validation.cpp
1 // Copyright (c) 2009-2010 Satoshi Nakamoto 2 // Copyright (c) 2009-2022 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 #if defined(HAVE_CONFIG_H) 7 #include <config/bitcoin-config.h> 8 #endif 9 10 #include <validation.h> 11 12 #include <arith_uint256.h> 13 #include <chain.h> 14 #include <checkqueue.h> 15 #include <clientversion.h> 16 #include <consensus/amount.h> 17 #include <consensus/consensus.h> 18 #include <consensus/merkle.h> 19 #include <consensus/tx_check.h> 20 #include <consensus/tx_verify.h> 21 #include <consensus/validation.h> 22 #include <cuckoocache.h> 23 #include <flatfile.h> 24 #include <hash.h> 25 #include <kernel/chain.h> 26 #include <kernel/chainparams.h> 27 #include <kernel/coinstats.h> 28 #include <kernel/disconnected_transactions.h> 29 #include <kernel/mempool_entry.h> 30 #include <kernel/messagestartchars.h> 31 #include <kernel/notifications_interface.h> 32 #include <logging.h> 33 #include <logging/timer.h> 34 #include <node/blockstorage.h> 35 #include <node/utxo_snapshot.h> 36 #include <policy/v3_policy.h> 37 #include <policy/policy.h> 38 #include <policy/rbf.h> 39 #include <policy/settings.h> 40 #include <pow.h> 41 #include <primitives/block.h> 42 #include <primitives/transaction.h> 43 #include <random.h> 44 #include <reverse_iterator.h> 45 #include <script/script.h> 46 #include <script/sigcache.h> 47 #include <signet.h> 48 #include <tinyformat.h> 49 #include <txdb.h> 50 #include <txmempool.h> 51 #include <uint256.h> 52 #include <undo.h> 53 #include <util/check.h> 54 #include <util/fs.h> 55 #include <util/fs_helpers.h> 56 #include <util/hasher.h> 57 #include <util/moneystr.h> 58 #include <util/rbf.h> 59 #include <util/result.h> 60 #include <util/signalinterrupt.h> 61 #include <util/strencodings.h> 62 #include <util/time.h> 63 #include <util/trace.h> 64 #include <util/translation.h> 65 #include <validationinterface.h> 66 #include <warnings.h> 67 68 #include <algorithm> 69 #include <cassert> 70 #include <chrono> 71 #include <deque> 72 #include <numeric> 73 #include <optional> 74 #include <string> 75 #include <tuple> 76 #include <utility> 77 78 using kernel::CCoinsStats; 79 using kernel::CoinStatsHashType; 80 using kernel::ComputeUTXOStats; 81 using kernel::Notifications; 82 83 using fsbridge::FopenFn; 84 using node::BlockManager; 85 using node::BlockMap; 86 using node::CBlockIndexHeightOnlyComparator; 87 using node::CBlockIndexWorkComparator; 88 using node::fReindex; 89 using node::SnapshotMetadata; 90 91 /** Time to wait between writing blocks/block index to disk. */ 92 static constexpr std::chrono::hours DATABASE_WRITE_INTERVAL{1}; 93 /** Time to wait between flushing chainstate to disk. */ 94 static constexpr std::chrono::hours DATABASE_FLUSH_INTERVAL{24}; 95 /** Maximum age of our tip for us to be considered current for fee estimation */ 96 static constexpr std::chrono::hours MAX_FEE_ESTIMATION_TIP_AGE{3}; 97 const std::vector<std::string> CHECKLEVEL_DOC { 98 "level 0 reads the blocks from disk", 99 "level 1 verifies block validity", 100 "level 2 verifies undo data", 101 "level 3 checks disconnection of tip blocks", 102 "level 4 tries to reconnect the blocks", 103 "each level includes the checks of the previous levels", 104 }; 105 /** The number of blocks to keep below the deepest prune lock. 106 * There is nothing special about this number. It is higher than what we 107 * expect to see in regular mainnet reorgs, but not so high that it would 108 * noticeably interfere with the pruning mechanism. 109 * */ 110 static constexpr int PRUNE_LOCK_BUFFER{10}; 111 112 GlobalMutex g_best_block_mutex; 113 std::condition_variable g_best_block_cv; 114 uint256 g_best_block; 115 116 const CBlockIndex* Chainstate::FindForkInGlobalIndex(const CBlockLocator& locator) const 117 { 118 AssertLockHeld(cs_main); 119 120 // Find the latest block common to locator and chain - we expect that 121 // locator.vHave is sorted descending by height. 122 for (const uint256& hash : locator.vHave) { 123 const CBlockIndex* pindex{m_blockman.LookupBlockIndex(hash)}; 124 if (pindex) { 125 if (m_chain.Contains(pindex)) { 126 return pindex; 127 } 128 if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) { 129 return m_chain.Tip(); 130 } 131 } 132 } 133 return m_chain.Genesis(); 134 } 135 136 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state, 137 const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore, 138 bool cacheFullScriptStore, PrecomputedTransactionData& txdata, 139 std::vector<CScriptCheck>* pvChecks = nullptr) 140 EXCLUSIVE_LOCKS_REQUIRED(cs_main); 141 142 bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx) 143 { 144 AssertLockHeld(cs_main); 145 146 // CheckFinalTxAtTip() uses active_chain_tip.Height()+1 to evaluate 147 // nLockTime because when IsFinalTx() is called within 148 // AcceptBlock(), the height of the block *being* 149 // evaluated is what is used. Thus if we want to know if a 150 // transaction can be part of the *next* block, we need to call 151 // IsFinalTx() with one more than active_chain_tip.Height(). 152 const int nBlockHeight = active_chain_tip.nHeight + 1; 153 154 // BIP113 requires that time-locked transactions have nLockTime set to 155 // less than the median time of the previous block they're contained in. 156 // When the next block is created its previous block will be the current 157 // chain tip, so we use that to calculate the median time passed to 158 // IsFinalTx(). 159 const int64_t nBlockTime{active_chain_tip.GetMedianTimePast()}; 160 161 return IsFinalTx(tx, nBlockHeight, nBlockTime); 162 } 163 164 namespace { 165 /** 166 * A helper which calculates heights of inputs of a given transaction. 167 * 168 * @param[in] tip The current chain tip. If an input belongs to a mempool 169 * transaction, we assume it will be confirmed in the next block. 170 * @param[in] coins Any CCoinsView that provides access to the relevant coins. 171 * @param[in] tx The transaction being evaluated. 172 * 173 * @returns A vector of input heights or nullopt, in case of an error. 174 */ 175 std::optional<std::vector<int>> CalculatePrevHeights( 176 const CBlockIndex& tip, 177 const CCoinsView& coins, 178 const CTransaction& tx) 179 { 180 std::vector<int> prev_heights; 181 prev_heights.resize(tx.vin.size()); 182 for (size_t i = 0; i < tx.vin.size(); ++i) { 183 const CTxIn& txin = tx.vin[i]; 184 Coin coin; 185 if (!coins.GetCoin(txin.prevout, coin)) { 186 LogPrintf("ERROR: %s: Missing input %d in transaction \'%s\'\n", __func__, i, tx.GetHash().GetHex()); 187 return std::nullopt; 188 } 189 if (coin.nHeight == MEMPOOL_HEIGHT) { 190 // Assume all mempool transaction confirm in the next block. 191 prev_heights[i] = tip.nHeight + 1; 192 } else { 193 prev_heights[i] = coin.nHeight; 194 } 195 } 196 return prev_heights; 197 } 198 } // namespace 199 200 std::optional<LockPoints> CalculateLockPointsAtTip( 201 CBlockIndex* tip, 202 const CCoinsView& coins_view, 203 const CTransaction& tx) 204 { 205 assert(tip); 206 207 auto prev_heights{CalculatePrevHeights(*tip, coins_view, tx)}; 208 if (!prev_heights.has_value()) return std::nullopt; 209 210 CBlockIndex next_tip; 211 next_tip.pprev = tip; 212 // When SequenceLocks() is called within ConnectBlock(), the height 213 // of the block *being* evaluated is what is used. 214 // Thus if we want to know if a transaction can be part of the 215 // *next* block, we need to use one more than active_chainstate.m_chain.Height() 216 next_tip.nHeight = tip->nHeight + 1; 217 const auto [min_height, min_time] = CalculateSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS, prev_heights.value(), next_tip); 218 219 // Also store the hash of the block with the highest height of 220 // all the blocks which have sequence locked prevouts. 221 // This hash needs to still be on the chain 222 // for these LockPoint calculations to be valid 223 // Note: It is impossible to correctly calculate a maxInputBlock 224 // if any of the sequence locked inputs depend on unconfirmed txs, 225 // except in the special case where the relative lock time/height 226 // is 0, which is equivalent to no sequence lock. Since we assume 227 // input height of tip+1 for mempool txs and test the resulting 228 // min_height and min_time from CalculateSequenceLocks against tip+1. 229 int max_input_height{0}; 230 for (const int height : prev_heights.value()) { 231 // Can ignore mempool inputs since we'll fail if they had non-zero locks 232 if (height != next_tip.nHeight) { 233 max_input_height = std::max(max_input_height, height); 234 } 235 } 236 237 // tip->GetAncestor(max_input_height) should never return a nullptr 238 // because max_input_height is always less than the tip height. 239 // It would, however, be a bad bug to continue execution, since a 240 // LockPoints object with the maxInputBlock member set to nullptr 241 // signifies no relative lock time. 242 return LockPoints{min_height, min_time, Assert(tip->GetAncestor(max_input_height))}; 243 } 244 245 bool CheckSequenceLocksAtTip(CBlockIndex* tip, 246 const LockPoints& lock_points) 247 { 248 assert(tip != nullptr); 249 250 CBlockIndex index; 251 index.pprev = tip; 252 // CheckSequenceLocksAtTip() uses active_chainstate.m_chain.Height()+1 to evaluate 253 // height based locks because when SequenceLocks() is called within 254 // ConnectBlock(), the height of the block *being* 255 // evaluated is what is used. 256 // Thus if we want to know if a transaction can be part of the 257 // *next* block, we need to use one more than active_chainstate.m_chain.Height() 258 index.nHeight = tip->nHeight + 1; 259 260 return EvaluateSequenceLocks(index, {lock_points.height, lock_points.time}); 261 } 262 263 // Returns the script flags which should be checked for a given block 264 static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman); 265 266 static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache) 267 EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs) 268 { 269 AssertLockHeld(::cs_main); 270 AssertLockHeld(pool.cs); 271 int expired = pool.Expire(GetTime<std::chrono::seconds>() - pool.m_expiry); 272 if (expired != 0) { 273 LogPrint(BCLog::MEMPOOL, "Expired %i transactions from the memory pool\n", expired); 274 } 275 276 std::vector<COutPoint> vNoSpendsRemaining; 277 pool.TrimToSize(pool.m_max_size_bytes, &vNoSpendsRemaining); 278 for (const COutPoint& removed : vNoSpendsRemaining) 279 coins_cache.Uncache(removed); 280 } 281 282 static bool IsCurrentForFeeEstimation(Chainstate& active_chainstate) EXCLUSIVE_LOCKS_REQUIRED(cs_main) 283 { 284 AssertLockHeld(cs_main); 285 if (active_chainstate.m_chainman.IsInitialBlockDownload()) { 286 return false; 287 } 288 if (active_chainstate.m_chain.Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE)) 289 return false; 290 if (active_chainstate.m_chain.Height() < active_chainstate.m_chainman.m_best_header->nHeight - 1) { 291 return false; 292 } 293 return true; 294 } 295 296 void Chainstate::MaybeUpdateMempoolForReorg( 297 DisconnectedBlockTransactions& disconnectpool, 298 bool fAddToMempool) 299 { 300 if (!m_mempool) return; 301 302 AssertLockHeld(cs_main); 303 AssertLockHeld(m_mempool->cs); 304 std::vector<uint256> vHashUpdate; 305 { 306 // disconnectpool is ordered so that the front is the most recently-confirmed 307 // transaction (the last tx of the block at the tip) in the disconnected chain. 308 // Iterate disconnectpool in reverse, so that we add transactions 309 // back to the mempool starting with the earliest transaction that had 310 // been previously seen in a block. 311 const auto queuedTx = disconnectpool.take(); 312 auto it = queuedTx.rbegin(); 313 while (it != queuedTx.rend()) { 314 // ignore validation errors in resurrected transactions 315 if (!fAddToMempool || (*it)->IsCoinBase() || 316 AcceptToMemoryPool(*this, *it, GetTime(), 317 /*bypass_limits=*/true, /*test_accept=*/false).m_result_type != 318 MempoolAcceptResult::ResultType::VALID) { 319 // If the transaction doesn't make it in to the mempool, remove any 320 // transactions that depend on it (which would now be orphans). 321 m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG); 322 } else if (m_mempool->exists(GenTxid::Txid((*it)->GetHash()))) { 323 vHashUpdate.push_back((*it)->GetHash()); 324 } 325 ++it; 326 } 327 } 328 329 // AcceptToMemoryPool/addUnchecked all assume that new mempool entries have 330 // no in-mempool children, which is generally not true when adding 331 // previously-confirmed transactions back to the mempool. 332 // UpdateTransactionsFromBlock finds descendants of any transactions in 333 // the disconnectpool that were added back and cleans up the mempool state. 334 m_mempool->UpdateTransactionsFromBlock(vHashUpdate); 335 336 // Predicate to use for filtering transactions in removeForReorg. 337 // Checks whether the transaction is still final and, if it spends a coinbase output, mature. 338 // Also updates valid entries' cached LockPoints if needed. 339 // If false, the tx is still valid and its lockpoints are updated. 340 // If true, the tx would be invalid in the next block; remove this entry and all of its descendants. 341 // Note that v3 rules are not applied here, so reorgs may cause violations of v3 inheritance or 342 // topology restrictions. 343 const auto filter_final_and_mature = [&](CTxMemPool::txiter it) 344 EXCLUSIVE_LOCKS_REQUIRED(m_mempool->cs, ::cs_main) { 345 AssertLockHeld(m_mempool->cs); 346 AssertLockHeld(::cs_main); 347 const CTransaction& tx = it->GetTx(); 348 349 // The transaction must be final. 350 if (!CheckFinalTxAtTip(*Assert(m_chain.Tip()), tx)) return true; 351 352 const LockPoints& lp = it->GetLockPoints(); 353 // CheckSequenceLocksAtTip checks if the transaction will be final in the next block to be 354 // created on top of the new chain. 355 if (TestLockPointValidity(m_chain, lp)) { 356 if (!CheckSequenceLocksAtTip(m_chain.Tip(), lp)) { 357 return true; 358 } 359 } else { 360 const CCoinsViewMemPool view_mempool{&CoinsTip(), *m_mempool}; 361 const std::optional<LockPoints> new_lock_points{CalculateLockPointsAtTip(m_chain.Tip(), view_mempool, tx)}; 362 if (new_lock_points.has_value() && CheckSequenceLocksAtTip(m_chain.Tip(), *new_lock_points)) { 363 // Now update the mempool entry lockpoints as well. 364 it->UpdateLockPoints(*new_lock_points); 365 } else { 366 return true; 367 } 368 } 369 370 // If the transaction spends any coinbase outputs, it must be mature. 371 if (it->GetSpendsCoinbase()) { 372 for (const CTxIn& txin : tx.vin) { 373 if (m_mempool->exists(GenTxid::Txid(txin.prevout.hash))) continue; 374 const Coin& coin{CoinsTip().AccessCoin(txin.prevout)}; 375 assert(!coin.IsSpent()); 376 const auto mempool_spend_height{m_chain.Tip()->nHeight + 1}; 377 if (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY) { 378 return true; 379 } 380 } 381 } 382 // Transaction is still valid and cached LockPoints are updated. 383 return false; 384 }; 385 386 // We also need to remove any now-immature transactions 387 m_mempool->removeForReorg(m_chain, filter_final_and_mature); 388 // Re-limit mempool size, in case we added any transactions 389 LimitMempoolSize(*m_mempool, this->CoinsTip()); 390 } 391 392 /** 393 * Checks to avoid mempool polluting consensus critical paths since cached 394 * signature and script validity results will be reused if we validate this 395 * transaction again during block validation. 396 * */ 397 static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, TxValidationState& state, 398 const CCoinsViewCache& view, const CTxMemPool& pool, 399 unsigned int flags, PrecomputedTransactionData& txdata, CCoinsViewCache& coins_tip) 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); 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 const bool m_test_accept; 462 /** Whether we allow transactions to replace mempool transactions by BIP125 rules. If false, 463 * any transaction spending the same inputs as a transaction in the mempool is considered 464 * a conflict. */ 465 const bool m_allow_replacement; 466 /** When true, the mempool will not be trimmed when any transactions are submitted in 467 * Finalize(). Instead, limits should be enforced at the end to ensure the package is not 468 * partially submitted. 469 */ 470 const bool m_package_submission; 471 /** When true, use package feerates instead of individual transaction feerates for fee-based 472 * policies such as mempool min fee and min relay fee. 473 */ 474 const bool m_package_feerates; 475 /** Used for local submission of transactions to catch "absurd" fees 476 * due to fee miscalculation by wallets. std:nullopt implies unset, allowing any feerates. 477 * Any individual transaction failing this check causes immediate failure. 478 */ 479 const std::optional<CFeeRate> m_client_maxfeerate; 480 481 /** Parameters for single transaction mempool validation. */ 482 static ATMPArgs SingleAccept(const CChainParams& chainparams, int64_t accept_time, 483 bool bypass_limits, std::vector<COutPoint>& coins_to_uncache, 484 bool test_accept) { 485 return ATMPArgs{/* m_chainparams */ chainparams, 486 /* m_accept_time */ accept_time, 487 /* m_bypass_limits */ bypass_limits, 488 /* m_coins_to_uncache */ coins_to_uncache, 489 /* m_test_accept */ test_accept, 490 /* m_allow_replacement */ true, 491 /* m_package_submission */ false, 492 /* m_package_feerates */ false, 493 /* m_client_maxfeerate */ {}, // checked by caller 494 }; 495 } 496 497 /** Parameters for test package mempool validation through testmempoolaccept. */ 498 static ATMPArgs PackageTestAccept(const CChainParams& chainparams, int64_t accept_time, 499 std::vector<COutPoint>& coins_to_uncache) { 500 return ATMPArgs{/* m_chainparams */ chainparams, 501 /* m_accept_time */ accept_time, 502 /* m_bypass_limits */ false, 503 /* m_coins_to_uncache */ coins_to_uncache, 504 /* m_test_accept */ true, 505 /* m_allow_replacement */ false, 506 /* m_package_submission */ false, // not submitting to mempool 507 /* m_package_feerates */ false, 508 /* m_client_maxfeerate */ {}, // checked by caller 509 }; 510 } 511 512 /** Parameters for child-with-unconfirmed-parents package validation. */ 513 static ATMPArgs PackageChildWithParents(const CChainParams& chainparams, int64_t accept_time, 514 std::vector<COutPoint>& coins_to_uncache, const std::optional<CFeeRate>& client_maxfeerate) { 515 return ATMPArgs{/* m_chainparams */ chainparams, 516 /* m_accept_time */ accept_time, 517 /* m_bypass_limits */ false, 518 /* m_coins_to_uncache */ coins_to_uncache, 519 /* m_test_accept */ false, 520 /* m_allow_replacement */ false, 521 /* m_package_submission */ true, 522 /* m_package_feerates */ true, 523 /* m_client_maxfeerate */ client_maxfeerate, 524 }; 525 } 526 527 /** Parameters for a single transaction within a package. */ 528 static ATMPArgs SingleInPackageAccept(const ATMPArgs& package_args) { 529 return ATMPArgs{/* m_chainparams */ package_args.m_chainparams, 530 /* m_accept_time */ package_args.m_accept_time, 531 /* m_bypass_limits */ false, 532 /* m_coins_to_uncache */ package_args.m_coins_to_uncache, 533 /* m_test_accept */ package_args.m_test_accept, 534 /* m_allow_replacement */ true, 535 /* m_package_submission */ true, // do not LimitMempoolSize in Finalize() 536 /* m_package_feerates */ false, // only 1 transaction 537 /* m_client_maxfeerate */ package_args.m_client_maxfeerate, 538 }; 539 } 540 541 private: 542 // Private ctor to avoid exposing details to clients and allowing the possibility of 543 // mixing up the order of the arguments. Use static functions above instead. 544 ATMPArgs(const CChainParams& chainparams, 545 int64_t accept_time, 546 bool bypass_limits, 547 std::vector<COutPoint>& coins_to_uncache, 548 bool test_accept, 549 bool allow_replacement, 550 bool package_submission, 551 bool package_feerates, 552 std::optional<CFeeRate> client_maxfeerate) 553 : m_chainparams{chainparams}, 554 m_accept_time{accept_time}, 555 m_bypass_limits{bypass_limits}, 556 m_coins_to_uncache{coins_to_uncache}, 557 m_test_accept{test_accept}, 558 m_allow_replacement{allow_replacement}, 559 m_package_submission{package_submission}, 560 m_package_feerates{package_feerates}, 561 m_client_maxfeerate{client_maxfeerate} 562 { 563 } 564 }; 565 566 /** Clean up all non-chainstate coins from m_view and m_viewmempool. */ 567 void CleanupTemporaryCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 568 569 // Single transaction acceptance 570 MempoolAcceptResult AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 571 572 /** 573 * Multiple transaction acceptance. Transactions may or may not be interdependent, but must not 574 * conflict with each other, and the transactions cannot already be in the mempool. Parents must 575 * come before children if any dependencies exist. 576 */ 577 PackageMempoolAcceptResult AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 578 579 /** 580 * Submission of a subpackage. 581 * If subpackage size == 1, calls AcceptSingleTransaction() with adjusted ATMPArgs to avoid 582 * package policy restrictions like no CPFP carve out (PackageMempoolChecks) and disabled RBF 583 * (m_allow_replacement), and creates a PackageMempoolAcceptResult wrapping the result. 584 * 585 * If subpackage size > 1, calls AcceptMultipleTransactions() with the provided ATMPArgs. 586 * 587 * Also cleans up all non-chainstate coins from m_view at the end. 588 */ 589 PackageMempoolAcceptResult AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args) 590 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 591 592 /** 593 * Package (more specific than just multiple transactions) acceptance. Package must be a child 594 * with all of its unconfirmed parents, and topologically sorted. 595 */ 596 PackageMempoolAcceptResult AcceptPackage(const Package& package, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 597 598 private: 599 // All the intermediate state that gets passed between the various levels 600 // of checking a given transaction. 601 struct Workspace { 602 explicit Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {} 603 /** Txids of mempool transactions that this transaction directly conflicts with or may 604 * replace via sibling eviction. */ 605 std::set<Txid> m_conflicts; 606 /** Iterators to mempool entries that this transaction directly conflicts with or may 607 * replace via sibling eviction. */ 608 CTxMemPool::setEntries m_iters_conflicting; 609 /** Iterators to all mempool entries that would be replaced by this transaction, including 610 * m_conflicts and their descendants. */ 611 CTxMemPool::setEntries m_all_conflicting; 612 /** All mempool ancestors of this transaction. */ 613 CTxMemPool::setEntries m_ancestors; 614 /** Mempool entry constructed for this transaction. Constructed in PreChecks() but not 615 * inserted into the mempool until Finalize(). */ 616 std::unique_ptr<CTxMemPoolEntry> m_entry; 617 /** Pointers to the transactions that have been removed from the mempool and replaced by 618 * this transaction (everything in m_all_conflicting), used to return to the MemPoolAccept caller. Only populated if 619 * validation is successful and the original transactions are removed. */ 620 std::list<CTransactionRef> m_replaced_transactions; 621 /** Whether RBF-related data structures (m_conflicts, m_iters_conflicting, m_all_conflicting, 622 * m_replaced_transactions) include a sibling in addition to txns with conflicting inputs. */ 623 bool m_sibling_eviction{false}; 624 625 /** Virtual size of the transaction as used by the mempool, calculated using serialized size 626 * of the transaction and sigops. */ 627 int64_t m_vsize; 628 /** Fees paid by this transaction: total input amounts subtracted by total output amounts. */ 629 CAmount m_base_fees; 630 /** Base fees + any fee delta set by the user with prioritisetransaction. */ 631 CAmount m_modified_fees; 632 /** Total modified fees of all transactions being replaced. */ 633 CAmount m_conflicting_fees{0}; 634 /** Total virtual size of all transactions being replaced. */ 635 size_t m_conflicting_size{0}; 636 637 /** If we're doing package validation (i.e. m_package_feerates=true), the "effective" 638 * package feerate of this transaction is the total fees divided by the total size of 639 * transactions (which may include its ancestors and/or descendants). */ 640 CFeeRate m_package_feerate{0}; 641 642 const CTransactionRef& m_ptx; 643 /** Txid. */ 644 const Txid& m_hash; 645 TxValidationState m_state; 646 /** A temporary cache containing serialized transaction data for signature verification. 647 * Reused across PolicyScriptChecks and ConsensusScriptChecks. */ 648 PrecomputedTransactionData m_precomputed_txdata; 649 }; 650 651 // Run the policy checks on a given transaction, excluding any script checks. 652 // Looks up inputs, calculates feerate, considers replacement, evaluates 653 // package limits, etc. As this function can be invoked for "free" by a peer, 654 // only tests that are fast should be done here (to avoid CPU DoS). 655 bool PreChecks(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 656 657 // Run checks for mempool replace-by-fee. 658 bool ReplacementChecks(Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 659 660 // Enforce package mempool ancestor/descendant limits (distinct from individual 661 // ancestor/descendant limits done in PreChecks). 662 bool PackageMempoolChecks(const std::vector<CTransactionRef>& txns, 663 int64_t total_vsize, 664 PackageValidationState& package_state) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 665 666 // Run the script checks using our policy flags. As this can be slow, we should 667 // only invoke this on transactions that have otherwise passed policy checks. 668 bool PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 669 670 // Re-run the script checks, using consensus flags, and try to cache the 671 // result in the scriptcache. This should be done after 672 // PolicyScriptChecks(). This requires that all inputs either be in our 673 // utxo set or in the mempool. 674 bool ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 675 676 // Try to add the transaction to the mempool, removing any conflicts first. 677 // Returns true if the transaction is in the mempool after any size 678 // limiting is performed, false otherwise. 679 bool Finalize(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 680 681 // Submit all transactions to the mempool and call ConsensusScriptChecks to add to the script 682 // cache - should only be called after successful validation of all transactions in the package. 683 // Does not call LimitMempoolSize(), so mempool max_size_bytes may be temporarily exceeded. 684 bool SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, PackageValidationState& package_state, 685 std::map<uint256, MempoolAcceptResult>& results) 686 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 687 688 // Compare a package's feerate against minimum allowed. 689 bool CheckFeeRate(size_t package_size, CAmount package_fee, TxValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) 690 { 691 AssertLockHeld(::cs_main); 692 AssertLockHeld(m_pool.cs); 693 CAmount mempoolRejectFee = m_pool.GetMinFee().GetFee(package_size); 694 if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) { 695 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee)); 696 } 697 698 if (package_fee < m_pool.m_min_relay_feerate.GetFee(package_size)) { 699 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "min relay fee not met", 700 strprintf("%d < %d", package_fee, m_pool.m_min_relay_feerate.GetFee(package_size))); 701 } 702 return true; 703 } 704 705 private: 706 CTxMemPool& m_pool; 707 CCoinsViewCache m_view; 708 CCoinsViewMemPool m_viewmempool; 709 CCoinsView m_dummy; 710 711 Chainstate& m_active_chainstate; 712 713 /** Whether the transaction(s) would replace any mempool transactions and/or evict any siblings. 714 * If so, RBF rules apply. */ 715 bool m_rbf{false}; 716 }; 717 718 bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws) 719 { 720 AssertLockHeld(cs_main); 721 AssertLockHeld(m_pool.cs); 722 const CTransactionRef& ptx = ws.m_ptx; 723 const CTransaction& tx = *ws.m_ptx; 724 const Txid& hash = ws.m_hash; 725 726 // Copy/alias what we need out of args 727 const int64_t nAcceptTime = args.m_accept_time; 728 const bool bypass_limits = args.m_bypass_limits; 729 std::vector<COutPoint>& coins_to_uncache = args.m_coins_to_uncache; 730 731 // Alias what we need out of ws 732 TxValidationState& state = ws.m_state; 733 std::unique_ptr<CTxMemPoolEntry>& entry = ws.m_entry; 734 735 if (!CheckTransaction(tx, state)) { 736 return false; // state filled in by CheckTransaction 737 } 738 739 // Coinbase is only valid in a block, not as a loose transaction 740 if (tx.IsCoinBase()) 741 return state.Invalid(TxValidationResult::TX_CONSENSUS, "coinbase"); 742 743 // Rather not work on nonstandard transactions (unless -testnet/-regtest) 744 std::string reason; 745 if (m_pool.m_require_standard && !IsStandardTx(tx, m_pool.m_max_datacarrier_bytes, m_pool.m_permit_bare_multisig, m_pool.m_dust_relay_feerate, reason)) { 746 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason); 747 } 748 749 // Transactions smaller than 65 non-witness bytes are not relayed to mitigate CVE-2017-12842. 750 if (::GetSerializeSize(TX_NO_WITNESS(tx)) < MIN_STANDARD_TX_NONWITNESS_SIZE) 751 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "tx-size-small"); 752 753 // Only accept nLockTime-using transactions that can be mined in the next 754 // block; we don't want our mempool filled up with transactions that can't 755 // be mined yet. 756 if (!CheckFinalTxAtTip(*Assert(m_active_chainstate.m_chain.Tip()), tx)) { 757 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-final"); 758 } 759 760 if (m_pool.exists(GenTxid::Wtxid(tx.GetWitnessHash()))) { 761 // Exact transaction already exists in the mempool. 762 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-in-mempool"); 763 } else if (m_pool.exists(GenTxid::Txid(tx.GetHash()))) { 764 // Transaction with the same non-witness data but different witness (same txid, different 765 // wtxid) already exists in the mempool. 766 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-same-nonwitness-data-in-mempool"); 767 } 768 769 // Check for conflicts with in-memory transactions 770 for (const CTxIn &txin : tx.vin) 771 { 772 const CTransaction* ptxConflicting = m_pool.GetConflictTx(txin.prevout); 773 if (ptxConflicting) { 774 if (!args.m_allow_replacement) { 775 // Transaction conflicts with a mempool tx, but we're not allowing replacements. 776 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "bip125-replacement-disallowed"); 777 } 778 if (!ws.m_conflicts.count(ptxConflicting->GetHash())) 779 { 780 // Transactions that don't explicitly signal replaceability are 781 // *not* replaceable with the current logic, even if one of their 782 // unconfirmed ancestors signals replaceability. This diverges 783 // from BIP125's inherited signaling description (see CVE-2021-31876). 784 // Applications relying on first-seen mempool behavior should 785 // check all unconfirmed ancestors; otherwise an opt-in ancestor 786 // might be replaced, causing removal of this descendant. 787 // 788 // All V3 transactions are considered replaceable. 789 // 790 // Replaceability signaling of the original transactions may be 791 // ignored due to node setting. 792 const bool allow_rbf{m_pool.m_full_rbf || SignalsOptInRBF(*ptxConflicting) || ptxConflicting->nVersion == 3}; 793 if (!allow_rbf) { 794 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "txn-mempool-conflict"); 795 } 796 797 ws.m_conflicts.insert(ptxConflicting->GetHash()); 798 } 799 } 800 } 801 802 m_view.SetBackend(m_viewmempool); 803 804 const CCoinsViewCache& coins_cache = m_active_chainstate.CoinsTip(); 805 // do all inputs exist? 806 for (const CTxIn& txin : tx.vin) { 807 if (!coins_cache.HaveCoinInCache(txin.prevout)) { 808 coins_to_uncache.push_back(txin.prevout); 809 } 810 811 // Note: this call may add txin.prevout to the coins cache 812 // (coins_cache.cacheCoins) by way of FetchCoin(). It should be removed 813 // later (via coins_to_uncache) if this tx turns out to be invalid. 814 if (!m_view.HaveCoin(txin.prevout)) { 815 // Are inputs missing because we already have the tx? 816 for (size_t out = 0; out < tx.vout.size(); out++) { 817 // Optimistically just do efficient check of cache for outputs 818 if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) { 819 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-known"); 820 } 821 } 822 // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet 823 return state.Invalid(TxValidationResult::TX_MISSING_INPUTS, "bad-txns-inputs-missingorspent"); 824 } 825 } 826 827 // This is const, but calls into the back end CoinsViews. The CCoinsViewDB at the bottom of the 828 // hierarchy brings the best block into scope. See CCoinsViewDB::GetBestBlock(). 829 m_view.GetBestBlock(); 830 831 // we have all inputs cached now, so switch back to dummy (to protect 832 // against bugs where we pull more inputs from disk that miss being added 833 // to coins_to_uncache) 834 m_view.SetBackend(m_dummy); 835 836 assert(m_active_chainstate.m_blockman.LookupBlockIndex(m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip()); 837 838 // Only accept BIP68 sequence locked transactions that can be mined in the next 839 // block; we don't want our mempool filled up with transactions that can't 840 // be mined yet. 841 // Pass in m_view which has all of the relevant inputs cached. Note that, since m_view's 842 // backend was removed, it no longer pulls coins from the mempool. 843 const std::optional<LockPoints> lock_points{CalculateLockPointsAtTip(m_active_chainstate.m_chain.Tip(), m_view, tx)}; 844 if (!lock_points.has_value() || !CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(), *lock_points)) { 845 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-BIP68-final"); 846 } 847 848 // The mempool holds txs for the next block, so pass height+1 to CheckTxInputs 849 if (!Consensus::CheckTxInputs(tx, state, m_view, m_active_chainstate.m_chain.Height() + 1, ws.m_base_fees)) { 850 return false; // state filled in by CheckTxInputs 851 } 852 853 if (m_pool.m_require_standard && !AreInputsStandard(tx, m_view)) { 854 return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs"); 855 } 856 857 // Check for non-standard witnesses. 858 if (tx.HasWitness() && m_pool.m_require_standard && !IsWitnessStandard(tx, m_view)) { 859 return state.Invalid(TxValidationResult::TX_WITNESS_MUTATED, "bad-witness-nonstandard"); 860 } 861 862 int64_t nSigOpsCost = GetTransactionSigOpCost(tx, m_view, STANDARD_SCRIPT_VERIFY_FLAGS); 863 864 // ws.m_modified_fees includes any fee deltas from PrioritiseTransaction 865 ws.m_modified_fees = ws.m_base_fees; 866 m_pool.ApplyDelta(hash, ws.m_modified_fees); 867 868 // Keep track of transactions that spend a coinbase, which we re-scan 869 // during reorgs to ensure COINBASE_MATURITY is still met. 870 bool fSpendsCoinbase = false; 871 for (const CTxIn &txin : tx.vin) { 872 const Coin &coin = m_view.AccessCoin(txin.prevout); 873 if (coin.IsCoinBase()) { 874 fSpendsCoinbase = true; 875 break; 876 } 877 } 878 879 // Set entry_sequence to 0 when bypass_limits is used; this allows txs from a block 880 // reorg to be marked earlier than any child txs that were already in the mempool. 