their conflicts. */
747 std::unique_ptr<CTxMemPool::ChangeSet> m_changeset;
748
750 CAmount m_conflicting_fees{0};
752 size_t m_conflicting_size{0};
753 };
754
755 struct SubPackageState m_subpackage;
756
758 void ClearSubPackageState() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs)
759 {
760 m_subpackage = SubPackageState{};
761
762 // And clean coins while at it
763 CleanupTemporaryCoins();
764 }
765};
766
767bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
768{
770 AssertLockHeld(m_pool.cs);
771 const CTransactionRef& ptx = ws.m_ptx;
772 const CTransaction& tx = *ws.m_ptx;
773 const Txid& hash = ws.m_hash;
774
775 // Copy/alias what we need out of args
776 const int64_t nAcceptTime = args.m_accept_time;
777 const bool bypass_limits = args.m_bypass_limits;
778 std::vector<COutPoint>& coins_to_uncache = args.m_coins_to_uncache;
779
780 // Alias what we need out of ws
781 TxValidationState& state = ws.m_state;
782
783 if (!CheckTransaction(tx, state)) {
784 return false; // state filled in by CheckTransaction
785 }
786
787 // Coinbase is only valid in a block, not as a loose transaction
788 if (tx.IsCoinBase())
789 return state.Invalid(TxValidationResult::TX_CONSENSUS, "coinbase");
790
791 // Rather not work on nonstandard transactions (unless -testnet/-regtest)
792 std::string reason;
793 if (m_pool.m_opts.require_standard && !IsStandardTx(tx, m_pool.m_opts.max_datacarrier_bytes, m_pool.m_opts.permit_bare_multisig, m_pool.m_opts.dust_relay_feerate, reason)) {
794 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason);
795 }
796
797 // Transactions smaller than 65 non-witness bytes are not relayed to mitigate CVE-2017-12842.
799 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "tx-size-small");
800
801 // Only accept nLockTime-using transactions that can be mined in the next
802 // block; we don't want our mempool filled up with transactions that can't
803 // be mined yet.
804 if (!CheckFinalTxAtTip(*Assert(m_active_chainstate.m_chain.Tip()), tx)) {
805 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-final");
806 }
807
808 if (m_pool.exists(GenTxid::Wtxid(tx.GetWitnessHash()))) {
809 // Exact transaction already exists in the mempool.
810 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-in-mempool");
811 } else if (m_pool.exists(GenTxid::Txid(tx.GetHash()))) {
812 // Transaction with the same non-witness data but different witness (same txid, different
813 // wtxid) already exists in the mempool.
814 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-same-nonwitness-data-in-mempool");
815 }
816
817 // Check for conflicts with in-memory transactions
818 for (const CTxIn &txin : tx.vin)
819 {
820 const CTransaction* ptxConflicting = m_pool.GetConflictTx(txin.prevout);
821 if (ptxConflicting) {
822 if (!args.m_allow_replacement) {
823 // Transaction conflicts with a mempool tx, but we're not allowing replacements in this context.
824 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "bip125-replacement-disallowed");
825 }
826 ws.m_conflicts.insert(ptxConflicting->GetHash());
827 }
828 }
829
830 m_view.SetBackend(m_viewmempool);
831
832 const CCoinsViewCache& coins_cache = m_active_chainstate.CoinsTip();
833 // do all inputs exist?
834 for (const CTxIn& txin : tx.vin) {
835 if (!coins_cache.HaveCoinInCache(txin.prevout)) {
836 coins_to_uncache.push_back(txin.prevout);
837 }
838
839 // Note: this call may add txin.prevout to the coins cache
840 // (coins_cache.cacheCoins) by way of FetchCoin(). It should be removed
841 // later (via coins_to_uncache) if this tx turns out to be invalid.
842 if (!m_view.HaveCoin(txin.prevout)) {
843 // Are inputs missing because we already have the tx?
844 for (size_t out = 0; out < tx.vout.size(); out++) {
845 // Optimistically just do efficient check of cache for outputs
846 if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) {
847 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-known");
848 }
849 }
850 // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet
851 return state.Invalid(TxValidationResult::TX_MISSING_INPUTS, "bad-txns-inputs-missingorspent");
852 }
853 }
854
855 // This is const, but calls into the back end CoinsViews. The CCoinsViewDB at the bottom of the
856 // hierarchy brings the best block into scope. See CCoinsViewDB::GetBestBlock().
857 m_view.GetBestBlock();
858
859 // we have all inputs cached now, so switch back to dummy (to protect
860 // against bugs where we pull more inputs from disk that miss being added
861 // to coins_to_uncache)
862 m_view.SetBackend(m_dummy);
863
864 assert(m_active_chainstate.m_blockman.LookupBlockIndex(m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip());
865
866 // Only accept BIP68 sequence locked transactions that can be mined in the next
867 // block; we don't want our mempool filled up with transactions that can't
868 // be mined yet.
869 // Pass in m_view which has all of the relevant inputs cached. Note that, since m_view's
870 // backend was removed, it no longer pulls coins from the mempool.
871 const std::optional<LockPoints> lock_points{CalculateLockPointsAtTip(m_active_chainstate.m_chain.Tip(), m_view, tx)};
872 if (!lock_points.has_value() || !CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(), *lock_points)) {
873 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-BIP68-final");
874 }
875
876 // The mempool holds txs for the next block, so pass height+1 to CheckTxInputs
877 if (!Consensus::CheckTxInputs(tx, state, m_view, m_active_chainstate.m_chain.Height() + 1, ws.m_base_fees)) {
878 return false; // state filled in by CheckTxInputs
879 }
880
881 if (m_pool.m_opts.require_standard && !AreInputsStandard(tx, m_view)) {
882 return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs");
883 }
884
885 // Check for non-standard witnesses.
886 if (tx.HasWitness() && m_pool.m_opts.require_standard && !IsWitnessStandard(tx, m_view)) {
887 return state.Invalid(TxValidationResult::TX_WITNESS_MUTATED, "bad-witness-nonstandard");
888 }
889
890 int64_t nSigOpsCost = GetTransactionSigOpCost(tx, m_view, STANDARD_SCRIPT_VERIFY_FLAGS);
891
892 // Keep track of transactions that spend a coinbase, which we re-scan
893 // during reorgs to ensure COINBASE_MATURITY is still met.
894 bool fSpendsCoinbase = false;
895 for (const CTxIn &txin : tx.vin) {
896 const Coin &coin = m_view.AccessCoin(txin.prevout);
897 if (coin.IsCoinBase()) {
898 fSpendsCoinbase = true;
899 break;
900 }
901 }
902
903 // Set entry_sequence to 0 when bypass_limits is used; this allows txs from a block
904 // reorg to be marked earlier than any child txs that were already in the mempool.
905 const uint64_t entry_sequence = bypass_limits ? 0 : m_pool.GetSequence();
906 if (!m_subpackage.m_changeset) {
907 m_subpackage.m_changeset = m_pool.GetChangeSet();
908 }
909 ws.m_tx_handle = m_subpackage.m_changeset->StageAddition(ptx, ws.m_base_fees, nAcceptTime, m_active_chainstate.m_chain.Height(), entry_sequence, fSpendsCoinbase, nSigOpsCost, lock_points.value());
910
911 // ws.m_modified_fees includes any fee deltas from PrioritiseTransaction
912 ws.m_modified_fees = ws.m_tx_handle->GetModifiedFee();
913
914 ws.m_vsize = ws.m_tx_handle->GetTxSize();
915
916 // Enforces 0-fee for dust transactions, no incentive to be mined alone
917 if (m_pool.m_opts.require_standard) {
918 if (!PreCheckEphemeralTx(*ptx, m_pool.m_opts.dust_relay_feerate, ws.m_base_fees, ws.m_modified_fees, state)) {
919 return false; // state filled in by PreCheckEphemeralTx
920 }
921 }
922
923 if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST)
924 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "bad-txns-too-many-sigops",
925 strprintf("%d", nSigOpsCost));
926
927 // No individual transactions are allowed below the min relay feerate except from disconnected blocks.
928 // This requirement, unlike CheckFeeRate, cannot be bypassed using m_package_feerates because,
929 // while a tx could be package CPFP'd when entering the mempool, we do not have a DoS-resistant
930 // method of ensuring the tx remains bumped. For example, the fee-bumping child could disappear
931 // due to a replacement.
932 // The only exception is TRUC transactions.
933 if (!bypass_limits && ws.m_ptx->version != TRUC_VERSION && ws.m_modified_fees < m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize)) {
934 // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not
935 // TX_RECONSIDERABLE, because it cannot be bypassed using package validation.
936 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met",
937 strprintf("%d < %d", ws.m_modified_fees, m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize)));
938 }
939 // No individual transactions are allowed below the mempool min feerate except from disconnected
940 // blocks and transactions in a package. Package transactions will be checked using package
941 // feerate later.
942 if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false;
943
944 ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts);
945
946 // Note that these modifications are only applicable to single transaction scenarios;
947 // carve-outs are disabled for multi-transaction evaluations.
948 CTxMemPool::Limits maybe_rbf_limits = m_pool.m_opts.limits;
949
950 // Calculate in-mempool ancestors, up to a limit.
951 if (ws.m_conflicts.size() == 1 && args.m_allow_carveouts) {
952 // In general, when we receive an RBF transaction with mempool conflicts, we want to know whether we
953 // would meet the chain limits after the conflicts have been removed. However, there isn't a practical
954 // way to do this short of calculating the ancestor and descendant sets with an overlay cache of
955 // changed mempool entries. Due to both implementation and runtime complexity concerns, this isn't
956 // very realistic, thus we only ensure a limited set of transactions are RBF'able despite mempool
957 // conflicts here. Importantly, we need to ensure that some transactions which were accepted using
958 // the below carve-out are able to be RBF'ed, without impacting the security the carve-out provides
959 // for off-chain contract systems (see link in the comment below).
960 //
961 // Specifically, the subset of RBF transactions which we allow despite chain limits are those which
962 // conflict directly with exactly one other transaction (but may evict children of said transaction),
963 // and which are not adding any new mempool dependencies. Note that the "no new mempool dependencies"
964 // check is accomplished later, so we don't bother doing anything about it here, but if our
965 // policy changes, we may need to move that check to here instead of removing it wholesale.
966 //
967 // Such transactions are clearly not merging any existing packages, so we are only concerned with
968 // ensuring that (a) no package is growing past the package size (not count) limits and (b) we are
969 // not allowing something to effectively use the (below) carve-out spot when it shouldn't be allowed
970 // to.
971 //
972 // To check these we first check if we meet the RBF criteria, above, and increment the descendant
973 // limits by the direct conflict and its descendants (as these are recalculated in
974 // CalculateMempoolAncestors by assuming the new transaction being added is a new descendant, with no
975 // removals, of each parent's existing dependent set). The ancestor count limits are unmodified (as
976 // the ancestor limits should be the same for both our new transaction and any conflicts).
977 // We don't bother incrementing m_limit_descendants by the full removal count as that limit never comes
978 // into force here (as we're only adding a single transaction).
979 assert(ws.m_iters_conflicting.size() == 1);
980 CTxMemPool::txiter conflict = *ws.m_iters_conflicting.begin();
981
982 maybe_rbf_limits.descendant_count += 1;
983 maybe_rbf_limits.descendant_size_vbytes += conflict->GetSizeWithDescendants();
984 }
985
986 if (auto ancestors{m_subpackage.m_changeset->CalculateMemPoolAncestors(ws.m_tx_handle, maybe_rbf_limits)}) {
987 ws.m_ancestors = std::move(*ancestors);
988 } else {
989 // If CalculateMemPoolAncestors fails second time, we want the original error string.
990 const auto error_message{util::ErrorString(ancestors).original};
991
992 // Carve-out is not allowed in this context; fail
993 if (!args.m_allow_carveouts) {
994 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message);
995 }
996
997 // Contracting/payment channels CPFP carve-out:
998 // If the new transaction is relatively small (up to 40k weight)
999 // and has at most one ancestor (ie ancestor limit of 2, including
1000 // the new transaction), allow it if its parent has exactly the
1001 // descendant limit descendants. The transaction also cannot be TRUC,
1002 // as its topology restrictions do not allow a second child.
1003 //
1004 // This allows protocols which rely on distrusting counterparties
1005 // being able to broadcast descendants of an unconfirmed transaction
1006 // to be secure by simply only having two immediately-spendable
1007 // outputs - one for each counterparty. For more info on the uses for
1008 // this, see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html
1009 CTxMemPool::Limits cpfp_carve_out_limits{
1010 .ancestor_count = 2,
1011 .ancestor_size_vbytes = maybe_rbf_limits.ancestor_size_vbytes,
1012 .descendant_count = maybe_rbf_limits.descendant_count + 1,
1013 .descendant_size_vbytes = maybe_rbf_limits.descendant_size_vbytes + EXTRA_DESCENDANT_TX_SIZE_LIMIT,
1014 };
1015 if (ws.m_vsize > EXTRA_DESCENDANT_TX_SIZE_LIMIT || ws.m_ptx->version == TRUC_VERSION) {
1016 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message);
1017 }
1018 if (auto ancestors_retry{m_subpackage.m_changeset->CalculateMemPoolAncestors(ws.m_tx_handle, cpfp_carve_out_limits)}) {
1019 ws.m_ancestors = std::move(*ancestors_retry);
1020 } else {
1021 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message);
1022 }
1023 }
1024
1025 // Even though just checking direct mempool parents for inheritance would be sufficient, we
1026 // check using the full ancestor set here because it's more convenient to use what we have
1027 // already calculated.
1028 if (const auto err{SingleTRUCChecks(ws.m_ptx, ws.m_ancestors, ws.m_conflicts, ws.m_vsize)}) {
1029 // Single transaction contexts only.
1030 if (args.m_allow_sibling_eviction && err->second != nullptr) {
1031 // We should only be considering where replacement is considered valid as well.
1032 Assume(args.m_allow_replacement);
1033
1034 // Potential sibling eviction. Add the sibling to our list of mempool conflicts to be
1035 // included in RBF checks.
1036 ws.m_conflicts.insert(err->second->GetHash());
1037 // Adding the sibling to m_iters_conflicting here means that it doesn't count towards
1038 // RBF Carve Out above. This is correct, since removing to-be-replaced transactions from
1039 // the descendant count is done separately in SingleTRUCChecks for TRUC transactions.
1040 ws.m_iters_conflicting.insert(m_pool.GetIter(err->second->GetHash()).value());
1041 ws.m_sibling_eviction = true;
1042 // The sibling will be treated as part of the to-be-replaced set in ReplacementChecks.
1043 // Note that we are not checking whether it opts in to replaceability via BIP125 or TRUC
1044 // (which is normally done in PreChecks). However, the only way a TRUC transaction can
1045 // have a non-TRUC and non-BIP125 descendant is due to a reorg.
1046 } else {
1047 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "TRUC-violation", err->first);
1048 }
1049 }
1050
1051 // A transaction that spends outputs that would be replaced by it is invalid. Now
1052 // that we have the set of all ancestors we can detect this
1053 // pathological case by making sure ws.m_conflicts and ws.m_ancestors don't
1054 // intersect.
1055 if (const auto err_string{EntriesAndTxidsDisjoint(ws.m_ancestors, ws.m_conflicts, hash)}) {
1056 // We classify this as a consensus error because a transaction depending on something it
1057 // conflicts with would be inconsistent.
1058 return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-spends-conflicting-tx", *err_string);
1059 }
1060
1061 // We want to detect conflicts in any tx in a package to trigger package RBF logic
1062 m_subpackage.m_rbf |= !ws.m_conflicts.empty();
1063 return true;
1064}
1065
1066bool MemPoolAccept::ReplacementChecks(Workspace& ws)
1067{
1069 AssertLockHeld(m_pool.cs);
1070
1071 const CTransaction& tx = *ws.m_ptx;
1072 const uint256& hash = ws.m_hash;
1073 TxValidationState& state = ws.m_state;
1074
1075 CFeeRate newFeeRate(ws.m_modified_fees, ws.m_vsize);
1076 // Enforce Rule #6. The replacement transaction must have a higher feerate than its direct conflicts.
1077 // - The motivation for this check is to ensure that the replacement transaction is preferable for
1078 // block-inclusion, compared to what would be removed from the mempool.
1079 // - This logic predates ancestor feerate-based transaction selection, which is why it doesn't
1080 // consider feerates of descendants.
1081 // - Note: Ancestor feerate-based transaction selection has made this comparison insufficient to
1082 // guarantee that this is incentive-compatible for miners, because it is possible for a
1083 // descendant transaction of a direct conflict to pay a higher feerate than the transaction that
1084 // might replace them, under these rules.
1085 if (const auto err_string{PaysMoreThanConflicts(ws.m_iters_conflicting, newFeeRate, hash)}) {
1086 // This fee-related failure is TX_RECONSIDERABLE because validating in a package may change
1087 // the result.
1089 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string);
1090 }
1091
1092 CTxMemPool::setEntries all_conflicts;
1093
1094 // Calculate all conflicting entries and enforce Rule #5.
1095 if (const auto err_string{GetEntriesForConflicts(tx, m_pool, ws.m_iters_conflicting, all_conflicts)}) {
1097 strprintf("too many potential replacements%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string);
1098 }
1099 // Enforce Rule #2.
1100 if (const auto err_string{HasNoNewUnconfirmed(tx, m_pool, all_conflicts)}) {
1101 // Sibling eviction is only done for TRUC transactions, which cannot have multiple ancestors.
1102 Assume(!ws.m_sibling_eviction);
1104 strprintf("replacement-adds-unconfirmed%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string);
1105 }
1106
1107 // Check if it's economically rational to mine this transaction rather than the ones it
1108 // replaces and pays for its own relay fees. Enforce Rules #3 and #4.
1109 for (CTxMemPool::txiter it : all_conflicts) {
1110 m_subpackage.m_conflicting_fees += it->GetModifiedFee();
1111 m_subpackage.m_conflicting_size += it->GetTxSize();
1112 }
1113 if (const auto err_string{PaysForRBF(m_subpackage.m_conflicting_fees, ws.m_modified_fees, ws.m_vsize,
1114 m_pool.m_opts.incremental_relay_feerate, hash)}) {
1115 // Result may change in a package context
1117 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string);
1118 }
1119
1120 // Add all the to-be-removed transactions to the changeset.
1121 for (auto it : all_conflicts) {
1122 m_subpackage.m_changeset->StageRemoval(it);
1123 }
1124 return true;
1125}
1126
1127bool MemPoolAccept::PackageMempoolChecks(const std::vector<CTransactionRef>& txns,
1128 std::vector<Workspace>& workspaces,
1129 const int64_t total_vsize,
1130 PackageValidationState& package_state)
1131{
1133 AssertLockHeld(m_pool.cs);
1134
1135 // CheckPackageLimits expects the package transactions to not already be in the mempool.
1136 assert(std::all_of(txns.cbegin(), txns.cend(), [this](const auto& tx)
1137 { return !m_pool.exists(GenTxid::Txid(tx->GetHash()));}));
1138
1139 assert(txns.size() == workspaces.size());
1140
1141 auto result = m_pool.CheckPackageLimits(txns, total_vsize);
1142 if (!result) {
1143 // This is a package-wide error, separate from an individual transaction error.
1144 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package-mempool-limits", util::ErrorString(result).original);
1145 }
1146
1147 // No conflicts means we're finished. Further checks are all RBF-only.
1148 if (!m_subpackage.m_rbf) return true;
1149
1150 // We're in package RBF context; replacement proposal must be size 2
1151 if (workspaces.size() != 2 || !Assume(IsChildWithParents(txns))) {
1152 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: package must be 1-parent-1-child");
1153 }
1154
1155 // If the package has in-mempool ancestors, we won't consider a package RBF
1156 // since it would result in a cluster larger than 2.
1157 // N.B. To relax this constraint we will need to revisit how CCoinsViewMemPool::PackageAddTransaction
1158 // is being used inside AcceptMultipleTransactions to track available inputs while processing a package.
1159 for (const auto& ws : workspaces) {
1160 if (!ws.m_ancestors.empty()) {
1161 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: new transaction cannot have mempool ancestors");
1162 }
1163 }
1164
1165 // Aggregate all conflicts into one set.
1166 CTxMemPool::setEntries direct_conflict_iters;
1167 for (Workspace& ws : workspaces) {
1168 // Aggregate all conflicts into one set.
1169 direct_conflict_iters.merge(ws.m_iters_conflicting);
1170 }
1171
1172 const auto& parent_ws = workspaces[0];
1173 const auto& child_ws = workspaces[1];
1174
1175 // Don't consider replacements that would cause us to remove a large number of mempool entries.
1176 // This limit is not increased in a package RBF. Use the aggregate number of transactions.
1177 CTxMemPool::setEntries all_conflicts;
1178 if (const auto err_string{GetEntriesForConflicts(*child_ws.m_ptx, m_pool, direct_conflict_iters,
1179 all_conflicts)}) {
1180 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1181 "package RBF failed: too many potential replacements", *err_string);
1182 }
1183
1184
1185 for (CTxMemPool::txiter it : all_conflicts) {
1186 m_subpackage.m_changeset->StageRemoval(it);
1187 m_subpackage.m_conflicting_fees += it->GetModifiedFee();
1188 m_subpackage.m_conflicting_size += it->GetTxSize();
1189 }
1190
1191 // Use the child as the transaction for attributing errors to.
