validation.cpp
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/chain.h> 24 #include <kernel/chainparams.h> 25 #include <kernel/coinstats.h> 26 #include <kernel/disconnected_transactions.h> 27 #include <kernel/mempool_entry.h> 28 #include <kernel/messagestartchars.h> 29 #include <kernel/notifications_interface.h> 30 #include <kernel/warning.h> 31 #include <logging.h> 32 #include <logging/timer.h> 33 #include <node/blockstorage.h> 34 #include <node/utxo_snapshot.h> 35 #include <policy/ephemeral_policy.h> 36 #include <policy/policy.h> 37 #include <policy/rbf.h> 38 #include <policy/settings.h> 39 #include <policy/truc_policy.h> 40 #include <pow.h> 41 #include <primitives/block.h> 42 #include <primitives/transaction.h> 43 #include <random.h> 44 #include <script/script.h> 45 #include <script/sigcache.h> 46 #include <signet.h> 47 #include <tinyformat.h> 48 #include <txdb.h> 49 #include <txmempool.h> 50 #include <uint256.h> 51 #include <undo.h> 52 #include <util/check.h> 53 #include <util/fs.h> 54 #include <util/fs_helpers.h> 55 #include <util/hasher.h> 56 #include <util/moneystr.h> 57 #include <util/rbf.h> 58 #include <util/result.h> 59 #include <util/signalinterrupt.h> 60 #include <util/strencodings.h> 61 #include <util/string.h> 62 #include <util/time.h> 63 #include <util/trace.h> 64 #include <util/translation.h> 65 #include <validationinterface.h> 66 67 #include <algorithm> 68 #include <cassert> 69 #include <chrono> 70 #include <deque> 71 #include <numeric> 72 #include <optional> 73 #include <ranges> 74 #include <span> 75 #include <string> 76 #include <tuple> 77 #include <utility> 78 79 using kernel::CCoinsStats; 80 using kernel::CoinStatsHashType; 81 using kernel::ComputeUTXOStats; 82 using kernel::Notifications; 83 84 using fsbridge::FopenFn; 85 using node::BlockManager; 86 using node::BlockMap; 87 using node::CBlockIndexHeightOnlyComparator; 88 using node::CBlockIndexWorkComparator; 89 using node::SnapshotMetadata; 90 91 /** Size threshold for warning about slow UTXO set flush to disk. */ 92 static constexpr size_t WARN_FLUSH_COINS_SIZE = 1 << 30; // 1 GiB 93 /** Time window to wait between writing blocks/block index and chainstate to disk. 94 * Randomize writing time inside the window to prevent a situation where the 95 * network over time settles into a few cohorts of synchronized writers. 96 */ 97 static constexpr auto DATABASE_WRITE_INTERVAL_MIN{50min}; 98 static constexpr auto DATABASE_WRITE_INTERVAL_MAX{70min}; 99 /** Maximum age of our tip for us to be considered current for fee estimation */ 100 static constexpr std::chrono::hours MAX_FEE_ESTIMATION_TIP_AGE{3}; 101 const std::vector<std::string> CHECKLEVEL_DOC { 102 "level 0 reads the blocks from disk", 103 "level 1 verifies block validity", 104 "level 2 verifies undo data", 105 "level 3 checks disconnection of tip blocks", 106 "level 4 tries to reconnect the blocks", 107 "each level includes the checks of the previous levels", 108 }; 109 /** The number of blocks to keep below the deepest prune lock. 110 * There is nothing special about this number. It is higher than what we 111 * expect to see in regular mainnet reorgs, but not so high that it would 112 * noticeably interfere with the pruning mechanism. 113 * */ 114 static constexpr int PRUNE_LOCK_BUFFER{10}; 115 116 TRACEPOINT_SEMAPHORE(validation, block_connected); 117 TRACEPOINT_SEMAPHORE(utxocache, flush); 118 TRACEPOINT_SEMAPHORE(mempool, replaced); 119 TRACEPOINT_SEMAPHORE(mempool, rejected); 120 121 const CBlockIndex* Chainstate::FindForkInGlobalIndex(const CBlockLocator& locator) const 122 { 123 AssertLockHeld(cs_main); 124 125 // Find the latest block common to locator and chain - we expect that 126 // locator.vHave is sorted descending by height. 127 for (const uint256& hash : locator.vHave) { 128 const CBlockIndex* pindex{m_blockman.LookupBlockIndex(hash)}; 129 if (pindex) { 130 if (m_chain.Contains(pindex)) { 131 return pindex; 132 } 133 if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) { 134 return m_chain.Tip(); 135 } 136 } 137 } 138 return m_chain.Genesis(); 139 } 140 141 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state, 142 const CCoinsViewCache& inputs, script_verify_flags flags, bool cacheSigStore, 143 bool cacheFullScriptStore, PrecomputedTransactionData& txdata, 144 ValidationCache& validation_cache, 145 std::vector<CScriptCheck>* pvChecks = nullptr) 146 EXCLUSIVE_LOCKS_REQUIRED(cs_main); 147 148 bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx) 149 { 150 AssertLockHeld(cs_main); 151 152 // CheckFinalTxAtTip() uses active_chain_tip.Height()+1 to evaluate 153 // nLockTime because when IsFinalTx() is called within 154 // AcceptBlock(), the height of the block *being* 155 // evaluated is what is used. Thus if we want to know if a 156 // transaction can be part of the *next* block, we need to call 157 // IsFinalTx() with one more than active_chain_tip.Height(). 158 const int nBlockHeight = active_chain_tip.nHeight + 1; 159 160 // BIP113 requires that time-locked transactions have nLockTime set to 161 // less than the median time of the previous block they're contained in. 162 // When the next block is created its previous block will be the current 163 // chain tip, so we use that to calculate the median time passed to 164 // IsFinalTx(). 165 const int64_t nBlockTime{active_chain_tip.GetMedianTimePast()}; 166 167 return IsFinalTx(tx, nBlockHeight, nBlockTime); 168 } 169 170 namespace { 171 /** 172 * A helper which calculates heights of inputs of a given transaction. 173 * 174 * @param[in] tip The current chain tip. If an input belongs to a mempool 175 * transaction, we assume it will be confirmed in the next block. 176 * @param[in] coins Any CCoinsView that provides access to the relevant coins. 177 * @param[in] tx The transaction being evaluated. 178 * 179 * @returns A vector of input heights or nullopt, in case of an error. 180 */ 181 std::optional<std::vector<int>> CalculatePrevHeights( 182 const CBlockIndex& tip, 183 const CCoinsView& coins, 184 const CTransaction& tx) 185 { 186 std::vector<int> prev_heights; 187 prev_heights.resize(tx.vin.size()); 188 for (size_t i = 0; i < tx.vin.size(); ++i) { 189 if (auto coin{coins.GetCoin(tx.vin[i].prevout)}) { 190 prev_heights[i] = coin->nHeight == MEMPOOL_HEIGHT 191 ? tip.nHeight + 1 // Assume all mempool transaction confirm in the next block. 192 : coin->nHeight; 193 } else { 194 LogPrintf("ERROR: %s: Missing input %d in transaction \'%s\'\n", __func__, i, tx.GetHash().GetHex()); 195 return std::nullopt; 196 } 197 } 198 return prev_heights; 199 } 200 } // namespace 201 202 std::optional<LockPoints> CalculateLockPointsAtTip( 203 CBlockIndex* tip, 204 const CCoinsView& coins_view, 205 const CTransaction& tx) 206 { 207 assert(tip); 208 209 auto prev_heights{CalculatePrevHeights(*tip, coins_view, tx)}; 210 if (!prev_heights.has_value()) return std::nullopt; 211 212 CBlockIndex next_tip; 213 next_tip.pprev = tip; 214 // When SequenceLocks() is called within ConnectBlock(), the height 215 // of the block *being* evaluated is what is used. 216 // Thus if we want to know if a transaction can be part of the 217 // *next* block, we need to use one more than active_chainstate.m_chain.Height() 218 next_tip.nHeight = tip->nHeight + 1; 219 const auto [min_height, min_time] = CalculateSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS, prev_heights.value(), next_tip); 220 221 // Also store the hash of the block with the highest height of 222 // all the blocks which have sequence locked prevouts. 223 // This hash needs to still be on the chain 224 // for these LockPoint calculations to be valid 225 // Note: It is impossible to correctly calculate a maxInputBlock 226 // if any of the sequence locked inputs depend on unconfirmed txs, 227 // except in the special case where the relative lock time/height 228 // is 0, which is equivalent to no sequence lock. Since we assume 229 // input height of tip+1 for mempool txs and test the resulting 230 // min_height and min_time from CalculateSequenceLocks against tip+1. 231 int max_input_height{0}; 232 for (const int height : prev_heights.value()) { 233 // Can ignore mempool inputs since we'll fail if they had non-zero locks 234 if (height != next_tip.nHeight) { 235 max_input_height = std::max(max_input_height, height); 236 } 237 } 238 239 // tip->GetAncestor(max_input_height) should never return a nullptr 240 // because max_input_height is always less than the tip height. 241 // It would, however, be a bad bug to continue execution, since a 242 // LockPoints object with the maxInputBlock member set to nullptr 243 // signifies no relative lock time. 244 return LockPoints{min_height, min_time, Assert(tip->GetAncestor(max_input_height))}; 245 } 246 247 bool CheckSequenceLocksAtTip(CBlockIndex* tip, 248 const LockPoints& lock_points) 249 { 250 assert(tip != nullptr); 251 252 CBlockIndex index; 253 index.pprev = tip; 254 // CheckSequenceLocksAtTip() uses active_chainstate.m_chain.Height()+1 to evaluate 255 // height based locks because when SequenceLocks() is called within 256 // ConnectBlock(), the height of the block *being* 257 // evaluated is what is used. 258 // Thus if we want to know if a transaction can be part of the 259 // *next* block, we need to use one more than active_chainstate.m_chain.Height() 260 index.nHeight = tip->nHeight + 1; 261 262 return EvaluateSequenceLocks(index, {lock_points.height, lock_points.time}); 263 } 264 265 static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache) 266 EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs) 267 { 268 AssertLockHeld(::cs_main); 269 AssertLockHeld(pool.cs); 270 int expired = pool.Expire(GetTime<std::chrono::seconds>() - pool.m_opts.expiry); 271 if (expired != 0) { 272 LogDebug(BCLog::MEMPOOL, "Expired %i transactions from the memory pool\n", expired); 273 } 274 275 std::vector<COutPoint> vNoSpendsRemaining; 276 pool.TrimToSize(pool.m_opts.max_size_bytes, &vNoSpendsRemaining); 277 for (const COutPoint& removed : vNoSpendsRemaining) 278 coins_cache.Uncache(removed); 279 } 280 281 static bool IsCurrentForFeeEstimation(Chainstate& active_chainstate) EXCLUSIVE_LOCKS_REQUIRED(cs_main) 282 { 283 AssertLockHeld(cs_main); 284 if (active_chainstate.m_chainman.IsInitialBlockDownload()) { 285 return false; 286 } 287 if (active_chainstate.m_chain.Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE)) 288 return false; 289 if (active_chainstate.m_chain.Height() < active_chainstate.m_chainman.m_best_header->nHeight - 1) { 290 return false; 291 } 292 return true; 293 } 294 295 void Chainstate::MaybeUpdateMempoolForReorg( 296 DisconnectedBlockTransactions& disconnectpool, 297 bool fAddToMempool) 298 { 299 if (!m_mempool) return; 300 301 AssertLockHeld(cs_main); 302 AssertLockHeld(m_mempool->cs); 303 std::vector<Txid> vHashUpdate; 304 { 305 // disconnectpool is ordered so that the front is the most recently-confirmed 306 // transaction (the last tx of the block at the tip) in the disconnected chain. 307 // Iterate disconnectpool in reverse, so that we add transactions 308 // back to the mempool starting with the earliest transaction that had 309 // been previously seen in a block. 310 const auto queuedTx = disconnectpool.take(); 311 auto it = queuedTx.rbegin(); 312 while (it != queuedTx.rend()) { 313 // ignore validation errors in resurrected transactions 314 if (!fAddToMempool || (*it)->IsCoinBase() || 315 AcceptToMemoryPool(*this, *it, GetTime(), 316 /*bypass_limits=*/true, /*test_accept=*/false).m_result_type != 317 MempoolAcceptResult::ResultType::VALID) { 318 // If the transaction doesn't make it in to the mempool, remove any 319 // transactions that depend on it (which would now be orphans). 320 m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG); 321 } else if (m_mempool->exists((*it)->GetHash())) { 322 vHashUpdate.push_back((*it)->GetHash()); 323 } 324 ++it; 325 } 326 } 327 328 // AcceptToMemoryPool/addNewTransaction all assume that new mempool entries have 329 // no in-mempool children, which is generally not true when adding 330 // previously-confirmed transactions back to the mempool. 331 // UpdateTransactionsFromBlock finds descendants of any transactions in 332 // the disconnectpool that were added back and cleans up the mempool state. 333 m_mempool->UpdateTransactionsFromBlock(vHashUpdate); 334 335 // Predicate to use for filtering transactions in removeForReorg. 336 // Checks whether the transaction is still final and, if it spends a coinbase output, mature. 337 // Also updates valid entries' cached LockPoints if needed. 338 // If false, the tx is still valid and its lockpoints are updated. 339 // If true, the tx would be invalid in the next block; remove this entry and all of its descendants. 340 // Note that TRUC rules are not applied here, so reorgs may cause violations of TRUC inheritance or 341 // topology restrictions. 342 const auto filter_final_and_mature = [&](CTxMemPool::txiter it) 343 EXCLUSIVE_LOCKS_REQUIRED(m_mempool->cs, ::cs_main) { 344 AssertLockHeld(m_mempool->cs); 345 AssertLockHeld(::cs_main); 346 const CTransaction& tx = it->GetTx(); 347 348 // The transaction must be final. 349 if (!CheckFinalTxAtTip(*Assert(m_chain.Tip()), tx)) return true; 350 351 const LockPoints& lp = it->GetLockPoints(); 352 // CheckSequenceLocksAtTip checks if the transaction will be final in the next block to be 353 // created on top of the new chain. 354 if (TestLockPointValidity(m_chain, lp)) { 355 if (!CheckSequenceLocksAtTip(m_chain.Tip(), lp)) { 356 return true; 357 } 358 } else { 359 const CCoinsViewMemPool view_mempool{&CoinsTip(), *m_mempool}; 360 const std::optional<LockPoints> new_lock_points{CalculateLockPointsAtTip(m_chain.Tip(), view_mempool, tx)}; 361 if (new_lock_points.has_value() && CheckSequenceLocksAtTip(m_chain.Tip(), *new_lock_points)) { 362 // Now update the mempool entry lockpoints as well. 363 it->UpdateLockPoints(*new_lock_points); 364 } else { 365 return true; 366 } 367 } 368 369 // If the transaction spends any coinbase outputs, it must be mature. 370 if (it->GetSpendsCoinbase()) { 371 for (const CTxIn& txin : tx.vin) { 372 if (m_mempool->exists(txin.prevout.hash)) continue; 373 const Coin& coin{CoinsTip().AccessCoin(txin.prevout)}; 374 assert(!coin.IsSpent()); 375 const auto mempool_spend_height{m_chain.Tip()->nHeight + 1}; 376 if (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY) { 377 return true; 378 } 379 } 380 } 381 // Transaction is still valid and cached LockPoints are updated. 382 return false; 383 }; 384 385 // We also need to remove any now-immature transactions 386 m_mempool->removeForReorg(m_chain, filter_final_and_mature); 387 // Re-limit mempool size, in case we added any transactions 388 LimitMempoolSize(*m_mempool, this->CoinsTip()); 389 } 390 391 /** 392 * Checks to avoid mempool polluting consensus critical paths since cached 393 * signature and script validity results will be reused if we validate this 394 * transaction again during block validation. 395 * */ 396 static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, TxValidationState& state, 397 const CCoinsViewCache& view, const CTxMemPool& pool, 398 script_verify_flags flags, PrecomputedTransactionData& txdata, CCoinsViewCache& coins_tip, 399 ValidationCache& validation_cache) 400 EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs) 401 { 402 AssertLockHeld(cs_main); 403 AssertLockHeld(pool.cs); 404 405 assert(!tx.IsCoinBase()); 406 for (const CTxIn& txin : tx.vin) { 407 const Coin& coin = view.AccessCoin(txin.prevout); 408 409 // This coin was checked in PreChecks and MemPoolAccept 410 // has been holding cs_main since then. 411 Assume(!coin.IsSpent()); 412 if (coin.IsSpent()) return false; 413 414 // If the Coin is available, there are 2 possibilities: 415 // it is available in our current ChainstateActive UTXO set, 416 // or it's a UTXO provided by a transaction in our mempool. 417 // Ensure the scriptPubKeys in Coins from CoinsView are correct. 418 const CTransactionRef& txFrom = pool.get(txin.prevout.hash); 419 if (txFrom) { 420 assert(txFrom->GetHash() == txin.prevout.hash); 421 assert(txFrom->vout.size() > txin.prevout.n); 422 assert(txFrom->vout[txin.prevout.n] == coin.out); 423 } else { 424 const Coin& coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout); 425 assert(!coinFromUTXOSet.IsSpent()); 426 assert(coinFromUTXOSet.out == coin.out); 427 } 428 } 429 430 // Call CheckInputScripts() to cache signature and script validity against current tip consensus rules. 431 return CheckInputScripts(tx, state, view, flags, /* cacheSigStore= */ true, /* cacheFullScriptStore= */ true, txdata, validation_cache); 432 } 433 434 namespace { 435 436 class MemPoolAccept 437 { 438 public: 439 explicit MemPoolAccept(CTxMemPool& mempool, Chainstate& active_chainstate) : 440 m_pool(mempool), 441 m_view(&m_dummy), 442 m_viewmempool(&active_chainstate.CoinsTip(), m_pool), 443 m_active_chainstate(active_chainstate) 444 { 445 } 446 447 // We put the arguments we're handed into a struct, so we can pass them 448 // around easier. 449 struct ATMPArgs { 450 const CChainParams& m_chainparams; 451 const int64_t m_accept_time; 452 const bool m_bypass_limits; 453 /* 454 * Return any outpoints which were not previously present in the coins 455 * cache, but were added as a result of validating the tx for mempool 456 * acceptance. This allows the caller to optionally remove the cache 457 * additions if the associated transaction ends up being rejected by 458 * the mempool. 459 */ 460 std::vector<COutPoint>& m_coins_to_uncache; 461 /** When true, the transaction or package will not be submitted to the mempool. */ 462 const bool m_test_accept; 463 /** Whether we allow transactions to replace mempool transactions. If false, 464 * any transaction spending the same inputs as a transaction in the mempool is considered 465 * a conflict. */ 466 const bool m_allow_replacement; 467 /** When true, allow sibling eviction. This only occurs in single transaction package settings. */ 468 const bool m_allow_sibling_eviction; 469 /** Used to skip the LimitMempoolSize() call within AcceptSingleTransaction(). This should be used when multiple 470 * AcceptSubPackage calls are expected and the mempool will be trimmed at the end of AcceptPackage(). */ 471 const bool m_package_submission; 472 /** When true, use package feerates instead of individual transaction feerates for fee-based 473 * policies such as mempool min fee and min relay fee. 474 */ 475 const bool m_package_feerates; 476 /** Used for local submission of transactions to catch "absurd" fees 477 * due to fee miscalculation by wallets. std:nullopt implies unset, allowing any feerates. 478 * Any individual transaction failing this check causes immediate failure. 479 */ 480 const std::optional<CFeeRate> m_client_maxfeerate; 481 482 /** Parameters for single transaction mempool validation. */ 483 static ATMPArgs SingleAccept(const CChainParams& chainparams, int64_t accept_time, 484 bool bypass_limits, std::vector<COutPoint>& coins_to_uncache, 485 bool test_accept) { 486 return ATMPArgs{/* m_chainparams */ chainparams, 487 /* m_accept_time */ accept_time, 488 /* m_bypass_limits */ bypass_limits, 489 /* m_coins_to_uncache */ coins_to_uncache, 490 /* m_test_accept */ test_accept, 491 /* m_allow_replacement */ true, 492 /* m_allow_sibling_eviction */ true, 493 /* m_package_submission */ false, 494 /* m_package_feerates */ false, 495 /* m_client_maxfeerate */ {}, // checked by caller 496 }; 497 } 498 499 /** Parameters for test package mempool validation through testmempoolaccept. */ 500 static ATMPArgs PackageTestAccept(const CChainParams& chainparams, int64_t accept_time, 501 std::vector<COutPoint>& coins_to_uncache) { 502 return ATMPArgs{/* m_chainparams */ chainparams, 503 /* m_accept_time */ accept_time, 504 /* m_bypass_limits */ false, 505 /* m_coins_to_uncache */ coins_to_uncache, 506 /* m_test_accept */ true, 507 /* m_allow_replacement */ false, 508 /* m_allow_sibling_eviction */ false, 509 /* m_package_submission */ false, // not submitting to mempool 510 /* m_package_feerates */ false, 511 /* m_client_maxfeerate */ {}, // checked by caller 512 }; 513 } 514 515 /** Parameters for child-with-parents package validation. */ 516 static ATMPArgs PackageChildWithParents(const CChainParams& chainparams, int64_t accept_time, 517 std::vector<COutPoint>& coins_to_uncache, const std::optional<CFeeRate>& client_maxfeerate) { 518 return ATMPArgs{/* m_chainparams */ chainparams, 519 /* m_accept_time */ accept_time, 520 /* m_bypass_limits */ false, 521 /* m_coins_to_uncache */ coins_to_uncache, 522 /* m_test_accept */ false, 523 /* m_allow_replacement */ true, 524 /* m_allow_sibling_eviction */ false, 525 /* m_package_submission */ true, 526 /* m_package_feerates */ true, 527 /* m_client_maxfeerate */ client_maxfeerate, 528 }; 529 } 530 531 /** Parameters for a single transaction within a package. */ 532 static ATMPArgs SingleInPackageAccept(const ATMPArgs& package_args) { 533 return ATMPArgs{/* m_chainparams */ package_args.m_chainparams, 534 /* m_accept_time */ package_args.m_accept_time, 535 /* m_bypass_limits */ false, 536 /* m_coins_to_uncache */ package_args.m_coins_to_uncache, 537 /* m_test_accept */ package_args.m_test_accept, 538 /* m_allow_replacement */ true, 539 /* m_allow_sibling_eviction */ true, 540 /* m_package_submission */ true, // trim at the end of AcceptPackage() 541 /* m_package_feerates */ false, // only 1 transaction 542 /* m_client_maxfeerate */ package_args.m_client_maxfeerate, 543 }; 544 } 545 546 private: 547 // Private ctor to avoid exposing details to clients and allowing the possibility of 548 // mixing up the order of the arguments. Use static functions above instead. 549 ATMPArgs(const CChainParams& chainparams, 550 int64_t accept_time, 551 bool bypass_limits, 552 std::vector<COutPoint>& coins_to_uncache, 553 bool test_accept, 554 bool allow_replacement, 555 bool allow_sibling_eviction, 556 bool package_submission, 557 bool package_feerates, 558 std::optional<CFeeRate> client_maxfeerate) 559 : m_chainparams{chainparams}, 560 m_accept_time{accept_time}, 561 m_bypass_limits{bypass_limits}, 562 m_coins_to_uncache{coins_to_uncache}, 563 m_test_accept{test_accept}, 564 m_allow_replacement{allow_replacement}, 565 m_allow_sibling_eviction{allow_sibling_eviction}, 566 m_package_submission{package_submission}, 567 m_package_feerates{package_feerates}, 568 m_client_maxfeerate{client_maxfeerate} 569 { 570 // If we are using package feerates, we must be doing package submission. 571 // It also means sibling eviction is not permitted. 572 if (m_package_feerates) { 573 Assume(m_package_submission); 574 Assume(!m_allow_sibling_eviction); 575 } 576 if (m_allow_sibling_eviction) Assume(m_allow_replacement); 577 } 578 }; 579 580 /** Clean up all non-chainstate coins from m_view and m_viewmempool. */ 581 void CleanupTemporaryCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 582 583 // Single transaction acceptance 584 MempoolAcceptResult AcceptSingleTransactionAndCleanup(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { 585 LOCK(m_pool.cs); 586 MempoolAcceptResult result = AcceptSingleTransactionInternal(ptx, args); 587 ClearSubPackageState(); 588 return result; 589 } 590 MempoolAcceptResult AcceptSingleTransactionInternal(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 591 592 /** 593 * Multiple transaction acceptance. Transactions may or may not be interdependent, but must not 594 * conflict with each other, and the transactions cannot already be in the mempool. Parents must 595 * come before children if any dependencies exist. 596 */ 597 PackageMempoolAcceptResult AcceptMultipleTransactionsAndCleanup(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { 598 LOCK(m_pool.cs); 599 PackageMempoolAcceptResult result = AcceptMultipleTransactionsInternal(txns, args); 600 ClearSubPackageState(); 601 return result; 602 } 603 PackageMempoolAcceptResult AcceptMultipleTransactionsInternal(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 604 605 /** 606 * Submission of a subpackage. 607 * If subpackage size == 1, calls AcceptSingleTransaction() with adjusted ATMPArgs to 608 * enable sibling eviction and creates a PackageMempoolAcceptResult 609 * wrapping the result. 610 * 611 * If subpackage size > 1, calls AcceptMultipleTransactions() with the provided ATMPArgs. 612 * 613 * Also cleans up all non-chainstate coins from m_view at the end. 614 */ 615 PackageMempoolAcceptResult AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args) 616 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 617 618 /** 619 * Package (more specific than just multiple transactions) acceptance. Package must be a child 620 * with all of its unconfirmed parents, and topologically sorted. 621 */ 622 PackageMempoolAcceptResult AcceptPackage(const Package& package, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 623 624 private: 625 // All the intermediate state that gets passed between the various levels 626 // of checking a given transaction. 627 struct Workspace { 628 explicit Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {} 629 /** Txids of mempool transactions that this transaction directly conflicts with or may 630 * replace via sibling eviction. */ 631 std::set<Txid> m_conflicts; 632 /** Iterators to mempool entries that this transaction directly conflicts with or may 633 * replace via sibling eviction. */ 634 CTxMemPool::setEntries m_iters_conflicting; 635 /** All mempool parents of this transaction. */ 636 std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> m_parents; 637 /* Handle to the tx in the changeset */ 638 CTxMemPool::ChangeSet::TxHandle m_tx_handle; 639 /** Whether RBF-related data structures (m_conflicts, m_iters_conflicting, 640 * m_replaced_transactions) include a sibling in addition to txns with conflicting inputs. */ 641 bool m_sibling_eviction{false}; 642 643 /** Virtual size of the transaction as used by the mempool, calculated using serialized size 644 * of the transaction and sigops. */ 645 int64_t m_vsize; 646 /** Fees paid by this transaction: total input amounts subtracted by total output amounts. */ 647 CAmount m_base_fees; 648 /** Base fees + any fee delta set by the user with prioritisetransaction. */ 649 CAmount m_modified_fees; 650 651 /** If we're doing package validation (i.e. m_package_feerates=true), the "effective" 652 * package feerate of this transaction is the total fees divided by the total size of 653 * transactions (which may include its ancestors and/or descendants). */ 654 CFeeRate m_package_feerate{0}; 655 656 const CTransactionRef& m_ptx; 657 /** Txid. */ 658 const Txid& m_hash; 659 TxValidationState m_state; 660 /** A temporary cache containing serialized transaction data for signature verification. 661 * Reused across PolicyScriptChecks and ConsensusScriptChecks. */ 662 PrecomputedTransactionData m_precomputed_txdata; 663 }; 664 665 // Run the policy checks on a given transaction, excluding any script checks. 666 // Looks up inputs, calculates feerate, considers replacement, evaluates 667 // package limits, etc. As this function can be invoked for "free" by a peer, 668 // only tests that are fast should be done here (to avoid CPU DoS). 669 bool PreChecks(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 670 671 // Run checks for mempool replace-by-fee, only used in AcceptSingleTransaction. 672 bool ReplacementChecks(Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 673 674 // Enforce package mempool ancestor/descendant limits (distinct from individual 675 // ancestor/descendant limits done in PreChecks) and run Package RBF checks. 676 bool PackageMempoolChecks(const std::vector<CTransactionRef>& txns, 677 std::vector<Workspace>& workspaces, 678 int64_t total_vsize, 679 PackageValidationState& package_state) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 680 681 // Run the script checks using our policy flags. As this can be slow, we should 682 // only invoke this on transactions that have otherwise passed policy checks. 683 bool PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 684 685 // Re-run the script checks, using consensus flags, and try to cache the 686 // result in the scriptcache. This should be done after 687 // PolicyScriptChecks(). This requires that all inputs either be in our 688 // utxo set or in the mempool. 689 bool ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 690 691 // Try to add the transaction to the mempool, removing any conflicts first. 692 void FinalizeSubpackage(const ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 693 694 // Submit all transactions to the mempool and call ConsensusScriptChecks to add to the script 695 // cache - should only be called after successful validation of all transactions in the package. 696 // Does not call LimitMempoolSize(), so mempool max_size_bytes may be temporarily exceeded. 697 bool SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, PackageValidationState& package_state, 698 std::map<Wtxid, MempoolAcceptResult>& results) 699 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 700 701 // Compare a package's feerate against minimum allowed. 702 bool CheckFeeRate(size_t package_size, CAmount package_fee, TxValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) 703 { 704 AssertLockHeld(::cs_main); 705 AssertLockHeld(m_pool.cs); 706 CAmount mempoolRejectFee = m_pool.GetMinFee().GetFee(package_size); 707 if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) { 708 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee)); 709 } 710 711 if (package_fee < m_pool.m_opts.min_relay_feerate.GetFee(package_size)) { 712 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "min relay fee not met", 713 strprintf("%d < %d", package_fee, m_pool.m_opts.min_relay_feerate.GetFee(package_size))); 714 } 715 return true; 716 } 717 718 ValidationCache& GetValidationCache() 719 { 720 return m_active_chainstate.m_chainman.m_validation_cache; 721 } 722 723 private: 724 CTxMemPool& m_pool; 725 726 /** Holds a cached view of available coins from the UTXO set, mempool, and artificial temporary coins (to enable package validation). 727 * The view doesn't track whether a coin previously existed but has now been spent. We detect conflicts in other ways: 728 * - conflicts within a transaction are checked in CheckTransaction (bad-txns-inputs-duplicate) 729 * - conflicts within a package are checked in IsWellFormedPackage (conflict-in-package) 730 * - conflicts with an existing mempool transaction are found in CTxMemPool::GetConflictTx and replacements are allowed 731 * The temporary coins should persist between individual transaction checks so that package validation is possible, 732 * but must be cleaned up when we finish validating a subpackage, whether accepted or rejected. The cache must also 733 * be cleared when mempool contents change (when a changeset is applied or when the mempool trims itself) because it 734 * can return cached coins that no longer exist in the backend. Use CleanupTemporaryCoins() anytime you are finished 735 * with a SubPackageState or call LimitMempoolSize(). 736 */ 737 CCoinsViewCache m_view; 738 739 // These are the two possible backends for m_view. 740 /** When m_view is connected to m_viewmempool as its backend, it can pull coins from the mempool and from the UTXO 741 * set. This is also where temporary coins are stored. */ 742 CCoinsViewMemPool m_viewmempool; 743 /** When m_view is connected to m_dummy, it can no longer look up coins from the mempool or UTXO set (meaning no disk 744 * operations happen), but can still return coins it accessed previously. Useful for keeping track of which coins 745 * were pulled from disk. */ 746 CCoinsView m_dummy; 747 748 Chainstate& m_active_chainstate; 749 750 // Fields below are per *sub*package state and must be reset prior to subsequent 751 // AcceptSingleTransaction and AcceptMultipleTransactions invocations 752 struct SubPackageState { 753 /** Aggregated modified fees of all transactions, used to calculate package feerate. */ 754 CAmount m_total_modified_fees{0}; 755 /** Aggregated virtual size of all transactions, used to calculate package feerate. */ 756 int64_t m_total_vsize{0}; 757 758 // RBF-related members 759 /** Whether the transaction(s) would replace any mempool transactions and/or evict any siblings. 760 * If so, RBF rules apply. */ 761 bool m_rbf{false}; 762 /** Mempool transactions that were replaced. */ 763 std::list<CTransactionRef> m_replaced_transactions; 764 /* Changeset representing adding transactions and removing their conflicts. */ 765 std::unique_ptr<CTxMemPool::ChangeSet> m_changeset; 766 767 /** Total modified fees of mempool transactions being replaced. */ 768 CAmount m_conflicting_fees{0}; 769 /** Total size (in virtual bytes) of mempool transactions being replaced. */ 770 size_t m_conflicting_size{0}; 771 }; 772 773 struct SubPackageState m_subpackage; 774 775 /** Re-set sub-package state to not leak between evaluations */ 776 void ClearSubPackageState() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs) 777 { 778 m_subpackage = SubPackageState{}; 779 780 // And clean coins while at it 781 CleanupTemporaryCoins(); 782 } 783 }; 784 785 bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws) 786 { 787 AssertLockHeld(cs_main); 788 AssertLockHeld(m_pool.cs); 789 const CTransactionRef& ptx = ws.m_ptx; 790 const CTransaction& tx = *ws.m_ptx; 791 const Txid& hash = ws.m_hash; 792 793 // Copy/alias what we need out of args 794 const int64_t nAcceptTime = args.m_accept_time; 795 const bool bypass_limits = args.m_bypass_limits; 796 std::vector<COutPoint>& coins_to_uncache = args.m_coins_to_uncache; 797 798 // Alias what we need out of ws 799 TxValidationState& state = ws.m_state; 800 801 if (!CheckTransaction(tx, state)) { 802 return false; // state filled in by CheckTransaction 803 } 804 805 // Coinbase is only valid in a block, not as a loose transaction 806 if (tx.IsCoinBase()) 807 return state.Invalid(TxValidationResult::TX_CONSENSUS, "coinbase"); 808 809 // Rather not work on nonstandard transactions (unless -testnet/-regtest) 810 std::string reason; 811 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)) { 812 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason); 813 } 814 815 // Transactions smaller than 65 non-witness bytes are not relayed to mitigate CVE-2017-12842. 816 if (::GetSerializeSize(TX_NO_WITNESS(tx)) < MIN_STANDARD_TX_NONWITNESS_SIZE) 817 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "tx-size-small"); 818 819 // Only accept nLockTime-using transactions that can be mined in the next 820 // block; we don't want our mempool filled up with transactions that can't 821 // be mined yet. 822 if (!CheckFinalTxAtTip(*Assert(m_active_chainstate.m_chain.Tip()), tx)) { 823 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-final"); 824 } 825 826 if (m_pool.exists(tx.GetWitnessHash())) { 827 // Exact transaction already exists in the mempool. 828 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-in-mempool"); 829 } else if (m_pool.exists(tx.GetHash())) { 830 // Transaction with the same non-witness data but different witness (same txid, different 831 // wtxid) already exists in the mempool. 832 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-same-nonwitness-data-in-mempool"); 833 } 834 835 // Check for conflicts with in-memory transactions 836 for (const CTxIn &txin : tx.vin) 837 { 838 const CTransaction* ptxConflicting = m_pool.GetConflictTx(txin.prevout); 839 if (ptxConflicting) { 840 if (!args.m_allow_replacement) { 841 // Transaction conflicts with a mempool tx, but we're not allowing replacements in this context. 842 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "bip125-replacement-disallowed"); 843 } 844 ws.m_conflicts.insert(ptxConflicting->GetHash()); 845 } 846 } 847 848 m_view.SetBackend(m_viewmempool); 849 850 const CCoinsViewCache& coins_cache = m_active_chainstate.CoinsTip(); 851 // do all inputs exist? 852 for (const CTxIn& txin : tx.vin) { 853 if (!coins_cache.HaveCoinInCache(txin.prevout)) { 854 coins_to_uncache.push_back(txin.prevout); 855 } 856 857 // Note: this call may add txin.prevout to the coins cache 858 // (coins_cache.cacheCoins) by way of FetchCoin(). It should be removed 859 // later (via coins_to_uncache) if this tx turns out to be invalid. 