881 const uint64_t entry_sequence = bypass_limits ? 0 : m_pool.GetSequence(); 882 entry.reset(new CTxMemPoolEntry(ptx, ws.m_base_fees, nAcceptTime, m_active_chainstate.m_chain.Height(), entry_sequence, 883 fSpendsCoinbase, nSigOpsCost, lock_points.value())); 884 ws.m_vsize = entry->GetTxSize(); 885 886 if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST) 887 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "bad-txns-too-many-sigops", 888 strprintf("%d", nSigOpsCost)); 889 890 // No individual transactions are allowed below the min relay feerate except from disconnected blocks. 891 // This requirement, unlike CheckFeeRate, cannot be bypassed using m_package_feerates because, 892 // while a tx could be package CPFP'd when entering the mempool, we do not have a DoS-resistant 893 // method of ensuring the tx remains bumped. For example, the fee-bumping child could disappear 894 // due to a replacement. 895 // The only exception is v3 transactions. 896 if (!bypass_limits && ws.m_ptx->nVersion != 3 && ws.m_modified_fees < m_pool.m_min_relay_feerate.GetFee(ws.m_vsize)) { 897 // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not 898 // TX_RECONSIDERABLE, because it cannot be bypassed using package validation. 899 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met", 900 strprintf("%d < %d", ws.m_modified_fees, m_pool.m_min_relay_feerate.GetFee(ws.m_vsize))); 901 } 902 // No individual transactions are allowed below the mempool min feerate except from disconnected 903 // blocks and transactions in a package. Package transactions will be checked using package 904 // feerate later. 905 if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false; 906 907 ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts); 908 909 // Note that these modifications are only applicable to single transaction scenarios; 910 // carve-outs and package RBF are disabled for multi-transaction evaluations. 911 CTxMemPool::Limits maybe_rbf_limits = m_pool.m_limits; 912 913 // Calculate in-mempool ancestors, up to a limit. 914 if (ws.m_conflicts.size() == 1) { 915 // In general, when we receive an RBF transaction with mempool conflicts, we want to know whether we 916 // would meet the chain limits after the conflicts have been removed. However, there isn't a practical 917 // way to do this short of calculating the ancestor and descendant sets with an overlay cache of 918 // changed mempool entries. Due to both implementation and runtime complexity concerns, this isn't 919 // very realistic, thus we only ensure a limited set of transactions are RBF'able despite mempool 920 // conflicts here. Importantly, we need to ensure that some transactions which were accepted using 921 // the below carve-out are able to be RBF'ed, without impacting the security the carve-out provides 922 // for off-chain contract systems (see link in the comment below). 923 // 924 // Specifically, the subset of RBF transactions which we allow despite chain limits are those which 925 // conflict directly with exactly one other transaction (but may evict children of said transaction), 926 // and which are not adding any new mempool dependencies. Note that the "no new mempool dependencies" 927 // check is accomplished later, so we don't bother doing anything about it here, but if our 928 // policy changes, we may need to move that check to here instead of removing it wholesale. 929 // 930 // Such transactions are clearly not merging any existing packages, so we are only concerned with 931 // ensuring that (a) no package is growing past the package size (not count) limits and (b) we are 932 // not allowing something to effectively use the (below) carve-out spot when it shouldn't be allowed 933 // to. 934 // 935 // To check these we first check if we meet the RBF criteria, above, and increment the descendant 936 // limits by the direct conflict and its descendants (as these are recalculated in 937 // CalculateMempoolAncestors by assuming the new transaction being added is a new descendant, with no 938 // removals, of each parent's existing dependent set). The ancestor count limits are unmodified (as 939 // the ancestor limits should be the same for both our new transaction and any conflicts). 940 // We don't bother incrementing m_limit_descendants by the full removal count as that limit never comes 941 // into force here (as we're only adding a single transaction). 942 assert(ws.m_iters_conflicting.size() == 1); 943 CTxMemPool::txiter conflict = *ws.m_iters_conflicting.begin(); 944 945 maybe_rbf_limits.descendant_count += 1; 946 maybe_rbf_limits.descendant_size_vbytes += conflict->GetSizeWithDescendants(); 947 } 948 949 auto ancestors{m_pool.CalculateMemPoolAncestors(*entry, maybe_rbf_limits)}; 950 if (!ancestors) { 951 // If CalculateMemPoolAncestors fails second time, we want the original error string. 952 // Contracting/payment channels CPFP carve-out: 953 // If the new transaction is relatively small (up to 40k weight) 954 // and has at most one ancestor (ie ancestor limit of 2, including 955 // the new transaction), allow it if its parent has exactly the 956 // descendant limit descendants. 957 // 958 // This allows protocols which rely on distrusting counterparties 959 // being able to broadcast descendants of an unconfirmed transaction 960 // to be secure by simply only having two immediately-spendable 961 // outputs - one for each counterparty. For more info on the uses for 962 // this, see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html 963 CTxMemPool::Limits cpfp_carve_out_limits{ 964 .ancestor_count = 2, 965 .ancestor_size_vbytes = maybe_rbf_limits.ancestor_size_vbytes, 966 .descendant_count = maybe_rbf_limits.descendant_count + 1, 967 .descendant_size_vbytes = maybe_rbf_limits.descendant_size_vbytes + EXTRA_DESCENDANT_TX_SIZE_LIMIT, 968 }; 969 const auto error_message{util::ErrorString(ancestors).original}; 970 if (ws.m_vsize > EXTRA_DESCENDANT_TX_SIZE_LIMIT) { 971 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message); 972 } 973 ancestors = m_pool.CalculateMemPoolAncestors(*entry, cpfp_carve_out_limits); 974 if (!ancestors) return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message); 975 } 976 977 ws.m_ancestors = *ancestors; 978 // Even though just checking direct mempool parents for inheritance would be sufficient, we 979 // check using the full ancestor set here because it's more convenient to use what we have 980 // already calculated. 981 if (const auto err{SingleV3Checks(ws.m_ptx, ws.m_ancestors, ws.m_conflicts, ws.m_vsize)}) { 982 // Disabled within package validation. 983 if (err->second != nullptr && args.m_allow_replacement) { 984 // Potential sibling eviction. Add the sibling to our list of mempool conflicts to be 985 // included in RBF checks. 986 ws.m_conflicts.insert(err->second->GetHash()); 987 // Adding the sibling to m_iters_conflicting here means that it doesn't count towards 988 // RBF Carve Out above. This is correct, since removing to-be-replaced transactions from 989 // the descendant count is done separately in SingleV3Checks for v3 transactions. 990 ws.m_iters_conflicting.insert(m_pool.GetIter(err->second->GetHash()).value()); 991 ws.m_sibling_eviction = true; 992 // The sibling will be treated as part of the to-be-replaced set in ReplacementChecks. 993 // Note that we are not checking whether it opts in to replaceability via BIP125 or v3 994 // (which is normally done in PreChecks). However, the only way a v3 transaction can 995 // have a non-v3 and non-BIP125 descendant is due to a reorg. 996 } else { 997 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "v3-rule-violation", err->first); 998 } 999 } 1000 1001 // A transaction that spends outputs that would be replaced by it is invalid. Now 1002 // that we have the set of all ancestors we can detect this 1003 // pathological case by making sure ws.m_conflicts and ws.m_ancestors don't 1004 // intersect. 1005 if (const auto err_string{EntriesAndTxidsDisjoint(ws.m_ancestors, ws.m_conflicts, hash)}) { 1006 // We classify this as a consensus error because a transaction depending on something it 1007 // conflicts with would be inconsistent. 1008 return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-spends-conflicting-tx", *err_string); 1009 } 1010 1011 m_rbf = !ws.m_conflicts.empty(); 1012 return true; 1013 } 1014 1015 bool MemPoolAccept::ReplacementChecks(Workspace& ws) 1016 { 1017 AssertLockHeld(cs_main); 1018 AssertLockHeld(m_pool.cs); 1019 1020 const CTransaction& tx = *ws.m_ptx; 1021 const uint256& hash = ws.m_hash; 1022 TxValidationState& state = ws.m_state; 1023 1024 CFeeRate newFeeRate(ws.m_modified_fees, ws.m_vsize); 1025 // Enforce Rule #6. The replacement transaction must have a higher feerate than its direct conflicts. 1026 // - The motivation for this check is to ensure that the replacement transaction is preferable for 1027 // block-inclusion, compared to what would be removed from the mempool. 1028 // - This logic predates ancestor feerate-based transaction selection, which is why it doesn't 1029 // consider feerates of descendants. 1030 // - Note: Ancestor feerate-based transaction selection has made this comparison insufficient to 1031 // guarantee that this is incentive-compatible for miners, because it is possible for a 1032 // descendant transaction of a direct conflict to pay a higher feerate than the transaction that 1033 // might replace them, under these rules. 1034 if (const auto err_string{PaysMoreThanConflicts(ws.m_iters_conflicting, newFeeRate, hash)}) { 1035 // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not 1036 // TX_RECONSIDERABLE, because it cannot be bypassed using package validation. 1037 // This must be changed if package RBF is enabled. 1038 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, 1039 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1040 } 1041 1042 // Calculate all conflicting entries and enforce Rule #5. 1043 if (const auto err_string{GetEntriesForConflicts(tx, m_pool, ws.m_iters_conflicting, ws.m_all_conflicting)}) { 1044 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, 1045 strprintf("too many potential replacements%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1046 } 1047 // Enforce Rule #2. 1048 if (const auto err_string{HasNoNewUnconfirmed(tx, m_pool, ws.m_iters_conflicting)}) { 1049 // Sibling eviction is only done for v3 transactions, which cannot have multiple ancestors. 1050 Assume(!ws.m_sibling_eviction); 1051 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, 1052 strprintf("replacement-adds-unconfirmed%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1053 } 1054 // Check if it's economically rational to mine this transaction rather than the ones it 1055 // replaces and pays for its own relay fees. Enforce Rules #3 and #4. 1056 for (CTxMemPool::txiter it : ws.m_all_conflicting) { 1057 ws.m_conflicting_fees += it->GetModifiedFee(); 1058 ws.m_conflicting_size += it->GetTxSize(); 1059 } 1060 if (const auto err_string{PaysForRBF(ws.m_conflicting_fees, ws.m_modified_fees, ws.m_vsize, 1061 m_pool.m_incremental_relay_feerate, hash)}) { 1062 // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not 1063 // TX_RECONSIDERABLE, because it cannot be bypassed using package validation. 1064 // This must be changed if package RBF is enabled. 1065 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, 1066 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1067 } 1068 return true; 1069 } 1070 1071 bool MemPoolAccept::PackageMempoolChecks(const std::vector<CTransactionRef>& txns, 1072 const int64_t total_vsize, 1073 PackageValidationState& package_state) 1074 { 1075 AssertLockHeld(cs_main); 1076 AssertLockHeld(m_pool.cs); 1077 1078 // CheckPackageLimits expects the package transactions to not already be in the mempool. 1079 assert(std::all_of(txns.cbegin(), txns.cend(), [this](const auto& tx) 1080 { return !m_pool.exists(GenTxid::Txid(tx->GetHash()));})); 1081 1082 auto result = m_pool.CheckPackageLimits(txns, total_vsize); 1083 if (!result) { 1084 // This is a package-wide error, separate from an individual transaction error. 1085 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package-mempool-limits", util::ErrorString(result).original); 1086 } 1087 return true; 1088 } 1089 1090 bool MemPoolAccept::PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) 1091 { 1092 AssertLockHeld(cs_main); 1093 AssertLockHeld(m_pool.cs); 1094 const CTransaction& tx = *ws.m_ptx; 1095 TxValidationState& state = ws.m_state; 1096 1097 constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS; 1098 1099 // Check input scripts and signatures. 1100 // This is done last to help prevent CPU exhaustion denial-of-service attacks. 1101 if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false, ws.m_precomputed_txdata)) { 1102 // SCRIPT_VERIFY_CLEANSTACK requires SCRIPT_VERIFY_WITNESS, so we 1103 // need to turn both off, and compare against just turning off CLEANSTACK 1104 // to see if the failure is specifically due to witness validation. 1105 TxValidationState state_dummy; // Want reported failures to be from first CheckInputScripts 1106 if (!tx.HasWitness() && CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, ws.m_precomputed_txdata) && 1107 !CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, ws.m_precomputed_txdata)) { 1108 // Only the witness is missing, so the transaction itself may be fine. 1109 state.Invalid(TxValidationResult::TX_WITNESS_STRIPPED, 1110 state.GetRejectReason(), state.GetDebugMessage()); 1111 } 1112 return false; // state filled in by CheckInputScripts 1113 } 1114 1115 return true; 1116 } 1117 1118 bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) 1119 { 1120 AssertLockHeld(cs_main); 1121 AssertLockHeld(m_pool.cs); 1122 const CTransaction& tx = *ws.m_ptx; 1123 const uint256& hash = ws.m_hash; 1124 TxValidationState& state = ws.m_state; 1125 1126 // Check again against the current block tip's script verification 1127 // flags to cache our script execution flags. This is, of course, 1128 // useless if the next block has different script flags from the 1129 // previous one, but because the cache tracks script flags for us it 1130 // will auto-invalidate and we'll just have a few blocks of extra 1131 // misses on soft-fork activation. 1132 // 1133 // This is also useful in case of bugs in the standard flags that cause 1134 // transactions to pass as valid when they're actually invalid. For 1135 // instance the STRICTENC flag was incorrectly allowing certain 1136 // CHECKSIG NOT scripts to pass, even though they were invalid. 1137 // 1138 // There is a similar check in CreateNewBlock() to prevent creating 1139 // invalid blocks (using TestBlockValidity), however allowing such 1140 // transactions into the mempool can be exploited as a DoS attack. 1141 unsigned int currentBlockScriptVerifyFlags{GetBlockScriptFlags(*m_active_chainstate.m_chain.Tip(), m_active_chainstate.m_chainman)}; 1142 if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags, 1143 ws.m_precomputed_txdata, m_active_chainstate.CoinsTip())) { 1144 LogPrintf("BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s\n", hash.ToString(), state.ToString()); 1145 return Assume(false); 1146 } 1147 1148 return true; 1149 } 1150 1151 bool MemPoolAccept::Finalize(const ATMPArgs& args, Workspace& ws) 1152 { 1153 AssertLockHeld(cs_main); 1154 AssertLockHeld(m_pool.cs); 1155 const CTransaction& tx = *ws.m_ptx; 1156 const uint256& hash = ws.m_hash; 1157 TxValidationState& state = ws.m_state; 1158 const bool bypass_limits = args.m_bypass_limits; 1159 1160 std::unique_ptr<CTxMemPoolEntry>& entry = ws.m_entry; 1161 1162 // Remove conflicting transactions from the mempool 1163 for (CTxMemPool::txiter it : ws.m_all_conflicting) 1164 { 1165 LogPrint(BCLog::MEMPOOL, "replacing tx %s (wtxid=%s) with %s (wtxid=%s) for %s additional fees, %d delta bytes\n", 1166 it->GetTx().GetHash().ToString(), 1167 it->GetTx().GetWitnessHash().ToString(), 1168 hash.ToString(), 1169 tx.GetWitnessHash().ToString(), 1170 FormatMoney(ws.m_modified_fees - ws.m_conflicting_fees), 1171 (int)entry->GetTxSize() - (int)ws.m_conflicting_size); 1172 TRACE7(mempool, replaced, 1173 it->GetTx().GetHash().data(), 1174 it->GetTxSize(), 1175 it->GetFee(), 1176 std::chrono::duration_cast<std::chrono::duration<std::uint64_t>>(it->GetTime()).count(), 1177 hash.data(), 1178 entry->GetTxSize(), 1179 entry->GetFee() 1180 ); 1181 ws.m_replaced_transactions.push_back(it->GetSharedTx()); 1182 } 1183 m_pool.RemoveStaged(ws.m_all_conflicting, false, MemPoolRemovalReason::REPLACED); 1184 // Store transaction in memory 1185 m_pool.addUnchecked(*entry, ws.m_ancestors); 1186 1187 // trim mempool and check if tx was trimmed 1188 // If we are validating a package, don't trim here because we could evict a previous transaction 1189 // in the package. LimitMempoolSize() should be called at the very end to make sure the mempool 1190 // is still within limits and package submission happens atomically. 1191 if (!args.m_package_submission && !bypass_limits) { 1192 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip()); 1193 if (!m_pool.exists(GenTxid::Txid(hash))) 1194 // The tx no longer meets our (new) mempool minimum feerate but could be reconsidered in a package. 1195 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool full"); 1196 } 1197 return true; 1198 } 1199 1200 bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, 1201 PackageValidationState& package_state, 1202 std::map<uint256, MempoolAcceptResult>& results) 1203 { 1204 AssertLockHeld(cs_main); 1205 AssertLockHeld(m_pool.cs); 1206 // Sanity check: none of the transactions should be in the mempool, and none of the transactions 1207 // should have a same-txid-different-witness equivalent in the mempool. 1208 assert(std::all_of(workspaces.cbegin(), workspaces.cend(), [this](const auto& ws){ 1209 return !m_pool.exists(GenTxid::Txid(ws.m_ptx->GetHash())); })); 1210 1211 bool all_submitted = true; 1212 // ConsensusScriptChecks adds to the script cache and is therefore consensus-critical; 1213 // CheckInputsFromMempoolAndCache asserts that transactions only spend coins available from the 1214 // mempool or UTXO set. Submit each transaction to the mempool immediately after calling 1215 // ConsensusScriptChecks to make the outputs available for subsequent transactions. 1216 for (Workspace& ws : workspaces) { 1217 if (!ConsensusScriptChecks(args, ws)) { 1218 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1219 // Since PolicyScriptChecks() passed, this should never fail. 1220 Assume(false); 1221 all_submitted = false; 1222 package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR, 1223 strprintf("BUG! PolicyScriptChecks succeeded but ConsensusScriptChecks failed: %s", 1224 ws.m_ptx->GetHash().ToString())); 1225 } 1226 1227 // Re-calculate mempool ancestors to call addUnchecked(). They may have changed since the 1228 // last calculation done in PreChecks, since package ancestors have already been submitted. 1229 { 1230 auto ancestors{m_pool.CalculateMemPoolAncestors(*ws.m_entry, m_pool.m_limits)}; 1231 if(!ancestors) { 1232 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1233 // Since PreChecks() and PackageMempoolChecks() both enforce limits, this should never fail. 1234 Assume(false); 1235 all_submitted = false; 1236 package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR, 1237 strprintf("BUG! Mempool ancestors or descendants were underestimated: %s", 1238 ws.m_ptx->GetHash().ToString())); 1239 } 1240 ws.m_ancestors = std::move(ancestors).value_or(ws.m_ancestors); 1241 } 1242 // If we call LimitMempoolSize() for each individual Finalize(), the mempool will not take 1243 // the transaction's descendant feerate into account because it hasn't seen them yet. Also, 1244 // we risk evicting a transaction that a subsequent package transaction depends on. Instead, 1245 // allow the mempool to temporarily bypass limits, the maximum package size) while 1246 // submitting transactions individually and then trim at the very end. 1247 if (!Finalize(args, ws)) { 1248 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1249 // Since LimitMempoolSize() won't be called, this should never fail. 1250 Assume(false); 1251 all_submitted = false; 1252 package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR, 1253 strprintf("BUG! Adding to mempool failed: %s", ws.m_ptx->GetHash().ToString())); 1254 } 1255 } 1256 1257 std::vector<Wtxid> all_package_wtxids; 1258 all_package_wtxids.reserve(workspaces.size()); 1259 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids), 1260 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); }); 1261 1262 // Add successful results. The returned results may change later if LimitMempoolSize() evicts them. 1263 for (Workspace& ws : workspaces) { 1264 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate : 1265 CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)}; 1266 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids : 1267 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()}; 1268 results.emplace(ws.m_ptx->GetWitnessHash(), 1269 MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize, 1270 ws.m_base_fees, effective_feerate, effective_feerate_wtxids)); 1271 if (!m_pool.m_signals) continue; 1272 const CTransaction& tx = *ws.m_ptx; 1273 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees, 1274 ws.m_vsize, ws.m_entry->GetHeight(), 1275 args.m_bypass_limits, args.m_package_submission, 1276 IsCurrentForFeeEstimation(m_active_chainstate), 1277 m_pool.HasNoInputsOf(tx)); 1278 m_pool.m_signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence()); 1279 } 1280 return all_submitted; 1281 } 1282 1283 MempoolAcceptResult MemPoolAccept::AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) 1284 { 1285 AssertLockHeld(cs_main); 1286 LOCK(m_pool.cs); // mempool "read lock" (held through m_pool.m_signals->TransactionAddedToMempool()) 1287 1288 Workspace ws(ptx); 1289 const std::vector<Wtxid> single_wtxid{ws.m_ptx->GetWitnessHash()}; 1290 1291 if (!PreChecks(args, ws)) { 1292 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) { 1293 // Failed for fee reasons. Provide the effective feerate and which tx was included. 1294 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid); 1295 } 1296 return MempoolAcceptResult::Failure(ws.m_state); 1297 } 1298 1299 // Individual modified feerate exceeded caller-defined max; abort 1300 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) { 1301 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", ""); 1302 return MempoolAcceptResult::Failure(ws.m_state); 1303 } 1304 1305 if (m_rbf && !ReplacementChecks(ws)) return MempoolAcceptResult::Failure(ws.m_state); 1306 1307 // Perform the inexpensive checks first and avoid hashing and signature verification unless 1308 // those checks pass, to mitigate CPU exhaustion denial-of-service attacks. 1309 if (!PolicyScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state); 1310 1311 if (!ConsensusScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state); 1312 1313 const CFeeRate effective_feerate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)}; 1314 // Tx was accepted, but not added 1315 if (args.m_test_accept) { 1316 return MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize, 1317 ws.m_base_fees, effective_feerate, single_wtxid); 1318 } 1319 1320 if (!Finalize(args, ws)) { 1321 // The only possible failure reason is fee-related (mempool full). 1322 // Failed for fee reasons. Provide the effective feerate and which txns were included. 1323 Assume(ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE); 1324 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), {ws.m_ptx->GetWitnessHash()}); 1325 } 1326 1327 if (m_pool.m_signals) { 1328 const CTransaction& tx = *ws.m_ptx; 1329 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees, 1330 ws.m_vsize, ws.m_entry->GetHeight(), 1331 args.m_bypass_limits, args.m_package_submission, 1332 IsCurrentForFeeEstimation(m_active_chainstate), 1333 m_pool.HasNoInputsOf(tx)); 1334 m_pool.m_signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence()); 1335 } 1336 1337 return MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize, ws.m_base_fees, 1338 effective_feerate, single_wtxid); 1339 } 1340 1341 PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args) 1342 { 1343 AssertLockHeld(cs_main); 1344 1345 // These context-free package limits can be done before taking the mempool lock. 1346 PackageValidationState package_state; 1347 if (!IsWellFormedPackage(txns, package_state, /*require_sorted=*/true)) return PackageMempoolAcceptResult(package_state, {}); 1348 1349 std::vector<Workspace> workspaces{}; 1350 workspaces.reserve(txns.size()); 1351 std::transform(txns.cbegin(), txns.cend(), std::back_inserter(workspaces), 1352 [](const auto& tx) { return Workspace(tx); }); 1353 std::map<uint256, MempoolAcceptResult> results; 1354 1355 LOCK(m_pool.cs); 1356 1357 // Do all PreChecks first and fail fast to avoid running expensive script checks when unnecessary. 1358 for (Workspace& ws : workspaces) { 1359 if (!PreChecks(args, ws)) { 1360 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1361 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1362 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1363 return PackageMempoolAcceptResult(package_state, std::move(results)); 1364 } 1365 1366 // Individual modified feerate exceeded caller-defined max; abort 1367 // N.B. this doesn't take into account CPFPs. Chunk-aware validation may be more robust. 1368 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) { 1369 package_state.Invalid(PackageValidationResult::PCKG_TX, "max feerate exceeded"); 1370 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1371 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1372 return PackageMempoolAcceptResult(package_state, std::move(results)); 1373 } 1374 1375 // Make the coins created by this transaction available for subsequent transactions in the 1376 // package to spend. Since we already checked conflicts in the package and we don't allow 1377 // replacements, we don't need to track the coins spent. Note that this logic will need to be 1378 // updated if package replace-by-fee is allowed in the future. 1379 assert(!args.m_allow_replacement); 1380 m_viewmempool.PackageAddTransaction(ws.m_ptx); 1381 } 1382 1383 // At this point we have all in-mempool ancestors, and we know every transaction's vsize. 1384 // Run the v3 checks on the package. 1385 for (Workspace& ws : workspaces) { 1386 if (auto err{PackageV3Checks(ws.m_ptx, ws.m_vsize, txns, ws.m_ancestors)}) { 1387 package_state.Invalid(PackageValidationResult::PCKG_POLICY, "v3-violation", err.value()); 1388 return PackageMempoolAcceptResult(package_state, {}); 1389 } 1390 } 1391 1392 // Transactions must meet two minimum feerates: the mempool minimum fee and min relay fee. 1393 // For transactions consisting of exactly one child and its parents, it suffices to use the 1394 // package feerate (total modified fees / total virtual size) to check this requirement. 1395 // Note that this is an aggregate feerate; this function has not checked that there are transactions 1396 // too low feerate to pay for themselves, or that the child transactions are higher feerate than 1397 // their parents. Using aggregate feerate may allow "parents pay for child" behavior and permit 1398 // a child that is below mempool minimum feerate. To avoid these behaviors, callers of 1399 // AcceptMultipleTransactions need to restrict txns topology (e.g. to ancestor sets) and check 1400 // the feerates of individuals and subsets. 1401 const auto m_total_vsize = std::accumulate(workspaces.cbegin(), workspaces.cend(), int64_t{0}, 1402 [](int64_t sum, auto& ws) { return sum + ws.m_vsize; }); 1403 const auto m_total_modified_fees = std::accumulate(workspaces.cbegin(), workspaces.cend(), CAmount{0}, 1404 [](CAmount sum, auto& ws) { return sum + ws.m_modified_fees; }); 1405 const CFeeRate package_feerate(m_total_modified_fees, m_total_vsize); 1406 std::vector<Wtxid> all_package_wtxids; 1407 all_package_wtxids.reserve(workspaces.size()); 1408 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids), 1409 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); }); 1410 TxValidationState placeholder_state; 1411 if (args.m_package_feerates && 1412 !CheckFeeRate(m_total_vsize, m_total_modified_fees, placeholder_state)) { 1413 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1414 return PackageMempoolAcceptResult(package_state, {{workspaces.back().m_ptx->GetWitnessHash(), 1415 MempoolAcceptResult::FeeFailure(placeholder_state, CFeeRate(m_total_modified_fees, m_total_vsize), all_package_wtxids)}}); 1416 } 1417 1418 // Apply package mempool ancestor/descendant limits. Skip if there is only one transaction, 1419 // because it's unnecessary. Also, CPFP carve out can increase the limit for individual 1420 // transactions, but this exemption is not extended to packages in CheckPackageLimits(). 1421 std::string err_string; 1422 if (txns.size() > 1 && !PackageMempoolChecks(txns, m_total_vsize, package_state)) { 1423 return PackageMempoolAcceptResult(package_state, std::move(results)); 1424 } 1425 1426 for (Workspace& ws : workspaces) { 1427 ws.m_package_feerate = package_feerate; 1428 if (!PolicyScriptChecks(args, ws)) { 1429 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1430 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1431 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1432 return PackageMempoolAcceptResult(package_state, std::move(results)); 1433 } 1434 if (args.m_test_accept) { 1435 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate : 1436 CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)}; 1437 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids : 1438 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()}; 1439 results.emplace(ws.m_ptx->GetWitnessHash(), 1440 MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), 1441 ws.m_vsize, ws.m_base_fees, effective_feerate, 1442 effective_feerate_wtxids)); 1443 } 1444 } 1445 1446 if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, std::move(results)); 1447 1448 if (!SubmitPackage(args, workspaces, package_state, results)) { 1449 // PackageValidationState filled in by SubmitPackage(). 1450 return PackageMempoolAcceptResult(package_state, std::move(results)); 1451 } 1452 1453 return PackageMempoolAcceptResult(package_state, std::move(results)); 1454 } 1455 1456 void MemPoolAccept::CleanupTemporaryCoins() 1457 { 1458 // There are 3 kinds of coins in m_view: 1459 // (1) Temporary coins from the transactions in subpackage, constructed by m_viewmempool. 1460 // (2) Mempool coins from transactions in the mempool, constructed by m_viewmempool. 1461 // (3) Confirmed coins fetched from our current UTXO set. 1462 // 1463 // (1) Temporary coins need to be removed, regardless of whether the transaction was submitted. 1464 // If the transaction was submitted to the mempool, m_viewmempool will be able to fetch them from 1465 // there. If it wasn't submitted to mempool, it is incorrect to keep them - future calls may try 1466 // to spend those coins that don't actually exist. 1467 // (2) Mempool coins also need to be removed. If the mempool contents have changed as a result 1468 // of submitting or replacing transactions, coins previously fetched from mempool may now be 1469 // spent or nonexistent. Those coins need to be deleted from m_view. 1470 // (3) Confirmed coins don't need to be removed. The chainstate has not changed (we are 1471 // holding cs_main and no blocks have been processed) so the confirmed tx cannot disappear like 1472 // a mempool tx can. The coin may now be spent after we submitted a tx to mempool, but 1473 // we have already checked that the package does not have 2 transactions spending the same coin. 1474 // Keeping them in m_view is an optimization to not re-fetch confirmed coins if we later look up 1475 // inputs for this transaction again. 1476 for (const auto& outpoint : m_viewmempool.GetNonBaseCoins()) { 1477 // In addition to resetting m_viewmempool, we also need to manually delete these coins from 1478 // m_view because it caches copies of the coins it fetched from m_viewmempool previously. 1479 m_view.Uncache(outpoint); 1480 } 1481 // This deletes the temporary and mempool coins. 1482 m_viewmempool.Reset(); 1483 } 1484 1485 PackageMempoolAcceptResult MemPoolAccept::AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args) 1486 { 1487 AssertLockHeld(::cs_main); 1488 AssertLockHeld(m_pool.cs); 1489 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) { 1490 if (subpackage.size() > 1) { 1491 return AcceptMultipleTransactions(subpackage, args); 1492 } 1493 const auto& tx = subpackage.front(); 1494 ATMPArgs single_args = ATMPArgs::SingleInPackageAccept(args); 1495 const auto single_res = AcceptSingleTransaction(tx, single_args); 1496 PackageValidationState package_state_wrapped; 1497 if (single_res.m_result_type != MempoolAcceptResult::ResultType::VALID) { 1498 package_state_wrapped.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1499 } 1500 return PackageMempoolAcceptResult(package_state_wrapped, {{tx->GetWitnessHash(), single_res}}); 1501 }(); 1502 1503 // Clean up m_view and m_viewmempool so that other subpackage evaluations don't have access to 1504 // coins they shouldn't. Keep some coins in order to minimize re-fetching coins from the UTXO set. 1505 CleanupTemporaryCoins(); 1506 1507 return result; 1508 } 1509 1510 PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, ATMPArgs& args) 1511 { 1512 AssertLockHeld(cs_main); 1513 // Used if returning a PackageMempoolAcceptResult directly from this function. 1514 PackageValidationState package_state_quit_early; 1515 1516 // Check that the package is well-formed. If it isn't, we won't try to validate any of the 1517 // transactions and thus won't return any MempoolAcceptResults, just a package-wide error. 1518 1519 // Context-free package checks. 1520 if (!IsWellFormedPackage(package, package_state_quit_early, /*require_sorted=*/true)) { 1521 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1522 } 1523 1524 // All transactions in the package must be a parent of the last transaction. This is just an 1525 // opportunity for us to fail fast on a context-free check without taking the mempool lock. 1526 if (!IsChildWithParents(package)) { 1527 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents"); 1528 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1529 } 1530 1531 // IsChildWithParents() guarantees the package is > 1 transactions. 1532 assert(package.size() > 1); 1533 // The package must be 1 child with all of its unconfirmed parents. The package is expected to 1534 // be sorted, so the last transaction is the child. 