1192 const Txid& child_hash = child_ws.m_ptx->GetHash();
1193 if (const auto err_string{PaysForRBF(/*original_fees=*/m_subpackage.m_conflicting_fees,
1194 /*replacement_fees=*/m_subpackage.m_total_modified_fees,
1195 /*replacement_vsize=*/m_subpackage.m_total_vsize,
1196 m_pool.m_opts.incremental_relay_feerate, child_hash)}) {
1197 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1198 "package RBF failed: insufficient anti-DoS fees", *err_string);
1199 }
1200
1201 // Ensure this two transaction package is a "chunk" on its own; we don't want the child
1202 // to be only paying anti-DoS fees
1203 const CFeeRate parent_feerate(parent_ws.m_modified_fees, parent_ws.m_vsize);
1204 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize);
1205 if (package_feerate <= parent_feerate) {
1206 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1207 "package RBF failed: package feerate is less than or equal to parent feerate",
1208 strprintf("package feerate %s <= parent feerate is %s", package_feerate.ToString(), parent_feerate.ToString()));
1209 }
1210
1211 // Check if it's economically rational to mine this package rather than the ones it replaces.
1212 // This takes the place of ReplacementChecks()'s PaysMoreThanConflicts() in the package RBF setting.
1213 if (const auto err_tup{ImprovesFeerateDiagram(*m_subpackage.m_changeset)}) {
1214 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1215 "package RBF failed: " + err_tup.value().second, "");
1216 }
1217
1218 LogDebug(BCLog::TXPACKAGES, "package RBF checks passed: parent %s (wtxid=%s), child %s (wtxid=%s), package hash (%s)\n",
1219 txns.front()->GetHash().ToString(), txns.front()->GetWitnessHash().ToString(),
1220 txns.back()->GetHash().ToString(), txns.back()->GetWitnessHash().ToString(),
1221 GetPackageHash(txns).ToString());
1222
1223
1224 return true;
1225}
1226
1227bool MemPoolAccept::PolicyScriptChecks(const ATMPArgs& args, Workspace& ws)
1228{
1230 AssertLockHeld(m_pool.cs);
1231 const CTransaction& tx = *ws.m_ptx;
1232 TxValidationState& state = ws.m_state;
1233
1234 constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
1235
1236 // Check input scripts and signatures.
1237 // This is done last to help prevent CPU exhaustion denial-of-service attacks.
1238 if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false, ws.m_precomputed_txdata, GetValidationCache())) {
1239 // SCRIPT_VERIFY_CLEANSTACK requires SCRIPT_VERIFY_WITNESS, so we
1240 // need to turn both off, and compare against just turning off CLEANSTACK
1241 // to see if the failure is specifically due to witness validation.
1242 TxValidationState state_dummy; // Want reported failures to be from first CheckInputScripts
1243 if (!tx.HasWitness() && CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, ws.m_precomputed_txdata, GetValidationCache()) &&
1244 !CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, ws.m_precomputed_txdata, GetValidationCache())) {
1245 // Only the witness is missing, so the transaction itself may be fine.
1247 state.GetRejectReason(), state.GetDebugMessage());
1248 }
1249 return false; // state filled in by CheckInputScripts
1250 }
1251
1252 return true;
1253}
1254
1255bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws)
1256{
1258 AssertLockHeld(m_pool.cs);
1259 const CTransaction& tx = *ws.m_ptx;
1260 const uint256& hash = ws.m_hash;
1261 TxValidationState& state = ws.m_state;
1262
1263 // Check again against the current block tip's script verification
1264 // flags to cache our script execution flags. This is, of course,
1265 // useless if the next block has different script flags from the
1266 // previous one, but because the cache tracks script flags for us it
1267 // will auto-invalidate and we'll just have a few blocks of extra
1268 // misses on soft-fork activation.
1269 //
1270 // This is also useful in case of bugs in the standard flags that cause
1271 // transactions to pass as valid when they're actually invalid. For
1272 // instance the STRICTENC flag was incorrectly allowing certain
1273 // CHECKSIG NOT scripts to pass, even though they were invalid.
1274 //
1275 // There is a similar check in CreateNewBlock() to prevent creating
1276 // invalid blocks (using TestBlockValidity), however allowing such
1277 // transactions into the mempool can be exploited as a DoS attack.
1278 unsigned int currentBlockScriptVerifyFlags{GetBlockScriptFlags(*m_active_chainstate.m_chain.Tip(), m_active_chainstate.m_chainman)};
1279 if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags,
1280 ws.m_precomputed_txdata, m_active_chainstate.CoinsTip(), GetValidationCache())) {
1281 LogPrintf("BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s\n", hash.ToString(), state.ToString());
1282 return Assume(false);
1283 }
1284
1285 return true;
1286}
1287
1288void MemPoolAccept::FinalizeSubpackage(const ATMPArgs& args)
1289{
1291 AssertLockHeld(m_pool.cs);
1292
1293 if (!m_subpackage.m_changeset->GetRemovals().empty()) Assume(args.m_allow_replacement);
1294 // Remove conflicting transactions from the mempool
1295 for (CTxMemPool::txiter it : m_subpackage.m_changeset->GetRemovals())
1296 {
1297 std::string log_string = strprintf("replacing mempool tx %s (wtxid=%s, fees=%s, vsize=%s). ",
1298 it->GetTx().GetHash().ToString(),
1299 it->GetTx().GetWitnessHash().ToString(),
1300 it->GetFee(),
1301 it->GetTxSize());
1302 FeeFrac feerate{m_subpackage.m_total_modified_fees, int32_t(m_subpackage.m_total_vsize)};
1303 uint256 tx_or_package_hash{};
1304 const bool replaced_with_tx{m_subpackage.m_changeset->GetTxCount() == 1};
1305 if (replaced_with_tx) {
1306 const CTransaction& tx = m_subpackage.m_changeset->GetAddedTxn(0);
1307 tx_or_package_hash = tx.GetHash();
1308 log_string += strprintf("New tx %s (wtxid=%s, fees=%s, vsize=%s)",
1309 tx.GetHash().ToString(),
1310 tx.GetWitnessHash().ToString(),
1311 feerate.fee,
1312 feerate.size);
1313 } else {
1314 tx_or_package_hash = GetPackageHash(m_subpackage.m_changeset->GetAddedTxns());
1315 log_string += strprintf("New package %s with %lu txs, fees=%s, vsize=%s",
1316 tx_or_package_hash.ToString(),
1317 m_subpackage.m_changeset->GetTxCount(),
1318 feerate.fee,
1319 feerate.size);
1320
1321 }
1322 LogDebug(BCLog::MEMPOOL, "%s\n", log_string);
1323 TRACEPOINT(mempool, replaced,
1324 it->GetTx().GetHash().data(),
1325 it->GetTxSize(),
1326 it->GetFee(),
1327 std::chrono::duration_cast<std::chrono::duration<std::uint64_t>>(it->GetTime()).count(),
1328 tx_or_package_hash.data(),
1329 feerate.size,
1330 feerate.fee,
1331 replaced_with_tx
1332 );
1333 m_subpackage.m_replaced_transactions.push_back(it->GetSharedTx());
1334 }
1335 m_subpackage.m_changeset->Apply();
1336 m_subpackage.m_changeset.reset();
1337}
1338
1339bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces,
1340 PackageValidationState& package_state,
1341 std::map<uint256, MempoolAcceptResult>& results)
1342{
1344 AssertLockHeld(m_pool.cs);
1345 // Sanity check: none of the transactions should be in the mempool, and none of the transactions
1346 // should have a same-txid-different-witness equivalent in the mempool.
1347 assert(std::all_of(workspaces.cbegin(), workspaces.cend(), [this](const auto& ws){
1348 return !m_pool.exists(GenTxid::Txid(ws.m_ptx->GetHash())); }));
1349
1350 bool all_submitted = true;
1351 FinalizeSubpackage(args);
1352 // ConsensusScriptChecks adds to the script cache and is therefore consensus-critical;
1353 // CheckInputsFromMempoolAndCache asserts that transactions only spend coins available from the
1354 // mempool or UTXO set. Submit each transaction to the mempool immediately after calling
1355 // ConsensusScriptChecks to make the outputs available for subsequent transactions.
1356 for (Workspace& ws : workspaces) {
1357 if (!ConsensusScriptChecks(args, ws)) {
1358 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1359 // Since PolicyScriptChecks() passed, this should never fail.
1360 Assume(false);
1361 all_submitted = false;
1363 strprintf("BUG! PolicyScriptChecks succeeded but ConsensusScriptChecks failed: %s",
1364 ws.m_ptx->GetHash().ToString()));
1365 // Remove the transaction from the mempool.
1366 if (!m_subpackage.m_changeset) m_subpackage.m_changeset = m_pool.GetChangeSet();
1367 m_subpackage.m_changeset->StageRemoval(m_pool.GetIter(ws.m_ptx->GetHash()).value());
1368 }
1369 }
1370 if (!all_submitted) {
1371 Assume(m_subpackage.m_changeset);
1372 // This code should be unreachable; it's here as belt-and-suspenders
1373 // to try to ensure we have no consensus-invalid transactions in the
1374 // mempool.
1375 m_subpackage.m_changeset->Apply();
1376 m_subpackage.m_changeset.reset();
1377 return false;
1378 }
1379
1380 std::vector<Wtxid> all_package_wtxids;
1381 all_package_wtxids.reserve(workspaces.size());
1382 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids),
1383 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); });
1384
1385 if (!m_subpackage.m_replaced_transactions.empty()) {
1386 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with %u new one(s) for %s additional fees, %d delta bytes\n",
1387 m_subpackage.m_replaced_transactions.size(), workspaces.size(),
1388 m_subpackage.m_total_modified_fees - m_subpackage.m_conflicting_fees,
1389 m_subpackage.m_total_vsize - static_cast<int>(m_subpackage.m_conflicting_size));
1390 }
1391
1392 // Add successful results. The returned results may change later if LimitMempoolSize() evicts them.
1393 for (Workspace& ws : workspaces) {
1394 auto iter = m_pool.GetIter(ws.m_ptx->GetHash());
1395 Assume(iter.has_value());
1396 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate :
1397 CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)};
1398 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids :
1399 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()};
1400 results.emplace(ws.m_ptx->GetWitnessHash(),
1401 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize,
1402 ws.m_base_fees, effective_feerate, effective_feerate_wtxids));
1403 if (!m_pool.m_opts.signals) continue;
1404 const CTransaction& tx = *ws.m_ptx;
1405 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees,
1406 ws.m_vsize, (*iter)->GetHeight(),
1407 args.m_bypass_limits, args.m_package_submission,
1408 IsCurrentForFeeEstimation(m_active_chainstate),
1409 m_pool.HasNoInputsOf(tx));
1410 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
1411 }
1412 return all_submitted;
1413}
1414
1415MempoolAcceptResult MemPoolAccept::AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args)
1416{
1418 LOCK(m_pool.cs); // mempool "read lock" (held through m_pool.m_opts.signals->TransactionAddedToMempool())
1419
1420 Workspace ws(ptx);
1421 const std::vector<Wtxid> single_wtxid{ws.m_ptx->GetWitnessHash()};
1422
1423 if (!PreChecks(args, ws)) {
1424 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) {
1425 // Failed for fee reasons. Provide the effective feerate and which tx was included.
1426 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid);
1427 }
1428 return MempoolAcceptResult::Failure(ws.m_state);
1429 }
1430
1431 m_subpackage.m_total_vsize = ws.m_vsize;
1432 m_subpackage.m_total_modified_fees = ws.m_modified_fees;
1433
1434 // Individual modified feerate exceeded caller-defined max; abort
1435 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) {
1436 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", "");
1437 return MempoolAcceptResult::Failure(ws.m_state);
1438 }
1439
1440 if (m_pool.m_opts.require_standard) {
1441 Txid dummy_txid;
1442 if (!CheckEphemeralSpends(/*package=*/{ptx}, m_pool.m_opts.dust_relay_feerate, m_pool, ws.m_state, dummy_txid)) {
1443 return MempoolAcceptResult::Failure(ws.m_state);
1444 }
1445 }
1446
1447 if (m_subpackage.m_rbf && !ReplacementChecks(ws)) {
1448 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) {
1449 // Failed for incentives-based fee reasons. Provide the effective feerate and which tx was included.
1450 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid);
1451 }
1452 return MempoolAcceptResult::Failure(ws.m_state);
1453 }
1454
1455 // Perform the inexpensive checks first and avoid hashing and signature verification unless
1456 // those checks pass, to mitigate CPU exhaustion denial-of-service attacks.
1457 if (!PolicyScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
1458
1459 if (!ConsensusScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
1460
1461 const CFeeRate effective_feerate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)};
1462 // Tx was accepted, but not added
1463 if (args.m_test_accept) {
1464 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize,
1465 ws.m_base_fees, effective_feerate, single_wtxid);
1466 }
1467
1468 FinalizeSubpackage(args);
1469
1470 // Limit the mempool, if appropriate.
1471 if (!args.m_package_submission && !args.m_bypass_limits) {
1472 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip());
1473 if (!m_pool.exists(GenTxid::Txid(ws.m_hash))) {
1474 // The tx no longer meets our (new) mempool minimum feerate but could be reconsidered in a package.
1475 ws.m_state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool full");
1476 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), {ws.m_ptx->GetWitnessHash()});
1477 }
1478 }
1479
1480 if (m_pool.m_opts.signals) {
1481 const CTransaction& tx = *ws.m_ptx;
1482 auto iter = m_pool.GetIter(tx.GetHash());
1483 Assume(iter.has_value());
1484 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees,
1485 ws.m_vsize, (*iter)->GetHeight(),
1486 args.m_bypass_limits, args.m_package_submission,
1487 IsCurrentForFeeEstimation(m_active_chainstate),
1488 m_pool.HasNoInputsOf(tx));
1489 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
1490 }
1491
1492 if (!m_subpackage.m_replaced_transactions.empty()) {
1493 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with 1 new transaction for %s additional fees, %d delta bytes\n",
1494 m_subpackage.m_replaced_transactions.size(),
1495 ws.m_modified_fees - m_subpackage.m_conflicting_fees,
1496 ws.m_vsize - static_cast<int>(m_subpackage.m_conflicting_size));
1497 }
1498
1499 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, ws.m_base_fees,
1500 effective_feerate, single_wtxid);
1501}
1502
1503PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args)
1504{
1506
1507 // These context-free package limits can be done before taking the mempool lock.
1508 PackageValidationState package_state;
1509 if (!IsWellFormedPackage(txns, package_state, /*require_sorted=*/true)) return PackageMempoolAcceptResult(package_state, {});
1510
1511 std::vector<Workspace> workspaces{};
1512 workspaces.reserve(txns.size());
1513 std::transform(txns.cbegin(), txns.cend(), std::back_inserter(workspaces),
1514 [](const auto& tx) { return Workspace(tx); });
1515 std::map<uint256, MempoolAcceptResult> results;
1516
1517 LOCK(m_pool.cs);
1518
1519 // Do all PreChecks first and fail fast to avoid running expensive script checks when unnecessary.
1520 for (Workspace& ws : workspaces) {
1521 if (!PreChecks(args, ws)) {
1522 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1523 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
1524 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1525 return PackageMempoolAcceptResult(package_state, std::move(results));
1526 }
1527
1528 // Individual modified feerate exceeded caller-defined max; abort
1529 // N.B. this doesn't take into account CPFPs. Chunk-aware validation may be more robust.
1530 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) {
1531 // Need to set failure here both individually and at package level
1532 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", "");
1533 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1534 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
1535 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1536 return PackageMempoolAcceptResult(package_state, std::move(results));
1537 }
1538
1539 // Make the coins created by this transaction available for subsequent transactions in the
1540 // package to spend. If there are no conflicts within the package, no transaction can spend a coin
1541 // needed by another transaction in the package. We also need to make sure that no package
1542 // tx replaces (or replaces the ancestor of) the parent of another package tx. As long as we
1543 // check these two things, we don't need to track the coins spent.
1544 // If a package tx conflicts with a mempool tx, PackageMempoolChecks() ensures later that any package RBF attempt
1545 // has *no* in-mempool ancestors, so we don't have to worry about subsequent transactions in
1546 // same package spending the same in-mempool outpoints. This needs to be revisited for general
1547 // package RBF.
1548 m_viewmempool.PackageAddTransaction(ws.m_ptx);
1549 }
1550
1551 // At this point we have all in-mempool ancestors, and we know every transaction's vsize.
1552 // Run the TRUC checks on the package.
1553 for (Workspace& ws : workspaces) {
1554 if (auto err{PackageTRUCChecks(ws.m_ptx, ws.m_vsize, txns, ws.m_ancestors)}) {
1555 package_state.Invalid(PackageValidationResult::PCKG_POLICY, "TRUC-violation", err.value());
1556 return PackageMempoolAcceptResult(package_state, {});
1557 }
1558 }
1559
1560 // Transactions must meet two minimum feerates: the mempool minimum fee and min relay fee.
1561 // For transactions consisting of exactly one child and its parents, it suffices to use the
1562 // package feerate (total modified fees / total virtual size) to check this requirement.
1563 // Note that this is an aggregate feerate; this function has not checked that there are transactions
1564 // too low feerate to pay for themselves, or that the child transactions are higher feerate than
1565 // their parents. Using aggregate feerate may allow "parents pay for child" behavior and permit
1566 // a child that is below mempool minimum feerate. To avoid these behaviors, callers of
1567 // AcceptMultipleTransactions need to restrict txns topology (e.g. to ancestor sets) and check
1568 // the feerates of individuals and subsets.
1569 m_subpackage.m_total_vsize = std::accumulate(workspaces.cbegin(), workspaces.cend(), int64_t{0},
1570 [](int64_t sum, auto& ws) { return sum + ws.m_vsize; });
1571 m_subpackage.m_total_modified_fees = std::accumulate(workspaces.cbegin(), workspaces.cend(), CAmount{0},
1572 [](CAmount sum, auto& ws) { return sum + ws.m_modified_fees; });
1573 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize);
1574 std::vector<Wtxid> all_package_wtxids;
1575 all_package_wtxids.reserve(workspaces.size());
1576 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids),
1577 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); });
1578 TxValidationState placeholder_state;
1579 if (args.m_package_feerates &&
1580 !CheckFeeRate(m_subpackage.m_total_vsize, m_subpackage.m_total_modified_fees, placeholder_state)) {
1581 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1582 return PackageMempoolAcceptResult(package_state, {{workspaces.back().m_ptx->GetWitnessHash(),
1583 MempoolAcceptResult::FeeFailure(placeholder_state, CFeeRate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize), all_package_wtxids)}});
1584 }
1585
1586 // Apply package mempool ancestor/descendant limits. Skip if there is only one transaction,
1587 // because it's unnecessary.
1588 if (txns.size() > 1 && !PackageMempoolChecks(txns, workspaces, m_subpackage.m_total_vsize, package_state)) {
1589 return PackageMempoolAcceptResult(package_state, std::move(results));
1590 }
1591
1592 // Now that we've bounded the resulting possible ancestry count, check package for dust spends
1593 if (m_pool.m_opts.require_standard) {
1594 TxValidationState child_state;
1595 Txid child_txid;
1596 if (!CheckEphemeralSpends(txns, m_pool.m_opts.dust_relay_feerate, m_pool, child_state, child_txid)) {
1597 package_state.Invalid(PackageValidationResult::PCKG_TX, "unspent-dust");
1598 results.emplace(child_txid, MempoolAcceptResult::Failure(child_state));
1599 return PackageMempoolAcceptResult(package_state, std::move(results));
1600 }
1601 }
1602
1603 for (Workspace& ws : workspaces) {
1604 ws.m_package_feerate = package_feerate;
1605 if (!PolicyScriptChecks(args, ws)) {
1606 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
1607 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1608 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1609 return PackageMempoolAcceptResult(package_state, std::move(results));
1610 }
1611 if (args.m_test_accept) {
1612 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate :
1613 CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)};
1614 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids :
1615 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()};
1616 results.emplace(ws.m_ptx->GetWitnessHash(),
1617 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions),
1618 ws.m_vsize, ws.m_base_fees, effective_feerate,
1619 effective_feerate_wtxids));
1620 }
1621 }
1622
1623 if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, std::move(results));
1624
1625 if (!SubmitPackage(args, workspaces, package_state, results)) {
1626 // PackageValidationState filled in by SubmitPackage().
1627 return PackageMempoolAcceptResult(package_state, std::move(results));
1628 }
1629
1630 return PackageMempoolAcceptResult(package_state, std::move(results));
1631}
1632
1633void MemPoolAccept::CleanupTemporaryCoins()
1634{
1635 // There are 3 kinds of coins in m_view:
1636 // (1) Temporary coins from the transactions in subpackage, constructed by m_viewmempool.
1637 // (2) Mempool coins from transactions in the mempool, constructed by m_viewmempool.
1638 // (3) Confirmed coins fetched from our current UTXO set.
1639 //
1640 // (1) Temporary coins need to be removed, regardless of whether the transaction was submitted.
1641 // If the transaction was submitted to the mempool, m_viewmempool will be able to fetch them from
1642 // there. If it wasn't submitted to mempool, it is incorrect to keep them - future calls may try
1643 // to spend those coins that don't actually exist.
1644 // (2) Mempool coins also need to be removed. If the mempool contents have changed as a result
1645 // of submitting or replacing transactions, coins previously fetched from mempool may now be
1646 // spent or nonexistent. Those coins need to be deleted from m_view.
1647 // (3) Confirmed coins don't need to be removed. The chainstate has not changed (we are
1648 // holding cs_main and no blocks have been processed) so the confirmed tx cannot disappear like
1649 // a mempool tx can. The coin may now be spent after we submitted a tx to mempool, but
1650 // we have already checked that the package does not have 2 transactions spending the same coin.