860 if (!m_view.HaveCoin(txin.prevout)) { 861 // Are inputs missing because we already have the tx? 862 for (size_t out = 0; out < tx.vout.size(); out++) { 863 // Optimistically just do efficient check of cache for outputs 864 if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) { 865 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-known"); 866 } 867 } 868 // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet 869 return state.Invalid(TxValidationResult::TX_MISSING_INPUTS, "bad-txns-inputs-missingorspent"); 870 } 871 } 872 873 // This is const, but calls into the back end CoinsViews. The CCoinsViewDB at the bottom of the 874 // hierarchy brings the best block into scope. See CCoinsViewDB::GetBestBlock(). 875 m_view.GetBestBlock(); 876 877 // we have all inputs cached now, so switch back to dummy (to protect 878 // against bugs where we pull more inputs from disk that miss being added 879 // to coins_to_uncache) 880 m_view.SetBackend(m_dummy); 881 882 assert(m_active_chainstate.m_blockman.LookupBlockIndex(m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip()); 883 884 // Only accept BIP68 sequence locked transactions that can be mined in the next 885 // block; we don't want our mempool filled up with transactions that can't 886 // be mined yet. 887 // Pass in m_view which has all of the relevant inputs cached. Note that, since m_view's 888 // backend was removed, it no longer pulls coins from the mempool. 889 const std::optional<LockPoints> lock_points{CalculateLockPointsAtTip(m_active_chainstate.m_chain.Tip(), m_view, tx)}; 890 if (!lock_points.has_value() || !CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(), *lock_points)) { 891 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-BIP68-final"); 892 } 893 894 // The mempool holds txs for the next block, so pass height+1 to CheckTxInputs 895 if (!Consensus::CheckTxInputs(tx, state, m_view, m_active_chainstate.m_chain.Height() + 1, ws.m_base_fees)) { 896 return false; // state filled in by CheckTxInputs 897 } 898 899 if (m_pool.m_opts.require_standard && !AreInputsStandard(tx, m_view)) { 900 return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs"); 901 } 902 903 // Check for non-standard witnesses. 904 if (tx.HasWitness() && m_pool.m_opts.require_standard && !IsWitnessStandard(tx, m_view)) { 905 return state.Invalid(TxValidationResult::TX_WITNESS_MUTATED, "bad-witness-nonstandard"); 906 } 907 908 int64_t nSigOpsCost = GetTransactionSigOpCost(tx, m_view, STANDARD_SCRIPT_VERIFY_FLAGS); 909 910 // Keep track of transactions that spend a coinbase, which we re-scan 911 // during reorgs to ensure COINBASE_MATURITY is still met. 912 bool fSpendsCoinbase = false; 913 for (const CTxIn &txin : tx.vin) { 914 const Coin &coin = m_view.AccessCoin(txin.prevout); 915 if (coin.IsCoinBase()) { 916 fSpendsCoinbase = true; 917 break; 918 } 919 } 920 921 // Set entry_sequence to 0 when bypass_limits is used; this allows txs from a block 922 // reorg to be marked earlier than any child txs that were already in the mempool. 923 const uint64_t entry_sequence = bypass_limits ? 0 : m_pool.GetSequence(); 924 if (!m_subpackage.m_changeset) { 925 m_subpackage.m_changeset = m_pool.GetChangeSet(); 926 } 927 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()); 928 929 // ws.m_modified_fees includes any fee deltas from PrioritiseTransaction 930 ws.m_modified_fees = ws.m_tx_handle->GetModifiedFee(); 931 932 ws.m_vsize = ws.m_tx_handle->GetTxSize(); 933 934 // Enforces 0-fee for dust transactions, no incentive to be mined alone 935 if (m_pool.m_opts.require_standard) { 936 if (!PreCheckEphemeralTx(*ptx, m_pool.m_opts.dust_relay_feerate, ws.m_base_fees, ws.m_modified_fees, state)) { 937 return false; // state filled in by PreCheckEphemeralTx 938 } 939 } 940 941 if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST) 942 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "bad-txns-too-many-sigops", 943 strprintf("%d", nSigOpsCost)); 944 945 // No individual transactions are allowed below the min relay feerate except from disconnected blocks. 946 // This requirement, unlike CheckFeeRate, cannot be bypassed using m_package_feerates because, 947 // while a tx could be package CPFP'd when entering the mempool, we do not have a DoS-resistant 948 // method of ensuring the tx remains bumped. For example, the fee-bumping child could disappear 949 // due to a replacement. 950 // The only exception is TRUC transactions. 951 if (!bypass_limits && ws.m_ptx->version != TRUC_VERSION && ws.m_modified_fees < m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize)) { 952 // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not 953 // TX_RECONSIDERABLE, because it cannot be bypassed using package validation. 954 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met", 955 strprintf("%d < %d", ws.m_modified_fees, m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize))); 956 } 957 // No individual transactions are allowed below the mempool min feerate except from disconnected 958 // blocks and transactions in a package. Package transactions will be checked using package 959 // feerate later. 960 if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false; 961 962 ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts); 963 964 ws.m_parents = m_pool.GetParents(*ws.m_tx_handle); 965 966 if (!args.m_bypass_limits) { 967 // Perform the TRUC checks, using the in-mempool parents. 968 if (const auto err{SingleTRUCChecks(m_pool, ws.m_ptx, ws.m_parents, ws.m_conflicts, ws.m_vsize)}) { 969 // Single transaction contexts only. 970 if (args.m_allow_sibling_eviction && err->second != nullptr) { 971 // We should only be considering where replacement is considered valid as well. 972 Assume(args.m_allow_replacement); 973 // Potential sibling eviction. Add the sibling to our list of mempool conflicts to be 974 // included in RBF checks. 975 ws.m_conflicts.insert(err->second->GetHash()); 976 // Adding the sibling to m_iters_conflicting here means that it doesn't count towards 977 // RBF Carve Out above. This is correct, since removing to-be-replaced transactions from 978 // the descendant count is done separately in SingleTRUCChecks for TRUC transactions. 979 ws.m_iters_conflicting.insert(m_pool.GetIter(err->second->GetHash()).value()); 980 ws.m_sibling_eviction = true; 981 // The sibling will be treated as part of the to-be-replaced set in ReplacementChecks. 982 // Note that we are not checking whether it opts in to replaceability via BIP125 or TRUC 983 // (which is normally done in PreChecks). However, the only way a TRUC transaction can 984 // have a non-TRUC and non-BIP125 descendant is due to a reorg. 985 } else { 986 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "TRUC-violation", err->first); 987 } 988 } 989 } 990 991 // We want to detect conflicts in any tx in a package to trigger package RBF logic 992 m_subpackage.m_rbf |= !ws.m_conflicts.empty(); 993 return true; 994 } 995 996 bool MemPoolAccept::ReplacementChecks(Workspace& ws) 997 { 998 AssertLockHeld(cs_main); 999 AssertLockHeld(m_pool.cs); 1000 1001 const CTransaction& tx = *ws.m_ptx; 1002 const Txid& hash = ws.m_hash; 1003 TxValidationState& state = ws.m_state; 1004 1005 CFeeRate newFeeRate(ws.m_modified_fees, ws.m_vsize); 1006 1007 CTxMemPool::setEntries all_conflicts; 1008 1009 // Calculate all conflicting entries and enforce Rule #5. 1010 if (const auto err_string{GetEntriesForConflicts(tx, m_pool, ws.m_iters_conflicting, all_conflicts)}) { 1011 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, 1012 strprintf("too many potential replacements%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1013 } 1014 1015 // Check if it's economically rational to mine this transaction rather than the ones it 1016 // replaces and pays for its own relay fees. Enforce Rules #3 and #4. 1017 for (CTxMemPool::txiter it : all_conflicts) { 1018 m_subpackage.m_conflicting_fees += it->GetModifiedFee(); 1019 m_subpackage.m_conflicting_size += it->GetTxSize(); 1020 } 1021 1022 if (const auto err_string{PaysForRBF(m_subpackage.m_conflicting_fees, ws.m_modified_fees, ws.m_vsize, 1023 m_pool.m_opts.incremental_relay_feerate, hash)}) { 1024 // Result may change in a package context 1025 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, 1026 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1027 } 1028 1029 // Add all the to-be-removed transactions to the changeset. 1030 for (auto it : all_conflicts) { 1031 m_subpackage.m_changeset->StageRemoval(it); 1032 } 1033 1034 // Run cluster size limit checks and fail if we exceed them. 1035 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) { 1036 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-large-cluster", ""); 1037 } 1038 1039 if (const auto err_string{ImprovesFeerateDiagram(*m_subpackage.m_changeset)}) { 1040 // We checked above for the cluster size limits being respected, so a 1041 // failure here can only be due to an insufficient fee. 1042 Assume(err_string->first == DiagramCheckError::FAILURE); 1043 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "replacement-failed", err_string->second); 1044 } 1045 1046 return true; 1047 } 1048 1049 bool MemPoolAccept::PackageMempoolChecks(const std::vector<CTransactionRef>& txns, 1050 std::vector<Workspace>& workspaces, 1051 const int64_t total_vsize, 1052 PackageValidationState& package_state) 1053 { 1054 AssertLockHeld(cs_main); 1055 AssertLockHeld(m_pool.cs); 1056 1057 assert(std::all_of(txns.cbegin(), txns.cend(), [this](const auto& tx) 1058 { return !m_pool.exists(tx->GetHash());})); 1059 1060 assert(txns.size() == workspaces.size()); 1061 1062 // No conflicts means we're finished. Further checks are all RBF-only. 1063 if (!m_subpackage.m_rbf) return true; 1064 1065 // We're in package RBF context; replacement proposal must be size 2 1066 if (workspaces.size() != 2 || !Assume(IsChildWithParents(txns))) { 1067 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: package must be 1-parent-1-child"); 1068 } 1069 1070 // If the package has in-mempool parents, we won't consider a package RBF 1071 // since it would result in a cluster larger than 2. 1072 // N.B. To relax this constraint we will need to revisit how CCoinsViewMemPool::PackageAddTransaction 1073 // is being used inside AcceptMultipleTransactions to track available inputs while processing a package. 1074 // Specifically we would need to check that the ancestors of the new 1075 // transactions don't intersect with the set of transactions to be removed 1076 // due to RBF, which is not checked at all in the package acceptance 1077 // context. 1078 for (const auto& ws : workspaces) { 1079 if (!ws.m_parents.empty()) { 1080 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: new transaction cannot have mempool ancestors"); 1081 } 1082 } 1083 1084 // Aggregate all conflicts into one set. 1085 CTxMemPool::setEntries direct_conflict_iters; 1086 for (Workspace& ws : workspaces) { 1087 // Aggregate all conflicts into one set. 1088 direct_conflict_iters.merge(ws.m_iters_conflicting); 1089 } 1090 1091 const auto& parent_ws = workspaces[0]; 1092 const auto& child_ws = workspaces[1]; 1093 1094 // Don't consider replacements that would cause us to remove a large number of mempool entries. 1095 // This limit is not increased in a package RBF. Use the aggregate number of transactions. 1096 CTxMemPool::setEntries all_conflicts; 1097 if (const auto err_string{GetEntriesForConflicts(*child_ws.m_ptx, m_pool, direct_conflict_iters, 1098 all_conflicts)}) { 1099 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1100 "package RBF failed: too many potential replacements", *err_string); 1101 } 1102 1103 for (CTxMemPool::txiter it : all_conflicts) { 1104 m_subpackage.m_changeset->StageRemoval(it); 1105 m_subpackage.m_conflicting_fees += it->GetModifiedFee(); 1106 m_subpackage.m_conflicting_size += it->GetTxSize(); 1107 } 1108 1109 // Use the child as the transaction for attributing errors to. 1110 const Txid& child_hash = child_ws.m_ptx->GetHash(); 1111 if (const auto err_string{PaysForRBF(/*original_fees=*/m_subpackage.m_conflicting_fees, 1112 /*replacement_fees=*/m_subpackage.m_total_modified_fees, 1113 /*replacement_vsize=*/m_subpackage.m_total_vsize, 1114 m_pool.m_opts.incremental_relay_feerate, child_hash)}) { 1115 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1116 "package RBF failed: insufficient anti-DoS fees", *err_string); 1117 } 1118 1119 // Ensure this two transaction package is a "chunk" on its own; we don't want the child 1120 // to be only paying anti-DoS fees 1121 const CFeeRate parent_feerate(parent_ws.m_modified_fees, parent_ws.m_vsize); 1122 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize); 1123 if (package_feerate <= parent_feerate) { 1124 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1125 "package RBF failed: package feerate is less than or equal to parent feerate", 1126 strprintf("package feerate %s <= parent feerate is %s", package_feerate.ToString(), parent_feerate.ToString())); 1127 } 1128 1129 // Run cluster size limit checks and fail if we exceed them. 1130 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) { 1131 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "too-large-cluster", ""); 1132 } 1133 1134 // Check if it's economically rational to mine this package rather than the ones it replaces. 1135 if (const auto err_tup{ImprovesFeerateDiagram(*m_subpackage.m_changeset)}) { 1136 Assume(err_tup->first == DiagramCheckError::FAILURE); 1137 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1138 "package RBF failed: " + err_tup.value().second, ""); 1139 } 1140 1141 LogDebug(BCLog::TXPACKAGES, "package RBF checks passed: parent %s (wtxid=%s), child %s (wtxid=%s), package hash (%s)\n", 1142 txns.front()->GetHash().ToString(), txns.front()->GetWitnessHash().ToString(), 1143 txns.back()->GetHash().ToString(), txns.back()->GetWitnessHash().ToString(), 1144 GetPackageHash(txns).ToString()); 1145 1146 1147 return true; 1148 } 1149 1150 bool MemPoolAccept::PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) 1151 { 1152 AssertLockHeld(cs_main); 1153 AssertLockHeld(m_pool.cs); 1154 const CTransaction& tx = *ws.m_ptx; 1155 TxValidationState& state = ws.m_state; 1156 1157 constexpr script_verify_flags scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS; 1158 1159 // Check input scripts and signatures. 1160 // This is done last to help prevent CPU exhaustion denial-of-service attacks. 1161 if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false, ws.m_precomputed_txdata, GetValidationCache())) { 1162 // Detect a failure due to a missing witness so that p2p code can handle rejection caching appropriately. 1163 if (!tx.HasWitness() && SpendsNonAnchorWitnessProg(tx, m_view)) { 1164 state.Invalid(TxValidationResult::TX_WITNESS_STRIPPED, 1165 state.GetRejectReason(), state.GetDebugMessage()); 1166 } 1167 return false; // state filled in by CheckInputScripts 1168 } 1169 1170 return true; 1171 } 1172 1173 bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) 1174 { 1175 AssertLockHeld(cs_main); 1176 AssertLockHeld(m_pool.cs); 1177 const CTransaction& tx = *ws.m_ptx; 1178 const Txid& hash = ws.m_hash; 1179 TxValidationState& state = ws.m_state; 1180 1181 // Check again against the current block tip's script verification 1182 // flags to cache our script execution flags. This is, of course, 1183 // useless if the next block has different script flags from the 1184 // previous one, but because the cache tracks script flags for us it 1185 // will auto-invalidate and we'll just have a few blocks of extra 1186 // misses on soft-fork activation. 1187 // 1188 // This is also useful in case of bugs in the standard flags that cause 1189 // transactions to pass as valid when they're actually invalid. For 1190 // instance the STRICTENC flag was incorrectly allowing certain 1191 // CHECKSIG NOT scripts to pass, even though they were invalid. 1192 // 1193 // There is a similar check in CreateNewBlock() to prevent creating 1194 // invalid blocks (using TestBlockValidity), however allowing such 1195 // transactions into the mempool can be exploited as a DoS attack. 1196 script_verify_flags currentBlockScriptVerifyFlags{GetBlockScriptFlags(*m_active_chainstate.m_chain.Tip(), m_active_chainstate.m_chainman)}; 1197 if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags, 1198 ws.m_precomputed_txdata, m_active_chainstate.CoinsTip(), GetValidationCache())) { 1199 LogError("BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s", hash.ToString(), state.ToString()); 1200 return Assume(false); 1201 } 1202 1203 return true; 1204 } 1205 1206 void MemPoolAccept::FinalizeSubpackage(const ATMPArgs& args) 1207 { 1208 AssertLockHeld(cs_main); 1209 AssertLockHeld(m_pool.cs); 1210 1211 if (!m_subpackage.m_changeset->GetRemovals().empty()) Assume(args.m_allow_replacement); 1212 // Remove conflicting transactions from the mempool 1213 for (CTxMemPool::txiter it : m_subpackage.m_changeset->GetRemovals()) 1214 { 1215 std::string log_string = strprintf("replacing mempool tx %s (wtxid=%s, fees=%s, vsize=%s). ", 1216 it->GetTx().GetHash().ToString(), 1217 it->GetTx().GetWitnessHash().ToString(), 1218 it->GetFee(), 1219 it->GetTxSize()); 1220 FeeFrac feerate{m_subpackage.m_total_modified_fees, int32_t(m_subpackage.m_total_vsize)}; 1221 uint256 tx_or_package_hash{}; 1222 const bool replaced_with_tx{m_subpackage.m_changeset->GetTxCount() == 1}; 1223 if (replaced_with_tx) { 1224 const CTransaction& tx = m_subpackage.m_changeset->GetAddedTxn(0); 1225 tx_or_package_hash = tx.GetHash().ToUint256(); 1226 log_string += strprintf("New tx %s (wtxid=%s, fees=%s, vsize=%s)", 1227 tx.GetHash().ToString(), 1228 tx.GetWitnessHash().ToString(), 1229 feerate.fee, 1230 feerate.size); 1231 } else { 1232 tx_or_package_hash = GetPackageHash(m_subpackage.m_changeset->GetAddedTxns()); 1233 log_string += strprintf("New package %s with %lu txs, fees=%s, vsize=%s", 1234 tx_or_package_hash.ToString(), 1235 m_subpackage.m_changeset->GetTxCount(), 1236 feerate.fee, 1237 feerate.size); 1238 1239 } 1240 LogDebug(BCLog::MEMPOOL, "%s\n", log_string); 1241 TRACEPOINT(mempool, replaced, 1242 it->GetTx().GetHash().data(), 1243 it->GetTxSize(), 1244 it->GetFee(), 1245 std::chrono::duration_cast<std::chrono::duration<std::uint64_t>>(it->GetTime()).count(), 1246 tx_or_package_hash.data(), 1247 feerate.size, 1248 feerate.fee, 1249 replaced_with_tx 1250 ); 1251 m_subpackage.m_replaced_transactions.push_back(it->GetSharedTx()); 1252 } 1253 m_subpackage.m_changeset->Apply(); 1254 m_subpackage.m_changeset.reset(); 1255 } 1256 1257 bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, 1258 PackageValidationState& package_state, 1259 std::map<Wtxid, MempoolAcceptResult>& results) 1260 { 1261 AssertLockHeld(cs_main); 1262 AssertLockHeld(m_pool.cs); 1263 // Sanity check: none of the transactions should be in the mempool, and none of the transactions 1264 // should have a same-txid-different-witness equivalent in the mempool. 1265 assert(std::all_of(workspaces.cbegin(), workspaces.cend(), [this](const auto& ws) { return !m_pool.exists(ws.m_ptx->GetHash()); })); 1266 1267 bool all_submitted = true; 1268 FinalizeSubpackage(args); 1269 // ConsensusScriptChecks adds to the script cache and is therefore consensus-critical; 1270 // CheckInputsFromMempoolAndCache asserts that transactions only spend coins available from the 1271 // mempool or UTXO set. Submit each transaction to the mempool immediately after calling 1272 // ConsensusScriptChecks to make the outputs available for subsequent transactions. 1273 for (Workspace& ws : workspaces) { 1274 if (!ConsensusScriptChecks(args, ws)) { 1275 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1276 // Since PolicyScriptChecks() passed, this should never fail. 1277 Assume(false); 1278 all_submitted = false; 1279 package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR, 1280 strprintf("BUG! PolicyScriptChecks succeeded but ConsensusScriptChecks failed: %s", 1281 ws.m_ptx->GetHash().ToString())); 1282 // Remove the transaction from the mempool. 1283 if (!m_subpackage.m_changeset) m_subpackage.m_changeset = m_pool.GetChangeSet(); 1284 m_subpackage.m_changeset->StageRemoval(m_pool.GetIter(ws.m_ptx->GetHash()).value()); 1285 } 1286 } 1287 if (!all_submitted) { 1288 Assume(m_subpackage.m_changeset); 1289 // This code should be unreachable; it's here as belt-and-suspenders 1290 // to try to ensure we have no consensus-invalid transactions in the 1291 // mempool. 1292 m_subpackage.m_changeset->Apply(); 1293 m_subpackage.m_changeset.reset(); 1294 return false; 1295 } 1296 1297 std::vector<Wtxid> all_package_wtxids; 1298 all_package_wtxids.reserve(workspaces.size()); 1299 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids), 1300 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); }); 1301 1302 if (!m_subpackage.m_replaced_transactions.empty()) { 1303 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with %u new one(s) for %s additional fees, %d delta bytes\n", 1304 m_subpackage.m_replaced_transactions.size(), workspaces.size(), 1305 m_subpackage.m_total_modified_fees - m_subpackage.m_conflicting_fees, 1306 m_subpackage.m_total_vsize - static_cast<int>(m_subpackage.m_conflicting_size)); 1307 } 1308 1309 // Add successful results. The returned results may change later if LimitMempoolSize() evicts them. 1310 for (Workspace& ws : workspaces) { 1311 auto iter = m_pool.GetIter(ws.m_ptx->GetHash()); 1312 Assume(iter.has_value()); 1313 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate : 1314 CFeeRate{ws.m_modified_fees, static_cast<int32_t>(ws.m_vsize)}; 1315 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids : 1316 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()}; 1317 results.emplace(ws.m_ptx->GetWitnessHash(), 1318 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, 1319 ws.m_base_fees, effective_feerate, effective_feerate_wtxids)); 1320 if (!m_pool.m_opts.signals) continue; 1321 const CTransaction& tx = *ws.m_ptx; 1322 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees, 1323 ws.m_vsize, (*iter)->GetHeight(), 1324 args.m_bypass_limits, args.m_package_submission, 1325 IsCurrentForFeeEstimation(m_active_chainstate), 1326 m_pool.HasNoInputsOf(tx)); 1327 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence()); 1328 } 1329 return all_submitted; 1330 } 1331 1332 MempoolAcceptResult MemPoolAccept::AcceptSingleTransactionInternal(const CTransactionRef& ptx, ATMPArgs& args) 1333 { 1334 AssertLockHeld(cs_main); 1335 AssertLockHeld(m_pool.cs); 1336 1337 Workspace ws(ptx); 1338 const std::vector<Wtxid> single_wtxid{ws.m_ptx->GetWitnessHash()}; 1339 1340 if (!PreChecks(args, ws)) { 1341 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) { 1342 // Failed for 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 if (m_subpackage.m_rbf && !ReplacementChecks(ws)) { 1349 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) { 1350 // Failed for incentives-based fee reasons. Provide the effective feerate and which tx was included. 1351 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid); 1352 } 1353 return MempoolAcceptResult::Failure(ws.m_state); 1354 } 1355 1356 // Check if the transaction would exceed the cluster size limit. 1357 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) { 1358 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-large-cluster", ""); 1359 return MempoolAcceptResult::Failure(ws.m_state); 1360 } 1361 1362 // Now that we've verified the cluster limit is respected, we can perform 1363 // calculations involving the full ancestors of the tx. 1364 if (ws.m_conflicts.size()) { 1365 auto ancestors = m_subpackage.m_changeset->CalculateMemPoolAncestors(ws.m_tx_handle); 1366 1367 // A transaction that spends outputs that would be replaced by it is invalid. Now 1368 // that we have the set of all ancestors we can detect this 1369 // pathological case by making sure ws.m_conflicts and this tx's ancestors don't 1370 // intersect. 1371 if (const auto err_string{EntriesAndTxidsDisjoint(ancestors, ws.m_conflicts, ptx->GetHash())}) { 1372 // We classify this as a consensus error because a transaction depending on something it 1373 // conflicts with would be inconsistent. 1374 ws.m_state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-spends-conflicting-tx", *err_string); 1375 return MempoolAcceptResult::Failure(ws.m_state); 1376 } 1377 } 1378 1379 m_subpackage.m_total_vsize = ws.m_vsize; 1380 m_subpackage.m_total_modified_fees = ws.m_modified_fees; 1381 1382 // Individual modified feerate exceeded caller-defined max; abort 1383 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) { 1384 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", ""); 1385 return MempoolAcceptResult::Failure(ws.m_state); 1386 } 1387 1388 if (m_pool.m_opts.require_standard) { 1389 Wtxid dummy_wtxid; 1390 if (!CheckEphemeralSpends(/*package=*/{ptx}, m_pool.m_opts.dust_relay_feerate, m_pool, ws.m_state, dummy_wtxid)) { 1391 return MempoolAcceptResult::Failure(ws.m_state); 1392 } 1393 } 1394 1395 // Perform the inexpensive checks first and avoid hashing and signature verification unless 1396 // those checks pass, to mitigate CPU exhaustion denial-of-service attacks. 1397 if (!PolicyScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state); 1398 1399 if (!ConsensusScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state); 1400 1401 const CFeeRate effective_feerate{ws.m_modified_fees, static_cast<int32_t>(ws.m_vsize)}; 1402 // Tx was accepted, but not added 1403 if (args.m_test_accept) { 1404 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, 1405 ws.m_base_fees, effective_feerate, single_wtxid); 1406 } 1407 1408 FinalizeSubpackage(args); 1409 1410 // Limit the mempool, if appropriate. 1411 if (!args.m_package_submission && !args.m_bypass_limits) { 1412 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip()); 1413 // If mempool contents change, then the m_view cache is dirty. Given this isn't a package 1414 // submission, we won't be using the cache anymore, but clear it anyway for clarity. 1415 CleanupTemporaryCoins(); 1416 1417 if (!m_pool.exists(ws.m_hash)) { 1418 // The tx no longer meets our (new) mempool minimum feerate but could be reconsidered in a package. 1419 ws.m_state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool full"); 1420 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), {ws.m_ptx->GetWitnessHash()}); 1421 } 1422 } 1423 1424 if (m_pool.m_opts.signals) { 1425 const CTransaction& tx = *ws.m_ptx; 1426 auto iter = m_pool.GetIter(tx.GetHash()); 1427 Assume(iter.has_value()); 1428 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees, 1429 ws.m_vsize, (*iter)->GetHeight(), 1430 args.m_bypass_limits, args.m_package_submission, 1431 IsCurrentForFeeEstimation(m_active_chainstate), 1432 m_pool.HasNoInputsOf(tx)); 1433 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence()); 1434 } 1435 1436 if (!m_subpackage.m_replaced_transactions.empty()) { 1437 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with 1 new transaction for %s additional fees, %d delta bytes\n", 1438 m_subpackage.m_replaced_transactions.size(), 1439 ws.m_modified_fees - m_subpackage.m_conflicting_fees, 1440 ws.m_vsize - static_cast<int>(m_subpackage.m_conflicting_size)); 1441 } 1442 1443 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, ws.m_base_fees, 1444 effective_feerate, single_wtxid); 1445 } 1446 1447 PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactionsInternal(const std::vector<CTransactionRef>& txns, ATMPArgs& args) 1448 { 1449 AssertLockHeld(cs_main); 1450 AssertLockHeld(m_pool.cs); 1451 1452 // These context-free package limits can be done before taking the mempool lock. 1453 PackageValidationState package_state; 1454 if (!IsWellFormedPackage(txns, package_state, /*require_sorted=*/true)) return PackageMempoolAcceptResult(package_state, {}); 1455 1456 std::vector<Workspace> workspaces{}; 1457 workspaces.reserve(txns.size()); 1458 std::transform(txns.cbegin(), txns.cend(), std::back_inserter(workspaces), 1459 [](const auto& tx) { return Workspace(tx); }); 1460 std::map<Wtxid, MempoolAcceptResult> results; 1461 1462 // Do all PreChecks first and fail fast to avoid running expensive script checks when unnecessary. 1463 for (Workspace& ws : workspaces) { 1464 if (!PreChecks(args, ws)) { 1465 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1466 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1467 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1468 return PackageMempoolAcceptResult(package_state, std::move(results)); 1469 } 1470 1471 // Individual modified feerate exceeded caller-defined max; abort 1472 // N.B. this doesn't take into account CPFPs. Chunk-aware validation may be more robust. 1473 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) { 1474 // Need to set failure here both individually and at package level 1475 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", ""); 1476 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1477 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1478 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1479 return PackageMempoolAcceptResult(package_state, std::move(results)); 1480 } 1481 1482 // Make the coins created by this transaction available for subsequent transactions in the 1483 // package to spend. If there are no conflicts within the package, no transaction can spend a coin 1484 // needed by another transaction in the package. We also need to make sure that no package 1485 // tx replaces (or replaces the ancestor of) the parent of another package tx. As long as we 1486 // check these two things, we don't need to track the coins spent. 1487 // If a package tx conflicts with a mempool tx, PackageMempoolChecks() ensures later that any package RBF attempt 1488 // has *no* in-mempool ancestors, so we don't have to worry about subsequent transactions in 1489 // same package spending the same in-mempool outpoints. This needs to be revisited for general 1490 // package RBF. 1491 m_viewmempool.PackageAddTransaction(ws.m_ptx); 1492 } 1493 1494 // At this point we have all in-mempool parents, and we know every transaction's vsize. 1495 // Run the TRUC checks on the package. 1496 for (Workspace& ws : workspaces) { 1497 if (auto err{PackageTRUCChecks(m_pool, ws.m_ptx, ws.m_vsize, txns, ws.m_parents)}) { 1498 package_state.Invalid(PackageValidationResult::PCKG_POLICY, "TRUC-violation", err.value()); 1499 return PackageMempoolAcceptResult(package_state, {}); 1500 } 1501 } 1502 1503 // Transactions must meet two minimum feerates: the mempool minimum fee and min relay fee. 1504 // For transactions consisting of exactly one child and its parents, it suffices to use the 1505 // package feerate (total modified fees / total virtual size) to check this requirement. 1506 // Note that this is an aggregate feerate; this function has not checked that there are transactions 1507 // too low feerate to pay for themselves, or that the child transactions are higher feerate than 1508 // their parents. Using aggregate feerate may allow "parents pay for child" behavior and permit 1509 // a child that is below mempool minimum feerate. To avoid these behaviors, callers of 1510 // AcceptMultipleTransactions need to restrict txns topology (e.g. to ancestor sets) and check 1511 // the feerates of individuals and subsets. 1512 m_subpackage.m_total_vsize = std::accumulate(workspaces.cbegin(), workspaces.cend(), int64_t{0}, 1513 [](int64_t sum, auto& ws) { return sum + ws.m_vsize; }); 1514 m_subpackage.m_total_modified_fees = std::accumulate(workspaces.cbegin(), workspaces.cend(), CAmount{0}, 1515 [](CAmount sum, auto& ws) { return sum + ws.m_modified_fees; }); 1516 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize); 1517 std::vector<Wtxid> all_package_wtxids; 1518 all_package_wtxids.reserve(workspaces.size()); 1519 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids), 1520 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); }); 1521 TxValidationState placeholder_state; 1522 if (args.m_package_feerates && 1523 !CheckFeeRate(m_subpackage.m_total_vsize, m_subpackage.m_total_modified_fees, placeholder_state)) { 1524 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1525 return PackageMempoolAcceptResult(package_state, {{workspaces.back().m_ptx->GetWitnessHash(), 1526 MempoolAcceptResult::FeeFailure(placeholder_state, CFeeRate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize), all_package_wtxids)}}); 1527 } 1528 1529 // Apply package mempool RBF checks. 1530 if (!PackageMempoolChecks(txns, workspaces, m_subpackage.m_total_vsize, package_state)) { 1531 return PackageMempoolAcceptResult(package_state, std::move(results)); 1532 } 1533 1534 // Check if the transactions would exceed the cluster size limit. 1535 if (!m_subpackage.m_changeset->CheckMemPoolPolicyLimits()) { 1536 package_state.Invalid(PackageValidationResult::PCKG_POLICY, "too-large-cluster", ""); 1537 return PackageMempoolAcceptResult(package_state, std::move(results)); 1538 } 1539 1540 // Now that we've bounded the resulting possible ancestry count, check package for dust spends 1541 if (m_pool.m_opts.require_standard) { 1542 TxValidationState child_state; 1543 Wtxid child_wtxid; 1544 if (!CheckEphemeralSpends(txns, m_pool.m_opts.dust_relay_feerate, m_pool, child_state, child_wtxid)) { 1545 package_state.Invalid(PackageValidationResult::PCKG_TX, "unspent-dust"); 1546 results.emplace(child_wtxid, MempoolAcceptResult::Failure(child_state)); 1547 return PackageMempoolAcceptResult(package_state, std::move(results)); 1548 } 1549 } 1550 1551 for (Workspace& ws : workspaces) { 1552 ws.m_package_feerate = package_feerate; 1553 if (!PolicyScriptChecks(args, ws)) { 1554 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1555 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1556 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1557 return PackageMempoolAcceptResult(package_state, std::move(results)); 1558 } 1559 if (args.m_test_accept) { 1560 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate : 1561 CFeeRate{ws.m_modified_fees, static_cast<int32_t>(ws.m_vsize)}; 1562 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids : 1563 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()}; 1564 results.emplace(ws.m_ptx->GetWitnessHash(), 1565 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), 1566 ws.m_vsize, ws.m_base_fees, effective_feerate, 1567 effective_feerate_wtxids)); 1568 } 1569 } 1570 1571 if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, std::move(results)); 1572 1573 if (!SubmitPackage(args, workspaces, package_state, results)) { 1574 // PackageValidationState filled in by SubmitPackage(). 1575 return PackageMempoolAcceptResult(package_state, std::move(results)); 1576 } 1577 1578 return PackageMempoolAcceptResult(package_state, std::move(results)); 1579 } 1580 1581 void MemPoolAccept::CleanupTemporaryCoins() 1582 { 1583 // There are 3 kinds of coins in m_view: 1584 // (1) Temporary coins from the transactions in subpackage, constructed by m_viewmempool. 1585 // (2) Mempool coins from transactions in the mempool, constructed by m_viewmempool. 1586 // (3) Confirmed coins fetched from our current UTXO set. 1587 // 1588 // (1) Temporary coins need to be removed, regardless of whether the transaction was submitted. 1589 // If the transaction was submitted to the mempool, m_viewmempool will be able to fetch them from 1590 // there. If it wasn't submitted to mempool, it is incorrect to keep them - future calls may try 1591 // to spend those coins that don't actually exist. 1592 // (2) Mempool coins also need to be removed. If the mempool contents have changed as a result 1593 // of submitting or replacing transactions, coins previously fetched from mempool may now be 1594 // spent or nonexistent. Those coins need to be deleted from m_view. 1595 // (3) Confirmed coins don't need to be removed. The chainstate has not changed (we are 1596 // holding cs_main and no blocks have been processed) so the confirmed tx cannot disappear like 1597 // a mempool tx can. The coin may now be spent after we submitted a tx to mempool, but 1598 // we have already checked that the package does not have 2 transactions spending the same coin 1599 // and we check whether a mempool transaction spends conflicting coins (CTxMemPool::GetConflictTx). 