validation.cpp
1 // Copyright (c) 2009-2010 Satoshi Nakamoto 2 // Copyright (c) 2009-present The Bitcoin Core developers 3 // Distributed under the MIT software license, see the accompanying 4 // file COPYING or http://www.opensource.org/licenses/mit-license.php. 5 6 #include <bitcoin-build-config.h> // IWYU pragma: keep 7 8 #include <validation.h> 9 10 #include <arith_uint256.h> 11 #include <chain.h> 12 #include <checkqueue.h> 13 #include <clientversion.h> 14 #include <consensus/amount.h> 15 #include <consensus/consensus.h> 16 #include <consensus/merkle.h> 17 #include <consensus/tx_check.h> 18 #include <consensus/tx_verify.h> 19 #include <consensus/validation.h> 20 #include <cuckoocache.h> 21 #include <flatfile.h> 22 #include <hash.h> 23 #include <kernel/chain.h> 24 #include <kernel/chainparams.h> 25 #include <kernel/coinstats.h> 26 #include <kernel/disconnected_transactions.h> 27 #include <kernel/mempool_entry.h> 28 #include <kernel/messagestartchars.h> 29 #include <kernel/notifications_interface.h> 30 #include <kernel/warning.h> 31 #include <logging.h> 32 #include <logging/timer.h> 33 #include <node/blockstorage.h> 34 #include <node/utxo_snapshot.h> 35 #include <policy/ephemeral_policy.h> 36 #include <policy/policy.h> 37 #include <policy/rbf.h> 38 #include <policy/settings.h> 39 #include <policy/truc_policy.h> 40 #include <pow.h> 41 #include <primitives/block.h> 42 #include <primitives/transaction.h> 43 #include <random.h> 44 #include <script/script.h> 45 #include <script/sigcache.h> 46 #include <signet.h> 47 #include <tinyformat.h> 48 #include <txdb.h> 49 #include <txmempool.h> 50 #include <uint256.h> 51 #include <undo.h> 52 #include <util/check.h> 53 #include <util/fs.h> 54 #include <util/fs_helpers.h> 55 #include <util/hasher.h> 56 #include <util/moneystr.h> 57 #include <util/rbf.h> 58 #include <util/result.h> 59 #include <util/signalinterrupt.h> 60 #include <util/strencodings.h> 61 #include <util/string.h> 62 #include <util/time.h> 63 #include <util/trace.h> 64 #include <util/translation.h> 65 #include <validationinterface.h> 66 67 #include <algorithm> 68 #include <cassert> 69 #include <chrono> 70 #include <deque> 71 #include <numeric> 72 #include <optional> 73 #include <ranges> 74 #include <span> 75 #include <string> 76 #include <tuple> 77 #include <utility> 78 79 using kernel::CCoinsStats; 80 using kernel::CoinStatsHashType; 81 using kernel::ComputeUTXOStats; 82 using kernel::Notifications; 83 84 using fsbridge::FopenFn; 85 using node::BlockManager; 86 using node::BlockMap; 87 using node::CBlockIndexHeightOnlyComparator; 88 using node::CBlockIndexWorkComparator; 89 using node::SnapshotMetadata; 90 91 /** Size threshold for warning about slow UTXO set flush to disk. */ 92 static constexpr size_t WARN_FLUSH_COINS_SIZE = 1 << 30; // 1 GiB 93 /** Time window to wait between writing blocks/block index and chainstate to disk. 94 * Randomize writing time inside the window to prevent a situation where the 95 * network over time settles into a few cohorts of synchronized writers. 96 */ 97 static constexpr auto DATABASE_WRITE_INTERVAL_MIN{50min}; 98 static constexpr auto DATABASE_WRITE_INTERVAL_MAX{70min}; 99 /** Maximum age of our tip for us to be considered current for fee estimation */ 100 static constexpr std::chrono::hours MAX_FEE_ESTIMATION_TIP_AGE{3}; 101 const std::vector<std::string> CHECKLEVEL_DOC { 102 "level 0 reads the blocks from disk", 103 "level 1 verifies block validity", 104 "level 2 verifies undo data", 105 "level 3 checks disconnection of tip blocks", 106 "level 4 tries to reconnect the blocks", 107 "each level includes the checks of the previous levels", 108 }; 109 /** The number of blocks to keep below the deepest prune lock. 110 * There is nothing special about this number. It is higher than what we 111 * expect to see in regular mainnet reorgs, but not so high that it would 112 * noticeably interfere with the pruning mechanism. 113 * */ 114 static constexpr int PRUNE_LOCK_BUFFER{10}; 115 116 TRACEPOINT_SEMAPHORE(validation, block_connected); 117 TRACEPOINT_SEMAPHORE(utxocache, flush); 118 TRACEPOINT_SEMAPHORE(mempool, replaced); 119 TRACEPOINT_SEMAPHORE(mempool, rejected); 120 121 const CBlockIndex* Chainstate::FindForkInGlobalIndex(const CBlockLocator& locator) const 122 { 123 AssertLockHeld(cs_main); 124 125 // Find the latest block common to locator and chain - we expect that 126 // locator.vHave is sorted descending by height. 127 for (const uint256& hash : locator.vHave) { 128 const CBlockIndex* pindex{m_blockman.LookupBlockIndex(hash)}; 129 if (pindex) { 130 if (m_chain.Contains(pindex)) { 131 return pindex; 132 } 133 if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) { 134 return m_chain.Tip(); 135 } 136 } 137 } 138 return m_chain.Genesis(); 139 } 140 141 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state, 142 const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore, 143 bool cacheFullScriptStore, PrecomputedTransactionData& txdata, 144 ValidationCache& validation_cache, 145 std::vector<CScriptCheck>* pvChecks = nullptr) 146 EXCLUSIVE_LOCKS_REQUIRED(cs_main); 147 148 bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx) 149 { 150 AssertLockHeld(cs_main); 151 152 // CheckFinalTxAtTip() uses active_chain_tip.Height()+1 to evaluate 153 // nLockTime because when IsFinalTx() is called within 154 // AcceptBlock(), the height of the block *being* 155 // evaluated is what is used. Thus if we want to know if a 156 // transaction can be part of the *next* block, we need to call 157 // IsFinalTx() with one more than active_chain_tip.Height(). 158 const int nBlockHeight = active_chain_tip.nHeight + 1; 159 160 // BIP113 requires that time-locked transactions have nLockTime set to 161 // less than the median time of the previous block they're contained in. 162 // When the next block is created its previous block will be the current 163 // chain tip, so we use that to calculate the median time passed to 164 // IsFinalTx(). 165 const int64_t nBlockTime{active_chain_tip.GetMedianTimePast()}; 166 167 return IsFinalTx(tx, nBlockHeight, nBlockTime); 168 } 169 170 namespace { 171 /** 172 * A helper which calculates heights of inputs of a given transaction. 173 * 174 * @param[in] tip The current chain tip. If an input belongs to a mempool 175 * transaction, we assume it will be confirmed in the next block. 176 * @param[in] coins Any CCoinsView that provides access to the relevant coins. 177 * @param[in] tx The transaction being evaluated. 178 * 179 * @returns A vector of input heights or nullopt, in case of an error. 180 */ 181 std::optional<std::vector<int>> CalculatePrevHeights( 182 const CBlockIndex& tip, 183 const CCoinsView& coins, 184 const CTransaction& tx) 185 { 186 std::vector<int> prev_heights; 187 prev_heights.resize(tx.vin.size()); 188 for (size_t i = 0; i < tx.vin.size(); ++i) { 189 if (auto coin{coins.GetCoin(tx.vin[i].prevout)}) { 190 prev_heights[i] = coin->nHeight == MEMPOOL_HEIGHT 191 ? tip.nHeight + 1 // Assume all mempool transaction confirm in the next block. 192 : coin->nHeight; 193 } else { 194 LogPrintf("ERROR: %s: Missing input %d in transaction \'%s\'\n", __func__, i, tx.GetHash().GetHex()); 195 return std::nullopt; 196 } 197 } 198 return prev_heights; 199 } 200 } // namespace 201 202 std::optional<LockPoints> CalculateLockPointsAtTip( 203 CBlockIndex* tip, 204 const CCoinsView& coins_view, 205 const CTransaction& tx) 206 { 207 assert(tip); 208 209 auto prev_heights{CalculatePrevHeights(*tip, coins_view, tx)}; 210 if (!prev_heights.has_value()) return std::nullopt; 211 212 CBlockIndex next_tip; 213 next_tip.pprev = tip; 214 // When SequenceLocks() is called within ConnectBlock(), the height 215 // of the block *being* evaluated is what is used. 216 // Thus if we want to know if a transaction can be part of the 217 // *next* block, we need to use one more than active_chainstate.m_chain.Height() 218 next_tip.nHeight = tip->nHeight + 1; 219 const auto [min_height, min_time] = CalculateSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS, prev_heights.value(), next_tip); 220 221 // Also store the hash of the block with the highest height of 222 // all the blocks which have sequence locked prevouts. 223 // This hash needs to still be on the chain 224 // for these LockPoint calculations to be valid 225 // Note: It is impossible to correctly calculate a maxInputBlock 226 // if any of the sequence locked inputs depend on unconfirmed txs, 227 // except in the special case where the relative lock time/height 228 // is 0, which is equivalent to no sequence lock. Since we assume 229 // input height of tip+1 for mempool txs and test the resulting 230 // min_height and min_time from CalculateSequenceLocks against tip+1. 231 int max_input_height{0}; 232 for (const int height : prev_heights.value()) { 233 // Can ignore mempool inputs since we'll fail if they had non-zero locks 234 if (height != next_tip.nHeight) { 235 max_input_height = std::max(max_input_height, height); 236 } 237 } 238 239 // tip->GetAncestor(max_input_height) should never return a nullptr 240 // because max_input_height is always less than the tip height. 241 // It would, however, be a bad bug to continue execution, since a 242 // LockPoints object with the maxInputBlock member set to nullptr 243 // signifies no relative lock time. 244 return LockPoints{min_height, min_time, Assert(tip->GetAncestor(max_input_height))}; 245 } 246 247 bool CheckSequenceLocksAtTip(CBlockIndex* tip, 248 const LockPoints& lock_points) 249 { 250 assert(tip != nullptr); 251 252 CBlockIndex index; 253 index.pprev = tip; 254 // CheckSequenceLocksAtTip() uses active_chainstate.m_chain.Height()+1 to evaluate 255 // height based locks because when SequenceLocks() is called within 256 // ConnectBlock(), the height of the block *being* 257 // evaluated is what is used. 258 // Thus if we want to know if a transaction can be part of the 259 // *next* block, we need to use one more than active_chainstate.m_chain.Height() 260 index.nHeight = tip->nHeight + 1; 261 262 return EvaluateSequenceLocks(index, {lock_points.height, lock_points.time}); 263 } 264 265 // Returns the script flags which should be checked for a given block 266 static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman); 267 268 static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache) 269 EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs) 270 { 271 AssertLockHeld(::cs_main); 272 AssertLockHeld(pool.cs); 273 int expired = pool.Expire(GetTime<std::chrono::seconds>() - pool.m_opts.expiry); 274 if (expired != 0) { 275 LogDebug(BCLog::MEMPOOL, "Expired %i transactions from the memory pool\n", expired); 276 } 277 278 std::vector<COutPoint> vNoSpendsRemaining; 279 pool.TrimToSize(pool.m_opts.max_size_bytes, &vNoSpendsRemaining); 280 for (const COutPoint& removed : vNoSpendsRemaining) 281 coins_cache.Uncache(removed); 282 } 283 284 static bool IsCurrentForFeeEstimation(Chainstate& active_chainstate) EXCLUSIVE_LOCKS_REQUIRED(cs_main) 285 { 286 AssertLockHeld(cs_main); 287 if (active_chainstate.m_chainman.IsInitialBlockDownload()) { 288 return false; 289 } 290 if (active_chainstate.m_chain.Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE)) 291 return false; 292 if (active_chainstate.m_chain.Height() < active_chainstate.m_chainman.m_best_header->nHeight - 1) { 293 return false; 294 } 295 return true; 296 } 297 298 void Chainstate::MaybeUpdateMempoolForReorg( 299 DisconnectedBlockTransactions& disconnectpool, 300 bool fAddToMempool) 301 { 302 if (!m_mempool) return; 303 304 AssertLockHeld(cs_main); 305 AssertLockHeld(m_mempool->cs); 306 std::vector<uint256> vHashUpdate; 307 { 308 // disconnectpool is ordered so that the front is the most recently-confirmed 309 // transaction (the last tx of the block at the tip) in the disconnected chain. 310 // Iterate disconnectpool in reverse, so that we add transactions 311 // back to the mempool starting with the earliest transaction that had 312 // been previously seen in a block. 313 const auto queuedTx = disconnectpool.take(); 314 auto it = queuedTx.rbegin(); 315 while (it != queuedTx.rend()) { 316 // ignore validation errors in resurrected transactions 317 if (!fAddToMempool || (*it)->IsCoinBase() || 318 AcceptToMemoryPool(*this, *it, GetTime(), 319 /*bypass_limits=*/true, /*test_accept=*/false).m_result_type != 320 MempoolAcceptResult::ResultType::VALID) { 321 // If the transaction doesn't make it in to the mempool, remove any 322 // transactions that depend on it (which would now be orphans). 323 m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG); 324 } else if (m_mempool->exists(GenTxid::Txid((*it)->GetHash()))) { 325 vHashUpdate.push_back((*it)->GetHash()); 326 } 327 ++it; 328 } 329 } 330 331 // AcceptToMemoryPool/addNewTransaction all assume that new mempool entries have 332 // no in-mempool children, which is generally not true when adding 333 // previously-confirmed transactions back to the mempool. 334 // UpdateTransactionsFromBlock finds descendants of any transactions in 335 // the disconnectpool that were added back and cleans up the mempool state. 336 m_mempool->UpdateTransactionsFromBlock(vHashUpdate); 337 338 // Predicate to use for filtering transactions in removeForReorg. 339 // Checks whether the transaction is still final and, if it spends a coinbase output, mature. 340 // Also updates valid entries' cached LockPoints if needed. 341 // If false, the tx is still valid and its lockpoints are updated. 342 // If true, the tx would be invalid in the next block; remove this entry and all of its descendants. 343 // Note that TRUC rules are not applied here, so reorgs may cause violations of TRUC inheritance or 344 // topology restrictions. 345 const auto filter_final_and_mature = [&](CTxMemPool::txiter it) 346 EXCLUSIVE_LOCKS_REQUIRED(m_mempool->cs, ::cs_main) { 347 AssertLockHeld(m_mempool->cs); 348 AssertLockHeld(::cs_main); 349 const CTransaction& tx = it->GetTx(); 350 351 // The transaction must be final. 352 if (!CheckFinalTxAtTip(*Assert(m_chain.Tip()), tx)) return true; 353 354 const LockPoints& lp = it->GetLockPoints(); 355 // CheckSequenceLocksAtTip checks if the transaction will be final in the next block to be 356 // created on top of the new chain. 357 if (TestLockPointValidity(m_chain, lp)) { 358 if (!CheckSequenceLocksAtTip(m_chain.Tip(), lp)) { 359 return true; 360 } 361 } else { 362 const CCoinsViewMemPool view_mempool{&CoinsTip(), *m_mempool}; 363 const std::optional<LockPoints> new_lock_points{CalculateLockPointsAtTip(m_chain.Tip(), view_mempool, tx)}; 364 if (new_lock_points.has_value() && CheckSequenceLocksAtTip(m_chain.Tip(), *new_lock_points)) { 365 // Now update the mempool entry lockpoints as well. 366 it->UpdateLockPoints(*new_lock_points); 367 } else { 368 return true; 369 } 370 } 371 372 // If the transaction spends any coinbase outputs, it must be mature. 373 if (it->GetSpendsCoinbase()) { 374 for (const CTxIn& txin : tx.vin) { 375 if (m_mempool->exists(GenTxid::Txid(txin.prevout.hash))) continue; 376 const Coin& coin{CoinsTip().AccessCoin(txin.prevout)}; 377 assert(!coin.IsSpent()); 378 const auto mempool_spend_height{m_chain.Tip()->nHeight + 1}; 379 if (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY) { 380 return true; 381 } 382 } 383 } 384 // Transaction is still valid and cached LockPoints are updated. 385 return false; 386 }; 387 388 // We also need to remove any now-immature transactions 389 m_mempool->removeForReorg(m_chain, filter_final_and_mature); 390 // Re-limit mempool size, in case we added any transactions 391 LimitMempoolSize(*m_mempool, this->CoinsTip()); 392 } 393 394 /** 395 * Checks to avoid mempool polluting consensus critical paths since cached 396 * signature and script validity results will be reused if we validate this 397 * transaction again during block validation. 398 * */ 399 static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, TxValidationState& state, 400 const CCoinsViewCache& view, const CTxMemPool& pool, 401 unsigned int flags, PrecomputedTransactionData& txdata, CCoinsViewCache& coins_tip, 402 ValidationCache& validation_cache) 403 EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs) 404 { 405 AssertLockHeld(cs_main); 406 AssertLockHeld(pool.cs); 407 408 assert(!tx.IsCoinBase()); 409 for (const CTxIn& txin : tx.vin) { 410 const Coin& coin = view.AccessCoin(txin.prevout); 411 412 // This coin was checked in PreChecks and MemPoolAccept 413 // has been holding cs_main since then. 414 Assume(!coin.IsSpent()); 415 if (coin.IsSpent()) return false; 416 417 // If the Coin is available, there are 2 possibilities: 418 // it is available in our current ChainstateActive UTXO set, 419 // or it's a UTXO provided by a transaction in our mempool. 420 // Ensure the scriptPubKeys in Coins from CoinsView are correct. 421 const CTransactionRef& txFrom = pool.get(txin.prevout.hash); 422 if (txFrom) { 423 assert(txFrom->GetHash() == txin.prevout.hash); 424 assert(txFrom->vout.size() > txin.prevout.n); 425 assert(txFrom->vout[txin.prevout.n] == coin.out); 426 } else { 427 const Coin& coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout); 428 assert(!coinFromUTXOSet.IsSpent()); 429 assert(coinFromUTXOSet.out == coin.out); 430 } 431 } 432 433 // Call CheckInputScripts() to cache signature and script validity against current tip consensus rules. 434 return CheckInputScripts(tx, state, view, flags, /* cacheSigStore= */ true, /* cacheFullScriptStore= */ true, txdata, validation_cache); 435 } 436 437 namespace { 438 439 class MemPoolAccept 440 { 441 public: 442 explicit MemPoolAccept(CTxMemPool& mempool, Chainstate& active_chainstate) : 443 m_pool(mempool), 444 m_view(&m_dummy), 445 m_viewmempool(&active_chainstate.CoinsTip(), m_pool), 446 m_active_chainstate(active_chainstate) 447 { 448 } 449 450 // We put the arguments we're handed into a struct, so we can pass them 451 // around easier. 452 struct ATMPArgs { 453 const CChainParams& m_chainparams; 454 const int64_t m_accept_time; 455 const bool m_bypass_limits; 456 /* 457 * Return any outpoints which were not previously present in the coins 458 * cache, but were added as a result of validating the tx for mempool 459 * acceptance. This allows the caller to optionally remove the cache 460 * additions if the associated transaction ends up being rejected by 461 * the mempool. 462 */ 463 std::vector<COutPoint>& m_coins_to_uncache; 464 /** When true, the transaction or package will not be submitted to the mempool. */ 465 const bool m_test_accept; 466 /** Whether we allow transactions to replace mempool transactions. If false, 467 * any transaction spending the same inputs as a transaction in the mempool is considered 468 * a conflict. */ 469 const bool m_allow_replacement; 470 /** When true, allow sibling eviction. This only occurs in single transaction package settings. */ 471 const bool m_allow_sibling_eviction; 472 /** When true, the mempool will not be trimmed when any transactions are submitted in 473 * Finalize(). Instead, limits should be enforced at the end to ensure the package is not 474 * partially submitted. 475 */ 476 const bool m_package_submission; 477 /** When true, use package feerates instead of individual transaction feerates for fee-based 478 * policies such as mempool min fee and min relay fee. 479 */ 480 const bool m_package_feerates; 481 /** Used for local submission of transactions to catch "absurd" fees 482 * due to fee miscalculation by wallets. std:nullopt implies unset, allowing any feerates. 483 * Any individual transaction failing this check causes immediate failure. 484 */ 485 const std::optional<CFeeRate> m_client_maxfeerate; 486 487 /** Whether CPFP carveout and RBF carveout are granted. */ 488 const bool m_allow_carveouts; 489 490 /** Parameters for single transaction mempool validation. */ 491 static ATMPArgs SingleAccept(const CChainParams& chainparams, int64_t accept_time, 492 bool bypass_limits, std::vector<COutPoint>& coins_to_uncache, 493 bool test_accept) { 494 return ATMPArgs{/* m_chainparams */ chainparams, 495 /* m_accept_time */ accept_time, 496 /* m_bypass_limits */ bypass_limits, 497 /* m_coins_to_uncache */ coins_to_uncache, 498 /* m_test_accept */ test_accept, 499 /* m_allow_replacement */ true, 500 /* m_allow_sibling_eviction */ true, 501 /* m_package_submission */ false, 502 /* m_package_feerates */ false, 503 /* m_client_maxfeerate */ {}, // checked by caller 504 /* m_allow_carveouts */ true, 505 }; 506 } 507 508 /** Parameters for test package mempool validation through testmempoolaccept. */ 509 static ATMPArgs PackageTestAccept(const CChainParams& chainparams, int64_t accept_time, 510 std::vector<COutPoint>& coins_to_uncache) { 511 return ATMPArgs{/* m_chainparams */ chainparams, 512 /* m_accept_time */ accept_time, 513 /* m_bypass_limits */ false, 514 /* m_coins_to_uncache */ coins_to_uncache, 515 /* m_test_accept */ true, 516 /* m_allow_replacement */ false, 517 /* m_allow_sibling_eviction */ false, 518 /* m_package_submission */ false, // not submitting to mempool 519 /* m_package_feerates */ false, 520 /* m_client_maxfeerate */ {}, // checked by caller 521 /* m_allow_carveouts */ false, 522 }; 523 } 524 525 /** Parameters for child-with-unconfirmed-parents package validation. */ 526 static ATMPArgs PackageChildWithParents(const CChainParams& chainparams, int64_t accept_time, 527 std::vector<COutPoint>& coins_to_uncache, const std::optional<CFeeRate>& client_maxfeerate) { 528 return ATMPArgs{/* m_chainparams */ chainparams, 529 /* m_accept_time */ accept_time, 530 /* m_bypass_limits */ false, 531 /* m_coins_to_uncache */ coins_to_uncache, 532 /* m_test_accept */ false, 533 /* m_allow_replacement */ true, 534 /* m_allow_sibling_eviction */ false, 535 /* m_package_submission */ true, 536 /* m_package_feerates */ true, 537 /* m_client_maxfeerate */ client_maxfeerate, 538 /* m_allow_carveouts */ false, 539 }; 540 } 541 542 /** Parameters for a single transaction within a package. */ 543 static ATMPArgs SingleInPackageAccept(const ATMPArgs& package_args) { 544 return ATMPArgs{/* m_chainparams */ package_args.m_chainparams, 545 /* m_accept_time */ package_args.m_accept_time, 546 /* m_bypass_limits */ false, 547 /* m_coins_to_uncache */ package_args.m_coins_to_uncache, 548 /* m_test_accept */ package_args.m_test_accept, 549 /* m_allow_replacement */ true, 550 /* m_allow_sibling_eviction */ true, 551 /* m_package_submission */ true, // do not LimitMempoolSize in Finalize() 552 /* m_package_feerates */ false, // only 1 transaction 553 /* m_client_maxfeerate */ package_args.m_client_maxfeerate, 554 /* m_allow_carveouts */ false, 555 }; 556 } 557 558 private: 559 // Private ctor to avoid exposing details to clients and allowing the possibility of 560 // mixing up the order of the arguments. Use static functions above instead. 561 ATMPArgs(const CChainParams& chainparams, 562 int64_t accept_time, 563 bool bypass_limits, 564 std::vector<COutPoint>& coins_to_uncache, 565 bool test_accept, 566 bool allow_replacement, 567 bool allow_sibling_eviction, 568 bool package_submission, 569 bool package_feerates, 570 std::optional<CFeeRate> client_maxfeerate, 571 bool allow_carveouts) 572 : m_chainparams{chainparams}, 573 m_accept_time{accept_time}, 574 m_bypass_limits{bypass_limits}, 575 m_coins_to_uncache{coins_to_uncache}, 576 m_test_accept{test_accept}, 577 m_allow_replacement{allow_replacement}, 578 m_allow_sibling_eviction{allow_sibling_eviction}, 579 m_package_submission{package_submission}, 580 m_package_feerates{package_feerates}, 581 m_client_maxfeerate{client_maxfeerate}, 582 m_allow_carveouts{allow_carveouts} 583 { 584 // If we are using package feerates, we must be doing package submission. 585 // It also means carveouts and sibling eviction are not permitted. 586 if (m_package_feerates) { 587 Assume(m_package_submission); 588 Assume(!m_allow_carveouts); 589 Assume(!m_allow_sibling_eviction); 590 } 591 if (m_allow_sibling_eviction) Assume(m_allow_replacement); 592 } 593 }; 594 595 /** Clean up all non-chainstate coins from m_view and m_viewmempool. */ 596 void CleanupTemporaryCoins() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 597 598 // Single transaction acceptance 599 MempoolAcceptResult AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 600 601 /** 602 * Multiple transaction acceptance. Transactions may or may not be interdependent, but must not 603 * conflict with each other, and the transactions cannot already be in the mempool. Parents must 604 * come before children if any dependencies exist. 605 */ 606 PackageMempoolAcceptResult AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 607 608 /** 609 * Submission of a subpackage. 610 * If subpackage size == 1, calls AcceptSingleTransaction() with adjusted ATMPArgs to avoid 611 * package policy restrictions like no CPFP carve out (PackageMempoolChecks) 612 * and creates a PackageMempoolAcceptResult wrapping the result. 613 * 614 * If subpackage size > 1, calls AcceptMultipleTransactions() with the provided ATMPArgs. 615 * 616 * Also cleans up all non-chainstate coins from m_view at the end. 617 */ 618 PackageMempoolAcceptResult AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args) 619 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 620 621 /** 622 * Package (more specific than just multiple transactions) acceptance. Package must be a child 623 * with all of its unconfirmed parents, and topologically sorted. 624 */ 625 PackageMempoolAcceptResult AcceptPackage(const Package& package, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 626 627 private: 628 // All the intermediate state that gets passed between the various levels 629 // of checking a given transaction. 630 struct Workspace { 631 explicit Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {} 632 /** Txids of mempool transactions that this transaction directly conflicts with or may 633 * replace via sibling eviction. */ 634 std::set<Txid> m_conflicts; 635 /** Iterators to mempool entries that this transaction directly conflicts with or may 636 * replace via sibling eviction. */ 637 CTxMemPool::setEntries m_iters_conflicting; 638 /** All mempool ancestors of this transaction. */ 639 CTxMemPool::setEntries m_ancestors; 640 /* Handle to the tx in the changeset */ 641 CTxMemPool::ChangeSet::TxHandle m_tx_handle; 642 /** Whether RBF-related data structures (m_conflicts, m_iters_conflicting, 643 * m_replaced_transactions) include a sibling in addition to txns with conflicting inputs. */ 644 bool m_sibling_eviction{false}; 645 646 /** Virtual size of the transaction as used by the mempool, calculated using serialized size 647 * of the transaction and sigops. */ 648 int64_t m_vsize; 649 /** Fees paid by this transaction: total input amounts subtracted by total output amounts. */ 650 CAmount m_base_fees; 651 /** Base fees + any fee delta set by the user with prioritisetransaction. */ 652 CAmount m_modified_fees; 653 654 /** If we're doing package validation (i.e. m_package_feerates=true), the "effective" 655 * package feerate of this transaction is the total fees divided by the total size of 656 * transactions (which may include its ancestors and/or descendants). */ 657 CFeeRate m_package_feerate{0}; 658 659 const CTransactionRef& m_ptx; 660 /** Txid. */ 661 const Txid& m_hash; 662 TxValidationState m_state; 663 /** A temporary cache containing serialized transaction data for signature verification. 664 * Reused across PolicyScriptChecks and ConsensusScriptChecks. */ 665 PrecomputedTransactionData m_precomputed_txdata; 666 }; 667 668 // Run the policy checks on a given transaction, excluding any script checks. 669 // Looks up inputs, calculates feerate, considers replacement, evaluates 670 // package limits, etc. As this function can be invoked for "free" by a peer, 671 // only tests that are fast should be done here (to avoid CPU DoS). 672 bool PreChecks(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 673 674 // Run checks for mempool replace-by-fee, only used in AcceptSingleTransaction. 675 bool ReplacementChecks(Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 676 677 // Enforce package mempool ancestor/descendant limits (distinct from individual 678 // ancestor/descendant limits done in PreChecks) and run Package RBF checks. 679 bool PackageMempoolChecks(const std::vector<CTransactionRef>& txns, 680 std::vector<Workspace>& workspaces, 681 int64_t total_vsize, 682 PackageValidationState& package_state) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 683 684 // Run the script checks using our policy flags. As this can be slow, we should 685 // only invoke this on transactions that have otherwise passed policy checks. 686 bool PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 687 688 // Re-run the script checks, using consensus flags, and try to cache the 689 // result in the scriptcache. This should be done after 690 // PolicyScriptChecks(). This requires that all inputs either be in our 691 // utxo set or in the mempool. 692 bool ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 693 694 // Try to add the transaction to the mempool, removing any conflicts first. 695 void FinalizeSubpackage(const ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 696 697 // Submit all transactions to the mempool and call ConsensusScriptChecks to add to the script 698 // cache - should only be called after successful validation of all transactions in the package. 699 // Does not call LimitMempoolSize(), so mempool max_size_bytes may be temporarily exceeded. 700 bool SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, PackageValidationState& package_state, 701 std::map<Wtxid, MempoolAcceptResult>& results) 702 EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); 703 704 // Compare a package's feerate against minimum allowed. 705 bool CheckFeeRate(size_t package_size, CAmount package_fee, TxValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) 706 { 707 AssertLockHeld(::cs_main); 708 AssertLockHeld(m_pool.cs); 709 CAmount mempoolRejectFee = m_pool.GetMinFee().GetFee(package_size); 710 if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) { 711 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee)); 712 } 713 714 if (package_fee < m_pool.m_opts.min_relay_feerate.GetFee(package_size)) { 715 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "min relay fee not met", 716 strprintf("%d < %d", package_fee, m_pool.m_opts.min_relay_feerate.GetFee(package_size))); 717 } 718 return true; 719 } 720 721 ValidationCache& GetValidationCache() 722 { 723 return m_active_chainstate.m_chainman.m_validation_cache; 724 } 725 726 private: 727 CTxMemPool& m_pool; 728 CCoinsViewCache m_view; 729 CCoinsViewMemPool m_viewmempool; 730 CCoinsView m_dummy; 731 732 Chainstate& m_active_chainstate; 733 734 // Fields below are per *sub*package state and must be reset prior to subsequent 735 // AcceptSingleTransaction and AcceptMultipleTransactions invocations 736 struct SubPackageState { 737 /** Aggregated modified fees of all transactions, used to calculate package feerate. */ 738 CAmount m_total_modified_fees{0}; 739 /** Aggregated virtual size of all transactions, used to calculate package feerate. */ 740 int64_t m_total_vsize{0}; 741 742 // RBF-related members 743 /** Whether the transaction(s) would replace any mempool transactions and/or evict any siblings. 744 * If so, RBF rules apply. */ 745 bool m_rbf{false}; 746 /** Mempool transactions that were replaced. */ 747 std::list<CTransactionRef> m_replaced_transactions; 748 /* Changeset representing adding transactions and removing their conflicts. */ 749 std::unique_ptr<CTxMemPool::ChangeSet> m_changeset; 750 751 /** Total modified fees of mempool transactions being replaced. */ 752 CAmount m_conflicting_fees{0}; 753 /** Total size (in virtual bytes) of mempool transactions being replaced. */ 754 size_t m_conflicting_size{0}; 755 }; 756 757 struct SubPackageState m_subpackage; 758 759 /** Re-set sub-package state to not leak between evaluations */ 760 void ClearSubPackageState() EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs) 761 { 762 m_subpackage = SubPackageState{}; 763 764 // And clean coins while at it 765 CleanupTemporaryCoins(); 766 } 767 }; 768 769 bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws) 770 { 771 AssertLockHeld(cs_main); 772 AssertLockHeld(m_pool.cs); 773 const CTransactionRef& ptx = ws.m_ptx; 774 const CTransaction& tx = *ws.m_ptx; 775 const Txid& hash = ws.m_hash; 776 777 // Copy/alias what we need out of args 778 const int64_t nAcceptTime = args.m_accept_time; 779 const bool bypass_limits = args.m_bypass_limits; 780 std::vector<COutPoint>& coins_to_uncache = args.m_coins_to_uncache; 781 782 // Alias what we need out of ws 783 TxValidationState& state = ws.m_state; 784 785 if (!CheckTransaction(tx, state)) { 786 return false; // state filled in by CheckTransaction 787 } 788 789 // Coinbase is only valid in a block, not as a loose transaction 790 if (tx.IsCoinBase()) 791 return state.Invalid(TxValidationResult::TX_CONSENSUS, "coinbase"); 792 793 // Rather not work on nonstandard transactions (unless -testnet/-regtest) 794 std::string reason; 795 if (m_pool.m_opts.require_standard && !IsStandardTx(tx, m_pool.m_opts.max_datacarrier_bytes, m_pool.m_opts.permit_bare_multisig, m_pool.m_opts.dust_relay_feerate, reason)) { 796 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason); 797 } 798 799 // Transactions smaller than 65 non-witness bytes are not relayed to mitigate CVE-2017-12842. 800 if (::GetSerializeSize(TX_NO_WITNESS(tx)) < MIN_STANDARD_TX_NONWITNESS_SIZE) 801 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "tx-size-small"); 802 803 // Only accept nLockTime-using transactions that can be mined in the next 804 // block; we don't want our mempool filled up with transactions that can't 805 // be mined yet. 806 if (!CheckFinalTxAtTip(*Assert(m_active_chainstate.m_chain.Tip()), tx)) { 807 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-final"); 808 } 809 810 if (m_pool.exists(GenTxid::Wtxid(tx.GetWitnessHash()))) { 811 // Exact transaction already exists in the mempool. 812 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-in-mempool"); 813 } else if (m_pool.exists(GenTxid::Txid(tx.GetHash()))) { 814 // Transaction with the same non-witness data but different witness (same txid, different 815 // wtxid) already exists in the mempool. 816 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-same-nonwitness-data-in-mempool"); 817 } 818 819 // Check for conflicts with in-memory transactions 820 for (const CTxIn &txin : tx.vin) 821 { 822 const CTransaction* ptxConflicting = m_pool.GetConflictTx(txin.prevout); 823 if (ptxConflicting) { 824 if (!args.m_allow_replacement) { 825 // Transaction conflicts with a mempool tx, but we're not allowing replacements in this context. 826 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "bip125-replacement-disallowed"); 827 } 828 ws.m_conflicts.insert(ptxConflicting->GetHash()); 829 } 830 } 831 832 m_view.SetBackend(m_viewmempool); 833 834 const CCoinsViewCache& coins_cache = m_active_chainstate.CoinsTip(); 835 // do all inputs exist? 836 for (const CTxIn& txin : tx.vin) { 837 if (!coins_cache.HaveCoinInCache(txin.prevout)) { 838 coins_to_uncache.push_back(txin.prevout); 839 } 840 841 // Note: this call may add txin.prevout to the coins cache 842 // (coins_cache.cacheCoins) by way of FetchCoin(). It should be removed 843 // later (via coins_to_uncache) if this tx turns out to be invalid. 844 if (!m_view.HaveCoin(txin.prevout)) { 845 // Are inputs missing because we already have the tx? 846 for (size_t out = 0; out < tx.vout.size(); out++) { 847 // Optimistically just do efficient check of cache for outputs 848 if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) { 849 return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-known"); 850 } 851 } 852 // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet 853 return state.Invalid(TxValidationResult::TX_MISSING_INPUTS, "bad-txns-inputs-missingorspent"); 854 } 855 } 856 857 // This is const, but calls into the back end CoinsViews. The CCoinsViewDB at the bottom of the 858 // hierarchy brings the best block into scope. See CCoinsViewDB::GetBestBlock(). 859 m_view.GetBestBlock(); 860 861 // we have all inputs cached now, so switch back to dummy (to protect 862 // against bugs where we pull more inputs from disk that miss being added 863 // to coins_to_uncache) 864 m_view.SetBackend(m_dummy); 865 866 assert(m_active_chainstate.m_blockman.LookupBlockIndex(m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip()); 867 868 // Only accept BIP68 sequence locked transactions that can be mined in the next 869 // block; we don't want our mempool filled up with transactions that can't 870 // be mined yet. 871 // Pass in m_view which has all of the relevant inputs cached. Note that, since m_view's 872 // backend was removed, it no longer pulls coins from the mempool. 