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>
19 #include <consensus/validation.h>
20 #include <cuckoocache.h>
21 #include <flatfile.h>
22 #include <hash.h>
23 #include <kernel/chainparams.h>
24 #include <kernel/coinstats.h>
25 #include <kernel/disconnected_transactions.h>
26 #include <kernel/mempool_entry.h>
27 #include <kernel/messagestartchars.h>
28 #include <kernel/notifications_interface.h>
29 #include <kernel/types.h>
30 #include <kernel/warning.h>
31 #include <logging/timer.h>
32 #include <node/blockstorage.h>
33 #include <node/utxo_snapshot.h>
34 #include <policy/ephemeral_policy.h>
35 #include <policy/policy.h>
36 #include <policy/rbf.h>
37 #include <policy/settings.h>
38 #include <policy/truc_policy.h>
39 #include <pow.h>
40 #include <primitives/block.h>
41 #include <primitives/transaction.h>
42 #include <random.h>
43 #include <script/script.h>
44 #include <script/sigcache.h>
45 #include <signet.h>
46 #include <tinyformat.h>
47 #include <txdb.h>
48 #include <txmempool.h>
49 #include <uint256.h>
50 #include <undo.h>
51 #include <util/byte_units.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/log.h>
57 #include <util/moneystr.h>
58 #include <util/rbf.h>
59 #include <util/result.h>
60 #include <util/signalinterrupt.h>
61 #include <util/strencodings.h>
62 #include <util/string.h>
63 #include <util/threadpool.h>
64 #include <util/time.h>
65 #include <util/trace.h>
66 #include <util/translation.h>
67 #include <validationinterface.h>
68 69 #include <algorithm>
70 #include <cassert>
71 #include <chrono>
72 #include <deque>
73 #include <numeric>
74 #include <optional>
75 #include <ranges>
76 #include <span>
77 #include <string>
78 #include <tuple>
79 #include <utility>
80 81 using kernel::CCoinsStats;
82 using kernel::ChainstateRole;
83 using kernel::CoinStatsHashType;
84 using kernel::ComputeUTXOStats;
85 using kernel::Notifications;
86 87 using fsbridge::FopenFn;
88 using node::BlockManager;
89 using node::BlockMap;
90 using node::CBlockIndexHeightOnlyComparator;
91 using node::CBlockIndexWorkComparator;
92 using node::SnapshotMetadata;
93 94 /** Time window to wait between writing blocks/block index and chainstate to disk.
95 * Randomize writing time inside the window to prevent a situation where the
96 * network over time settles into a few cohorts of synchronized writers.
97 */
98 static constexpr auto DATABASE_WRITE_INTERVAL_MIN{50min};
99 static constexpr auto DATABASE_WRITE_INTERVAL_MAX{70min};
100 /** Maximum age of our tip for us to be considered current for fee estimation */
101 static constexpr std::chrono::hours MAX_FEE_ESTIMATION_TIP_AGE{3};
102 const std::vector<std::string> CHECKLEVEL_DOC {
103 "level 0 reads the blocks from disk",
104 "level 1 verifies block validity",
105 "level 2 verifies undo data",
106 "level 3 checks disconnection of tip blocks",
107 "level 4 tries to reconnect the blocks",
108 "each level includes the checks of the previous levels",
109 };
110 /** The number of blocks to keep below the deepest prune lock.
111 * There is nothing special about this number. It is higher than what we
112 * expect to see in regular mainnet reorgs, but not so high that it would
113 * noticeably interfere with the pruning mechanism.
114 * */
115 static constexpr int PRUNE_LOCK_BUFFER{10};
116 117 // Return whether the completed full flush should compact chainstate
118 static bool ShouldCompactChainstate(bool in_ibd)
119 {
120 static constexpr uint32_t flush_ratio{320}; // Roughly every 2 weeks with hourly flushes
121 return !in_ibd && FastRandomContext().randrange(flush_ratio) == 0;
122 }
123 124 TRACEPOINT_SEMAPHORE(validation, block_connected);
125 TRACEPOINT_SEMAPHORE(utxocache, flush);
126 TRACEPOINT_SEMAPHORE(mempool, replaced);
127 TRACEPOINT_SEMAPHORE(mempool, rejected);
128 129 const CBlockIndex* Chainstate::FindForkInGlobalIndex(const CBlockLocator& locator) const
130 {
131 AssertLockHeld(cs_main);
132 133 // Find the latest block common to locator and chain - we expect that
134 // locator.vHave is sorted descending by height.
135 for (const uint256& hash : locator.vHave) {
136 const CBlockIndex* pindex{m_blockman.LookupBlockIndex(hash)};
137 if (pindex) {
138 if (m_chain.Contains(*pindex)) {
139 return pindex;
140 }
141 if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) {
142 return m_chain.Tip();
143 }
144 }
145 }
146 return m_chain.Genesis();
147 }
148 149 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state,
150 const CCoinsViewCache& inputs, script_verify_flags flags, bool cacheSigStore,
151 bool cacheFullScriptStore, PrecomputedTransactionData& txdata,
152 ValidationCache& validation_cache,
153 std::vector<CScriptCheck>* pvChecks = nullptr)
154 EXCLUSIVE_LOCKS_REQUIRED(cs_main);
155 156 bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx)
157 {
158 AssertLockHeld(cs_main);
159 160 // CheckFinalTxAtTip() uses active_chain_tip.Height()+1 to evaluate
161 // nLockTime because when IsFinalTx() is called within
162 // AcceptBlock(), the height of the block *being*
163 // evaluated is what is used. Thus if we want to know if a
164 // transaction can be part of the *next* block, we need to call
165 // IsFinalTx() with one more than active_chain_tip.Height().
166 const int nBlockHeight = active_chain_tip.nHeight + 1;
167 168 // BIP113 requires that time-locked transactions have nLockTime set to
169 // less than the median time of the previous block they're contained in.
170 // When the next block is created its previous block will be the current
171 // chain tip, so we use that to calculate the median time passed to
172 // IsFinalTx().
173 const int64_t nBlockTime{active_chain_tip.GetMedianTimePast()};
174 175 return IsFinalTx(tx, nBlockHeight, nBlockTime);
176 }
177 178 namespace {
179 /**
180 * A helper which calculates heights of inputs of a given transaction.
181 *
182 * @param[in] tip The current chain tip. If an input belongs to a mempool
183 * transaction, we assume it will be confirmed in the next block.
184 * @param[in] coins Any CCoinsView that provides access to the relevant coins.
185 * @param[in] tx The transaction being evaluated.
186 *
187 * @returns A vector of input heights or nullopt, in case of an error.
188 */
189 std::optional<std::vector<int>> CalculatePrevHeights(
190 const CBlockIndex& tip,
191 const CCoinsView& coins,
192 const CTransaction& tx)
193 {
194 std::vector<int> prev_heights;
195 prev_heights.resize(tx.vin.size());
196 for (size_t i = 0; i < tx.vin.size(); ++i) {
197 if (auto coin{coins.GetCoin(tx.vin[i].prevout)}) {
198 prev_heights[i] = coin->nHeight == MEMPOOL_HEIGHT
199 ? tip.nHeight + 1 // Assume all mempool transaction confirm in the next block.
200 : coin->nHeight;
201 } else {
202 LogInfo("ERROR: %s: Missing input %d in transaction \'%s\'\n", __func__, i, tx.GetHash().GetHex());
203 return std::nullopt;
204 }
205 }
206 return prev_heights;
207 }
208 } // namespace
209 210 std::optional<LockPoints> CalculateLockPointsAtTip(
211 CBlockIndex* tip,
212 const CCoinsView& coins_view,
213 const CTransaction& tx)
214 {
215 assert(tip);
216 217 auto prev_heights{CalculatePrevHeights(*tip, coins_view, tx)};
218 if (!prev_heights.has_value()) return std::nullopt;
219 220 CBlockIndex next_tip;
221 next_tip.pprev = tip;
222 // When SequenceLocks() is called within ConnectBlock(), the height
223 // of the block *being* evaluated is what is used.
224 // Thus if we want to know if a transaction can be part of the
225 // *next* block, we need to use one more than active_chainstate.m_chain.Height()
226 next_tip.nHeight = tip->nHeight + 1;
227 const auto [min_height, min_time] = CalculateSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS, prev_heights.value(), next_tip);
228 229 // Also store the hash of the block with the highest height of
230 // all the blocks which have sequence locked prevouts.
231 // This hash needs to still be on the chain
232 // for these LockPoint calculations to be valid
233 // Note: It is impossible to correctly calculate a maxInputBlock
234 // if any of the sequence locked inputs depend on unconfirmed txs,
235 // except in the special case where the relative lock time/height
236 // is 0, which is equivalent to no sequence lock. Since we assume
237 // input height of tip+1 for mempool txs and test the resulting
238 // min_height and min_time from CalculateSequenceLocks against tip+1.
239 int max_input_height{0};
240 for (const int height : prev_heights.value()) {
241 // Can ignore mempool inputs since we'll fail if they had non-zero locks
242 if (height != next_tip.nHeight) {
243 max_input_height = std::max(max_input_height, height);
244 }
245 }
246 247 // tip->GetAncestor(max_input_height) should never return a nullptr
248 // because max_input_height is always less than the tip height.
249 // It would, however, be a bad bug to continue execution, since a
250 // LockPoints object with the maxInputBlock member set to nullptr
251 // signifies no relative lock time.
252 return LockPoints{min_height, min_time, Assert(tip->GetAncestor(max_input_height))};
253 }
254 255 bool CheckSequenceLocksAtTip(CBlockIndex* tip,
256 const LockPoints& lock_points)
257 {
258 assert(tip != nullptr);
259 260 CBlockIndex index;
261 index.pprev = tip;
262 // CheckSequenceLocksAtTip() uses active_chainstate.m_chain.Height()+1 to evaluate
263 // height based locks because when SequenceLocks() is called within
264 // ConnectBlock(), the height of the block *being*
265 // evaluated is what is used.
266 // Thus if we want to know if a transaction can be part of the
267 // *next* block, we need to use one more than active_chainstate.m_chain.Height()
268 index.nHeight = tip->nHeight + 1;
269 270 return EvaluateSequenceLocks(index, {lock_points.height, lock_points.time});
271 }
272 273 static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache)
274 EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs)
275 {
276 AssertLockHeld(::cs_main);
277 AssertLockHeld(pool.cs);
278 int expired = pool.Expire(GetTime<std::chrono::seconds>() - pool.m_opts.expiry);
279 if (expired != 0) {
280 LogDebug(BCLog::MEMPOOL, "Expired %i transactions from the memory pool\n", expired);
281 }
282 283 std::vector<COutPoint> vNoSpendsRemaining;
284 pool.TrimToSize(pool.m_opts.max_size_bytes, &vNoSpendsRemaining);
285 for (const COutPoint& removed : vNoSpendsRemaining)
286 coins_cache.Uncache(removed);
287 }
288 289 static bool IsCurrentForFeeEstimation(Chainstate& active_chainstate) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
290 {
291 AssertLockHeld(cs_main);
292 if (active_chainstate.m_chainman.IsInitialBlockDownload()) {
293 return false;
294 }
295 if (active_chainstate.m_chain.Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE))
296 return false;
297 if (active_chainstate.m_chain.Height() < active_chainstate.m_chainman.m_best_header->nHeight - 1) {
298 return false;
299 }
300 return true;
301 }
302 303 void Chainstate::MaybeUpdateMempoolForReorg(
304 DisconnectedBlockTransactions& disconnectpool,
305 bool fAddToMempool)
306 {
307 if (!m_mempool) return;
308 309 AssertLockHeld(cs_main);
310 AssertLockHeld(m_mempool->cs);
311 std::vector<Txid> vHashUpdate;
312 {
313 // disconnectpool is ordered so that the front is the most recently-confirmed
314 // transaction (the last tx of the block at the tip) in the disconnected chain.
315 // Iterate disconnectpool in reverse, so that we add transactions
316 // back to the mempool starting with the earliest transaction that had
317 // been previously seen in a block.
318 const auto queuedTx = disconnectpool.take();
319 auto it = queuedTx.rbegin();
320 while (it != queuedTx.rend()) {
321 // ignore validation errors in resurrected transactions
322 if (!fAddToMempool || (*it)->IsCoinBase() ||
323 AcceptToMemoryPool(*this, *it, GetTime(),
324 /*bypass_limits=*/true, /*test_accept=*/false).m_result_type !=
325 MempoolAcceptResult::ResultType::VALID) {
326 // If the transaction doesn't make it in to the mempool, remove any
327 // transactions that depend on it (which would now be orphans).
328 m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG);
329 } else if (m_mempool->exists((*it)->GetHash())) {
330 vHashUpdate.push_back((*it)->GetHash());
331 }
332 ++it;
333 }
334 }
335 336 // AcceptToMemoryPool/addNewTransaction all assume that new mempool entries have
337 // no in-mempool children, which is generally not true when adding
338 // previously-confirmed transactions back to the mempool.
339 // UpdateTransactionsFromBlock finds descendants of any transactions in
340 // the disconnectpool that were added back and cleans up the mempool state.
341 m_mempool->UpdateTransactionsFromBlock(vHashUpdate);
342 343 // Predicate to use for filtering transactions in removeForReorg.
344 // Checks whether the transaction is still final and, if it spends a coinbase output, mature.
345 // Also updates valid entries' cached LockPoints if needed.
346 // If false, the tx is still valid and its lockpoints are updated.
347 // If true, the tx would be invalid in the next block; remove this entry and all of its descendants.
348 // Note that TRUC rules are not applied here, so reorgs may cause violations of TRUC inheritance or
349 // topology restrictions.
350 const auto filter_final_and_mature = [&](CTxMemPool::txiter it)
351 EXCLUSIVE_LOCKS_REQUIRED(m_mempool->cs, ::cs_main) {
352 AssertLockHeld(m_mempool->cs);
353 AssertLockHeld(::cs_main);
354 const CTransaction& tx = it->GetTx();
355 356 // The transaction must be final.
357 if (!CheckFinalTxAtTip(*Assert(m_chain.Tip()), tx)) return true;
358 359 const LockPoints& lp = it->GetLockPoints();
360 // CheckSequenceLocksAtTip checks if the transaction will be final in the next block to be
361 // created on top of the new chain.
362 if (TestLockPointValidity(m_chain, lp)) {
363 if (!CheckSequenceLocksAtTip(m_chain.Tip(), lp)) {
364 return true;
365 }
366 } else {
367 const CCoinsViewMemPool view_mempool{&CoinsTip(), *m_mempool};
368 const std::optional<LockPoints> new_lock_points{CalculateLockPointsAtTip(m_chain.Tip(), view_mempool, tx)};
369 if (new_lock_points.has_value() && CheckSequenceLocksAtTip(m_chain.Tip(), *new_lock_points)) {
370 // Now update the mempool entry lockpoints as well.
371 it->UpdateLockPoints(*new_lock_points);
372 } else {
373 return true;
374 }
375 }
376 377 // If the transaction spends any coinbase outputs, it must be mature.
378 if (it->GetSpendsCoinbase()) {
379 for (const CTxIn& txin : tx.vin) {
380 if (m_mempool->exists(txin.prevout.hash)) continue;
381 const Coin& coin{CoinsTip().AccessCoin(txin.prevout)};
382 assert(!coin.IsSpent());
383 const auto mempool_spend_height{m_chain.Tip()->nHeight + 1};
384 if (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY) {
385 return true;
386 }
387 }
388 }
389 // Transaction is still valid and cached LockPoints are updated.
390 return false;
391 };
392 393 // We also need to remove any now-immature transactions
394 m_mempool->removeForReorg(m_chain, filter_final_and_mature);
395 // Re-limit mempool size, in case we added any transactions
396 LimitMempoolSize(*m_mempool, this->CoinsTip());
397 }
398 399 /**
400 * Checks to avoid mempool polluting consensus critical paths since cached
401 * signature and script validity results will be reused if we validate this
402 * transaction again during block validation.
403 * */
404 static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, TxValidationState& state,
405 const CCoinsViewCache& view, const CTxMemPool& pool,
406 script_verify_flags flags, PrecomputedTransactionData& txdata, CCoinsViewCache& coins_tip,
407 ValidationCache& validation_cache)
408 EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
409 {
410 AssertLockHeld(cs_main);
411 AssertLockHeld(pool.cs);
412 413 assert(!tx.IsCoinBase());
414 for (const CTxIn& txin : tx.vin) {
415 const Coin& coin = view.AccessCoin(txin.prevout);
416 417 // This coin was checked in PreChecks and MemPoolAccept
418 // has been holding cs_main since then.
419 Assume(!coin.IsSpent());
420 if (coin.IsSpent()) return false;
421 422 // If the Coin is available, there are 2 possibilities:
423 // it is available in our current ChainstateActive UTXO set,
424 // or it's a UTXO provided by a transaction in our mempool.
425 // Ensure the scriptPubKeys in Coins from CoinsView are correct.
426 const CTransactionRef& txFrom = pool.get(txin.prevout.hash);
427 if (txFrom) {
428 assert(txFrom->GetHash() == txin.prevout.hash);
429 assert(txFrom->vout.size() > txin.prevout.n);
430 assert(txFrom->vout[txin.prevout.n] == coin.out);
431 } else {
432 const Coin& coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout);
433 assert(!coinFromUTXOSet.IsSpent());
434 assert(coinFromUTXOSet.out == coin.out);
435 }
436 }
437 438 // Call CheckInputScripts() to cache signature and script validity against current tip consensus rules.
439 return CheckInputScripts(tx, state, view, flags, /* cacheSigStore= */ true, /* cacheFullScriptStore= */ true, txdata, validation_cache);
440 }
441 442 namespace {
443 444 class MemPoolAccept
445 {
446 public:
447 explicit MemPoolAccept(CTxMemPool& mempool, Chainstate& active_chainstate) :
448 m_pool(mempool),
449 m_view(&CoinsViewEmpty::Get()),
450 m_viewmempool(&active_chainstate.CoinsTip(), m_pool),
451 m_active_chainstate(active_chainstate)
452 {
453 }
454 455 // We put the arguments we're handed into a struct, so we can pass them
456 // around easier.
457 struct ATMPArgs {
458 const CChainParams& m_chainparams;
459 const int64_t m_accept_time;
460 const bool m_bypass_limits;
461 /*
462 * Return any outpoints which were not previously present in the coins
463 * cache, but were added as a result of validating the tx for mempool
464 * acceptance. This allows the caller to optionally remove the cache
465 * additions if the associated transaction ends up being rejected by
466 * the mempool.
467 */
468 std::vector<COutPoint>& m_coins_to_uncache;
469 /** When true, the transaction or package will not be submitted to the mempool. */
470 const bool m_test_accept;
471 /** Whether we allow transactions to replace mempool transactions. If false,
472 * any transaction spending the same inputs as a transaction in the mempool is considered
473 * a conflict. */
474 const bool m_allow_replacement;
475 /** When true, allow sibling eviction. This only occurs in single transaction package settings. */
476 const bool m_allow_sibling_eviction;
477 /** Used to skip the LimitMempoolSize() call within AcceptSingleTransaction(). This should be used when multiple
478 * AcceptSubPackage calls are expected and the mempool will be trimmed at the end of AcceptPackage(). */
479 const bool m_package_submission;
480 /** When true, use package feerates instead of individual transaction feerates for fee-based
481 * policies such as mempool min fee and min relay fee.
482 */
483 const bool m_package_feerates;
484 /** Used for local submission of transactions to catch "absurd" fees
485 * due to fee miscalculation by wallets. std:nullopt implies unset, allowing any feerates.
486 * Any individual transaction failing this check causes immediate failure.
487 */
488 const std::optional<CFeeRate> m_client_maxfeerate;
489 490 /** Parameters for single transaction mempool validation. */
491 static ATMPArgs SingleAccept(const CChainParams& chainparams, int64_t accept_time,
492 bool bypass_limits, std::vector<COutPoint>& coins_to_uncache,
493 bool test_accept) {
494 return ATMPArgs{/*chainparams=*/ chainparams,
495 /*accept_time=*/ accept_time,
496 /*bypass_limits=*/ bypass_limits,
497 /*coins_to_uncache=*/ coins_to_uncache,
498 /*test_accept=*/ test_accept,
499 /*allow_replacement=*/ true,
500 /*allow_sibling_eviction=*/ true,
501 /*package_submission=*/ false,
502 /*package_feerates=*/ false,
503 /*client_maxfeerate=*/ {}, // checked by caller
504 };
505 }
506 507 /** Parameters for test package mempool validation through testmempoolaccept. */
508 static ATMPArgs PackageTestAccept(const CChainParams& chainparams, int64_t accept_time,
509 std::vector<COutPoint>& coins_to_uncache) {
510 return ATMPArgs{/*chainparams=*/ chainparams,
511 /*accept_time=*/ accept_time,
512 /*bypass_limits=*/ false,
513 /*coins_to_uncache=*/ coins_to_uncache,
514 /*test_accept=*/ true,
515 /*allow_replacement=*/ false,
516 /*allow_sibling_eviction=*/ false,
517 /*package_submission=*/ false, // not submitting to mempool
518 /*package_feerates=*/ false,
519 /*client_maxfeerate=*/ {}, // checked by caller
520 };
521 }
522 523 /** Parameters for child-with-parents package validation. */
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{/*chainparams=*/ chainparams,
527 /*accept_time=*/ accept_time,
528 /*bypass_limits=*/ false,
529 /*coins_to_uncache=*/ coins_to_uncache,
530 /*test_accept=*/ false,
531 /*allow_replacement=*/ true,
532 /*allow_sibling_eviction=*/ false,
533 /*package_submission=*/ true,
534 /*package_feerates=*/ true,
535 /*client_maxfeerate=*/ client_maxfeerate,
536 };
537 }
538 539 /** Parameters for a single transaction within a package. */
540 static ATMPArgs SingleInPackageAccept(const ATMPArgs& package_args) {
541 return ATMPArgs{/*chainparams=*/ package_args.m_chainparams,
542 /*accept_time=*/ package_args.m_accept_time,
543 /*bypass_limits=*/ false,
544 /*coins_to_uncache=*/ package_args.m_coins_to_uncache,
545 /*test_accept=*/ package_args.m_test_accept,
546 /*allow_replacement=*/ true,
547 /*allow_sibling_eviction=*/ true,
548 /*package_submission=*/ true, // trim at the end of AcceptPackage()
549 /*package_feerates=*/ false, // only 1 transaction
550 /*client_maxfeerate=*/ package_args.m_client_maxfeerate,
551 };
552 }
553 554 private:
555 // Private ctor to avoid exposing details to clients and allowing the possibility of
556 // mixing up the order of the arguments. Use static functions above instead.
557 ATMPArgs(const CChainParams& chainparams,
558 int64_t accept_time,
559 bool bypass_limits,
560 std::vector<COutPoint>& coins_to_uncache,
561 bool test_accept,
562 bool allow_replacement,
563 bool allow_sibling_eviction,
564 bool package_submission,
565 bool package_feerates,
566 std::optional<CFeeRate> client_maxfeerate)
567 : m_chainparams{chainparams},
568 m_accept_time{accept_time},
569 m_bypass_limits{bypass_limits},
570 m_coins_to_uncache{coins_to_uncache},
571 m_test_accept{test_accept},
572 m_allow_replacement{allow_replacement},
573 m_allow_sibling_eviction{allow_sibling_eviction},
574 m_package_submission{package_submission},
575 m_package_feerates{package_feerates},
576 m_client_maxfeerate{client_maxfeerate}
577 {
578 // If we are using package feerates, we must be doing package submission.
579 // It also means sibling eviction is not permitted.
580 if (m_package_feerates) {
581 Assume(m_package_submission);
582 Assume(!m_allow_sibling_eviction);
583 }
584 if (m_allow_sibling_eviction) Assume(m_allow_replacement);
585 }
586 };
587 588 /** Clean up all non-chainstate coins from m_view and m_viewmempool. */
589 void CleanupTemporaryCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
590 591 // Single transaction acceptance
592 MempoolAcceptResult AcceptSingleTransactionAndCleanup(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
593 LOCK(m_pool.cs);
594 MempoolAcceptResult result = AcceptSingleTransactionInternal(ptx, args);
595 ClearSubPackageState();
596 return result;
597 }
598 MempoolAcceptResult AcceptSingleTransactionInternal(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
599 600 /**
601 * Multiple transaction acceptance. Transactions may or may not be interdependent, but must not
602 * conflict with each other, and the transactions cannot already be in the mempool. Parents must
603 * come before children if any dependencies exist.
604 */
605 PackageMempoolAcceptResult AcceptMultipleTransactionsAndCleanup(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
606 LOCK(m_pool.cs);
607 PackageMempoolAcceptResult result = AcceptMultipleTransactionsInternal(txns, args);
608 ClearSubPackageState();
609 return result;
610 }
611 PackageMempoolAcceptResult AcceptMultipleTransactionsInternal(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
612 613 /**
614 * Submission of a subpackage.
615 * If subpackage size == 1, calls AcceptSingleTransaction() with adjusted ATMPArgs to
616 * enable sibling eviction and creates a PackageMempoolAcceptResult
617 * wrapping the result.
618 *
619 * If subpackage size > 1, calls AcceptMultipleTransactions() with the provided ATMPArgs.
620 *
621 * Also cleans up all non-chainstate coins from m_view at the end.
622 */
623 PackageMempoolAcceptResult AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args)
624 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
625 626 /**
627 * Package (more specific than just multiple transactions) acceptance. Package must be a child
628 * with all of its unconfirmed parents, and topologically sorted.
629 */
630 PackageMempoolAcceptResult AcceptPackage(const Package& package, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
631 632 private:
633 // All the intermediate state that gets passed between the various levels
634 // of checking a given transaction.
635 struct Workspace {
636 explicit Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {}
637 /** Txids of mempool transactions that this transaction directly conflicts with or may
638 * replace via sibling eviction. */
639 std::set<Txid> m_conflicts;
640 /** Iterators to mempool entries that this transaction directly conflicts with or may
641 * replace via sibling eviction. */
642 CTxMemPool::setEntries m_iters_conflicting;
643 /** All mempool parents of this transaction. */
644 std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> m_parents;
645 /* Handle to the tx in the changeset */
646 CTxMemPool::ChangeSet::TxHandle m_tx_handle;
647 /** Whether RBF-related data structures (m_conflicts, m_iters_conflicting,
648 * m_replaced_transactions) include a sibling in addition to txns with conflicting inputs. */
649 bool m_sibling_eviction{false};
650 651 /** Virtual size of the transaction as used by the mempool, calculated using serialized size
652 * of the transaction and sigops. */
653 int64_t m_vsize;
654 /** Fees paid by this transaction: total input amounts subtracted by total output amounts. */
655 CAmount m_base_fees;
656 /** Base fees + any fee delta set by the user with prioritisetransaction. */
657 CAmount m_modified_fees;
658 659 /** If we're doing package validation (i.e. m_package_feerates=true), the "effective"
660 * package feerate of this transaction is the total fees divided by the total size of
661 * transactions (which may include its ancestors and/or descendants). */
662 CFeeRate m_package_feerate{0};
663 664 const CTransactionRef& m_ptx;
665 /** Txid. */
666 const Txid& m_hash;
667 TxValidationState m_state;
668 /** A temporary cache containing serialized transaction data for signature verification.
669 * Reused across PolicyScriptChecks and ConsensusScriptChecks. */
670 PrecomputedTransactionData m_precomputed_txdata;
671 };
672 673 // Run the policy checks on a given transaction, excluding any script checks.
674 // Looks up inputs, calculates feerate, considers replacement, evaluates
675 // package limits, etc. As this function can be invoked for "free" by a peer,
676 // only tests that are fast should be done here (to avoid CPU DoS).
677 bool PreChecks(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
678 679 // Run checks for mempool replace-by-fee, only used in AcceptSingleTransaction.
680 bool ReplacementChecks(Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
681 682 bool PackageRBFChecks(const std::vector<CTransactionRef>& txns,
683 std::vector<Workspace>& workspaces,
684 int64_t total_vsize,
685 PackageValidationState& package_state) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
686 687 // Run the script checks using our policy flags. As this can be slow, we should
688 // only invoke this on transactions that have otherwise passed policy checks.
689 bool PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
690 691 // Re-run the script checks, using consensus flags, and try to cache the
692 // result in the scriptcache. This should be done after
693 // PolicyScriptChecks(). This requires that all inputs either be in our
694 // utxo set or in the mempool.
695 bool ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
696 697 // Try to add the transaction to the mempool, removing any conflicts first.
698 void FinalizeSubpackage(const ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
699 700 // Submit all transactions to the mempool and call ConsensusScriptChecks to add to the script
701 // cache - should only be called after successful validation of all transactions in the package.
702 // Does not call LimitMempoolSize(), so mempool max_size_bytes may be temporarily exceeded.
703 bool SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, PackageValidationState& package_state,
704 std::map<Wtxid, MempoolAcceptResult>& results)
705 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
706 707 // Compare a package's feerate against minimum allowed.
708 bool CheckFeeRate(size_t package_size, CAmount package_fee, TxValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs)
709 {
710 AssertLockHeld(::cs_main);
711 AssertLockHeld(m_pool.cs);
712 CAmount mempoolRejectFee = m_pool.GetMinFee().GetFee(package_size);
713 if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) {
714 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee));
715 }
716 717 if (package_fee < m_pool.m_opts.min_relay_feerate.GetFee(package_size)) {
718 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "min relay fee not met",
719 strprintf("%d < %d", package_fee, m_pool.m_opts.min_relay_feerate.GetFee(package_size)));
720 }
721 return true;
722 }
723 724 ValidationCache& GetValidationCache()
725 {
726 return m_active_chainstate.m_chainman.m_validation_cache;
727 }
728 729 private:
730 CTxMemPool& m_pool;
731 732 /** Holds a cached view of available coins from the UTXO set, mempool, and artificial temporary coins (to enable package validation).
733 * The view doesn't track whether a coin previously existed but has now been spent. We detect conflicts in other ways:
734 * - conflicts within a transaction are checked in CheckTransaction (bad-txns-inputs-duplicate)
735 * - conflicts within a package are checked in IsWellFormedPackage (conflict-in-package)
736 * - conflicts with an existing mempool transaction are found in CTxMemPool::GetConflictTx and replacements are allowed
737 * The temporary coins should persist between individual transaction checks so that package validation is possible,
738 * but must be cleaned up when we finish validating a subpackage, whether accepted or rejected. The cache must also
739 * be cleared when mempool contents change (when a changeset is applied or when the mempool trims itself) because it
740 * can return cached coins that no longer exist in the backend. Use CleanupTemporaryCoins() anytime you are finished
741 * with a SubPackageState or call LimitMempoolSize().
742 */
743 CCoinsViewCache m_view;
744 745 // These are the two possible backends for m_view.
746 /** When m_view is connected to m_viewmempool as its backend, it can pull coins from the mempool and from the UTXO
747 * set. This is also where temporary coins are stored. */
748 CCoinsViewMemPool m_viewmempool;
749 750 Chainstate& m_active_chainstate;
751 752 // Fields below are per *sub*package state and must be reset prior to subsequent
753 // AcceptSingleTransaction and AcceptMultipleTransactions invocations
754 struct SubPackageState {
755 /** Aggregated modified fees of all transactions, used to calculate package feerate. */
756 CAmount m_total_modified_fees{0};
757 /** Aggregated virtual size of all transactions, used to calculate package feerate. */
758 int64_t m_total_vsize{0};
759 760 // RBF-related members
761 /** Whether the transaction(s) would replace any mempool transactions and/or evict any siblings.
762 * If so, RBF rules apply. */
763 bool m_rbf{false};
764 /** Mempool transactions that were replaced. */
765 std::list<CTransactionRef> m_replaced_transactions;
766 /* Changeset representing adding transactions and removing their conflicts. */
767 std::unique_ptr<CTxMemPool::ChangeSet> m_changeset;
768 769 /** Total modified fees of mempool transactions being replaced. */
770 CAmount m_conflicting_fees{0};
771 /** Total size (in virtual bytes) of mempool transactions being replaced. */
772 size_t m_conflicting_size{0};
773 };
774 775 struct SubPackageState m_subpackage;
776 777 /** Re-set sub-package state to not leak between evaluations */
778 void ClearSubPackageState() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs)
779 {
780 m_subpackage = SubPackageState{};
781 782 // And clean coins while at it
783 CleanupTemporaryCoins();
784 }
785 };
786 787 bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
788 {
789 AssertLockHeld(cs_main);
790 AssertLockHeld(m_pool.cs);
791 const CTransactionRef& ptx = ws.m_ptx;
792 const CTransaction& tx = *ws.m_ptx;
793 const Txid& hash = ws.m_hash;
794 795 // Copy/alias what we need out of args
796 const int64_t nAcceptTime = args.m_accept_time;
797 const bool bypass_limits = args.m_bypass_limits;
798 std::vector<COutPoint>& coins_to_uncache = args.m_coins_to_uncache;
799 800 // Alias what we need out of ws
801 TxValidationState& state = ws.m_state;
802 803 if (!CheckTransaction(tx, state)) {
804 return false; // state filled in by CheckTransaction
805 }
806 807 // Coinbase is only valid in a block, not as a loose transaction
808 if (tx.IsCoinBase())
809 return state.Invalid(TxValidationResult::TX_CONSENSUS, "coinbase");
810 811 // Rather not work on nonstandard transactions (unless -testnet/-regtest)
812 std::string reason;
813 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)) {
814 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason);
815 }
816 817 // Transactions smaller than 65 non-witness bytes are not relayed to mitigate CVE-2017-12842.
818 if (::GetSerializeSize(TX_NO_WITNESS(tx)) < MIN_STANDARD_TX_NONWITNESS_SIZE)
819 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "tx-size-small");
820 821 // Only accept nLockTime-using transactions that can be mined in the next
822 // block; we don't want our mempool filled up with transactions that can't
823 // be mined yet.
824 if (!CheckFinalTxAtTip(*Assert(m_active_chainstate.m_chain.Tip()), tx)) {
825 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-final");
826 }
827 828 if (m_pool.exists(tx.GetWitnessHash())) {
829 // Exact transaction already exists in the mempool.
830 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-in-mempool");
831 } else if (m_pool.exists(tx.GetHash())) {
832 // Transaction with the same non-witness data but different witness (same txid, different
833 // wtxid) already exists in the mempool.
834 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-same-nonwitness-data-in-mempool");
835 }
836 837 // Check for conflicts with in-memory transactions
838 for (const CTxIn &txin : tx.vin)
839 {
840 const CTransaction* ptxConflicting = m_pool.GetConflictTx(txin.prevout);
841 if (ptxConflicting) {
842 if (!args.m_allow_replacement) {
843 // Transaction conflicts with a mempool tx, but we're not allowing replacements in this context.
844 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "bip125-replacement-disallowed");
845 }
846 ws.m_conflicts.insert(ptxConflicting->GetHash());
847 }
848 }
849 850 m_view.SetBackend(m_viewmempool);
851 852 const CCoinsViewCache& coins_cache = m_active_chainstate.CoinsTip();
853 // do all inputs exist?
854 for (const CTxIn& txin : tx.vin) {
855 if (!coins_cache.HaveCoinInCache(txin.prevout)) {
856 coins_to_uncache.push_back(txin.prevout);
857 }
858 859 // Note: this call may add txin.prevout to the coins cache
860 // (coins_cache.cacheCoins) by way of FetchCoin(). It should be removed
861 // later (via coins_to_uncache) if this tx turns out to be invalid.
862 if (!m_view.HaveCoin(txin.prevout)) {
863 // Are inputs missing because we already have the tx?
864 for (size_t out = 0; out < tx.vout.size(); out++) {
865 // Optimistically just do efficient check of cache for outputs
866 if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) {
867 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-known");
868 }
869 }
870 // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet
871 return state.Invalid(TxValidationResult::TX_MISSING_INPUTS, "bad-txns-inputs-missingorspent");
872 }
873 }
874 875 // This is const, but calls into `CCoinsViewCache::GetBestBlock()` to refresh
876 // the cached best block through `m_viewmempool` after caching inputs.
877 (void)m_view.GetBestBlock();
878 879 // All required inputs are cached now, so switch m_view to the empty backend.
880 // This keeps already-fetched cache entries for later checks and prevents new
881 // backend lookups (which would avoid coins_to_uncache tracking).
882 m_view.SetBackend(CoinsViewEmpty::Get());
883 884 assert(m_active_chainstate.m_blockman.LookupBlockIndex(m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip());
885 886 // Only accept BIP68 sequence locked transactions that can be mined in the next
887 // block; we don't want our mempool filled up with transactions that can't
888 // be mined yet.
889 // Pass in m_view which has all of the relevant inputs cached. Note that, since m_view's
890 // backend was removed, it no longer pulls coins from the mempool.
891 const std::optional<LockPoints> lock_points{CalculateLockPointsAtTip(m_active_chainstate.m_chain.Tip(), m_view, tx)};
892 if (!lock_points.has_value() || !CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(), *lock_points)) {
893 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-BIP68-final");
894 }
895 896 // The mempool holds txs for the next block, so pass height+1 to CheckTxInputs
897 if (!Consensus::CheckTxInputs(tx, state, m_view, m_active_chainstate.m_chain.Height() + 1, ws.m_base_fees)) {
898 return false; // state filled in by CheckTxInputs
899 }
900 901 if (m_pool.m_opts.require_standard) {
902 state = ValidateInputsStandardness(tx, m_view);
903 if (state.IsInvalid()) {
904 return false;
905 }
906 }
907 908 // Check for non-standard witnesses.