1600 // Keeping them in m_view is an optimization to not re-fetch confirmed coins if we later look up 1601 // inputs for this transaction again. 1602 for (const auto& outpoint : m_viewmempool.GetNonBaseCoins()) { 1603 // In addition to resetting m_viewmempool, we also need to manually delete these coins from 1604 // m_view because it caches copies of the coins it fetched from m_viewmempool previously. 1605 m_view.Uncache(outpoint); 1606 } 1607 // This deletes the temporary and mempool coins. 1608 m_viewmempool.Reset(); 1609 } 1610 1611 PackageMempoolAcceptResult MemPoolAccept::AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args) 1612 { 1613 AssertLockHeld(::cs_main); 1614 AssertLockHeld(m_pool.cs); 1615 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) { 1616 if (subpackage.size() > 1) { 1617 return AcceptMultipleTransactionsInternal(subpackage, args); 1618 } 1619 const auto& tx = subpackage.front(); 1620 ATMPArgs single_args = ATMPArgs::SingleInPackageAccept(args); 1621 const auto single_res = AcceptSingleTransactionInternal(tx, single_args); 1622 PackageValidationState package_state_wrapped; 1623 if (single_res.m_result_type != MempoolAcceptResult::ResultType::VALID) { 1624 package_state_wrapped.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1625 } 1626 return PackageMempoolAcceptResult(package_state_wrapped, {{tx->GetWitnessHash(), single_res}}); 1627 }(); 1628 1629 // Clean up m_view and m_viewmempool so that other subpackage evaluations don't have access to 1630 // coins they shouldn't. Keep some coins in order to minimize re-fetching coins from the UTXO set. 1631 // Clean up package feerate and rbf calculations 1632 ClearSubPackageState(); 1633 1634 return result; 1635 } 1636 1637 PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, ATMPArgs& args) 1638 { 1639 Assert(!package.empty()); 1640 AssertLockHeld(cs_main); 1641 // Used if returning a PackageMempoolAcceptResult directly from this function. 1642 PackageValidationState package_state_quit_early; 1643 1644 // There are two topologies we are able to handle through this function: 1645 // (1) A single transaction 1646 // (2) A child-with-parents package. 1647 // Check that the package is well-formed. If it isn't, we won't try to validate any of the 1648 // transactions and thus won't return any MempoolAcceptResults, just a package-wide error. 1649 1650 // Context-free package checks. 1651 if (!IsWellFormedPackage(package, package_state_quit_early, /*require_sorted=*/true)) { 1652 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1653 } 1654 1655 if (package.size() > 1 && !IsChildWithParents(package)) { 1656 // All transactions in the package must be a parent of the last transaction. This is just an 1657 // opportunity for us to fail fast on a context-free check without taking the mempool lock. 1658 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents"); 1659 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1660 } 1661 1662 LOCK(m_pool.cs); 1663 // Stores results from which we will create the returned PackageMempoolAcceptResult. 1664 // A result may be changed if a mempool transaction is evicted later due to LimitMempoolSize(). 1665 std::map<Wtxid, MempoolAcceptResult> results_final; 1666 // Results from individual validation which will be returned if no other result is available for 1667 // this transaction. "Nonfinal" because if a transaction fails by itself but succeeds later 1668 // (i.e. when evaluated with a fee-bumping child), the result in this map may be discarded. 1669 std::map<Wtxid, MempoolAcceptResult> individual_results_nonfinal; 1670 // Tracks whether we think package submission could result in successful entry to the mempool 1671 bool quit_early{false}; 1672 std::vector<CTransactionRef> txns_package_eval; 1673 for (const auto& tx : package) { 1674 const auto& wtxid = tx->GetWitnessHash(); 1675 const auto& txid = tx->GetHash(); 1676 // There are 3 possibilities: already in mempool, same-txid-diff-wtxid already in mempool, 1677 // or not in mempool. An already confirmed tx is treated as one not in mempool, because all 1678 // we know is that the inputs aren't available. 1679 if (m_pool.exists(wtxid)) { 1680 // Exact transaction already exists in the mempool. 1681 // Node operators are free to set their mempool policies however they please, nodes may receive 1682 // transactions in different orders, and malicious counterparties may try to take advantage of 1683 // policy differences to pin or delay propagation of transactions. As such, it's possible for 1684 // some package transaction(s) to already be in the mempool, and we don't want to reject the 1685 // entire package in that case (as that could be a censorship vector). De-duplicate the 1686 // transactions that are already in the mempool, and only call AcceptMultipleTransactions() with 1687 // the new transactions. This ensures we don't double-count transaction counts and sizes when 1688 // checking ancestor/descendant limits, or double-count transaction fees for fee-related policy. 1689 const auto& entry{*Assert(m_pool.GetEntry(txid))}; 1690 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTx(entry.GetTxSize(), entry.GetFee())); 1691 } else if (m_pool.exists(txid)) { 1692 // Transaction with the same non-witness data but different witness (same txid, 1693 // different wtxid) already exists in the mempool. 1694 // 1695 // We don't allow replacement transactions right now, so just swap the package 1696 // transaction for the mempool one. Note that we are ignoring the validity of the 1697 // package transaction passed in. 1698 // TODO: allow witness replacement in packages. 1699 const auto& entry{*Assert(m_pool.GetEntry(txid))}; 1700 // Provide the wtxid of the mempool tx so that the caller can look it up in the mempool. 1701 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTxDifferentWitness(entry.GetTx().GetWitnessHash())); 1702 } else { 1703 // Transaction does not already exist in the mempool. 1704 // Try submitting the transaction on its own. 1705 const auto single_package_res = AcceptSubPackage({tx}, args); 1706 const auto& single_res = single_package_res.m_tx_results.at(wtxid); 1707 if (single_res.m_result_type == MempoolAcceptResult::ResultType::VALID) { 1708 // The transaction succeeded on its own and is now in the mempool. Don't include it 1709 // in package validation, because its fees should only be "used" once. 1710 assert(m_pool.exists(wtxid)); 1711 results_final.emplace(wtxid, single_res); 1712 } else if (package.size() == 1 || // If there is only one transaction, no need to retry it "as a package" 1713 (single_res.m_state.GetResult() != TxValidationResult::TX_RECONSIDERABLE && 1714 single_res.m_state.GetResult() != TxValidationResult::TX_MISSING_INPUTS)) { 1715 // Package validation policy only differs from individual policy in its evaluation 1716 // of feerate. For example, if a transaction fails here due to violation of a 1717 // consensus rule, the result will not change when it is submitted as part of a 1718 // package. To minimize the amount of repeated work, unless the transaction fails 1719 // due to feerate or missing inputs (its parent is a previous transaction in the 1720 // package that failed due to feerate), don't run package validation. Note that this 1721 // decision might not make sense if different types of packages are allowed in the 1722 // future. Continue individually validating the rest of the transactions, because 1723 // some of them may still be valid. 1724 quit_early = true; 1725 package_state_quit_early.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1726 individual_results_nonfinal.emplace(wtxid, single_res); 1727 } else { 1728 individual_results_nonfinal.emplace(wtxid, single_res); 1729 txns_package_eval.push_back(tx); 1730 } 1731 } 1732 } 1733 1734 auto multi_submission_result = quit_early || txns_package_eval.empty() ? PackageMempoolAcceptResult(package_state_quit_early, {}) : 1735 AcceptSubPackage(txns_package_eval, args); 1736 PackageValidationState& package_state_final = multi_submission_result.m_state; 1737 1738 // This is invoked by AcceptSubPackage() already, so this is just here for 1739 // clarity (since it's not permitted to invoke LimitMempoolSize() while a 1740 // changeset is outstanding). 1741 ClearSubPackageState(); 1742 1743 // Make sure we haven't exceeded max mempool size. 1744 // Package transactions that were submitted to mempool or already in mempool may be evicted. 1745 // If mempool contents change, then the m_view cache is dirty. It has already been cleared above. 1746 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip()); 1747 1748 for (const auto& tx : package) { 1749 const auto& wtxid = tx->GetWitnessHash(); 1750 if (multi_submission_result.m_tx_results.count(wtxid) > 0) { 1751 // We shouldn't have re-submitted if the tx result was already in results_final. 1752 Assume(results_final.count(wtxid) == 0); 1753 // If it was submitted, check to see if the tx is still in the mempool. It could have 1754 // been evicted due to LimitMempoolSize() above. 1755 const auto& txresult = multi_submission_result.m_tx_results.at(wtxid); 1756 if (txresult.m_result_type == MempoolAcceptResult::ResultType::VALID && !m_pool.exists(wtxid)) { 1757 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1758 TxValidationState mempool_full_state; 1759 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full"); 1760 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state)); 1761 } else { 1762 results_final.emplace(wtxid, txresult); 1763 } 1764 } else if (const auto it{results_final.find(wtxid)}; it != results_final.end()) { 1765 // Already-in-mempool transaction. Check to see if it's still there, as it could have 1766 // been evicted when LimitMempoolSize() was called. 1767 Assume(it->second.m_result_type != MempoolAcceptResult::ResultType::INVALID); 1768 Assume(individual_results_nonfinal.count(wtxid) == 0); 1769 // Query by txid to include the same-txid-different-witness ones. 1770 if (!m_pool.exists(tx->GetHash())) { 1771 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1772 TxValidationState mempool_full_state; 1773 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full"); 1774 // Replace the previous result. 1775 results_final.erase(wtxid); 1776 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state)); 1777 } 1778 } else if (const auto it{individual_results_nonfinal.find(wtxid)}; it != individual_results_nonfinal.end()) { 1779 Assume(it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID); 1780 // Interesting result from previous processing. 1781 results_final.emplace(wtxid, it->second); 1782 } 1783 } 1784 Assume(results_final.size() == package.size()); 1785 return PackageMempoolAcceptResult(package_state_final, std::move(results_final)); 1786 } 1787 1788 } // anon namespace 1789 1790 MempoolAcceptResult AcceptToMemoryPool(Chainstate& active_chainstate, const CTransactionRef& tx, 1791 int64_t accept_time, bool bypass_limits, bool test_accept) 1792 { 1793 AssertLockHeld(::cs_main); 1794 const CChainParams& chainparams{active_chainstate.m_chainman.GetParams()}; 1795 assert(active_chainstate.GetMempool() != nullptr); 1796 CTxMemPool& pool{*active_chainstate.GetMempool()}; 1797 1798 std::vector<COutPoint> coins_to_uncache; 1799 1800 auto args = MemPoolAccept::ATMPArgs::SingleAccept(chainparams, accept_time, bypass_limits, coins_to_uncache, test_accept); 1801 MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate).AcceptSingleTransactionAndCleanup(tx, args); 1802 1803 if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) { 1804 // Remove coins that were not present in the coins cache before calling 1805 // AcceptSingleTransaction(); this is to prevent memory DoS in case we receive a large 1806 // number of invalid transactions that attempt to overrun the in-memory coins cache 1807 // (`CCoinsViewCache::cacheCoins`). 1808 1809 for (const COutPoint& hashTx : coins_to_uncache) 1810 active_chainstate.CoinsTip().Uncache(hashTx); 1811 TRACEPOINT(mempool, rejected, 1812 tx->GetHash().data(), 1813 result.m_state.GetRejectReason().c_str() 1814 ); 1815 } 1816 // After we've (potentially) uncached entries, ensure our coins cache is still within its size limits 1817 BlockValidationState state_dummy; 1818 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC); 1819 return result; 1820 } 1821 1822 PackageMempoolAcceptResult ProcessNewPackage(Chainstate& active_chainstate, CTxMemPool& pool, 1823 const Package& package, bool test_accept, const std::optional<CFeeRate>& client_maxfeerate) 1824 { 1825 AssertLockHeld(cs_main); 1826 assert(!package.empty()); 1827 assert(std::all_of(package.cbegin(), package.cend(), [](const auto& tx){return tx != nullptr;})); 1828 1829 std::vector<COutPoint> coins_to_uncache; 1830 const CChainParams& chainparams = active_chainstate.m_chainman.GetParams(); 1831 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) { 1832 AssertLockHeld(cs_main); 1833 if (test_accept) { 1834 auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(chainparams, GetTime(), coins_to_uncache); 1835 return MemPoolAccept(pool, active_chainstate).AcceptMultipleTransactionsAndCleanup(package, args); 1836 } else { 1837 auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(chainparams, GetTime(), coins_to_uncache, client_maxfeerate); 1838 return MemPoolAccept(pool, active_chainstate).AcceptPackage(package, args); 1839 } 1840 }(); 1841 1842 // Uncache coins pertaining to transactions that were not submitted to the mempool. 1843 if (test_accept || result.m_state.IsInvalid()) { 1844 for (const COutPoint& hashTx : coins_to_uncache) { 1845 active_chainstate.CoinsTip().Uncache(hashTx); 1846 } 1847 } 1848 // Ensure the coins cache is still within limits. 1849 BlockValidationState state_dummy; 1850 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC); 1851 return result; 1852 } 1853 1854 CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams) 1855 { 1856 int halvings = nHeight / consensusParams.nSubsidyHalvingInterval; 1857 // Force block reward to zero when right shift is undefined. 1858 if (halvings >= 64) 1859 return 0; 1860 1861 CAmount nSubsidy = 50 * COIN; 1862 // Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years. 1863 nSubsidy >>= halvings; 1864 return nSubsidy; 1865 } 1866 1867 CoinsViews::CoinsViews(DBParams db_params, CoinsViewOptions options) 1868 : m_dbview{std::move(db_params), std::move(options)}, 1869 m_catcherview(&m_dbview) {} 1870 1871 void CoinsViews::InitCache() 1872 { 1873 AssertLockHeld(::cs_main); 1874 m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview); 1875 } 1876 1877 Chainstate::Chainstate( 1878 CTxMemPool* mempool, 1879 BlockManager& blockman, 1880 ChainstateManager& chainman, 1881 std::optional<uint256> from_snapshot_blockhash) 1882 : m_mempool(mempool), 1883 m_blockman(blockman), 1884 m_chainman(chainman), 1885 m_from_snapshot_blockhash(from_snapshot_blockhash) {} 1886 1887 const CBlockIndex* Chainstate::SnapshotBase() const 1888 { 1889 if (!m_from_snapshot_blockhash) return nullptr; 1890 if (!m_cached_snapshot_base) m_cached_snapshot_base = Assert(m_chainman.m_blockman.LookupBlockIndex(*m_from_snapshot_blockhash)); 1891 return m_cached_snapshot_base; 1892 } 1893 1894 void Chainstate::InitCoinsDB( 1895 size_t cache_size_bytes, 1896 bool in_memory, 1897 bool should_wipe, 1898 fs::path leveldb_name) 1899 { 1900 if (m_from_snapshot_blockhash) { 1901 leveldb_name += node::SNAPSHOT_CHAINSTATE_SUFFIX; 1902 } 1903 1904 m_coins_views = std::make_unique<CoinsViews>( 1905 DBParams{ 1906 .path = m_chainman.m_options.datadir / leveldb_name, 1907 .cache_bytes = cache_size_bytes, 1908 .memory_only = in_memory, 1909 .wipe_data = should_wipe, 1910 .obfuscate = true, 1911 .options = m_chainman.m_options.coins_db}, 1912 m_chainman.m_options.coins_view); 1913 1914 m_coinsdb_cache_size_bytes = cache_size_bytes; 1915 } 1916 1917 void Chainstate::InitCoinsCache(size_t cache_size_bytes) 1918 { 1919 AssertLockHeld(::cs_main); 1920 assert(m_coins_views != nullptr); 1921 m_coinstip_cache_size_bytes = cache_size_bytes; 1922 m_coins_views->InitCache(); 1923 } 1924 1925 // Note that though this is marked const, we may end up modifying `m_cached_finished_ibd`, which 1926 // is a performance-related implementation detail. This function must be marked 1927 // `const` so that `CValidationInterface` clients (which are given a `const Chainstate*`) 1928 // can call it. 1929 // 1930 bool ChainstateManager::IsInitialBlockDownload() const 1931 { 1932 // Optimization: pre-test latch before taking the lock. 1933 if (m_cached_finished_ibd.load(std::memory_order_relaxed)) 1934 return false; 1935 1936 LOCK(cs_main); 1937 if (m_cached_finished_ibd.load(std::memory_order_relaxed)) 1938 return false; 1939 if (m_blockman.LoadingBlocks()) { 1940 return true; 1941 } 1942 CChain& chain{ActiveChain()}; 1943 if (chain.Tip() == nullptr) { 1944 return true; 1945 } 1946 if (chain.Tip()->nChainWork < MinimumChainWork()) { 1947 return true; 1948 } 1949 if (chain.Tip()->Time() < Now<NodeSeconds>() - m_options.max_tip_age) { 1950 return true; 1951 } 1952 LogInfo("Leaving InitialBlockDownload (latching to false)"); 1953 m_cached_finished_ibd.store(true, std::memory_order_relaxed); 1954 return false; 1955 } 1956 1957 void Chainstate::CheckForkWarningConditions() 1958 { 1959 AssertLockHeld(cs_main); 1960 1961 // Before we get past initial download, we cannot reliably alert about forks 1962 // (we assume we don't get stuck on a fork before finishing our initial sync) 1963 // Also not applicable to the background chainstate 1964 if (m_chainman.IsInitialBlockDownload() || this->GetRole() == ChainstateRole::BACKGROUND) { 1965 return; 1966 } 1967 1968 if (m_chainman.m_best_invalid && m_chainman.m_best_invalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) { 1969 LogWarning("Found invalid chain at least ~6 blocks longer than our best chain. Chain state database corruption likely."); 1970 m_chainman.GetNotifications().warningSet( 1971 kernel::Warning::LARGE_WORK_INVALID_CHAIN, 1972 _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.")); 1973 } else { 1974 m_chainman.GetNotifications().warningUnset(kernel::Warning::LARGE_WORK_INVALID_CHAIN); 1975 } 1976 } 1977 1978 // Called both upon regular invalid block discovery *and* InvalidateBlock 1979 void Chainstate::InvalidChainFound(CBlockIndex* pindexNew) 1980 { 1981 AssertLockHeld(cs_main); 1982 if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) { 1983 m_chainman.m_best_invalid = pindexNew; 1984 } 1985 SetBlockFailureFlags(pindexNew); 1986 if (m_chainman.m_best_header != nullptr && m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) == pindexNew) { 1987 m_chainman.RecalculateBestHeader(); 1988 } 1989 1990 LogPrintf("%s: invalid block=%s height=%d log2_work=%f date=%s\n", __func__, 1991 pindexNew->GetBlockHash().ToString(), pindexNew->nHeight, 1992 log(pindexNew->nChainWork.getdouble())/log(2.0), FormatISO8601DateTime(pindexNew->GetBlockTime())); 1993 CBlockIndex *tip = m_chain.Tip(); 1994 assert (tip); 1995 LogPrintf("%s: current best=%s height=%d log2_work=%f date=%s\n", __func__, 1996 tip->GetBlockHash().ToString(), m_chain.Height(), log(tip->nChainWork.getdouble())/log(2.0), 1997 FormatISO8601DateTime(tip->GetBlockTime())); 1998 CheckForkWarningConditions(); 1999 } 2000 2001 // Same as InvalidChainFound, above, except not called directly from InvalidateBlock, 2002 // which does its own setBlockIndexCandidates management. 2003 void Chainstate::InvalidBlockFound(CBlockIndex* pindex, const BlockValidationState& state) 2004 { 2005 AssertLockHeld(cs_main); 2006 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 2007 pindex->nStatus |= BLOCK_FAILED_VALID; 2008 m_blockman.m_dirty_blockindex.insert(pindex); 2009 setBlockIndexCandidates.erase(pindex); 2010 InvalidChainFound(pindex); 2011 } 2012 } 2013 2014 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, CTxUndo &txundo, int nHeight) 2015 { 2016 // mark inputs spent 2017 if (!tx.IsCoinBase()) { 2018 txundo.vprevout.reserve(tx.vin.size()); 2019 for (const CTxIn &txin : tx.vin) { 2020 txundo.vprevout.emplace_back(); 2021 bool is_spent = inputs.SpendCoin(txin.prevout, &txundo.vprevout.back()); 2022 assert(is_spent); 2023 } 2024 } 2025 // add outputs 2026 AddCoins(inputs, tx, nHeight); 2027 } 2028 2029 std::optional<std::pair<ScriptError, std::string>> CScriptCheck::operator()() { 2030 const CScript &scriptSig = ptxTo->vin[nIn].scriptSig; 2031 const CScriptWitness *witness = &ptxTo->vin[nIn].scriptWitness; 2032 ScriptError error{SCRIPT_ERR_UNKNOWN_ERROR}; 2033 if (VerifyScript(scriptSig, m_tx_out.scriptPubKey, witness, m_flags, CachingTransactionSignatureChecker(ptxTo, nIn, m_tx_out.nValue, cacheStore, *m_signature_cache, *txdata), &error)) { 2034 return std::nullopt; 2035 } else { 2036 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); 2037 return std::make_pair(error, std::move(debug_str)); 2038 } 2039 } 2040 2041 ValidationCache::ValidationCache(const size_t script_execution_cache_bytes, const size_t signature_cache_bytes) 2042 : m_signature_cache{signature_cache_bytes} 2043 { 2044 // Setup the salted hasher 2045 uint256 nonce = GetRandHash(); 2046 // We want the nonce to be 64 bytes long to force the hasher to process 2047 // this chunk, which makes later hash computations more efficient. We 2048 // just write our 32-byte entropy twice to fill the 64 bytes. 2049 m_script_execution_cache_hasher.Write(nonce.begin(), 32); 2050 m_script_execution_cache_hasher.Write(nonce.begin(), 32); 2051 2052 const auto [num_elems, approx_size_bytes] = m_script_execution_cache.setup_bytes(script_execution_cache_bytes); 2053 LogInfo("Using %zu MiB out of %zu MiB requested for script execution cache, able to store %zu elements", 2054 approx_size_bytes >> 20, script_execution_cache_bytes >> 20, num_elems); 2055 } 2056 2057 /** 2058 * Check whether all of this transaction's input scripts succeed. 2059 * 2060 * This involves ECDSA signature checks so can be computationally intensive. This function should 2061 * only be called after the cheap sanity checks in CheckTxInputs passed. 2062 * 2063 * If pvChecks is not nullptr, script checks are pushed onto it instead of being performed inline. Any 2064 * script checks which are not necessary (eg due to script execution cache hits) are, obviously, 2065 * not pushed onto pvChecks/run. 2066 * 2067 * Setting cacheSigStore/cacheFullScriptStore to false will remove elements from the corresponding cache 2068 * which are matched. This is useful for checking blocks where we will likely never need the cache 2069 * entry again. 2070 * 2071 * Note that we may set state.reason to NOT_STANDARD for extra soft-fork flags in flags, block-checking 2072 * callers should probably reset it to CONSENSUS in such cases. 2073 * 2074 * Non-static (and redeclared) in src/test/txvalidationcache_tests.cpp 2075 */ 2076 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state, 2077 const CCoinsViewCache& inputs, script_verify_flags flags, bool cacheSigStore, 2078 bool cacheFullScriptStore, PrecomputedTransactionData& txdata, 2079 ValidationCache& validation_cache, 2080 std::vector<CScriptCheck>* pvChecks) 2081 { 2082 if (tx.IsCoinBase()) return true; 2083 2084 if (pvChecks) { 2085 pvChecks->reserve(tx.vin.size()); 2086 } 2087 2088 // First check if script executions have been cached with the same 2089 // flags. Note that this assumes that the inputs provided are 2090 // correct (ie that the transaction hash which is in tx's prevouts 2091 // properly commits to the scriptPubKey in the inputs view of that 2092 // transaction). 2093 uint256 hashCacheEntry; 2094 CSHA256 hasher = validation_cache.ScriptExecutionCacheHasher(); 2095 hasher.Write(UCharCast(tx.GetWitnessHash().begin()), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin()); 2096 AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks 2097 if (validation_cache.m_script_execution_cache.contains(hashCacheEntry, !cacheFullScriptStore)) { 2098 return true; 2099 } 2100 2101 if (!txdata.m_spent_outputs_ready) { 2102 std::vector<CTxOut> spent_outputs; 2103 spent_outputs.reserve(tx.vin.size()); 2104 2105 for (const auto& txin : tx.vin) { 2106 const COutPoint& prevout = txin.prevout; 2107 const Coin& coin = inputs.AccessCoin(prevout); 2108 assert(!coin.IsSpent()); 2109 spent_outputs.emplace_back(coin.out); 2110 } 2111 txdata.Init(tx, std::move(spent_outputs)); 2112 } 2113 assert(txdata.m_spent_outputs.size() == tx.vin.size()); 2114 2115 for (unsigned int i = 0; i < tx.vin.size(); i++) { 2116 2117 // We very carefully only pass in things to CScriptCheck which 2118 // are clearly committed to by tx' witness hash. This provides 2119 // a sanity check that our caching is not introducing consensus 2120 // failures through additional data in, eg, the coins being 2121 // spent being checked as a part of CScriptCheck. 2122 2123 // Verify signature 2124 CScriptCheck check(txdata.m_spent_outputs[i], tx, validation_cache.m_signature_cache, i, flags, cacheSigStore, &txdata); 2125 if (pvChecks) { 2126 pvChecks->emplace_back(std::move(check)); 2127 } else if (auto result = check(); result.has_value()) { 2128 // Tx failures never trigger disconnections/bans. 2129 // This is so that network splits aren't triggered 2130 // either due to non-consensus relay policies (such as 2131 // non-standard DER encodings or non-null dummy 2132 // arguments) or due to new consensus rules introduced in 2133 // soft forks. 2134 if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) { 2135 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, strprintf("mempool-script-verify-flag-failed (%s)", ScriptErrorString(result->first)), result->second); 2136 } else { 2137 return state.Invalid(TxValidationResult::TX_CONSENSUS, strprintf("block-script-verify-flag-failed (%s)", ScriptErrorString(result->first)), result->second); 2138 } 2139 } 2140 } 2141 2142 if (cacheFullScriptStore && !pvChecks) { 2143 // We executed all of the provided scripts, and were told to 2144 // cache the result. Do so now. 2145 validation_cache.m_script_execution_cache.insert(hashCacheEntry); 2146 } 2147 2148 return true; 2149 } 2150 2151 bool FatalError(Notifications& notifications, BlockValidationState& state, const bilingual_str& message) 2152 { 2153 notifications.fatalError(message); 2154 return state.Error(message.original); 2155 } 2156 2157 /** 2158 * Restore the UTXO in a Coin at a given COutPoint 2159 * @param undo The Coin to be restored. 2160 * @param view The coins view to which to apply the changes. 2161 * @param out The out point that corresponds to the tx input. 2162 * @return A DisconnectResult as an int 2163 */ 2164 int ApplyTxInUndo(Coin&& undo, CCoinsViewCache& view, const COutPoint& out) 2165 { 2166 bool fClean = true; 2167 2168 if (view.HaveCoin(out)) fClean = false; // overwriting transaction output 2169 2170 if (undo.nHeight == 0) { 2171 // Missing undo metadata (height and coinbase). Older versions included this 2172 // information only in undo records for the last spend of a transactions' 2173 // outputs. This implies that it must be present for some other output of the same tx. 2174 const Coin& alternate = AccessByTxid(view, out.hash); 2175 if (!alternate.IsSpent()) { 2176 undo.nHeight = alternate.nHeight; 2177 undo.fCoinBase = alternate.fCoinBase; 2178 } else { 2179 return DISCONNECT_FAILED; // adding output for transaction without known metadata 2180 } 2181 } 2182 // If the coin already exists as an unspent coin in the cache, then the 2183 // possible_overwrite parameter to AddCoin must be set to true. We have 2184 // already checked whether an unspent coin exists above using HaveCoin, so 2185 // we don't need to guess. When fClean is false, an unspent coin already 2186 // existed and it is an overwrite. 2187 view.AddCoin(out, std::move(undo), !fClean); 2188 2189 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN; 2190 } 2191 2192 /** Undo the effects of this block (with given index) on the UTXO set represented by coins. 2193 * When FAILED is returned, view is left in an indeterminate state. */ 2194 DisconnectResult Chainstate::DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view) 2195 { 2196 AssertLockHeld(::cs_main); 2197 bool fClean = true; 2198 2199 CBlockUndo blockUndo; 2200 if (!m_blockman.ReadBlockUndo(blockUndo, *pindex)) { 2201 LogError("DisconnectBlock(): failure reading undo data\n"); 2202 return DISCONNECT_FAILED; 2203 } 2204 2205 if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) { 2206 LogError("DisconnectBlock(): block and undo data inconsistent\n"); 2207 return DISCONNECT_FAILED; 2208 } 2209 2210 // Ignore blocks that contain transactions which are 'overwritten' by later transactions, 2211 // unless those are already completely spent. 2212 // See https://github.com/bitcoin/bitcoin/issues/22596 for additional information. 2213 // Note: the blocks specified here are different than the ones used in ConnectBlock because DisconnectBlock 2214 // unwinds the blocks in reverse. As a result, the inconsistency is not discovered until the earlier 2215 // blocks with the duplicate coinbase transactions are disconnected. 2216 bool fEnforceBIP30 = !((pindex->nHeight==91722 && pindex->GetBlockHash() == uint256{"00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e"}) || 2217 (pindex->nHeight==91812 && pindex->GetBlockHash() == uint256{"00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"})); 2218 2219 // undo transactions in reverse order 2220 for (int i = block.vtx.size() - 1; i >= 0; i--) { 2221 const CTransaction &tx = *(block.vtx[i]); 2222 Txid hash = tx.GetHash(); 2223 bool is_coinbase = tx.IsCoinBase(); 2224 bool is_bip30_exception = (is_coinbase && !fEnforceBIP30); 2225 2226 // Check that all outputs are available and match the outputs in the block itself 2227 // exactly. 2228 for (size_t o = 0; o < tx.vout.size(); o++) { 2229 if (!tx.vout[o].scriptPubKey.IsUnspendable()) { 2230 COutPoint out(hash, o); 2231 Coin coin; 2232 bool is_spent = view.SpendCoin(out, &coin); 2233 if (!is_spent || tx.vout[o] != coin.out || pindex->nHeight != coin.nHeight || is_coinbase != coin.fCoinBase) { 2234 if (!is_bip30_exception) { 2235 fClean = false; // transaction output mismatch 2236 } 2237 } 2238 } 2239 } 2240 2241 // restore inputs 2242 if (i > 0) { // not coinbases 2243 CTxUndo &txundo = blockUndo.vtxundo[i-1]; 2244 if (txundo.vprevout.size() != tx.vin.size()) { 2245 LogError("DisconnectBlock(): transaction and undo data inconsistent\n"); 2246 return DISCONNECT_FAILED; 2247 } 2248 for (unsigned int j = tx.vin.size(); j > 0;) { 2249 --j; 2250 const COutPoint& out = tx.vin[j].prevout; 2251 int res = ApplyTxInUndo(std::move(txundo.vprevout[j]), view, out); 2252 if (res == DISCONNECT_FAILED) return DISCONNECT_FAILED; 2253 fClean = fClean && res != DISCONNECT_UNCLEAN; 2254 } 2255 // At this point, all of txundo.vprevout should have been moved out. 2256 } 2257 } 2258 2259 // move best block pointer to prevout block 2260 view.SetBestBlock(pindex->pprev->GetBlockHash()); 2261 2262 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN; 2263 } 2264 2265 script_verify_flags GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman) 2266 { 2267 const Consensus::Params& consensusparams = chainman.GetConsensus(); 2268 2269 // BIP16 didn't become active until Apr 1 2012 (on mainnet, and 2270 // retroactively applied to testnet) 2271 // However, only one historical block violated the P2SH rules (on both 2272 // mainnet and testnet). 2273 // Similarly, only one historical block violated the TAPROOT rules on 2274 // mainnet. 2275 // For simplicity, always leave P2SH+WITNESS+TAPROOT on except for the two 2276 // violating blocks. 2277 script_verify_flags flags{SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_TAPROOT}; 2278 const auto it{consensusparams.script_flag_exceptions.find(*Assert(block_index.phashBlock))}; 2279 if (it != consensusparams.script_flag_exceptions.end()) { 2280 flags = it->second; 2281 } 2282 2283 // Enforce the DERSIG (BIP66) rule 2284 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_DERSIG)) { 2285 flags |= SCRIPT_VERIFY_DERSIG; 2286 } 2287 2288 // Enforce CHECKLOCKTIMEVERIFY (BIP65) 2289 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CLTV)) { 2290 flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY; 2291 } 2292 2293 // Enforce CHECKSEQUENCEVERIFY (BIP112) 2294 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CSV)) { 2295 flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY; 2296 } 2297 2298 // Enforce BIP147 NULLDUMMY (activated simultaneously with segwit) 2299 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_SEGWIT)) { 2300 flags |= SCRIPT_VERIFY_NULLDUMMY; 2301 } 2302 2303 return flags; 2304 } 2305 2306 2307 /** Apply the effects of this block (with given index) on the UTXO set represented by coins. 2308 * Validity checks that depend on the UTXO set are also done; ConnectBlock() 2309 * can fail if those validity checks fail (among other reasons). */ 2310 bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex, 2311 CCoinsViewCache& view, bool fJustCheck) 2312 { 2313 AssertLockHeld(cs_main); 2314 assert(pindex); 2315 2316 uint256 block_hash{block.GetHash()}; 2317 assert(*pindex->phashBlock == block_hash); 2318 2319 const auto time_start{SteadyClock::now()}; 2320 const CChainParams& params{m_chainman.GetParams()}; 2321 2322 // Check it again in case a previous version let a bad block in 2323 // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or 2324 // ContextualCheckBlockHeader() here. This means that if we add a new 2325 // consensus rule that is enforced in one of those two functions, then we 2326 // may have let in a block that violates the rule prior to updating the 2327 // software, and we would NOT be enforcing the rule here. Fully solving 2328 // upgrade from one software version to the next after a consensus rule 2329 // change is potentially tricky and issue-specific (see NeedsRedownload() 2330 // for one approach that was used for BIP 141 deployment). 2331 // Also, currently the rule against blocks more than 2 hours in the future 2332 // is enforced in ContextualCheckBlockHeader(); we wouldn't want to 2333 // re-enforce that rule here (at least until we make it impossible for 2334 // the clock to go backward). 2335 if (!CheckBlock(block, state, params.GetConsensus(), !fJustCheck, !fJustCheck)) { 2336 if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) { 2337 // We don't write down blocks to disk if they may have been 2338 // corrupted, so this should be impossible unless we're having hardware 2339 // problems. 2340 return FatalError(m_chainman.GetNotifications(), state, _("Corrupt block found indicating potential hardware failure.")); 2341 } 2342 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString()); 2343 return false; 2344 } 2345 2346 // verify that the view's current state corresponds to the previous block 2347 uint256 hashPrevBlock = pindex->pprev == nullptr ? uint256() : pindex->pprev->GetBlockHash(); 2348 assert(hashPrevBlock == view.GetBestBlock()); 2349 2350 m_chainman.num_blocks_total++; 2351 2352 // Special case for the genesis block, skipping connection of its transactions 2353 // (its coinbase is unspendable) 2354 if (block_hash == params.GetConsensus().hashGenesisBlock) { 2355 if (!fJustCheck) 2356 view.SetBestBlock(pindex->GetBlockHash()); 2357 return true; 2358 } 2359 2360 const char* script_check_reason; 2361 if (m_chainman.AssumedValidBlock().IsNull()) { 2362 script_check_reason = "assumevalid=0 (always verify)"; 2363 } else { 2364 constexpr int64_t TWO_WEEKS_IN_SECONDS{60 * 60 * 24 * 7 * 2}; 2365 // We've been configured with the hash of a block which has been externally verified to have a valid history. 2366 // A suitable default value is included with the software and updated from time to time. Because validity 2367 // relative to a piece of software is an objective fact these defaults can be easily reviewed. 2368 // This setting doesn't force the selection of any particular chain but makes validating some faster by 2369 // effectively caching the result of part of the verification. 