1535 const auto& child = package.back(); 1536 std::unordered_set<uint256, SaltedTxidHasher> unconfirmed_parent_txids; 1537 std::transform(package.cbegin(), package.cend() - 1, 1538 std::inserter(unconfirmed_parent_txids, unconfirmed_parent_txids.end()), 1539 [](const auto& tx) { return tx->GetHash(); }); 1540 1541 // All child inputs must refer to a preceding package transaction or a confirmed UTXO. The only 1542 // way to verify this is to look up the child's inputs in our current coins view (not including 1543 // mempool), and enforce that all parents not present in the package be available at chain tip. 1544 // Since this check can bring new coins into the coins cache, keep track of these coins and 1545 // uncache them if we don't end up submitting this package to the mempool. 1546 const CCoinsViewCache& coins_tip_cache = m_active_chainstate.CoinsTip(); 1547 for (const auto& input : child->vin) { 1548 if (!coins_tip_cache.HaveCoinInCache(input.prevout)) { 1549 args.m_coins_to_uncache.push_back(input.prevout); 1550 } 1551 } 1552 // Using the MemPoolAccept m_view cache allows us to look up these same coins faster later. 1553 // This should be connecting directly to CoinsTip, not to m_viewmempool, because we specifically 1554 // require inputs to be confirmed if they aren't in the package. 1555 m_view.SetBackend(m_active_chainstate.CoinsTip()); 1556 const auto package_or_confirmed = [this, &unconfirmed_parent_txids](const auto& input) { 1557 return unconfirmed_parent_txids.count(input.prevout.hash) > 0 || m_view.HaveCoin(input.prevout); 1558 }; 1559 if (!std::all_of(child->vin.cbegin(), child->vin.cend(), package_or_confirmed)) { 1560 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-unconfirmed-parents"); 1561 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1562 } 1563 // Protect against bugs where we pull more inputs from disk that miss being added to 1564 // coins_to_uncache. The backend will be connected again when needed in PreChecks. 1565 m_view.SetBackend(m_dummy); 1566 1567 LOCK(m_pool.cs); 1568 // Stores results from which we will create the returned PackageMempoolAcceptResult. 1569 // A result may be changed if a mempool transaction is evicted later due to LimitMempoolSize(). 1570 std::map<uint256, MempoolAcceptResult> results_final; 1571 // Results from individual validation which will be returned if no other result is available for 1572 // this transaction. "Nonfinal" because if a transaction fails by itself but succeeds later 1573 // (i.e. when evaluated with a fee-bumping child), the result in this map may be discarded. 1574 std::map<uint256, MempoolAcceptResult> individual_results_nonfinal; 1575 bool quit_early{false}; 1576 std::vector<CTransactionRef> txns_package_eval; 1577 for (const auto& tx : package) { 1578 const auto& wtxid = tx->GetWitnessHash(); 1579 const auto& txid = tx->GetHash(); 1580 // There are 3 possibilities: already in mempool, same-txid-diff-wtxid already in mempool, 1581 // or not in mempool. An already confirmed tx is treated as one not in mempool, because all 1582 // we know is that the inputs aren't available. 1583 if (m_pool.exists(GenTxid::Wtxid(wtxid))) { 1584 // Exact transaction already exists in the mempool. 1585 // Node operators are free to set their mempool policies however they please, nodes may receive 1586 // transactions in different orders, and malicious counterparties may try to take advantage of 1587 // policy differences to pin or delay propagation of transactions. As such, it's possible for 1588 // some package transaction(s) to already be in the mempool, and we don't want to reject the 1589 // entire package in that case (as that could be a censorship vector). De-duplicate the 1590 // transactions that are already in the mempool, and only call AcceptMultipleTransactions() with 1591 // the new transactions. This ensures we don't double-count transaction counts and sizes when 1592 // checking ancestor/descendant limits, or double-count transaction fees for fee-related policy. 1593 const auto& entry{*Assert(m_pool.GetEntry(txid))}; 1594 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTx(entry.GetTxSize(), entry.GetFee())); 1595 } else if (m_pool.exists(GenTxid::Txid(txid))) { 1596 // Transaction with the same non-witness data but different witness (same txid, 1597 // different wtxid) already exists in the mempool. 1598 // 1599 // We don't allow replacement transactions right now, so just swap the package 1600 // transaction for the mempool one. Note that we are ignoring the validity of the 1601 // package transaction passed in. 1602 // TODO: allow witness replacement in packages. 1603 const auto& entry{*Assert(m_pool.GetEntry(txid))}; 1604 // Provide the wtxid of the mempool tx so that the caller can look it up in the mempool. 1605 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTxDifferentWitness(entry.GetTx().GetWitnessHash())); 1606 } else { 1607 // Transaction does not already exist in the mempool. 1608 // Try submitting the transaction on its own. 1609 const auto single_package_res = AcceptSubPackage({tx}, args); 1610 const auto& single_res = single_package_res.m_tx_results.at(wtxid); 1611 if (single_res.m_result_type == MempoolAcceptResult::ResultType::VALID) { 1612 // The transaction succeeded on its own and is now in the mempool. Don't include it 1613 // in package validation, because its fees should only be "used" once. 1614 assert(m_pool.exists(GenTxid::Wtxid(wtxid))); 1615 results_final.emplace(wtxid, single_res); 1616 } else if (single_res.m_state.GetResult() != TxValidationResult::TX_RECONSIDERABLE && 1617 single_res.m_state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) { 1618 // Package validation policy only differs from individual policy in its evaluation 1619 // of feerate. For example, if a transaction fails here due to violation of a 1620 // consensus rule, the result will not change when it is submitted as part of a 1621 // package. To minimize the amount of repeated work, unless the transaction fails 1622 // due to feerate or missing inputs (its parent is a previous transaction in the 1623 // package that failed due to feerate), don't run package validation. Note that this 1624 // decision might not make sense if different types of packages are allowed in the 1625 // future. Continue individually validating the rest of the transactions, because 1626 // some of them may still be valid. 1627 quit_early = true; 1628 package_state_quit_early.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1629 individual_results_nonfinal.emplace(wtxid, single_res); 1630 } else { 1631 individual_results_nonfinal.emplace(wtxid, single_res); 1632 txns_package_eval.push_back(tx); 1633 } 1634 } 1635 } 1636 1637 auto multi_submission_result = quit_early || txns_package_eval.empty() ? PackageMempoolAcceptResult(package_state_quit_early, {}) : 1638 AcceptSubPackage(txns_package_eval, args); 1639 PackageValidationState& package_state_final = multi_submission_result.m_state; 1640 1641 // Make sure we haven't exceeded max mempool size. 1642 // Package transactions that were submitted to mempool or already in mempool may be evicted. 1643 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip()); 1644 1645 for (const auto& tx : package) { 1646 const auto& wtxid = tx->GetWitnessHash(); 1647 if (multi_submission_result.m_tx_results.count(wtxid) > 0) { 1648 // We shouldn't have re-submitted if the tx result was already in results_final. 1649 Assume(results_final.count(wtxid) == 0); 1650 // If it was submitted, check to see if the tx is still in the mempool. It could have 1651 // been evicted due to LimitMempoolSize() above. 1652 const auto& txresult = multi_submission_result.m_tx_results.at(wtxid); 1653 if (txresult.m_result_type == MempoolAcceptResult::ResultType::VALID && !m_pool.exists(GenTxid::Wtxid(wtxid))) { 1654 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1655 TxValidationState mempool_full_state; 1656 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full"); 1657 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state)); 1658 } else { 1659 results_final.emplace(wtxid, txresult); 1660 } 1661 } else if (const auto it{results_final.find(wtxid)}; it != results_final.end()) { 1662 // Already-in-mempool transaction. Check to see if it's still there, as it could have 1663 // been evicted when LimitMempoolSize() was called. 1664 Assume(it->second.m_result_type != MempoolAcceptResult::ResultType::INVALID); 1665 Assume(individual_results_nonfinal.count(wtxid) == 0); 1666 // Query by txid to include the same-txid-different-witness ones. 1667 if (!m_pool.exists(GenTxid::Txid(tx->GetHash()))) { 1668 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1669 TxValidationState mempool_full_state; 1670 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full"); 1671 // Replace the previous result. 1672 results_final.erase(wtxid); 1673 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state)); 1674 } 1675 } else if (const auto it{individual_results_nonfinal.find(wtxid)}; it != individual_results_nonfinal.end()) { 1676 Assume(it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID); 1677 // Interesting result from previous processing. 1678 results_final.emplace(wtxid, it->second); 1679 } 1680 } 1681 Assume(results_final.size() == package.size()); 1682 return PackageMempoolAcceptResult(package_state_final, std::move(results_final)); 1683 } 1684 1685 } // anon namespace 1686 1687 MempoolAcceptResult AcceptToMemoryPool(Chainstate& active_chainstate, const CTransactionRef& tx, 1688 int64_t accept_time, bool bypass_limits, bool test_accept) 1689 EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 1690 { 1691 AssertLockHeld(::cs_main); 1692 const CChainParams& chainparams{active_chainstate.m_chainman.GetParams()}; 1693 assert(active_chainstate.GetMempool() != nullptr); 1694 CTxMemPool& pool{*active_chainstate.GetMempool()}; 1695 1696 std::vector<COutPoint> coins_to_uncache; 1697 auto args = MemPoolAccept::ATMPArgs::SingleAccept(chainparams, accept_time, bypass_limits, coins_to_uncache, test_accept); 1698 MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate).AcceptSingleTransaction(tx, args); 1699 if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) { 1700 // Remove coins that were not present in the coins cache before calling 1701 // AcceptSingleTransaction(); this is to prevent memory DoS in case we receive a large 1702 // number of invalid transactions that attempt to overrun the in-memory coins cache 1703 // (`CCoinsViewCache::cacheCoins`). 1704 1705 for (const COutPoint& hashTx : coins_to_uncache) 1706 active_chainstate.CoinsTip().Uncache(hashTx); 1707 TRACE2(mempool, rejected, 1708 tx->GetHash().data(), 1709 result.m_state.GetRejectReason().c_str() 1710 ); 1711 } 1712 // After we've (potentially) uncached entries, ensure our coins cache is still within its size limits 1713 BlockValidationState state_dummy; 1714 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC); 1715 return result; 1716 } 1717 1718 PackageMempoolAcceptResult ProcessNewPackage(Chainstate& active_chainstate, CTxMemPool& pool, 1719 const Package& package, bool test_accept, const std::optional<CFeeRate>& client_maxfeerate) 1720 { 1721 AssertLockHeld(cs_main); 1722 assert(!package.empty()); 1723 assert(std::all_of(package.cbegin(), package.cend(), [](const auto& tx){return tx != nullptr;})); 1724 1725 std::vector<COutPoint> coins_to_uncache; 1726 const CChainParams& chainparams = active_chainstate.m_chainman.GetParams(); 1727 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) { 1728 AssertLockHeld(cs_main); 1729 if (test_accept) { 1730 auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(chainparams, GetTime(), coins_to_uncache); 1731 return MemPoolAccept(pool, active_chainstate).AcceptMultipleTransactions(package, args); 1732 } else { 1733 auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(chainparams, GetTime(), coins_to_uncache, client_maxfeerate); 1734 return MemPoolAccept(pool, active_chainstate).AcceptPackage(package, args); 1735 } 1736 }(); 1737 1738 // Uncache coins pertaining to transactions that were not submitted to the mempool. 1739 if (test_accept || result.m_state.IsInvalid()) { 1740 for (const COutPoint& hashTx : coins_to_uncache) { 1741 active_chainstate.CoinsTip().Uncache(hashTx); 1742 } 1743 } 1744 // Ensure the coins cache is still within limits. 1745 BlockValidationState state_dummy; 1746 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC); 1747 return result; 1748 } 1749 1750 CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams) 1751 { 1752 int halvings = nHeight / consensusParams.nSubsidyHalvingInterval; 1753 // Force block reward to zero when right shift is undefined. 1754 if (halvings >= 64) 1755 return 0; 1756 1757 CAmount nSubsidy = 50 * COIN; 1758 // Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years. 1759 nSubsidy >>= halvings; 1760 return nSubsidy; 1761 } 1762 1763 CoinsViews::CoinsViews(DBParams db_params, CoinsViewOptions options) 1764 : m_dbview{std::move(db_params), std::move(options)}, 1765 m_catcherview(&m_dbview) {} 1766 1767 void CoinsViews::InitCache() 1768 { 1769 AssertLockHeld(::cs_main); 1770 m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview); 1771 } 1772 1773 Chainstate::Chainstate( 1774 CTxMemPool* mempool, 1775 BlockManager& blockman, 1776 ChainstateManager& chainman, 1777 std::optional<uint256> from_snapshot_blockhash) 1778 : m_mempool(mempool), 1779 m_blockman(blockman), 1780 m_chainman(chainman), 1781 m_from_snapshot_blockhash(from_snapshot_blockhash) {} 1782 1783 const CBlockIndex* Chainstate::SnapshotBase() 1784 { 1785 if (!m_from_snapshot_blockhash) return nullptr; 1786 if (!m_cached_snapshot_base) m_cached_snapshot_base = Assert(m_chainman.m_blockman.LookupBlockIndex(*m_from_snapshot_blockhash)); 1787 return m_cached_snapshot_base; 1788 } 1789 1790 void Chainstate::InitCoinsDB( 1791 size_t cache_size_bytes, 1792 bool in_memory, 1793 bool should_wipe, 1794 fs::path leveldb_name) 1795 { 1796 if (m_from_snapshot_blockhash) { 1797 leveldb_name += node::SNAPSHOT_CHAINSTATE_SUFFIX; 1798 } 1799 1800 m_coins_views = std::make_unique<CoinsViews>( 1801 DBParams{ 1802 .path = m_chainman.m_options.datadir / leveldb_name, 1803 .cache_bytes = cache_size_bytes, 1804 .memory_only = in_memory, 1805 .wipe_data = should_wipe, 1806 .obfuscate = true, 1807 .options = m_chainman.m_options.coins_db}, 1808 m_chainman.m_options.coins_view); 1809 } 1810 1811 void Chainstate::InitCoinsCache(size_t cache_size_bytes) 1812 { 1813 AssertLockHeld(::cs_main); 1814 assert(m_coins_views != nullptr); 1815 m_coinstip_cache_size_bytes = cache_size_bytes; 1816 m_coins_views->InitCache(); 1817 } 1818 1819 // Note that though this is marked const, we may end up modifying `m_cached_finished_ibd`, which 1820 // is a performance-related implementation detail. This function must be marked 1821 // `const` so that `CValidationInterface` clients (which are given a `const Chainstate*`) 1822 // can call it. 1823 // 1824 bool ChainstateManager::IsInitialBlockDownload() const 1825 { 1826 // Optimization: pre-test latch before taking the lock. 1827 if (m_cached_finished_ibd.load(std::memory_order_relaxed)) 1828 return false; 1829 1830 LOCK(cs_main); 1831 if (m_cached_finished_ibd.load(std::memory_order_relaxed)) 1832 return false; 1833 if (m_blockman.LoadingBlocks()) { 1834 return true; 1835 } 1836 CChain& chain{ActiveChain()}; 1837 if (chain.Tip() == nullptr) { 1838 return true; 1839 } 1840 if (chain.Tip()->nChainWork < MinimumChainWork()) { 1841 return true; 1842 } 1843 if (chain.Tip()->Time() < Now<NodeSeconds>() - m_options.max_tip_age) { 1844 return true; 1845 } 1846 LogPrintf("Leaving InitialBlockDownload (latching to false)\n"); 1847 m_cached_finished_ibd.store(true, std::memory_order_relaxed); 1848 return false; 1849 } 1850 1851 void Chainstate::CheckForkWarningConditions() 1852 { 1853 AssertLockHeld(cs_main); 1854 1855 // Before we get past initial download, we cannot reliably alert about forks 1856 // (we assume we don't get stuck on a fork before finishing our initial sync) 1857 if (m_chainman.IsInitialBlockDownload()) { 1858 return; 1859 } 1860 1861 if (m_chainman.m_best_invalid && m_chainman.m_best_invalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) { 1862 LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n", __func__); 1863 SetfLargeWorkInvalidChainFound(true); 1864 } else { 1865 SetfLargeWorkInvalidChainFound(false); 1866 } 1867 } 1868 1869 // Called both upon regular invalid block discovery *and* InvalidateBlock 1870 void Chainstate::InvalidChainFound(CBlockIndex* pindexNew) 1871 { 1872 AssertLockHeld(cs_main); 1873 if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) { 1874 m_chainman.m_best_invalid = pindexNew; 1875 } 1876 if (m_chainman.m_best_header != nullptr && m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) == pindexNew) { 1877 m_chainman.m_best_header = m_chain.Tip(); 1878 } 1879 1880 LogPrintf("%s: invalid block=%s height=%d log2_work=%f date=%s\n", __func__, 1881 pindexNew->GetBlockHash().ToString(), pindexNew->nHeight, 1882 log(pindexNew->nChainWork.getdouble())/log(2.0), FormatISO8601DateTime(pindexNew->GetBlockTime())); 1883 CBlockIndex *tip = m_chain.Tip(); 1884 assert (tip); 1885 LogPrintf("%s: current best=%s height=%d log2_work=%f date=%s\n", __func__, 1886 tip->GetBlockHash().ToString(), m_chain.Height(), log(tip->nChainWork.getdouble())/log(2.0), 1887 FormatISO8601DateTime(tip->GetBlockTime())); 1888 CheckForkWarningConditions(); 1889 } 1890 1891 // Same as InvalidChainFound, above, except not called directly from InvalidateBlock, 1892 // which does its own setBlockIndexCandidates management. 1893 void Chainstate::InvalidBlockFound(CBlockIndex* pindex, const BlockValidationState& state) 1894 { 1895 AssertLockHeld(cs_main); 1896 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 1897 pindex->nStatus |= BLOCK_FAILED_VALID; 1898 m_chainman.m_failed_blocks.insert(pindex); 1899 m_blockman.m_dirty_blockindex.insert(pindex); 1900 setBlockIndexCandidates.erase(pindex); 1901 InvalidChainFound(pindex); 1902 } 1903 } 1904 1905 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, CTxUndo &txundo, int nHeight) 1906 { 1907 // mark inputs spent 1908 if (!tx.IsCoinBase()) { 1909 txundo.vprevout.reserve(tx.vin.size()); 1910 for (const CTxIn &txin : tx.vin) { 1911 txundo.vprevout.emplace_back(); 1912 bool is_spent = inputs.SpendCoin(txin.prevout, &txundo.vprevout.back()); 1913 assert(is_spent); 1914 } 1915 } 1916 // add outputs 1917 AddCoins(inputs, tx, nHeight); 1918 } 1919 1920 bool CScriptCheck::operator()() { 1921 const CScript &scriptSig = ptxTo->vin[nIn].scriptSig; 1922 const CScriptWitness *witness = &ptxTo->vin[nIn].scriptWitness; 1923 return VerifyScript(scriptSig, m_tx_out.scriptPubKey, witness, nFlags, CachingTransactionSignatureChecker(ptxTo, nIn, m_tx_out.nValue, cacheStore, *txdata), &error); 1924 } 1925 1926 static CuckooCache::cache<uint256, SignatureCacheHasher> g_scriptExecutionCache; 1927 static CSHA256 g_scriptExecutionCacheHasher; 1928 1929 bool InitScriptExecutionCache(size_t max_size_bytes) 1930 { 1931 // Setup the salted hasher 1932 uint256 nonce = GetRandHash(); 1933 // We want the nonce to be 64 bytes long to force the hasher to process 1934 // this chunk, which makes later hash computations more efficient. We 1935 // just write our 32-byte entropy twice to fill the 64 bytes. 1936 g_scriptExecutionCacheHasher.Write(nonce.begin(), 32); 1937 g_scriptExecutionCacheHasher.Write(nonce.begin(), 32); 1938 1939 auto setup_results = g_scriptExecutionCache.setup_bytes(max_size_bytes); 1940 if (!setup_results) return false; 1941 1942 const auto [num_elems, approx_size_bytes] = *setup_results; 1943 LogPrintf("Using %zu MiB out of %zu MiB requested for script execution cache, able to store %zu elements\n", 1944 approx_size_bytes >> 20, max_size_bytes >> 20, num_elems); 1945 return true; 1946 } 1947 1948 /** 1949 * Check whether all of this transaction's input scripts succeed. 1950 * 1951 * This involves ECDSA signature checks so can be computationally intensive. This function should 1952 * only be called after the cheap sanity checks in CheckTxInputs passed. 1953 * 1954 * If pvChecks is not nullptr, script checks are pushed onto it instead of being performed inline. Any 1955 * script checks which are not necessary (eg due to script execution cache hits) are, obviously, 1956 * not pushed onto pvChecks/run. 1957 * 1958 * Setting cacheSigStore/cacheFullScriptStore to false will remove elements from the corresponding cache 1959 * which are matched. This is useful for checking blocks where we will likely never need the cache 1960 * entry again. 1961 * 1962 * Note that we may set state.reason to NOT_STANDARD for extra soft-fork flags in flags, block-checking 1963 * callers should probably reset it to CONSENSUS in such cases. 1964 * 1965 * Non-static (and re-declared) in src/test/txvalidationcache_tests.cpp 1966 */ 1967 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state, 1968 const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore, 1969 bool cacheFullScriptStore, PrecomputedTransactionData& txdata, 1970 std::vector<CScriptCheck>* pvChecks) 1971 { 1972 if (tx.IsCoinBase()) return true; 1973 1974 if (pvChecks) { 1975 pvChecks->reserve(tx.vin.size()); 1976 } 1977 1978 // First check if script executions have been cached with the same 1979 // flags. Note that this assumes that the inputs provided are 1980 // correct (ie that the transaction hash which is in tx's prevouts 1981 // properly commits to the scriptPubKey in the inputs view of that 1982 // transaction). 1983 uint256 hashCacheEntry; 1984 CSHA256 hasher = g_scriptExecutionCacheHasher; 1985 hasher.Write(UCharCast(tx.GetWitnessHash().begin()), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin()); 1986 AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks 1987 if (g_scriptExecutionCache.contains(hashCacheEntry, !cacheFullScriptStore)) { 1988 return true; 1989 } 1990 1991 if (!txdata.m_spent_outputs_ready) { 1992 std::vector<CTxOut> spent_outputs; 1993 spent_outputs.reserve(tx.vin.size()); 1994 1995 for (const auto& txin : tx.vin) { 1996 const COutPoint& prevout = txin.prevout; 1997 const Coin& coin = inputs.AccessCoin(prevout); 1998 assert(!coin.IsSpent()); 1999 spent_outputs.emplace_back(coin.out); 2000 } 2001 txdata.Init(tx, std::move(spent_outputs)); 2002 } 2003 assert(txdata.m_spent_outputs.size() == tx.vin.size()); 2004 2005 for (unsigned int i = 0; i < tx.vin.size(); i++) { 2006 2007 // We very carefully only pass in things to CScriptCheck which 2008 // are clearly committed to by tx' witness hash. This provides 2009 // a sanity check that our caching is not introducing consensus 2010 // failures through additional data in, eg, the coins being 2011 // spent being checked as a part of CScriptCheck. 2012 2013 // Verify signature 2014 CScriptCheck check(txdata.m_spent_outputs[i], tx, i, flags, cacheSigStore, &txdata); 2015 if (pvChecks) { 2016 pvChecks->emplace_back(std::move(check)); 2017 } else if (!check()) { 2018 if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) { 2019 // Check whether the failure was caused by a 2020 // non-mandatory script verification check, such as 2021 // non-standard DER encodings or non-null dummy 2022 // arguments; if so, ensure we return NOT_STANDARD 2023 // instead of CONSENSUS to avoid downstream users 2024 // splitting the network between upgraded and 2025 // non-upgraded nodes by banning CONSENSUS-failing 2026 // data providers. 2027 CScriptCheck check2(txdata.m_spent_outputs[i], tx, i, 2028 flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheSigStore, &txdata); 2029 if (check2()) 2030 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(check.GetScriptError()))); 2031 } 2032 // MANDATORY flag failures correspond to 2033 // TxValidationResult::TX_CONSENSUS. Because CONSENSUS 2034 // failures are the most serious case of validation 2035 // failures, we may need to consider using 2036 // RECENT_CONSENSUS_CHANGE for any script failure that 2037 // could be due to non-upgraded nodes which we may want to 2038 // support, to avoid splitting the network (but this 2039 // depends on the details of how net_processing handles 2040 // such errors). 2041 return state.Invalid(TxValidationResult::TX_CONSENSUS, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(check.GetScriptError()))); 2042 } 2043 } 2044 2045 if (cacheFullScriptStore && !pvChecks) { 2046 // We executed all of the provided scripts, and were told to 2047 // cache the result. Do so now. 2048 g_scriptExecutionCache.insert(hashCacheEntry); 2049 } 2050 2051 return true; 2052 } 2053 2054 bool FatalError(Notifications& notifications, BlockValidationState& state, const bilingual_str& message) 2055 { 2056 notifications.fatalError(message); 2057 return state.Error(message.original); 2058 } 2059 2060 /** 2061 * Restore the UTXO in a Coin at a given COutPoint 2062 * @param undo The Coin to be restored. 2063 * @param view The coins view to which to apply the changes. 2064 * @param out The out point that corresponds to the tx input. 2065 * @return A DisconnectResult as an int 2066 */ 2067 int ApplyTxInUndo(Coin&& undo, CCoinsViewCache& view, const COutPoint& out) 2068 { 2069 bool fClean = true; 2070 2071 if (view.HaveCoin(out)) fClean = false; // overwriting transaction output 2072 2073 if (undo.nHeight == 0) { 2074 // Missing undo metadata (height and coinbase). Older versions included this 2075 // information only in undo records for the last spend of a transactions' 2076 // outputs. This implies that it must be present for some other output of the same tx. 2077 const Coin& alternate = AccessByTxid(view, out.hash); 2078 if (!alternate.IsSpent()) { 2079 undo.nHeight = alternate.nHeight; 2080 undo.fCoinBase = alternate.fCoinBase; 2081 } else { 2082 return DISCONNECT_FAILED; // adding output for transaction without known metadata 2083 } 2084 } 2085 // If the coin already exists as an unspent coin in the cache, then the 2086 // possible_overwrite parameter to AddCoin must be set to true. We have 2087 // already checked whether an unspent coin exists above using HaveCoin, so 2088 // we don't need to guess. When fClean is false, an unspent coin already 2089 // existed and it is an overwrite. 2090 view.AddCoin(out, std::move(undo), !fClean); 2091 2092 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN; 2093 } 2094 2095 /** Undo the effects of this block (with given index) on the UTXO set represented by coins. 2096 * When FAILED is returned, view is left in an indeterminate state. */ 2097 DisconnectResult Chainstate::DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view) 2098 { 2099 AssertLockHeld(::cs_main); 2100 bool fClean = true; 2101 2102 CBlockUndo blockUndo; 2103 if (!m_blockman.UndoReadFromDisk(blockUndo, *pindex)) { 2104 LogError("DisconnectBlock(): failure reading undo data\n"); 2105 return DISCONNECT_FAILED; 2106 } 2107 2108 if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) { 2109 LogError("DisconnectBlock(): block and undo data inconsistent\n"); 2110 return DISCONNECT_FAILED; 2111 } 2112 2113 // Ignore blocks that contain transactions which are 'overwritten' by later transactions, 2114 // unless those are already completely spent. 2115 // See https://github.com/bitcoin/bitcoin/issues/22596 for additional information. 2116 // Note: the blocks specified here are different than the ones used in ConnectBlock because DisconnectBlock 2117 // unwinds the blocks in reverse. As a result, the inconsistency is not discovered until the earlier 2118 // blocks with the duplicate coinbase transactions are disconnected. 2119 bool fEnforceBIP30 = !((pindex->nHeight==91722 && pindex->GetBlockHash() == uint256S("0x00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e")) || 2120 (pindex->nHeight==91812 && pindex->GetBlockHash() == uint256S("0x00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"))); 2121 2122 // undo transactions in reverse order 2123 for (int i = block.vtx.size() - 1; i >= 0; i--) { 2124 const CTransaction &tx = *(block.vtx[i]); 2125 Txid hash = tx.GetHash(); 2126 bool is_coinbase = tx.IsCoinBase(); 2127 bool is_bip30_exception = (is_coinbase && !fEnforceBIP30); 2128 2129 // Check that all outputs are available and match the outputs in the block itself 2130 // exactly. 2131 for (size_t o = 0; o < tx.vout.size(); o++) { 2132 if (!tx.vout[o].scriptPubKey.IsUnspendable()) { 2133 COutPoint out(hash, o); 2134 Coin coin; 2135 bool is_spent = view.SpendCoin(out, &coin); 2136 if (!is_spent || tx.vout[o] != coin.out || pindex->nHeight != coin.nHeight || is_coinbase != coin.fCoinBase) { 2137 if (!is_bip30_exception) { 2138 fClean = false; // transaction output mismatch 2139 } 2140 } 2141 } 2142 } 2143 2144 // restore inputs 2145 if (i > 0) { // not coinbases 2146 CTxUndo &txundo = blockUndo.vtxundo[i-1]; 2147 if (txundo.vprevout.size() != tx.vin.size()) { 2148 LogError("DisconnectBlock(): transaction and undo data inconsistent\n"); 2149 return DISCONNECT_FAILED; 2150 } 2151 for (unsigned int j = tx.vin.size(); j > 0;) { 2152 --j; 2153 const COutPoint& out = tx.vin[j].prevout; 2154 int res = ApplyTxInUndo(std::move(txundo.vprevout[j]), view, out); 2155 if (res == DISCONNECT_FAILED) return DISCONNECT_FAILED; 2156 fClean = fClean && res != DISCONNECT_UNCLEAN; 2157 } 2158 // At this point, all of txundo.vprevout should have been moved out. 2159 } 2160 } 2161 2162 // move best block pointer to prevout block 2163 view.SetBestBlock(pindex->pprev->GetBlockHash()); 2164 2165 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN; 2166 } 2167 2168 /** 2169 * Threshold condition checker that triggers when unknown versionbits are seen on the network. 2170 */ 2171 class WarningBitsConditionChecker : public AbstractThresholdConditionChecker 2172 { 2173 private: 2174 const ChainstateManager& m_chainman; 2175 int m_bit; 2176 2177 public: 2178 explicit WarningBitsConditionChecker(const ChainstateManager& chainman, int bit) : m_chainman{chainman}, m_bit(bit) {} 2179 2180 int64_t BeginTime(const Consensus::Params& params) const override { return 0; } 2181 int64_t EndTime(const Consensus::Params& params) const override { return std::numeric_limits<int64_t>::max(); } 2182 int Period(const Consensus::Params& params) const override { return params.nMinerConfirmationWindow; } 2183 int Threshold(const Consensus::Params& params) const override { return params.nRuleChangeActivationThreshold; } 2184 2185 bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const override 2186 { 2187 return pindex->nHeight >= params.MinBIP9WarningHeight && 2188 ((pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS) && 2189 ((pindex->nVersion >> m_bit) & 1) != 0 && 2190 ((m_chainman.m_versionbitscache.ComputeBlockVersion(pindex->pprev, params) >> m_bit) & 1) == 0; 2191 } 2192 }; 2193 2194 static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman) 2195 { 2196 const Consensus::Params& consensusparams = chainman.GetConsensus(); 2197 2198 // BIP16 didn't become active until Apr 1 2012 (on mainnet, and 2199 // retroactively applied to testnet) 2200 // However, only one historical block violated the P2SH rules (on both 2201 // mainnet and testnet). 2202 // Similarly, only one historical block violated the TAPROOT rules on 2203 // mainnet. 2204 // For simplicity, always leave P2SH+WITNESS+TAPROOT on except for the two 2205 // violating blocks. 2206 uint32_t flags{SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_TAPROOT}; 2207 const auto it{consensusparams.script_flag_exceptions.find(*Assert(block_index.phashBlock))}; 2208 if (it != consensusparams.script_flag_exceptions.end()) { 2209 flags = it->second; 2210 } 2211 2212 // Enforce the DERSIG (BIP66) rule 2213 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_DERSIG)) { 2214 flags |= SCRIPT_VERIFY_DERSIG; 2215 } 2216 2217 // Enforce CHECKLOCKTIMEVERIFY (BIP65) 2218 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CLTV)) { 2219 flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY; 2220 } 2221 2222 // Enforce CHECKSEQUENCEVERIFY (BIP112) 2223 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CSV)) { 2224 flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY; 2225 } 2226 2227 // Enforce BIP147 NULLDUMMY (activated simultaneously with segwit) 2228 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_SEGWIT)) { 2229 flags |= SCRIPT_VERIFY_NULLDUMMY; 2230 } 2231 2232 return flags; 2233 } 2234 2235 2236 static SteadyClock::duration time_check{}; 2237 static SteadyClock::duration time_forks{}; 2238 static SteadyClock::duration time_connect{}; 2239 static SteadyClock::duration time_verify{}; 2240 static SteadyClock::duration time_undo{}; 2241 static SteadyClock::duration time_index{}; 2242 static SteadyClock::duration time_total{}; 2243 static int64_t num_blocks_total = 0; 2244 2245 /** Apply the effects of this block (with given index) on the UTXO set represented by coins. 2246 * Validity checks that depend on the UTXO set are also done; ConnectBlock() 2247 * can fail if those validity checks fail (among other reasons). */ 2248 bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex, 2249 CCoinsViewCache& view, bool fJustCheck) 2250 { 2251 AssertLockHeld(cs_main); 2252 assert(pindex); 2253 2254 uint256 block_hash{block.GetHash()}; 2255 assert(*pindex->phashBlock == block_hash); 2256 const bool parallel_script_checks{m_chainman.GetCheckQueue().HasThreads()}; 2257 2258 const auto time_start{SteadyClock::now()}; 2259 const CChainParams& params{m_chainman.GetParams()}; 2260 2261 // Check it again in case a previous version let a bad block in 2262 // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or 2263 // ContextualCheckBlockHeader() here. This means that if we add a new 2264 // consensus rule that is enforced in one of those two functions, then we 2265 // may have let in a block that violates the rule prior to updating the 2266 // software, and we would NOT be enforcing the rule here. Fully solving 2267 // upgrade from one software version to the next after a consensus rule 2268 // change is potentially tricky and issue-specific (see NeedsRedownload() 2269 // for one approach that was used for BIP 141 deployment). 2270 // Also, currently the rule against blocks more than 2 hours in the future 2271 // is enforced in ContextualCheckBlockHeader(); we wouldn't want to 2272 // re-enforce that rule here (at least until we make it impossible for 2273 // the clock to go backward). 2274 if (!CheckBlock(block, state, params.GetConsensus(), !fJustCheck, !fJustCheck)) { 2275 if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) { 2276 // We don't write down blocks to disk if they may have been 2277 // corrupted, so this should be impossible unless we're having hardware 2278 // problems. 