// Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2009-2020 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #ifndef BITCOIN_VALIDATION_H #define BITCOIN_VALIDATION_H #if defined(HAVE_CONFIG_H) #include <config/bitcoin-config.h> #endif #include <amount.h> #include <attributes.h> #include <coins.h> #include <consensus/validation.h> #include <crypto/common.h> // for ReadLE64 #include <fs.h> #include <node/utxo_snapshot.h> #include <policy/feerate.h> #include <policy/packages.h> #include <protocol.h> // For CMessageHeader::MessageStartChars #include <script/script_error.h> #include <sync.h> #include <txmempool.h> // For CTxMemPool::cs #include <txdb.h> #include <serialize.h> #include <util/check.h> #include <util/hasher.h> #include <util/translation.h> #include <atomic> #include <map> #include <memory> #include <optional> #include <set> #include <stdint.h> #include <string> #include <thread> #include <utility> #include <vector> class CChainState; class BlockValidationState; class CBlockIndex; class CBlockTreeDB; class CBlockUndo; class CChainParams; struct CCheckpointData; class CInv; class CConnman; class CScriptCheck; class CTxMemPool; class ChainstateManager; struct ChainTxData; struct DisconnectedBlockTransactions; struct PrecomputedTransactionData; struct LockPoints; struct AssumeutxoData; /** Default for -minrelaytxfee, minimum relay fee for transactions */ static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 1000; /** Default for -limitancestorcount, max number of in-mempool ancestors */ static const unsigned int DEFAULT_ANCESTOR_LIMIT = 25; /** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */ static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT = 101; /** Default for -limitdescendantcount, max number of in-mempool descendants */ static const unsigned int DEFAULT_DESCENDANT_LIMIT = 25; /** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */ static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT = 101; /** Default for -mempoolexpiry, expiration time for mempool transactions in hours */ static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 336; /** Maximum number of dedicated script-checking threads allowed */ static const int MAX_SCRIPTCHECK_THREADS = 15; /** -par default (number of script-checking threads, 0 = auto) */ static const int DEFAULT_SCRIPTCHECK_THREADS = 0; static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60; static const bool DEFAULT_CHECKPOINTS_ENABLED = true; static const bool DEFAULT_TXINDEX = false; static constexpr bool DEFAULT_COINSTATSINDEX{false}; static const char* const DEFAULT_BLOCKFILTERINDEX = "0"; /** Default for -persistmempool */ static const bool DEFAULT_PERSIST_MEMPOOL = true; /** Default for -stopatheight */ static const int DEFAULT_STOPATHEIGHT = 0; /** Block files containing a block-height within MIN_BLOCKS_TO_KEEP of ::ChainActive().Tip() will not be pruned. */ static const unsigned int MIN_BLOCKS_TO_KEEP = 288; static const signed int DEFAULT_CHECKBLOCKS = 6; static const unsigned int DEFAULT_CHECKLEVEL = 3; // Require that user allocate at least 550 MiB for block & undo files (blk???.dat and rev???.dat) // At 1MB per block, 288 blocks = 288MB. // Add 15% for Undo data = 331MB // Add 20% for Orphan block rate = 397MB // We want the low water mark after pruning to be at least 397 MB and since we prune in // full block file chunks, we need the high water mark which triggers the prune to be // one 128MB block file + added 15% undo data = 147MB greater for a total of 545MB // Setting the target to >= 550 MiB will make it likely we can respect the target. static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024; /** Current sync state passed to tip changed callbacks. */ enum class SynchronizationState { INIT_REINDEX, INIT_DOWNLOAD, POST_INIT }; extern RecursiveMutex cs_main; typedef std::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap; extern Mutex g_best_block_mutex; extern std::condition_variable g_best_block_cv; extern uint256 g_best_block; /** Whether there are dedicated script-checking threads running. * False indicates all script checking is done on the main threadMessageHandler thread. */ extern bool g_parallel_script_checks; extern bool fRequireStandard; extern bool fCheckBlockIndex; extern bool fCheckpointsEnabled; /** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */ extern CFeeRate minRelayTxFee; /** If the tip is older than