2370 BlockMap::const_iterator it{m_blockman.m_block_index.find(m_chainman.AssumedValidBlock())}; 2371 if (it == m_blockman.m_block_index.end()) { 2372 script_check_reason = "assumevalid hash not in headers"; 2373 } else if (it->second.GetAncestor(pindex->nHeight) != pindex) { 2374 script_check_reason = (pindex->nHeight > it->second.nHeight) ? "block height above assumevalid height" : "block not in assumevalid chain"; 2375 } else if (m_chainman.m_best_header->GetAncestor(pindex->nHeight) != pindex) { 2376 script_check_reason = "block not in best header chain"; 2377 } else if (m_chainman.m_best_header->nChainWork < m_chainman.MinimumChainWork()) { 2378 script_check_reason = "best header chainwork below minimumchainwork"; 2379 } else if (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, params.GetConsensus()) <= TWO_WEEKS_IN_SECONDS) { 2380 script_check_reason = "block too recent relative to best header"; 2381 } else { 2382 // This block is a member of the assumed verified chain and an ancestor of the best header. 2383 // Script verification is skipped when connecting blocks under the 2384 // assumevalid block. Assuming the assumevalid block is valid this 2385 // is safe because block merkle hashes are still computed and checked, 2386 // Of course, if an assumed valid block is invalid due to false scriptSigs 2387 // this optimization would allow an invalid chain to be accepted. 2388 // The equivalent time check discourages hash power from extorting the network via DOS attack 2389 // into accepting an invalid block through telling users they must manually set assumevalid. 2390 // Requiring a software change or burying the invalid block, regardless of the setting, makes 2391 // it hard to hide the implication of the demand. This also avoids having release candidates 2392 // that are hardly doing any signature verification at all in testing without having to 2393 // artificially set the default assumed verified block further back. 2394 // The test against the minimum chain work prevents the skipping when denied access to any chain at 2395 // least as good as the expected chain. 2396 script_check_reason = nullptr; 2397 } 2398 } 2399 2400 const auto time_1{SteadyClock::now()}; 2401 m_chainman.time_check += time_1 - time_start; 2402 LogDebug(BCLog::BENCH, " - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n", 2403 Ticks<MillisecondsDouble>(time_1 - time_start), 2404 Ticks<SecondsDouble>(m_chainman.time_check), 2405 Ticks<MillisecondsDouble>(m_chainman.time_check) / m_chainman.num_blocks_total); 2406 2407 // Do not allow blocks that contain transactions which 'overwrite' older transactions, 2408 // unless those are already completely spent. 2409 // If such overwrites are allowed, coinbases and transactions depending upon those 2410 // can be duplicated to remove the ability to spend the first instance -- even after 2411 // being sent to another address. 2412 // See BIP30, CVE-2012-1909, and https://r6.ca/blog/20120206T005236Z.html for more information. 2413 // This rule was originally applied to all blocks with a timestamp after March 15, 2012, 0:00 UTC. 2414 // Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the 2415 // two in the chain that violate it. This prevents exploiting the issue against nodes during their 2416 // initial block download. 2417 bool fEnforceBIP30 = !IsBIP30Repeat(*pindex); 2418 2419 // Once BIP34 activated it was not possible to create new duplicate coinbases and thus other than starting 2420 // with the 2 existing duplicate coinbase pairs, not possible to create overwriting txs. But by the 2421 // time BIP34 activated, in each of the existing pairs the duplicate coinbase had overwritten the first 2422 // before the first had been spent. Since those coinbases are sufficiently buried it's no longer possible to create further 2423 // duplicate transactions descending from the known pairs either. 2424 // 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. 2425 2426 // BIP34 requires that a block at height X (block X) has its coinbase 2427 // scriptSig start with a CScriptNum of X (indicated height X). The above 2428 // logic of no longer requiring BIP30 once BIP34 activates is flawed in the 2429 // case that there is a block X before the BIP34 height of 227,931 which has 2430 // an indicated height Y where Y is greater than X. The coinbase for block 2431 // X would also be a valid coinbase for block Y, which could be a BIP30 2432 // violation. An exhaustive search of all mainnet coinbases before the 2433 // BIP34 height which have an indicated height greater than the block height 2434 // reveals many occurrences. The 3 lowest indicated heights found are 2435 // 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3 2436 // heights would be the first opportunity for BIP30 to be violated. 2437 2438 // The search reveals a great many blocks which have an indicated height 2439 // greater than 1,983,702, so we simply remove the optimization to skip 2440 // BIP30 checking for blocks at height 1,983,702 or higher. Before we reach 2441 // that block in another 25 years or so, we should take advantage of a 2442 // future consensus change to do a new and improved version of BIP34 that 2443 // will actually prevent ever creating any duplicate coinbases in the 2444 // future. 2445 static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702; 2446 2447 // There is no potential to create a duplicate coinbase at block 209,921 2448 // because this is still before the BIP34 height and so explicit BIP30 2449 // checking is still active. 2450 2451 // The final case is block 176,684 which has an indicated height of 2452 // 490,897. Unfortunately, this issue was not discovered until about 2 weeks 2453 // before block 490,897 so there was not much opportunity to address this 2454 // case other than to carefully analyze it and determine it would not be a 2455 // problem. Block 490,897 was, in fact, mined with a different coinbase than 2456 // block 176,684, but it is important to note that even if it hadn't been or 2457 // is remined on an alternate fork with a duplicate coinbase, we would still 2458 // not run into a BIP30 violation. This is because the coinbase for 176,684 2459 // is spent in block 185,956 in transaction 2460 // d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781. This 2461 // spending transaction can't be duplicated because it also spends coinbase 2462 // 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29. This 2463 // coinbase has an indicated height of over 4.2 billion, and wouldn't be 2464 // duplicatable until that height, and it's currently impossible to create a 2465 // chain that long. Nevertheless we may wish to consider a future soft fork 2466 // which retroactively prevents block 490,897 from creating a duplicate 2467 // coinbase. The two historical BIP30 violations often provide a confusing 2468 // edge case when manipulating the UTXO and it would be simpler not to have 2469 // another edge case to deal with. 2470 2471 // testnet3 has no blocks before the BIP34 height with indicated heights 2472 // post BIP34 before approximately height 486,000,000. After block 2473 // 1,983,702 testnet3 starts doing unnecessary BIP30 checking again. 2474 assert(pindex->pprev); 2475 CBlockIndex* pindexBIP34height = pindex->pprev->GetAncestor(params.GetConsensus().BIP34Height); 2476 //Only continue to enforce if we're below BIP34 activation height or the block hash at that height doesn't correspond. 2477 fEnforceBIP30 = fEnforceBIP30 && (!pindexBIP34height || !(pindexBIP34height->GetBlockHash() == params.GetConsensus().BIP34Hash)); 2478 2479 // TODO: Remove BIP30 checking from block height 1,983,702 on, once we have a 2480 // consensus change that ensures coinbases at those heights cannot 2481 // duplicate earlier coinbases. 2482 if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) { 2483 for (const auto& tx : block.vtx) { 2484 for (size_t o = 0; o < tx->vout.size(); o++) { 2485 if (view.HaveCoin(COutPoint(tx->GetHash(), o))) { 2486 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-BIP30", 2487 "tried to overwrite transaction"); 2488 } 2489 } 2490 } 2491 } 2492 2493 // Enforce BIP68 (sequence locks) 2494 int nLockTimeFlags = 0; 2495 if (DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_CSV)) { 2496 nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE; 2497 } 2498 2499 // Get the script flags for this block 2500 script_verify_flags flags{GetBlockScriptFlags(*pindex, m_chainman)}; 2501 2502 const auto time_2{SteadyClock::now()}; 2503 m_chainman.time_forks += time_2 - time_1; 2504 LogDebug(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n", 2505 Ticks<MillisecondsDouble>(time_2 - time_1), 2506 Ticks<SecondsDouble>(m_chainman.time_forks), 2507 Ticks<MillisecondsDouble>(m_chainman.time_forks) / m_chainman.num_blocks_total); 2508 2509 const bool fScriptChecks{!!script_check_reason}; 2510 if (script_check_reason != m_last_script_check_reason_logged && GetRole() == ChainstateRole::NORMAL) { 2511 if (fScriptChecks) { 2512 LogInfo("Enabling script verification at block #%d (%s): %s.", 2513 pindex->nHeight, block_hash.ToString(), script_check_reason); 2514 } else { 2515 LogInfo("Disabling script verification at block #%d (%s).", 2516 pindex->nHeight, block_hash.ToString()); 2517 } 2518 m_last_script_check_reason_logged = script_check_reason; 2519 } 2520 2521 CBlockUndo blockundo; 2522 2523 // Precomputed transaction data pointers must not be invalidated 2524 // until after `control` has run the script checks (potentially 2525 // in multiple threads). Preallocate the vector size so a new allocation 2526 // doesn't invalidate pointers into the vector, and keep txsdata in scope 2527 // for as long as `control`. 2528 std::optional<CCheckQueueControl<CScriptCheck>> control; 2529 if (auto& queue = m_chainman.GetCheckQueue(); queue.HasThreads() && fScriptChecks) control.emplace(queue); 2530 2531 std::vector<PrecomputedTransactionData> txsdata(block.vtx.size()); 2532 2533 std::vector<int> prevheights; 2534 CAmount nFees = 0; 2535 int nInputs = 0; 2536 int64_t nSigOpsCost = 0; 2537 blockundo.vtxundo.reserve(block.vtx.size() - 1); 2538 for (unsigned int i = 0; i < block.vtx.size(); i++) 2539 { 2540 if (!state.IsValid()) break; 2541 const CTransaction &tx = *(block.vtx[i]); 2542 2543 nInputs += tx.vin.size(); 2544 2545 if (!tx.IsCoinBase()) 2546 { 2547 CAmount txfee = 0; 2548 TxValidationState tx_state; 2549 if (!Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight, txfee)) { 2550 // Any transaction validation failure in ConnectBlock is a block consensus failure 2551 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, 2552 tx_state.GetRejectReason(), 2553 tx_state.GetDebugMessage() + " in transaction " + tx.GetHash().ToString()); 2554 break; 2555 } 2556 nFees += txfee; 2557 if (!MoneyRange(nFees)) { 2558 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-accumulated-fee-outofrange", 2559 "accumulated fee in the block out of range"); 2560 break; 2561 } 2562 2563 // Check that transaction is BIP68 final 2564 // BIP68 lock checks (as opposed to nLockTime checks) must 2565 // be in ConnectBlock because they require the UTXO set 2566 prevheights.resize(tx.vin.size()); 2567 for (size_t j = 0; j < tx.vin.size(); j++) { 2568 prevheights[j] = view.AccessCoin(tx.vin[j].prevout).nHeight; 2569 } 2570 2571 if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) { 2572 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", 2573 "contains a non-BIP68-final transaction " + tx.GetHash().ToString()); 2574 break; 2575 } 2576 } 2577 2578 // GetTransactionSigOpCost counts 3 types of sigops: 2579 // * legacy (always) 2580 // * p2sh (when P2SH enabled in flags and excludes coinbase) 2581 // * witness (when witness enabled in flags and excludes coinbase) 2582 nSigOpsCost += GetTransactionSigOpCost(tx, view, flags); 2583 if (nSigOpsCost > MAX_BLOCK_SIGOPS_COST) { 2584 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "too many sigops"); 2585 break; 2586 } 2587 2588 if (!tx.IsCoinBase() && fScriptChecks) 2589 { 2590 bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */ 2591 bool tx_ok; 2592 TxValidationState tx_state; 2593 // If CheckInputScripts is called with a pointer to a checks vector, the resulting checks are appended to it. In that case 2594 // they need to be added to control which runs them asynchronously. Otherwise, CheckInputScripts runs the checks before returning. 2595 if (control) { 2596 std::vector<CScriptCheck> vChecks; 2597 tx_ok = CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], m_chainman.m_validation_cache, &vChecks); 2598 if (tx_ok) control->Add(std::move(vChecks)); 2599 } else { 2600 tx_ok = CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], m_chainman.m_validation_cache); 2601 } 2602 if (!tx_ok) { 2603 // Any transaction validation failure in ConnectBlock is a block consensus failure 2604 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, 2605 tx_state.GetRejectReason(), tx_state.GetDebugMessage()); 2606 break; 2607 } 2608 } 2609 2610 CTxUndo undoDummy; 2611 if (i > 0) { 2612 blockundo.vtxundo.emplace_back(); 2613 } 2614 UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight); 2615 } 2616 const auto time_3{SteadyClock::now()}; 2617 m_chainman.time_connect += time_3 - time_2; 2618 LogDebug(BCLog::BENCH, " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(), 2619 Ticks<MillisecondsDouble>(time_3 - time_2), Ticks<MillisecondsDouble>(time_3 - time_2) / block.vtx.size(), 2620 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_3 - time_2) / (nInputs - 1), 2621 Ticks<SecondsDouble>(m_chainman.time_connect), 2622 Ticks<MillisecondsDouble>(m_chainman.time_connect) / m_chainman.num_blocks_total); 2623 2624 CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, params.GetConsensus()); 2625 if (block.vtx[0]->GetValueOut() > blockReward && state.IsValid()) { 2626 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-amount", 2627 strprintf("coinbase pays too much (actual=%d vs limit=%d)", block.vtx[0]->GetValueOut(), blockReward)); 2628 } 2629 if (control) { 2630 auto parallel_result = control->Complete(); 2631 if (parallel_result.has_value() && state.IsValid()) { 2632 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, strprintf("block-script-verify-flag-failed (%s)", ScriptErrorString(parallel_result->first)), parallel_result->second); 2633 } 2634 } 2635 if (!state.IsValid()) { 2636 LogInfo("Block validation error: %s", state.ToString()); 2637 return false; 2638 } 2639 const auto time_4{SteadyClock::now()}; 2640 m_chainman.time_verify += time_4 - time_2; 2641 LogDebug(BCLog::BENCH, " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n", nInputs - 1, 2642 Ticks<MillisecondsDouble>(time_4 - time_2), 2643 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_4 - time_2) / (nInputs - 1), 2644 Ticks<SecondsDouble>(m_chainman.time_verify), 2645 Ticks<MillisecondsDouble>(m_chainman.time_verify) / m_chainman.num_blocks_total); 2646 2647 if (fJustCheck) { 2648 return true; 2649 } 2650 2651 if (!m_blockman.WriteBlockUndo(blockundo, state, *pindex)) { 2652 return false; 2653 } 2654 2655 const auto time_5{SteadyClock::now()}; 2656 m_chainman.time_undo += time_5 - time_4; 2657 LogDebug(BCLog::BENCH, " - Write undo data: %.2fms [%.2fs (%.2fms/blk)]\n", 2658 Ticks<MillisecondsDouble>(time_5 - time_4), 2659 Ticks<SecondsDouble>(m_chainman.time_undo), 2660 Ticks<MillisecondsDouble>(m_chainman.time_undo) / m_chainman.num_blocks_total); 2661 2662 if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) { 2663 pindex->RaiseValidity(BLOCK_VALID_SCRIPTS); 2664 m_blockman.m_dirty_blockindex.insert(pindex); 2665 } 2666 2667 // add this block to the view's block chain 2668 view.SetBestBlock(pindex->GetBlockHash()); 2669 2670 const auto time_6{SteadyClock::now()}; 2671 m_chainman.time_index += time_6 - time_5; 2672 LogDebug(BCLog::BENCH, " - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n", 2673 Ticks<MillisecondsDouble>(time_6 - time_5), 2674 Ticks<SecondsDouble>(m_chainman.time_index), 2675 Ticks<MillisecondsDouble>(m_chainman.time_index) / m_chainman.num_blocks_total); 2676 2677 TRACEPOINT(validation, block_connected, 2678 block_hash.data(), 2679 pindex->nHeight, 2680 block.vtx.size(), 2681 nInputs, 2682 nSigOpsCost, 2683 Ticks<std::chrono::nanoseconds>(time_5 - time_start) 2684 ); 2685 2686 return true; 2687 } 2688 2689 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState() 2690 { 2691 AssertLockHeld(::cs_main); 2692 return this->GetCoinsCacheSizeState( 2693 m_coinstip_cache_size_bytes, 2694 m_mempool ? m_mempool->m_opts.max_size_bytes : 0); 2695 } 2696 2697 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState( 2698 size_t max_coins_cache_size_bytes, 2699 size_t max_mempool_size_bytes) 2700 { 2701 AssertLockHeld(::cs_main); 2702 const int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0; 2703 int64_t cacheSize = CoinsTip().DynamicMemoryUsage(); 2704 int64_t nTotalSpace = 2705 max_coins_cache_size_bytes + std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0); 2706 2707 if (cacheSize > nTotalSpace) { 2708 LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize, nTotalSpace); 2709 return CoinsCacheSizeState::CRITICAL; 2710 } else if (cacheSize > LargeCoinsCacheThreshold(nTotalSpace)) { 2711 return CoinsCacheSizeState::LARGE; 2712 } 2713 return CoinsCacheSizeState::OK; 2714 } 2715 2716 bool Chainstate::FlushStateToDisk( 2717 BlockValidationState &state, 2718 FlushStateMode mode, 2719 int nManualPruneHeight) 2720 { 2721 LOCK(cs_main); 2722 assert(this->CanFlushToDisk()); 2723 std::set<int> setFilesToPrune; 2724 bool full_flush_completed = false; 2725 2726 const size_t coins_count = CoinsTip().GetCacheSize(); 2727 const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage(); 2728 2729 try { 2730 { 2731 bool fFlushForPrune = false; 2732 2733 CoinsCacheSizeState cache_state = GetCoinsCacheSizeState(); 2734 LOCK(m_blockman.cs_LastBlockFile); 2735 if (m_blockman.IsPruneMode() && (m_blockman.m_check_for_pruning || nManualPruneHeight > 0) && m_chainman.m_blockman.m_blockfiles_indexed) { 2736 // make sure we don't prune above any of the prune locks bestblocks 2737 // pruning is height-based 2738 int last_prune{m_chain.Height()}; // last height we can prune 2739 std::optional<std::string> limiting_lock; // prune lock that actually was the limiting factor, only used for logging 2740 2741 for (const auto& prune_lock : m_blockman.m_prune_locks) { 2742 if (prune_lock.second.height_first == std::numeric_limits<int>::max()) continue; 2743 // Remove the buffer and one additional block here to get actual height that is outside of the buffer 2744 const int lock_height{prune_lock.second.height_first - PRUNE_LOCK_BUFFER - 1}; 2745 last_prune = std::max(1, std::min(last_prune, lock_height)); 2746 if (last_prune == lock_height) { 2747 limiting_lock = prune_lock.first; 2748 } 2749 } 2750 2751 if (limiting_lock) { 2752 LogDebug(BCLog::PRUNE, "%s limited pruning to height %d\n", limiting_lock.value(), last_prune); 2753 } 2754 2755 if (nManualPruneHeight > 0) { 2756 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune (manual)", BCLog::BENCH); 2757 2758 m_blockman.FindFilesToPruneManual( 2759 setFilesToPrune, 2760 std::min(last_prune, nManualPruneHeight), 2761 *this, m_chainman); 2762 } else { 2763 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune", BCLog::BENCH); 2764 2765 m_blockman.FindFilesToPrune(setFilesToPrune, last_prune, *this, m_chainman); 2766 m_blockman.m_check_for_pruning = false; 2767 } 2768 if (!setFilesToPrune.empty()) { 2769 fFlushForPrune = true; 2770 if (!m_blockman.m_have_pruned) { 2771 m_blockman.m_block_tree_db->WriteFlag("prunedblockfiles", true); 2772 m_blockman.m_have_pruned = true; 2773 } 2774 } 2775 } 2776 const auto nNow{NodeClock::now()}; 2777 // 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). 2778 bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE; 2779 // The cache is over the limit, we have to write now. 2780 bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL; 2781 // 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. 2782 bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow >= m_next_write; 2783 // Combine all conditions that result in a write to disk. 2784 bool should_write = (mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicWrite || fFlushForPrune; 2785 // Write blocks, block index and best chain related state to disk. 2786 if (should_write) { 2787 LogDebug(BCLog::COINDB, "Writing chainstate to disk: flush mode=%s, prune=%d, large=%d, critical=%d, periodic=%d", 2788 FlushStateModeNames[size_t(mode)], fFlushForPrune, fCacheLarge, fCacheCritical, fPeriodicWrite); 2789 2790 // Ensure we can write block index 2791 if (!CheckDiskSpace(m_blockman.m_opts.blocks_dir)) { 2792 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!")); 2793 } 2794 { 2795 LOG_TIME_MILLIS_WITH_CATEGORY("write block and undo data to disk", BCLog::BENCH); 2796 2797 // First make sure all block and undo data is flushed to disk. 2798 // TODO: Handle return error, or add detailed comment why it is 2799 // safe to not return an error upon failure. 2800 if (!m_blockman.FlushChainstateBlockFile(m_chain.Height())) { 2801 LogPrintLevel(BCLog::VALIDATION, BCLog::Level::Warning, "%s: Failed to flush block file.\n", __func__); 2802 } 2803 } 2804 2805 // Then update all block file information (which may refer to block and undo files). 2806 { 2807 LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk", BCLog::BENCH); 2808 2809 m_blockman.WriteBlockIndexDB(); 2810 } 2811 // Finally remove any pruned files 2812 if (fFlushForPrune) { 2813 LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files", BCLog::BENCH); 2814 2815 m_blockman.UnlinkPrunedFiles(setFilesToPrune); 2816 } 2817 2818 if (!CoinsTip().GetBestBlock().IsNull()) { 2819 if (coins_mem_usage >= WARN_FLUSH_COINS_SIZE) LogWarning("Flushing large (%d GiB) UTXO set to disk, it may take several minutes", coins_mem_usage >> 30); 2820 LOG_TIME_MILLIS_WITH_CATEGORY(strprintf("write coins cache to disk (%d coins, %.2fKiB)", 2821 coins_count, coins_mem_usage >> 10), BCLog::BENCH); 2822 2823 // Typical Coin structures on disk are around 48 bytes in size. 2824 // Pushing a new one to the database can cause it to be written 2825 // twice (once in the log, and once in the tables). This is already 2826 // an overestimation, as most will delete an existing entry or 2827 // overwrite one. Still, use a conservative safety factor of 2. 2828 if (!CheckDiskSpace(m_chainman.m_options.datadir, 48 * 2 * 2 * CoinsTip().GetCacheSize())) { 2829 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!")); 2830 } 2831 // Flush the chainstate (which may refer to block index entries). 2832 const auto empty_cache{(mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical}; 2833 if (empty_cache ? !CoinsTip().Flush() : !CoinsTip().Sync()) { 2834 return FatalError(m_chainman.GetNotifications(), state, _("Failed to write to coin database.")); 2835 } 2836 full_flush_completed = true; 2837 TRACEPOINT(utxocache, flush, 2838 int64_t{Ticks<std::chrono::microseconds>(NodeClock::now() - nNow)}, 2839 (uint32_t)mode, 2840 (uint64_t)coins_count, 2841 (uint64_t)coins_mem_usage, 2842 (bool)fFlushForPrune); 2843 } 2844 } 2845 2846 if (should_write || m_next_write == NodeClock::time_point::max()) { 2847 constexpr auto range{DATABASE_WRITE_INTERVAL_MAX - DATABASE_WRITE_INTERVAL_MIN}; 2848 m_next_write = FastRandomContext().rand_uniform_delay(NodeClock::now() + DATABASE_WRITE_INTERVAL_MIN, range); 2849 } 2850 } 2851 if (full_flush_completed && m_chainman.m_options.signals) { 2852 // Update best block in wallet (so we can detect restored wallets). 2853 m_chainman.m_options.signals->ChainStateFlushed(this->GetRole(), GetLocator(m_chain.Tip())); 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() 2862 { 2863 BlockValidationState state; 2864 if (!this->FlushStateToDisk(state, FlushStateMode::ALWAYS)) { 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) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 2885 { 2886 2887 AssertLockHeld(::cs_main); 2888 2889 // Disable rate limiting in LogPrintLevel_ so this source location may log during IBD. 2890 LogPrintLevel_(BCLog::LogFlags::ALL, BCLog::Level::Info, /*should_ratelimit=*/false, "%s%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%lu date='%s' progress=%f cache=%.1fMiB(%utxo)%s\n", 2891 prefix, func_name, 2892 tip->GetBlockHash().ToString(), tip->nHeight, tip->nVersion, 2893 log(tip->nChainWork.getdouble()) / log(2.0), tip->m_chain_tx_count, 2894 FormatISO8601DateTime(tip->GetBlockTime()), 2895 chainman.GuessVerificationProgress(tip), 2896 coins_tip.DynamicMemoryUsage() * (1.0 / (1 << 20)), 2897 coins_tip.GetCacheSize(), 2898 !warning_messages.empty() ? strprintf(" warning='%s'", warning_messages) : ""); 2899 } 2900 2901 void Chainstate::UpdateTip(const CBlockIndex* pindexNew) 2902 { 2903 AssertLockHeld(::cs_main); 2904 const auto& coins_tip = this->CoinsTip(); 2905 2906 // The remainder of the function isn't relevant if we are not acting on 2907 // the active chainstate, so return if need be. 2908 if (this != &m_chainman.ActiveChainstate()) { 2909 // Only log every so often so that we don't bury log messages at the tip. 2910 constexpr int BACKGROUND_LOG_INTERVAL = 2000; 2911 if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) { 2912 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "[background validation] ", ""); 2913 } 2914 return; 2915 } 2916 2917 // New best block 2918 if (m_mempool) { 2919 m_mempool->AddTransactionsUpdated(1); 2920 } 2921 2922 std::vector<bilingual_str> warning_messages; 2923 if (!m_chainman.IsInitialBlockDownload()) { 2924 auto bits = m_chainman.m_versionbitscache.CheckUnknownActivations(pindexNew, m_chainman.GetParams()); 2925 for (auto [bit, active] : bits) { 2926 const bilingual_str warning = strprintf(_("Unknown new rules activated (versionbit %i)"), bit); 2927 if (active) { 2928 m_chainman.GetNotifications().warningSet(kernel::Warning::UNKNOWN_NEW_RULES_ACTIVATED, warning); 2929 } else { 2930 warning_messages.push_back(warning); 2931 } 2932 } 2933 } 2934 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "", 2935 util::Join(warning_messages, Untranslated(", ")).original); 2936 } 2937 2938 /** Disconnect m_chain's tip. 2939 * After calling, the mempool will be in an inconsistent state, with 2940 * transactions from disconnected blocks being added to disconnectpool. You 2941 * should make the mempool consistent again by calling MaybeUpdateMempoolForReorg. 2942 * with cs_main held. 2943 * 2944 * If disconnectpool is nullptr, then no disconnected transactions are added to 2945 * disconnectpool (note that the caller is responsible for mempool consistency 2946 * in any case). 2947 */ 2948 bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTransactions* disconnectpool) 2949 { 2950 AssertLockHeld(cs_main); 2951 if (m_mempool) AssertLockHeld(m_mempool->cs); 2952 2953 CBlockIndex *pindexDelete = m_chain.Tip(); 2954 assert(pindexDelete); 2955 assert(pindexDelete->pprev); 2956 // Read block from disk. 2957 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); 2958 CBlock& block = *pblock; 2959 if (!m_blockman.ReadBlock(block, *pindexDelete)) { 2960 LogError("DisconnectTip(): Failed to read block\n"); 2961 return false; 2962 } 2963 // Apply the block atomically to the chain state. 2964 const auto time_start{SteadyClock::now()}; 2965 { 2966 CCoinsViewCache view(&CoinsTip()); 2967 assert(view.GetBestBlock() == pindexDelete->GetBlockHash()); 2968 if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK) { 2969 LogError("DisconnectTip(): DisconnectBlock %s failed\n", pindexDelete->GetBlockHash().ToString()); 2970 return false; 2971 } 2972 bool flushed = view.Flush(); 2973 assert(flushed); 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 3004 UpdateTip(pindexDelete->pprev); 3005 // Let wallets know transactions went from 1-confirmed to 3006 // 0-confirmed or conflicted: 3007 if (m_chainman.m_options.signals) { 3008 m_chainman.m_options.signals->BlockDisconnected(pblock, pindexDelete); 3009 } 3010 return true; 3011 } 3012 3013 struct PerBlockConnectTrace { 3014 CBlockIndex* pindex = nullptr; 3015 std::shared_ptr<const CBlock> pblock; 3016 PerBlockConnectTrace() = default; 3017 }; 3018 /** 3019 * Used to track blocks whose transactions were applied to the UTXO state as a 3020 * part of a single ActivateBestChainStep call. 3021 * 3022 * This class is single-use, once you call GetBlocksConnected() you have to throw 3023 * it away and make a new one. 3024 */ 3025 class ConnectTrace { 3026 private: 3027 std::vector<PerBlockConnectTrace> blocksConnected; 3028 3029 public: 3030 explicit ConnectTrace() : blocksConnected(1) {} 3031 3032 void BlockConnected(CBlockIndex* pindex, std::shared_ptr<const CBlock> pblock) { 3033 assert(!blocksConnected.back().pindex); 3034 assert(pindex); 3035 assert(pblock); 3036 blocksConnected.back().pindex = pindex; 3037 blocksConnected.back().pblock = std::move(pblock); 3038 blocksConnected.emplace_back(); 3039 } 3040 3041 std::vector<PerBlockConnectTrace>& GetBlocksConnected() { 3042 // We always keep one extra block at the end of our list because 3043 // blocks are added after all the conflicted transactions have 3044 // been filled in. Thus, the last entry should always be an empty 3045 // one waiting for the transactions from the next block. We pop 3046 // the last entry here to make sure the list we return is sane. 3047 assert(!blocksConnected.back().pindex); 3048 blocksConnected.pop_back(); 3049 return blocksConnected; 3050 } 3051 }; 3052 3053 /** 3054 * Connect a new block to m_chain. block_to_connect is either nullptr or a pointer to a CBlock 3055 * corresponding to pindexNew, to bypass loading it again from disk. 3056 * 3057 * The block is added to connectTrace if connection succeeds. 3058 */ 3059 bool Chainstate::ConnectTip( 3060 BlockValidationState& state, 3061 CBlockIndex* pindexNew, 3062 std::shared_ptr<const CBlock> block_to_connect, 3063 ConnectTrace& connectTrace, 3064 DisconnectedBlockTransactions& disconnectpool) 3065 { 3066 AssertLockHeld(cs_main); 3067 if (m_mempool) AssertLockHeld(m_mempool->cs); 3068 3069 assert(pindexNew->pprev == m_chain.Tip()); 3070 // Read block from disk. 3071 const auto time_1{SteadyClock::now()}; 3072 if (!block_to_connect) { 3073 std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>(); 3074 if (!m_blockman.ReadBlock(*pblockNew, *pindexNew)) { 3075 return FatalError(m_chainman.GetNotifications(), state, _("Failed to read block.")); 3076 } 3077 block_to_connect = std::move(pblockNew); 3078 } else { 3079 LogDebug(BCLog::BENCH, " - Using cached block\n"); 3080 } 3081 // Apply the block atomically to the chain state. 3082 const auto time_2{SteadyClock::now()}; 3083 SteadyClock::time_point time_3; 3084 // When adding aggregate statistics in the future, keep in mind that 3085 // num_blocks_total may be zero until the ConnectBlock() call below. 3086 LogDebug(BCLog::BENCH, " - Load block from disk: %.2fms\n", 3087 Ticks<MillisecondsDouble>(time_2 - time_1)); 3088 { 3089 CCoinsViewCache view(&CoinsTip()); 3090 bool rv = ConnectBlock(*block_to_connect, state, pindexNew, view); 3091 if (m_chainman.m_options.signals) { 3092 m_chainman.m_options.signals->BlockChecked(block_to_connect, state); 3093 } 3094 if (!rv) { 3095 if (state.IsInvalid()) 3096 InvalidBlockFound(pindexNew, state); 3097 LogError("%s: ConnectBlock %s failed, %s\n", __func__, pindexNew->GetBlockHash().ToString(), state.ToString()); 3098 return false; 3099 } 3100 time_3 = SteadyClock::now(); 3101 m_chainman.time_connect_total += time_3 - time_2; 3102 assert(m_chainman.num_blocks_total > 0); 3103 LogDebug(BCLog::BENCH, " - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n", 3104 Ticks<MillisecondsDouble>(time_3 - time_2), 3105 Ticks<SecondsDouble>(m_chainman.time_connect_total), 3106 Ticks<MillisecondsDouble>(m_chainman.time_connect_total) / m_chainman.num_blocks_total); 3107 bool flushed = view.Flush(); 3108 assert(flushed); 3109 } 3110 const auto time_4{SteadyClock::now()}; 3111 m_chainman.time_flush += time_4 - time_3; 3112 LogDebug(BCLog::BENCH, " - Flush: %.2fms [%.2fs (%.2fms/blk)]\n", 3113 Ticks<MillisecondsDouble>(time_4 - time_3), 3114 Ticks<SecondsDouble>(m_chainman.time_flush), 3115 Ticks<MillisecondsDouble>(m_chainman.time_flush) / m_chainman.num_blocks_total); 3116 // Write the chain state to disk, if necessary. 3117 if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) { 3118 return false; 3119 } 3120 const auto time_5{SteadyClock::now()}; 3121 m_chainman.time_chainstate += time_5 - time_4; 3122 LogDebug(BCLog::BENCH, " - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n", 3123 Ticks<MillisecondsDouble>(time_5 - time_4), 3124 Ticks<SecondsDouble>(m_chainman.time_chainstate), 3125 Ticks<MillisecondsDouble>(m_chainman.time_chainstate) / m_chainman.num_blocks_total); 3126 // Remove conflicting transactions from the mempool.; 3127 if (m_mempool) { 3128 m_mempool->removeForBlock(block_to_connect->vtx, pindexNew->nHeight); 3129 disconnectpool.removeForBlock(block_to_connect->vtx); 3130 } 3131 // Update m_chain & related variables. 3132 m_chain.SetTip(*pindexNew); 3133 UpdateTip(pindexNew); 3134 3135 const auto time_6{SteadyClock::now()}; 3136 m_chainman.time_post_connect += time_6 - time_5; 3137 m_chainman.time_total += time_6 - time_1; 3138 LogDebug(BCLog::BENCH, " - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n", 3139 Ticks<MillisecondsDouble>(time_6 - time_5), 3140 Ticks<SecondsDouble>(m_chainman.time_post_connect), 3141 Ticks<MillisecondsDouble>(m_chainman.time_post_connect) / m_chainman.num_blocks_total); 3142 LogDebug(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n", 3143 Ticks<MillisecondsDouble>(time_6 - time_1), 3144 Ticks<SecondsDouble>(m_chainman.time_total), 3145 Ticks<MillisecondsDouble>(m_chainman.time_total) / m_chainman.num_blocks_total); 3146 3147 // If we are the background validation chainstate, check to see if we are done 3148 // validating the snapshot (i.e. our tip has reached the snapshot's base block). 3149 if (this != &m_chainman.ActiveChainstate()) { 3150 // This call may set `m_disabled`, which is referenced immediately afterwards in 3151 // ActivateBestChain, so that we stop connecting blocks past the snapshot base. 3152 m_chainman.MaybeCompleteSnapshotValidation(); 3153 } 3154 3155 connectTrace.BlockConnected(pindexNew, std::move(block_to_connect)); 3156 return true; 3157 } 3158 3159 /** 3160 * Return the tip of the chain with the most work in it, that isn't 3161 * known to be invalid (it's however far from certain to be valid). 3162 */ 3163 CBlockIndex* Chainstate::FindMostWorkChain() 3164 { 3165 AssertLockHeld(::cs_main); 3166 do { 3167 CBlockIndex *pindexNew = nullptr; 3168 3169 // Find the best candidate header. 3170 { 3171 std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexCandidates.rbegin(); 3172 if (it == setBlockIndexCandidates.rend()) 3173 return nullptr; 3174 pindexNew = *it; 3175 } 3176 3177 // Check whether all blocks on the path between the currently active chain and the candidate are valid. 3178 // Just going until the active chain is an optimization, as we know all blocks in it are valid already. 3179 CBlockIndex *pindexTest = pindexNew; 3180 bool fInvalidAncestor = false; 3181 while (pindexTest && !m_chain.Contains(pindexTest)) { 3182 assert(pindexTest->HaveNumChainTxs() || pindexTest->nHeight == 0); 3183 3184 // Pruned nodes may have entries in setBlockIndexCandidates for 3185 // which block files have been deleted. Remove those as candidates 3186 // for the most work chain if we come across them; we can't switch 3187 // to a chain unless we have all the non-active-chain parent blocks. 3188 bool fFailedChain = pindexTest->nStatus & BLOCK_FAILED_MASK; 3189 bool fMissingData = !(pindexTest->nStatus & BLOCK_HAVE_DATA); 3190 if (fFailedChain || fMissingData) { 3191 // Candidate chain is not usable (either invalid or missing data) 3192 if (fFailedChain && (m_chainman.m_best_invalid == nullptr || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork)) { 3193 m_chainman.m_best_invalid = pindexNew; 3194 } 3195 CBlockIndex *pindexFailed = pindexNew; 3196 // Remove the entire chain from the set. 3197 while (pindexTest != pindexFailed) { 3198 if (fFailedChain) { 3199 pindexFailed->nStatus |= BLOCK_FAILED_CHILD; 3200 m_blockman.m_dirty_blockindex.insert(pindexFailed); 3201 } else if (fMissingData) { 3202 // If we're missing data, then add back to m_blocks_unlinked, 3203 // so that if the block arrives in the future we can try adding 3204 // to setBlockIndexCandidates again. 