909 if (tx.HasWitness() && m_pool.m_opts.require_standard && !IsWitnessStandard(tx, m_view)) {
910 return state.Invalid(TxValidationResult::TX_WITNESS_MUTATED, "bad-witness-nonstandard");
911 }
912 913 int64_t nSigOpsCost = GetTransactionSigOpCost(tx, m_view, STANDARD_SCRIPT_VERIFY_FLAGS);
914 915 // Keep track of transactions that spend a coinbase, which we re-scan
916 // during reorgs to ensure COINBASE_MATURITY is still met.
917 bool fSpendsCoinbase = false;
918 for (const CTxIn &txin : tx.vin) {
919 const Coin &coin = m_view.AccessCoin(txin.prevout);
920 if (coin.IsCoinBase()) {
921 fSpendsCoinbase = true;
922 break;
923 }
924 }
925 926 // Set entry_sequence to 0 when bypass_limits is used; this allows txs from a block
927 // reorg to be marked earlier than any child txs that were already in the mempool.
928 const uint64_t entry_sequence = bypass_limits ? 0 : m_pool.GetSequence();
929 if (!m_subpackage.m_changeset) {
930 m_subpackage.m_changeset = m_pool.GetChangeSet();
931 }
932 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());
933 934 // ws.m_modified_fees includes any fee deltas from PrioritiseTransaction
935 ws.m_modified_fees = ws.m_tx_handle->GetModifiedFee();
936 937 ws.m_vsize = ws.m_tx_handle->GetTxSize();
938 939 // Enforces 0-fee for dust transactions, no incentive to be mined alone
940 if (m_pool.m_opts.require_standard) {
941 if (!PreCheckEphemeralTx(*ptx, m_pool.m_opts.dust_relay_feerate, ws.m_base_fees, ws.m_modified_fees, state)) {
942 return false; // state filled in by PreCheckEphemeralTx
943 }
944 }
945 946 if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST)
947 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "bad-txns-too-many-sigops",
948 strprintf("%d", nSigOpsCost));
949 950 // No individual transactions are allowed below the mempool min feerate except from disconnected
951 // blocks and transactions in a package. Package transactions will be checked using package
952 // feerate later.
953 if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false;
954 955 ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts);
956 957 ws.m_parents = m_pool.GetParents(*ws.m_tx_handle);
958 959 if (!args.m_bypass_limits) {
960 // Perform the TRUC checks, using the in-mempool parents.
961 if (const auto err{SingleTRUCChecks(m_pool, ws.m_ptx, ws.m_parents, ws.m_conflicts, ws.m_vsize)}) {
962 // Single transaction contexts only.
963 if (args.m_allow_sibling_eviction && err->second != nullptr) {
964 // We should only be considering where replacement is considered valid as well.
965 Assume(args.m_allow_replacement);
966 // Potential sibling eviction. Add the sibling to our list of mempool conflicts to be
967 // included in RBF checks.
968 ws.m_conflicts.insert(err->second->GetHash());
969 // Adding the sibling to m_iters_conflicting here means that it doesn't count towards
970 // RBF Carve Out above. This is correct, since removing to-be-replaced transactions from
971 // the descendant count is done separately in SingleTRUCChecks for TRUC transactions.
972 ws.m_iters_conflicting.insert(m_pool.GetIter(err->second->GetHash()).value());
973 ws.m_sibling_eviction = true;
974 // The sibling will be treated as part of the to-be-replaced set in ReplacementChecks.
975 // Note that we are not checking whether it opts in to replaceability via BIP125 or TRUC
976 // (which is normally done in PreChecks). However, the only way a TRUC transaction can
977 // have a non-TRUC and non-BIP125 descendant is due to a reorg.
978 } else {
979 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "TRUC-violation", err->first);
980 }
981 }
982 }
983 984 // We want to detect conflicts in any tx in a package to trigger package RBF logic
985 m_subpackage.m_rbf |= !ws.m_conflicts.empty();
986 return true;
987 }
988 989 bool MemPoolAccept::ReplacementChecks(Workspace& ws)
990 {
991 AssertLockHeld(cs_main);
992 AssertLockHeld(m_pool.cs);
993 994 const CTransaction& tx = *ws.m_ptx;
995 const Txid& hash = ws.m_hash;
996 TxValidationState& state = ws.m_state;
997 998 CFeeRate newFeeRate(ws.m_modified_fees, ws.m_vsize);
999 1000 CTxMemPool::setEntries all_conflicts;
1001 1002 // Calculate all conflicting entries and enforce Rule #5.
1003 if (const auto err_string{GetEntriesForConflicts(tx, m_pool, ws.m_iters_conflicting, all_conflicts)}) {
1004 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
1005 strprintf("too many potential replacements%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string);
1006 }
1007 1008 // Check if it's economically rational to mine this transaction rather than the ones it
1009 // replaces and pays for its own relay fees. Enforce Rules #3 and #4.
1010 for (CTxMemPool::txiter it : all_conflicts) {
1011 m_subpackage.m_conflicting_fees += it->GetModifiedFee();
1012 m_subpackage.m_conflicting_size += it->GetTxSize();
1013 }
1014 1015 if (const auto err_string{PaysForRBF(m_subpackage.m_conflicting_fees, ws.m_modified_fees, ws.m_vsize,
1016 m_pool.m_opts.incremental_relay_feerate, hash)}) {
1017 // Result may change in a package context
1018 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE,
1019 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string);
1020 }
1021 1022 // Add all the to-be-removed transactions to the changeset.
1023 for (auto it : all_conflicts) {
1024 m_subpackage.m_changeset->StageRemoval(it);
1025 }
1026 1027 // Run cluster size limit checks and fail if we exceed them.
1028 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) {
1029 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-large-cluster", "");
1030 }
1031 1032 if (const auto err_string{ImprovesFeerateDiagram(*m_subpackage.m_changeset)}) {
1033 // We checked above for the cluster size limits being respected, so a
1034 // failure here can only be due to an insufficient fee.
1035 Assume(err_string->first == DiagramCheckError::FAILURE);
1036 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "replacement-failed", err_string->second);
1037 }
1038 1039 return true;
1040 }
1041 1042 bool MemPoolAccept::PackageRBFChecks(const std::vector<CTransactionRef>& txns,
1043 std::vector<Workspace>& workspaces,
1044 const int64_t total_vsize,
1045 PackageValidationState& package_state)
1046 {
1047 AssertLockHeld(cs_main);
1048 AssertLockHeld(m_pool.cs);
1049 1050 assert(std::all_of(txns.cbegin(), txns.cend(), [this](const auto& tx)
1051 { return !m_pool.exists(tx->GetHash());}));
1052 1053 assert(txns.size() == workspaces.size());
1054 1055 // We're in package RBF context; replacement proposal must be size 2
1056 if (workspaces.size() != 2 || !Assume(IsChildWithParents(txns))) {
1057 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: package must be 1-parent-1-child");
1058 }
1059 1060 // If the package has in-mempool parents, we won't consider a package RBF
1061 // since it would result in a cluster larger than 2.
1062 // N.B. To relax this constraint we will need to revisit how CCoinsViewMemPool::PackageAddTransaction
1063 // is being used inside AcceptMultipleTransactions to track available inputs while processing a package.
1064 // Specifically we would need to check that the ancestors of the new
1065 // transactions don't intersect with the set of transactions to be removed
1066 // due to RBF, which is not checked at all in the package acceptance
1067 // context.
1068 for (const auto& ws : workspaces) {
1069 if (!ws.m_parents.empty()) {
1070 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: new transaction cannot have mempool ancestors");
1071 }
1072 }
1073 1074 // Aggregate all conflicts into one set.
1075 CTxMemPool::setEntries direct_conflict_iters;
1076 for (Workspace& ws : workspaces) {
1077 // Aggregate all conflicts into one set.
1078 direct_conflict_iters.merge(ws.m_iters_conflicting);
1079 }
1080 1081 const auto& parent_ws = workspaces[0];
1082 const auto& child_ws = workspaces[1];
1083 1084 // Don't consider replacements that would cause us to remove a large number of mempool entries.
1085 // This limit is not increased in a package RBF. Use the aggregate number of transactions.
1086 CTxMemPool::setEntries all_conflicts;
1087 if (const auto err_string{GetEntriesForConflicts(*child_ws.m_ptx, m_pool, direct_conflict_iters,
1088 all_conflicts)}) {
1089 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1090 "package RBF failed: too many potential replacements", *err_string);
1091 }
1092 1093 for (CTxMemPool::txiter it : all_conflicts) {
1094 m_subpackage.m_changeset->StageRemoval(it);
1095 m_subpackage.m_conflicting_fees += it->GetModifiedFee();
1096 m_subpackage.m_conflicting_size += it->GetTxSize();
1097 }
1098 1099 // Use the child as the transaction for attributing errors to.
1100 const Txid& child_hash = child_ws.m_ptx->GetHash();
1101 if (const auto err_string{PaysForRBF(/*original_fees=*/m_subpackage.m_conflicting_fees,
1102 /*replacement_fees=*/m_subpackage.m_total_modified_fees,
1103 /*replacement_vsize=*/m_subpackage.m_total_vsize,
1104 m_pool.m_opts.incremental_relay_feerate, child_hash)}) {
1105 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1106 "package RBF failed: insufficient anti-DoS fees", *err_string);
1107 }
1108 1109 // Ensure this two transaction package is a "chunk" on its own; we don't want the child
1110 // to be only paying anti-DoS fees
1111 const CFeeRate parent_feerate(parent_ws.m_modified_fees, parent_ws.m_vsize);
1112 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize);
1113 if (package_feerate <= parent_feerate) {
1114 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1115 "package RBF failed: package feerate is less than or equal to parent feerate",
1116 strprintf("package feerate %s <= parent feerate is %s", package_feerate.ToString(), parent_feerate.ToString()));
1117 }
1118 1119 // Run cluster size limit checks and fail if we exceed them.
1120 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) {
1121 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "too-large-cluster", "");
1122 }
1123 1124 // Check if it's economically rational to mine this package rather than the ones it replaces.
1125 if (const auto err_tup{ImprovesFeerateDiagram(*m_subpackage.m_changeset)}) {
1126 Assume(err_tup->first == DiagramCheckError::FAILURE);
1127 return package_state.Invalid(PackageValidationResult::PCKG_POLICY,
1128 "package RBF failed: " + err_tup.value().second, "");
1129 }
1130 1131 LogDebug(BCLog::TXPACKAGES, "package RBF checks passed: parent %s (wtxid=%s), child %s (wtxid=%s), package hash (%s)\n",
1132 txns.front()->GetHash().ToString(), txns.front()->GetWitnessHash().ToString(),
1133 txns.back()->GetHash().ToString(), txns.back()->GetWitnessHash().ToString(),
1134 GetPackageHash(txns).ToString());
1135 1136 1137 return true;
1138 }
1139 1140 bool MemPoolAccept::PolicyScriptChecks(const ATMPArgs& args, Workspace& ws)
1141 {
1142 AssertLockHeld(cs_main);
1143 AssertLockHeld(m_pool.cs);
1144 const CTransaction& tx = *ws.m_ptx;
1145 TxValidationState& state = ws.m_state;
1146 1147 constexpr script_verify_flags scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
1148 1149 // Check input scripts and signatures.
1150 // This is done last to help prevent CPU exhaustion denial-of-service attacks.
1151 if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false, ws.m_precomputed_txdata, GetValidationCache())) {
1152 // Detect a failure due to a missing witness so that p2p code can handle rejection caching appropriately.
1153 if (!tx.HasWitness() && SpendsNonAnchorWitnessProg(tx, m_view)) {
1154 state.Invalid(TxValidationResult::TX_WITNESS_STRIPPED,
1155 state.GetRejectReason(), state.GetDebugMessage());
1156 }
1157 return false; // state filled in by CheckInputScripts
1158 }
1159 1160 return true;
1161 }
1162 1163 bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws)
1164 {
1165 AssertLockHeld(cs_main);
1166 AssertLockHeld(m_pool.cs);
1167 const CTransaction& tx = *ws.m_ptx;
1168 const Txid& hash = ws.m_hash;
1169 TxValidationState& state = ws.m_state;
1170 1171 // Check again against the current block tip's script verification
1172 // flags to cache our script execution flags. This is, of course,
1173 // useless if the next block has different script flags from the
1174 // previous one, but because the cache tracks script flags for us it
1175 // will auto-invalidate and we'll just have a few blocks of extra
1176 // misses on soft-fork activation.
1177 //
1178 // This is also useful in case of bugs in the standard flags that cause
1179 // transactions to pass as valid when they're actually invalid. For
1180 // instance the STRICTENC flag was incorrectly allowing certain
1181 // CHECKSIG NOT scripts to pass, even though they were invalid.
1182 //
1183 // There is a similar check in CreateNewBlock() to prevent creating
1184 // invalid blocks (using TestBlockValidity), however allowing such
1185 // transactions into the mempool can be exploited as a DoS attack.
1186 script_verify_flags currentBlockScriptVerifyFlags{GetBlockScriptFlags(*m_active_chainstate.m_chain.Tip(), m_active_chainstate.m_chainman)};
1187 if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags,
1188 ws.m_precomputed_txdata, m_active_chainstate.CoinsTip(), GetValidationCache())) {
1189 LogError("BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s", hash.ToString(), state.ToString());
1190 return Assume(false);
1191 }
1192 1193 return true;
1194 }
1195 1196 void MemPoolAccept::FinalizeSubpackage(const ATMPArgs& args)
1197 {
1198 AssertLockHeld(cs_main);
1199 AssertLockHeld(m_pool.cs);
1200 1201 if (!m_subpackage.m_changeset->GetRemovals().empty()) Assume(args.m_allow_replacement);
1202 // Remove conflicting transactions from the mempool
1203 for (CTxMemPool::txiter it : m_subpackage.m_changeset->GetRemovals())
1204 {
1205 std::string log_string = strprintf("replacing mempool tx %s (wtxid=%s, fees=%s, vsize=%s). ",
1206 it->GetTx().GetHash().ToString(),
1207 it->GetTx().GetWitnessHash().ToString(),
1208 it->GetFee(),
1209 it->GetTxSize());
1210 FeeFrac feerate{m_subpackage.m_total_modified_fees, int32_t(m_subpackage.m_total_vsize)};
1211 uint256 tx_or_package_hash{};
1212 const bool replaced_with_tx{m_subpackage.m_changeset->GetTxCount() == 1};
1213 if (replaced_with_tx) {
1214 const CTransaction& tx = m_subpackage.m_changeset->GetAddedTxn(0);
1215 tx_or_package_hash = tx.GetHash().ToUint256();
1216 log_string += strprintf("New tx %s (wtxid=%s, fees=%s, vsize=%s)",
1217 tx.GetHash().ToString(),
1218 tx.GetWitnessHash().ToString(),
1219 feerate.fee,
1220 feerate.size);
1221 } else {
1222 tx_or_package_hash = GetPackageHash(m_subpackage.m_changeset->GetAddedTxns());
1223 log_string += strprintf("New package %s with %lu txs, fees=%s, vsize=%s",
1224 tx_or_package_hash.ToString(),
1225 m_subpackage.m_changeset->GetTxCount(),
1226 feerate.fee,
1227 feerate.size);
1228 1229 }
1230 LogDebug(BCLog::MEMPOOL, "%s\n", log_string);
1231 TRACEPOINT(mempool, replaced,
1232 it->GetTx().GetHash().data(),
1233 it->GetTxSize(),
1234 it->GetFee(),
1235 std::chrono::duration_cast<std::chrono::duration<std::uint64_t>>(it->GetTime()).count(),
1236 tx_or_package_hash.data(),
1237 feerate.size,
1238 feerate.fee,
1239 replaced_with_tx
1240 );
1241 m_subpackage.m_replaced_transactions.push_back(it->GetSharedTx());
1242 }
1243 m_subpackage.m_changeset->Apply();
1244 m_subpackage.m_changeset.reset();
1245 }
1246 1247 bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces,
1248 PackageValidationState& package_state,
1249 std::map<Wtxid, MempoolAcceptResult>& results)
1250 {
1251 AssertLockHeld(cs_main);
1252 AssertLockHeld(m_pool.cs);
1253 // Sanity check: none of the transactions should be in the mempool, and none of the transactions
1254 // should have a same-txid-different-witness equivalent in the mempool.
1255 assert(std::all_of(workspaces.cbegin(), workspaces.cend(), [this](const auto& ws) { return !m_pool.exists(ws.m_ptx->GetHash()); }));
1256 1257 bool all_submitted = true;
1258 FinalizeSubpackage(args);
1259 // ConsensusScriptChecks adds to the script cache and is therefore consensus-critical;
1260 // CheckInputsFromMempoolAndCache asserts that transactions only spend coins available from the
1261 // mempool or UTXO set. Submit each transaction to the mempool immediately after calling
1262 // ConsensusScriptChecks to make the outputs available for subsequent transactions.
1263 for (Workspace& ws : workspaces) {
1264 if (!ConsensusScriptChecks(args, ws)) {
1265 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1266 // Since PolicyScriptChecks() passed, this should never fail.
1267 Assume(false);
1268 all_submitted = false;
1269 package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR,
1270 strprintf("BUG! PolicyScriptChecks succeeded but ConsensusScriptChecks failed: %s",
1271 ws.m_ptx->GetHash().ToString()));
1272 }
1273 // Remove first failing tx and all subsequent in package
1274 if (!all_submitted) {
1275 if (!m_subpackage.m_changeset) m_subpackage.m_changeset = m_pool.GetChangeSet();
1276 m_subpackage.m_changeset->StageRemoval(m_pool.GetIter(ws.m_ptx->GetHash()).value());
1277 }
1278 }
1279 if (!all_submitted) {
1280 Assume(m_subpackage.m_changeset);
1281 // This code should be unreachable; it's here as belt-and-suspenders
1282 // to try to ensure we have no consensus-invalid transactions in the
1283 // mempool.
1284 m_subpackage.m_changeset->Apply();
1285 m_subpackage.m_changeset.reset();
1286 return false;
1287 }
1288 1289 std::vector<Wtxid> all_package_wtxids;
1290 all_package_wtxids.reserve(workspaces.size());
1291 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids),
1292 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); });
1293 1294 if (!m_subpackage.m_replaced_transactions.empty()) {
1295 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with %u new one(s) for %s additional fees, %d delta bytes\n",
1296 m_subpackage.m_replaced_transactions.size(), workspaces.size(),
1297 m_subpackage.m_total_modified_fees - m_subpackage.m_conflicting_fees,
1298 m_subpackage.m_total_vsize - static_cast<int>(m_subpackage.m_conflicting_size));
1299 }
1300 1301 // Add successful results. The returned results may change later if LimitMempoolSize() evicts them.
1302 for (Workspace& ws : workspaces) {
1303 auto iter = m_pool.GetIter(ws.m_ptx->GetHash());
1304 Assume(iter.has_value());
1305 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate :
1306 CFeeRate{ws.m_modified_fees, static_cast<int32_t>(ws.m_vsize)};
1307 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids :
1308 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()};
1309 results.emplace(ws.m_ptx->GetWitnessHash(),
1310 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize,
1311 ws.m_base_fees, effective_feerate, effective_feerate_wtxids));
1312 if (!m_pool.m_opts.signals) continue;
1313 const CTransaction& tx = *ws.m_ptx;
1314 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees,
1315 ws.m_vsize, (*iter)->GetHeight(),
1316 args.m_bypass_limits, args.m_package_submission,
1317 IsCurrentForFeeEstimation(m_active_chainstate),
1318 m_pool.HasNoInputsOf(tx));
1319 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
1320 }
1321 return all_submitted;
1322 }
1323 1324 MempoolAcceptResult MemPoolAccept::AcceptSingleTransactionInternal(const CTransactionRef& ptx, ATMPArgs& args)
1325 {
1326 AssertLockHeld(cs_main);
1327 AssertLockHeld(m_pool.cs);
1328 1329 Workspace ws(ptx);
1330 const std::vector<Wtxid> single_wtxid{ws.m_ptx->GetWitnessHash()};
1331 1332 if (!PreChecks(args, ws)) {
1333 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) {
1334 // Failed for fee reasons. Provide the effective feerate and which tx was included.
1335 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid);
1336 }
1337 return MempoolAcceptResult::Failure(ws.m_state);
1338 }
1339 1340 if (m_subpackage.m_rbf && !ReplacementChecks(ws)) {
1341 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) {
1342 // Failed for incentives-based fee reasons. Provide the effective feerate and which tx was included.
1343 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid);
1344 }
1345 return MempoolAcceptResult::Failure(ws.m_state);
1346 }
1347 1348 // Check if the transaction would exceed the cluster size limit.
1349 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) {
1350 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-large-cluster", "");
1351 return MempoolAcceptResult::Failure(ws.m_state);
1352 }
1353 1354 // Now that we've verified the cluster limit is respected, we can perform
1355 // calculations involving the full ancestors of the tx.
1356 if (ws.m_conflicts.size()) {
1357 auto ancestors = m_subpackage.m_changeset->CalculateMemPoolAncestors(ws.m_tx_handle);
1358 1359 // A transaction that spends outputs that would be replaced by it is invalid. Now
1360 // that we have the set of all ancestors we can detect this
1361 // pathological case by making sure ws.m_conflicts and this tx's ancestors don't
1362 // intersect.
1363 if (const auto err_string{EntriesAndTxidsDisjoint(ancestors, ws.m_conflicts, ptx->GetHash())}) {
1364 // We classify this as a consensus error because a transaction depending on something it
1365 // conflicts with would be inconsistent.
1366 ws.m_state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-spends-conflicting-tx", *err_string);
1367 return MempoolAcceptResult::Failure(ws.m_state);
1368 }
1369 }
1370 1371 m_subpackage.m_total_vsize = ws.m_vsize;
1372 m_subpackage.m_total_modified_fees = ws.m_modified_fees;
1373 1374 // Individual modified feerate exceeded caller-defined max; abort
1375 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) {
1376 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", "");
1377 return MempoolAcceptResult::Failure(ws.m_state);
1378 }
1379 1380 if (!args.m_bypass_limits && m_pool.m_opts.require_standard) {
1381 Wtxid dummy_wtxid;
1382 if (!CheckEphemeralSpends(/*package=*/{ptx}, m_pool.m_opts.dust_relay_feerate, m_pool, ws.m_state, dummy_wtxid)) {
1383 return MempoolAcceptResult::Failure(ws.m_state);
1384 }
1385 }
1386 1387 // Perform the inexpensive checks first and avoid hashing and signature verification unless
1388 // those checks pass, to mitigate CPU exhaustion denial-of-service attacks.
1389 if (!PolicyScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
1390 1391 if (!ConsensusScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
1392 1393 const CFeeRate effective_feerate{ws.m_modified_fees, static_cast<int32_t>(ws.m_vsize)};
1394 // Tx was accepted, but not added
1395 if (args.m_test_accept) {
1396 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize,
1397 ws.m_base_fees, effective_feerate, single_wtxid);
1398 }
1399 1400 FinalizeSubpackage(args);
1401 1402 // Limit the mempool, if appropriate.
1403 if (!args.m_package_submission && !args.m_bypass_limits) {
1404 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip());
1405 // If mempool contents change, then the m_view cache is dirty. Given this isn't a package
1406 // submission, we won't be using the cache anymore, but clear it anyway for clarity.
1407 CleanupTemporaryCoins();
1408 1409 if (!m_pool.exists(ws.m_hash)) {
1410 // The tx no longer meets our (new) mempool minimum feerate but could be reconsidered in a package.
1411 ws.m_state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool full");
1412 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), {ws.m_ptx->GetWitnessHash()});
1413 }
1414 }
1415 1416 if (m_pool.m_opts.signals) {
1417 const CTransaction& tx = *ws.m_ptx;
1418 auto iter = m_pool.GetIter(tx.GetHash());
1419 Assume(iter.has_value());
1420 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees,
1421 ws.m_vsize, (*iter)->GetHeight(),
1422 args.m_bypass_limits, args.m_package_submission,
1423 IsCurrentForFeeEstimation(m_active_chainstate),
1424 m_pool.HasNoInputsOf(tx));
1425 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
1426 }
1427 1428 if (!m_subpackage.m_replaced_transactions.empty()) {
1429 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with 1 new transaction for %s additional fees, %d delta bytes\n",
1430 m_subpackage.m_replaced_transactions.size(),
1431 ws.m_modified_fees - m_subpackage.m_conflicting_fees,
1432 ws.m_vsize - static_cast<int>(m_subpackage.m_conflicting_size));
1433 }
1434 1435 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, ws.m_base_fees,
1436 effective_feerate, single_wtxid);
1437 }
1438 1439 PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactionsInternal(const std::vector<CTransactionRef>& txns, ATMPArgs& args)
1440 {
1441 AssertLockHeld(cs_main);
1442 AssertLockHeld(m_pool.cs);
1443 1444 // These context-free package limits can be done before taking the mempool lock.
1445 PackageValidationState package_state;
1446 if (!IsWellFormedPackage(txns, package_state)) return PackageMempoolAcceptResult(package_state, {});
1447 1448 std::vector<Workspace> workspaces{};
1449 workspaces.reserve(txns.size());
1450 std::transform(txns.cbegin(), txns.cend(), std::back_inserter(workspaces),
1451 [](const auto& tx) { return Workspace(tx); });
1452 std::map<Wtxid, MempoolAcceptResult> results;
1453 1454 // Do all PreChecks first and fail fast to avoid running expensive script checks when unnecessary.
1455 for (Workspace& ws : workspaces) {
1456 if (!PreChecks(args, ws)) {
1457 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1458 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
1459 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1460 return PackageMempoolAcceptResult(package_state, std::move(results));
1461 }
1462 1463 // Individual modified feerate exceeded caller-defined max; abort
1464 // N.B. this doesn't take into account CPFPs. Chunk-aware validation may be more robust.
1465 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) {
1466 // Need to set failure here both individually and at package level
1467 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", "");
1468 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1469 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
1470 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1471 return PackageMempoolAcceptResult(package_state, std::move(results));
1472 }
1473 1474 // Make the coins created by this transaction available for subsequent transactions in the
1475 // package to spend. If there are no conflicts within the package, no transaction can spend a coin
1476 // needed by another transaction in the package. We also need to make sure that no package
1477 // tx replaces (or replaces the ancestor of) the parent of another package tx. As long as we
1478 // check these two things, we don't need to track the coins spent.
1479 // If a package tx conflicts with a mempool tx, PackageRBFChecks() ensures later that any package RBF attempt
1480 // has *no* in-mempool ancestors, so we don't have to worry about subsequent transactions in
1481 // same package spending the same in-mempool outpoints. This needs to be revisited for general
1482 // package RBF.
1483 m_viewmempool.PackageAddTransaction(ws.m_ptx);
1484 }
1485 1486 // At this point we have all in-mempool parents, and we know every transaction's vsize.
1487 // Run the TRUC checks on the package.
1488 for (Workspace& ws : workspaces) {
1489 if (auto err{PackageTRUCChecks(m_pool, ws.m_ptx, ws.m_vsize, txns, ws.m_parents)}) {
1490 package_state.Invalid(PackageValidationResult::PCKG_POLICY, "TRUC-violation", err.value());
1491 return PackageMempoolAcceptResult(package_state, {});
1492 }
1493 }
1494 1495 // Transactions must meet two minimum feerates: the mempool minimum fee and min relay fee.
1496 // For transactions consisting of exactly one child and its parents, it suffices to use the
1497 // package feerate (total modified fees / total virtual size) to check this requirement.
1498 // Note that this is an aggregate feerate; this function has not checked that there are transactions
1499 // too low feerate to pay for themselves, or that the child transactions are higher feerate than
1500 // their parents. Using aggregate feerate may allow "parents pay for child" behavior and permit
1501 // a child that is below mempool minimum feerate. To avoid these behaviors, callers of
1502 // AcceptMultipleTransactions need to restrict txns topology (e.g. to ancestor sets) and check
1503 // the feerates of individuals and subsets.
1504 m_subpackage.m_total_vsize = std::accumulate(workspaces.cbegin(), workspaces.cend(), int64_t{0},
1505 [](int64_t sum, auto& ws) { return sum + ws.m_vsize; });
1506 m_subpackage.m_total_modified_fees = std::accumulate(workspaces.cbegin(), workspaces.cend(), CAmount{0},
1507 [](CAmount sum, auto& ws) { return sum + ws.m_modified_fees; });
1508 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize);
1509 std::vector<Wtxid> all_package_wtxids;
1510 all_package_wtxids.reserve(workspaces.size());
1511 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids),
1512 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); });
1513 TxValidationState placeholder_state;
1514 if (args.m_package_feerates &&
1515 !CheckFeeRate(m_subpackage.m_total_vsize, m_subpackage.m_total_modified_fees, placeholder_state)) {
1516 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1517 return PackageMempoolAcceptResult(package_state, {{workspaces.back().m_ptx->GetWitnessHash(),
1518 MempoolAcceptResult::FeeFailure(placeholder_state, CFeeRate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize), all_package_wtxids)}});
1519 }
1520 1521 // Apply package mempool RBF checks.
1522 if (m_subpackage.m_rbf && !PackageRBFChecks(txns, workspaces, m_subpackage.m_total_vsize, package_state)) {
1523 return PackageMempoolAcceptResult(package_state, std::move(results));
1524 }
1525 1526 // Check if the transactions would exceed the cluster size limit.
1527 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) {
1528 package_state.Invalid(PackageValidationResult::PCKG_POLICY, "too-large-cluster", "");
1529 return PackageMempoolAcceptResult(package_state, std::move(results));
1530 }
1531 1532 // Now that we've bounded the resulting possible ancestry count, check package for dust spends
1533 if (m_pool.m_opts.require_standard) {
1534 TxValidationState child_state;
1535 Wtxid child_wtxid;
1536 if (!CheckEphemeralSpends(txns, m_pool.m_opts.dust_relay_feerate, m_pool, child_state, child_wtxid)) {
1537 package_state.Invalid(PackageValidationResult::PCKG_TX, "unspent-dust");
1538 results.emplace(child_wtxid, MempoolAcceptResult::Failure(child_state));
1539 return PackageMempoolAcceptResult(package_state, std::move(results));
1540 }
1541 }
1542 1543 for (Workspace& ws : workspaces) {
1544 ws.m_package_feerate = package_feerate;
1545 if (!PolicyScriptChecks(args, ws)) {
1546 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
1547 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1548 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
1549 return PackageMempoolAcceptResult(package_state, std::move(results));
1550 }
1551 if (args.m_test_accept) {
1552 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate :
1553 CFeeRate{ws.m_modified_fees, static_cast<int32_t>(ws.m_vsize)};
1554 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids :
1555 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()};
1556 results.emplace(ws.m_ptx->GetWitnessHash(),
1557 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions),
1558 ws.m_vsize, ws.m_base_fees, effective_feerate,
1559 effective_feerate_wtxids));
1560 }
1561 }
1562 1563 if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, std::move(results));
1564 1565 if (!SubmitPackage(args, workspaces, package_state, results)) {
1566 // PackageValidationState filled in by SubmitPackage().
1567 return PackageMempoolAcceptResult(package_state, std::move(results));
1568 }
1569 1570 return PackageMempoolAcceptResult(package_state, std::move(results));
1571 }
1572 1573 void MemPoolAccept::CleanupTemporaryCoins()
1574 {
1575 // There are 3 kinds of coins in m_view:
1576 // (1) Temporary coins from the transactions in subpackage, constructed by m_viewmempool.
1577 // (2) Mempool coins from transactions in the mempool, constructed by m_viewmempool.
1578 // (3) Confirmed coins fetched from our current UTXO set.
1579 //
1580 // (1) Temporary coins need to be removed, regardless of whether the transaction was submitted.
1581 // If the transaction was submitted to the mempool, m_viewmempool will be able to fetch them from
1582 // there. If it wasn't submitted to mempool, it is incorrect to keep them - future calls may try
1583 // to spend those coins that don't actually exist.
1584 // (2) Mempool coins also need to be removed. If the mempool contents have changed as a result
1585 // of submitting or replacing transactions, coins previously fetched from mempool may now be
1586 // spent or nonexistent. Those coins need to be deleted from m_view.
1587 // (3) Confirmed coins don't need to be removed. The chainstate has not changed (we are
1588 // holding cs_main and no blocks have been processed) so the confirmed tx cannot disappear like
1589 // a mempool tx can. The coin may now be spent after we submitted a tx to mempool, but
1590 // we have already checked that the package does not have 2 transactions spending the same coin
1591 // and we check whether a mempool transaction spends conflicting coins (CTxMemPool::GetConflictTx).
1592 // Keeping them in m_view is an optimization to not re-fetch confirmed coins if we later look up
1593 // inputs for this transaction again.
1594 for (const auto& outpoint : m_viewmempool.GetNonBaseCoins()) {
1595 // In addition to resetting m_viewmempool, we also need to manually delete these coins from
1596 // m_view because it caches copies of the coins it fetched from m_viewmempool previously.
1597 m_view.Uncache(outpoint);
1598 }
1599 // This deletes the temporary and mempool coins.
1600 m_viewmempool.Reset();
1601 }
1602 1603 PackageMempoolAcceptResult MemPoolAccept::AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args)
1604 {
1605 AssertLockHeld(::cs_main);
1606 AssertLockHeld(m_pool.cs);
1607 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) {
1608 if (subpackage.size() > 1) {
1609 return AcceptMultipleTransactionsInternal(subpackage, args);
1610 }
1611 const auto& tx = subpackage.front();
1612 ATMPArgs single_args = ATMPArgs::SingleInPackageAccept(args);
1613 const auto single_res = AcceptSingleTransactionInternal(tx, single_args);
1614 PackageValidationState package_state_wrapped;
1615 if (single_res.m_result_type != MempoolAcceptResult::ResultType::VALID) {
1616 package_state_wrapped.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1617 }
1618 return PackageMempoolAcceptResult(package_state_wrapped, {{tx->GetWitnessHash(), single_res}});
1619 }();
1620 1621 // Clean up m_view and m_viewmempool so that other subpackage evaluations don't have access to
1622 // coins they shouldn't. Keep some coins in order to minimize re-fetching coins from the UTXO set.
1623 // Clean up package feerate and rbf calculations
1624 ClearSubPackageState();
1625 1626 return result;
1627 }
1628 1629 PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, ATMPArgs& args)
1630 {
1631 Assert(!package.empty());
1632 AssertLockHeld(cs_main);
1633 // Used if returning a PackageMempoolAcceptResult directly from this function.
1634 PackageValidationState package_state_quit_early;
1635 1636 // There are two topologies we are able to handle through this function:
1637 // (1) A single transaction
1638 // (2) A child-with-parents package.
1639 // Check that the package is well-formed. If it isn't, we won't try to validate any of the
1640 // transactions and thus won't return any MempoolAcceptResults, just a package-wide error.
1641 1642 // Context-free package checks.
1643 if (!IsWellFormedPackage(package, package_state_quit_early)) {
1644 return PackageMempoolAcceptResult(package_state_quit_early, {});
1645 }
1646 1647 if (package.size() > 1 && !IsChildWithParents(package)) {
1648 // All transactions in the package must be a parent of the last transaction. This is just an
1649 // opportunity for us to fail fast on a context-free check without taking the mempool lock.
1650 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents");
1651 return PackageMempoolAcceptResult(package_state_quit_early, {});
1652 }
1653 1654 LOCK(m_pool.cs);
1655 // Stores results from which we will create the returned PackageMempoolAcceptResult.
1656 // A result may be changed if a mempool transaction is evicted later due to LimitMempoolSize().
1657 std::map<Wtxid, MempoolAcceptResult> results_final;
1658 // Results from individual validation which will be returned if no other result is available for
1659 // this transaction. "Nonfinal" because if a transaction fails by itself but succeeds later
1660 // (i.e. when evaluated with a fee-bumping child), the result in this map may be discarded.
1661 std::map<Wtxid, MempoolAcceptResult> individual_results_nonfinal;
1662 // Tracks whether we think package submission could result in successful entry to the mempool
1663 bool quit_early{false};
1664 std::vector<CTransactionRef> txns_package_eval;
1665 for (const auto& tx : package) {
1666 const auto& wtxid = tx->GetWitnessHash();
1667 const auto& txid = tx->GetHash();
1668 // There are 3 possibilities: already in mempool, same-txid-diff-wtxid already in mempool,
1669 // or not in mempool. An already confirmed tx is treated as one not in mempool, because all
1670 // we know is that the inputs aren't available.
1671 if (m_pool.exists(wtxid)) {
1672 // Exact transaction already exists in the mempool.
1673 // Node operators are free to set their mempool policies however they please, nodes may receive
1674 // transactions in different orders, and malicious counterparties may try to take advantage of
1675 // policy differences to pin or delay propagation of transactions. As such, it's possible for
1676 // some package transaction(s) to already be in the mempool, and we don't want to reject the
1677 // entire package in that case (as that could be a censorship vector). De-duplicate the
1678 // transactions that are already in the mempool, and only call AcceptMultipleTransactions() with
1679 // the new transactions. This ensures we don't double-count transaction counts and sizes when
1680 // checking ancestor/descendant limits, or double-count transaction fees for fee-related policy.