2279 return FatalError(m_chainman.GetNotifications(), state, _("Corrupt block found indicating potential hardware failure.")); 2280 } 2281 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString()); 2282 return false; 2283 } 2284 2285 // verify that the view's current state corresponds to the previous block 2286 uint256 hashPrevBlock = pindex->pprev == nullptr ? uint256() : pindex->pprev->GetBlockHash(); 2287 assert(hashPrevBlock == view.GetBestBlock()); 2288 2289 num_blocks_total++; 2290 2291 // Special case for the genesis block, skipping connection of its transactions 2292 // (its coinbase is unspendable) 2293 if (block_hash == params.GetConsensus().hashGenesisBlock) { 2294 if (!fJustCheck) 2295 view.SetBestBlock(pindex->GetBlockHash()); 2296 return true; 2297 } 2298 2299 bool fScriptChecks = true; 2300 if (!m_chainman.AssumedValidBlock().IsNull()) { 2301 // We've been configured with the hash of a block which has been externally verified to have a valid history. 2302 // A suitable default value is included with the software and updated from time to time. Because validity 2303 // relative to a piece of software is an objective fact these defaults can be easily reviewed. 2304 // This setting doesn't force the selection of any particular chain but makes validating some faster by 2305 // effectively caching the result of part of the verification. 2306 BlockMap::const_iterator it{m_blockman.m_block_index.find(m_chainman.AssumedValidBlock())}; 2307 if (it != m_blockman.m_block_index.end()) { 2308 if (it->second.GetAncestor(pindex->nHeight) == pindex && 2309 m_chainman.m_best_header->GetAncestor(pindex->nHeight) == pindex && 2310 m_chainman.m_best_header->nChainWork >= m_chainman.MinimumChainWork()) { 2311 // This block is a member of the assumed verified chain and an ancestor of the best header. 2312 // Script verification is skipped when connecting blocks under the 2313 // assumevalid block. Assuming the assumevalid block is valid this 2314 // is safe because block merkle hashes are still computed and checked, 2315 // Of course, if an assumed valid block is invalid due to false scriptSigs 2316 // this optimization would allow an invalid chain to be accepted. 2317 // The equivalent time check discourages hash power from extorting the network via DOS attack 2318 // into accepting an invalid block through telling users they must manually set assumevalid. 2319 // Requiring a software change or burying the invalid block, regardless of the setting, makes 2320 // it hard to hide the implication of the demand. This also avoids having release candidates 2321 // that are hardly doing any signature verification at all in testing without having to 2322 // artificially set the default assumed verified block further back. 2323 // The test against the minimum chain work prevents the skipping when denied access to any chain at 2324 // least as good as the expected chain. 2325 fScriptChecks = (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, params.GetConsensus()) <= 60 * 60 * 24 * 7 * 2); 2326 } 2327 } 2328 } 2329 2330 const auto time_1{SteadyClock::now()}; 2331 time_check += time_1 - time_start; 2332 LogPrint(BCLog::BENCH, " - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n", 2333 Ticks<MillisecondsDouble>(time_1 - time_start), 2334 Ticks<SecondsDouble>(time_check), 2335 Ticks<MillisecondsDouble>(time_check) / num_blocks_total); 2336 2337 // Do not allow blocks that contain transactions which 'overwrite' older transactions, 2338 // unless those are already completely spent. 2339 // If such overwrites are allowed, coinbases and transactions depending upon those 2340 // can be duplicated to remove the ability to spend the first instance -- even after 2341 // being sent to another address. 2342 // See BIP30, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html for more information. 2343 // This rule was originally applied to all blocks with a timestamp after March 15, 2012, 0:00 UTC. 2344 // Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the 2345 // two in the chain that violate it. This prevents exploiting the issue against nodes during their 2346 // initial block download. 2347 bool fEnforceBIP30 = !IsBIP30Repeat(*pindex); 2348 2349 // Once BIP34 activated it was not possible to create new duplicate coinbases and thus other than starting 2350 // with the 2 existing duplicate coinbase pairs, not possible to create overwriting txs. But by the 2351 // time BIP34 activated, in each of the existing pairs the duplicate coinbase had overwritten the first 2352 // before the first had been spent. Since those coinbases are sufficiently buried it's no longer possible to create further 2353 // duplicate transactions descending from the known pairs either. 2354 // 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. 2355 2356 // BIP34 requires that a block at height X (block X) has its coinbase 2357 // scriptSig start with a CScriptNum of X (indicated height X). The above 2358 // logic of no longer requiring BIP30 once BIP34 activates is flawed in the 2359 // case that there is a block X before the BIP34 height of 227,931 which has 2360 // an indicated height Y where Y is greater than X. The coinbase for block 2361 // X would also be a valid coinbase for block Y, which could be a BIP30 2362 // violation. An exhaustive search of all mainnet coinbases before the 2363 // BIP34 height which have an indicated height greater than the block height 2364 // reveals many occurrences. The 3 lowest indicated heights found are 2365 // 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3 2366 // heights would be the first opportunity for BIP30 to be violated. 2367 2368 // The search reveals a great many blocks which have an indicated height 2369 // greater than 1,983,702, so we simply remove the optimization to skip 2370 // BIP30 checking for blocks at height 1,983,702 or higher. Before we reach 2371 // that block in another 25 years or so, we should take advantage of a 2372 // future consensus change to do a new and improved version of BIP34 that 2373 // will actually prevent ever creating any duplicate coinbases in the 2374 // future. 2375 static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702; 2376 2377 // There is no potential to create a duplicate coinbase at block 209,921 2378 // because this is still before the BIP34 height and so explicit BIP30 2379 // checking is still active. 2380 2381 // The final case is block 176,684 which has an indicated height of 2382 // 490,897. Unfortunately, this issue was not discovered until about 2 weeks 2383 // before block 490,897 so there was not much opportunity to address this 2384 // case other than to carefully analyze it and determine it would not be a 2385 // problem. Block 490,897 was, in fact, mined with a different coinbase than 2386 // block 176,684, but it is important to note that even if it hadn't been or 2387 // is remined on an alternate fork with a duplicate coinbase, we would still 2388 // not run into a BIP30 violation. This is because the coinbase for 176,684 2389 // is spent in block 185,956 in transaction 2390 // d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781. This 2391 // spending transaction can't be duplicated because it also spends coinbase 2392 // 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29. This 2393 // coinbase has an indicated height of over 4.2 billion, and wouldn't be 2394 // duplicatable until that height, and it's currently impossible to create a 2395 // chain that long. Nevertheless we may wish to consider a future soft fork 2396 // which retroactively prevents block 490,897 from creating a duplicate 2397 // coinbase. The two historical BIP30 violations often provide a confusing 2398 // edge case when manipulating the UTXO and it would be simpler not to have 2399 // another edge case to deal with. 2400 2401 // testnet3 has no blocks before the BIP34 height with indicated heights 2402 // post BIP34 before approximately height 486,000,000. After block 2403 // 1,983,702 testnet3 starts doing unnecessary BIP30 checking again. 2404 assert(pindex->pprev); 2405 CBlockIndex* pindexBIP34height = pindex->pprev->GetAncestor(params.GetConsensus().BIP34Height); 2406 //Only continue to enforce if we're below BIP34 activation height or the block hash at that height doesn't correspond. 2407 fEnforceBIP30 = fEnforceBIP30 && (!pindexBIP34height || !(pindexBIP34height->GetBlockHash() == params.GetConsensus().BIP34Hash)); 2408 2409 // TODO: Remove BIP30 checking from block height 1,983,702 on, once we have a 2410 // consensus change that ensures coinbases at those heights cannot 2411 // duplicate earlier coinbases. 2412 if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) { 2413 for (const auto& tx : block.vtx) { 2414 for (size_t o = 0; o < tx->vout.size(); o++) { 2415 if (view.HaveCoin(COutPoint(tx->GetHash(), o))) { 2416 LogPrintf("ERROR: ConnectBlock(): tried to overwrite transaction\n"); 2417 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-BIP30"); 2418 } 2419 } 2420 } 2421 } 2422 2423 // Enforce BIP68 (sequence locks) 2424 int nLockTimeFlags = 0; 2425 if (DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_CSV)) { 2426 nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE; 2427 } 2428 2429 // Get the script flags for this block 2430 unsigned int flags{GetBlockScriptFlags(*pindex, m_chainman)}; 2431 2432 const auto time_2{SteadyClock::now()}; 2433 time_forks += time_2 - time_1; 2434 LogPrint(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n", 2435 Ticks<MillisecondsDouble>(time_2 - time_1), 2436 Ticks<SecondsDouble>(time_forks), 2437 Ticks<MillisecondsDouble>(time_forks) / num_blocks_total); 2438 2439 CBlockUndo blockundo; 2440 2441 // Precomputed transaction data pointers must not be invalidated 2442 // until after `control` has run the script checks (potentially 2443 // in multiple threads). Preallocate the vector size so a new allocation 2444 // doesn't invalidate pointers into the vector, and keep txsdata in scope 2445 // for as long as `control`. 2446 CCheckQueueControl<CScriptCheck> control(fScriptChecks && parallel_script_checks ? &m_chainman.GetCheckQueue() : nullptr); 2447 std::vector<PrecomputedTransactionData> txsdata(block.vtx.size()); 2448 2449 std::vector<int> prevheights; 2450 CAmount nFees = 0; 2451 int nInputs = 0; 2452 int64_t nSigOpsCost = 0; 2453 blockundo.vtxundo.reserve(block.vtx.size() - 1); 2454 for (unsigned int i = 0; i < block.vtx.size(); i++) 2455 { 2456 const CTransaction &tx = *(block.vtx[i]); 2457 2458 nInputs += tx.vin.size(); 2459 2460 if (!tx.IsCoinBase()) 2461 { 2462 CAmount txfee = 0; 2463 TxValidationState tx_state; 2464 if (!Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight, txfee)) { 2465 // Any transaction validation failure in ConnectBlock is a block consensus failure 2466 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, 2467 tx_state.GetRejectReason(), tx_state.GetDebugMessage()); 2468 LogError("%s: Consensus::CheckTxInputs: %s, %s\n", __func__, tx.GetHash().ToString(), state.ToString()); 2469 return false; 2470 } 2471 nFees += txfee; 2472 if (!MoneyRange(nFees)) { 2473 LogPrintf("ERROR: %s: accumulated fee in the block out of range.\n", __func__); 2474 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-accumulated-fee-outofrange"); 2475 } 2476 2477 // Check that transaction is BIP68 final 2478 // BIP68 lock checks (as opposed to nLockTime checks) must 2479 // be in ConnectBlock because they require the UTXO set 2480 prevheights.resize(tx.vin.size()); 2481 for (size_t j = 0; j < tx.vin.size(); j++) { 2482 prevheights[j] = view.AccessCoin(tx.vin[j].prevout).nHeight; 2483 } 2484 2485 if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) { 2486 LogPrintf("ERROR: %s: contains a non-BIP68-final transaction\n", __func__); 2487 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal"); 2488 } 2489 } 2490 2491 // GetTransactionSigOpCost counts 3 types of sigops: 2492 // * legacy (always) 2493 // * p2sh (when P2SH enabled in flags and excludes coinbase) 2494 // * witness (when witness enabled in flags and excludes coinbase) 2495 nSigOpsCost += GetTransactionSigOpCost(tx, view, flags); 2496 if (nSigOpsCost > MAX_BLOCK_SIGOPS_COST) { 2497 LogPrintf("ERROR: ConnectBlock(): too many sigops\n"); 2498 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops"); 2499 } 2500 2501 if (!tx.IsCoinBase()) 2502 { 2503 std::vector<CScriptCheck> vChecks; 2504 bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */ 2505 TxValidationState tx_state; 2506 if (fScriptChecks && !CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], parallel_script_checks ? &vChecks : nullptr)) { 2507 // Any transaction validation failure in ConnectBlock is a block consensus failure 2508 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, 2509 tx_state.GetRejectReason(), tx_state.GetDebugMessage()); 2510 LogError("ConnectBlock(): CheckInputScripts on %s failed with %s\n", 2511 tx.GetHash().ToString(), state.ToString()); 2512 return false; 2513 } 2514 control.Add(std::move(vChecks)); 2515 } 2516 2517 CTxUndo undoDummy; 2518 if (i > 0) { 2519 blockundo.vtxundo.emplace_back(); 2520 } 2521 UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight); 2522 } 2523 const auto time_3{SteadyClock::now()}; 2524 time_connect += time_3 - time_2; 2525 LogPrint(BCLog::BENCH, " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(), 2526 Ticks<MillisecondsDouble>(time_3 - time_2), Ticks<MillisecondsDouble>(time_3 - time_2) / block.vtx.size(), 2527 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_3 - time_2) / (nInputs - 1), 2528 Ticks<SecondsDouble>(time_connect), 2529 Ticks<MillisecondsDouble>(time_connect) / num_blocks_total); 2530 2531 CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, params.GetConsensus()); 2532 if (block.vtx[0]->GetValueOut() > blockReward) { 2533 LogPrintf("ERROR: ConnectBlock(): coinbase pays too much (actual=%d vs limit=%d)\n", block.vtx[0]->GetValueOut(), blockReward); 2534 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-amount"); 2535 } 2536 2537 if (!control.Wait()) { 2538 LogPrintf("ERROR: %s: CheckQueue failed\n", __func__); 2539 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "block-validation-failed"); 2540 } 2541 const auto time_4{SteadyClock::now()}; 2542 time_verify += time_4 - time_2; 2543 LogPrint(BCLog::BENCH, " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n", nInputs - 1, 2544 Ticks<MillisecondsDouble>(time_4 - time_2), 2545 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_4 - time_2) / (nInputs - 1), 2546 Ticks<SecondsDouble>(time_verify), 2547 Ticks<MillisecondsDouble>(time_verify) / num_blocks_total); 2548 2549 if (fJustCheck) 2550 return true; 2551 2552 if (!m_blockman.WriteUndoDataForBlock(blockundo, state, *pindex)) { 2553 return false; 2554 } 2555 2556 const auto time_5{SteadyClock::now()}; 2557 time_undo += time_5 - time_4; 2558 LogPrint(BCLog::BENCH, " - Write undo data: %.2fms [%.2fs (%.2fms/blk)]\n", 2559 Ticks<MillisecondsDouble>(time_5 - time_4), 2560 Ticks<SecondsDouble>(time_undo), 2561 Ticks<MillisecondsDouble>(time_undo) / num_blocks_total); 2562 2563 if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) { 2564 pindex->RaiseValidity(BLOCK_VALID_SCRIPTS); 2565 m_blockman.m_dirty_blockindex.insert(pindex); 2566 } 2567 2568 // add this block to the view's block chain 2569 view.SetBestBlock(pindex->GetBlockHash()); 2570 2571 const auto time_6{SteadyClock::now()}; 2572 time_index += time_6 - time_5; 2573 LogPrint(BCLog::BENCH, " - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n", 2574 Ticks<MillisecondsDouble>(time_6 - time_5), 2575 Ticks<SecondsDouble>(time_index), 2576 Ticks<MillisecondsDouble>(time_index) / num_blocks_total); 2577 2578 TRACE6(validation, block_connected, 2579 block_hash.data(), 2580 pindex->nHeight, 2581 block.vtx.size(), 2582 nInputs, 2583 nSigOpsCost, 2584 time_5 - time_start // in microseconds (µs) 2585 ); 2586 2587 return true; 2588 } 2589 2590 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState() 2591 { 2592 AssertLockHeld(::cs_main); 2593 return this->GetCoinsCacheSizeState( 2594 m_coinstip_cache_size_bytes, 2595 m_mempool ? m_mempool->m_max_size_bytes : 0); 2596 } 2597 2598 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState( 2599 size_t max_coins_cache_size_bytes, 2600 size_t max_mempool_size_bytes) 2601 { 2602 AssertLockHeld(::cs_main); 2603 const int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0; 2604 int64_t cacheSize = CoinsTip().DynamicMemoryUsage(); 2605 int64_t nTotalSpace = 2606 max_coins_cache_size_bytes + std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0); 2607 2608 //! No need to periodic flush if at least this much space still available. 2609 static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES = 10 * 1024 * 1024; // 10MB 2610 int64_t large_threshold = 2611 std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES); 2612 2613 if (cacheSize > nTotalSpace) { 2614 LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize, nTotalSpace); 2615 return CoinsCacheSizeState::CRITICAL; 2616 } else if (cacheSize > large_threshold) { 2617 return CoinsCacheSizeState::LARGE; 2618 } 2619 return CoinsCacheSizeState::OK; 2620 } 2621 2622 bool Chainstate::FlushStateToDisk( 2623 BlockValidationState &state, 2624 FlushStateMode mode, 2625 int nManualPruneHeight) 2626 { 2627 LOCK(cs_main); 2628 assert(this->CanFlushToDisk()); 2629 std::set<int> setFilesToPrune; 2630 bool full_flush_completed = false; 2631 2632 const size_t coins_count = CoinsTip().GetCacheSize(); 2633 const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage(); 2634 2635 try { 2636 { 2637 bool fFlushForPrune = false; 2638 bool fDoFullFlush = false; 2639 2640 CoinsCacheSizeState cache_state = GetCoinsCacheSizeState(); 2641 LOCK(m_blockman.cs_LastBlockFile); 2642 if (m_blockman.IsPruneMode() && (m_blockman.m_check_for_pruning || nManualPruneHeight > 0) && !fReindex) { 2643 // make sure we don't prune above any of the prune locks bestblocks 2644 // pruning is height-based 2645 int last_prune{m_chain.Height()}; // last height we can prune 2646 std::optional<std::string> limiting_lock; // prune lock that actually was the limiting factor, only used for logging 2647 2648 for (const auto& prune_lock : m_blockman.m_prune_locks) { 2649 if (prune_lock.second.height_first == std::numeric_limits<int>::max()) continue; 2650 // Remove the buffer and one additional block here to get actual height that is outside of the buffer 2651 const int lock_height{prune_lock.second.height_first - PRUNE_LOCK_BUFFER - 1}; 2652 last_prune = std::max(1, std::min(last_prune, lock_height)); 2653 if (last_prune == lock_height) { 2654 limiting_lock = prune_lock.first; 2655 } 2656 } 2657 2658 if (limiting_lock) { 2659 LogPrint(BCLog::PRUNE, "%s limited pruning to height %d\n", limiting_lock.value(), last_prune); 2660 } 2661 2662 if (nManualPruneHeight > 0) { 2663 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune (manual)", BCLog::BENCH); 2664 2665 m_blockman.FindFilesToPruneManual( 2666 setFilesToPrune, 2667 std::min(last_prune, nManualPruneHeight), 2668 *this, m_chainman); 2669 } else { 2670 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune", BCLog::BENCH); 2671 2672 m_blockman.FindFilesToPrune(setFilesToPrune, last_prune, *this, m_chainman); 2673 m_blockman.m_check_for_pruning = false; 2674 } 2675 if (!setFilesToPrune.empty()) { 2676 fFlushForPrune = true; 2677 if (!m_blockman.m_have_pruned) { 2678 m_blockman.m_block_tree_db->WriteFlag("prunedblockfiles", true); 2679 m_blockman.m_have_pruned = true; 2680 } 2681 } 2682 } 2683 const auto nNow{SteadyClock::now()}; 2684 // Avoid writing/flushing immediately after startup. 2685 if (m_last_write == decltype(m_last_write){}) { 2686 m_last_write = nNow; 2687 } 2688 if (m_last_flush == decltype(m_last_flush){}) { 2689 m_last_flush = nNow; 2690 } 2691 // 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). 2692 bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE; 2693 // The cache is over the limit, we have to write now. 2694 bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL; 2695 // It's been a while since we wrote the block index to disk. Do this frequently, so we don't need to redownload after a crash. 2696 bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow > m_last_write + DATABASE_WRITE_INTERVAL; 2697 // It's been very long since we flushed the cache. Do this infrequently, to optimize cache usage. 2698 bool fPeriodicFlush = mode == FlushStateMode::PERIODIC && nNow > m_last_flush + DATABASE_FLUSH_INTERVAL; 2699 // Combine all conditions that result in a full cache flush. 2700 fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicFlush || fFlushForPrune; 2701 // Write blocks and block index to disk. 2702 if (fDoFullFlush || fPeriodicWrite) { 2703 // Ensure we can write block index 2704 if (!CheckDiskSpace(m_blockman.m_opts.blocks_dir)) { 2705 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!")); 2706 } 2707 { 2708 LOG_TIME_MILLIS_WITH_CATEGORY("write block and undo data to disk", BCLog::BENCH); 2709 2710 // First make sure all block and undo data is flushed to disk. 2711 // TODO: Handle return error, or add detailed comment why it is 2712 // safe to not return an error upon failure. 2713 if (!m_blockman.FlushChainstateBlockFile(m_chain.Height())) { 2714 LogPrintLevel(BCLog::VALIDATION, BCLog::Level::Warning, "%s: Failed to flush block file.\n", __func__); 2715 } 2716 } 2717 2718 // Then update all block file information (which may refer to block and undo files). 2719 { 2720 LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk", BCLog::BENCH); 2721 2722 if (!m_blockman.WriteBlockIndexDB()) { 2723 return FatalError(m_chainman.GetNotifications(), state, _("Failed to write to block index database.")); 2724 } 2725 } 2726 // Finally remove any pruned files 2727 if (fFlushForPrune) { 2728 LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files", BCLog::BENCH); 2729 2730 m_blockman.UnlinkPrunedFiles(setFilesToPrune); 2731 } 2732 m_last_write = nNow; 2733 } 2734 // Flush best chain related state. This can only be done if the blocks / block index write was also done. 2735 if (fDoFullFlush && !CoinsTip().GetBestBlock().IsNull()) { 2736 LOG_TIME_MILLIS_WITH_CATEGORY(strprintf("write coins cache to disk (%d coins, %.2fkB)", 2737 coins_count, coins_mem_usage / 1000), BCLog::BENCH); 2738 2739 // Typical Coin structures on disk are around 48 bytes in size. 2740 // Pushing a new one to the database can cause it to be written 2741 // twice (once in the log, and once in the tables). This is already 2742 // an overestimation, as most will delete an existing entry or 2743 // overwrite one. Still, use a conservative safety factor of 2. 2744 if (!CheckDiskSpace(m_chainman.m_options.datadir, 48 * 2 * 2 * CoinsTip().GetCacheSize())) { 2745 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!")); 2746 } 2747 // Flush the chainstate (which may refer to block index entries). 2748 if (!CoinsTip().Flush()) 2749 return FatalError(m_chainman.GetNotifications(), state, _("Failed to write to coin database.")); 2750 m_last_flush = nNow; 2751 full_flush_completed = true; 2752 TRACE5(utxocache, flush, 2753 int64_t{Ticks<std::chrono::microseconds>(SteadyClock::now() - nNow)}, 2754 (uint32_t)mode, 2755 (uint64_t)coins_count, 2756 (uint64_t)coins_mem_usage, 2757 (bool)fFlushForPrune); 2758 } 2759 } 2760 if (full_flush_completed && m_chainman.m_options.signals) { 2761 // Update best block in wallet (so we can detect restored wallets). 2762 m_chainman.m_options.signals->ChainStateFlushed(this->GetRole(), m_chain.GetLocator()); 2763 } 2764 } catch (const std::runtime_error& e) { 2765 return FatalError(m_chainman.GetNotifications(), state, strprintf(_("System error while flushing: %s"), e.what())); 2766 } 2767 return true; 2768 } 2769 2770 void Chainstate::ForceFlushStateToDisk() 2771 { 2772 BlockValidationState state; 2773 if (!this->FlushStateToDisk(state, FlushStateMode::ALWAYS)) { 2774 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString()); 2775 } 2776 } 2777 2778 void Chainstate::PruneAndFlush() 2779 { 2780 BlockValidationState state; 2781 m_blockman.m_check_for_pruning = true; 2782 if (!this->FlushStateToDisk(state, FlushStateMode::NONE)) { 2783 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString()); 2784 } 2785 } 2786 2787 /** Private helper function that concatenates warning messages. */ 2788 static void AppendWarning(bilingual_str& res, const bilingual_str& warn) 2789 { 2790 if (!res.empty()) res += Untranslated(", "); 2791 res += warn; 2792 } 2793 2794 static void UpdateTipLog( 2795 const CCoinsViewCache& coins_tip, 2796 const CBlockIndex* tip, 2797 const CChainParams& params, 2798 const std::string& func_name, 2799 const std::string& prefix, 2800 const std::string& warning_messages) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 2801 { 2802 2803 AssertLockHeld(::cs_main); 2804 LogPrintf("%s%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%lu date='%s' progress=%f cache=%.1fMiB(%utxo)%s\n", 2805 prefix, func_name, 2806 tip->GetBlockHash().ToString(), tip->nHeight, tip->nVersion, 2807 log(tip->nChainWork.getdouble()) / log(2.0), (unsigned long)tip->nChainTx, 2808 FormatISO8601DateTime(tip->GetBlockTime()), 2809 GuessVerificationProgress(params.TxData(), tip), 2810 coins_tip.DynamicMemoryUsage() * (1.0 / (1 << 20)), 2811 coins_tip.GetCacheSize(), 2812 !warning_messages.empty() ? strprintf(" warning='%s'", warning_messages) : ""); 2813 } 2814 2815 void Chainstate::UpdateTip(const CBlockIndex* pindexNew) 2816 { 2817 AssertLockHeld(::cs_main); 2818 const auto& coins_tip = this->CoinsTip(); 2819 2820 const CChainParams& params{m_chainman.GetParams()}; 2821 2822 // The remainder of the function isn't relevant if we are not acting on 2823 // the active chainstate, so return if need be. 2824 if (this != &m_chainman.ActiveChainstate()) { 2825 // Only log every so often so that we don't bury log messages at the tip. 2826 constexpr int BACKGROUND_LOG_INTERVAL = 2000; 2827 if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) { 2828 UpdateTipLog(coins_tip, pindexNew, params, __func__, "[background validation] ", ""); 2829 } 2830 return; 2831 } 2832 2833 // New best block 2834 if (m_mempool) { 2835 m_mempool->AddTransactionsUpdated(1); 2836 } 2837 2838 { 2839 LOCK(g_best_block_mutex); 2840 g_best_block = pindexNew->GetBlockHash(); 2841 g_best_block_cv.notify_all(); 2842 } 2843 2844 bilingual_str warning_messages; 2845 if (!m_chainman.IsInitialBlockDownload()) { 2846 const CBlockIndex* pindex = pindexNew; 2847 for (int bit = 0; bit < VERSIONBITS_NUM_BITS; bit++) { 2848 WarningBitsConditionChecker checker(m_chainman, bit); 2849 ThresholdState state = checker.GetStateFor(pindex, params.GetConsensus(), m_chainman.m_warningcache.at(bit)); 2850 if (state == ThresholdState::ACTIVE || state == ThresholdState::LOCKED_IN) { 2851 const bilingual_str warning = strprintf(_("Unknown new rules activated (versionbit %i)"), bit); 2852 if (state == ThresholdState::ACTIVE) { 2853 m_chainman.GetNotifications().warning(warning); 2854 } else { 2855 AppendWarning(warning_messages, warning); 2856 } 2857 } 2858 } 2859 } 2860 UpdateTipLog(coins_tip, pindexNew, params, __func__, "", warning_messages.original); 2861 } 2862 2863 /** Disconnect m_chain's tip. 2864 * After calling, the mempool will be in an inconsistent state, with 2865 * transactions from disconnected blocks being added to disconnectpool. You 2866 * should make the mempool consistent again by calling MaybeUpdateMempoolForReorg. 2867 * with cs_main held. 2868 * 2869 * If disconnectpool is nullptr, then no disconnected transactions are added to 2870 * disconnectpool (note that the caller is responsible for mempool consistency 2871 * in any case). 2872 */ 2873 bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTransactions* disconnectpool) 2874 { 2875 AssertLockHeld(cs_main); 2876 if (m_mempool) AssertLockHeld(m_mempool->cs); 2877 2878 CBlockIndex *pindexDelete = m_chain.Tip(); 2879 assert(pindexDelete); 2880 assert(pindexDelete->pprev); 2881 // Read block from disk. 2882 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); 2883 CBlock& block = *pblock; 2884 if (!m_blockman.ReadBlockFromDisk(block, *pindexDelete)) { 2885 LogError("DisconnectTip(): Failed to read block\n"); 2886 return false; 2887 } 2888 // Apply the block atomically to the chain state. 2889 const auto time_start{SteadyClock::now()}; 2890 { 2891 CCoinsViewCache view(&CoinsTip()); 2892 assert(view.GetBestBlock() == pindexDelete->GetBlockHash()); 2893 if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK) { 2894 LogError("DisconnectTip(): DisconnectBlock %s failed\n", pindexDelete->GetBlockHash().ToString()); 2895 return false; 2896 } 2897 bool flushed = view.Flush(); 2898 assert(flushed); 2899 } 2900 LogPrint(BCLog::BENCH, "- Disconnect block: %.2fms\n", 2901 Ticks<MillisecondsDouble>(SteadyClock::now() - time_start)); 2902 2903 { 2904 // Prune locks that began at or after the tip should be moved backward so they get a chance to reorg 2905 const int max_height_first{pindexDelete->nHeight - 1}; 2906 for (auto& prune_lock : m_blockman.m_prune_locks) { 2907 if (prune_lock.second.height_first <= max_height_first) continue; 2908 2909 prune_lock.second.height_first = max_height_first; 2910 LogPrint(BCLog::PRUNE, "%s prune lock moved back to %d\n", prune_lock.first, max_height_first); 2911 } 2912 } 2913 2914 // Write the chain state to disk, if necessary. 2915 if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) { 2916 return false; 2917 } 2918 2919 if (disconnectpool && m_mempool) { 2920 // Save transactions to re-add to mempool at end of reorg. If any entries are evicted for 2921 // exceeding memory limits, remove them and their descendants from the mempool. 2922 for (auto&& evicted_tx : disconnectpool->AddTransactionsFromBlock(block.vtx)) { 2923 m_mempool->removeRecursive(*evicted_tx, MemPoolRemovalReason::REORG); 2924 } 2925 } 2926 2927 m_chain.SetTip(*pindexDelete->pprev); 2928 2929 UpdateTip(pindexDelete->pprev); 2930 // Let wallets know transactions went from 1-confirmed to 2931 // 0-confirmed or conflicted: 2932 if (m_chainman.m_options.signals) { 2933 m_chainman.m_options.signals->BlockDisconnected(pblock, pindexDelete); 2934 } 2935 return true; 2936 } 2937 2938 static SteadyClock::duration time_connect_total{}; 2939 static SteadyClock::duration time_flush{}; 2940 static SteadyClock::duration time_chainstate{}; 2941 static SteadyClock::duration time_post_connect{}; 2942 2943 struct PerBlockConnectTrace { 2944 CBlockIndex* pindex = nullptr; 2945 std::shared_ptr<const CBlock> pblock; 2946 PerBlockConnectTrace() = default; 2947 }; 2948 /** 2949 * Used to track blocks whose transactions were applied to the UTXO state as a 2950 * part of a single ActivateBestChainStep call. 2951 * 2952 * This class is single-use, once you call GetBlocksConnected() you have to throw 2953 * it away and make a new one. 2954 */ 2955 class ConnectTrace { 2956 private: 2957 std::vector<PerBlockConnectTrace> blocksConnected; 2958 2959 public: 2960 explicit ConnectTrace() : blocksConnected(1) {} 2961 2962 void BlockConnected(CBlockIndex* pindex, std::shared_ptr<const CBlock> pblock) { 2963 assert(!blocksConnected.back().pindex); 2964 assert(pindex); 2965 assert(pblock); 2966 blocksConnected.back().pindex = pindex; 2967 blocksConnected.back().pblock = std::move(pblock); 2968 blocksConnected.emplace_back(); 2969 } 2970 2971 std::vector<PerBlockConnectTrace>& GetBlocksConnected() { 2972 // We always keep one extra block at the end of our list because 2973 // blocks are added after all the conflicted transactions have 2974 // been filled in. Thus, the last entry should always be an empty 2975 // one waiting for the transactions from the next block. We pop 2976 // the last entry here to make sure the list we return is sane. 2977 assert(!blocksConnected.back().pindex); 2978 blocksConnected.pop_back(); 2979 return blocksConnected; 2980 } 2981 }; 2982 2983 /** 2984 * Connect a new block to m_chain. pblock is either nullptr or a pointer to a CBlock 2985 * corresponding to pindexNew, to bypass loading it again from disk. 2986 * 2987 * The block is added to connectTrace if connection succeeds. 2988 */ 2989 bool Chainstate::ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool) 2990 { 2991 AssertLockHeld(cs_main); 2992 if (m_mempool) AssertLockHeld(m_mempool->cs); 2993 2994 assert(pindexNew->pprev == m_chain.Tip()); 2995 // Read block from disk. 2996 const auto time_1{SteadyClock::now()}; 2997 std::shared_ptr<const CBlock> pthisBlock; 2998 if (!pblock) { 2999 std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>(); 3000 if (!m_blockman.ReadBlockFromDisk(*pblockNew, *pindexNew)) { 3001 return FatalError(m_chainman.GetNotifications(), state, _("Failed to read block.")); 3002 } 3003 pthisBlock = pblockNew; 3004 } else { 3005 LogPrint(BCLog::BENCH, " - Using cached block\n"); 3006 pthisBlock = pblock; 3007 } 3008 const CBlock& blockConnecting = *pthisBlock; 3009 // Apply the block atomically to the chain state. 3010 const auto time_2{SteadyClock::now()}; 3011 SteadyClock::time_point time_3; 3012 // When adding aggregate statistics in the future, keep in mind that 3013 // num_blocks_total may be zero until the ConnectBlock() call below. 3014 LogPrint(BCLog::BENCH, " - Load block from disk: %.2fms\n", 3015 Ticks<MillisecondsDouble>(time_2 - time_1)); 3016 { 3017 CCoinsViewCache view(&CoinsTip()); 3018 bool rv = ConnectBlock(blockConnecting, state, pindexNew, view); 3019 if (m_chainman.m_options.signals) { 3020 m_chainman.m_options.signals->BlockChecked(blockConnecting, state); 3021 } 3022 if (!rv) { 3023 if (state.IsInvalid()) 3024 InvalidBlockFound(pindexNew, state); 3025 LogError("%s: ConnectBlock %s failed, %s\n", __func__, pindexNew->GetBlockHash().ToString(), state.ToString()); 3026 return false; 3027 } 3028 time_3 = SteadyClock::now(); 3029 time_connect_total += time_3 - time_2; 3030 assert(num_blocks_total > 0); 3031 LogPrint(BCLog::BENCH, " - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n", 3032 Ticks<MillisecondsDouble>(time_3 - time_2), 3033 Ticks<SecondsDouble>(time_connect_total), 3034 Ticks<MillisecondsDouble>(time_connect_total) / num_blocks_total); 3035 bool flushed = view.Flush(); 3036 assert(flushed); 3037 } 3038 const auto time_4{SteadyClock::now()}; 3039 time_flush += time_4 - time_3; 3040 LogPrint(BCLog::BENCH, " - Flush: %.2fms [%.2fs (%.2fms/blk)]\n", 3041 Ticks<MillisecondsDouble>(time_4 - time_3), 3042 Ticks<SecondsDouble>(time_flush), 3043 Ticks<MillisecondsDouble>(time_flush) / num_blocks_total); 3044 // Write the chain state to disk, if necessary. 3045 if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) { 3046 return false; 3047 } 3048 const auto time_5{SteadyClock::now()}; 3049 time_chainstate += time_5 - time_4; 3050 LogPrint(BCLog::BENCH, " - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n", 3051 Ticks<MillisecondsDouble>(time_5 - time_4), 3052 Ticks<SecondsDouble>(time_chainstate), 3053 Ticks<MillisecondsDouble>(time_chainstate) / num_blocks_total); 3054 // Remove conflicting transactions from the mempool.; 3055 if (m_mempool) { 3056 m_mempool->removeForBlock(blockConnecting.vtx, pindexNew->nHeight); 3057 disconnectpool.removeForBlock(blockConnecting.vtx); 3058 } 3059 // Update m_chain & related variables. 