3205 m_blockman.m_blocks_unlinked.insert( 3206 std::make_pair(pindexFailed->pprev, pindexFailed)); 3207 } 3208 setBlockIndexCandidates.erase(pindexFailed); 3209 pindexFailed = pindexFailed->pprev; 3210 } 3211 setBlockIndexCandidates.erase(pindexTest); 3212 fInvalidAncestor = true; 3213 break; 3214 } 3215 pindexTest = pindexTest->pprev; 3216 } 3217 if (!fInvalidAncestor) 3218 return pindexNew; 3219 } while(true); 3220 } 3221 3222 /** Delete all entries in setBlockIndexCandidates that are worse than the current tip. */ 3223 void Chainstate::PruneBlockIndexCandidates() { 3224 // Note that we can't delete the current block itself, as we may need to return to it later in case a 3225 // reorganization to a better block fails. 3226 std::set<CBlockIndex*, CBlockIndexWorkComparator>::iterator it = setBlockIndexCandidates.begin(); 3227 while (it != setBlockIndexCandidates.end() && setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) { 3228 setBlockIndexCandidates.erase(it++); 3229 } 3230 // Either the current tip or a successor of it we're working towards is left in setBlockIndexCandidates. 3231 assert(!setBlockIndexCandidates.empty()); 3232 } 3233 3234 /** 3235 * Try to make some progress towards making pindexMostWork the active block. 3236 * pblock is either nullptr or a pointer to a CBlock corresponding to pindexMostWork. 3237 * 3238 * @returns true unless a system error occurred 3239 */ 3240 bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) 3241 { 3242 AssertLockHeld(cs_main); 3243 if (m_mempool) AssertLockHeld(m_mempool->cs); 3244 3245 const CBlockIndex* pindexOldTip = m_chain.Tip(); 3246 const CBlockIndex* pindexFork = m_chain.FindFork(pindexMostWork); 3247 3248 // Disconnect active blocks which are no longer in the best chain. 3249 bool fBlocksDisconnected = false; 3250 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES}; 3251 while (m_chain.Tip() && m_chain.Tip() != pindexFork) { 3252 if (!DisconnectTip(state, &disconnectpool)) { 3253 // This is likely a fatal error, but keep the mempool consistent, 3254 // just in case. Only remove from the mempool in this case. 3255 MaybeUpdateMempoolForReorg(disconnectpool, false); 3256 3257 // If we're unable to disconnect a block during normal operation, 3258 // then that is a failure of our local system -- we should abort 3259 // rather than stay on a less work chain. 3260 FatalError(m_chainman.GetNotifications(), state, _("Failed to disconnect block.")); 3261 return false; 3262 } 3263 fBlocksDisconnected = true; 3264 } 3265 3266 // Build list of new blocks to connect (in descending height order). 3267 std::vector<CBlockIndex*> vpindexToConnect; 3268 bool fContinue = true; 3269 int nHeight = pindexFork ? pindexFork->nHeight : -1; 3270 while (fContinue && nHeight != pindexMostWork->nHeight) { 3271 // Don't iterate the entire list of potential improvements toward the best tip, as we likely only need 3272 // a few blocks along the way. 3273 int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight); 3274 vpindexToConnect.clear(); 3275 vpindexToConnect.reserve(nTargetHeight - nHeight); 3276 CBlockIndex* pindexIter = pindexMostWork->GetAncestor(nTargetHeight); 3277 while (pindexIter && pindexIter->nHeight != nHeight) { 3278 vpindexToConnect.push_back(pindexIter); 3279 pindexIter = pindexIter->pprev; 3280 } 3281 nHeight = nTargetHeight; 3282 3283 // Connect new blocks. 3284 for (CBlockIndex* pindexConnect : vpindexToConnect | std::views::reverse) { 3285 if (!ConnectTip(state, pindexConnect, pindexConnect == pindexMostWork ? pblock : std::shared_ptr<const CBlock>(), connectTrace, disconnectpool)) { 3286 if (state.IsInvalid()) { 3287 // The block violates a consensus rule. 3288 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 3289 InvalidChainFound(vpindexToConnect.front()); 3290 } 3291 state = BlockValidationState(); 3292 fInvalidFound = true; 3293 fContinue = false; 3294 break; 3295 } else { 3296 // A system error occurred (disk space, database error, ...). 3297 // Make the mempool consistent with the current tip, just in case 3298 // any observers try to use it before shutdown. 3299 MaybeUpdateMempoolForReorg(disconnectpool, false); 3300 return false; 3301 } 3302 } else { 3303 PruneBlockIndexCandidates(); 3304 if (!pindexOldTip || m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) { 3305 // We're in a better position than we were. Return temporarily to release the lock. 3306 fContinue = false; 3307 break; 3308 } 3309 } 3310 } 3311 } 3312 3313 if (fBlocksDisconnected) { 3314 // If any blocks were disconnected, disconnectpool may be non empty. Add 3315 // any disconnected transactions back to the mempool. 3316 MaybeUpdateMempoolForReorg(disconnectpool, true); 3317 } 3318 if (m_mempool) m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1); 3319 3320 CheckForkWarningConditions(); 3321 3322 return true; 3323 } 3324 3325 static SynchronizationState GetSynchronizationState(bool init, bool blockfiles_indexed) 3326 { 3327 if (!init) return SynchronizationState::POST_INIT; 3328 if (!blockfiles_indexed) return SynchronizationState::INIT_REINDEX; 3329 return SynchronizationState::INIT_DOWNLOAD; 3330 } 3331 3332 bool ChainstateManager::NotifyHeaderTip() 3333 { 3334 bool fNotify = false; 3335 bool fInitialBlockDownload = false; 3336 CBlockIndex* pindexHeader = nullptr; 3337 { 3338 LOCK(GetMutex()); 3339 pindexHeader = m_best_header; 3340 3341 if (pindexHeader != m_last_notified_header) { 3342 fNotify = true; 3343 fInitialBlockDownload = IsInitialBlockDownload(); 3344 m_last_notified_header = pindexHeader; 3345 } 3346 } 3347 // Send block tip changed notifications without the lock held 3348 if (fNotify) { 3349 GetNotifications().headerTip(GetSynchronizationState(fInitialBlockDownload, m_blockman.m_blockfiles_indexed), pindexHeader->nHeight, pindexHeader->nTime, false); 3350 } 3351 return fNotify; 3352 } 3353 3354 static void LimitValidationInterfaceQueue(ValidationSignals& signals) LOCKS_EXCLUDED(cs_main) { 3355 AssertLockNotHeld(cs_main); 3356 3357 if (signals.CallbacksPending() > 10) { 3358 signals.SyncWithValidationInterfaceQueue(); 3359 } 3360 } 3361 3362 bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<const CBlock> pblock) 3363 { 3364 AssertLockNotHeld(m_chainstate_mutex); 3365 3366 // Note that while we're often called here from ProcessNewBlock, this is 3367 // far from a guarantee. Things in the P2P/RPC will often end up calling 3368 // us in the middle of ProcessNewBlock - do not assume pblock is set 3369 // sanely for performance or correctness! 3370 AssertLockNotHeld(::cs_main); 3371 3372 // ABC maintains a fair degree of expensive-to-calculate internal state 3373 // because this function periodically releases cs_main so that it does not lock up other threads for too long 3374 // during large connects - and to allow for e.g. the callback queue to drain 3375 // we use m_chainstate_mutex to enforce mutual exclusion so that only one caller may execute this function at a time 3376 LOCK(m_chainstate_mutex); 3377 3378 // Belt-and-suspenders check that we aren't attempting to advance the background 3379 // chainstate past the snapshot base block. 3380 if (WITH_LOCK(::cs_main, return m_disabled)) { 3381 LogError("m_disabled is set - this chainstate should not be in operation. " 3382 "Please report this as a bug. %s", CLIENT_BUGREPORT); 3383 return false; 3384 } 3385 3386 CBlockIndex *pindexMostWork = nullptr; 3387 CBlockIndex *pindexNewTip = nullptr; 3388 bool exited_ibd{false}; 3389 do { 3390 // Block until the validation queue drains. This should largely 3391 // never happen in normal operation, however may happen during 3392 // reindex, causing memory blowup if we run too far ahead. 3393 // Note that if a validationinterface callback ends up calling 3394 // ActivateBestChain this may lead to a deadlock! We should 3395 // probably have a DEBUG_LOCKORDER test for this in the future. 3396 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals); 3397 3398 { 3399 LOCK(cs_main); 3400 { 3401 // Lock transaction pool for at least as long as it takes for connectTrace to be consumed 3402 LOCK(MempoolMutex()); 3403 const bool was_in_ibd = m_chainman.IsInitialBlockDownload(); 3404 CBlockIndex* starting_tip = m_chain.Tip(); 3405 bool blocks_connected = false; 3406 do { 3407 // We absolutely may not unlock cs_main until we've made forward progress 3408 // (with the exception of shutdown due to hardware issues, low disk space, etc). 3409 ConnectTrace connectTrace; // Destructed before cs_main is unlocked 3410 3411 if (pindexMostWork == nullptr) { 3412 pindexMostWork = FindMostWorkChain(); 3413 } 3414 3415 // Whether we have anything to do at all. 3416 if (pindexMostWork == nullptr || pindexMostWork == m_chain.Tip()) { 3417 break; 3418 } 3419 3420 bool fInvalidFound = false; 3421 std::shared_ptr<const CBlock> nullBlockPtr; 3422 // BlockConnected signals must be sent for the original role; 3423 // in case snapshot validation is completed during ActivateBestChainStep, the 3424 // result of GetRole() changes from BACKGROUND to NORMAL. 3425 const ChainstateRole chainstate_role{this->GetRole()}; 3426 if (!ActivateBestChainStep(state, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace)) { 3427 // A system error occurred 3428 return false; 3429 } 3430 blocks_connected = true; 3431 3432 if (fInvalidFound) { 3433 // Wipe cache, we may need another branch now. 3434 pindexMostWork = nullptr; 3435 } 3436 pindexNewTip = m_chain.Tip(); 3437 3438 for (const PerBlockConnectTrace& trace : connectTrace.GetBlocksConnected()) { 3439 assert(trace.pblock && trace.pindex); 3440 if (m_chainman.m_options.signals) { 3441 m_chainman.m_options.signals->BlockConnected(chainstate_role, trace.pblock, trace.pindex); 3442 } 3443 } 3444 3445 // This will have been toggled in 3446 // ActivateBestChainStep -> ConnectTip -> MaybeCompleteSnapshotValidation, 3447 // if at all, so we should catch it here. 3448 // 3449 // Break this do-while to ensure we don't advance past the base snapshot. 3450 if (m_disabled) { 3451 break; 3452 } 3453 } while (!m_chain.Tip() || (starting_tip && CBlockIndexWorkComparator()(m_chain.Tip(), starting_tip))); 3454 if (!blocks_connected) return true; 3455 3456 const CBlockIndex* pindexFork = m_chain.FindFork(starting_tip); 3457 bool still_in_ibd = m_chainman.IsInitialBlockDownload(); 3458 3459 if (was_in_ibd && !still_in_ibd) { 3460 // Active chainstate has exited IBD. 3461 exited_ibd = true; 3462 } 3463 3464 // Notify external listeners about the new tip. 3465 // Enqueue while holding cs_main to ensure that UpdatedBlockTip is called in the order in which blocks are connected 3466 if (this == &m_chainman.ActiveChainstate() && pindexFork != pindexNewTip) { 3467 // Notify ValidationInterface subscribers 3468 if (m_chainman.m_options.signals) { 3469 m_chainman.m_options.signals->UpdatedBlockTip(pindexNewTip, pindexFork, still_in_ibd); 3470 } 3471 3472 if (kernel::IsInterrupted(m_chainman.GetNotifications().blockTip( 3473 /*state=*/GetSynchronizationState(still_in_ibd, m_chainman.m_blockman.m_blockfiles_indexed), 3474 /*index=*/*pindexNewTip, 3475 /*verification_progress=*/m_chainman.GuessVerificationProgress(pindexNewTip)))) 3476 { 3477 // Just breaking and returning success for now. This could 3478 // be changed to bubble up the kernel::Interrupted value to 3479 // the caller so the caller could distinguish between 3480 // completed and interrupted operations. 3481 break; 3482 } 3483 } 3484 } // release MempoolMutex 3485 // Notify external listeners about the new tip, even if pindexFork == pindexNewTip. 3486 if (m_chainman.m_options.signals && this == &m_chainman.ActiveChainstate()) { 3487 m_chainman.m_options.signals->ActiveTipChange(*Assert(pindexNewTip), m_chainman.IsInitialBlockDownload()); 3488 } 3489 } // release cs_main 3490 // When we reach this point, we switched to a new tip (stored in pindexNewTip). 3491 3492 if (exited_ibd) { 3493 // If a background chainstate is in use, we may need to rebalance our 3494 // allocation of caches once a chainstate exits initial block download. 3495 LOCK(::cs_main); 3496 m_chainman.MaybeRebalanceCaches(); 3497 } 3498 3499 if (WITH_LOCK(::cs_main, return m_disabled)) { 3500 // Background chainstate has reached the snapshot base block, so exit. 3501 3502 // Restart indexes to resume indexing for all blocks unique to the snapshot 3503 // chain. This resumes indexing "in order" from where the indexing on the 3504 // background validation chain left off. 3505 // 3506 // This cannot be done while holding cs_main (within 3507 // MaybeCompleteSnapshotValidation) or a cs_main deadlock will occur. 3508 if (m_chainman.snapshot_download_completed) { 3509 m_chainman.snapshot_download_completed(); 3510 } 3511 break; 3512 } 3513 3514 // We check interrupt only after giving ActivateBestChainStep a chance to run once so that we 3515 // never interrupt before connecting the genesis block during LoadChainTip(). Previously this 3516 // caused an assert() failure during interrupt in such cases as the UTXO DB flushing checks 3517 // that the best block hash is non-null. 3518 if (m_chainman.m_interrupt) break; 3519 } while (pindexNewTip != pindexMostWork); 3520 3521 m_chainman.CheckBlockIndex(); 3522 3523 // Write changes periodically to disk, after relay. 3524 if (!FlushStateToDisk(state, FlushStateMode::PERIODIC)) { 3525 return false; 3526 } 3527 3528 return true; 3529 } 3530 3531 bool Chainstate::PreciousBlock(BlockValidationState& state, CBlockIndex* pindex) 3532 { 3533 AssertLockNotHeld(m_chainstate_mutex); 3534 AssertLockNotHeld(::cs_main); 3535 { 3536 LOCK(cs_main); 3537 if (pindex->nChainWork < m_chain.Tip()->nChainWork) { 3538 // Nothing to do, this block is not at the tip. 3539 return true; 3540 } 3541 if (m_chain.Tip()->nChainWork > m_chainman.nLastPreciousChainwork) { 3542 // The chain has been extended since the last call, reset the counter. 3543 m_chainman.nBlockReverseSequenceId = -1; 3544 } 3545 m_chainman.nLastPreciousChainwork = m_chain.Tip()->nChainWork; 3546 setBlockIndexCandidates.erase(pindex); 3547 pindex->nSequenceId = m_chainman.nBlockReverseSequenceId; 3548 if (m_chainman.nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) { 3549 // We can't keep reducing the counter if somebody really wants to 3550 // call preciousblock 2**31-1 times on the same set of tips... 3551 m_chainman.nBlockReverseSequenceId--; 3552 } 3553 if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && pindex->HaveNumChainTxs()) { 3554 setBlockIndexCandidates.insert(pindex); 3555 PruneBlockIndexCandidates(); 3556 } 3557 } 3558 3559 return ActivateBestChain(state, std::shared_ptr<const CBlock>()); 3560 } 3561 3562 bool Chainstate::InvalidateBlock(BlockValidationState& state, CBlockIndex* pindex) 3563 { 3564 AssertLockNotHeld(m_chainstate_mutex); 3565 AssertLockNotHeld(::cs_main); 3566 3567 // Genesis block can't be invalidated 3568 assert(pindex); 3569 if (pindex->nHeight == 0) return false; 3570 3571 CBlockIndex* to_mark_failed = pindex; 3572 bool pindex_was_in_chain = false; 3573 int disconnected = 0; 3574 3575 // We do not allow ActivateBestChain() to run while InvalidateBlock() is 3576 // running, as that could cause the tip to change while we disconnect 3577 // blocks. 3578 LOCK(m_chainstate_mutex); 3579 3580 // We'll be acquiring and releasing cs_main below, to allow the validation 3581 // callbacks to run. However, we should keep the block index in a 3582 // consistent state as we disconnect blocks -- in particular we need to 3583 // add equal-work blocks to setBlockIndexCandidates as we disconnect. 3584 // To avoid walking the block index repeatedly in search of candidates, 3585 // build a map once so that we can look up candidate blocks by chain 3586 // work as we go. 3587 std::multimap<const arith_uint256, CBlockIndex*> highpow_outofchain_headers; 3588 3589 { 3590 LOCK(cs_main); 3591 for (auto& entry : m_blockman.m_block_index) { 3592 CBlockIndex* candidate = &entry.second; 3593 // We don't need to put anything in our active chain into the 3594 // multimap, because those candidates will be found and considered 3595 // as we disconnect. 3596 // Instead, consider only non-active-chain blocks that score 3597 // at least as good with CBlockIndexWorkComparator as the new tip. 3598 if (!m_chain.Contains(candidate) && 3599 !CBlockIndexWorkComparator()(candidate, pindex->pprev) && 3600 !(candidate->nStatus & BLOCK_FAILED_MASK)) { 3601 highpow_outofchain_headers.insert({candidate->nChainWork, candidate}); 3602 } 3603 } 3604 } 3605 3606 // Disconnect (descendants of) pindex, and mark them invalid. 3607 while (true) { 3608 if (m_chainman.m_interrupt) break; 3609 3610 // Make sure the queue of validation callbacks doesn't grow unboundedly. 3611 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals); 3612 3613 LOCK(cs_main); 3614 // Lock for as long as disconnectpool is in scope to make sure MaybeUpdateMempoolForReorg is 3615 // called after DisconnectTip without unlocking in between 3616 LOCK(MempoolMutex()); 3617 if (!m_chain.Contains(pindex)) break; 3618 pindex_was_in_chain = true; 3619 CBlockIndex *invalid_walk_tip = m_chain.Tip(); 3620 3621 // ActivateBestChain considers blocks already in m_chain 3622 // unconditionally valid already, so force disconnect away from it. 3623 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES}; 3624 bool ret = DisconnectTip(state, &disconnectpool); 3625 // DisconnectTip will add transactions to disconnectpool. 3626 // Adjust the mempool to be consistent with the new tip, adding 3627 // transactions back to the mempool if disconnecting was successful, 3628 // and we're not doing a very deep invalidation (in which case 3629 // keeping the mempool up to date is probably futile anyway). 3630 MaybeUpdateMempoolForReorg(disconnectpool, /* fAddToMempool = */ (++disconnected <= 10) && ret); 3631 if (!ret) return false; 3632 assert(invalid_walk_tip->pprev == m_chain.Tip()); 3633 3634 // We immediately mark the disconnected blocks as invalid. 3635 // This prevents a case where pruned nodes may fail to invalidateblock 3636 // and be left unable to start as they have no tip candidates (as there 3637 // are no blocks that meet the "have data and are not invalid per 3638 // nStatus" criteria for inclusion in setBlockIndexCandidates). 3639 invalid_walk_tip->nStatus |= BLOCK_FAILED_VALID; 3640 m_blockman.m_dirty_blockindex.insert(invalid_walk_tip); 3641 setBlockIndexCandidates.erase(invalid_walk_tip); 3642 setBlockIndexCandidates.insert(invalid_walk_tip->pprev); 3643 if (invalid_walk_tip == to_mark_failed->pprev && (to_mark_failed->nStatus & BLOCK_FAILED_VALID)) { 3644 // We only want to mark the last disconnected block as BLOCK_FAILED_VALID; its children 3645 // need to be BLOCK_FAILED_CHILD instead. 3646 to_mark_failed->nStatus = (to_mark_failed->nStatus ^ BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD; 3647 m_blockman.m_dirty_blockindex.insert(to_mark_failed); 3648 } 3649 3650 // Mark out-of-chain descendants of the invalidated block as invalid 3651 // (possibly replacing a pre-existing BLOCK_FAILED_VALID with BLOCK_FAILED_CHILD) 3652 // Add any equal or more work headers that are not invalidated to setBlockIndexCandidates 3653 // Recalculate m_best_header if it became invalid. 3654 auto candidate_it = highpow_outofchain_headers.lower_bound(invalid_walk_tip->pprev->nChainWork); 3655 3656 const bool best_header_needs_update{m_chainman.m_best_header->GetAncestor(invalid_walk_tip->nHeight) == invalid_walk_tip}; 3657 if (best_header_needs_update) { 3658 // pprev is definitely still valid at this point, but there may be better ones 3659 m_chainman.m_best_header = invalid_walk_tip->pprev; 3660 } 3661 3662 while (candidate_it != highpow_outofchain_headers.end()) { 3663 CBlockIndex* candidate{candidate_it->second}; 3664 if (candidate->GetAncestor(invalid_walk_tip->nHeight) == invalid_walk_tip) { 3665 // Children of failed blocks should be marked as BLOCK_FAILED_CHILD instead. 3666 candidate->nStatus &= ~BLOCK_FAILED_VALID; 3667 candidate->nStatus |= BLOCK_FAILED_CHILD; 3668 m_blockman.m_dirty_blockindex.insert(candidate); 3669 // If invalidated, the block is irrelevant for setBlockIndexCandidates 3670 // and for m_best_header and can be removed from the cache. 3671 candidate_it = highpow_outofchain_headers.erase(candidate_it); 3672 continue; 3673 } 3674 if (!CBlockIndexWorkComparator()(candidate, invalid_walk_tip->pprev) && 3675 candidate->IsValid(BLOCK_VALID_TRANSACTIONS) && 3676 candidate->HaveNumChainTxs()) { 3677 setBlockIndexCandidates.insert(candidate); 3678 // Do not remove candidate from the highpow_outofchain_headers cache, because it might be a descendant of the block being invalidated 3679 // which needs to be marked failed later. 3680 } 3681 if (best_header_needs_update && 3682 m_chainman.m_best_header->nChainWork < candidate->nChainWork) { 3683 m_chainman.m_best_header = candidate; 3684 } 3685 ++candidate_it; 3686 } 3687 3688 // Track the last disconnected block, so we can correct its BLOCK_FAILED_CHILD status in future 3689 // iterations, or, if it's the last one, call InvalidChainFound on it. 3690 to_mark_failed = invalid_walk_tip; 3691 } 3692 3693 m_chainman.CheckBlockIndex(); 3694 3695 { 3696 LOCK(cs_main); 3697 if (m_chain.Contains(to_mark_failed)) { 3698 // If the to-be-marked invalid block is in the active chain, something is interfering and we can't proceed. 3699 return false; 3700 } 3701 3702 // Mark pindex as invalid if it never was in the main chain 3703 if (!pindex_was_in_chain && !(pindex->nStatus & BLOCK_FAILED_MASK)) { 3704 pindex->nStatus |= BLOCK_FAILED_VALID; 3705 m_blockman.m_dirty_blockindex.insert(pindex); 3706 setBlockIndexCandidates.erase(pindex); 3707 } 3708 3709 // If any new blocks somehow arrived while we were disconnecting 3710 // (above), then the pre-calculation of what should go into 3711 // setBlockIndexCandidates may have missed entries. This would 3712 // technically be an inconsistency in the block index, but if we clean 3713 // it up here, this should be an essentially unobservable error. 3714 // Loop back over all block index entries and add any missing entries 3715 // to setBlockIndexCandidates. 3716 for (auto& [_, block_index] : m_blockman.m_block_index) { 3717 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && !setBlockIndexCandidates.value_comp()(&block_index, m_chain.Tip())) { 3718 setBlockIndexCandidates.insert(&block_index); 3719 } 3720 } 3721 3722 InvalidChainFound(to_mark_failed); 3723 } 3724 3725 // Only notify about a new block tip if the active chain was modified. 3726 if (pindex_was_in_chain) { 3727 // Ignoring return value for now, this could be changed to bubble up 3728 // kernel::Interrupted value to the caller so the caller could 3729 // distinguish between completed and interrupted operations. It might 3730 // also make sense for the blockTip notification to have an enum 3731 // parameter indicating the source of the tip change so hooks can 3732 // distinguish user-initiated invalidateblock changes from other 3733 // changes. 3734 (void)m_chainman.GetNotifications().blockTip( 3735 /*state=*/GetSynchronizationState(m_chainman.IsInitialBlockDownload(), m_chainman.m_blockman.m_blockfiles_indexed), 3736 /*index=*/*to_mark_failed->pprev, 3737 /*verification_progress=*/WITH_LOCK(m_chainman.GetMutex(), return m_chainman.GuessVerificationProgress(to_mark_failed->pprev))); 3738 3739 // Fire ActiveTipChange now for the current chain tip to make sure clients are notified. 3740 // ActivateBestChain may call this as well, but not necessarily. 3741 if (m_chainman.m_options.signals) { 3742 m_chainman.m_options.signals->ActiveTipChange(*Assert(m_chain.Tip()), m_chainman.IsInitialBlockDownload()); 3743 } 3744 } 3745 return true; 3746 } 3747 3748 void Chainstate::SetBlockFailureFlags(CBlockIndex* invalid_block) 3749 { 3750 AssertLockHeld(cs_main); 3751 3752 for (auto& [_, block_index] : m_blockman.m_block_index) { 3753 if (invalid_block != &block_index && block_index.GetAncestor(invalid_block->nHeight) == invalid_block) { 3754 block_index.nStatus = (block_index.nStatus & ~BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD; 3755 m_blockman.m_dirty_blockindex.insert(&block_index); 3756 } 3757 } 3758 } 3759 3760 void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex) { 3761 AssertLockHeld(cs_main); 3762 3763 int nHeight = pindex->nHeight; 3764 3765 // Remove the invalidity flag from this block and all its descendants and ancestors. 3766 for (auto& [_, block_index] : m_blockman.m_block_index) { 3767 if ((block_index.nStatus & BLOCK_FAILED_MASK) && (block_index.GetAncestor(nHeight) == pindex || pindex->GetAncestor(block_index.nHeight) == &block_index)) { 3768 block_index.nStatus &= ~BLOCK_FAILED_MASK; 3769 m_blockman.m_dirty_blockindex.insert(&block_index); 3770 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &block_index)) { 3771 setBlockIndexCandidates.insert(&block_index); 3772 } 3773 if (&block_index == m_chainman.m_best_invalid) { 3774 // Reset invalid block marker if it was pointing to one of those. 3775 m_chainman.m_best_invalid = nullptr; 3776 } 3777 } 3778 } 3779 } 3780 3781 void Chainstate::TryAddBlockIndexCandidate(CBlockIndex* pindex) 3782 { 3783 AssertLockHeld(cs_main); 3784 // The block only is a candidate for the most-work-chain if it has the same 3785 // or more work than our current tip. 3786 if (m_chain.Tip() != nullptr && setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) { 3787 return; 3788 } 3789 3790 bool is_active_chainstate = this == &m_chainman.ActiveChainstate(); 3791 if (is_active_chainstate) { 3792 // The active chainstate should always add entries that have more 3793 // work than the tip. 3794 setBlockIndexCandidates.insert(pindex); 3795 } else if (!m_disabled) { 3796 // For the background chainstate, we only consider connecting blocks 3797 // towards the snapshot base (which can't be nullptr or else we'll 3798 // never make progress). 3799 const CBlockIndex* snapshot_base{Assert(m_chainman.GetSnapshotBaseBlock())}; 3800 if (snapshot_base->GetAncestor(pindex->nHeight) == pindex) { 3801 setBlockIndexCandidates.insert(pindex); 3802 } 3803 } 3804 } 3805 3806 /** Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS). */ 3807 void ChainstateManager::ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos) 3808 { 3809 AssertLockHeld(cs_main); 3810 pindexNew->nTx = block.vtx.size(); 3811 // Typically m_chain_tx_count will be 0 at this point, but it can be nonzero if this 3812 // is a pruned block which is being downloaded again, or if this is an 3813 // assumeutxo snapshot block which has a hardcoded m_chain_tx_count value from the 3814 // snapshot metadata. If the pindex is not the snapshot block and the 3815 // m_chain_tx_count value is not zero, assert that value is actually correct. 3816 auto prev_tx_sum = [](CBlockIndex& block) { return block.nTx + (block.pprev ? block.pprev->m_chain_tx_count : 0); }; 3817 if (!Assume(pindexNew->m_chain_tx_count == 0 || pindexNew->m_chain_tx_count == prev_tx_sum(*pindexNew) || 3818 pindexNew == GetSnapshotBaseBlock())) { 3819 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", 3820 pindexNew->nHeight, pindexNew->m_chain_tx_count, prev_tx_sum(*pindexNew), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT); 3821 pindexNew->m_chain_tx_count = 0; 3822 } 3823 pindexNew->nFile = pos.nFile; 3824 pindexNew->nDataPos = pos.nPos; 3825 pindexNew->nUndoPos = 0; 3826 pindexNew->nStatus |= BLOCK_HAVE_DATA; 3827 if (DeploymentActiveAt(*pindexNew, *this, Consensus::DEPLOYMENT_SEGWIT)) { 3828 pindexNew->nStatus |= BLOCK_OPT_WITNESS; 3829 } 3830 pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS); 3831 m_blockman.m_dirty_blockindex.insert(pindexNew); 3832 3833 if (pindexNew->pprev == nullptr || pindexNew->pprev->HaveNumChainTxs()) { 3834 // If pindexNew is the genesis block or all parents are BLOCK_VALID_TRANSACTIONS. 3835 std::deque<CBlockIndex*> queue; 3836 queue.push_back(pindexNew); 3837 3838 // Recursively process any descendant blocks that now may be eligible to be connected. 3839 while (!queue.empty()) { 3840 CBlockIndex *pindex = queue.front(); 3841 queue.pop_front(); 3842 // Before setting m_chain_tx_count, assert that it is 0 or already set to 3843 // the correct value. This assert will fail after receiving the 3844 // assumeutxo snapshot block if assumeutxo snapshot metadata has an 3845 // incorrect hardcoded AssumeutxoData::m_chain_tx_count value. 3846 if (!Assume(pindex->m_chain_tx_count == 0 || pindex->m_chain_tx_count == prev_tx_sum(*pindex))) { 3847 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", 3848 pindex->nHeight, pindex->m_chain_tx_count, prev_tx_sum(*pindex), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT); 3849 } 3850 pindex->m_chain_tx_count = prev_tx_sum(*pindex); 3851 pindex->nSequenceId = nBlockSequenceId++; 3852 for (Chainstate *c : GetAll()) { 3853 c->TryAddBlockIndexCandidate(pindex); 3854 } 3855 std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> range = m_blockman.m_blocks_unlinked.equal_range(pindex); 3856 while (range.first != range.second) { 3857 std::multimap<CBlockIndex*, CBlockIndex*>::iterator it = range.first; 3858 queue.push_back(it->second); 3859 range.first++; 3860 m_blockman.m_blocks_unlinked.erase(it); 3861 } 3862 } 3863 } else { 3864 if (pindexNew->pprev && pindexNew->pprev->IsValid(BLOCK_VALID_TREE)) { 3865 m_blockman.m_blocks_unlinked.insert(std::make_pair(pindexNew->pprev, pindexNew)); 3866 } 3867 } 3868 } 3869 3870 static bool CheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true) 3871 { 3872 // Check proof of work matches claimed amount 3873 if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, consensusParams)) 3874 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "high-hash", "proof of work failed"); 3875 3876 return true; 3877 } 3878 3879 static bool CheckMerkleRoot(const CBlock& block, BlockValidationState& state) 3880 { 3881 if (block.m_checked_merkle_root) return true; 3882 3883 bool mutated; 3884 uint256 merkle_root = BlockMerkleRoot(block, &mutated); 3885 if (block.hashMerkleRoot != merkle_root) { 3886 return state.Invalid( 3887 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3888 /*reject_reason=*/"bad-txnmrklroot", 3889 /*debug_message=*/"hashMerkleRoot mismatch"); 3890 } 3891 3892 // Check for merkle tree malleability (CVE-2012-2459): repeating sequences 3893 // of transactions in a block without affecting the merkle root of a block, 3894 // while still invalidating it. 3895 if (mutated) { 3896 return state.Invalid( 3897 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3898 /*reject_reason=*/"bad-txns-duplicate", 3899 /*debug_message=*/"duplicate transaction"); 3900 } 3901 3902 block.m_checked_merkle_root = true; 3903 return true; 3904 } 3905 3906 /** CheckWitnessMalleation performs checks for block malleation with regard to 3907 * its witnesses. 3908 * 3909 * Note: If the witness commitment is expected (i.e. `expect_witness_commitment 3910 * = true`), then the block is required to have at least one transaction and the 3911 * first transaction needs to have at least one input. */ 3912 static bool CheckWitnessMalleation(const CBlock& block, bool expect_witness_commitment, BlockValidationState& state) 3913 { 3914 if (expect_witness_commitment) { 3915 if (block.m_checked_witness_commitment) return true; 3916 3917 int commitpos = GetWitnessCommitmentIndex(block); 3918 if (commitpos != NO_WITNESS_COMMITMENT) { 3919 assert(!block.vtx.empty() && !block.vtx[0]->vin.empty()); 3920 const auto& witness_stack{block.vtx[0]->vin[0].scriptWitness.stack}; 3921 3922 if (witness_stack.size() != 1 || witness_stack[0].size() != 32) { 3923 return state.Invalid( 3924 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3925 /*reject_reason=*/"bad-witness-nonce-size", 3926 /*debug_message=*/strprintf("%s : invalid witness reserved value size", __func__)); 3927 } 3928 3929 // The malleation check is ignored; as the transaction tree itself 3930 // already does not permit it, it is impossible to trigger in the 3931 // witness tree. 3932 uint256 hash_witness = BlockWitnessMerkleRoot(block, /*mutated=*/nullptr); 3933 3934 CHash256().Write(hash_witness).Write(witness_stack[0]).Finalize(hash_witness); 3935 if (memcmp(hash_witness.begin(), &block.vtx[0]->vout[commitpos].scriptPubKey[6], 32)) { 3936 return state.Invalid( 3937 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3938 /*reject_reason=*/"bad-witness-merkle-match", 3939 /*debug_message=*/strprintf("%s : witness merkle commitment mismatch", __func__)); 3940 } 3941 3942 block.m_checked_witness_commitment = true; 3943 return true; 3944 } 3945 } 3946 3947 // No witness data is allowed in blocks that don't commit to witness data, as this would otherwise leave room for spam 3948 for (const auto& tx : block.vtx) { 3949 if (tx->HasWitness()) { 3950 return state.Invalid( 3951 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3952 /*reject_reason=*/"unexpected-witness", 3953 /*debug_message=*/strprintf("%s : unexpected witness data found", __func__)); 3954 } 3955 } 3956 3957 return true; 3958 } 3959 3960 bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW, bool fCheckMerkleRoot) 3961 { 3962 // These are checks that are independent of context. 3963 3964 if (block.fChecked) 3965 return true; 3966 3967 // Check that the header is valid (particularly PoW). This is mostly 3968 // redundant with the call in AcceptBlockHeader. 3969 if (!CheckBlockHeader(block, state, consensusParams, fCheckPOW)) 3970 return false; 3971 3972 // Signet only: check block solution 3973 if (consensusParams.signet_blocks && fCheckPOW && !CheckSignetBlockSolution(block, consensusParams)) { 3974 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-signet-blksig", "signet block signature validation failure"); 3975 } 3976 3977 // Check the merkle root. 3978 if (fCheckMerkleRoot && !CheckMerkleRoot(block, state)) { 3979 return false; 3980 } 3981 3982 // All potential-corruption validation must be done before we do any 3983 // transaction validation, as otherwise we may mark the header as invalid 3984 // because we receive the wrong transactions for it. 3985 // Note that witness malleability is checked in ContextualCheckBlock, so no 3986 // checks that use witness data may be performed here. 3987 3988 // Size limits 3989 if (block.vtx.empty() || block.vtx.size() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT || ::GetSerializeSize(TX_NO_WITNESS(block)) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT) 3990 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-length", "size limits failed"); 3991 3992 // First transaction must be coinbase, the rest must not be 3993 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) 3994 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-missing", "first tx is not coinbase"); 3995 for (unsigned int i = 1; i < block.vtx.size(); i++) 3996 if (block.vtx[i]->IsCoinBase()) 3997 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-multiple", "more than one coinbase"); 3998 3999 // Check transactions 4000 // Must check for duplicate inputs (see CVE-2018-17144) 4001 for (const auto& tx : block.vtx) { 4002 TxValidationState tx_state; 4003 if (!CheckTransaction(*tx, tx_state)) { 4004 // CheckBlock() does context-free validation checks. The only 4005 // possible failures are consensus failures. 4006 assert(tx_state.GetResult() == TxValidationResult::TX_CONSENSUS); 4007 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, tx_state.GetRejectReason(), 4008 strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), tx_state.GetDebugMessage())); 4009 } 4010 } 4011 // This underestimates the number of sigops, because unlike ConnectBlock it 4012 // does not count witness and p2sh sigops. 