1681 const auto& entry{*Assert(m_pool.GetEntry(txid))};
1682 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTx(entry.GetTxSize(), entry.GetFee()));
1683 } else if (m_pool.exists(txid)) {
1684 // Transaction with the same non-witness data but different witness (same txid,
1685 // different wtxid) already exists in the mempool.
1686 //
1687 // We don't allow replacement transactions right now, so just swap the package
1688 // transaction for the mempool one. Note that we are ignoring the validity of the
1689 // package transaction passed in.
1690 // TODO: allow witness replacement in packages.
1691 const auto& entry{*Assert(m_pool.GetEntry(txid))};
1692 // Provide the wtxid of the mempool tx so that the caller can look it up in the mempool.
1693 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTxDifferentWitness(entry.GetTx().GetWitnessHash()));
1694 } else {
1695 // Transaction does not already exist in the mempool.
1696 // Try submitting the transaction on its own.
1697 const auto single_package_res = AcceptSubPackage({tx}, args);
1698 const auto& single_res = single_package_res.m_tx_results.at(wtxid);
1699 if (single_res.m_result_type == MempoolAcceptResult::ResultType::VALID) {
1700 // The transaction succeeded on its own and is now in the mempool. Don't include it
1701 // in package validation, because its fees should only be "used" once.
1702 assert(m_pool.exists(wtxid));
1703 results_final.emplace(wtxid, single_res);
1704 } else if (package.size() == 1 || // If there is only one transaction, no need to retry it "as a package"
1705 (single_res.m_state.GetResult() != TxValidationResult::TX_RECONSIDERABLE &&
1706 single_res.m_state.GetResult() != TxValidationResult::TX_MISSING_INPUTS)) {
1707 // Package validation policy only differs from individual policy in its evaluation
1708 // of feerate. For example, if a transaction fails here due to violation of a
1709 // consensus rule, the result will not change when it is submitted as part of a
1710 // package. To minimize the amount of repeated work, unless the transaction fails
1711 // due to feerate or missing inputs (its parent is a previous transaction in the
1712 // package that failed due to feerate), don't run package validation. Note that this
1713 // decision might not make sense if different types of packages are allowed in the
1714 // future. Continue individually validating the rest of the transactions, because
1715 // some of them may still be valid.
1716 quit_early = true;
1717 package_state_quit_early.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1718 individual_results_nonfinal.emplace(wtxid, single_res);
1719 } else {
1720 individual_results_nonfinal.emplace(wtxid, single_res);
1721 txns_package_eval.push_back(tx);
1722 }
1723 }
1724 }
1725 1726 auto multi_submission_result = quit_early || txns_package_eval.empty() ? PackageMempoolAcceptResult(package_state_quit_early, {}) :
1727 AcceptSubPackage(txns_package_eval, args);
1728 PackageValidationState& package_state_final = multi_submission_result.m_state;
1729 1730 // This is invoked by AcceptSubPackage() already, so this is just here for
1731 // clarity (since it's not permitted to invoke LimitMempoolSize() while a
1732 // changeset is outstanding).
1733 ClearSubPackageState();
1734 1735 // Make sure we haven't exceeded max mempool size.
1736 // Package transactions that were submitted to mempool or already in mempool may be evicted.
1737 // If mempool contents change, then the m_view cache is dirty. It has already been cleared above.
1738 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip());
1739 1740 for (const auto& tx : package) {
1741 const auto& wtxid = tx->GetWitnessHash();
1742 if (multi_submission_result.m_tx_results.contains(wtxid)) {
1743 // We shouldn't have re-submitted if the tx result was already in results_final.
1744 Assume(!results_final.contains(wtxid));
1745 // If it was submitted, check to see if the tx is still in the mempool. It could have
1746 // been evicted due to LimitMempoolSize() above.
1747 const auto& txresult = multi_submission_result.m_tx_results.at(wtxid);
1748 if (txresult.m_result_type == MempoolAcceptResult::ResultType::VALID && !m_pool.exists(wtxid)) {
1749 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1750 TxValidationState mempool_full_state;
1751 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full");
1752 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state));
1753 } else {
1754 results_final.emplace(wtxid, txresult);
1755 }
1756 } else if (const auto it{results_final.find(wtxid)}; it != results_final.end()) {
1757 // Already-in-mempool transaction. Check to see if it's still there, as it could have
1758 // been evicted when LimitMempoolSize() was called.
1759 Assume(it->second.m_result_type != MempoolAcceptResult::ResultType::INVALID);
1760 Assume(!individual_results_nonfinal.contains(wtxid));
1761 // Query by txid to include the same-txid-different-witness ones.
1762 if (!m_pool.exists(tx->GetHash())) {
1763 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
1764 TxValidationState mempool_full_state;
1765 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full");
1766 // Replace the previous result.
1767 results_final.erase(wtxid);
1768 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state));
1769 }
1770 } else if (const auto it{individual_results_nonfinal.find(wtxid)}; it != individual_results_nonfinal.end()) {
1771 Assume(it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID);
1772 // Interesting result from previous processing.
1773 results_final.emplace(wtxid, it->second);
1774 }
1775 }
1776 Assume(results_final.size() == package.size());
1777 return PackageMempoolAcceptResult(package_state_final, std::move(results_final));
1778 }
1779 1780 } // anon namespace
1781 1782 MempoolAcceptResult AcceptToMemoryPool(Chainstate& active_chainstate, const CTransactionRef& tx,
1783 int64_t accept_time, bool bypass_limits, bool test_accept)
1784 {
1785 AssertLockHeld(::cs_main);
1786 const CChainParams& chainparams{active_chainstate.m_chainman.GetParams()};
1787 assert(active_chainstate.GetMempool() != nullptr);
1788 CTxMemPool& pool{*active_chainstate.GetMempool()};
1789 1790 std::vector<COutPoint> coins_to_uncache;
1791 1792 auto args = MemPoolAccept::ATMPArgs::SingleAccept(chainparams, accept_time, bypass_limits, coins_to_uncache, test_accept);
1793 MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate).AcceptSingleTransactionAndCleanup(tx, args);
1794 1795 if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
1796 // Remove coins that were not present in the coins cache before calling
1797 // AcceptSingleTransaction(); this is to prevent memory DoS in case we receive a large
1798 // number of invalid transactions that attempt to overrun the in-memory coins cache
1799 // (`CCoinsViewCache::cacheCoins`).
1800 1801 for (const COutPoint& hashTx : coins_to_uncache)
1802 active_chainstate.CoinsTip().Uncache(hashTx);
1803 TRACEPOINT(mempool, rejected,
1804 tx->GetHash().data(),
1805 result.m_state.GetRejectReason().c_str()
1806 );
1807 }
1808 // After we've (potentially) uncached entries, ensure our coins cache is still within its size limits
1809 BlockValidationState state_dummy;
1810 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
1811 return result;
1812 }
1813 1814 PackageMempoolAcceptResult ProcessNewPackage(Chainstate& active_chainstate, CTxMemPool& pool,
1815 const Package& package, bool test_accept, const std::optional<CFeeRate>& client_maxfeerate)
1816 {
1817 AssertLockHeld(cs_main);
1818 assert(!package.empty());
1819 assert(std::all_of(package.cbegin(), package.cend(), [](const auto& tx){return tx != nullptr;}));
1820 1821 std::vector<COutPoint> coins_to_uncache;
1822 const CChainParams& chainparams = active_chainstate.m_chainman.GetParams();
1823 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
1824 AssertLockHeld(cs_main);
1825 if (test_accept) {
1826 auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(chainparams, GetTime(), coins_to_uncache);
1827 return MemPoolAccept(pool, active_chainstate).AcceptMultipleTransactionsAndCleanup(package, args);
1828 } else {
1829 auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(chainparams, GetTime(), coins_to_uncache, client_maxfeerate);
1830 return MemPoolAccept(pool, active_chainstate).AcceptPackage(package, args);
1831 }
1832 }();
1833 1834 // Uncache coins pertaining to transactions that were not submitted to the mempool.
1835 if (test_accept || result.m_state.IsInvalid()) {
1836 for (const COutPoint& hashTx : coins_to_uncache) {
1837 active_chainstate.CoinsTip().Uncache(hashTx);
1838 }
1839 }
1840 // Ensure the coins cache is still within limits.
1841 BlockValidationState state_dummy;
1842 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
1843 return result;
1844 }
1845 1846 CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)
1847 {
1848 int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
1849 // Force block reward to zero when right shift is undefined.
1850 if (halvings >= 64)
1851 return 0;
1852 1853 CAmount nSubsidy = 50 * COIN;
1854 // Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years.
1855 nSubsidy >>= halvings;
1856 return nSubsidy;
1857 }
1858 1859 CoinsViews::CoinsViews(DBParams db_params, CoinsViewOptions options)
1860 : m_dbview{std::move(db_params), std::move(options)},
1861 m_catcherview(&m_dbview) {}
1862 1863 void CoinsViews::InitCache(int32_t prevoutfetch_threads)
1864 {
1865 AssertLockHeld(::cs_main);
1866 m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview);
1867 auto thread_pool{std::make_shared<ThreadPool>("prevout")};
1868 if (prevoutfetch_threads > 0) {
1869 thread_pool->Start(prevoutfetch_threads);
1870 LogInfo("Block input prevout fetching uses %d additional threads", prevoutfetch_threads);
1871 }
1872 m_connect_block_view = std::make_unique<CoinsViewOverlay>(&*m_cacheview, std::move(thread_pool));
1873 }
1874 1875 Chainstate::Chainstate(
1876 CTxMemPool* mempool,
1877 BlockManager& blockman,
1878 ChainstateManager& chainman,
1879 std::optional<uint256> from_snapshot_blockhash)
1880 : m_mempool(mempool),
1881 m_blockman(blockman),
1882 m_chainman(chainman),
1883 m_assumeutxo(from_snapshot_blockhash ? Assumeutxo::UNVALIDATED : Assumeutxo::VALIDATED),
1884 m_from_snapshot_blockhash(from_snapshot_blockhash) {}
1885 1886 fs::path Chainstate::StoragePath() const
1887 {
1888 fs::path path{m_chainman.m_options.datadir / "chainstate"};
1889 if (m_from_snapshot_blockhash) {
1890 path += node::SNAPSHOT_CHAINSTATE_SUFFIX;
1891 }
1892 return path;
1893 }
1894 1895 const CBlockIndex* Chainstate::SnapshotBase() const
1896 {
1897 if (!m_from_snapshot_blockhash) return nullptr;
1898 if (!m_cached_snapshot_base) m_cached_snapshot_base = Assert(m_chainman.m_blockman.LookupBlockIndex(*m_from_snapshot_blockhash));
1899 return m_cached_snapshot_base;
1900 }
1901 1902 const CBlockIndex* Chainstate::TargetBlock() const
1903 {
1904 if (!m_target_blockhash) return nullptr;
1905 if (!m_cached_target_block) m_cached_target_block = Assert(m_chainman.m_blockman.LookupBlockIndex(*m_target_blockhash));
1906 return m_cached_target_block;
1907 }
1908 1909 void Chainstate::SetTargetBlock(CBlockIndex* block)
1910 {
1911 if (block) {
1912 m_target_blockhash = block->GetBlockHash();
1913 } else {
1914 m_target_blockhash.reset();
1915 }
1916 m_cached_target_block = block;
1917 }
1918 1919 void Chainstate::SetTargetBlockHash(uint256 block_hash)
1920 {
1921 m_target_blockhash = block_hash;
1922 m_cached_target_block = nullptr;
1923 }
1924 1925 void Chainstate::InitCoinsDB(
1926 size_t cache_size_bytes,
1927 bool in_memory,
1928 bool should_wipe)
1929 {
1930 m_coins_views = std::make_unique<CoinsViews>(
1931 DBParams{
1932 .path = StoragePath(),
1933 .cache_bytes = cache_size_bytes,
1934 .memory_only = in_memory,
1935 .wipe_data = should_wipe,
1936 .obfuscate = true,
1937 .options = m_chainman.m_options.coins_db},
1938 m_chainman.m_options.coins_view);
1939 1940 m_coinsdb_cache_size_bytes = cache_size_bytes;
1941 }
1942 1943 void Chainstate::InitCoinsCache(size_t cache_size_bytes)
1944 {
1945 AssertLockHeld(::cs_main);
1946 assert(m_coins_views != nullptr);
1947 m_coinstip_cache_size_bytes = cache_size_bytes;
1948 m_coins_views->InitCache(m_chainman.m_options.prevoutfetch_threads_num);
1949 }
1950 1951 // Lock-free: depends on `m_cached_is_ibd`, which is latched by `UpdateIBDStatus()`.
1952 bool ChainstateManager::IsInitialBlockDownload() const noexcept
1953 {
1954 return m_cached_is_ibd.load(std::memory_order_relaxed);
1955 }
1956 1957 void Chainstate::CheckForkWarningConditions()
1958 {
1959 AssertLockHeld(cs_main);
1960 1961 if (this->GetRole().historical) {
1962 return;
1963 }
1964 1965 if (m_chainman.m_best_invalid && m_chainman.m_best_invalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) {
1966 LogWarning("Found invalid chain more than 6 blocks longer than our best chain. This could be due to database corruption or consensus incompatibility with peers.");
1967 m_chainman.GetNotifications().warningSet(
1968 kernel::Warning::LARGE_WORK_INVALID_CHAIN,
1969 _("Warning: Found invalid chain more than 6 blocks longer than our best chain. This could be due to database corruption or consensus incompatibility with peers."));
1970 } else {
1971 m_chainman.GetNotifications().warningUnset(kernel::Warning::LARGE_WORK_INVALID_CHAIN);
1972 }
1973 }
1974 1975 // Called both upon regular invalid block discovery *and* InvalidateBlock
1976 void Chainstate::InvalidChainFound(CBlockIndex* pindexNew)
1977 {
1978 AssertLockHeld(cs_main);
1979 if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) {
1980 m_chainman.m_best_invalid = pindexNew;
1981 }
1982 SetBlockFailureFlags(pindexNew);
1983 if (m_chainman.m_best_header != nullptr && m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) == pindexNew) {
1984 m_chainman.RecalculateBestHeader();
1985 }
1986 1987 LogInfo("%s: invalid block=%s height=%d log2_work=%f date=%s", __func__,
1988 pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
1989 log(pindexNew->nChainWork.getdouble())/log(2.0), FormatISO8601DateTime(pindexNew->GetBlockTime()));
1990 CBlockIndex *tip = m_chain.Tip();
1991 assert (tip);
1992 LogInfo("%s: current best=%s height=%d log2_work=%f date=%s", __func__,
1993 tip->GetBlockHash().ToString(), m_chain.Height(), log(tip->nChainWork.getdouble())/log(2.0),
1994 FormatISO8601DateTime(tip->GetBlockTime()));
1995 CheckForkWarningConditions();
1996 }
1997 1998 // Same as InvalidChainFound, above, except not called directly from InvalidateBlock,
1999 // which does its own setBlockIndexCandidates management.
2000 void Chainstate::InvalidBlockFound(CBlockIndex* pindex, const BlockValidationState& state)
2001 {
2002 AssertLockHeld(cs_main);
2003 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
2004 pindex->nStatus |= BLOCK_FAILED_VALID;
2005 m_blockman.m_dirty_blockindex.insert(pindex);
2006 setBlockIndexCandidates.erase(pindex);
2007 InvalidChainFound(pindex);
2008 }
2009 }
2010 2011 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, CTxUndo &txundo, int nHeight)
2012 {
2013 // mark inputs spent
2014 if (!tx.IsCoinBase()) {
2015 txundo.vprevout.reserve(tx.vin.size());
2016 for (const CTxIn &txin : tx.vin) {
2017 txundo.vprevout.emplace_back();
2018 bool is_spent = inputs.SpendCoin(txin.prevout, &txundo.vprevout.back());
2019 assert(is_spent);
2020 }
2021 }
2022 // add outputs
2023 AddCoins(inputs, tx, nHeight);
2024 }
2025 2026 std::optional<std::pair<ScriptError, std::string>> CScriptCheck::operator()() {
2027 const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
2028 const CScriptWitness *witness = &ptxTo->vin[nIn].scriptWitness;
2029 ScriptError error{SCRIPT_ERR_UNKNOWN_ERROR};
2030 if (VerifyScript(scriptSig, m_tx_out.scriptPubKey, witness, m_flags, CachingTransactionSignatureChecker(ptxTo, nIn, m_tx_out.nValue, cacheStore, *m_signature_cache, *txdata), &error)) {
2031 return std::nullopt;
2032 } else {
2033 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);
2034 return std::make_pair(error, std::move(debug_str));
2035 }
2036 }
2037 2038 ValidationCache::ValidationCache(const size_t script_execution_cache_bytes, const size_t signature_cache_bytes)
2039 : m_signature_cache{signature_cache_bytes}
2040 {
2041 // Setup the salted hasher
2042 uint256 nonce = GetRandHash();
2043 // We want the nonce to be 64 bytes long to force the hasher to process
2044 // this chunk, which makes later hash computations more efficient. We
2045 // just write our 32-byte entropy twice to fill the 64 bytes.
2046 m_script_execution_cache_hasher.Write(nonce.begin(), 32);
2047 m_script_execution_cache_hasher.Write(nonce.begin(), 32);
2048 2049 const auto [num_elems, approx_size_bytes] = m_script_execution_cache.setup_bytes(script_execution_cache_bytes);
2050 LogInfo("Using %zu MiB out of %zu MiB requested for script execution cache, able to store %zu elements",
2051 approx_size_bytes >> 20, script_execution_cache_bytes >> 20, num_elems);
2052 }
2053 2054 /**
2055 * Check whether all of this transaction's input scripts succeed.
2056 *
2057 * This involves ECDSA signature checks so can be computationally intensive. This function should
2058 * only be called after the cheap sanity checks in CheckTxInputs passed.
2059 *
2060 * If pvChecks is not nullptr, script checks are pushed onto it instead of being performed inline. Any
2061 * script checks which are not necessary (eg due to script execution cache hits) are, obviously,
2062 * not pushed onto pvChecks/run.
2063 *
2064 * Setting cacheSigStore/cacheFullScriptStore to false will remove elements from the corresponding cache
2065 * which are matched. This is useful for checking blocks where we will likely never need the cache
2066 * entry again.
2067 *
2068 * Note that we may set state.reason to NOT_STANDARD for extra soft-fork flags in flags, block-checking
2069 * callers should probably reset it to CONSENSUS in such cases.
2070 *
2071 * Non-static (and redeclared) in src/test/txvalidationcache_tests.cpp
2072 */
2073 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state,
2074 const CCoinsViewCache& inputs, script_verify_flags flags, bool cacheSigStore,
2075 bool cacheFullScriptStore, PrecomputedTransactionData& txdata,
2076 ValidationCache& validation_cache,
2077 std::vector<CScriptCheck>* pvChecks)
2078 {
2079 if (tx.IsCoinBase()) return true;
2080 2081 if (pvChecks) {
2082 pvChecks->reserve(tx.vin.size());
2083 }
2084 2085 // First check if script executions have been cached with the same
2086 // flags. Note that this assumes that the inputs provided are
2087 // correct (ie that the transaction hash which is in tx's prevouts
2088 // properly commits to the scriptPubKey in the inputs view of that
2089 // transaction).
2090 uint256 hashCacheEntry;
2091 CSHA256 hasher = validation_cache.ScriptExecutionCacheHasher();
2092 hasher.Write(UCharCast(tx.GetWitnessHash().begin()), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin());
2093 AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks
2094 if (validation_cache.m_script_execution_cache.contains(hashCacheEntry, !cacheFullScriptStore)) {
2095 return true;
2096 }
2097 2098 if (!txdata.m_spent_outputs_ready) {
2099 std::vector<CTxOut> spent_outputs;
2100 spent_outputs.reserve(tx.vin.size());
2101 2102 for (const auto& txin : tx.vin) {
2103 const COutPoint& prevout = txin.prevout;
2104 const Coin& coin = inputs.AccessCoin(prevout);
2105 assert(!coin.IsSpent());
2106 spent_outputs.emplace_back(coin.out);
2107 }
2108 txdata.Init(tx, std::move(spent_outputs));
2109 }
2110 assert(txdata.m_spent_outputs.size() == tx.vin.size());
2111 2112 for (unsigned int i = 0; i < tx.vin.size(); i++) {
2113 2114 // We very carefully only pass in things to CScriptCheck which
2115 // are clearly committed to by tx' witness hash. This provides
2116 // a sanity check that our caching is not introducing consensus
2117 // failures through additional data in, eg, the coins being
2118 // spent being checked as a part of CScriptCheck.
2119 2120 // Verify signature
2121 CScriptCheck check(txdata.m_spent_outputs[i], tx, validation_cache.m_signature_cache, i, flags, cacheSigStore, &txdata);
2122 if (pvChecks) {
2123 pvChecks->emplace_back(std::move(check));
2124 } else if (auto result = check(); result.has_value()) {
2125 // Tx failures never trigger disconnections/bans.
2126 // This is so that network splits aren't triggered
2127 // either due to non-consensus relay policies (such as
2128 // non-standard DER encodings or non-null dummy
2129 // arguments) or due to new consensus rules introduced in
2130 // soft forks.
2131 if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {
2132 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, strprintf("mempool-script-verify-flag-failed (%s)", ScriptErrorString(result->first)), result->second);
2133 } else {
2134 return state.Invalid(TxValidationResult::TX_CONSENSUS, strprintf("block-script-verify-flag-failed (%s)", ScriptErrorString(result->first)), result->second);
2135 }
2136 }
2137 }
2138 2139 if (cacheFullScriptStore && !pvChecks) {
2140 // We executed all of the provided scripts, and were told to
2141 // cache the result. Do so now.
2142 validation_cache.m_script_execution_cache.insert(hashCacheEntry);
2143 }
2144 2145 return true;
2146 }
2147 2148 bool FatalError(Notifications& notifications, BlockValidationState& state, const bilingual_str& message)
2149 {
2150 notifications.fatalError(message);
2151 return state.Error(message.original);
2152 }
2153 2154 /**
2155 * Restore the UTXO in a Coin at a given COutPoint
2156 * @param undo The Coin to be restored.
2157 * @param view The coins view to which to apply the changes.
2158 * @param out The out point that corresponds to the tx input.
2159 * @return A DisconnectResult as an int
2160 */
2161 int ApplyTxInUndo(Coin&& undo, CCoinsViewCache& view, const COutPoint& out)
2162 {
2163 bool fClean = true;
2164 2165 if (view.HaveCoin(out)) fClean = false; // overwriting transaction output
2166 2167 if (undo.nHeight == 0) {
2168 // Missing undo metadata (height and coinbase). Older versions included this
2169 // information only in undo records for the last spend of a transactions'
2170 // outputs. This implies that it must be present for some other output of the same tx.
2171 const Coin& alternate = AccessByTxid(view, out.hash);
2172 if (!alternate.IsSpent()) {
2173 undo.nHeight = alternate.nHeight;
2174 undo.fCoinBase = alternate.fCoinBase;
2175 } else {
2176 return DISCONNECT_FAILED; // adding output for transaction without known metadata
2177 }
2178 }
2179 // If the coin already exists as an unspent coin in the cache, then the
2180 // possible_overwrite parameter to AddCoin must be set to true. We have
2181 // already checked whether an unspent coin exists above using HaveCoin, so
2182 // we don't need to guess. When fClean is false, an unspent coin already
2183 // existed and it is an overwrite.
2184 view.AddCoin(out, std::move(undo), !fClean);
2185 2186 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
2187 }
2188 2189 /** Undo the effects of this block (with given index) on the UTXO set represented by coins.
2190 * When FAILED is returned, view is left in an indeterminate state. */
2191 DisconnectResult Chainstate::DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view)
2192 {
2193 AssertLockHeld(::cs_main);
2194 bool fClean = true;
2195 2196 CBlockUndo blockUndo;
2197 if (!m_blockman.ReadBlockUndo(blockUndo, *pindex)) {
2198 LogError("DisconnectBlock(): failure reading undo data\n");
2199 return DISCONNECT_FAILED;
2200 }
2201 2202 if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) {
2203 LogError("DisconnectBlock(): block and undo data inconsistent\n");
2204 return DISCONNECT_FAILED;
2205 }
2206 2207 // Ignore blocks that contain transactions which are 'overwritten' by later transactions,
2208 // unless those are already completely spent.
2209 // See https://github.com/bitcoin/bitcoin/issues/22596 for additional information.
2210 // Note: the blocks specified here are different than the ones used in ConnectBlock because DisconnectBlock
2211 // unwinds the blocks in reverse. As a result, the inconsistency is not discovered until the earlier
2212 // blocks with the duplicate coinbase transactions are disconnected.
2213 bool fEnforceBIP30 = !((pindex->nHeight==91722 && pindex->GetBlockHash() == uint256{"00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e"}) ||
2214 (pindex->nHeight==91812 && pindex->GetBlockHash() == uint256{"00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"}));
2215 2216 // undo transactions in reverse order
2217 for (int i = block.vtx.size() - 1; i >= 0; i--) {
2218 const CTransaction &tx = *(block.vtx[i]);
2219 Txid hash = tx.GetHash();
2220 bool is_coinbase = tx.IsCoinBase();
2221 bool is_bip30_exception = (is_coinbase && !fEnforceBIP30);
2222 2223 // Check that all outputs are available and match the outputs in the block itself
2224 // exactly.
2225 for (size_t o = 0; o < tx.vout.size(); o++) {
2226 if (!tx.vout[o].scriptPubKey.IsUnspendable()) {
2227 COutPoint out(hash, o);
2228 Coin coin;
2229 bool is_spent = view.SpendCoin(out, &coin);
2230 if (!is_spent || tx.vout[o] != coin.out || pindex->nHeight != coin.nHeight || is_coinbase != coin.IsCoinBase()) {
2231 if (!is_bip30_exception) {
2232 fClean = false; // transaction output mismatch
2233 }
2234 }
2235 }
2236 }
2237 2238 // restore inputs
2239 if (i > 0) { // not coinbases
2240 CTxUndo &txundo = blockUndo.vtxundo[i-1];
2241 if (txundo.vprevout.size() != tx.vin.size()) {
2242 LogError("DisconnectBlock(): transaction and undo data inconsistent\n");
2243 return DISCONNECT_FAILED;
2244 }
2245 for (unsigned int j = tx.vin.size(); j > 0;) {
2246 --j;
2247 const COutPoint& out = tx.vin[j].prevout;
2248 int res = ApplyTxInUndo(std::move(txundo.vprevout[j]), view, out);
2249 if (res == DISCONNECT_FAILED) return DISCONNECT_FAILED;
2250 fClean = fClean && res != DISCONNECT_UNCLEAN;
2251 }
2252 // At this point, all of txundo.vprevout should have been moved out.
2253 }
2254 }
2255 2256 // move best block pointer to prevout block
2257 view.SetBestBlock(pindex->pprev->GetBlockHash());
2258 2259 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
2260 }
2261 2262 script_verify_flags GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman)
2263 {
2264 const Consensus::Params& consensusparams = chainman.GetConsensus();
2265 2266 // BIP16 didn't become active until Apr 1 2012 (on mainnet, and
2267 // retroactively applied to testnet)
2268 // However, only one historical block violated the P2SH rules (on both
2269 // mainnet and testnet).
2270 // Similarly, only one historical block violated the TAPROOT rules on
2271 // mainnet.
2272 // For simplicity, always leave P2SH+WITNESS+TAPROOT on except for the two
2273 // violating blocks.
2274 script_verify_flags flags{SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_TAPROOT};
2275 const auto it{consensusparams.script_flag_exceptions.find(*Assert(block_index.phashBlock))};
2276 if (it != consensusparams.script_flag_exceptions.end()) {
2277 flags = it->second;
2278 }
2279 2280 // Enforce the DERSIG (BIP66) rule
2281 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_DERSIG)) {
2282 flags |= SCRIPT_VERIFY_DERSIG;
2283 }
2284 2285 // Enforce CHECKLOCKTIMEVERIFY (BIP65)
2286 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CLTV)) {
2287 flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
2288 }
2289 2290 // Enforce CHECKSEQUENCEVERIFY (BIP112)
2291 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CSV)) {
2292 flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
2293 }
2294 2295 // Enforce BIP147 NULLDUMMY (activated simultaneously with segwit)
2296 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_SEGWIT)) {
2297 flags |= SCRIPT_VERIFY_NULLDUMMY;
2298 }
2299 2300 return flags;
2301 }
2302 2303 2304 /** Apply the effects of this block (with given index) on the UTXO set represented by coins.
2305 * Validity checks that depend on the UTXO set are also done; ConnectBlock()
2306 * can fail if those validity checks fail (among other reasons). */
2307 bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex,
2308 CCoinsViewCache& view, bool fJustCheck)
2309 {
2310 AssertLockHeld(cs_main);
2311 assert(pindex);
2312 2313 uint256 block_hash{block.GetHash()};
2314 assert(*pindex->phashBlock == block_hash);
2315 2316 const auto time_start{SteadyClock::now()};
2317 const CChainParams& params{m_chainman.GetParams()};
2318 2319 // Check it again in case a previous version let a bad block in
2320 // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
2321 // ContextualCheckBlockHeader() here. This means that if we add a new
2322 // consensus rule that is enforced in one of those two functions, then we
2323 // may have let in a block that violates the rule prior to updating the
2324 // software, and we would NOT be enforcing the rule here. Fully solving
2325 // upgrade from one software version to the next after a consensus rule
2326 // change is potentially tricky and issue-specific (see NeedsRedownload()
2327 // for one approach that was used for BIP 141 deployment).
2328 // Also, currently the rule against blocks more than 2 hours in the future
2329 // is enforced in ContextualCheckBlockHeader(); we wouldn't want to
2330 // re-enforce that rule here (at least until we make it impossible for
2331 // the clock to go backward).
2332 if (!CheckBlock(block, state, params.GetConsensus(), !fJustCheck, !fJustCheck)) {
2333 if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) {
2334 // We don't write down blocks to disk if they may have been
2335 // corrupted, so this should be impossible unless we're having hardware
2336 // problems.
2337 return FatalError(m_chainman.GetNotifications(), state, _("Corrupt block found indicating potential hardware failure."));
2338 }
2339 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString());
2340 return false;
2341 }
2342 2343 // verify that the view's current state corresponds to the previous block
2344 uint256 hashPrevBlock = pindex->pprev == nullptr ? uint256() : pindex->pprev->GetBlockHash();
2345 assert(hashPrevBlock == view.GetBestBlock());
2346 2347 m_chainman.num_blocks_total++;
2348 2349 // Special case for the genesis block, skipping connection of its transactions
2350 // (its coinbase is unspendable)
2351 if (block_hash == params.GetConsensus().hashGenesisBlock) {
2352 if (!fJustCheck)
2353 view.SetBestBlock(pindex->GetBlockHash());
2354 return true;
2355 }
2356 2357 const char* script_check_reason;
2358 if (m_chainman.AssumedValidBlock().IsNull()) {
2359 script_check_reason = "assumevalid=0 (always verify)";
2360 } else {
2361 constexpr int64_t TWO_WEEKS_IN_SECONDS{60 * 60 * 24 * 7 * 2};
2362 // We've been configured with the hash of a block which has been externally verified to have a valid history.
2363 // A suitable default value is included with the software and updated from time to time. Because validity
2364 // relative to a piece of software is an objective fact these defaults can be easily reviewed.
2365 // This setting doesn't force the selection of any particular chain but makes validating some faster by
2366 // effectively caching the result of part of the verification.
2367 BlockMap::const_iterator it{m_blockman.m_block_index.find(m_chainman.AssumedValidBlock())};
2368 if (it == m_blockman.m_block_index.end()) {
2369 script_check_reason = "assumevalid hash not in headers";
2370 } else if (it->second.GetAncestor(pindex->nHeight) != pindex) {
2371 script_check_reason = (pindex->nHeight > it->second.nHeight) ? "block height above assumevalid height" : "block not in assumevalid chain";
2372 } else if (m_chainman.m_best_header->GetAncestor(pindex->nHeight) != pindex) {
2373 script_check_reason = "block not in best header chain";
2374 } else if (m_chainman.m_best_header->nChainWork < m_chainman.MinimumChainWork()) {
2375 script_check_reason = "best header chainwork below minimumchainwork";
2376 } else if (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, params.GetConsensus()) <= TWO_WEEKS_IN_SECONDS) {
2377 script_check_reason = "block too recent relative to best header";
2378 } else {
2379 // This block is a member of the assumed verified chain and an ancestor of the best header.
2380 // Script verification is skipped when connecting blocks under the
2381 // assumevalid block. Assuming the assumevalid block is valid this
2382 // is safe because block merkle hashes are still computed and checked,
2383 // Of course, if an assumed valid block is invalid due to false scriptSigs
2384 // this optimization would allow an invalid chain to be accepted.
2385 // The equivalent time check discourages hash power from extorting the network via DOS attack
2386 // into accepting an invalid block through telling users they must manually set assumevalid.
2387 // Requiring a software change or burying the invalid block, regardless of the setting, makes
2388 // it hard to hide the implication of the demand. This also avoids having release candidates
2389 // that are hardly doing any signature verification at all in testing without having to
2390 // artificially set the default assumed verified block further back.
2391 // The test against the minimum chain work prevents the skipping when denied access to any chain at
2392 // least as good as the expected chain.
2393 script_check_reason = nullptr;
2394 }
2395 }
2396 2397 const auto time_1{SteadyClock::now()};
2398 m_chainman.time_check += time_1 - time_start;
2399 LogDebug(BCLog::BENCH, " - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
2400 Ticks<MillisecondsDouble>(time_1 - time_start),
2401 Ticks<SecondsDouble>(m_chainman.time_check),
2402 Ticks<MillisecondsDouble>(m_chainman.time_check) / m_chainman.num_blocks_total);
2403 2404 // Do not allow blocks that contain transactions which 'overwrite' older transactions,
2405 // unless those are already completely spent.
2406 // If such overwrites are allowed, coinbases and transactions depending upon those
2407 // can be duplicated to remove the ability to spend the first instance -- even after
2408 // being sent to another address.
2409 // See BIP30, CVE-2012-1909, and https://r6.ca/blog/20120206T005236Z.html for more information.
2410 // This rule was originally applied to all blocks with a timestamp after March 15, 2012, 0:00 UTC.
2411 // Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the
2412 // two in the chain that violate it. This prevents exploiting the issue against nodes during their
2413 // initial block download.
2414 bool fEnforceBIP30 = !IsBIP30Repeat(*pindex);
2415 2416 // Once BIP34 activated it was not possible to create new duplicate coinbases and thus other than starting
2417 // with the 2 existing duplicate coinbase pairs, not possible to create overwriting txs. But by the
2418 // time BIP34 activated, in each of the existing pairs the duplicate coinbase had overwritten the first
2419 // before the first had been spent. Since those coinbases are sufficiently buried it's no longer possible to create further
2420 // duplicate transactions descending from the known pairs either.
2421 // 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.
2422 2423 // BIP34 requires that a block at height X (block X) has its coinbase
2424 // scriptSig start with a CScriptNum of X (indicated height X). The above
2425 // logic of no longer requiring BIP30 once BIP34 activates is flawed in the
2426 // case that there is a block X before the BIP34 height of 227,931 which has
2427 // an indicated height Y where Y is greater than X. The coinbase for block
2428 // X would also be a valid coinbase for block Y, which could be a BIP30
2429 // violation. An exhaustive search of all mainnet coinbases before the
2430 // BIP34 height which have an indicated height greater than the block height
2431 // reveals many occurrences. The 3 lowest indicated heights found are
2432 // 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3
2433 // heights would be the first opportunity for BIP30 to be violated.
2434 2435 // The search reveals a great many blocks which have an indicated height
2436 // greater than 1,983,702, so we simply remove the optimization to skip
2437 // BIP30 checking for blocks at height 1,983,702 or higher. Before we reach
2438 // that block in another 25 years or so, we should take advantage of a
2439 // future consensus change to do a new and improved version of BIP34 that
2440 // will actually prevent ever creating any duplicate coinbases in the
2441 // future.
2442 static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702;
2443 2444 // There is no potential to create a duplicate coinbase at block 209,921
2445 // because this is still before the BIP34 height and so explicit BIP30
2446 // checking is still active.
2447 2448 // The final case is block 176,684 which has an indicated height of
2449 // 490,897. Unfortunately, this issue was not discovered until about 2 weeks
2450 // before block 490,897 so there was not much opportunity to address this
2451 // case other than to carefully analyze it and determine it would not be a
2452 // problem. Block 490,897 was, in fact, mined with a different coinbase than
2453 // block 176,684, but it is important to note that even if it hadn't been or
2454 // is remined on an alternate fork with a duplicate coinbase, we would still
2455 // not run into a BIP30 violation. This is because the coinbase for 176,684
2456 // is spent in block 185,956 in transaction
2457 // d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781. This
2458 // spending transaction can't be duplicated because it also spends coinbase
2459 // 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29. This
2460 // coinbase has an indicated height of over 4.2 billion, and wouldn't be
2461 // duplicatable until that height, and it's currently impossible to create a
2462 // chain that long. Nevertheless we may wish to consider a future soft fork
2463 // which retroactively prevents block 490,897 from creating a duplicate
2464 // coinbase. The two historical BIP30 violations often provide a confusing
2465 // edge case when manipulating the UTXO and it would be simpler not to have
2466 // another edge case to deal with.