1651 // Keeping them in m_view is an optimization to not re-fetch confirmed coins if we later look up
1652 // inputs for this transaction again.
1653 for (const auto& outpoint : m_viewmempool.GetNonBaseCoins()) {
1654 // In addition to resetting m_viewmempool, we also need to manually delete these coins from
1655 // m_view because it caches copies of the coins it fetched from m_viewmempool previously.
1656 m_view.Uncache(outpoint);
1657 }
1658 // This deletes the temporary and mempool coins.
1659 m_viewmempool.Reset();
1660}
1661
1662PackageMempoolAcceptResult MemPoolAccept::AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args)
1663{
1665 AssertLockHeld(m_pool.cs);
1666 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) {
1667 if (subpackage.size() > 1) {
1668 return AcceptMultipleTransactions(subpackage, args);
1669 }
1670 const auto& tx = subpackage.front();
1671 ATMPArgs single_args = ATMPArgs::SingleInPackageAccept(args);
1672 const auto single_res = AcceptSingleTransaction(tx, single_args);
1673 PackageValidationState package_state_wrapped;
1674 if (single_res.m_result_type != MempoolAcceptResult::ResultType::VALID) {
1675 package_state_wrapped.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1676 }
1677 return PackageMempoolAcceptResult(package_state_wrapped, {{tx->GetWitnessHash(), single_res}});
1678 }();
1679
1680 // Clean up m_view and m_viewmempool so that other subpackage evaluations don't have access to
1681 // coins they shouldn't. Keep some coins in order to minimize re-fetching coins from the UTXO set.
1682 // Clean up package feerate and rbf calculations
1683 ClearSubPackageState();
1684
1685 return result;
1686}
1687
1688PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, ATMPArgs& args)
1689{
1690 Assert(!package.empty());
1692 // Used if returning a PackageMempoolAcceptResult directly from this function.
1693 PackageValidationState package_state_quit_early;
1694
1695 // There are two topologies we are able to handle through this function:
1696 // (1) A single transaction
1697 // (2) A child-with-unconfirmed-parents package.
1698 // Check that the package is well-formed. If it isn't, we won't try to validate any of the
1699 // transactions and thus won't return any MempoolAcceptResults, just a package-wide error.
1700
1701 // Context-free package checks.
1702 if (!IsWellFormedPackage(package, package_state_quit_early, /*require_sorted=*/true)) {
1703 return PackageMempoolAcceptResult(package_state_quit_early, {});
1704 }
1705
1706 if (package.size() > 1) {
1707 // All transactions in the package must be a parent of the last transaction. This is just an
1708 // opportunity for us to fail fast on a context-free check without taking the mempool lock.
1709 if (!IsChildWithParents(package)) {
1710 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents");
1711 return PackageMempoolAcceptResult(package_state_quit_early, {});
1712 }
1713
1714 // IsChildWithParents() guarantees the package is > 1 transactions.
1715 assert(package.size() > 1);
1716 // The package must be 1 child with all of its unconfirmed parents. The package is expected to
1717 // be sorted, so the last transaction is the child.
1718 const auto& child = package.back();
1719 std::unordered_set<uint256, SaltedTxidHasher> unconfirmed_parent_txids;
1720 std::transform(package.cbegin(), package.cend() - 1,
1721 std::inserter(unconfirmed_parent_txids, unconfirmed_parent_txids.end()),
1722 [](const auto& tx) { return tx->GetHash(); });
1723
1724 // All child inputs must refer to a preceding package transaction or a confirmed UTXO. The only
1725 // way to verify this is to look up the child's inputs in our current coins view (not including
1726 // mempool), and enforce that all parents not present in the package be available at chain tip.
1727 // Since this check can bring new coins into the coins cache, keep track of these coins and
1728 // uncache them if we don't end up submitting this package to the mempool.
1729 const CCoinsViewCache& coins_tip_cache = m_active_chainstate.CoinsTip();
1730 for (const auto& input : child->vin) {
1731 if (!coins_tip_cache.HaveCoinInCache(input.prevout)) {
1732 args.m_coins_to_uncache.push_back(input.prevout);
1733 }
1734 }
1735 // Using the MemPoolAccept m_view cache allows us to look up these same coins faster later.
1736 // This should be connecting directly to CoinsTip, not to m_viewmempool, because we specifically
1737 // require inputs to be confirmed if they aren't in the package.
1738 m_view.SetBackend(m_active_chainstate.CoinsTip());
1739 const auto package_or_confirmed = [this, &unconfirmed_parent_txids](const auto& input) {
1740 return unconfirmed_parent_txids.count(input.prevout.hash) > 0 || m_view.HaveCoin(input.prevout);
1741 };
1742 if (!std::all_of(child->vin.cbegin(), child->vin.cend(), package_or_confirmed)) {
1743 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-unconfirmed-parents");
1744 return PackageMempoolAcceptResult(package_state_quit_early, {});
1745 }
1746 // Protect against bugs where we pull more inputs from disk that miss being added to
1747 // coins_to_uncache. The backend will be connected again when needed in PreChecks.
1748 m_view.SetBackend(m_dummy);
1749 }
1750
1751 LOCK(m_pool.cs);
1752 // Stores results from which we will create the returned PackageMempoolAcceptResult.
1753 // A result may be changed if a mempool transaction is evicted later due to LimitMempoolSize().
1754 std::map<uint256, MempoolAcceptResult> results_final;
1755 // Results from individual validation which will be returned if no other result is available for
1756 // this transaction. "Nonfinal" because if a transaction fails by itself but succeeds later
1757 // (i.e. when evaluated with a fee-bumping child), the result in this map may be discarded.
1758 std::map<uint256, MempoolAcceptResult> individual_results_nonfinal;
1759 // Tracks whether we think package submission could result in successful entry to the mempool
1760 bool quit_early{false};
1761 std::vector<CTransactionRef> txns_package_eval;
1762 for (const auto& tx : package) {
1763 const auto& wtxid = tx->GetWitnessHash();
1764 const auto& txid = tx->GetHash();
1765 // There are 3 possibilities: already in mempool, same-txid-diff-wtxid already in mempool,
1766 // or not in mempool. An already confirmed tx is treated as one not in mempool, because all
1767 // we know is that the inputs aren't available.
1768 if (m_pool.exists(GenTxid::Wtxid(wtxid))) {
1769 // Exact transaction already exists in the mempool.
1770 // Node operators are free to set their mempool policies however they please, nodes may receive
1771 // transactions in different orders, and malicious counterparties may try to take advantage of
1772 // policy differences to pin or delay propagation of transactions. As such, it's possible for
1773 // some package transaction(s) to already be in the mempool, and we don't want to reject the
1774 // entire package in that case (as that could be a censorship vector). De-duplicate the
1775 // transactions that are already in the mempool, and only call AcceptMultipleTransactions() with
1776 // the new transactions. This ensures we don't double-count transaction counts and sizes when
1777 // checking ancestor/descendant limits, or double-count transaction fees for fee-related policy.
1778 const auto& entry{*Assert(m_pool.GetEntry(txid))};
1779 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTx(entry.GetTxSize(), entry.GetFee()));
1780 } else if (m_pool.exists(GenTxid::Txid(txid))) {
1781 // Transaction with the same non-witness data but different witness (same txid,
1782 // different wtxid) already exists in the mempool.
1783 //
1784 // We don't allow replacement transactions right now, so just swap the package
1785 // transaction for the mempool one. Note that we are ignoring the validity of the
1786 // package transaction passed in.
1787 // TODO: allow witness replacement in packages.
1788 const auto& entry{*Assert(m_pool.GetEntry(txid))};
1789 // Provide the wtxid of the mempool tx so that the caller can look it up in the mempool.
1790 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTxDifferentWitness(entry.GetTx().GetWitnessHash()));
1791 } else {
1792 // Transaction does not already exist in the mempool.
1793 // Try submitting the transaction on its own.
1794 const auto single_package_res = AcceptSubPackage({tx}, args);
1795 const auto& single_res = single_package_res.m_tx_results.at(wtxid);
1796 if (single_res.m_result_type == MempoolAcceptResult::ResultType::VALID) {
1797 // The transaction succeeded on its own and is now in the mempool. Don't include it
1798 // in package validation, because its fees should only be "used" once.
1799 assert(m_pool.exists(GenTxid::Wtxid(wtxid)));
1800 results_final.emplace(wtxid, single_res);
1801 } else if (package.size() == 1 || // If there is only one transaction, no need to retry it "as a package"
1802 (single_res.m_state.GetResult() != TxValidationResult::TX_RECONSIDERABLE &&
1803 single_res.m_state.GetResult() != TxValidationResult::TX_MISSING_INPUTS)) {
1804 // Package validation policy only differs from individual policy in its evaluation
1805 // of feerate. For example, if a transaction fails here due to violation of a
1806 // consensus rule, the result will not change when it is submitted as part of a
1807 // package. To minimize the amount of repeated work, unless the transaction fails
1808 // due to feerate or missing inputs (its parent is a previous transaction in the
1809 // package that failed due to feerate), don't run package validation. Note that this
1810 // decision might not make sense if different types of packages are allowed in the
1811 // future. Continue individually validating the rest of the transactions, because
1812 // some of them may still be valid.
1813 quit_early = true;
1814 package_state_quit_early.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1815 individual_results_nonfinal.emplace(wtxid, single_res);
1816 } else {
1817 individual_results_nonfinal.emplace(wtxid, single_res);
1818 txns_package_eval.push_back(tx);
1819 }
1820 }
1821 }
1822
1823 auto multi_submission_result = quit_early || txns_package_eval.empty() ? PackageMempoolAcceptResult(package_state_quit_early, {}) :
1824 AcceptSubPackage(txns_package_eval, args);
1825 PackageValidationState& package_state_final = multi_submission_result.m_state;
1826
1827 // This is invoked by AcceptSubPackage() already, so this is just here for
1828 // clarity (since it's not permitted to invoke LimitMempoolSize() while a
1829 // changeset is outstanding).
1830 ClearSubPackageState();
1831
1832 // Make sure we haven't exceeded max mempool size.
1833 // Package transactions that were submitted to mempool or already in mempool may be evicted.
1834 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip());
1835
1836 for (const auto& tx : package) {
1837 const auto& wtxid = tx->GetWitnessHash();
1838 if (multi_submission_result.m_tx_results.count(wtxid) > 0) {
1839 // We shouldn't have re-submitted if the tx result was already in results_final.
1840 Assume(results_final.count(wtxid) == 0);
1841 // If it was submitted, check to see if the tx is still in the mempool. It could have
1842 // been evicted due to LimitMempoolSize() above.
1843 const auto& txresult = multi_submission_result.m_tx_results.at(wtxid);
1844 if (txresult.m_result_type == MempoolAcceptResult::ResultType::VALID && !m_pool.exists(GenTxid::Wtxid(wtxid))) {
1845 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1846 TxValidationState mempool_full_state;
1847 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full");
1848 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state));
1849 } else {
1850 results_final.emplace(wtxid, txresult);
1851 }
1852 } else if (const auto it{results_final.find(wtxid)}; it != results_final.end()) {
1853 // Already-in-mempool transaction. Check to see if it's still there, as it could have
1854 // been evicted when LimitMempoolSize() was called.
1855 Assume(it->second.m_result_type != MempoolAcceptResult::ResultType::INVALID);
1856 Assume(individual_results_nonfinal.count(wtxid) == 0);
1857 // Query by txid to include the same-txid-different-witness ones.
1858 if (!m_pool.exists(GenTxid::Txid(tx->GetHash()))) {
1859 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1860 TxValidationState mempool_full_state;
1861 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full");
1862 // Replace the previous result.
1863 results_final.erase(wtxid);
1864 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state));
1865 }
1866 } else if (const auto it{individual_results_nonfinal.find(wtxid)}; it != individual_results_nonfinal.end()) {
1867 Assume(it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID);
1868 // Interesting result from previous processing.
1869 results_final.emplace(wtxid, it->second);
1870 }
1871 }
1872 Assume(results_final.size() == package.size());
1873 return PackageMempoolAcceptResult(package_state_final, std::move(results_final));
1874}
1875
1876} // anon namespace
1877
1879 int64_t accept_time, bool bypass_limits, bool test_accept)
1880{
1882 const CChainParams& chainparams{active_chainstate.m_chainman.GetParams()};
1883 assert(active_chainstate.GetMempool() != nullptr);
1884 CTxMemPool& pool{*active_chainstate.GetMempool()};
1885
1886 std::vector<COutPoint> coins_to_uncache;
1887 auto args = MemPoolAccept::ATMPArgs::SingleAccept(chainparams, accept_time, bypass_limits, coins_to_uncache, test_accept);
1888 MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate).AcceptSingleTransaction(tx, args);
1890 // Remove coins that were not present in the coins cache before calling
1891 // AcceptSingleTransaction(); this is to prevent memory DoS in case we receive a large
1892 // number of invalid transactions that attempt to overrun the in-memory coins cache
1893 // (`CCoinsViewCache::cacheCoins`).
1894
1895 for (const COutPoint& hashTx : coins_to_uncache)
1896 active_chainstate.CoinsTip().Uncache(hashTx);
1897 TRACEPOINT(mempool, rejected,
1898 tx->GetHash().data(),
1899 result.m_state.GetRejectReason().c_str()
1900 );
1901 }
1902 // After we've (potentially) uncached entries, ensure our coins cache is still within its size limits
1903 BlockValidationState state_dummy;
1904 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
1905 return result;
1906}
1907
1909 const Package& package, bool test_accept, const std::optional<CFeeRate>& client_maxfeerate)
1910{
1912 assert(!package.empty());
1913 assert(std::all_of(package.cbegin(), package.cend(), [](const auto& tx){return tx != nullptr;}));
1914
1915 std::vector<COutPoint> coins_to_uncache;
1916 const CChainParams& chainparams = active_chainstate.m_chainman.GetParams();
1917 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
1919 if (test_accept) {
1920 auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(chainparams, GetTime(), coins_to_uncache);
1921 return MemPoolAccept(pool, active_chainstate).AcceptMultipleTransactions(package, args);
1922 } else {
1923 auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(chainparams, GetTime(), coins_to_uncache, client_maxfeerate);
1924 return MemPoolAccept(pool, active_chainstate).AcceptPackage(package, args);
1925 }
1926 }();
1927
1928 // Uncache coins pertaining to transactions that were not submitted to the mempool.
1929 if (test_accept || result.m_state.IsInvalid()) {
1930 for (const COutPoint& hashTx : coins_to_uncache) {
1931 active_chainstate.CoinsTip().Uncache(hashTx);
1932 }
1933 }
1934 // Ensure the coins cache is still within limits.
1935 BlockValidationState state_dummy;
1936 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
1937 return result;
1938}
1939
1941{
1942 int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
1943 // Force block reward to zero when right shift is undefined.
1944 if (halvings >= 64)
1945 return 0;
1946
1947 CAmount nSubsidy = 50 * COIN;
1948 // Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years.
1949 nSubsidy >>= halvings;
1950 return nSubsidy;
1951}
1952
1954 : m_dbview{std::move(db_params), std::move(options)},
1955 m_catcherview(&m_dbview) {}
1956
1957void CoinsViews::InitCache()
1958{
1960 m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview);
1961}
1962
1964 CTxMemPool* mempool,
1965 BlockManager& blockman,
1966 ChainstateManager& chainman,
1967 std::optional<uint256> from_snapshot_blockhash)
1968 : m_mempool(mempool),
1969 m_blockman(blockman),
1970 m_chainman(chainman),
1971 m_from_snapshot_blockhash(from_snapshot_blockhash) {}
1972
1973const CBlockIndex* Chainstate::SnapshotBase()
1974{
1975 if (!m_from_snapshot_blockhash) return nullptr;
1976 if (!m_cached_snapshot_base) m_cached_snapshot_base = Assert(m_chainman.m_blockman.LookupBlockIndex(*m_from_snapshot_blockhash));
1977 return m_cached_snapshot_base;
1978}
1979
1981 size_t cache_size_bytes,
1982 bool in_memory,
1983 bool should_wipe,
1984 fs::path leveldb_name)
1985{
1987 leveldb_name += node::SNAPSHOT_CHAINSTATE_SUFFIX;
1988 }
1989
1990 m_coins_views = std::make_unique<CoinsViews>(
1991 DBParams{
1992 .path = m_chainman.m_options.datadir / leveldb_name,
1993 .cache_bytes = cache_size_bytes,
1994 .memory_only = in_memory,
1995 .wipe_data = should_wipe,
1996 .obfuscate = true,
1997 .options = m_chainman.m_options.coins_db},
1999
2000 m_coinsdb_cache_size_bytes = cache_size_bytes;
2001}
2002
2003void Chainstate::InitCoinsCache(size_t cache_size_bytes)
2004{
2006 assert(m_coins_views != nullptr);
2007 m_coinstip_cache_size_bytes = cache_size_bytes;
2008 m_coins_views->InitCache();
2009}
2010
2011// Note that though this is marked const, we may end up modifying `m_cached_finished_ibd`, which
2012// is a performance-related implementation detail. This function must be marked
2013// `const` so that `CValidationInterface` clients (which are given a `const Chainstate*`)
2014// can call it.
2015//
2017{
2018 // Optimization: pre-test latch before taking the lock.
2019 if (m_cached_finished_ibd.load(std::memory_order_relaxed))
2020 return false;
2021
2022 LOCK(cs_main);
2023 if (m_cached_finished_ibd.load(std::memory_order_relaxed))
2024 return false;
2025 if (m_blockman.LoadingBlocks()) {
2026 return true;
2027 }
2028 CChain& chain{ActiveChain()};
2029 if (chain.Tip() == nullptr) {
2030 return true;
2031 }
2032 if (chain.Tip()->nChainWork < MinimumChainWork()) {
2033 return true;
2034 }
2035 if (chain.Tip()->Time() < Now<NodeSeconds>() - m_options.max_tip_age) {
2036 return true;
2037 }
2038 LogPrintf("Leaving InitialBlockDownload (latching to false)\n");
2039 m_cached_finished_ibd.store(true, std::memory_order_relaxed);
2040 return false;
2041}
2042
2044{
2046
2047 // Before we get past initial download, we cannot reliably alert about forks
2048 // (we assume we don't get stuck on a fork before finishing our initial sync)
2049 // Also not applicable to the background chainstate
2050 if (m_chainman.IsInitialBlockDownload() || this->GetRole() == ChainstateRole::BACKGROUND) {
2051 return;
2052 }
2053
2054 if (m_chainman.m_best_invalid && m_chainman.m_best_invalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) {
2055 LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n", __func__);
2058 _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade."));
2059 } else {
2061 }
2062}
2063
2064// Called both upon regular invalid block discovery *and* InvalidateBlock
2066{
2068 if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) {
2069 m_chainman.m_best_invalid = pindexNew;
2070 }
2071 SetBlockFailureFlags(pindexNew);
2072 if (m_chainman.m_best_header != nullptr && m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) == pindexNew) {
2073 m_chainman.RecalculateBestHeader();
2074 }
2075
2076 LogPrintf("%s: invalid block=%s height=%d log2_work=%f date=%s\n", __func__,
2077 pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
2078 log(pindexNew->nChainWork.getdouble())/log(2.0), FormatISO8601DateTime(pindexNew->GetBlockTime()));
2079 CBlockIndex *tip = m_chain.Tip();
2080 assert (tip);
2081 LogPrintf("%s: current best=%s height=%d log2_work=%f date=%s\n", __func__,
2082 tip->GetBlockHash().ToString(), m_chain.Height(), log(tip->nChainWork.getdouble())/log(2.0),
2085}
2086
2087// Same as InvalidChainFound, above, except not called directly from InvalidateBlock,
2088// which does its own setBlockIndexCandidates management.
2090{
2093 pindex->nStatus |= BLOCK_FAILED_VALID;
2094 m_chainman.m_failed_blocks.insert(pindex);
2095 m_blockman.m_dirty_blockindex.insert(pindex);
2096 setBlockIndexCandidates.erase(pindex);
2097 InvalidChainFound(pindex);
2098 }
2099}
2100
2101void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, CTxUndo &txundo, int nHeight)
2102{
2103 // mark inputs spent
2104 if (!tx.IsCoinBase()) {
2105 txundo.vprevout.reserve(tx.vin.size());
2106 for (const CTxIn &txin : tx.vin) {
2107 txundo.vprevout.emplace_back();
2108 bool is_spent = inputs.SpendCoin(txin.prevout, &txundo.vprevout.back());
2109 assert(is_spent);
2110 }
2111 }
2112 // add outputs
2113 AddCoins(inputs, tx, nHeight);
2114}
2115
2116std::optional<std::pair<ScriptError, std::string>> CScriptCheck::operator()() {
2117 const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
2118 const CScriptWitness *witness = &ptxTo->vin[nIn].scriptWitness;
2121 return std::nullopt;
2122 } else {
2123 auto debug_str = strprintf("input %i of %s (wtxid %s), spending %s:%i", nIn, ptxTo->GetHash().ToString(), ptxTo->GetWitnessHash().ToString(), ptxTo->vin[nIn].prevout.hash.ToString(), ptxTo->vin[nIn].prevout.n);
2124 return std::make_pair(error, std::move(debug_str));
2125 }
2126}
2127
2128ValidationCache::ValidationCache(const size_t script_execution_cache_bytes, const size_t signature_cache_bytes)
2129 : m_signature_cache{signature_cache_bytes}
2130{
2131 // Setup the salted hasher
2133 // We want the nonce to be 64 bytes long to force the hasher to process
2134 // this chunk, which makes later hash computations more efficient. We
2135 // just write our 32-byte entropy twice to fill the 64 bytes.