873 const std::optional<LockPoints> lock_points{CalculateLockPointsAtTip(m_active_chainstate.m_chain.Tip(), m_view, tx)}; 874 if (!lock_points.has_value() || !CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(), *lock_points)) { 875 return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-BIP68-final"); 876 } 877 878 // The mempool holds txs for the next block, so pass height+1 to CheckTxInputs 879 if (!Consensus::CheckTxInputs(tx, state, m_view, m_active_chainstate.m_chain.Height() + 1, ws.m_base_fees)) { 880 return false; // state filled in by CheckTxInputs 881 } 882 883 if (m_pool.m_opts.require_standard && !AreInputsStandard(tx, m_view)) { 884 return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs"); 885 } 886 887 // Check for non-standard witnesses. 888 if (tx.HasWitness() && m_pool.m_opts.require_standard && !IsWitnessStandard(tx, m_view)) { 889 return state.Invalid(TxValidationResult::TX_WITNESS_MUTATED, "bad-witness-nonstandard"); 890 } 891 892 int64_t nSigOpsCost = GetTransactionSigOpCost(tx, m_view, STANDARD_SCRIPT_VERIFY_FLAGS); 893 894 // Keep track of transactions that spend a coinbase, which we re-scan 895 // during reorgs to ensure COINBASE_MATURITY is still met. 896 bool fSpendsCoinbase = false; 897 for (const CTxIn &txin : tx.vin) { 898 const Coin &coin = m_view.AccessCoin(txin.prevout); 899 if (coin.IsCoinBase()) { 900 fSpendsCoinbase = true; 901 break; 902 } 903 } 904 905 // Set entry_sequence to 0 when bypass_limits is used; this allows txs from a block 906 // reorg to be marked earlier than any child txs that were already in the mempool. 907 const uint64_t entry_sequence = bypass_limits ? 0 : m_pool.GetSequence(); 908 if (!m_subpackage.m_changeset) { 909 m_subpackage.m_changeset = m_pool.GetChangeSet(); 910 } 911 ws.m_tx_handle = m_subpackage.m_changeset->StageAddition(ptx, ws.m_base_fees, nAcceptTime, m_active_chainstate.m_chain.Height(), entry_sequence, fSpendsCoinbase, nSigOpsCost, lock_points.value()); 912 913 // ws.m_modified_fees includes any fee deltas from PrioritiseTransaction 914 ws.m_modified_fees = ws.m_tx_handle->GetModifiedFee(); 915 916 ws.m_vsize = ws.m_tx_handle->GetTxSize(); 917 918 // Enforces 0-fee for dust transactions, no incentive to be mined alone 919 if (m_pool.m_opts.require_standard) { 920 if (!PreCheckEphemeralTx(*ptx, m_pool.m_opts.dust_relay_feerate, ws.m_base_fees, ws.m_modified_fees, state)) { 921 return false; // state filled in by PreCheckEphemeralTx 922 } 923 } 924 925 if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST) 926 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "bad-txns-too-many-sigops", 927 strprintf("%d", nSigOpsCost)); 928 929 // No individual transactions are allowed below the min relay feerate except from disconnected blocks. 930 // This requirement, unlike CheckFeeRate, cannot be bypassed using m_package_feerates because, 931 // while a tx could be package CPFP'd when entering the mempool, we do not have a DoS-resistant 932 // method of ensuring the tx remains bumped. For example, the fee-bumping child could disappear 933 // due to a replacement. 934 // The only exception is TRUC transactions. 935 if (!bypass_limits && ws.m_ptx->version != TRUC_VERSION && ws.m_modified_fees < m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize)) { 936 // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not 937 // TX_RECONSIDERABLE, because it cannot be bypassed using package validation. 938 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met", 939 strprintf("%d < %d", ws.m_modified_fees, m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize))); 940 } 941 // No individual transactions are allowed below the mempool min feerate except from disconnected 942 // blocks and transactions in a package. Package transactions will be checked using package 943 // feerate later. 944 if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false; 945 946 ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts); 947 948 // Note that these modifications are only applicable to single transaction scenarios; 949 // carve-outs are disabled for multi-transaction evaluations. 950 CTxMemPool::Limits maybe_rbf_limits = m_pool.m_opts.limits; 951 952 // Calculate in-mempool ancestors, up to a limit. 953 if (ws.m_conflicts.size() == 1 && args.m_allow_carveouts) { 954 // In general, when we receive an RBF transaction with mempool conflicts, we want to know whether we 955 // would meet the chain limits after the conflicts have been removed. However, there isn't a practical 956 // way to do this short of calculating the ancestor and descendant sets with an overlay cache of 957 // changed mempool entries. Due to both implementation and runtime complexity concerns, this isn't 958 // very realistic, thus we only ensure a limited set of transactions are RBF'able despite mempool 959 // conflicts here. Importantly, we need to ensure that some transactions which were accepted using 960 // the below carve-out are able to be RBF'ed, without impacting the security the carve-out provides 961 // for off-chain contract systems (see link in the comment below). 962 // 963 // Specifically, the subset of RBF transactions which we allow despite chain limits are those which 964 // conflict directly with exactly one other transaction (but may evict children of said transaction), 965 // and which are not adding any new mempool dependencies. Note that the "no new mempool dependencies" 966 // check is accomplished later, so we don't bother doing anything about it here, but if our 967 // policy changes, we may need to move that check to here instead of removing it wholesale. 968 // 969 // Such transactions are clearly not merging any existing packages, so we are only concerned with 970 // ensuring that (a) no package is growing past the package size (not count) limits and (b) we are 971 // not allowing something to effectively use the (below) carve-out spot when it shouldn't be allowed 972 // to. 973 // 974 // To check these we first check if we meet the RBF criteria, above, and increment the descendant 975 // limits by the direct conflict and its descendants (as these are recalculated in 976 // CalculateMempoolAncestors by assuming the new transaction being added is a new descendant, with no 977 // removals, of each parent's existing dependent set). The ancestor count limits are unmodified (as 978 // the ancestor limits should be the same for both our new transaction and any conflicts). 979 // We don't bother incrementing m_limit_descendants by the full removal count as that limit never comes 980 // into force here (as we're only adding a single transaction). 981 assert(ws.m_iters_conflicting.size() == 1); 982 CTxMemPool::txiter conflict = *ws.m_iters_conflicting.begin(); 983 984 maybe_rbf_limits.descendant_count += 1; 985 maybe_rbf_limits.descendant_size_vbytes += conflict->GetSizeWithDescendants(); 986 } 987 988 if (auto ancestors{m_subpackage.m_changeset->CalculateMemPoolAncestors(ws.m_tx_handle, maybe_rbf_limits)}) { 989 ws.m_ancestors = std::move(*ancestors); 990 } else { 991 // If CalculateMemPoolAncestors fails second time, we want the original error string. 992 const auto error_message{util::ErrorString(ancestors).original}; 993 994 // Carve-out is not allowed in this context; fail 995 if (!args.m_allow_carveouts) { 996 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message); 997 } 998 999 // Contracting/payment channels CPFP carve-out: 1000 // If the new transaction is relatively small (up to 40k weight) 1001 // and has at most one ancestor (ie ancestor limit of 2, including 1002 // the new transaction), allow it if its parent has exactly the 1003 // descendant limit descendants. The transaction also cannot be TRUC, 1004 // as its topology restrictions do not allow a second child. 1005 // 1006 // This allows protocols which rely on distrusting counterparties 1007 // being able to broadcast descendants of an unconfirmed transaction 1008 // to be secure by simply only having two immediately-spendable 1009 // outputs - one for each counterparty. For more info on the uses for 1010 // this, see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html 1011 CTxMemPool::Limits cpfp_carve_out_limits{ 1012 .ancestor_count = 2, 1013 .ancestor_size_vbytes = maybe_rbf_limits.ancestor_size_vbytes, 1014 .descendant_count = maybe_rbf_limits.descendant_count + 1, 1015 .descendant_size_vbytes = maybe_rbf_limits.descendant_size_vbytes + EXTRA_DESCENDANT_TX_SIZE_LIMIT, 1016 }; 1017 if (ws.m_vsize > EXTRA_DESCENDANT_TX_SIZE_LIMIT || ws.m_ptx->version == TRUC_VERSION) { 1018 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message); 1019 } 1020 if (auto ancestors_retry{m_subpackage.m_changeset->CalculateMemPoolAncestors(ws.m_tx_handle, cpfp_carve_out_limits)}) { 1021 ws.m_ancestors = std::move(*ancestors_retry); 1022 } else { 1023 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message); 1024 } 1025 } 1026 1027 // Even though just checking direct mempool parents for inheritance would be sufficient, we 1028 // check using the full ancestor set here because it's more convenient to use what we have 1029 // already calculated. 1030 if (const auto err{SingleTRUCChecks(ws.m_ptx, ws.m_ancestors, ws.m_conflicts, ws.m_vsize)}) { 1031 // Single transaction contexts only. 1032 if (args.m_allow_sibling_eviction && err->second != nullptr) { 1033 // We should only be considering where replacement is considered valid as well. 1034 Assume(args.m_allow_replacement); 1035 1036 // Potential sibling eviction. Add the sibling to our list of mempool conflicts to be 1037 // included in RBF checks. 1038 ws.m_conflicts.insert(err->second->GetHash()); 1039 // Adding the sibling to m_iters_conflicting here means that it doesn't count towards 1040 // RBF Carve Out above. This is correct, since removing to-be-replaced transactions from 1041 // the descendant count is done separately in SingleTRUCChecks for TRUC transactions. 1042 ws.m_iters_conflicting.insert(m_pool.GetIter(err->second->GetHash()).value()); 1043 ws.m_sibling_eviction = true; 1044 // The sibling will be treated as part of the to-be-replaced set in ReplacementChecks. 1045 // Note that we are not checking whether it opts in to replaceability via BIP125 or TRUC 1046 // (which is normally done in PreChecks). However, the only way a TRUC transaction can 1047 // have a non-TRUC and non-BIP125 descendant is due to a reorg. 1048 } else { 1049 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "TRUC-violation", err->first); 1050 } 1051 } 1052 1053 // A transaction that spends outputs that would be replaced by it is invalid. Now 1054 // that we have the set of all ancestors we can detect this 1055 // pathological case by making sure ws.m_conflicts and ws.m_ancestors don't 1056 // intersect. 1057 if (const auto err_string{EntriesAndTxidsDisjoint(ws.m_ancestors, ws.m_conflicts, hash)}) { 1058 // We classify this as a consensus error because a transaction depending on something it 1059 // conflicts with would be inconsistent. 1060 return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-spends-conflicting-tx", *err_string); 1061 } 1062 1063 // We want to detect conflicts in any tx in a package to trigger package RBF logic 1064 m_subpackage.m_rbf |= !ws.m_conflicts.empty(); 1065 return true; 1066 } 1067 1068 bool MemPoolAccept::ReplacementChecks(Workspace& ws) 1069 { 1070 AssertLockHeld(cs_main); 1071 AssertLockHeld(m_pool.cs); 1072 1073 const CTransaction& tx = *ws.m_ptx; 1074 const uint256& hash = ws.m_hash; 1075 TxValidationState& state = ws.m_state; 1076 1077 CFeeRate newFeeRate(ws.m_modified_fees, ws.m_vsize); 1078 // Enforce Rule #6. The replacement transaction must have a higher feerate than its direct conflicts. 1079 // - The motivation for this check is to ensure that the replacement transaction is preferable for 1080 // block-inclusion, compared to what would be removed from the mempool. 1081 // - This logic predates ancestor feerate-based transaction selection, which is why it doesn't 1082 // consider feerates of descendants. 1083 // - Note: Ancestor feerate-based transaction selection has made this comparison insufficient to 1084 // guarantee that this is incentive-compatible for miners, because it is possible for a 1085 // descendant transaction of a direct conflict to pay a higher feerate than the transaction that 1086 // might replace them, under these rules. 1087 if (const auto err_string{PaysMoreThanConflicts(ws.m_iters_conflicting, newFeeRate, hash)}) { 1088 // This fee-related failure is TX_RECONSIDERABLE because validating in a package may change 1089 // the result. 1090 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, 1091 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1092 } 1093 1094 CTxMemPool::setEntries all_conflicts; 1095 1096 // Calculate all conflicting entries and enforce Rule #5. 1097 if (const auto err_string{GetEntriesForConflicts(tx, m_pool, ws.m_iters_conflicting, all_conflicts)}) { 1098 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, 1099 strprintf("too many potential replacements%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1100 } 1101 // Enforce Rule #2. 1102 if (const auto err_string{HasNoNewUnconfirmed(tx, m_pool, all_conflicts)}) { 1103 // Sibling eviction is only done for TRUC transactions, which cannot have multiple ancestors. 1104 Assume(!ws.m_sibling_eviction); 1105 return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, 1106 strprintf("replacement-adds-unconfirmed%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1107 } 1108 1109 // Check if it's economically rational to mine this transaction rather than the ones it 1110 // replaces and pays for its own relay fees. Enforce Rules #3 and #4. 1111 for (CTxMemPool::txiter it : all_conflicts) { 1112 m_subpackage.m_conflicting_fees += it->GetModifiedFee(); 1113 m_subpackage.m_conflicting_size += it->GetTxSize(); 1114 } 1115 if (const auto err_string{PaysForRBF(m_subpackage.m_conflicting_fees, ws.m_modified_fees, ws.m_vsize, 1116 m_pool.m_opts.incremental_relay_feerate, hash)}) { 1117 // Result may change in a package context 1118 return state.Invalid(TxValidationResult::TX_RECONSIDERABLE, 1119 strprintf("insufficient fee%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string); 1120 } 1121 1122 // Add all the to-be-removed transactions to the changeset. 1123 for (auto it : all_conflicts) { 1124 m_subpackage.m_changeset->StageRemoval(it); 1125 } 1126 return true; 1127 } 1128 1129 bool MemPoolAccept::PackageMempoolChecks(const std::vector<CTransactionRef>& txns, 1130 std::vector<Workspace>& workspaces, 1131 const int64_t total_vsize, 1132 PackageValidationState& package_state) 1133 { 1134 AssertLockHeld(cs_main); 1135 AssertLockHeld(m_pool.cs); 1136 1137 // CheckPackageLimits expects the package transactions to not already be in the mempool. 1138 assert(std::all_of(txns.cbegin(), txns.cend(), [this](const auto& tx) 1139 { return !m_pool.exists(GenTxid::Txid(tx->GetHash()));})); 1140 1141 assert(txns.size() == workspaces.size()); 1142 1143 auto result = m_pool.CheckPackageLimits(txns, total_vsize); 1144 if (!result) { 1145 // This is a package-wide error, separate from an individual transaction error. 1146 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package-mempool-limits", util::ErrorString(result).original); 1147 } 1148 1149 // No conflicts means we're finished. Further checks are all RBF-only. 1150 if (!m_subpackage.m_rbf) return true; 1151 1152 // We're in package RBF context; replacement proposal must be size 2 1153 if (workspaces.size() != 2 || !Assume(IsChildWithParents(txns))) { 1154 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: package must be 1-parent-1-child"); 1155 } 1156 1157 // If the package has in-mempool ancestors, we won't consider a package RBF 1158 // since it would result in a cluster larger than 2. 1159 // N.B. To relax this constraint we will need to revisit how CCoinsViewMemPool::PackageAddTransaction 1160 // is being used inside AcceptMultipleTransactions to track available inputs while processing a package. 1161 for (const auto& ws : workspaces) { 1162 if (!ws.m_ancestors.empty()) { 1163 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package RBF failed: new transaction cannot have mempool ancestors"); 1164 } 1165 } 1166 1167 // Aggregate all conflicts into one set. 1168 CTxMemPool::setEntries direct_conflict_iters; 1169 for (Workspace& ws : workspaces) { 1170 // Aggregate all conflicts into one set. 1171 direct_conflict_iters.merge(ws.m_iters_conflicting); 1172 } 1173 1174 const auto& parent_ws = workspaces[0]; 1175 const auto& child_ws = workspaces[1]; 1176 1177 // Don't consider replacements that would cause us to remove a large number of mempool entries. 1178 // This limit is not increased in a package RBF. Use the aggregate number of transactions. 1179 CTxMemPool::setEntries all_conflicts; 1180 if (const auto err_string{GetEntriesForConflicts(*child_ws.m_ptx, m_pool, direct_conflict_iters, 1181 all_conflicts)}) { 1182 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1183 "package RBF failed: too many potential replacements", *err_string); 1184 } 1185 1186 1187 for (CTxMemPool::txiter it : all_conflicts) { 1188 m_subpackage.m_changeset->StageRemoval(it); 1189 m_subpackage.m_conflicting_fees += it->GetModifiedFee(); 1190 m_subpackage.m_conflicting_size += it->GetTxSize(); 1191 } 1192 1193 // Use the child as the transaction for attributing errors to. 1194 const Txid& child_hash = child_ws.m_ptx->GetHash(); 1195 if (const auto err_string{PaysForRBF(/*original_fees=*/m_subpackage.m_conflicting_fees, 1196 /*replacement_fees=*/m_subpackage.m_total_modified_fees, 1197 /*replacement_vsize=*/m_subpackage.m_total_vsize, 1198 m_pool.m_opts.incremental_relay_feerate, child_hash)}) { 1199 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1200 "package RBF failed: insufficient anti-DoS fees", *err_string); 1201 } 1202 1203 // Ensure this two transaction package is a "chunk" on its own; we don't want the child 1204 // to be only paying anti-DoS fees 1205 const CFeeRate parent_feerate(parent_ws.m_modified_fees, parent_ws.m_vsize); 1206 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize); 1207 if (package_feerate <= parent_feerate) { 1208 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1209 "package RBF failed: package feerate is less than or equal to parent feerate", 1210 strprintf("package feerate %s <= parent feerate is %s", package_feerate.ToString(), parent_feerate.ToString())); 1211 } 1212 1213 // Check if it's economically rational to mine this package rather than the ones it replaces. 1214 // This takes the place of ReplacementChecks()'s PaysMoreThanConflicts() in the package RBF setting. 1215 if (const auto err_tup{ImprovesFeerateDiagram(*m_subpackage.m_changeset)}) { 1216 return package_state.Invalid(PackageValidationResult::PCKG_POLICY, 1217 "package RBF failed: " + err_tup.value().second, ""); 1218 } 1219 1220 LogDebug(BCLog::TXPACKAGES, "package RBF checks passed: parent %s (wtxid=%s), child %s (wtxid=%s), package hash (%s)\n", 1221 txns.front()->GetHash().ToString(), txns.front()->GetWitnessHash().ToString(), 1222 txns.back()->GetHash().ToString(), txns.back()->GetWitnessHash().ToString(), 1223 GetPackageHash(txns).ToString()); 1224 1225 1226 return true; 1227 } 1228 1229 bool MemPoolAccept::PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) 1230 { 1231 AssertLockHeld(cs_main); 1232 AssertLockHeld(m_pool.cs); 1233 const CTransaction& tx = *ws.m_ptx; 1234 TxValidationState& state = ws.m_state; 1235 1236 constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS; 1237 1238 // Check input scripts and signatures. 1239 // This is done last to help prevent CPU exhaustion denial-of-service attacks. 1240 if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false, ws.m_precomputed_txdata, GetValidationCache())) { 1241 // SCRIPT_VERIFY_CLEANSTACK requires SCRIPT_VERIFY_WITNESS, so we 1242 // need to turn both off, and compare against just turning off CLEANSTACK 1243 // to see if the failure is specifically due to witness validation. 1244 TxValidationState state_dummy; // Want reported failures to be from first CheckInputScripts 1245 if (!tx.HasWitness() && CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, ws.m_precomputed_txdata, GetValidationCache()) && 1246 !CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, ws.m_precomputed_txdata, GetValidationCache())) { 1247 // Only the witness is missing, so the transaction itself may be fine. 1248 state.Invalid(TxValidationResult::TX_WITNESS_STRIPPED, 1249 state.GetRejectReason(), state.GetDebugMessage()); 1250 } 1251 return false; // state filled in by CheckInputScripts 1252 } 1253 1254 return true; 1255 } 1256 1257 bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) 1258 { 1259 AssertLockHeld(cs_main); 1260 AssertLockHeld(m_pool.cs); 1261 const CTransaction& tx = *ws.m_ptx; 1262 const uint256& hash = ws.m_hash; 1263 TxValidationState& state = ws.m_state; 1264 1265 // Check again against the current block tip's script verification 1266 // flags to cache our script execution flags. This is, of course, 1267 // useless if the next block has different script flags from the 1268 // previous one, but because the cache tracks script flags for us it 1269 // will auto-invalidate and we'll just have a few blocks of extra 1270 // misses on soft-fork activation. 1271 // 1272 // This is also useful in case of bugs in the standard flags that cause 1273 // transactions to pass as valid when they're actually invalid. For 1274 // instance the STRICTENC flag was incorrectly allowing certain 1275 // CHECKSIG NOT scripts to pass, even though they were invalid. 1276 // 1277 // There is a similar check in CreateNewBlock() to prevent creating 1278 // invalid blocks (using TestBlockValidity), however allowing such 1279 // transactions into the mempool can be exploited as a DoS attack. 1280 unsigned int currentBlockScriptVerifyFlags{GetBlockScriptFlags(*m_active_chainstate.m_chain.Tip(), m_active_chainstate.m_chainman)}; 1281 if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags, 1282 ws.m_precomputed_txdata, m_active_chainstate.CoinsTip(), GetValidationCache())) { 1283 LogPrintf("BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s\n", hash.ToString(), state.ToString()); 1284 return Assume(false); 1285 } 1286 1287 return true; 1288 } 1289 1290 void MemPoolAccept::FinalizeSubpackage(const ATMPArgs& args) 1291 { 1292 AssertLockHeld(cs_main); 1293 AssertLockHeld(m_pool.cs); 1294 1295 if (!m_subpackage.m_changeset->GetRemovals().empty()) Assume(args.m_allow_replacement); 1296 // Remove conflicting transactions from the mempool 1297 for (CTxMemPool::txiter it : m_subpackage.m_changeset->GetRemovals()) 1298 { 1299 std::string log_string = strprintf("replacing mempool tx %s (wtxid=%s, fees=%s, vsize=%s). ", 1300 it->GetTx().GetHash().ToString(), 1301 it->GetTx().GetWitnessHash().ToString(), 1302 it->GetFee(), 1303 it->GetTxSize()); 1304 FeeFrac feerate{m_subpackage.m_total_modified_fees, int32_t(m_subpackage.m_total_vsize)}; 1305 uint256 tx_or_package_hash{}; 1306 const bool replaced_with_tx{m_subpackage.m_changeset->GetTxCount() == 1}; 1307 if (replaced_with_tx) { 1308 const CTransaction& tx = m_subpackage.m_changeset->GetAddedTxn(0); 1309 tx_or_package_hash = tx.GetHash(); 1310 log_string += strprintf("New tx %s (wtxid=%s, fees=%s, vsize=%s)", 1311 tx.GetHash().ToString(), 1312 tx.GetWitnessHash().ToString(), 1313 feerate.fee, 1314 feerate.size); 1315 } else { 1316 tx_or_package_hash = GetPackageHash(m_subpackage.m_changeset->GetAddedTxns()); 1317 log_string += strprintf("New package %s with %lu txs, fees=%s, vsize=%s", 1318 tx_or_package_hash.ToString(), 1319 m_subpackage.m_changeset->GetTxCount(), 1320 feerate.fee, 1321 feerate.size); 1322 1323 } 1324 LogDebug(BCLog::MEMPOOL, "%s\n", log_string); 1325 TRACEPOINT(mempool, replaced, 1326 it->GetTx().GetHash().data(), 1327 it->GetTxSize(), 1328 it->GetFee(), 1329 std::chrono::duration_cast<std::chrono::duration<std::uint64_t>>(it->GetTime()).count(), 1330 tx_or_package_hash.data(), 1331 feerate.size, 1332 feerate.fee, 1333 replaced_with_tx 1334 ); 1335 m_subpackage.m_replaced_transactions.push_back(it->GetSharedTx()); 1336 } 1337 m_subpackage.m_changeset->Apply(); 1338 m_subpackage.m_changeset.reset(); 1339 } 1340 1341 bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, 1342 PackageValidationState& package_state, 1343 std::map<Wtxid, MempoolAcceptResult>& results) 1344 { 1345 AssertLockHeld(cs_main); 1346 AssertLockHeld(m_pool.cs); 1347 // Sanity check: none of the transactions should be in the mempool, and none of the transactions 1348 // should have a same-txid-different-witness equivalent in the mempool. 1349 assert(std::all_of(workspaces.cbegin(), workspaces.cend(), [this](const auto& ws){ 1350 return !m_pool.exists(GenTxid::Txid(ws.m_ptx->GetHash())); })); 1351 1352 bool all_submitted = true; 1353 FinalizeSubpackage(args); 1354 // ConsensusScriptChecks adds to the script cache and is therefore consensus-critical; 1355 // CheckInputsFromMempoolAndCache asserts that transactions only spend coins available from the 1356 // mempool or UTXO set. Submit each transaction to the mempool immediately after calling 1357 // ConsensusScriptChecks to make the outputs available for subsequent transactions. 1358 for (Workspace& ws : workspaces) { 1359 if (!ConsensusScriptChecks(args, ws)) { 1360 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1361 // Since PolicyScriptChecks() passed, this should never fail. 1362 Assume(false); 1363 all_submitted = false; 1364 package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR, 1365 strprintf("BUG! PolicyScriptChecks succeeded but ConsensusScriptChecks failed: %s", 1366 ws.m_ptx->GetHash().ToString())); 1367 // Remove the transaction from the mempool. 1368 if (!m_subpackage.m_changeset) m_subpackage.m_changeset = m_pool.GetChangeSet(); 1369 m_subpackage.m_changeset->StageRemoval(m_pool.GetIter(ws.m_ptx->GetHash()).value()); 1370 } 1371 } 1372 if (!all_submitted) { 1373 Assume(m_subpackage.m_changeset); 1374 // This code should be unreachable; it's here as belt-and-suspenders 1375 // to try to ensure we have no consensus-invalid transactions in the 1376 // mempool. 1377 m_subpackage.m_changeset->Apply(); 1378 m_subpackage.m_changeset.reset(); 1379 return false; 1380 } 1381 1382 std::vector<Wtxid> all_package_wtxids; 1383 all_package_wtxids.reserve(workspaces.size()); 1384 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids), 1385 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); }); 1386 1387 if (!m_subpackage.m_replaced_transactions.empty()) { 1388 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with %u new one(s) for %s additional fees, %d delta bytes\n", 1389 m_subpackage.m_replaced_transactions.size(), workspaces.size(), 1390 m_subpackage.m_total_modified_fees - m_subpackage.m_conflicting_fees, 1391 m_subpackage.m_total_vsize - static_cast<int>(m_subpackage.m_conflicting_size)); 1392 } 1393 1394 // Add successful results. The returned results may change later if LimitMempoolSize() evicts them. 1395 for (Workspace& ws : workspaces) { 1396 auto iter = m_pool.GetIter(ws.m_ptx->GetHash()); 1397 Assume(iter.has_value()); 1398 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate : 1399 CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)}; 1400 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids : 1401 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()}; 1402 results.emplace(ws.m_ptx->GetWitnessHash(), 1403 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, 1404 ws.m_base_fees, effective_feerate, effective_feerate_wtxids)); 1405 if (!m_pool.m_opts.signals) continue; 1406 const CTransaction& tx = *ws.m_ptx; 1407 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees, 1408 ws.m_vsize, (*iter)->GetHeight(), 1409 args.m_bypass_limits, args.m_package_submission, 1410 IsCurrentForFeeEstimation(m_active_chainstate), 1411 m_pool.HasNoInputsOf(tx)); 1412 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence()); 1413 } 1414 return all_submitted; 1415 } 1416 1417 MempoolAcceptResult MemPoolAccept::AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) 1418 { 1419 AssertLockHeld(cs_main); 1420 LOCK(m_pool.cs); // mempool "read lock" (held through m_pool.m_opts.signals->TransactionAddedToMempool()) 1421 1422 Workspace ws(ptx); 1423 const std::vector<Wtxid> single_wtxid{ws.m_ptx->GetWitnessHash()}; 1424 1425 if (!PreChecks(args, ws)) { 1426 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) { 1427 // Failed for fee reasons. Provide the effective feerate and which tx was included. 1428 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid); 1429 } 1430 return MempoolAcceptResult::Failure(ws.m_state); 1431 } 1432 1433 m_subpackage.m_total_vsize = ws.m_vsize; 1434 m_subpackage.m_total_modified_fees = ws.m_modified_fees; 1435 1436 // Individual modified feerate exceeded caller-defined max; abort 1437 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) { 1438 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", ""); 1439 return MempoolAcceptResult::Failure(ws.m_state); 1440 } 1441 1442 if (m_pool.m_opts.require_standard) { 1443 Wtxid dummy_wtxid; 1444 if (!CheckEphemeralSpends(/*package=*/{ptx}, m_pool.m_opts.dust_relay_feerate, m_pool, ws.m_state, dummy_wtxid)) { 1445 return MempoolAcceptResult::Failure(ws.m_state); 1446 } 1447 } 1448 1449 if (m_subpackage.m_rbf && !ReplacementChecks(ws)) { 1450 if (ws.m_state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) { 1451 // Failed for incentives-based fee reasons. Provide the effective feerate and which tx was included. 1452 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), single_wtxid); 1453 } 1454 return MempoolAcceptResult::Failure(ws.m_state); 1455 } 1456 1457 // Perform the inexpensive checks first and avoid hashing and signature verification unless 1458 // those checks pass, to mitigate CPU exhaustion denial-of-service attacks. 1459 if (!PolicyScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state); 1460 1461 if (!ConsensusScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state); 1462 1463 const CFeeRate effective_feerate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)}; 1464 // Tx was accepted, but not added 1465 if (args.m_test_accept) { 1466 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, 1467 ws.m_base_fees, effective_feerate, single_wtxid); 1468 } 1469 1470 FinalizeSubpackage(args); 1471 1472 // Limit the mempool, if appropriate. 1473 if (!args.m_package_submission && !args.m_bypass_limits) { 1474 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip()); 1475 if (!m_pool.exists(GenTxid::Txid(ws.m_hash))) { 1476 // The tx no longer meets our (new) mempool minimum feerate but could be reconsidered in a package. 1477 ws.m_state.Invalid(TxValidationResult::TX_RECONSIDERABLE, "mempool full"); 1478 return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), {ws.m_ptx->GetWitnessHash()}); 1479 } 1480 } 1481 1482 if (m_pool.m_opts.signals) { 1483 const CTransaction& tx = *ws.m_ptx; 1484 auto iter = m_pool.GetIter(tx.GetHash()); 1485 Assume(iter.has_value()); 1486 const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees, 1487 ws.m_vsize, (*iter)->GetHeight(), 1488 args.m_bypass_limits, args.m_package_submission, 1489 IsCurrentForFeeEstimation(m_active_chainstate), 1490 m_pool.HasNoInputsOf(tx)); 1491 m_pool.m_opts.signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence()); 1492 } 1493 1494 if (!m_subpackage.m_replaced_transactions.empty()) { 1495 LogDebug(BCLog::MEMPOOL, "replaced %u mempool transactions with 1 new transaction for %s additional fees, %d delta bytes\n", 1496 m_subpackage.m_replaced_transactions.size(), 1497 ws.m_modified_fees - m_subpackage.m_conflicting_fees, 1498 ws.m_vsize - static_cast<int>(m_subpackage.m_conflicting_size)); 1499 } 1500 1501 return MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), ws.m_vsize, ws.m_base_fees, 1502 effective_feerate, single_wtxid); 1503 } 1504 1505 PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args) 1506 { 1507 AssertLockHeld(cs_main); 1508 1509 // These context-free package limits can be done before taking the mempool lock. 1510 PackageValidationState package_state; 1511 if (!IsWellFormedPackage(txns, package_state, /*require_sorted=*/true)) return PackageMempoolAcceptResult(package_state, {}); 1512 1513 std::vector<Workspace> workspaces{}; 1514 workspaces.reserve(txns.size()); 1515 std::transform(txns.cbegin(), txns.cend(), std::back_inserter(workspaces), 1516 [](const auto& tx) { return Workspace(tx); }); 1517 std::map<Wtxid, MempoolAcceptResult> results; 1518 1519 LOCK(m_pool.cs); 1520 1521 // Do all PreChecks first and fail fast to avoid running expensive script checks when unnecessary. 1522 for (Workspace& ws : workspaces) { 1523 if (!PreChecks(args, ws)) { 1524 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1525 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1526 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1527 return PackageMempoolAcceptResult(package_state, std::move(results)); 1528 } 1529 1530 // Individual modified feerate exceeded caller-defined max; abort 1531 // N.B. this doesn't take into account CPFPs. Chunk-aware validation may be more robust. 1532 if (args.m_client_maxfeerate && CFeeRate(ws.m_modified_fees, ws.m_vsize) > args.m_client_maxfeerate.value()) { 1533 // Need to set failure here both individually and at package level 1534 ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "max feerate exceeded", ""); 1535 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1536 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1537 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1538 return PackageMempoolAcceptResult(package_state, std::move(results)); 1539 } 1540 1541 // Make the coins created by this transaction available for subsequent transactions in the 1542 // package to spend. If there are no conflicts within the package, no transaction can spend a coin 1543 // needed by another transaction in the package. We also need to make sure that no package 1544 // tx replaces (or replaces the ancestor of) the parent of another package tx. As long as we 1545 // check these two things, we don't need to track the coins spent. 1546 // If a package tx conflicts with a mempool tx, PackageMempoolChecks() ensures later that any package RBF attempt 1547 // has *no* in-mempool ancestors, so we don't have to worry about subsequent transactions in 1548 // same package spending the same in-mempool outpoints. This needs to be revisited for general 1549 // package RBF. 1550 m_viewmempool.PackageAddTransaction(ws.m_ptx); 1551 } 1552 1553 // At this point we have all in-mempool ancestors, and we know every transaction's vsize. 1554 // Run the TRUC checks on the package. 1555 for (Workspace& ws : workspaces) { 1556 if (auto err{PackageTRUCChecks(ws.m_ptx, ws.m_vsize, txns, ws.m_ancestors)}) { 1557 package_state.Invalid(PackageValidationResult::PCKG_POLICY, "TRUC-violation", err.value()); 1558 return PackageMempoolAcceptResult(package_state, {}); 1559 } 1560 } 1561 1562 // Transactions must meet two minimum feerates: the mempool minimum fee and min relay fee. 1563 // For transactions consisting of exactly one child and its parents, it suffices to use the 1564 // package feerate (total modified fees / total virtual size) to check this requirement. 1565 // Note that this is an aggregate feerate; this function has not checked that there are transactions 1566 // too low feerate to pay for themselves, or that the child transactions are higher feerate than 1567 // their parents. Using aggregate feerate may allow "parents pay for child" behavior and permit 1568 // a child that is below mempool minimum feerate. To avoid these behaviors, callers of 1569 // AcceptMultipleTransactions need to restrict txns topology (e.g. to ancestor sets) and check 1570 // the feerates of individuals and subsets. 1571 m_subpackage.m_total_vsize = std::accumulate(workspaces.cbegin(), workspaces.cend(), int64_t{0}, 1572 [](int64_t sum, auto& ws) { return sum + ws.m_vsize; }); 1573 m_subpackage.m_total_modified_fees = std::accumulate(workspaces.cbegin(), workspaces.cend(), CAmount{0}, 1574 [](CAmount sum, auto& ws) { return sum + ws.m_modified_fees; }); 1575 const CFeeRate package_feerate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize); 1576 std::vector<Wtxid> all_package_wtxids; 1577 all_package_wtxids.reserve(workspaces.size()); 1578 std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids), 1579 [](const auto& ws) { return ws.m_ptx->GetWitnessHash(); }); 1580 TxValidationState placeholder_state; 1581 if (args.m_package_feerates && 1582 !CheckFeeRate(m_subpackage.m_total_vsize, m_subpackage.m_total_modified_fees, placeholder_state)) { 1583 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1584 return PackageMempoolAcceptResult(package_state, {{workspaces.back().m_ptx->GetWitnessHash(), 1585 MempoolAcceptResult::FeeFailure(placeholder_state, CFeeRate(m_subpackage.m_total_modified_fees, m_subpackage.m_total_vsize), all_package_wtxids)}}); 1586 } 1587 1588 // Apply package mempool ancestor/descendant limits. Skip if there is only one transaction, 1589 // because it's unnecessary. 