4013 unsigned int nSigOps = 0; 4014 for (const auto& tx : block.vtx) 4015 { 4016 nSigOps += GetLegacySigOpCount(*tx); 4017 } 4018 if (nSigOps * WITNESS_SCALE_FACTOR > MAX_BLOCK_SIGOPS_COST) 4019 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "out-of-bounds SigOpCount"); 4020 4021 if (fCheckPOW && fCheckMerkleRoot) 4022 block.fChecked = true; 4023 4024 return true; 4025 } 4026 4027 void ChainstateManager::UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev) const 4028 { 4029 int commitpos = GetWitnessCommitmentIndex(block); 4030 static const std::vector<unsigned char> nonce(32, 0x00); 4031 if (commitpos != NO_WITNESS_COMMITMENT && DeploymentActiveAfter(pindexPrev, *this, Consensus::DEPLOYMENT_SEGWIT) && !block.vtx[0]->HasWitness()) { 4032 CMutableTransaction tx(*block.vtx[0]); 4033 tx.vin[0].scriptWitness.stack.resize(1); 4034 tx.vin[0].scriptWitness.stack[0] = nonce; 4035 block.vtx[0] = MakeTransactionRef(std::move(tx)); 4036 } 4037 } 4038 4039 std::vector<unsigned char> ChainstateManager::GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev) const 4040 { 4041 std::vector<unsigned char> commitment; 4042 int commitpos = GetWitnessCommitmentIndex(block); 4043 std::vector<unsigned char> ret(32, 0x00); 4044 if (commitpos == NO_WITNESS_COMMITMENT) { 4045 uint256 witnessroot = BlockWitnessMerkleRoot(block, nullptr); 4046 CHash256().Write(witnessroot).Write(ret).Finalize(witnessroot); 4047 CTxOut out; 4048 out.nValue = 0; 4049 out.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT); 4050 out.scriptPubKey[0] = OP_RETURN; 4051 out.scriptPubKey[1] = 0x24; 4052 out.scriptPubKey[2] = 0xaa; 4053 out.scriptPubKey[3] = 0x21; 4054 out.scriptPubKey[4] = 0xa9; 4055 out.scriptPubKey[5] = 0xed; 4056 memcpy(&out.scriptPubKey[6], witnessroot.begin(), 32); 4057 commitment = std::vector<unsigned char>(out.scriptPubKey.begin(), out.scriptPubKey.end()); 4058 CMutableTransaction tx(*block.vtx[0]); 4059 tx.vout.push_back(out); 4060 block.vtx[0] = MakeTransactionRef(std::move(tx)); 4061 } 4062 UpdateUncommittedBlockStructures(block, pindexPrev); 4063 return commitment; 4064 } 4065 4066 bool HasValidProofOfWork(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams) 4067 { 4068 return std::all_of(headers.cbegin(), headers.cend(), 4069 [&](const auto& header) { return CheckProofOfWork(header.GetHash(), header.nBits, consensusParams);}); 4070 } 4071 4072 bool IsBlockMutated(const CBlock& block, bool check_witness_root) 4073 { 4074 BlockValidationState state; 4075 if (!CheckMerkleRoot(block, state)) { 4076 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString()); 4077 return true; 4078 } 4079 4080 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) { 4081 // Consider the block mutated if any transaction is 64 bytes in size (see 3.1 4082 // in "Weaknesses in Bitcoin’s Merkle Root Construction": 4083 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20190225/a27d8837/attachment-0001.pdf). 4084 // 4085 // Note: This is not a consensus change as this only applies to blocks that 4086 // don't have a coinbase transaction and would therefore already be invalid. 4087 return std::any_of(block.vtx.begin(), block.vtx.end(), 4088 [](auto& tx) { return GetSerializeSize(TX_NO_WITNESS(tx)) == 64; }); 4089 } else { 4090 // Theoretically it is still possible for a block with a 64 byte 4091 // coinbase transaction to be mutated but we neglect that possibility 4092 // here as it requires at least 224 bits of work. 4093 } 4094 4095 if (!CheckWitnessMalleation(block, check_witness_root, state)) { 4096 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString()); 4097 return true; 4098 } 4099 4100 return false; 4101 } 4102 4103 arith_uint256 CalculateClaimedHeadersWork(std::span<const CBlockHeader> headers) 4104 { 4105 arith_uint256 total_work{0}; 4106 for (const CBlockHeader& header : headers) { 4107 CBlockIndex dummy(header); 4108 total_work += GetBlockProof(dummy); 4109 } 4110 return total_work; 4111 } 4112 4113 /** Context-dependent validity checks. 4114 * By "context", we mean only the previous block headers, but not the UTXO 4115 * set; UTXO-related validity checks are done in ConnectBlock(). 4116 * NOTE: This function is not currently invoked by ConnectBlock(), so we 4117 * should consider upgrade issues if we change which consensus rules are 4118 * enforced in this function (eg by adding a new consensus rule). See comment 4119 * in ConnectBlock(). 4120 * Note that -reindex-chainstate skips the validation that happens here! 4121 * 4122 * NOTE: failing to check the header's height against the last checkpoint's opened a DoS vector between 4123 * v0.12 and v0.15 (when no additional protection was in place) whereby an attacker could unboundedly 4124 * grow our in-memory block index. See https://bitcoincore.org/en/2024/07/03/disclose-header-spam. 4125 */ 4126 static bool ContextualCheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, BlockManager& blockman, const ChainstateManager& chainman, const CBlockIndex* pindexPrev) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 4127 { 4128 AssertLockHeld(::cs_main); 4129 assert(pindexPrev != nullptr); 4130 const int nHeight = pindexPrev->nHeight + 1; 4131 4132 // Check proof of work 4133 const Consensus::Params& consensusParams = chainman.GetConsensus(); 4134 if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams)) 4135 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "bad-diffbits", "incorrect proof of work"); 4136 4137 // Check timestamp against prev 4138 if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast()) 4139 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-too-old", "block's timestamp is too early"); 4140 4141 // Testnet4 and regtest only: Check timestamp against prev for difficulty-adjustment 4142 // blocks to prevent timewarp attacks (see https://github.com/bitcoin/bitcoin/pull/15482). 4143 if (consensusParams.enforce_BIP94) { 4144 // Check timestamp for the first block of each difficulty adjustment 4145 // interval, except the genesis block. 4146 if (nHeight % consensusParams.DifficultyAdjustmentInterval() == 0) { 4147 if (block.GetBlockTime() < pindexPrev->GetBlockTime() - MAX_TIMEWARP) { 4148 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-timewarp-attack", "block's timestamp is too early on diff adjustment block"); 4149 } 4150 } 4151 } 4152 4153 // Check timestamp 4154 if (block.Time() > NodeClock::now() + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) { 4155 return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE, "time-too-new", "block timestamp too far in the future"); 4156 } 4157 4158 // Reject blocks with outdated version 4159 if ((block.nVersion < 2 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) || 4160 (block.nVersion < 3 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_DERSIG)) || 4161 (block.nVersion < 4 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CLTV))) { 4162 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, strprintf("bad-version(0x%08x)", block.nVersion), 4163 strprintf("rejected nVersion=0x%08x block", block.nVersion)); 4164 } 4165 4166 return true; 4167 } 4168 4169 /** NOTE: This function is not currently invoked by ConnectBlock(), so we 4170 * should consider upgrade issues if we change which consensus rules are 4171 * enforced in this function (eg by adding a new consensus rule). See comment 4172 * in ConnectBlock(). 4173 * Note that -reindex-chainstate skips the validation that happens here! 4174 */ 4175 static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& state, const ChainstateManager& chainman, const CBlockIndex* pindexPrev) 4176 { 4177 const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1; 4178 4179 // Enforce BIP113 (Median Time Past). 4180 bool enforce_locktime_median_time_past{false}; 4181 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CSV)) { 4182 assert(pindexPrev != nullptr); 4183 enforce_locktime_median_time_past = true; 4184 } 4185 4186 const int64_t nLockTimeCutoff{enforce_locktime_median_time_past ? 4187 pindexPrev->GetMedianTimePast() : 4188 block.GetBlockTime()}; 4189 4190 // Check that all transactions are finalized 4191 for (const auto& tx : block.vtx) { 4192 if (!IsFinalTx(*tx, nHeight, nLockTimeCutoff)) { 4193 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", "non-final transaction"); 4194 } 4195 } 4196 4197 // Enforce rule that the coinbase starts with serialized block height 4198 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) 4199 { 4200 CScript expect = CScript() << nHeight; 4201 if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() || 4202 !std::equal(expect.begin(), expect.end(), block.vtx[0]->vin[0].scriptSig.begin())) { 4203 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-height", "block height mismatch in coinbase"); 4204 } 4205 } 4206 4207 // Validation for witness commitments. 4208 // * We compute the witness hash (which is the hash including witnesses) of all the block's transactions, except the 4209 // coinbase (where 0x0000....0000 is used instead). 4210 // * The coinbase scriptWitness is a stack of a single 32-byte vector, containing a witness reserved value (unconstrained). 4211 // * We build a merkle tree with all those witness hashes as leaves (similar to the hashMerkleRoot in the block header). 4212 // * There must be at least one output whose scriptPubKey is a single 36-byte push, the first 4 bytes of which are 4213 // {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness reserved value). In case there are 4214 // multiple, the last one is used. 4215 if (!CheckWitnessMalleation(block, DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_SEGWIT), state)) { 4216 return false; 4217 } 4218 4219 // After the coinbase witness reserved value and commitment are verified, 4220 // we can check if the block weight passes (before we've checked the 4221 // coinbase witness, it would be possible for the weight to be too 4222 // large by filling up the coinbase witness, which doesn't change 4223 // the block hash, so we couldn't mark the block as permanently 4224 // failed). 4225 if (GetBlockWeight(block) > MAX_BLOCK_WEIGHT) { 4226 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-weight", strprintf("%s : weight limit failed", __func__)); 4227 } 4228 4229 return true; 4230 } 4231 4232 bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationState& state, CBlockIndex** ppindex, bool min_pow_checked) 4233 { 4234 AssertLockHeld(cs_main); 4235 4236 // Check for duplicate 4237 uint256 hash = block.GetHash(); 4238 BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)}; 4239 if (hash != GetConsensus().hashGenesisBlock) { 4240 if (miSelf != m_blockman.m_block_index.end()) { 4241 // Block header is already known. 4242 CBlockIndex* pindex = &(miSelf->second); 4243 if (ppindex) 4244 *ppindex = pindex; 4245 if (pindex->nStatus & BLOCK_FAILED_MASK) { 4246 LogDebug(BCLog::VALIDATION, "%s: block %s is marked invalid\n", __func__, hash.ToString()); 4247 return state.Invalid(BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate-invalid"); 4248 } 4249 return true; 4250 } 4251 4252 if (!CheckBlockHeader(block, state, GetConsensus())) { 4253 LogDebug(BCLog::VALIDATION, "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString()); 4254 return false; 4255 } 4256 4257 // Get prev block index 4258 CBlockIndex* pindexPrev = nullptr; 4259 BlockMap::iterator mi{m_blockman.m_block_index.find(block.hashPrevBlock)}; 4260 if (mi == m_blockman.m_block_index.end()) { 4261 LogDebug(BCLog::VALIDATION, "header %s has prev block not found: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4262 return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV, "prev-blk-not-found"); 4263 } 4264 pindexPrev = &((*mi).second); 4265 if (pindexPrev->nStatus & BLOCK_FAILED_MASK) { 4266 LogDebug(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4267 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk"); 4268 } 4269 if (!ContextualCheckBlockHeader(block, state, m_blockman, *this, pindexPrev)) { 4270 LogDebug(BCLog::VALIDATION, "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString()); 4271 return false; 4272 } 4273 } 4274 if (!min_pow_checked) { 4275 LogDebug(BCLog::VALIDATION, "%s: not adding new block header %s, missing anti-dos proof-of-work validation\n", __func__, hash.ToString()); 4276 return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK, "too-little-chainwork"); 4277 } 4278 CBlockIndex* pindex{m_blockman.AddToBlockIndex(block, m_best_header)}; 4279 4280 if (ppindex) 4281 *ppindex = pindex; 4282 4283 return true; 4284 } 4285 4286 // Exposed wrapper for AcceptBlockHeader 4287 bool ChainstateManager::ProcessNewBlockHeaders(std::span<const CBlockHeader> headers, bool min_pow_checked, BlockValidationState& state, const CBlockIndex** ppindex) 4288 { 4289 AssertLockNotHeld(cs_main); 4290 { 4291 LOCK(cs_main); 4292 for (const CBlockHeader& header : headers) { 4293 CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast 4294 bool accepted{AcceptBlockHeader(header, state, &pindex, min_pow_checked)}; 4295 CheckBlockIndex(); 4296 4297 if (!accepted) { 4298 return false; 4299 } 4300 if (ppindex) { 4301 *ppindex = pindex; 4302 } 4303 } 4304 } 4305 if (NotifyHeaderTip()) { 4306 if (IsInitialBlockDownload() && ppindex && *ppindex) { 4307 const CBlockIndex& last_accepted{**ppindex}; 4308 int64_t blocks_left{(NodeClock::now() - last_accepted.Time()) / GetConsensus().PowTargetSpacing()}; 4309 blocks_left = std::max<int64_t>(0, blocks_left); 4310 const double progress{100.0 * last_accepted.nHeight / (last_accepted.nHeight + blocks_left)}; 4311 LogInfo("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress); 4312 } 4313 } 4314 return true; 4315 } 4316 4317 void ChainstateManager::ReportHeadersPresync(const arith_uint256& work, int64_t height, int64_t timestamp) 4318 { 4319 AssertLockNotHeld(GetMutex()); 4320 { 4321 LOCK(GetMutex()); 4322 // Don't report headers presync progress if we already have a post-minchainwork header chain. 4323 // This means we lose reporting for potentially legitimate, but unlikely, deep reorgs, but 4324 // prevent attackers that spam low-work headers from filling our logs. 4325 if (m_best_header->nChainWork >= UintToArith256(GetConsensus().nMinimumChainWork)) return; 4326 // Rate limit headers presync updates to 4 per second, as these are not subject to DoS 4327 // protection. 4328 auto now = MockableSteadyClock::now(); 4329 if (now < m_last_presync_update + std::chrono::milliseconds{250}) return; 4330 m_last_presync_update = now; 4331 } 4332 bool initial_download = IsInitialBlockDownload(); 4333 GetNotifications().headerTip(GetSynchronizationState(initial_download, m_blockman.m_blockfiles_indexed), height, timestamp, /*presync=*/true); 4334 if (initial_download) { 4335 int64_t blocks_left{(NodeClock::now() - NodeSeconds{std::chrono::seconds{timestamp}}) / GetConsensus().PowTargetSpacing()}; 4336 blocks_left = std::max<int64_t>(0, blocks_left); 4337 const double progress{100.0 * height / (height + blocks_left)}; 4338 LogInfo("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress); 4339 } 4340 } 4341 4342 /** Store block on disk. If dbp is non-nullptr, the file is known to already reside on disk */ 4343 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) 4344 { 4345 const CBlock& block = *pblock; 4346 4347 if (fNewBlock) *fNewBlock = false; 4348 AssertLockHeld(cs_main); 4349 4350 CBlockIndex *pindexDummy = nullptr; 4351 CBlockIndex *&pindex = ppindex ? *ppindex : pindexDummy; 4352 4353 bool accepted_header{AcceptBlockHeader(block, state, &pindex, min_pow_checked)}; 4354 CheckBlockIndex(); 4355 4356 if (!accepted_header) 4357 return false; 4358 4359 // Check all requested blocks that we do not already have for validity and 4360 // save them to disk. Skip processing of unrequested blocks as an anti-DoS 4361 // measure, unless the blocks have more work than the active chain tip, and 4362 // aren't too far ahead of it, so are likely to be attached soon. 4363 bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA; 4364 bool fHasMoreOrSameWork = (ActiveTip() ? pindex->nChainWork >= ActiveTip()->nChainWork : true); 4365 // Blocks that are too out-of-order needlessly limit the effectiveness of 4366 // pruning, because pruning will not delete block files that contain any 4367 // blocks which are too close in height to the tip. Apply this test 4368 // regardless of whether pruning is enabled; it should generally be safe to 4369 // not process unrequested blocks. 4370 bool fTooFarAhead{pindex->nHeight > ActiveHeight() + int(MIN_BLOCKS_TO_KEEP)}; 4371 4372 // TODO: Decouple this function from the block download logic by removing fRequested 4373 // This requires some new chain data structure to efficiently look up if a 4374 // block is in a chain leading to a candidate for best tip, despite not 4375 // being such a candidate itself. 4376 // Note that this would break the getblockfrompeer RPC 4377 4378 // TODO: deal better with return value and error conditions for duplicate 4379 // and unrequested blocks. 4380 if (fAlreadyHave) return true; 4381 if (!fRequested) { // If we didn't ask for it: 4382 if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned 4383 if (!fHasMoreOrSameWork) return true; // Don't process less-work chains 4384 if (fTooFarAhead) return true; // Block height is too high 4385 4386 // Protect against DoS attacks from low-work chains. 4387 // If our tip is behind, a peer could try to send us 4388 // low-work blocks on a fake chain that we would never 4389 // request; don't process these. 4390 if (pindex->nChainWork < MinimumChainWork()) return true; 4391 } 4392 4393 const CChainParams& params{GetParams()}; 4394 4395 if (!CheckBlock(block, state, params.GetConsensus()) || 4396 !ContextualCheckBlock(block, state, *this, pindex->pprev)) { 4397 if (Assume(state.IsInvalid())) { 4398 ActiveChainstate().InvalidBlockFound(pindex, state); 4399 } 4400 LogError("%s: %s\n", __func__, state.ToString()); 4401 return false; 4402 } 4403 4404 // Header is valid/has work, merkle tree and segwit merkle tree are good...RELAY NOW 4405 // (but if it does not build on our best tip, let the SendMessages loop relay it) 4406 if (!IsInitialBlockDownload() && ActiveTip() == pindex->pprev && m_options.signals) { 4407 m_options.signals->NewPoWValidBlock(pindex, pblock); 4408 } 4409 4410 // Write block to history file 4411 if (fNewBlock) *fNewBlock = true; 4412 try { 4413 FlatFilePos blockPos{}; 4414 if (dbp) { 4415 blockPos = *dbp; 4416 m_blockman.UpdateBlockInfo(block, pindex->nHeight, blockPos); 4417 } else { 4418 blockPos = m_blockman.WriteBlock(block, pindex->nHeight); 4419 if (blockPos.IsNull()) { 4420 state.Error(strprintf("%s: Failed to find position to write new block to disk", __func__)); 4421 return false; 4422 } 4423 } 4424 ReceivedBlockTransactions(block, pindex, blockPos); 4425 } catch (const std::runtime_error& e) { 4426 return FatalError(GetNotifications(), state, strprintf(_("System error while saving block to disk: %s"), e.what())); 4427 } 4428 4429 // TODO: FlushStateToDisk() handles flushing of both block and chainstate 4430 // data, so we should move this to ChainstateManager so that we can be more 4431 // intelligent about how we flush. 4432 // For now, since FlushStateMode::NONE is used, all that can happen is that 4433 // the block files may be pruned, so we can just call this on one 4434 // chainstate (particularly if we haven't implemented pruning with 4435 // background validation yet). 4436 ActiveChainstate().FlushStateToDisk(state, FlushStateMode::NONE); 4437 4438 CheckBlockIndex(); 4439 4440 return true; 4441 } 4442 4443 bool ChainstateManager::ProcessNewBlock(const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked, bool* new_block) 4444 { 4445 AssertLockNotHeld(cs_main); 4446 4447 { 4448 CBlockIndex *pindex = nullptr; 4449 if (new_block) *new_block = false; 4450 BlockValidationState state; 4451 4452 // CheckBlock() does not support multi-threaded block validation because CBlock::fChecked can cause data race. 4453 // Therefore, the following critical section must include the CheckBlock() call as well. 4454 LOCK(cs_main); 4455 4456 // Skipping AcceptBlock() for CheckBlock() failures means that we will never mark a block as invalid if 4457 // CheckBlock() fails. This is protective against consensus failure if there are any unknown forms of block 4458 // malleability that cause CheckBlock() to fail; see e.g. CVE-2012-2459 and 4459 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html. Because CheckBlock() is 4460 // not very expensive, the anti-DoS benefits of caching failure (of a definitely-invalid block) are not substantial. 4461 bool ret = CheckBlock(*block, state, GetConsensus()); 4462 if (ret) { 4463 // Store to disk 4464 ret = AcceptBlock(block, state, &pindex, force_processing, nullptr, new_block, min_pow_checked); 4465 } 4466 if (!ret) { 4467 if (m_options.signals) { 4468 m_options.signals->BlockChecked(block, state); 4469 } 4470 LogError("%s: AcceptBlock FAILED (%s)\n", __func__, state.ToString()); 4471 return false; 4472 } 4473 } 4474 4475 NotifyHeaderTip(); 4476 4477 BlockValidationState state; // Only used to report errors, not invalidity - ignore it 4478 if (!ActiveChainstate().ActivateBestChain(state, block)) { 4479 LogError("%s: ActivateBestChain failed (%s)\n", __func__, state.ToString()); 4480 return false; 4481 } 4482 4483 Chainstate* bg_chain{WITH_LOCK(cs_main, return BackgroundSyncInProgress() ? m_ibd_chainstate.get() : nullptr)}; 4484 BlockValidationState bg_state; 4485 if (bg_chain && !bg_chain->ActivateBestChain(bg_state, block)) { 4486 LogError("%s: [background] ActivateBestChain failed (%s)\n", __func__, bg_state.ToString()); 4487 return false; 4488 } 4489 4490 return true; 4491 } 4492 4493 MempoolAcceptResult ChainstateManager::ProcessTransaction(const CTransactionRef& tx, bool test_accept) 4494 { 4495 AssertLockHeld(cs_main); 4496 Chainstate& active_chainstate = ActiveChainstate(); 4497 if (!active_chainstate.GetMempool()) { 4498 TxValidationState state; 4499 state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool"); 4500 return MempoolAcceptResult::Failure(state); 4501 } 4502 auto result = AcceptToMemoryPool(active_chainstate, tx, GetTime(), /*bypass_limits=*/ false, test_accept); 4503 active_chainstate.GetMempool()->check(active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1); 4504 return result; 4505 } 4506 4507 4508 BlockValidationState TestBlockValidity( 4509 Chainstate& chainstate, 4510 const CBlock& block, 4511 const bool check_pow, 4512 const bool check_merkle_root) 4513 { 4514 // Lock must be held throughout this function for two reasons: 4515 // 1. We don't want the tip to change during several of the validation steps 4516 // 2. To prevent a CheckBlock() race condition for fChecked, see ProcessNewBlock() 4517 AssertLockHeld(chainstate.m_chainman.GetMutex()); 4518 4519 BlockValidationState state; 4520 CBlockIndex* tip{Assert(chainstate.m_chain.Tip())}; 4521 4522 if (block.hashPrevBlock != *Assert(tip->phashBlock)) { 4523 state.Invalid({}, "inconclusive-not-best-prevblk"); 4524 return state; 4525 } 4526 4527 // For signets CheckBlock() verifies the challenge iff fCheckPow is set. 4528 if (!CheckBlock(block, state, chainstate.m_chainman.GetConsensus(), /*fCheckPow=*/check_pow, /*fCheckMerkleRoot=*/check_merkle_root)) { 4529 // This should never happen, but belt-and-suspenders don't approve the 4530 // block if it does. 4531 if (state.IsValid()) NONFATAL_UNREACHABLE(); 4532 return state; 4533 } 4534 4535 /** 4536 * At this point ProcessNewBlock would call AcceptBlock(), but we 4537 * don't want to store the block or its header. Run individual checks 4538 * instead: 4539 * - skip AcceptBlockHeader() because: 4540 * - we don't want to update the block index 4541 * - we do not care about duplicates 4542 * - we already ran CheckBlockHeader() via CheckBlock() 4543 * - we already checked for prev-blk-not-found 4544 * - we know the tip is valid, so no need to check bad-prevblk 4545 * - we already ran CheckBlock() 4546 * - do run ContextualCheckBlockHeader() 4547 * - do run ContextualCheckBlock() 4548 */ 4549 4550 if (!ContextualCheckBlockHeader(block, state, chainstate.m_blockman, chainstate.m_chainman, tip)) { 4551 if (state.IsValid()) NONFATAL_UNREACHABLE(); 4552 return state; 4553 } 4554 4555 if (!ContextualCheckBlock(block, state, chainstate.m_chainman, tip)) { 4556 if (state.IsValid()) NONFATAL_UNREACHABLE(); 4557 return state; 4558 } 4559 4560 // We don't want ConnectBlock to update the actual chainstate, so create 4561 // a cache on top of it, along with a dummy block index. 4562 CBlockIndex index_dummy{block}; 4563 uint256 block_hash(block.GetHash()); 4564 index_dummy.pprev = tip; 4565 index_dummy.nHeight = tip->nHeight + 1; 4566 index_dummy.phashBlock = &block_hash; 4567 CCoinsViewCache view_dummy(&chainstate.CoinsTip()); 4568 4569 // Set fJustCheck to true in order to update, and not clear, validation caches. 4570 if(!chainstate.ConnectBlock(block, state, &index_dummy, view_dummy, /*fJustCheck=*/true)) { 4571 if (state.IsValid()) NONFATAL_UNREACHABLE(); 4572 return state; 4573 } 4574 4575 // Ensure no check returned successfully while also setting an invalid state. 4576 if (!state.IsValid()) NONFATAL_UNREACHABLE(); 4577 4578 return state; 4579 } 4580 4581 /* This function is called from the RPC code for pruneblockchain */ 4582 void PruneBlockFilesManual(Chainstate& active_chainstate, int nManualPruneHeight) 4583 { 4584 BlockValidationState state; 4585 if (!active_chainstate.FlushStateToDisk( 4586 state, FlushStateMode::NONE, nManualPruneHeight)) { 4587 LogWarning("Failed to flush state after manual prune (%s)", state.ToString()); 4588 } 4589 } 4590 4591 bool Chainstate::LoadChainTip() 4592 { 4593 AssertLockHeld(cs_main); 4594 const CCoinsViewCache& coins_cache = CoinsTip(); 4595 assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty 4596 CBlockIndex* tip = m_chain.Tip(); 4597 4598 if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) { 4599 return true; 4600 } 4601 4602 // Load pointer to end of best chain 4603 CBlockIndex* pindex = m_blockman.LookupBlockIndex(coins_cache.GetBestBlock()); 4604 if (!pindex) { 4605 return false; 4606 } 4607 m_chain.SetTip(*pindex); 4608 tip = m_chain.Tip(); 4609 4610 // Make sure our chain tip before shutting down scores better than any other candidate 4611 // to maintain a consistent best tip over reboots in case of a tie. 4612 auto target = tip; 4613 while (target) { 4614 target->nSequenceId = SEQ_ID_BEST_CHAIN_FROM_DISK; 4615 target = target->pprev; 4616 } 4617 4618 // Block index candidates are loaded before the chain tip, so we need to replace this entry 4619 // Otherwise the scoring will be based on the memory address location instead of the nSequenceId 4620 setBlockIndexCandidates.erase(tip); 4621 TryAddBlockIndexCandidate(tip); 4622 PruneBlockIndexCandidates(); 4623 4624 tip = m_chain.Tip(); 4625 LogInfo("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f", 4626 tip->GetBlockHash().ToString(), 4627 m_chain.Height(), 4628 FormatISO8601DateTime(tip->GetBlockTime()), 4629 m_chainman.GuessVerificationProgress(tip)); 4630 4631 // Ensure KernelNotifications m_tip_block is set even if no new block arrives. 4632 if (this->GetRole() != ChainstateRole::BACKGROUND) { 4633 // Ignoring return value for now. 4634 (void)m_chainman.GetNotifications().blockTip( 4635 /*state=*/GetSynchronizationState(/*init=*/true, m_chainman.m_blockman.m_blockfiles_indexed), 4636 /*index=*/*pindex, 4637 /*verification_progress=*/m_chainman.GuessVerificationProgress(tip)); 4638 } 4639 4640 return true; 4641 } 4642 4643 CVerifyDB::CVerifyDB(Notifications& notifications) 4644 : m_notifications{notifications} 4645 { 4646 m_notifications.progress(_("Verifying blocks…"), 0, false); 4647 } 4648 4649 CVerifyDB::~CVerifyDB() 4650 { 4651 m_notifications.progress(bilingual_str{}, 100, false); 4652 } 4653 4654 VerifyDBResult CVerifyDB::VerifyDB( 4655 Chainstate& chainstate, 4656 const Consensus::Params& consensus_params, 4657 CCoinsView& coinsview, 4658 int nCheckLevel, int nCheckDepth) 4659 { 4660 AssertLockHeld(cs_main); 4661 4662 if (chainstate.m_chain.Tip() == nullptr || chainstate.m_chain.Tip()->pprev == nullptr) { 4663 return VerifyDBResult::SUCCESS; 4664 } 4665 4666 // Verify blocks in the best chain 4667 if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) { 4668 nCheckDepth = chainstate.m_chain.Height(); 4669 } 4670 nCheckLevel = std::max(0, std::min(4, nCheckLevel)); 4671 LogInfo("Verifying last %i blocks at level %i", nCheckDepth, nCheckLevel); 4672 CCoinsViewCache coins(&coinsview); 4673 CBlockIndex* pindex; 4674 CBlockIndex* pindexFailure = nullptr; 4675 int nGoodTransactions = 0; 4676 BlockValidationState state; 4677 int reportDone = 0; 4678 bool skipped_no_block_data{false}; 4679 bool skipped_l3_checks{false}; 4680 LogInfo("Verification progress: 0%%"); 4681 4682 const bool is_snapshot_cs{chainstate.m_from_snapshot_blockhash}; 4683 4684 for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev; pindex = pindex->pprev) { 4685 const int percentageDone = std::max(1, std::min(99, (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100)))); 4686 if (reportDone < percentageDone / 10) { 4687 // report every 10% step 4688 LogInfo("Verification progress: %d%%", percentageDone); 4689 reportDone = percentageDone / 10; 4690 } 4691 m_notifications.progress(_("Verifying blocks…"), percentageDone, false); 4692 if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) { 4693 break; 4694 } 4695 if ((chainstate.m_blockman.IsPruneMode() || is_snapshot_cs) && !(pindex->nStatus & BLOCK_HAVE_DATA)) { 4696 // If pruning or running under an assumeutxo snapshot, only go 4697 // back as far as we have data. 4698 LogInfo("Block verification stopping at height %d (no data). This could be due to pruning or use of an assumeutxo snapshot.", pindex->nHeight); 4699 skipped_no_block_data = true; 4700 break; 4701 } 4702 CBlock block; 4703 // check level 0: read from disk 4704 if (!chainstate.m_blockman.ReadBlock(block, *pindex)) { 4705 LogError("Verification error: ReadBlock failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString()); 4706 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4707 } 4708 // check level 1: verify block validity 4709 if (nCheckLevel >= 1 && !CheckBlock(block, state, consensus_params)) { 4710 LogError("Verification error: found bad block at %d, hash=%s (%s)", 4711 pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString()); 4712 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4713 } 4714 // check level 2: verify undo validity 4715 if (nCheckLevel >= 2 && pindex) { 4716 CBlockUndo undo; 4717 if (!pindex->GetUndoPos().IsNull()) { 4718 if (!chainstate.m_blockman.ReadBlockUndo(undo, *pindex)) { 4719 LogError("Verification error: found bad undo data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString()); 4720 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4721 } 4722 } 4723 } 4724 // check level 3: check for inconsistencies during memory-only disconnect of tip blocks 4725 size_t curr_coins_usage = coins.DynamicMemoryUsage() + chainstate.CoinsTip().DynamicMemoryUsage(); 4726 4727 if (nCheckLevel >= 3) { 4728 if (curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) { 4729 assert(coins.GetBestBlock() == pindex->GetBlockHash()); 4730 DisconnectResult res = chainstate.DisconnectBlock(block, pindex, coins); 4731 if (res == DISCONNECT_FAILED) { 4732 LogError("Verification error: irrecoverable inconsistency in block data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString()); 4733 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4734 } 4735 if (res == DISCONNECT_UNCLEAN) { 4736 nGoodTransactions = 0; 4737 pindexFailure = pindex; 4738 } else { 4739 nGoodTransactions += block.vtx.size(); 4740 } 4741 } else { 4742 skipped_l3_checks = true; 4743 } 4744 } 4745 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED; 4746 } 4747 if (pindexFailure) { 4748 LogError("Verification error: coin database inconsistencies found (last %i blocks, %i good transactions before that)", chainstate.m_chain.Height() - pindexFailure->nHeight + 1, nGoodTransactions); 4749 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4750 } 4751 if (skipped_l3_checks) { 4752 LogWarning("Skipped verification of level >=3 (insufficient database cache size). Consider increasing -dbcache."); 4753 } 4754 4755 // store block count as we move pindex at check level >= 4 4756 int block_count = chainstate.m_chain.Height() - pindex->nHeight; 4757 4758 // check level 4: try reconnecting blocks 4759 if (nCheckLevel >= 4 && !skipped_l3_checks) { 4760 while (pindex != chainstate.m_chain.Tip()) { 4761 const int percentageDone = std::max(1, std::min(99, 100 - (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * 50))); 4762 if (reportDone < percentageDone / 10) { 4763 // report every 10% step 4764 LogInfo("Verification progress: %d%%", percentageDone); 4765 reportDone = percentageDone / 10; 4766 } 4767 m_notifications.progress(_("Verifying blocks…"), percentageDone, false); 4768 pindex = chainstate.m_chain.Next(pindex); 4769 CBlock block; 4770 if (!chainstate.m_blockman.ReadBlock(block, *pindex)) { 4771 LogError("Verification error: ReadBlock failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString()); 4772 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4773 } 4774 if (!chainstate.ConnectBlock(block, state, pindex, coins)) { 4775 LogError("Verification error: found unconnectable block at %d, hash=%s (%s)", pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString()); 4776 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4777 } 4778 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED; 4779 } 4780 } 4781 4782 LogInfo("Verification: No coin database inconsistencies in last %i blocks (%i transactions)", block_count, nGoodTransactions); 4783 4784 if (skipped_l3_checks) { 4785 return VerifyDBResult::SKIPPED_L3_CHECKS; 4786 } 4787 if (skipped_no_block_data) { 4788 return VerifyDBResult::SKIPPED_MISSING_BLOCKS; 4789 } 4790 return VerifyDBResult::SUCCESS; 4791 } 4792 4793 /** Apply the effects of a block on the utxo cache, ignoring that it may already have been applied. */ 4794 bool Chainstate::RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs) 4795 { 4796 AssertLockHeld(cs_main); 4797 // TODO: merge with ConnectBlock 4798 CBlock block; 4799 if (!m_blockman.ReadBlock(block, *pindex)) { 4800 LogError("ReplayBlock(): ReadBlock failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4801 return false; 4802 } 4803 4804 for (const CTransactionRef& tx : block.vtx) { 4805 if (!tx->IsCoinBase()) { 4806 for (const CTxIn &txin : tx->vin) { 4807 inputs.SpendCoin(txin.prevout); 4808 } 4809 } 4810 // Pass check = true as every addition may be an overwrite. 4811 AddCoins(inputs, *tx, pindex->nHeight, true); 4812 } 4813 return true; 4814 } 4815 4816 bool Chainstate::ReplayBlocks() 4817 { 4818 LOCK(cs_main); 4819 4820 CCoinsView& db = this->CoinsDB(); 4821 CCoinsViewCache cache(&db); 4822 4823 std::vector<uint256> hashHeads = db.GetHeadBlocks(); 4824 if (hashHeads.empty()) return true; // We're already in a consistent state. 4825 if (hashHeads.size() != 2) { 4826 LogError("ReplayBlocks(): unknown inconsistent state\n"); 4827 return false; 4828 } 4829 4830 m_chainman.GetNotifications().progress(_("Replaying blocks…"), 0, false); 4831 LogInfo("Replaying blocks"); 4832 4833 const CBlockIndex* pindexOld = nullptr; // Old tip during the interrupted flush. 4834 const CBlockIndex* pindexNew; // New tip during the interrupted flush. 4835 const CBlockIndex* pindexFork = nullptr; // Latest block common to both the old and the new tip. 4836 4837 if (m_blockman.m_block_index.count(hashHeads[0]) == 0) { 4838 LogError("ReplayBlocks(): reorganization to unknown block requested\n"); 4839 return false; 4840 } 4841 pindexNew = &(m_blockman.m_block_index[hashHeads[0]]); 4842 4843 if (!hashHeads[1].IsNull()) { // The old tip is allowed to be 0, indicating it's the first flush. 4844 if (m_blockman.m_block_index.count(hashHeads[1]) == 0) { 4845 LogError("ReplayBlocks(): reorganization from unknown block requested\n"); 4846 return false; 4847 } 4848 pindexOld = &(m_blockman.m_block_index[hashHeads[1]]); 4849 pindexFork = LastCommonAncestor(pindexOld, pindexNew); 4850 assert(pindexFork != nullptr); 4851 } 4852 4853 // Rollback along the old branch. 4854 const int nForkHeight{pindexFork ? pindexFork->nHeight : 0}; 4855 if (pindexOld != pindexFork) { 4856 LogInfo("Rolling back from %s (%i to %i)", pindexOld->GetBlockHash().ToString(), pindexOld->nHeight, nForkHeight); 4857 while (pindexOld != pindexFork) { 4858 if (pindexOld->nHeight > 0) { // Never disconnect the genesis block. 