3060 m_chain.SetTip(*pindexNew); 3061 UpdateTip(pindexNew); 3062 3063 const auto time_6{SteadyClock::now()}; 3064 time_post_connect += time_6 - time_5; 3065 time_total += time_6 - time_1; 3066 LogPrint(BCLog::BENCH, " - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n", 3067 Ticks<MillisecondsDouble>(time_6 - time_5), 3068 Ticks<SecondsDouble>(time_post_connect), 3069 Ticks<MillisecondsDouble>(time_post_connect) / num_blocks_total); 3070 LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n", 3071 Ticks<MillisecondsDouble>(time_6 - time_1), 3072 Ticks<SecondsDouble>(time_total), 3073 Ticks<MillisecondsDouble>(time_total) / num_blocks_total); 3074 3075 // If we are the background validation chainstate, check to see if we are done 3076 // validating the snapshot (i.e. our tip has reached the snapshot's base block). 3077 if (this != &m_chainman.ActiveChainstate()) { 3078 // This call may set `m_disabled`, which is referenced immediately afterwards in 3079 // ActivateBestChain, so that we stop connecting blocks past the snapshot base. 3080 m_chainman.MaybeCompleteSnapshotValidation(); 3081 } 3082 3083 connectTrace.BlockConnected(pindexNew, std::move(pthisBlock)); 3084 return true; 3085 } 3086 3087 /** 3088 * Return the tip of the chain with the most work in it, that isn't 3089 * known to be invalid (it's however far from certain to be valid). 3090 */ 3091 CBlockIndex* Chainstate::FindMostWorkChain() 3092 { 3093 AssertLockHeld(::cs_main); 3094 do { 3095 CBlockIndex *pindexNew = nullptr; 3096 3097 // Find the best candidate header. 3098 { 3099 std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexCandidates.rbegin(); 3100 if (it == setBlockIndexCandidates.rend()) 3101 return nullptr; 3102 pindexNew = *it; 3103 } 3104 3105 // Check whether all blocks on the path between the currently active chain and the candidate are valid. 3106 // Just going until the active chain is an optimization, as we know all blocks in it are valid already. 3107 CBlockIndex *pindexTest = pindexNew; 3108 bool fInvalidAncestor = false; 3109 while (pindexTest && !m_chain.Contains(pindexTest)) { 3110 assert(pindexTest->HaveNumChainTxs() || pindexTest->nHeight == 0); 3111 3112 // Pruned nodes may have entries in setBlockIndexCandidates for 3113 // which block files have been deleted. Remove those as candidates 3114 // for the most work chain if we come across them; we can't switch 3115 // to a chain unless we have all the non-active-chain parent blocks. 3116 bool fFailedChain = pindexTest->nStatus & BLOCK_FAILED_MASK; 3117 bool fMissingData = !(pindexTest->nStatus & BLOCK_HAVE_DATA); 3118 if (fFailedChain || fMissingData) { 3119 // Candidate chain is not usable (either invalid or missing data) 3120 if (fFailedChain && (m_chainman.m_best_invalid == nullptr || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork)) { 3121 m_chainman.m_best_invalid = pindexNew; 3122 } 3123 CBlockIndex *pindexFailed = pindexNew; 3124 // Remove the entire chain from the set. 3125 while (pindexTest != pindexFailed) { 3126 if (fFailedChain) { 3127 pindexFailed->nStatus |= BLOCK_FAILED_CHILD; 3128 m_blockman.m_dirty_blockindex.insert(pindexFailed); 3129 } else if (fMissingData) { 3130 // If we're missing data, then add back to m_blocks_unlinked, 3131 // so that if the block arrives in the future we can try adding 3132 // to setBlockIndexCandidates again. 3133 m_blockman.m_blocks_unlinked.insert( 3134 std::make_pair(pindexFailed->pprev, pindexFailed)); 3135 } 3136 setBlockIndexCandidates.erase(pindexFailed); 3137 pindexFailed = pindexFailed->pprev; 3138 } 3139 setBlockIndexCandidates.erase(pindexTest); 3140 fInvalidAncestor = true; 3141 break; 3142 } 3143 pindexTest = pindexTest->pprev; 3144 } 3145 if (!fInvalidAncestor) 3146 return pindexNew; 3147 } while(true); 3148 } 3149 3150 /** Delete all entries in setBlockIndexCandidates that are worse than the current tip. */ 3151 void Chainstate::PruneBlockIndexCandidates() { 3152 // Note that we can't delete the current block itself, as we may need to return to it later in case a 3153 // reorganization to a better block fails. 3154 std::set<CBlockIndex*, CBlockIndexWorkComparator>::iterator it = setBlockIndexCandidates.begin(); 3155 while (it != setBlockIndexCandidates.end() && setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) { 3156 setBlockIndexCandidates.erase(it++); 3157 } 3158 // Either the current tip or a successor of it we're working towards is left in setBlockIndexCandidates. 3159 assert(!setBlockIndexCandidates.empty()); 3160 } 3161 3162 /** 3163 * Try to make some progress towards making pindexMostWork the active block. 3164 * pblock is either nullptr or a pointer to a CBlock corresponding to pindexMostWork. 3165 * 3166 * @returns true unless a system error occurred 3167 */ 3168 bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) 3169 { 3170 AssertLockHeld(cs_main); 3171 if (m_mempool) AssertLockHeld(m_mempool->cs); 3172 3173 const CBlockIndex* pindexOldTip = m_chain.Tip(); 3174 const CBlockIndex* pindexFork = m_chain.FindFork(pindexMostWork); 3175 3176 // Disconnect active blocks which are no longer in the best chain. 3177 bool fBlocksDisconnected = false; 3178 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES}; 3179 while (m_chain.Tip() && m_chain.Tip() != pindexFork) { 3180 if (!DisconnectTip(state, &disconnectpool)) { 3181 // This is likely a fatal error, but keep the mempool consistent, 3182 // just in case. Only remove from the mempool in this case. 3183 MaybeUpdateMempoolForReorg(disconnectpool, false); 3184 3185 // If we're unable to disconnect a block during normal operation, 3186 // then that is a failure of our local system -- we should abort 3187 // rather than stay on a less work chain. 3188 FatalError(m_chainman.GetNotifications(), state, _("Failed to disconnect block.")); 3189 return false; 3190 } 3191 fBlocksDisconnected = true; 3192 } 3193 3194 // Build list of new blocks to connect (in descending height order). 3195 std::vector<CBlockIndex*> vpindexToConnect; 3196 bool fContinue = true; 3197 int nHeight = pindexFork ? pindexFork->nHeight : -1; 3198 while (fContinue && nHeight != pindexMostWork->nHeight) { 3199 // Don't iterate the entire list of potential improvements toward the best tip, as we likely only need 3200 // a few blocks along the way. 3201 int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight); 3202 vpindexToConnect.clear(); 3203 vpindexToConnect.reserve(nTargetHeight - nHeight); 3204 CBlockIndex* pindexIter = pindexMostWork->GetAncestor(nTargetHeight); 3205 while (pindexIter && pindexIter->nHeight != nHeight) { 3206 vpindexToConnect.push_back(pindexIter); 3207 pindexIter = pindexIter->pprev; 3208 } 3209 nHeight = nTargetHeight; 3210 3211 // Connect new blocks. 3212 for (CBlockIndex* pindexConnect : reverse_iterate(vpindexToConnect)) { 3213 if (!ConnectTip(state, pindexConnect, pindexConnect == pindexMostWork ? pblock : std::shared_ptr<const CBlock>(), connectTrace, disconnectpool)) { 3214 if (state.IsInvalid()) { 3215 // The block violates a consensus rule. 3216 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 3217 InvalidChainFound(vpindexToConnect.front()); 3218 } 3219 state = BlockValidationState(); 3220 fInvalidFound = true; 3221 fContinue = false; 3222 break; 3223 } else { 3224 // A system error occurred (disk space, database error, ...). 3225 // Make the mempool consistent with the current tip, just in case 3226 // any observers try to use it before shutdown. 3227 MaybeUpdateMempoolForReorg(disconnectpool, false); 3228 return false; 3229 } 3230 } else { 3231 PruneBlockIndexCandidates(); 3232 if (!pindexOldTip || m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) { 3233 // We're in a better position than we were. Return temporarily to release the lock. 3234 fContinue = false; 3235 break; 3236 } 3237 } 3238 } 3239 } 3240 3241 if (fBlocksDisconnected) { 3242 // If any blocks were disconnected, disconnectpool may be non empty. Add 3243 // any disconnected transactions back to the mempool. 3244 MaybeUpdateMempoolForReorg(disconnectpool, true); 3245 } 3246 if (m_mempool) m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1); 3247 3248 CheckForkWarningConditions(); 3249 3250 return true; 3251 } 3252 3253 static SynchronizationState GetSynchronizationState(bool init) 3254 { 3255 if (!init) return SynchronizationState::POST_INIT; 3256 if (::fReindex) return SynchronizationState::INIT_REINDEX; 3257 return SynchronizationState::INIT_DOWNLOAD; 3258 } 3259 3260 static bool NotifyHeaderTip(ChainstateManager& chainman) LOCKS_EXCLUDED(cs_main) 3261 { 3262 bool fNotify = false; 3263 bool fInitialBlockDownload = false; 3264 static CBlockIndex* pindexHeaderOld = nullptr; 3265 CBlockIndex* pindexHeader = nullptr; 3266 { 3267 LOCK(cs_main); 3268 pindexHeader = chainman.m_best_header; 3269 3270 if (pindexHeader != pindexHeaderOld) { 3271 fNotify = true; 3272 fInitialBlockDownload = chainman.IsInitialBlockDownload(); 3273 pindexHeaderOld = pindexHeader; 3274 } 3275 } 3276 // Send block tip changed notifications without cs_main 3277 if (fNotify) { 3278 chainman.GetNotifications().headerTip(GetSynchronizationState(fInitialBlockDownload), pindexHeader->nHeight, pindexHeader->nTime, false); 3279 } 3280 return fNotify; 3281 } 3282 3283 static void LimitValidationInterfaceQueue(ValidationSignals& signals) LOCKS_EXCLUDED(cs_main) { 3284 AssertLockNotHeld(cs_main); 3285 3286 if (signals.CallbacksPending() > 10) { 3287 signals.SyncWithValidationInterfaceQueue(); 3288 } 3289 } 3290 3291 bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<const CBlock> pblock) 3292 { 3293 AssertLockNotHeld(m_chainstate_mutex); 3294 3295 // Note that while we're often called here from ProcessNewBlock, this is 3296 // far from a guarantee. Things in the P2P/RPC will often end up calling 3297 // us in the middle of ProcessNewBlock - do not assume pblock is set 3298 // sanely for performance or correctness! 3299 AssertLockNotHeld(::cs_main); 3300 3301 // ABC maintains a fair degree of expensive-to-calculate internal state 3302 // because this function periodically releases cs_main so that it does not lock up other threads for too long 3303 // during large connects - and to allow for e.g. the callback queue to drain 3304 // we use m_chainstate_mutex to enforce mutual exclusion so that only one caller may execute this function at a time 3305 LOCK(m_chainstate_mutex); 3306 3307 // Belt-and-suspenders check that we aren't attempting to advance the background 3308 // chainstate past the snapshot base block. 3309 if (WITH_LOCK(::cs_main, return m_disabled)) { 3310 LogPrintf("m_disabled is set - this chainstate should not be in operation. " 3311 "Please report this as a bug. %s\n", PACKAGE_BUGREPORT); 3312 return false; 3313 } 3314 3315 CBlockIndex *pindexMostWork = nullptr; 3316 CBlockIndex *pindexNewTip = nullptr; 3317 bool exited_ibd{false}; 3318 do { 3319 // Block until the validation queue drains. This should largely 3320 // never happen in normal operation, however may happen during 3321 // reindex, causing memory blowup if we run too far ahead. 3322 // Note that if a validationinterface callback ends up calling 3323 // ActivateBestChain this may lead to a deadlock! We should 3324 // probably have a DEBUG_LOCKORDER test for this in the future. 3325 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals); 3326 3327 { 3328 LOCK(cs_main); 3329 // Lock transaction pool for at least as long as it takes for connectTrace to be consumed 3330 LOCK(MempoolMutex()); 3331 const bool was_in_ibd = m_chainman.IsInitialBlockDownload(); 3332 CBlockIndex* starting_tip = m_chain.Tip(); 3333 bool blocks_connected = false; 3334 do { 3335 // We absolutely may not unlock cs_main until we've made forward progress 3336 // (with the exception of shutdown due to hardware issues, low disk space, etc). 3337 ConnectTrace connectTrace; // Destructed before cs_main is unlocked 3338 3339 if (pindexMostWork == nullptr) { 3340 pindexMostWork = FindMostWorkChain(); 3341 } 3342 3343 // Whether we have anything to do at all. 3344 if (pindexMostWork == nullptr || pindexMostWork == m_chain.Tip()) { 3345 break; 3346 } 3347 3348 bool fInvalidFound = false; 3349 std::shared_ptr<const CBlock> nullBlockPtr; 3350 if (!ActivateBestChainStep(state, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace)) { 3351 // A system error occurred 3352 return false; 3353 } 3354 blocks_connected = true; 3355 3356 if (fInvalidFound) { 3357 // Wipe cache, we may need another branch now. 3358 pindexMostWork = nullptr; 3359 } 3360 pindexNewTip = m_chain.Tip(); 3361 3362 for (const PerBlockConnectTrace& trace : connectTrace.GetBlocksConnected()) { 3363 assert(trace.pblock && trace.pindex); 3364 if (m_chainman.m_options.signals) { 3365 m_chainman.m_options.signals->BlockConnected(this->GetRole(), trace.pblock, trace.pindex); 3366 } 3367 } 3368 3369 // This will have been toggled in 3370 // ActivateBestChainStep -> ConnectTip -> MaybeCompleteSnapshotValidation, 3371 // if at all, so we should catch it here. 3372 // 3373 // Break this do-while to ensure we don't advance past the base snapshot. 3374 if (m_disabled) { 3375 break; 3376 } 3377 } while (!m_chain.Tip() || (starting_tip && CBlockIndexWorkComparator()(m_chain.Tip(), starting_tip))); 3378 if (!blocks_connected) return true; 3379 3380 const CBlockIndex* pindexFork = m_chain.FindFork(starting_tip); 3381 bool still_in_ibd = m_chainman.IsInitialBlockDownload(); 3382 3383 if (was_in_ibd && !still_in_ibd) { 3384 // Active chainstate has exited IBD. 3385 exited_ibd = true; 3386 } 3387 3388 // Notify external listeners about the new tip. 3389 // Enqueue while holding cs_main to ensure that UpdatedBlockTip is called in the order in which blocks are connected 3390 if (this == &m_chainman.ActiveChainstate() && pindexFork != pindexNewTip) { 3391 // Notify ValidationInterface subscribers 3392 if (m_chainman.m_options.signals) { 3393 m_chainman.m_options.signals->UpdatedBlockTip(pindexNewTip, pindexFork, still_in_ibd); 3394 } 3395 3396 // Always notify the UI if a new block tip was connected 3397 if (kernel::IsInterrupted(m_chainman.GetNotifications().blockTip(GetSynchronizationState(still_in_ibd), *pindexNewTip))) { 3398 // Just breaking and returning success for now. This could 3399 // be changed to bubble up the kernel::Interrupted value to 3400 // the caller so the caller could distinguish between 3401 // completed and interrupted operations. 3402 break; 3403 } 3404 } 3405 } 3406 // When we reach this point, we switched to a new tip (stored in pindexNewTip). 3407 3408 if (exited_ibd) { 3409 // If a background chainstate is in use, we may need to rebalance our 3410 // allocation of caches once a chainstate exits initial block download. 3411 LOCK(::cs_main); 3412 m_chainman.MaybeRebalanceCaches(); 3413 } 3414 3415 if (WITH_LOCK(::cs_main, return m_disabled)) { 3416 // Background chainstate has reached the snapshot base block, so exit. 3417 3418 // Restart indexes to resume indexing for all blocks unique to the snapshot 3419 // chain. This resumes indexing "in order" from where the indexing on the 3420 // background validation chain left off. 3421 // 3422 // This cannot be done while holding cs_main (within 3423 // MaybeCompleteSnapshotValidation) or a cs_main deadlock will occur. 3424 if (m_chainman.restart_indexes) { 3425 m_chainman.restart_indexes(); 3426 } 3427 break; 3428 } 3429 3430 // We check interrupt only after giving ActivateBestChainStep a chance to run once so that we 3431 // never interrupt before connecting the genesis block during LoadChainTip(). Previously this 3432 // caused an assert() failure during interrupt in such cases as the UTXO DB flushing checks 3433 // that the best block hash is non-null. 3434 if (m_chainman.m_interrupt) break; 3435 } while (pindexNewTip != pindexMostWork); 3436 3437 m_chainman.CheckBlockIndex(); 3438 3439 // Write changes periodically to disk, after relay. 3440 if (!FlushStateToDisk(state, FlushStateMode::PERIODIC)) { 3441 return false; 3442 } 3443 3444 return true; 3445 } 3446 3447 bool Chainstate::PreciousBlock(BlockValidationState& state, CBlockIndex* pindex) 3448 { 3449 AssertLockNotHeld(m_chainstate_mutex); 3450 AssertLockNotHeld(::cs_main); 3451 { 3452 LOCK(cs_main); 3453 if (pindex->nChainWork < m_chain.Tip()->nChainWork) { 3454 // Nothing to do, this block is not at the tip. 3455 return true; 3456 } 3457 if (m_chain.Tip()->nChainWork > m_chainman.nLastPreciousChainwork) { 3458 // The chain has been extended since the last call, reset the counter. 3459 m_chainman.nBlockReverseSequenceId = -1; 3460 } 3461 m_chainman.nLastPreciousChainwork = m_chain.Tip()->nChainWork; 3462 setBlockIndexCandidates.erase(pindex); 3463 pindex->nSequenceId = m_chainman.nBlockReverseSequenceId; 3464 if (m_chainman.nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) { 3465 // We can't keep reducing the counter if somebody really wants to 3466 // call preciousblock 2**31-1 times on the same set of tips... 3467 m_chainman.nBlockReverseSequenceId--; 3468 } 3469 if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && pindex->HaveNumChainTxs()) { 3470 setBlockIndexCandidates.insert(pindex); 3471 PruneBlockIndexCandidates(); 3472 } 3473 } 3474 3475 return ActivateBestChain(state, std::shared_ptr<const CBlock>()); 3476 } 3477 3478 bool Chainstate::InvalidateBlock(BlockValidationState& state, CBlockIndex* pindex) 3479 { 3480 AssertLockNotHeld(m_chainstate_mutex); 3481 AssertLockNotHeld(::cs_main); 3482 3483 // Genesis block can't be invalidated 3484 assert(pindex); 3485 if (pindex->nHeight == 0) return false; 3486 3487 CBlockIndex* to_mark_failed = pindex; 3488 bool pindex_was_in_chain = false; 3489 int disconnected = 0; 3490 3491 // We do not allow ActivateBestChain() to run while InvalidateBlock() is 3492 // running, as that could cause the tip to change while we disconnect 3493 // blocks. 3494 LOCK(m_chainstate_mutex); 3495 3496 // We'll be acquiring and releasing cs_main below, to allow the validation 3497 // callbacks to run. However, we should keep the block index in a 3498 // consistent state as we disconnect blocks -- in particular we need to 3499 // add equal-work blocks to setBlockIndexCandidates as we disconnect. 3500 // To avoid walking the block index repeatedly in search of candidates, 3501 // build a map once so that we can look up candidate blocks by chain 3502 // work as we go. 3503 std::multimap<const arith_uint256, CBlockIndex *> candidate_blocks_by_work; 3504 3505 { 3506 LOCK(cs_main); 3507 for (auto& entry : m_blockman.m_block_index) { 3508 CBlockIndex* candidate = &entry.second; 3509 // We don't need to put anything in our active chain into the 3510 // multimap, because those candidates will be found and considered 3511 // as we disconnect. 3512 // Instead, consider only non-active-chain blocks that have at 3513 // least as much work as where we expect the new tip to end up. 3514 if (!m_chain.Contains(candidate) && 3515 !CBlockIndexWorkComparator()(candidate, pindex->pprev) && 3516 candidate->IsValid(BLOCK_VALID_TRANSACTIONS) && 3517 candidate->HaveNumChainTxs()) { 3518 candidate_blocks_by_work.insert(std::make_pair(candidate->nChainWork, candidate)); 3519 } 3520 } 3521 } 3522 3523 // Disconnect (descendants of) pindex, and mark them invalid. 3524 while (true) { 3525 if (m_chainman.m_interrupt) break; 3526 3527 // Make sure the queue of validation callbacks doesn't grow unboundedly. 3528 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals); 3529 3530 LOCK(cs_main); 3531 // Lock for as long as disconnectpool is in scope to make sure MaybeUpdateMempoolForReorg is 3532 // called after DisconnectTip without unlocking in between 3533 LOCK(MempoolMutex()); 3534 if (!m_chain.Contains(pindex)) break; 3535 pindex_was_in_chain = true; 3536 CBlockIndex *invalid_walk_tip = m_chain.Tip(); 3537 3538 // ActivateBestChain considers blocks already in m_chain 3539 // unconditionally valid already, so force disconnect away from it. 3540 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES}; 3541 bool ret = DisconnectTip(state, &disconnectpool); 3542 // DisconnectTip will add transactions to disconnectpool. 3543 // Adjust the mempool to be consistent with the new tip, adding 3544 // transactions back to the mempool if disconnecting was successful, 3545 // and we're not doing a very deep invalidation (in which case 3546 // keeping the mempool up to date is probably futile anyway). 3547 MaybeUpdateMempoolForReorg(disconnectpool, /* fAddToMempool = */ (++disconnected <= 10) && ret); 3548 if (!ret) return false; 3549 assert(invalid_walk_tip->pprev == m_chain.Tip()); 3550 3551 // We immediately mark the disconnected blocks as invalid. 3552 // This prevents a case where pruned nodes may fail to invalidateblock 3553 // and be left unable to start as they have no tip candidates (as there 3554 // are no blocks that meet the "have data and are not invalid per 3555 // nStatus" criteria for inclusion in setBlockIndexCandidates). 3556 invalid_walk_tip->nStatus |= BLOCK_FAILED_VALID; 3557 m_blockman.m_dirty_blockindex.insert(invalid_walk_tip); 3558 setBlockIndexCandidates.erase(invalid_walk_tip); 3559 setBlockIndexCandidates.insert(invalid_walk_tip->pprev); 3560 if (invalid_walk_tip->pprev == to_mark_failed && (to_mark_failed->nStatus & BLOCK_FAILED_VALID)) { 3561 // We only want to mark the last disconnected block as BLOCK_FAILED_VALID; its children 3562 // need to be BLOCK_FAILED_CHILD instead. 3563 to_mark_failed->nStatus = (to_mark_failed->nStatus ^ BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD; 3564 m_blockman.m_dirty_blockindex.insert(to_mark_failed); 3565 } 3566 3567 // Add any equal or more work headers to setBlockIndexCandidates 3568 auto candidate_it = candidate_blocks_by_work.lower_bound(invalid_walk_tip->pprev->nChainWork); 3569 while (candidate_it != candidate_blocks_by_work.end()) { 3570 if (!CBlockIndexWorkComparator()(candidate_it->second, invalid_walk_tip->pprev)) { 3571 setBlockIndexCandidates.insert(candidate_it->second); 3572 candidate_it = candidate_blocks_by_work.erase(candidate_it); 3573 } else { 3574 ++candidate_it; 3575 } 3576 } 3577 3578 // Track the last disconnected block, so we can correct its BLOCK_FAILED_CHILD status in future 3579 // iterations, or, if it's the last one, call InvalidChainFound on it. 3580 to_mark_failed = invalid_walk_tip; 3581 } 3582 3583 m_chainman.CheckBlockIndex(); 3584 3585 { 3586 LOCK(cs_main); 3587 if (m_chain.Contains(to_mark_failed)) { 3588 // If the to-be-marked invalid block is in the active chain, something is interfering and we can't proceed. 3589 return false; 3590 } 3591 3592 // Mark pindex (or the last disconnected block) as invalid, even when it never was in the main chain 3593 to_mark_failed->nStatus |= BLOCK_FAILED_VALID; 3594 m_blockman.m_dirty_blockindex.insert(to_mark_failed); 3595 setBlockIndexCandidates.erase(to_mark_failed); 3596 m_chainman.m_failed_blocks.insert(to_mark_failed); 3597 3598 // If any new blocks somehow arrived while we were disconnecting 3599 // (above), then the pre-calculation of what should go into 3600 // setBlockIndexCandidates may have missed entries. This would 3601 // technically be an inconsistency in the block index, but if we clean 3602 // it up here, this should be an essentially unobservable error. 3603 // Loop back over all block index entries and add any missing entries 3604 // to setBlockIndexCandidates. 3605 for (auto& [_, block_index] : m_blockman.m_block_index) { 3606 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && !setBlockIndexCandidates.value_comp()(&block_index, m_chain.Tip())) { 3607 setBlockIndexCandidates.insert(&block_index); 3608 } 3609 } 3610 3611 InvalidChainFound(to_mark_failed); 3612 } 3613 3614 // Only notify about a new block tip if the active chain was modified. 3615 if (pindex_was_in_chain) { 3616 // Ignoring return value for now, this could be changed to bubble up 3617 // kernel::Interrupted value to the caller so the caller could 3618 // distinguish between completed and interrupted operations. It might 3619 // also make sense for the blockTip notification to have an enum 3620 // parameter indicating the source of the tip change so hooks can 3621 // distinguish user-initiated invalidateblock changes from other 3622 // changes. 3623 (void)m_chainman.GetNotifications().blockTip(GetSynchronizationState(m_chainman.IsInitialBlockDownload()), *to_mark_failed->pprev); 3624 } 3625 return true; 3626 } 3627 3628 void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex) { 3629 AssertLockHeld(cs_main); 3630 3631 int nHeight = pindex->nHeight; 3632 3633 // Remove the invalidity flag from this block and all its descendants. 3634 for (auto& [_, block_index] : m_blockman.m_block_index) { 3635 if (!block_index.IsValid() && block_index.GetAncestor(nHeight) == pindex) { 3636 block_index.nStatus &= ~BLOCK_FAILED_MASK; 3637 m_blockman.m_dirty_blockindex.insert(&block_index); 3638 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &block_index)) { 3639 setBlockIndexCandidates.insert(&block_index); 3640 } 3641 if (&block_index == m_chainman.m_best_invalid) { 3642 // Reset invalid block marker if it was pointing to one of those. 3643 m_chainman.m_best_invalid = nullptr; 3644 } 3645 m_chainman.m_failed_blocks.erase(&block_index); 3646 } 3647 } 3648 3649 // Remove the invalidity flag from all ancestors too. 3650 while (pindex != nullptr) { 3651 if (pindex->nStatus & BLOCK_FAILED_MASK) { 3652 pindex->nStatus &= ~BLOCK_FAILED_MASK; 3653 m_blockman.m_dirty_blockindex.insert(pindex); 3654 m_chainman.m_failed_blocks.erase(pindex); 3655 } 3656 pindex = pindex->pprev; 3657 } 3658 } 3659 3660 void Chainstate::TryAddBlockIndexCandidate(CBlockIndex* pindex) 3661 { 3662 AssertLockHeld(cs_main); 3663 // The block only is a candidate for the most-work-chain if it has the same 3664 // or more work than our current tip. 3665 if (m_chain.Tip() != nullptr && setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) { 3666 return; 3667 } 3668 3669 bool is_active_chainstate = this == &m_chainman.ActiveChainstate(); 3670 if (is_active_chainstate) { 3671 // The active chainstate should always add entries that have more 3672 // work than the tip. 3673 setBlockIndexCandidates.insert(pindex); 3674 } else if (!m_disabled) { 3675 // For the background chainstate, we only consider connecting blocks 3676 // towards the snapshot base (which can't be nullptr or else we'll 3677 // never make progress). 3678 const CBlockIndex* snapshot_base{Assert(m_chainman.GetSnapshotBaseBlock())}; 3679 if (snapshot_base->GetAncestor(pindex->nHeight) == pindex) { 3680 setBlockIndexCandidates.insert(pindex); 3681 } 3682 } 3683 } 3684 3685 /** Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS). */ 3686 void ChainstateManager::ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos) 3687 { 3688 AssertLockHeld(cs_main); 3689 pindexNew->nTx = block.vtx.size(); 3690 // Typically nChainTx will be 0 at this point, but it can be nonzero if this 3691 // is a pruned block which is being downloaded again, or if this is an 3692 // assumeutxo snapshot block which has a hardcoded nChainTx value from the 3693 // snapshot metadata. If the pindex is not the snapshot block and the 3694 // nChainTx value is not zero, assert that value is actually correct. 3695 auto prev_tx_sum = [](CBlockIndex& block) { return block.nTx + (block.pprev ? block.pprev->nChainTx : 0); }; 3696 if (!Assume(pindexNew->nChainTx == 0 || pindexNew->nChainTx == prev_tx_sum(*pindexNew) || 3697 pindexNew == GetSnapshotBaseBlock())) { 3698 LogWarning("Internal bug detected: block %d has unexpected nChainTx %i that should be %i (%s %s). Please report this issue here: %s\n", 3699 pindexNew->nHeight, pindexNew->nChainTx, prev_tx_sum(*pindexNew), PACKAGE_NAME, FormatFullVersion(), PACKAGE_BUGREPORT); 3700 pindexNew->nChainTx = 0; 3701 } 3702 pindexNew->nFile = pos.nFile; 3703 pindexNew->nDataPos = pos.nPos; 3704 pindexNew->nUndoPos = 0; 3705 pindexNew->nStatus |= BLOCK_HAVE_DATA; 3706 if (DeploymentActiveAt(*pindexNew, *this, Consensus::DEPLOYMENT_SEGWIT)) { 3707 pindexNew->nStatus |= BLOCK_OPT_WITNESS; 3708 } 3709 pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS); 3710 m_blockman.m_dirty_blockindex.insert(pindexNew); 3711 3712 if (pindexNew->pprev == nullptr || pindexNew->pprev->HaveNumChainTxs()) { 3713 // If pindexNew is the genesis block or all parents are BLOCK_VALID_TRANSACTIONS. 3714 std::deque<CBlockIndex*> queue; 3715 queue.push_back(pindexNew); 3716 3717 // Recursively process any descendant blocks that now may be eligible to be connected. 3718 while (!queue.empty()) { 3719 CBlockIndex *pindex = queue.front(); 3720 queue.pop_front(); 3721 // Before setting nChainTx, assert that it is 0 or already set to 3722 // the correct value. This assert will fail after receiving the 3723 // assumeutxo snapshot block if assumeutxo snapshot metadata has an 3724 // incorrect hardcoded AssumeutxoData::nChainTx value. 3725 if (!Assume(pindex->nChainTx == 0 || pindex->nChainTx == prev_tx_sum(*pindex))) { 3726 LogWarning("Internal bug detected: block %d has unexpected nChainTx %i that should be %i (%s %s). Please report this issue here: %s\n", 3727 pindex->nHeight, pindex->nChainTx, prev_tx_sum(*pindex), PACKAGE_NAME, FormatFullVersion(), PACKAGE_BUGREPORT); 3728 } 3729 pindex->nChainTx = prev_tx_sum(*pindex); 3730 pindex->nSequenceId = nBlockSequenceId++; 3731 for (Chainstate *c : GetAll()) { 3732 c->TryAddBlockIndexCandidate(pindex); 3733 } 3734 std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> range = m_blockman.m_blocks_unlinked.equal_range(pindex); 3735 while (range.first != range.second) { 3736 std::multimap<CBlockIndex*, CBlockIndex*>::iterator it = range.first; 3737 queue.push_back(it->second); 3738 range.first++; 3739 m_blockman.m_blocks_unlinked.erase(it); 3740 } 3741 } 3742 } else { 3743 if (pindexNew->pprev && pindexNew->pprev->IsValid(BLOCK_VALID_TREE)) { 3744 m_blockman.m_blocks_unlinked.insert(std::make_pair(pindexNew->pprev, pindexNew)); 3745 } 3746 } 3747 } 3748 3749 static bool CheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true) 3750 { 3751 // Check proof of work matches claimed amount 3752 if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, consensusParams)) 3753 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "high-hash", "proof of work failed"); 3754 3755 return true; 3756 } 3757 3758 static bool CheckMerkleRoot(const CBlock& block, BlockValidationState& state) 3759 { 3760 if (block.m_checked_merkle_root) return true; 3761 3762 bool mutated; 3763 uint256 merkle_root = BlockMerkleRoot(block, &mutated); 3764 if (block.hashMerkleRoot != merkle_root) { 3765 return state.Invalid( 3766 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3767 /*reject_reason=*/"bad-txnmrklroot", 3768 /*debug_message=*/"hashMerkleRoot mismatch"); 3769 } 3770 3771 // Check for merkle tree malleability (CVE-2012-2459): repeating sequences 3772 // of transactions in a block without affecting the merkle root of a block, 3773 // while still invalidating it. 3774 if (mutated) { 3775 return state.Invalid( 3776 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3777 /*reject_reason=*/"bad-txns-duplicate", 3778 /*debug_message=*/"duplicate transaction"); 3779 } 3780 3781 block.m_checked_merkle_root = true; 3782 return true; 3783 } 3784 3785 /** CheckWitnessMalleation performs checks for block malleation with regard to 3786 * its witnesses. 3787 * 3788 * Note: If the witness commitment is expected (i.e. `expect_witness_commitment 3789 * = true`), then the block is required to have at least one transaction and the 3790 * first transaction needs to have at least one input. */ 3791 static bool CheckWitnessMalleation(const CBlock& block, bool expect_witness_commitment, BlockValidationState& state) 3792 { 3793 if (expect_witness_commitment) { 3794 if (block.m_checked_witness_commitment) return true; 3795 3796 int commitpos = GetWitnessCommitmentIndex(block); 3797 if (commitpos != NO_WITNESS_COMMITMENT) { 3798 assert(!block.vtx.empty() && !block.vtx[0]->vin.empty()); 3799 const auto& witness_stack{block.vtx[0]->vin[0].scriptWitness.stack}; 3800 3801 if (witness_stack.size() != 1 || witness_stack[0].size() != 32) { 3802 return state.Invalid( 3803 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3804 /*reject_reason=*/"bad-witness-nonce-size", 3805 /*debug_message=*/strprintf("%s : invalid witness reserved value size", __func__)); 3806 } 3807 3808 // The malleation check is ignored; as the transaction tree itself 3809 // already does not permit it, it is impossible to trigger in the 3810 // witness tree. 3811 uint256 hash_witness = BlockWitnessMerkleRoot(block, /*mutated=*/nullptr); 3812 3813 CHash256().Write(hash_witness).Write(witness_stack[0]).Finalize(hash_witness); 3814 if (memcmp(hash_witness.begin(), &block.vtx[0]->vout[commitpos].scriptPubKey[6], 32)) { 3815 return state.Invalid( 3816 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3817 /*reject_reason=*/"bad-witness-merkle-match", 3818 /*debug_message=*/strprintf("%s : witness merkle commitment mismatch", __func__)); 3819 } 3820 3821 block.m_checked_witness_commitment = true; 3822 return true; 3823 } 3824 } 3825 3826 // No witness data is allowed in blocks that don't commit to witness data, as this would otherwise leave room for spam 3827 for (const auto& tx : block.vtx) { 3828 if (tx->HasWitness()) { 3829 return state.Invalid( 3830 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3831 /*reject_reason=*/"unexpected-witness", 3832 /*debug_message=*/strprintf("%s : unexpected witness data found", __func__)); 3833 } 3834 } 3835 3836 return true; 3837 } 3838 3839 bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW, bool fCheckMerkleRoot) 3840 { 3841 // These are checks that are independent of context. 3842 3843 if (block.fChecked) 3844 return true; 3845 3846 // Check that the header is valid (particularly PoW). This is mostly 3847 // redundant with the call in AcceptBlockHeader. 3848 if (!CheckBlockHeader(block, state, consensusParams, fCheckPOW)) 3849 return false; 3850 3851 // Signet only: check block solution 3852 if (consensusParams.signet_blocks && fCheckPOW && !CheckSignetBlockSolution(block, consensusParams)) { 3853 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-signet-blksig", "signet block signature validation failure"); 3854 } 3855 3856 // Check the merkle root. 3857 if (fCheckMerkleRoot && !CheckMerkleRoot(block, state)) { 3858 return false; 3859 } 3860 3861 // All potential-corruption validation must be done before we do any 3862 // transaction validation, as otherwise we may mark the header as invalid 3863 // because we receive the wrong transactions for it. 3864 // Note that witness malleability is checked in ContextualCheckBlock, so no 3865 // checks that use witness data may be performed here. 3866 3867 // Size limits 3868 if (block.vtx.empty() || block.vtx.size() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT || ::GetSerializeSize(TX_NO_WITNESS(block)) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT) 3869 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-length", "size limits failed"); 3870 3871 // First transaction must be coinbase, the rest must not be 3872 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) 3873 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-missing", "first tx is not coinbase"); 3874 for (unsigned int i = 1; i < block.vtx.size(); i++) 3875 if (block.vtx[i]->IsCoinBase()) 3876 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-multiple", "more than one coinbase"); 3877 3878 // Check transactions 3879 // Must check for duplicate inputs (see CVE-2018-17144) 3880 for (const auto& tx : block.vtx) { 3881 TxValidationState tx_state; 3882 if (!CheckTransaction(*tx, tx_state)) { 3883 // CheckBlock() does context-free validation checks. The only 3884 // possible failures are consensus failures. 