1590 if (txns.size() > 1 && !PackageMempoolChecks(txns, workspaces, m_subpackage.m_total_vsize, package_state)) { 1591 return PackageMempoolAcceptResult(package_state, std::move(results)); 1592 } 1593 1594 // Now that we've bounded the resulting possible ancestry count, check package for dust spends 1595 if (m_pool.m_opts.require_standard) { 1596 TxValidationState child_state; 1597 Wtxid child_wtxid; 1598 if (!CheckEphemeralSpends(txns, m_pool.m_opts.dust_relay_feerate, m_pool, child_state, child_wtxid)) { 1599 package_state.Invalid(PackageValidationResult::PCKG_TX, "unspent-dust"); 1600 results.emplace(child_wtxid, MempoolAcceptResult::Failure(child_state)); 1601 return PackageMempoolAcceptResult(package_state, std::move(results)); 1602 } 1603 } 1604 1605 for (Workspace& ws : workspaces) { 1606 ws.m_package_feerate = package_feerate; 1607 if (!PolicyScriptChecks(args, ws)) { 1608 // Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished. 1609 package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1610 results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state)); 1611 return PackageMempoolAcceptResult(package_state, std::move(results)); 1612 } 1613 if (args.m_test_accept) { 1614 const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate : 1615 CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)}; 1616 const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids : 1617 std::vector<Wtxid>{ws.m_ptx->GetWitnessHash()}; 1618 results.emplace(ws.m_ptx->GetWitnessHash(), 1619 MempoolAcceptResult::Success(std::move(m_subpackage.m_replaced_transactions), 1620 ws.m_vsize, ws.m_base_fees, effective_feerate, 1621 effective_feerate_wtxids)); 1622 } 1623 } 1624 1625 if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, std::move(results)); 1626 1627 if (!SubmitPackage(args, workspaces, package_state, results)) { 1628 // PackageValidationState filled in by SubmitPackage(). 1629 return PackageMempoolAcceptResult(package_state, std::move(results)); 1630 } 1631 1632 return PackageMempoolAcceptResult(package_state, std::move(results)); 1633 } 1634 1635 void MemPoolAccept::CleanupTemporaryCoins() 1636 { 1637 // There are 3 kinds of coins in m_view: 1638 // (1) Temporary coins from the transactions in subpackage, constructed by m_viewmempool. 1639 // (2) Mempool coins from transactions in the mempool, constructed by m_viewmempool. 1640 // (3) Confirmed coins fetched from our current UTXO set. 1641 // 1642 // (1) Temporary coins need to be removed, regardless of whether the transaction was submitted. 1643 // If the transaction was submitted to the mempool, m_viewmempool will be able to fetch them from 1644 // there. If it wasn't submitted to mempool, it is incorrect to keep them - future calls may try 1645 // to spend those coins that don't actually exist. 1646 // (2) Mempool coins also need to be removed. If the mempool contents have changed as a result 1647 // of submitting or replacing transactions, coins previously fetched from mempool may now be 1648 // spent or nonexistent. Those coins need to be deleted from m_view. 1649 // (3) Confirmed coins don't need to be removed. The chainstate has not changed (we are 1650 // holding cs_main and no blocks have been processed) so the confirmed tx cannot disappear like 1651 // a mempool tx can. The coin may now be spent after we submitted a tx to mempool, but 1652 // we have already checked that the package does not have 2 transactions spending the same coin. 1653 // Keeping them in m_view is an optimization to not re-fetch confirmed coins if we later look up 1654 // inputs for this transaction again. 1655 for (const auto& outpoint : m_viewmempool.GetNonBaseCoins()) { 1656 // In addition to resetting m_viewmempool, we also need to manually delete these coins from 1657 // m_view because it caches copies of the coins it fetched from m_viewmempool previously. 1658 m_view.Uncache(outpoint); 1659 } 1660 // This deletes the temporary and mempool coins. 1661 m_viewmempool.Reset(); 1662 } 1663 1664 PackageMempoolAcceptResult MemPoolAccept::AcceptSubPackage(const std::vector<CTransactionRef>& subpackage, ATMPArgs& args) 1665 { 1666 AssertLockHeld(::cs_main); 1667 AssertLockHeld(m_pool.cs); 1668 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) { 1669 if (subpackage.size() > 1) { 1670 return AcceptMultipleTransactions(subpackage, args); 1671 } 1672 const auto& tx = subpackage.front(); 1673 ATMPArgs single_args = ATMPArgs::SingleInPackageAccept(args); 1674 const auto single_res = AcceptSingleTransaction(tx, single_args); 1675 PackageValidationState package_state_wrapped; 1676 if (single_res.m_result_type != MempoolAcceptResult::ResultType::VALID) { 1677 package_state_wrapped.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1678 } 1679 return PackageMempoolAcceptResult(package_state_wrapped, {{tx->GetWitnessHash(), single_res}}); 1680 }(); 1681 1682 // Clean up m_view and m_viewmempool so that other subpackage evaluations don't have access to 1683 // coins they shouldn't. Keep some coins in order to minimize re-fetching coins from the UTXO set. 1684 // Clean up package feerate and rbf calculations 1685 ClearSubPackageState(); 1686 1687 return result; 1688 } 1689 1690 PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, ATMPArgs& args) 1691 { 1692 Assert(!package.empty()); 1693 AssertLockHeld(cs_main); 1694 // Used if returning a PackageMempoolAcceptResult directly from this function. 1695 PackageValidationState package_state_quit_early; 1696 1697 // There are two topologies we are able to handle through this function: 1698 // (1) A single transaction 1699 // (2) A child-with-unconfirmed-parents package. 1700 // Check that the package is well-formed. If it isn't, we won't try to validate any of the 1701 // transactions and thus won't return any MempoolAcceptResults, just a package-wide error. 1702 1703 // Context-free package checks. 1704 if (!IsWellFormedPackage(package, package_state_quit_early, /*require_sorted=*/true)) { 1705 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1706 } 1707 1708 if (package.size() > 1) { 1709 // All transactions in the package must be a parent of the last transaction. This is just an 1710 // opportunity for us to fail fast on a context-free check without taking the mempool lock. 1711 if (!IsChildWithParents(package)) { 1712 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents"); 1713 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1714 } 1715 1716 // IsChildWithParents() guarantees the package is > 1 transactions. 1717 assert(package.size() > 1); 1718 // The package must be 1 child with all of its unconfirmed parents. The package is expected to 1719 // be sorted, so the last transaction is the child. 1720 const auto& child = package.back(); 1721 std::unordered_set<uint256, SaltedTxidHasher> unconfirmed_parent_txids; 1722 std::transform(package.cbegin(), package.cend() - 1, 1723 std::inserter(unconfirmed_parent_txids, unconfirmed_parent_txids.end()), 1724 [](const auto& tx) { return tx->GetHash(); }); 1725 1726 // All child inputs must refer to a preceding package transaction or a confirmed UTXO. The only 1727 // way to verify this is to look up the child's inputs in our current coins view (not including 1728 // mempool), and enforce that all parents not present in the package be available at chain tip. 1729 // Since this check can bring new coins into the coins cache, keep track of these coins and 1730 // uncache them if we don't end up submitting this package to the mempool. 1731 const CCoinsViewCache& coins_tip_cache = m_active_chainstate.CoinsTip(); 1732 for (const auto& input : child->vin) { 1733 if (!coins_tip_cache.HaveCoinInCache(input.prevout)) { 1734 args.m_coins_to_uncache.push_back(input.prevout); 1735 } 1736 } 1737 // Using the MemPoolAccept m_view cache allows us to look up these same coins faster later. 1738 // This should be connecting directly to CoinsTip, not to m_viewmempool, because we specifically 1739 // require inputs to be confirmed if they aren't in the package. 1740 m_view.SetBackend(m_active_chainstate.CoinsTip()); 1741 const auto package_or_confirmed = [this, &unconfirmed_parent_txids](const auto& input) { 1742 return unconfirmed_parent_txids.count(input.prevout.hash) > 0 || m_view.HaveCoin(input.prevout); 1743 }; 1744 if (!std::all_of(child->vin.cbegin(), child->vin.cend(), package_or_confirmed)) { 1745 package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-unconfirmed-parents"); 1746 return PackageMempoolAcceptResult(package_state_quit_early, {}); 1747 } 1748 // Protect against bugs where we pull more inputs from disk that miss being added to 1749 // coins_to_uncache. The backend will be connected again when needed in PreChecks. 1750 m_view.SetBackend(m_dummy); 1751 } 1752 1753 LOCK(m_pool.cs); 1754 // Stores results from which we will create the returned PackageMempoolAcceptResult. 1755 // A result may be changed if a mempool transaction is evicted later due to LimitMempoolSize(). 1756 std::map<Wtxid, MempoolAcceptResult> results_final; 1757 // Results from individual validation which will be returned if no other result is available for 1758 // this transaction. "Nonfinal" because if a transaction fails by itself but succeeds later 1759 // (i.e. when evaluated with a fee-bumping child), the result in this map may be discarded. 1760 std::map<Wtxid, MempoolAcceptResult> individual_results_nonfinal; 1761 // Tracks whether we think package submission could result in successful entry to the mempool 1762 bool quit_early{false}; 1763 std::vector<CTransactionRef> txns_package_eval; 1764 for (const auto& tx : package) { 1765 const auto& wtxid = tx->GetWitnessHash(); 1766 const auto& txid = tx->GetHash(); 1767 // There are 3 possibilities: already in mempool, same-txid-diff-wtxid already in mempool, 1768 // or not in mempool. An already confirmed tx is treated as one not in mempool, because all 1769 // we know is that the inputs aren't available. 1770 if (m_pool.exists(GenTxid::Wtxid(wtxid))) { 1771 // Exact transaction already exists in the mempool. 1772 // Node operators are free to set their mempool policies however they please, nodes may receive 1773 // transactions in different orders, and malicious counterparties may try to take advantage of 1774 // policy differences to pin or delay propagation of transactions. As such, it's possible for 1775 // some package transaction(s) to already be in the mempool, and we don't want to reject the 1776 // entire package in that case (as that could be a censorship vector). De-duplicate the 1777 // transactions that are already in the mempool, and only call AcceptMultipleTransactions() with 1778 // the new transactions. This ensures we don't double-count transaction counts and sizes when 1779 // checking ancestor/descendant limits, or double-count transaction fees for fee-related policy. 1780 const auto& entry{*Assert(m_pool.GetEntry(txid))}; 1781 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTx(entry.GetTxSize(), entry.GetFee())); 1782 } else if (m_pool.exists(GenTxid::Txid(txid))) { 1783 // Transaction with the same non-witness data but different witness (same txid, 1784 // different wtxid) already exists in the mempool. 1785 // 1786 // We don't allow replacement transactions right now, so just swap the package 1787 // transaction for the mempool one. Note that we are ignoring the validity of the 1788 // package transaction passed in. 1789 // TODO: allow witness replacement in packages. 1790 const auto& entry{*Assert(m_pool.GetEntry(txid))}; 1791 // Provide the wtxid of the mempool tx so that the caller can look it up in the mempool. 1792 results_final.emplace(wtxid, MempoolAcceptResult::MempoolTxDifferentWitness(entry.GetTx().GetWitnessHash())); 1793 } else { 1794 // Transaction does not already exist in the mempool. 1795 // Try submitting the transaction on its own. 1796 const auto single_package_res = AcceptSubPackage({tx}, args); 1797 const auto& single_res = single_package_res.m_tx_results.at(wtxid); 1798 if (single_res.m_result_type == MempoolAcceptResult::ResultType::VALID) { 1799 // The transaction succeeded on its own and is now in the mempool. Don't include it 1800 // in package validation, because its fees should only be "used" once. 1801 assert(m_pool.exists(GenTxid::Wtxid(wtxid))); 1802 results_final.emplace(wtxid, single_res); 1803 } else if (package.size() == 1 || // If there is only one transaction, no need to retry it "as a package" 1804 (single_res.m_state.GetResult() != TxValidationResult::TX_RECONSIDERABLE && 1805 single_res.m_state.GetResult() != TxValidationResult::TX_MISSING_INPUTS)) { 1806 // Package validation policy only differs from individual policy in its evaluation 1807 // of feerate. For example, if a transaction fails here due to violation of a 1808 // consensus rule, the result will not change when it is submitted as part of a 1809 // package. To minimize the amount of repeated work, unless the transaction fails 1810 // due to feerate or missing inputs (its parent is a previous transaction in the 1811 // package that failed due to feerate), don't run package validation. Note that this 1812 // decision might not make sense if different types of packages are allowed in the 1813 // future. Continue individually validating the rest of the transactions, because 1814 // some of them may still be valid. 1815 quit_early = true; 1816 package_state_quit_early.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1817 individual_results_nonfinal.emplace(wtxid, single_res); 1818 } else { 1819 individual_results_nonfinal.emplace(wtxid, single_res); 1820 txns_package_eval.push_back(tx); 1821 } 1822 } 1823 } 1824 1825 auto multi_submission_result = quit_early || txns_package_eval.empty() ? PackageMempoolAcceptResult(package_state_quit_early, {}) : 1826 AcceptSubPackage(txns_package_eval, args); 1827 PackageValidationState& package_state_final = multi_submission_result.m_state; 1828 1829 // This is invoked by AcceptSubPackage() already, so this is just here for 1830 // clarity (since it's not permitted to invoke LimitMempoolSize() while a 1831 // changeset is outstanding). 1832 ClearSubPackageState(); 1833 1834 // Make sure we haven't exceeded max mempool size. 1835 // Package transactions that were submitted to mempool or already in mempool may be evicted. 1836 LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip()); 1837 1838 for (const auto& tx : package) { 1839 const auto& wtxid = tx->GetWitnessHash(); 1840 if (multi_submission_result.m_tx_results.count(wtxid) > 0) { 1841 // We shouldn't have re-submitted if the tx result was already in results_final. 1842 Assume(results_final.count(wtxid) == 0); 1843 // If it was submitted, check to see if the tx is still in the mempool. It could have 1844 // been evicted due to LimitMempoolSize() above. 1845 const auto& txresult = multi_submission_result.m_tx_results.at(wtxid); 1846 if (txresult.m_result_type == MempoolAcceptResult::ResultType::VALID && !m_pool.exists(GenTxid::Wtxid(wtxid))) { 1847 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1848 TxValidationState mempool_full_state; 1849 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full"); 1850 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state)); 1851 } else { 1852 results_final.emplace(wtxid, txresult); 1853 } 1854 } else if (const auto it{results_final.find(wtxid)}; it != results_final.end()) { 1855 // Already-in-mempool transaction. Check to see if it's still there, as it could have 1856 // been evicted when LimitMempoolSize() was called. 1857 Assume(it->second.m_result_type != MempoolAcceptResult::ResultType::INVALID); 1858 Assume(individual_results_nonfinal.count(wtxid) == 0); 1859 // Query by txid to include the same-txid-different-witness ones. 1860 if (!m_pool.exists(GenTxid::Txid(tx->GetHash()))) { 1861 package_state_final.Invalid(PackageValidationResult::PCKG_TX, "transaction failed"); 1862 TxValidationState mempool_full_state; 1863 mempool_full_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full"); 1864 // Replace the previous result. 1865 results_final.erase(wtxid); 1866 results_final.emplace(wtxid, MempoolAcceptResult::Failure(mempool_full_state)); 1867 } 1868 } else if (const auto it{individual_results_nonfinal.find(wtxid)}; it != individual_results_nonfinal.end()) { 1869 Assume(it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID); 1870 // Interesting result from previous processing. 1871 results_final.emplace(wtxid, it->second); 1872 } 1873 } 1874 Assume(results_final.size() == package.size()); 1875 return PackageMempoolAcceptResult(package_state_final, std::move(results_final)); 1876 } 1877 1878 } // anon namespace 1879 1880 MempoolAcceptResult AcceptToMemoryPool(Chainstate& active_chainstate, const CTransactionRef& tx, 1881 int64_t accept_time, bool bypass_limits, bool test_accept) 1882 { 1883 AssertLockHeld(::cs_main); 1884 const CChainParams& chainparams{active_chainstate.m_chainman.GetParams()}; 1885 assert(active_chainstate.GetMempool() != nullptr); 1886 CTxMemPool& pool{*active_chainstate.GetMempool()}; 1887 1888 std::vector<COutPoint> coins_to_uncache; 1889 auto args = MemPoolAccept::ATMPArgs::SingleAccept(chainparams, accept_time, bypass_limits, coins_to_uncache, test_accept); 1890 MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate).AcceptSingleTransaction(tx, args); 1891 if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) { 1892 // Remove coins that were not present in the coins cache before calling 1893 // AcceptSingleTransaction(); this is to prevent memory DoS in case we receive a large 1894 // number of invalid transactions that attempt to overrun the in-memory coins cache 1895 // (`CCoinsViewCache::cacheCoins`). 1896 1897 for (const COutPoint& hashTx : coins_to_uncache) 1898 active_chainstate.CoinsTip().Uncache(hashTx); 1899 TRACEPOINT(mempool, rejected, 1900 tx->GetHash().data(), 1901 result.m_state.GetRejectReason().c_str() 1902 ); 1903 } 1904 // After we've (potentially) uncached entries, ensure our coins cache is still within its size limits 1905 BlockValidationState state_dummy; 1906 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC); 1907 return result; 1908 } 1909 1910 PackageMempoolAcceptResult ProcessNewPackage(Chainstate& active_chainstate, CTxMemPool& pool, 1911 const Package& package, bool test_accept, const std::optional<CFeeRate>& client_maxfeerate) 1912 { 1913 AssertLockHeld(cs_main); 1914 assert(!package.empty()); 1915 assert(std::all_of(package.cbegin(), package.cend(), [](const auto& tx){return tx != nullptr;})); 1916 1917 std::vector<COutPoint> coins_to_uncache; 1918 const CChainParams& chainparams = active_chainstate.m_chainman.GetParams(); 1919 auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) { 1920 AssertLockHeld(cs_main); 1921 if (test_accept) { 1922 auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(chainparams, GetTime(), coins_to_uncache); 1923 return MemPoolAccept(pool, active_chainstate).AcceptMultipleTransactions(package, args); 1924 } else { 1925 auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(chainparams, GetTime(), coins_to_uncache, client_maxfeerate); 1926 return MemPoolAccept(pool, active_chainstate).AcceptPackage(package, args); 1927 } 1928 }(); 1929 1930 // Uncache coins pertaining to transactions that were not submitted to the mempool. 1931 if (test_accept || result.m_state.IsInvalid()) { 1932 for (const COutPoint& hashTx : coins_to_uncache) { 1933 active_chainstate.CoinsTip().Uncache(hashTx); 1934 } 1935 } 1936 // Ensure the coins cache is still within limits. 1937 BlockValidationState state_dummy; 1938 active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC); 1939 return result; 1940 } 1941 1942 CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams) 1943 { 1944 int halvings = nHeight / consensusParams.nSubsidyHalvingInterval; 1945 // Force block reward to zero when right shift is undefined. 1946 if (halvings >= 64) 1947 return 0; 1948 1949 CAmount nSubsidy = 50 * COIN; 1950 // Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years. 1951 nSubsidy >>= halvings; 1952 return nSubsidy; 1953 } 1954 1955 CoinsViews::CoinsViews(DBParams db_params, CoinsViewOptions options) 1956 : m_dbview{std::move(db_params), std::move(options)}, 1957 m_catcherview(&m_dbview) {} 1958 1959 void CoinsViews::InitCache() 1960 { 1961 AssertLockHeld(::cs_main); 1962 m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview); 1963 } 1964 1965 Chainstate::Chainstate( 1966 CTxMemPool* mempool, 1967 BlockManager& blockman, 1968 ChainstateManager& chainman, 1969 std::optional<uint256> from_snapshot_blockhash) 1970 : m_mempool(mempool), 1971 m_blockman(blockman), 1972 m_chainman(chainman), 1973 m_from_snapshot_blockhash(from_snapshot_blockhash) {} 1974 1975 const CBlockIndex* Chainstate::SnapshotBase() 1976 { 1977 if (!m_from_snapshot_blockhash) return nullptr; 1978 if (!m_cached_snapshot_base) m_cached_snapshot_base = Assert(m_chainman.m_blockman.LookupBlockIndex(*m_from_snapshot_blockhash)); 1979 return m_cached_snapshot_base; 1980 } 1981 1982 void Chainstate::InitCoinsDB( 1983 size_t cache_size_bytes, 1984 bool in_memory, 1985 bool should_wipe, 1986 fs::path leveldb_name) 1987 { 1988 if (m_from_snapshot_blockhash) { 1989 leveldb_name += node::SNAPSHOT_CHAINSTATE_SUFFIX; 1990 } 1991 1992 m_coins_views = std::make_unique<CoinsViews>( 1993 DBParams{ 1994 .path = m_chainman.m_options.datadir / leveldb_name, 1995 .cache_bytes = cache_size_bytes, 1996 .memory_only = in_memory, 1997 .wipe_data = should_wipe, 1998 .obfuscate = true, 1999 .options = m_chainman.m_options.coins_db}, 2000 m_chainman.m_options.coins_view); 2001 2002 m_coinsdb_cache_size_bytes = cache_size_bytes; 2003 } 2004 2005 void Chainstate::InitCoinsCache(size_t cache_size_bytes) 2006 { 2007 AssertLockHeld(::cs_main); 2008 assert(m_coins_views != nullptr); 2009 m_coinstip_cache_size_bytes = cache_size_bytes; 2010 m_coins_views->InitCache(); 2011 } 2012 2013 // Note that though this is marked const, we may end up modifying `m_cached_finished_ibd`, which 2014 // is a performance-related implementation detail. This function must be marked 2015 // `const` so that `CValidationInterface` clients (which are given a `const Chainstate*`) 2016 // can call it. 2017 // 2018 bool ChainstateManager::IsInitialBlockDownload() const 2019 { 2020 // Optimization: pre-test latch before taking the lock. 2021 if (m_cached_finished_ibd.load(std::memory_order_relaxed)) 2022 return false; 2023 2024 LOCK(cs_main); 2025 if (m_cached_finished_ibd.load(std::memory_order_relaxed)) 2026 return false; 2027 if (m_blockman.LoadingBlocks()) { 2028 return true; 2029 } 2030 CChain& chain{ActiveChain()}; 2031 if (chain.Tip() == nullptr) { 2032 return true; 2033 } 2034 if (chain.Tip()->nChainWork < MinimumChainWork()) { 2035 return true; 2036 } 2037 if (chain.Tip()->Time() < Now<NodeSeconds>() - m_options.max_tip_age) { 2038 return true; 2039 } 2040 LogPrintf("Leaving InitialBlockDownload (latching to false)\n"); 2041 m_cached_finished_ibd.store(true, std::memory_order_relaxed); 2042 return false; 2043 } 2044 2045 void Chainstate::CheckForkWarningConditions() 2046 { 2047 AssertLockHeld(cs_main); 2048 2049 // Before we get past initial download, we cannot reliably alert about forks 2050 // (we assume we don't get stuck on a fork before finishing our initial sync) 2051 // Also not applicable to the background chainstate 2052 if (m_chainman.IsInitialBlockDownload() || this->GetRole() == ChainstateRole::BACKGROUND) { 2053 return; 2054 } 2055 2056 if (m_chainman.m_best_invalid && m_chainman.m_best_invalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) { 2057 LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n", __func__); 2058 m_chainman.GetNotifications().warningSet( 2059 kernel::Warning::LARGE_WORK_INVALID_CHAIN, 2060 _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.")); 2061 } else { 2062 m_chainman.GetNotifications().warningUnset(kernel::Warning::LARGE_WORK_INVALID_CHAIN); 2063 } 2064 } 2065 2066 // Called both upon regular invalid block discovery *and* InvalidateBlock 2067 void Chainstate::InvalidChainFound(CBlockIndex* pindexNew) 2068 { 2069 AssertLockHeld(cs_main); 2070 if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) { 2071 m_chainman.m_best_invalid = pindexNew; 2072 } 2073 SetBlockFailureFlags(pindexNew); 2074 if (m_chainman.m_best_header != nullptr && m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) == pindexNew) { 2075 m_chainman.RecalculateBestHeader(); 2076 } 2077 2078 LogPrintf("%s: invalid block=%s height=%d log2_work=%f date=%s\n", __func__, 2079 pindexNew->GetBlockHash().ToString(), pindexNew->nHeight, 2080 log(pindexNew->nChainWork.getdouble())/log(2.0), FormatISO8601DateTime(pindexNew->GetBlockTime())); 2081 CBlockIndex *tip = m_chain.Tip(); 2082 assert (tip); 2083 LogPrintf("%s: current best=%s height=%d log2_work=%f date=%s\n", __func__, 2084 tip->GetBlockHash().ToString(), m_chain.Height(), log(tip->nChainWork.getdouble())/log(2.0), 2085 FormatISO8601DateTime(tip->GetBlockTime())); 2086 CheckForkWarningConditions(); 2087 } 2088 2089 // Same as InvalidChainFound, above, except not called directly from InvalidateBlock, 2090 // which does its own setBlockIndexCandidates management. 2091 void Chainstate::InvalidBlockFound(CBlockIndex* pindex, const BlockValidationState& state) 2092 { 2093 AssertLockHeld(cs_main); 2094 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 2095 pindex->nStatus |= BLOCK_FAILED_VALID; 2096 m_chainman.m_failed_blocks.insert(pindex); 2097 m_blockman.m_dirty_blockindex.insert(pindex); 2098 setBlockIndexCandidates.erase(pindex); 2099 InvalidChainFound(pindex); 2100 } 2101 } 2102 2103 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, CTxUndo &txundo, int nHeight) 2104 { 2105 // mark inputs spent 2106 if (!tx.IsCoinBase()) { 2107 txundo.vprevout.reserve(tx.vin.size()); 2108 for (const CTxIn &txin : tx.vin) { 2109 txundo.vprevout.emplace_back(); 2110 bool is_spent = inputs.SpendCoin(txin.prevout, &txundo.vprevout.back()); 2111 assert(is_spent); 2112 } 2113 } 2114 // add outputs 2115 AddCoins(inputs, tx, nHeight); 2116 } 2117 2118 std::optional<std::pair<ScriptError, std::string>> CScriptCheck::operator()() { 2119 const CScript &scriptSig = ptxTo->vin[nIn].scriptSig; 2120 const CScriptWitness *witness = &ptxTo->vin[nIn].scriptWitness; 2121 ScriptError error{SCRIPT_ERR_UNKNOWN_ERROR}; 2122 if (VerifyScript(scriptSig, m_tx_out.scriptPubKey, witness, nFlags, CachingTransactionSignatureChecker(ptxTo, nIn, m_tx_out.nValue, cacheStore, *m_signature_cache, *txdata), &error)) { 2123 return std::nullopt; 2124 } else { 2125 auto debug_str = strprintf("input %i of %s (wtxid %s), spending %s:%i", nIn, ptxTo->GetHash().ToString(), ptxTo->GetWitnessHash().ToString(), ptxTo->vin[nIn].prevout.hash.ToString(), ptxTo->vin[nIn].prevout.n); 2126 return std::make_pair(error, std::move(debug_str)); 2127 } 2128 } 2129 2130 ValidationCache::ValidationCache(const size_t script_execution_cache_bytes, const size_t signature_cache_bytes) 2131 : m_signature_cache{signature_cache_bytes} 2132 { 2133 // Setup the salted hasher 2134 uint256 nonce = GetRandHash(); 2135 // We want the nonce to be 64 bytes long to force the hasher to process 2136 // this chunk, which makes later hash computations more efficient. We 2137 // just write our 32-byte entropy twice to fill the 64 bytes. 2138 m_script_execution_cache_hasher.Write(nonce.begin(), 32); 2139 m_script_execution_cache_hasher.Write(nonce.begin(), 32); 2140 2141 const auto [num_elems, approx_size_bytes] = m_script_execution_cache.setup_bytes(script_execution_cache_bytes); 2142 LogPrintf("Using %zu MiB out of %zu MiB requested for script execution cache, able to store %zu elements\n", 2143 approx_size_bytes >> 20, script_execution_cache_bytes >> 20, num_elems); 2144 } 2145 2146 /** 2147 * Check whether all of this transaction's input scripts succeed. 2148 * 2149 * This involves ECDSA signature checks so can be computationally intensive. This function should 2150 * only be called after the cheap sanity checks in CheckTxInputs passed. 2151 * 2152 * If pvChecks is not nullptr, script checks are pushed onto it instead of being performed inline. Any 2153 * script checks which are not necessary (eg due to script execution cache hits) are, obviously, 2154 * not pushed onto pvChecks/run. 2155 * 2156 * Setting cacheSigStore/cacheFullScriptStore to false will remove elements from the corresponding cache 2157 * which are matched. This is useful for checking blocks where we will likely never need the cache 2158 * entry again. 2159 * 2160 * Note that we may set state.reason to NOT_STANDARD for extra soft-fork flags in flags, block-checking 2161 * callers should probably reset it to CONSENSUS in such cases. 2162 * 2163 * Non-static (and redeclared) in src/test/txvalidationcache_tests.cpp 2164 */ 2165 bool CheckInputScripts(const CTransaction& tx, TxValidationState& state, 2166 const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore, 2167 bool cacheFullScriptStore, PrecomputedTransactionData& txdata, 2168 ValidationCache& validation_cache, 2169 std::vector<CScriptCheck>* pvChecks) 2170 { 2171 if (tx.IsCoinBase()) return true; 2172 2173 if (pvChecks) { 2174 pvChecks->reserve(tx.vin.size()); 2175 } 2176 2177 // First check if script executions have been cached with the same 2178 // flags. Note that this assumes that the inputs provided are 2179 // correct (ie that the transaction hash which is in tx's prevouts 2180 // properly commits to the scriptPubKey in the inputs view of that 2181 // transaction). 2182 uint256 hashCacheEntry; 2183 CSHA256 hasher = validation_cache.ScriptExecutionCacheHasher(); 2184 hasher.Write(UCharCast(tx.GetWitnessHash().begin()), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin()); 2185 AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks 2186 if (validation_cache.m_script_execution_cache.contains(hashCacheEntry, !cacheFullScriptStore)) { 2187 return true; 2188 } 2189 2190 if (!txdata.m_spent_outputs_ready) { 2191 std::vector<CTxOut> spent_outputs; 2192 spent_outputs.reserve(tx.vin.size()); 2193 2194 for (const auto& txin : tx.vin) { 2195 const COutPoint& prevout = txin.prevout; 2196 const Coin& coin = inputs.AccessCoin(prevout); 2197 assert(!coin.IsSpent()); 2198 spent_outputs.emplace_back(coin.out); 2199 } 2200 txdata.Init(tx, std::move(spent_outputs)); 2201 } 2202 assert(txdata.m_spent_outputs.size() == tx.vin.size()); 2203 2204 for (unsigned int i = 0; i < tx.vin.size(); i++) { 2205 2206 // We very carefully only pass in things to CScriptCheck which 2207 // are clearly committed to by tx' witness hash. This provides 2208 // a sanity check that our caching is not introducing consensus 2209 // failures through additional data in, eg, the coins being 2210 // spent being checked as a part of CScriptCheck. 2211 2212 // Verify signature 2213 CScriptCheck check(txdata.m_spent_outputs[i], tx, validation_cache.m_signature_cache, i, flags, cacheSigStore, &txdata); 2214 if (pvChecks) { 2215 pvChecks->emplace_back(std::move(check)); 2216 } else if (auto result = check(); result.has_value()) { 2217 if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) { 2218 // Check whether the failure was caused by a 2219 // non-mandatory script verification check, such as 2220 // non-standard DER encodings or non-null dummy 2221 // arguments; if so, ensure we return NOT_STANDARD 2222 // instead of CONSENSUS to avoid downstream users 2223 // splitting the network between upgraded and 2224 // non-upgraded nodes by banning CONSENSUS-failing 2225 // data providers. 2226 CScriptCheck check2(txdata.m_spent_outputs[i], tx, validation_cache.m_signature_cache, i, 2227 flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheSigStore, &txdata); 2228 auto mandatory_result = check2(); 2229 if (!mandatory_result.has_value()) { 2230 return state.Invalid(TxValidationResult::TX_NOT_STANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(result->first)), result->second); 2231 } else { 2232 // If the second check failed, it failed due to a mandatory script verification 2233 // flag, but the first check might have failed on a non-mandatory script 2234 // verification flag. 2235 // 2236 // Avoid reporting a mandatory script check failure with a non-mandatory error 2237 // string by reporting the error from the second check. 2238 result = mandatory_result; 2239 } 2240 } 2241 2242 // MANDATORY flag failures correspond to 2243 // TxValidationResult::TX_CONSENSUS. 2244 return state.Invalid(TxValidationResult::TX_CONSENSUS, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(result->first)), result->second); 2245 } 2246 } 2247 2248 if (cacheFullScriptStore && !pvChecks) { 2249 // We executed all of the provided scripts, and were told to 2250 // cache the result. Do so now. 2251 validation_cache.m_script_execution_cache.insert(hashCacheEntry); 2252 } 2253 2254 return true; 2255 } 2256 2257 bool FatalError(Notifications& notifications, BlockValidationState& state, const bilingual_str& message) 2258 { 2259 notifications.fatalError(message); 2260 return state.Error(message.original); 2261 } 2262 2263 /** 2264 * Restore the UTXO in a Coin at a given COutPoint 2265 * @param undo The Coin to be restored. 2266 * @param view The coins view to which to apply the changes. 2267 * @param out The out point that corresponds to the tx input. 2268 * @return A DisconnectResult as an int 2269 */ 2270 int ApplyTxInUndo(Coin&& undo, CCoinsViewCache& view, const COutPoint& out) 2271 { 2272 bool fClean = true; 2273 2274 if (view.HaveCoin(out)) fClean = false; // overwriting transaction output 2275 2276 if (undo.nHeight == 0) { 2277 // Missing undo metadata (height and coinbase). Older versions included this 2278 // information only in undo records for the last spend of a transactions' 2279 // outputs. This implies that it must be present for some other output of the same tx. 2280 const Coin& alternate = AccessByTxid(view, out.hash); 2281 if (!alternate.IsSpent()) { 2282 undo.nHeight = alternate.nHeight; 2283 undo.fCoinBase = alternate.fCoinBase; 2284 } else { 2285 return DISCONNECT_FAILED; // adding output for transaction without known metadata 2286 } 2287 } 2288 // If the coin already exists as an unspent coin in the cache, then the 2289 // possible_overwrite parameter to AddCoin must be set to true. We have 2290 // already checked whether an unspent coin exists above using HaveCoin, so 2291 // we don't need to guess. When fClean is false, an unspent coin already 2292 // existed and it is an overwrite. 2293 view.AddCoin(out, std::move(undo), !fClean); 2294 2295 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN; 2296 } 2297 2298 /** Undo the effects of this block (with given index) on the UTXO set represented by coins. 2299 * When FAILED is returned, view is left in an indeterminate state. */ 2300 DisconnectResult Chainstate::DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view) 2301 { 2302 AssertLockHeld(::cs_main); 2303 bool fClean = true; 2304 2305 CBlockUndo blockUndo; 2306 if (!m_blockman.ReadBlockUndo(blockUndo, *pindex)) { 2307 LogError("DisconnectBlock(): failure reading undo data\n"); 2308 return DISCONNECT_FAILED; 2309 } 2310 2311 if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) { 2312 LogError("DisconnectBlock(): block and undo data inconsistent\n"); 2313 return DISCONNECT_FAILED; 2314 } 2315 2316 // Ignore blocks that contain transactions which are 'overwritten' by later transactions, 2317 // unless those are already completely spent. 2318 // See https://github.com/bitcoin/bitcoin/issues/22596 for additional information. 2319 // Note: the blocks specified here are different than the ones used in ConnectBlock because DisconnectBlock 2320 // unwinds the blocks in reverse. As a result, the inconsistency is not discovered until the earlier 2321 // blocks with the duplicate coinbase transactions are disconnected. 2322 bool fEnforceBIP30 = !((pindex->nHeight==91722 && pindex->GetBlockHash() == uint256{"00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e"}) || 2323 (pindex->nHeight==91812 && pindex->GetBlockHash() == uint256{"00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"})); 2324 2325 // undo transactions in reverse order 2326 for (int i = block.vtx.size() - 1; i >= 0; i--) { 2327 const CTransaction &tx = *(block.vtx[i]); 2328 Txid hash = tx.GetHash(); 2329 bool is_coinbase = tx.IsCoinBase(); 2330 bool is_bip30_exception = (is_coinbase && !fEnforceBIP30); 2331 2332 // Check that all outputs are available and match the outputs in the block itself 2333 // exactly. 