this (in seconds), the node is considered to be in initial block download. */ extern int64_t nMaxTipAge; /** Block hash whose ancestors we will assume to have valid scripts without checking them. */ extern uint256 hashAssumeValid; /** Minimum work we will assume exists on some valid chain. */ extern arith_uint256 nMinimumChainWork; /** Best header we've seen so far (used for getheaders queries' starting points). */ extern CBlockIndex *pindexBestHeader; /** Documentation for argument 'checklevel'. */ extern const std::vector<std::string> CHECKLEVEL_DOC; /** Unload database information */ void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman); /** Run instances of script checking worker threads */ void StartScriptCheckWorkerThreads(int threads_num); /** Stop all of the script checking worker threads */ void StopScriptCheckWorkerThreads(); CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams); bool AbortNode(BlockValidationState& state, const std::string& strMessage, const bilingual_str& userMessage = bilingual_str{}); /** Guess verification progress (as a fraction between 0.0=genesis and 1.0=current tip). */ double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex* pindex); /** Prune block files up to a given height */ void PruneBlockFilesManual(CChainState& active_chainstate, int nManualPruneHeight); /** * Validation result for a single transaction mempool acceptance. */ struct MempoolAcceptResult { /** Used to indicate the results of mempool validation. */ enum class ResultType { VALID, //!> Fully validated, valid. INVALID, //!> Invalid. }; const ResultType m_result_type; const TxValidationState m_state; // The following fields are only present when m_result_type = ResultType::VALID /** Mempool transactions replaced by the tx per BIP 125 rules. */ const std::optional<std::list<CTransactionRef>> m_replaced_transactions; /** Raw base fees in satoshis. */ const std::optional<CAmount> m_base_fees; static MempoolAcceptResult Failure(TxValidationState state) { return MempoolAcceptResult(state); } static MempoolAcceptResult Success(std::list<CTransactionRef>&& replaced_txns, CAmount fees) { return MempoolAcceptResult(std::move(replaced_txns), fees); } // Private constructors. Use static methods MempoolAcceptResult::Success, etc. to construct. private: /** Constructor for failure case */ explicit MempoolAcceptResult(TxValidationState state) : m_result_type(ResultType::INVALID), m_state(state) { Assume(!state.IsValid()); // Can be invalid or error } /** Constructor for success case */ explicit MempoolAcceptResult(std::list<CTransactionRef>&& replaced_txns, CAmount fees) : m_result_type(ResultType::VALID), m_replaced_transactions(std::move(replaced_txns)), m_base_fees(fees) {} }; /** * Validation result for package mempool acceptance. */ struct PackageMempoolAcceptResult { const PackageValidationState m_state; /** * Map from wtxid to finished MempoolAcceptResults. The client is responsible * for keeping track of the transaction objects themselves. If a result is not * present, it means validation was unfinished for that transaction. If there * was a package-wide error (see result in m_state), m_tx_results will be empty. */ std::map<const uint256, const MempoolAcceptResult> m_tx_results; explicit PackageMempoolAcceptResult(PackageValidationState state, std::map<const uint256, const MempoolAcceptResult>&& results) : m_state{state}, m_tx_results(std::move(results)) {} /** Constructor to create a PackageMempoolAcceptResult from a single MempoolAcceptResult */ explicit PackageMempoolAcceptResult(const uint256& wtxid, const MempoolAcceptResult& result) : m_tx_results{ {wtxid, result} } {} }; /** * (Try to) add a transaction to the memory pool. * @param[in] bypass_limits When true, don't enforce mempool fee limits. * @param[in] test_accept When true, run validation checks but don't submit to mempool. */ MempoolAcceptResult AcceptToMemoryPool(CChainState& active_chainstate, CTxMemPool& pool, const CTransactionRef& tx, bool bypass_limits, bool test_accept=false) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** * Atomically test acceptance of a package. If the package only contains one tx, package rules still * apply. Package validation does not allow BIP125 replacements, so the transaction(s) cannot spend * the same inputs as any transaction in the mempool. * @param[in] txns Group of transactions which may be independent or contain * parent-child dependencies. The transactions must not conflict * with each other, i.e., must not spend the same inputs. If any * dependencies exist, parents must appear anywhere in the list * before their children. * @returns a PackageMempoolAcceptResult which includes a MempoolAcceptResult for each transaction. * If a transaction fails, validation will exit early and some results may be missing. */ PackageMempoolAcceptResult ProcessNewPackage(CChainState& active_chainstate, CTxMemPool& pool, const Package& txns, bool test_accept) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Apply the effects of this transaction on the UTXO set represented by view */ void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, int nHeight); /** Transaction validation functions */ /** * Check if transaction will be final in the next block to be created. * * Calls IsFinalTx() with current block height and appropriate block time. * * See consensus/consensus.h for flag definitions. */ bool CheckFinalTx(const CBlockIndex* active_chain_tip, const CTransaction &tx, int flags = -1) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** * Test whether the LockPoints height and time are still valid on the current chain */ bool TestLockPointValidity(CChain& active_chain, const LockPoints* lp) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** * Check if transaction will be BIP68 final in the next block to be created on top of tip. * @param[in] tip Chain tip to check tx sequence locks against. For example, * the tip of the current active chain. * @param[in] coins_view Any CCoinsView that provides access to the relevant coins for * checking sequence locks. For example, it can be a CCoinsViewCache * that isn't connected to anything but contains all the relevant * coins, or a CCoinsViewMemPool that is connected to the * mempool and chainstate UTXO set. In the latter case, the caller is * responsible for holding the appropriate locks to ensure that * calls to GetCoin() return correct coins. * Simulates calling SequenceLocks() with data from the tip passed in. * Optionally stores in LockPoints the resulting height and time calculated and the hash * of the block needed for calculation or skips the calculation and uses the LockPoints * passed in for evaluation. * The LockPoints should not be considered valid if CheckSequenceLocks returns false. * * See consensus/consensus.h for flag definitions. */ bool CheckSequenceLocks(CBlockIndex* tip, const CCoinsView& coins_view, const CTransaction& tx, int flags, LockPoints* lp = nullptr, bool useExistingLockPoints = false); /** * Closure representing one script verification * Note that this stores references to the spending transaction */ class CScriptCheck { private: CTxOut m_tx_out; const CTransaction *ptxTo; unsigned int nIn; unsigned int nFlags; bool cacheStore; ScriptError error; PrecomputedTransactionData *txdata; public: CScriptCheck(): ptxTo(nullptr), nIn(0), nFlags(0), cacheStore(false), error(SCRIPT_ERR_UNKNOWN_ERROR) {} CScriptCheck(const CTxOut& outIn, const CTransaction& txToIn, unsigned int nInIn, unsigned int nFlagsIn, bool cacheIn, PrecomputedTransactionData* txdataIn) : m_tx_out(outIn), ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn), cacheStore(cacheIn), error(SCRIPT_ERR_UNKNOWN_ERROR), txdata(txdataIn) { } bool operator()(); void swap(CScriptCheck &check) { std::swap(ptxTo, check.ptxTo); std::swap(m_tx_out, check.m_tx_out); std::swap(nIn, check.nIn); std::swap(nFlags, check.nFlags); std::swap(cacheStore, check.cacheStore); std::swap(error, check.error); std::swap(txdata, check.txdata); } ScriptError GetScriptError() const { return error; } }; /** Initializes the script-execution cache */ void InitScriptExecutionCache(); /** Functions for validating blocks and updating the block tree */ /** Context-independent validity checks */ bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true, bool fCheckMerkleRoot = true); /** Check a block is completely valid from start to finish (only works on top of our current best block) */ bool TestBlockValidity(BlockValidationState& state, const CChainParams& chainparams, CChainState& chainstate, const CBlock& block, CBlockIndex* pindexPrev, bool fCheckPOW = true, bool fCheckMerkleRoot = true) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Update uncommitted block structures (currently: only the witness reserved value). This is safe for submitted blocks. */ void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams); /** Produce the necessary coinbase commitment for a block (modifies the hash, don't call for mined blocks). */ std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams); /** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */ class CVerifyDB { public: CVerifyDB(); ~CVerifyDB(); bool VerifyDB( CChainState& chainstate, const CChainParams& chainparams, CCoinsView& coinsview, int nCheckLevel, int nCheckDepth) EXCLUSIVE_LOCKS_REQUIRED(cs_main); }; enum DisconnectResult { DISCONNECT_OK, // All good. DISCONNECT_UNCLEAN, // Rolled back, but UTXO set was inconsistent with block. DISCONNECT_FAILED // Something else went wrong. }; class ConnectTrace; /** @see CChainState::FlushStateToDisk */ enum class FlushStateMode { NONE, IF_NEEDED, PERIODIC, ALWAYS }; struct CBlockIndexWorkComparator { bool operator()(const CBlockIndex *pa, const CBlockIndex *pb) const; }; /** * Maintains a tree of blocks (stored in `m_block_index`) which is consulted * to determine where the most-work tip is. * * This data is used mostly in `CChainState` - information about, e.g., * candidate tips is not maintained here. */ class BlockManager { friend CChainState; private: /* Calculate the block/rev files to delete based on height specified by user with RPC command pruneblockchain */ void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight, int chain_tip_height); /** * Prune block and undo files (blk???.dat and undo???.dat) so that the disk space used is less than a user-defined target. * The user sets the target (in MB) on the command line or in config file. This will be run on startup and whenever new * space is allocated in a block or undo file, staying below the target. Changing back to unpruned requires a reindex * (which in this case means the blockchain must be re-downloaded.) * * Pruning functions are called from FlushStateToDisk when the global fCheckForPruning flag has been set. * Block and undo files are deleted in lock-step (when blk00003.dat is deleted, so is rev00003.dat.) * Pruning cannot take place until the longest chain is at least a certain length (100000 on mainnet, 1000 on testnet, 1000 on regtest). * Pruning will never delete a block within a defined distance (currently 288) from the active chain's tip. * The block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any blocks that were stored in the deleted files. * A db flag records the fact that at least some block files have been pruned. * * @param[out] setFilesToPrune The set of file indices that can be unlinked will be returned */ void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight, int chain_tip_height, int prune_height, bool is_ibd); public: BlockMap m_block_index GUARDED_BY(cs_main); /** In order to efficiently track invalidity of headers, we keep the set of * blocks which we tried to connect and found to be invalid here (ie which * were set to BLOCK_FAILED_VALID since the last restart). We can then * walk this set and check if a new header is a descendant of something in * this set, preventing us from having to walk m_block_index when we try * to connect a bad block and fail. * * While this is more complicated than marking everything which descends * from an invalid block as invalid at the time we discover it to be * invalid, doing so would require walking all of m_block_index to find all * descendants. Since this case should be very rare, keeping track of all * BLOCK_FAILED_VALID blocks in a set should be just fine and work just as * well. * * Because we already walk m_block_index in height-order at startup, we go * ahead and mark descendants of invalid blocks as FAILED_CHILD at that time, * instead of putting things in this set. */ std::set<CBlockIndex*> m_failed_blocks; /** * All pairs A->B, where A (or one of its ancestors) misses transactions, but B has transactions. * Pruned nodes may have entries where B is missing data. */ std::multimap<CBlockIndex*, CBlockIndex*> m_blocks_unlinked; std::unique_ptr<CBlockTreeDB> m_block_tree_db GUARDED_BY(::cs_main); bool LoadBlockIndexDB(std::set<CBlockIndex*, CBlockIndexWorkComparator>& setBlockIndexCandidates) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); /** * Load the blocktree off disk and into memory. Populate certain metadata * per index entry (nStatus, nChainWork, nTimeMax, etc.) as well as peripheral * collections like setDirtyBlockIndex. * * @param[out] block_index_candidates