3885 assert(tx_state.GetResult() == TxValidationResult::TX_CONSENSUS); 3886 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, tx_state.GetRejectReason(), 3887 strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), tx_state.GetDebugMessage())); 3888 } 3889 } 3890 unsigned int nSigOps = 0; 3891 for (const auto& tx : block.vtx) 3892 { 3893 nSigOps += GetLegacySigOpCount(*tx); 3894 } 3895 if (nSigOps * WITNESS_SCALE_FACTOR > MAX_BLOCK_SIGOPS_COST) 3896 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "out-of-bounds SigOpCount"); 3897 3898 if (fCheckPOW && fCheckMerkleRoot) 3899 block.fChecked = true; 3900 3901 return true; 3902 } 3903 3904 void ChainstateManager::UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev) const 3905 { 3906 int commitpos = GetWitnessCommitmentIndex(block); 3907 static const std::vector<unsigned char> nonce(32, 0x00); 3908 if (commitpos != NO_WITNESS_COMMITMENT && DeploymentActiveAfter(pindexPrev, *this, Consensus::DEPLOYMENT_SEGWIT) && !block.vtx[0]->HasWitness()) { 3909 CMutableTransaction tx(*block.vtx[0]); 3910 tx.vin[0].scriptWitness.stack.resize(1); 3911 tx.vin[0].scriptWitness.stack[0] = nonce; 3912 block.vtx[0] = MakeTransactionRef(std::move(tx)); 3913 } 3914 } 3915 3916 std::vector<unsigned char> ChainstateManager::GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev) const 3917 { 3918 std::vector<unsigned char> commitment; 3919 int commitpos = GetWitnessCommitmentIndex(block); 3920 std::vector<unsigned char> ret(32, 0x00); 3921 if (commitpos == NO_WITNESS_COMMITMENT) { 3922 uint256 witnessroot = BlockWitnessMerkleRoot(block, nullptr); 3923 CHash256().Write(witnessroot).Write(ret).Finalize(witnessroot); 3924 CTxOut out; 3925 out.nValue = 0; 3926 out.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT); 3927 out.scriptPubKey[0] = OP_RETURN; 3928 out.scriptPubKey[1] = 0x24; 3929 out.scriptPubKey[2] = 0xaa; 3930 out.scriptPubKey[3] = 0x21; 3931 out.scriptPubKey[4] = 0xa9; 3932 out.scriptPubKey[5] = 0xed; 3933 memcpy(&out.scriptPubKey[6], witnessroot.begin(), 32); 3934 commitment = std::vector<unsigned char>(out.scriptPubKey.begin(), out.scriptPubKey.end()); 3935 CMutableTransaction tx(*block.vtx[0]); 3936 tx.vout.push_back(out); 3937 block.vtx[0] = MakeTransactionRef(std::move(tx)); 3938 } 3939 UpdateUncommittedBlockStructures(block, pindexPrev); 3940 return commitment; 3941 } 3942 3943 bool HasValidProofOfWork(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams) 3944 { 3945 return std::all_of(headers.cbegin(), headers.cend(), 3946 [&](const auto& header) { return CheckProofOfWork(header.GetHash(), header.nBits, consensusParams);}); 3947 } 3948 3949 bool IsBlockMutated(const CBlock& block, bool check_witness_root) 3950 { 3951 BlockValidationState state; 3952 if (!CheckMerkleRoot(block, state)) { 3953 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString()); 3954 return true; 3955 } 3956 3957 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) { 3958 // Consider the block mutated if any transaction is 64 bytes in size (see 3.1 3959 // in "Weaknesses in Bitcoin’s Merkle Root Construction": 3960 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20190225/a27d8837/attachment-0001.pdf). 3961 // 3962 // Note: This is not a consensus change as this only applies to blocks that 3963 // don't have a coinbase transaction and would therefore already be invalid. 3964 return std::any_of(block.vtx.begin(), block.vtx.end(), 3965 [](auto& tx) { return GetSerializeSize(TX_NO_WITNESS(tx)) == 64; }); 3966 } else { 3967 // Theoretically it is still possible for a block with a 64 byte 3968 // coinbase transaction to be mutated but we neglect that possibility 3969 // here as it requires at least 224 bits of work. 3970 } 3971 3972 if (!CheckWitnessMalleation(block, check_witness_root, state)) { 3973 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString()); 3974 return true; 3975 } 3976 3977 return false; 3978 } 3979 3980 arith_uint256 CalculateClaimedHeadersWork(const std::vector<CBlockHeader>& headers) 3981 { 3982 arith_uint256 total_work{0}; 3983 for (const CBlockHeader& header : headers) { 3984 CBlockIndex dummy(header); 3985 total_work += GetBlockProof(dummy); 3986 } 3987 return total_work; 3988 } 3989 3990 /** Context-dependent validity checks. 3991 * By "context", we mean only the previous block headers, but not the UTXO 3992 * set; UTXO-related validity checks are done in ConnectBlock(). 3993 * NOTE: This function is not currently invoked by ConnectBlock(), so we 3994 * should consider upgrade issues if we change which consensus rules are 3995 * enforced in this function (eg by adding a new consensus rule). See comment 3996 * in ConnectBlock(). 3997 * Note that -reindex-chainstate skips the validation that happens here! 3998 */ 3999 static bool ContextualCheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, BlockManager& blockman, const ChainstateManager& chainman, const CBlockIndex* pindexPrev) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 4000 { 4001 AssertLockHeld(::cs_main); 4002 assert(pindexPrev != nullptr); 4003 const int nHeight = pindexPrev->nHeight + 1; 4004 4005 // Check proof of work 4006 const Consensus::Params& consensusParams = chainman.GetConsensus(); 4007 if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams)) 4008 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "bad-diffbits", "incorrect proof of work"); 4009 4010 // Check against checkpoints 4011 if (chainman.m_options.checkpoints_enabled) { 4012 // Don't accept any forks from the main chain prior to last checkpoint. 4013 // GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's in our 4014 // BlockIndex(). 4015 const CBlockIndex* pcheckpoint = blockman.GetLastCheckpoint(chainman.GetParams().Checkpoints()); 4016 if (pcheckpoint && nHeight < pcheckpoint->nHeight) { 4017 LogPrintf("ERROR: %s: forked chain older than last checkpoint (height %d)\n", __func__, nHeight); 4018 return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT, "bad-fork-prior-to-checkpoint"); 4019 } 4020 } 4021 4022 // Check timestamp against prev 4023 if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast()) 4024 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-too-old", "block's timestamp is too early"); 4025 4026 // Check timestamp 4027 if (block.Time() > NodeClock::now() + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) { 4028 return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE, "time-too-new", "block timestamp too far in the future"); 4029 } 4030 4031 // Reject blocks with outdated version 4032 if ((block.nVersion < 2 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) || 4033 (block.nVersion < 3 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_DERSIG)) || 4034 (block.nVersion < 4 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CLTV))) { 4035 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, strprintf("bad-version(0x%08x)", block.nVersion), 4036 strprintf("rejected nVersion=0x%08x block", block.nVersion)); 4037 } 4038 4039 return true; 4040 } 4041 4042 /** NOTE: This function is not currently invoked by ConnectBlock(), so we 4043 * should consider upgrade issues if we change which consensus rules are 4044 * enforced in this function (eg by adding a new consensus rule). See comment 4045 * in ConnectBlock(). 4046 * Note that -reindex-chainstate skips the validation that happens here! 4047 */ 4048 static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& state, const ChainstateManager& chainman, const CBlockIndex* pindexPrev) 4049 { 4050 const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1; 4051 4052 // Enforce BIP113 (Median Time Past). 4053 bool enforce_locktime_median_time_past{false}; 4054 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CSV)) { 4055 assert(pindexPrev != nullptr); 4056 enforce_locktime_median_time_past = true; 4057 } 4058 4059 const int64_t nLockTimeCutoff{enforce_locktime_median_time_past ? 4060 pindexPrev->GetMedianTimePast() : 4061 block.GetBlockTime()}; 4062 4063 // Check that all transactions are finalized 4064 for (const auto& tx : block.vtx) { 4065 if (!IsFinalTx(*tx, nHeight, nLockTimeCutoff)) { 4066 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", "non-final transaction"); 4067 } 4068 } 4069 4070 // Enforce rule that the coinbase starts with serialized block height 4071 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) 4072 { 4073 CScript expect = CScript() << nHeight; 4074 if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() || 4075 !std::equal(expect.begin(), expect.end(), block.vtx[0]->vin[0].scriptSig.begin())) { 4076 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-height", "block height mismatch in coinbase"); 4077 } 4078 } 4079 4080 // Validation for witness commitments. 4081 // * We compute the witness hash (which is the hash including witnesses) of all the block's transactions, except the 4082 // coinbase (where 0x0000....0000 is used instead). 4083 // * The coinbase scriptWitness is a stack of a single 32-byte vector, containing a witness reserved value (unconstrained). 4084 // * We build a merkle tree with all those witness hashes as leaves (similar to the hashMerkleRoot in the block header). 4085 // * There must be at least one output whose scriptPubKey is a single 36-byte push, the first 4 bytes of which are 4086 // {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness reserved value). In case there are 4087 // multiple, the last one is used. 4088 if (!CheckWitnessMalleation(block, DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_SEGWIT), state)) { 4089 return false; 4090 } 4091 4092 // After the coinbase witness reserved value and commitment are verified, 4093 // we can check if the block weight passes (before we've checked the 4094 // coinbase witness, it would be possible for the weight to be too 4095 // large by filling up the coinbase witness, which doesn't change 4096 // the block hash, so we couldn't mark the block as permanently 4097 // failed). 4098 if (GetBlockWeight(block) > MAX_BLOCK_WEIGHT) { 4099 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-weight", strprintf("%s : weight limit failed", __func__)); 4100 } 4101 4102 return true; 4103 } 4104 4105 bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationState& state, CBlockIndex** ppindex, bool min_pow_checked) 4106 { 4107 AssertLockHeld(cs_main); 4108 4109 // Check for duplicate 4110 uint256 hash = block.GetHash(); 4111 BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)}; 4112 if (hash != GetConsensus().hashGenesisBlock) { 4113 if (miSelf != m_blockman.m_block_index.end()) { 4114 // Block header is already known. 4115 CBlockIndex* pindex = &(miSelf->second); 4116 if (ppindex) 4117 *ppindex = pindex; 4118 if (pindex->nStatus & BLOCK_FAILED_MASK) { 4119 LogPrint(BCLog::VALIDATION, "%s: block %s is marked invalid\n", __func__, hash.ToString()); 4120 return state.Invalid(BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate"); 4121 } 4122 return true; 4123 } 4124 4125 if (!CheckBlockHeader(block, state, GetConsensus())) { 4126 LogPrint(BCLog::VALIDATION, "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString()); 4127 return false; 4128 } 4129 4130 // Get prev block index 4131 CBlockIndex* pindexPrev = nullptr; 4132 BlockMap::iterator mi{m_blockman.m_block_index.find(block.hashPrevBlock)}; 4133 if (mi == m_blockman.m_block_index.end()) { 4134 LogPrint(BCLog::VALIDATION, "header %s has prev block not found: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4135 return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV, "prev-blk-not-found"); 4136 } 4137 pindexPrev = &((*mi).second); 4138 if (pindexPrev->nStatus & BLOCK_FAILED_MASK) { 4139 LogPrint(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4140 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk"); 4141 } 4142 if (!ContextualCheckBlockHeader(block, state, m_blockman, *this, pindexPrev)) { 4143 LogPrint(BCLog::VALIDATION, "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString()); 4144 return false; 4145 } 4146 4147 /* Determine if this block descends from any block which has been found 4148 * invalid (m_failed_blocks), then mark pindexPrev and any blocks between 4149 * them as failed. For example: 4150 * 4151 * D3 4152 * / 4153 * B2 - C2 4154 * / \ 4155 * A D2 - E2 - F2 4156 * \ 4157 * B1 - C1 - D1 - E1 4158 * 4159 * In the case that we attempted to reorg from E1 to F2, only to find 4160 * C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD 4161 * but NOT D3 (it was not in any of our candidate sets at the time). 4162 * 4163 * In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart 4164 * in LoadBlockIndex. 4165 */ 4166 if (!pindexPrev->IsValid(BLOCK_VALID_SCRIPTS)) { 4167 // The above does not mean "invalid": it checks if the previous block 4168 // hasn't been validated up to BLOCK_VALID_SCRIPTS. This is a performance 4169 // optimization, in the common case of adding a new block to the tip, 4170 // we don't need to iterate over the failed blocks list. 4171 for (const CBlockIndex* failedit : m_failed_blocks) { 4172 if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) { 4173 assert(failedit->nStatus & BLOCK_FAILED_VALID); 4174 CBlockIndex* invalid_walk = pindexPrev; 4175 while (invalid_walk != failedit) { 4176 invalid_walk->nStatus |= BLOCK_FAILED_CHILD; 4177 m_blockman.m_dirty_blockindex.insert(invalid_walk); 4178 invalid_walk = invalid_walk->pprev; 4179 } 4180 LogPrint(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4181 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk"); 4182 } 4183 } 4184 } 4185 } 4186 if (!min_pow_checked) { 4187 LogPrint(BCLog::VALIDATION, "%s: not adding new block header %s, missing anti-dos proof-of-work validation\n", __func__, hash.ToString()); 4188 return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK, "too-little-chainwork"); 4189 } 4190 CBlockIndex* pindex{m_blockman.AddToBlockIndex(block, m_best_header)}; 4191 4192 if (ppindex) 4193 *ppindex = pindex; 4194 4195 // Since this is the earliest point at which we have determined that a 4196 // header is both new and valid, log here. 4197 // 4198 // These messages are valuable for detecting potential selfish mining behavior; 4199 // if multiple displacing headers are seen near simultaneously across many 4200 // nodes in the network, this might be an indication of selfish mining. Having 4201 // this log by default when not in IBD ensures broad availability of this data 4202 // in case investigation is merited. 4203 const auto msg = strprintf( 4204 "Saw new header hash=%s height=%d", hash.ToString(), pindex->nHeight); 4205 4206 if (IsInitialBlockDownload()) { 4207 LogPrintLevel(BCLog::VALIDATION, BCLog::Level::Debug, "%s\n", msg); 4208 } else { 4209 LogPrintf("%s\n", msg); 4210 } 4211 4212 return true; 4213 } 4214 4215 // Exposed wrapper for AcceptBlockHeader 4216 bool ChainstateManager::ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, bool min_pow_checked, BlockValidationState& state, const CBlockIndex** ppindex) 4217 { 4218 AssertLockNotHeld(cs_main); 4219 { 4220 LOCK(cs_main); 4221 for (const CBlockHeader& header : headers) { 4222 CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast 4223 bool accepted{AcceptBlockHeader(header, state, &pindex, min_pow_checked)}; 4224 CheckBlockIndex(); 4225 4226 if (!accepted) { 4227 return false; 4228 } 4229 if (ppindex) { 4230 *ppindex = pindex; 4231 } 4232 } 4233 } 4234 if (NotifyHeaderTip(*this)) { 4235 if (IsInitialBlockDownload() && ppindex && *ppindex) { 4236 const CBlockIndex& last_accepted{**ppindex}; 4237 int64_t blocks_left{(NodeClock::now() - last_accepted.Time()) / GetConsensus().PowTargetSpacing()}; 4238 blocks_left = std::max<int64_t>(0, blocks_left); 4239 const double progress{100.0 * last_accepted.nHeight / (last_accepted.nHeight + blocks_left)}; 4240 LogInfo("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress); 4241 } 4242 } 4243 return true; 4244 } 4245 4246 void ChainstateManager::ReportHeadersPresync(const arith_uint256& work, int64_t height, int64_t timestamp) 4247 { 4248 AssertLockNotHeld(cs_main); 4249 { 4250 LOCK(cs_main); 4251 // Don't report headers presync progress if we already have a post-minchainwork header chain. 4252 // This means we lose reporting for potentially legitimate, but unlikely, deep reorgs, but 4253 // prevent attackers that spam low-work headers from filling our logs. 4254 if (m_best_header->nChainWork >= UintToArith256(GetConsensus().nMinimumChainWork)) return; 4255 // Rate limit headers presync updates to 4 per second, as these are not subject to DoS 4256 // protection. 4257 auto now = std::chrono::steady_clock::now(); 4258 if (now < m_last_presync_update + std::chrono::milliseconds{250}) return; 4259 m_last_presync_update = now; 4260 } 4261 bool initial_download = IsInitialBlockDownload(); 4262 GetNotifications().headerTip(GetSynchronizationState(initial_download), height, timestamp, /*presync=*/true); 4263 if (initial_download) { 4264 int64_t blocks_left{(NodeClock::now() - NodeSeconds{std::chrono::seconds{timestamp}}) / GetConsensus().PowTargetSpacing()}; 4265 blocks_left = std::max<int64_t>(0, blocks_left); 4266 const double progress{100.0 * height / (height + blocks_left)}; 4267 LogInfo("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress); 4268 } 4269 } 4270 4271 /** Store block on disk. If dbp is non-nullptr, the file is known to already reside on disk */ 4272 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) 4273 { 4274 const CBlock& block = *pblock; 4275 4276 if (fNewBlock) *fNewBlock = false; 4277 AssertLockHeld(cs_main); 4278 4279 CBlockIndex *pindexDummy = nullptr; 4280 CBlockIndex *&pindex = ppindex ? *ppindex : pindexDummy; 4281 4282 bool accepted_header{AcceptBlockHeader(block, state, &pindex, min_pow_checked)}; 4283 CheckBlockIndex(); 4284 4285 if (!accepted_header) 4286 return false; 4287 4288 // Check all requested blocks that we do not already have for validity and 4289 // save them to disk. Skip processing of unrequested blocks as an anti-DoS 4290 // measure, unless the blocks have more work than the active chain tip, and 4291 // aren't too far ahead of it, so are likely to be attached soon. 4292 bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA; 4293 bool fHasMoreOrSameWork = (ActiveTip() ? pindex->nChainWork >= ActiveTip()->nChainWork : true); 4294 // Blocks that are too out-of-order needlessly limit the effectiveness of 4295 // pruning, because pruning will not delete block files that contain any 4296 // blocks which are too close in height to the tip. Apply this test 4297 // regardless of whether pruning is enabled; it should generally be safe to 4298 // not process unrequested blocks. 4299 bool fTooFarAhead{pindex->nHeight > ActiveHeight() + int(MIN_BLOCKS_TO_KEEP)}; 4300 4301 // TODO: Decouple this function from the block download logic by removing fRequested 4302 // This requires some new chain data structure to efficiently look up if a 4303 // block is in a chain leading to a candidate for best tip, despite not 4304 // being such a candidate itself. 4305 // Note that this would break the getblockfrompeer RPC 4306 4307 // TODO: deal better with return value and error conditions for duplicate 4308 // and unrequested blocks. 4309 if (fAlreadyHave) return true; 4310 if (!fRequested) { // If we didn't ask for it: 4311 if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned 4312 if (!fHasMoreOrSameWork) return true; // Don't process less-work chains 4313 if (fTooFarAhead) return true; // Block height is too high 4314 4315 // Protect against DoS attacks from low-work chains. 4316 // If our tip is behind, a peer could try to send us 4317 // low-work blocks on a fake chain that we would never 4318 // request; don't process these. 4319 if (pindex->nChainWork < MinimumChainWork()) return true; 4320 } 4321 4322 const CChainParams& params{GetParams()}; 4323 4324 if (!CheckBlock(block, state, params.GetConsensus()) || 4325 !ContextualCheckBlock(block, state, *this, pindex->pprev)) { 4326 if (state.IsInvalid() && state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 4327 pindex->nStatus |= BLOCK_FAILED_VALID; 4328 m_blockman.m_dirty_blockindex.insert(pindex); 4329 } 4330 LogError("%s: %s\n", __func__, state.ToString()); 4331 return false; 4332 } 4333 4334 // Header is valid/has work, merkle tree and segwit merkle tree are good...RELAY NOW 4335 // (but if it does not build on our best tip, let the SendMessages loop relay it) 4336 if (!IsInitialBlockDownload() && ActiveTip() == pindex->pprev && m_options.signals) { 4337 m_options.signals->NewPoWValidBlock(pindex, pblock); 4338 } 4339 4340 // Write block to history file 4341 if (fNewBlock) *fNewBlock = true; 4342 try { 4343 FlatFilePos blockPos{m_blockman.SaveBlockToDisk(block, pindex->nHeight, dbp)}; 4344 if (blockPos.IsNull()) { 4345 state.Error(strprintf("%s: Failed to find position to write new block to disk", __func__)); 4346 return false; 4347 } 4348 ReceivedBlockTransactions(block, pindex, blockPos); 4349 } catch (const std::runtime_error& e) { 4350 return FatalError(GetNotifications(), state, strprintf(_("System error while saving block to disk: %s"), e.what())); 4351 } 4352 4353 // TODO: FlushStateToDisk() handles flushing of both block and chainstate 4354 // data, so we should move this to ChainstateManager so that we can be more 4355 // intelligent about how we flush. 4356 // For now, since FlushStateMode::NONE is used, all that can happen is that 4357 // the block files may be pruned, so we can just call this on one 4358 // chainstate (particularly if we haven't implemented pruning with 4359 // background validation yet). 4360 ActiveChainstate().FlushStateToDisk(state, FlushStateMode::NONE); 4361 4362 CheckBlockIndex(); 4363 4364 return true; 4365 } 4366 4367 bool ChainstateManager::ProcessNewBlock(const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked, bool* new_block) 4368 { 4369 AssertLockNotHeld(cs_main); 4370 4371 { 4372 CBlockIndex *pindex = nullptr; 4373 if (new_block) *new_block = false; 4374 BlockValidationState state; 4375 4376 // CheckBlock() does not support multi-threaded block validation because CBlock::fChecked can cause data race. 4377 // Therefore, the following critical section must include the CheckBlock() call as well. 4378 LOCK(cs_main); 4379 4380 // Skipping AcceptBlock() for CheckBlock() failures means that we will never mark a block as invalid if 4381 // CheckBlock() fails. This is protective against consensus failure if there are any unknown forms of block 4382 // malleability that cause CheckBlock() to fail; see e.g. CVE-2012-2459 and 4383 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html. Because CheckBlock() is 4384 // not very expensive, the anti-DoS benefits of caching failure (of a definitely-invalid block) are not substantial. 4385 bool ret = CheckBlock(*block, state, GetConsensus()); 4386 if (ret) { 4387 // Store to disk 4388 ret = AcceptBlock(block, state, &pindex, force_processing, nullptr, new_block, min_pow_checked); 4389 } 4390 if (!ret) { 4391 if (m_options.signals) { 4392 m_options.signals->BlockChecked(*block, state); 4393 } 4394 LogError("%s: AcceptBlock FAILED (%s)\n", __func__, state.ToString()); 4395 return false; 4396 } 4397 } 4398 4399 NotifyHeaderTip(*this); 4400 4401 BlockValidationState state; // Only used to report errors, not invalidity - ignore it 4402 if (!ActiveChainstate().ActivateBestChain(state, block)) { 4403 LogError("%s: ActivateBestChain failed (%s)\n", __func__, state.ToString()); 4404 return false; 4405 } 4406 4407 Chainstate* bg_chain{WITH_LOCK(cs_main, return BackgroundSyncInProgress() ? m_ibd_chainstate.get() : nullptr)}; 4408 BlockValidationState bg_state; 4409 if (bg_chain && !bg_chain->ActivateBestChain(bg_state, block)) { 4410 LogError("%s: [background] ActivateBestChain failed (%s)\n", __func__, bg_state.ToString()); 4411 return false; 4412 } 4413 4414 return true; 4415 } 4416 4417 MempoolAcceptResult ChainstateManager::ProcessTransaction(const CTransactionRef& tx, bool test_accept) 4418 { 4419 AssertLockHeld(cs_main); 4420 Chainstate& active_chainstate = ActiveChainstate(); 4421 if (!active_chainstate.GetMempool()) { 4422 TxValidationState state; 4423 state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool"); 4424 return MempoolAcceptResult::Failure(state); 4425 } 4426 auto result = AcceptToMemoryPool(active_chainstate, tx, GetTime(), /*bypass_limits=*/ false, test_accept); 4427 active_chainstate.GetMempool()->check(active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1); 4428 return result; 4429 } 4430 4431 bool TestBlockValidity(BlockValidationState& state, 4432 const CChainParams& chainparams, 4433 Chainstate& chainstate, 4434 const CBlock& block, 4435 CBlockIndex* pindexPrev, 4436 bool fCheckPOW, 4437 bool fCheckMerkleRoot) 4438 { 4439 AssertLockHeld(cs_main); 4440 assert(pindexPrev && pindexPrev == chainstate.m_chain.Tip()); 4441 CCoinsViewCache viewNew(&chainstate.CoinsTip()); 4442 uint256 block_hash(block.GetHash()); 4443 CBlockIndex indexDummy(block); 4444 indexDummy.pprev = pindexPrev; 4445 indexDummy.nHeight = pindexPrev->nHeight + 1; 4446 indexDummy.phashBlock = &block_hash; 4447 4448 // NOTE: CheckBlockHeader is called by CheckBlock 4449 if (!ContextualCheckBlockHeader(block, state, chainstate.m_blockman, chainstate.m_chainman, pindexPrev)) { 4450 LogError("%s: Consensus::ContextualCheckBlockHeader: %s\n", __func__, state.ToString()); 4451 return false; 4452 } 4453 if (!CheckBlock(block, state, chainparams.GetConsensus(), fCheckPOW, fCheckMerkleRoot)) { 4454 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString()); 4455 return false; 4456 } 4457 if (!ContextualCheckBlock(block, state, chainstate.m_chainman, pindexPrev)) { 4458 LogError("%s: Consensus::ContextualCheckBlock: %s\n", __func__, state.ToString()); 4459 return false; 4460 } 4461 if (!chainstate.ConnectBlock(block, state, &indexDummy, viewNew, true)) { 4462 return false; 4463 } 4464 assert(state.IsValid()); 4465 4466 return true; 4467 } 4468 4469 /* This function is called from the RPC code for pruneblockchain */ 4470 void PruneBlockFilesManual(Chainstate& active_chainstate, int nManualPruneHeight) 4471 { 4472 BlockValidationState state; 4473 if (!active_chainstate.FlushStateToDisk( 4474 state, FlushStateMode::NONE, nManualPruneHeight)) { 4475 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString()); 4476 } 4477 } 4478 4479 bool Chainstate::LoadChainTip() 4480 { 4481 AssertLockHeld(cs_main); 4482 const CCoinsViewCache& coins_cache = CoinsTip(); 4483 assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty 4484 const CBlockIndex* tip = m_chain.Tip(); 4485 4486 if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) { 4487 return true; 4488 } 4489 4490 // Load pointer to end of best chain 4491 CBlockIndex* pindex = m_blockman.LookupBlockIndex(coins_cache.GetBestBlock()); 4492 if (!pindex) { 4493 return false; 4494 } 4495 m_chain.SetTip(*pindex); 4496 PruneBlockIndexCandidates(); 4497 4498 tip = m_chain.Tip(); 4499 LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n", 4500 tip->GetBlockHash().ToString(), 4501 m_chain.Height(), 4502 FormatISO8601DateTime(tip->GetBlockTime()), 4503 GuessVerificationProgress(m_chainman.GetParams().TxData(), tip)); 4504 return true; 4505 } 4506 4507 CVerifyDB::CVerifyDB(Notifications& notifications) 4508 : m_notifications{notifications} 4509 { 4510 m_notifications.progress(_("Verifying blocks…"), 0, false); 4511 } 4512 4513 CVerifyDB::~CVerifyDB() 4514 { 4515 m_notifications.progress(bilingual_str{}, 100, false); 4516 } 4517 4518 VerifyDBResult CVerifyDB::VerifyDB( 4519 Chainstate& chainstate, 4520 const Consensus::Params& consensus_params, 4521 CCoinsView& coinsview, 4522 int nCheckLevel, int nCheckDepth) 4523 { 4524 AssertLockHeld(cs_main); 4525 4526 if (chainstate.m_chain.Tip() == nullptr || chainstate.m_chain.Tip()->pprev == nullptr) { 4527 return VerifyDBResult::SUCCESS; 4528 } 4529 4530 // Verify blocks in the best chain 4531 if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) { 4532 nCheckDepth = chainstate.m_chain.Height(); 4533 } 4534 nCheckLevel = std::max(0, std::min(4, nCheckLevel)); 4535 LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel); 4536 CCoinsViewCache coins(&coinsview); 4537 CBlockIndex* pindex; 4538 CBlockIndex* pindexFailure = nullptr; 4539 int nGoodTransactions = 0; 4540 BlockValidationState state; 4541 int reportDone = 0; 4542 bool skipped_no_block_data{false}; 4543 bool skipped_l3_checks{false}; 4544 LogPrintf("Verification progress: 0%%\n"); 4545 4546 const bool is_snapshot_cs{chainstate.m_from_snapshot_blockhash}; 4547 4548 for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev; pindex = pindex->pprev) { 4549 const int percentageDone = std::max(1, std::min(99, (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100)))); 4550 if (reportDone < percentageDone / 10) { 4551 // report every 10% step 4552 LogPrintf("Verification progress: %d%%\n", percentageDone); 4553 reportDone = percentageDone / 10; 4554 } 4555 m_notifications.progress(_("Verifying blocks…"), percentageDone, false); 4556 if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) { 4557 break; 4558 } 4559 if ((chainstate.m_blockman.IsPruneMode() || is_snapshot_cs) && !(pindex->nStatus & BLOCK_HAVE_DATA)) { 4560 // If pruning or running under an assumeutxo snapshot, only go 4561 // back as far as we have data. 4562 LogPrintf("VerifyDB(): block verification stopping at height %d (no data). This could be due to pruning or use of an assumeutxo snapshot.\n", pindex->nHeight); 4563 skipped_no_block_data = true; 4564 break; 4565 } 4566 CBlock block; 4567 // check level 0: read from disk 4568 if (!chainstate.m_blockman.ReadBlockFromDisk(block, *pindex)) { 4569 LogPrintf("Verification error: ReadBlockFromDisk failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4570 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4571 } 4572 // check level 1: verify block validity 4573 if (nCheckLevel >= 1 && !CheckBlock(block, state, consensus_params)) { 4574 LogPrintf("Verification error: found bad block at %d, hash=%s (%s)\n", 4575 pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString()); 4576 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4577 } 4578 // check level 2: verify undo validity 4579 if (nCheckLevel >= 2 && pindex) { 4580 CBlockUndo undo; 4581 if (!pindex->GetUndoPos().IsNull()) { 4582 if (!chainstate.m_blockman.UndoReadFromDisk(undo, *pindex)) { 4583 LogPrintf("Verification error: found bad undo data at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4584 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4585 } 4586 } 4587 } 4588 // check level 3: check for inconsistencies during memory-only disconnect of tip blocks 4589 size_t curr_coins_usage = coins.DynamicMemoryUsage() + chainstate.CoinsTip().DynamicMemoryUsage(); 4590 4591 if (nCheckLevel >= 3) { 4592 if (curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) { 4593 assert(coins.GetBestBlock() == pindex->GetBlockHash()); 4594 DisconnectResult res = chainstate.DisconnectBlock(block, pindex, coins); 4595 if (res == DISCONNECT_FAILED) { 4596 LogPrintf("Verification error: irrecoverable inconsistency in block data at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4597 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4598 } 4599 if (res == DISCONNECT_UNCLEAN) { 4600 nGoodTransactions = 0; 4601 pindexFailure = pindex; 4602 } else { 4603 nGoodTransactions += block.vtx.size(); 4604 } 4605 } else { 4606 skipped_l3_checks = true; 4607 } 4608 } 4609 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED; 4610 } 4611 if (pindexFailure) { 4612 LogPrintf("Verification error: coin database inconsistencies found (last %i blocks, %i good transactions before that)\n", chainstate.m_chain.Height() - pindexFailure->nHeight + 1, nGoodTransactions); 4613 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4614 } 4615 if (skipped_l3_checks) { 4616 LogPrintf("Skipped verification of level >=3 (insufficient database cache size). Consider increasing -dbcache.\n"); 4617 } 4618 4619 // store block count as we move pindex at check level >= 4 4620 int block_count = chainstate.m_chain.Height() - pindex->nHeight; 4621 4622 // check level 4: try reconnecting blocks 4623 if (nCheckLevel >= 4 && !skipped_l3_checks) { 4624 while (pindex != chainstate.m_chain.Tip()) { 4625 const int percentageDone = std::max(1, std::min(99, 100 - (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * 50))); 4626 if (reportDone < percentageDone / 10) { 4627 // report every 10% step 4628 LogPrintf("Verification progress: %d%%\n", percentageDone); 4629 reportDone = percentageDone / 10; 4630 } 4631 m_notifications.progress(_("Verifying blocks…"), percentageDone, false); 4632 pindex = chainstate.m_chain.Next(pindex); 4633 CBlock block; 4634 if (!chainstate.m_blockman.ReadBlockFromDisk(block, *pindex)) { 4635 LogPrintf("Verification error: ReadBlockFromDisk failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4636 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4637 } 4638 if (!chainstate.ConnectBlock(block, state, pindex, coins)) { 4639 LogPrintf("Verification error: found unconnectable block at %d, hash=%s (%s)\n", pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString()); 4640 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4641 } 4642 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED; 4643 } 4644 } 4645 4646 LogPrintf("Verification: No coin database inconsistencies in last %i blocks (%i transactions)\n", block_count, nGoodTransactions); 4647 4648 if (skipped_l3_checks) { 4649 return VerifyDBResult::SKIPPED_L3_CHECKS; 4650 } 4651 if (skipped_no_block_data) { 4652 return VerifyDBResult::SKIPPED_MISSING_BLOCKS; 4653 } 4654 return VerifyDBResult::SUCCESS; 4655 } 4656 4657 /** Apply the effects of a block on the utxo cache, ignoring that it may already have been applied. */ 4658 bool Chainstate::RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs) 4659 { 4660 AssertLockHeld(cs_main); 4661 // TODO: merge with ConnectBlock 4662 CBlock block; 4663 if (!m_blockman.ReadBlockFromDisk(block, *pindex)) { 4664 LogError("ReplayBlock(): ReadBlockFromDisk failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4665 return false; 4666 } 4667 4668 for (const CTransactionRef& tx : block.vtx) { 4669 if (!tx->IsCoinBase()) { 4670 for (const CTxIn &txin : tx->vin) { 4671 inputs.SpendCoin(txin.prevout); 4672 } 4673 } 4674 // Pass check = true as every addition may be an overwrite. 