2334 for (size_t o = 0; o < tx.vout.size(); o++) { 2335 if (!tx.vout[o].scriptPubKey.IsUnspendable()) { 2336 COutPoint out(hash, o); 2337 Coin coin; 2338 bool is_spent = view.SpendCoin(out, &coin); 2339 if (!is_spent || tx.vout[o] != coin.out || pindex->nHeight != coin.nHeight || is_coinbase != coin.fCoinBase) { 2340 if (!is_bip30_exception) { 2341 fClean = false; // transaction output mismatch 2342 } 2343 } 2344 } 2345 } 2346 2347 // restore inputs 2348 if (i > 0) { // not coinbases 2349 CTxUndo &txundo = blockUndo.vtxundo[i-1]; 2350 if (txundo.vprevout.size() != tx.vin.size()) { 2351 LogError("DisconnectBlock(): transaction and undo data inconsistent\n"); 2352 return DISCONNECT_FAILED; 2353 } 2354 for (unsigned int j = tx.vin.size(); j > 0;) { 2355 --j; 2356 const COutPoint& out = tx.vin[j].prevout; 2357 int res = ApplyTxInUndo(std::move(txundo.vprevout[j]), view, out); 2358 if (res == DISCONNECT_FAILED) return DISCONNECT_FAILED; 2359 fClean = fClean && res != DISCONNECT_UNCLEAN; 2360 } 2361 // At this point, all of txundo.vprevout should have been moved out. 2362 } 2363 } 2364 2365 // move best block pointer to prevout block 2366 view.SetBestBlock(pindex->pprev->GetBlockHash()); 2367 2368 return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN; 2369 } 2370 2371 static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman) 2372 { 2373 const Consensus::Params& consensusparams = chainman.GetConsensus(); 2374 2375 // BIP16 didn't become active until Apr 1 2012 (on mainnet, and 2376 // retroactively applied to testnet) 2377 // However, only one historical block violated the P2SH rules (on both 2378 // mainnet and testnet). 2379 // Similarly, only one historical block violated the TAPROOT rules on 2380 // mainnet. 2381 // For simplicity, always leave P2SH+WITNESS+TAPROOT on except for the two 2382 // violating blocks. 2383 uint32_t flags{SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_TAPROOT}; 2384 const auto it{consensusparams.script_flag_exceptions.find(*Assert(block_index.phashBlock))}; 2385 if (it != consensusparams.script_flag_exceptions.end()) { 2386 flags = it->second; 2387 } 2388 2389 // Enforce the DERSIG (BIP66) rule 2390 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_DERSIG)) { 2391 flags |= SCRIPT_VERIFY_DERSIG; 2392 } 2393 2394 // Enforce CHECKLOCKTIMEVERIFY (BIP65) 2395 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CLTV)) { 2396 flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY; 2397 } 2398 2399 // Enforce CHECKSEQUENCEVERIFY (BIP112) 2400 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CSV)) { 2401 flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY; 2402 } 2403 2404 // Enforce BIP147 NULLDUMMY (activated simultaneously with segwit) 2405 if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_SEGWIT)) { 2406 flags |= SCRIPT_VERIFY_NULLDUMMY; 2407 } 2408 2409 return flags; 2410 } 2411 2412 2413 /** Apply the effects of this block (with given index) on the UTXO set represented by coins. 2414 * Validity checks that depend on the UTXO set are also done; ConnectBlock() 2415 * can fail if those validity checks fail (among other reasons). */ 2416 bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex, 2417 CCoinsViewCache& view, bool fJustCheck) 2418 { 2419 AssertLockHeld(cs_main); 2420 assert(pindex); 2421 2422 uint256 block_hash{block.GetHash()}; 2423 assert(*pindex->phashBlock == block_hash); 2424 const bool parallel_script_checks{m_chainman.GetCheckQueue().HasThreads()}; 2425 2426 const auto time_start{SteadyClock::now()}; 2427 const CChainParams& params{m_chainman.GetParams()}; 2428 2429 // Check it again in case a previous version let a bad block in 2430 // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or 2431 // ContextualCheckBlockHeader() here. This means that if we add a new 2432 // consensus rule that is enforced in one of those two functions, then we 2433 // may have let in a block that violates the rule prior to updating the 2434 // software, and we would NOT be enforcing the rule here. Fully solving 2435 // upgrade from one software version to the next after a consensus rule 2436 // change is potentially tricky and issue-specific (see NeedsRedownload() 2437 // for one approach that was used for BIP 141 deployment). 2438 // Also, currently the rule against blocks more than 2 hours in the future 2439 // is enforced in ContextualCheckBlockHeader(); we wouldn't want to 2440 // re-enforce that rule here (at least until we make it impossible for 2441 // the clock to go backward). 2442 if (!CheckBlock(block, state, params.GetConsensus(), !fJustCheck, !fJustCheck)) { 2443 if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) { 2444 // We don't write down blocks to disk if they may have been 2445 // corrupted, so this should be impossible unless we're having hardware 2446 // problems. 2447 return FatalError(m_chainman.GetNotifications(), state, _("Corrupt block found indicating potential hardware failure.")); 2448 } 2449 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString()); 2450 return false; 2451 } 2452 2453 // verify that the view's current state corresponds to the previous block 2454 uint256 hashPrevBlock = pindex->pprev == nullptr ? uint256() : pindex->pprev->GetBlockHash(); 2455 assert(hashPrevBlock == view.GetBestBlock()); 2456 2457 m_chainman.num_blocks_total++; 2458 2459 // Special case for the genesis block, skipping connection of its transactions 2460 // (its coinbase is unspendable) 2461 if (block_hash == params.GetConsensus().hashGenesisBlock) { 2462 if (!fJustCheck) 2463 view.SetBestBlock(pindex->GetBlockHash()); 2464 return true; 2465 } 2466 2467 bool fScriptChecks = true; 2468 if (!m_chainman.AssumedValidBlock().IsNull()) { 2469 // We've been configured with the hash of a block which has been externally verified to have a valid history. 2470 // A suitable default value is included with the software and updated from time to time. Because validity 2471 // relative to a piece of software is an objective fact these defaults can be easily reviewed. 2472 // This setting doesn't force the selection of any particular chain but makes validating some faster by 2473 // effectively caching the result of part of the verification. 2474 BlockMap::const_iterator it{m_blockman.m_block_index.find(m_chainman.AssumedValidBlock())}; 2475 if (it != m_blockman.m_block_index.end()) { 2476 if (it->second.GetAncestor(pindex->nHeight) == pindex && 2477 m_chainman.m_best_header->GetAncestor(pindex->nHeight) == pindex && 2478 m_chainman.m_best_header->nChainWork >= m_chainman.MinimumChainWork()) { 2479 // This block is a member of the assumed verified chain and an ancestor of the best header. 2480 // Script verification is skipped when connecting blocks under the 2481 // assumevalid block. Assuming the assumevalid block is valid this 2482 // is safe because block merkle hashes are still computed and checked, 2483 // Of course, if an assumed valid block is invalid due to false scriptSigs 2484 // this optimization would allow an invalid chain to be accepted. 2485 // The equivalent time check discourages hash power from extorting the network via DOS attack 2486 // into accepting an invalid block through telling users they must manually set assumevalid. 2487 // Requiring a software change or burying the invalid block, regardless of the setting, makes 2488 // it hard to hide the implication of the demand. This also avoids having release candidates 2489 // that are hardly doing any signature verification at all in testing without having to 2490 // artificially set the default assumed verified block further back. 2491 // The test against the minimum chain work prevents the skipping when denied access to any chain at 2492 // least as good as the expected chain. 2493 fScriptChecks = (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, params.GetConsensus()) <= 60 * 60 * 24 * 7 * 2); 2494 } 2495 } 2496 } 2497 2498 const auto time_1{SteadyClock::now()}; 2499 m_chainman.time_check += time_1 - time_start; 2500 LogDebug(BCLog::BENCH, " - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n", 2501 Ticks<MillisecondsDouble>(time_1 - time_start), 2502 Ticks<SecondsDouble>(m_chainman.time_check), 2503 Ticks<MillisecondsDouble>(m_chainman.time_check) / m_chainman.num_blocks_total); 2504 2505 // Do not allow blocks that contain transactions which 'overwrite' older transactions, 2506 // unless those are already completely spent. 2507 // If such overwrites are allowed, coinbases and transactions depending upon those 2508 // can be duplicated to remove the ability to spend the first instance -- even after 2509 // being sent to another address. 2510 // See BIP30, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html for more information. 2511 // This rule was originally applied to all blocks with a timestamp after March 15, 2012, 0:00 UTC. 2512 // Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the 2513 // two in the chain that violate it. This prevents exploiting the issue against nodes during their 2514 // initial block download. 2515 bool fEnforceBIP30 = !IsBIP30Repeat(*pindex); 2516 2517 // Once BIP34 activated it was not possible to create new duplicate coinbases and thus other than starting 2518 // with the 2 existing duplicate coinbase pairs, not possible to create overwriting txs. But by the 2519 // time BIP34 activated, in each of the existing pairs the duplicate coinbase had overwritten the first 2520 // before the first had been spent. Since those coinbases are sufficiently buried it's no longer possible to create further 2521 // duplicate transactions descending from the known pairs either. 2522 // 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. 2523 2524 // BIP34 requires that a block at height X (block X) has its coinbase 2525 // scriptSig start with a CScriptNum of X (indicated height X). The above 2526 // logic of no longer requiring BIP30 once BIP34 activates is flawed in the 2527 // case that there is a block X before the BIP34 height of 227,931 which has 2528 // an indicated height Y where Y is greater than X. The coinbase for block 2529 // X would also be a valid coinbase for block Y, which could be a BIP30 2530 // violation. An exhaustive search of all mainnet coinbases before the 2531 // BIP34 height which have an indicated height greater than the block height 2532 // reveals many occurrences. The 3 lowest indicated heights found are 2533 // 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3 2534 // heights would be the first opportunity for BIP30 to be violated. 2535 2536 // The search reveals a great many blocks which have an indicated height 2537 // greater than 1,983,702, so we simply remove the optimization to skip 2538 // BIP30 checking for blocks at height 1,983,702 or higher. Before we reach 2539 // that block in another 25 years or so, we should take advantage of a 2540 // future consensus change to do a new and improved version of BIP34 that 2541 // will actually prevent ever creating any duplicate coinbases in the 2542 // future. 2543 static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702; 2544 2545 // There is no potential to create a duplicate coinbase at block 209,921 2546 // because this is still before the BIP34 height and so explicit BIP30 2547 // checking is still active. 2548 2549 // The final case is block 176,684 which has an indicated height of 2550 // 490,897. Unfortunately, this issue was not discovered until about 2 weeks 2551 // before block 490,897 so there was not much opportunity to address this 2552 // case other than to carefully analyze it and determine it would not be a 2553 // problem. Block 490,897 was, in fact, mined with a different coinbase than 2554 // block 176,684, but it is important to note that even if it hadn't been or 2555 // is remined on an alternate fork with a duplicate coinbase, we would still 2556 // not run into a BIP30 violation. This is because the coinbase for 176,684 2557 // is spent in block 185,956 in transaction 2558 // d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781. This 2559 // spending transaction can't be duplicated because it also spends coinbase 2560 // 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29. This 2561 // coinbase has an indicated height of over 4.2 billion, and wouldn't be 2562 // duplicatable until that height, and it's currently impossible to create a 2563 // chain that long. Nevertheless we may wish to consider a future soft fork 2564 // which retroactively prevents block 490,897 from creating a duplicate 2565 // coinbase. The two historical BIP30 violations often provide a confusing 2566 // edge case when manipulating the UTXO and it would be simpler not to have 2567 // another edge case to deal with. 2568 2569 // testnet3 has no blocks before the BIP34 height with indicated heights 2570 // post BIP34 before approximately height 486,000,000. After block 2571 // 1,983,702 testnet3 starts doing unnecessary BIP30 checking again. 2572 assert(pindex->pprev); 2573 CBlockIndex* pindexBIP34height = pindex->pprev->GetAncestor(params.GetConsensus().BIP34Height); 2574 //Only continue to enforce if we're below BIP34 activation height or the block hash at that height doesn't correspond. 2575 fEnforceBIP30 = fEnforceBIP30 && (!pindexBIP34height || !(pindexBIP34height->GetBlockHash() == params.GetConsensus().BIP34Hash)); 2576 2577 // TODO: Remove BIP30 checking from block height 1,983,702 on, once we have a 2578 // consensus change that ensures coinbases at those heights cannot 2579 // duplicate earlier coinbases. 2580 if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) { 2581 for (const auto& tx : block.vtx) { 2582 for (size_t o = 0; o < tx->vout.size(); o++) { 2583 if (view.HaveCoin(COutPoint(tx->GetHash(), o))) { 2584 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-BIP30", 2585 "tried to overwrite transaction"); 2586 } 2587 } 2588 } 2589 } 2590 2591 // Enforce BIP68 (sequence locks) 2592 int nLockTimeFlags = 0; 2593 if (DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_CSV)) { 2594 nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE; 2595 } 2596 2597 // Get the script flags for this block 2598 unsigned int flags{GetBlockScriptFlags(*pindex, m_chainman)}; 2599 2600 const auto time_2{SteadyClock::now()}; 2601 m_chainman.time_forks += time_2 - time_1; 2602 LogDebug(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n", 2603 Ticks<MillisecondsDouble>(time_2 - time_1), 2604 Ticks<SecondsDouble>(m_chainman.time_forks), 2605 Ticks<MillisecondsDouble>(m_chainman.time_forks) / m_chainman.num_blocks_total); 2606 2607 CBlockUndo blockundo; 2608 2609 // Precomputed transaction data pointers must not be invalidated 2610 // until after `control` has run the script checks (potentially 2611 // in multiple threads). Preallocate the vector size so a new allocation 2612 // doesn't invalidate pointers into the vector, and keep txsdata in scope 2613 // for as long as `control`. 2614 CCheckQueueControl<CScriptCheck> control(fScriptChecks && parallel_script_checks ? &m_chainman.GetCheckQueue() : nullptr); 2615 std::vector<PrecomputedTransactionData> txsdata(block.vtx.size()); 2616 2617 std::vector<int> prevheights; 2618 CAmount nFees = 0; 2619 int nInputs = 0; 2620 int64_t nSigOpsCost = 0; 2621 blockundo.vtxundo.reserve(block.vtx.size() - 1); 2622 for (unsigned int i = 0; i < block.vtx.size(); i++) 2623 { 2624 if (!state.IsValid()) break; 2625 const CTransaction &tx = *(block.vtx[i]); 2626 2627 nInputs += tx.vin.size(); 2628 2629 if (!tx.IsCoinBase()) 2630 { 2631 CAmount txfee = 0; 2632 TxValidationState tx_state; 2633 if (!Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight, txfee)) { 2634 // Any transaction validation failure in ConnectBlock is a block consensus failure 2635 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, 2636 tx_state.GetRejectReason(), 2637 tx_state.GetDebugMessage() + " in transaction " + tx.GetHash().ToString()); 2638 break; 2639 } 2640 nFees += txfee; 2641 if (!MoneyRange(nFees)) { 2642 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-accumulated-fee-outofrange", 2643 "accumulated fee in the block out of range"); 2644 break; 2645 } 2646 2647 // Check that transaction is BIP68 final 2648 // BIP68 lock checks (as opposed to nLockTime checks) must 2649 // be in ConnectBlock because they require the UTXO set 2650 prevheights.resize(tx.vin.size()); 2651 for (size_t j = 0; j < tx.vin.size(); j++) { 2652 prevheights[j] = view.AccessCoin(tx.vin[j].prevout).nHeight; 2653 } 2654 2655 if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) { 2656 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", 2657 "contains a non-BIP68-final transaction " + tx.GetHash().ToString()); 2658 break; 2659 } 2660 } 2661 2662 // GetTransactionSigOpCost counts 3 types of sigops: 2663 // * legacy (always) 2664 // * p2sh (when P2SH enabled in flags and excludes coinbase) 2665 // * witness (when witness enabled in flags and excludes coinbase) 2666 nSigOpsCost += GetTransactionSigOpCost(tx, view, flags); 2667 if (nSigOpsCost > MAX_BLOCK_SIGOPS_COST) { 2668 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "too many sigops"); 2669 break; 2670 } 2671 2672 if (!tx.IsCoinBase()) 2673 { 2674 std::vector<CScriptCheck> vChecks; 2675 bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */ 2676 TxValidationState tx_state; 2677 if (fScriptChecks && !CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], m_chainman.m_validation_cache, parallel_script_checks ? &vChecks : nullptr)) { 2678 // Any transaction validation failure in ConnectBlock is a block consensus failure 2679 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, 2680 tx_state.GetRejectReason(), tx_state.GetDebugMessage()); 2681 break; 2682 } 2683 control.Add(std::move(vChecks)); 2684 } 2685 2686 CTxUndo undoDummy; 2687 if (i > 0) { 2688 blockundo.vtxundo.emplace_back(); 2689 } 2690 UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight); 2691 } 2692 const auto time_3{SteadyClock::now()}; 2693 m_chainman.time_connect += time_3 - time_2; 2694 LogDebug(BCLog::BENCH, " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(), 2695 Ticks<MillisecondsDouble>(time_3 - time_2), Ticks<MillisecondsDouble>(time_3 - time_2) / block.vtx.size(), 2696 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_3 - time_2) / (nInputs - 1), 2697 Ticks<SecondsDouble>(m_chainman.time_connect), 2698 Ticks<MillisecondsDouble>(m_chainman.time_connect) / m_chainman.num_blocks_total); 2699 2700 CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, params.GetConsensus()); 2701 if (block.vtx[0]->GetValueOut() > blockReward && state.IsValid()) { 2702 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-amount", 2703 strprintf("coinbase pays too much (actual=%d vs limit=%d)", block.vtx[0]->GetValueOut(), blockReward)); 2704 } 2705 2706 auto parallel_result = control.Complete(); 2707 if (parallel_result.has_value() && state.IsValid()) { 2708 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(parallel_result->first)), parallel_result->second); 2709 } 2710 if (!state.IsValid()) { 2711 LogInfo("Block validation error: %s", state.ToString()); 2712 return false; 2713 } 2714 const auto time_4{SteadyClock::now()}; 2715 m_chainman.time_verify += time_4 - time_2; 2716 LogDebug(BCLog::BENCH, " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n", nInputs - 1, 2717 Ticks<MillisecondsDouble>(time_4 - time_2), 2718 nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_4 - time_2) / (nInputs - 1), 2719 Ticks<SecondsDouble>(m_chainman.time_verify), 2720 Ticks<MillisecondsDouble>(m_chainman.time_verify) / m_chainman.num_blocks_total); 2721 2722 if (fJustCheck) { 2723 return true; 2724 } 2725 2726 if (!m_blockman.WriteBlockUndo(blockundo, state, *pindex)) { 2727 return false; 2728 } 2729 2730 const auto time_5{SteadyClock::now()}; 2731 m_chainman.time_undo += time_5 - time_4; 2732 LogDebug(BCLog::BENCH, " - Write undo data: %.2fms [%.2fs (%.2fms/blk)]\n", 2733 Ticks<MillisecondsDouble>(time_5 - time_4), 2734 Ticks<SecondsDouble>(m_chainman.time_undo), 2735 Ticks<MillisecondsDouble>(m_chainman.time_undo) / m_chainman.num_blocks_total); 2736 2737 if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) { 2738 pindex->RaiseValidity(BLOCK_VALID_SCRIPTS); 2739 m_blockman.m_dirty_blockindex.insert(pindex); 2740 } 2741 2742 // add this block to the view's block chain 2743 view.SetBestBlock(pindex->GetBlockHash()); 2744 2745 const auto time_6{SteadyClock::now()}; 2746 m_chainman.time_index += time_6 - time_5; 2747 LogDebug(BCLog::BENCH, " - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n", 2748 Ticks<MillisecondsDouble>(time_6 - time_5), 2749 Ticks<SecondsDouble>(m_chainman.time_index), 2750 Ticks<MillisecondsDouble>(m_chainman.time_index) / m_chainman.num_blocks_total); 2751 2752 TRACEPOINT(validation, block_connected, 2753 block_hash.data(), 2754 pindex->nHeight, 2755 block.vtx.size(), 2756 nInputs, 2757 nSigOpsCost, 2758 Ticks<std::chrono::nanoseconds>(time_5 - time_start) 2759 ); 2760 2761 return true; 2762 } 2763 2764 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState() 2765 { 2766 AssertLockHeld(::cs_main); 2767 return this->GetCoinsCacheSizeState( 2768 m_coinstip_cache_size_bytes, 2769 m_mempool ? m_mempool->m_opts.max_size_bytes : 0); 2770 } 2771 2772 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState( 2773 size_t max_coins_cache_size_bytes, 2774 size_t max_mempool_size_bytes) 2775 { 2776 AssertLockHeld(::cs_main); 2777 const int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0; 2778 int64_t cacheSize = CoinsTip().DynamicMemoryUsage(); 2779 int64_t nTotalSpace = 2780 max_coins_cache_size_bytes + std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0); 2781 2782 //! No need to periodic flush if at least this much space still available. 2783 static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES = 10 * 1024 * 1024; // 10MB 2784 int64_t large_threshold = 2785 std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES); 2786 2787 if (cacheSize > nTotalSpace) { 2788 LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize, nTotalSpace); 2789 return CoinsCacheSizeState::CRITICAL; 2790 } else if (cacheSize > large_threshold) { 2791 return CoinsCacheSizeState::LARGE; 2792 } 2793 return CoinsCacheSizeState::OK; 2794 } 2795 2796 bool Chainstate::FlushStateToDisk( 2797 BlockValidationState &state, 2798 FlushStateMode mode, 2799 int nManualPruneHeight) 2800 { 2801 LOCK(cs_main); 2802 assert(this->CanFlushToDisk()); 2803 std::set<int> setFilesToPrune; 2804 bool full_flush_completed = false; 2805 2806 const size_t coins_count = CoinsTip().GetCacheSize(); 2807 const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage(); 2808 2809 try { 2810 { 2811 bool fFlushForPrune = false; 2812 2813 CoinsCacheSizeState cache_state = GetCoinsCacheSizeState(); 2814 LOCK(m_blockman.cs_LastBlockFile); 2815 if (m_blockman.IsPruneMode() && (m_blockman.m_check_for_pruning || nManualPruneHeight > 0) && m_chainman.m_blockman.m_blockfiles_indexed) { 2816 // make sure we don't prune above any of the prune locks bestblocks 2817 // pruning is height-based 2818 int last_prune{m_chain.Height()}; // last height we can prune 2819 std::optional<std::string> limiting_lock; // prune lock that actually was the limiting factor, only used for logging 2820 2821 for (const auto& prune_lock : m_blockman.m_prune_locks) { 2822 if (prune_lock.second.height_first == std::numeric_limits<int>::max()) continue; 2823 // Remove the buffer and one additional block here to get actual height that is outside of the buffer 2824 const int lock_height{prune_lock.second.height_first - PRUNE_LOCK_BUFFER - 1}; 2825 last_prune = std::max(1, std::min(last_prune, lock_height)); 2826 if (last_prune == lock_height) { 2827 limiting_lock = prune_lock.first; 2828 } 2829 } 2830 2831 if (limiting_lock) { 2832 LogDebug(BCLog::PRUNE, "%s limited pruning to height %d\n", limiting_lock.value(), last_prune); 2833 } 2834 2835 if (nManualPruneHeight > 0) { 2836 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune (manual)", BCLog::BENCH); 2837 2838 m_blockman.FindFilesToPruneManual( 2839 setFilesToPrune, 2840 std::min(last_prune, nManualPruneHeight), 2841 *this, m_chainman); 2842 } else { 2843 LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune", BCLog::BENCH); 2844 2845 m_blockman.FindFilesToPrune(setFilesToPrune, last_prune, *this, m_chainman); 2846 m_blockman.m_check_for_pruning = false; 2847 } 2848 if (!setFilesToPrune.empty()) { 2849 fFlushForPrune = true; 2850 if (!m_blockman.m_have_pruned) { 2851 m_blockman.m_block_tree_db->WriteFlag("prunedblockfiles", true); 2852 m_blockman.m_have_pruned = true; 2853 } 2854 } 2855 } 2856 const auto nNow{NodeClock::now()}; 2857 // 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). 2858 bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE; 2859 // The cache is over the limit, we have to write now. 2860 bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL; 2861 // It's been a while since we wrote the block index and chain state to disk. Do this frequently, so we don't need to redownload or reindex after a crash. 2862 bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow >= m_next_write; 2863 // Combine all conditions that result in a write to disk. 2864 bool should_write = (mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicWrite || fFlushForPrune; 2865 // Write blocks, block index and best chain related state to disk. 2866 if (should_write) { 2867 // Ensure we can write block index 2868 if (!CheckDiskSpace(m_blockman.m_opts.blocks_dir)) { 2869 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!")); 2870 } 2871 { 2872 LOG_TIME_MILLIS_WITH_CATEGORY("write block and undo data to disk", BCLog::BENCH); 2873 2874 // First make sure all block and undo data is flushed to disk. 2875 // TODO: Handle return error, or add detailed comment why it is 2876 // safe to not return an error upon failure. 2877 if (!m_blockman.FlushChainstateBlockFile(m_chain.Height())) { 2878 LogPrintLevel(BCLog::VALIDATION, BCLog::Level::Warning, "%s: Failed to flush block file.\n", __func__); 2879 } 2880 } 2881 2882 // Then update all block file information (which may refer to block and undo files). 2883 { 2884 LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk", BCLog::BENCH); 2885 2886 if (!m_blockman.WriteBlockIndexDB()) { 2887 return FatalError(m_chainman.GetNotifications(), state, _("Failed to write to block index database.")); 2888 } 2889 } 2890 // Finally remove any pruned files 2891 if (fFlushForPrune) { 2892 LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files", BCLog::BENCH); 2893 2894 m_blockman.UnlinkPrunedFiles(setFilesToPrune); 2895 } 2896 2897 if (!CoinsTip().GetBestBlock().IsNull()) { 2898 if (coins_mem_usage >= WARN_FLUSH_COINS_SIZE) LogWarning("Flushing large (%d GiB) UTXO set to disk, it may take several minutes", coins_mem_usage >> 30); 2899 LOG_TIME_MILLIS_WITH_CATEGORY(strprintf("write coins cache to disk (%d coins, %.2fKiB)", 2900 coins_count, coins_mem_usage >> 10), BCLog::BENCH); 2901 2902 // Typical Coin structures on disk are around 48 bytes in size. 2903 // Pushing a new one to the database can cause it to be written 2904 // twice (once in the log, and once in the tables). This is already 2905 // an overestimation, as most will delete an existing entry or 2906 // overwrite one. Still, use a conservative safety factor of 2. 2907 if (!CheckDiskSpace(m_chainman.m_options.datadir, 48 * 2 * 2 * CoinsTip().GetCacheSize())) { 2908 return FatalError(m_chainman.GetNotifications(), state, _("Disk space is too low!")); 2909 } 2910 // Flush the chainstate (which may refer to block index entries). 2911 const auto empty_cache{(mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical}; 2912 if (empty_cache ? !CoinsTip().Flush() : !CoinsTip().Sync()) { 2913 return FatalError(m_chainman.GetNotifications(), state, _("Failed to write to coin database.")); 2914 } 2915 full_flush_completed = true; 2916 TRACEPOINT(utxocache, flush, 2917 int64_t{Ticks<std::chrono::microseconds>(NodeClock::now() - nNow)}, 2918 (uint32_t)mode, 2919 (uint64_t)coins_count, 2920 (uint64_t)coins_mem_usage, 2921 (bool)fFlushForPrune); 2922 } 2923 } 2924 2925 if (should_write || m_next_write == NodeClock::time_point::max()) { 2926 constexpr auto range{DATABASE_WRITE_INTERVAL_MAX - DATABASE_WRITE_INTERVAL_MIN}; 2927 m_next_write = FastRandomContext().rand_uniform_delay(NodeClock::now() + DATABASE_WRITE_INTERVAL_MIN, range); 2928 } 2929 } 2930 if (full_flush_completed && m_chainman.m_options.signals) { 2931 // Update best block in wallet (so we can detect restored wallets). 2932 m_chainman.m_options.signals->ChainStateFlushed(this->GetRole(), m_chain.GetLocator()); 2933 } 2934 } catch (const std::runtime_error& e) { 2935 return FatalError(m_chainman.GetNotifications(), state, strprintf(_("System error while flushing: %s"), e.what())); 2936 } 2937 return true; 2938 } 2939 2940 void Chainstate::ForceFlushStateToDisk() 2941 { 2942 BlockValidationState state; 2943 if (!this->FlushStateToDisk(state, FlushStateMode::ALWAYS)) { 2944 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString()); 2945 } 2946 } 2947 2948 void Chainstate::PruneAndFlush() 2949 { 2950 BlockValidationState state; 2951 m_blockman.m_check_for_pruning = true; 2952 if (!this->FlushStateToDisk(state, FlushStateMode::NONE)) { 2953 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString()); 2954 } 2955 } 2956 2957 static void UpdateTipLog( 2958 const ChainstateManager& chainman, 2959 const CCoinsViewCache& coins_tip, 2960 const CBlockIndex* tip, 2961 const std::string& func_name, 2962 const std::string& prefix, 2963 const std::string& warning_messages) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 2964 { 2965 2966 AssertLockHeld(::cs_main); 2967 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", 2968 prefix, func_name, 2969 tip->GetBlockHash().ToString(), tip->nHeight, tip->nVersion, 2970 log(tip->nChainWork.getdouble()) / log(2.0), tip->m_chain_tx_count, 2971 FormatISO8601DateTime(tip->GetBlockTime()), 2972 chainman.GuessVerificationProgress(tip), 2973 coins_tip.DynamicMemoryUsage() * (1.0 / (1 << 20)), 2974 coins_tip.GetCacheSize(), 2975 !warning_messages.empty() ? strprintf(" warning='%s'", warning_messages) : ""); 2976 } 2977 2978 void Chainstate::UpdateTip(const CBlockIndex* pindexNew) 2979 { 2980 AssertLockHeld(::cs_main); 2981 const auto& coins_tip = this->CoinsTip(); 2982 2983 // The remainder of the function isn't relevant if we are not acting on 2984 // the active chainstate, so return if need be. 2985 if (this != &m_chainman.ActiveChainstate()) { 2986 // Only log every so often so that we don't bury log messages at the tip. 2987 constexpr int BACKGROUND_LOG_INTERVAL = 2000; 2988 if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) { 2989 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "[background validation] ", ""); 2990 } 2991 return; 2992 } 2993 2994 // New best block 2995 if (m_mempool) { 2996 m_mempool->AddTransactionsUpdated(1); 2997 } 2998 2999 std::vector<bilingual_str> warning_messages; 3000 if (!m_chainman.IsInitialBlockDownload()) { 3001 auto bits = m_chainman.m_versionbitscache.CheckUnknownActivations(pindexNew, m_chainman.GetParams()); 3002 for (auto [bit, active] : bits) { 3003 const bilingual_str warning = strprintf(_("Unknown new rules activated (versionbit %i)"), bit); 3004 if (active) { 3005 m_chainman.GetNotifications().warningSet(kernel::Warning::UNKNOWN_NEW_RULES_ACTIVATED, warning); 3006 } else { 3007 warning_messages.push_back(warning); 3008 } 3009 } 3010 } 3011 UpdateTipLog(m_chainman, coins_tip, pindexNew, __func__, "", 3012 util::Join(warning_messages, Untranslated(", ")).original); 3013 } 3014 3015 /** Disconnect m_chain's tip. 3016 * After calling, the mempool will be in an inconsistent state, with 3017 * transactions from disconnected blocks being added to disconnectpool. You 3018 * should make the mempool consistent again by calling MaybeUpdateMempoolForReorg. 3019 * with cs_main held. 3020 * 3021 * If disconnectpool is nullptr, then no disconnected transactions are added to 3022 * disconnectpool (note that the caller is responsible for mempool consistency 3023 * in any case). 3024 */ 3025 bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTransactions* disconnectpool) 3026 { 3027 AssertLockHeld(cs_main); 3028 if (m_mempool) AssertLockHeld(m_mempool->cs); 3029 3030 CBlockIndex *pindexDelete = m_chain.Tip(); 3031 assert(pindexDelete); 3032 assert(pindexDelete->pprev); 3033 // Read block from disk. 3034 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); 3035 CBlock& block = *pblock; 3036 if (!m_blockman.ReadBlock(block, *pindexDelete)) { 3037 LogError("DisconnectTip(): Failed to read block\n"); 3038 return false; 3039 } 3040 // Apply the block atomically to the chain state. 3041 const auto time_start{SteadyClock::now()}; 3042 { 3043 CCoinsViewCache view(&CoinsTip()); 3044 assert(view.GetBestBlock() == pindexDelete->GetBlockHash()); 3045 if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK) { 3046 LogError("DisconnectTip(): DisconnectBlock %s failed\n", pindexDelete->GetBlockHash().ToString()); 3047 return false; 3048 } 3049 bool flushed = view.Flush(); 3050 assert(flushed); 3051 } 3052 LogDebug(BCLog::BENCH, "- Disconnect block: %.2fms\n", 3053 Ticks<MillisecondsDouble>(SteadyClock::now() - time_start)); 3054 3055 { 3056 // Prune locks that began at or after the tip should be moved backward so they get a chance to reorg 3057 const int max_height_first{pindexDelete->nHeight - 1}; 3058 for (auto& prune_lock : m_blockman.m_prune_locks) { 3059 if (prune_lock.second.height_first <= max_height_first) continue; 3060 3061 prune_lock.second.height_first = max_height_first; 3062 LogDebug(BCLog::PRUNE, "%s prune lock moved back to %d\n", prune_lock.first, max_height_first); 3063 } 3064 } 3065 3066 // Write the chain state to disk, if necessary. 3067 if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) { 3068 return false; 3069 } 3070 3071 if (disconnectpool && m_mempool) { 3072 // Save transactions to re-add to mempool at end of reorg. If any entries are evicted for 3073 // exceeding memory limits, remove them and their descendants from the mempool. 3074 for (auto&& evicted_tx : disconnectpool->AddTransactionsFromBlock(block.vtx)) { 3075 m_mempool->removeRecursive(*evicted_tx, MemPoolRemovalReason::REORG); 3076 } 3077 } 3078 3079 m_chain.SetTip(*pindexDelete->pprev); 3080 3081 UpdateTip(pindexDelete->pprev); 3082 // Let wallets know transactions went from 1-confirmed to 3083 // 0-confirmed or conflicted: 3084 if (m_chainman.m_options.signals) { 3085 m_chainman.m_options.signals->BlockDisconnected(pblock, pindexDelete); 3086 } 3087 return true; 3088 } 3089 3090 struct PerBlockConnectTrace { 3091 CBlockIndex* pindex = nullptr; 3092 std::shared_ptr<const CBlock> pblock; 3093 PerBlockConnectTrace() = default; 3094 }; 3095 /** 3096 * Used to track blocks whose transactions were applied to the UTXO state as a 3097 * part of a single ActivateBestChainStep call. 3098 * 3099 * This class is single-use, once you call GetBlocksConnected() you have to throw 3100 * it away and make a new one. 3101 */ 3102 class ConnectTrace { 3103 private: 3104 std::vector<PerBlockConnectTrace> blocksConnected; 3105 3106 public: 3107 explicit ConnectTrace() : blocksConnected(1) {} 3108 3109 void BlockConnected(CBlockIndex* pindex, std::shared_ptr<const CBlock> pblock) { 3110 assert(!blocksConnected.back().pindex); 3111 assert(pindex); 3112 assert(pblock); 3113 blocksConnected.back().pindex = pindex; 3114 blocksConnected.back().pblock = std::move(pblock); 3115 blocksConnected.emplace_back(); 3116 } 3117 3118 std::vector<PerBlockConnectTrace>& GetBlocksConnected() { 3119 // We always keep one extra block at the end of our list because 3120 // blocks are added after all the conflicted transactions have 3121 // been filled in. Thus, the last entry should always be an empty 3122 // one waiting for the transactions from the next block. We pop 3123 // the last entry here to make sure the list we return is sane. 3124 assert(!blocksConnected.back().pindex); 3125 blocksConnected.pop_back(); 3126 return blocksConnected; 3127 } 3128 }; 3129 3130 /** 3131 * Connect a new block to m_chain. pblock is either nullptr or a pointer to a CBlock 3132 * corresponding to pindexNew, to bypass loading it again from disk. 3133 * 3134 * The block is added to connectTrace if connection succeeds. 3135 */ 3136 bool Chainstate::ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool) 3137 { 3138 AssertLockHeld(cs_main); 3139 if (m_mempool) AssertLockHeld(m_mempool->cs); 3140 3141 assert(pindexNew->pprev == m_chain.Tip()); 3142 // Read block from disk. 3143 const auto time_1{SteadyClock::now()}; 3144 std::shared_ptr<const CBlock> pthisBlock; 3145 if (!pblock) { 3146 std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>(); 3147 if (!m_blockman.ReadBlock(*pblockNew, *pindexNew)) { 3148 return FatalError(m_chainman.GetNotifications(), state, _("Failed to read block.")); 3149 } 3150 pthisBlock = pblockNew; 3151 } else { 3152 LogDebug(BCLog::BENCH, " - Using cached block\n"); 3153 pthisBlock = pblock; 3154 } 3155 const CBlock& blockConnecting = *pthisBlock; 3156 // Apply the block atomically to the chain state. 3157 const auto time_2{SteadyClock::now()}; 3158 SteadyClock::time_point time_3; 3159 // When adding aggregate statistics in the future, keep in mind that 3160 // num_blocks_total may be zero until the ConnectBlock() call below. 