Fill this set with any valid blocks for * which we've downloaded all transactions. */ bool LoadBlockIndex( const Consensus::Params& consensus_params, std::set<CBlockIndex*, CBlockIndexWorkComparator>& block_index_candidates) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Clear all data members. */ void Unload() EXCLUSIVE_LOCKS_REQUIRED(cs_main); CBlockIndex* AddToBlockIndex(const CBlockHeader& block) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Create a new block index entry for a given block hash */ CBlockIndex* InsertBlockIndex(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); //! Mark one block file as pruned (modify associated database entries) void PruneOneBlockFile(const int fileNumber) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** * If a block header hasn't already been seen, call CheckBlockHeader on it, ensure * that it doesn't descend from an invalid block, and then add it to m_block_index. */ bool AcceptBlockHeader( const CBlockHeader& block, BlockValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main); CBlockIndex* LookupBlockIndex(const uint256& hash) const EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Find the last common block between the parameter chain and a locator. */ CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator) EXCLUSIVE_LOCKS_REQUIRED(cs_main); //! Returns last CBlockIndex* that is a checkpoint CBlockIndex* GetLastCheckpoint(const CCheckpointData& data) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** * Return the spend height, which is one more than the inputs.GetBestBlock(). * While checking, GetBestBlock() refers to the parent block. (protected by cs_main) * This is also true for mempool checks. */ int GetSpendHeight(const CCoinsViewCache& inputs) EXCLUSIVE_LOCKS_REQUIRED(cs_main); ~BlockManager() { Unload(); } }; /** * A convenience class for constructing the CCoinsView* hierarchy used * to facilitate access to the UTXO set. * * This class consists of an arrangement of layered CCoinsView objects, * preferring to store and retrieve coins in memory via `m_cacheview` but * ultimately falling back on cache misses to the canonical store of UTXOs on * disk, `m_dbview`. */ class CoinsViews { public: //! The lowest level of the CoinsViews cache hierarchy sits in a leveldb database on disk. //! All unspent coins reside in this store. CCoinsViewDB m_dbview GUARDED_BY(cs_main); //! This view wraps access to the leveldb instance and handles read errors gracefully. CCoinsViewErrorCatcher m_catcherview GUARDED_BY(cs_main); //! This is the top layer of the cache hierarchy - it keeps as many coins in memory as //! can fit per the dbcache setting. std::unique_ptr<CCoinsViewCache> m_cacheview GUARDED_BY(cs_main); //! This constructor initializes CCoinsViewDB and CCoinsViewErrorCatcher instances, but it //! *does not* create a CCoinsViewCache instance by default. This is done separately because the //! presence of the cache has implications on whether or not we're allowed to flush the cache's //! state to disk, which should not be done until the health of the database is verified. //! //! All arguments forwarded onto CCoinsViewDB. CoinsViews(std::string ldb_name, size_t cache_size_bytes, bool in_memory, bool should_wipe); //! Initialize the CCoinsViewCache member. void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); }; enum class CoinsCacheSizeState { //! The coins cache is in immediate need of a flush. CRITICAL = 2, //! The cache is at >= 90% capacity. LARGE = 1, OK = 0 }; /** * CChainState stores and provides an API to update our local knowledge of the * current best chain. * * Eventually, the API here is targeted at being exposed externally as a * consumable libconsensus library, so any functions added must only call * other class member functions, pure functions in other parts of the consensus * library, callbacks via the validation interface, or read/write-to-disk * functions (eventually this will also be via callbacks). * * Anything that is contingent on the current tip of the chain is stored here, * whereas block information and metadata independent of the current tip is * kept in `BlockManager`. */ class CChainState { protected: /** * Every received block is assigned a unique and increasing identifier, so we * know which one to give priority in case of a fork. */ /** Blocks loaded from disk are assigned id 0, so start the counter at 1. */ int32_t