4675 AddCoins(inputs, *tx, pindex->nHeight, true); 4676 } 4677 return true; 4678 } 4679 4680 bool Chainstate::ReplayBlocks() 4681 { 4682 LOCK(cs_main); 4683 4684 CCoinsView& db = this->CoinsDB(); 4685 CCoinsViewCache cache(&db); 4686 4687 std::vector<uint256> hashHeads = db.GetHeadBlocks(); 4688 if (hashHeads.empty()) return true; // We're already in a consistent state. 4689 if (hashHeads.size() != 2) { 4690 LogError("ReplayBlocks(): unknown inconsistent state\n"); 4691 return false; 4692 } 4693 4694 m_chainman.GetNotifications().progress(_("Replaying blocks…"), 0, false); 4695 LogPrintf("Replaying blocks\n"); 4696 4697 const CBlockIndex* pindexOld = nullptr; // Old tip during the interrupted flush. 4698 const CBlockIndex* pindexNew; // New tip during the interrupted flush. 4699 const CBlockIndex* pindexFork = nullptr; // Latest block common to both the old and the new tip. 4700 4701 if (m_blockman.m_block_index.count(hashHeads[0]) == 0) { 4702 LogError("ReplayBlocks(): reorganization to unknown block requested\n"); 4703 return false; 4704 } 4705 pindexNew = &(m_blockman.m_block_index[hashHeads[0]]); 4706 4707 if (!hashHeads[1].IsNull()) { // The old tip is allowed to be 0, indicating it's the first flush. 4708 if (m_blockman.m_block_index.count(hashHeads[1]) == 0) { 4709 LogError("ReplayBlocks(): reorganization from unknown block requested\n"); 4710 return false; 4711 } 4712 pindexOld = &(m_blockman.m_block_index[hashHeads[1]]); 4713 pindexFork = LastCommonAncestor(pindexOld, pindexNew); 4714 assert(pindexFork != nullptr); 4715 } 4716 4717 // Rollback along the old branch. 4718 while (pindexOld != pindexFork) { 4719 if (pindexOld->nHeight > 0) { // Never disconnect the genesis block. 4720 CBlock block; 4721 if (!m_blockman.ReadBlockFromDisk(block, *pindexOld)) { 4722 LogError("RollbackBlock(): ReadBlockFromDisk() failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString()); 4723 return false; 4724 } 4725 LogPrintf("Rolling back %s (%i)\n", pindexOld->GetBlockHash().ToString(), pindexOld->nHeight); 4726 DisconnectResult res = DisconnectBlock(block, pindexOld, cache); 4727 if (res == DISCONNECT_FAILED) { 4728 LogError("RollbackBlock(): DisconnectBlock failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString()); 4729 return false; 4730 } 4731 // If DISCONNECT_UNCLEAN is returned, it means a non-existing UTXO was deleted, or an existing UTXO was 4732 // overwritten. It corresponds to cases where the block-to-be-disconnect never had all its operations 4733 // applied to the UTXO set. However, as both writing a UTXO and deleting a UTXO are idempotent operations, 4734 // the result is still a version of the UTXO set with the effects of that block undone. 4735 } 4736 pindexOld = pindexOld->pprev; 4737 } 4738 4739 // Roll forward from the forking point to the new tip. 4740 int nForkHeight = pindexFork ? pindexFork->nHeight : 0; 4741 for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight; ++nHeight) { 4742 const CBlockIndex& pindex{*Assert(pindexNew->GetAncestor(nHeight))}; 4743 4744 LogPrintf("Rolling forward %s (%i)\n", pindex.GetBlockHash().ToString(), nHeight); 4745 m_chainman.GetNotifications().progress(_("Replaying blocks…"), (int)((nHeight - nForkHeight) * 100.0 / (pindexNew->nHeight - nForkHeight)), false); 4746 if (!RollforwardBlock(&pindex, cache)) return false; 4747 } 4748 4749 cache.SetBestBlock(pindexNew->GetBlockHash()); 4750 cache.Flush(); 4751 m_chainman.GetNotifications().progress(bilingual_str{}, 100, false); 4752 return true; 4753 } 4754 4755 bool Chainstate::NeedsRedownload() const 4756 { 4757 AssertLockHeld(cs_main); 4758 4759 // At and above m_params.SegwitHeight, segwit consensus rules must be validated 4760 CBlockIndex* block{m_chain.Tip()}; 4761 4762 while (block != nullptr && DeploymentActiveAt(*block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) { 4763 if (!(block->nStatus & BLOCK_OPT_WITNESS)) { 4764 // block is insufficiently validated for a segwit client 4765 return true; 4766 } 4767 block = block->pprev; 4768 } 4769 4770 return false; 4771 } 4772 4773 void Chainstate::ClearBlockIndexCandidates() 4774 { 4775 AssertLockHeld(::cs_main); 4776 setBlockIndexCandidates.clear(); 4777 } 4778 4779 bool ChainstateManager::LoadBlockIndex() 4780 { 4781 AssertLockHeld(cs_main); 4782 // Load block index from databases 4783 bool needs_init = fReindex; 4784 if (!fReindex) { 4785 bool ret{m_blockman.LoadBlockIndexDB(SnapshotBlockhash())}; 4786 if (!ret) return false; 4787 4788 m_blockman.ScanAndUnlinkAlreadyPrunedFiles(); 4789 4790 std::vector<CBlockIndex*> vSortedByHeight{m_blockman.GetAllBlockIndices()}; 4791 std::sort(vSortedByHeight.begin(), vSortedByHeight.end(), 4792 CBlockIndexHeightOnlyComparator()); 4793 4794 for (CBlockIndex* pindex : vSortedByHeight) { 4795 if (m_interrupt) return false; 4796 // If we have an assumeutxo-based chainstate, then the snapshot 4797 // block will be a candidate for the tip, but it may not be 4798 // VALID_TRANSACTIONS (eg if we haven't yet downloaded the block), 4799 // so we special-case the snapshot block as a potential candidate 4800 // here. 4801 if (pindex == GetSnapshotBaseBlock() || 4802 (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && 4803 (pindex->HaveNumChainTxs() || pindex->pprev == nullptr))) { 4804 4805 for (Chainstate* chainstate : GetAll()) { 4806 chainstate->TryAddBlockIndexCandidate(pindex); 4807 } 4808 } 4809 if (pindex->nStatus & BLOCK_FAILED_MASK && (!m_best_invalid || pindex->nChainWork > m_best_invalid->nChainWork)) { 4810 m_best_invalid = pindex; 4811 } 4812 if (pindex->IsValid(BLOCK_VALID_TREE) && (m_best_header == nullptr || CBlockIndexWorkComparator()(m_best_header, pindex))) 4813 m_best_header = pindex; 4814 } 4815 4816 needs_init = m_blockman.m_block_index.empty(); 4817 } 4818 4819 if (needs_init) { 4820 // Everything here is for *new* reindex/DBs. Thus, though 4821 // LoadBlockIndexDB may have set fReindex if we shut down 4822 // mid-reindex previously, we don't check fReindex and 4823 // instead only check it prior to LoadBlockIndexDB to set 4824 // needs_init. 4825 4826 LogPrintf("Initializing databases...\n"); 4827 } 4828 return true; 4829 } 4830 4831 bool Chainstate::LoadGenesisBlock() 4832 { 4833 LOCK(cs_main); 4834 4835 const CChainParams& params{m_chainman.GetParams()}; 4836 4837 // Check whether we're already initialized by checking for genesis in 4838 // m_blockman.m_block_index. Note that we can't use m_chain here, since it is 4839 // set based on the coins db, not the block index db, which is the only 4840 // thing loaded at this point. 4841 if (m_blockman.m_block_index.count(params.GenesisBlock().GetHash())) 4842 return true; 4843 4844 try { 4845 const CBlock& block = params.GenesisBlock(); 4846 FlatFilePos blockPos{m_blockman.SaveBlockToDisk(block, 0, nullptr)}; 4847 if (blockPos.IsNull()) { 4848 LogError("%s: writing genesis block to disk failed\n", __func__); 4849 return false; 4850 } 4851 CBlockIndex* pindex = m_blockman.AddToBlockIndex(block, m_chainman.m_best_header); 4852 m_chainman.ReceivedBlockTransactions(block, pindex, blockPos); 4853 } catch (const std::runtime_error& e) { 4854 LogError("%s: failed to write genesis block: %s\n", __func__, e.what()); 4855 return false; 4856 } 4857 4858 return true; 4859 } 4860 4861 void ChainstateManager::LoadExternalBlockFile( 4862 AutoFile& file_in, 4863 FlatFilePos* dbp, 4864 std::multimap<uint256, FlatFilePos>* blocks_with_unknown_parent) 4865 { 4866 // Either both should be specified (-reindex), or neither (-loadblock). 4867 assert(!dbp == !blocks_with_unknown_parent); 4868 4869 const auto start{SteadyClock::now()}; 4870 const CChainParams& params{GetParams()}; 4871 4872 int nLoaded = 0; 4873 try { 4874 BufferedFile blkdat{file_in, 2 * MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE + 8}; 4875 // nRewind indicates where to resume scanning in case something goes wrong, 4876 // such as a block fails to deserialize. 4877 uint64_t nRewind = blkdat.GetPos(); 4878 while (!blkdat.eof()) { 4879 if (m_interrupt) return; 4880 4881 blkdat.SetPos(nRewind); 4882 nRewind++; // start one byte further next time, in case of failure 4883 blkdat.SetLimit(); // remove former limit 4884 unsigned int nSize = 0; 4885 try { 4886 // locate a header 4887 MessageStartChars buf; 4888 blkdat.FindByte(std::byte(params.MessageStart()[0])); 4889 nRewind = blkdat.GetPos() + 1; 4890 blkdat >> buf; 4891 if (buf != params.MessageStart()) { 4892 continue; 4893 } 4894 // read size 4895 blkdat >> nSize; 4896 if (nSize < 80 || nSize > MAX_BLOCK_SERIALIZED_SIZE) 4897 continue; 4898 } catch (const std::exception&) { 4899 // no valid block header found; don't complain 4900 // (this happens at the end of every blk.dat file) 4901 break; 4902 } 4903 try { 4904 // read block header 4905 const uint64_t nBlockPos{blkdat.GetPos()}; 4906 if (dbp) 4907 dbp->nPos = nBlockPos; 4908 blkdat.SetLimit(nBlockPos + nSize); 4909 CBlockHeader header; 4910 blkdat >> header; 4911 const uint256 hash{header.GetHash()}; 4912 // Skip the rest of this block (this may read from disk into memory); position to the marker before the 4913 // next block, but it's still possible to rewind to the start of the current block (without a disk read). 4914 nRewind = nBlockPos + nSize; 4915 blkdat.SkipTo(nRewind); 4916 4917 std::shared_ptr<CBlock> pblock{}; // needs to remain available after the cs_main lock is released to avoid duplicate reads from disk 4918 4919 { 4920 LOCK(cs_main); 4921 // detect out of order blocks, and store them for later 4922 if (hash != params.GetConsensus().hashGenesisBlock && !m_blockman.LookupBlockIndex(header.hashPrevBlock)) { 4923 LogPrint(BCLog::REINDEX, "%s: Out of order block %s, parent %s not known\n", __func__, hash.ToString(), 4924 header.hashPrevBlock.ToString()); 4925 if (dbp && blocks_with_unknown_parent) { 4926 blocks_with_unknown_parent->emplace(header.hashPrevBlock, *dbp); 4927 } 4928 continue; 4929 } 4930 4931 // process in case the block isn't known yet 4932 const CBlockIndex* pindex = m_blockman.LookupBlockIndex(hash); 4933 if (!pindex || (pindex->nStatus & BLOCK_HAVE_DATA) == 0) { 4934 // This block can be processed immediately; rewind to its start, read and deserialize it. 4935 blkdat.SetPos(nBlockPos); 4936 pblock = std::make_shared<CBlock>(); 4937 blkdat >> TX_WITH_WITNESS(*pblock); 4938 nRewind = blkdat.GetPos(); 4939 4940 BlockValidationState state; 4941 if (AcceptBlock(pblock, state, nullptr, true, dbp, nullptr, true)) { 4942 nLoaded++; 4943 } 4944 if (state.IsError()) { 4945 break; 4946 } 4947 } else if (hash != params.GetConsensus().hashGenesisBlock && pindex->nHeight % 1000 == 0) { 4948 LogPrint(BCLog::REINDEX, "Block Import: already had block %s at height %d\n", hash.ToString(), pindex->nHeight); 4949 } 4950 } 4951 4952 // Activate the genesis block so normal node progress can continue 4953 if (hash == params.GetConsensus().hashGenesisBlock) { 4954 bool genesis_activation_failure = false; 4955 for (auto c : GetAll()) { 4956 BlockValidationState state; 4957 if (!c->ActivateBestChain(state, nullptr)) { 4958 genesis_activation_failure = true; 4959 break; 4960 } 4961 } 4962 if (genesis_activation_failure) { 4963 break; 4964 } 4965 } 4966 4967 if (m_blockman.IsPruneMode() && !fReindex && pblock) { 4968 // must update the tip for pruning to work while importing with -loadblock. 4969 // this is a tradeoff to conserve disk space at the expense of time 4970 // spent updating the tip to be able to prune. 4971 // otherwise, ActivateBestChain won't be called by the import process 4972 // until after all of the block files are loaded. ActivateBestChain can be 4973 // called by concurrent network message processing. but, that is not 4974 // reliable for the purpose of pruning while importing. 4975 bool activation_failure = false; 4976 for (auto c : GetAll()) { 4977 BlockValidationState state; 4978 if (!c->ActivateBestChain(state, pblock)) { 4979 LogPrint(BCLog::REINDEX, "failed to activate chain (%s)\n", state.ToString()); 4980 activation_failure = true; 4981 break; 4982 } 4983 } 4984 if (activation_failure) { 4985 break; 4986 } 4987 } 4988 4989 NotifyHeaderTip(*this); 4990 4991 if (!blocks_with_unknown_parent) continue; 4992 4993 // Recursively process earlier encountered successors of this block 4994 std::deque<uint256> queue; 4995 queue.push_back(hash); 4996 while (!queue.empty()) { 4997 uint256 head = queue.front(); 4998 queue.pop_front(); 4999 auto range = blocks_with_unknown_parent->equal_range(head); 5000 while (range.first != range.second) { 5001 std::multimap<uint256, FlatFilePos>::iterator it = range.first; 5002 std::shared_ptr<CBlock> pblockrecursive = std::make_shared<CBlock>(); 5003 if (m_blockman.ReadBlockFromDisk(*pblockrecursive, it->second)) { 5004 LogPrint(BCLog::REINDEX, "%s: Processing out of order child %s of %s\n", __func__, pblockrecursive->GetHash().ToString(), 5005 head.ToString()); 5006 LOCK(cs_main); 5007 BlockValidationState dummy; 5008 if (AcceptBlock(pblockrecursive, dummy, nullptr, true, &it->second, nullptr, true)) { 5009 nLoaded++; 5010 queue.push_back(pblockrecursive->GetHash()); 5011 } 5012 } 5013 range.first++; 5014 blocks_with_unknown_parent->erase(it); 5015 NotifyHeaderTip(*this); 5016 } 5017 } 5018 } catch (const std::exception& e) { 5019 // historical bugs added extra data to the block files that does not deserialize cleanly. 5020 // commonly this data is between readable blocks, but it does not really matter. such data is not fatal to the import process. 5021 // the code that reads the block files deals with invalid data by simply ignoring it. 5022 // it continues to search for the next {4 byte magic message start bytes + 4 byte length + block} that does deserialize cleanly 5023 // and passes all of the other block validation checks dealing with POW and the merkle root, etc... 5024 // we merely note with this informational log message when unexpected data is encountered. 5025 // we could also be experiencing a storage system read error, or a read of a previous bad write. these are possible, but 5026 // less likely scenarios. we don't have enough information to tell a difference here. 5027 // the reindex process is not the place to attempt to clean and/or compact the block files. if so desired, a studious node operator 5028 // may use knowledge of the fact that the block files are not entirely pristine in order to prepare a set of pristine, and 5029 // perhaps ordered, block files for later reindexing. 5030 LogPrint(BCLog::REINDEX, "%s: unexpected data at file offset 0x%x - %s. continuing\n", __func__, (nRewind - 1), e.what()); 5031 } 5032 } 5033 } catch (const std::runtime_error& e) { 5034 GetNotifications().fatalError(strprintf(_("System error while loading external block file: %s"), e.what())); 5035 } 5036 LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded, Ticks<std::chrono::milliseconds>(SteadyClock::now() - start)); 5037 } 5038 5039 void ChainstateManager::CheckBlockIndex() 5040 { 5041 if (!ShouldCheckBlockIndex()) { 5042 return; 5043 } 5044 5045 LOCK(cs_main); 5046 5047 // During a reindex, we read the genesis block and call CheckBlockIndex before ActivateBestChain, 5048 // so we have the genesis block in m_blockman.m_block_index but no active chain. (A few of the 5049 // tests when iterating the block tree require that m_chain has been initialized.) 5050 if (ActiveChain().Height() < 0) { 5051 assert(m_blockman.m_block_index.size() <= 1); 5052 return; 5053 } 5054 5055 // Build forward-pointing map of the entire block tree. 5056 std::multimap<CBlockIndex*,CBlockIndex*> forward; 5057 for (auto& [_, block_index] : m_blockman.m_block_index) { 5058 forward.emplace(block_index.pprev, &block_index); 5059 } 5060 5061 assert(forward.size() == m_blockman.m_block_index.size()); 5062 5063 std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangeGenesis = forward.equal_range(nullptr); 5064 CBlockIndex *pindex = rangeGenesis.first->second; 5065 rangeGenesis.first++; 5066 assert(rangeGenesis.first == rangeGenesis.second); // There is only one index entry with parent nullptr. 5067 5068 // Iterate over the entire block tree, using depth-first search. 5069 // Along the way, remember whether there are blocks on the path from genesis 5070 // block being explored which are the first to have certain properties. 5071 size_t nNodes = 0; 5072 int nHeight = 0; 5073 CBlockIndex* pindexFirstInvalid = nullptr; // Oldest ancestor of pindex which is invalid. 5074 CBlockIndex* pindexFirstMissing = nullptr; // Oldest ancestor of pindex which does not have BLOCK_HAVE_DATA, since assumeutxo snapshot if used. 5075 CBlockIndex* pindexFirstNeverProcessed = nullptr; // Oldest ancestor of pindex for which nTx == 0, since assumeutxo snapshot if used. 5076 CBlockIndex* pindexFirstNotTreeValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE (regardless of being valid or not). 5077 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. 5078 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. 5079 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. 5080 5081 // After checking an assumeutxo snapshot block, reset pindexFirst pointers 5082 // to earlier blocks that have not been downloaded or validated yet, so 5083 // checks for later blocks can assume the earlier blocks were validated and 5084 // be stricter, testing for more requirements. 5085 const CBlockIndex* snap_base{GetSnapshotBaseBlock()}; 5086 CBlockIndex *snap_first_missing{}, *snap_first_notx{}, *snap_first_notv{}, *snap_first_nocv{}, *snap_first_nosv{}; 5087 auto snap_update_firsts = [&] { 5088 if (pindex == snap_base) { 5089 std::swap(snap_first_missing, pindexFirstMissing); 5090 std::swap(snap_first_notx, pindexFirstNeverProcessed); 5091 std::swap(snap_first_notv, pindexFirstNotTransactionsValid); 5092 std::swap(snap_first_nocv, pindexFirstNotChainValid); 5093 std::swap(snap_first_nosv, pindexFirstNotScriptsValid); 5094 } 5095 }; 5096 5097 while (pindex != nullptr) { 5098 nNodes++; 5099 if (pindexFirstInvalid == nullptr && pindex->nStatus & BLOCK_FAILED_VALID) pindexFirstInvalid = pindex; 5100 if (pindexFirstMissing == nullptr && !(pindex->nStatus & BLOCK_HAVE_DATA)) { 5101 pindexFirstMissing = pindex; 5102 } 5103 if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) pindexFirstNeverProcessed = pindex; 5104 if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr && (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TREE) pindexFirstNotTreeValid = pindex; 5105 5106 if (pindex->pprev != nullptr) { 5107 if (pindexFirstNotTransactionsValid == nullptr && 5108 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TRANSACTIONS) { 5109 pindexFirstNotTransactionsValid = pindex; 5110 } 5111 5112 if (pindexFirstNotChainValid == nullptr && 5113 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_CHAIN) { 5114 pindexFirstNotChainValid = pindex; 5115 } 5116 5117 if (pindexFirstNotScriptsValid == nullptr && 5118 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_SCRIPTS) { 5119 pindexFirstNotScriptsValid = pindex; 5120 } 5121 } 5122 5123 // Begin: actual consistency checks. 5124 if (pindex->pprev == nullptr) { 5125 // Genesis block checks. 5126 assert(pindex->GetBlockHash() == GetConsensus().hashGenesisBlock); // Genesis block's hash must match. 5127 for (auto c : GetAll()) { 5128 if (c->m_chain.Genesis() != nullptr) { 5129 assert(pindex == c->m_chain.Genesis()); // The chain's genesis block must be this block. 5130 } 5131 } 5132 } 5133 if (!pindex->HaveNumChainTxs()) assert(pindex->nSequenceId <= 0); // nSequenceId can't be set positive for blocks that aren't linked (negative is used for preciousblock) 5134 // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or not pruning has occurred). 5135 // HAVE_DATA is only equivalent to nTx > 0 (or VALID_TRANSACTIONS) if no pruning has occurred. 5136 if (!m_blockman.m_have_pruned) { 5137 // If we've never pruned, then HAVE_DATA should be equivalent to nTx > 0 5138 assert(!(pindex->nStatus & BLOCK_HAVE_DATA) == (pindex->nTx == 0)); 5139 assert(pindexFirstMissing == pindexFirstNeverProcessed); 5140 } else { 5141 // If we have pruned, then we can only say that HAVE_DATA implies nTx > 0 5142 if (pindex->nStatus & BLOCK_HAVE_DATA) assert(pindex->nTx > 0); 5143 } 5144 if (pindex->nStatus & BLOCK_HAVE_UNDO) assert(pindex->nStatus & BLOCK_HAVE_DATA); 5145 if (snap_base && snap_base->GetAncestor(pindex->nHeight) == pindex) { 5146 // Assumed-valid blocks should connect to the main chain. 5147 assert((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE); 5148 } 5149 // There should only be an nTx value if we have 5150 // actually seen a block's transactions. 5151 assert(((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS) == (pindex->nTx > 0)); // This is pruning-independent. 5152 // All parents having had data (at some point) is equivalent to all parents being VALID_TRANSACTIONS, which is equivalent to HaveNumChainTxs(). 5153 // HaveNumChainTxs will also be set in the assumeutxo snapshot block from snapshot metadata. 5154 assert((pindexFirstNeverProcessed == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs()); 5155 assert((pindexFirstNotTransactionsValid == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs()); 5156 assert(pindex->nHeight == nHeight); // nHeight must be consistent. 5157 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. 5158 assert(nHeight < 2 || (pindex->pskip && (pindex->pskip->nHeight < nHeight))); // The pskip pointer must point back for all but the first 2 blocks. 5159 assert(pindexFirstNotTreeValid == nullptr); // All m_blockman.m_block_index entries must at least be TREE valid 5160 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE) assert(pindexFirstNotTreeValid == nullptr); // TREE valid implies all parents are TREE valid 5161 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_CHAIN) assert(pindexFirstNotChainValid == nullptr); // CHAIN valid implies all parents are CHAIN valid 5162 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_SCRIPTS) assert(pindexFirstNotScriptsValid == nullptr); // SCRIPTS valid implies all parents are SCRIPTS valid 5163 if (pindexFirstInvalid == nullptr) { 5164 // Checks for not-invalid blocks. 5165 assert((pindex->nStatus & BLOCK_FAILED_MASK) == 0); // The failed mask cannot be set for blocks without invalid parents. 5166 } 5167 // Make sure nChainTx sum is correctly computed. 5168 if (!pindex->pprev) { 5169 // If no previous block, nTx and nChainTx must be the same. 5170 assert(pindex->nChainTx == pindex->nTx); 5171 } else if (pindex->pprev->nChainTx > 0 && pindex->nTx > 0) { 5172 // If previous nChainTx is set and number of transactions in block is known, sum must be set. 5173 assert(pindex->nChainTx == pindex->nTx + pindex->pprev->nChainTx); 5174 } else { 5175 // Otherwise nChainTx should only be set if this is a snapshot 5176 // block, and must be set if it is. 5177 assert((pindex->nChainTx != 0) == (pindex == snap_base)); 5178 } 5179 5180 // Chainstate-specific checks on setBlockIndexCandidates 5181 for (auto c : GetAll()) { 5182 if (c->m_chain.Tip() == nullptr) continue; 5183 // Two main factors determine whether pindex is a candidate in 5184 // setBlockIndexCandidates: 5185 // 5186 // - If pindex has less work than the chain tip, it should not be a 5187 // candidate, and this will be asserted below. Otherwise it is a 5188 // potential candidate. 5189 // 5190 // - If pindex or one of its parent blocks back to the genesis block 5191 // or an assumeutxo snapshot never downloaded transactions 5192 // (pindexFirstNeverProcessed is non-null), it should not be a 5193 // candidate, and this will be asserted below. The only exception 5194 // is if pindex itself is an assumeutxo snapshot block. Then it is 5195 // also a potential candidate. 5196 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && (pindexFirstNeverProcessed == nullptr || pindex == snap_base)) { 5197 // If pindex was detected as invalid (pindexFirstInvalid is 5198 // non-null), it is not required to be in 5199 // setBlockIndexCandidates. 5200 if (pindexFirstInvalid == nullptr) { 5201 // If pindex and all its parents back to the genesis block 5202 // or an assumeutxo snapshot block downloaded transactions, 5203 // and the transactions were not pruned (pindexFirstMissing 5204 // is null), it is a potential candidate. The check 5205 // excludes pruned blocks, because if any blocks were 5206 // pruned between pindex the current chain tip, pindex will 5207 // only temporarily be added to setBlockIndexCandidates, 5208 // before being moved to m_blocks_unlinked. This check 5209 // could be improved to verify that if all blocks between 5210 // the chain tip and pindex have data, pindex must be a 5211 // candidate. 5212 // 5213 // If pindex is the chain tip, it also is a potential 5214 // candidate. 5215 // 5216 // If the chainstate was loaded from a snapshot and pindex 5217 // is the base of the snapshot, pindex is also a potential 5218 // candidate. 5219 if (pindexFirstMissing == nullptr || pindex == c->m_chain.Tip() || pindex == c->SnapshotBase()) { 5220 // If this chainstate is the active chainstate, pindex 5221 // must be in setBlockIndexCandidates. Otherwise, this 5222 // chainstate is a background validation chainstate, and 5223 // pindex only needs to be added if it is an ancestor of 5224 // the snapshot that is being validated. 5225 if (c == &ActiveChainstate() || snap_base->GetAncestor(pindex->nHeight) == pindex) { 5226 assert(c->setBlockIndexCandidates.count(pindex)); 5227 } 5228 } 5229 // If some parent is missing, then it could be that this block was in 5230 // setBlockIndexCandidates but had to be removed because of the missing data. 5231 // In this case it must be in m_blocks_unlinked -- see test below. 5232 } 5233 } else { // If this block sorts worse than the current tip or some ancestor's block has never been seen, it cannot be in setBlockIndexCandidates. 5234 assert(c->setBlockIndexCandidates.count(pindex) == 0); 5235 } 5236 } 5237 // Check whether this block is in m_blocks_unlinked. 5238 std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangeUnlinked = m_blockman.m_blocks_unlinked.equal_range(pindex->pprev); 5239 bool foundInUnlinked = false; 5240 while (rangeUnlinked.first != rangeUnlinked.second) { 5241 assert(rangeUnlinked.first->first == pindex->pprev); 5242 if (rangeUnlinked.first->second == pindex) { 5243 foundInUnlinked = true; 5244 break; 5245 } 5246 rangeUnlinked.first++; 5247 } 5248 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed != nullptr && pindexFirstInvalid == nullptr) { 5249 // If this block has block data available, some parent was never received, and has no invalid parents, it must be in m_blocks_unlinked. 5250 assert(foundInUnlinked); 5251 } 5252 if (!(pindex->nStatus & BLOCK_HAVE_DATA)) assert(!foundInUnlinked); // Can't be in m_blocks_unlinked if we don't HAVE_DATA 5253 if (pindexFirstMissing == nullptr) assert(!foundInUnlinked); // We aren't missing data for any parent -- cannot be in m_blocks_unlinked. 5254 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed == nullptr && pindexFirstMissing != nullptr) { 5255 // We HAVE_DATA for this block, have received data for all parents at some point, but we're currently missing data for some parent. 5256 assert(m_blockman.m_have_pruned); 5257 // This block may have entered m_blocks_unlinked if: 5258 // - it has a descendant that at some point had more work than the 5259 // tip, and 5260 // - we tried switching to that descendant but were missing 5261 // data for some intermediate block between m_chain and the 5262 // tip. 5263 // So if this block is itself better than any m_chain.Tip() and it wasn't in 5264 // setBlockIndexCandidates, then it must be in m_blocks_unlinked. 5265 for (auto c : GetAll()) { 5266 const bool is_active = c == &ActiveChainstate(); 5267 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && c->setBlockIndexCandidates.count(pindex) == 0) { 5268 if (pindexFirstInvalid == nullptr) { 5269 if (is_active || snap_base->GetAncestor(pindex->nHeight) == pindex) { 5270 assert(foundInUnlinked); 5271 } 5272 } 5273 } 5274 } 5275 } 5276 // assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash()); // Perhaps too slow 5277 // End: actual consistency checks. 5278 5279 // Try descending into the first subnode. 5280 snap_update_firsts(); 5281 std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> range = forward.equal_range(pindex); 5282 if (range.first != range.second) { 5283 // A subnode was found. 5284 pindex = range.first->second; 5285 nHeight++; 5286 continue; 5287 } 5288 // This is a leaf node. 5289 // Move upwards until we reach a node of which we have not yet visited the last child. 5290 while (pindex) { 5291 // We are going to either move to a parent or a sibling of pindex. 5292 snap_update_firsts(); 5293 // If pindex was the first with a certain property, unset the corresponding variable. 5294 if (pindex == pindexFirstInvalid) pindexFirstInvalid = nullptr; 5295 if (pindex == pindexFirstMissing) pindexFirstMissing = nullptr; 5296 if (pindex == pindexFirstNeverProcessed) pindexFirstNeverProcessed = nullptr; 5297 if (pindex == pindexFirstNotTreeValid) pindexFirstNotTreeValid = nullptr; 5298 if (pindex == pindexFirstNotTransactionsValid) pindexFirstNotTransactionsValid = nullptr; 5299 if (pindex == pindexFirstNotChainValid) pindexFirstNotChainValid = nullptr; 5300 if (pindex == pindexFirstNotScriptsValid) pindexFirstNotScriptsValid = nullptr; 5301 // Find our parent. 5302 CBlockIndex* pindexPar = pindex->pprev; 5303 // Find which child we just visited. 5304 std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangePar = forward.equal_range(pindexPar); 5305 while (rangePar.first->second != pindex) { 5306 assert(rangePar.first != rangePar.second); // Our parent must have at least the node we're coming from as child. 5307 rangePar.first++; 5308 } 5309 // Proceed to the next one. 5310 rangePar.first++; 5311 if (rangePar.first != rangePar.second) { 5312 // Move to the sibling. 5313 pindex = rangePar.first->second; 5314 break; 5315 } else { 5316 // Move up further. 5317 pindex = pindexPar; 5318 nHeight--; 5319 continue; 5320 } 5321 } 5322 } 5323 5324 // Check that we actually traversed the entire map. 5325 assert(nNodes == forward.size()); 5326 } 5327 5328 std::string Chainstate::ToString() 5329 { 5330 AssertLockHeld(::cs_main); 5331 CBlockIndex* tip = m_chain.Tip(); 5332 return strprintf("Chainstate [%s] @ height %d (%s)", 5333 m_from_snapshot_blockhash ? "snapshot" : "ibd", 5334 tip ? tip->nHeight : -1, tip ? tip->GetBlockHash().ToString() : "null"); 5335 } 5336 5337 bool Chainstate::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size) 5338 { 5339 AssertLockHeld(::cs_main); 5340 if (coinstip_size == m_coinstip_cache_size_bytes && 5341 coinsdb_size == m_coinsdb_cache_size_bytes) { 5342 // Cache sizes are unchanged, no need to continue. 5343 return true; 5344 } 5345 size_t old_coinstip_size = m_coinstip_cache_size_bytes; 5346 m_coinstip_cache_size_bytes = coinstip_size; 5347 m_coinsdb_cache_size_bytes = coinsdb_size; 5348 CoinsDB().ResizeCache(coinsdb_size); 5349 5350 LogPrintf("[%s] resized coinsdb cache to %.1f MiB\n", 5351 this->ToString(), coinsdb_size * (1.0 / 1024 / 1024)); 5352 LogPrintf("[%s] resized coinstip cache to %.1f MiB\n", 5353 this->ToString(), coinstip_size * (1.0 / 1024 / 1024)); 5354 5355 BlockValidationState state; 5356 bool ret; 5357 5358 if (coinstip_size > old_coinstip_size) { 5359 // Likely no need to flush if cache sizes have grown. 5360 ret = FlushStateToDisk(state, FlushStateMode::IF_NEEDED); 5361 } else { 5362 // Otherwise, flush state to disk and deallocate the in-memory coins map. 5363 ret = FlushStateToDisk(state, FlushStateMode::ALWAYS); 5364 } 5365 return ret; 5366 } 5367 5368 //! Guess how far we are in the verification process at the given block index 5369 //! require cs_main if pindex has not been validated yet (because nChainTx might be unset) 5370 double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex *pindex) { 5371 if (pindex == nullptr) 5372 return 0.0; 5373 5374 if (!Assume(pindex->nChainTx > 0)) { 5375 LogWarning("Internal bug detected: block %d has unset nChainTx (%s %s). Please report this issue here: %s\n", 5376 pindex->nHeight, PACKAGE_NAME, FormatFullVersion(), PACKAGE_BUGREPORT); 5377 return 0.0; 5378 } 5379 5380 int64_t nNow = time(nullptr); 5381 5382 double fTxTotal; 5383 5384 if (pindex->nChainTx <= data.nTxCount) { 5385 fTxTotal = data.nTxCount + (nNow - data.nTime) * data.dTxRate; 5386 } else { 5387 fTxTotal = pindex->nChainTx + (nNow - pindex->GetBlockTime()) * data.dTxRate; 5388 } 5389 5390 return std::min<double>(pindex->nChainTx / fTxTotal, 1.0); 5391 } 5392 5393 std::optional<uint256> ChainstateManager::SnapshotBlockhash() const 5394 { 5395 LOCK(::cs_main); 5396 if (m_active_chainstate && m_active_chainstate->m_from_snapshot_blockhash) { 5397 // If a snapshot chainstate exists, it will always be our active. 5398 return m_active_chainstate->m_from_snapshot_blockhash; 5399 } 5400 return std::nullopt; 5401 } 5402 5403 std::vector<Chainstate*> ChainstateManager::GetAll() 5404 { 5405 LOCK(::cs_main); 5406 std::vector<Chainstate*> out; 5407 5408 for (Chainstate* cs : {m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) { 5409 if (this->IsUsable(cs)) out.push_back(cs); 5410 } 5411 5412 return out; 5413 } 5414 5415 Chainstate& ChainstateManager::InitializeChainstate(CTxMemPool* mempool) 5416 { 5417 AssertLockHeld(::cs_main); 5418 assert(!m_ibd_chainstate); 5419 assert(!m_active_chainstate); 5420 5421 m_ibd_chainstate = std::make_unique<Chainstate>(mempool, m_blockman, *this); 5422 m_active_chainstate = m_ibd_chainstate.get(); 5423 return *m_active_chainstate; 5424 } 5425 5426 [[nodiscard]] static bool DeleteCoinsDBFromDisk(const fs::path db_path, bool is_snapshot) 5427 EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 5428 { 5429 AssertLockHeld(::cs_main); 5430 5431 if (is_snapshot) { 5432 fs::path base_blockhash_path = db_path / node::SNAPSHOT_BLOCKHASH_FILENAME; 5433 5434 try { 5435 bool existed = fs::remove(base_blockhash_path); 5436 if (!existed) { 5437 LogPrintf("[snapshot] snapshot chainstate dir being removed lacks %s file\n", 5438 fs::PathToString(node::SNAPSHOT_BLOCKHASH_FILENAME)); 5439 } 5440 } catch (const fs::filesystem_error& e) { 5441 LogPrintf("[snapshot] failed to remove file %s: %s\n", 5442 fs::PathToString(base_blockhash_path), fsbridge::get_filesystem_error_message(e)); 5443 } 5444 } 5445 5446 std::string path_str = fs::PathToString(db_path); 5447 LogPrintf("Removing leveldb dir at %s\n", path_str); 5448 5449 // We have to destruct before this call leveldb::DB in order to release the db 5450 // lock, otherwise `DestroyDB` will fail. See `leveldb::~DBImpl()`. 