3161 LogDebug(BCLog::BENCH, " - Load block from disk: %.2fms\n", 3162 Ticks<MillisecondsDouble>(time_2 - time_1)); 3163 { 3164 CCoinsViewCache view(&CoinsTip()); 3165 bool rv = ConnectBlock(blockConnecting, state, pindexNew, view); 3166 if (m_chainman.m_options.signals) { 3167 m_chainman.m_options.signals->BlockChecked(blockConnecting, state); 3168 } 3169 if (!rv) { 3170 if (state.IsInvalid()) 3171 InvalidBlockFound(pindexNew, state); 3172 LogError("%s: ConnectBlock %s failed, %s\n", __func__, pindexNew->GetBlockHash().ToString(), state.ToString()); 3173 return false; 3174 } 3175 time_3 = SteadyClock::now(); 3176 m_chainman.time_connect_total += time_3 - time_2; 3177 assert(m_chainman.num_blocks_total > 0); 3178 LogDebug(BCLog::BENCH, " - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n", 3179 Ticks<MillisecondsDouble>(time_3 - time_2), 3180 Ticks<SecondsDouble>(m_chainman.time_connect_total), 3181 Ticks<MillisecondsDouble>(m_chainman.time_connect_total) / m_chainman.num_blocks_total); 3182 bool flushed = view.Flush(); 3183 assert(flushed); 3184 } 3185 const auto time_4{SteadyClock::now()}; 3186 m_chainman.time_flush += time_4 - time_3; 3187 LogDebug(BCLog::BENCH, " - Flush: %.2fms [%.2fs (%.2fms/blk)]\n", 3188 Ticks<MillisecondsDouble>(time_4 - time_3), 3189 Ticks<SecondsDouble>(m_chainman.time_flush), 3190 Ticks<MillisecondsDouble>(m_chainman.time_flush) / m_chainman.num_blocks_total); 3191 // Write the chain state to disk, if necessary. 3192 if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) { 3193 return false; 3194 } 3195 const auto time_5{SteadyClock::now()}; 3196 m_chainman.time_chainstate += time_5 - time_4; 3197 LogDebug(BCLog::BENCH, " - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n", 3198 Ticks<MillisecondsDouble>(time_5 - time_4), 3199 Ticks<SecondsDouble>(m_chainman.time_chainstate), 3200 Ticks<MillisecondsDouble>(m_chainman.time_chainstate) / m_chainman.num_blocks_total); 3201 // Remove conflicting transactions from the mempool.; 3202 if (m_mempool) { 3203 m_mempool->removeForBlock(blockConnecting.vtx, pindexNew->nHeight); 3204 disconnectpool.removeForBlock(blockConnecting.vtx); 3205 } 3206 // Update m_chain & related variables. 3207 m_chain.SetTip(*pindexNew); 3208 UpdateTip(pindexNew); 3209 3210 const auto time_6{SteadyClock::now()}; 3211 m_chainman.time_post_connect += time_6 - time_5; 3212 m_chainman.time_total += time_6 - time_1; 3213 LogDebug(BCLog::BENCH, " - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n", 3214 Ticks<MillisecondsDouble>(time_6 - time_5), 3215 Ticks<SecondsDouble>(m_chainman.time_post_connect), 3216 Ticks<MillisecondsDouble>(m_chainman.time_post_connect) / m_chainman.num_blocks_total); 3217 LogDebug(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n", 3218 Ticks<MillisecondsDouble>(time_6 - time_1), 3219 Ticks<SecondsDouble>(m_chainman.time_total), 3220 Ticks<MillisecondsDouble>(m_chainman.time_total) / m_chainman.num_blocks_total); 3221 3222 // If we are the background validation chainstate, check to see if we are done 3223 // validating the snapshot (i.e. our tip has reached the snapshot's base block). 3224 if (this != &m_chainman.ActiveChainstate()) { 3225 // This call may set `m_disabled`, which is referenced immediately afterwards in 3226 // ActivateBestChain, so that we stop connecting blocks past the snapshot base. 3227 m_chainman.MaybeCompleteSnapshotValidation(); 3228 } 3229 3230 connectTrace.BlockConnected(pindexNew, std::move(pthisBlock)); 3231 return true; 3232 } 3233 3234 /** 3235 * Return the tip of the chain with the most work in it, that isn't 3236 * known to be invalid (it's however far from certain to be valid). 3237 */ 3238 CBlockIndex* Chainstate::FindMostWorkChain() 3239 { 3240 AssertLockHeld(::cs_main); 3241 do { 3242 CBlockIndex *pindexNew = nullptr; 3243 3244 // Find the best candidate header. 3245 { 3246 std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexCandidates.rbegin(); 3247 if (it == setBlockIndexCandidates.rend()) 3248 return nullptr; 3249 pindexNew = *it; 3250 } 3251 3252 // Check whether all blocks on the path between the currently active chain and the candidate are valid. 3253 // Just going until the active chain is an optimization, as we know all blocks in it are valid already. 3254 CBlockIndex *pindexTest = pindexNew; 3255 bool fInvalidAncestor = false; 3256 while (pindexTest && !m_chain.Contains(pindexTest)) { 3257 assert(pindexTest->HaveNumChainTxs() || pindexTest->nHeight == 0); 3258 3259 // Pruned nodes may have entries in setBlockIndexCandidates for 3260 // which block files have been deleted. Remove those as candidates 3261 // for the most work chain if we come across them; we can't switch 3262 // to a chain unless we have all the non-active-chain parent blocks. 3263 bool fFailedChain = pindexTest->nStatus & BLOCK_FAILED_MASK; 3264 bool fMissingData = !(pindexTest->nStatus & BLOCK_HAVE_DATA); 3265 if (fFailedChain || fMissingData) { 3266 // Candidate chain is not usable (either invalid or missing data) 3267 if (fFailedChain && (m_chainman.m_best_invalid == nullptr || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork)) { 3268 m_chainman.m_best_invalid = pindexNew; 3269 } 3270 CBlockIndex *pindexFailed = pindexNew; 3271 // Remove the entire chain from the set. 3272 while (pindexTest != pindexFailed) { 3273 if (fFailedChain) { 3274 pindexFailed->nStatus |= BLOCK_FAILED_CHILD; 3275 m_blockman.m_dirty_blockindex.insert(pindexFailed); 3276 } else if (fMissingData) { 3277 // If we're missing data, then add back to m_blocks_unlinked, 3278 // so that if the block arrives in the future we can try adding 3279 // to setBlockIndexCandidates again. 3280 m_blockman.m_blocks_unlinked.insert( 3281 std::make_pair(pindexFailed->pprev, pindexFailed)); 3282 } 3283 setBlockIndexCandidates.erase(pindexFailed); 3284 pindexFailed = pindexFailed->pprev; 3285 } 3286 setBlockIndexCandidates.erase(pindexTest); 3287 fInvalidAncestor = true; 3288 break; 3289 } 3290 pindexTest = pindexTest->pprev; 3291 } 3292 if (!fInvalidAncestor) 3293 return pindexNew; 3294 } while(true); 3295 } 3296 3297 /** Delete all entries in setBlockIndexCandidates that are worse than the current tip. */ 3298 void Chainstate::PruneBlockIndexCandidates() { 3299 // Note that we can't delete the current block itself, as we may need to return to it later in case a 3300 // reorganization to a better block fails. 3301 std::set<CBlockIndex*, CBlockIndexWorkComparator>::iterator it = setBlockIndexCandidates.begin(); 3302 while (it != setBlockIndexCandidates.end() && setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) { 3303 setBlockIndexCandidates.erase(it++); 3304 } 3305 // Either the current tip or a successor of it we're working towards is left in setBlockIndexCandidates. 3306 assert(!setBlockIndexCandidates.empty()); 3307 } 3308 3309 /** 3310 * Try to make some progress towards making pindexMostWork the active block. 3311 * pblock is either nullptr or a pointer to a CBlock corresponding to pindexMostWork. 3312 * 3313 * @returns true unless a system error occurred 3314 */ 3315 bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) 3316 { 3317 AssertLockHeld(cs_main); 3318 if (m_mempool) AssertLockHeld(m_mempool->cs); 3319 3320 const CBlockIndex* pindexOldTip = m_chain.Tip(); 3321 const CBlockIndex* pindexFork = m_chain.FindFork(pindexMostWork); 3322 3323 // Disconnect active blocks which are no longer in the best chain. 3324 bool fBlocksDisconnected = false; 3325 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES}; 3326 while (m_chain.Tip() && m_chain.Tip() != pindexFork) { 3327 if (!DisconnectTip(state, &disconnectpool)) { 3328 // This is likely a fatal error, but keep the mempool consistent, 3329 // just in case. Only remove from the mempool in this case. 3330 MaybeUpdateMempoolForReorg(disconnectpool, false); 3331 3332 // If we're unable to disconnect a block during normal operation, 3333 // then that is a failure of our local system -- we should abort 3334 // rather than stay on a less work chain. 3335 FatalError(m_chainman.GetNotifications(), state, _("Failed to disconnect block.")); 3336 return false; 3337 } 3338 fBlocksDisconnected = true; 3339 } 3340 3341 // Build list of new blocks to connect (in descending height order). 3342 std::vector<CBlockIndex*> vpindexToConnect; 3343 bool fContinue = true; 3344 int nHeight = pindexFork ? pindexFork->nHeight : -1; 3345 while (fContinue && nHeight != pindexMostWork->nHeight) { 3346 // Don't iterate the entire list of potential improvements toward the best tip, as we likely only need 3347 // a few blocks along the way. 3348 int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight); 3349 vpindexToConnect.clear(); 3350 vpindexToConnect.reserve(nTargetHeight - nHeight); 3351 CBlockIndex* pindexIter = pindexMostWork->GetAncestor(nTargetHeight); 3352 while (pindexIter && pindexIter->nHeight != nHeight) { 3353 vpindexToConnect.push_back(pindexIter); 3354 pindexIter = pindexIter->pprev; 3355 } 3356 nHeight = nTargetHeight; 3357 3358 // Connect new blocks. 3359 for (CBlockIndex* pindexConnect : vpindexToConnect | std::views::reverse) { 3360 if (!ConnectTip(state, pindexConnect, pindexConnect == pindexMostWork ? pblock : std::shared_ptr<const CBlock>(), connectTrace, disconnectpool)) { 3361 if (state.IsInvalid()) { 3362 // The block violates a consensus rule. 3363 if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 3364 InvalidChainFound(vpindexToConnect.front()); 3365 } 3366 state = BlockValidationState(); 3367 fInvalidFound = true; 3368 fContinue = false; 3369 break; 3370 } else { 3371 // A system error occurred (disk space, database error, ...). 3372 // Make the mempool consistent with the current tip, just in case 3373 // any observers try to use it before shutdown. 3374 MaybeUpdateMempoolForReorg(disconnectpool, false); 3375 return false; 3376 } 3377 } else { 3378 PruneBlockIndexCandidates(); 3379 if (!pindexOldTip || m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) { 3380 // We're in a better position than we were. Return temporarily to release the lock. 3381 fContinue = false; 3382 break; 3383 } 3384 } 3385 } 3386 } 3387 3388 if (fBlocksDisconnected) { 3389 // If any blocks were disconnected, disconnectpool may be non empty. Add 3390 // any disconnected transactions back to the mempool. 3391 MaybeUpdateMempoolForReorg(disconnectpool, true); 3392 } 3393 if (m_mempool) m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1); 3394 3395 CheckForkWarningConditions(); 3396 3397 return true; 3398 } 3399 3400 static SynchronizationState GetSynchronizationState(bool init, bool blockfiles_indexed) 3401 { 3402 if (!init) return SynchronizationState::POST_INIT; 3403 if (!blockfiles_indexed) return SynchronizationState::INIT_REINDEX; 3404 return SynchronizationState::INIT_DOWNLOAD; 3405 } 3406 3407 bool ChainstateManager::NotifyHeaderTip() 3408 { 3409 bool fNotify = false; 3410 bool fInitialBlockDownload = false; 3411 CBlockIndex* pindexHeader = nullptr; 3412 { 3413 LOCK(GetMutex()); 3414 pindexHeader = m_best_header; 3415 3416 if (pindexHeader != m_last_notified_header) { 3417 fNotify = true; 3418 fInitialBlockDownload = IsInitialBlockDownload(); 3419 m_last_notified_header = pindexHeader; 3420 } 3421 } 3422 // Send block tip changed notifications without the lock held 3423 if (fNotify) { 3424 GetNotifications().headerTip(GetSynchronizationState(fInitialBlockDownload, m_blockman.m_blockfiles_indexed), pindexHeader->nHeight, pindexHeader->nTime, false); 3425 } 3426 return fNotify; 3427 } 3428 3429 static void LimitValidationInterfaceQueue(ValidationSignals& signals) LOCKS_EXCLUDED(cs_main) { 3430 AssertLockNotHeld(cs_main); 3431 3432 if (signals.CallbacksPending() > 10) { 3433 signals.SyncWithValidationInterfaceQueue(); 3434 } 3435 } 3436 3437 bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<const CBlock> pblock) 3438 { 3439 AssertLockNotHeld(m_chainstate_mutex); 3440 3441 // Note that while we're often called here from ProcessNewBlock, this is 3442 // far from a guarantee. Things in the P2P/RPC will often end up calling 3443 // us in the middle of ProcessNewBlock - do not assume pblock is set 3444 // sanely for performance or correctness! 3445 AssertLockNotHeld(::cs_main); 3446 3447 // ABC maintains a fair degree of expensive-to-calculate internal state 3448 // because this function periodically releases cs_main so that it does not lock up other threads for too long 3449 // during large connects - and to allow for e.g. the callback queue to drain 3450 // we use m_chainstate_mutex to enforce mutual exclusion so that only one caller may execute this function at a time 3451 LOCK(m_chainstate_mutex); 3452 3453 // Belt-and-suspenders check that we aren't attempting to advance the background 3454 // chainstate past the snapshot base block. 3455 if (WITH_LOCK(::cs_main, return m_disabled)) { 3456 LogPrintf("m_disabled is set - this chainstate should not be in operation. " 3457 "Please report this as a bug. %s\n", CLIENT_BUGREPORT); 3458 return false; 3459 } 3460 3461 CBlockIndex *pindexMostWork = nullptr; 3462 CBlockIndex *pindexNewTip = nullptr; 3463 bool exited_ibd{false}; 3464 do { 3465 // Block until the validation queue drains. This should largely 3466 // never happen in normal operation, however may happen during 3467 // reindex, causing memory blowup if we run too far ahead. 3468 // Note that if a validationinterface callback ends up calling 3469 // ActivateBestChain this may lead to a deadlock! We should 3470 // probably have a DEBUG_LOCKORDER test for this in the future. 3471 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals); 3472 3473 { 3474 LOCK(cs_main); 3475 { 3476 // Lock transaction pool for at least as long as it takes for connectTrace to be consumed 3477 LOCK(MempoolMutex()); 3478 const bool was_in_ibd = m_chainman.IsInitialBlockDownload(); 3479 CBlockIndex* starting_tip = m_chain.Tip(); 3480 bool blocks_connected = false; 3481 do { 3482 // We absolutely may not unlock cs_main until we've made forward progress 3483 // (with the exception of shutdown due to hardware issues, low disk space, etc). 3484 ConnectTrace connectTrace; // Destructed before cs_main is unlocked 3485 3486 if (pindexMostWork == nullptr) { 3487 pindexMostWork = FindMostWorkChain(); 3488 } 3489 3490 // Whether we have anything to do at all. 3491 if (pindexMostWork == nullptr || pindexMostWork == m_chain.Tip()) { 3492 break; 3493 } 3494 3495 bool fInvalidFound = false; 3496 std::shared_ptr<const CBlock> nullBlockPtr; 3497 // BlockConnected signals must be sent for the original role; 3498 // in case snapshot validation is completed during ActivateBestChainStep, the 3499 // result of GetRole() changes from BACKGROUND to NORMAL. 3500 const ChainstateRole chainstate_role{this->GetRole()}; 3501 if (!ActivateBestChainStep(state, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace)) { 3502 // A system error occurred 3503 return false; 3504 } 3505 blocks_connected = true; 3506 3507 if (fInvalidFound) { 3508 // Wipe cache, we may need another branch now. 3509 pindexMostWork = nullptr; 3510 } 3511 pindexNewTip = m_chain.Tip(); 3512 3513 for (const PerBlockConnectTrace& trace : connectTrace.GetBlocksConnected()) { 3514 assert(trace.pblock && trace.pindex); 3515 if (m_chainman.m_options.signals) { 3516 m_chainman.m_options.signals->BlockConnected(chainstate_role, trace.pblock, trace.pindex); 3517 } 3518 } 3519 3520 // This will have been toggled in 3521 // ActivateBestChainStep -> ConnectTip -> MaybeCompleteSnapshotValidation, 3522 // if at all, so we should catch it here. 3523 // 3524 // Break this do-while to ensure we don't advance past the base snapshot. 3525 if (m_disabled) { 3526 break; 3527 } 3528 } while (!m_chain.Tip() || (starting_tip && CBlockIndexWorkComparator()(m_chain.Tip(), starting_tip))); 3529 if (!blocks_connected) return true; 3530 3531 const CBlockIndex* pindexFork = m_chain.FindFork(starting_tip); 3532 bool still_in_ibd = m_chainman.IsInitialBlockDownload(); 3533 3534 if (was_in_ibd && !still_in_ibd) { 3535 // Active chainstate has exited IBD. 3536 exited_ibd = true; 3537 } 3538 3539 // Notify external listeners about the new tip. 3540 // Enqueue while holding cs_main to ensure that UpdatedBlockTip is called in the order in which blocks are connected 3541 if (this == &m_chainman.ActiveChainstate() && pindexFork != pindexNewTip) { 3542 // Notify ValidationInterface subscribers 3543 if (m_chainman.m_options.signals) { 3544 m_chainman.m_options.signals->UpdatedBlockTip(pindexNewTip, pindexFork, still_in_ibd); 3545 } 3546 3547 if (kernel::IsInterrupted(m_chainman.GetNotifications().blockTip(GetSynchronizationState(still_in_ibd, m_chainman.m_blockman.m_blockfiles_indexed), *pindexNewTip))) { 3548 // Just breaking and returning success for now. This could 3549 // be changed to bubble up the kernel::Interrupted value to 3550 // the caller so the caller could distinguish between 3551 // completed and interrupted operations. 3552 break; 3553 } 3554 } 3555 } // release MempoolMutex 3556 // Notify external listeners about the new tip, even if pindexFork == pindexNewTip. 3557 if (m_chainman.m_options.signals && this == &m_chainman.ActiveChainstate()) { 3558 m_chainman.m_options.signals->ActiveTipChange(*Assert(pindexNewTip), m_chainman.IsInitialBlockDownload()); 3559 } 3560 } // release cs_main 3561 // When we reach this point, we switched to a new tip (stored in pindexNewTip). 3562 3563 if (exited_ibd) { 3564 // If a background chainstate is in use, we may need to rebalance our 3565 // allocation of caches once a chainstate exits initial block download. 3566 LOCK(::cs_main); 3567 m_chainman.MaybeRebalanceCaches(); 3568 } 3569 3570 if (WITH_LOCK(::cs_main, return m_disabled)) { 3571 // Background chainstate has reached the snapshot base block, so exit. 3572 3573 // Restart indexes to resume indexing for all blocks unique to the snapshot 3574 // chain. This resumes indexing "in order" from where the indexing on the 3575 // background validation chain left off. 3576 // 3577 // This cannot be done while holding cs_main (within 3578 // MaybeCompleteSnapshotValidation) or a cs_main deadlock will occur. 3579 if (m_chainman.snapshot_download_completed) { 3580 m_chainman.snapshot_download_completed(); 3581 } 3582 break; 3583 } 3584 3585 // We check interrupt only after giving ActivateBestChainStep a chance to run once so that we 3586 // never interrupt before connecting the genesis block during LoadChainTip(). Previously this 3587 // caused an assert() failure during interrupt in such cases as the UTXO DB flushing checks 3588 // that the best block hash is non-null. 3589 if (m_chainman.m_interrupt) break; 3590 } while (pindexNewTip != pindexMostWork); 3591 3592 m_chainman.CheckBlockIndex(); 3593 3594 // Write changes periodically to disk, after relay. 3595 if (!FlushStateToDisk(state, FlushStateMode::PERIODIC)) { 3596 return false; 3597 } 3598 3599 return true; 3600 } 3601 3602 bool Chainstate::PreciousBlock(BlockValidationState& state, CBlockIndex* pindex) 3603 { 3604 AssertLockNotHeld(m_chainstate_mutex); 3605 AssertLockNotHeld(::cs_main); 3606 { 3607 LOCK(cs_main); 3608 if (pindex->nChainWork < m_chain.Tip()->nChainWork) { 3609 // Nothing to do, this block is not at the tip. 3610 return true; 3611 } 3612 if (m_chain.Tip()->nChainWork > m_chainman.nLastPreciousChainwork) { 3613 // The chain has been extended since the last call, reset the counter. 3614 m_chainman.nBlockReverseSequenceId = -1; 3615 } 3616 m_chainman.nLastPreciousChainwork = m_chain.Tip()->nChainWork; 3617 setBlockIndexCandidates.erase(pindex); 3618 pindex->nSequenceId = m_chainman.nBlockReverseSequenceId; 3619 if (m_chainman.nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) { 3620 // We can't keep reducing the counter if somebody really wants to 3621 // call preciousblock 2**31-1 times on the same set of tips... 3622 m_chainman.nBlockReverseSequenceId--; 3623 } 3624 if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && pindex->HaveNumChainTxs()) { 3625 setBlockIndexCandidates.insert(pindex); 3626 PruneBlockIndexCandidates(); 3627 } 3628 } 3629 3630 return ActivateBestChain(state, std::shared_ptr<const CBlock>()); 3631 } 3632 3633 bool Chainstate::InvalidateBlock(BlockValidationState& state, CBlockIndex* pindex) 3634 { 3635 AssertLockNotHeld(m_chainstate_mutex); 3636 AssertLockNotHeld(::cs_main); 3637 3638 // Genesis block can't be invalidated 3639 assert(pindex); 3640 if (pindex->nHeight == 0) return false; 3641 3642 CBlockIndex* to_mark_failed = pindex; 3643 bool pindex_was_in_chain = false; 3644 int disconnected = 0; 3645 3646 // We do not allow ActivateBestChain() to run while InvalidateBlock() is 3647 // running, as that could cause the tip to change while we disconnect 3648 // blocks. 3649 LOCK(m_chainstate_mutex); 3650 3651 // We'll be acquiring and releasing cs_main below, to allow the validation 3652 // callbacks to run. However, we should keep the block index in a 3653 // consistent state as we disconnect blocks -- in particular we need to 3654 // add equal-work blocks to setBlockIndexCandidates as we disconnect. 3655 // To avoid walking the block index repeatedly in search of candidates, 3656 // build a map once so that we can look up candidate blocks by chain 3657 // work as we go. 3658 std::multimap<const arith_uint256, CBlockIndex *> candidate_blocks_by_work; 3659 3660 { 3661 LOCK(cs_main); 3662 for (auto& entry : m_blockman.m_block_index) { 3663 CBlockIndex* candidate = &entry.second; 3664 // We don't need to put anything in our active chain into the 3665 // multimap, because those candidates will be found and considered 3666 // as we disconnect. 3667 // Instead, consider only non-active-chain blocks that have at 3668 // least as much work as where we expect the new tip to end up. 3669 if (!m_chain.Contains(candidate) && 3670 !CBlockIndexWorkComparator()(candidate, pindex->pprev) && 3671 candidate->IsValid(BLOCK_VALID_TRANSACTIONS) && 3672 candidate->HaveNumChainTxs()) { 3673 candidate_blocks_by_work.insert(std::make_pair(candidate->nChainWork, candidate)); 3674 } 3675 } 3676 } 3677 3678 // Disconnect (descendants of) pindex, and mark them invalid. 3679 while (true) { 3680 if (m_chainman.m_interrupt) break; 3681 3682 // Make sure the queue of validation callbacks doesn't grow unboundedly. 3683 if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals); 3684 3685 LOCK(cs_main); 3686 // Lock for as long as disconnectpool is in scope to make sure MaybeUpdateMempoolForReorg is 3687 // called after DisconnectTip without unlocking in between 3688 LOCK(MempoolMutex()); 3689 if (!m_chain.Contains(pindex)) break; 3690 pindex_was_in_chain = true; 3691 CBlockIndex *invalid_walk_tip = m_chain.Tip(); 3692 3693 // ActivateBestChain considers blocks already in m_chain 3694 // unconditionally valid already, so force disconnect away from it. 3695 DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_BYTES}; 3696 bool ret = DisconnectTip(state, &disconnectpool); 3697 // DisconnectTip will add transactions to disconnectpool. 3698 // Adjust the mempool to be consistent with the new tip, adding 3699 // transactions back to the mempool if disconnecting was successful, 3700 // and we're not doing a very deep invalidation (in which case 3701 // keeping the mempool up to date is probably futile anyway). 3702 MaybeUpdateMempoolForReorg(disconnectpool, /* fAddToMempool = */ (++disconnected <= 10) && ret); 3703 if (!ret) return false; 3704 assert(invalid_walk_tip->pprev == m_chain.Tip()); 3705 3706 // We immediately mark the disconnected blocks as invalid. 3707 // This prevents a case where pruned nodes may fail to invalidateblock 3708 // and be left unable to start as they have no tip candidates (as there 3709 // are no blocks that meet the "have data and are not invalid per 3710 // nStatus" criteria for inclusion in setBlockIndexCandidates). 3711 invalid_walk_tip->nStatus |= BLOCK_FAILED_VALID; 3712 m_blockman.m_dirty_blockindex.insert(invalid_walk_tip); 3713 setBlockIndexCandidates.erase(invalid_walk_tip); 3714 setBlockIndexCandidates.insert(invalid_walk_tip->pprev); 3715 if (invalid_walk_tip == to_mark_failed->pprev && (to_mark_failed->nStatus & BLOCK_FAILED_VALID)) { 3716 // We only want to mark the last disconnected block as BLOCK_FAILED_VALID; its children 3717 // need to be BLOCK_FAILED_CHILD instead. 3718 to_mark_failed->nStatus = (to_mark_failed->nStatus ^ BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD; 3719 m_blockman.m_dirty_blockindex.insert(to_mark_failed); 3720 } 3721 3722 // Add any equal or more work headers to setBlockIndexCandidates 3723 auto candidate_it = candidate_blocks_by_work.lower_bound(invalid_walk_tip->pprev->nChainWork); 3724 while (candidate_it != candidate_blocks_by_work.end()) { 3725 if (!CBlockIndexWorkComparator()(candidate_it->second, invalid_walk_tip->pprev)) { 3726 setBlockIndexCandidates.insert(candidate_it->second); 3727 candidate_it = candidate_blocks_by_work.erase(candidate_it); 3728 } else { 3729 ++candidate_it; 3730 } 3731 } 3732 3733 // Track the last disconnected block, so we can correct its BLOCK_FAILED_CHILD status in future 3734 // iterations, or, if it's the last one, call InvalidChainFound on it. 3735 to_mark_failed = invalid_walk_tip; 3736 } 3737 3738 m_chainman.CheckBlockIndex(); 3739 3740 { 3741 LOCK(cs_main); 3742 if (m_chain.Contains(to_mark_failed)) { 3743 // If the to-be-marked invalid block is in the active chain, something is interfering and we can't proceed. 3744 return false; 3745 } 3746 3747 // Mark pindex as invalid if it never was in the main chain 3748 if (!pindex_was_in_chain && !(pindex->nStatus & BLOCK_FAILED_MASK)) { 3749 pindex->nStatus |= BLOCK_FAILED_VALID; 3750 m_blockman.m_dirty_blockindex.insert(pindex); 3751 setBlockIndexCandidates.erase(pindex); 3752 m_chainman.m_failed_blocks.insert(pindex); 3753 } 3754 3755 // If any new blocks somehow arrived while we were disconnecting 3756 // (above), then the pre-calculation of what should go into 3757 // setBlockIndexCandidates may have missed entries. This would 3758 // technically be an inconsistency in the block index, but if we clean 3759 // it up here, this should be an essentially unobservable error. 3760 // Loop back over all block index entries and add any missing entries 3761 // to setBlockIndexCandidates. 3762 for (auto& [_, block_index] : m_blockman.m_block_index) { 3763 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && !setBlockIndexCandidates.value_comp()(&block_index, m_chain.Tip())) { 3764 setBlockIndexCandidates.insert(&block_index); 3765 } 3766 } 3767 3768 InvalidChainFound(to_mark_failed); 3769 } 3770 3771 // Only notify about a new block tip if the active chain was modified. 3772 if (pindex_was_in_chain) { 3773 // Ignoring return value for now, this could be changed to bubble up 3774 // kernel::Interrupted value to the caller so the caller could 3775 // distinguish between completed and interrupted operations. It might 3776 // also make sense for the blockTip notification to have an enum 3777 // parameter indicating the source of the tip change so hooks can 3778 // distinguish user-initiated invalidateblock changes from other 3779 // changes. 3780 (void)m_chainman.GetNotifications().blockTip(GetSynchronizationState(m_chainman.IsInitialBlockDownload(), m_chainman.m_blockman.m_blockfiles_indexed), *to_mark_failed->pprev); 3781 3782 // Fire ActiveTipChange now for the current chain tip to make sure clients are notified. 3783 // ActivateBestChain may call this as well, but not necessarily. 3784 if (m_chainman.m_options.signals) { 3785 m_chainman.m_options.signals->ActiveTipChange(*Assert(m_chain.Tip()), m_chainman.IsInitialBlockDownload()); 3786 } 3787 } 3788 return true; 3789 } 3790 3791 void Chainstate::SetBlockFailureFlags(CBlockIndex* invalid_block) 3792 { 3793 AssertLockHeld(cs_main); 3794 3795 for (auto& [_, block_index] : m_blockman.m_block_index) { 3796 if (invalid_block != &block_index && block_index.GetAncestor(invalid_block->nHeight) == invalid_block) { 3797 block_index.nStatus = (block_index.nStatus & ~BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD; 3798 m_blockman.m_dirty_blockindex.insert(&block_index); 3799 } 3800 } 3801 } 3802 3803 void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex) { 3804 AssertLockHeld(cs_main); 3805 3806 int nHeight = pindex->nHeight; 3807 3808 // Remove the invalidity flag from this block and all its descendants. 3809 for (auto& [_, block_index] : m_blockman.m_block_index) { 3810 if (!block_index.IsValid() && block_index.GetAncestor(nHeight) == pindex) { 3811 block_index.nStatus &= ~BLOCK_FAILED_MASK; 3812 m_blockman.m_dirty_blockindex.insert(&block_index); 3813 if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveNumChainTxs() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &block_index)) { 3814 setBlockIndexCandidates.insert(&block_index); 3815 } 3816 if (&block_index == m_chainman.m_best_invalid) { 3817 // Reset invalid block marker if it was pointing to one of those. 3818 m_chainman.m_best_invalid = nullptr; 3819 } 3820 m_chainman.m_failed_blocks.erase(&block_index); 3821 } 3822 } 3823 3824 // Remove the invalidity flag from all ancestors too. 3825 while (pindex != nullptr) { 3826 if (pindex->nStatus & BLOCK_FAILED_MASK) { 3827 pindex->nStatus &= ~BLOCK_FAILED_MASK; 3828 m_blockman.m_dirty_blockindex.insert(pindex); 3829 m_chainman.m_failed_blocks.erase(pindex); 3830 } 3831 pindex = pindex->pprev; 3832 } 3833 } 3834 3835 void Chainstate::TryAddBlockIndexCandidate(CBlockIndex* pindex) 3836 { 3837 AssertLockHeld(cs_main); 3838 // The block only is a candidate for the most-work-chain if it has the same 3839 // or more work than our current tip. 3840 if (m_chain.Tip() != nullptr && setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) { 3841 return; 3842 } 3843 3844 bool is_active_chainstate = this == &m_chainman.ActiveChainstate(); 3845 if (is_active_chainstate) { 3846 // The active chainstate should always add entries that have more 3847 // work than the tip. 3848 setBlockIndexCandidates.insert(pindex); 3849 } else if (!m_disabled) { 3850 // For the background chainstate, we only consider connecting blocks 3851 // towards the snapshot base (which can't be nullptr or else we'll 3852 // never make progress). 3853 const CBlockIndex* snapshot_base{Assert(m_chainman.GetSnapshotBaseBlock())}; 3854 if (snapshot_base->GetAncestor(pindex->nHeight) == pindex) { 3855 setBlockIndexCandidates.insert(pindex); 3856 } 3857 } 3858 } 3859 3860 /** Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS). */ 3861 void ChainstateManager::ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos) 3862 { 3863 AssertLockHeld(cs_main); 3864 pindexNew->nTx = block.vtx.size(); 3865 // Typically m_chain_tx_count will be 0 at this point, but it can be nonzero if this 3866 // is a pruned block which is being downloaded again, or if this is an 3867 // assumeutxo snapshot block which has a hardcoded m_chain_tx_count value from the 3868 // snapshot metadata. If the pindex is not the snapshot block and the 3869 // m_chain_tx_count value is not zero, assert that value is actually correct. 3870 auto prev_tx_sum = [](CBlockIndex& block) { return block.nTx + (block.pprev ? block.pprev->m_chain_tx_count : 0); }; 3871 if (!Assume(pindexNew->m_chain_tx_count == 0 || pindexNew->m_chain_tx_count == prev_tx_sum(*pindexNew) || 3872 pindexNew == GetSnapshotBaseBlock())) { 3873 LogWarning("Internal bug detected: block %d has unexpected m_chain_tx_count %i that should be %i (%s %s). Please report this issue here: %s\n", 3874 pindexNew->nHeight, pindexNew->m_chain_tx_count, prev_tx_sum(*pindexNew), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT); 3875 pindexNew->m_chain_tx_count = 0; 3876 } 3877 pindexNew->nFile = pos.nFile; 3878 pindexNew->nDataPos = pos.nPos; 3879 pindexNew->nUndoPos = 0; 3880 pindexNew->nStatus |= BLOCK_HAVE_DATA; 3881 if (DeploymentActiveAt(*pindexNew, *this, Consensus::DEPLOYMENT_SEGWIT)) { 3882 pindexNew->nStatus |= BLOCK_OPT_WITNESS; 3883 } 3884 pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS); 3885 m_blockman.m_dirty_blockindex.insert(pindexNew); 3886 3887 if (pindexNew->pprev == nullptr || pindexNew->pprev->HaveNumChainTxs()) { 3888 // If pindexNew is the genesis block or all parents are BLOCK_VALID_TRANSACTIONS. 3889 std::deque<CBlockIndex*> queue; 3890 queue.push_back(pindexNew); 3891 3892 // Recursively process any descendant blocks that now may be eligible to be connected. 3893 while (!queue.empty()) { 3894 CBlockIndex *pindex = queue.front(); 3895 queue.pop_front(); 3896 // Before setting m_chain_tx_count, assert that it is 0 or already set to 3897 // the correct value. This assert will fail after receiving the 3898 // assumeutxo snapshot block if assumeutxo snapshot metadata has an 3899 // incorrect hardcoded AssumeutxoData::m_chain_tx_count value. 3900 if (!Assume(pindex->m_chain_tx_count == 0 || pindex->m_chain_tx_count == prev_tx_sum(*pindex))) { 3901 LogWarning("Internal bug detected: block %d has unexpected m_chain_tx_count %i that should be %i (%s %s). Please report this issue here: %s\n", 3902 pindex->nHeight, pindex->m_chain_tx_count, prev_tx_sum(*pindex), CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT); 3903 } 3904 pindex->m_chain_tx_count = prev_tx_sum(*pindex); 3905 pindex->nSequenceId = nBlockSequenceId++; 3906 for (Chainstate *c : GetAll()) { 3907 c->TryAddBlockIndexCandidate(pindex); 3908 } 3909 std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> range = m_blockman.m_blocks_unlinked.equal_range(pindex); 3910 while (range.first != range.second) { 3911 std::multimap<CBlockIndex*, CBlockIndex*>::iterator it = range.first; 3912 queue.push_back(it->second); 3913 range.first++; 3914 m_blockman.m_blocks_unlinked.erase(it); 3915 } 3916 } 3917 } else { 3918 if (pindexNew->pprev && pindexNew->pprev->IsValid(BLOCK_VALID_TREE)) { 3919 m_blockman.m_blocks_unlinked.insert(std::make_pair(pindexNew->pprev, pindexNew)); 3920 } 3921 } 3922 } 3923 3924 static bool CheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true) 3925 { 3926 // Check proof of work matches claimed amount 3927 if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, consensusParams)) 3928 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "high-hash", "proof of work failed"); 3929 3930 return true; 3931 } 3932 3933 static bool CheckMerkleRoot(const CBlock& block, BlockValidationState& state) 3934 { 3935 if (block.m_checked_merkle_root) return true; 3936 3937 bool mutated; 3938 uint256 merkle_root = BlockMerkleRoot(block, &mutated); 3939 if (block.hashMerkleRoot != merkle_root) { 3940 return state.Invalid( 3941 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3942 /*reject_reason=*/"bad-txnmrklroot", 3943 /*debug_message=*/"hashMerkleRoot mismatch"); 3944 } 3945 3946 // Check for merkle tree malleability (CVE-2012-2459): repeating sequences 3947 // of transactions in a block without affecting the merkle root of a block, 3948 // while still invalidating it. 3949 if (mutated) { 3950 return state.Invalid( 3951 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3952 /*reject_reason=*/"bad-txns-duplicate", 3953 /*debug_message=*/"duplicate transaction"); 3954 } 3955 3956 block.m_checked_merkle_root = true; 3957 return true; 3958 } 3959 3960 /** CheckWitnessMalleation performs checks for block malleation with regard to 3961 * its witnesses. 3962 * 3963 * Note: If the witness commitment is expected (i.e. `expect_witness_commitment 3964 * = true`), then the block is required to have at least one transaction and the 3965 * first transaction needs to have at least one input. */ 3966 static bool CheckWitnessMalleation(const CBlock& block, bool expect_witness_commitment, BlockValidationState& state) 3967 { 3968 if (expect_witness_commitment) { 3969 if (block.m_checked_witness_commitment) return true; 3970 3971 int commitpos = GetWitnessCommitmentIndex(block); 3972 if (commitpos != NO_WITNESS_COMMITMENT) { 3973 assert(!block.vtx.empty() && !block.vtx[0]->vin.empty()); 3974 const auto& witness_stack{block.vtx[0]->vin[0].scriptWitness.stack}; 3975 3976 if (witness_stack.size() != 1 || witness_stack[0].size() != 32) { 3977 return state.Invalid( 3978 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3979 /*reject_reason=*/"bad-witness-nonce-size", 3980 /*debug_message=*/strprintf("%s : invalid witness reserved value size", __func__)); 3981 } 3982 3983 // The malleation check is ignored; as the transaction tree itself 3984 // already does not permit it, it is impossible to trigger in the 3985 // witness tree. 3986 uint256 hash_witness = BlockWitnessMerkleRoot(block, /*mutated=*/nullptr); 3987 3988 CHash256().Write(hash_witness).Write(witness_stack[0]).Finalize(hash_witness); 3989 if (memcmp(hash_witness.begin(), &block.vtx[0]->vout[commitpos].scriptPubKey[6], 32)) { 3990 return state.Invalid( 3991 /*result=*/BlockValidationResult::BLOCK_MUTATED, 3992 /*reject_reason=*/"bad-witness-merkle-match", 3993 /*debug_message=*/strprintf("%s : witness merkle commitment mismatch", __func__)); 3994 } 3995 3996 block.m_checked_witness_commitment = true; 3997 return true; 3998 } 3999 } 4000 4001 // No witness data is allowed in blocks that don't commit to witness data, as this would otherwise leave room for spam 4002 for (const auto& tx : block.vtx) { 4003 if (tx->HasWitness()) { 4004 return state.Invalid( 4005 /*result=*/BlockValidationResult::BLOCK_MUTATED, 4006 /*reject_reason=*/"unexpected-witness", 4007 /*debug_message=*/strprintf("%s : unexpected witness data found", __func__)); 4008 } 4009 } 4010 4011 return true; 4012 } 4013 4014 bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW, bool fCheckMerkleRoot) 4015 { 4016 // These are checks that are independent of context. 