2138
2139 const auto [num_elems, approx_size_bytes] = m_script_execution_cache.setup_bytes(script_execution_cache_bytes);
2140 LogPrintf("Using %zu MiB out of %zu MiB requested for script execution cache, able to store %zu elements\n",
2141 approx_size_bytes >> 20, script_execution_cache_bytes >> 20, num_elems);
2142}
2143
2164 const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore,
2165 bool cacheFullScriptStore, PrecomputedTransactionData& txdata,
2166 ValidationCache& validation_cache,
2167 std::vector<CScriptCheck>* pvChecks)
2168{
2169 if (tx.IsCoinBase()) return true;
2170
2171 if (pvChecks) {
2172 pvChecks->reserve(tx.vin.size());
2173 }
2174
2175 // First check if script executions have been cached with the same
2176 // flags. Note that this assumes that the inputs provided are
2177 // correct (ie that the transaction hash which is in tx's prevouts
2178 // properly commits to the scriptPubKey in the inputs view of that
2179 // transaction).
2180 uint256 hashCacheEntry;
2181 CSHA256 hasher = validation_cache.ScriptExecutionCacheHasher();
2182 hasher.Write(UCharCast(tx.GetWitnessHash().begin()), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin());
2183 AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks
2184 if (validation_cache.m_script_execution_cache.contains(hashCacheEntry, !cacheFullScriptStore)) {
2185 return true;
2186 }
2187
2188 if (!txdata.m_spent_outputs_ready) {
2189 std::vector<CTxOut> spent_outputs;
2190 spent_outputs.reserve(tx.vin.size());
2191
2192 for (const auto& txin : tx.vin) {
2193 const COutPoint& prevout = txin.prevout;
2194 const Coin& coin = inputs.AccessCoin(prevout);
2195 assert(!coin.IsSpent());
2196 spent_outputs.emplace_back(coin.out);
2197 }
2198 txdata.Init(tx, std::move(spent_outputs));
2199 }
2200 assert(txdata.m_spent_outputs.size() == tx.vin.size());
2201
2202 for (unsigned int i = 0; i < tx.vin.size(); i++) {
2203
2204 // We very carefully only pass in things to CScriptCheck which
2205 // are clearly committed to by tx' witness hash. This provides
2206 // a sanity check that our caching is not introducing consensus
2207 // failures through additional data in, eg, the coins being
2208 // spent being checked as a part of CScriptCheck.
2209
2210 // Verify signature
2211 CScriptCheck check(txdata.m_spent_outputs[i], tx, validation_cache.m_signature_cache, i, flags, cacheSigStore, &txdata);
2212 if (pvChecks) {
2213 pvChecks->emplace_back(std::move(check));
2214 } else if (auto result = check(); result.has_value()) {
2216 // Check whether the failure was caused by a
2217 // non-mandatory script verification check, such as
2218 // non-standard DER encodings or non-null dummy
2219 // arguments; if so, ensure we return NOT_STANDARD
2220 // instead of CONSENSUS to avoid downstream users
2221 // splitting the network between upgraded and
2222 // non-upgraded nodes by banning CONSENSUS-failing
2223 // data providers.
2224 CScriptCheck check2(txdata.m_spent_outputs[i], tx, validation_cache.m_signature_cache, i,
2225 flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheSigStore, &txdata);
2226 auto mandatory_result = check2();
2227 if (!mandatory_result.has_value()) {
2228 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(result->first)), result->second);
2229 } else {
2230 // If the second check failed, it failed due to a mandatory script verification
2231 // flag, but the first check might have failed on a non-mandatory script
2232 // verification flag.
2233 //
2234 // Avoid reporting a mandatory script check failure with a non-mandatory error
2235 // string by reporting the error from the second check.
2236 result = mandatory_result;
2237 }
2238 }
2239
2240 // MANDATORY flag failures correspond to
2241 // TxValidationResult::TX_CONSENSUS.
2242 return state.Invalid(TxValidationResult::TX_CONSENSUS, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(result->first)), result->second);
2243 }
2244 }
2245
2246 if (cacheFullScriptStore && !pvChecks) {
2247 // We executed all of the provided scripts, and were told to
2248 // cache the result. Do so now.
2249 validation_cache.m_script_execution_cache.insert(hashCacheEntry);
2250 }
2251
2252 return true;
2253}
2254
2255bool FatalError(Notifications& notifications, BlockValidationState& state, const bilingual_str& message)
2256{
2257 notifications.fatalError(message);
2258 return state.Error(message.original);
2259}
2260
2269{
2270 bool fClean = true;
2271
2272 if (view.HaveCoin(out)) fClean = false; // overwriting transaction output
2273
2274 if (undo.nHeight == 0) {
2275 // Missing undo metadata (height and coinbase). Older versions included this
2276 // information only in undo records for the last spend of a transactions'
2277 // outputs. This implies that it must be present for some other output of the same tx.
2278 const Coin& alternate = AccessByTxid(view, out.hash);
2279 if (!alternate.IsSpent()) {
2280 undo.nHeight = alternate.nHeight;
2281 undo.fCoinBase = alternate.fCoinBase;
2282 } else {
2283 return DISCONNECT_FAILED; // adding output for transaction without known metadata
2284 }
2285 }
2286 // If the coin already exists as an unspent coin in the cache, then the
2287 // possible_overwrite parameter to AddCoin must be set to true. We have
2288 // already checked whether an unspent coin exists above using HaveCoin, so
2289 // we don't need to guess. When fClean is false, an unspent coin already
2290 // existed and it is an overwrite.
2291 view.AddCoin(out, std::move(undo), !fClean);
2292
2293 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
2294}
2295
2298DisconnectResult Chainstate::DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view)
2299{
2301 bool fClean = true;
2302
2303 CBlockUndo blockUndo;
2304 if (!m_blockman.ReadBlockUndo(blockUndo, *pindex)) {
2305 LogError("DisconnectBlock(): failure reading undo data\n");
2306 return DISCONNECT_FAILED;
2307 }
2308
2309 if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) {
2310 LogError("DisconnectBlock(): block and undo data inconsistent\n");
2311 return DISCONNECT_FAILED;
2312 }
2313
2314 // Ignore blocks that contain transactions which are 'overwritten' by later transactions,
2315 // unless those are already completely spent.
2316 // See https://github.com/bitcoin/bitcoin/issues/22596 for additional information.
2317 // Note: the blocks specified here are different than the ones used in ConnectBlock because DisconnectBlock
2318 // unwinds the blocks in reverse. As a result, the inconsistency is not discovered until the earlier
2319 // blocks with the duplicate coinbase transactions are disconnected.
2320 bool fEnforceBIP30 = !((pindex->nHeight==91722 && pindex->GetBlockHash() == uint256{"00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e"}) ||
2321 (pindex->nHeight==91812 && pindex->GetBlockHash() == uint256{"00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"}));
2322
2323 // undo transactions in reverse order
2324 for (int i = block.vtx.size() - 1; i >= 0; i--) {
2325 const CTransaction &tx = *(block.vtx[i]);
2326 Txid hash = tx.GetHash();
2327 bool is_coinbase = tx.IsCoinBase();
2328 bool is_bip30_exception = (is_coinbase && !fEnforceBIP30);
2329
2330 // Check that all outputs are available and match the outputs in the block itself
2331 // exactly.
2332 for (size_t o = 0; o < tx.vout.size(); o++) {
2333 if (!tx.vout[o].scriptPubKey.IsUnspendable()) {
2334 COutPoint out(hash, o);
2335 Coin coin;
2336 bool is_spent = view.SpendCoin(out, &coin);
2337 if (!is_spent || tx.vout[o] != coin.out || pindex->nHeight != coin.nHeight || is_coinbase != coin.fCoinBase) {
2338 if (!is_bip30_exception) {
2339 fClean = false; // transaction output mismatch
2340 }
2341 }
2342 }
2343 }
2344
2345 // restore inputs
2346 if (i > 0) { // not coinbases
2347 CTxUndo &txundo = blockUndo.vtxundo[i-1];
2348 if (txundo.vprevout.size() != tx.vin.size()) {
2349 LogError("DisconnectBlock(): transaction and undo data inconsistent\n");
2350 return DISCONNECT_FAILED;
2351 }
2352 for (unsigned int j = tx.vin.size(); j > 0;) {
2353 --j;
2354 const COutPoint& out = tx.vin[j].prevout;
2355 int res = ApplyTxInUndo(std::move(txundo.vprevout[j]), view, out);
2356 if (res == DISCONNECT_FAILED) return DISCONNECT_FAILED;
2357 fClean = fClean && res != DISCONNECT_UNCLEAN;
2358 }
2359 // At this point, all of txundo.vprevout should have been moved out.
2360 }
2361 }
2362
2363 // move best block pointer to prevout block
2364 view.SetBestBlock(pindex->pprev->GetBlockHash());
2365
2366 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
2367}
2368
2373{
2374private:
2377
2378public:
2379 explicit WarningBitsConditionChecker(const ChainstateManager& chainman, int bit) : m_chainman{chainman}, m_bit(bit) {}
2380
2381 int64_t BeginTime(const Consensus::Params& params) const override { return 0; }
2382 int64_t EndTime(const Consensus::Params& params) const override { return std::numeric_limits<int64_t>::max(); }
2383 int Period(const Consensus::Params& params) const override { return params.nMinerConfirmationWindow; }
2384 int Threshold(const Consensus::Params& params) const override { return params.nRuleChangeActivationThreshold; }
2385
2386 bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const override
2387 {
2388 return pindex->nHeight >= params.MinBIP9WarningHeight &&
2390 ((pindex->nVersion >> m_bit) & 1) != 0 &&
2391 ((m_chainman.m_versionbitscache.ComputeBlockVersion(pindex->pprev, params) >> m_bit) & 1) == 0;
2392 }
2393};
2394
2395static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman)
2396{
2397 const Consensus::Params& consensusparams = chainman.GetConsensus();
2398
2399 // BIP16 didn't become active until Apr 1 2012 (on mainnet, and
2400 // retroactively applied to testnet)
2401 // However, only one historical block violated the P2SH rules (on both
2402 // mainnet and testnet).
2403 // Similarly, only one historical block violated the TAPROOT rules on
2404 // mainnet.
2405 // For simplicity, always leave P2SH+WITNESS+TAPROOT on except for the two
2406 // violating blocks.
2408 const auto it{consensusparams.script_flag_exceptions.find(*Assert(block_index.phashBlock))};
2409 if (it != consensusparams.script_flag_exceptions.end()) {
2410 flags = it->second;
2411 }
2412
2413 // Enforce the DERSIG (BIP66) rule
2414 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_DERSIG)) {
2416 }
2417
2418 // Enforce CHECKLOCKTIMEVERIFY (BIP65)
2419 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CLTV)) {
2421 }
2422
2423 // Enforce CHECKSEQUENCEVERIFY (BIP112)
2424 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CSV)) {
2426 }
2427
2428 // Enforce BIP147 NULLDUMMY (activated simultaneously with segwit)
2429 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_SEGWIT)) {
2431 }
2432
2433 return flags;
2434}
2435
2436
2440bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex,
2441 CCoinsViewCache& view, bool fJustCheck)
2442{
2444 assert(pindex);
2445
2446 uint256 block_hash{block.GetHash()};
2447 assert(*pindex->phashBlock == block_hash);
2448 const bool parallel_script_checks{m_chainman.GetCheckQueue().HasThreads()};
2449
2450 const auto time_start{SteadyClock::now()};
2451 const CChainParams& params{m_chainman.GetParams()};
2452
2453 // Check it again in case a previous version let a bad block in
2454 // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
2455 // ContextualCheckBlockHeader() here. This means that if we add a new
2456 // consensus rule that is enforced in one of those two functions, then we
2457 // may have let in a block that violates the rule prior to updating the
2458 // software, and we would NOT be enforcing the rule here. Fully solving
2459 // upgrade from one software version to the next after a consensus rule
2460 // change is potentially tricky and issue-specific (see NeedsRedownload()
2461 // for one approach that was used for BIP 141 deployment).
2462 // Also, currently the rule against blocks more than 2 hours in the future
2463 // is enforced in ContextualCheckBlockHeader(); we wouldn't want to
2464 // re-enforce that rule here (at least until we make it impossible for
2465 // the clock to go backward).
2466 if (!CheckBlock(block, state, params.GetConsensus(), !fJustCheck, !fJustCheck)) {
2468 // We don't write down blocks to disk if they may have been
2469 // corrupted, so this should be impossible unless we're having hardware
2470 // problems.
2471 return FatalError(m_chainman.GetNotifications(), state, _("Corrupt block found indicating potential hardware failure."));
2472 }
2473 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString());
2474 return false;
2475 }
2476
2477 // verify that the view's current state corresponds to the previous block
2478 uint256 hashPrevBlock = pindex->pprev == nullptr ? uint256() : pindex->pprev->GetBlockHash();
2479 assert(hashPrevBlock == view.GetBestBlock());
2480
2481 m_chainman.num_blocks_total++;
2482
2483 // Special case for the genesis block, skipping connection of its transactions
2484 // (its coinbase is unspendable)
2485 if (block_hash == params.GetConsensus().hashGenesisBlock) {
2486 if (!fJustCheck)
2487 view.SetBestBlock(pindex->GetBlockHash());
2488 return true;
2489 }
2490
2491 bool fScriptChecks = true;
2493 // We've been configured with the hash of a block which has been externally verified to have a valid history.
2494 // A suitable default value is included with the software and updated from time to time. Because validity
2495 // relative to a piece of software is an objective fact these defaults can be easily reviewed.
2496 // This setting doesn't force the selection of any particular chain but makes validating some faster by
2497 // effectively caching the result of part of the verification.
2498 BlockMap::const_iterator it{m_blockman.m_block_index.find(m_chainman.AssumedValidBlock())};
2499 if (it != m_blockman.m_block_index.end()) {
2500 if (it->second.GetAncestor(pindex->nHeight) == pindex &&
2501 m_chainman.m_best_header->GetAncestor(pindex->nHeight) == pindex &&
2502 m_chainman.m_best_header->nChainWork >= m_chainman.MinimumChainWork()) {
2503 // This block is a member of the assumed verified chain and an ancestor of the best header.
2504 // Script verification is skipped when connecting blocks under the
2505 // assumevalid block. Assuming the assumevalid block is valid this
2506 // is safe because block merkle hashes are still computed and checked,
2507 // Of course, if an assumed valid block is invalid due to false scriptSigs
2508 // this optimization would allow an invalid chain to be accepted.
2509 // The equivalent time check discourages hash power from extorting the network via DOS attack
2510 // into accepting an invalid block through telling users they must manually set assumevalid.
2511 // Requiring a software change or burying the invalid block, regardless of the setting, makes
2512 // it hard to hide the implication of the demand. This also avoids having release candidates
2513 // that are hardly doing any signature verification at all in testing without having to
2514 // artificially set the default assumed verified block further back.
2515 // The test against the minimum chain work prevents the skipping when denied access to any chain at
2516 // least as good as the expected chain.
2517 fScriptChecks = (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, params.GetConsensus()) <= 60 * 60 * 24 * 7 * 2);
2518 }
2519 }
2520 }
2521
2522 const auto time_1{SteadyClock::now()};
2523 m_chainman.time_check += time_1 - time_start;
2524 LogDebug(BCLog::BENCH, " - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
2525 Ticks<MillisecondsDouble>(time_1 - time_start),
2526 Ticks<SecondsDouble>(m_chainman.time_check),
2527 Ticks<MillisecondsDouble>(m_chainman.time_check) / m_chainman.num_blocks_total);
2528
2529 // Do not allow blocks that contain transactions which 'overwrite' older transactions,
2530 // unless those are already completely spent.
2531 // If such overwrites are allowed, coinbases and transactions depending upon those
2532 // can be duplicated to remove the ability to spend the first instance -- even after
2533 // being sent to another address.
2534 // See BIP30, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html for more information.
2535 // This rule was originally applied to all blocks with a timestamp after March 15, 2012, 0:00 UTC.
2536 // Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the
2537 // two in the chain that violate it. This prevents exploiting the issue against nodes during their
2538 // initial block download.
2539 bool fEnforceBIP30 = !IsBIP30Repeat(*pindex);
2540
2541 // Once BIP34 activated it was not possible to create new duplicate coinbases and thus other than starting
2542 // with the 2 existing duplicate coinbase pairs, not possible to create overwriting txs. But by the
2543 // time BIP34 activated, in each of the existing pairs the duplicate coinbase had overwritten the first
2544 // before the first had been spent. Since those coinbases are sufficiently buried it's no longer possible to create further
2545 // duplicate transactions descending from the known pairs either.
2546 // If we're on the known chain at height greater than where BIP34 activated, we can save the db accesses needed for the BIP30 check.
2547
2548 // BIP34 requires that a block at height X (block X) has its coinbase
2549 // scriptSig start with a CScriptNum of X (indicated height X). The above
2550 // logic of no longer requiring BIP30 once BIP34 activates is flawed in the
2551 // case that there is a block X before the BIP34 height of 227,931 which has
2552 // an indicated height Y where Y is greater than X. The coinbase for block
2553 // X would also be a valid coinbase for block Y, which could be a BIP30
2554 // violation. An exhaustive search of all mainnet coinbases before the
2555 // BIP34 height which have an indicated height greater than the block height
2556 // reveals many occurrences. The 3 lowest indicated heights found are
2557 // 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3
2558 // heights would be the first opportunity for BIP30 to be violated.
2559
2560 // The search reveals a great many blocks which have an indicated height
2561 // greater than 1,983,702, so we simply remove the optimization to skip
2562 // BIP30 checking for blocks at height 1,983,702 or higher. Before we reach
2563 // that block in another 25 years or so, we should take advantage of a
2564 // future consensus change to do a new and improved version of BIP34 that
2565 // will actually prevent ever creating any duplicate coinbases in the
2566 // future.
2567 static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702;
2568
2569 // There is no potential to create a duplicate coinbase at block 209,921
2570 // because this is still before the BIP34 height and so explicit BIP30
2571 // checking is still active.
2572
2573 // The final case is block 176,684 which has an indicated height of
2574 // 490,897. Unfortunately, this issue was not discovered until about 2 weeks
2575 // before block 490,897 so there was not much opportunity to address this
2576 // case other than to carefully analyze it and determine it would not be a
2577 // problem. Block 490,897 was, in fact, mined with a different coinbase than
2578 // block 176,684, but it is important to note that even if it hadn't been or
2579 // is remined on an alternate fork with a duplicate coinbase, we would still
2580 // not run into a BIP30 violation. This is because the coinbase for 176,684
2581 // is spent in block 185,956 in transaction
2582 // d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781. This
2583 // spending transaction can't be duplicated because it also spends coinbase
2584 // 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29. This
2585 // coinbase has an indicated height of over 4.2 billion, and wouldn't be
2586 // duplicatable until that height, and it's currently impossible to create a
2587 // chain that long. Nevertheless we may wish to consider a future soft fork
2588 // which retroactively prevents block 490,897 from creating a duplicate
2589 // coinbase. The two historical BIP30 violations often provide a confusing
2590 // edge case when manipulating the UTXO and it would be simpler not to have
2591 // another edge case to deal with.
2592
2593 // testnet3 has no blocks before the BIP34 height with indicated heights
2594 // post BIP34 before approximately height 486,000,000. After block
2595 // 1,983,702 testnet3 starts doing unnecessary BIP30 checking again.
2596 assert(pindex->pprev);
2597 CBlockIndex* pindexBIP34height = pindex->pprev->GetAncestor(params.GetConsensus().BIP34Height);
2598 //Only continue to enforce if we're below BIP34 activation height or the block hash at that height doesn't correspond.
2599 fEnforceBIP30 = fEnforceBIP30 && (!pindexBIP34height || !(pindexBIP34height->GetBlockHash() == params.GetConsensus().BIP34Hash));
2600
2601 // TODO: Remove BIP30 checking from block height 1,983,702 on, once we have a
2602 // consensus change that ensures coinbases at those heights cannot
2603 // duplicate earlier coinbases.
2604 if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) {
2605 for (const auto& tx : block.vtx) {
2606 for (size_t o = 0; o < tx->vout.size(); o++) {
2607 if (view.HaveCoin(COutPoint(tx->GetHash(), o))) {
2608 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-BIP30",
2609 "tried to overwrite transaction");
2610 }
2611 }
2612 }
2613 }
2614
2615 // Enforce BIP68 (sequence locks)
2616 int nLockTimeFlags = 0;
2618 nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
2619 }
2620
2621 // Get the script flags for this block
2622 unsigned int flags{GetBlockScriptFlags(*pindex, m_chainman)};
2623
2624 const auto time_2{SteadyClock::now()};
2625 m_chainman.time_forks += time_2 - time_1;
2626 LogDebug(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
2627 Ticks<MillisecondsDouble>(time_2 - time_1),
2628 Ticks<SecondsDouble>(m_chainman.time_forks),
2629 Ticks<MillisecondsDouble>(m_chainman.time_forks) / m_chainman.num_blocks_total);
2630
2631 CBlockUndo blockundo;
2632
2633 // Precomputed transaction data pointers must not be invalidated
2634 // until after `control` has run the script checks (potentially
2635 // in multiple threads). Preallocate the vector size so a new allocation
2636 // doesn't invalidate pointers into the vector, and keep txsdata in scope
2637 // for as long as `control`.