2467 2468 // testnet3 has no blocks before the BIP34 height with indicated heights
2469 // post BIP34 before approximately height 486,000,000. After block
2470 // 1,983,702 testnet3 starts doing unnecessary BIP30 checking again.
2471 assert(pindex->pprev);
2472 CBlockIndex* pindexBIP34height = pindex->pprev->GetAncestor(params.GetConsensus().BIP34Height);
2473 //Only continue to enforce if we're below BIP34 activation height or the block hash at that height doesn't correspond.
2474 fEnforceBIP30 = fEnforceBIP30 && (!pindexBIP34height || !(pindexBIP34height->GetBlockHash() == params.GetConsensus().BIP34Hash));
2475 2476 // TODO: Remove BIP30 checking from block height 1,983,702 on, once we have a
2477 // consensus change that ensures coinbases at those heights cannot
2478 // duplicate earlier coinbases.
2479 if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) {
2480 for (const auto& tx : block.vtx) {
2481 for (size_t o = 0; o < tx->vout.size(); o++) {
2482 if (view.HaveCoin(COutPoint(tx->GetHash(), o))) {
2483 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-BIP30",
2484 "tried to overwrite transaction");
2485 }
2486 }
2487 }
2488 }
2489 2490 // Enforce BIP68 (sequence locks)
2491 int nLockTimeFlags = 0;
2492 if (DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_CSV)) {
2493 nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
2494 }
2495 2496 // Get the script flags for this block
2497 script_verify_flags flags{GetBlockScriptFlags(*pindex, m_chainman)};
2498 2499 const auto time_2{SteadyClock::now()};
2500 m_chainman.time_forks += time_2 - time_1;
2501 LogDebug(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
2502 Ticks<MillisecondsDouble>(time_2 - time_1),
2503 Ticks<SecondsDouble>(m_chainman.time_forks),
2504 Ticks<MillisecondsDouble>(m_chainman.time_forks) / m_chainman.num_blocks_total);
2505 2506 const bool fScriptChecks{!!script_check_reason};
2507 const kernel::ChainstateRole role{GetRole()};
2508 if (script_check_reason != m_last_script_check_reason_logged && role.validated && !role.historical) {
2509 if (fScriptChecks) {
2510 LogInfo("Enabling script verification at block #%d (%s): %s.",
2511 pindex->nHeight, block_hash.ToString(), script_check_reason);
2512 } else {
2513 LogInfo("Disabling script verification at block #%d (%s).",
2514 pindex->nHeight, block_hash.ToString());
2515 }
2516 m_last_script_check_reason_logged = script_check_reason;
2517 }
2518 2519 CBlockUndo blockundo;
2520 2521 // Precomputed transaction data pointers must not be invalidated
2522 // until after `control` has run the script checks (potentially
2523 // in multiple threads). Preallocate the vector size so a new allocation
2524 // doesn't invalidate pointers into the vector, and keep txsdata in scope
2525 // for as long as `control`.
2526 std::vector<PrecomputedTransactionData> txsdata(block.vtx.size());
2527 std::optional<CCheckQueueControl<CScriptCheck>> control;
2528 if (auto& queue = m_chainman.GetCheckQueue(); queue.HasThreads() && fScriptChecks) control.emplace(queue);
2529 2530 std::vector<int> prevheights;
2531 CAmount nFees = 0;
2532 int nInputs = 0;
2533 int64_t nSigOpsCost = 0;
2534 blockundo.vtxundo.reserve(block.vtx.size() - 1);
2535 for (unsigned int i = 0; i < block.vtx.size(); i++)
2536 {
2537 if (!state.IsValid()) break;
2538 const CTransaction &tx = *(block.vtx[i]);
2539 2540 nInputs += tx.vin.size();
2541 2542 if (!tx.IsCoinBase())
2543 {
2544 CAmount txfee = 0;
2545 TxValidationState tx_state;
2546 if (!Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight, txfee)) {
2547 // Any transaction validation failure in ConnectBlock is a block consensus failure
2548 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
2549 tx_state.GetRejectReason(),
2550 tx_state.GetDebugMessage() + " in transaction " + tx.GetHash().ToString());
2551 break;
2552 }
2553 nFees += txfee;
2554 if (!MoneyRange(nFees)) {
2555 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-accumulated-fee-outofrange",
2556 "accumulated fee in the block out of range");
2557 break;
2558 }
2559 2560 // Check that transaction is BIP68 final
2561 // BIP68 lock checks (as opposed to nLockTime checks) must
2562 // be in ConnectBlock because they require the UTXO set
2563 prevheights.resize(tx.vin.size());
2564 for (size_t j = 0; j < tx.vin.size(); j++) {
2565 prevheights[j] = view.AccessCoin(tx.vin[j].prevout).nHeight;
2566 }
2567 2568 if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) {
2569 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal",
2570 "contains a non-BIP68-final transaction " + tx.GetHash().ToString());
2571 break;
2572 }
2573 }
2574 2575 // GetTransactionSigOpCost counts 3 types of sigops:
2576 // * legacy (always)
2577 // * p2sh (when P2SH enabled in flags and excludes coinbase)
2578 // * witness (when witness enabled in flags and excludes coinbase)
2579 nSigOpsCost += GetTransactionSigOpCost(tx, view, flags);
2580 if (nSigOpsCost > MAX_BLOCK_SIGOPS_COST) {
2581 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "too many sigops");
2582 break;
2583 }
2584 2585 if (!tx.IsCoinBase() && fScriptChecks)
2586 {
2587 bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */
2588 bool tx_ok;
2589 TxValidationState tx_state;
2590 // If CheckInputScripts is called with a pointer to a checks vector, the resulting checks are appended to it. In that case
2591 // they need to be added to control which runs them asynchronously. Otherwise, CheckInputScripts runs the checks before returning.
2592 if (control) {
2593 std::vector<CScriptCheck> vChecks;
2594 tx_ok = CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], m_chainman.m_validation_cache, &vChecks);
2595 if (tx_ok) control->Add(std::move(vChecks));
2596 } else {
2597 tx_ok = CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], m_chainman.m_validation_cache);
2598 }
2599 if (!tx_ok) {
2600 // Any transaction validation failure in ConnectBlock is a block consensus failure
2601 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
2602 tx_state.GetRejectReason(), tx_state.GetDebugMessage());
2603 break;
2604 }
2605 }
2606 2607 CTxUndo undoDummy;
2608 if (i > 0) {
2609 blockundo.vtxundo.emplace_back();
2610 }
2611 UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight);
2612 }
2613 const auto time_3{SteadyClock::now()};
2614 m_chainman.time_connect += time_3 - time_2;
2615 LogDebug(BCLog::BENCH, " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(),
2616 Ticks<MillisecondsDouble>(time_3 - time_2), Ticks<MillisecondsDouble>(time_3 - time_2) / block.vtx.size(),
2617 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_3 - time_2) / (nInputs - 1),
2618 Ticks<SecondsDouble>(m_chainman.time_connect),
2619 Ticks<MillisecondsDouble>(m_chainman.time_connect) / m_chainman.num_blocks_total);
2620 2621 CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, params.GetConsensus());
2622 if (block.vtx[0]->GetValueOut() > blockReward && state.IsValid()) {
2623 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-amount",
2624 strprintf("coinbase pays too much (actual=%d vs limit=%d)", block.vtx[0]->GetValueOut(), blockReward));
2625 }
2626 if (control) {
2627 auto parallel_result = control->Complete();
2628 if (parallel_result.has_value() && state.IsValid()) {
2629 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, strprintf("block-script-verify-flag-failed (%s)", ScriptErrorString(parallel_result->first)), parallel_result->second);
2630 }
2631 }
2632 if (!state.IsValid()) {
2633 LogInfo("Block validation error: %s", state.ToString());
2634 return false;
2635 }
2636 const auto time_4{SteadyClock::now()};
2637 m_chainman.time_verify += time_4 - time_2;
2638 LogDebug(BCLog::BENCH, " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n", nInputs - 1,
2639 Ticks<MillisecondsDouble>(time_4 - time_2),
2640 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_4 - time_2) / (nInputs - 1),
2641 Ticks<SecondsDouble>(m_chainman.time_verify),
2642 Ticks<MillisecondsDouble>(m_chainman.time_verify) / m_chainman.num_blocks_total);
2643 2644 if (fJustCheck) {
2645 return true;
2646 }
2647 2648 if (!m_blockman.WriteBlockUndo(blockundo, state, *pindex)) {
2649 return false;
2650 }
2651 2652 const auto time_5{SteadyClock::now()};
2653 m_chainman.time_undo += time_5 - time_4;
2654 LogDebug(BCLog::BENCH, " - Write undo data: %.2fms [%.2fs (%.2fms/blk)]\n",
2655 Ticks<MillisecondsDouble>(time_5 - time_4),
2656 Ticks<SecondsDouble>(m_chainman.time_undo),
2657 Ticks<MillisecondsDouble>(m_chainman.time_undo) / m_chainman.num_blocks_total);
2658 2659 if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) {
2660 pindex->RaiseValidity(BLOCK_VALID_SCRIPTS);
2661 m_blockman.m_dirty_blockindex.insert(pindex);
2662 }
2663 2664 // add this block to the view's block chain
2665 view.SetBestBlock(pindex->GetBlockHash());
2666 2667 const auto time_6{SteadyClock::now()};
2668 m_chainman.time_index += time_6 - time_5;
2669 LogDebug(BCLog::BENCH, " - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
2670 Ticks<MillisecondsDouble>(time_6 - time_5),
2671 Ticks<SecondsDouble>(m_chainman.time_index),
2672 Ticks<MillisecondsDouble>(m_chainman.time_index) / m_chainman.num_blocks_total);
2673 2674 TRACEPOINT(validation, block_connected,
2675 block_hash.data(),
2676 pindex->nHeight,
2677 block.vtx.size(),
2678 nInputs,
2679 nSigOpsCost,
2680 Ticks<std::chrono::nanoseconds>(time_5 - time_start)
2681 );
2682 2683 return true;
2684 }
2685 2686 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState()
2687 {
2688 AssertLockHeld(::cs_main);
2689 return this->GetCoinsCacheSizeState(
2690 m_coinstip_cache_size_bytes,
2691 m_mempool ? m_mempool->m_opts.max_size_bytes : 0);
2692 }
2693 2694 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState(
2695 size_t max_coins_cache_size_bytes,
2696 size_t max_mempool_size_bytes)
2697 {
2698 AssertLockHeld(::cs_main);
2699 const int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0;
2700 int64_t cacheSize = CoinsTip().DynamicMemoryUsage();
2701 int64_t nTotalSpace =
2702 max_coins_cache_size_bytes + std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0);
2703 2704 if (cacheSize > nTotalSpace) {
2705 LogInfo("Cache size (%s) exceeds total space (%s)\n", cacheSize, nTotalSpace);
2706 return CoinsCacheSizeState::CRITICAL;
2707 } else if (cacheSize > LargeCoinsCacheThreshold(nTotalSpace)) {
2708 return CoinsCacheSizeState::LARGE;
2709 }
2710 return CoinsCacheSizeState::OK;
2711 }
2712 2713 bool Chainstate::FlushStateToDisk(
2714 BlockValidationState &state,
2715 FlushStateMode mode,
2716 int nManualPruneHeight)
2717 {
2718 LOCK(cs_main);
2719 assert(this->CanFlushToDisk());
2720 std::set<int> setFilesToPrune;
2721 bool full_flush_completed = false;
2722 2723 [[maybe_unused]] const size_t coins_count{CoinsTip().GetCacheSize()};
2724 [[maybe_unused]] const size_t coins_mem_usage{CoinsTip().DynamicMemoryUsage()};
2725 2726 try {
2727 {
2728 bool fFlushForPrune = false;
2729 2730 CoinsCacheSizeState cache_state = GetCoinsCacheSizeState();
2731 if (m_blockman.IsPruneMode() && (m_blockman.m_check_for_pruning || nManualPruneHeight > 0) && m_chainman.m_blockman.m_blockfiles_indexed) {
2732 // make sure we don't prune above any of the prune locks bestblocks
2733 // pruning is height-based
2734 int last_prune{m_chain.Height()}; // last height we can prune
2735 std::optional<std::string> limiting_lock; // prune lock that actually was the limiting factor, only used for logging
2736 2737 for (const auto& prune_lock : m_blockman.m_prune_locks) {
2738 if (prune_lock.second.height_first == std::numeric_limits<int>::max()) continue;
2739 // Remove the buffer and one additional block here to get actual height that is outside of the buffer
2740 const int lock_height{prune_lock.second.height_first - PRUNE_LOCK_BUFFER - 1};
2741 last_prune = std::max(1, std::min(last_prune, lock_height));
2742 if (last_prune == lock_height) {
2743 limiting_lock = prune_lock.first;
2744 }
2745 }
2746 2747 if (limiting_lock) {
2748 LogDebug(BCLog::PRUNE, "%s limited pruning to height %d\n", limiting_lock.value(), last_prune);
2749 }
2750 2751 if (nManualPruneHeight > 0) {
2752 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune (manual)", BCLog::BENCH);
2753 2754 m_blockman.FindFilesToPruneManual(
2755 setFilesToPrune,
2756 std::min(last_prune, nManualPruneHeight),
2757 *this);
2758 } else {
2759 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune", BCLog::BENCH);
2760 2761 m_blockman.FindFilesToPrune(setFilesToPrune, last_prune, *this, m_chainman);
2762 m_blockman.m_check_for_pruning = false;
2763 }
2764 if (!setFilesToPrune.empty()) {
2765 fFlushForPrune = true;
2766 if (!m_blockman.m_have_pruned) {
2767 m_blockman.m_block_tree_db->WriteFlag("prunedblockfiles", true);
2768 m_blockman.m_have_pruned = true;
2769 }
2770 }
2771 }
2772 const auto nNow{NodeClock::now()};
2773 // 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).
2774 bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE;
2775 // The cache is over the limit, we have to write now.
2776 bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL;
2777 // It's been a while since we wrote the block index and chain state to disk. Do this frequently, so we don't need to redownload or reindex after a crash.
2778 bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow >= m_next_write;
2779 const auto empty_cache{(mode == FlushStateMode::FORCE_FLUSH) || fCacheLarge || fCacheCritical};
2780 // Combine all conditions that result in a write to disk.
2781 bool should_write = (mode == FlushStateMode::FORCE_SYNC) || empty_cache || fPeriodicWrite || fFlushForPrune;
2782 // Write blocks, block index and best chain related state to disk.
2783 if (should_write) {
2784 LogDebug(BCLog::COINDB, "Writing chainstate to disk: flush mode=%s, prune=%d, large=%d, critical=%d, periodic=%d",
2785 FlushStateModeNames[size_t(mode)], fFlushForPrune, fCacheLarge, fCacheCritical, fPeriodicWrite);
2786 2787 // Ensure we can write block index
2788 if (!CheckDiskSpace(m_blockman.m_opts.blocks_dir)) {
2789 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!"));
2790 }
2791 {
2792 LOG_TIME_MILLIS_WITH_CATEGORY("write block and undo data to disk", BCLog::BENCH);
2793 2794 // First make sure all block and undo data is flushed to disk.
2795 // TODO: Handle return error, or add detailed comment why it is
2796 // safe to not return an error upon failure.
2797 if (!m_blockman.FlushChainstateBlockFile(m_chain.Height())) {
2798 LogWarning("%s: Failed to flush block file.\n", __func__);
2799 }
2800 }
2801 2802 // Then update all block file information (which may refer to block and undo files).
2803 {
2804 LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk", BCLog::BENCH);
2805 2806 m_blockman.WriteBlockIndexDB();
2807 }
2808 // Finally remove any pruned files
2809 if (fFlushForPrune) {
2810 LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files", BCLog::BENCH);
2811 2812 m_blockman.UnlinkPrunedFiles(setFilesToPrune);
2813 }
2814 2815 if (!CoinsTip().GetBestBlock().IsNull()) {
2816 // Typical Coin structures on disk are around 48 bytes in size.
2817 // Pushing a new one to the database can cause it to be written
2818 // twice (once in the log, and once in the tables). This is already
2819 // an overestimation, as most will delete an existing entry or
2820 // overwrite one. Still, use a conservative safety factor of 2.
2821 if (!CheckDiskSpace(m_chainman.m_options.datadir, 48 * 2 * 2 * CoinsTip().GetDirtyCount())) {
2822 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!"));
2823 }
2824 // Flush the chainstate (which may refer to block index entries).
2825 empty_cache ? CoinsTip().Flush() : CoinsTip().Sync();
2826 m_last_flushed_block = m_blockman.LookupBlockIndex(CoinsTip().GetBestBlock());
2827 full_flush_completed = true;
2828 TRACEPOINT(utxocache, flush,
2829 int64_t{Ticks<std::chrono::microseconds>(NodeClock::now() - nNow)},
2830 (uint32_t)mode,
2831 (uint64_t)coins_count,
2832 (uint64_t)coins_mem_usage,
2833 (bool)fFlushForPrune);
2834 }
2835 }
2836 2837 if (should_write || m_next_write == NodeClock::time_point::max()) {
2838 constexpr auto range{DATABASE_WRITE_INTERVAL_MAX - DATABASE_WRITE_INTERVAL_MIN};
2839 m_next_write = FastRandomContext().rand_uniform_delay(NodeClock::now() + DATABASE_WRITE_INTERVAL_MIN, range);
2840 }
2841 }
2842 if (full_flush_completed) {
2843 if (m_chainman.m_options.signals) {
2844 m_chainman.m_options.signals->ChainStateFlushed(this->GetRole(), GetLocator(m_last_flushed_block));
2845 }
2846 2847 if (!m_chainman.m_interrupt && ShouldCompactChainstate(m_chainman.IsInitialBlockDownload())) {
2848 try {
2849 CoinsDB().CompactFullAsync();
2850 } catch (const std::exception& e) {
2851 LogWarning("Failed to start chainstate compaction (%s)", e.what());
2852 }
2853 }
2854 }
2855 } catch (const std::runtime_error& e) {
2856 return FatalError(m_chainman.GetNotifications(), state, strprintf(_("System error while flushing: %s"), e.what()));
2857 }
2858 return true;
2859 }
2860 2861 void Chainstate::ForceFlushStateToDisk(bool wipe_cache)
2862 {
2863 BlockValidationState state;
2864 if (!this->FlushStateToDisk(state, wipe_cache ? FlushStateMode::FORCE_FLUSH : FlushStateMode::FORCE_SYNC)) {
2865 LogWarning("Failed to force flush state (%s)", state.ToString());
2866 }
2867 }
2868 2869 void Chainstate::PruneAndFlush()
2870 {
2871 BlockValidationState state;
2872 m_blockman.m_check_for_pruning = true;
2873 if (!this->FlushStateToDisk(state, FlushStateMode::NONE)) {
2874 LogWarning("Failed to flush state (%s)", state.ToString());
2875 }
2876 }
2877 2878 static void UpdateTipLog(
2879 const ChainstateManager& chainman,
2880 const CCoinsViewCache& coins_tip,
2881 const CBlockIndex* tip,
2882 const std::string& func_name,
2883 const std::string& prefix,
2884 const std::string& warning_messages,
2885 const bool background_validation) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
2886 {
2887 2888 AssertLockHeld(::cs_main);
2889 2890 // Disable rate limiting as this may log frequently during IBD.
2891 LogInfo(util::log::NO_RATE_LIMIT, "%s%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%lu date='%s' progress=%f cache=%.1fMiB(%utxo)%s\n",
2892 prefix, func_name,
2893 tip->GetBlockHash().ToString(), tip->nHeight, tip->nVersion,
2894 log(tip->nChainWork.getdouble()) / log(2.0), tip->m_chain_tx_count,
2895 FormatISO8601DateTime(tip->GetBlockTime()),
2896 background_validation ? chainman.GetBackgroundVerificationProgress(*tip) : chainman.GuessVerificationProgress(tip),
2897 coins_tip.DynamicMemoryUsage() / double(1_MiB),
2898 coins_tip.GetCacheSize(),
2899 !warning_messages.empty() ? strprintf(" warning='%s'", warning_messages) : "");
2900 }
2901 2902 void Chainstate::UpdateTip(const CBlockIndex* pindexNew)
2903 {
2904 AssertLockHeld(::cs_main);
2905 const auto& coins_tip = this->CoinsTip();
2906 2907 // The remainder of the function isn't relevant if we are not acting on
2908 // the active chainstate, so return if need be.
2909 if (this != &m_chainman.ActiveChainstate()) {
2910 // Only log every so often so that we don't bury log messages at the tip.
2911 constexpr int BACKGROUND_LOG_INTERVAL = 2000;
2912 if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) {
2913 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "[background validation] ", "", /*background_validation=*/true);
2914 }
2915 return;
2916 }
2917 2918 // New best block
2919 if (m_mempool) {
2920 m_mempool->AddTransactionsUpdated(1);
2921 }
2922 2923 std::vector<bilingual_str> warning_messages;
2924 if (!m_chainman.IsInitialBlockDownload()) {
2925 auto bits = m_chainman.m_versionbitscache.CheckUnknownActivations(pindexNew, m_chainman.GetParams());
2926 for (auto [bit, active] : bits) {
2927 const bilingual_str warning = strprintf(_("Unknown new rules activated (versionbit %i)"), bit);
2928 if (active) {
2929 m_chainman.GetNotifications().warningSet(kernel::Warning::UNKNOWN_NEW_RULES_ACTIVATED, warning);
2930 } else {
2931 warning_messages.push_back(warning);
2932 }
2933 }
2934 }
2935 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "",
2936 util::Join(warning_messages, Untranslated(", ")).original, /*background_validation=*/false);
2937 }
2938 2939 /** Disconnect m_chain's tip.
2940 * After calling, the mempool will be in an inconsistent state, with
2941 * transactions from disconnected blocks being added to disconnectpool. You
2942 * should make the mempool consistent again by calling MaybeUpdateMempoolForReorg.
2943 * with cs_main held.
2944 *
2945 * If disconnectpool is nullptr, then no disconnected transactions are added to
2946 * disconnectpool (note that the caller is responsible for mempool consistency
2947 * in any case).
2948 */
2949 bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTransactions* disconnectpool)
2950 {
2951 AssertLockHeld(cs_main);
2952 if (m_mempool) AssertLockHeld(m_mempool->cs);
2953 2954 CBlockIndex *pindexDelete = m_chain.Tip();
2955 assert(pindexDelete);
2956 assert(pindexDelete->pprev);
2957 // Read block from disk.
2958 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
2959 CBlock& block = *pblock;
2960 if (!m_blockman.ReadBlock(block, *pindexDelete)) {
2961 LogError("DisconnectTip(): Failed to read block\n");
2962 return false;
2963 }
2964 // Apply the block atomically to the chain state.
2965 const auto time_start{SteadyClock::now()};
2966 {
2967 CCoinsViewCache view(&CoinsTip());
2968 assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
2969 if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK) {
2970 LogError("DisconnectTip(): DisconnectBlock %s failed\n", pindexDelete->GetBlockHash().ToString());
2971 return false;
2972 }
2973 view.Flush(/*reallocate_cache=*/false); // local CCoinsViewCache goes out of scope
2974 }
2975 LogDebug(BCLog::BENCH, "- Disconnect block: %.2fms\n",
2976 Ticks<MillisecondsDouble>(SteadyClock::now() - time_start));
2977 2978 {
2979 // Prune locks that began at or after the tip should be moved backward so they get a chance to reorg
2980 const int max_height_first{pindexDelete->nHeight - 1};
2981 for (auto& prune_lock : m_blockman.m_prune_locks) {
2982 if (prune_lock.second.height_first <= max_height_first) continue;
2983 2984 prune_lock.second.height_first = max_height_first;
2985 LogDebug(BCLog::PRUNE, "%s prune lock moved back to %d\n", prune_lock.first, max_height_first);
2986 }
2987 }
2988 2989 // Write the chain state to disk, if necessary.
2990 if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
2991 return false;
2992 }
2993 2994 if (disconnectpool && m_mempool) {
2995 // Save transactions to re-add to mempool at end of reorg. If any entries are evicted for
2996 // exceeding memory limits, remove them and their descendants from the mempool.
2997 for (auto&& evicted_tx : disconnectpool->AddTransactionsFromBlock(block.vtx)) {
2998 m_mempool->removeRecursive(*evicted_tx, MemPoolRemovalReason::REORG);
2999 }
3000 }
3001 3002 m_chain.SetTip(*pindexDelete->pprev);
3003 m_chainman.UpdateIBDStatus();
3004 3005 UpdateTip(pindexDelete->pprev);
3006 // Let wallets know transactions went from 1-confirmed to
3007 // 0-confirmed or conflicted:
3008 if (m_chainman.m_options.signals) {
3009 m_chainman.m_options.signals->BlockDisconnected(std::move(pblock), pindexDelete);
3010 }
3011 return true;
3012 }
3013 3014 struct ConnectedBlock {
3015 const CBlockIndex* pindex;
3016 std::shared_ptr<const CBlock> pblock;
3017 };
3018 3019 /**
3020 * Connect a new block to m_chain. block_to_connect is either nullptr or a pointer to a CBlock
3021 * corresponding to pindexNew, to bypass loading it again from disk.
3022 *
3023 * The block is added to connected_blocks if connection succeeds.
3024 */
3025 bool Chainstate::ConnectTip(
3026 BlockValidationState& state,
3027 CBlockIndex* pindexNew,
3028 std::shared_ptr<const CBlock> block_to_connect,
3029 std::vector<ConnectedBlock>& connected_blocks,
3030 DisconnectedBlockTransactions& disconnectpool)
3031 {
3032 AssertLockHeld(cs_main);
3033 if (m_mempool) AssertLockHeld(m_mempool->cs);
3034 3035 assert(pindexNew->pprev == m_chain.Tip());
3036 // Read block from disk.
3037 const auto time_1{SteadyClock::now()};
3038 if (!block_to_connect) {
3039 std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
3040 if (!m_blockman.ReadBlock(*pblockNew, *pindexNew)) {
3041 return FatalError(m_chainman.GetNotifications(), state, _("Failed to read block."));
3042 }
3043 block_to_connect = std::move(pblockNew);
3044 } else {
3045 LogDebug(BCLog::BENCH, " - Using cached block\n");
3046 }
3047 // Apply the block atomically to the chain state.
3048 const auto time_2{SteadyClock::now()};
3049 SteadyClock::time_point time_3;
3050 // When adding aggregate statistics in the future, keep in mind that
3051 // num_blocks_total may be zero until the ConnectBlock() call below.
3052 LogDebug(BCLog::BENCH, " - Load block from disk: %.2fms\n",
3053 Ticks<MillisecondsDouble>(time_2 - time_1));
3054 {
3055 CoinsViewOverlay& view{*m_coins_views->m_connect_block_view};
3056 const auto reset_guard{view.StartFetching(*block_to_connect)};
3057 bool rv = ConnectBlock(*block_to_connect, state, pindexNew, view);
3058 if (m_chainman.m_options.signals) {
3059 m_chainman.m_options.signals->BlockChecked(block_to_connect, state);
3060 }
3061 if (!rv) {
3062 if (state.IsInvalid())
3063 InvalidBlockFound(pindexNew, state);
3064 LogError("%s: ConnectBlock %s failed, %s\n", __func__, pindexNew->GetBlockHash().ToString(), state.ToString());
3065 return false;
3066 }
3067 time_3 = SteadyClock::now();
3068 m_chainman.time_connect_total += time_3 - time_2;
3069 assert(m_chainman.num_blocks_total > 0);
3070 LogDebug(BCLog::BENCH, " - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
3071 Ticks<MillisecondsDouble>(time_3 - time_2),
3072 Ticks<SecondsDouble>(m_chainman.time_connect_total),
3073 Ticks<MillisecondsDouble>(m_chainman.time_connect_total) / m_chainman.num_blocks_total);
3074 view.Flush(/*reallocate_cache=*/false); // No need to reallocate since it only has capacity for 1 block
3075 }
3076 const auto time_4{SteadyClock::now()};
3077 m_chainman.time_flush += time_4 - time_3;
3078 LogDebug(BCLog::BENCH, " - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
3079 Ticks<MillisecondsDouble>(time_4 - time_3),
3080 Ticks<SecondsDouble>(m_chainman.time_flush),
3081 Ticks<MillisecondsDouble>(m_chainman.time_flush) / m_chainman.num_blocks_total);
3082 // Write the chain state to disk, if necessary.
3083 if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
3084 return false;
3085 }
3086 const auto time_5{SteadyClock::now()};
3087 m_chainman.time_chainstate += time_5 - time_4;
3088 LogDebug(BCLog::BENCH, " - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
3089 Ticks<MillisecondsDouble>(time_5 - time_4),
3090 Ticks<SecondsDouble>(m_chainman.time_chainstate),
3091 Ticks<MillisecondsDouble>(m_chainman.time_chainstate) / m_chainman.num_blocks_total);
3092 // Remove conflicting transactions from the mempool.;
3093 if (m_mempool) {
3094 m_mempool->removeForBlock(block_to_connect->vtx, pindexNew->nHeight);
3095 disconnectpool.removeForBlock(block_to_connect->vtx);
3096 }
3097 // Update m_chain & related variables.
3098 m_chain.SetTip(*pindexNew);
3099 m_chainman.UpdateIBDStatus();
3100 UpdateTip(pindexNew);
3101 3102 const auto time_6{SteadyClock::now()};
3103 m_chainman.time_post_connect += time_6 - time_5;
3104 m_chainman.time_total += time_6 - time_1;
3105 LogDebug(BCLog::BENCH, " - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
3106 Ticks<MillisecondsDouble>(time_6 - time_5),
3107 Ticks<SecondsDouble>(m_chainman.time_post_connect),
3108 Ticks<MillisecondsDouble>(m_chainman.time_post_connect) / m_chainman.num_blocks_total);
3109 LogDebug(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
3110 Ticks<MillisecondsDouble>(time_6 - time_1),
3111 Ticks<SecondsDouble>(m_chainman.time_total),
3112 Ticks<MillisecondsDouble>(m_chainman.time_total) / m_chainman.num_blocks_total);
3113 3114 // See if this chainstate has reached a target block and can be used to
3115 // validate an assumeutxo snapshot. If it can, hashing the UTXO database
3116 // will be slow, and cs_main could remain locked here for several minutes.
3117 // If the snapshot is validated, the UTXO hash will be saved to
3118 // this->m_target_utxohash, causing HistoricalChainstate() to return null
3119 // and this chainstate to no longer be used. ActivateBestChain() will also
3120 // stop connecting blocks to this chainstate because this->ReachedTarget()
3121 // will be true and this->setBlockIndexCandidates will not have additional
3122 // blocks.
3123 Chainstate& current_cs{m_chainman.CurrentChainstate()};
3124 m_chainman.MaybeValidateSnapshot(*this, current_cs);
3125 3126 connected_blocks.emplace_back(pindexNew, std::move(block_to_connect));
3127 return true;
3128 }
3129 3130 /**
3131 * Return the tip of the chain with the most work in it, that isn't
3132 * known to be invalid (it's however far from certain to be valid).
3133 */
3134 CBlockIndex* Chainstate::FindMostWorkChain()
3135 {
3136 AssertLockHeld(::cs_main);
3137 do {
3138 CBlockIndex *pindexNew = nullptr;
3139 3140 // Find the best candidate header.
3141 {
3142 std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexCandidates.rbegin();
3143 if (it == setBlockIndexCandidates.rend())
3144 return nullptr;
3145 pindexNew = *it;
3146 }
3147 3148 // Check whether all blocks on the path between the currently active chain and the candidate are valid.
3149 // Just going until the active chain is an optimization, as we know all blocks in it are valid already.
3150 bool fInvalidAncestor = false;
3151 for (CBlockIndex *pindexTest = pindexNew; pindexTest && !m_chain.Contains(*pindexTest); pindexTest = pindexTest->pprev) {
3152 assert(pindexTest->HaveNumChainTxs() || pindexTest->nHeight == 0);
3153 3154 // Pruned nodes may have entries in setBlockIndexCandidates for
3155 // which block files have been deleted. Remove those as candidates
3156 // for the most work chain if we come across them; we can't switch
3157 // to a chain unless we have all the non-active-chain parent blocks.
3158 bool fFailedChain = pindexTest->nStatus & BLOCK_FAILED_VALID;
3159 bool fMissingData = !(pindexTest->nStatus & BLOCK_HAVE_DATA);
3160 if (fFailedChain || fMissingData) {
3161 // Candidate chain is not usable (either invalid or missing data)
3162 if (fFailedChain && (m_chainman.m_best_invalid == nullptr || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork)) {
3163 m_chainman.m_best_invalid = pindexNew;
3164 }
3165 // Remove the entire chain from the set.
3166 for (CBlockIndex *pindexFailed = pindexNew; pindexFailed != pindexTest; pindexFailed = pindexFailed->pprev) {
3167 // If we're missing data and not a descendant of an invalid block,
3168 // then add back to m_blocks_unlinked, so that if the block arrives in the future
3169 // we can try adding to setBlockIndexCandidates again.
3170 if (fMissingData && !fFailedChain) {
3171 // Avoid duplicate entries in m_blocks_unlinked. If the same entry is
3172 // processed twice in ReceivedBlockTransactions(), it may be re-added to
3173 // setBlockIndexCandidates with a modified nSequenceId, breaking ordering
3174 // guarantees and leading to undefined behavior.
3175 m_blockman.AddUnlinkedBlock(pindexFailed);
3176 }
3177 setBlockIndexCandidates.erase(pindexFailed);
3178 }
3179 setBlockIndexCandidates.erase(pindexTest);
3180 fInvalidAncestor = true;
3181 break;
3182 }
3183 }
3184 if (!fInvalidAncestor)
3185 return pindexNew;
3186 } while(true);
3187 }
3188 3189 /** Delete all entries in setBlockIndexCandidates that are worse than the current tip. */
3190 void Chainstate::PruneBlockIndexCandidates() {
3191 // Note that we can't delete the current block itself, as we may need to return to it later in case a
3192 // reorganization to a better block fails.
3193 std::set<CBlockIndex*, CBlockIndexWorkComparator>::iterator it = setBlockIndexCandidates.begin();
3194 while (it != setBlockIndexCandidates.end() && setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) {
3195 setBlockIndexCandidates.erase(it++);
3196 }
3197 // Either the current tip or a successor of it we're working towards is left in setBlockIndexCandidates.
3198 assert(!setBlockIndexCandidates.empty());
3199 }
3200 3201 /**
3202 * Try to make some progress towards making index_most_work the active block.
3203 * pblock is either nullptr or a pointer to a CBlock corresponding to index_most_work.
3204 *
3205 * @returns true unless a system error occurred
3206 */
3207 bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex& index_most_work, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, std::vector<ConnectedBlock>& connected_blocks)
3208 {
3209 AssertLockHeld(cs_main);
3210 if (m_mempool) AssertLockHeld(m_mempool->cs);
3211 3212 const CBlockIndex* pindexOldTip = m_chain.Tip();
3213 const CBlockIndex* pindexFork = m_chain.FindFork(index_most_work);
3214 3215 // Disconnect active blocks which are no longer in the best chain.
3216 bool fBlocksDisconnected = false;
3217 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES};
3218 while (m_chain.Tip() && m_chain.Tip() != pindexFork) {
3219 if (!DisconnectTip(state, &disconnectpool)) {
3220 // This is likely a fatal error, but keep the mempool consistent,
3221 // just in case. Only remove from the mempool in this case.
3222 MaybeUpdateMempoolForReorg(disconnectpool, false);
3223 3224 // If we're unable to disconnect a block during normal operation,
3225 // then that is a failure of our local system -- we should abort
3226 // rather than stay on a less work chain.
3227 FatalError(m_chainman.GetNotifications(), state, _("Failed to disconnect block."));
3228 return false;
3229 }
3230 fBlocksDisconnected = true;
3231 }
3232 3233 // Build list of new blocks to connect (in descending height order).
3234 std::vector<CBlockIndex*> vpindexToConnect;
3235 bool fContinue = true;
3236 int nHeight = pindexFork ? pindexFork->nHeight : -1;
3237 while (fContinue && nHeight != index_most_work.nHeight) {
3238 // Don't iterate the entire list of potential improvements toward the best tip, as we likely only need
3239 // a few blocks along the way.
3240 int nTargetHeight = std::min(nHeight + 32, index_most_work.nHeight);
3241 vpindexToConnect.clear();
3242 vpindexToConnect.reserve(nTargetHeight - nHeight);
3243 CBlockIndex* pindexIter = index_most_work.GetAncestor(nTargetHeight);
3244 while (pindexIter && pindexIter->nHeight != nHeight) {
3245 vpindexToConnect.push_back(pindexIter);
3246 pindexIter = pindexIter->pprev;
3247 }
3248 nHeight = nTargetHeight;
3249 3250 // Connect new blocks.
3251 for (CBlockIndex* pindexConnect : vpindexToConnect | std::views::reverse) {
3252 if (!ConnectTip(state, pindexConnect, pindexConnect == &index_most_work ? pblock : std::shared_ptr<const CBlock>(), connected_blocks, disconnectpool)) {
3253 if (state.IsInvalid()) {
3254 // The block violates a consensus rule.