4017 4018 if (block.fChecked) 4019 return true; 4020 4021 // Check that the header is valid (particularly PoW). This is mostly 4022 // redundant with the call in AcceptBlockHeader. 4023 if (!CheckBlockHeader(block, state, consensusParams, fCheckPOW)) 4024 return false; 4025 4026 // Signet only: check block solution 4027 if (consensusParams.signet_blocks && fCheckPOW && !CheckSignetBlockSolution(block, consensusParams)) { 4028 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-signet-blksig", "signet block signature validation failure"); 4029 } 4030 4031 // Check the merkle root. 4032 if (fCheckMerkleRoot && !CheckMerkleRoot(block, state)) { 4033 return false; 4034 } 4035 4036 // All potential-corruption validation must be done before we do any 4037 // transaction validation, as otherwise we may mark the header as invalid 4038 // because we receive the wrong transactions for it. 4039 // Note that witness malleability is checked in ContextualCheckBlock, so no 4040 // checks that use witness data may be performed here. 4041 4042 // Size limits 4043 if (block.vtx.empty() || block.vtx.size() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT || ::GetSerializeSize(TX_NO_WITNESS(block)) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT) 4044 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-length", "size limits failed"); 4045 4046 // First transaction must be coinbase, the rest must not be 4047 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) 4048 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-missing", "first tx is not coinbase"); 4049 for (unsigned int i = 1; i < block.vtx.size(); i++) 4050 if (block.vtx[i]->IsCoinBase()) 4051 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-multiple", "more than one coinbase"); 4052 4053 // Check transactions 4054 // Must check for duplicate inputs (see CVE-2018-17144) 4055 for (const auto& tx : block.vtx) { 4056 TxValidationState tx_state; 4057 if (!CheckTransaction(*tx, tx_state)) { 4058 // CheckBlock() does context-free validation checks. The only 4059 // possible failures are consensus failures. 4060 assert(tx_state.GetResult() == TxValidationResult::TX_CONSENSUS); 4061 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, tx_state.GetRejectReason(), 4062 strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), tx_state.GetDebugMessage())); 4063 } 4064 } 4065 unsigned int nSigOps = 0; 4066 for (const auto& tx : block.vtx) 4067 { 4068 nSigOps += GetLegacySigOpCount(*tx); 4069 } 4070 if (nSigOps * WITNESS_SCALE_FACTOR > MAX_BLOCK_SIGOPS_COST) 4071 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "out-of-bounds SigOpCount"); 4072 4073 if (fCheckPOW && fCheckMerkleRoot) 4074 block.fChecked = true; 4075 4076 return true; 4077 } 4078 4079 void ChainstateManager::UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev) const 4080 { 4081 int commitpos = GetWitnessCommitmentIndex(block); 4082 static const std::vector<unsigned char> nonce(32, 0x00); 4083 if (commitpos != NO_WITNESS_COMMITMENT && DeploymentActiveAfter(pindexPrev, *this, Consensus::DEPLOYMENT_SEGWIT) && !block.vtx[0]->HasWitness()) { 4084 CMutableTransaction tx(*block.vtx[0]); 4085 tx.vin[0].scriptWitness.stack.resize(1); 4086 tx.vin[0].scriptWitness.stack[0] = nonce; 4087 block.vtx[0] = MakeTransactionRef(std::move(tx)); 4088 } 4089 } 4090 4091 std::vector<unsigned char> ChainstateManager::GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev) const 4092 { 4093 std::vector<unsigned char> commitment; 4094 int commitpos = GetWitnessCommitmentIndex(block); 4095 std::vector<unsigned char> ret(32, 0x00); 4096 if (commitpos == NO_WITNESS_COMMITMENT) { 4097 uint256 witnessroot = BlockWitnessMerkleRoot(block, nullptr); 4098 CHash256().Write(witnessroot).Write(ret).Finalize(witnessroot); 4099 CTxOut out; 4100 out.nValue = 0; 4101 out.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT); 4102 out.scriptPubKey[0] = OP_RETURN; 4103 out.scriptPubKey[1] = 0x24; 4104 out.scriptPubKey[2] = 0xaa; 4105 out.scriptPubKey[3] = 0x21; 4106 out.scriptPubKey[4] = 0xa9; 4107 out.scriptPubKey[5] = 0xed; 4108 memcpy(&out.scriptPubKey[6], witnessroot.begin(), 32); 4109 commitment = std::vector<unsigned char>(out.scriptPubKey.begin(), out.scriptPubKey.end()); 4110 CMutableTransaction tx(*block.vtx[0]); 4111 tx.vout.push_back(out); 4112 block.vtx[0] = MakeTransactionRef(std::move(tx)); 4113 } 4114 UpdateUncommittedBlockStructures(block, pindexPrev); 4115 return commitment; 4116 } 4117 4118 bool HasValidProofOfWork(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams) 4119 { 4120 return std::all_of(headers.cbegin(), headers.cend(), 4121 [&](const auto& header) { return CheckProofOfWork(header.GetHash(), header.nBits, consensusParams);}); 4122 } 4123 4124 bool IsBlockMutated(const CBlock& block, bool check_witness_root) 4125 { 4126 BlockValidationState state; 4127 if (!CheckMerkleRoot(block, state)) { 4128 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString()); 4129 return true; 4130 } 4131 4132 if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) { 4133 // Consider the block mutated if any transaction is 64 bytes in size (see 3.1 4134 // in "Weaknesses in Bitcoin’s Merkle Root Construction": 4135 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20190225/a27d8837/attachment-0001.pdf). 4136 // 4137 // Note: This is not a consensus change as this only applies to blocks that 4138 // don't have a coinbase transaction and would therefore already be invalid. 4139 return std::any_of(block.vtx.begin(), block.vtx.end(), 4140 [](auto& tx) { return GetSerializeSize(TX_NO_WITNESS(tx)) == 64; }); 4141 } else { 4142 // Theoretically it is still possible for a block with a 64 byte 4143 // coinbase transaction to be mutated but we neglect that possibility 4144 // here as it requires at least 224 bits of work. 4145 } 4146 4147 if (!CheckWitnessMalleation(block, check_witness_root, state)) { 4148 LogDebug(BCLog::VALIDATION, "Block mutated: %s\n", state.ToString()); 4149 return true; 4150 } 4151 4152 return false; 4153 } 4154 4155 arith_uint256 CalculateClaimedHeadersWork(std::span<const CBlockHeader> headers) 4156 { 4157 arith_uint256 total_work{0}; 4158 for (const CBlockHeader& header : headers) { 4159 CBlockIndex dummy(header); 4160 total_work += GetBlockProof(dummy); 4161 } 4162 return total_work; 4163 } 4164 4165 /** Context-dependent validity checks. 4166 * By "context", we mean only the previous block headers, but not the UTXO 4167 * set; UTXO-related validity checks are done in ConnectBlock(). 4168 * NOTE: This function is not currently invoked by ConnectBlock(), so we 4169 * should consider upgrade issues if we change which consensus rules are 4170 * enforced in this function (eg by adding a new consensus rule). See comment 4171 * in ConnectBlock(). 4172 * Note that -reindex-chainstate skips the validation that happens here! 4173 * 4174 * NOTE: failing to check the header's height against the last checkpoint's opened a DoS vector between 4175 * v0.12 and v0.15 (when no additional protection was in place) whereby an attacker could unboundedly 4176 * grow our in-memory block index. See https://bitcoincore.org/en/2024/07/03/disclose-header-spam. 4177 */ 4178 static bool ContextualCheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, BlockManager& blockman, const ChainstateManager& chainman, const CBlockIndex* pindexPrev) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 4179 { 4180 AssertLockHeld(::cs_main); 4181 assert(pindexPrev != nullptr); 4182 const int nHeight = pindexPrev->nHeight + 1; 4183 4184 // Check proof of work 4185 const Consensus::Params& consensusParams = chainman.GetConsensus(); 4186 if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams)) 4187 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "bad-diffbits", "incorrect proof of work"); 4188 4189 // Check timestamp against prev 4190 if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast()) 4191 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-too-old", "block's timestamp is too early"); 4192 4193 // Testnet4 and regtest only: Check timestamp against prev for difficulty-adjustment 4194 // blocks to prevent timewarp attacks (see https://github.com/bitcoin/bitcoin/pull/15482). 4195 if (consensusParams.enforce_BIP94) { 4196 // Check timestamp for the first block of each difficulty adjustment 4197 // interval, except the genesis block. 4198 if (nHeight % consensusParams.DifficultyAdjustmentInterval() == 0) { 4199 if (block.GetBlockTime() < pindexPrev->GetBlockTime() - MAX_TIMEWARP) { 4200 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-timewarp-attack", "block's timestamp is too early on diff adjustment block"); 4201 } 4202 } 4203 } 4204 4205 // Check timestamp 4206 if (block.Time() > NodeClock::now() + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) { 4207 return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE, "time-too-new", "block timestamp too far in the future"); 4208 } 4209 4210 // Reject blocks with outdated version 4211 if ((block.nVersion < 2 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) || 4212 (block.nVersion < 3 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_DERSIG)) || 4213 (block.nVersion < 4 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CLTV))) { 4214 return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, strprintf("bad-version(0x%08x)", block.nVersion), 4215 strprintf("rejected nVersion=0x%08x block", block.nVersion)); 4216 } 4217 4218 return true; 4219 } 4220 4221 /** NOTE: This function is not currently invoked by ConnectBlock(), so we 4222 * should consider upgrade issues if we change which consensus rules are 4223 * enforced in this function (eg by adding a new consensus rule). See comment 4224 * in ConnectBlock(). 4225 * Note that -reindex-chainstate skips the validation that happens here! 4226 */ 4227 static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& state, const ChainstateManager& chainman, const CBlockIndex* pindexPrev) 4228 { 4229 const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1; 4230 4231 // Enforce BIP113 (Median Time Past). 4232 bool enforce_locktime_median_time_past{false}; 4233 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CSV)) { 4234 assert(pindexPrev != nullptr); 4235 enforce_locktime_median_time_past = true; 4236 } 4237 4238 const int64_t nLockTimeCutoff{enforce_locktime_median_time_past ? 4239 pindexPrev->GetMedianTimePast() : 4240 block.GetBlockTime()}; 4241 4242 // Check that all transactions are finalized 4243 for (const auto& tx : block.vtx) { 4244 if (!IsFinalTx(*tx, nHeight, nLockTimeCutoff)) { 4245 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", "non-final transaction"); 4246 } 4247 } 4248 4249 // Enforce rule that the coinbase starts with serialized block height 4250 if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) 4251 { 4252 CScript expect = CScript() << nHeight; 4253 if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() || 4254 !std::equal(expect.begin(), expect.end(), block.vtx[0]->vin[0].scriptSig.begin())) { 4255 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-height", "block height mismatch in coinbase"); 4256 } 4257 } 4258 4259 // Validation for witness commitments. 4260 // * We compute the witness hash (which is the hash including witnesses) of all the block's transactions, except the 4261 // coinbase (where 0x0000....0000 is used instead). 4262 // * The coinbase scriptWitness is a stack of a single 32-byte vector, containing a witness reserved value (unconstrained). 4263 // * We build a merkle tree with all those witness hashes as leaves (similar to the hashMerkleRoot in the block header). 4264 // * There must be at least one output whose scriptPubKey is a single 36-byte push, the first 4 bytes of which are 4265 // {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness reserved value). In case there are 4266 // multiple, the last one is used. 4267 if (!CheckWitnessMalleation(block, DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_SEGWIT), state)) { 4268 return false; 4269 } 4270 4271 // After the coinbase witness reserved value and commitment are verified, 4272 // we can check if the block weight passes (before we've checked the 4273 // coinbase witness, it would be possible for the weight to be too 4274 // large by filling up the coinbase witness, which doesn't change 4275 // the block hash, so we couldn't mark the block as permanently 4276 // failed). 4277 if (GetBlockWeight(block) > MAX_BLOCK_WEIGHT) { 4278 return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-weight", strprintf("%s : weight limit failed", __func__)); 4279 } 4280 4281 return true; 4282 } 4283 4284 bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationState& state, CBlockIndex** ppindex, bool min_pow_checked) 4285 { 4286 AssertLockHeld(cs_main); 4287 4288 // Check for duplicate 4289 uint256 hash = block.GetHash(); 4290 BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)}; 4291 if (hash != GetConsensus().hashGenesisBlock) { 4292 if (miSelf != m_blockman.m_block_index.end()) { 4293 // Block header is already known. 4294 CBlockIndex* pindex = &(miSelf->second); 4295 if (ppindex) 4296 *ppindex = pindex; 4297 if (pindex->nStatus & BLOCK_FAILED_MASK) { 4298 LogDebug(BCLog::VALIDATION, "%s: block %s is marked invalid\n", __func__, hash.ToString()); 4299 return state.Invalid(BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate-invalid"); 4300 } 4301 return true; 4302 } 4303 4304 if (!CheckBlockHeader(block, state, GetConsensus())) { 4305 LogDebug(BCLog::VALIDATION, "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString()); 4306 return false; 4307 } 4308 4309 // Get prev block index 4310 CBlockIndex* pindexPrev = nullptr; 4311 BlockMap::iterator mi{m_blockman.m_block_index.find(block.hashPrevBlock)}; 4312 if (mi == m_blockman.m_block_index.end()) { 4313 LogDebug(BCLog::VALIDATION, "header %s has prev block not found: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4314 return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV, "prev-blk-not-found"); 4315 } 4316 pindexPrev = &((*mi).second); 4317 if (pindexPrev->nStatus & BLOCK_FAILED_MASK) { 4318 LogDebug(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4319 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk"); 4320 } 4321 if (!ContextualCheckBlockHeader(block, state, m_blockman, *this, pindexPrev)) { 4322 LogDebug(BCLog::VALIDATION, "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString()); 4323 return false; 4324 } 4325 4326 /* Determine if this block descends from any block which has been found 4327 * invalid (m_failed_blocks), then mark pindexPrev and any blocks between 4328 * them as failed. For example: 4329 * 4330 * D3 4331 * / 4332 * B2 - C2 4333 * / \ 4334 * A D2 - E2 - F2 4335 * \ 4336 * B1 - C1 - D1 - E1 4337 * 4338 * In the case that we attempted to reorg from E1 to F2, only to find 4339 * C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD 4340 * but NOT D3 (it was not in any of our candidate sets at the time). 4341 * 4342 * In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart 4343 * in LoadBlockIndex. 4344 */ 4345 if (!pindexPrev->IsValid(BLOCK_VALID_SCRIPTS)) { 4346 // The above does not mean "invalid": it checks if the previous block 4347 // hasn't been validated up to BLOCK_VALID_SCRIPTS. This is a performance 4348 // optimization, in the common case of adding a new block to the tip, 4349 // we don't need to iterate over the failed blocks list. 4350 for (const CBlockIndex* failedit : m_failed_blocks) { 4351 if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) { 4352 assert(failedit->nStatus & BLOCK_FAILED_VALID); 4353 CBlockIndex* invalid_walk = pindexPrev; 4354 while (invalid_walk != failedit) { 4355 invalid_walk->nStatus |= BLOCK_FAILED_CHILD; 4356 m_blockman.m_dirty_blockindex.insert(invalid_walk); 4357 invalid_walk = invalid_walk->pprev; 4358 } 4359 LogDebug(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString()); 4360 return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk"); 4361 } 4362 } 4363 } 4364 } 4365 if (!min_pow_checked) { 4366 LogDebug(BCLog::VALIDATION, "%s: not adding new block header %s, missing anti-dos proof-of-work validation\n", __func__, hash.ToString()); 4367 return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK, "too-little-chainwork"); 4368 } 4369 CBlockIndex* pindex{m_blockman.AddToBlockIndex(block, m_best_header)}; 4370 4371 if (ppindex) 4372 *ppindex = pindex; 4373 4374 return true; 4375 } 4376 4377 // Exposed wrapper for AcceptBlockHeader 4378 bool ChainstateManager::ProcessNewBlockHeaders(std::span<const CBlockHeader> headers, bool min_pow_checked, BlockValidationState& state, const CBlockIndex** ppindex) 4379 { 4380 AssertLockNotHeld(cs_main); 4381 { 4382 LOCK(cs_main); 4383 for (const CBlockHeader& header : headers) { 4384 CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast 4385 bool accepted{AcceptBlockHeader(header, state, &pindex, min_pow_checked)}; 4386 CheckBlockIndex(); 4387 4388 if (!accepted) { 4389 return false; 4390 } 4391 if (ppindex) { 4392 *ppindex = pindex; 4393 } 4394 } 4395 } 4396 if (NotifyHeaderTip()) { 4397 if (IsInitialBlockDownload() && ppindex && *ppindex) { 4398 const CBlockIndex& last_accepted{**ppindex}; 4399 int64_t blocks_left{(NodeClock::now() - last_accepted.Time()) / GetConsensus().PowTargetSpacing()}; 4400 blocks_left = std::max<int64_t>(0, blocks_left); 4401 const double progress{100.0 * last_accepted.nHeight / (last_accepted.nHeight + blocks_left)}; 4402 LogInfo("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress); 4403 } 4404 } 4405 return true; 4406 } 4407 4408 void ChainstateManager::ReportHeadersPresync(const arith_uint256& work, int64_t height, int64_t timestamp) 4409 { 4410 AssertLockNotHeld(GetMutex()); 4411 { 4412 LOCK(GetMutex()); 4413 // Don't report headers presync progress if we already have a post-minchainwork header chain. 4414 // This means we lose reporting for potentially legitimate, but unlikely, deep reorgs, but 4415 // prevent attackers that spam low-work headers from filling our logs. 4416 if (m_best_header->nChainWork >= UintToArith256(GetConsensus().nMinimumChainWork)) return; 4417 // Rate limit headers presync updates to 4 per second, as these are not subject to DoS 4418 // protection. 4419 auto now = MockableSteadyClock::now(); 4420 if (now < m_last_presync_update + std::chrono::milliseconds{250}) return; 4421 m_last_presync_update = now; 4422 } 4423 bool initial_download = IsInitialBlockDownload(); 4424 GetNotifications().headerTip(GetSynchronizationState(initial_download, m_blockman.m_blockfiles_indexed), height, timestamp, /*presync=*/true); 4425 if (initial_download) { 4426 int64_t blocks_left{(NodeClock::now() - NodeSeconds{std::chrono::seconds{timestamp}}) / GetConsensus().PowTargetSpacing()}; 4427 blocks_left = std::max<int64_t>(0, blocks_left); 4428 const double progress{100.0 * height / (height + blocks_left)}; 4429 LogInfo("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress); 4430 } 4431 } 4432 4433 /** Store block on disk. If dbp is non-nullptr, the file is known to already reside on disk */ 4434 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) 4435 { 4436 const CBlock& block = *pblock; 4437 4438 if (fNewBlock) *fNewBlock = false; 4439 AssertLockHeld(cs_main); 4440 4441 CBlockIndex *pindexDummy = nullptr; 4442 CBlockIndex *&pindex = ppindex ? *ppindex : pindexDummy; 4443 4444 bool accepted_header{AcceptBlockHeader(block, state, &pindex, min_pow_checked)}; 4445 CheckBlockIndex(); 4446 4447 if (!accepted_header) 4448 return false; 4449 4450 // Check all requested blocks that we do not already have for validity and 4451 // save them to disk. Skip processing of unrequested blocks as an anti-DoS 4452 // measure, unless the blocks have more work than the active chain tip, and 4453 // aren't too far ahead of it, so are likely to be attached soon. 4454 bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA; 4455 bool fHasMoreOrSameWork = (ActiveTip() ? pindex->nChainWork >= ActiveTip()->nChainWork : true); 4456 // Blocks that are too out-of-order needlessly limit the effectiveness of 4457 // pruning, because pruning will not delete block files that contain any 4458 // blocks which are too close in height to the tip. Apply this test 4459 // regardless of whether pruning is enabled; it should generally be safe to 4460 // not process unrequested blocks. 4461 bool fTooFarAhead{pindex->nHeight > ActiveHeight() + int(MIN_BLOCKS_TO_KEEP)}; 4462 4463 // TODO: Decouple this function from the block download logic by removing fRequested 4464 // This requires some new chain data structure to efficiently look up if a 4465 // block is in a chain leading to a candidate for best tip, despite not 4466 // being such a candidate itself. 4467 // Note that this would break the getblockfrompeer RPC 4468 4469 // TODO: deal better with return value and error conditions for duplicate 4470 // and unrequested blocks. 4471 if (fAlreadyHave) return true; 4472 if (!fRequested) { // If we didn't ask for it: 4473 if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned 4474 if (!fHasMoreOrSameWork) return true; // Don't process less-work chains 4475 if (fTooFarAhead) return true; // Block height is too high 4476 4477 // Protect against DoS attacks from low-work chains. 4478 // If our tip is behind, a peer could try to send us 4479 // low-work blocks on a fake chain that we would never 4480 // request; don't process these. 4481 if (pindex->nChainWork < MinimumChainWork()) return true; 4482 } 4483 4484 const CChainParams& params{GetParams()}; 4485 4486 if (!CheckBlock(block, state, params.GetConsensus()) || 4487 !ContextualCheckBlock(block, state, *this, pindex->pprev)) { 4488 if (state.IsInvalid() && state.GetResult() != BlockValidationResult::BLOCK_MUTATED) { 4489 pindex->nStatus |= BLOCK_FAILED_VALID; 4490 m_blockman.m_dirty_blockindex.insert(pindex); 4491 } 4492 LogError("%s: %s\n", __func__, state.ToString()); 4493 return false; 4494 } 4495 4496 // Header is valid/has work, merkle tree and segwit merkle tree are good...RELAY NOW 4497 // (but if it does not build on our best tip, let the SendMessages loop relay it) 4498 if (!IsInitialBlockDownload() && ActiveTip() == pindex->pprev && m_options.signals) { 4499 m_options.signals->NewPoWValidBlock(pindex, pblock); 4500 } 4501 4502 // Write block to history file 4503 if (fNewBlock) *fNewBlock = true; 4504 try { 4505 FlatFilePos blockPos{}; 4506 if (dbp) { 4507 blockPos = *dbp; 4508 m_blockman.UpdateBlockInfo(block, pindex->nHeight, blockPos); 4509 } else { 4510 blockPos = m_blockman.WriteBlock(block, pindex->nHeight); 4511 if (blockPos.IsNull()) { 4512 state.Error(strprintf("%s: Failed to find position to write new block to disk", __func__)); 4513 return false; 4514 } 4515 } 4516 ReceivedBlockTransactions(block, pindex, blockPos); 4517 } catch (const std::runtime_error& e) { 4518 return FatalError(GetNotifications(), state, strprintf(_("System error while saving block to disk: %s"), e.what())); 4519 } 4520 4521 // TODO: FlushStateToDisk() handles flushing of both block and chainstate 4522 // data, so we should move this to ChainstateManager so that we can be more 4523 // intelligent about how we flush. 4524 // For now, since FlushStateMode::NONE is used, all that can happen is that 4525 // the block files may be pruned, so we can just call this on one 4526 // chainstate (particularly if we haven't implemented pruning with 4527 // background validation yet). 4528 ActiveChainstate().FlushStateToDisk(state, FlushStateMode::NONE); 4529 4530 CheckBlockIndex(); 4531 4532 return true; 4533 } 4534 4535 bool ChainstateManager::ProcessNewBlock(const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked, bool* new_block) 4536 { 4537 AssertLockNotHeld(cs_main); 4538 4539 { 4540 CBlockIndex *pindex = nullptr; 4541 if (new_block) *new_block = false; 4542 BlockValidationState state; 4543 4544 // CheckBlock() does not support multi-threaded block validation because CBlock::fChecked can cause data race. 4545 // Therefore, the following critical section must include the CheckBlock() call as well. 4546 LOCK(cs_main); 4547 4548 // Skipping AcceptBlock() for CheckBlock() failures means that we will never mark a block as invalid if 4549 // CheckBlock() fails. This is protective against consensus failure if there are any unknown forms of block 4550 // malleability that cause CheckBlock() to fail; see e.g. CVE-2012-2459 and 4551 // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html. Because CheckBlock() is 4552 // not very expensive, the anti-DoS benefits of caching failure (of a definitely-invalid block) are not substantial. 4553 bool ret = CheckBlock(*block, state, GetConsensus()); 4554 if (ret) { 4555 // Store to disk 4556 ret = AcceptBlock(block, state, &pindex, force_processing, nullptr, new_block, min_pow_checked); 4557 } 4558 if (!ret) { 4559 if (m_options.signals) { 4560 m_options.signals->BlockChecked(*block, state); 4561 } 4562 LogError("%s: AcceptBlock FAILED (%s)\n", __func__, state.ToString()); 4563 return false; 4564 } 4565 } 4566 4567 NotifyHeaderTip(); 4568 4569 BlockValidationState state; // Only used to report errors, not invalidity - ignore it 4570 if (!ActiveChainstate().ActivateBestChain(state, block)) { 4571 LogError("%s: ActivateBestChain failed (%s)\n", __func__, state.ToString()); 4572 return false; 4573 } 4574 4575 Chainstate* bg_chain{WITH_LOCK(cs_main, return BackgroundSyncInProgress() ? m_ibd_chainstate.get() : nullptr)}; 4576 BlockValidationState bg_state; 4577 if (bg_chain && !bg_chain->ActivateBestChain(bg_state, block)) { 4578 LogError("%s: [background] ActivateBestChain failed (%s)\n", __func__, bg_state.ToString()); 4579 return false; 4580 } 4581 4582 return true; 4583 } 4584 4585 MempoolAcceptResult ChainstateManager::ProcessTransaction(const CTransactionRef& tx, bool test_accept) 4586 { 4587 AssertLockHeld(cs_main); 4588 Chainstate& active_chainstate = ActiveChainstate(); 4589 if (!active_chainstate.GetMempool()) { 4590 TxValidationState state; 4591 state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool"); 4592 return MempoolAcceptResult::Failure(state); 4593 } 4594 auto result = AcceptToMemoryPool(active_chainstate, tx, GetTime(), /*bypass_limits=*/ false, test_accept); 4595 active_chainstate.GetMempool()->check(active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1); 4596 return result; 4597 } 4598 4599 bool TestBlockValidity(BlockValidationState& state, 4600 const CChainParams& chainparams, 4601 Chainstate& chainstate, 4602 const CBlock& block, 4603 CBlockIndex* pindexPrev, 4604 bool fCheckPOW, 4605 bool fCheckMerkleRoot) 4606 { 4607 AssertLockHeld(cs_main); 4608 assert(pindexPrev && pindexPrev == chainstate.m_chain.Tip()); 4609 CCoinsViewCache viewNew(&chainstate.CoinsTip()); 4610 uint256 block_hash(block.GetHash()); 4611 CBlockIndex indexDummy(block); 4612 indexDummy.pprev = pindexPrev; 4613 indexDummy.nHeight = pindexPrev->nHeight + 1; 4614 indexDummy.phashBlock = &block_hash; 4615 4616 // NOTE: CheckBlockHeader is called by CheckBlock 4617 if (!ContextualCheckBlockHeader(block, state, chainstate.m_blockman, chainstate.m_chainman, pindexPrev)) { 4618 LogError("%s: Consensus::ContextualCheckBlockHeader: %s\n", __func__, state.ToString()); 4619 return false; 4620 } 4621 if (!CheckBlock(block, state, chainparams.GetConsensus(), fCheckPOW, fCheckMerkleRoot)) { 4622 LogError("%s: Consensus::CheckBlock: %s\n", __func__, state.ToString()); 4623 return false; 4624 } 4625 if (!ContextualCheckBlock(block, state, chainstate.m_chainman, pindexPrev)) { 4626 LogError("%s: Consensus::ContextualCheckBlock: %s\n", __func__, state.ToString()); 4627 return false; 4628 } 4629 if (!chainstate.ConnectBlock(block, state, &indexDummy, viewNew, true)) { 4630 return false; 4631 } 4632 assert(state.IsValid()); 4633 4634 return true; 4635 } 4636 4637 /* This function is called from the RPC code for pruneblockchain */ 4638 void PruneBlockFilesManual(Chainstate& active_chainstate, int nManualPruneHeight) 4639 { 4640 BlockValidationState state; 4641 if (!active_chainstate.FlushStateToDisk( 4642 state, FlushStateMode::NONE, nManualPruneHeight)) { 4643 LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString()); 4644 } 4645 } 4646 4647 bool Chainstate::LoadChainTip() 4648 { 4649 AssertLockHeld(cs_main); 4650 const CCoinsViewCache& coins_cache = CoinsTip(); 4651 assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty 4652 const CBlockIndex* tip = m_chain.Tip(); 4653 4654 if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) { 4655 return true; 4656 } 4657 4658 // Load pointer to end of best chain 4659 CBlockIndex* pindex = m_blockman.LookupBlockIndex(coins_cache.GetBestBlock()); 4660 if (!pindex) { 4661 return false; 4662 } 4663 m_chain.SetTip(*pindex); 4664 PruneBlockIndexCandidates(); 4665 4666 tip = m_chain.Tip(); 4667 LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n", 4668 tip->GetBlockHash().ToString(), 4669 m_chain.Height(), 4670 FormatISO8601DateTime(tip->GetBlockTime()), 4671 m_chainman.GuessVerificationProgress(tip)); 4672 4673 // Ensure KernelNotifications m_tip_block is set even if no new block arrives. 4674 if (this->GetRole() != ChainstateRole::BACKGROUND) { 4675 // Ignoring return value for now. 4676 (void)m_chainman.GetNotifications().blockTip(GetSynchronizationState(/*init=*/true, m_chainman.m_blockman.m_blockfiles_indexed), *pindex); 4677 } 4678 4679 return true; 4680 } 4681 4682 CVerifyDB::CVerifyDB(Notifications& notifications) 4683 : m_notifications{notifications} 4684 { 4685 m_notifications.progress(_("Verifying blocks…"), 0, false); 4686 } 4687 4688 CVerifyDB::~CVerifyDB() 4689 { 4690 m_notifications.progress(bilingual_str{}, 100, false); 4691 } 4692 4693 VerifyDBResult CVerifyDB::VerifyDB( 4694 Chainstate& chainstate, 4695 const Consensus::Params& consensus_params, 4696 CCoinsView& coinsview, 4697 int nCheckLevel, int nCheckDepth) 4698 { 4699 AssertLockHeld(cs_main); 4700 4701 if (chainstate.m_chain.Tip() == nullptr || chainstate.m_chain.Tip()->pprev == nullptr) { 4702 return VerifyDBResult::SUCCESS; 4703 } 4704 4705 // Verify blocks in the best chain 4706 if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) { 4707 nCheckDepth = chainstate.m_chain.Height(); 4708 } 4709 nCheckLevel = std::max(0, std::min(4, nCheckLevel)); 4710 LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel); 4711 CCoinsViewCache coins(&coinsview); 4712 CBlockIndex* pindex; 4713 CBlockIndex* pindexFailure = nullptr; 4714 int nGoodTransactions = 0; 4715 BlockValidationState state; 4716 int reportDone = 0; 4717 bool skipped_no_block_data{false}; 4718 bool skipped_l3_checks{false}; 4719 LogPrintf("Verification progress: 0%%\n"); 4720 4721 const bool is_snapshot_cs{chainstate.m_from_snapshot_blockhash}; 4722 4723 for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev; pindex = pindex->pprev) { 4724 const int percentageDone = std::max(1, std::min(99, (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100)))); 4725 if (reportDone < percentageDone / 10) { 4726 // report every 10% step 4727 LogPrintf("Verification progress: %d%%\n", percentageDone); 4728 reportDone = percentageDone / 10; 4729 } 4730 m_notifications.progress(_("Verifying blocks…"), percentageDone, false); 4731 if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) { 4732 break; 4733 } 4734 if ((chainstate.m_blockman.IsPruneMode() || is_snapshot_cs) && !(pindex->nStatus & BLOCK_HAVE_DATA)) { 4735 // If pruning or running under an assumeutxo snapshot, only go 4736 // back as far as we have data. 4737 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); 4738 skipped_no_block_data = true; 4739 break; 4740 } 4741 CBlock block; 4742 // check level 0: read from disk 4743 if (!chainstate.m_blockman.ReadBlock(block, *pindex)) { 4744 LogPrintf("Verification error: ReadBlock failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4745 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4746 } 4747 // check level 1: verify block validity 4748 if (nCheckLevel >= 1 && !CheckBlock(block, state, consensus_params)) { 4749 LogPrintf("Verification error: found bad block at %d, hash=%s (%s)\n", 4750 pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString()); 4751 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4752 } 4753 // check level 2: verify undo validity 4754 if (nCheckLevel >= 2 && pindex) { 4755 CBlockUndo undo; 4756 if (!pindex->GetUndoPos().IsNull()) { 4757 if (!chainstate.m_blockman.ReadBlockUndo(undo, *pindex)) { 4758 LogPrintf("Verification error: found bad undo data at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4759 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4760 } 4761 } 4762 } 4763 // check level 3: check for inconsistencies during memory-only disconnect of tip blocks 4764 size_t curr_coins_usage = coins.DynamicMemoryUsage() + chainstate.CoinsTip().DynamicMemoryUsage(); 4765 4766 if (nCheckLevel >= 3) { 4767 if (curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) { 4768 assert(coins.GetBestBlock() == pindex->GetBlockHash()); 4769 DisconnectResult res = chainstate.DisconnectBlock(block, pindex, coins); 4770 if (res == DISCONNECT_FAILED) { 4771 LogPrintf("Verification error: irrecoverable inconsistency in block data at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4772 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4773 } 4774 if (res == DISCONNECT_UNCLEAN) { 4775 nGoodTransactions = 0; 4776 pindexFailure = pindex; 4777 } else { 4778 nGoodTransactions += block.vtx.size(); 4779 } 4780 } else { 4781 skipped_l3_checks = true; 4782 } 4783 } 4784 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED; 4785 } 4786 if (pindexFailure) { 4787 LogPrintf("Verification error: coin database inconsistencies found (last %i blocks, %i good transactions before that)\n", chainstate.m_chain.Height() - pindexFailure->nHeight + 1, nGoodTransactions); 4788 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4789 } 4790 if (skipped_l3_checks) { 4791 LogPrintf("Skipped verification of level >=3 (insufficient database cache size). Consider increasing -dbcache.\n"); 4792 } 4793 4794 // store block count as we move pindex at check level >= 4 4795 int block_count = chainstate.m_chain.Height() - pindex->nHeight; 4796 4797 // check level 4: try reconnecting blocks 4798 if (nCheckLevel >= 4 && !skipped_l3_checks) { 4799 while (pindex != chainstate.m_chain.Tip()) { 4800 const int percentageDone = std::max(1, std::min(99, 100 - (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * 50))); 4801 if (reportDone < percentageDone / 10) { 4802 // report every 10% step 4803 LogPrintf("Verification progress: %d%%\n", percentageDone); 4804 reportDone = percentageDone / 10; 4805 } 4806 m_notifications.progress(_("Verifying blocks…"), percentageDone, false); 4807 pindex = chainstate.m_chain.Next(pindex); 4808 CBlock block; 4809 if (!chainstate.m_blockman.ReadBlock(block, *pindex)) { 4810 LogPrintf("Verification error: ReadBlock failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4811 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4812 } 4813 if (!chainstate.ConnectBlock(block, state, pindex, coins)) { 4814 LogPrintf("Verification error: found unconnectable block at %d, hash=%s (%s)\n", pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString()); 4815 return VerifyDBResult::CORRUPTED_BLOCK_DB; 4816 } 4817 if (chainstate.m_chainman.m_interrupt) return VerifyDBResult::INTERRUPTED; 4818 } 4819 } 4820 4821 LogPrintf("Verification: No coin database inconsistencies in last %i blocks (%i transactions)\n", block_count, nGoodTransactions); 4822 4823 if (skipped_l3_checks) { 4824 return VerifyDBResult::SKIPPED_L3_CHECKS; 4825 } 4826 if (skipped_no_block_data) { 4827 return VerifyDBResult::SKIPPED_MISSING_BLOCKS; 4828 } 4829 return VerifyDBResult::SUCCESS; 4830 } 4831 4832 /** Apply the effects of a block on the utxo cache, ignoring that it may already have been applied. */ 4833 bool Chainstate::RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs) 4834 { 4835 AssertLockHeld(cs_main); 4836 // TODO: merge with ConnectBlock 4837 CBlock block; 4838 if (!m_blockman.ReadBlock(block, *pindex)) { 4839 LogError("ReplayBlock(): ReadBlock failed at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4840 return false; 4841 } 4842 4843 for (const CTransactionRef& tx : block.vtx) { 4844 if (!tx->IsCoinBase()) { 4845 for (const CTxIn &txin : tx->vin) { 4846 inputs.SpendCoin(txin.prevout); 4847 } 4848 } 4849 // Pass check = true as every addition may be an overwrite. 