5451 const bool destroyed = DestroyDB(path_str); 5452 5453 if (!destroyed) { 5454 LogPrintf("error: leveldb DestroyDB call failed on %s\n", path_str); 5455 } 5456 5457 // Datadir should be removed from filesystem; otherwise initialization may detect 5458 // it on subsequent statups and get confused. 5459 // 5460 // If the base_blockhash_path removal above fails in the case of snapshot 5461 // chainstates, this will return false since leveldb won't remove a non-empty 5462 // directory. 5463 return destroyed && !fs::exists(db_path); 5464 } 5465 5466 bool ChainstateManager::ActivateSnapshot( 5467 AutoFile& coins_file, 5468 const SnapshotMetadata& metadata, 5469 bool in_memory) 5470 { 5471 uint256 base_blockhash = metadata.m_base_blockhash; 5472 5473 if (this->SnapshotBlockhash()) { 5474 LogPrintf("[snapshot] can't activate a snapshot-based chainstate more than once\n"); 5475 return false; 5476 } 5477 5478 { 5479 LOCK(::cs_main); 5480 if (Assert(m_active_chainstate->GetMempool())->size() > 0) { 5481 LogPrintf("[snapshot] can't activate a snapshot when mempool not empty\n"); 5482 return false; 5483 } 5484 } 5485 5486 int64_t current_coinsdb_cache_size{0}; 5487 int64_t current_coinstip_cache_size{0}; 5488 5489 // Cache percentages to allocate to each chainstate. 5490 // 5491 // These particular percentages don't matter so much since they will only be 5492 // relevant during snapshot activation; caches are rebalanced at the conclusion of 5493 // this function. We want to give (essentially) all available cache capacity to the 5494 // snapshot to aid the bulk load later in this function. 5495 static constexpr double IBD_CACHE_PERC = 0.01; 5496 static constexpr double SNAPSHOT_CACHE_PERC = 0.99; 5497 5498 { 5499 LOCK(::cs_main); 5500 // Resize the coins caches to ensure we're not exceeding memory limits. 5501 // 5502 // Allocate the majority of the cache to the incoming snapshot chainstate, since 5503 // (optimistically) getting to its tip will be the top priority. We'll need to call 5504 // `MaybeRebalanceCaches()` once we're done with this function to ensure 5505 // the right allocation (including the possibility that no snapshot was activated 5506 // and that we should restore the active chainstate caches to their original size). 5507 // 5508 current_coinsdb_cache_size = this->ActiveChainstate().m_coinsdb_cache_size_bytes; 5509 current_coinstip_cache_size = this->ActiveChainstate().m_coinstip_cache_size_bytes; 5510 5511 // Temporarily resize the active coins cache to make room for the newly-created 5512 // snapshot chain. 5513 this->ActiveChainstate().ResizeCoinsCaches( 5514 static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC), 5515 static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC)); 5516 } 5517 5518 auto snapshot_chainstate = WITH_LOCK(::cs_main, 5519 return std::make_unique<Chainstate>( 5520 /*mempool=*/nullptr, m_blockman, *this, base_blockhash)); 5521 5522 { 5523 LOCK(::cs_main); 5524 snapshot_chainstate->InitCoinsDB( 5525 static_cast<size_t>(current_coinsdb_cache_size * SNAPSHOT_CACHE_PERC), 5526 in_memory, false, "chainstate"); 5527 snapshot_chainstate->InitCoinsCache( 5528 static_cast<size_t>(current_coinstip_cache_size * SNAPSHOT_CACHE_PERC)); 5529 } 5530 5531 auto cleanup_bad_snapshot = [&](const char* reason) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 5532 LogPrintf("[snapshot] activation failed - %s\n", reason); 5533 this->MaybeRebalanceCaches(); 5534 5535 // PopulateAndValidateSnapshot can return (in error) before the leveldb datadir 5536 // has been created, so only attempt removal if we got that far. 5537 if (auto snapshot_datadir = node::FindSnapshotChainstateDir(m_options.datadir)) { 5538 // We have to destruct leveldb::DB in order to release the db lock, otherwise 5539 // DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See `leveldb::~DBImpl()`. 5540 // Destructing the chainstate (and so resetting the coinsviews object) does this. 5541 snapshot_chainstate.reset(); 5542 bool removed = DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true); 5543 if (!removed) { 5544 GetNotifications().fatalError(strprintf(_("Failed to remove snapshot chainstate dir (%s). " 5545 "Manually remove it before restarting.\n"), fs::PathToString(*snapshot_datadir))); 5546 } 5547 } 5548 return false; 5549 }; 5550 5551 if (!this->PopulateAndValidateSnapshot(*snapshot_chainstate, coins_file, metadata)) { 5552 LOCK(::cs_main); 5553 return cleanup_bad_snapshot("population failed"); 5554 } 5555 5556 LOCK(::cs_main); // cs_main required for rest of snapshot activation. 5557 5558 // Do a final check to ensure that the snapshot chainstate is actually a more 5559 // work chain than the active chainstate; a user could have loaded a snapshot 5560 // very late in the IBD process, and we wouldn't want to load a useless chainstate. 5561 if (!CBlockIndexWorkComparator()(ActiveTip(), snapshot_chainstate->m_chain.Tip())) { 5562 return cleanup_bad_snapshot("work does not exceed active chainstate"); 5563 } 5564 // If not in-memory, persist the base blockhash for use during subsequent 5565 // initialization. 5566 if (!in_memory) { 5567 if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) { 5568 return cleanup_bad_snapshot("could not write base blockhash"); 5569 } 5570 } 5571 5572 assert(!m_snapshot_chainstate); 5573 m_snapshot_chainstate.swap(snapshot_chainstate); 5574 const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip(); 5575 assert(chaintip_loaded); 5576 5577 // Transfer possession of the mempool to the snapshot chainstate. 5578 // Mempool is empty at this point because we're still in IBD. 5579 Assert(m_active_chainstate->m_mempool->size() == 0); 5580 Assert(!m_snapshot_chainstate->m_mempool); 5581 m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool; 5582 m_active_chainstate->m_mempool = nullptr; 5583 m_active_chainstate = m_snapshot_chainstate.get(); 5584 m_blockman.m_snapshot_height = this->GetSnapshotBaseHeight(); 5585 5586 LogPrintf("[snapshot] successfully activated snapshot %s\n", base_blockhash.ToString()); 5587 LogPrintf("[snapshot] (%.2f MB)\n", 5588 m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() / (1000 * 1000)); 5589 5590 this->MaybeRebalanceCaches(); 5591 return true; 5592 } 5593 5594 static void FlushSnapshotToDisk(CCoinsViewCache& coins_cache, bool snapshot_loaded) 5595 { 5596 LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE( 5597 strprintf("%s (%.2f MB)", 5598 snapshot_loaded ? "saving snapshot chainstate" : "flushing coins cache", 5599 coins_cache.DynamicMemoryUsage() / (1000 * 1000)), 5600 BCLog::LogFlags::ALL); 5601 5602 coins_cache.Flush(); 5603 } 5604 5605 struct StopHashingException : public std::exception 5606 { 5607 const char* what() const noexcept override 5608 { 5609 return "ComputeUTXOStats interrupted."; 5610 } 5611 }; 5612 5613 static void SnapshotUTXOHashBreakpoint(const util::SignalInterrupt& interrupt) 5614 { 5615 if (interrupt) throw StopHashingException(); 5616 } 5617 5618 bool ChainstateManager::PopulateAndValidateSnapshot( 5619 Chainstate& snapshot_chainstate, 5620 AutoFile& coins_file, 5621 const SnapshotMetadata& metadata) 5622 { 5623 // It's okay to release cs_main before we're done using `coins_cache` because we know 5624 // that nothing else will be referencing the newly created snapshot_chainstate yet. 5625 CCoinsViewCache& coins_cache = *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip()); 5626 5627 uint256 base_blockhash = metadata.m_base_blockhash; 5628 5629 CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash)); 5630 5631 if (!snapshot_start_block) { 5632 // Needed for ComputeUTXOStats to determine the 5633 // height and to avoid a crash when base_blockhash.IsNull() 5634 LogPrintf("[snapshot] Did not find snapshot start blockheader %s\n", 5635 base_blockhash.ToString()); 5636 return false; 5637 } 5638 5639 int base_height = snapshot_start_block->nHeight; 5640 const auto& maybe_au_data = GetParams().AssumeutxoForHeight(base_height); 5641 5642 if (!maybe_au_data) { 5643 LogPrintf("[snapshot] assumeutxo height in snapshot metadata not recognized " 5644 "(%d) - refusing to load snapshot\n", base_height); 5645 return false; 5646 } 5647 5648 const AssumeutxoData& au_data = *maybe_au_data; 5649 5650 // This work comparison is a duplicate check with the one performed later in 5651 // ActivateSnapshot(), but is done so that we avoid doing the long work of staging 5652 // a snapshot that isn't actually usable. 5653 if (WITH_LOCK(::cs_main, return !CBlockIndexWorkComparator()(ActiveTip(), snapshot_start_block))) { 5654 LogPrintf("[snapshot] activation failed - work does not exceed active chainstate\n"); 5655 return false; 5656 } 5657 5658 COutPoint outpoint; 5659 Coin coin; 5660 const uint64_t coins_count = metadata.m_coins_count; 5661 uint64_t coins_left = metadata.m_coins_count; 5662 5663 LogPrintf("[snapshot] loading coins from snapshot %s\n", base_blockhash.ToString()); 5664 int64_t coins_processed{0}; 5665 5666 while (coins_left > 0) { 5667 try { 5668 coins_file >> outpoint; 5669 coins_file >> coin; 5670 } catch (const std::ios_base::failure&) { 5671 LogPrintf("[snapshot] bad snapshot format or truncated snapshot after deserializing %d coins\n", 5672 coins_count - coins_left); 5673 return false; 5674 } 5675 if (coin.nHeight > base_height || 5676 outpoint.n >= std::numeric_limits<decltype(outpoint.n)>::max() // Avoid integer wrap-around in coinstats.cpp:ApplyHash 5677 ) { 5678 LogPrintf("[snapshot] bad snapshot data after deserializing %d coins\n", 5679 coins_count - coins_left); 5680 return false; 5681 } 5682 if (!MoneyRange(coin.out.nValue)) { 5683 LogPrintf("[snapshot] bad snapshot data after deserializing %d coins - bad tx out value\n", 5684 coins_count - coins_left); 5685 return false; 5686 } 5687 5688 coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint), std::move(coin)); 5689 5690 --coins_left; 5691 ++coins_processed; 5692 5693 if (coins_processed % 1000000 == 0) { 5694 LogPrintf("[snapshot] %d coins loaded (%.2f%%, %.2f MB)\n", 5695 coins_processed, 5696 static_cast<float>(coins_processed) * 100 / static_cast<float>(coins_count), 5697 coins_cache.DynamicMemoryUsage() / (1000 * 1000)); 5698 } 5699 5700 // Batch write and flush (if we need to) every so often. 5701 // 5702 // If our average Coin size is roughly 41 bytes, checking every 120,000 coins 5703 // means <5MB of memory imprecision. 5704 if (coins_processed % 120000 == 0) { 5705 if (m_interrupt) { 5706 return false; 5707 } 5708 5709 const auto snapshot_cache_state = WITH_LOCK(::cs_main, 5710 return snapshot_chainstate.GetCoinsCacheSizeState()); 5711 5712 if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) { 5713 // This is a hack - we don't know what the actual best block is, but that 5714 // doesn't matter for the purposes of flushing the cache here. We'll set this 5715 // to its correct value (`base_blockhash`) below after the coins are loaded. 5716 coins_cache.SetBestBlock(GetRandHash()); 5717 5718 // No need to acquire cs_main since this chainstate isn't being used yet. 5719 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/false); 5720 } 5721 } 5722 } 5723 5724 // Important that we set this. This and the coins_cache accesses above are 5725 // sort of a layer violation, but either we reach into the innards of 5726 // CCoinsViewCache here or we have to invert some of the Chainstate to 5727 // embed them in a snapshot-activation-specific CCoinsViewCache bulk load 5728 // method. 5729 coins_cache.SetBestBlock(base_blockhash); 5730 5731 bool out_of_coins{false}; 5732 try { 5733 coins_file >> outpoint; 5734 } catch (const std::ios_base::failure&) { 5735 // We expect an exception since we should be out of coins. 5736 out_of_coins = true; 5737 } 5738 if (!out_of_coins) { 5739 LogPrintf("[snapshot] bad snapshot - coins left over after deserializing %d coins\n", 5740 coins_count); 5741 return false; 5742 } 5743 5744 LogPrintf("[snapshot] loaded %d (%.2f MB) coins from snapshot %s\n", 5745 coins_count, 5746 coins_cache.DynamicMemoryUsage() / (1000 * 1000), 5747 base_blockhash.ToString()); 5748 5749 // No need to acquire cs_main since this chainstate isn't being used yet. 5750 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/true); 5751 5752 assert(coins_cache.GetBestBlock() == base_blockhash); 5753 5754 // As above, okay to immediately release cs_main here since no other context knows 5755 // about the snapshot_chainstate. 5756 CCoinsViewDB* snapshot_coinsdb = WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB()); 5757 5758 std::optional<CCoinsStats> maybe_stats; 5759 5760 try { 5761 maybe_stats = ComputeUTXOStats( 5762 CoinStatsHashType::HASH_SERIALIZED, snapshot_coinsdb, m_blockman, [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); }); 5763 } catch (StopHashingException const&) { 5764 return false; 5765 } 5766 if (!maybe_stats.has_value()) { 5767 LogPrintf("[snapshot] failed to generate coins stats\n"); 5768 return false; 5769 } 5770 5771 // Assert that the deserialized chainstate contents match the expected assumeutxo value. 5772 if (AssumeutxoHash{maybe_stats->hashSerialized} != au_data.hash_serialized) { 5773 LogPrintf("[snapshot] bad snapshot content hash: expected %s, got %s\n", 5774 au_data.hash_serialized.ToString(), maybe_stats->hashSerialized.ToString()); 5775 return false; 5776 } 5777 5778 snapshot_chainstate.m_chain.SetTip(*snapshot_start_block); 5779 5780 // The remainder of this function requires modifying data protected by cs_main. 5781 LOCK(::cs_main); 5782 5783 // Fake various pieces of CBlockIndex state: 5784 CBlockIndex* index = nullptr; 5785 5786 // Don't make any modifications to the genesis block since it shouldn't be 5787 // neccessary, and since the genesis block doesn't have normal flags like 5788 // BLOCK_VALID_SCRIPTS set. 5789 constexpr int AFTER_GENESIS_START{1}; 5790 5791 for (int i = AFTER_GENESIS_START; i <= snapshot_chainstate.m_chain.Height(); ++i) { 5792 index = snapshot_chainstate.m_chain[i]; 5793 5794 // Fake BLOCK_OPT_WITNESS so that Chainstate::NeedsRedownload() 5795 // won't ask to rewind the entire assumed-valid chain on startup. 5796 if (DeploymentActiveAt(*index, *this, Consensus::DEPLOYMENT_SEGWIT)) { 5797 index->nStatus |= BLOCK_OPT_WITNESS; 5798 } 5799 5800 m_blockman.m_dirty_blockindex.insert(index); 5801 // Changes to the block index will be flushed to disk after this call 5802 // returns in `ActivateSnapshot()`, when `MaybeRebalanceCaches()` is 5803 // called, since we've added a snapshot chainstate and therefore will 5804 // have to downsize the IBD chainstate, which will result in a call to 5805 // `FlushStateToDisk(ALWAYS)`. 5806 } 5807 5808 assert(index); 5809 assert(index == snapshot_start_block); 5810 index->nChainTx = au_data.nChainTx; 5811 snapshot_chainstate.setBlockIndexCandidates.insert(snapshot_start_block); 5812 5813 LogPrintf("[snapshot] validated snapshot (%.2f MB)\n", 5814 coins_cache.DynamicMemoryUsage() / (1000 * 1000)); 5815 return true; 5816 } 5817 5818 // Currently, this function holds cs_main for its duration, which could be for 5819 // multiple minutes due to the ComputeUTXOStats call. This hold is necessary 5820 // because we need to avoid advancing the background validation chainstate 5821 // farther than the snapshot base block - and this function is also invoked 5822 // from within ConnectTip, i.e. from within ActivateBestChain, so cs_main is 5823 // held anyway. 5824 // 5825 // Eventually (TODO), we could somehow separate this function's runtime from 5826 // maintenance of the active chain, but that will either require 5827 // 5828 // (i) setting `m_disabled` immediately and ensuring all chainstate accesses go 5829 // through IsUsable() checks, or 5830 // 5831 // (ii) giving each chainstate its own lock instead of using cs_main for everything. 5832 SnapshotCompletionResult ChainstateManager::MaybeCompleteSnapshotValidation() 5833 { 5834 AssertLockHeld(cs_main); 5835 if (m_ibd_chainstate.get() == &this->ActiveChainstate() || 5836 !this->IsUsable(m_snapshot_chainstate.get()) || 5837 !this->IsUsable(m_ibd_chainstate.get()) || 5838 !m_ibd_chainstate->m_chain.Tip()) { 5839 // Nothing to do - this function only applies to the background 5840 // validation chainstate. 5841 return SnapshotCompletionResult::SKIPPED; 5842 } 5843 const int snapshot_tip_height = this->ActiveHeight(); 5844 const int snapshot_base_height = *Assert(this->GetSnapshotBaseHeight()); 5845 const CBlockIndex& index_new = *Assert(m_ibd_chainstate->m_chain.Tip()); 5846 5847 if (index_new.nHeight < snapshot_base_height) { 5848 // Background IBD not complete yet. 5849 return SnapshotCompletionResult::SKIPPED; 5850 } 5851 5852 assert(SnapshotBlockhash()); 5853 uint256 snapshot_blockhash = *Assert(SnapshotBlockhash()); 5854 5855 auto handle_invalid_snapshot = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 5856 bilingual_str user_error = strprintf(_( 5857 "%s failed to validate the -assumeutxo snapshot state. " 5858 "This indicates a hardware problem, or a bug in the software, or a " 5859 "bad software modification that allowed an invalid snapshot to be " 5860 "loaded. As a result of this, the node will shut down and stop using any " 5861 "state that was built on the snapshot, resetting the chain height " 5862 "from %d to %d. On the next " 5863 "restart, the node will resume syncing from %d " 5864 "without using any snapshot data. " 5865 "Please report this incident to %s, including how you obtained the snapshot. " 5866 "The invalid snapshot chainstate will be left on disk in case it is " 5867 "helpful in diagnosing the issue that caused this error."), 5868 PACKAGE_NAME, snapshot_tip_height, snapshot_base_height, snapshot_base_height, PACKAGE_BUGREPORT 5869 ); 5870 5871 LogPrintf("[snapshot] !!! %s\n", user_error.original); 5872 LogPrintf("[snapshot] deleting snapshot, reverting to validated chain, and stopping node\n"); 5873 5874 m_active_chainstate = m_ibd_chainstate.get(); 5875 m_snapshot_chainstate->m_disabled = true; 5876 assert(!this->IsUsable(m_snapshot_chainstate.get())); 5877 assert(this->IsUsable(m_ibd_chainstate.get())); 5878 5879 auto rename_result = m_snapshot_chainstate->InvalidateCoinsDBOnDisk(); 5880 if (!rename_result) { 5881 user_error = strprintf(Untranslated("%s\n%s"), user_error, util::ErrorString(rename_result)); 5882 } 5883 5884 GetNotifications().fatalError(user_error); 5885 }; 5886 5887 if (index_new.GetBlockHash() != snapshot_blockhash) { 5888 LogPrintf("[snapshot] supposed base block %s does not match the " 5889 "snapshot base block %s (height %d). Snapshot is not valid.\n", 5890 index_new.ToString(), snapshot_blockhash.ToString(), snapshot_base_height); 5891 handle_invalid_snapshot(); 5892 return SnapshotCompletionResult::BASE_BLOCKHASH_MISMATCH; 5893 } 5894 5895 assert(index_new.nHeight == snapshot_base_height); 5896 5897 int curr_height = m_ibd_chainstate->m_chain.Height(); 5898 5899 assert(snapshot_base_height == curr_height); 5900 assert(snapshot_base_height == index_new.nHeight); 5901 assert(this->IsUsable(m_snapshot_chainstate.get())); 5902 assert(this->GetAll().size() == 2); 5903 5904 CCoinsViewDB& ibd_coins_db = m_ibd_chainstate->CoinsDB(); 5905 m_ibd_chainstate->ForceFlushStateToDisk(); 5906 5907 const auto& maybe_au_data = m_options.chainparams.AssumeutxoForHeight(curr_height); 5908 if (!maybe_au_data) { 5909 LogPrintf("[snapshot] assumeutxo data not found for height " 5910 "(%d) - refusing to validate snapshot\n", curr_height); 5911 handle_invalid_snapshot(); 5912 return SnapshotCompletionResult::MISSING_CHAINPARAMS; 5913 } 5914 5915 const AssumeutxoData& au_data = *maybe_au_data; 5916 std::optional<CCoinsStats> maybe_ibd_stats; 5917 LogPrintf("[snapshot] computing UTXO stats for background chainstate to validate " 5918 "snapshot - this could take a few minutes\n"); 5919 try { 5920 maybe_ibd_stats = ComputeUTXOStats( 5921 CoinStatsHashType::HASH_SERIALIZED, 5922 &ibd_coins_db, 5923 m_blockman, 5924 [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); }); 5925 } catch (StopHashingException const&) { 5926 return SnapshotCompletionResult::STATS_FAILED; 5927 } 5928 5929 // XXX note that this function is slow and will hold cs_main for potentially minutes. 5930 if (!maybe_ibd_stats) { 5931 LogPrintf("[snapshot] failed to generate stats for validation coins db\n"); 5932 // While this isn't a problem with the snapshot per se, this condition 5933 // prevents us from validating the snapshot, so we should shut down and let the 5934 // user handle the issue manually. 5935 handle_invalid_snapshot(); 5936 return SnapshotCompletionResult::STATS_FAILED; 5937 } 5938 const auto& ibd_stats = *maybe_ibd_stats; 5939 5940 // Compare the background validation chainstate's UTXO set hash against the hard-coded 5941 // assumeutxo hash we expect. 5942 // 5943 // TODO: For belt-and-suspenders, we could cache the UTXO set 5944 // hash for the snapshot when it's loaded in its chainstate's leveldb. We could then 5945 // reference that here for an additional check. 5946 if (AssumeutxoHash{ibd_stats.hashSerialized} != au_data.hash_serialized) { 5947 LogPrintf("[snapshot] hash mismatch: actual=%s, expected=%s\n", 5948 ibd_stats.hashSerialized.ToString(), 5949 au_data.hash_serialized.ToString()); 5950 handle_invalid_snapshot(); 5951 return SnapshotCompletionResult::HASH_MISMATCH; 5952 } 5953 5954 LogPrintf("[snapshot] snapshot beginning at %s has been fully validated\n", 5955 snapshot_blockhash.ToString()); 5956 5957 m_ibd_chainstate->m_disabled = true; 5958 this->MaybeRebalanceCaches(); 5959 5960 return SnapshotCompletionResult::SUCCESS; 5961 } 5962 5963 Chainstate& ChainstateManager::ActiveChainstate() const 5964 { 5965 LOCK(::cs_main); 5966 assert(m_active_chainstate); 5967 return *m_active_chainstate; 5968 } 5969 5970 bool ChainstateManager::IsSnapshotActive() const 5971 { 5972 LOCK(::cs_main); 5973 return m_snapshot_chainstate && m_active_chainstate == m_snapshot_chainstate.get(); 5974 } 5975 5976 void ChainstateManager::MaybeRebalanceCaches() 5977 { 5978 AssertLockHeld(::cs_main); 5979 bool ibd_usable = this->IsUsable(m_ibd_chainstate.get()); 5980 bool snapshot_usable = this->IsUsable(m_snapshot_chainstate.get()); 5981 assert(ibd_usable || snapshot_usable); 5982 5983 if (ibd_usable && !snapshot_usable) { 5984 // Allocate everything to the IBD chainstate. This will always happen 5985 // when we are not using a snapshot. 5986 m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache); 5987 } 5988 else if (snapshot_usable && !ibd_usable) { 5989 // If background validation has completed and snapshot is our active chain... 5990 LogPrintf("[snapshot] allocating all cache to the snapshot chainstate\n"); 5991 // Allocate everything to the snapshot chainstate. 5992 m_snapshot_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache); 5993 } 5994 else if (ibd_usable && snapshot_usable) { 5995 // If both chainstates exist, determine who needs more cache based on IBD status. 5996 // 5997 // Note: shrink caches first so that we don't inadvertently overwhelm available memory. 5998 if (IsInitialBlockDownload()) { 5999 m_ibd_chainstate->ResizeCoinsCaches( 6000 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05); 6001 m_snapshot_chainstate->ResizeCoinsCaches( 6002 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95); 6003 } else { 6004 m_snapshot_chainstate->ResizeCoinsCaches( 6005 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05); 6006 m_ibd_chainstate->ResizeCoinsCaches( 6007 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95); 6008 } 6009 } 6010 } 6011 6012 void ChainstateManager::ResetChainstates() 6013 { 6014 m_ibd_chainstate.reset(); 6015 m_snapshot_chainstate.reset(); 6016 m_active_chainstate = nullptr; 6017 } 6018 6019 /** 6020 * Apply default chain params to nullopt members. 6021 * This helps to avoid coding errors around the accidental use of the compare 6022 * operators that accept nullopt, thus ignoring the intended default value. 6023 */ 6024 static ChainstateManager::Options&& Flatten(ChainstateManager::Options&& opts) 6025 { 6026 if (!opts.check_block_index.has_value()) opts.check_block_index = opts.chainparams.DefaultConsistencyChecks(); 6027 if (!opts.minimum_chain_work.has_value()) opts.minimum_chain_work = UintToArith256(opts.chainparams.GetConsensus().nMinimumChainWork); 6028 if (!opts.assumed_valid_block.has_value()) opts.assumed_valid_block = opts.chainparams.GetConsensus().defaultAssumeValid; 6029 return std::move(opts); 6030 } 6031 6032 ChainstateManager::ChainstateManager(const util::SignalInterrupt& interrupt, Options options, node::BlockManager::Options blockman_options) 6033 : m_script_check_queue{/*batch_size=*/128, options.worker_threads_num}, 6034 m_interrupt{interrupt}, 6035 m_options{Flatten(std::move(options))}, 6036 m_blockman{interrupt, std::move(blockman_options)} 6037 { 6038 } 6039 6040 ChainstateManager::~ChainstateManager() 6041 { 6042 LOCK(::cs_main); 6043 6044 m_versionbitscache.Clear(); 6045 } 6046 6047 bool ChainstateManager::DetectSnapshotChainstate() 6048 { 6049 assert(!m_snapshot_chainstate); 6050 std::optional<fs::path> path = node::FindSnapshotChainstateDir(m_options.datadir); 6051 if (!path) { 6052 return false; 6053 } 6054 std::optional<uint256> base_blockhash = node::ReadSnapshotBaseBlockhash(*path); 6055 if (!base_blockhash) { 6056 return false; 6057 } 6058 LogPrintf("[snapshot] detected active snapshot chainstate (%s) - loading\n", 6059 fs::PathToString(*path)); 6060 6061 this->ActivateExistingSnapshot(*base_blockhash); 6062 return true; 6063 } 6064 6065 Chainstate& ChainstateManager::ActivateExistingSnapshot(uint256 base_blockhash) 6066 { 6067 assert(!m_snapshot_chainstate); 6068 m_snapshot_chainstate = 6069 std::make_unique<Chainstate>(nullptr, m_blockman, *this, base_blockhash); 6070 LogPrintf("[snapshot] switching active chainstate to %s\n", m_snapshot_chainstate->ToString()); 6071 6072 // Mempool is empty at this point because we're still in IBD. 6073 Assert(m_active_chainstate->m_mempool->size() == 0); 6074 Assert(!m_snapshot_chainstate->m_mempool); 6075 m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool; 6076 m_active_chainstate->m_mempool = nullptr; 6077 m_active_chainstate = m_snapshot_chainstate.get(); 6078 return *m_snapshot_chainstate; 6079 } 6080 6081 bool IsBIP30Repeat(const CBlockIndex& block_index) 6082 { 6083 return (block_index.nHeight==91842 && block_index.GetBlockHash() == uint256S("0x00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec")) || 6084 (block_index.nHeight==91880 && block_index.GetBlockHash() == uint256S("0x00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721")); 6085 } 6086 6087 bool IsBIP30Unspendable(const CBlockIndex& block_index) 6088 { 6089 return (block_index.nHeight==91722 && block_index.GetBlockHash() == uint256S("0x00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e")) || 6090 (block_index.nHeight==91812 && block_index.GetBlockHash() == uint256S("0x00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f")); 6091 } 6092 6093 static fs::path GetSnapshotCoinsDBPath(Chainstate& cs) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 6094 { 6095 AssertLockHeld(::cs_main); 6096 // Should never be called on a non-snapshot chainstate. 6097 assert(cs.m_from_snapshot_blockhash); 6098 auto storage_path_maybe = cs.CoinsDB().StoragePath(); 6099 // Should never be called with a non-existent storage path. 6100 assert(storage_path_maybe); 6101 return *storage_path_maybe; 6102 } 6103 6104 util::Result<void> Chainstate::InvalidateCoinsDBOnDisk() 6105 { 6106 fs::path snapshot_datadir = GetSnapshotCoinsDBPath(*this); 6107 6108 // Coins views no longer usable. 6109 m_coins_views.reset(); 6110 6111 auto invalid_path = snapshot_datadir + "_INVALID"; 6112 std::string dbpath = fs::PathToString(snapshot_datadir); 6113 std::string target = fs::PathToString(invalid_path); 6114 LogPrintf("[snapshot] renaming snapshot datadir %s to %s\n", dbpath, target); 6115 6116 // The invalid snapshot datadir is simply moved and not deleted because we may 6117 // want to do forensics later during issue investigation. The user is instructed 6118 // accordingly in MaybeCompleteSnapshotValidation(). 6119 try { 6120 fs::rename(snapshot_datadir, invalid_path); 6121 } catch (const fs::filesystem_error& e) { 6122 auto src_str = fs::PathToString(snapshot_datadir); 6123 auto dest_str = fs::PathToString(invalid_path); 6124 6125 LogPrintf("%s: error renaming file '%s' -> '%s': %s\n", 6126 __func__, src_str, dest_str, e.what()); 6127 return util::Error{strprintf(_( 6128 "Rename of '%s' -> '%s' failed. " 6129 "You should resolve this by manually moving or deleting the invalid " 6130 "snapshot directory %s, otherwise you will encounter the same error again " 6131 "on the next startup."), 6132 src_str, dest_str, src_str)}; 6133 } 6134 return {}; 6135 } 6136 6137 bool ChainstateManager::DeleteSnapshotChainstate() 6138 { 6139 AssertLockHeld(::cs_main); 6140 Assert(m_snapshot_chainstate); 6141 Assert(m_ibd_chainstate); 6142 6143 fs::path snapshot_datadir = GetSnapshotCoinsDBPath(*m_snapshot_chainstate); 6144 if (!DeleteCoinsDBFromDisk(snapshot_datadir, /*is_snapshot=*/ true)) { 6145 LogPrintf("Deletion of %s failed. Please remove it manually to continue reindexing.\n", 6146 fs::PathToString(snapshot_datadir)); 6147 return false; 6148 } 6149 m_active_chainstate = m_ibd_chainstate.get(); 6150 m_snapshot_chainstate.reset(); 6151 return true; 6152 } 6153 6154 ChainstateRole Chainstate::GetRole() const 6155 { 6156 if (m_chainman.GetAll().size() <= 1) { 6157 return ChainstateRole::NORMAL; 6158 } 6159 return (this != &m_chainman.ActiveChainstate()) ? 6160 ChainstateRole::BACKGROUND : 6161 ChainstateRole::ASSUMEDVALID; 6162 } 6163 6164 const CBlockIndex* ChainstateManager::GetSnapshotBaseBlock() const 6165 { 6166 return m_active_chainstate ? m_active_chainstate->SnapshotBase() : nullptr; 6167 } 6168 6169 std::optional<int> ChainstateManager::GetSnapshotBaseHeight() const 6170 { 6171 const CBlockIndex* base = this->GetSnapshotBaseBlock(); 6172 return base ? std::make_optional(base->nHeight) : std::nullopt; 6173 } 6174 6175 bool ChainstateManager::ValidatedSnapshotCleanup() 6176 { 6177 AssertLockHeld(::cs_main); 6178 auto get_storage_path = [](auto& chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) -> std::optional<fs::path> { 6179 if (!(chainstate && chainstate->HasCoinsViews())) { 6180 return {}; 6181 } 6182 return chainstate->CoinsDB().StoragePath(); 6183 }; 6184 std::optional<fs::path> ibd_chainstate_path_maybe = get_storage_path(m_ibd_chainstate); 6185 std::optional<fs::path> snapshot_chainstate_path_maybe = get_storage_path(m_snapshot_chainstate); 6186 6187 if (!this->IsSnapshotValidated()) { 6188 // No need to clean up. 6189 return false; 6190 } 6191 // If either path doesn't exist, that means at least one of the chainstates 6192 // is in-memory, in which case we can't do on-disk cleanup. You'd better be 6193 // in a unittest! 6194 if (!ibd_chainstate_path_maybe || !snapshot_chainstate_path_maybe) { 6195 LogPrintf("[snapshot] snapshot chainstate cleanup cannot happen with " 6196 "in-memory chainstates. You are testing, right?\n"); 6197 return false; 6198 } 6199 6200 const auto& snapshot_chainstate_path = *snapshot_chainstate_path_maybe; 6201 const auto& ibd_chainstate_path = *ibd_chainstate_path_maybe; 6202 6203 // Since we're going to be moving around the underlying leveldb filesystem content 6204 // for each chainstate, make sure that the chainstates (and their constituent 6205 // CoinsViews members) have been destructed first. 6206 // 6207 // The caller of this method will be responsible for reinitializing chainstates 6208 // if they want to continue operation. 6209 this->ResetChainstates(); 6210 6211 // No chainstates should be considered usable. 6212 assert(this->GetAll().size() == 0); 6213 6214 LogPrintf("[snapshot] deleting background chainstate directory (now unnecessary) (%s)\n", 6215 fs::PathToString(ibd_chainstate_path)); 6216 6217 fs::path tmp_old{ibd_chainstate_path + "_todelete"}; 6218 6219 auto rename_failed_abort = [this]( 6220 fs::path p_old, 6221 fs::path p_new, 6222 const fs::filesystem_error& err) { 6223 LogPrintf("Error renaming path (%s) -> (%s): %s\n", 6224 fs::PathToString(p_old), fs::PathToString(p_new), err.what()); 6225 GetNotifications().fatalError(strprintf(_( 6226 "Rename of '%s' -> '%s' failed. " 6227 "Cannot clean up the background chainstate leveldb directory."), 6228 fs::PathToString(p_old), fs::PathToString(p_new))); 6229 }; 6230 6231 try { 6232 fs::rename(ibd_chainstate_path, tmp_old); 6233 } catch (const fs::filesystem_error& e) { 6234 rename_failed_abort(ibd_chainstate_path, tmp_old, e); 6235 throw; 6236 } 6237 6238 LogPrintf("[snapshot] moving snapshot chainstate (%s) to " 6239 "default chainstate directory (%s)\n", 6240 fs::PathToString(snapshot_chainstate_path), fs::PathToString(ibd_chainstate_path)); 6241 6242 try { 6243 fs::rename(snapshot_chainstate_path, ibd_chainstate_path); 6244 } catch (const fs::filesystem_error& e) { 6245 rename_failed_abort(snapshot_chainstate_path, ibd_chainstate_path, e); 6246 throw; 6247 } 6248 6249 if (!DeleteCoinsDBFromDisk(tmp_old, /*is_snapshot=*/false)) { 6250 // No need to FatalError because once the unneeded bg chainstate data is 6251 // moved, it will not interfere with subsequent initialization. 6252 LogPrintf("Deletion of %s failed. Please remove it manually, as the " 6253 "directory is now unnecessary.\n", 6254 fs::PathToString(tmp_old)); 6255 } else { 6256 LogPrintf("[snapshot] deleted background chainstate directory (%s)\n", 6257 fs::PathToString(ibd_chainstate_path)); 6258 } 6259 return true; 6260 } 6261 6262 Chainstate& ChainstateManager::GetChainstateForIndexing() 6263 { 6264 // We can't always return `m_ibd_chainstate` because after background validation 6265 // has completed, `m_snapshot_chainstate == m_active_chainstate`, but it can be 6266 // indexed. 6267 return (this->GetAll().size() > 1) ? *m_ibd_chainstate : *m_active_chainstate; 6268 } 6269 6270 std::pair<int, int> ChainstateManager::GetPruneRange(const Chainstate& chainstate, int last_height_can_prune) 6271 { 6272 if (chainstate.m_chain.Height() <= 0) { 6273 return {0, 0}; 6274 } 6275 int prune_start{0}; 6276 6277 if (this->GetAll().size() > 1 && m_snapshot_chainstate.get() == &chainstate) { 6278 // Leave the blocks in the background IBD chain alone if we're pruning 6279 // the snapshot chain. 6280 prune_start = *Assert(GetSnapshotBaseHeight()) + 1; 6281 } 6282 6283 int max_prune = std::max<int>( 6284 0, chainstate.m_chain.Height() - static_cast<int>(MIN_BLOCKS_TO_KEEP)); 6285 6286 // last block to prune is the lesser of (caller-specified height, MIN_BLOCKS_TO_KEEP from the tip) 6287 // 6288 // While you might be tempted to prune the background chainstate more 6289 // aggressively (i.e. fewer MIN_BLOCKS_TO_KEEP), this won't work with index 6290 // building - specifically blockfilterindex requires undo data, and if 6291 // we don't maintain this trailing window, we hit indexing failures. 6292 int prune_end = std::min(last_height_can_prune, max_prune); 6293 6294 return {prune_start, prune_end}; 6295 }