2638 CCheckQueueControl<CScriptCheck> control(fScriptChecks && parallel_script_checks ? &m_chainman.GetCheckQueue() : nullptr);
2639 std::vector<PrecomputedTransactionData> txsdata(block.vtx.size());
2640
2641 std::vector<int> prevheights;
2642 CAmount nFees = 0;
2643 int nInputs = 0;
2644 int64_t nSigOpsCost = 0;
2645 blockundo.vtxundo.reserve(block.vtx.size() - 1);
2646 for (unsigned int i = 0; i < block.vtx.size(); i++)
2647 {
2648 if (!state.IsValid()) break;
2649 const CTransaction &tx = *(block.vtx[i]);
2650
2651 nInputs += tx.vin.size();
2652
2653 if (!tx.IsCoinBase())
2654 {
2655 CAmount txfee = 0;
2656 TxValidationState tx_state;
2657 if (!Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight, txfee)) {
2658 // Any transaction validation failure in ConnectBlock is a block consensus failure
2660 tx_state.GetRejectReason(),
2661 tx_state.GetDebugMessage() + " in transaction " + tx.GetHash().ToString());
2662 break;
2663 }
2664 nFees += txfee;
2665 if (!MoneyRange(nFees)) {
2666 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-accumulated-fee-outofrange",
2667 "accumulated fee in the block out of range");
2668 break;
2669 }
2670
2671 // Check that transaction is BIP68 final
2672 // BIP68 lock checks (as opposed to nLockTime checks) must
2673 // be in ConnectBlock because they require the UTXO set
2674 prevheights.resize(tx.vin.size());
2675 for (size_t j = 0; j < tx.vin.size(); j++) {
2676 prevheights[j] = view.AccessCoin(tx.vin[j].prevout).nHeight;
2677 }
2678
2679 if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) {
2680 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal",
2681 "contains a non-BIP68-final transaction " + tx.GetHash().ToString());
2682 break;
2683 }
2684 }
2685
2686 // GetTransactionSigOpCost counts 3 types of sigops:
2687 // * legacy (always)
2688 // * p2sh (when P2SH enabled in flags and excludes coinbase)
2689 // * witness (when witness enabled in flags and excludes coinbase)
2690 nSigOpsCost += GetTransactionSigOpCost(tx, view, flags);
2691 if (nSigOpsCost > MAX_BLOCK_SIGOPS_COST) {
2692 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "too many sigops");
2693 break;
2694 }
2695
2696 if (!tx.IsCoinBase())
2697 {
2698 std::vector<CScriptCheck> vChecks;
2699 bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */
2700 TxValidationState tx_state;
2701 if (fScriptChecks && !CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], m_chainman.m_validation_cache, parallel_script_checks ? &vChecks : nullptr)) {
2702 // Any transaction validation failure in ConnectBlock is a block consensus failure
2704 tx_state.GetRejectReason(), tx_state.GetDebugMessage());
2705 break;
2706 }
2707 control.Add(std::move(vChecks));
2708 }
2709
2710 CTxUndo undoDummy;
2711 if (i > 0) {
2712 blockundo.vtxundo.emplace_back();
2713 }
2714 UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight);
2715 }
2716 const auto time_3{SteadyClock::now()};
2717 m_chainman.time_connect += time_3 - time_2;
2718 LogDebug(BCLog::BENCH, " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(),
2719 Ticks<MillisecondsDouble>(time_3 - time_2), Ticks<MillisecondsDouble>(time_3 - time_2) / block.vtx.size(),
2720 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_3 - time_2) / (nInputs - 1),
2721 Ticks<SecondsDouble>(m_chainman.time_connect),
2722 Ticks<MillisecondsDouble>(m_chainman.time_connect) / m_chainman.num_blocks_total);
2723
2724 CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, params.GetConsensus());
2725 if (block.vtx[0]->GetValueOut() > blockReward && state.IsValid()) {
2726 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-amount",
2727 strprintf("coinbase pays too much (actual=%d vs limit=%d)", block.vtx[0]->GetValueOut(), blockReward));
2728 }
2729
2730 auto parallel_result = control.Complete();
2731 if (parallel_result.has_value() && state.IsValid()) {
2732 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(parallel_result->first)), parallel_result->second);
2733 }
2734 if (!state.IsValid()) {
2735 LogInfo("Block validation error: %s", state.ToString());
2736 return false;
2737 }
2738 const auto time_4{SteadyClock::now()};
2739 m_chainman.time_verify += time_4 - time_2;
2740 LogDebug(BCLog::BENCH, " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n", nInputs - 1,
2741 Ticks<MillisecondsDouble>(time_4 - time_2),
2742 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_4 - time_2) / (nInputs - 1),
2743 Ticks<SecondsDouble>(m_chainman.time_verify),
2744 Ticks<MillisecondsDouble>(m_chainman.time_verify) / m_chainman.num_blocks_total);
2745
2746 if (fJustCheck) {
2747 return true;
2748 }
2749
2750 if (!m_blockman.WriteBlockUndo(blockundo, state, *pindex)) {
2751 return false;
2752 }
2753
2754 const auto time_5{SteadyClock::now()};
2755 m_chainman.time_undo += time_5 - time_4;
2756 LogDebug(BCLog::BENCH, " - Write undo data: %.2fms [%.2fs (%.2fms/blk)]\n",
2757 Ticks<MillisecondsDouble>(time_5 - time_4),
2758 Ticks<SecondsDouble>(m_chainman.time_undo),
2759 Ticks<MillisecondsDouble>(m_chainman.time_undo) / m_chainman.num_blocks_total);
2760
2761 if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) {
2763 m_blockman.m_dirty_blockindex.insert(pindex);
2764 }
2765
2766 // add this block to the view's block chain
2767 view.SetBestBlock(pindex->GetBlockHash());
2768
2769 const auto time_6{SteadyClock::now()};
2770 m_chainman.time_index += time_6 - time_5;
2771 LogDebug(BCLog::BENCH, " - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
2772 Ticks<MillisecondsDouble>(time_6 - time_5),
2773 Ticks<SecondsDouble>(m_chainman.time_index),
2774 Ticks<MillisecondsDouble>(m_chainman.time_index) / m_chainman.num_blocks_total);
2775
2776 TRACEPOINT(validation, block_connected,
2777 block_hash.data(),
2778 pindex->nHeight,
2779 block.vtx.size(),
2780 nInputs,
2781 nSigOpsCost,
2782 Ticks<std::chrono::nanoseconds>(time_5 - time_start)
2783 );
2784
2785 return true;
2786}
2787
2788CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState()
2789{
2791 return this->GetCoinsCacheSizeState(
2794}
2795
2796CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState(
2797 size_t max_coins_cache_size_bytes,
2798 size_t max_mempool_size_bytes)
2799{
2801 const int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0;
2802 int64_t cacheSize = CoinsTip().DynamicMemoryUsage();
2803 int64_t nTotalSpace =
2804 max_coins_cache_size_bytes + std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0);
2805
2807 static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES = 10 * 1024 * 1024; // 10MB
2808 int64_t large_threshold =
2809 std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES);
2810
2811 if (cacheSize > nTotalSpace) {
2812 LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize, nTotalSpace);
2814 } else if (cacheSize > large_threshold) {
2816 }
2818}
2819
2821 BlockValidationState &state,
2822 FlushStateMode mode,
2823 int nManualPruneHeight)
2824{
2825 LOCK(cs_main);
2826 assert(this->CanFlushToDisk());
2827 std::set<int> setFilesToPrune;
2828 bool full_flush_completed = false;
2829
2830 const size_t coins_count = CoinsTip().GetCacheSize();
2831 const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage();
2832
2833 try {
2834 {
2835 bool fFlushForPrune = false;
2836 bool fDoFullFlush = false;
2837
2838 CoinsCacheSizeState cache_state = GetCoinsCacheSizeState();
2841 // make sure we don't prune above any of the prune locks bestblocks
2842 // pruning is height-based
2843 int last_prune{m_chain.Height()}; // last height we can prune
2844 std::optional<std::string> limiting_lock; // prune lock that actually was the limiting factor, only used for logging
2845
2846 for (const auto& prune_lock : m_blockman.m_prune_locks) {
2847 if (prune_lock.second.height_first == std::numeric_limits<int>::max()) continue;
2848 // Remove the buffer and one additional block here to get actual height that is outside of the buffer
2849 const int lock_height{prune_lock.second.height_first - PRUNE_LOCK_BUFFER - 1};
2850 last_prune = std::max(1, std::min(last_prune, lock_height));
2851 if (last_prune == lock_height) {
2852 limiting_lock = prune_lock.first;
2853 }
2854 }
2855
2856 if (limiting_lock) {
2857 LogDebug(BCLog::PRUNE, "%s limited pruning to height %d\n", limiting_lock.value(), last_prune);
2858 }
2859
2860 if (nManualPruneHeight > 0) {
2861 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune (manual)", BCLog::BENCH);
2862
2864 setFilesToPrune,
2865 std::min(last_prune, nManualPruneHeight),
2866 *this, m_chainman);
2867 } else {
2868 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune", BCLog::BENCH);
2869
2870 m_blockman.FindFilesToPrune(setFilesToPrune, last_prune, *this, m_chainman);
2872 }
2873 if (!setFilesToPrune.empty()) {
2874 fFlushForPrune = true;
2876 m_blockman.m_block_tree_db->WriteFlag("prunedblockfiles", true);
2878 }
2879 }
2880 }
2881 const auto nNow{SteadyClock::now()};
2882 // Avoid writing/flushing immediately after startup.
2883 if (m_last_write == decltype(m_last_write){}) {
2884 m_last_write = nNow;
2885 }
2886 if (m_last_flush == decltype(m_last_flush){}) {
2887 m_last_flush = nNow;
2888 }
2889 // The cache is large and we're within 10% and 10 MiB of the limit, but we have time now (not in the middle of a block processing).
2890 bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE;
2891 // The cache is over the limit, we have to write now.
2892 bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL;
2893 // It's been a while since we wrote the block index to disk. Do this frequently, so we don't need to redownload after a crash.
2894 bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow > m_last_write + DATABASE_WRITE_INTERVAL;
2895 // It's been very long since we flushed the cache. Do this infrequently, to optimize cache usage.
2896 bool fPeriodicFlush = mode == FlushStateMode::PERIODIC && nNow > m_last_flush + DATABASE_FLUSH_INTERVAL;
2897 // Combine all conditions that result in a full cache flush.
2898 fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicFlush || fFlushForPrune;
2899 // Write blocks and block index to disk.
2900 if (fDoFullFlush || fPeriodicWrite) {
2901 // Ensure we can write block index
2903 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!"));
2904 }
2905 {
2906 LOG_TIME_MILLIS_WITH_CATEGORY("write block and undo data to disk", BCLog::BENCH);
2907
2908 // First make sure all block and undo data is flushed to disk.
2909 // TODO: Handle return error, or add detailed comment why it is
2910 // safe to not return an error upon failure.
2912 LogPrintLevel(BCLog::VALIDATION, BCLog::Level::Warning, "%s: Failed to flush block file.\n", __func__);
2913 }
2914 }
2915
2916 // Then update all block file information (which may refer to block and undo files).
2917 {
2918 LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk", BCLog::BENCH);
2919
2920 if (!m_blockman.WriteBlockIndexDB()) {
2921 return FatalError(m_chainman.GetNotifications(), state, _("Failed to write to block index database."));
2922 }
2923 }
2924 // Finally remove any pruned files
2925 if (fFlushForPrune) {
2926 LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files", BCLog::BENCH);
2927
2928 m_blockman.UnlinkPrunedFiles(setFilesToPrune);
2929 }
2930 m_last_write = nNow;
2931 }
2932 // Flush best chain related state. This can only be done if the blocks / block index write was also done.
2933 if (fDoFullFlush && !CoinsTip().GetBestBlock().IsNull()) {
2934 if (coins_mem_usage >= WARN_FLUSH_COINS_SIZE) LogWarning("Flushing large (%d GiB) UTXO set to disk, it may take several minutes", coins_mem_usage >> 30);
2935 LOG_TIME_MILLIS_WITH_CATEGORY(strprintf("write coins cache to disk (%d coins, %.2fKiB)",
2936 coins_count, coins_mem_usage >> 10), BCLog::BENCH);
2937
2938 // Typical Coin structures on disk are around 48 bytes in size.
2939 // Pushing a new one to the database can cause it to be written
2940 // twice (once in the log, and once in the tables). This is already
2941 // an overestimation, as most will delete an existing entry or
2942 // overwrite one. Still, use a conservative safety factor of 2.
2943 if (!CheckDiskSpace(m_chainman.m_options.datadir, 48 * 2 * 2 * CoinsTip().GetCacheSize())) {
2944 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!"));
2945 }
2946 // Flush the chainstate (which may refer to block index entries).
2947 const auto empty_cache{(mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical};
2948 if (empty_cache ? !CoinsTip().Flush() : !CoinsTip().Sync()) {
2949 return FatalError(m_chainman.GetNotifications(), state, _("Failed to write to coin database."));
2950 }
2951 m_last_flush = nNow;
2952 full_flush_completed = true;
2953 TRACEPOINT(utxocache, flush,
2954 int64_t{Ticks<std::chrono::microseconds>(SteadyClock::now() - nNow)},
2955 (uint32_t)mode,
2956 (uint64_t)coins_count,
2957 (uint64_t)coins_mem_usage,
2958 (bool)fFlushForPrune);
2959 }
2960 }
2961 if (full_flush_completed && m_chainman.m_options.signals) {
2962 // Update best block in wallet (so we can detect restored wallets).
2964 }
2965 } catch (const std::runtime_error& e) {
2966 return FatalError(m_chainman.GetNotifications(), state, strprintf(_("System error while flushing: %s"), e.what()));
2967 }
2968 return true;
2969}
2970
2972{
2974 if (!this->FlushStateToDisk(state, FlushStateMode::ALWAYS)) {
2975 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString());
2976 }
2977}
2978
2980{
2983 if (!this->FlushStateToDisk(state, FlushStateMode::NONE)) {
2984 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString());
2985 }
2986}
2987
2988static void UpdateTipLog(
2989 const ChainstateManager& chainman,
2990 const CCoinsViewCache& coins_tip,
2991 const CBlockIndex* tip,
2992 const std::string& func_name,
2993 const std::string& prefix,
2994 const std::string& warning_messages) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
2995{
2996
2998 LogPrintf("%s%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%lu date='%s' progress=%f cache=%.1fMiB(%utxo)%s\n",
2999 prefix, func_name,
3000 tip->GetBlockHash().ToString(), tip->nHeight, tip->nVersion,
3001 log(tip->nChainWork.getdouble()) / log(2.0), tip->m_chain_tx_count,
3003 chainman.GuessVerificationProgress(tip),
3004 coins_tip.DynamicMemoryUsage() * (1.0 / (1 << 20)),
3005 coins_tip.GetCacheSize(),
3006 !warning_messages.empty() ? strprintf(" warning='%s'", warning_messages) : "");
3007}
3008
3009void Chainstate::UpdateTip(const CBlockIndex* pindexNew)
3010{
3012 const auto& coins_tip = this->CoinsTip();
3013
3014 // The remainder of the function isn't relevant if we are not acting on
3015 // the active chainstate, so return if need be.
3016 if (this != &m_chainman.ActiveChainstate()) {
3017 // Only log every so often so that we don't bury log messages at the tip.
3018 constexpr int BACKGROUND_LOG_INTERVAL = 2000;
3019 if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) {
3020 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "[background validation] ", "");
3021 }
3022 return;
3023 }
3024
3025 // New best block
3026 if (m_mempool) {
3028 }
3029
3030 std::vector<bilingual_str> warning_messages;
3032 const CBlockIndex* pindex = pindexNew;
3033 for (int bit = 0; bit < VERSIONBITS_NUM_BITS; bit++) {
3035 ThresholdState state = checker.GetStateFor(pindex, m_chainman.GetConsensus(), m_chainman.m_warningcache.at(bit));
3036 if (state == ThresholdState::ACTIVE || state == ThresholdState::LOCKED_IN) {
3037 const bilingual_str warning = strprintf(_("Unknown new rules activated (versionbit %i)"), bit);
3038 if (state == ThresholdState::ACTIVE) {
3040 } else {
3041 warning_messages.push_back(warning);
3042 }
3043 }
3044 }
3045 }
3046 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "",
3047 util::Join(warning_messages, Untranslated(", ")).original);
3048}
3049
3061{
3064
3065 CBlockIndex *pindexDelete = m_chain.Tip();
3066 assert(pindexDelete);
3067 assert(pindexDelete->pprev);
3068 // Read block from disk.
3069 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
3070 CBlock& block = *pblock;
3071 if (!m_blockman.ReadBlock(block, *pindexDelete)) {
3072 LogError("DisconnectTip(): Failed to read block\n");
3073 return false;
3074 }
3075 // Apply the block atomically to the chain state.
3076 const auto time_start{SteadyClock::now()};
3077 {
3078 CCoinsViewCache view(&CoinsTip());
3079 assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
3080 if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK) {
3081 LogError("DisconnectTip(): DisconnectBlock %s failed\n", pindexDelete->GetBlockHash().ToString());
3082 return false;
3083 }
3084 bool flushed = view.Flush();
3085 assert(flushed);
3086 }
3087 LogDebug(BCLog::BENCH, "- Disconnect block: %.2fms\n",
3088 Ticks<MillisecondsDouble>(SteadyClock::now() - time_start));
3089
3090 {
3091 // Prune locks that began at or after the tip should be moved backward so they get a chance to reorg
3092 const int max_height_first{pindexDelete->nHeight - 1};
3093 for (auto& prune_lock : m_blockman.m_prune_locks) {
3094 if (prune_lock.second.height_first <= max_height_first) continue;
3095
3096 prune_lock.second.height_first = max_height_first;
3097 LogDebug(BCLog::PRUNE, "%s prune lock moved back to %d\n", prune_lock.first, max_height_first);
3098 }
3099 }
3100
3101 // Write the chain state to disk, if necessary.
3103 return false;
3104 }
3105
3106 if (disconnectpool && m_mempool) {
3107 // Save transactions to re-add to mempool at end of reorg. If any entries are evicted for
3108 // exceeding memory limits, remove them and their descendants from the mempool.
3109 for (auto&& evicted_tx : disconnectpool->AddTransactionsFromBlock(block.vtx)) {
3111 }
3112 }
3113
3114 m_chain.SetTip(*pindexDelete->pprev);
3115
3116 UpdateTip(pindexDelete->pprev);
3117 // Let wallets know transactions went from 1-confirmed to
3118 // 0-confirmed or conflicted:
3120 m_chainman.m_options.signals->BlockDisconnected(pblock, pindexDelete);
3121 }
3122 return true;
3123}
3124
3127 std::shared_ptr<const CBlock> pblock;
3129};
3138private:
3139 std::vector<PerBlockConnectTrace> blocksConnected;
3140
3141public:
3143
3144 void BlockConnected(CBlockIndex* pindex, std::shared_ptr<const CBlock> pblock) {
3145 assert(!blocksConnected.back().pindex);
3146 assert(pindex);
3147 assert(pblock);
3148 blocksConnected.back().pindex = pindex;
3149 blocksConnected.back().pblock = std::move(pblock);
3150 blocksConnected.emplace_back();
3151 }
3152
3153 std::vector<PerBlockConnectTrace>& GetBlocksConnected() {
3154 // We always keep one extra block at the end of our list because
3155 // blocks are added after all the conflicted transactions have
3156 // been filled in. Thus, the last entry should always be an empty
3157 // one waiting for the transactions from the next block. We pop
3158 // the last entry here to make sure the list we return is sane.
3159 assert(!blocksConnected.back().pindex);
3160 blocksConnected.pop_back();
3161 return blocksConnected;
3162 }
3163};
3164
3171bool Chainstate::ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool)
3172{
3175
3176 assert(pindexNew->pprev == m_chain.Tip());
3177 // Read block from disk.
3178 const auto time_1{SteadyClock::now()};
3179 std::shared_ptr<const CBlock> pthisBlock;
3180 if (!pblock) {
3181 std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
3182 if (!m_blockman.ReadBlock(*pblockNew, *pindexNew)) {
3183 return FatalError(m_chainman.GetNotifications(), state, _("Failed to read block."));
3184 }
3185 pthisBlock = pblockNew;
3186 } else {
3187 LogDebug(BCLog::BENCH, " - Using cached block\n");
3188 pthisBlock = pblock;
3189 }
3190 const CBlock& blockConnecting = *pthisBlock;
3191 // Apply the block atomically to the chain state.
3192 const auto time_2{SteadyClock::now()};
3193 SteadyClock::time_point time_3;
3194 // When adding aggregate statistics in the future, keep in mind that
3195 // num_blocks_total may be zero until the ConnectBlock() call below.