4850 AddCoins(inputs, *tx, pindex->nHeight, true); 4851 } 4852 return true; 4853 } 4854 4855 bool Chainstate::ReplayBlocks() 4856 { 4857 LOCK(cs_main); 4858 4859 CCoinsView& db = this->CoinsDB(); 4860 CCoinsViewCache cache(&db); 4861 4862 std::vector<uint256> hashHeads = db.GetHeadBlocks(); 4863 if (hashHeads.empty()) return true; // We're already in a consistent state. 4864 if (hashHeads.size() != 2) { 4865 LogError("ReplayBlocks(): unknown inconsistent state\n"); 4866 return false; 4867 } 4868 4869 m_chainman.GetNotifications().progress(_("Replaying blocks…"), 0, false); 4870 LogPrintf("Replaying blocks\n"); 4871 4872 const CBlockIndex* pindexOld = nullptr; // Old tip during the interrupted flush. 4873 const CBlockIndex* pindexNew; // New tip during the interrupted flush. 4874 const CBlockIndex* pindexFork = nullptr; // Latest block common to both the old and the new tip. 4875 4876 if (m_blockman.m_block_index.count(hashHeads[0]) == 0) { 4877 LogError("ReplayBlocks(): reorganization to unknown block requested\n"); 4878 return false; 4879 } 4880 pindexNew = &(m_blockman.m_block_index[hashHeads[0]]); 4881 4882 if (!hashHeads[1].IsNull()) { // The old tip is allowed to be 0, indicating it's the first flush. 4883 if (m_blockman.m_block_index.count(hashHeads[1]) == 0) { 4884 LogError("ReplayBlocks(): reorganization from unknown block requested\n"); 4885 return false; 4886 } 4887 pindexOld = &(m_blockman.m_block_index[hashHeads[1]]); 4888 pindexFork = LastCommonAncestor(pindexOld, pindexNew); 4889 assert(pindexFork != nullptr); 4890 } 4891 4892 // Rollback along the old branch. 4893 while (pindexOld != pindexFork) { 4894 if (pindexOld->nHeight > 0) { // Never disconnect the genesis block. 4895 CBlock block; 4896 if (!m_blockman.ReadBlock(block, *pindexOld)) { 4897 LogError("RollbackBlock(): ReadBlock() failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString()); 4898 return false; 4899 } 4900 LogPrintf("Rolling back %s (%i)\n", pindexOld->GetBlockHash().ToString(), pindexOld->nHeight); 4901 DisconnectResult res = DisconnectBlock(block, pindexOld, cache); 4902 if (res == DISCONNECT_FAILED) { 4903 LogError("RollbackBlock(): DisconnectBlock failed at %d, hash=%s\n", pindexOld->nHeight, pindexOld->GetBlockHash().ToString()); 4904 return false; 4905 } 4906 // If DISCONNECT_UNCLEAN is returned, it means a non-existing UTXO was deleted, or an existing UTXO was 4907 // overwritten. It corresponds to cases where the block-to-be-disconnect never had all its operations 4908 // applied to the UTXO set. However, as both writing a UTXO and deleting a UTXO are idempotent operations, 4909 // the result is still a version of the UTXO set with the effects of that block undone. 4910 } 4911 pindexOld = pindexOld->pprev; 4912 } 4913 4914 // Roll forward from the forking point to the new tip. 4915 int nForkHeight = pindexFork ? pindexFork->nHeight : 0; 4916 for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight; ++nHeight) { 4917 const CBlockIndex& pindex{*Assert(pindexNew->GetAncestor(nHeight))}; 4918 4919 LogPrintf("Rolling forward %s (%i)\n", pindex.GetBlockHash().ToString(), nHeight); 4920 m_chainman.GetNotifications().progress(_("Replaying blocks…"), (int)((nHeight - nForkHeight) * 100.0 / (pindexNew->nHeight - nForkHeight)), false); 4921 if (!RollforwardBlock(&pindex, cache)) return false; 4922 } 4923 4924 cache.SetBestBlock(pindexNew->GetBlockHash()); 4925 cache.Flush(); 4926 m_chainman.GetNotifications().progress(bilingual_str{}, 100, false); 4927 return true; 4928 } 4929 4930 bool Chainstate::NeedsRedownload() const 4931 { 4932 AssertLockHeld(cs_main); 4933 4934 // At and above m_params.SegwitHeight, segwit consensus rules must be validated 4935 CBlockIndex* block{m_chain.Tip()}; 4936 4937 while (block != nullptr && DeploymentActiveAt(*block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) { 4938 if (!(block->nStatus & BLOCK_OPT_WITNESS)) { 4939 // block is insufficiently validated for a segwit client 4940 return true; 4941 } 4942 block = block->pprev; 4943 } 4944 4945 return false; 4946 } 4947 4948 void Chainstate::ClearBlockIndexCandidates() 4949 { 4950 AssertLockHeld(::cs_main); 4951 setBlockIndexCandidates.clear(); 4952 } 4953 4954 bool ChainstateManager::LoadBlockIndex() 4955 { 4956 AssertLockHeld(cs_main); 4957 // Load block index from databases 4958 if (m_blockman.m_blockfiles_indexed) { 4959 bool ret{m_blockman.LoadBlockIndexDB(SnapshotBlockhash())}; 4960 if (!ret) return false; 4961 4962 m_blockman.ScanAndUnlinkAlreadyPrunedFiles(); 4963 4964 std::vector<CBlockIndex*> vSortedByHeight{m_blockman.GetAllBlockIndices()}; 4965 std::sort(vSortedByHeight.begin(), vSortedByHeight.end(), 4966 CBlockIndexHeightOnlyComparator()); 4967 4968 for (CBlockIndex* pindex : vSortedByHeight) { 4969 if (m_interrupt) return false; 4970 // If we have an assumeutxo-based chainstate, then the snapshot 4971 // block will be a candidate for the tip, but it may not be 4972 // VALID_TRANSACTIONS (eg if we haven't yet downloaded the block), 4973 // so we special-case the snapshot block as a potential candidate 4974 // here. 4975 if (pindex == GetSnapshotBaseBlock() || 4976 (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && 4977 (pindex->HaveNumChainTxs() || pindex->pprev == nullptr))) { 4978 4979 for (Chainstate* chainstate : GetAll()) { 4980 chainstate->TryAddBlockIndexCandidate(pindex); 4981 } 4982 } 4983 if (pindex->nStatus & BLOCK_FAILED_MASK && (!m_best_invalid || pindex->nChainWork > m_best_invalid->nChainWork)) { 4984 m_best_invalid = pindex; 4985 } 4986 if (pindex->IsValid(BLOCK_VALID_TREE) && (m_best_header == nullptr || CBlockIndexWorkComparator()(m_best_header, pindex))) 4987 m_best_header = pindex; 4988 } 4989 } 4990 return true; 4991 } 4992 4993 bool Chainstate::LoadGenesisBlock() 4994 { 4995 LOCK(cs_main); 4996 4997 const CChainParams& params{m_chainman.GetParams()}; 4998 4999 // Check whether we're already initialized by checking for genesis in 5000 // m_blockman.m_block_index. Note that we can't use m_chain here, since it is 5001 // set based on the coins db, not the block index db, which is the only 5002 // thing loaded at this point. 5003 if (m_blockman.m_block_index.count(params.GenesisBlock().GetHash())) 5004 return true; 5005 5006 try { 5007 const CBlock& block = params.GenesisBlock(); 5008 FlatFilePos blockPos{m_blockman.WriteBlock(block, 0)}; 5009 if (blockPos.IsNull()) { 5010 LogError("%s: writing genesis block to disk failed\n", __func__); 5011 return false; 5012 } 5013 CBlockIndex* pindex = m_blockman.AddToBlockIndex(block, m_chainman.m_best_header); 5014 m_chainman.ReceivedBlockTransactions(block, pindex, blockPos); 5015 } catch (const std::runtime_error& e) { 5016 LogError("%s: failed to write genesis block: %s\n", __func__, e.what()); 5017 return false; 5018 } 5019 5020 return true; 5021 } 5022 5023 void ChainstateManager::LoadExternalBlockFile( 5024 AutoFile& file_in, 5025 FlatFilePos* dbp, 5026 std::multimap<uint256, FlatFilePos>* blocks_with_unknown_parent) 5027 { 5028 // Either both should be specified (-reindex), or neither (-loadblock). 5029 assert(!dbp == !blocks_with_unknown_parent); 5030 5031 const auto start{SteadyClock::now()}; 5032 const CChainParams& params{GetParams()}; 5033 5034 int nLoaded = 0; 5035 try { 5036 BufferedFile blkdat{file_in, 2 * MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE + 8}; 5037 // nRewind indicates where to resume scanning in case something goes wrong, 5038 // such as a block fails to deserialize. 5039 uint64_t nRewind = blkdat.GetPos(); 5040 while (!blkdat.eof()) { 5041 if (m_interrupt) return; 5042 5043 blkdat.SetPos(nRewind); 5044 nRewind++; // start one byte further next time, in case of failure 5045 blkdat.SetLimit(); // remove former limit 5046 unsigned int nSize = 0; 5047 try { 5048 // locate a header 5049 MessageStartChars buf; 5050 blkdat.FindByte(std::byte(params.MessageStart()[0])); 5051 nRewind = blkdat.GetPos() + 1; 5052 blkdat >> buf; 5053 if (buf != params.MessageStart()) { 5054 continue; 5055 } 5056 // read size 5057 blkdat >> nSize; 5058 if (nSize < 80 || nSize > MAX_BLOCK_SERIALIZED_SIZE) 5059 continue; 5060 } catch (const std::exception&) { 5061 // no valid block header found; don't complain 5062 // (this happens at the end of every blk.dat file) 5063 break; 5064 } 5065 try { 5066 // read block header 5067 const uint64_t nBlockPos{blkdat.GetPos()}; 5068 if (dbp) 5069 dbp->nPos = nBlockPos; 5070 blkdat.SetLimit(nBlockPos + nSize); 5071 CBlockHeader header; 5072 blkdat >> header; 5073 const uint256 hash{header.GetHash()}; 5074 // Skip the rest of this block (this may read from disk into memory); position to the marker before the 5075 // next block, but it's still possible to rewind to the start of the current block (without a disk read). 5076 nRewind = nBlockPos + nSize; 5077 blkdat.SkipTo(nRewind); 5078 5079 std::shared_ptr<CBlock> pblock{}; // needs to remain available after the cs_main lock is released to avoid duplicate reads from disk 5080 5081 { 5082 LOCK(cs_main); 5083 // detect out of order blocks, and store them for later 5084 if (hash != params.GetConsensus().hashGenesisBlock && !m_blockman.LookupBlockIndex(header.hashPrevBlock)) { 5085 LogDebug(BCLog::REINDEX, "%s: Out of order block %s, parent %s not known\n", __func__, hash.ToString(), 5086 header.hashPrevBlock.ToString()); 5087 if (dbp && blocks_with_unknown_parent) { 5088 blocks_with_unknown_parent->emplace(header.hashPrevBlock, *dbp); 5089 } 5090 continue; 5091 } 5092 5093 // process in case the block isn't known yet 5094 const CBlockIndex* pindex = m_blockman.LookupBlockIndex(hash); 5095 if (!pindex || (pindex->nStatus & BLOCK_HAVE_DATA) == 0) { 5096 // This block can be processed immediately; rewind to its start, read and deserialize it. 5097 blkdat.SetPos(nBlockPos); 5098 pblock = std::make_shared<CBlock>(); 5099 blkdat >> TX_WITH_WITNESS(*pblock); 5100 nRewind = blkdat.GetPos(); 5101 5102 BlockValidationState state; 5103 if (AcceptBlock(pblock, state, nullptr, true, dbp, nullptr, true)) { 5104 nLoaded++; 5105 } 5106 if (state.IsError()) { 5107 break; 5108 } 5109 } else if (hash != params.GetConsensus().hashGenesisBlock && pindex->nHeight % 1000 == 0) { 5110 LogDebug(BCLog::REINDEX, "Block Import: already had block %s at height %d\n", hash.ToString(), pindex->nHeight); 5111 } 5112 } 5113 5114 // Activate the genesis block so normal node progress can continue 5115 // During first -reindex, this will only connect Genesis since 5116 // ActivateBestChain only connects blocks which are in the block tree db, 5117 // which only contains blocks whose parents are in it. 5118 // But do this only if genesis isn't activated yet, to avoid connecting many blocks 5119 // without assumevalid in the case of a continuation of a reindex that 5120 // was interrupted by the user. 5121 if (hash == params.GetConsensus().hashGenesisBlock && WITH_LOCK(::cs_main, return ActiveHeight()) == -1) { 5122 BlockValidationState state; 5123 if (!ActiveChainstate().ActivateBestChain(state, nullptr)) { 5124 break; 5125 } 5126 } 5127 5128 if (m_blockman.IsPruneMode() && m_blockman.m_blockfiles_indexed && pblock) { 5129 // must update the tip for pruning to work while importing with -loadblock. 5130 // this is a tradeoff to conserve disk space at the expense of time 5131 // spent updating the tip to be able to prune. 5132 // otherwise, ActivateBestChain won't be called by the import process 5133 // until after all of the block files are loaded. ActivateBestChain can be 5134 // called by concurrent network message processing. but, that is not 5135 // reliable for the purpose of pruning while importing. 5136 bool activation_failure = false; 5137 for (auto c : GetAll()) { 5138 BlockValidationState state; 5139 if (!c->ActivateBestChain(state, pblock)) { 5140 LogDebug(BCLog::REINDEX, "failed to activate chain (%s)\n", state.ToString()); 5141 activation_failure = true; 5142 break; 5143 } 5144 } 5145 if (activation_failure) { 5146 break; 5147 } 5148 } 5149 5150 NotifyHeaderTip(); 5151 5152 if (!blocks_with_unknown_parent) continue; 5153 5154 // Recursively process earlier encountered successors of this block 5155 std::deque<uint256> queue; 5156 queue.push_back(hash); 5157 while (!queue.empty()) { 5158 uint256 head = queue.front(); 5159 queue.pop_front(); 5160 auto range = blocks_with_unknown_parent->equal_range(head); 5161 while (range.first != range.second) { 5162 std::multimap<uint256, FlatFilePos>::iterator it = range.first; 5163 std::shared_ptr<CBlock> pblockrecursive = std::make_shared<CBlock>(); 5164 if (m_blockman.ReadBlock(*pblockrecursive, it->second)) { 5165 LogDebug(BCLog::REINDEX, "%s: Processing out of order child %s of %s\n", __func__, pblockrecursive->GetHash().ToString(), 5166 head.ToString()); 5167 LOCK(cs_main); 5168 BlockValidationState dummy; 5169 if (AcceptBlock(pblockrecursive, dummy, nullptr, true, &it->second, nullptr, true)) { 5170 nLoaded++; 5171 queue.push_back(pblockrecursive->GetHash()); 5172 } 5173 } 5174 range.first++; 5175 blocks_with_unknown_parent->erase(it); 5176 NotifyHeaderTip(); 5177 } 5178 } 5179 } catch (const std::exception& e) { 5180 // historical bugs added extra data to the block files that does not deserialize cleanly. 5181 // commonly this data is between readable blocks, but it does not really matter. such data is not fatal to the import process. 5182 // the code that reads the block files deals with invalid data by simply ignoring it. 5183 // it continues to search for the next {4 byte magic message start bytes + 4 byte length + block} that does deserialize cleanly 5184 // and passes all of the other block validation checks dealing with POW and the merkle root, etc... 5185 // we merely note with this informational log message when unexpected data is encountered. 5186 // we could also be experiencing a storage system read error, or a read of a previous bad write. these are possible, but 5187 // less likely scenarios. we don't have enough information to tell a difference here. 5188 // the reindex process is not the place to attempt to clean and/or compact the block files. if so desired, a studious node operator 5189 // may use knowledge of the fact that the block files are not entirely pristine in order to prepare a set of pristine, and 5190 // perhaps ordered, block files for later reindexing. 5191 LogDebug(BCLog::REINDEX, "%s: unexpected data at file offset 0x%x - %s. continuing\n", __func__, (nRewind - 1), e.what()); 5192 } 5193 } 5194 } catch (const std::runtime_error& e) { 5195 GetNotifications().fatalError(strprintf(_("System error while loading external block file: %s"), e.what())); 5196 } 5197 LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded, Ticks<std::chrono::milliseconds>(SteadyClock::now() - start)); 5198 } 5199 5200 bool ChainstateManager::ShouldCheckBlockIndex() const 5201 { 5202 // Assert to verify Flatten() has been called. 5203 if (!*Assert(m_options.check_block_index)) return false; 5204 if (FastRandomContext().randrange(*m_options.check_block_index) >= 1) return false; 5205 return true; 5206 } 5207 5208 void ChainstateManager::CheckBlockIndex() 5209 { 5210 if (!ShouldCheckBlockIndex()) { 5211 return; 5212 } 5213 5214 LOCK(cs_main); 5215 5216 // During a reindex, we read the genesis block and call CheckBlockIndex before ActivateBestChain, 5217 // so we have the genesis block in m_blockman.m_block_index but no active chain. (A few of the 5218 // tests when iterating the block tree require that m_chain has been initialized.) 5219 if (ActiveChain().Height() < 0) { 5220 assert(m_blockman.m_block_index.size() <= 1); 5221 return; 5222 } 5223 5224 // Build forward-pointing data structure for the entire block tree. 5225 // For performance reasons, indexes of the best header chain are stored in a vector (within CChain). 5226 // All remaining blocks are stored in a multimap. 5227 // The best header chain can differ from the active chain: E.g. its entries may belong to blocks that 5228 // are not yet validated. 5229 CChain best_hdr_chain; 5230 assert(m_best_header); 5231 best_hdr_chain.SetTip(*m_best_header); 5232 5233 std::multimap<CBlockIndex*,CBlockIndex*> forward; 5234 for (auto& [_, block_index] : m_blockman.m_block_index) { 5235 // Only save indexes in forward that are not part of the best header chain. 5236 if (!best_hdr_chain.Contains(&block_index)) { 5237 // Only genesis, which must be part of the best header chain, can have a nullptr parent. 5238 assert(block_index.pprev); 5239 forward.emplace(block_index.pprev, &block_index); 5240 } 5241 } 5242 assert(forward.size() + best_hdr_chain.Height() + 1 == m_blockman.m_block_index.size()); 5243 5244 CBlockIndex* pindex = best_hdr_chain[0]; 5245 assert(pindex); 5246 // Iterate over the entire block tree, using depth-first search. 5247 // Along the way, remember whether there are blocks on the path from genesis 5248 // block being explored which are the first to have certain properties. 5249 size_t nNodes = 0; 5250 int nHeight = 0; 5251 CBlockIndex* pindexFirstInvalid = nullptr; // Oldest ancestor of pindex which is invalid. 5252 CBlockIndex* pindexFirstMissing = nullptr; // Oldest ancestor of pindex which does not have BLOCK_HAVE_DATA, since assumeutxo snapshot if used. 5253 CBlockIndex* pindexFirstNeverProcessed = nullptr; // Oldest ancestor of pindex for which nTx == 0, since assumeutxo snapshot if used. 5254 CBlockIndex* pindexFirstNotTreeValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE (regardless of being valid or not). 5255 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. 5256 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. 5257 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. 5258 5259 // After checking an assumeutxo snapshot block, reset pindexFirst pointers 5260 // to earlier blocks that have not been downloaded or validated yet, so 5261 // checks for later blocks can assume the earlier blocks were validated and 5262 // be stricter, testing for more requirements. 5263 const CBlockIndex* snap_base{GetSnapshotBaseBlock()}; 5264 CBlockIndex *snap_first_missing{}, *snap_first_notx{}, *snap_first_notv{}, *snap_first_nocv{}, *snap_first_nosv{}; 5265 auto snap_update_firsts = [&] { 5266 if (pindex == snap_base) { 5267 std::swap(snap_first_missing, pindexFirstMissing); 5268 std::swap(snap_first_notx, pindexFirstNeverProcessed); 5269 std::swap(snap_first_notv, pindexFirstNotTransactionsValid); 5270 std::swap(snap_first_nocv, pindexFirstNotChainValid); 5271 std::swap(snap_first_nosv, pindexFirstNotScriptsValid); 5272 } 5273 }; 5274 5275 while (pindex != nullptr) { 5276 nNodes++; 5277 if (pindexFirstInvalid == nullptr && pindex->nStatus & BLOCK_FAILED_VALID) pindexFirstInvalid = pindex; 5278 if (pindexFirstMissing == nullptr && !(pindex->nStatus & BLOCK_HAVE_DATA)) { 5279 pindexFirstMissing = pindex; 5280 } 5281 if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) pindexFirstNeverProcessed = pindex; 5282 if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr && (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TREE) pindexFirstNotTreeValid = pindex; 5283 5284 if (pindex->pprev != nullptr) { 5285 if (pindexFirstNotTransactionsValid == nullptr && 5286 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TRANSACTIONS) { 5287 pindexFirstNotTransactionsValid = pindex; 5288 } 5289 5290 if (pindexFirstNotChainValid == nullptr && 5291 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_CHAIN) { 5292 pindexFirstNotChainValid = pindex; 5293 } 5294 5295 if (pindexFirstNotScriptsValid == nullptr && 5296 (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_SCRIPTS) { 5297 pindexFirstNotScriptsValid = pindex; 5298 } 5299 } 5300 5301 // Begin: actual consistency checks. 5302 if (pindex->pprev == nullptr) { 5303 // Genesis block checks. 5304 assert(pindex->GetBlockHash() == GetConsensus().hashGenesisBlock); // Genesis block's hash must match. 5305 for (auto c : GetAll()) { 5306 if (c->m_chain.Genesis() != nullptr) { 5307 assert(pindex == c->m_chain.Genesis()); // The chain's genesis block must be this block. 5308 } 5309 } 5310 } 5311 if (!pindex->HaveNumChainTxs()) assert(pindex->nSequenceId <= 0); // nSequenceId can't be set positive for blocks that aren't linked (negative is used for preciousblock) 5312 // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or not pruning has occurred). 5313 // HAVE_DATA is only equivalent to nTx > 0 (or VALID_TRANSACTIONS) if no pruning has occurred. 5314 if (!m_blockman.m_have_pruned) { 5315 // If we've never pruned, then HAVE_DATA should be equivalent to nTx > 0 5316 assert(!(pindex->nStatus & BLOCK_HAVE_DATA) == (pindex->nTx == 0)); 5317 assert(pindexFirstMissing == pindexFirstNeverProcessed); 5318 } else { 5319 // If we have pruned, then we can only say that HAVE_DATA implies nTx > 0 5320 if (pindex->nStatus & BLOCK_HAVE_DATA) assert(pindex->nTx > 0); 5321 } 5322 if (pindex->nStatus & BLOCK_HAVE_UNDO) assert(pindex->nStatus & BLOCK_HAVE_DATA); 5323 if (snap_base && snap_base->GetAncestor(pindex->nHeight) == pindex) { 5324 // Assumed-valid blocks should connect to the main chain. 5325 assert((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE); 5326 } 5327 // There should only be an nTx value if we have 5328 // actually seen a block's transactions. 5329 assert(((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS) == (pindex->nTx > 0)); // This is pruning-independent. 5330 // All parents having had data (at some point) is equivalent to all parents being VALID_TRANSACTIONS, which is equivalent to HaveNumChainTxs(). 5331 // HaveNumChainTxs will also be set in the assumeutxo snapshot block from snapshot metadata. 5332 assert((pindexFirstNeverProcessed == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs()); 5333 assert((pindexFirstNotTransactionsValid == nullptr || pindex == snap_base) == pindex->HaveNumChainTxs()); 5334 assert(pindex->nHeight == nHeight); // nHeight must be consistent. 5335 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. 5336 assert(nHeight < 2 || (pindex->pskip && (pindex->pskip->nHeight < nHeight))); // The pskip pointer must point back for all but the first 2 blocks. 5337 assert(pindexFirstNotTreeValid == nullptr); // All m_blockman.m_block_index entries must at least be TREE valid 5338 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE) assert(pindexFirstNotTreeValid == nullptr); // TREE valid implies all parents are TREE valid 5339 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_CHAIN) assert(pindexFirstNotChainValid == nullptr); // CHAIN valid implies all parents are CHAIN valid 5340 if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_SCRIPTS) assert(pindexFirstNotScriptsValid == nullptr); // SCRIPTS valid implies all parents are SCRIPTS valid 5341 if (pindexFirstInvalid == nullptr) { 5342 // Checks for not-invalid blocks. 5343 assert((pindex->nStatus & BLOCK_FAILED_MASK) == 0); // The failed mask cannot be set for blocks without invalid parents. 5344 } 5345 // Make sure m_chain_tx_count sum is correctly computed. 5346 if (!pindex->pprev) { 5347 // If no previous block, nTx and m_chain_tx_count must be the same. 5348 assert(pindex->m_chain_tx_count == pindex->nTx); 5349 } else if (pindex->pprev->m_chain_tx_count > 0 && pindex->nTx > 0) { 5350 // If previous m_chain_tx_count is set and number of transactions in block is known, sum must be set. 5351 assert(pindex->m_chain_tx_count == pindex->nTx + pindex->pprev->m_chain_tx_count); 5352 } else { 5353 // Otherwise m_chain_tx_count should only be set if this is a snapshot 5354 // block, and must be set if it is. 5355 assert((pindex->m_chain_tx_count != 0) == (pindex == snap_base)); 5356 } 5357 5358 // Chainstate-specific checks on setBlockIndexCandidates 5359 for (auto c : GetAll()) { 5360 if (c->m_chain.Tip() == nullptr) continue; 5361 // Two main factors determine whether pindex is a candidate in 5362 // setBlockIndexCandidates: 5363 // 5364 // - If pindex has less work than the chain tip, it should not be a 5365 // candidate, and this will be asserted below. Otherwise it is a 5366 // potential candidate. 5367 // 5368 // - If pindex or one of its parent blocks back to the genesis block 5369 // or an assumeutxo snapshot never downloaded transactions 5370 // (pindexFirstNeverProcessed is non-null), it should not be a 5371 // candidate, and this will be asserted below. The only exception 5372 // is if pindex itself is an assumeutxo snapshot block. Then it is 5373 // also a potential candidate. 5374 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && (pindexFirstNeverProcessed == nullptr || pindex == snap_base)) { 5375 // If pindex was detected as invalid (pindexFirstInvalid is 5376 // non-null), it is not required to be in 5377 // setBlockIndexCandidates. 5378 if (pindexFirstInvalid == nullptr) { 5379 // If pindex and all its parents back to the genesis block 5380 // or an assumeutxo snapshot block downloaded transactions, 5381 // and the transactions were not pruned (pindexFirstMissing 5382 // is null), it is a potential candidate. The check 5383 // excludes pruned blocks, because if any blocks were 5384 // pruned between pindex and the current chain tip, pindex will 5385 // only temporarily be added to setBlockIndexCandidates, 5386 // before being moved to m_blocks_unlinked. This check 5387 // could be improved to verify that if all blocks between 5388 // the chain tip and pindex have data, pindex must be a 5389 // candidate. 5390 // 5391 // If pindex is the chain tip, it also is a potential 5392 // candidate. 5393 // 5394 // If the chainstate was loaded from a snapshot and pindex 5395 // is the base of the snapshot, pindex is also a potential 5396 // candidate. 5397 if (pindexFirstMissing == nullptr || pindex == c->m_chain.Tip() || pindex == c->SnapshotBase()) { 5398 // If this chainstate is the active chainstate, pindex 5399 // must be in setBlockIndexCandidates. Otherwise, this 5400 // chainstate is a background validation chainstate, and 5401 // pindex only needs to be added if it is an ancestor of 5402 // the snapshot that is being validated. 5403 if (c == &ActiveChainstate() || snap_base->GetAncestor(pindex->nHeight) == pindex) { 5404 assert(c->setBlockIndexCandidates.count(pindex)); 5405 } 5406 } 5407 // If some parent is missing, then it could be that this block was in 5408 // setBlockIndexCandidates but had to be removed because of the missing data. 5409 // In this case it must be in m_blocks_unlinked -- see test below. 5410 } 5411 } else { // If this block sorts worse than the current tip or some ancestor's block has never been seen, it cannot be in setBlockIndexCandidates. 5412 assert(c->setBlockIndexCandidates.count(pindex) == 0); 5413 } 5414 } 5415 // Check whether this block is in m_blocks_unlinked. 5416 std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangeUnlinked = m_blockman.m_blocks_unlinked.equal_range(pindex->pprev); 5417 bool foundInUnlinked = false; 5418 while (rangeUnlinked.first != rangeUnlinked.second) { 5419 assert(rangeUnlinked.first->first == pindex->pprev); 5420 if (rangeUnlinked.first->second == pindex) { 5421 foundInUnlinked = true; 5422 break; 5423 } 5424 rangeUnlinked.first++; 5425 } 5426 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed != nullptr && pindexFirstInvalid == nullptr) { 5427 // If this block has block data available, some parent was never received, and has no invalid parents, it must be in m_blocks_unlinked. 5428 assert(foundInUnlinked); 5429 } 5430 if (!(pindex->nStatus & BLOCK_HAVE_DATA)) assert(!foundInUnlinked); // Can't be in m_blocks_unlinked if we don't HAVE_DATA 5431 if (pindexFirstMissing == nullptr) assert(!foundInUnlinked); // We aren't missing data for any parent -- cannot be in m_blocks_unlinked. 5432 if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed == nullptr && pindexFirstMissing != nullptr) { 5433 // We HAVE_DATA for this block, have received data for all parents at some point, but we're currently missing data for some parent. 5434 assert(m_blockman.m_have_pruned); 5435 // This block may have entered m_blocks_unlinked if: 5436 // - it has a descendant that at some point had more work than the 5437 // tip, and 5438 // - we tried switching to that descendant but were missing 5439 // data for some intermediate block between m_chain and the 5440 // tip. 5441 // So if this block is itself better than any m_chain.Tip() and it wasn't in 5442 // setBlockIndexCandidates, then it must be in m_blocks_unlinked. 5443 for (auto c : GetAll()) { 5444 const bool is_active = c == &ActiveChainstate(); 5445 if (!CBlockIndexWorkComparator()(pindex, c->m_chain.Tip()) && c->setBlockIndexCandidates.count(pindex) == 0) { 5446 if (pindexFirstInvalid == nullptr) { 5447 if (is_active || snap_base->GetAncestor(pindex->nHeight) == pindex) { 5448 assert(foundInUnlinked); 5449 } 5450 } 5451 } 5452 } 5453 } 5454 // assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash()); // Perhaps too slow 5455 // End: actual consistency checks. 5456 5457 5458 // Try descending into the first subnode. Always process forks first and the best header chain after. 5459 snap_update_firsts(); 5460 std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> range = forward.equal_range(pindex); 5461 if (range.first != range.second) { 5462 // A subnode not part of the best header chain was found. 5463 pindex = range.first->second; 5464 nHeight++; 5465 continue; 5466 } else if (best_hdr_chain.Contains(pindex)) { 5467 // Descend further into best header chain. 5468 nHeight++; 5469 pindex = best_hdr_chain[nHeight]; 5470 if (!pindex) break; // we are finished, since the best header chain is always processed last 5471 continue; 5472 } 5473 // This is a leaf node. 5474 // Move upwards until we reach a node of which we have not yet visited the last child. 5475 while (pindex) { 5476 // We are going to either move to a parent or a sibling of pindex. 5477 snap_update_firsts(); 5478 // If pindex was the first with a certain property, unset the corresponding variable. 5479 if (pindex == pindexFirstInvalid) pindexFirstInvalid = nullptr; 5480 if (pindex == pindexFirstMissing) pindexFirstMissing = nullptr; 5481 if (pindex == pindexFirstNeverProcessed) pindexFirstNeverProcessed = nullptr; 5482 if (pindex == pindexFirstNotTreeValid) pindexFirstNotTreeValid = nullptr; 5483 if (pindex == pindexFirstNotTransactionsValid) pindexFirstNotTransactionsValid = nullptr; 5484 if (pindex == pindexFirstNotChainValid) pindexFirstNotChainValid = nullptr; 5485 if (pindex == pindexFirstNotScriptsValid) pindexFirstNotScriptsValid = nullptr; 5486 // Find our parent. 5487 CBlockIndex* pindexPar = pindex->pprev; 5488 // Find which child we just visited. 5489 std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangePar = forward.equal_range(pindexPar); 5490 while (rangePar.first->second != pindex) { 5491 assert(rangePar.first != rangePar.second); // Our parent must have at least the node we're coming from as child. 5492 rangePar.first++; 5493 } 5494 // Proceed to the next one. 5495 rangePar.first++; 5496 if (rangePar.first != rangePar.second) { 5497 // Move to a sibling not part of the best header chain. 5498 pindex = rangePar.first->second; 5499 break; 5500 } else if (pindexPar == best_hdr_chain[nHeight - 1]) { 5501 // Move to pindex's sibling on the best-chain, if it has one. 5502 pindex = best_hdr_chain[nHeight]; 5503 // There will not be a next block if (and only if) parent block is the best header. 5504 assert((pindex == nullptr) == (pindexPar == best_hdr_chain.Tip())); 5505 break; 5506 } else { 5507 // Move up further. 5508 pindex = pindexPar; 5509 nHeight--; 5510 continue; 5511 } 5512 } 5513 } 5514 5515 // Check that we actually traversed the entire block index. 5516 assert(nNodes == forward.size() + best_hdr_chain.Height() + 1); 5517 } 5518 5519 std::string Chainstate::ToString() 5520 { 5521 AssertLockHeld(::cs_main); 5522 CBlockIndex* tip = m_chain.Tip(); 5523 return strprintf("Chainstate [%s] @ height %d (%s)", 5524 m_from_snapshot_blockhash ? "snapshot" : "ibd", 5525 tip ? tip->nHeight : -1, tip ? tip->GetBlockHash().ToString() : "null"); 5526 } 5527 5528 bool Chainstate::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size) 5529 { 5530 AssertLockHeld(::cs_main); 5531 if (coinstip_size == m_coinstip_cache_size_bytes && 5532 coinsdb_size == m_coinsdb_cache_size_bytes) { 5533 // Cache sizes are unchanged, no need to continue. 5534 return true; 5535 } 5536 size_t old_coinstip_size = m_coinstip_cache_size_bytes; 5537 m_coinstip_cache_size_bytes = coinstip_size; 5538 m_coinsdb_cache_size_bytes = coinsdb_size; 5539 CoinsDB().ResizeCache(coinsdb_size); 5540 5541 LogPrintf("[%s] resized coinsdb cache to %.1f MiB\n", 5542 this->ToString(), coinsdb_size * (1.0 / 1024 / 1024)); 5543 LogPrintf("[%s] resized coinstip cache to %.1f MiB\n", 5544 this->ToString(), coinstip_size * (1.0 / 1024 / 1024)); 5545 5546 BlockValidationState state; 5547 bool ret; 5548 5549 if (coinstip_size > old_coinstip_size) { 5550 // Likely no need to flush if cache sizes have grown. 5551 ret = FlushStateToDisk(state, FlushStateMode::IF_NEEDED); 5552 } else { 5553 // Otherwise, flush state to disk and deallocate the in-memory coins map. 5554 ret = FlushStateToDisk(state, FlushStateMode::ALWAYS); 5555 } 5556 return ret; 5557 } 5558 5559 //! Guess how far we are in the verification process at the given block index 5560 //! require cs_main if pindex has not been validated yet (because m_chain_tx_count might be unset) 5561 double ChainstateManager::GuessVerificationProgress(const CBlockIndex* pindex) const 5562 { 5563 const ChainTxData& data{GetParams().TxData()}; 5564 if (pindex == nullptr) { 5565 return 0.0; 5566 } 5567 5568 if (pindex->m_chain_tx_count == 0) { 5569 LogDebug(BCLog::VALIDATION, "Block %d has unset m_chain_tx_count. Unable to estimate verification progress.\n", pindex->nHeight); 5570 return 0.0; 5571 } 5572 5573 int64_t nNow = time(nullptr); 5574 5575 double fTxTotal; 5576 5577 if (pindex->m_chain_tx_count <= data.tx_count) { 5578 fTxTotal = data.tx_count + (nNow - data.nTime) * data.dTxRate; 5579 } else { 5580 fTxTotal = pindex->m_chain_tx_count + (nNow - pindex->GetBlockTime()) * data.dTxRate; 5581 } 5582 5583 return std::min<double>(pindex->m_chain_tx_count / fTxTotal, 1.0); 5584 } 5585 5586 std::optional<uint256> ChainstateManager::SnapshotBlockhash() const 5587 { 5588 LOCK(::cs_main); 5589 if (m_active_chainstate && m_active_chainstate->m_from_snapshot_blockhash) { 5590 // If a snapshot chainstate exists, it will always be our active. 5591 return m_active_chainstate->m_from_snapshot_blockhash; 5592 } 5593 return std::nullopt; 5594 } 5595 5596 std::vector<Chainstate*> ChainstateManager::GetAll() 5597 { 5598 LOCK(::cs_main); 5599 std::vector<Chainstate*> out; 5600 5601 for (Chainstate* cs : {m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) { 5602 if (this->IsUsable(cs)) out.push_back(cs); 5603 } 5604 5605 return out; 5606 } 5607 5608 Chainstate& ChainstateManager::InitializeChainstate(CTxMemPool* mempool) 5609 { 5610 AssertLockHeld(::cs_main); 5611 assert(!m_ibd_chainstate); 5612 assert(!m_active_chainstate); 5613 5614 m_ibd_chainstate = std::make_unique<Chainstate>(mempool, m_blockman, *this); 5615 m_active_chainstate = m_ibd_chainstate.get(); 5616 return *m_active_chainstate; 5617 } 5618 5619 [[nodiscard]] static bool DeleteCoinsDBFromDisk(const fs::path db_path, bool is_snapshot) 5620 EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 5621 { 5622 AssertLockHeld(::cs_main); 5623 5624 if (is_snapshot) { 5625 fs::path base_blockhash_path = db_path / node::SNAPSHOT_BLOCKHASH_FILENAME; 5626 5627 try { 5628 bool existed = fs::remove(base_blockhash_path); 5629 if (!existed) { 5630 LogPrintf("[snapshot] snapshot chainstate dir being removed lacks %s file\n", 5631 fs::PathToString(node::SNAPSHOT_BLOCKHASH_FILENAME)); 5632 } 5633 } catch (const fs::filesystem_error& e) { 5634 LogWarning("[snapshot] failed to remove file %s: %s\n", 5635 fs::PathToString(base_blockhash_path), e.code().message()); 5636 } 5637 } 5638 5639 std::string path_str = fs::PathToString(db_path); 5640 LogPrintf("Removing leveldb dir at %s\n", path_str); 5641 5642 // We have to destruct before this call leveldb::DB in order to release the db 5643 // lock, otherwise `DestroyDB` will fail. See `leveldb::~DBImpl()`. 5644 const bool destroyed = DestroyDB(path_str); 5645 5646 if (!destroyed) { 5647 LogPrintf("error: leveldb DestroyDB call failed on %s\n", path_str); 5648 } 5649 5650 // Datadir should be removed from filesystem; otherwise initialization may detect 5651 // it on subsequent statups and get confused. 5652 // 5653 // If the base_blockhash_path removal above fails in the case of snapshot 5654 // chainstates, this will return false since leveldb won't remove a non-empty 5655 // directory. 