4859 CBlock block; 4860 if (!m_blockman.ReadBlock(block, *pindexOld)) { 4861 LogError("RollbackBlock(): ReadBlock() failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString()); 4862 return false; 4863 } 4864 if (pindexOld->nHeight % 10'000 == 0) { 4865 LogInfo("Rolling back %s (%i)", pindexOld->GetBlockHash().ToString(), pindexOld->nHeight); 4866 } 4867 DisconnectResult res = DisconnectBlock(block, pindexOld, cache); 4868 if (res == DISCONNECT_FAILED) { 4869 LogError("RollbackBlock(): DisconnectBlock failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString()); 4870 return false; 4871 } 4872 // If DISCONNECT_UNCLEAN is returned, it means a non-existing UTXO was deleted, or an existing UTXO was 4873 // overwritten. It corresponds to cases where the block-to-be-disconnect never had all its operations 4874 // applied to the UTXO set. However, as both writing a UTXO and deleting a UTXO are idempotent operations, 4875 // the result is still a version of the UTXO set with the effects of that block undone. 4876 } 4877 pindexOld = pindexOld->pprev; 4878 } 4879 LogInfo("Rolled back to %s", pindexFork->GetBlockHash().ToString()); 4880 } 4881 4882 // Roll forward from the forking point to the new tip. 4883 if (nForkHeight < pindexNew->nHeight) { 4884 LogInfo("Rolling forward to %s (%i to %i)", pindexNew->GetBlockHash().ToString(), nForkHeight, pindexNew->nHeight); 4885 for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight; ++nHeight) { 4886 const CBlockIndex& pindex{*Assert(pindexNew->GetAncestor(nHeight))}; 4887 4888 if (nHeight % 10'000 == 0) { 4889 LogInfo("Rolling forward %s (%i)", pindex.GetBlockHash().ToString(), nHeight); 4890 } 4891 m_chainman.GetNotifications().progress(_("Replaying blocks…"), (int)((nHeight - nForkHeight) * 100.0 / (pindexNew->nHeight - nForkHeight)), false); 4892 if (!RollforwardBlock(&pindex, cache)) return false; 4893 } 4894 LogInfo("Rolled forward to %s", pindexNew->GetBlockHash().ToString()); 4895 } 4896 4897 cache.SetBestBlock(pindexNew->GetBlockHash()); 4898 cache.Flush(); 4899 m_chainman.GetNotifications().progress(bilingual_str{}, 100, false); 4900 return true; 4901 } 4902 4903 bool Chainstate::NeedsRedownload() const 4904 { 4905 AssertLockHeld(cs_main); 4906 4907 // At and above m_params.SegwitHeight, segwit consensus rules must be validated 4908 CBlockIndex* block{m_chain.Tip()}; 4909 4910 while (block != nullptr && DeploymentActiveAt(*block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) { 4911 if (!(block->nStatus & BLOCK_OPT_WITNESS)) { 4912 // block is insufficiently validated for a segwit client 4913 return true; 4914 } 4915 block = block->pprev; 4916 } 4917 4918 return false; 4919 } 4920 4921 void Chainstate::ClearBlockIndexCandidates() 4922 { 4923 AssertLockHeld(::cs_main); 4924 setBlockIndexCandidates.clear(); 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(SnapshotBlockhash())}; 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 we have an assumeutxo-based chainstate, then the snapshot 4944 // block will be a candidate for the tip, but it may not be 4945 // VALID_TRANSACTIONS (eg if we haven't yet downloaded the block), 4946 // so we special-case the snapshot block as a potential candidate 4947 // here. 4948 if (pindex == GetSnapshotBaseBlock() || 4949 (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && 4950 (pindex->HaveNumChainTxs() || pindex->pprev == nullptr))) { 4951 4952 for (Chainstate* chainstate : GetAll()) { 4953 chainstate->TryAddBlockIndexCandidate(pindex); 4954 } 4955 } 4956 if (pindex->nStatus & BLOCK_FAILED_MASK && (!m_best_invalid || pindex->nChainWork > m_best_invalid->nChainWork)) { 4957 m_best_invalid = pindex; 4958 } 4959 if (pindex->IsValid(BLOCK_VALID_TREE) && (m_best_header == nullptr || CBlockIndexWorkComparator()(m_best_header, pindex))) 4960 m_best_header = pindex; 4961 } 4962 } 4963 return true; 4964 } 4965 4966 bool Chainstate::LoadGenesisBlock() 4967 { 4968 LOCK(cs_main); 4969 4970 const CChainParams& params{m_chainman.GetParams()}; 4971 4972 // Check whether we're already initialized by checking for genesis in 4973 // m_blockman.m_block_index. Note that we can't use m_chain here, since it is 4974 // set based on the coins db, not the block index db, which is the only 4975 // thing loaded at this point. 4976 if (m_blockman.m_block_index.count(params.GenesisBlock().GetHash())) 4977 return true; 4978 4979 try { 4980 const CBlock& block = params.GenesisBlock(); 4981 FlatFilePos blockPos{m_blockman.WriteBlock(block, 0)}; 4982 if (blockPos.IsNull()) { 4983 LogError("%s: writing genesis block to disk failed\n", __func__); 4984 return false; 4985 } 4986 CBlockIndex* pindex = m_blockman.AddToBlockIndex(block, m_chainman.m_best_header); 4987 m_chainman.ReceivedBlockTransactions(block, pindex, blockPos); 4988 } catch (const std::runtime_error& e) { 4989 LogError("%s: failed to write genesis block: %s\n", __func__, e.what()); 4990 return false; 4991 } 4992 4993 return true; 4994 } 4995 4996 void ChainstateManager::LoadExternalBlockFile( 4997 AutoFile& file_in, 4998 FlatFilePos* dbp, 4999 std::multimap<uint256, FlatFilePos>* blocks_with_unknown_parent) 5000 { 5001 // Either both should be specified (-reindex), or neither (-loadblock). 5002 assert(!dbp == !blocks_with_unknown_parent); 5003 5004 const auto start{SteadyClock::now()}; 5005 const CChainParams& params{GetParams()}; 5006 5007 int nLoaded = 0; 5008 try { 5009 BufferedFile blkdat{file_in, 2 * MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE + 8}; 5010 // nRewind indicates where to resume scanning in case something goes wrong, 5011 // such as a block fails to deserialize. 5012 uint64_t nRewind = blkdat.GetPos(); 5013 while (!blkdat.eof()) { 5014 if (m_interrupt) return; 5015 5016 blkdat.SetPos(nRewind); 5017 nRewind++; // start one byte further next time, in case of failure 5018 blkdat.SetLimit(); // remove former limit 5019 unsigned int nSize = 0; 5020 try { 5021 // locate a header 5022 MessageStartChars buf; 5023 blkdat.FindByte(std::byte(params.MessageStart()[0])); 5024 nRewind = blkdat.GetPos() + 1; 5025 blkdat >> buf; 5026 if (buf != params.MessageStart()) { 5027 continue; 5028 } 5029 // read size 5030 blkdat >> nSize; 5031 if (nSize < 80 || nSize > MAX_BLOCK_SERIALIZED_SIZE) 5032 continue; 5033 } catch (const std::exception&) { 5034 // no valid block header found; don't complain 5035 // (this happens at the end of every blk.dat file) 5036 break; 5037 } 5038 try { 5039 // read block header 5040 const uint64_t nBlockPos{blkdat.GetPos()}; 5041 if (dbp) 5042 dbp->nPos = nBlockPos; 5043 blkdat.SetLimit(nBlockPos + nSize); 5044 CBlockHeader header; 5045 blkdat >> header; 5046 const uint256 hash{header.GetHash()}; 5047 // Skip the rest of this block (this may read from disk into memory); position to the marker before the 5048 // next block, but it's still possible to rewind to the start of the current block (without a disk read). 5049 nRewind = nBlockPos + nSize; 5050 blkdat.SkipTo(nRewind); 5051 5052 std::shared_ptr<CBlock> pblock{}; // needs to remain available after the cs_main lock is released to avoid duplicate reads from disk 5053 5054 { 5055 LOCK(cs_main); 5056 // detect out of order blocks, and store them for later 5057 if (hash != params.GetConsensus().hashGenesisBlock && !m_blockman.LookupBlockIndex(header.hashPrevBlock)) { 5058 LogDebug(BCLog::REINDEX, "%s: Out of order block %s, parent %s not known\n", __func__, hash.ToString(), 5059 header.hashPrevBlock.ToString()); 5060 if (dbp && blocks_with_unknown_parent) { 5061 blocks_with_unknown_parent->emplace(header.hashPrevBlock, *dbp); 5062 } 5063 continue; 5064 } 5065 5066 // process in case the block isn't known yet 5067 const CBlockIndex* pindex = m_blockman.LookupBlockIndex(hash); 5068 if (!pindex || (pindex->nStatus & BLOCK_HAVE_DATA) == 0) { 5069 // This block can be processed immediately; rewind to its start, read and deserialize it. 5070 blkdat.SetPos(nBlockPos); 5071 pblock = std::make_shared<CBlock>(); 5072 blkdat >> TX_WITH_WITNESS(*pblock); 5073 nRewind = blkdat.GetPos(); 5074 5075 BlockValidationState state; 5076 if (AcceptBlock(pblock, state, nullptr, true, dbp, nullptr, true)) { 5077 nLoaded++; 5078 } 5079 if (state.IsError()) { 5080 break; 5081 } 5082 } else if (hash != params.GetConsensus().hashGenesisBlock && pindex->nHeight % 1000 == 0) { 5083 LogDebug(BCLog::REINDEX, "Block Import: already had block %s at height %d\n", hash.ToString(), pindex->nHeight); 5084 } 5085 } 5086 5087 // Activate the genesis block so normal node progress can continue 5088 // During first -reindex, this will only connect Genesis since 5089 // ActivateBestChain only connects blocks which are in the block tree db, 5090 // which only contains blocks whose parents are in it. 5091 // But do this only if genesis isn't activated yet, to avoid connecting many blocks 5092 // without assumevalid in the case of a continuation of a reindex that 5093 // was interrupted by the user. 5094 if (hash == params.GetConsensus().hashGenesisBlock && WITH_LOCK(::cs_main, return ActiveHeight()) == -1) { 5095 BlockValidationState state; 5096 if (!ActiveChainstate().ActivateBestChain(state, nullptr)) { 5097 break; 5098 } 5099 } 5100 5101 if (m_blockman.IsPruneMode() && m_blockman.m_blockfiles_indexed && pblock) { 5102 // must update the tip for pruning to work while importing with -loadblock. 5103 // this is a tradeoff to conserve disk space at the expense of time 5104 // spent updating the tip to be able to prune. 5105 // otherwise, ActivateBestChain won't be called by the import process 5106 // until after all of the block files are loaded. ActivateBestChain can be 5107 // called by concurrent network message processing. but, that is not 5108 // reliable for the purpose of pruning while importing. 5109 bool activation_failure = false; 5110 for (auto c : GetAll()) { 5111 BlockValidationState state; 5112 if (!c->ActivateBestChain(state, pblock)) { 5113 LogDebug(BCLog::REINDEX, "failed to activate chain (%s)\n", state.ToString()); 5114 activation_failure = true; 5115 break; 5116 } 5117 } 5118 if (activation_failure) { 5119 break; 5120 } 5121 } 5122 5123 NotifyHeaderTip(); 5124 5125 if (!blocks_with_unknown_parent) continue; 5126 5127 // Recursively process earlier encountered successors of this block 5128 std::deque<uint256> queue; 5129 queue.push_back(hash); 5130 while (!queue.empty()) { 5131 uint256 head = queue.front(); 5132 queue.pop_front(); 5133 auto range = blocks_with_unknown_parent->equal_range(head); 5134 while (range.first != range.second) { 5135 std::multimap<uint256, FlatFilePos>::iterator it = range.first; 5136 std::shared_ptr<CBlock> pblockrecursive = std::make_shared<CBlock>(); 5137 if (m_blockman.ReadBlock(*pblockrecursive, it->second, {})) { 5138 const auto& block_hash{pblockrecursive->GetHash()}; 5139 LogDebug(BCLog::REINDEX, "%s: Processing out of order child %s of %s", __func__, block_hash.ToString(), head.ToString()); 5140 LOCK(cs_main); 5141 BlockValidationState dummy; 5142 if (AcceptBlock(pblockrecursive, dummy, nullptr, true, &it->second, nullptr, true)) { 5143 nLoaded++; 5144 queue.push_back(block_hash); 5145 } 5146 } 5147 range.first++; 5148 blocks_with_unknown_parent->erase(it); 5149 NotifyHeaderTip(); 5150 } 5151 } 5152 } catch (const std::exception& e) { 5153 // historical bugs added extra data to the block files that does not deserialize cleanly. 5154 // commonly this data is between readable blocks, but it does not really matter. such data is not fatal to the import process. 5155 // the code that reads the block files deals with invalid data by simply ignoring it. 5156 // it continues to search for the next {4 byte magic message start bytes + 4 byte length + block} that does deserialize cleanly 5157 // and passes all of the other block validation checks dealing with POW and the merkle root, etc... 5158 // we merely note with this informational log message when unexpected data is encountered. 5159 // we could also be experiencing a storage system read error, or a read of a previous bad write. these are possible, but 5160 // less likely scenarios. we don't have enough information to tell a difference here. 5161 // the reindex process is not the place to attempt to clean and/or compact the block files. if so desired, a studious node operator 5162 // may use knowledge of the fact that the block files are not entirely pristine in order to prepare a set of pristine, and 5163 // perhaps ordered, block files for later reindexing. 5164 LogDebug(BCLog::REINDEX, "%s: unexpected data at file offset 0x%x - %s. continuing\n", __func__, (nRewind - 1), e.what()); 5165 } 5166 } 5167 } catch (const std::runtime_error& e) { 5168 GetNotifications().fatalError(strprintf(_("System error while loading external block file: %s"), e.what())); 5169 } 5170 LogInfo("Loaded %i blocks from external file in %dms", nLoaded, Ticks<std::chrono::milliseconds>(SteadyClock::now() - start)); 5171 } 5172 5173 bool ChainstateManager::ShouldCheckBlockIndex() const 5174 { 5175 // Assert to verify Flatten() has been called. 5176 if (!*Assert(m_options.check_block_index)) return false; 5177 if (FastRandomContext().randrange(*m_options.check_block_index) >= 1) return false; 5178 return true; 5179 } 5180 5181 void ChainstateManager::CheckBlockIndex() const 5182 { 5183 if (!ShouldCheckBlockIndex()) { 5184 return; 5185 } 5186 5187 LOCK(cs_main); 5188 5189 // During a reindex, we read the genesis block and call CheckBlockIndex before ActivateBestChain, 5190 // so we have the genesis block in m_blockman.m_block_index but no active chain. (A few of the 5191 // tests when iterating the block tree require that m_chain has been initialized.) 5192 if (ActiveChain().Height() < 0) { 5193 assert(m_blockman.m_block_index.size() <= 1); 5194 return; 5195 } 5196 5197 // Build forward-pointing data structure for the entire block tree. 5198 // For performance reasons, indexes of the best header chain are stored in a vector (within CChain). 5199 // All remaining blocks are stored in a multimap. 5200 // The best header chain can differ from the active chain: E.g. its entries may belong to blocks that 5201 // are not yet validated. 5202 CChain best_hdr_chain; 5203 assert(m_best_header); 5204 assert(!(m_best_header->nStatus & BLOCK_FAILED_MASK)); 5205 best_hdr_chain.SetTip(*m_best_header); 5206 5207 std::multimap<const CBlockIndex*, const CBlockIndex*> forward; 5208 for (auto& [_, block_index] : m_blockman.m_block_index) { 5209 // Only save indexes in forward that are not part of the best header chain. 5210 if (!best_hdr_chain.Contains(&block_index)) { 5211 // Only genesis, which must be part of the best header chain, can have a nullptr parent. 5212 assert(block_index.pprev); 5213 forward.emplace(block_index.pprev, &block_index); 5214 } 5215 } 5216 assert(forward.size() + best_hdr_chain.Height() + 1 == m_blockman.m_block_index.size()); 5217 5218 const CBlockIndex* pindex = best_hdr_chain[0]; 5219 assert(pindex); 5220 // Iterate over the entire block tree, using depth-first search. 5221 // Along the way, remember whether there are blocks on the path from genesis 5222 // block being explored which are the first to have certain properties. 5223 size_t nNodes = 0; 5224 int nHeight = 0; 5225 const CBlockIndex* pindexFirstInvalid = nullptr; // Oldest ancestor of pindex which is invalid. 5226 const CBlockIndex* pindexFirstMissing = nullptr; // Oldest ancestor of pindex which does not have BLOCK_HAVE_DATA, since assumeutxo snapshot if used. 5227 const CBlockIndex* pindexFirstNeverProcessed = nullptr; // Oldest ancestor of pindex for which nTx == 0, since assumeutxo snapshot if used. 5228 const CBlockIndex* pindexFirstNotTreeValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE (regardless of being valid or not). 5229 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. 5230 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. 5231 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. 5232 5233 // After checking an assumeutxo snapshot block, reset pindexFirst pointers 5234 // to earlier blocks that have not been downloaded or validated yet, so 5235 // checks for later blocks can assume the earlier blocks were validated and 5236 // be stricter, testing for more requirements. 5237 const CBlockIndex* snap_base{GetSnapshotBaseBlock()}; 5238 const CBlockIndex *snap_first_missing{}, *snap_first_notx{}, *snap_first_notv{}, *snap_first_nocv{}, *snap_first_nosv{}; 5239 auto snap_update_firsts = [&] { 5240 if (pindex == snap_base) { 5241 std::swap(snap_first_missing, pindexFirstMissing); 5242 std::swap(snap_first_notx, pindexFirstNeverProcessed); 5243 std::swap(snap_first_notv, pindexFirstNotTransactionsValid); 5244 std::swap(snap_first_nocv, pindexFirstNotChainValid); 5245 std::swap(snap_first_nosv, pindexFirstNotScriptsValid); 5246 } 5247 }; 5248 5249 while (pindex != nullptr) { 5250 nNodes++; 5251 if (pindexFirstInvalid == nullptr && pindex->nStatus & BLOCK_FAILED_VALID) pindexFirstInvalid = pindex; 5252 if (pindexFirstMissing == nullptr && !(pindex->nStatus & BLOCK_HAVE_DATA)) { 5253 pindexFirstMissing = pindex; 5254 } 5255 if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) pindexFirstNeverProcessed = pindex; 5256 if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr && (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TREE) pindexFirstNotTreeValid = pindex; 5257 5258 if (pindex->pprev != nullptr) { 5259 if (pindexFirstNotTransactionsValid == nullptr && 5260 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TRANSACTIONS) { 5261 pindexFirstNotTransactionsValid = pindex; 5262 } 5263 5264 if (pindexFirstNotChainValid == nullptr && 5265 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_CHAIN) { 5266 pindexFirstNotChainValid = pindex; 5267 } 5268 5269 if (pindexFirstNotScriptsValid == nullptr && 5270 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_SCRIPTS) { 5271 pindexFirstNotScriptsValid = pindex; 5272 } 5273 } 5274 5275 // Begin: actual consistency checks. 5276 if (pindex->pprev == nullptr) { 5277 // Genesis block checks. 5278 assert(pindex->GetBlockHash() == GetConsensus().hashGenesisBlock); // Genesis block's hash must match. 5279 for (const Chainstate* c : {m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) { 5280 if (c && c->m_chain.Genesis() != nullptr) { 5281 assert(pindex == c->m_chain.Genesis()); // The chain's genesis block must be this block. 5282 } 5283 } 5284 } 5285 // nSequenceId can't be set higher than SEQ_ID_INIT_FROM_DISK{1} for blocks that aren't linked 5286 // (negative is used for preciousblock, SEQ_ID_BEST_CHAIN_FROM_DISK{0} for active chain when loaded from disk) 5287 if (!pindex->HaveNumChainTxs()) assert(pindex->nSequenceId <= SEQ_ID_INIT_FROM_DISK); 5288 // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or not pruning has occurred). 5289 // HAVE_DATA is only equivalent to nTx > 0 (or VALID_TRANSACTIONS) if no pruning has occurred. 5290 if (!m_blockman.m_have_pruned) { 5291 // If we've never pruned, then HAVE_DATA should be equivalent to nTx > 0 5292 assert(!(pindex->nStatus & BLOCK_HAVE_DATA) == (pindex->nTx == 0)); 5293 assert(pindexFirstMissing == pindexFirstNeverProcessed); 5294 } else { 5295 // If we have pruned, then we can only say that HAVE_DATA implies nTx > 0 5296 if (pindex->nStatus & BLOCK_HAVE_DATA) assert(pindex->nTx > 0); 5297 } 5298 if (pindex->nStatus & BLOCK_HAVE_UNDO) assert(pindex->nStatus & BLOCK_HAVE_DATA); 5299 if (snap_base && snap_base->GetAncestor(pindex->nHeight) == pindex) { 5300 // Assumed-valid blocks should connect to the main chain. 5301 assert((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE); 5302 } 5303 // There should only be an nTx value if we have 5304 // actually seen a block's transactions. 5305 assert(((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS) == (pindex->nTx > 0)); // This is pruning-independent. 5306 // All parents having had data (at some point) is equivalent to all parents being VALID_TRANSACTIONS, which is equivalent to HaveNumChainTxs(). 5307 // HaveNumChainTxs will also be set in the assumeutxo snapshot block from snapshot metadata. 5308 assert((pindexFirstNeverProcessed == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs()); 5309 assert((pindexFirstNotTransactionsValid == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs()); 5310 assert(pindex->nHeight == nHeight); // nHeight must be consistent. 5311 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. 5312 assert(nHeight < 2 || (pindex->pskip && (pindex->pskip->nHeight < nHeight))); // The pskip pointer must point back for all but the first 2 blocks. 5313 assert(pindexFirstNotTreeValid == nullptr); // All m_blockman.m_block_index entries must at least be TREE valid 5314 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE) assert(pindexFirstNotTreeValid == nullptr); // TREE valid implies all parents are TREE valid 5315 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_CHAIN) assert(pindexFirstNotChainValid == nullptr); // CHAIN valid implies all parents are CHAIN valid 5316 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_SCRIPTS) assert(pindexFirstNotScriptsValid == nullptr); // SCRIPTS valid implies all parents are SCRIPTS valid 5317 if (pindexFirstInvalid == nullptr) { 5318 // Checks for not-invalid blocks. 5319 assert((pindex->nStatus & BLOCK_FAILED_MASK) == 0); // The failed mask cannot be set for blocks without invalid parents. 5320 } else { 5321 assert(pindex->nStatus & BLOCK_FAILED_MASK); // Invalid blocks and their descendants must be marked as invalid 5322 } 5323 // Make sure m_chain_tx_count sum is correctly computed. 5324 if (!pindex->pprev) { 5325 // If no previous block, nTx and m_chain_tx_count must be the same. 5326 assert(pindex->m_chain_tx_count == pindex->nTx); 5327 } else if (pindex->pprev->m_chain_tx_count > 0 && pindex->nTx > 0) { 5328 // If previous m_chain_tx_count is set and number of transactions in block is known, sum must be set. 5329 assert(pindex->m_chain_tx_count == pindex->nTx + pindex->pprev->m_chain_tx_count); 5330 } else { 5331 // Otherwise m_chain_tx_count should only be set if this is a snapshot 5332 // block, and must be set if it is. 5333 assert((pindex->m_chain_tx_count != 0) == (pindex == snap_base)); 5334 } 5335 // There should be no block with more work than m_best_header, unless it's known to be invalid 5336 assert((pindex->nStatus & BLOCK_FAILED_MASK) || pindex->nChainWork <= m_best_header->nChainWork); 5337 5338 // Chainstate-specific checks on setBlockIndexCandidates 5339 for (const Chainstate* c : {m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) { 5340 if (!c || c->m_chain.Tip() == nullptr) continue; 5341 // Two main factors determine whether pindex is a candidate in 5342 // setBlockIndexCandidates: 5343 // 5344 // - If pindex has less work than the chain tip, it should not be a 5345 // candidate, and this will be asserted below. Otherwise it is a 5346 // potential candidate. 5347 // 5348 // - If pindex or one of its parent blocks back to the genesis block 5349 // or an assumeutxo snapshot never downloaded transactions 5350 // (pindexFirstNeverProcessed is non-null), it should not be a 5351 // candidate, and this will be asserted below. The only exception 5352 // is if pindex itself is an assumeutxo snapshot block. Then it is 5353 // also a potential candidate. 5354 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && (pindexFirstNeverProcessed == nullptr || pindex == snap_base)) { 5355 // If pindex was detected as invalid (pindexFirstInvalid is 5356 // non-null), it is not required to be in 5357 // setBlockIndexCandidates. 5358 if (pindexFirstInvalid == nullptr) { 5359 // If pindex and all its parents back to the genesis block 5360 // or an assumeutxo snapshot block downloaded transactions, 5361 // and the transactions were not pruned (pindexFirstMissing 5362 // is null), it is a potential candidate. The check 5363 // excludes pruned blocks, because if any blocks were 5364 // pruned between pindex and the current chain tip, pindex will 5365 // only temporarily be added to setBlockIndexCandidates, 5366 // before being moved to m_blocks_unlinked. This check 5367 // could be improved to verify that if all blocks between 5368 // the chain tip and pindex have data, pindex must be a 5369 // candidate. 5370 // 5371 // If pindex is the chain tip, it also is a potential 5372 // candidate. 5373 // 5374 // If the chainstate was loaded from a snapshot and pindex 5375 // is the base of the snapshot, pindex is also a potential 5376 // candidate. 5377 if (pindexFirstMissing == nullptr || pindex == c->m_chain.Tip() || pindex == c->SnapshotBase()) { 5378 // If this chainstate is the active chainstate, pindex 5379 // must be in setBlockIndexCandidates. Otherwise, this 5380 // chainstate is a background validation chainstate, and 5381 // pindex only needs to be added if it is an ancestor of 5382 // the snapshot that is being validated. 5383 if (c == &ActiveChainstate() || snap_base->GetAncestor(pindex->nHeight) == pindex) { 5384 assert(c->setBlockIndexCandidates.contains(const_cast<CBlockIndex*>(pindex))); 5385 } 5386 } 5387 // If some parent is missing, then it could be that this block was in 5388 // setBlockIndexCandidates but had to be removed because of the missing data. 5389 // In this case it must be in m_blocks_unlinked -- see test below. 5390 } 5391 } else { // If this block sorts worse than the current tip or some ancestor's block has never been seen, it cannot be in setBlockIndexCandidates. 5392 assert(!c->setBlockIndexCandidates.contains(const_cast<CBlockIndex*>(pindex))); 5393 } 5394 } 5395 // Check whether this block is in m_blocks_unlinked. 5396 auto rangeUnlinked{m_blockman.m_blocks_unlinked.equal_range(pindex->pprev)}; 5397 bool foundInUnlinked = false; 5398 while (rangeUnlinked.first != rangeUnlinked.second) { 5399 assert(rangeUnlinked.first->first == pindex->pprev); 5400 if (rangeUnlinked.first->second == pindex) { 5401 foundInUnlinked = true; 5402 break; 5403 } 5404 rangeUnlinked.first++; 5405 } 5406 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed != nullptr && pindexFirstInvalid == nullptr) { 5407 // If this block has block data available, some parent was never received, and has no invalid parents, it must be in m_blocks_unlinked. 5408 assert(foundInUnlinked); 5409 } 5410 if (!(pindex->nStatus & BLOCK_HAVE_DATA)) assert(!foundInUnlinked); // Can't be in m_blocks_unlinked if we don't HAVE_DATA 5411 if (pindexFirstMissing == nullptr) assert(!foundInUnlinked); // We aren't missing data for any parent -- cannot be in m_blocks_unlinked. 5412 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed == nullptr && pindexFirstMissing != nullptr) { 5413 // We HAVE_DATA for this block, have received data for all parents at some point, but we're currently missing data for some parent. 5414 assert(m_blockman.m_have_pruned); 5415 // This block may have entered m_blocks_unlinked if: 5416 // - it has a descendant that at some point had more work than the 5417 // tip, and 5418 // - we tried switching to that descendant but were missing 5419 // data for some intermediate block between m_chain and the 5420 // tip. 5421 // So if this block is itself better than any m_chain.Tip() and it wasn't in 5422 // setBlockIndexCandidates, then it must be in m_blocks_unlinked. 5423 for (const Chainstate* c : {m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) { 5424 if (!c) continue; 5425 const bool is_active = c == &ActiveChainstate(); 5426 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && !c->setBlockIndexCandidates.contains(const_cast<CBlockIndex*>(pindex))) { 5427 if (pindexFirstInvalid == nullptr) { 5428 if (is_active || snap_base->GetAncestor(pindex->nHeight) == pindex) { 5429 assert(foundInUnlinked); 5430 } 5431 } 5432 } 5433 } 5434 } 5435 // assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash()); // Perhaps too slow 5436 // End: actual consistency checks. 5437 5438 5439 // Try descending into the first subnode. Always process forks first and the best header chain after. 5440 snap_update_firsts(); 5441 auto range{forward.equal_range(pindex)}; 5442 if (range.first != range.second) { 5443 // A subnode not part of the best header chain was found. 5444 pindex = range.first->second; 5445 nHeight++; 5446 continue; 5447 } else if (best_hdr_chain.Contains(pindex)) { 5448 // Descend further into best header chain. 5449 nHeight++; 5450 pindex = best_hdr_chain[nHeight]; 5451 if (!pindex) break; // we are finished, since the best header chain is always processed last 5452 continue; 5453 } 5454 // This is a leaf node. 5455 // Move upwards until we reach a node of which we have not yet visited the last child. 5456 while (pindex) { 5457 // We are going to either move to a parent or a sibling of pindex. 5458 snap_update_firsts(); 5459 // If pindex was the first with a certain property, unset the corresponding variable. 5460 if (pindex == pindexFirstInvalid) pindexFirstInvalid = nullptr; 5461 if (pindex == pindexFirstMissing) pindexFirstMissing = nullptr; 5462 if (pindex == pindexFirstNeverProcessed) pindexFirstNeverProcessed = nullptr; 5463 if (pindex == pindexFirstNotTreeValid) pindexFirstNotTreeValid = nullptr; 5464 if (pindex == pindexFirstNotTransactionsValid) pindexFirstNotTransactionsValid = nullptr; 5465 if (pindex == pindexFirstNotChainValid) pindexFirstNotChainValid = nullptr; 5466 if (pindex == pindexFirstNotScriptsValid) pindexFirstNotScriptsValid = nullptr; 5467 // Find our parent. 5468 CBlockIndex* pindexPar = pindex->pprev; 5469 // Find which child we just visited. 5470 auto rangePar{forward.equal_range(pindexPar)}; 5471 while (rangePar.first->second != pindex) { 5472 assert(rangePar.first != rangePar.second); // Our parent must have at least the node we're coming from as child. 5473 rangePar.first++; 5474 } 5475 // Proceed to the next one. 5476 rangePar.first++; 5477 if (rangePar.first != rangePar.second) { 5478 // Move to a sibling not part of the best header chain. 5479 pindex = rangePar.first->second; 5480 break; 5481 } else if (pindexPar == best_hdr_chain[nHeight - 1]) { 5482 // Move to pindex's sibling on the best-chain, if it has one. 5483 pindex = best_hdr_chain[nHeight]; 5484 // There will not be a next block if (and only if) parent block is the best header. 5485 assert((pindex == nullptr) == (pindexPar == best_hdr_chain.Tip())); 5486 break; 5487 } else { 5488 // Move up further. 5489 pindex = pindexPar; 5490 nHeight--; 5491 continue; 5492 } 5493 } 5494 } 5495 5496 // Check that we actually traversed the entire block index. 5497 assert(nNodes == forward.size() + best_hdr_chain.Height() + 1); 5498 } 5499 5500 std::string Chainstate::ToString() 5501 { 5502 AssertLockHeld(::cs_main); 5503 CBlockIndex* tip = m_chain.Tip(); 5504 return strprintf("Chainstate [%s] @ height %d (%s)", 5505 m_from_snapshot_blockhash ? "snapshot" : "ibd", 5506 tip ? tip->nHeight : -1, tip ? tip->GetBlockHash().ToString() : "null"); 5507 } 5508 5509 bool Chainstate::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size) 5510 { 5511 AssertLockHeld(::cs_main); 5512 if (coinstip_size == m_coinstip_cache_size_bytes && 5513 coinsdb_size == m_coinsdb_cache_size_bytes) { 5514 // Cache sizes are unchanged, no need to continue. 5515 return true; 5516 } 5517 size_t old_coinstip_size = m_coinstip_cache_size_bytes; 5518 m_coinstip_cache_size_bytes = coinstip_size; 5519 m_coinsdb_cache_size_bytes = coinsdb_size; 5520 CoinsDB().ResizeCache(coinsdb_size); 5521 5522 LogInfo("[%s] resized coinsdb cache to %.1f MiB", 5523 this->ToString(), coinsdb_size * (1.0 / 1024 / 1024)); 5524 LogInfo("[%s] resized coinstip cache to %.1f MiB", 5525 this->ToString(), coinstip_size * (1.0 / 1024 / 1024)); 5526 5527 BlockValidationState state; 5528 bool ret; 5529 5530 if (coinstip_size > old_coinstip_size) { 5531 // Likely no need to flush if cache sizes have grown. 5532 ret = FlushStateToDisk(state, FlushStateMode::IF_NEEDED); 5533 } else { 5534 // Otherwise, flush state to disk and deallocate the in-memory coins map. 5535 ret = FlushStateToDisk(state, FlushStateMode::ALWAYS); 5536 } 5537 return ret; 5538 } 5539 5540 double ChainstateManager::GuessVerificationProgress(const CBlockIndex* pindex) const 5541 { 5542 AssertLockHeld(GetMutex()); 5543 const ChainTxData& data{GetParams().TxData()}; 5544 if (pindex == nullptr) { 5545 return 0.0; 5546 } 5547 5548 if (pindex->m_chain_tx_count == 0) { 5549 LogDebug(BCLog::VALIDATION, "Block %d has unset m_chain_tx_count. Unable to estimate verification progress.\n", pindex->nHeight); 5550 return 0.0; 5551 } 5552 5553 const int64_t nNow{TicksSinceEpoch<std::chrono::seconds>(NodeClock::now())}; 5554 const auto block_time{ 5555 (Assume(m_best_header) && std::abs(nNow - pindex->GetBlockTime()) <= Ticks<std::chrono::seconds>(2h) && 5556 Assume(m_best_header->nHeight >= pindex->nHeight)) ? 5557 // When the header is known to be recent, switch to a height-based 5558 // approach. This ensures the returned value is quantized when 5559 // close to "1.0", because some users expect it to be. This also 5560 // avoids relying too much on the exact miner-set timestamp, which 5561 // may be off. 5562 nNow - (m_best_header->nHeight - pindex->nHeight) * GetConsensus().nPowTargetSpacing : 5563 pindex->GetBlockTime(), 5564 }; 5565 5566 double fTxTotal; 5567 5568 if (pindex->m_chain_tx_count <= data.tx_count) { 5569 fTxTotal = data.tx_count + (nNow - data.nTime) * data.dTxRate; 5570 } else { 5571 fTxTotal = pindex->m_chain_tx_count + (nNow - block_time) * data.dTxRate; 5572 } 5573 5574 return std::min<double>(pindex->m_chain_tx_count / fTxTotal, 1.0); 5575 } 5576 5577 std::optional<uint256> ChainstateManager::SnapshotBlockhash() const 5578 { 5579 LOCK(::cs_main); 5580 if (m_active_chainstate && m_active_chainstate->m_from_snapshot_blockhash) { 5581 // If a snapshot chainstate exists, it will always be our active. 5582 return m_active_chainstate->m_from_snapshot_blockhash; 5583 } 5584 return std::nullopt; 5585 } 5586 5587 std::vector<Chainstate*> ChainstateManager::GetAll() 5588 { 5589 LOCK(::cs_main); 5590 std::vector<Chainstate*> out; 5591 5592 for (Chainstate* cs : {m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) { 5593 if (this->IsUsable(cs)) out.push_back(cs); 5594 } 5595 5596 return out; 5597 } 5598 5599 Chainstate& ChainstateManager::InitializeChainstate(CTxMemPool* mempool) 5600 { 5601 AssertLockHeld(::cs_main); 5602 assert(!m_ibd_chainstate); 5603 assert(!m_active_chainstate); 5604 5605 m_ibd_chainstate = std::make_unique<Chainstate>(mempool, m_blockman, *this); 5606 m_active_chainstate = m_ibd_chainstate.get(); 5607 return *m_active_chainstate; 5608 } 5609 5610 [[nodiscard]] static bool DeleteCoinsDBFromDisk(const fs::path db_path, bool is_snapshot) 5611 EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 5612 { 5613 AssertLockHeld(::cs_main); 5614 5615 if (is_snapshot) { 5616 fs::path base_blockhash_path = db_path / node::SNAPSHOT_BLOCKHASH_FILENAME; 5617 5618 try { 5619 bool existed = fs::remove(base_blockhash_path); 5620 if (!existed) { 5621 LogWarning("[snapshot] snapshot chainstate dir being removed lacks %s file", 5622 fs::PathToString(node::SNAPSHOT_BLOCKHASH_FILENAME)); 5623 } 5624 } catch (const fs::filesystem_error& e) { 5625 LogWarning("[snapshot] failed to remove file %s: %s\n", 5626 fs::PathToString(base_blockhash_path), e.code().message()); 5627 } 5628 } 5629 5630 std::string path_str = fs::PathToString(db_path); 5631 LogInfo("Removing leveldb dir at %s\n", path_str); 5632 5633 // We have to destruct before this call leveldb::DB in order to release the db 5634 // lock, otherwise `DestroyDB` will fail. See `leveldb::~DBImpl()`. 5635 const bool destroyed = DestroyDB(path_str); 5636 5637 if (!destroyed) { 5638 LogError("leveldb DestroyDB call failed on %s", path_str); 5639 } 5640 5641 // Datadir should be removed from filesystem; otherwise initialization may detect 5642 // it on subsequent statups and get confused. 5643 // 5644 // If the base_blockhash_path removal above fails in the case of snapshot 5645 // chainstates, this will return false since leveldb won't remove a non-empty 5646 // directory. 