3255 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
3256 InvalidChainFound(vpindexToConnect.front());
3257 }
3258 state = BlockValidationState();
3259 fInvalidFound = true;
3260 fContinue = false;
3261 break;
3262 } else {
3263 // A system error occurred (disk space, database error, ...).
3264 // Make the mempool consistent with the current tip, just in case
3265 // any observers try to use it before shutdown.
3266 MaybeUpdateMempoolForReorg(disconnectpool, false);
3267 return false;
3268 }
3269 } else {
3270 PruneBlockIndexCandidates();
3271 if (!pindexOldTip || m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) {
3272 // We're in a better position than we were. Return temporarily to release the lock.
3273 fContinue = false;
3274 break;
3275 }
3276 }
3277 }
3278 }
3279 3280 if (fBlocksDisconnected) {
3281 // If any blocks were disconnected, disconnectpool may be non empty. Add
3282 // any disconnected transactions back to the mempool.
3283 MaybeUpdateMempoolForReorg(disconnectpool, true);
3284 }
3285 if (m_mempool) m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1);
3286 3287 CheckForkWarningConditions();
3288 3289 return true;
3290 }
3291 3292 static SynchronizationState GetSynchronizationState(bool init, bool blockfiles_indexed)
3293 {
3294 if (!init) return SynchronizationState::POST_INIT;
3295 if (!blockfiles_indexed) return SynchronizationState::INIT_REINDEX;
3296 return SynchronizationState::INIT_DOWNLOAD;
3297 }
3298 3299 void ChainstateManager::UpdateIBDStatus()
3300 {
3301 AssertLockHeld(cs_main);
3302 if (!m_cached_is_ibd.load(std::memory_order_relaxed)) return;
3303 if (m_blockman.LoadingBlocks()) return;
3304 if (!CurrentChainstate().m_chain.IsTipRecent(MinimumChainWork(), m_options.max_tip_age)) return;
3305 LogInfo("Leaving InitialBlockDownload (latching to false)");
3306 m_cached_is_ibd.store(false, std::memory_order_relaxed);
3307 }
3308 3309 bool ChainstateManager::NotifyHeaderTip()
3310 {
3311 bool fNotify = false;
3312 bool fInitialBlockDownload = false;
3313 CBlockIndex* pindexHeader = nullptr;
3314 {
3315 LOCK(GetMutex());
3316 pindexHeader = m_best_header;
3317 3318 if (pindexHeader != m_last_notified_header) {
3319 fNotify = true;
3320 fInitialBlockDownload = IsInitialBlockDownload();
3321 m_last_notified_header = pindexHeader;
3322 }
3323 }
3324 // Send block tip changed notifications without the lock held
3325 if (fNotify) {
3326 GetNotifications().headerTip(GetSynchronizationState(fInitialBlockDownload, m_blockman.m_blockfiles_indexed), pindexHeader->nHeight, pindexHeader->nTime, false);
3327 }
3328 return fNotify;
3329 }
3330 3331 static void LimitValidationInterfaceQueue(ValidationSignals& signals) LOCKS_EXCLUDED(cs_main) {
3332 AssertLockNotHeld(cs_main);
3333 3334 if (signals.CallbacksPending() > 10) {
3335 signals.SyncWithValidationInterfaceQueue();
3336 }
3337 }
3338 3339 bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<const CBlock> pblock)
3340 {
3341 AssertLockNotHeld(m_chainstate_mutex);
3342 3343 // Note that while we're often called here from ProcessNewBlock, this is
3344 // far from a guarantee. Things in the P2P/RPC will often end up calling
3345 // us in the middle of ProcessNewBlock - do not assume pblock is set
3346 // sanely for performance or correctness!
3347 AssertLockNotHeld(::cs_main);
3348 3349 // ABC maintains a fair degree of expensive-to-calculate internal state
3350 // because this function periodically releases cs_main so that it does not lock up other threads for too long
3351 // during large connects - and to allow for e.g. the callback queue to drain
3352 // we use m_chainstate_mutex to enforce mutual exclusion so that only one caller may execute this function at a time
3353 LOCK(m_chainstate_mutex);
3354 3355 // Belt-and-suspenders check that we aren't attempting to advance the
3356 // chainstate past the target block.
3357 if (WITH_LOCK(::cs_main, return m_target_utxohash)) {
3358 LogError("%s", STR_INTERNAL_BUG("m_target_utxohash is set - this chainstate should not be in operation."));
3359 return Assume(false);
3360 }
3361 3362 CBlockIndex *pindexMostWork = nullptr;
3363 CBlockIndex *pindexNewTip = nullptr;
3364 bool exited_ibd{false};
3365 do {
3366 // Block until the validation queue drains. This should largely
3367 // never happen in normal operation, however may happen during
3368 // reindex, causing memory blowup if we run too far ahead.
3369 // Note that if a validationinterface callback ends up calling
3370 // ActivateBestChain this may lead to a deadlock! We should
3371 // probably have a DEBUG_LOCKORDER test for this in the future.
3372 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals);
3373 3374 {
3375 LOCK(cs_main);
3376 {
3377 // Lock transaction pool for at least as long as it takes for connected_blocks to be consumed
3378 LOCK(MempoolMutex());
3379 const bool was_in_ibd = m_chainman.IsInitialBlockDownload();
3380 CBlockIndex* starting_tip = m_chain.Tip();
3381 bool blocks_connected = false;
3382 do {
3383 // We absolutely may not unlock cs_main until we've made forward progress
3384 // (with the exception of shutdown due to hardware issues, low disk space, etc).
3385 std::vector<ConnectedBlock> connected_blocks; // Destructed before cs_main is unlocked
3386 3387 if (pindexMostWork == nullptr) {
3388 pindexMostWork = FindMostWorkChain();
3389 }
3390 3391 // Whether we have anything to do at all.
3392 if (pindexMostWork == nullptr || pindexMostWork == m_chain.Tip()) {
3393 break;
3394 }
3395 3396 bool fInvalidFound = false;
3397 std::shared_ptr<const CBlock> nullBlockPtr;
3398 // BlockConnected signals must be sent for the original role;
3399 // in case snapshot validation is completed during ActivateBestChainStep, the
3400 // result of GetRole() changes from BACKGROUND to NORMAL.
3401 const ChainstateRole chainstate_role{this->GetRole()};
3402 if (!ActivateBestChainStep(state, *pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connected_blocks)) {
3403 // A system error occurred
3404 return false;
3405 }
3406 blocks_connected = true;
3407 3408 if (fInvalidFound) {
3409 // Wipe cache, we may need another branch now.
3410 pindexMostWork = nullptr;
3411 }
3412 pindexNewTip = m_chain.Tip();
3413 3414 for (auto& [index, block] : std::move(connected_blocks)) {
3415 if (m_chainman.m_options.signals) {
3416 m_chainman.m_options.signals->BlockConnected(chainstate_role, std::move(Assert(block)), Assert(index));
3417 }
3418 }
3419 3420 // Break this do-while to ensure we don't advance past the target block.
3421 if (ReachedTarget()) {
3422 break;
3423 }
3424 } while (!m_chain.Tip() || (starting_tip && CBlockIndexWorkComparator()(m_chain.Tip(), starting_tip)));
3425 if (!blocks_connected) return true;
3426 3427 const CBlockIndex* pindexFork = starting_tip ? m_chain.FindFork(*starting_tip) : nullptr;
3428 bool still_in_ibd = m_chainman.IsInitialBlockDownload();
3429 3430 if (was_in_ibd && !still_in_ibd) {
3431 // Active chainstate has exited IBD.
3432 exited_ibd = true;
3433 }
3434 3435 // Notify external listeners about the new tip.
3436 // Enqueue while holding cs_main to ensure that UpdatedBlockTip is called in the order in which blocks are connected
3437 if (this == &m_chainman.ActiveChainstate() && pindexFork != pindexNewTip) {
3438 // Notify ValidationInterface subscribers
3439 if (m_chainman.m_options.signals) {
3440 m_chainman.m_options.signals->UpdatedBlockTip(pindexNewTip, pindexFork, still_in_ibd);
3441 }
3442 3443 if (kernel::IsInterrupted(m_chainman.GetNotifications().blockTip(
3444 /*state=*/GetSynchronizationState(still_in_ibd, m_chainman.m_blockman.m_blockfiles_indexed),
3445 /*index=*/*pindexNewTip,
3446 /*verification_progress=*/m_chainman.GuessVerificationProgress(pindexNewTip))))
3447 {
3448 // Just breaking and returning success for now. This could
3449 // be changed to bubble up the kernel::Interrupted value to
3450 // the caller so the caller could distinguish between
3451 // completed and interrupted operations.
3452 break;
3453 }
3454 }
3455 } // release MempoolMutex
3456 // Notify external listeners about the new tip, even if pindexFork == pindexNewTip.
3457 if (m_chainman.m_options.signals && this == &m_chainman.ActiveChainstate()) {
3458 m_chainman.m_options.signals->ActiveTipChange(*Assert(pindexNewTip), m_chainman.IsInitialBlockDownload());
3459 }
3460 } // release cs_main
3461 // When we reach this point, we switched to a new tip (stored in pindexNewTip).
3462 3463 bool reached_target;
3464 {
3465 LOCK(m_chainman.GetMutex());
3466 if (exited_ibd) {
3467 // If a background chainstate is in use, we may need to rebalance our
3468 // allocation of caches once a chainstate exits initial block download.
3469 m_chainman.MaybeRebalanceCaches();
3470 }
3471 3472 // Write changes periodically to disk, after relay.
3473 if (!FlushStateToDisk(state, FlushStateMode::PERIODIC)) {
3474 return false;
3475 }
3476 3477 reached_target = ReachedTarget();
3478 }
3479 3480 if (reached_target) {
3481 // Chainstate has reached the target block, so exit.
3482 //
3483 // Restart indexes so indexes can resync and index new blocks after
3484 // the target block.
3485 //
3486 // This cannot be done while holding cs_main (within
3487 // MaybeValidateSnapshot) or a cs_main deadlock will occur.
3488 if (m_chainman.snapshot_download_completed) {
3489 m_chainman.snapshot_download_completed();
3490 }
3491 break;
3492 }
3493 3494 // We check interrupt only after giving ActivateBestChainStep a chance to run once so that we
3495 // never interrupt before connecting the genesis block during LoadChainTip(). Previously this
3496 // caused an assert() failure during interrupt in such cases as the UTXO DB flushing checks
3497 // that the best block hash is non-null.
3498 if (m_chainman.m_interrupt) break;
3499 } while (pindexNewTip != pindexMostWork);
3500 3501 m_chainman.CheckBlockIndex();
3502 3503 return true;
3504 }
3505 3506 bool Chainstate::PreciousBlock(BlockValidationState& state, CBlockIndex* pindex)
3507 {
3508 AssertLockNotHeld(m_chainstate_mutex);
3509 AssertLockNotHeld(::cs_main);
3510 {
3511 LOCK(cs_main);
3512 if (pindex->nChainWork < m_chain.Tip()->nChainWork) {
3513 // Nothing to do, this block is not at the tip.
3514 return true;
3515 }
3516 if (m_chain.Tip()->nChainWork > m_chainman.nLastPreciousChainwork) {
3517 // The chain has been extended since the last call, reset the counter.
3518 m_chainman.nBlockReverseSequenceId = -1;
3519 }
3520 m_chainman.nLastPreciousChainwork = m_chain.Tip()->nChainWork;
3521 setBlockIndexCandidates.erase(pindex);
3522 pindex->nSequenceId = m_chainman.nBlockReverseSequenceId;
3523 if (m_chainman.nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) {
3524 // We can't keep reducing the counter if somebody really wants to
3525 // call preciousblock 2**31-1 times on the same set of tips...
3526 m_chainman.nBlockReverseSequenceId--;
3527 }
3528 if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && pindex->HaveNumChainTxs()) {
3529 setBlockIndexCandidates.insert(pindex);
3530 PruneBlockIndexCandidates();
3531 }
3532 }
3533 3534 return ActivateBestChain(state, std::shared_ptr<const CBlock>());
3535 }
3536 3537 bool Chainstate::InvalidateBlock(BlockValidationState& state, CBlockIndex* const pindex)
3538 {
3539 AssertLockNotHeld(m_chainstate_mutex);
3540 AssertLockNotHeld(::cs_main);
3541 3542 // Genesis block can't be invalidated
3543 assert(pindex);
3544 if (pindex->nHeight == 0) return false;
3545 3546 // We do not allow ActivateBestChain() to run while InvalidateBlock() is
3547 // running, as that could cause the tip to change while we disconnect
3548 // blocks.
3549 LOCK(m_chainstate_mutex);
3550 3551 // We'll be acquiring and releasing cs_main below, to allow the validation
3552 // callbacks to run. However, we should keep the block index in a
3553 // consistent state as we disconnect blocks -- in particular we need to
3554 // add equal-work blocks to setBlockIndexCandidates as we disconnect.
3555 // To avoid walking the block index repeatedly in search of candidates,
3556 // build a map once so that we can look up candidate blocks by chain
3557 // work as we go.
3558 std::multimap<const arith_uint256, CBlockIndex*> highpow_outofchain_headers;
3559 3560 {
3561 LOCK(cs_main);
3562 for (auto& entry : m_blockman.m_block_index) {
3563 CBlockIndex& candidate = entry.second;
3564 // We don't need to put anything in our active chain into the
3565 // multimap, because those candidates will be found and considered
3566 // as we disconnect.
3567 // Instead, consider only non-active-chain blocks that score
3568 // at least as good with CBlockIndexWorkComparator as the new tip.
3569 if (!m_chain.Contains(candidate) &&
3570 !CBlockIndexWorkComparator()(&candidate, pindex->pprev) &&
3571 !(candidate.nStatus & BLOCK_FAILED_VALID)) {
3572 highpow_outofchain_headers.insert({candidate.nChainWork, &candidate});
3573 }
3574 }
3575 }
3576 3577 CBlockIndex* to_mark_failed = pindex;
3578 bool pindex_was_in_chain = false;
3579 int disconnected = 0;
3580 3581 // Disconnect (descendants of) pindex, and mark them invalid.
3582 while (true) {
3583 if (m_chainman.m_interrupt) break;
3584 3585 // Make sure the queue of validation callbacks doesn't grow unboundedly.
3586 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals);
3587 3588 LOCK(cs_main);
3589 // Lock for as long as disconnectpool is in scope to make sure MaybeUpdateMempoolForReorg is
3590 // called after DisconnectTip without unlocking in between
3591 LOCK(MempoolMutex());
3592 if (!m_chain.Contains(*pindex)) break;
3593 pindex_was_in_chain = true;
3594 CBlockIndex* const disconnected_tip{m_chain.Tip()};
3595 3596 // ActivateBestChain considers blocks already in m_chain
3597 // unconditionally valid already, so force disconnect away from it.
3598 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES};
3599 bool ret = DisconnectTip(state, &disconnectpool);
3600 // DisconnectTip will add transactions to disconnectpool.
3601 // Adjust the mempool to be consistent with the new tip, adding
3602 // transactions back to the mempool if disconnecting was successful,
3603 // and we're not doing a very deep invalidation (in which case
3604 // keeping the mempool up to date is probably futile anyway).
3605 MaybeUpdateMempoolForReorg(disconnectpool, /* fAddToMempool = */ (++disconnected <= 10) && ret);
3606 if (!ret) return false;
3607 CBlockIndex* new_tip{m_chain.Tip()};
3608 assert(disconnected_tip->pprev == new_tip);
3609 3610 // We immediately mark the disconnected blocks as invalid.
3611 // This prevents a case where pruned nodes may fail to invalidateblock
3612 // and be left unable to start as they have no tip candidates (as there
3613 // are no blocks that meet the "have data and are not invalid per
3614 // nStatus" criteria for inclusion in setBlockIndexCandidates).
3615 disconnected_tip->nStatus |= BLOCK_FAILED_VALID;
3616 m_blockman.m_dirty_blockindex.insert(disconnected_tip);
3617 setBlockIndexCandidates.erase(disconnected_tip);
3618 setBlockIndexCandidates.insert(new_tip);
3619 3620 // Mark out-of-chain descendants of the invalidated block as invalid
3621 // Add any equal or more work headers that are not invalidated to setBlockIndexCandidates
3622 // Recalculate m_best_header if it became invalid.
3623 auto candidate_it = highpow_outofchain_headers.lower_bound(new_tip->nChainWork);
3624 3625 const bool best_header_needs_update{m_chainman.m_best_header->GetAncestor(disconnected_tip->nHeight) == disconnected_tip};
3626 if (best_header_needs_update) {
3627 // new_tip is definitely still valid at this point, but there may be better ones
3628 m_chainman.m_best_header = new_tip;
3629 }
3630 3631 while (candidate_it != highpow_outofchain_headers.end()) {
3632 CBlockIndex* candidate{candidate_it->second};
3633 if (candidate->GetAncestor(disconnected_tip->nHeight) == disconnected_tip) {
3634 // Children of failed blocks are marked as BLOCK_FAILED_VALID.
3635 candidate->nStatus |= BLOCK_FAILED_VALID;
3636 m_blockman.m_dirty_blockindex.insert(candidate);
3637 // If invalidated, the block is irrelevant for setBlockIndexCandidates
3638 // and for m_best_header and can be removed from the cache.
3639 candidate_it = highpow_outofchain_headers.erase(candidate_it);
3640 continue;
3641 }
3642 if (!CBlockIndexWorkComparator()(candidate, new_tip) &&
3643 candidate->IsValid(BLOCK_VALID_TRANSACTIONS) &&
3644 candidate->HaveNumChainTxs()) {
3645 setBlockIndexCandidates.insert(candidate);
3646 // Do not remove candidate from the highpow_outofchain_headers cache, because it might be a descendant of the block being invalidated
3647 // which needs to be marked failed later.
3648 }
3649 if (best_header_needs_update &&
3650 m_chainman.m_best_header->nChainWork < candidate->nChainWork) {
3651 m_chainman.m_best_header = candidate;
3652 }
3653 ++candidate_it;
3654 }
3655 3656 // Track the last disconnected block to call InvalidChainFound on it.
3657 to_mark_failed = disconnected_tip;
3658 }
3659 3660 m_chainman.CheckBlockIndex();
3661 3662 {
3663 LOCK(cs_main);
3664 if (m_chain.Contains(*to_mark_failed)) {
3665 // If the to-be-marked invalid block is in the active chain, something is interfering and we can't proceed.
3666 return false;
3667 }
3668 3669 // Mark pindex as invalid if it never was in the main chain
3670 if (!pindex_was_in_chain && !(pindex->nStatus & BLOCK_FAILED_VALID)) {
3671 pindex->nStatus |= BLOCK_FAILED_VALID;
3672 m_blockman.m_dirty_blockindex.insert(pindex);
3673 setBlockIndexCandidates.erase(pindex);
3674 }
3675 3676 // If any new blocks somehow arrived while we were disconnecting
3677 // (above), then the pre-calculation of what should go into
3678 // setBlockIndexCandidates may have missed entries. This would
3679 // technically be an inconsistency in the block index, but if we clean
3680 // it up here, this should be an essentially unobservable error.
3681 // Loop back over all block index entries and add any missing entries
3682 // to setBlockIndexCandidates.
3683 for (auto& [_, block_index] : m_blockman.m_block_index) {
3684 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && !setBlockIndexCandidates.value_comp()(&block_index, m_chain.Tip())) {
3685 setBlockIndexCandidates.insert(&block_index);
3686 }
3687 }
3688 3689 InvalidChainFound(to_mark_failed);
3690 }
3691 3692 // Only notify about a new block tip if the active chain was modified.
3693 if (pindex_was_in_chain) {
3694 // Ignoring return value for now, this could be changed to bubble up
3695 // kernel::Interrupted value to the caller so the caller could
3696 // distinguish between completed and interrupted operations. It might
3697 // also make sense for the blockTip notification to have an enum
3698 // parameter indicating the source of the tip change so hooks can
3699 // distinguish user-initiated invalidateblock changes from other
3700 // changes.
3701 (void)m_chainman.GetNotifications().blockTip(
3702 /*state=*/GetSynchronizationState(m_chainman.IsInitialBlockDownload(), m_chainman.m_blockman.m_blockfiles_indexed),
3703 /*index=*/*to_mark_failed->pprev,
3704 /*verification_progress=*/WITH_LOCK(m_chainman.GetMutex(), return m_chainman.GuessVerificationProgress(to_mark_failed->pprev)));
3705 3706 // Fire ActiveTipChange now for the current chain tip to make sure clients are notified.
3707 // ActivateBestChain may call this as well, but not necessarily.
3708 if (m_chainman.m_options.signals) {
3709 m_chainman.m_options.signals->ActiveTipChange(*Assert(m_chain.Tip()), m_chainman.IsInitialBlockDownload());
3710 }
3711 }
3712 return true;
3713 }
3714 3715 void Chainstate::SetBlockFailureFlags(CBlockIndex* invalid_block)
3716 {
3717 AssertLockHeld(cs_main);
3718 3719 for (auto& [_, block_index] : m_blockman.m_block_index) {
3720 if (invalid_block != &block_index && block_index.GetAncestor(invalid_block->nHeight) == invalid_block) {
3721 block_index.nStatus |= BLOCK_FAILED_VALID;
3722 m_blockman.m_dirty_blockindex.insert(&block_index);
3723 }
3724 }
3725 }
3726 3727 void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex) {
3728 AssertLockHeld(cs_main);
3729 3730 int nHeight = pindex->nHeight;
3731 3732 // Remove the invalidity flag from this block and all its descendants and ancestors.
3733 for (auto& [_, block_index] : m_blockman.m_block_index) {
3734 if ((block_index.nStatus & BLOCK_FAILED_VALID) && (block_index.GetAncestor(nHeight) == pindex || pindex->GetAncestor(block_index.nHeight) == &block_index)) {
3735 block_index.nStatus &= ~BLOCK_FAILED_VALID;
3736 m_blockman.m_dirty_blockindex.insert(&block_index);
3737 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &block_index)) {
3738 setBlockIndexCandidates.insert(&block_index);
3739 }
3740 if (&block_index == m_chainman.m_best_invalid) {
3741 // Reset invalid block marker if it was pointing to one of those.
3742 m_chainman.m_best_invalid = nullptr;
3743 }
3744 }
3745 }
3746 }
3747 3748 void Chainstate::TryAddBlockIndexCandidate(CBlockIndex* pindex)
3749 {
3750 AssertLockHeld(cs_main);
3751 3752 // Do not continue building a chainstate that is based on an invalid
3753 // snapshot. This is a belt-and-suspenders type of check because if an
3754 // invalid snapshot is loaded, the node will shut down to force a manual
3755 // intervention. But it is good to handle this case correctly regardless.
3756 if (m_assumeutxo == Assumeutxo::INVALID) {
3757 return;
3758 }
3759 3760 // The block only is a candidate for the most-work-chain if it has the same
3761 // or more work than our current tip.
3762 if (m_chain.Tip() != nullptr && setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) {
3763 return;
3764 }
3765 3766 const CBlockIndex* target_block{TargetBlock()};
3767 if (!target_block) {
3768 // If no specific target block, add all entries that have more
3769 // work than the tip.
3770 setBlockIndexCandidates.insert(pindex);
3771 } else {
3772 // If there is a target block, only consider connecting blocks
3773 // towards the target block.
3774 if (target_block->GetAncestor(pindex->nHeight) == pindex) {
3775 setBlockIndexCandidates.insert(pindex);
3776 }
3777 }
3778 }
3779 3780 /** Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS). */
3781 void ChainstateManager::ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos)
3782 {
3783 AssertLockHeld(cs_main);
3784 pindexNew->nTx = block.vtx.size();
3785 // Typically m_chain_tx_count will be 0 at this point, but it can be nonzero if this
3786 // is a pruned block which is being downloaded again, or if this is an
3787 // assumeutxo snapshot block which has a hardcoded m_chain_tx_count value from the
3788 // snapshot metadata. If the pindex is not the snapshot block and the
3789 // m_chain_tx_count value is not zero, assert that value is actually correct.
3790 auto prev_tx_sum = [](CBlockIndex& block) { return block.nTx + (block.pprev ? block.pprev->m_chain_tx_count : 0); };
3791 if (!Assume(pindexNew->m_chain_tx_count == 0 || pindexNew->m_chain_tx_count == prev_tx_sum(*pindexNew) ||
3792 std::ranges::any_of(m_chainstates, [&](const auto& cs) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return cs->SnapshotBase() == pindexNew; }))) {
3793 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",
3794 pindexNew->nHeight, pindexNew->m_chain_tx_count, prev_tx_sum(*pindexNew), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT);
3795 pindexNew->m_chain_tx_count = 0;
3796 }
3797 pindexNew->nFile = pos.nFile;
3798 pindexNew->nDataPos = pos.nPos;
3799 pindexNew->nUndoPos = 0;
3800 pindexNew->nStatus |= BLOCK_HAVE_DATA;
3801 if (DeploymentActiveAt(*pindexNew, *this, Consensus::DEPLOYMENT_SEGWIT)) {
3802 pindexNew->nStatus |= BLOCK_OPT_WITNESS;
3803 }
3804 pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS);
3805 m_blockman.m_dirty_blockindex.insert(pindexNew);
3806 3807 if (pindexNew->pprev == nullptr || pindexNew->pprev->HaveNumChainTxs()) {
3808 // If pindexNew is the genesis block or all parents are BLOCK_VALID_TRANSACTIONS.
3809 std::deque<CBlockIndex*> queue;
3810 queue.push_back(pindexNew);
3811 3812 // Recursively process any descendant blocks that now may be eligible to be connected.
3813 while (!queue.empty()) {
3814 CBlockIndex *pindex = queue.front();
3815 queue.pop_front();
3816 // Before setting m_chain_tx_count, assert that it is 0 or already set to
3817 // the correct value. This assert will fail after receiving the
3818 // assumeutxo snapshot block if assumeutxo snapshot metadata has an
3819 // incorrect hardcoded AssumeutxoData::m_chain_tx_count value.
3820 if (!Assume(pindex->m_chain_tx_count == 0 || pindex->m_chain_tx_count == prev_tx_sum(*pindex))) {
3821 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",
3822 pindex->nHeight, pindex->m_chain_tx_count, prev_tx_sum(*pindex), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT);
3823 }
3824 pindex->m_chain_tx_count = prev_tx_sum(*pindex);
3825 pindex->nSequenceId = nBlockSequenceId++;
3826 for (const auto& c : m_chainstates) {
3827 c->TryAddBlockIndexCandidate(pindex);
3828 }
3829 std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> range = m_blockman.m_blocks_unlinked.equal_range(pindex);
3830 while (range.first != range.second) {
3831 std::multimap<CBlockIndex*, CBlockIndex*>::iterator it = range.first;
3832 queue.push_back(it->second);
3833 range.first++;
3834 m_blockman.m_blocks_unlinked.erase(it);
3835 }
3836 }
3837 } else {
3838 if (pindexNew->pprev && pindexNew->pprev->IsValid(BLOCK_VALID_TREE)) {
3839 m_blockman.AddUnlinkedBlock(pindexNew);
3840 }
3841 }
3842 }
3843 3844 static bool CheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true)
3845 {
3846 // Check proof of work matches claimed amount
3847 if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, consensusParams))
3848 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "high-hash", "proof of work failed");
3849 3850 return true;
3851 }
3852 3853 static bool CheckMerkleRoot(const CBlock& block, BlockValidationState& state)
3854 {
3855 if (block.m_checked_merkle_root) return true;
3856 3857 bool mutated;
3858 uint256 merkle_root = BlockMerkleRoot(block, &mutated);
3859 if (block.hashMerkleRoot != merkle_root) {
3860 return state.Invalid(
3861 /*result=*/BlockValidationResult::BLOCK_MUTATED,
3862 /*reject_reason=*/"bad-txnmrklroot",
3863 /*debug_message=*/"hashMerkleRoot mismatch");
3864 }
3865 3866 // Check for merkle tree malleability (CVE-2012-2459): repeating sequences
3867 // of transactions in a block without affecting the merkle root of a block,
3868 // while still invalidating it.
3869 if (mutated) {
3870 return state.Invalid(
3871 /*result=*/BlockValidationResult::BLOCK_MUTATED,
3872 /*reject_reason=*/"bad-txns-duplicate",
3873 /*debug_message=*/"duplicate transaction");
3874 }
3875 3876 block.m_checked_merkle_root = true;
3877 return true;
3878 }
3879 3880 /** CheckWitnessMalleation performs checks for block malleation with regard to
3881 * its witnesses.
3882 *
3883 * Note: If the witness commitment is expected (i.e. `expect_witness_commitment
3884 * = true`), then the block is required to have at least one transaction and the
3885 * first transaction needs to have at least one input. */
3886 static bool CheckWitnessMalleation(const CBlock& block, bool expect_witness_commitment, BlockValidationState& state)
3887 {
3888 if (expect_witness_commitment) {
3889 if (block.m_checked_witness_commitment) return true;
3890 3891 int commitpos = GetWitnessCommitmentIndex(block);
3892 if (commitpos != NO_WITNESS_COMMITMENT) {
3893 assert(!block.vtx.empty() && !block.vtx[0]->vin.empty());
3894 const auto& witness_stack{block.vtx[0]->vin[0].scriptWitness.stack};
3895 3896 if (witness_stack.size() != 1 || witness_stack[0].size() != 32) {
3897 return state.Invalid(
3898 /*result=*/BlockValidationResult::BLOCK_MUTATED,
3899 /*reject_reason=*/"bad-witness-nonce-size",
3900 /*debug_message=*/strprintf("%s : invalid witness reserved value size", __func__));
3901 }
3902 3903 // The malleation check is ignored; as the transaction tree itself
3904 // already does not permit it, it is impossible to trigger in the
3905 // witness tree.
3906 uint256 hash_witness = BlockWitnessMerkleRoot(block);
3907 3908 CHash256().Write(hash_witness).Write(witness_stack[0]).Finalize(hash_witness);
3909 if (memcmp(hash_witness.begin(), &block.vtx[0]->vout[commitpos].scriptPubKey[6], 32)) {
3910 return state.Invalid(
3911 /*result=*/BlockValidationResult::BLOCK_MUTATED,
3912 /*reject_reason=*/"bad-witness-merkle-match",
3913 /*debug_message=*/strprintf("%s : witness merkle commitment mismatch", __func__));
3914 }
3915 3916 block.m_checked_witness_commitment = true;
3917 return true;
3918 }
3919 }
3920 3921 // No witness data is allowed in blocks that don't commit to witness data, as this would otherwise leave room for spam
3922 for (const auto& tx : block.vtx) {
3923 if (tx->HasWitness()) {
3924 return state.Invalid(
3925 /*result=*/BlockValidationResult::BLOCK_MUTATED,
3926 /*reject_reason=*/"unexpected-witness",
3927 /*debug_message=*/strprintf("%s : unexpected witness data found", __func__));
3928 }
3929 }
3930 3931 return true;
3932 }
3933 3934 bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW, bool fCheckMerkleRoot)
3935 {
3936 // These are checks that are independent of context.
3937 3938 if (block.fChecked)
3939 return true;
3940 3941 // Check that the header is valid (particularly PoW). This is mostly
3942 // redundant with the call in AcceptBlockHeader.
3943 if (!CheckBlockHeader(block, state, consensusParams, fCheckPOW))
3944 return false;
3945 3946 // Signet only: check block solution
3947 if (consensusParams.signet_blocks && fCheckPOW && !CheckSignetBlockSolution(block, consensusParams)) {
3948 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-signet-blksig", "signet block signature validation failure");
3949 }
3950 3951 // Check the merkle root.
3952 if (fCheckMerkleRoot && !CheckMerkleRoot(block, state)) {
3953 return false;
3954 }
3955 3956 // All potential-corruption validation must be done before we do any
3957 // transaction validation, as otherwise we may mark the header as invalid
3958 // because we receive the wrong transactions for it.
3959 // Note that witness malleability is checked in ContextualCheckBlock, so no
3960 // checks that use witness data may be performed here.
3961 3962 // Size limits
3963 if (block.vtx.empty() || block.vtx.size() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT || ::GetSerializeSize(TX_NO_WITNESS(block)) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT)
3964 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-length", "size limits failed");
3965 3966 // First transaction must be coinbase, the rest must not be
3967 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase())
3968 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-missing", "first tx is not coinbase");
3969 for (unsigned int i = 1; i < block.vtx.size(); i++)
3970 if (block.vtx[i]->IsCoinBase())
3971 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-multiple", "more than one coinbase");
3972 3973 // Check transactions
3974 // Must check for duplicate inputs (see CVE-2018-17144)
3975 for (const auto& tx : block.vtx) {
3976 TxValidationState tx_state;
3977 if (!CheckTransaction(*tx, tx_state)) {
3978 // CheckBlock() does context-free validation checks. The only
3979 // possible failures are consensus failures.
3980 assert(tx_state.GetResult() == TxValidationResult::TX_CONSENSUS);
3981 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, tx_state.GetRejectReason(),
3982 strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), tx_state.GetDebugMessage()));
3983 }
3984 }
3985 // This underestimates the number of sigops, because unlike ConnectBlock it
3986 // does not count witness and p2sh sigops.
3987 unsigned int nSigOps = 0;
3988 for (const auto& tx : block.vtx)
3989 {
3990 nSigOps += GetLegacySigOpCount(*tx);
3991 }
3992 if (nSigOps * WITNESS_SCALE_FACTOR > MAX_BLOCK_SIGOPS_COST)
3993 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "out-of-bounds SigOpCount");
3994 3995 if (fCheckPOW && fCheckMerkleRoot)
3996 block.fChecked = true;
3997 3998 return true;
3999 }
4000 4001 void ChainstateManager::UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev) const
4002 {
4003 int commitpos = GetWitnessCommitmentIndex(block);
4004 static const std::vector<unsigned char> nonce(32, 0x00);
4005 if (commitpos != NO_WITNESS_COMMITMENT && DeploymentActiveAfter(pindexPrev, *this, Consensus::DEPLOYMENT_SEGWIT) && !block.vtx[0]->HasWitness()) {
4006 CMutableTransaction tx(*block.vtx[0]);
4007 tx.vin[0].scriptWitness.stack.resize(1);
4008 tx.vin[0].scriptWitness.stack[0] = nonce;
4009 block.vtx[0] = MakeTransactionRef(std::move(tx));
4010 }
4011 }
4012 4013 void ChainstateManager::GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev) const
4014 {
4015 int commitpos = GetWitnessCommitmentIndex(block);
4016 std::vector<unsigned char> ret(32, 0x00);
4017 if (commitpos == NO_WITNESS_COMMITMENT) {
4018 uint256 witnessroot = BlockWitnessMerkleRoot(block);
4019 CHash256().Write(witnessroot).Write(ret).Finalize(witnessroot);
4020 CTxOut out;
4021 out.nValue = 0;
4022 out.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT);
4023 out.scriptPubKey[0] = OP_RETURN;
4024 out.scriptPubKey[1] = 0x24;
4025 out.scriptPubKey[2] = 0xaa;
4026 out.scriptPubKey[3] = 0x21;
4027 out.scriptPubKey[4] = 0xa9;
4028 out.scriptPubKey[5] = 0xed;
4029 memcpy(&out.scriptPubKey[6], witnessroot.begin(), 32);
4030 CMutableTransaction tx(*block.vtx[0]);
4031 tx.vout.push_back(out);
4032 block.vtx[0] = MakeTransactionRef(std::move(tx));
4033 }
4034 UpdateUncommittedBlockStructures(block, pindexPrev);
4035 }
4036 4037 bool HasValidProofOfWork(std::span<const CBlockHeader> headers, const Consensus::Params& consensusParams)
4038 {
4039 return std::ranges::all_of(headers,
4040 [&](const auto& header) { return CheckProofOfWork(header.GetHash(), header.nBits, consensusParams); });
4041 }
4042 4043 bool IsBlockMutated(const CBlock& block, bool check_witness_root)
4044 {
4045 BlockValidationState state;
4046 if (!CheckMerkleRoot(block, state)) {
4047 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString());
4048 return true;
4049 }
4050 4051 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) {
4052 // Consider the block mutated if any transaction is 64 bytes in size (see 3.1
4053 // in "Weaknesses in Bitcoin’s Merkle Root Construction":
4054 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20190225/a27d8837/attachment-0001.pdf).
4055 //
4056 // Note: This is not a consensus change as this only applies to blocks that
4057 // don't have a coinbase transaction and would therefore already be invalid.
4058 return std::any_of(block.vtx.begin(), block.vtx.end(),
4059 [](auto& tx) { return GetSerializeSize(TX_NO_WITNESS(tx)) == 64; });
4060 } else {
4061 // Theoretically it is still possible for a block with a 64 byte
4062 // coinbase transaction to be mutated but we neglect that possibility
4063 // here as it requires at least 224 bits of work.
4064 }
4065 4066 if (!CheckWitnessMalleation(block, check_witness_root, state)) {
4067 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString());
4068 return true;
4069 }
4070 4071 return false;
4072 }
4073 4074 arith_uint256 CalculateClaimedHeadersWork(std::span<const CBlockHeader> headers)
4075 {
4076 arith_uint256 total_work{0};
4077 for (const CBlockHeader& header : headers) {
4078 total_work += GetBlockProof(header);
4079 }
4080 return total_work;
4081 }
4082 4083 /** Context-dependent validity checks.