5656 return destroyed && !fs::exists(db_path); 5657 } 5658 5659 util::Result<CBlockIndex*> ChainstateManager::ActivateSnapshot( 5660 AutoFile& coins_file, 5661 const SnapshotMetadata& metadata, 5662 bool in_memory) 5663 { 5664 uint256 base_blockhash = metadata.m_base_blockhash; 5665 5666 if (this->SnapshotBlockhash()) { 5667 return util::Error{Untranslated("Can't activate a snapshot-based chainstate more than once")}; 5668 } 5669 5670 CBlockIndex* snapshot_start_block{}; 5671 5672 { 5673 LOCK(::cs_main); 5674 5675 if (!GetParams().AssumeutxoForBlockhash(base_blockhash).has_value()) { 5676 auto available_heights = GetParams().GetAvailableSnapshotHeights(); 5677 std::string heights_formatted = util::Join(available_heights, ", ", [&](const auto& i) { return util::ToString(i); }); 5678 return util::Error{Untranslated(strprintf("assumeutxo block hash in snapshot metadata not recognized (hash: %s). The following snapshot heights are available: %s", 5679 base_blockhash.ToString(), 5680 heights_formatted))}; 5681 } 5682 5683 snapshot_start_block = m_blockman.LookupBlockIndex(base_blockhash); 5684 if (!snapshot_start_block) { 5685 return util::Error{Untranslated(strprintf("The base block header (%s) must appear in the headers chain. Make sure all headers are syncing, and call loadtxoutset again", 5686 base_blockhash.ToString()))}; 5687 } 5688 5689 bool start_block_invalid = snapshot_start_block->nStatus & BLOCK_FAILED_MASK; 5690 if (start_block_invalid) { 5691 return util::Error{Untranslated(strprintf("The base block header (%s) is part of an invalid chain", base_blockhash.ToString()))}; 5692 } 5693 5694 if (!m_best_header || m_best_header->GetAncestor(snapshot_start_block->nHeight) != snapshot_start_block) { 5695 return util::Error{Untranslated("A forked headers-chain with more work than the chain with the snapshot base block header exists. Please proceed to sync without AssumeUtxo.")}; 5696 } 5697 5698 auto mempool{m_active_chainstate->GetMempool()}; 5699 if (mempool && mempool->size() > 0) { 5700 return util::Error{Untranslated("Can't activate a snapshot when mempool not empty")}; 5701 } 5702 } 5703 5704 int64_t current_coinsdb_cache_size{0}; 5705 int64_t current_coinstip_cache_size{0}; 5706 5707 // Cache percentages to allocate to each chainstate. 5708 // 5709 // These particular percentages don't matter so much since they will only be 5710 // relevant during snapshot activation; caches are rebalanced at the conclusion of 5711 // this function. We want to give (essentially) all available cache capacity to the 5712 // snapshot to aid the bulk load later in this function. 5713 static constexpr double IBD_CACHE_PERC = 0.01; 5714 static constexpr double SNAPSHOT_CACHE_PERC = 0.99; 5715 5716 { 5717 LOCK(::cs_main); 5718 // Resize the coins caches to ensure we're not exceeding memory limits. 5719 // 5720 // Allocate the majority of the cache to the incoming snapshot chainstate, since 5721 // (optimistically) getting to its tip will be the top priority. We'll need to call 5722 // `MaybeRebalanceCaches()` once we're done with this function to ensure 5723 // the right allocation (including the possibility that no snapshot was activated 5724 // and that we should restore the active chainstate caches to their original size). 5725 // 5726 current_coinsdb_cache_size = this->ActiveChainstate().m_coinsdb_cache_size_bytes; 5727 current_coinstip_cache_size = this->ActiveChainstate().m_coinstip_cache_size_bytes; 5728 5729 // Temporarily resize the active coins cache to make room for the newly-created 5730 // snapshot chain. 5731 this->ActiveChainstate().ResizeCoinsCaches( 5732 static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC), 5733 static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC)); 5734 } 5735 5736 auto snapshot_chainstate = WITH_LOCK(::cs_main, 5737 return std::make_unique<Chainstate>( 5738 /*mempool=*/nullptr, m_blockman, *this, base_blockhash)); 5739 5740 { 5741 LOCK(::cs_main); 5742 snapshot_chainstate->InitCoinsDB( 5743 static_cast<size_t>(current_coinsdb_cache_size * SNAPSHOT_CACHE_PERC), 5744 in_memory, false, "chainstate"); 5745 snapshot_chainstate->InitCoinsCache( 5746 static_cast<size_t>(current_coinstip_cache_size * SNAPSHOT_CACHE_PERC)); 5747 } 5748 5749 auto cleanup_bad_snapshot = [&](bilingual_str reason) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 5750 this->MaybeRebalanceCaches(); 5751 5752 // PopulateAndValidateSnapshot can return (in error) before the leveldb datadir 5753 // has been created, so only attempt removal if we got that far. 5754 if (auto snapshot_datadir = node::FindSnapshotChainstateDir(m_options.datadir)) { 5755 // We have to destruct leveldb::DB in order to release the db lock, otherwise 5756 // DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See `leveldb::~DBImpl()`. 5757 // Destructing the chainstate (and so resetting the coinsviews object) does this. 5758 snapshot_chainstate.reset(); 5759 bool removed = DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true); 5760 if (!removed) { 5761 GetNotifications().fatalError(strprintf(_("Failed to remove snapshot chainstate dir (%s). " 5762 "Manually remove it before restarting.\n"), fs::PathToString(*snapshot_datadir))); 5763 } 5764 } 5765 return util::Error{std::move(reason)}; 5766 }; 5767 5768 if (auto res{this->PopulateAndValidateSnapshot(*snapshot_chainstate, coins_file, metadata)}; !res) { 5769 LOCK(::cs_main); 5770 return cleanup_bad_snapshot(Untranslated(strprintf("Population failed: %s", util::ErrorString(res).original))); 5771 } 5772 5773 LOCK(::cs_main); // cs_main required for rest of snapshot activation. 5774 5775 // Do a final check to ensure that the snapshot chainstate is actually a more 5776 // work chain than the active chainstate; a user could have loaded a snapshot 5777 // very late in the IBD process, and we wouldn't want to load a useless chainstate. 5778 if (!CBlockIndexWorkComparator()(ActiveTip(), snapshot_chainstate->m_chain.Tip())) { 5779 return cleanup_bad_snapshot(Untranslated("work does not exceed active chainstate")); 5780 } 5781 // If not in-memory, persist the base blockhash for use during subsequent 5782 // initialization. 5783 if (!in_memory) { 5784 if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) { 5785 return cleanup_bad_snapshot(Untranslated("could not write base blockhash")); 5786 } 5787 } 5788 5789 assert(!m_snapshot_chainstate); 5790 m_snapshot_chainstate.swap(snapshot_chainstate); 5791 const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip(); 5792 assert(chaintip_loaded); 5793 5794 // Transfer possession of the mempool to the snapshot chainstate. 5795 // Mempool is empty at this point because we're still in IBD. 5796 Assert(m_active_chainstate->m_mempool->size() == 0); 5797 Assert(!m_snapshot_chainstate->m_mempool); 5798 m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool; 5799 m_active_chainstate->m_mempool = nullptr; 5800 m_active_chainstate = m_snapshot_chainstate.get(); 5801 m_blockman.m_snapshot_height = this->GetSnapshotBaseHeight(); 5802 5803 LogPrintf("[snapshot] successfully activated snapshot %s\n", base_blockhash.ToString()); 5804 LogPrintf("[snapshot] (%.2f MB)\n", 5805 m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() / (1000 * 1000)); 5806 5807 this->MaybeRebalanceCaches(); 5808 return snapshot_start_block; 5809 } 5810 5811 static void FlushSnapshotToDisk(CCoinsViewCache& coins_cache, bool snapshot_loaded) 5812 { 5813 LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE( 5814 strprintf("%s (%.2f MB)", 5815 snapshot_loaded ? "saving snapshot chainstate" : "flushing coins cache", 5816 coins_cache.DynamicMemoryUsage() / (1000 * 1000)), 5817 BCLog::LogFlags::ALL); 5818 5819 coins_cache.Flush(); 5820 } 5821 5822 struct StopHashingException : public std::exception 5823 { 5824 const char* what() const noexcept override 5825 { 5826 return "ComputeUTXOStats interrupted."; 5827 } 5828 }; 5829 5830 static void SnapshotUTXOHashBreakpoint(const util::SignalInterrupt& interrupt) 5831 { 5832 if (interrupt) throw StopHashingException(); 5833 } 5834 5835 util::Result<void> ChainstateManager::PopulateAndValidateSnapshot( 5836 Chainstate& snapshot_chainstate, 5837 AutoFile& coins_file, 5838 const SnapshotMetadata& metadata) 5839 { 5840 // It's okay to release cs_main before we're done using `coins_cache` because we know 5841 // that nothing else will be referencing the newly created snapshot_chainstate yet. 5842 CCoinsViewCache& coins_cache = *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip()); 5843 5844 uint256 base_blockhash = metadata.m_base_blockhash; 5845 5846 CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash)); 5847 5848 if (!snapshot_start_block) { 5849 // Needed for ComputeUTXOStats to determine the 5850 // height and to avoid a crash when base_blockhash.IsNull() 5851 return util::Error{Untranslated(strprintf("Did not find snapshot start blockheader %s", 5852 base_blockhash.ToString()))}; 5853 } 5854 5855 int base_height = snapshot_start_block->nHeight; 5856 const auto& maybe_au_data = GetParams().AssumeutxoForHeight(base_height); 5857 5858 if (!maybe_au_data) { 5859 return util::Error{Untranslated(strprintf("Assumeutxo height in snapshot metadata not recognized " 5860 "(%d) - refusing to load snapshot", base_height))}; 5861 } 5862 5863 const AssumeutxoData& au_data = *maybe_au_data; 5864 5865 // This work comparison is a duplicate check with the one performed later in 5866 // ActivateSnapshot(), but is done so that we avoid doing the long work of staging 5867 // a snapshot that isn't actually usable. 5868 if (WITH_LOCK(::cs_main, return !CBlockIndexWorkComparator()(ActiveTip(), snapshot_start_block))) { 5869 return util::Error{Untranslated("Work does not exceed active chainstate")}; 5870 } 5871 5872 const uint64_t coins_count = metadata.m_coins_count; 5873 uint64_t coins_left = metadata.m_coins_count; 5874 5875 LogPrintf("[snapshot] loading %d coins from snapshot %s\n", coins_left, base_blockhash.ToString()); 5876 int64_t coins_processed{0}; 5877 5878 while (coins_left > 0) { 5879 try { 5880 Txid txid; 5881 coins_file >> txid; 5882 size_t coins_per_txid{0}; 5883 coins_per_txid = ReadCompactSize(coins_file); 5884 5885 if (coins_per_txid > coins_left) { 5886 return util::Error{Untranslated("Mismatch in coins count in snapshot metadata and actual snapshot data")}; 5887 } 5888 5889 for (size_t i = 0; i < coins_per_txid; i++) { 5890 COutPoint outpoint; 5891 Coin coin; 5892 outpoint.n = static_cast<uint32_t>(ReadCompactSize(coins_file)); 5893 outpoint.hash = txid; 5894 coins_file >> coin; 5895 if (coin.nHeight > base_height || 5896 outpoint.n >= std::numeric_limits<decltype(outpoint.n)>::max() // Avoid integer wrap-around in coinstats.cpp:ApplyHash 5897 ) { 5898 return util::Error{Untranslated(strprintf("Bad snapshot data after deserializing %d coins", 5899 coins_count - coins_left))}; 5900 } 5901 if (!MoneyRange(coin.out.nValue)) { 5902 return util::Error{Untranslated(strprintf("Bad snapshot data after deserializing %d coins - bad tx out value", 5903 coins_count - coins_left))}; 5904 } 5905 coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint), std::move(coin)); 5906 5907 --coins_left; 5908 ++coins_processed; 5909 5910 if (coins_processed % 1000000 == 0) { 5911 LogPrintf("[snapshot] %d coins loaded (%.2f%%, %.2f MB)\n", 5912 coins_processed, 5913 static_cast<float>(coins_processed) * 100 / static_cast<float>(coins_count), 5914 coins_cache.DynamicMemoryUsage() / (1000 * 1000)); 5915 } 5916 5917 // Batch write and flush (if we need to) every so often. 5918 // 5919 // If our average Coin size is roughly 41 bytes, checking every 120,000 coins 5920 // means <5MB of memory imprecision. 5921 if (coins_processed % 120000 == 0) { 5922 if (m_interrupt) { 5923 return util::Error{Untranslated("Aborting after an interrupt was requested")}; 5924 } 5925 5926 const auto snapshot_cache_state = WITH_LOCK(::cs_main, 5927 return snapshot_chainstate.GetCoinsCacheSizeState()); 5928 5929 if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) { 5930 // This is a hack - we don't know what the actual best block is, but that 5931 // doesn't matter for the purposes of flushing the cache here. We'll set this 5932 // to its correct value (`base_blockhash`) below after the coins are loaded. 5933 coins_cache.SetBestBlock(GetRandHash()); 5934 5935 // No need to acquire cs_main since this chainstate isn't being used yet. 5936 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/false); 5937 } 5938 } 5939 } 5940 } catch (const std::ios_base::failure&) { 5941 return util::Error{Untranslated(strprintf("Bad snapshot format or truncated snapshot after deserializing %d coins", 5942 coins_processed))}; 5943 } 5944 } 5945 5946 // Important that we set this. This and the coins_cache accesses above are 5947 // sort of a layer violation, but either we reach into the innards of 5948 // CCoinsViewCache here or we have to invert some of the Chainstate to 5949 // embed them in a snapshot-activation-specific CCoinsViewCache bulk load 5950 // method. 5951 coins_cache.SetBestBlock(base_blockhash); 5952 5953 bool out_of_coins{false}; 5954 try { 5955 std::byte left_over_byte; 5956 coins_file >> left_over_byte; 5957 } catch (const std::ios_base::failure&) { 5958 // We expect an exception since we should be out of coins. 5959 out_of_coins = true; 5960 } 5961 if (!out_of_coins) { 5962 return util::Error{Untranslated(strprintf("Bad snapshot - coins left over after deserializing %d coins", 5963 coins_count))}; 5964 } 5965 5966 LogPrintf("[snapshot] loaded %d (%.2f MB) coins from snapshot %s\n", 5967 coins_count, 5968 coins_cache.DynamicMemoryUsage() / (1000 * 1000), 5969 base_blockhash.ToString()); 5970 5971 // No need to acquire cs_main since this chainstate isn't being used yet. 5972 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/true); 5973 5974 assert(coins_cache.GetBestBlock() == base_blockhash); 5975 5976 // As above, okay to immediately release cs_main here since no other context knows 5977 // about the snapshot_chainstate. 5978 CCoinsViewDB* snapshot_coinsdb = WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB()); 5979 5980 std::optional<CCoinsStats> maybe_stats; 5981 5982 try { 5983 maybe_stats = ComputeUTXOStats( 5984 CoinStatsHashType::HASH_SERIALIZED, snapshot_coinsdb, m_blockman, [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); }); 5985 } catch (StopHashingException const&) { 5986 return util::Error{Untranslated("Aborting after an interrupt was requested")}; 5987 } 5988 if (!maybe_stats.has_value()) { 5989 return util::Error{Untranslated("Failed to generate coins stats")}; 5990 } 5991 5992 // Assert that the deserialized chainstate contents match the expected assumeutxo value. 5993 if (AssumeutxoHash{maybe_stats->hashSerialized} != au_data.hash_serialized) { 5994 return util::Error{Untranslated(strprintf("Bad snapshot content hash: expected %s, got %s", 5995 au_data.hash_serialized.ToString(), maybe_stats->hashSerialized.ToString()))}; 5996 } 5997 5998 snapshot_chainstate.m_chain.SetTip(*snapshot_start_block); 5999 6000 // The remainder of this function requires modifying data protected by cs_main. 6001 LOCK(::cs_main); 6002 6003 // Fake various pieces of CBlockIndex state: 6004 CBlockIndex* index = nullptr; 6005 6006 // Don't make any modifications to the genesis block since it shouldn't be 6007 // necessary, and since the genesis block doesn't have normal flags like 6008 // BLOCK_VALID_SCRIPTS set. 6009 constexpr int AFTER_GENESIS_START{1}; 6010 6011 for (int i = AFTER_GENESIS_START; i <= snapshot_chainstate.m_chain.Height(); ++i) { 6012 index = snapshot_chainstate.m_chain[i]; 6013 6014 // Fake BLOCK_OPT_WITNESS so that Chainstate::NeedsRedownload() 6015 // won't ask for -reindex on startup. 6016 if (DeploymentActiveAt(*index, *this, Consensus::DEPLOYMENT_SEGWIT)) { 6017 index->nStatus |= BLOCK_OPT_WITNESS; 6018 } 6019 6020 m_blockman.m_dirty_blockindex.insert(index); 6021 // Changes to the block index will be flushed to disk after this call 6022 // returns in `ActivateSnapshot()`, when `MaybeRebalanceCaches()` is 6023 // called, since we've added a snapshot chainstate and therefore will 6024 // have to downsize the IBD chainstate, which will result in a call to 6025 // `FlushStateToDisk(ALWAYS)`. 6026 } 6027 6028 assert(index); 6029 assert(index == snapshot_start_block); 6030 index->m_chain_tx_count = au_data.m_chain_tx_count; 6031 snapshot_chainstate.setBlockIndexCandidates.insert(snapshot_start_block); 6032 6033 LogPrintf("[snapshot] validated snapshot (%.2f MB)\n", 6034 coins_cache.DynamicMemoryUsage() / (1000 * 1000)); 6035 return {}; 6036 } 6037 6038 // Currently, this function holds cs_main for its duration, which could be for 6039 // multiple minutes due to the ComputeUTXOStats call. This hold is necessary 6040 // because we need to avoid advancing the background validation chainstate 6041 // farther than the snapshot base block - and this function is also invoked 6042 // from within ConnectTip, i.e. from within ActivateBestChain, so cs_main is 6043 // held anyway. 6044 // 6045 // Eventually (TODO), we could somehow separate this function's runtime from 6046 // maintenance of the active chain, but that will either require 6047 // 6048 // (i) setting `m_disabled` immediately and ensuring all chainstate accesses go 6049 // through IsUsable() checks, or 6050 // 6051 // (ii) giving each chainstate its own lock instead of using cs_main for everything. 6052 SnapshotCompletionResult ChainstateManager::MaybeCompleteSnapshotValidation() 6053 { 6054 AssertLockHeld(cs_main); 6055 if (m_ibd_chainstate.get() == &this->ActiveChainstate() || 6056 !this->IsUsable(m_snapshot_chainstate.get()) || 6057 !this->IsUsable(m_ibd_chainstate.get()) || 6058 !m_ibd_chainstate->m_chain.Tip()) { 6059 // Nothing to do - this function only applies to the background 6060 // validation chainstate. 6061 return SnapshotCompletionResult::SKIPPED; 6062 } 6063 const int snapshot_tip_height = this->ActiveHeight(); 6064 const int snapshot_base_height = *Assert(this->GetSnapshotBaseHeight()); 6065 const CBlockIndex& index_new = *Assert(m_ibd_chainstate->m_chain.Tip()); 6066 6067 if (index_new.nHeight < snapshot_base_height) { 6068 // Background IBD not complete yet. 6069 return SnapshotCompletionResult::SKIPPED; 6070 } 6071 6072 assert(SnapshotBlockhash()); 6073 uint256 snapshot_blockhash = *Assert(SnapshotBlockhash()); 6074 6075 auto handle_invalid_snapshot = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 6076 bilingual_str user_error = strprintf(_( 6077 "%s failed to validate the -assumeutxo snapshot state. " 6078 "This indicates a hardware problem, or a bug in the software, or a " 6079 "bad software modification that allowed an invalid snapshot to be " 6080 "loaded. As a result of this, the node will shut down and stop using any " 6081 "state that was built on the snapshot, resetting the chain height " 6082 "from %d to %d. On the next " 6083 "restart, the node will resume syncing from %d " 6084 "without using any snapshot data. " 6085 "Please report this incident to %s, including how you obtained the snapshot. " 6086 "The invalid snapshot chainstate will be left on disk in case it is " 6087 "helpful in diagnosing the issue that caused this error."), 6088 CLIENT_NAME, snapshot_tip_height, snapshot_base_height, snapshot_base_height, CLIENT_BUGREPORT 6089 ); 6090 6091 LogError("[snapshot] !!! %s\n", user_error.original); 6092 LogError("[snapshot] deleting snapshot, reverting to validated chain, and stopping node\n"); 6093 6094 m_active_chainstate = m_ibd_chainstate.get(); 6095 m_snapshot_chainstate->m_disabled = true; 6096 assert(!this->IsUsable(m_snapshot_chainstate.get())); 6097 assert(this->IsUsable(m_ibd_chainstate.get())); 6098 6099 auto rename_result = m_snapshot_chainstate->InvalidateCoinsDBOnDisk(); 6100 if (!rename_result) { 6101 user_error += Untranslated("\n") + util::ErrorString(rename_result); 6102 } 6103 6104 GetNotifications().fatalError(user_error); 6105 }; 6106 6107 if (index_new.GetBlockHash() != snapshot_blockhash) { 6108 LogPrintf("[snapshot] supposed base block %s does not match the " 6109 "snapshot base block %s (height %d). Snapshot is not valid.\n", 6110 index_new.ToString(), snapshot_blockhash.ToString(), snapshot_base_height); 6111 handle_invalid_snapshot(); 6112 return SnapshotCompletionResult::BASE_BLOCKHASH_MISMATCH; 6113 } 6114 6115 assert(index_new.nHeight == snapshot_base_height); 6116 6117 int curr_height = m_ibd_chainstate->m_chain.Height(); 6118 6119 assert(snapshot_base_height == curr_height); 6120 assert(snapshot_base_height == index_new.nHeight); 6121 assert(this->IsUsable(m_snapshot_chainstate.get())); 6122 assert(this->GetAll().size() == 2); 6123 6124 CCoinsViewDB& ibd_coins_db = m_ibd_chainstate->CoinsDB(); 6125 m_ibd_chainstate->ForceFlushStateToDisk(); 6126 6127 const auto& maybe_au_data = m_options.chainparams.AssumeutxoForHeight(curr_height); 6128 if (!maybe_au_data) { 6129 LogPrintf("[snapshot] assumeutxo data not found for height " 6130 "(%d) - refusing to validate snapshot\n", curr_height); 6131 handle_invalid_snapshot(); 6132 return SnapshotCompletionResult::MISSING_CHAINPARAMS; 6133 } 6134 6135 const AssumeutxoData& au_data = *maybe_au_data; 6136 std::optional<CCoinsStats> maybe_ibd_stats; 6137 LogPrintf("[snapshot] computing UTXO stats for background chainstate to validate " 6138 "snapshot - this could take a few minutes\n"); 6139 try { 6140 maybe_ibd_stats = ComputeUTXOStats( 6141 CoinStatsHashType::HASH_SERIALIZED, 6142 &ibd_coins_db, 6143 m_blockman, 6144 [&interrupt = m_interrupt] { SnapshotUTXOHashBreakpoint(interrupt); }); 6145 } catch (StopHashingException const&) { 6146 return SnapshotCompletionResult::STATS_FAILED; 6147 } 6148 6149 // XXX note that this function is slow and will hold cs_main for potentially minutes. 6150 if (!maybe_ibd_stats) { 6151 LogPrintf("[snapshot] failed to generate stats for validation coins db\n"); 6152 // While this isn't a problem with the snapshot per se, this condition 6153 // prevents us from validating the snapshot, so we should shut down and let the 6154 // user handle the issue manually. 6155 handle_invalid_snapshot(); 6156 return SnapshotCompletionResult::STATS_FAILED; 6157 } 6158 const auto& ibd_stats = *maybe_ibd_stats; 6159 6160 // Compare the background validation chainstate's UTXO set hash against the hard-coded 6161 // assumeutxo hash we expect. 6162 // 6163 // TODO: For belt-and-suspenders, we could cache the UTXO set 6164 // hash for the snapshot when it's loaded in its chainstate's leveldb. We could then 6165 // reference that here for an additional check. 6166 if (AssumeutxoHash{ibd_stats.hashSerialized} != au_data.hash_serialized) { 6167 LogPrintf("[snapshot] hash mismatch: actual=%s, expected=%s\n", 6168 ibd_stats.hashSerialized.ToString(), 6169 au_data.hash_serialized.ToString()); 6170 handle_invalid_snapshot(); 6171 return SnapshotCompletionResult::HASH_MISMATCH; 6172 } 6173 6174 LogPrintf("[snapshot] snapshot beginning at %s has been fully validated\n", 6175 snapshot_blockhash.ToString()); 6176 6177 m_ibd_chainstate->m_disabled = true; 6178 this->MaybeRebalanceCaches(); 6179 6180 return SnapshotCompletionResult::SUCCESS; 6181 } 6182 6183 Chainstate& ChainstateManager::ActiveChainstate() const 6184 { 6185 LOCK(::cs_main); 6186 assert(m_active_chainstate); 6187 return *m_active_chainstate; 6188 } 6189 6190 bool ChainstateManager::IsSnapshotActive() const 6191 { 6192 LOCK(::cs_main); 6193 return m_snapshot_chainstate && m_active_chainstate == m_snapshot_chainstate.get(); 6194 } 6195 6196 void ChainstateManager::MaybeRebalanceCaches() 6197 { 6198 AssertLockHeld(::cs_main); 6199 bool ibd_usable = this->IsUsable(m_ibd_chainstate.get()); 6200 bool snapshot_usable = this->IsUsable(m_snapshot_chainstate.get()); 6201 assert(ibd_usable || snapshot_usable); 6202 6203 if (ibd_usable && !snapshot_usable) { 6204 // Allocate everything to the IBD chainstate. This will always happen 6205 // when we are not using a snapshot. 6206 m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache); 6207 } 6208 else if (snapshot_usable && !ibd_usable) { 6209 // If background validation has completed and snapshot is our active chain... 6210 LogPrintf("[snapshot] allocating all cache to the snapshot chainstate\n"); 6211 // Allocate everything to the snapshot chainstate. 6212 m_snapshot_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache); 6213 } 6214 else if (ibd_usable && snapshot_usable) { 6215 // If both chainstates exist, determine who needs more cache based on IBD status. 6216 // 6217 // Note: shrink caches first so that we don't inadvertently overwhelm available memory. 6218 if (IsInitialBlockDownload()) { 6219 m_ibd_chainstate->ResizeCoinsCaches( 6220 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05); 6221 m_snapshot_chainstate->ResizeCoinsCaches( 6222 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95); 6223 } else { 6224 m_snapshot_chainstate->ResizeCoinsCaches( 6225 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05); 6226 m_ibd_chainstate->ResizeCoinsCaches( 6227 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95); 6228 } 6229 } 6230 } 6231 6232 void ChainstateManager::ResetChainstates() 6233 { 6234 m_ibd_chainstate.reset(); 6235 m_snapshot_chainstate.reset(); 6236 m_active_chainstate = nullptr; 6237 } 6238 6239 /** 6240 * Apply default chain params to nullopt members. 6241 * This helps to avoid coding errors around the accidental use of the compare 6242 * operators that accept nullopt, thus ignoring the intended default value. 6243 */ 6244 static ChainstateManager::Options&& Flatten(ChainstateManager::Options&& opts) 6245 { 6246 if (!opts.check_block_index.has_value()) opts.check_block_index = opts.chainparams.DefaultConsistencyChecks(); 6247 if (!opts.minimum_chain_work.has_value()) opts.minimum_chain_work = UintToArith256(opts.chainparams.GetConsensus().nMinimumChainWork); 6248 if (!opts.assumed_valid_block.has_value()) opts.assumed_valid_block = opts.chainparams.GetConsensus().defaultAssumeValid; 6249 return std::move(opts); 6250 } 6251 6252 ChainstateManager::ChainstateManager(const util::SignalInterrupt& interrupt, Options options, node::BlockManager::Options blockman_options) 6253 : m_script_check_queue{/*batch_size=*/128, std::clamp(options.worker_threads_num, 0, MAX_SCRIPTCHECK_THREADS)}, 6254 m_interrupt{interrupt}, 6255 m_options{Flatten(std::move(options))}, 6256 m_blockman{interrupt, std::move(blockman_options)}, 6257 m_validation_cache{m_options.script_execution_cache_bytes, m_options.signature_cache_bytes} 6258 { 6259 } 6260 6261 ChainstateManager::~ChainstateManager() 6262 { 6263 LOCK(::cs_main); 6264 6265 m_versionbitscache.Clear(); 6266 } 6267 6268 bool ChainstateManager::DetectSnapshotChainstate() 6269 { 6270 assert(!m_snapshot_chainstate); 6271 std::optional<fs::path> path = node::FindSnapshotChainstateDir(m_options.datadir); 6272 if (!path) { 6273 return false; 6274 } 6275 std::optional<uint256> base_blockhash = node::ReadSnapshotBaseBlockhash(*path); 6276 if (!base_blockhash) { 6277 return false; 6278 } 6279 LogPrintf("[snapshot] detected active snapshot chainstate (%s) - loading\n", 6280 fs::PathToString(*path)); 6281 6282 this->ActivateExistingSnapshot(*base_blockhash); 6283 return true; 6284 } 6285 6286 Chainstate& ChainstateManager::ActivateExistingSnapshot(uint256 base_blockhash) 6287 { 6288 assert(!m_snapshot_chainstate); 6289 m_snapshot_chainstate = 6290 std::make_unique<Chainstate>(nullptr, m_blockman, *this, base_blockhash); 6291 LogPrintf("[snapshot] switching active chainstate to %s\n", m_snapshot_chainstate->ToString()); 6292 6293 // Mempool is empty at this point because we're still in IBD. 6294 Assert(m_active_chainstate->m_mempool->size() == 0); 6295 Assert(!m_snapshot_chainstate->m_mempool); 6296 m_snapshot_chainstate->m_mempool = m_active_chainstate->m_mempool; 6297 m_active_chainstate->m_mempool = nullptr; 6298 m_active_chainstate = m_snapshot_chainstate.get(); 6299 return *m_snapshot_chainstate; 6300 } 6301 6302 bool IsBIP30Repeat(const CBlockIndex& block_index) 6303 { 6304 return (block_index.nHeight==91842 && block_index.GetBlockHash() == uint256{"00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec"}) || 6305 (block_index.nHeight==91880 && block_index.GetBlockHash() == uint256{"00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721"}); 6306 } 6307 6308 bool IsBIP30Unspendable(const CBlockIndex& block_index) 6309 { 6310 return (block_index.nHeight==91722 && block_index.GetBlockHash() == uint256{"00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e"}) || 6311 (block_index.nHeight==91812 && block_index.GetBlockHash() == uint256{"00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"}); 6312 } 6313 6314 static fs::path GetSnapshotCoinsDBPath(Chainstate& cs) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) 6315 { 6316 AssertLockHeld(::cs_main); 6317 // Should never be called on a non-snapshot chainstate. 6318 assert(cs.m_from_snapshot_blockhash); 6319 auto storage_path_maybe = cs.CoinsDB().StoragePath(); 6320 // Should never be called with a non-existent storage path. 6321 assert(storage_path_maybe); 6322 return *storage_path_maybe; 6323 } 6324 6325 util::Result<void> Chainstate::InvalidateCoinsDBOnDisk() 6326 { 6327 fs::path snapshot_datadir = GetSnapshotCoinsDBPath(*this); 6328 6329 // Coins views no longer usable. 6330 m_coins_views.reset(); 6331 6332 auto invalid_path = snapshot_datadir + "_INVALID"; 6333 std::string dbpath = fs::PathToString(snapshot_datadir); 6334 std::string target = fs::PathToString(invalid_path); 6335 LogPrintf("[snapshot] renaming snapshot datadir %s to %s\n", dbpath, target); 6336 6337 // The invalid snapshot datadir is simply moved and not deleted because we may 6338 // want to do forensics later during issue investigation. The user is instructed 6339 // accordingly in MaybeCompleteSnapshotValidation(). 6340 try { 6341 fs::rename(snapshot_datadir, invalid_path); 6342 } catch (const fs::filesystem_error& e) { 6343 auto src_str = fs::PathToString(snapshot_datadir); 6344 auto dest_str = fs::PathToString(invalid_path); 6345 6346 LogPrintf("%s: error renaming file '%s' -> '%s': %s\n", 6347 __func__, src_str, dest_str, e.what()); 6348 return util::Error{strprintf(_( 6349 "Rename of '%s' -> '%s' failed. " 6350 "You should resolve this by manually moving or deleting the invalid " 6351 "snapshot directory %s, otherwise you will encounter the same error again " 6352 "on the next startup."), 6353 src_str, dest_str, src_str)}; 6354 } 6355 return {}; 6356 } 6357 6358 bool ChainstateManager::DeleteSnapshotChainstate() 6359 { 6360 AssertLockHeld(::cs_main); 6361 Assert(m_snapshot_chainstate); 6362 Assert(m_ibd_chainstate); 6363 6364 fs::path snapshot_datadir = Assert(node::FindSnapshotChainstateDir(m_options.datadir)).value(); 6365 if (!DeleteCoinsDBFromDisk(snapshot_datadir, /*is_snapshot=*/ true)) { 6366 LogPrintf("Deletion of %s failed. Please remove it manually to continue reindexing.\n", 6367 fs::PathToString(snapshot_datadir)); 6368 return false; 6369 } 6370 m_active_chainstate = m_ibd_chainstate.get(); 6371 m_active_chainstate->m_mempool = m_snapshot_chainstate->m_mempool; 6372 m_snapshot_chainstate.reset(); 6373 return true; 6374 } 6375 6376 ChainstateRole Chainstate::GetRole() const 6377 { 6378 if (m_chainman.GetAll().size() <= 1) { 6379 return ChainstateRole::NORMAL; 6380 } 6381 return (this != &m_chainman.ActiveChainstate()) ? 6382 ChainstateRole::BACKGROUND : 6383 ChainstateRole::ASSUMEDVALID; 6384 } 6385 6386 const CBlockIndex* ChainstateManager::GetSnapshotBaseBlock() const 6387 { 6388 return m_active_chainstate ? m_active_chainstate->SnapshotBase() : nullptr; 6389 } 6390 6391 std::optional<int> ChainstateManager::GetSnapshotBaseHeight() const 6392 { 6393 const CBlockIndex* base = this->GetSnapshotBaseBlock(); 6394 return base ? std::make_optional(base->nHeight) : std::nullopt; 6395 } 6396 6397 void ChainstateManager::RecalculateBestHeader() 6398 { 6399 AssertLockHeld(cs_main); 6400 m_best_header = ActiveChain().Tip(); 6401 for (auto& entry : m_blockman.m_block_index) { 6402 if (!(entry.second.nStatus & BLOCK_FAILED_MASK) && m_best_header->nChainWork < entry.second.nChainWork) { 6403 m_best_header = &entry.second; 6404 } 6405 } 6406 } 6407 6408 bool ChainstateManager::ValidatedSnapshotCleanup() 6409 { 6410 AssertLockHeld(::cs_main); 6411 auto get_storage_path = [](auto& chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) -> std::optional<fs::path> { 6412 if (!(chainstate && chainstate->HasCoinsViews())) { 6413 return {}; 6414 } 6415 return chainstate->CoinsDB().StoragePath(); 6416 }; 6417 std::optional<fs::path> ibd_chainstate_path_maybe = get_storage_path(m_ibd_chainstate); 6418 std::optional<fs::path> snapshot_chainstate_path_maybe = get_storage_path(m_snapshot_chainstate); 6419 6420 if (!this->IsSnapshotValidated()) { 6421 // No need to clean up. 6422 return false; 6423 } 6424 // If either path doesn't exist, that means at least one of the chainstates 6425 // is in-memory, in which case we can't do on-disk cleanup. You'd better be 6426 // in a unittest! 6427 if (!ibd_chainstate_path_maybe || !snapshot_chainstate_path_maybe) { 6428 LogPrintf("[snapshot] snapshot chainstate cleanup cannot happen with " 6429 "in-memory chainstates. You are testing, right?\n"); 6430 return false; 6431 } 6432 6433 const auto& snapshot_chainstate_path = *snapshot_chainstate_path_maybe; 6434 const auto& ibd_chainstate_path = *ibd_chainstate_path_maybe; 6435 6436 // Since we're going to be moving around the underlying leveldb filesystem content 6437 // for each chainstate, make sure that the chainstates (and their constituent 6438 // CoinsViews members) have been destructed first. 6439 // 6440 // The caller of this method will be responsible for reinitializing chainstates 6441 // if they want to continue operation. 6442 this->ResetChainstates(); 6443 6444 // No chainstates should be considered usable. 6445 assert(this->GetAll().size() == 0); 6446 6447 LogPrintf("[snapshot] deleting background chainstate directory (now unnecessary) (%s)\n", 6448 fs::PathToString(ibd_chainstate_path)); 6449 6450 fs::path tmp_old{ibd_chainstate_path + "_todelete"}; 6451 6452 auto rename_failed_abort = [this]( 6453 fs::path p_old, 6454 fs::path p_new, 6455 const fs::filesystem_error& err) { 6456 LogError("[snapshot] Error renaming path (%s) -> (%s): %s\n", 6457 fs::PathToString(p_old), fs::PathToString(p_new), err.what()); 6458 GetNotifications().fatalError(strprintf(_( 6459 "Rename of '%s' -> '%s' failed. " 6460 "Cannot clean up the background chainstate leveldb directory."), 6461 fs::PathToString(p_old), fs::PathToString(p_new))); 6462 }; 6463 6464 try { 6465 fs::rename(ibd_chainstate_path, tmp_old); 6466 } catch (const fs::filesystem_error& e) { 6467 rename_failed_abort(ibd_chainstate_path, tmp_old, e); 6468 throw; 6469 } 6470 6471 LogPrintf("[snapshot] moving snapshot chainstate (%s) to " 6472 "default chainstate directory (%s)\n", 6473 fs::PathToString(snapshot_chainstate_path), fs::PathToString(ibd_chainstate_path)); 6474 6475 try { 6476 fs::rename(snapshot_chainstate_path, ibd_chainstate_path); 6477 } catch (const fs::filesystem_error& e) { 6478 rename_failed_abort(snapshot_chainstate_path, ibd_chainstate_path, e); 6479 throw; 6480 } 6481 6482 if (!DeleteCoinsDBFromDisk(tmp_old, /*is_snapshot=*/false)) { 6483 // No need to FatalError because once the unneeded bg chainstate data is 6484 // moved, it will not interfere with subsequent initialization. 6485 LogPrintf("Deletion of %s failed. Please remove it manually, as the " 6486 "directory is now unnecessary.\n", 6487 fs::PathToString(tmp_old)); 6488 } else { 6489 LogPrintf("[snapshot] deleted background chainstate directory (%s)\n", 6490 fs::PathToString(ibd_chainstate_path)); 6491 } 6492 return true; 6493 } 6494 6495 Chainstate& ChainstateManager::GetChainstateForIndexing() 6496 { 6497 // We can't always return `m_ibd_chainstate` because after background validation 6498 // has completed, `m_snapshot_chainstate == m_active_chainstate`, but it can be 6499 // indexed. 6500 return (this->GetAll().size() > 1) ? *m_ibd_chainstate : *m_active_chainstate; 6501 } 6502 6503 std::pair<int, int> ChainstateManager::GetPruneRange(const Chainstate& chainstate, int last_height_can_prune) 6504 { 6505 if (chainstate.m_chain.Height() <= 0) { 6506 return {0, 0}; 6507 } 6508 int prune_start{0}; 6509 6510 if (this->GetAll().size() > 1 && m_snapshot_chainstate.get() == &chainstate) { 6511 // Leave the blocks in the background IBD chain alone if we're pruning 6512 // the snapshot chain. 6513 prune_start = *Assert(GetSnapshotBaseHeight()) + 1; 6514 } 6515 6516 int max_prune = std::max<int>( 6517 0, chainstate.m_chain.Height() - static_cast<int>(MIN_BLOCKS_TO_KEEP)); 6518 6519 // last block to prune is the lesser of (caller-specified height, MIN_BLOCKS_TO_KEEP from the tip) 6520 // 6521 // While you might be tempted to prune the background chainstate more 6522 // aggressively (i.e. fewer MIN_BLOCKS_TO_KEEP), this won't work with index 6523 // building - specifically blockfilterindex requires undo data, and if 6524 // we don't maintain this trailing window, we hit indexing failures. 6525 int prune_end = std::min(last_height_can_prune, max_prune); 6526 6527 return {prune_start, prune_end}; 6528 }