5647 return destroyed && !fs::exists(db_path); 5648 } 5649 5650 util::Result<CBlockIndex*> ChainstateManager::ActivateSnapshot( 5651 AutoFile& coins_file, 5652 const SnapshotMetadata& metadata, 5653 bool in_memory) 5654 { 5655 uint256 base_blockhash = metadata.m_base_blockhash; 5656 5657 if (this->SnapshotBlockhash()) { 5658 return util::Error{Untranslated("Can't activate a snapshot-based chainstate more than once")}; 5659 } 5660 5661 CBlockIndex* snapshot_start_block{}; 5662 5663 { 5664 LOCK(::cs_main); 5665 5666 if (!GetParams().AssumeutxoForBlockhash(base_blockhash).has_value()) { 5667 auto available_heights = GetParams().GetAvailableSnapshotHeights(); 5668 std::string heights_formatted = util::Join(available_heights, ", ", [&](const auto& i) { return util::ToString(i); }); 5669 return util::Error{Untranslated(strprintf("assumeutxo block hash in snapshot metadata not recognized (hash: %s). The following snapshot heights are available: %s", 5670 base_blockhash.ToString(), 5671 heights_formatted))}; 5672 } 5673 5674 snapshot_start_block = m_blockman.LookupBlockIndex(base_blockhash); 5675 if (!snapshot_start_block) { 5676 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", 5677 base_blockhash.ToString()))}; 5678 } 5679 5680 bool start_block_invalid = snapshot_start_block->nStatus & BLOCK_FAILED_MASK; 5681 if (start_block_invalid) { 5682 return util::Error{Untranslated(strprintf("The base block header (%s) is part of an invalid chain", base_blockhash.ToString()))}; 5683 } 5684 5685 if (!m_best_header || m_best_header->GetAncestor(snapshot_start_block->nHeight) != snapshot_start_block) { 5686 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.")}; 5687 } 5688 5689 auto mempool{m_active_chainstate->GetMempool()}; 5690 if (mempool && mempool->size() > 0) { 5691 return util::Error{Untranslated("Can't activate a snapshot when mempool not empty")}; 5692 } 5693 } 5694 5695 int64_t current_coinsdb_cache_size{0}; 5696 int64_t current_coinstip_cache_size{0}; 5697 5698 // Cache percentages to allocate to each chainstate. 5699 // 5700 // These particular percentages don't matter so much since they will only be 5701 // relevant during snapshot activation; caches are rebalanced at the conclusion of 5702 // this function. We want to give (essentially) all available cache capacity to the 5703 // snapshot to aid the bulk load later in this function. 5704 static constexpr double IBD_CACHE_PERC = 0.01; 5705 static constexpr double SNAPSHOT_CACHE_PERC = 0.99; 5706 5707 { 5708 LOCK(::cs_main); 5709 // Resize the coins caches to ensure we're not exceeding memory limits. 5710 // 5711 // Allocate the majority of the cache to the incoming snapshot chainstate, since 5712 // (optimistically) getting to its tip will be the top priority. We'll need to call 5713 // `MaybeRebalanceCaches()` once we're done with this function to ensure 5714 // the right allocation (including the possibility that no snapshot was activated 5715 // and that we should restore the active chainstate caches to their original size). 5716 // 5717 current_coinsdb_cache_size = this->ActiveChainstate().m_coinsdb_cache_size_bytes; 5718 current_coinstip_cache_size = this->ActiveChainstate().m_coinstip_cache_size_bytes; 5719 5720 // Temporarily resize the active coins cache to make room for the newly-created 5721 // snapshot chain. 5722 this->ActiveChainstate().ResizeCoinsCaches( 5723 static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC), 5724 static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC)); 5725 } 5726 5727 auto snapshot_chainstate = WITH_LOCK(::cs_main, 5728 return std::make_unique<Chainstate>( 5729 /*mempool=*/nullptr, m_blockman, *this, base_blockhash)); 5730 5731 { 5732 LOCK(::cs_main); 5733 snapshot_chainstate->InitCoinsDB( 5734 static_cast<size_t>(current_coinsdb_cache_size * SNAPSHOT_CACHE_PERC), 5735 in_memory, false, "chainstate"); 5736 snapshot_chainstate->InitCoinsCache( 5737 static_cast<size_t>(current_coinstip_cache_size * SNAPSHOT_CACHE_PERC)); 5738 } 5739 5740 auto cleanup_bad_snapshot = [&](bilingual_str reason) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 5741 this->MaybeRebalanceCaches(); 5742 5743 // PopulateAndValidateSnapshot can return (in error) before the leveldb datadir 5744 // has been created, so only attempt removal if we got that far. 5745 if (auto snapshot_datadir = node::FindSnapshotChainstateDir(m_options.datadir)) { 5746 // We have to destruct leveldb::DB in order to release the db lock, otherwise 5747 // DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See `leveldb::~DBImpl()`. 5748 // Destructing the chainstate (and so resetting the coinsviews object) does this. 5749 snapshot_chainstate.reset(); 5750 bool removed = DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true); 5751 if (!removed) { 5752 GetNotifications().fatalError(strprintf(_("Failed to remove snapshot chainstate dir (%s). " 5753 "Manually remove it before restarting.\n"), fs::PathToString(*snapshot_datadir))); 5754 } 5755 } 5756 return util::Error{std::move(reason)}; 5757 }; 5758 5759 if (auto res{this->PopulateAndValidateSnapshot(*snapshot_chainstate, coins_file, metadata)}; !res) { 5760 LOCK(::cs_main); 5761 return cleanup_bad_snapshot(Untranslated(strprintf("Population failed: %s", util::ErrorString(res).original))); 5762 } 5763 5764 LOCK(::cs_main); // cs_main required for rest of snapshot activation. 5765 5766 // Do a final check to ensure that the snapshot chainstate is actually a more 5767 // work chain than the active chainstate; a user could have loaded a snapshot 5768 // very late in the IBD process, and we wouldn't want to load a useless chainstate. 5769 if (!CBlockIndexWorkComparator()(ActiveTip(), snapshot_chainstate->m_chain.Tip())) { 5770 return cleanup_bad_snapshot(Untranslated("work does not exceed active chainstate")); 5771 } 5772 // If not in-memory, persist the base blockhash for use during subsequent 5773 // initialization. 5774 if (!in_memory) { 5775 if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) { 5776 return cleanup_bad_snapshot(Untranslated("could not write base blockhash")); 5777 } 5778 } 5779 5780 assert(!m_snapshot_chainstate); 5781 m_snapshot_chainstate.swap(snapshot_chainstate); 5782 const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip(); 5783 assert(chaintip_loaded); 5784 5785 // Transfer possession of the mempool to the snapshot chainstate. 5786 // Mempool is empty at this point because we're still in IBD. 5787 Assert(m_active_chainstate->m_mempool->size() == 0); 5788 Assert(!m_snapshot_chainstate->m_mempool); 5789 m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool; 5790 m_active_chainstate->m_mempool = nullptr; 5791 m_active_chainstate = m_snapshot_chainstate.get(); 5792 m_blockman.m_snapshot_height = this->GetSnapshotBaseHeight(); 5793 5794 LogInfo("[snapshot] successfully activated snapshot %s", base_blockhash.ToString()); 5795 LogInfo("[snapshot] (%.2f MB)", 5796 m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() / (1000 * 1000)); 5797 5798 this->MaybeRebalanceCaches(); 5799 return snapshot_start_block; 5800 } 5801 5802 static void FlushSnapshotToDisk(CCoinsViewCache& coins_cache, bool snapshot_loaded) 5803 { 5804 LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE( 5805 strprintf("%s (%.2f MB)", 5806 snapshot_loaded ? "saving snapshot chainstate" : "flushing coins cache", 5807 coins_cache.DynamicMemoryUsage() / (1000 * 1000)), 5808 BCLog::LogFlags::ALL); 5809 5810 coins_cache.Flush(); 5811 } 5812 5813 struct StopHashingException : public std::exception 5814 { 5815 const char* what() const noexcept override 5816 { 5817 return "ComputeUTXOStats interrupted."; 5818 } 5819 }; 5820 5821 static void SnapshotUTXOHashBreakpoint(const util::SignalInterrupt& interrupt) 5822 { 5823 if (interrupt) throw StopHashingException(); 5824 } 5825 5826 util::Result<void> ChainstateManager::PopulateAndValidateSnapshot( 5827 Chainstate& snapshot_chainstate, 5828 AutoFile& coins_file, 5829 const SnapshotMetadata& metadata) 5830 { 5831 // It's okay to release cs_main before we're done using `coins_cache` because we know 5832 // that nothing else will be referencing the newly created snapshot_chainstate yet. 5833 CCoinsViewCache& coins_cache = *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip()); 5834 5835 uint256 base_blockhash = metadata.m_base_blockhash; 5836 5837 CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash)); 5838 5839 if (!snapshot_start_block) { 5840 // Needed for ComputeUTXOStats to determine the 5841 // height and to avoid a crash when base_blockhash.IsNull() 5842 return util::Error{Untranslated(strprintf("Did not find snapshot start blockheader %s", 5843 base_blockhash.ToString()))}; 5844 } 5845 5846 int base_height = snapshot_start_block->nHeight; 5847 const auto& maybe_au_data = GetParams().AssumeutxoForHeight(base_height); 5848 5849 if (!maybe_au_data) { 5850 return util::Error{Untranslated(strprintf("Assumeutxo height in snapshot metadata not recognized " 5851 "(%d) - refusing to load snapshot", base_height))}; 5852 } 5853 5854 const AssumeutxoData& au_data = *maybe_au_data; 5855 5856 // This work comparison is a duplicate check with the one performed later in 5857 // ActivateSnapshot(), but is done so that we avoid doing the long work of staging 5858 // a snapshot that isn't actually usable. 5859 if (WITH_LOCK(::cs_main, return !CBlockIndexWorkComparator()(ActiveTip(), snapshot_start_block))) { 5860 return util::Error{Untranslated("Work does not exceed active chainstate")}; 5861 } 5862 5863 const uint64_t coins_count = metadata.m_coins_count; 5864 uint64_t coins_left = metadata.m_coins_count; 5865 5866 LogInfo("[snapshot] loading %d coins from snapshot %s", coins_left, base_blockhash.ToString()); 5867 int64_t coins_processed{0}; 5868 5869 while (coins_left > 0) { 5870 try { 5871 Txid txid; 5872 coins_file >> txid; 5873 size_t coins_per_txid{0}; 5874 coins_per_txid = ReadCompactSize(coins_file); 5875 5876 if (coins_per_txid > coins_left) { 5877 return util::Error{Untranslated("Mismatch in coins count in snapshot metadata and actual snapshot data")}; 5878 } 5879 5880 for (size_t i = 0; i < coins_per_txid; i++) { 5881 COutPoint outpoint; 5882 Coin coin; 5883 outpoint.n = static_cast<uint32_t>(ReadCompactSize(coins_file)); 5884 outpoint.hash = txid; 5885 coins_file >> coin; 5886 if (coin.nHeight > base_height || 5887 outpoint.n >= std::numeric_limits<decltype(outpoint.n)>::max() // Avoid integer wrap-around in coinstats.cpp:ApplyHash 5888 ) { 5889 return util::Error{Untranslated(strprintf("Bad snapshot data after deserializing %d coins", 5890 coins_count - coins_left))}; 5891 } 5892 if (!MoneyRange(coin.out.nValue)) { 5893 return util::Error{Untranslated(strprintf("Bad snapshot data after deserializing %d coins - bad tx out value", 5894 coins_count - coins_left))}; 5895 } 5896 coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint), std::move(coin)); 5897 5898 --coins_left; 5899 ++coins_processed; 5900 5901 if (coins_processed % 1000000 == 0) { 5902 LogInfo("[snapshot] %d coins loaded (%.2f%%, %.2f MB)", 5903 coins_processed, 5904 static_cast<float>(coins_processed) * 100 / static_cast<float>(coins_count), 5905 coins_cache.DynamicMemoryUsage() / (1000 * 1000)); 5906 } 5907 5908 // Batch write and flush (if we need to) every so often. 5909 // 5910 // If our average Coin size is roughly 41 bytes, checking every 120,000 coins 5911 // means <5MB of memory imprecision. 5912 if (coins_processed % 120000 == 0) { 5913 if (m_interrupt) { 5914 return util::Error{Untranslated("Aborting after an interrupt was requested")}; 5915 } 5916 5917 const auto snapshot_cache_state = WITH_LOCK(::cs_main, 5918 return snapshot_chainstate.GetCoinsCacheSizeState()); 5919 5920 if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) { 5921 // This is a hack - we don't know what the actual best block is, but that 5922 // doesn't matter for the purposes of flushing the cache here. We'll set this 5923 // to its correct value (`base_blockhash`) below after the coins are loaded. 5924 coins_cache.SetBestBlock(GetRandHash()); 5925 5926 // No need to acquire cs_main since this chainstate isn't being used yet. 5927 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/false); 5928 } 5929 } 5930 } 5931 } catch (const std::ios_base::failure&) { 5932 return util::Error{Untranslated(strprintf("Bad snapshot format or truncated snapshot after deserializing %d coins", 5933 coins_processed))}; 5934 } 5935 } 5936 5937 // Important that we set this. This and the coins_cache accesses above are 5938 // sort of a layer violation, but either we reach into the innards of 5939 // CCoinsViewCache here or we have to invert some of the Chainstate to 5940 // embed them in a snapshot-activation-specific CCoinsViewCache bulk load 5941 // method. 5942 coins_cache.SetBestBlock(base_blockhash); 5943 5944 bool out_of_coins{false}; 5945 try { 5946 std::byte left_over_byte; 5947 coins_file >> left_over_byte; 5948 } catch (const std::ios_base::failure&) { 5949 // We expect an exception since we should be out of coins. 5950 out_of_coins = true; 5951 } 5952 if (!out_of_coins) { 5953 return util::Error{Untranslated(strprintf("Bad snapshot - coins left over after deserializing %d coins", 5954 coins_count))}; 5955 } 5956 5957 LogInfo("[snapshot] loaded %d (%.2f MB) coins from snapshot %s", 5958 coins_count, 5959 coins_cache.DynamicMemoryUsage() / (1000 * 1000), 5960 base_blockhash.ToString()); 5961 5962 // No need to acquire cs_main since this chainstate isn't being used yet. 5963 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/true); 5964 5965 assert(coins_cache.GetBestBlock() == base_blockhash); 5966 5967 // As above, okay to immediately release cs_main here since no other context knows 5968 // about the snapshot_chainstate. 5969 CCoinsViewDB* snapshot_coinsdb = WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB()); 5970 5971 std::optional<CCoinsStats> maybe_stats; 5972 5973 try { 5974 maybe_stats = ComputeUTXOStats( 5975 CoinStatsHashType::HASH_SERIALIZED, snapshot_coinsdb, m_blockman, [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); }); 5976 } catch (StopHashingException const&) { 5977 return util::Error{Untranslated("Aborting after an interrupt was requested")}; 5978 } 5979 if (!maybe_stats.has_value()) { 5980 return util::Error{Untranslated("Failed to generate coins stats")}; 5981 } 5982 5983 // Assert that the deserialized chainstate contents match the expected assumeutxo value. 5984 if (AssumeutxoHash{maybe_stats->hashSerialized} != au_data.hash_serialized) { 5985 return util::Error{Untranslated(strprintf("Bad snapshot content hash: expected %s, got %s", 5986 au_data.hash_serialized.ToString(), maybe_stats->hashSerialized.ToString()))}; 5987 } 5988 5989 snapshot_chainstate.m_chain.SetTip(*snapshot_start_block); 5990 5991 // The remainder of this function requires modifying data protected by cs_main. 5992 LOCK(::cs_main); 5993 5994 // Fake various pieces of CBlockIndex state: 5995 CBlockIndex* index = nullptr; 5996 5997 // Don't make any modifications to the genesis block since it shouldn't be 5998 // necessary, and since the genesis block doesn't have normal flags like 5999 // BLOCK_VALID_SCRIPTS set. 6000 constexpr int AFTER_GENESIS_START{1}; 6001 6002 for (int i = AFTER_GENESIS_START; i <= snapshot_chainstate.m_chain.Height(); ++i) { 6003 index = snapshot_chainstate.m_chain[i]; 6004 6005 // Fake BLOCK_OPT_WITNESS so that Chainstate::NeedsRedownload() 6006 // won't ask for -reindex on startup. 6007 if (DeploymentActiveAt(*index, *this, Consensus::DEPLOYMENT_SEGWIT)) { 6008 index->nStatus |= BLOCK_OPT_WITNESS; 6009 } 6010 6011 m_blockman.m_dirty_blockindex.insert(index); 6012 // Changes to the block index will be flushed to disk after this call 6013 // returns in `ActivateSnapshot()`, when `MaybeRebalanceCaches()` is 6014 // called, since we've added a snapshot chainstate and therefore will 6015 // have to downsize the IBD chainstate, which will result in a call to 6016 // `FlushStateToDisk(ALWAYS)`. 6017 } 6018 6019 assert(index); 6020 assert(index == snapshot_start_block); 6021 index->m_chain_tx_count = au_data.m_chain_tx_count; 6022 snapshot_chainstate.setBlockIndexCandidates.insert(snapshot_start_block); 6023 6024 LogInfo("[snapshot] validated snapshot (%.2f MB)", 6025 coins_cache.DynamicMemoryUsage() / (1000 * 1000)); 6026 return {}; 6027 } 6028 6029 // Currently, this function holds cs_main for its duration, which could be for 6030 // multiple minutes due to the ComputeUTXOStats call. This hold is necessary 6031 // because we need to avoid advancing the background validation chainstate 6032 // farther than the snapshot base block - and this function is also invoked 6033 // from within ConnectTip, i.e. from within ActivateBestChain, so cs_main is 6034 // held anyway. 6035 // 6036 // Eventually (TODO), we could somehow separate this function's runtime from 6037 // maintenance of the active chain, but that will either require 6038 // 6039 // (i) setting `m_disabled` immediately and ensuring all chainstate accesses go 6040 // through IsUsable() checks, or 6041 // 6042 // (ii) giving each chainstate its own lock instead of using cs_main for everything. 6043 SnapshotCompletionResult ChainstateManager::MaybeCompleteSnapshotValidation() 6044 { 6045 AssertLockHeld(cs_main); 6046 if (m_ibd_chainstate.get() == &this->ActiveChainstate() || 6047 !this->IsUsable(m_snapshot_chainstate.get()) || 6048 !this->IsUsable(m_ibd_chainstate.get()) || 6049 !m_ibd_chainstate->m_chain.Tip()) { 6050 // Nothing to do - this function only applies to the background 6051 // validation chainstate. 6052 return SnapshotCompletionResult::SKIPPED; 6053 } 6054 const int snapshot_tip_height = this->ActiveHeight(); 6055 const int snapshot_base_height = *Assert(this->GetSnapshotBaseHeight()); 6056 const CBlockIndex& index_new = *Assert(m_ibd_chainstate->m_chain.Tip()); 6057 6058 if (index_new.nHeight < snapshot_base_height) { 6059 // Background IBD not complete yet. 6060 return SnapshotCompletionResult::SKIPPED; 6061 } 6062 6063 assert(SnapshotBlockhash()); 6064 uint256 snapshot_blockhash = *Assert(SnapshotBlockhash()); 6065 6066 auto handle_invalid_snapshot = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 6067 bilingual_str user_error = strprintf(_( 6068 "%s failed to validate the -assumeutxo snapshot state. " 6069 "This indicates a hardware problem, or a bug in the software, or a " 6070 "bad software modification that allowed an invalid snapshot to be " 6071 "loaded. As a result of this, the node will shut down and stop using any " 6072 "state that was built on the snapshot, resetting the chain height " 6073 "from %d to %d. On the next " 6074 "restart, the node will resume syncing from %d " 6075 "without using any snapshot data. " 6076 "Please report this incident to %s, including how you obtained the snapshot. " 6077 "The invalid snapshot chainstate will be left on disk in case it is " 6078 "helpful in diagnosing the issue that caused this error."), 6079 CLIENT_NAME, snapshot_tip_height, snapshot_base_height, snapshot_base_height, CLIENT_BUGREPORT 6080 ); 6081 6082 LogError("[snapshot] !!! %s\n", user_error.original); 6083 LogError("[snapshot] deleting snapshot, reverting to validated chain, and stopping node\n"); 6084 6085 m_active_chainstate = m_ibd_chainstate.get(); 6086 m_snapshot_chainstate->m_disabled = true; 6087 assert(!this->IsUsable(m_snapshot_chainstate.get())); 6088 assert(this->IsUsable(m_ibd_chainstate.get())); 6089 6090 auto rename_result = m_snapshot_chainstate->InvalidateCoinsDBOnDisk(); 6091 if (!rename_result) { 6092 user_error += Untranslated("\n") + util::ErrorString(rename_result); 6093 } 6094 6095 GetNotifications().fatalError(user_error); 6096 }; 6097 6098 if (index_new.GetBlockHash() != snapshot_blockhash) { 6099 LogWarning("[snapshot] supposed base block %s does not match the " 6100 "snapshot base block %s (height %d). Snapshot is not valid.", 6101 index_new.ToString(), snapshot_blockhash.ToString(), snapshot_base_height); 6102 handle_invalid_snapshot(); 6103 return SnapshotCompletionResult::BASE_BLOCKHASH_MISMATCH; 6104 } 6105 6106 assert(index_new.nHeight == snapshot_base_height); 6107 6108 int curr_height = m_ibd_chainstate->m_chain.Height(); 6109 6110 assert(snapshot_base_height == curr_height); 6111 assert(snapshot_base_height == index_new.nHeight); 6112 assert(this->IsUsable(m_snapshot_chainstate.get())); 6113 assert(this->GetAll().size() == 2); 6114 6115 CCoinsViewDB& ibd_coins_db = m_ibd_chainstate->CoinsDB(); 6116 m_ibd_chainstate->ForceFlushStateToDisk(); 6117 6118 const auto& maybe_au_data = m_options.chainparams.AssumeutxoForHeight(curr_height); 6119 if (!maybe_au_data) { 6120 LogWarning("[snapshot] assumeutxo data not found for height " 6121 "(%d) - refusing to validate snapshot", curr_height); 6122 handle_invalid_snapshot(); 6123 return SnapshotCompletionResult::MISSING_CHAINPARAMS; 6124 } 6125 6126 const AssumeutxoData& au_data = *maybe_au_data; 6127 std::optional<CCoinsStats> maybe_ibd_stats; 6128 LogInfo("[snapshot] computing UTXO stats for background chainstate to validate " 6129 "snapshot - this could take a few minutes"); 6130 try { 6131 maybe_ibd_stats = ComputeUTXOStats( 6132 CoinStatsHashType::HASH_SERIALIZED, 6133 &ibd_coins_db, 6134 m_blockman, 6135 [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); }); 6136 } catch (StopHashingException const&) { 6137 return SnapshotCompletionResult::STATS_FAILED; 6138 } 6139 6140 // XXX note that this function is slow and will hold cs_main for potentially minutes. 6141 if (!maybe_ibd_stats) { 6142 LogWarning("[snapshot] failed to generate stats for validation coins db"); 6143 // While this isn't a problem with the snapshot per se, this condition 6144 // prevents us from validating the snapshot, so we should shut down and let the 6145 // user handle the issue manually. 6146 handle_invalid_snapshot(); 6147 return SnapshotCompletionResult::STATS_FAILED; 6148 } 6149 const auto& ibd_stats = *maybe_ibd_stats; 6150 6151 // Compare the background validation chainstate's UTXO set hash against the hard-coded 6152 // assumeutxo hash we expect. 6153 // 6154 // TODO: For belt-and-suspenders, we could cache the UTXO set 6155 // hash for the snapshot when it's loaded in its chainstate's leveldb. We could then 6156 // reference that here for an additional check. 6157 if (AssumeutxoHash{ibd_stats.hashSerialized} != au_data.hash_serialized) { 6158 LogWarning("[snapshot] hash mismatch: actual=%s, expected=%s", 6159 ibd_stats.hashSerialized.ToString(), 6160 au_data.hash_serialized.ToString()); 6161 handle_invalid_snapshot(); 6162 return SnapshotCompletionResult::HASH_MISMATCH; 6163 } 6164 6165 LogInfo("[snapshot] snapshot beginning at %s has been fully validated", 6166 snapshot_blockhash.ToString()); 6167 6168 m_ibd_chainstate->m_disabled = true; 6169 this->MaybeRebalanceCaches(); 6170 6171 return SnapshotCompletionResult::SUCCESS; 6172 } 6173 6174 Chainstate& ChainstateManager::ActiveChainstate() const 6175 { 6176 LOCK(::cs_main); 6177 assert(m_active_chainstate); 6178 return *m_active_chainstate; 6179 } 6180 6181 bool ChainstateManager::IsSnapshotActive() const 6182 { 6183 LOCK(::cs_main); 6184 return m_snapshot_chainstate && m_active_chainstate == m_snapshot_chainstate.get(); 6185 } 6186 6187 void ChainstateManager::MaybeRebalanceCaches() 6188 { 6189 AssertLockHeld(::cs_main); 6190 bool ibd_usable = this->IsUsable(m_ibd_chainstate.get()); 6191 bool snapshot_usable = this->IsUsable(m_snapshot_chainstate.get()); 6192 assert(ibd_usable || snapshot_usable); 6193 6194 if (ibd_usable && !snapshot_usable) { 6195 // Allocate everything to the IBD chainstate. This will always happen 6196 // when we are not using a snapshot. 6197 m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache); 6198 } 6199 else if (snapshot_usable && !ibd_usable) { 6200 // If background validation has completed and snapshot is our active chain... 6201 LogInfo("[snapshot] allocating all cache to the snapshot chainstate"); 6202 // Allocate everything to the snapshot chainstate. 6203 m_snapshot_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache); 6204 } 6205 else if (ibd_usable && snapshot_usable) { 6206 // If both chainstates exist, determine who needs more cache based on IBD status. 6207 // 6208 // Note: shrink caches first so that we don't inadvertently overwhelm available memory. 6209 if (IsInitialBlockDownload()) { 6210 m_ibd_chainstate->ResizeCoinsCaches( 6211 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05); 6212 m_snapshot_chainstate->ResizeCoinsCaches( 6213 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95); 6214 } else { 6215 m_snapshot_chainstate->ResizeCoinsCaches( 6216 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05); 6217 m_ibd_chainstate->ResizeCoinsCaches( 6218 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95); 6219 } 6220 } 6221 } 6222 6223 void ChainstateManager::ResetChainstates() 6224 { 6225 m_ibd_chainstate.reset(); 6226 m_snapshot_chainstate.reset(); 6227 m_active_chainstate = nullptr; 6228 } 6229 6230 /** 6231 * Apply default chain params to nullopt members. 6232 * This helps to avoid coding errors around the accidental use of the compare 6233 * operators that accept nullopt, thus ignoring the intended default value. 6234 */ 6235 static ChainstateManager::Options&& Flatten(ChainstateManager::Options&& opts) 6236 { 6237 if (!opts.check_block_index.has_value()) opts.check_block_index = opts.chainparams.DefaultConsistencyChecks(); 6238 if (!opts.minimum_chain_work.has_value()) opts.minimum_chain_work = UintToArith256(opts.chainparams.GetConsensus().nMinimumChainWork); 6239 if (!opts.assumed_valid_block.has_value()) opts.assumed_valid_block = opts.chainparams.GetConsensus().defaultAssumeValid; 6240 return std::move(opts); 6241 } 6242 6243 ChainstateManager::ChainstateManager(const util::SignalInterrupt& interrupt, Options options, node::BlockManager::Options blockman_options) 6244 : m_script_check_queue{/*batch_size=*/128, std::clamp(options.worker_threads_num, 0, MAX_SCRIPTCHECK_THREADS)}, 6245 m_interrupt{interrupt}, 6246 m_options{Flatten(std::move(options))}, 6247 m_blockman{interrupt, std::move(blockman_options)}, 6248 m_validation_cache{m_options.script_execution_cache_bytes, m_options.signature_cache_bytes} 6249 { 6250 } 6251 6252 ChainstateManager::~ChainstateManager() 6253 { 6254 LOCK(::cs_main); 6255 6256 m_versionbitscache.Clear(); 6257 } 6258 6259 bool ChainstateManager::DetectSnapshotChainstate() 6260 { 6261 assert(!m_snapshot_chainstate); 6262 std::optional<fs::path> path = node::FindSnapshotChainstateDir(m_options.datadir); 6263 if (!path) { 6264 return false; 6265 } 6266 std::optional<uint256> base_blockhash = node::ReadSnapshotBaseBlockhash(*path); 6267 if (!base_blockhash) { 6268 return false; 6269 } 6270 LogInfo("[snapshot] detected active snapshot chainstate (%s) - loading", 6271 fs::PathToString(*path)); 6272 6273 this->ActivateExistingSnapshot(*base_blockhash); 6274 return true; 6275 } 6276 6277 Chainstate& ChainstateManager::ActivateExistingSnapshot(uint256 base_blockhash) 6278 { 6279 assert(!m_snapshot_chainstate); 6280 m_snapshot_chainstate = 6281 std::make_unique<Chainstate>(nullptr, m_blockman, *this, base_blockhash); 6282 LogInfo("[snapshot] switching active chainstate to %s", m_snapshot_chainstate->ToString()); 6283 6284 // Mempool is empty at this point because we're still in IBD. 6285 Assert(m_active_chainstate->m_mempool->size() == 0); 6286 Assert(!m_snapshot_chainstate->m_mempool); 6287 m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool; 6288 m_active_chainstate->m_mempool = nullptr; 6289 m_active_chainstate = m_snapshot_chainstate.get(); 6290 return *m_snapshot_chainstate; 6291 } 6292 6293 bool IsBIP30Repeat(const CBlockIndex& block_index) 6294 { 6295 return (block_index.nHeight==91842 && block_index.GetBlockHash() == uint256{"00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec"}) || 6296 (block_index.nHeight==91880 && block_index.GetBlockHash() == uint256{"00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721"}); 6297 } 6298 6299 bool IsBIP30Unspendable(const uint256& block_hash, int block_height) 6300 { 6301 return (block_height==91722 && block_hash == uint256{"00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e"}) || 6302 (block_height==91812 && block_hash == uint256{"00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"}); 6303 } 6304 6305 static fs::path GetSnapshotCoinsDBPath(Chainstate& cs) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 6306 { 6307 AssertLockHeld(::cs_main); 6308 // Should never be called on a non-snapshot chainstate. 6309 assert(cs.m_from_snapshot_blockhash); 6310 auto storage_path_maybe = cs.CoinsDB().StoragePath(); 6311 // Should never be called with a non-existent storage path. 6312 assert(storage_path_maybe); 6313 return *storage_path_maybe; 6314 } 6315 6316 util::Result<void> Chainstate::InvalidateCoinsDBOnDisk() 6317 { 6318 fs::path snapshot_datadir = GetSnapshotCoinsDBPath(*this); 6319 6320 // Coins views no longer usable. 6321 m_coins_views.reset(); 6322 6323 auto invalid_path = snapshot_datadir + "_INVALID"; 6324 std::string dbpath = fs::PathToString(snapshot_datadir); 6325 std::string target = fs::PathToString(invalid_path); 6326 LogInfo("[snapshot] renaming snapshot datadir %s to %s", dbpath, target); 6327 6328 // The invalid snapshot datadir is simply moved and not deleted because we may 6329 // want to do forensics later during issue investigation. The user is instructed 6330 // accordingly in MaybeCompleteSnapshotValidation(). 6331 try { 6332 fs::rename(snapshot_datadir, invalid_path); 6333 } catch (const fs::filesystem_error& e) { 6334 auto src_str = fs::PathToString(snapshot_datadir); 6335 auto dest_str = fs::PathToString(invalid_path); 6336 6337 LogError("While invalidating the coins db: Error renaming file '%s' -> '%s': %s", 6338 src_str, dest_str, e.what()); 6339 return util::Error{strprintf(_( 6340 "Rename of '%s' -> '%s' failed. " 6341 "You should resolve this by manually moving or deleting the invalid " 6342 "snapshot directory %s, otherwise you will encounter the same error again " 6343 "on the next startup."), 6344 src_str, dest_str, src_str)}; 6345 } 6346 return {}; 6347 } 6348 6349 bool ChainstateManager::DeleteSnapshotChainstate() 6350 { 6351 AssertLockHeld(::cs_main); 6352 Assert(m_snapshot_chainstate); 6353 Assert(m_ibd_chainstate); 6354 6355 fs::path snapshot_datadir = Assert(node::FindSnapshotChainstateDir(m_options.datadir)).value(); 6356 if (!DeleteCoinsDBFromDisk(snapshot_datadir, /*is_snapshot=*/ true)) { 6357 LogError("Deletion of %s failed. Please remove it manually to continue reindexing.", 6358 fs::PathToString(snapshot_datadir)); 6359 return false; 6360 } 6361 m_active_chainstate = m_ibd_chainstate.get(); 6362 m_active_chainstate->m_mempool = m_snapshot_chainstate->m_mempool; 6363 m_snapshot_chainstate.reset(); 6364 return true; 6365 } 6366 6367 ChainstateRole Chainstate::GetRole() const 6368 { 6369 if (m_chainman.GetAll().size() <= 1) { 6370 return ChainstateRole::NORMAL; 6371 } 6372 return (this != &m_chainman.ActiveChainstate()) ? 6373 ChainstateRole::BACKGROUND : 6374 ChainstateRole::ASSUMEDVALID; 6375 } 6376 6377 const CBlockIndex* ChainstateManager::GetSnapshotBaseBlock() const 6378 { 6379 return m_active_chainstate ? m_active_chainstate->SnapshotBase() : nullptr; 6380 } 6381 6382 std::optional<int> ChainstateManager::GetSnapshotBaseHeight() const 6383 { 6384 const CBlockIndex* base = this->GetSnapshotBaseBlock(); 6385 return base ? std::make_optional(base->nHeight) : std::nullopt; 6386 } 6387 6388 void ChainstateManager::RecalculateBestHeader() 6389 { 6390 AssertLockHeld(cs_main); 6391 m_best_header = ActiveChain().Tip(); 6392 for (auto& entry : m_blockman.m_block_index) { 6393 if (!(entry.second.nStatus & BLOCK_FAILED_MASK) && m_best_header->nChainWork < entry.second.nChainWork) { 6394 m_best_header = &entry.second; 6395 } 6396 } 6397 } 6398 6399 bool ChainstateManager::ValidatedSnapshotCleanup() 6400 { 6401 AssertLockHeld(::cs_main); 6402 auto get_storage_path = [](auto& chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) -> std::optional<fs::path> { 6403 if (!(chainstate && chainstate->HasCoinsViews())) { 6404 return {}; 6405 } 6406 return chainstate->CoinsDB().StoragePath(); 6407 }; 6408 std::optional<fs::path> ibd_chainstate_path_maybe = get_storage_path(m_ibd_chainstate); 6409 std::optional<fs::path> snapshot_chainstate_path_maybe = get_storage_path(m_snapshot_chainstate); 6410 6411 if (!this->IsSnapshotValidated()) { 6412 // No need to clean up. 6413 return false; 6414 } 6415 // If either path doesn't exist, that means at least one of the chainstates 6416 // is in-memory, in which case we can't do on-disk cleanup. You'd better be 6417 // in a unittest! 6418 if (!ibd_chainstate_path_maybe || !snapshot_chainstate_path_maybe) { 6419 LogError("[snapshot] snapshot chainstate cleanup cannot happen with " 6420 "in-memory chainstates. You are testing, right?"); 6421 return false; 6422 } 6423 6424 const auto& snapshot_chainstate_path = *snapshot_chainstate_path_maybe; 6425 const auto& ibd_chainstate_path = *ibd_chainstate_path_maybe; 6426 6427 // Since we're going to be moving around the underlying leveldb filesystem content 6428 // for each chainstate, make sure that the chainstates (and their constituent 6429 // CoinsViews members) have been destructed first. 6430 // 6431 // The caller of this method will be responsible for reinitializing chainstates 6432 // if they want to continue operation. 6433 this->ResetChainstates(); 6434 6435 // No chainstates should be considered usable. 6436 assert(this->GetAll().size() == 0); 6437 6438 LogInfo("[snapshot] deleting background chainstate directory (now unnecessary) (%s)", 6439 fs::PathToString(ibd_chainstate_path)); 6440 6441 fs::path tmp_old{ibd_chainstate_path + "_todelete"}; 6442 6443 auto rename_failed_abort = [this]( 6444 fs::path p_old, 6445 fs::path p_new, 6446 const fs::filesystem_error& err) { 6447 LogError("[snapshot] Error renaming path (%s) -> (%s): %s\n", 6448 fs::PathToString(p_old), fs::PathToString(p_new), err.what()); 6449 GetNotifications().fatalError(strprintf(_( 6450 "Rename of '%s' -> '%s' failed. " 6451 "Cannot clean up the background chainstate leveldb directory."), 6452 fs::PathToString(p_old), fs::PathToString(p_new))); 6453 }; 6454 6455 try { 6456 fs::rename(ibd_chainstate_path, tmp_old); 6457 } catch (const fs::filesystem_error& e) { 6458 rename_failed_abort(ibd_chainstate_path, tmp_old, e); 6459 throw; 6460 } 6461 6462 LogInfo("[snapshot] moving snapshot chainstate (%s) to " 6463 "default chainstate directory (%s)", 6464 fs::PathToString(snapshot_chainstate_path), fs::PathToString(ibd_chainstate_path)); 6465 6466 try { 6467 fs::rename(snapshot_chainstate_path, ibd_chainstate_path); 6468 } catch (const fs::filesystem_error& e) { 6469 rename_failed_abort(snapshot_chainstate_path, ibd_chainstate_path, e); 6470 throw; 6471 } 6472 6473 if (!DeleteCoinsDBFromDisk(tmp_old, /*is_snapshot=*/false)) { 6474 // No need to FatalError because once the unneeded bg chainstate data is 6475 // moved, it will not interfere with subsequent initialization. 6476 LogWarning("Deletion of %s failed. Please remove it manually, as the " 6477 "directory is now unnecessary.", 6478 fs::PathToString(tmp_old)); 6479 } else { 6480 LogInfo("[snapshot] deleted background chainstate directory (%s)", 6481 fs::PathToString(ibd_chainstate_path)); 6482 } 6483 return true; 6484 } 6485 6486 Chainstate& ChainstateManager::GetChainstateForIndexing() 6487 { 6488 // We can't always return `m_ibd_chainstate` because after background validation 6489 // has completed, `m_snapshot_chainstate == m_active_chainstate`, but it can be 6490 // indexed. 6491 return (this->GetAll().size() > 1) ? *m_ibd_chainstate : *m_active_chainstate; 6492 } 6493 6494 std::pair<int, int> ChainstateManager::GetPruneRange(const Chainstate& chainstate, int last_height_can_prune) 6495 { 6496 if (chainstate.m_chain.Height() <= 0) { 6497 return {0, 0}; 6498 } 6499 int prune_start{0}; 6500 6501 if (this->GetAll().size() > 1 && m_snapshot_chainstate.get() == &chainstate) { 6502 // Leave the blocks in the background IBD chain alone if we're pruning 6503 // the snapshot chain. 6504 prune_start = *Assert(GetSnapshotBaseHeight()) + 1; 6505 } 6506 6507 int max_prune = std::max<int>( 6508 0, chainstate.m_chain.Height() - static_cast<int>(MIN_BLOCKS_TO_KEEP)); 6509 6510 // last block to prune is the lesser of (caller-specified height, MIN_BLOCKS_TO_KEEP from the tip) 6511 // 6512 // While you might be tempted to prune the background chainstate more 6513 // aggressively (i.e. fewer MIN_BLOCKS_TO_KEEP), this won't work with index 6514 // building - specifically blockfilterindex requires undo data, and if 6515 // we don't maintain this trailing window, we hit indexing failures. 6516 int prune_end = std::min(last_height_can_prune, max_prune); 6517 6518 return {prune_start, prune_end}; 6519 }