4084 * By "context", we mean only the previous block headers, but not the UTXO
4085 * set; UTXO-related validity checks are done in ConnectBlock().
4086 * NOTE: This function is not currently invoked by ConnectBlock(), so we
4087 * should consider upgrade issues if we change which consensus rules are
4088 * enforced in this function (eg by adding a new consensus rule). See comment
4089 * in ConnectBlock().
4090 * Note that -reindex-chainstate skips the validation that happens here!
4091 *
4092 * NOTE: failing to check the header's height against the last checkpoint's opened a DoS vector between
4093 * v0.12 and v0.15 (when no additional protection was in place) whereby an attacker could unboundedly
4094 * grow our in-memory block index. See https://bitcoincore.org/en/2024/07/03/disclose-header-spam.
4095 */
4096 static bool ContextualCheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, const ChainstateManager& chainman, const CBlockIndex* pindexPrev) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
4097 {
4098 AssertLockHeld(::cs_main);
4099 assert(pindexPrev != nullptr);
4100 const int nHeight = pindexPrev->nHeight + 1;
4101 4102 // Check proof of work
4103 const Consensus::Params& consensusParams = chainman.GetConsensus();
4104 if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams))
4105 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "bad-diffbits", "incorrect proof of work");
4106 4107 // Check timestamp against prev
4108 if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
4109 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-too-old", "block's timestamp is too early");
4110 4111 // Testnet4 and regtest only: Check timestamp against prev for difficulty-adjustment
4112 // blocks to prevent timewarp attacks (see https://github.com/bitcoin/bitcoin/pull/15482).
4113 if (consensusParams.enforce_BIP94) {
4114 // Check timestamp for the first block of each difficulty adjustment
4115 // interval, except the genesis block.
4116 if (nHeight % consensusParams.DifficultyAdjustmentInterval() == 0) {
4117 if (block.GetBlockTime() < pindexPrev->GetBlockTime() - MAX_TIMEWARP) {
4118 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-timewarp-attack", "block's timestamp is too early on diff adjustment block");
4119 }
4120 }
4121 }
4122 4123 // Check timestamp
4124 if (block.Time() > NodeClock::now() + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) {
4125 return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE, "time-too-new", "block timestamp too far in the future");
4126 }
4127 4128 // Reject blocks with outdated version
4129 if ((block.nVersion < 2 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) ||
4130 (block.nVersion < 3 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_DERSIG)) ||
4131 (block.nVersion < 4 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CLTV))) {
4132 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, strprintf("bad-version(0x%08x)", block.nVersion),
4133 strprintf("rejected nVersion=0x%08x block", block.nVersion));
4134 }
4135 4136 return true;
4137 }
4138 4139 /** NOTE: This function is not currently invoked by ConnectBlock(), so we
4140 * should consider upgrade issues if we change which consensus rules are
4141 * enforced in this function (eg by adding a new consensus rule). See comment
4142 * in ConnectBlock().
4143 * Note that -reindex-chainstate skips the validation that happens here!
4144 */
4145 static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& state, const ChainstateManager& chainman, const CBlockIndex* pindexPrev)
4146 {
4147 const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
4148 4149 // Enforce BIP113 (Median Time Past).
4150 bool enforce_locktime_median_time_past{false};
4151 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CSV)) {
4152 assert(pindexPrev != nullptr);
4153 enforce_locktime_median_time_past = true;
4154 }
4155 4156 const int64_t nLockTimeCutoff{enforce_locktime_median_time_past ?
4157 pindexPrev->GetMedianTimePast() :
4158 block.GetBlockTime()};
4159 4160 // Check that all transactions are finalized
4161 for (const auto& tx : block.vtx) {
4162 if (!IsFinalTx(*tx, nHeight, nLockTimeCutoff)) {
4163 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", "non-final transaction");
4164 }
4165 }
4166 4167 // Enforce rule that the coinbase starts with serialized block height
4168 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB))
4169 {
4170 CScript expect = CScript() << nHeight;
4171 if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
4172 !std::equal(expect.begin(), expect.end(), block.vtx[0]->vin[0].scriptSig.begin())) {
4173 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-height", "block height mismatch in coinbase");
4174 }
4175 }
4176 4177 // Validation for witness commitments.
4178 // * We compute the witness hash (which is the hash including witnesses) of all the block's transactions, except the
4179 // coinbase (where 0x0000....0000 is used instead).
4180 // * The coinbase scriptWitness is a stack of a single 32-byte vector, containing a witness reserved value (unconstrained).
4181 // * We build a merkle tree with all those witness hashes as leaves (similar to the hashMerkleRoot in the block header).
4182 // * There must be at least one output whose scriptPubKey is a single 36-byte push, the first 4 bytes of which are
4183 // {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness reserved value). In case there are
4184 // multiple, the last one is used.
4185 if (!CheckWitnessMalleation(block, DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_SEGWIT), state)) {
4186 return false;
4187 }
4188 4189 // After the coinbase witness reserved value and commitment are verified,
4190 // we can check if the block weight passes (before we've checked the
4191 // coinbase witness, it would be possible for the weight to be too
4192 // large by filling up the coinbase witness, which doesn't change
4193 // the block hash, so we couldn't mark the block as permanently
4194 // failed).
4195 if (GetBlockWeight(block) > MAX_BLOCK_WEIGHT) {
4196 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-weight", strprintf("%s : weight limit failed", __func__));
4197 }
4198 4199 return true;
4200 }
4201 4202 bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationState& state, CBlockIndex** ppindex, bool min_pow_checked)
4203 {
4204 AssertLockHeld(cs_main);
4205 4206 // Check for duplicate
4207 uint256 hash = block.GetHash();
4208 BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)};
4209 if (hash != GetConsensus().hashGenesisBlock) {
4210 if (miSelf != m_blockman.m_block_index.end()) {
4211 // Block header is already known.
4212 CBlockIndex* pindex = &(miSelf->second);
4213 if (ppindex)
4214 *ppindex = pindex;
4215 if (pindex->nStatus & BLOCK_FAILED_VALID) {
4216 LogDebug(BCLog::VALIDATION, "%s: block %s is marked invalid\n", __func__, hash.ToString());
4217 return state.Invalid(BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate-invalid",
4218 strprintf("block %s was previously marked invalid", hash.ToString()));
4219 }
4220 return true;
4221 }
4222 4223 if (!CheckBlockHeader(block, state, GetConsensus())) {
4224 LogDebug(BCLog::VALIDATION, "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
4225 return false;
4226 }
4227 4228 // Get prev block index
4229 CBlockIndex* pindexPrev = nullptr;
4230 BlockMap::iterator mi{m_blockman.m_block_index.find(block.hashPrevBlock)};
4231 if (mi == m_blockman.m_block_index.end()) {
4232 LogDebug(BCLog::VALIDATION, "header %s has prev block not found: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
4233 return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV, "prev-blk-not-found");
4234 }
4235 pindexPrev = &((*mi).second);
4236 if (pindexPrev->nStatus & BLOCK_FAILED_VALID) {
4237 LogDebug(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
4238 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk");
4239 }
4240 if (!ContextualCheckBlockHeader(block, state, *this, pindexPrev)) {
4241 LogDebug(BCLog::VALIDATION, "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
4242 return false;
4243 }
4244 }
4245 if (!min_pow_checked) {
4246 LogDebug(BCLog::VALIDATION, "%s: not adding new block header %s, missing anti-dos proof-of-work validation\n", __func__, hash.ToString());
4247 return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK, "too-little-chainwork");
4248 }
4249 CBlockIndex* pindex{m_blockman.AddToBlockIndex(block, m_best_header)};
4250 4251 if (ppindex)
4252 *ppindex = pindex;
4253 4254 return true;
4255 }
4256 4257 // Exposed wrapper for AcceptBlockHeader
4258 bool ChainstateManager::ProcessNewBlockHeaders(std::span<const CBlockHeader> headers, bool min_pow_checked, BlockValidationState& state, const CBlockIndex** ppindex)
4259 {
4260 AssertLockNotHeld(cs_main);
4261 {
4262 LOCK(cs_main);
4263 for (const CBlockHeader& header : headers) {
4264 CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast
4265 bool accepted{AcceptBlockHeader(header, state, &pindex, min_pow_checked)};
4266 CheckBlockIndex();
4267 4268 if (!accepted) {
4269 return false;
4270 }
4271 if (ppindex) {
4272 *ppindex = pindex;
4273 }
4274 }
4275 }
4276 if (NotifyHeaderTip()) {
4277 if (IsInitialBlockDownload() && ppindex && *ppindex) {
4278 const CBlockIndex& last_accepted{**ppindex};
4279 int64_t blocks_left{(NodeClock::now() - last_accepted.Time()) / GetConsensus().PowTargetSpacing()};
4280 blocks_left = std::max<int64_t>(0, blocks_left);
4281 const double progress{100.0 * last_accepted.nHeight / (last_accepted.nHeight + blocks_left)};
4282 LogInfo("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress);
4283 }
4284 }
4285 return true;
4286 }
4287 4288 void ChainstateManager::ReportHeadersPresync(int64_t height, int64_t timestamp)
4289 {
4290 AssertLockNotHeld(GetMutex());
4291 {
4292 LOCK(GetMutex());
4293 // Don't report headers presync progress if we already have a post-minchainwork header chain.
4294 // This means we lose reporting for potentially legitimate, but unlikely, deep reorgs, but
4295 // prevent attackers that spam low-work headers from filling our logs.
4296 if (m_best_header->nChainWork >= UintToArith256(GetConsensus().nMinimumChainWork)) return;
4297 // Rate limit headers presync updates to 4 per second, as these are not subject to DoS
4298 // protection.
4299 auto now = MockableSteadyClock::now();
4300 if (now < m_last_presync_update + std::chrono::milliseconds{250}) return;
4301 m_last_presync_update = now;
4302 }
4303 bool initial_download = IsInitialBlockDownload();
4304 GetNotifications().headerTip(GetSynchronizationState(initial_download, m_blockman.m_blockfiles_indexed), height, timestamp, /*presync=*/true);
4305 if (initial_download) {
4306 int64_t blocks_left{(NodeClock::now() - NodeSeconds{std::chrono::seconds{timestamp}}) / GetConsensus().PowTargetSpacing()};
4307 blocks_left = std::max<int64_t>(0, blocks_left);
4308 const double progress{100.0 * height / (height + blocks_left)};
4309 LogInfo("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress);
4310 }
4311 }
4312 4313 /** Store block on disk. If dbp is non-nullptr, the file is known to already reside on disk */
4314 bool ChainstateManager::AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockValidationState& state, CBlockIndex** ppindex, bool fRequested, const FlatFilePos* dbp, bool* fNewBlock, bool min_pow_checked)
4315 {
4316 const CBlock& block = *pblock;
4317 4318 if (fNewBlock) *fNewBlock = false;
4319 AssertLockHeld(cs_main);
4320 4321 CBlockIndex *pindexDummy = nullptr;
4322 CBlockIndex *&pindex = ppindex ? *ppindex : pindexDummy;
4323 4324 bool accepted_header{AcceptBlockHeader(block, state, &pindex, min_pow_checked)};
4325 CheckBlockIndex();
4326 4327 if (!accepted_header)
4328 return false;
4329 4330 // Check all requested blocks that we do not already have for validity and
4331 // save them to disk. Skip processing of unrequested blocks as an anti-DoS
4332 // measure, unless the blocks have more work than the active chain tip, and
4333 // aren't too far ahead of it, so are likely to be attached soon.
4334 bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA;
4335 bool fHasMoreOrSameWork = (ActiveTip() ? pindex->nChainWork >= ActiveTip()->nChainWork : true);
4336 // Blocks that are too out-of-order needlessly limit the effectiveness of
4337 // pruning, because pruning will not delete block files that contain any
4338 // blocks which are too close in height to the tip. Apply this test
4339 // regardless of whether pruning is enabled; it should generally be safe to
4340 // not process unrequested blocks.
4341 bool fTooFarAhead{pindex->nHeight > ActiveHeight() + int(MIN_BLOCKS_TO_KEEP)};
4342 4343 // TODO: Decouple this function from the block download logic by removing fRequested
4344 // This requires some new chain data structure to efficiently look up if a
4345 // block is in a chain leading to a candidate for best tip, despite not
4346 // being such a candidate itself.
4347 // Note that this would break the getblockfrompeer RPC
4348 4349 // TODO: deal better with return value and error conditions for duplicate
4350 // and unrequested blocks.
4351 if (fAlreadyHave) return true;
4352 if (!fRequested) { // If we didn't ask for it:
4353 if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned
4354 if (!fHasMoreOrSameWork) return true; // Don't process less-work chains
4355 if (fTooFarAhead) return true; // Block height is too high
4356 4357 // Protect against DoS attacks from low-work chains.
4358 // If our tip is behind, a peer could try to send us
4359 // low-work blocks on a fake chain that we would never
4360 // request; don't process these.
4361 if (pindex->nChainWork < MinimumChainWork()) return true;
4362 }
4363 4364 const CChainParams& params{GetParams()};
4365 4366 if (!CheckBlock(block, state, params.GetConsensus()) ||
4367 !ContextualCheckBlock(block, state, *this, pindex->pprev)) {
4368 if (Assume(state.IsInvalid())) {
4369 ActiveChainstate().InvalidBlockFound(pindex, state);
4370 }
4371 LogError("%s: %s\n", __func__, state.ToString());
4372 return false;
4373 }
4374 4375 // Header is valid/has work, merkle tree and segwit merkle tree are good...RELAY NOW
4376 // (but if it does not build on our best tip, let the SendMessages loop relay it)
4377 if (!IsInitialBlockDownload() && ActiveTip() == pindex->pprev && m_options.signals) {
4378 m_options.signals->NewPoWValidBlock(pindex, pblock);
4379 }
4380 4381 // Write block to history file
4382 if (fNewBlock) *fNewBlock = true;
4383 try {
4384 FlatFilePos blockPos{};
4385 if (dbp) {
4386 blockPos = *dbp;
4387 m_blockman.UpdateBlockInfo(block, pindex->nHeight, blockPos);
4388 } else {
4389 blockPos = m_blockman.WriteBlock(block, pindex->nHeight);
4390 if (blockPos.IsNull()) {
4391 state.Error(strprintf("%s: Failed to find position to write new block to disk", __func__));
4392 return false;
4393 }
4394 }
4395 ReceivedBlockTransactions(block, pindex, blockPos);
4396 } catch (const std::runtime_error& e) {
4397 return FatalError(GetNotifications(), state, strprintf(_("System error while saving block to disk: %s"), e.what()));
4398 }
4399 4400 // TODO: FlushStateToDisk() handles flushing of both block and chainstate
4401 // data, so we should move this to ChainstateManager so that we can be more
4402 // intelligent about how we flush.
4403 // For now, since FlushStateMode::NONE is used, all that can happen is that
4404 // the block files may be pruned, so we can just call this on one
4405 // chainstate (particularly if we haven't implemented pruning with
4406 // background validation yet).
4407 //
4408 // Flush errors (e.g. low disk space during pruning) are ignored, so that
4409 // callers can't mistreat a flush failure as a block validation failure.
4410 // The fatal error notification inside FlushStateToDisk still fires,
4411 // so the node will shut down on unrecoverable flush errors regardless.
4412 // For state a dummy value is used, and the return value is ignored.
4413 BlockValidationState flush_state_ignore;
4414 (void)ActiveChainstate().FlushStateToDisk(flush_state_ignore, FlushStateMode::NONE);
4415 4416 CheckBlockIndex();
4417 4418 return true;
4419 }
4420 4421 bool ChainstateManager::ProcessNewBlock(const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked, bool* new_block)
4422 {
4423 AssertLockNotHeld(cs_main);
4424 4425 {
4426 CBlockIndex *pindex = nullptr;
4427 if (new_block) *new_block = false;
4428 BlockValidationState state;
4429 4430 // CheckBlock() does not support multi-threaded block validation because CBlock::fChecked can cause data race.
4431 // Therefore, the following critical section must include the CheckBlock() call as well.
4432 LOCK(cs_main);
4433 4434 // Skipping AcceptBlock() for CheckBlock() failures means that we will never mark a block as invalid if
4435 // CheckBlock() fails. This is protective against consensus failure if there are any unknown forms of block
4436 // malleability that cause CheckBlock() to fail; see e.g. CVE-2012-2459 and
4437 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html. Because CheckBlock() is
4438 // not very expensive, the anti-DoS benefits of caching failure (of a definitely-invalid block) are not substantial.
4439 bool ret = CheckBlock(*block, state, GetConsensus());
4440 if (ret) {
4441 // Store to disk
4442 ret = AcceptBlock(block, state, &pindex, force_processing, nullptr, new_block, min_pow_checked);
4443 }
4444 if (!ret) {
4445 if (m_options.signals) {
4446 m_options.signals->BlockChecked(block, state);
4447 }
4448 LogError("%s: AcceptBlock FAILED (%s)\n", __func__, state.ToString());
4449 return false;
4450 }
4451 }
4452 4453 NotifyHeaderTip();
4454 4455 BlockValidationState state; // Only used to report errors, not invalidity - ignore it
4456 if (!ActiveChainstate().ActivateBestChain(state, block)) {
4457 LogError("%s: ActivateBestChain failed (%s)\n", __func__, state.ToString());
4458 return false;
4459 }
4460 4461 Chainstate* bg_chain{WITH_LOCK(cs_main, return HistoricalChainstate())};
4462 BlockValidationState bg_state;
4463 if (bg_chain && !bg_chain->ActivateBestChain(bg_state, block)) {
4464 LogError("%s: [background] ActivateBestChain failed (%s)\n", __func__, bg_state.ToString());
4465 return false;
4466 }
4467 4468 return true;
4469 }
4470 4471 MempoolAcceptResult ChainstateManager::ProcessTransaction(const CTransactionRef& tx, bool test_accept)
4472 {
4473 AssertLockHeld(cs_main);
4474 Chainstate& active_chainstate = ActiveChainstate();
4475 if (!active_chainstate.GetMempool()) {
4476 TxValidationState state;
4477 state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool");
4478 return MempoolAcceptResult::Failure(state);
4479 }
4480 auto result = AcceptToMemoryPool(active_chainstate, tx, GetTime(), /*bypass_limits=*/ false, test_accept);
4481 active_chainstate.GetMempool()->check(active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1);
4482 return result;
4483 }
4484 4485 4486 BlockValidationState TestBlockValidity(
4487 Chainstate& chainstate,
4488 const CBlock& block,
4489 const bool check_pow,
4490 const bool check_merkle_root)
4491 {
4492 // Lock must be held throughout this function for two reasons:
4493 // 1. We don't want the tip to change during several of the validation steps
4494 // 2. To prevent a CheckBlock() race condition for fChecked, see ProcessNewBlock()
4495 AssertLockHeld(chainstate.m_chainman.GetMutex());
4496 4497 BlockValidationState state;
4498 CBlockIndex* tip{Assert(chainstate.m_chain.Tip())};
4499 4500 if (block.hashPrevBlock != *Assert(tip->phashBlock)) {
4501 state.Invalid({}, "inconclusive-not-best-prevblk");
4502 return state;
4503 }
4504 4505 // For signets CheckBlock() verifies the challenge iff fCheckPow is set.
4506 if (!CheckBlock(block, state, chainstate.m_chainman.GetConsensus(), /*fCheckPow=*/check_pow, /*fCheckMerkleRoot=*/check_merkle_root)) {
4507 // This should never happen, but belt-and-suspenders don't approve the
4508 // block if it does.
4509 if (state.IsValid()) NONFATAL_UNREACHABLE();
4510 return state;
4511 }
4512 4513 /**
4514 * At this point ProcessNewBlock would call AcceptBlock(), but we
4515 * don't want to store the block or its header. Run individual checks
4516 * instead:
4517 * - skip AcceptBlockHeader() because:
4518 * - we don't want to update the block index
4519 * - we do not care about duplicates
4520 * - we already ran CheckBlockHeader() via CheckBlock()
4521 * - we already checked for prev-blk-not-found
4522 * - we know the tip is valid, so no need to check bad-prevblk
4523 * - we already ran CheckBlock()
4524 * - do run ContextualCheckBlockHeader()
4525 * - do run ContextualCheckBlock()
4526 */
4527 4528 if (!ContextualCheckBlockHeader(block, state, chainstate.m_chainman, tip)) {
4529 if (state.IsValid()) NONFATAL_UNREACHABLE();
4530 return state;
4531 }
4532 4533 if (!ContextualCheckBlock(block, state, chainstate.m_chainman, tip)) {
4534 if (state.IsValid()) NONFATAL_UNREACHABLE();
4535 return state;
4536 }
4537 4538 // We don't want ConnectBlock to update the actual chainstate, so create
4539 // a cache on top of it, along with a dummy block index.
4540 CBlockIndex index_dummy{block};
4541 uint256 block_hash(block.GetHash());
4542 index_dummy.pprev = tip;
4543 index_dummy.nHeight = tip->nHeight + 1;
4544 index_dummy.phashBlock = &block_hash;
4545 CCoinsViewCache view_dummy(&chainstate.CoinsTip());
4546 4547 // Set fJustCheck to true in order to update, and not clear, validation caches.
4548 if(!chainstate.ConnectBlock(block, state, &index_dummy, view_dummy, /*fJustCheck=*/true)) {
4549 if (state.IsValid()) NONFATAL_UNREACHABLE();
4550 return state;
4551 }
4552 4553 // Ensure no check returned successfully while also setting an invalid state.
4554 if (!state.IsValid()) NONFATAL_UNREACHABLE();
4555 4556 return state;
4557 }
4558 4559 /* This function is called from the RPC code for pruneblockchain */
4560 void PruneBlockFilesManual(Chainstate& active_chainstate, int nManualPruneHeight)
4561 {
4562 BlockValidationState state;
4563 if (!active_chainstate.FlushStateToDisk(
4564 state, FlushStateMode::NONE, nManualPruneHeight)) {
4565 LogWarning("Failed to flush state after manual prune (%s)", state.ToString());
4566 }
4567 }
4568 4569 bool Chainstate::LoadChainTip()
4570 {
4571 AssertLockHeld(cs_main);
4572 const CCoinsViewCache& coins_cache = CoinsTip();
4573 assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty
4574 CBlockIndex* tip = m_chain.Tip();
4575 4576 if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) {
4577 return true;
4578 }
4579 4580 // Load pointer to end of best chain
4581 CBlockIndex* pindex = m_blockman.LookupBlockIndex(coins_cache.GetBestBlock());
4582 if (!pindex) {
4583 return false;
4584 }
4585 m_chain.SetTip(*pindex);
4586 m_chainman.UpdateIBDStatus();
4587 m_last_flushed_block = pindex;
4588 tip = m_chain.Tip();
4589 4590 // nSequenceId is one of the keys used to sort setBlockIndexCandidates. Ensure all
4591 // candidate sets are empty to avoid UB, as nSequenceId is about to be modified.
4592 for (const auto& cs : m_chainman.m_chainstates) {
4593 assert(cs->setBlockIndexCandidates.empty());
4594 }
4595 4596 // Make sure our chain tip before shutting down scores better than any other candidate
4597 // to maintain a consistent best tip over reboots in case of a tie.
4598 auto target = tip;
4599 while (target) {
4600 target->nSequenceId = SEQ_ID_BEST_CHAIN_FROM_DISK;
4601 target = target->pprev;
4602 }
4603 4604 LogInfo("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f",
4605 tip->GetBlockHash().ToString(),
4606 m_chain.Height(),
4607 FormatISO8601DateTime(tip->GetBlockTime()),
4608 m_chainman.GuessVerificationProgress(tip));
4609 4610 // Ensure KernelNotifications m_tip_block is set even if no new block arrives.
4611 if (!this->GetRole().historical) {
4612 // Ignoring return value for now.
4613 (void)m_chainman.GetNotifications().blockTip(
4614 /*state=*/GetSynchronizationState(/*init=*/true, m_chainman.m_blockman.m_blockfiles_indexed),
4615 /*index=*/*pindex,
4616 /*verification_progress=*/m_chainman.GuessVerificationProgress(tip));
4617 }
4618 4619 CheckForkWarningConditions();
4620 4621 return true;
4622 }
4623 4624 CVerifyDB::CVerifyDB(Notifications& notifications)
4625 : m_notifications{notifications}
4626 {
4627 m_notifications.progress(_("Verifying blocks…"), 0, false);
4628 }
4629 4630 CVerifyDB::~CVerifyDB()
4631 {
4632 m_notifications.progress(bilingual_str{}, 100, false);
4633 }
4634 4635 VerifyDBResult CVerifyDB::VerifyDB(
4636 Chainstate& chainstate,
4637 const Consensus::Params& consensus_params,
4638 CCoinsView& coinsview,
4639 int nCheckLevel, int nCheckDepth)
4640 {
4641 AssertLockHeld(cs_main);
4642 4643 if (chainstate.m_chain.Tip() == nullptr || chainstate.m_chain.Tip()->pprev == nullptr) {
4644 return VerifyDBResult::SUCCESS;
4645 }
4646 4647 // Verify blocks in the best chain
4648 if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) {
4649 nCheckDepth = chainstate.m_chain.Height();
4650 }
4651 nCheckLevel = std::max(0, std::min(4, nCheckLevel));
4652 LogInfo("Verifying last %i blocks at level %i", nCheckDepth, nCheckLevel);
4653 CCoinsViewCache coins(&coinsview);
4654 CBlockIndex* pindex;
4655 CBlockIndex* pindexFailure = nullptr;
4656 int nGoodTransactions = 0;
4657 BlockValidationState state;
4658 int reportDone = 0;
4659 bool skipped_no_block_data{false};
4660 bool skipped_l3_checks{false};
4661 LogInfo("Verification progress: 0%%");
4662 4663 const bool is_snapshot_cs{chainstate.m_from_snapshot_blockhash};
4664 4665 for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev; pindex = pindex->pprev) {
4666 const int percentageDone = std::max(1, std::min(99, (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100))));
4667 if (reportDone < percentageDone / 10) {
4668 // report every 10% step
4669 LogInfo("Verification progress: %d%%", percentageDone);
4670 reportDone = percentageDone / 10;
4671 }
4672 m_notifications.progress(_("Verifying blocks…"), percentageDone, false);
4673 if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) {
4674 break;
4675 }
4676 if ((chainstate.m_blockman.IsPruneMode() || is_snapshot_cs) && !(pindex->nStatus & BLOCK_HAVE_DATA)) {
4677 // If pruning or running under an assumeutxo snapshot, only go
4678 // back as far as we have data.
4679 LogInfo("Block verification stopping at height %d (no data). This could be due to pruning or use of an assumeutxo snapshot.", pindex->nHeight);
4680 skipped_no_block_data = true;
4681 break;
4682 }
4683 CBlock block;
4684 // check level 0: read from disk
4685 if (!chainstate.m_blockman.ReadBlock(block, *pindex)) {
4686 LogError("Verification error: ReadBlock failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
4687 return VerifyDBResult::CORRUPTED_BLOCK_DB;
4688 }
4689 // check level 1: verify block validity
4690 if (nCheckLevel >= 1 && !CheckBlock(block, state, consensus_params)) {
4691 LogError("Verification error: found bad block at %d, hash=%s (%s)",
4692 pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString());
4693 return VerifyDBResult::CORRUPTED_BLOCK_DB;
4694 }
4695 // check level 2: verify undo validity
4696 if (nCheckLevel >= 2 && pindex) {
4697 CBlockUndo undo;
4698 if (!pindex->GetUndoPos().IsNull()) {
4699 if (!chainstate.m_blockman.ReadBlockUndo(undo, *pindex)) {
4700 LogError("Verification error: found bad undo data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
4701 return VerifyDBResult::CORRUPTED_BLOCK_DB;
4702 }
4703 }
4704 }
4705 // check level 3: check for inconsistencies during memory-only disconnect of tip blocks
4706 size_t curr_coins_usage = coins.DynamicMemoryUsage() + chainstate.CoinsTip().DynamicMemoryUsage();
4707 4708 if (nCheckLevel >= 3) {
4709 if (curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) {
4710 assert(coins.GetBestBlock() == pindex->GetBlockHash());
4711 DisconnectResult res = chainstate.DisconnectBlock(block, pindex, coins);
4712 if (res == DISCONNECT_FAILED) {
4713 LogError("Verification error: irrecoverable inconsistency in block data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
4714 return VerifyDBResult::CORRUPTED_BLOCK_DB;
4715 }
4716 if (res == DISCONNECT_UNCLEAN) {
4717 nGoodTransactions = 0;
4718 pindexFailure = pindex;
4719 } else {
4720 nGoodTransactions += block.vtx.size();
4721 }
4722 } else {
4723 skipped_l3_checks = true;
4724 }
4725 }
4726 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED;
4727 }
4728 if (pindexFailure) {
4729 LogError("Verification error: coin database inconsistencies found (last %i blocks, %i good transactions before that)", chainstate.m_chain.Height() - pindexFailure->nHeight + 1, nGoodTransactions);
4730 return VerifyDBResult::CORRUPTED_BLOCK_DB;
4731 }
4732 if (skipped_l3_checks) {
4733 LogWarning("Skipped verification of level >=3 (insufficient database cache size). Consider increasing -dbcache.");
4734 }
4735 4736 // store block count as we move pindex at check level >= 4
4737 int block_count = chainstate.m_chain.Height() - pindex->nHeight;
4738 4739 // check level 4: try reconnecting blocks
4740 if (nCheckLevel >= 4 && !skipped_l3_checks) {
4741 while (pindex != chainstate.m_chain.Tip()) {
4742 const int percentageDone = std::max(1, std::min(99, 100 - (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * 50)));
4743 if (reportDone < percentageDone / 10) {
4744 // report every 10% step
4745 LogInfo("Verification progress: %d%%", percentageDone);
4746 reportDone = percentageDone / 10;
4747 }
4748 m_notifications.progress(_("Verifying blocks…"), percentageDone, false);
4749 pindex = chainstate.m_chain.Next(*pindex);
4750 CBlock block;
4751 if (!chainstate.m_blockman.ReadBlock(block, *pindex)) {
4752 LogError("Verification error: ReadBlock failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
4753 return VerifyDBResult::CORRUPTED_BLOCK_DB;
4754 }
4755 if (!chainstate.ConnectBlock(block, state, pindex, coins)) {
4756 LogError("Verification error: found unconnectable block at %d, hash=%s (%s)", pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString());
4757 return VerifyDBResult::CORRUPTED_BLOCK_DB;
4758 }
4759 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED;
4760 }
4761 }
4762 4763 LogInfo("Verification: checked last %i blocks at level %i", block_count, nCheckLevel);
4764 if (nCheckLevel >= 3 && !skipped_l3_checks) {
4765 LogInfo("Verification: no coin database inconsistencies (%i transactions)", nGoodTransactions);
4766 }
4767 4768 if (skipped_l3_checks) {
4769 return VerifyDBResult::SKIPPED_L3_CHECKS;
4770 }
4771 if (skipped_no_block_data) {
4772 return VerifyDBResult::SKIPPED_MISSING_BLOCKS;
4773 }
4774 return VerifyDBResult::SUCCESS;
4775 }
4776 4777 /** Apply the effects of a block on the utxo cache, ignoring that it may already have been applied. */
4778 bool Chainstate::RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs)
4779 {
4780 AssertLockHeld(cs_main);
4781 // TODO: merge with ConnectBlock
4782 CBlock block;
4783 if (!m_blockman.ReadBlock(block, *pindex)) {
4784 LogError("ReplayBlock(): ReadBlock failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
4785 return false;
4786 }
4787 4788 for (const CTransactionRef& tx : block.vtx) {
4789 if (!tx->IsCoinBase()) {
4790 for (const CTxIn &txin : tx->vin) {
4791 inputs.SpendCoin(txin.prevout);
4792 }
4793 }
4794 // Pass check = true as every addition may be an overwrite.
4795 AddCoins(inputs, *tx, pindex->nHeight, true);
4796 }
4797 return true;
4798 }
4799 4800 bool Chainstate::ReplayBlocks()
4801 {
4802 LOCK(cs_main);
4803 4804 CCoinsView& db = this->CoinsDB();
4805 CCoinsViewCache cache(&db);
4806 4807 std::vector<uint256> hashHeads = db.GetHeadBlocks();
4808 if (hashHeads.empty()) return true; // We're already in a consistent state.
4809 if (hashHeads.size() != 2) {
4810 LogError("ReplayBlocks(): unknown inconsistent state\n");
4811 return false;
4812 }
4813 4814 m_chainman.GetNotifications().progress(_("Replaying blocks…"), 0, false);
4815 LogInfo("Replaying blocks");
4816 4817 const CBlockIndex* pindexOld = nullptr; // Old tip during the interrupted flush.
4818 const CBlockIndex* pindexNew; // New tip during the interrupted flush.
4819 const CBlockIndex* pindexFork = nullptr; // Latest block common to both the old and the new tip.
4820 4821 if (!m_blockman.m_block_index.contains(hashHeads[0])) {
4822 LogError("ReplayBlocks(): reorganization to unknown block requested\n");
4823 return false;
4824 }
4825 pindexNew = &(m_blockman.m_block_index[hashHeads[0]]);
4826 4827 if (!hashHeads[1].IsNull()) { // The old tip is allowed to be 0, indicating it's the first flush.
4828 if (!m_blockman.m_block_index.contains(hashHeads[1])) {
4829 LogError("ReplayBlocks(): reorganization from unknown block requested\n");
4830 return false;
4831 }
4832 pindexOld = &(m_blockman.m_block_index[hashHeads[1]]);
4833 pindexFork = LastCommonAncestor(pindexOld, pindexNew);
4834 assert(pindexFork != nullptr);
4835 }
4836 4837 // Rollback along the old branch.
4838 const int nForkHeight{pindexFork ? pindexFork->nHeight : 0};
4839 if (pindexOld != pindexFork) {
4840 LogInfo("Rolling back from %s (%i to %i)", pindexOld->GetBlockHash().ToString(), pindexOld->nHeight, nForkHeight);
4841 while (pindexOld != pindexFork) {
4842 if (pindexOld->nHeight > 0) { // Never disconnect the genesis block.
4843 CBlock block;
4844 if (!m_blockman.ReadBlock(block, *pindexOld)) {
4845 LogError("RollbackBlock(): ReadBlock() failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
4846 return false;
4847 }
4848 if (pindexOld->nHeight % 10'000 == 0) {
4849 LogInfo("Rolling back %s (%i)", pindexOld->GetBlockHash().ToString(), pindexOld->nHeight);
4850 }
4851 DisconnectResult res = DisconnectBlock(block, pindexOld, cache);
4852 if (res == DISCONNECT_FAILED) {
4853 LogError("RollbackBlock(): DisconnectBlock failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
4854 return false;
4855 }
4856 // If DISCONNECT_UNCLEAN is returned, it means a non-existing UTXO was deleted, or an existing UTXO was
4857 // overwritten. It corresponds to cases where the block-to-be-disconnect never had all its operations
4858 // applied to the UTXO set. However, as both writing a UTXO and deleting a UTXO are idempotent operations,
4859 // the result is still a version of the UTXO set with the effects of that block undone.
4860 }
4861 pindexOld = pindexOld->pprev;
4862 }
4863 LogInfo("Rolled back to %s", pindexFork->GetBlockHash().ToString());
4864 }
4865 4866 // Roll forward from the forking point to the new tip.
4867 if (nForkHeight < pindexNew->nHeight) {
4868 LogInfo("Rolling forward to %s (%i to %i)", pindexNew->GetBlockHash().ToString(), nForkHeight, pindexNew->nHeight);
4869 for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight; ++nHeight) {
4870 const CBlockIndex& pindex{*Assert(pindexNew->GetAncestor(nHeight))};
4871 4872 if (nHeight % 10'000 == 0) {
4873 LogInfo("Rolling forward %s (%i)", pindex.GetBlockHash().ToString(), nHeight);
4874 }
4875 m_chainman.GetNotifications().progress(_("Replaying blocks…"), (int)((nHeight - nForkHeight) * 100.0 / (pindexNew->nHeight - nForkHeight)), false);
4876 if (!RollforwardBlock(&pindex, cache)) return false;
4877 }
4878 LogInfo("Rolled forward to %s", pindexNew->GetBlockHash().ToString());
4879 }
4880 4881 cache.SetBestBlock(pindexNew->GetBlockHash());
4882 cache.Flush(/*reallocate_cache=*/false); // local CCoinsViewCache goes out of scope
4883 m_chainman.GetNotifications().progress(bilingual_str{}, 100, false);
4884 return true;
4885 }
4886 4887 bool Chainstate::NeedsRedownload() const
4888 {
4889 AssertLockHeld(cs_main);
4890 4891 // At and above m_params.SegwitHeight, segwit consensus rules must be validated
4892 CBlockIndex* block{m_chain.Tip()};
4893 4894 while (block != nullptr && DeploymentActiveAt(*block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) {
4895 if (!(block->nStatus & BLOCK_OPT_WITNESS)) {
4896 // block is insufficiently validated for a segwit client
4897 return true;
4898 }
4899 block = block->pprev;
4900 }
4901 4902 return false;
4903 }
4904 4905 void Chainstate::ClearBlockIndexCandidates()
4906 {
4907 AssertLockHeld(::cs_main);
4908 setBlockIndexCandidates.clear();
4909 }
4910 4911 void Chainstate::PopulateBlockIndexCandidates()
4912 {
4913 AssertLockHeld(::cs_main);
4914 4915 for (CBlockIndex* pindex : m_blockman.GetAllBlockIndices()) {
4916 // With assumeutxo, the snapshot block is a candidate for the tip, but it
4917 // may not have BLOCK_VALID_TRANSACTIONS (e.g. if we haven't yet downloaded
4918 // the block), so we special-case it here.