3196 LogDebug(BCLog::BENCH, " - Load block from disk: %.2fms\n",
3197 Ticks<MillisecondsDouble>(time_2 - time_1));
3198 {
3199 CCoinsViewCache view(&CoinsTip());
3200 bool rv = ConnectBlock(blockConnecting, state, pindexNew, view);
3202 m_chainman.m_options.signals->BlockChecked(blockConnecting, state);
3203 }
3204 if (!rv) {
3205 if (state.IsInvalid())
3206 InvalidBlockFound(pindexNew, state);
3207 LogError("%s: ConnectBlock %s failed, %s\n", __func__, pindexNew->GetBlockHash().ToString(), state.ToString());
3208 return false;
3209 }
3210 time_3 = SteadyClock::now();
3211 m_chainman.time_connect_total += time_3 - time_2;
3212 assert(m_chainman.num_blocks_total > 0);
3213 LogDebug(BCLog::BENCH, " - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
3214 Ticks<MillisecondsDouble>(time_3 - time_2),
3215 Ticks<SecondsDouble>(m_chainman.time_connect_total),
3216 Ticks<MillisecondsDouble>(m_chainman.time_connect_total) / m_chainman.num_blocks_total);
3217 bool flushed = view.Flush();
3218 assert(flushed);
3219 }
3220 const auto time_4{SteadyClock::now()};
3221 m_chainman.time_flush += time_4 - time_3;
3222 LogDebug(BCLog::BENCH, " - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
3223 Ticks<MillisecondsDouble>(time_4 - time_3),
3224 Ticks<SecondsDouble>(m_chainman.time_flush),
3225 Ticks<MillisecondsDouble>(m_chainman.time_flush) / m_chainman.num_blocks_total);
3226 // Write the chain state to disk, if necessary.
3228 return false;
3229 }
3230 const auto time_5{SteadyClock::now()};
3231 m_chainman.time_chainstate += time_5 - time_4;
3232 LogDebug(BCLog::BENCH, " - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
3233 Ticks<MillisecondsDouble>(time_5 - time_4),
3234 Ticks<SecondsDouble>(m_chainman.time_chainstate),
3235 Ticks<MillisecondsDouble>(m_chainman.time_chainstate) / m_chainman.num_blocks_total);
3236 // Remove conflicting transactions from the mempool.;
3237 if (m_mempool) {
3238 m_mempool->removeForBlock(blockConnecting.vtx, pindexNew->nHeight);
3239 disconnectpool.removeForBlock(blockConnecting.vtx);
3240 }
3241 // Update m_chain & related variables.
3242 m_chain.SetTip(*pindexNew);
3243 UpdateTip(pindexNew);
3244
3245 const auto time_6{SteadyClock::now()};
3246 m_chainman.time_post_connect += time_6 - time_5;
3247 m_chainman.time_total += time_6 - time_1;
3248 LogDebug(BCLog::BENCH, " - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
3249 Ticks<MillisecondsDouble>(time_6 - time_5),
3250 Ticks<SecondsDouble>(m_chainman.time_post_connect),
3251 Ticks<MillisecondsDouble>(m_chainman.time_post_connect) / m_chainman.num_blocks_total);
3252 LogDebug(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
3253 Ticks<MillisecondsDouble>(time_6 - time_1),
3254 Ticks<SecondsDouble>(m_chainman.time_total),
3255 Ticks<MillisecondsDouble>(m_chainman.time_total) / m_chainman.num_blocks_total);
3256
3257 // If we are the background validation chainstate, check to see if we are done
3258 // validating the snapshot (i.e. our tip has reached the snapshot's base block).
3259 if (this != &m_chainman.ActiveChainstate()) {
3260 // This call may set `m_disabled`, which is referenced immediately afterwards in
3261 // ActivateBestChain, so that we stop connecting blocks past the snapshot base.
3262 m_chainman.MaybeCompleteSnapshotValidation();
3263 }
3264
3265 connectTrace.BlockConnected(pindexNew, std::move(pthisBlock));
3266 return true;
3267}
3268
3274{
3276 do {
3277 CBlockIndex *pindexNew = nullptr;
3278
3279 // Find the best candidate header.
3280 {
3281 std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexCandidates.rbegin();
3282 if (it == setBlockIndexCandidates.rend())
3283 return nullptr;
3284 pindexNew = *it;
3285 }
3286
3287 // Check whether all blocks on the path between the currently active chain and the candidate are valid.
3288 // Just going until the active chain is an optimization, as we know all blocks in it are valid already.
3289 CBlockIndex *pindexTest = pindexNew;
3290 bool fInvalidAncestor = false;
3291 while (pindexTest && !m_chain.Contains(pindexTest)) {
3292 assert(pindexTest->HaveNumChainTxs() || pindexTest->nHeight == 0);
3293
3294 // Pruned nodes may have entries in setBlockIndexCandidates for
3295 // which block files have been deleted. Remove those as candidates
3296 // for the most work chain if we come across them; we can't switch
3297 // to a chain unless we have all the non-active-chain parent blocks.
3298 bool fFailedChain = pindexTest->nStatus & BLOCK_FAILED_MASK;
3299 bool fMissingData = !(pindexTest->nStatus & BLOCK_HAVE_DATA);
3300 if (fFailedChain || fMissingData) {
3301 // Candidate chain is not usable (either invalid or missing data)
3302 if (fFailedChain && (m_chainman.m_best_invalid == nullptr || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork)) {
3303 m_chainman.m_best_invalid = pindexNew;
3304 }
3305 CBlockIndex *pindexFailed = pindexNew;
3306 // Remove the entire chain from the set.
3307 while (pindexTest != pindexFailed) {
3308 if (fFailedChain) {
3309 pindexFailed->nStatus |= BLOCK_FAILED_CHILD;
3310 m_blockman.m_dirty_blockindex.insert(pindexFailed);
3311 } else if (fMissingData) {
3312 // If we're missing data, then add back to m_blocks_unlinked,
3313 // so that if the block arrives in the future we can try adding
3314 // to setBlockIndexCandidates again.
3316 std::make_pair(pindexFailed->pprev, pindexFailed));
3317 }
3318 setBlockIndexCandidates.erase(pindexFailed);
3319 pindexFailed = pindexFailed->pprev;
3320 }
3321 setBlockIndexCandidates.erase(pindexTest);
3322 fInvalidAncestor = true;
3323 break;
3324 }
3325 pindexTest = pindexTest->pprev;
3326 }
3327 if (!fInvalidAncestor)
3328 return pindexNew;
3329 } while(true);
3330}
3331
3334 // Note that we can't delete the current block itself, as we may need to return to it later in case a
3335 // reorganization to a better block fails.
3336 std::set<CBlockIndex*, CBlockIndexWorkComparator>::iterator it = setBlockIndexCandidates.begin();
3337 while (it != setBlockIndexCandidates.end() && setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) {
3338 setBlockIndexCandidates.erase(it++);
3339 }
3340 // Either the current tip or a successor of it we're working towards is left in setBlockIndexCandidates.
3342}
3343
3350bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace)
3351{
3354
3355 const CBlockIndex* pindexOldTip = m_chain.Tip();
3356 const CBlockIndex* pindexFork = m_chain.FindFork(pindexMostWork);
3357
3358 // Disconnect active blocks which are no longer in the best chain.
3359 bool fBlocksDisconnected = false;
3361 while (m_chain.Tip() && m_chain.Tip() != pindexFork) {
3362 if (!DisconnectTip(state, &disconnectpool)) {
3363 // This is likely a fatal error, but keep the mempool consistent,
3364 // just in case. Only remove from the mempool in this case.
3365 MaybeUpdateMempoolForReorg(disconnectpool, false);
3366
3367 // If we're unable to disconnect a block during normal operation,
3368 // then that is a failure of our local system -- we should abort
3369 // rather than stay on a less work chain.
3370 FatalError(m_chainman.GetNotifications(), state, _("Failed to disconnect block."));
3371 return false;
3372 }
3373 fBlocksDisconnected = true;
3374 }
3375
3376 // Build list of new blocks to connect (in descending height order).
3377 std::vector<CBlockIndex*> vpindexToConnect;
3378 bool fContinue = true;
3379 int nHeight = pindexFork ? pindexFork->nHeight : -1;
3380 while (fContinue && nHeight != pindexMostWork->nHeight) {
3381 // Don't iterate the entire list of potential improvements toward the best tip, as we likely only need
3382 // a few blocks along the way.
3383 int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
3384 vpindexToConnect.clear();
3385 vpindexToConnect.reserve(nTargetHeight - nHeight);
3386 CBlockIndex* pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
3387 while (pindexIter && pindexIter->nHeight != nHeight) {
3388 vpindexToConnect.push_back(pindexIter);
3389 pindexIter = pindexIter->pprev;
3390 }
3391 nHeight = nTargetHeight;
3392
3393 // Connect new blocks.
3394 for (CBlockIndex* pindexConnect : vpindexToConnect | std::views::reverse) {
3395 if (!ConnectTip(state, pindexConnect, pindexConnect == pindexMostWork ? pblock : std::shared_ptr<const CBlock>(), connectTrace, disconnectpool)) {
3396 if (state.IsInvalid()) {
3397 // The block violates a consensus rule.
3399 InvalidChainFound(vpindexToConnect.front());
3400 }
3401 state = BlockValidationState();
3402 fInvalidFound = true;
3403 fContinue = false;
3404 break;
3405 } else {
3406 // A system error occurred (disk space, database error, ...).
3407 // Make the mempool consistent with the current tip, just in case
3408 // any observers try to use it before shutdown.
3409 MaybeUpdateMempoolForReorg(disconnectpool, false);
3410 return false;
3411 }
3412 } else {
3414 if (!pindexOldTip || m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) {
3415 // We're in a better position than we were. Return temporarily to release the lock.
3416 fContinue = false;
3417 break;
3418 }
3419 }
3420 }
3421 }
3422
3423 if (fBlocksDisconnected) {
3424 // If any blocks were disconnected, disconnectpool may be non empty. Add
3425 // any disconnected transactions back to the mempool.
3426 MaybeUpdateMempoolForReorg(disconnectpool, true);
3427 }
3428 if (m_mempool) m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1);
3429
3431
3432 return true;
3433}
3434
3435static SynchronizationState GetSynchronizationState(bool init, bool blockfiles_indexed)
3436{
3438 if (!blockfiles_indexed) return SynchronizationState::INIT_REINDEX;
3440}
3441
3443{
3444 bool fNotify = false;
3445 bool fInitialBlockDownload = false;
3446 CBlockIndex* pindexHeader = nullptr;
3447 {
3448 LOCK(GetMutex());
3449 pindexHeader = m_best_header;
3450
3451 if (pindexHeader != m_last_notified_header) {
3452 fNotify = true;
3453 fInitialBlockDownload = IsInitialBlockDownload();
3454 m_last_notified_header = pindexHeader;
3455 }
3456 }
3457 // Send block tip changed notifications without the lock held
3458 if (fNotify) {
3459 GetNotifications().headerTip(GetSynchronizationState(fInitialBlockDownload, m_blockman.m_blockfiles_indexed), pindexHeader->nHeight, pindexHeader->nTime, false);
3460 }
3461 return fNotify;
3462}
3463
3466
3467 if (signals.CallbacksPending() > 10) {
3468 signals.SyncWithValidationInterfaceQueue();
3469 }
3470}
3471
3472bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<const CBlock> pblock)
3473{
3475
3476 // Note that while we're often called here from ProcessNewBlock, this is
3477 // far from a guarantee. Things in the P2P/RPC will often end up calling
3478 // us in the middle of ProcessNewBlock - do not assume pblock is set
3479 // sanely for performance or correctness!
3481
3482 // ABC maintains a fair degree of expensive-to-calculate internal state
3483 // because this function periodically releases cs_main so that it does not lock up other threads for too long
3484 // during large connects - and to allow for e.g. the callback queue to drain
3485 // we use m_chainstate_mutex to enforce mutual exclusion so that only one caller may execute this function at a time
3487
3488 // Belt-and-suspenders check that we aren't attempting to advance the background
3489 // chainstate past the snapshot base block.
3490 if (WITH_LOCK(::cs_main, return m_disabled)) {
3491 LogPrintf("m_disabled is set - this chainstate should not be in operation. "
3492 "Please report this as a bug. %s\n", CLIENT_BUGREPORT);
3493 return false;
3494 }
3495
3496 CBlockIndex *pindexMostWork = nullptr;
3497 CBlockIndex *pindexNewTip = nullptr;
3498 bool exited_ibd{false};
3499 do {
3500 // Block until the validation queue drains. This should largely
3501 // never happen in normal operation, however may happen during
3502 // reindex, causing memory blowup if we run too far ahead.
3503 // Note that if a validationinterface callback ends up calling
3504 // ActivateBestChain this may lead to a deadlock! We should
3505 // probably have a DEBUG_LOCKORDER test for this in the future.
3507
3508 {
3509 LOCK(cs_main);
3510 {
3511 // Lock transaction pool for at least as long as it takes for connectTrace to be consumed
3512 LOCK(MempoolMutex());
3513 const bool was_in_ibd = m_chainman.IsInitialBlockDownload();
3514 CBlockIndex* starting_tip = m_chain.Tip();
3515 bool blocks_connected = false;
3516 do {
3517 // We absolutely may not unlock cs_main until we've made forward progress
3518 // (with the exception of shutdown due to hardware issues, low disk space, etc).
3519 ConnectTrace connectTrace; // Destructed before cs_main is unlocked
3520
3521 if (pindexMostWork == nullptr) {
3522 pindexMostWork = FindMostWorkChain();
3523 }
3524
3525 // Whether we have anything to do at all.
3526 if (pindexMostWork == nullptr || pindexMostWork == m_chain.Tip()) {
3527 break;
3528 }
3529
3530 bool fInvalidFound = false;
3531 std::shared_ptr<const CBlock> nullBlockPtr;
3532 // BlockConnected signals must be sent for the original role;
3533 // in case snapshot validation is completed during ActivateBestChainStep, the
3534 // result of GetRole() changes from BACKGROUND to NORMAL.
3535 const ChainstateRole chainstate_role{this->GetRole()};
3536 if (!ActivateBestChainStep(state, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace)) {
3537 // A system error occurred
3538 return false;
3539 }
3540 blocks_connected = true;
3541
3542 if (fInvalidFound) {
3543 // Wipe cache, we may need another branch now.
3544 pindexMostWork = nullptr;
3545 }
3546 pindexNewTip = m_chain.Tip();
3547
3548 for (const PerBlockConnectTrace& trace : connectTrace.GetBlocksConnected()) {
3549 assert(trace.pblock && trace.pindex);
3551 m_chainman.m_options.signals->BlockConnected(chainstate_role, trace.pblock, trace.pindex);
3552 }
3553 }
3554
3555 // This will have been toggled in
3556 // ActivateBestChainStep -> ConnectTip -> MaybeCompleteSnapshotValidation,
3557 // if at all, so we should catch it here.
3558 //
3559 // Break this do-while to ensure we don't advance past the base snapshot.
3560 if (m_disabled) {
3561 break;
3562 }
3563 } while (!m_chain.Tip() || (starting_tip && CBlockIndexWorkComparator()(m_chain.Tip(), starting_tip)));
3564 if (!blocks_connected) return true;
3565
3566 const CBlockIndex* pindexFork = m_chain.FindFork(starting_tip);
3567 bool still_in_ibd = m_chainman.IsInitialBlockDownload();
3568
3569 if (was_in_ibd && !still_in_ibd) {
3570 // Active chainstate has exited IBD.
3571 exited_ibd = true;
3572 }
3573
3574 // Notify external listeners about the new tip.
3575 // Enqueue while holding cs_main to ensure that UpdatedBlockTip is called in the order in which blocks are connected
3576 if (this == &m_chainman.ActiveChainstate() && pindexFork != pindexNewTip) {
3577 // Notify ValidationInterface subscribers
3579 m_chainman.m_options.signals->UpdatedBlockTip(pindexNewTip, pindexFork, still_in_ibd);
3580 }
3581
3583 // Just breaking and returning success for now. This could
3584 // be changed to bubble up the kernel::Interrupted value to
3585 // the caller so the caller could distinguish between
3586 // completed and interrupted operations.
3587 break;
3588 }
3589 }
3590 } // release MempoolMutex
3591 // Notify external listeners about the new tip, even if pindexFork == pindexNewTip.
3594 }
3595 } // release cs_main
3596 // When we reach this point, we switched to a new tip (stored in pindexNewTip).
3597
3598 if (exited_ibd) {
3599 // If a background chainstate is in use, we may need to rebalance our
3600 // allocation of caches once a chainstate exits initial block download.
3601 LOCK(::cs_main);
3602 m_chainman.MaybeRebalanceCaches();
3603 }
3604
3605 if (WITH_LOCK(::cs_main, return m_disabled)) {
3606 // Background chainstate has reached the snapshot base block, so exit.
3607
3608 // Restart indexes to resume indexing for all blocks unique to the snapshot
3609 // chain. This resumes indexing "in order" from where the indexing on the
3610 // background validation chain left off.
3611 //
3612 // This cannot be done while holding cs_main (within
3613 // MaybeCompleteSnapshotValidation) or a cs_main deadlock will occur.
3616 }
3617 break;
3618 }
3619
3620 // We check interrupt only after giving ActivateBestChainStep a chance to run once so that we
3621 // never interrupt before connecting the genesis block during LoadChainTip(). Previously this
3622 // caused an assert() failure during interrupt in such cases as the UTXO DB flushing checks
3623 // that the best block hash is non-null.
3624 if (m_chainman.m_interrupt) break;
3625 } while (pindexNewTip != pindexMostWork);
3626
3628
3629 // Write changes periodically to disk, after relay.
3631 return false;
3632 }
3633
3634 return true;
3635}
3636
3637bool Chainstate::PreciousBlock(BlockValidationState& state, CBlockIndex* pindex)
3638{
3641 {
3642 LOCK(cs_main);
3643 if (pindex->nChainWork < m_chain.Tip()->nChainWork) {
3644 // Nothing to do, this block is not at the tip.
3645 return true;
3646 }
3648 // The chain has been extended since the last call, reset the counter.
3650 }
3652 setBlockIndexCandidates.erase(pindex);
3654 if (m_chainman.nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) {
3655 // We can't keep reducing the counter if somebody really wants to
3656 // call preciousblock 2**31-1 times on the same set of tips...
3658 }
3659 if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && pindex->HaveNumChainTxs()) {
3660 setBlockIndexCandidates.insert(pindex);
3662 }
3663 }
3664
3665 return ActivateBestChain(state, std::shared_ptr<const CBlock>());
3666}
3667
3669{
3672
3673 // Genesis block can't be invalidated
3674 assert(pindex);
3675 if (pindex->nHeight == 0) return false;
3676
3677 CBlockIndex* to_mark_failed = pindex;
3678 bool pindex_was_in_chain = false;
3679 int disconnected = 0;
3680
3681 // We do not allow ActivateBestChain() to run while InvalidateBlock() is
3682 // running, as that could cause the tip to change while we disconnect
3683 // blocks.
3685
3686 // We'll be acquiring and releasing cs_main below, to allow the validation
3687 // callbacks to run. However, we should keep the block index in a
3688 // consistent state as we disconnect blocks -- in particular we need to
3689 // add equal-work blocks to setBlockIndexCandidates as we disconnect.
3690 // To avoid walking the block index repeatedly in search of candidates,
3691 // build a map once so that we can look up candidate blocks by chain
3692 // work as we go.
3693 std::multimap<const arith_uint256, CBlockIndex *> candidate_blocks_by_work;
3694
3695 {
3696 LOCK(cs_main);
3697 for (auto& entry : m_blockman.m_block_index) {
3698 CBlockIndex* candidate = &entry.second;
3699 // We don't need to put anything in our active chain into the
3700 // multimap, because those candidates will be found and considered
3701 // as we disconnect.
3702 // Instead, consider only non-active-chain blocks that have at
3703 // least as much work as where we expect the new tip to end up.
3704 if (!m_chain.Contains(candidate) &&
3705 !CBlockIndexWorkComparator()(candidate, pindex->pprev) &&
3706 candidate->IsValid(BLOCK_VALID_TRANSACTIONS) &&
3707 candidate->HaveNumChainTxs()) {
3708 candidate_blocks_by_work.insert(std::make_pair(candidate->nChainWork, candidate));
3709 }
3710 }
3711 }
3712
3713 // Disconnect (descendants of) pindex, and mark them invalid.
3714 while (true) {
3715 if (m_chainman.m_interrupt) break;
3716
3717 // Make sure the queue of validation callbacks doesn't grow unboundedly.
3719
3720 LOCK(cs_main);
3721 // Lock for as long as disconnectpool is in scope to make sure MaybeUpdateMempoolForReorg is
3722 // called after DisconnectTip without unlocking in between
3723 LOCK(MempoolMutex());
3724 if (!m_chain.Contains(pindex)) break;
3725 pindex_was_in_chain = true;
3726 CBlockIndex *invalid_walk_tip = m_chain.Tip();
3727
3728 // ActivateBestChain considers blocks already in m_chain
3729 // unconditionally valid already, so force disconnect away from it.
3731 bool ret = DisconnectTip(state, &disconnectpool);
3732 // DisconnectTip will add transactions to disconnectpool.
3733 // Adjust the mempool to be consistent with the new tip, adding
3734 // transactions back to the mempool if disconnecting was successful,
3735 // and we're not doing a very deep invalidation (in which case
3736 // keeping the mempool up to date is probably futile anyway).
3737 MaybeUpdateMempoolForReorg(disconnectpool, /* fAddToMempool = */ (++disconnected <= 10) && ret);
3738 if (!ret) return false;
3739 assert(invalid_walk_tip->pprev == m_chain.Tip());
3740
3741 // We immediately mark the disconnected blocks as invalid.
3742 // This prevents a case where pruned nodes may fail to invalidateblock
3743 // and be left unable to start as they have no tip candidates (as there
3744 // are no blocks that meet the "have data and are not invalid per
3745 // nStatus" criteria for inclusion in setBlockIndexCandidates).