4919 if (pindex == SnapshotBase() ||
4920 (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) &&
4921 (pindex->HaveNumChainTxs() || pindex->pprev == nullptr))) {
4922 TryAddBlockIndexCandidate(pindex);
4923 }
4924 }
4925 }
4926 4927 bool ChainstateManager::LoadBlockIndex()
4928 {
4929 AssertLockHeld(cs_main);
4930 // Load block index from databases
4931 if (m_blockman.m_blockfiles_indexed) {
4932 bool ret{m_blockman.LoadBlockIndexDB(CurrentChainstate().m_from_snapshot_blockhash)};
4933 if (!ret) return false;
4934 4935 m_blockman.ScanAndUnlinkAlreadyPrunedFiles();
4936 4937 std::vector<CBlockIndex*> vSortedByHeight{m_blockman.GetAllBlockIndices()};
4938 std::sort(vSortedByHeight.begin(), vSortedByHeight.end(),
4939 CBlockIndexHeightOnlyComparator());
4940 4941 for (CBlockIndex* pindex : vSortedByHeight) {
4942 if (m_interrupt) return false;
4943 if (pindex->nStatus & BLOCK_FAILED_VALID && (!m_best_invalid || pindex->nChainWork > m_best_invalid->nChainWork)) {
4944 m_best_invalid = pindex;
4945 }
4946 if (pindex->IsValid(BLOCK_VALID_TREE) && (m_best_header == nullptr || CBlockIndexWorkComparator()(m_best_header, pindex)))
4947 m_best_header = pindex;
4948 }
4949 }
4950 return true;
4951 }
4952 4953 bool ChainstateManager::LoadGenesisBlock()
4954 {
4955 LOCK(cs_main);
4956 4957 const CBlock& genesis_block{GetParams().GenesisBlock()};
4958 4959 // Check whether we're already initialized by checking for genesis in
4960 // m_blockman.m_block_index. Note that we can't use a chainstate's m_chain here, since it is
4961 // set based on the coins db, not the block index db, which is the only
4962 // thing loaded at this point.
4963 if (m_blockman.m_block_index.contains(genesis_block.GetHash())) {
4964 return true;
4965 }
4966 4967 try {
4968 FlatFilePos blockPos{m_blockman.WriteBlock(genesis_block, 0)};
4969 if (blockPos.IsNull()) {
4970 LogError("Writing genesis block to disk failed");
4971 return false;
4972 }
4973 CBlockIndex* pindex{m_blockman.AddToBlockIndex(genesis_block, m_best_header)};
4974 ReceivedBlockTransactions(genesis_block, pindex, blockPos);
4975 } catch (const std::runtime_error& e) {
4976 LogError("Failed to write genesis block: %s", e.what());
4977 return false;
4978 }
4979 4980 return true;
4981 }
4982 4983 void ChainstateManager::LoadExternalBlockFile(
4984 AutoFile& file_in,
4985 FlatFilePos* dbp,
4986 std::multimap<uint256, FlatFilePos>* blocks_with_unknown_parent)
4987 {
4988 // Either both should be specified (-reindex), or neither (-loadblock).
4989 assert(!dbp == !blocks_with_unknown_parent);
4990 4991 const auto start{SteadyClock::now()};
4992 const CChainParams& params{GetParams()};
4993 4994 int nLoaded = 0;
4995 try {
4996 BufferedFile blkdat{file_in, 2 * MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE + 8};
4997 // nRewind indicates where to resume scanning in case something goes wrong,
4998 // such as a block fails to deserialize.
4999 uint64_t nRewind = blkdat.GetPos();
5000 while (!blkdat.eof()) {
5001 if (m_interrupt) return;
5002 5003 blkdat.SetPos(nRewind);
5004 nRewind++; // start one byte further next time, in case of failure
5005 blkdat.SetLimit(); // remove former limit
5006 unsigned int nSize = 0;
5007 try {
5008 // locate a header
5009 MessageStartChars buf;
5010 blkdat.FindByte(std::byte(params.MessageStart()[0]));
5011 nRewind = blkdat.GetPos() + 1;
5012 blkdat >> buf;
5013 if (buf != params.MessageStart()) {
5014 continue;
5015 }
5016 // read size
5017 blkdat >> nSize;
5018 if (nSize < 80 || nSize > MAX_BLOCK_SERIALIZED_SIZE)
5019 continue;
5020 } catch (const std::exception&) {
5021 // no valid block header found; don't complain
5022 // (this happens at the end of every blk.dat file)
5023 break;
5024 }
5025 try {
5026 // read block header
5027 const uint64_t nBlockPos{blkdat.GetPos()};
5028 if (dbp)
5029 dbp->nPos = nBlockPos;
5030 blkdat.SetLimit(nBlockPos + nSize);
5031 CBlockHeader header;
5032 blkdat >> header;
5033 const uint256 hash{header.GetHash()};
5034 // Skip the rest of this block (this may read from disk into memory); position to the marker before the
5035 // next block, but it's still possible to rewind to the start of the current block (without a disk read).
5036 nRewind = nBlockPos + nSize;
5037 blkdat.SkipTo(nRewind);
5038 5039 std::shared_ptr<CBlock> pblock{}; // needs to remain available after the cs_main lock is released to avoid duplicate reads from disk
5040 5041 {
5042 LOCK(cs_main);
5043 // detect out of order blocks, and store them for later
5044 if (hash != params.GetConsensus().hashGenesisBlock && !m_blockman.LookupBlockIndex(header.hashPrevBlock)) {
5045 LogDebug(BCLog::REINDEX, "%s: Out of order block %s, parent %s not known\n", __func__, hash.ToString(),
5046 header.hashPrevBlock.ToString());
5047 if (dbp && blocks_with_unknown_parent) {
5048 blocks_with_unknown_parent->emplace(header.hashPrevBlock, *dbp);
5049 }
5050 continue;
5051 }
5052 5053 // process in case the block isn't known yet
5054 const CBlockIndex* pindex = m_blockman.LookupBlockIndex(hash);
5055 if (!pindex || (pindex->nStatus & BLOCK_HAVE_DATA) == 0) {
5056 // This block can be processed immediately; rewind to its start, read and deserialize it.
5057 blkdat.SetPos(nBlockPos);
5058 pblock = std::make_shared<CBlock>();
5059 blkdat >> TX_WITH_WITNESS(*pblock);
5060 nRewind = blkdat.GetPos();
5061 5062 BlockValidationState state;
5063 if (AcceptBlock(pblock, state, nullptr, true, dbp, nullptr, true)) {
5064 nLoaded++;
5065 }
5066 if (state.IsError()) {
5067 break;
5068 }
5069 } else if (hash != params.GetConsensus().hashGenesisBlock && pindex->nHeight % 1000 == 0) {
5070 LogDebug(BCLog::REINDEX, "Block Import: already had block %s at height %d\n", hash.ToString(), pindex->nHeight);
5071 }
5072 }
5073 5074 // Activate the genesis block so normal node progress can continue
5075 // During first -reindex, this will only connect Genesis since
5076 // ActivateBestChain only connects blocks which are in the block tree db,
5077 // which only contains blocks whose parents are in it.
5078 // But do this only if genesis isn't activated yet, to avoid connecting many blocks
5079 // without assumevalid in the case of a continuation of a reindex that
5080 // was interrupted by the user.
5081 if (hash == params.GetConsensus().hashGenesisBlock && WITH_LOCK(::cs_main, return ActiveHeight()) == -1) {
5082 BlockValidationState state;
5083 if (!ActiveChainstate().ActivateBestChain(state, nullptr)) {
5084 break;
5085 }
5086 }
5087 5088 if (m_blockman.IsPruneMode() && m_blockman.m_blockfiles_indexed && pblock) {
5089 // must update the tip for pruning to work while importing with -loadblock.
5090 // this is a tradeoff to conserve disk space at the expense of time
5091 // spent updating the tip to be able to prune.
5092 // otherwise, ActivateBestChain won't be called by the import process
5093 // until after all of the block files are loaded. ActivateBestChain can be
5094 // called by concurrent network message processing. but, that is not
5095 // reliable for the purpose of pruning while importing.
5096 if (auto result{ActivateBestChains()}; !result) {
5097 LogDebug(BCLog::REINDEX, "%s\n", util::ErrorString(result).original);
5098 break;
5099 }
5100 }
5101 5102 NotifyHeaderTip();
5103 5104 if (!blocks_with_unknown_parent) continue;
5105 5106 // Recursively process earlier encountered successors of this block
5107 std::deque<uint256> queue;
5108 queue.push_back(hash);
5109 while (!queue.empty()) {
5110 uint256 head = queue.front();
5111 queue.pop_front();
5112 auto range = blocks_with_unknown_parent->equal_range(head);
5113 while (range.first != range.second) {
5114 std::multimap<uint256, FlatFilePos>::iterator it = range.first;
5115 std::shared_ptr<CBlock> pblockrecursive = std::make_shared<CBlock>();
5116 if (m_blockman.ReadBlock(*pblockrecursive, it->second, {})) {
5117 const auto& block_hash{pblockrecursive->GetHash()};
5118 LogDebug(BCLog::REINDEX, "%s: Processing out of order child %s of %s", __func__, block_hash.ToString(), head.ToString());
5119 LOCK(cs_main);
5120 BlockValidationState dummy;
5121 if (AcceptBlock(pblockrecursive, dummy, nullptr, true, &it->second, nullptr, true)) {
5122 nLoaded++;
5123 queue.push_back(block_hash);
5124 }
5125 }
5126 range.first++;
5127 blocks_with_unknown_parent->erase(it);
5128 NotifyHeaderTip();
5129 }
5130 }
5131 } catch (const std::exception& e) {
5132 // historical bugs added extra data to the block files that does not deserialize cleanly.
5133 // commonly this data is between readable blocks, but it does not really matter. such data is not fatal to the import process.
5134 // the code that reads the block files deals with invalid data by simply ignoring it.
5135 // it continues to search for the next {4 byte magic message start bytes + 4 byte length + block} that does deserialize cleanly
5136 // and passes all of the other block validation checks dealing with POW and the merkle root, etc...
5137 // we merely note with this informational log message when unexpected data is encountered.
5138 // we could also be experiencing a storage system read error, or a read of a previous bad write. these are possible, but
5139 // less likely scenarios. we don't have enough information to tell a difference here.
5140 // the reindex process is not the place to attempt to clean and/or compact the block files. if so desired, a studious node operator
5141 // may use knowledge of the fact that the block files are not entirely pristine in order to prepare a set of pristine, and
5142 // perhaps ordered, block files for later reindexing.
5143 LogDebug(BCLog::REINDEX, "%s: unexpected data at file offset 0x%x - %s. continuing\n", __func__, (nRewind - 1), e.what());
5144 }
5145 }
5146 } catch (const std::runtime_error& e) {
5147 GetNotifications().fatalError(strprintf(_("System error while loading external block file: %s"), e.what()));
5148 }
5149 LogInfo("Loaded %i blocks from external file in %dms", nLoaded, Ticks<std::chrono::milliseconds>(SteadyClock::now() - start));
5150 }
5151 5152 bool ChainstateManager::ShouldCheckBlockIndex() const
5153 {
5154 // Assert to verify Flatten() has been called.
5155 if (!*Assert(m_options.check_block_index)) return false;
5156 if (FastRandomContext().randrange(*m_options.check_block_index) >= 1) return false;
5157 return true;
5158 }
5159 5160 void ChainstateManager::CheckBlockIndex() const
5161 {
5162 if (!ShouldCheckBlockIndex()) {
5163 return;
5164 }
5165 5166 LOCK(cs_main);
5167 5168 // During a reindex, we read the genesis block and call CheckBlockIndex before ActivateBestChain,
5169 // so we have the genesis block in m_blockman.m_block_index but no active chain. (A few of the
5170 // tests when iterating the block tree require that m_chain has been initialized.)
5171 if (ActiveChain().Height() < 0) {
5172 assert(m_blockman.m_block_index.size() <= 1);
5173 return;
5174 }
5175 5176 // Build forward-pointing data structure for the entire block tree.
5177 // For performance reasons, indexes of the best header chain are stored in a vector (within CChain).
5178 // All remaining blocks are stored in a multimap.
5179 // The best header chain can differ from the active chain: E.g. its entries may belong to blocks that
5180 // are not yet validated.
5181 CChain best_hdr_chain;
5182 assert(m_best_header);
5183 assert(!(m_best_header->nStatus & BLOCK_FAILED_VALID));
5184 best_hdr_chain.SetTip(*m_best_header);
5185 5186 std::multimap<const CBlockIndex*, const CBlockIndex*> forward;
5187 for (auto& [_, block_index] : m_blockman.m_block_index) {
5188 // Only save indexes in forward that are not part of the best header chain.
5189 if (!best_hdr_chain.Contains(block_index)) {
5190 // Only genesis, which must be part of the best header chain, can have a nullptr parent.
5191 assert(block_index.pprev);
5192 forward.emplace(block_index.pprev, &block_index);
5193 }
5194 }
5195 assert(forward.size() + best_hdr_chain.Height() + 1 == m_blockman.m_block_index.size());
5196 5197 const CBlockIndex* pindex = best_hdr_chain[0];
5198 assert(pindex);
5199 // Iterate over the entire block tree, using depth-first search.
5200 // Along the way, remember whether there are blocks on the path from genesis
5201 // block being explored which are the first to have certain properties.
5202 size_t nNodes = 0;
5203 int nHeight = 0;
5204 const CBlockIndex* pindexFirstInvalid = nullptr; // Oldest ancestor of pindex which is invalid.
5205 const CBlockIndex* pindexFirstMissing = nullptr; // Oldest ancestor of pindex which does not have BLOCK_HAVE_DATA, since assumeutxo snapshot if used.
5206 const CBlockIndex* pindexFirstNeverProcessed = nullptr; // Oldest ancestor of pindex for which nTx == 0, since assumeutxo snapshot if used.
5207 const CBlockIndex* pindexFirstNotTreeValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE (regardless of being valid or not).
5208 const CBlockIndex* pindexFirstNotTransactionsValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_TRANSACTIONS (regardless of being valid or not), since assumeutxo snapshot if used.
5209 const CBlockIndex* pindexFirstNotChainValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_CHAIN (regardless of being valid or not), since assumeutxo snapshot if used.
5210 const CBlockIndex* pindexFirstNotScriptsValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_SCRIPTS (regardless of being valid or not), since assumeutxo snapshot if used.
5211 5212 // After checking an assumeutxo snapshot block, reset pindexFirst pointers
5213 // to earlier blocks that have not been downloaded or validated yet, so
5214 // checks for later blocks can assume the earlier blocks were validated and
5215 // be stricter, testing for more requirements.
5216 const CBlockIndex* snap_base{CurrentChainstate().SnapshotBase()};
5217 const CBlockIndex *snap_first_missing{}, *snap_first_notx{}, *snap_first_notv{}, *snap_first_nocv{}, *snap_first_nosv{};
5218 auto snap_update_firsts = [&] {
5219 if (pindex == snap_base) {
5220 std::swap(snap_first_missing, pindexFirstMissing);
5221 std::swap(snap_first_notx, pindexFirstNeverProcessed);
5222 std::swap(snap_first_notv, pindexFirstNotTransactionsValid);
5223 std::swap(snap_first_nocv, pindexFirstNotChainValid);
5224 std::swap(snap_first_nosv, pindexFirstNotScriptsValid);
5225 }
5226 };
5227 5228 while (pindex != nullptr) {
5229 nNodes++;
5230 if (pindexFirstInvalid == nullptr && pindex->nStatus & BLOCK_FAILED_VALID) pindexFirstInvalid = pindex;
5231 if (pindexFirstMissing == nullptr && !(pindex->nStatus & BLOCK_HAVE_DATA)) {
5232 pindexFirstMissing = pindex;
5233 }
5234 if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) pindexFirstNeverProcessed = pindex;
5235 if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr && (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TREE) pindexFirstNotTreeValid = pindex;
5236 5237 if (pindex->pprev != nullptr) {
5238 if (pindexFirstNotTransactionsValid == nullptr &&
5239 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TRANSACTIONS) {
5240 pindexFirstNotTransactionsValid = pindex;
5241 }
5242 5243 if (pindexFirstNotChainValid == nullptr &&
5244 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_CHAIN) {
5245 pindexFirstNotChainValid = pindex;
5246 }
5247 5248 if (pindexFirstNotScriptsValid == nullptr &&
5249 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_SCRIPTS) {
5250 pindexFirstNotScriptsValid = pindex;
5251 }
5252 }
5253 5254 // Begin: actual consistency checks.
5255 if (pindex->pprev == nullptr) {
5256 // Genesis block checks.
5257 assert(pindex->GetBlockHash() == GetConsensus().hashGenesisBlock); // Genesis block's hash must match.
5258 for (const auto& c : m_chainstates) {
5259 if (c->m_chain.Genesis() != nullptr) {
5260 assert(pindex == c->m_chain.Genesis()); // The chain's genesis block must be this block.
5261 }
5262 }
5263 }
5264 // nSequenceId can't be set higher than SEQ_ID_INIT_FROM_DISK{1} for blocks that aren't linked
5265 // (negative is used for preciousblock, SEQ_ID_BEST_CHAIN_FROM_DISK{0} for active chain when loaded from disk)
5266 if (!pindex->HaveNumChainTxs()) assert(pindex->nSequenceId <= SEQ_ID_INIT_FROM_DISK);
5267 // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or not pruning has occurred).
5268 // HAVE_DATA is only equivalent to nTx > 0 (or VALID_TRANSACTIONS) if no pruning has occurred.
5269 if (!m_blockman.m_have_pruned) {
5270 // If we've never pruned, then HAVE_DATA should be equivalent to nTx > 0
5271 assert(!(pindex->nStatus & BLOCK_HAVE_DATA) == (pindex->nTx == 0));
5272 assert(pindexFirstMissing == pindexFirstNeverProcessed);
5273 } else {
5274 // If we have pruned, then we can only say that HAVE_DATA implies nTx > 0
5275 if (pindex->nStatus & BLOCK_HAVE_DATA) assert(pindex->nTx > 0);
5276 }
5277 if (pindex->nStatus & BLOCK_HAVE_UNDO) assert(pindex->nStatus & BLOCK_HAVE_DATA);
5278 if (snap_base && snap_base->GetAncestor(pindex->nHeight) == pindex) {
5279 // Assumed-valid blocks should connect to the main chain.
5280 assert((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE);
5281 }
5282 // There should only be an nTx value if we have
5283 // actually seen a block's transactions.
5284 assert(((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS) == (pindex->nTx > 0)); // This is pruning-independent.
5285 // All parents having had data (at some point) is equivalent to all parents being VALID_TRANSACTIONS, which is equivalent to HaveNumChainTxs().
5286 // HaveNumChainTxs will also be set in the assumeutxo snapshot block from snapshot metadata.
5287 assert((pindexFirstNeverProcessed == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs());
5288 assert((pindexFirstNotTransactionsValid == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs());
5289 assert(pindex->nHeight == nHeight); // nHeight must be consistent.
5290 assert(pindex->pprev == nullptr || pindex->nChainWork >= pindex->pprev->nChainWork); // For every block except the genesis block, the chainwork must be larger than the parent's.
5291 assert(nHeight < 2 || (pindex->pskip && (pindex->pskip->nHeight < nHeight))); // The pskip pointer must point back for all but the first 2 blocks.
5292 assert(pindexFirstNotTreeValid == nullptr); // All m_blockman.m_block_index entries must at least be TREE valid
5293 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE) assert(pindexFirstNotTreeValid == nullptr); // TREE valid implies all parents are TREE valid
5294 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_CHAIN) assert(pindexFirstNotChainValid == nullptr); // CHAIN valid implies all parents are CHAIN valid
5295 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_SCRIPTS) assert(pindexFirstNotScriptsValid == nullptr); // SCRIPTS valid implies all parents are SCRIPTS valid
5296 if (pindexFirstInvalid == nullptr) {
5297 // Checks for not-invalid blocks.
5298 assert((pindex->nStatus & BLOCK_FAILED_VALID) == 0); // The failed flag cannot be set for blocks without invalid parents.
5299 } else {
5300 assert(pindex->nStatus & BLOCK_FAILED_VALID); // Invalid blocks and their descendants must be marked as invalid
5301 }
5302 // Make sure m_chain_tx_count sum is correctly computed.
5303 if (!pindex->pprev) {
5304 // If no previous block, nTx and m_chain_tx_count must be the same.
5305 assert(pindex->m_chain_tx_count == pindex->nTx);
5306 } else if (pindex->pprev->m_chain_tx_count > 0 && pindex->nTx > 0) {
5307 // If previous m_chain_tx_count is set and number of transactions in block is known, sum must be set.
5308 assert(pindex->m_chain_tx_count == pindex->nTx + pindex->pprev->m_chain_tx_count);
5309 } else {
5310 // Otherwise m_chain_tx_count should only be set if this is a snapshot
5311 // block, and must be set if it is.
5312 assert((pindex->m_chain_tx_count != 0) == (pindex == snap_base));
5313 }
5314 // There should be no block with more work than m_best_header, unless it's known to be invalid
5315 assert((pindex->nStatus & BLOCK_FAILED_VALID) || pindex->nChainWork <= m_best_header->nChainWork);
5316 5317 // Chainstate-specific checks on setBlockIndexCandidates
5318 for (const auto& c : m_chainstates) {
5319 if (c->m_chain.Tip() == nullptr) continue;
5320 // Two main factors determine whether pindex is a candidate in
5321 // setBlockIndexCandidates:
5322 //
5323 // - If pindex has less work than the chain tip, it should not be a
5324 // candidate, and this will be asserted below. Otherwise it is a
5325 // potential candidate.
5326 //
5327 // - If pindex or one of its parent blocks back to the genesis block
5328 // or an assumeutxo snapshot never downloaded transactions
5329 // (pindexFirstNeverProcessed is non-null), it should not be a
5330 // candidate, and this will be asserted below. The only exception
5331 // is if pindex itself is an assumeutxo snapshot block. Then it is
5332 // also a potential candidate.
5333 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && (pindexFirstNeverProcessed == nullptr || pindex == snap_base)) {
5334 // If pindex was detected as invalid (pindexFirstInvalid is
5335 // non-null), it is not required to be in
5336 // setBlockIndexCandidates.
5337 if (pindexFirstInvalid == nullptr) {
5338 // If pindex and all its parents back to the genesis block
5339 // or an assumeutxo snapshot block downloaded transactions,
5340 // and the transactions were not pruned (pindexFirstMissing
5341 // is null), it is a potential candidate. The check
5342 // excludes pruned blocks, because if any blocks were
5343 // pruned between pindex and the current chain tip, pindex will
5344 // only temporarily be added to setBlockIndexCandidates,
5345 // before being moved to m_blocks_unlinked. This check
5346 // could be improved to verify that if all blocks between
5347 // the chain tip and pindex have data, pindex must be a
5348 // candidate.
5349 //
5350 // If pindex is the chain tip, it also is a potential
5351 // candidate.
5352 //
5353 // If the chainstate was loaded from a snapshot and pindex
5354 // is the base of the snapshot, pindex is also a potential
5355 // candidate.
5356 if (pindexFirstMissing == nullptr || pindex == c->m_chain.Tip() || pindex == c->SnapshotBase()) {
5357 // If this chainstate is not a historical chainstate
5358 // targeting a specific block, pindex must be in
5359 // setBlockIndexCandidates. Otherwise, pindex only
5360 // needs to be added if it is an ancestor of the target
5361 // block.
5362 if (!c->TargetBlock() || c->TargetBlock()->GetAncestor(pindex->nHeight) == pindex) {
5363 assert(c->setBlockIndexCandidates.contains(pindex));
5364 }
5365 }
5366 // If some parent is missing, then it could be that this block was in
5367 // setBlockIndexCandidates but had to be removed because of the missing data.
5368 // In this case it must be in m_blocks_unlinked -- see test below.
5369 }
5370 } else { // If this block sorts worse than the current tip or some ancestor's block has never been seen, it cannot be in setBlockIndexCandidates.
5371 assert(!c->setBlockIndexCandidates.contains(pindex));
5372 }
5373 }
5374 // Check whether this block is in m_blocks_unlinked.
5375 auto rangeUnlinked{m_blockman.m_blocks_unlinked.equal_range(pindex->pprev)};
5376 bool foundInUnlinked = false;
5377 for (auto it = rangeUnlinked.first; it != rangeUnlinked.second; ++it) {
5378 assert(it->first == pindex->pprev);
5379 if (it->second == pindex) {
5380 assert(!foundInUnlinked); // No duplicates in m_blocks_unlinked
5381 foundInUnlinked = true;
5382 }
5383 }
5384 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed != nullptr && pindexFirstInvalid == nullptr) {
5385 // If this block has block data available, some parent was never received, and has no invalid parents, it must be in m_blocks_unlinked.
5386 assert(foundInUnlinked);
5387 }
5388 if (!(pindex->nStatus & BLOCK_HAVE_DATA)) assert(!foundInUnlinked); // Can't be in m_blocks_unlinked if we don't HAVE_DATA
5389 if (pindexFirstMissing == nullptr) assert(!foundInUnlinked); // We aren't missing data for any parent -- cannot be in m_blocks_unlinked.
5390 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed == nullptr && pindexFirstMissing != nullptr) {
5391 // We HAVE_DATA for this block, have received data for all parents at some point, but we're currently missing data for some parent.
5392 assert(m_blockman.m_have_pruned);
5393 // This block may have entered m_blocks_unlinked if:
5394 // - it has a descendant that at some point had more work than the
5395 // tip, and
5396 // - we tried switching to that descendant but were missing
5397 // data for some intermediate block between m_chain and the
5398 // tip.
5399 // So if this block is itself better than any m_chain.Tip() and it wasn't in
5400 // setBlockIndexCandidates, then it must be in m_blocks_unlinked.
5401 for (const auto& c : m_chainstates) {
5402 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && !c->setBlockIndexCandidates.contains(pindex)) {
5403 if (pindexFirstInvalid == nullptr) {
5404 if (!c->TargetBlock() || c->TargetBlock()->GetAncestor(pindex->nHeight) == pindex) {
5405 assert(foundInUnlinked);
5406 }
5407 }
5408 }
5409 }
5410 }
5411 // assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash()); // Perhaps too slow
5412 // End: actual consistency checks.
5413 5414 5415 // Try descending into the first subnode. Always process forks first and the best header chain after.
5416 snap_update_firsts();
5417 auto range{forward.equal_range(pindex)};
5418 if (range.first != range.second) {
5419 // A subnode not part of the best header chain was found.
5420 pindex = range.first->second;
5421 nHeight++;
5422 continue;
5423 } else if (best_hdr_chain.Contains(*pindex)) {
5424 // Descend further into best header chain.
5425 nHeight++;
5426 pindex = best_hdr_chain[nHeight];
5427 if (!pindex) break; // we are finished, since the best header chain is always processed last
5428 continue;
5429 }
5430 // This is a leaf node.
5431 // Move upwards until we reach a node of which we have not yet visited the last child.
5432 while (pindex) {
5433 // We are going to either move to a parent or a sibling of pindex.
5434 snap_update_firsts();
5435 // If pindex was the first with a certain property, unset the corresponding variable.
5436 if (pindex == pindexFirstInvalid) pindexFirstInvalid = nullptr;
5437 if (pindex == pindexFirstMissing) pindexFirstMissing = nullptr;
5438 if (pindex == pindexFirstNeverProcessed) pindexFirstNeverProcessed = nullptr;
5439 if (pindex == pindexFirstNotTreeValid) pindexFirstNotTreeValid = nullptr;
5440 if (pindex == pindexFirstNotTransactionsValid) pindexFirstNotTransactionsValid = nullptr;
5441 if (pindex == pindexFirstNotChainValid) pindexFirstNotChainValid = nullptr;
5442 if (pindex == pindexFirstNotScriptsValid) pindexFirstNotScriptsValid = nullptr;
5443 // Find our parent.
5444 CBlockIndex* pindexPar = pindex->pprev;
5445 // Find which child we just visited.
5446 auto rangePar{forward.equal_range(pindexPar)};
5447 while (rangePar.first->second != pindex) {
5448 assert(rangePar.first != rangePar.second); // Our parent must have at least the node we're coming from as child.
5449 rangePar.first++;
5450 }
5451 // Proceed to the next one.
5452 rangePar.first++;
5453 if (rangePar.first != rangePar.second) {
5454 // Move to a sibling not part of the best header chain.
5455 pindex = rangePar.first->second;
5456 break;
5457 } else if (pindexPar == best_hdr_chain[nHeight - 1]) {
5458 // Move to pindex's sibling on the best-chain, if it has one.
5459 pindex = best_hdr_chain[nHeight];
5460 // There will not be a next block if (and only if) parent block is the best header.
5461 assert((pindex == nullptr) == (pindexPar == best_hdr_chain.Tip()));
5462 break;
5463 } else {
5464 // Move up further.
5465 pindex = pindexPar;
5466 nHeight--;
5467 continue;
5468 }
5469 }
5470 }
5471 5472 // Check that we actually traversed the entire block index.
5473 assert(nNodes == forward.size() + best_hdr_chain.Height() + 1);
5474 }
5475 5476 std::string Chainstate::ToString()
5477 {
5478 AssertLockHeld(::cs_main);
5479 CBlockIndex* tip = m_chain.Tip();
5480 return strprintf("Chainstate [%s] @ height %d (%s)",
5481 m_from_snapshot_blockhash ? "snapshot" : "ibd",
5482 tip ? tip->nHeight : -1, tip ? tip->GetBlockHash().ToString() : "null");
5483 }
5484 5485 bool Chainstate::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size)
5486 {
5487 AssertLockHeld(::cs_main);
5488 if (coinstip_size == m_coinstip_cache_size_bytes &&
5489 coinsdb_size == m_coinsdb_cache_size_bytes) {
5490 // Cache sizes are unchanged, no need to continue.
5491 return true;
5492 }
5493 size_t old_coinstip_size = m_coinstip_cache_size_bytes;
5494 m_coinstip_cache_size_bytes = coinstip_size;
5495 m_coinsdb_cache_size_bytes = coinsdb_size;
5496 CoinsDB().ResizeCache(coinsdb_size);
5497 5498 LogInfo("[%s] resized coinsdb cache to %.1f MiB",
5499 this->ToString(), coinsdb_size / double(1_MiB));
5500 LogInfo("[%s] resized coinstip cache to %.1f MiB",
5501 this->ToString(), coinstip_size / double(1_MiB));
5502 5503 BlockValidationState state;
5504 bool ret;
5505 5506 if (coinstip_size > old_coinstip_size) {
5507 // Likely no need to flush if cache sizes have grown.
5508 ret = FlushStateToDisk(state, FlushStateMode::IF_NEEDED);
5509 } else {
5510 // Otherwise, flush state to disk and deallocate the in-memory coins map.
5511 ret = FlushStateToDisk(state, FlushStateMode::FORCE_FLUSH);
5512 }
5513 return ret;
5514 }
5515 5516 double ChainstateManager::GuessVerificationProgress(const CBlockIndex* pindex) const
5517 {
5518 AssertLockHeld(GetMutex());
5519 const ChainTxData& data{GetParams().TxData()};
5520 if (pindex == nullptr) {
5521 return 0.0;
5522 }
5523 5524 if (pindex->m_chain_tx_count == 0) {
5525 LogDebug(BCLog::VALIDATION, "Block %d has unset m_chain_tx_count. Unable to estimate verification progress.\n", pindex->nHeight);
5526 return 0.0;
5527 }
5528 5529 const int64_t nNow{TicksSinceEpoch<std::chrono::seconds>(NodeClock::now())};
5530 const auto block_time{
5531 (Assume(m_best_header) && std::abs(nNow - pindex->GetBlockTime()) <= Ticks<std::chrono::seconds>(2h) &&
5532 Assume(m_best_header->nHeight >= pindex->nHeight)) ?
5533 // When the header is known to be recent, switch to a height-based
5534 // approach. This ensures the returned value is quantized when
5535 // close to "1.0", because some users expect it to be. This also
5536 // avoids relying too much on the exact miner-set timestamp, which
5537 // may be off.
5538 nNow - (m_best_header->nHeight - pindex->nHeight) * GetConsensus().nPowTargetSpacing :
5539 pindex->GetBlockTime(),
5540 };
5541 5542 double fTxTotal;
5543 5544 if (pindex->m_chain_tx_count <= data.tx_count) {
5545 fTxTotal = data.tx_count + (nNow - data.nTime) * data.dTxRate;
5546 } else {
5547 fTxTotal = pindex->m_chain_tx_count + (nNow - block_time) * data.dTxRate;
5548 }
5549 5550 return std::min<double>(pindex->m_chain_tx_count / fTxTotal, 1.0);
5551 }
5552 5553 double ChainstateManager::GetBackgroundVerificationProgress(const CBlockIndex& pindex) const
5554 {
5555 AssertLockHeld(GetMutex());
5556 Assert(HistoricalChainstate());
5557 auto target_block = HistoricalChainstate()->TargetBlock();
5558 5559 if (pindex.m_chain_tx_count == 0 || target_block->m_chain_tx_count == 0) {
5560 LogDebug(BCLog::VALIDATION, "[background validation] Block %d has unset m_chain_tx_count. Unable to estimate verification progress.", pindex.nHeight);
5561 return 0.0;
5562 }
5563 return static_cast<double>(pindex.m_chain_tx_count) / static_cast<double>(target_block->m_chain_tx_count);
5564 }
5565 5566 Chainstate& ChainstateManager::InitializeChainstate(CTxMemPool* mempool)
5567 {
5568 AssertLockHeld(::cs_main);
5569 assert(m_chainstates.empty());
5570 m_chainstates.emplace_back(std::make_unique<Chainstate>(mempool, m_blockman, *this));
5571 return *m_chainstates.back();
5572 }
5573 5574 [[nodiscard]] static bool DeleteCoinsDBFromDisk(const fs::path db_path, bool is_snapshot)
5575 EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
5576 {
5577 AssertLockHeld(::cs_main);
5578 5579 if (is_snapshot) {
5580 fs::path base_blockhash_path = db_path / node::SNAPSHOT_BLOCKHASH_FILENAME;
5581 5582 try {
5583 bool existed = fs::remove(base_blockhash_path);
5584 if (!existed) {
5585 LogWarning("[snapshot] snapshot chainstate dir being removed lacks %s file",
5586 fs::PathToString(node::SNAPSHOT_BLOCKHASH_FILENAME));
5587 }
5588 } catch (const fs::filesystem_error& e) {
5589 LogWarning("[snapshot] failed to remove file %s: %s\n",
5590 fs::PathToString(base_blockhash_path), e.code().message());
5591 }
5592 }
5593 5594 std::string path_str = fs::PathToString(db_path);
5595 LogInfo("Removing leveldb dir at %s\n", path_str);
5596 5597 // We have to destruct before this call leveldb::DB in order to release the db
5598 // lock, otherwise `DestroyDB` will fail. See `leveldb::~DBImpl()`.
5599 const bool destroyed = DestroyDB(path_str);
5600 5601 if (!destroyed) {
5602 LogError("leveldb DestroyDB call failed on %s", path_str);
5603 }
5604 5605 // Datadir should be removed from filesystem; otherwise initialization may detect
5606 // it on subsequent statups and get confused.
5607 //
5608 // If the base_blockhash_path removal above fails in the case of snapshot
5609 // chainstates, this will return false since leveldb won't remove a non-empty
5610 // directory.
5611 return destroyed && !fs::exists(db_path);
5612 }
5613 5614 util::Result<CBlockIndex*> ChainstateManager::ActivateSnapshot(
5615 AutoFile& coins_file,
5616 const SnapshotMetadata& metadata,
5617 bool in_memory)
5618 {
5619 uint256 base_blockhash = metadata.m_base_blockhash;
5620 5621 CBlockIndex* snapshot_start_block{};
5622 5623 {
5624 LOCK(::cs_main);
5625 5626 if (this->CurrentChainstate().m_from_snapshot_blockhash) {
5627 return util::Error{Untranslated("Can't activate a snapshot-based chainstate more than once")};
5628 }
5629 if (!GetParams().AssumeutxoForBlockhash(base_blockhash).has_value()) {
5630 auto available_heights = GetParams().GetAvailableSnapshotHeights();
5631 std::string heights_formatted = util::Join(available_heights, ", ", [&](const auto& i) { return util::ToString(i); });
5632 return util::Error{Untranslated(strprintf("assumeutxo block hash in snapshot metadata not recognized (hash: %s). The following snapshot heights are available: %s",
5633 base_blockhash.ToString(),
5634 heights_formatted))};
5635 }
5636 5637 snapshot_start_block = m_blockman.LookupBlockIndex(base_blockhash);
5638 if (!snapshot_start_block) {
5639 return util::Error{Untranslated(strprintf("The base block header (%s) must appear in the headers chain. Make sure all headers are syncing, and call loadtxoutset again",
5640 base_blockhash.ToString()))};
5641 }
5642 5643 bool start_block_invalid = snapshot_start_block->nStatus & BLOCK_FAILED_VALID;
5644 if (start_block_invalid) {
5645 return util::Error{Untranslated(strprintf("The base block header (%s) is part of an invalid chain", base_blockhash.ToString()))};
5646 }
5647 5648 if (!m_best_header || m_best_header->GetAncestor(snapshot_start_block->nHeight) != snapshot_start_block) {
5649 return util::Error{Untranslated("A forked headers-chain with more work than the chain with the snapshot base block header exists. Please proceed to sync without AssumeUtxo.")};
5650 }
5651 5652 auto mempool{CurrentChainstate().GetMempool()};
5653 if (mempool && mempool->size() > 0) {
5654 return util::Error{Untranslated("Can't activate a snapshot when mempool not empty")};
5655 }
5656 }
5657 5658 int64_t current_coinsdb_cache_size{0};
5659 int64_t current_coinstip_cache_size{0};
5660 5661 // Cache percentages to allocate to each chainstate.
5662 //
5663 // These particular percentages don't matter so much since they will only be
5664 // relevant during snapshot activation; caches are rebalanced at the conclusion of
5665 // this function. We want to give (essentially) all available cache capacity to the
5666 // snapshot to aid the bulk load later in this function.
5667 static constexpr double IBD_CACHE_PERC = 0.01;
5668 static constexpr double SNAPSHOT_CACHE_PERC = 0.99;
5669 5670 {
5671 LOCK(::cs_main);
5672 // Resize the coins caches to ensure we're not exceeding memory limits.
5673 //
5674 // Allocate the majority of the cache to the incoming snapshot chainstate, since
5675 // (optimistically) getting to its tip will be the top priority. We'll need to call
5676 // `MaybeRebalanceCaches()` once we're done with this function to ensure
5677 // the right allocation (including the possibility that no snapshot was activated
5678 // and that we should restore the active chainstate caches to their original size).
5679 //
5680 current_coinsdb_cache_size = this->ActiveChainstate().m_coinsdb_cache_size_bytes;
5681 current_coinstip_cache_size = this->ActiveChainstate().m_coinstip_cache_size_bytes;
5682 5683 // Temporarily resize the active coins cache to make room for the newly-created
5684 // snapshot chain.
5685 this->ActiveChainstate().ResizeCoinsCaches(
5686 static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC),
5687 static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC));
5688 }
5689 5690 auto snapshot_chainstate = WITH_LOCK(::cs_main,
5691 return std::make_unique<Chainstate>(
5692 /*mempool=*/nullptr, m_blockman, *this, base_blockhash));
5693 5694 {
5695 LOCK(::cs_main);
5696 snapshot_chainstate->InitCoinsDB(
5697 static_cast<size_t>(current_coinsdb_cache_size * SNAPSHOT_CACHE_PERC),
5698 in_memory, /*should_wipe=*/false);
5699 snapshot_chainstate->InitCoinsCache(
5700 static_cast<size_t>(current_coinstip_cache_size * SNAPSHOT_CACHE_PERC));
5701 }
5702 5703 auto cleanup_bad_snapshot = [&](bilingual_str reason) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
5704 this->MaybeRebalanceCaches();
5705 5706 // PopulateAndValidateSnapshot can return (in error) before the leveldb datadir
5707 // has been created, so only attempt removal if we got that far.
5708 if (auto snapshot_datadir = node::FindAssumeutxoChainstateDir(m_options.datadir)) {
5709 // We have to destruct leveldb::DB in order to release the db lock, otherwise
5710 // DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See `leveldb::~DBImpl()`.
5711 // Destructing the chainstate (and so resetting the coinsviews object) does this.
5712 snapshot_chainstate.reset();
5713 bool removed = DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true);
5714 if (!removed) {
5715 GetNotifications().fatalError(strprintf(_("Failed to remove snapshot chainstate dir (%s). "
5716 "Manually remove it before restarting.\n"), fs::PathToString(*snapshot_datadir)));
5717 }
5718 }
5719 return util::Error{std::move(reason)};
5720 };
5721 5722 if (auto res{this->PopulateAndValidateSnapshot(*snapshot_chainstate, coins_file, metadata)}; !res) {
5723 LOCK(::cs_main);
5724 return cleanup_bad_snapshot(Untranslated(strprintf("Population failed: %s", util::ErrorString(res).original)));
5725 }
5726 5727 LOCK(::cs_main); // cs_main required for rest of snapshot activation.
5728 5729 // Do a final check to ensure that the snapshot chainstate is actually a more
5730 // work chain than the active chainstate; a user could have loaded a snapshot
5731 // very late in the IBD process, and we wouldn't want to load a useless chainstate.
5732 if (!CBlockIndexWorkComparator()(ActiveTip(), snapshot_chainstate->m_chain.Tip())) {
5733 return cleanup_bad_snapshot(Untranslated("work does not exceed active chainstate"));
5734 }
5735 // If not in-memory, persist the base blockhash for use during subsequent
5736 // initialization.
5737 if (!in_memory) {
5738 if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) {
5739 return cleanup_bad_snapshot(Untranslated("could not write base blockhash"));
5740 }
5741 }
5742 5743 Chainstate& chainstate{AddChainstate(std::move(snapshot_chainstate))};
5744 m_blockman.m_snapshot_height = Assert(chainstate.SnapshotBase())->nHeight;
5745 5746 chainstate.PopulateBlockIndexCandidates();
5747 5748 LogInfo("[snapshot] successfully activated snapshot %s", base_blockhash.ToString());
5749 LogInfo("[snapshot] (%.2f MB)",
5750 chainstate.CoinsTip().DynamicMemoryUsage() / (1000 * 1000));
5751 5752 this->MaybeRebalanceCaches();
5753 return snapshot_start_block;
5754 }
5755 5756 static void FlushSnapshotToDisk(CCoinsViewCache& coins_cache, bool snapshot_loaded)
5757 {
5758 LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE(
5759 strprintf("%s (%.2f MB)",
5760 snapshot_loaded ? "saving snapshot chainstate" : "flushing coins cache",
5761 coins_cache.DynamicMemoryUsage() / (1000 * 1000)),
5762 BCLog::LogFlags::ALL);
5763 5764 coins_cache.Flush();
5765 }
5766 5767 struct StopHashingException : public std::exception
5768 {
5769 const char* what() const noexcept override
5770 {
5771 return "ComputeUTXOStats interrupted.";
5772 }
5773 };
5774 5775 static void SnapshotUTXOHashBreakpoint(const util::SignalInterrupt& interrupt)
5776 {
5777 if (interrupt) throw StopHashingException();
5778 }
5779 5780 util::Result<void> ChainstateManager::PopulateAndValidateSnapshot(
5781 Chainstate& snapshot_chainstate,
5782 AutoFile& coins_file,
5783 const SnapshotMetadata& metadata)
5784 {
5785 // It's okay to release cs_main before we're done using `coins_cache` because we know
5786 // that nothing else will be referencing the newly created snapshot_chainstate yet.
5787 CCoinsViewCache& coins_cache = *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip());
5788 5789 uint256 base_blockhash = metadata.m_base_blockhash;
5790 5791 CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));
5792 5793 if (!snapshot_start_block) {
5794 // Needed for ComputeUTXOStats to determine the
5795 // height and to avoid a crash when base_blockhash.IsNull()
5796 return util::Error{Untranslated(strprintf("Did not find snapshot start blockheader %s",
5797 base_blockhash.ToString()))};
5798 }
5799 5800 int base_height = snapshot_start_block->nHeight;
5801 const auto& maybe_au_data = GetParams().AssumeutxoForHeight(base_height);
5802 5803 if (!maybe_au_data) {
5804 return util::Error{Untranslated(strprintf("Assumeutxo height in snapshot metadata not recognized "
5805 "(%d) - refusing to load snapshot", base_height))};
5806 }
5807 5808 const AssumeutxoData& au_data = *maybe_au_data;
5809 5810 // This work comparison is a duplicate check with the one performed later in
5811 // ActivateSnapshot(), but is done so that we avoid doing the long work of staging
5812 // a snapshot that isn't actually usable.
5813 if (WITH_LOCK(::cs_main, return !CBlockIndexWorkComparator()(ActiveTip(), snapshot_start_block))) {
5814 return util::Error{Untranslated("Work does not exceed active chainstate")};
5815 }
5816 5817 const uint64_t coins_count = metadata.m_coins_count;
5818 uint64_t coins_left = metadata.m_coins_count;
5819 5820 LogInfo("[snapshot] loading %d coins from snapshot %s", coins_left, base_blockhash.ToString());
5821 int64_t coins_processed{0};
5822 5823 while (coins_left > 0) {
5824 try {
5825 Txid txid;
5826 coins_file >> txid;
5827 size_t coins_per_txid{0};
5828 coins_per_txid = ReadCompactSize(coins_file);
5829 5830 if (coins_per_txid > coins_left) {
5831 return util::Error{Untranslated("Mismatch in coins count in snapshot metadata and actual snapshot data")};
5832 }
5833 5834 for (size_t i = 0; i < coins_per_txid; i++) {
5835 COutPoint outpoint;
5836 Coin coin;
5837 outpoint.n = static_cast<uint32_t>(ReadCompactSize(coins_file));
5838 outpoint.hash = txid;
5839 coins_file >> coin;
5840 if (coin.nHeight > base_height ||
5841 outpoint.n >= std::numeric_limits<decltype(outpoint.n)>::max() // Avoid integer wrap-around in coinstats.cpp:ApplyHash
5842 ) {
5843 return util::Error{Untranslated(strprintf("Bad snapshot data after deserializing %d coins",
5844 coins_count - coins_left))};
5845 }
5846 if (!MoneyRange(coin.out.nValue)) {
5847 return util::Error{Untranslated(strprintf("Bad snapshot data after deserializing %d coins - bad tx out value",
5848 coins_count - coins_left))};
5849 }
5850 coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint), std::move(coin));
5851 5852 --coins_left;
5853 ++coins_processed;
5854 5855 if (coins_processed % 1000000 == 0) {
5856 LogInfo("[snapshot] %d coins loaded (%.2f%%, %.2f MB)",
5857 coins_processed,
5858 static_cast<float>(coins_processed) * 100 / static_cast<float>(coins_count),
5859 coins_cache.DynamicMemoryUsage() / (1000 * 1000));
5860 }
5861 5862 // Batch write and flush (if we need to) every so often.
5863 //
5864 // If our average Coin size is roughly 41 bytes, checking every 120,000 coins
5865 // means <5MB of memory imprecision.
5866 if (coins_processed % 120000 == 0) {
5867 if (m_interrupt) {
5868 return util::Error{Untranslated("Aborting after an interrupt was requested")};
5869 }
5870 5871 const auto snapshot_cache_state = WITH_LOCK(::cs_main,
5872 return snapshot_chainstate.GetCoinsCacheSizeState());
5873 5874 if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) {
5875 // This is a hack - we don't know what the actual best block is, but that
5876 // doesn't matter for the purposes of flushing the cache here. We'll set this
5877 // to its correct value (`base_blockhash`) below after the coins are loaded.
5878 coins_cache.SetBestBlock(GetRandHash());
5879 5880 // No need to acquire cs_main since this chainstate isn't being used yet.
5881 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/false);
5882 }
5883 }
5884 }
5885 } catch (const std::ios_base::failure&) {
5886 return util::Error{Untranslated(strprintf("Bad snapshot format or truncated snapshot after deserializing %d coins",
5887 coins_processed))};
5888 }
5889 }
5890 5891 // Important that we set this. This and the coins_cache accesses above are
5892 // sort of a layer violation, but either we reach into the innards of
5893 // CCoinsViewCache here or we have to invert some of the Chainstate to
5894 // embed them in a snapshot-activation-specific CCoinsViewCache bulk load
5895 // method.
5896 coins_cache.SetBestBlock(base_blockhash);
5897 5898 bool out_of_coins{false};
5899 try {
5900 std::byte left_over_byte;
5901 coins_file >> left_over_byte;
5902 } catch (const std::ios_base::failure&) {
5903 // We expect an exception since we should be out of coins.
5904 out_of_coins = true;
5905 }
5906 if (!out_of_coins) {
5907 return util::Error{Untranslated(strprintf("Bad snapshot - coins left over after deserializing %d coins",
5908 coins_count))};
5909 }
5910 5911 LogInfo("[snapshot] loaded %d (%.2f MB) coins from snapshot %s",
5912 coins_count,
5913 coins_cache.DynamicMemoryUsage() / (1000 * 1000),
5914 base_blockhash.ToString());
5915 5916 // No need to acquire cs_main since this chainstate isn't being used yet.
5917 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/true);
5918 5919 assert(coins_cache.GetBestBlock() == base_blockhash);
5920 5921 // As above, okay to immediately release cs_main here since no other context knows
5922 // about the snapshot_chainstate.
5923 CCoinsViewDB* snapshot_coinsdb = WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB());
5924 5925 std::optional<CCoinsStats> maybe_stats;
5926 5927 try {
5928 maybe_stats = ComputeUTXOStats(
5929 CoinStatsHashType::HASH_SERIALIZED, snapshot_coinsdb, m_blockman, [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); });
5930 } catch (StopHashingException const&) {
5931 return util::Error{Untranslated("Aborting after an interrupt was requested")};
5932 }
5933 if (!maybe_stats.has_value()) {
5934 return util::Error{Untranslated("Failed to generate coins stats")};
5935 }
5936 5937 // Assert that the deserialized chainstate contents match the expected assumeutxo value.
5938 if (AssumeutxoHash{maybe_stats->hashSerialized} != au_data.hash_serialized) {
5939 return util::Error{Untranslated(strprintf("Bad snapshot content hash: expected %s, got %s",
5940 au_data.hash_serialized.ToString(), maybe_stats->hashSerialized.ToString()))};
5941 }
5942 5943 snapshot_chainstate.m_chain.SetTip(*snapshot_start_block);
5944 5945 // The remainder of this function requires modifying data protected by cs_main.
5946 LOCK(::cs_main);
5947 5948 // Fake various pieces of CBlockIndex state:
5949 CBlockIndex* index = nullptr;
5950 5951 // Don't make any modifications to the genesis block since it shouldn't be
5952 // necessary, and since the genesis block doesn't have normal flags like
5953 // BLOCK_VALID_SCRIPTS set.
5954 constexpr int AFTER_GENESIS_START{1};
5955 5956 for (int i = AFTER_GENESIS_START; i <= snapshot_chainstate.m_chain.Height(); ++i) {
5957 index = snapshot_chainstate.m_chain[i];
5958 5959 // Fake BLOCK_OPT_WITNESS so that Chainstate::NeedsRedownload()
5960 // won't ask for -reindex on startup.
5961 if (DeploymentActiveAt(*index, *this, Consensus::DEPLOYMENT_SEGWIT)) {
5962 index->nStatus |= BLOCK_OPT_WITNESS;
5963 }
5964 5965 m_blockman.m_dirty_blockindex.insert(index);
5966 // Changes to the block index will be flushed to disk after this call
5967 // returns in `ActivateSnapshot()`, when `MaybeRebalanceCaches()` is
5968 // called, since we've added a snapshot chainstate and therefore will
5969 // have to downsize the IBD chainstate, which will result in a call to
5970 // `FlushStateToDisk(FORCE_FLUSH)`.
5971 }
5972 5973 assert(index);
5974 assert(index == snapshot_start_block);
5975 index->m_chain_tx_count = au_data.m_chain_tx_count;
5976 5977 LogInfo("[snapshot] validated snapshot (%.2f MB)",
5978 coins_cache.DynamicMemoryUsage() / (1000 * 1000));
5979 return {};
5980 }
5981 5982 // Currently, this function holds cs_main for its duration, which could be for
5983 // multiple minutes due to the ComputeUTXOStats call. Holding cs_main used to be
5984 // necessary (before d43a1f1a2fa3) to avoid advancing validated_cs farther than
5985 // its target block. Now it should be possible to avoid this, but simply
5986 // releasing cs_main here would not be possible because this function is invoked
5987 // by ConnectTip within ActivateBestChain.
5988 //
5989 // Eventually (TODO) it would be better to call this function outside of
5990 // ActivateBestChain, on a separate thread that should not require cs_main to
5991 // hash, because the UTXO set is only hashed after the historical chainstate
5992 // reaches its target block and is no longer changing.
5993 SnapshotCompletionResult ChainstateManager::MaybeValidateSnapshot(Chainstate& validated_cs, Chainstate& unvalidated_cs)
5994 {
5995 AssertLockHeld(cs_main);
5996 5997 // If the snapshot does not need to be validated...
5998 if (unvalidated_cs.m_assumeutxo != Assumeutxo::UNVALIDATED ||
5999 // Or if either chainstate is unusable...
6000 !unvalidated_cs.m_from_snapshot_blockhash ||
6001 validated_cs.m_assumeutxo != Assumeutxo::VALIDATED ||
6002 !validated_cs.m_chain.Tip() ||
6003 // Or the validated chainstate is not targeting the snapshot block...
6004 !validated_cs.m_target_blockhash ||
6005 *validated_cs.m_target_blockhash != *unvalidated_cs.m_from_snapshot_blockhash ||
6006 // Or the validated chainstate has not reached the snapshot block yet...
6007 !validated_cs.ReachedTarget()) {
6008 // Then the snapshot cannot be validated and there is nothing to do.
6009 return SnapshotCompletionResult::SKIPPED;
6010 }
6011 assert(validated_cs.TargetBlock() == validated_cs.m_chain.Tip());
6012 6013 auto handle_invalid_snapshot = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
6014 bilingual_str user_error = strprintf(_(
6015 "%s failed to validate the -assumeutxo snapshot state. "
6016 "This indicates a hardware problem, or a bug in the software, or a "
6017 "bad software modification that allowed an invalid snapshot to be "
6018 "loaded. As a result of this, the node will shut down and stop using any "
6019 "state that was built on the snapshot, resetting the chain height "
6020 "from %d to %d. On the next "
6021 "restart, the node will resume syncing from %d "
6022 "without using any snapshot data. "
6023 "Please report this incident to %s, including how you obtained the snapshot. "
6024 "The invalid snapshot chainstate will be left on disk in case it is "
6025 "helpful in diagnosing the issue that caused this error."),
6026 CLIENT_NAME, unvalidated_cs.m_chain.Height(),
6027 validated_cs.m_chain.Height(),
6028 validated_cs.m_chain.Height(), CLIENT_BUGREPORT);
6029 6030 LogError("[snapshot] !!! %s\n", user_error.original);
6031 LogError("[snapshot] deleting snapshot, reverting to validated chain, and stopping node\n");
6032 6033 // Reset chainstate target to network tip instead of snapshot block.
6034 validated_cs.SetTargetBlock(nullptr);
6035 6036 unvalidated_cs.m_assumeutxo = Assumeutxo::INVALID;
6037 6038 auto rename_result = unvalidated_cs.InvalidateCoinsDBOnDisk();
6039 if (!rename_result) {
6040 user_error += Untranslated("\n") + util::ErrorString(rename_result);
6041 }
6042 6043 GetNotifications().fatalError(user_error);
6044 };
6045 6046 CCoinsViewDB& validated_coins_db = validated_cs.CoinsDB();
6047 validated_cs.ForceFlushStateToDisk();
6048 6049 const auto& maybe_au_data = m_options.chainparams.AssumeutxoForHeight(validated_cs.m_chain.Height());
6050 if (!maybe_au_data) {
6051 LogWarning("[snapshot] assumeutxo data not found for height "
6052 "(%d) - refusing to validate snapshot", validated_cs.m_chain.Height());
6053 handle_invalid_snapshot();
6054 return SnapshotCompletionResult::MISSING_CHAINPARAMS;
6055 }
6056 6057 const AssumeutxoData& au_data = *maybe_au_data;
6058 std::optional<CCoinsStats> validated_cs_stats;
6059 LogInfo("[snapshot] computing UTXO stats for background chainstate to validate "
6060 "snapshot - this could take a few minutes");
6061 try {
6062 validated_cs_stats = ComputeUTXOStats(
6063 CoinStatsHashType::HASH_SERIALIZED,
6064 &validated_coins_db,
6065 m_blockman,
6066 [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); });
6067 } catch (StopHashingException const&) {
6068 return SnapshotCompletionResult::STATS_FAILED;
6069 }
6070 6071 // XXX note that this function is slow and will hold cs_main for potentially minutes.
6072 if (!validated_cs_stats) {
6073 LogWarning("[snapshot] failed to generate stats for validation coins db");
6074 // While this isn't a problem with the snapshot per se, this condition
6075 // prevents us from validating the snapshot, so we should shut down and let the
6076 // user handle the issue manually.
6077 handle_invalid_snapshot();
6078 return SnapshotCompletionResult::STATS_FAILED;
6079 }
6080 6081 // Compare the validated chainstate's UTXO set hash against the hard-coded
6082 // assumeutxo hash we expect.
6083 //
6084 // TODO: For belt-and-suspenders, we could cache the UTXO set
6085 // hash for the snapshot when it's loaded in its chainstate's leveldb. We could then
6086 // reference that here for an additional check.
6087 if (AssumeutxoHash{validated_cs_stats->hashSerialized} != au_data.hash_serialized) {
6088 LogWarning("[snapshot] hash mismatch: actual=%s, expected=%s",
6089 validated_cs_stats->hashSerialized.ToString(),
6090 au_data.hash_serialized.ToString());
6091 handle_invalid_snapshot();
6092 return SnapshotCompletionResult::HASH_MISMATCH;
6093 }
6094 6095 LogInfo("[snapshot] snapshot beginning at %s has been fully validated",
6096 unvalidated_cs.m_from_snapshot_blockhash->ToString());
6097 6098 unvalidated_cs.m_assumeutxo = Assumeutxo::VALIDATED;
6099 validated_cs.m_target_utxohash = AssumeutxoHash{validated_cs_stats->hashSerialized};
6100 this->MaybeRebalanceCaches();
6101 6102 return SnapshotCompletionResult::SUCCESS;
6103 }
6104 6105 Chainstate& ChainstateManager::ActiveChainstate() const
6106 {
6107 LOCK(::cs_main);
6108 return CurrentChainstate();
6109 }
6110 6111 void ChainstateManager::MaybeRebalanceCaches()
6112 {
6113 AssertLockHeld(::cs_main);
6114 Chainstate& current_cs{CurrentChainstate()};
6115 Chainstate* historical_cs{HistoricalChainstate()};
6116 if (!historical_cs && !current_cs.m_from_snapshot_blockhash) {
6117 // Allocate everything to the IBD chainstate. This will always happen
6118 // when we are not using a snapshot.
6119 current_cs.ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache);
6120 } else if (!historical_cs) {
6121 // If background validation has completed and snapshot is our active chain...
6122 LogInfo("[snapshot] allocating all cache to the snapshot chainstate");
6123 // Allocate everything to the snapshot chainstate.
6124 current_cs.ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache);
6125 } else {
6126 // If both chainstates exist, determine who needs more cache based on IBD status.
6127 //
6128 // Note: shrink caches first so that we don't inadvertently overwhelm available memory.
6129 if (IsInitialBlockDownload()) {
6130 historical_cs->ResizeCoinsCaches(
6131 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05);
6132 current_cs.ResizeCoinsCaches(
6133 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95);
6134 } else {
6135 current_cs.ResizeCoinsCaches(
6136 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05);
6137 historical_cs->ResizeCoinsCaches(
6138 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95);
6139 }
6140 }
6141 }
6142 6143 void ChainstateManager::ResetChainstates()
6144 {
6145 m_chainstates.clear();
6146 }
6147 6148 /**
6149 * Apply default chain params to nullopt members.
6150 * This helps to avoid coding errors around the accidental use of the compare
6151 * operators that accept nullopt, thus ignoring the intended default value.
6152 */
6153 static ChainstateManager::Options&& Flatten(ChainstateManager::Options&& opts)
6154 {
6155 if (!opts.check_block_index.has_value()) opts.check_block_index = opts.chainparams.DefaultConsistencyChecks();
6156 if (!opts.minimum_chain_work.has_value()) opts.minimum_chain_work = UintToArith256(opts.chainparams.GetConsensus().nMinimumChainWork);
6157 if (!opts.assumed_valid_block.has_value()) opts.assumed_valid_block = opts.chainparams.GetConsensus().defaultAssumeValid;
6158 return std::move(opts);
6159 }
6160 6161 ChainstateManager::ChainstateManager(const util::SignalInterrupt& interrupt, Options options, node::BlockManager::Options blockman_options)
6162 : m_script_check_queue{/*batch_size=*/128, std::clamp(options.worker_threads_num, 0, MAX_SCRIPTCHECK_THREADS)},
6163 m_interrupt{interrupt},
6164 m_options{Flatten(std::move(options))},
6165 m_blockman{interrupt, std::move(blockman_options)},
6166 m_validation_cache{m_options.script_execution_cache_bytes, m_options.signature_cache_bytes}
6167 {
6168 }
6169 6170 ChainstateManager::~ChainstateManager()
6171 {
6172 LOCK(::cs_main);
6173 6174 m_versionbitscache.Clear();
6175 }
6176 6177 Chainstate* ChainstateManager::LoadAssumeutxoChainstate()
6178 {
6179 assert(!CurrentChainstate().m_from_snapshot_blockhash);
6180 std::optional<fs::path> path = node::FindAssumeutxoChainstateDir(m_options.datadir);
6181 if (!path) {
6182 return nullptr;
6183 }
6184 std::optional<uint256> base_blockhash = node::ReadSnapshotBaseBlockhash(*path);
6185 if (!base_blockhash) {
6186 return nullptr;
6187 }
6188 LogInfo("[snapshot] detected active snapshot chainstate (%s) - loading",
6189 fs::PathToString(*path));
6190 6191 auto snapshot_chainstate{std::make_unique<Chainstate>(nullptr, m_blockman, *this, base_blockhash)};
6192 LogInfo("[snapshot] switching active chainstate to %s", snapshot_chainstate->ToString());
6193 return &this->AddChainstate(std::move(snapshot_chainstate));
6194 }
6195 6196 Chainstate& ChainstateManager::AddChainstate(std::unique_ptr<Chainstate> chainstate)
6197 {
6198 Chainstate& prev_chainstate{CurrentChainstate()};
6199 assert(prev_chainstate.m_assumeutxo == Assumeutxo::VALIDATED);
6200 // Set target block for historical chainstate to snapshot block.
6201 assert(!prev_chainstate.m_target_blockhash);
6202 prev_chainstate.m_target_blockhash = chainstate->m_from_snapshot_blockhash;
6203 m_chainstates.push_back(std::move(chainstate));
6204 Chainstate& curr_chainstate{CurrentChainstate()};
6205 assert(&curr_chainstate == m_chainstates.back().get());
6206 6207 // Transfer possession of the mempool to the chainstate.
6208 // Mempool is empty at this point because we're still in IBD.
6209 assert(!prev_chainstate.m_mempool || prev_chainstate.m_mempool->size() == 0);
6210 assert(!curr_chainstate.m_mempool);
6211 std::swap(curr_chainstate.m_mempool, prev_chainstate.m_mempool);
6212 return curr_chainstate;
6213 }
6214 6215 bool IsBIP30Repeat(const CBlockIndex& block_index)
6216 {
6217 return (block_index.nHeight==91842 && block_index.GetBlockHash() == uint256{"00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec"}) ||
6218 (block_index.nHeight==91880 && block_index.GetBlockHash() == uint256{"00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721"});
6219 }
6220 6221 bool IsBIP30Unspendable(const uint256& block_hash, int block_height)
6222 {
6223 return (block_height==91722 && block_hash == uint256{"00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e"}) ||
6224 (block_height==91812 && block_hash == uint256{"00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"});
6225 }
6226 6227 util::Result<void> Chainstate::InvalidateCoinsDBOnDisk()
6228 {
6229 // Should never be called on a non-snapshot chainstate.
6230 assert(m_from_snapshot_blockhash);
6231 6232 // Coins views no longer usable.
6233 m_coins_views.reset();
6234 6235 const fs::path db_path{StoragePath()};
6236 const fs::path invalid_path{db_path + "_INVALID"};
6237 const std::string db_path_str{fs::PathToString(db_path)};
6238 const std::string invalid_path_str{fs::PathToString(invalid_path)};
6239 LogInfo("[snapshot] renaming snapshot datadir %s to %s", db_path_str, invalid_path_str);
6240 6241 // The invalid storage directory is simply moved and not deleted because we may
6242 // want to do forensics later during issue investigation. The user is instructed
6243 // accordingly in MaybeValidateSnapshot().
6244 try {
6245 fs::rename(db_path, invalid_path);
6246 } catch (const fs::filesystem_error& e) {
6247 LogError("While invalidating the coins db: Error renaming file '%s' -> '%s': %s",
6248 db_path_str, invalid_path_str, e.what());
6249 return util::Error{strprintf(_(
6250 "Rename of '%s' -> '%s' failed. "
6251 "You should resolve this by manually moving or deleting the invalid "
6252 "snapshot directory %s, otherwise you will encounter the same error again "
6253 "on the next startup."),
6254 db_path_str, invalid_path_str, db_path_str)};
6255 }
6256 return {};
6257 }
6258 6259 bool ChainstateManager::DeleteChainstate(Chainstate& chainstate)
6260 {
6261 AssertLockHeld(::cs_main);
6262 assert(!chainstate.m_coins_views);
6263 const fs::path db_path{chainstate.StoragePath()};
6264 if (!DeleteCoinsDBFromDisk(db_path, /*is_snapshot=*/bool{chainstate.m_from_snapshot_blockhash})) {
6265 LogError("Deletion of %s failed. Please remove it manually to continue reindexing.",
6266 fs::PathToString(db_path));
6267 return false;
6268 }
6269 std::unique_ptr<Chainstate> prev_chainstate{Assert(RemoveChainstate(chainstate))};
6270 Chainstate& curr_chainstate{CurrentChainstate()};
6271 assert(prev_chainstate->m_mempool->size() == 0);
6272 assert(!curr_chainstate.m_mempool);
6273 std::swap(curr_chainstate.m_mempool, prev_chainstate->m_mempool);
6274 return true;
6275 }
6276 6277 ChainstateRole Chainstate::GetRole() const
6278 {
6279 return ChainstateRole{.validated = m_assumeutxo == Assumeutxo::VALIDATED, .historical = bool{m_target_blockhash}};
6280 }
6281 6282 void ChainstateManager::RecalculateBestHeader()
6283 {
6284 AssertLockHeld(cs_main);
6285 m_best_header = ActiveChain().Tip();
6286 for (auto& entry : m_blockman.m_block_index) {
6287 if (!(entry.second.nStatus & BLOCK_FAILED_VALID) && m_best_header->nChainWork < entry.second.nChainWork) {
6288 m_best_header = &entry.second;
6289 }
6290 }
6291 }
6292 6293 std::optional<int> ChainstateManager::BlocksAheadOfTip() const
6294 {
6295 LOCK(::cs_main);
6296 const CBlockIndex* best_header{m_best_header};
6297 const CBlockIndex* tip{ActiveChain().Tip()};
6298 // Only consider headers that extend the active tip; ignore competing branches.
6299 if (best_header && tip && best_header->nChainWork > tip->nChainWork &&
6300 best_header->GetAncestor(tip->nHeight) == tip) {
6301 return best_header->nHeight - tip->nHeight;
6302 }
6303 return std::nullopt;
6304 }
6305 6306 bool ChainstateManager::ValidatedSnapshotCleanup(Chainstate& validated_cs, Chainstate& unvalidated_cs)
6307 {
6308 AssertLockHeld(::cs_main);
6309 if (unvalidated_cs.m_assumeutxo != Assumeutxo::VALIDATED) {
6310 // No need to clean up.
6311 return false;
6312 }
6313 6314 const fs::path validated_path{validated_cs.StoragePath()};
6315 const fs::path assumed_valid_path{unvalidated_cs.StoragePath()};
6316 const fs::path delete_path{validated_path + "_todelete"};
6317 6318 // Since we're going to be moving around the underlying leveldb filesystem content
6319 // for each chainstate, make sure that the chainstates (and their constituent
6320 // CoinsViews members) have been destructed first.
6321 //
6322 // The caller of this method will be responsible for reinitializing chainstates
6323 // if they want to continue operation.
6324 this->ResetChainstates();
6325 assert(this->m_chainstates.size() == 0);
6326 6327 LogInfo("[snapshot] deleting background chainstate directory (now unnecessary) (%s)",
6328 fs::PathToString(validated_path));
6329 6330 auto rename_failed_abort = [this](
6331 fs::path p_old,
6332 fs::path p_new,
6333 const fs::filesystem_error& err) {
6334 LogError("[snapshot] Error renaming path (%s) -> (%s): %s\n",
6335 fs::PathToString(p_old), fs::PathToString(p_new), err.what());
6336 GetNotifications().fatalError(strprintf(_(
6337 "Rename of '%s' -> '%s' failed. "
6338 "Cannot clean up the background chainstate leveldb directory."),
6339 fs::PathToString(p_old), fs::PathToString(p_new)));
6340 };
6341 6342 try {
6343 fs::rename(validated_path, delete_path);
6344 } catch (const fs::filesystem_error& e) {
6345 rename_failed_abort(validated_path, delete_path, e);
6346 throw;
6347 }
6348 6349 LogInfo("[snapshot] moving snapshot chainstate (%s) to "
6350 "default chainstate directory (%s)",
6351 fs::PathToString(assumed_valid_path), fs::PathToString(validated_path));
6352 6353 try {
6354 fs::rename(assumed_valid_path, validated_path);
6355 } catch (const fs::filesystem_error& e) {
6356 rename_failed_abort(assumed_valid_path, validated_path, e);
6357 throw;
6358 }
6359 6360 if (!DeleteCoinsDBFromDisk(delete_path, /*is_snapshot=*/false)) {
6361 // No need to FatalError because once the unneeded bg chainstate data is
6362 // moved, it will not interfere with subsequent initialization.
6363 LogWarning("Deletion of %s failed. Please remove it manually, as the "
6364 "directory is now unnecessary.",
6365 fs::PathToString(delete_path));
6366 } else {
6367 LogInfo("[snapshot] deleted background chainstate directory (%s)",
6368 fs::PathToString(validated_path));
6369 }
6370 return true;
6371 }
6372 6373 std::pair<int, int> Chainstate::GetPruneRange(int last_height_can_prune) const
6374 {
6375 if (m_chain.Height() <= 0) {
6376 return {0, 0};
6377 }
6378 int prune_start{0};
6379 6380 if (m_from_snapshot_blockhash && m_assumeutxo != Assumeutxo::VALIDATED) {
6381 // Only prune blocks _after_ the snapshot if this is a snapshot chain
6382 // that has not been fully validated yet. The earlier blocks need to be
6383 // kept to validate the snapshot
6384 prune_start = Assert(SnapshotBase())->nHeight + 1;
6385 }
6386 6387 int max_prune = std::max<int>(
6388 0, m_chain.Height() - static_cast<int>(MIN_BLOCKS_TO_KEEP));
6389 6390 // last block to prune is the lesser of (caller-specified height, MIN_BLOCKS_TO_KEEP from the tip)
6391 //
6392 // While you might be tempted to prune the background chainstate more
6393 // aggressively (i.e. fewer MIN_BLOCKS_TO_KEEP), this won't work with index
6394 // building - specifically blockfilterindex requires undo data, and if
6395 // we don't maintain this trailing window, we hit indexing failures.
6396 int prune_end = std::min(last_height_can_prune, max_prune);
6397 6398 return {prune_start, prune_end};
6399 }
6400 6401 std::optional<std::pair<const CBlockIndex*, const CBlockIndex*>> ChainstateManager::GetHistoricalBlockRange() const
6402 {
6403 const Chainstate* chainstate{HistoricalChainstate()};
6404 if (!chainstate) return {};
6405 return std::make_pair(chainstate->m_chain.Tip(), chainstate->TargetBlock());
6406 }
6407 6408 util::Result<void> ChainstateManager::ActivateBestChains()
6409 {
6410 // We can't hold cs_main during ActivateBestChain even though we're accessing
6411 // the chainman unique_ptrs since ABC requires us not to be holding cs_main, so retrieve
6412 // the relevant pointers before the ABC call.
6413 AssertLockNotHeld(cs_main);
6414 std::vector<Chainstate*> chainstates;
6415 {
6416 LOCK(GetMutex());
6417 chainstates.reserve(m_chainstates.size());
6418 for (const auto& chainstate : m_chainstates) {
6419 if (chainstate && chainstate->m_assumeutxo != Assumeutxo::INVALID && !chainstate->m_target_utxohash) {
6420 chainstates.push_back(chainstate.get());
6421 }
6422 }
6423 }
6424 for (Chainstate* chainstate : chainstates) {
6425 BlockValidationState state;
6426 if (!chainstate->ActivateBestChain(state, nullptr)) {
6427 LOCK(GetMutex());
6428 return util::Error{Untranslated(strprintf("%s Failed to connect best block (%s)", chainstate->ToString(), state.ToString()))};
6429 }
6430 }
6431 return {};
6432 }
6433