3746 invalid_walk_tip->nStatus |= BLOCK_FAILED_VALID;
3747 m_blockman.m_dirty_blockindex.insert(invalid_walk_tip);
3748 setBlockIndexCandidates.erase(invalid_walk_tip);
3749 setBlockIndexCandidates.insert(invalid_walk_tip->pprev);
3750 if (invalid_walk_tip->pprev == to_mark_failed && (to_mark_failed->nStatus & BLOCK_FAILED_VALID)) {
3751 // We only want to mark the last disconnected block as BLOCK_FAILED_VALID; its children
3752 // need to be BLOCK_FAILED_CHILD instead.
3753 to_mark_failed->nStatus = (to_mark_failed->nStatus ^ BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD;
3754 m_blockman.m_dirty_blockindex.insert(to_mark_failed);
3755 }
3756
3757 // Add any equal or more work headers to setBlockIndexCandidates
3758 auto candidate_it = candidate_blocks_by_work.lower_bound(invalid_walk_tip->pprev->nChainWork);
3759 while (candidate_it != candidate_blocks_by_work.end()) {
3760 if (!CBlockIndexWorkComparator()(candidate_it->second, invalid_walk_tip->pprev)) {
3761 setBlockIndexCandidates.insert(candidate_it->second);
3762 candidate_it = candidate_blocks_by_work.erase(candidate_it);
3763 } else {
3764 ++candidate_it;
3765 }
3766 }
3767
3768 // Track the last disconnected block, so we can correct its BLOCK_FAILED_CHILD status in future
3769 // iterations, or, if it's the last one, call InvalidChainFound on it.
3770 to_mark_failed = invalid_walk_tip;
3771 }
3772
3774
3775 {
3776 LOCK(cs_main);
3777 if (m_chain.Contains(to_mark_failed)) {
3778 // If the to-be-marked invalid block is in the active chain, something is interfering and we can't proceed.
3779 return false;
3780 }
3781
3782 // Mark pindex (or the last disconnected block) as invalid, even when it never was in the main chain
3783 to_mark_failed->nStatus |= BLOCK_FAILED_VALID;
3784 m_blockman.m_dirty_blockindex.insert(to_mark_failed);
3785 setBlockIndexCandidates.erase(to_mark_failed);
3786 m_chainman.m_failed_blocks.insert(to_mark_failed);
3787
3788 // If any new blocks somehow arrived while we were disconnecting
3789 // (above), then the pre-calculation of what should go into
3790 // setBlockIndexCandidates may have missed entries. This would
3791 // technically be an inconsistency in the block index, but if we clean
3792 // it up here, this should be an essentially unobservable error.
3793 // Loop back over all block index entries and add any missing entries
3794 // to setBlockIndexCandidates.
3795 for (auto& [_, block_index] : m_blockman.m_block_index) {
3796 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && !setBlockIndexCandidates.value_comp()(&block_index, m_chain.Tip())) {
3797 setBlockIndexCandidates.insert(&block_index);
3798 }
3799 }
3800
3801 InvalidChainFound(to_mark_failed);
3802 }
3803
3804 // Only notify about a new block tip if the active chain was modified.
3805 if (pindex_was_in_chain) {
3806 // Ignoring return value for now, this could be changed to bubble up
3807 // kernel::Interrupted value to the caller so the caller could
3808 // distinguish between completed and interrupted operations. It might
3809 // also make sense for the blockTip notification to have an enum
3810 // parameter indicating the source of the tip change so hooks can
3811 // distinguish user-initiated invalidateblock changes from other
3812 // changes.
3814
3815 // Fire ActiveTipChange now for the current chain tip to make sure clients are notified.
3816 // ActivateBestChain may call this as well, but not necessarily.
3819 }
3820 }
3821 return true;
3822}
3823
3824void Chainstate::SetBlockFailureFlags(CBlockIndex* invalid_block)
3825{
3827
3828 for (auto& [_, block_index] : m_blockman.m_block_index) {
3829 if (block_index.GetAncestor(invalid_block->nHeight) == invalid_block && !(block_index.nStatus & BLOCK_FAILED_MASK)) {
3830 block_index.nStatus |= BLOCK_FAILED_CHILD;
3831 }
3832 }
3833}
3834
3837
3838 int nHeight = pindex->nHeight;
3839
3840 // Remove the invalidity flag from this block and all its descendants.
3841 for (auto& [_, block_index] : m_blockman.m_block_index) {
3842 if (!block_index.IsValid() && block_index.GetAncestor(nHeight) == pindex) {
3843 block_index.nStatus &= ~BLOCK_FAILED_MASK;
3844 m_blockman.m_dirty_blockindex.insert(&block_index);
3845 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &block_index)) {
3846 setBlockIndexCandidates.insert(&block_index);
3847 }
3848 if (&block_index == m_chainman.m_best_invalid) {
3849 // Reset invalid block marker if it was pointing to one of those.
3850 m_chainman.m_best_invalid = nullptr;
3851 }
3852 m_chainman.m_failed_blocks.erase(&block_index);
3853 }
3854 }
3855
3856 // Remove the invalidity flag from all ancestors too.
3857 while (pindex != nullptr) {
3858 if (pindex->nStatus & BLOCK_FAILED_MASK) {
3859 pindex->nStatus &= ~BLOCK_FAILED_MASK;
3860 m_blockman.m_dirty_blockindex.insert(pindex);
3861 m_chainman.m_failed_blocks.erase(pindex);
3862 }
3863 pindex = pindex->pprev;
3864 }
3865}
3866
3868{
3870 // The block only is a candidate for the most-work-chain if it has the same
3871 // or more work than our current tip.
3872 if (m_chain.Tip() != nullptr && setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) {
3873 return;
3874 }
3875
3876 bool is_active_chainstate = this == &m_chainman.ActiveChainstate();
3877 if (is_active_chainstate) {
3878 // The active chainstate should always add entries that have more
3879 // work than the tip.
3880 setBlockIndexCandidates.insert(pindex);
3881 } else if (!m_disabled) {
3882 // For the background chainstate, we only consider connecting blocks
3883 // towards the snapshot base (which can't be nullptr or else we'll
3884 // never make progress).
3885 const CBlockIndex* snapshot_base{Assert(m_chainman.GetSnapshotBaseBlock())};
3886 if (snapshot_base->GetAncestor(pindex->nHeight) == pindex) {
3887 setBlockIndexCandidates.insert(pindex);
3888 }
3889 }
3890}
3891
3894{
3896 pindexNew->nTx = block.vtx.size();
3897 // Typically m_chain_tx_count will be 0 at this point, but it can be nonzero if this
3898 // is a pruned block which is being downloaded again, or if this is an
3899 // assumeutxo snapshot block which has a hardcoded m_chain_tx_count value from the
3900 // snapshot metadata. If the pindex is not the snapshot block and the
3901 // m_chain_tx_count value is not zero, assert that value is actually correct.
3902 auto prev_tx_sum = [](CBlockIndex& block) { return block.nTx + (block.pprev ? block.pprev->m_chain_tx_count : 0); };
3903 if (!Assume(pindexNew->m_chain_tx_count == 0 || pindexNew->m_chain_tx_count == prev_tx_sum(*pindexNew) ||
3904 pindexNew == GetSnapshotBaseBlock())) {
3905 LogWarning("Internal bug detected: block %d has unexpected m_chain_tx_count %i that should be %i (%s %s). Please report this issue here: %s\n",
3906 pindexNew->nHeight, pindexNew->m_chain_tx_count, prev_tx_sum(*pindexNew), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT);
3907 pindexNew->m_chain_tx_count = 0;
3908 }
3909 pindexNew->nFile = pos.nFile;
3910 pindexNew->nDataPos = pos.nPos;
3911 pindexNew->nUndoPos = 0;
3912 pindexNew->nStatus |= BLOCK_HAVE_DATA;
3913 if (DeploymentActiveAt(*pindexNew, *this, Consensus::DEPLOYMENT_SEGWIT)) {
3914 pindexNew->nStatus |= BLOCK_OPT_WITNESS;
3915 }
3917 m_blockman.m_dirty_blockindex.insert(pindexNew);
3918
3919 if (pindexNew->pprev == nullptr || pindexNew->pprev->HaveNumChainTxs()) {
3920 // If pindexNew is the genesis block or all parents are BLOCK_VALID_TRANSACTIONS.
3921 std::deque<CBlockIndex*> queue;
3922 queue.push_back(pindexNew);
3923
3924 // Recursively process any descendant blocks that now may be eligible to be connected.
3925 while (!queue.empty()) {
3926 CBlockIndex *pindex = queue.front();
3927 queue.pop_front();
3928 // Before setting m_chain_tx_count, assert that it is 0 or already set to
3929 // the correct value. This assert will fail after receiving the
3930 // assumeutxo snapshot block if assumeutxo snapshot metadata has an
3931 // incorrect hardcoded AssumeutxoData::m_chain_tx_count value.
3932 if (!Assume(pindex->m_chain_tx_count == 0 || pindex->m_chain_tx_count == prev_tx_sum(*pindex))) {
3933 LogWarning("Internal bug detected: block %d has unexpected m_chain_tx_count %i that should be %i (%s %s). Please report this issue here: %s\n",
3934 pindex->nHeight, pindex->m_chain_tx_count, prev_tx_sum(*pindex), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT);
3935 }
3936 pindex->m_chain_tx_count = prev_tx_sum(*pindex);
3937 pindex->nSequenceId = nBlockSequenceId++;
3938 for (Chainstate *c : GetAll()) {
3939 c->TryAddBlockIndexCandidate(pindex);
3940 }
3941 std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> range = m_blockman.m_blocks_unlinked.equal_range(pindex);
3942 while (range.first != range.second) {
3943 std::multimap<CBlockIndex*, CBlockIndex*>::iterator it = range.first;
3944 queue.push_back(it->second);
3945 range.first++;
3946 m_blockman.m_blocks_unlinked.erase(it);
3947 }
3948 }
3949 } else {
3950 if (pindexNew->pprev && pindexNew->pprev->IsValid(BLOCK_VALID_TREE)) {
3951 m_blockman.m_blocks_unlinked.insert(std::make_pair(pindexNew->pprev, pindexNew));
3952 }
3953 }
3954}
3955
3956static bool CheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true)
3957{
3958 // Check proof of work matches claimed amount
3959 if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, consensusParams))
3960 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "high-hash", "proof of work failed");
3961
3962 return true;
3963}
3964
3965static bool CheckMerkleRoot(const CBlock& block, BlockValidationState& state)
3966{
3967 if (block.m_checked_merkle_root) return true;
3968
3969 bool mutated;
3970 uint256 merkle_root = BlockMerkleRoot(block, &mutated);
3971 if (block.hashMerkleRoot != merkle_root) {
3972 return state.Invalid(
3974 /*reject_reason=*/"bad-txnmrklroot",
3975 /*debug_message=*/"hashMerkleRoot mismatch");
3976 }
3977
3978 // Check for merkle tree malleability (CVE-2012-2459): repeating sequences
3979 // of transactions in a block without affecting the merkle root of a block,
3980 // while still invalidating it.
3981 if (mutated) {
3982 return state.Invalid(
3984 /*reject_reason=*/"bad-txns-duplicate",
3985 /*debug_message=*/"duplicate transaction");
3986 }
3987
3988 block.m_checked_merkle_root = true;
3989 return true;
3990}
3991
3998static bool CheckWitnessMalleation(const CBlock& block, bool expect_witness_commitment, BlockValidationState& state)
3999{
4000 if (expect_witness_commitment) {
4001 if (block.m_checked_witness_commitment) return true;
4002
4003 int commitpos = GetWitnessCommitmentIndex(block);
4004 if (commitpos != NO_WITNESS_COMMITMENT) {
4005 assert(!block.vtx.empty() && !block.vtx[0]->vin.empty());
4006 const auto& witness_stack{block.vtx[0]->vin[0].scriptWitness.stack};
4007
4008 if (witness_stack.size() != 1 || witness_stack[0].size() != 32) {
4009 return state.Invalid(
4011 /*reject_reason=*/"bad-witness-nonce-size",
4012 /*debug_message=*/strprintf("%s : invalid witness reserved value size", __func__));
4013 }
4014
4015 // The malleation check is ignored; as the transaction tree itself
4016 // already does not permit it, it is impossible to trigger in the
4017 // witness tree.
4018 uint256 hash_witness = BlockWitnessMerkleRoot(block, /*mutated=*/nullptr);
4019
4020 CHash256().Write(hash_witness).Write(witness_stack[0]).Finalize(hash_witness);
4021 if (memcmp(hash_witness.begin(), &block.vtx[0]->vout[commitpos].scriptPubKey[6], 32)) {
4022 return state.Invalid(
4024 /*reject_reason=*/"bad-witness-merkle-match",
4025 /*debug_message=*/strprintf("%s : witness merkle commitment mismatch", __func__));
4026 }
4027
4028 block.m_checked_witness_commitment = true;
4029 return true;
4030 }
4031 }
4032
4033 // No witness data is allowed in blocks that don't commit to witness data, as this would otherwise leave room for spam
4034 for (const auto& tx : block.vtx) {
4035 if (tx->HasWitness()) {
4036 return state.Invalid(
4038 /*reject_reason=*/"unexpected-witness",
4039 /*debug_message=*/strprintf("%s : unexpected witness data found", __func__));
4040 }
4041 }
4042
4043 return true;
4044}
4045
4046bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW, bool fCheckMerkleRoot)
4047{
4048 // These are checks that are independent of context.
4049
4050 if (block.fChecked)
4051 return true;
4052
4053 // Check that the header is valid (particularly PoW). This is mostly
4054 // redundant with the call in AcceptBlockHeader.
4055 if (!CheckBlockHeader(block, state, consensusParams, fCheckPOW))
4056 return false;
4057
4058 // Signet only: check block solution
4059 if (consensusParams.signet_blocks && fCheckPOW && !CheckSignetBlockSolution(block, consensusParams)) {
4060 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-signet-blksig", "signet block signature validation failure");
4061 }
4062
4063 // Check the merkle root.
4064 if (fCheckMerkleRoot && !CheckMerkleRoot(block, state)) {
4065 return false;
4066 }
4067
4068 // All potential-corruption validation must be done before we do any
4069 // transaction validation, as otherwise we may mark the header as invalid
4070 // because we receive the wrong transactions for it.
4071 // Note that witness malleability is checked in ContextualCheckBlock, so no
4072 // checks that use witness data may be performed here.
4073
4074 // Size limits
4076 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-length", "size limits failed");
4077
4078 // First transaction must be coinbase, the rest must not be
4079 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase())
4080 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-missing", "first tx is not coinbase");
4081 for (unsigned int i = 1; i < block.vtx.size(); i++)
4082 if (block.vtx[i]->IsCoinBase())
4083 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-multiple", "more than one coinbase");
4084
4085 // Check transactions
4086 // Must check for duplicate inputs (see CVE-2018-17144)
4087 for (const auto& tx : block.vtx) {
4088 TxValidationState tx_state;
4089 if (!CheckTransaction(*tx, tx_state)) {
4090 // CheckBlock() does context-free validation checks. The only
4091 // possible failures are consensus failures.
4094 strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), tx_state.GetDebugMessage()));
4095 }
4096 }
4097 unsigned int nSigOps = 0;
4098 for (const auto& tx : block.vtx)
4099 {
4100 nSigOps += GetLegacySigOpCount(*tx);
4101 }
4103 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "out-of-bounds SigOpCount");
4104
4105 if (fCheckPOW && fCheckMerkleRoot)
4106 block.fChecked = true;
4107
4108 return true;
4109}
4110
4112{
4113 int commitpos = GetWitnessCommitmentIndex(block);
4114 static const std::vector<unsigned char> nonce(32, 0x00);
4115 if (commitpos != NO_WITNESS_COMMITMENT && DeploymentActiveAfter(pindexPrev, *this, Consensus::DEPLOYMENT_SEGWIT) && !block.vtx[0]->HasWitness()) {
4116 CMutableTransaction tx(*block.vtx[0]);
4117 tx.vin[0].scriptWitness.stack.resize(1);
4118 tx.vin[0].scriptWitness.stack[0] = nonce;
4119 block.vtx[0] = MakeTransactionRef(std::move(tx));
4120 }
4121}
4122
4123std::vector<unsigned char> ChainstateManager::GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev) const
4124{
4125 std::vector<unsigned char> commitment;
4126 int commitpos = GetWitnessCommitmentIndex(block);
4127 std::vector<unsigned char> ret(32, 0x00);
4128 if (commitpos == NO_WITNESS_COMMITMENT) {
4129 uint256 witnessroot = BlockWitnessMerkleRoot(block, nullptr);
4130 CHash256().Write(witnessroot).Write(ret).Finalize(witnessroot);
4131 CTxOut out;
4132 out.nValue = 0;
4133 out.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT);
4134 out.scriptPubKey[0] = OP_RETURN;
4135 out.scriptPubKey[1] = 0x24;
4136 out.scriptPubKey[2] = 0xaa;
4137 out.scriptPubKey[3] = 0x21;
4138 out.scriptPubKey[4] = 0xa9;
4139 out.scriptPubKey[5] = 0xed;
4140 memcpy(&out.scriptPubKey[6], witnessroot.begin(), 32);
4141 commitment = std::vector<unsigned char>(out.scriptPubKey.begin(), out.scriptPubKey.end());
4142 CMutableTransaction tx(*block.vtx[0]);
4143 tx.vout.push_back(out);
4144 block.vtx[0] = MakeTransactionRef(std::move(tx));
4145 }
4146 UpdateUncommittedBlockStructures(block, pindexPrev);
4147 return commitment;
4148}
4149
4150bool HasValidProofOfWork(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams)
4151{
4152 return std::all_of(headers.cbegin(), headers.cend(),
4153 [&](const auto& header) { return CheckProofOfWork(header.GetHash(), header.nBits, consensusParams);});
4154}
4155
4156bool IsBlockMutated(const CBlock& block, bool check_witness_root)
4157{
4159 if (!CheckMerkleRoot(block, state)) {
4160 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString());
4161 return true;
4162 }
4163
4164 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) {
4165 // Consider the block mutated if any transaction is 64 bytes in size (see 3.1
4166 // in "Weaknesses in Bitcoin’s Merkle Root Construction":
4167 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20190225/a27d8837/attachment-0001.pdf).
4168 //
4169 // Note: This is not a consensus change as this only applies to blocks that
4170 // don't have a coinbase transaction and would therefore already be invalid.
4171 return std::any_of(block.vtx.begin(), block.vtx.end(),
4172 [](auto& tx) { return GetSerializeSize(TX_NO_WITNESS(tx)) == 64; });
4173 } else {
4174 // Theoretically it is still possible for a block with a 64 byte
4175 // coinbase transaction to be mutated but we neglect that possibility
4176 // here as it requires at least 224 bits of work.
4177 }
4178
4179 if (!CheckWitnessMalleation(block, check_witness_root, state)) {
4180 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString());
4181 return true;
4182 }
4183
4184 return false;
4185}
4186
4187arith_uint256 CalculateClaimedHeadersWork(std::span<const CBlockHeader> headers)
4188{
4189 arith_uint256 total_work{0};
4190 for (const CBlockHeader& header : headers) {
4191 CBlockIndex dummy(header);
4192 total_work += GetBlockProof(dummy);
4193 }
4194 return total_work;
4195}
4196
4207{
4209 assert(pindexPrev != nullptr);
4210 const int nHeight = pindexPrev->nHeight + 1;
4211
4212 // Check proof of work
4213 const Consensus::Params& consensusParams = chainman.GetConsensus();
4214 if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams))
4215 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "bad-diffbits", "incorrect proof of work");
4216
4217 // Check against checkpoints
4218 if (chainman.m_options.checkpoints_enabled) {
4219 // Don't accept any forks from the main chain prior to last checkpoint.
4220 // GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's in our
4221 // BlockIndex().
4222 const CBlockIndex* pcheckpoint = blockman.GetLastCheckpoint(chainman.GetParams().Checkpoints());
4223 if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
4224 LogPrintf("ERROR: %s: forked chain older than last checkpoint (height %d)\n", __func__, nHeight);
4225 return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT, "bad-fork-prior-to-checkpoint");
4226 }
4227 }
4228
4229 // Check timestamp against prev
4230 if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
4231 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-too-old", "block's timestamp is too early");
4232
4233 // Testnet4 and regtest only: Check timestamp against prev for difficulty-adjustment
4234 // blocks to prevent timewarp attacks (see https://github.com/bitcoin/bitcoin/pull/15482).
4235 if (consensusParams.enforce_BIP94) {
4236 // Check timestamp for the first block of each difficulty adjustment
4237 // interval, except the genesis block.
4238 if (nHeight % consensusParams.DifficultyAdjustmentInterval() == 0) {
4239 if (block.GetBlockTime() < pindexPrev->GetBlockTime() - MAX_TIMEWARP) {
4240 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-timewarp-attack", "block's timestamp is too early on diff adjustment block");
4241 }
4242 }
4243 }
4244
4245 // Check timestamp
4246 if (block.Time() > NodeClock::now() + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) {
4247 return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE, "time-too-new", "block timestamp too far in the future");
4248 }
4249
4250 // Reject blocks with outdated version
4251 if ((block.nVersion < 2 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) ||
4252 (block.nVersion < 3 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_DERSIG)) ||
4253 (block.nVersion < 4 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CLTV))) {
4254 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, strprintf("bad-version(0x%08x)", block.nVersion),
4255 strprintf("rejected nVersion=0x%08x block", block.nVersion));
4256 }
4257
4258 return true;
4259}
4260
4267static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& state, const ChainstateManager& chainman, const CBlockIndex* pindexPrev)
4268{
4269 const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
4270
4271 // Enforce BIP113 (Median Time Past).
4272 bool enforce_locktime_median_time_past{false};
4273 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CSV)) {
4274 assert(pindexPrev != nullptr);
4275 enforce_locktime_median_time_past = true;
4276 }
4277
4278 const int64_t nLockTimeCutoff{enforce_locktime_median_time_past ?
4279 pindexPrev->GetMedianTimePast() :
4280 block.GetBlockTime()};
4281
4282 // Check that all transactions are finalized
4283 for (const auto& tx : block.vtx) {
4284 if (!IsFinalTx(*tx, nHeight, nLockTimeCutoff)) {
4285 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", "non-final transaction");
4286 }
4287 }
4288
4289 // Enforce rule that the coinbase starts with serialized block height
4291 {
4293 if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
4294 !std::equal(expect.begin(), expect.end(), block.vtx[0]->vin[0].scriptSig.begin())) {
4295 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-height", "block height mismatch in coinbase");
4296 }
4297 }
4298
4299 // Validation for witness commitments.
4300 // * We compute the witness hash (which is the hash including witnesses) of all the block's transactions, except the
4301 // coinbase (where 0x0000....0000 is used instead).
4302 // * The coinbase scriptWitness is a stack of a single 32-byte vector, containing a witness reserved value (unconstrained).
4303 // * We build a merkle tree with all those witness hashes as leaves (similar to the hashMerkleRoot in the block header).
4304 // * There must be at least one output whose scriptPubKey is a single 36-byte push, the first 4 bytes of which are
4305 // {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness reserved value). In case there are
4306 // multiple, the last one is used.
4307 if (!CheckWitnessMalleation(block, DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_SEGWIT), state)) {
4308 return false;
4309 }
4310
4311 // After the coinbase witness reserved value and commitment are verified,
4312 // we can check if the block weight passes (before we've checked the
4313 // coinbase witness, it would be possible for the weight to be too
4314 // large by filling up the coinbase witness, which doesn't change
4315 // the block hash, so we couldn't mark the block as permanently
4316 // failed).
4317 if (GetBlockWeight(block) > MAX_BLOCK_WEIGHT) {
4318 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-weight", strprintf("%s : weight limit failed", __func__));
4319 }
4320
4321 return true;
4322}
4323
4324bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationState& state, CBlockIndex** ppindex, bool min_pow_checked)
4325{
4327
4328 // Check for duplicate
4329 uint256 hash = block.GetHash();
4330 BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)};
4331 if (hash != GetConsensus().hashGenesisBlock) {
4332 if (miSelf != m_blockman.m_block_index.end()) {
4333 // Block header is already known.
4334 CBlockIndex* pindex = &(miSelf->second);
4335 if (ppindex)
4336 *ppindex = pindex;
4337 if (pindex->nStatus & BLOCK_FAILED_MASK) {
4338 LogDebug(BCLog::VALIDATION, "%s: block %s is marked invalid\n", __func__, hash.ToString());
4339 return state.Invalid(BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate-invalid");
4340 }
4341 return true;
4342 }
4343
4344 if (!CheckBlockHeader(block, state, GetConsensus())) {
4345 LogDebug(BCLog::VALIDATION, "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
4346 return false;
4347 }
4348
4349 // Get prev block index
4350 CBlockIndex* pindexPrev = nullptr;
4351 BlockMap::iterator mi{m_blockman.m_block_index.find(block.hashPrevBlock)};
4352 if (mi == m_blockman.m_block_index.end()) {
4353 LogDebug(BCLog::VALIDATION, "header %s has prev block not found: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
4354 return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV, "prev-blk-not-found");
4355 }
4356 pindexPrev = &((*mi).second);
4357 if (pindexPrev->nStatus & BLOCK_FAILED_MASK) {
4358 LogDebug(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
4359 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk");
4360 }
4361 if (!ContextualCheckBlockHeader(block, state, m_blockman, *this, pindexPrev)) {
4362 LogDebug(BCLog::VALIDATION, "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
4363 return false;
4364 }
4365
4366 /* Determine if this block descends from any block which has been found
4367 * invalid (m_failed_blocks), then mark pindexPrev and any blocks between
4368 * them as failed. For example:
4369 *
4370 * D3
4371 * /
4372 * B2 - C2
4373 * / \
4374 * A D2 - E2 - F2
4375 * \
4376 * B1 - C1 - D1 - E1
4377 *
4378 * In the case that we attempted to reorg from E1 to F2, only to find
4379 * C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD
4380 * but NOT D3 (it was not in any of our candidate sets at the time).
4381 *
4382 * In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart
4383 * in LoadBlockIndex.
4384 */
4385 if (!pindexPrev->IsValid(BLOCK_VALID_SCRIPTS)) {
4386 // The above does not mean "invalid": it checks if the previous block
4387 // hasn't been validated up to BLOCK_VALID_SCRIPTS. This is a performance
4388 // optimization, in the common case of adding a new block to the tip,
4389 // we don't need to iterate over the failed blocks list.
4390 for (const CBlockIndex* failedit : m_failed_blocks) {
4391 if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) {
4392 assert(failedit->nStatus & BLOCK_FAILED_VALID);
4393 CBlockIndex* invalid_walk = pindexPrev;
4394 while (invalid_walk != failedit) {
4395 invalid_walk->nStatus |= BLOCK_FAILED_CHILD;
4396 m_blockman.m_dirty_blockindex.insert(invalid_walk);
4397 invalid_walk = invalid_walk->pprev;
4398 }
4399 LogDebug(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
4400 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk");
4401 }
4402 }
4403 }
4404 }
4405 if (!min_pow_checked) {
4406 LogDebug(BCLog::VALIDATION, "%s: not adding new block header %s, missing anti-dos proof-of-work validation\n", __func__, hash.ToString());
4407 return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK, "too-little-chainwork");
4408 }
4409 CBlockIndex* pindex{m_blockman.AddToBlockIndex(block, m_best_header)};
4410
4411 if (ppindex)
4412 *ppindex = pindex;
4413
4414 // Since this is the earliest point at which we have determined that a
4415 // header is both new and valid, log here.
4416 //
4417 // These messages are valuable for detecting potential selfish mining behavior;
4418 // if multiple displacing headers are seen near simultaneously across many
4419 // nodes in the network, this might be an indication of selfish mining. Having
4420 // this log by default when not in IBD ensures broad availability of this data
4421 // in case investigation is merited.
4422 const auto msg = strprintf(
4423 "Saw new header hash=%s height=%d", hash.ToString(), pindex->nHeight);
4424
4425 if (IsInitialBlockDownload()) {
4427 } else {
4428 LogPrintf("%s\n", msg);
4429 }
4430
4431 return true;
4432}
4433
4434// Exposed wrapper for AcceptBlockHeader
4435bool ChainstateManager::ProcessNewBlockHeaders(std::span<const CBlockHeader> headers, bool min_pow_checked, BlockValidationState& state, const CBlockIndex** ppindex)
4436{
4438 {
4439 LOCK(cs_main);
4440 for (const CBlockHeader& header : headers) {
4441 CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast
4442 bool accepted{AcceptBlockHeader(header, state, &pindex, min_pow_checked)};
4444
4445 if (!accepted) {
4446 return false;
4447 }
4448 if (ppindex) {
4449 *ppindex = pindex;
4450 }
4451 }
4452 }
4453 if (NotifyHeaderTip()) {
4454 if (IsInitialBlockDownload() && ppindex && *ppindex) {
4455 const CBlockIndex& last_accepted{**ppindex};
4456 int64_t blocks_left{(NodeClock::now() - last_accepted.Time()) / GetConsensus().PowTargetSpacing()};
4457 blocks_left = std::max<int64_t>(0, blocks_left);
4458 const double progress{100.0 * last_accepted.nHeight / (last_accepted.nHeight + blocks_left)};
4459 LogInfo("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress);
4460 }
4461 }
4462 return true;
4463}
4464
4465void ChainstateManager::ReportHeadersPresync(const arith_uint256& work, int64_t height, int64_t timestamp)
4466{
4468 {
4469 LOCK(cs_main);
4470 // Don't report headers presync progress if we already have a post-minchainwork header chain.
4471 // This means we lose reporting for potentially legitimate, but unlikely, deep reorgs, but
4472 // prevent attackers that spam low-work headers from filling our logs.
4473 if (m_best_header->nChainWork >= UintToArith256(GetConsensus().nMinimumChainWork)) return;
4474 // Rate limit headers presync updates to 4 per second, as these are not subject to DoS
4475 // protection.
4476 auto now = std::chrono::steady_clock::now();
4477 if (now < m_last_presync_update + std::chrono::milliseconds{250}) return;
4478 m_last_presync_update = now;
4479 }
4480 bool initial_download = IsInitialBlockDownload();
4481 GetNotifications().headerTip(GetSynchronizationState(initial_download, m_blockman.m_blockfiles_indexed), height, timestamp, /*presync=*/true);
4482 if (initial_download) {
4483 int64_t blocks_left{(NodeClock::now() - NodeSeconds{std::chrono::seconds{timestamp}}) / GetConsensus().PowTargetSpacing()};
4484 blocks_left = std::max<int64_t>(0, blocks_left);
4485 const double progress{100.0 * height / (height + blocks_left)};
4486 LogInfo("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress);
4487 }
4488}
4489
4491bool ChainstateManager::AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockValidationState& state, CBlockIndex** ppindex, bool fRequested, const FlatFilePos* dbp, bool* fNewBlock, bool min_pow_checked)
4492{
4493 const CBlock& block = *pblock;
4494
4495 if (fNewBlock) *fNewBlock = false;
4497
4498 CBlockIndex *pindexDummy = nullptr;
4499 CBlockIndex *&pindex = ppindex ? *ppindex : pindexDummy;
4500
4501 bool accepted_header{AcceptBlockHeader(block, state, &pindex, min_pow_checked)};
4503
4504 if (!accepted_header)
4505 return false;
4506
4507 // Check all requested blocks that we do not already have for validity and
4508 // save them to disk. Skip processing of unrequested blocks as an anti-DoS
4509 // measure, unless the blocks have more work than the active chain tip, and
4510 // aren't too far ahead of it, so are likely to be attached soon.
4511 bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA;
4512 bool fHasMoreOrSameWork = (ActiveTip() ? pindex->nChainWork >= ActiveTip()->nChainWork : true);
4513 // Blocks that are too out-of-order needlessly limit the effectiveness of
4514 // pruning, because pruning will not delete block files that contain any
4515 // blocks which are too close in height to the tip. Apply this test
4516 // regardless of whether pruning is enabled; it should generally be safe to
4517 // not process unrequested blocks.
4518 bool fTooFarAhead{pindex->nHeight > ActiveHeight() + int(MIN_BLOCKS_TO_KEEP)};
4519
4520 // TODO: Decouple this function from the block download logic by removing fRequested
4521 // This requires some new chain data structure to efficiently look up if a
4522 // block is in a chain leading to a candidate for best tip, despite not
4523 // being such a candidate itself.
4524 // Note that this would break the getblockfrompeer RPC
4525
4526 // TODO: deal better with return value and error conditions for duplicate
4527 // and unrequested blocks.
4528 if (fAlreadyHave) return true;
4529 if (!fRequested) { // If we didn't ask for it:
4530 if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned
4531 if (!fHasMoreOrSameWork) return true; // Don't process less-work chains
4532 if (fTooFarAhead) return true; // Block height is too high
4533
4534 // Protect against DoS attacks from low-work chains.
4535 // If our tip is behind, a peer could try to send us
4536 // low-work blocks on a fake chain that we would never
4537 // request; don't process these.
4538 if (pindex->nChainWork < MinimumChainWork()) return true;
4539 }
4540
4541 const CChainParams& params{GetParams()};
4542
4543 if (!CheckBlock(block, state, params.GetConsensus()) ||
4544 !ContextualCheckBlock(block, state, *this, pindex->pprev)) {
4545 if (state.IsInvalid() && state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
4546 pindex->nStatus |= BLOCK_FAILED_VALID;
4547 m_blockman.m_dirty_blockindex.insert(pindex);
4548 }
4549 LogError("%s: %s\n", __func__, state.ToString());
4550 return false;
4551 }
4552
4553 // Header is valid/has work, merkle tree and segwit merkle tree are good...RELAY NOW
4554 // (but if it does not build on our best tip, let the SendMessages loop relay it)
4555 if (!IsInitialBlockDownload() && ActiveTip() == pindex->pprev && m_options.signals) {
4556 m_options.signals->NewPoWValidBlock(pindex, pblock);
4557 }
4558
4559 // Write block to history file
4560 if (fNewBlock) *fNewBlock = true;
4561 try {
4562 FlatFilePos blockPos{};
4563 if (dbp) {
4564 blockPos = *dbp;
4565 m_blockman.UpdateBlockInfo(block, pindex->nHeight, blockPos);
4566 } else {
4567 blockPos = m_blockman.WriteBlock(block, pindex->nHeight);
4568 if (blockPos.IsNull()) {
4569 state.Error(strprintf("%s: Failed to find position to write new block to disk", __func__));
4570 return false;
4571 }
4572 }
4573 ReceivedBlockTransactions(block, pindex, blockPos);
4574 } catch (const std::runtime_error& e) {
4575 return FatalError(GetNotifications(), state, strprintf(_("System error while saving block to disk: %s"), e.what()));
4576 }
4577
4578 // TODO: FlushStateToDisk() handles flushing of both block and chainstate
4579 // data, so we should move this to ChainstateManager so that we can be more
4580 // intelligent about how we flush.
4581 // For now, since FlushStateMode::NONE is used, all that can happen is that
4582 // the block files may be pruned, so we can just call this on one
4583 // chainstate (particularly if we haven't implemented pruning with
4584 // background validation yet).
4585 ActiveChainstate().FlushStateToDisk(state, FlushStateMode::NONE);
4586
4588
4589 return true;
4590}
4591
4592bool ChainstateManager::ProcessNewBlock(const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked, bool* new_block)
4593{
4595
4596 {
4597 CBlockIndex *pindex = nullptr;
4598 if (new_block) *new_block = false;
4600
4601 // CheckBlock() does not support multi-threaded block validation because CBlock::fChecked can cause data race.
4602 // Therefore, the following critical section must include the CheckBlock() call as well.
4603 LOCK(cs_main);
4604
4605 // Skipping AcceptBlock() for CheckBlock() failures means that we will never mark a block as invalid if
4606 // CheckBlock() fails. This is protective against consensus failure if there are any unknown forms of block
4607 // malleability that cause CheckBlock() to fail; see e.g. CVE-2012-2459 and
4608 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html. Because CheckBlock() is
4609 // not very expensive, the anti-DoS benefits of caching failure (of a definitely-invalid block) are not substantial.
4610 bool ret = CheckBlock(*block, state, GetConsensus());
4611 if (ret) {
4612 // Store to disk
4613 ret = AcceptBlock(block, state, &pindex, force_processing, nullptr, new_block, min_pow_checked);
4614 }
4615 if (!ret) {
4616 if (m_options.signals) {
4617 m_options.signals->BlockChecked(*block, state);
4618 }
4619 LogError("%s: AcceptBlock FAILED (%s)\n", __func__, state.ToString());
4620 return false;
4621 }
4622 }
4623
4625
4626 BlockValidationState state; // Only used to report errors, not invalidity - ignore it
4627 if (!ActiveChainstate().ActivateBestChain(state, block)) {
4628 LogError("%s: ActivateBestChain failed (%s)\n", __func__, state.ToString());
4629 return false;
4630 }
4631
4632 Chainstate* bg_chain{WITH_LOCK(cs_main, return BackgroundSyncInProgress() ? m_ibd_chainstate.get() : nullptr)};
4633 BlockValidationState bg_state;
4634 if (bg_chain && !bg_chain->ActivateBestChain(bg_state, block)) {
4635 LogError("%s: [background] ActivateBestChain failed (%s)\n", __func__, bg_state.ToString());
4636 return false;
4637 }
4638
4639 return true;
4640}
4641
4643{
4645 Chainstate& active_chainstate = ActiveChainstate();
4646 if (!active_chainstate.GetMempool()) {
4647 TxValidationState state;
4648 state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool");
4649 return MempoolAcceptResult::Failure(state);
4650 }
4651 auto result = AcceptToMemoryPool(active_chainstate, tx, GetTime(), /*bypass_limits=*/ false, test_accept);
4652 active_chainstate.GetMempool()->check(active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1);
4653 return result;
4654}
4655
4657 const CChainParams& chainparams,
4658 Chainstate& chainstate,
4659 const CBlock& block,
4660 CBlockIndex* pindexPrev,
4661 bool fCheckPOW,
4662 bool fCheckMerkleRoot)
4663{
4665 assert(pindexPrev && pindexPrev == chainstate.m_chain.Tip());
4666 CCoinsViewCache viewNew(&chainstate.CoinsTip());
4667 uint256 block_hash(block.GetHash());
4668 CBlockIndex indexDummy(block);
4669 indexDummy.pprev = pindexPrev;
4670 indexDummy.nHeight = pindexPrev->nHeight + 1;
4671 indexDummy.phashBlock = &block_hash;
4672
4673 // NOTE: CheckBlockHeader is called by CheckBlock
4674 if (!ContextualCheckBlockHeader(block, state, chainstate.m_blockman, chainstate.m_chainman, pindexPrev)) {
4675 LogError("%s: Consensus::ContextualCheckBlockHeader: %s\n", __func__, state.ToString());
4676 return false;
4677 }
4678 if (!CheckBlock(block, state, chainparams.GetConsensus(), fCheckPOW, fCheckMerkleRoot)) {
4679 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString());
4680 return false;
4681 }
4682 if (!ContextualCheckBlock(block, state, chainstate.m_chainman, pindexPrev)) {
4683 LogError("%s: Consensus::ContextualCheckBlock: %s\n", __func__, state.ToString());
4684 return false;
4685 }
4686 if (!chainstate.ConnectBlock(block, state, &indexDummy, viewNew, true)) {
4687 return false;
4688 }
4689 assert(state.IsValid());
4690
4691 return true;
4692}
4693
4694/* This function is called from the RPC code for pruneblockchain */
4695void PruneBlockFilesManual(Chainstate& active_chainstate, int nManualPruneHeight)
4696{
4698 if (!active_chainstate.FlushStateToDisk(
4699 state, FlushStateMode::NONE, nManualPruneHeight)) {
4700 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString());
4701 }
4702}
4703
4705{
4707 const CCoinsViewCache& coins_cache = CoinsTip();
4708 assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty
4709 const CBlockIndex* tip = m_chain.Tip();
4710
4711 if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) {
4712 return true;
4713 }
4714
4715 // Load pointer to end of best chain
4716 CBlockIndex* pindex = m_blockman.LookupBlockIndex(coins_cache.GetBestBlock());
4717 if (!pindex) {
4718 return false;
4719 }
4720 m_chain.SetTip(*pindex);
4722
4723 tip = m_chain.Tip();
4724 LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
4725 tip->GetBlockHash().ToString(),
4726 m_chain.Height(),
4729
4730 // Ensure KernelNotifications m_tip_block is set even if no new block arrives.
4731 if (this->GetRole() != ChainstateRole::BACKGROUND) {
4732 // Ignoring return value for now.
4734 }
4735
4736 return true;
4737}
4738
4740 : m_notifications{notifications}
4741{
4742 m_notifications.progress(_("Verifying blocks…"), 0, false);
4743}
4744
4746{
4747 m_notifications.progress(bilingual_str{}, 100, false);
4748}
4749
4751 Chainstate& chainstate,
4752 const Consensus::Params& consensus_params,
4753 CCoinsView& coinsview,
4754 int nCheckLevel, int nCheckDepth)
4755{
4757
4758 if (chainstate.m_chain.Tip() == nullptr || chainstate.m_chain.Tip()->pprev == nullptr) {
4760 }
4761
4762 // Verify blocks in the best chain
4763 if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) {
4764 nCheckDepth = chainstate.m_chain.Height();
4765 }
4766 nCheckLevel = std::max(0, std::min(4, nCheckLevel));
4767 LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel);
4768 CCoinsViewCache coins(&coinsview);
4769 CBlockIndex* pindex;
4770 CBlockIndex* pindexFailure = nullptr;
4771 int nGoodTransactions = 0;
4773 int reportDone = 0;
4774 bool skipped_no_block_data{false};
4775 bool skipped_l3_checks{false};
4776 LogPrintf("Verification progress: 0%%\n");
4777
4778 const bool is_snapshot_cs{chainstate.m_from_snapshot_blockhash};
4779
4780 for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev; pindex = pindex->pprev) {
4781 const int percentageDone = std::max(1, std::min(99, (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100))));
4782 if (reportDone < percentageDone / 10) {
4783 // report every 10% step
4784 LogPrintf("Verification progress: %d%%\n", percentageDone);
4785 reportDone = percentageDone / 10;
4786 }
4787 m_notifications.progress(_("Verifying blocks…"), percentageDone, false);
4788 if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) {
4789 break;
4790 }
4791 if ((chainstate.m_blockman.IsPruneMode() || is_snapshot_cs) && !(pindex->nStatus & BLOCK_HAVE_DATA)) {
4792 // If pruning or running under an assumeutxo snapshot, only go
4793 // back as far as we have data.
4794 LogPrintf("VerifyDB(): block verification stopping at height %d (no data). This could be due to pruning or use of an assumeutxo snapshot.\n", pindex->nHeight);
4795 skipped_no_block_data = true;
4796 break;
4797 }
4798 CBlock block;
4799 // check level 0: read from disk
4800 if (!chainstate.m_blockman.ReadBlock(block, *pindex)) {
4801