nBlockSequenceId GUARDED_BY(::cs_main) = 1; /** Decreasing counter (used by subsequent preciousblock calls). */ int32_t nBlockReverseSequenceId = -1; /** chainwork for the last block that preciousblock has been applied to. */ arith_uint256 nLastPreciousChainwork = 0; /** * the ChainState CriticalSection * A lock that must be held when modifying this ChainState - held in ActivateBestChain() */ RecursiveMutex m_cs_chainstate; /** * Whether this chainstate is undergoing initial block download. * * Mutable because we need to be able to mark IsInitialBlockDownload() * const, which latches this for caching purposes. */ mutable std::atomic<bool> m_cached_finished_ibd{false}; //! Optional mempool that is kept in sync with the chain. //! Only the active chainstate has a mempool. CTxMemPool* m_mempool; const CChainParams& m_params; //! Manages the UTXO set, which is a reflection of the contents of `m_chain`. std::unique_ptr<CoinsViews> m_coins_views; public: //! Reference to a BlockManager instance which itself is shared across all //! CChainState instances. BlockManager& m_blockman; explicit CChainState( CTxMemPool* mempool, BlockManager& blockman, std::optional<uint256> from_snapshot_blockhash = std::nullopt); /** * Initialize the CoinsViews UTXO set database management data structures. The in-memory * cache is initialized separately. * * All parameters forwarded to CoinsViews. */ void InitCoinsDB( size_t cache_size_bytes, bool in_memory, bool should_wipe, std::string leveldb_name = "chainstate"); //! Initialize the in-memory coins cache (to be done after the health of the on-disk database //! is verified). void InitCoinsCache(size_t cache_size_bytes) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); //! @returns whether or not the CoinsViews object has been fully initialized and we can //! safely flush this object to disk. bool CanFlushToDisk() const EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return m_coins_views && m_coins_views->m_cacheview; } //! The current chain of blockheaders we consult and build on. //! @see CChain, CBlockIndex. CChain m_chain; /** * The blockhash which is the base of the snapshot this chainstate was created from. * * std::nullopt if this chainstate was not created from a snapshot. */ const std::optional<uint256> m_from_snapshot_blockhash; /** * The set of all CBlockIndex entries with BLOCK_VALID_TRANSACTIONS (for itself and all ancestors) and * as good as our current tip or better. Entries may be failed, though, and pruning nodes may be * missing the data for the block. */ std::set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexCandidates; //! @returns A reference to the in-memory cache of the UTXO set. CCoinsViewCache& CoinsTip() EXCLUSIVE_LOCKS_REQUIRED(cs_main) { assert(m_coins_views->m_cacheview); return *m_coins_views->m_cacheview.get(); } //! @returns A reference to the on-disk UTXO set database. CCoinsViewDB& CoinsDB() EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return m_coins_views->m_dbview; } //! @returns A reference to a wrapped view of the in-memory UTXO set that //! handles disk read errors gracefully. CCoinsViewErrorCatcher& CoinsErrorCatcher() EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return m_coins_views->m_catcherview; } //! Destructs all objects related to accessing the UTXO set. void ResetCoinsViews() { m_coins_views.reset(); } //! The cache size of the on-disk coins view. size_t m_coinsdb_cache_size_bytes{0}; //! The cache size of the in-memory coins view. size_t m_coinstip_cache_size_bytes{0}; //! Resize the CoinsViews caches dynamically and flush state to disk. //! @returns true unless an error occurred during the flush. bool ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); /** Import blocks from an external file */ void LoadExternalBlockFile(FILE* fileIn, FlatFilePos* dbp = nullptr); /** * Update the on-disk chain state. * The caches and indexes are flushed depending on the mode we're called with * if they're too large, if it's been a while since the last write, * or always and in all cases if we're in prune mode and are deleting files. * * If FlushStateMode::NONE is used, then FlushStateToDisk(...) won't do anything * besides checking if we need to prune. * * @returns true unless a system error occurred */ bool FlushStateToDisk( BlockValidationState& state, FlushStateMode mode, int nManualPruneHeight = 0); //! Unconditionally flush all changes to disk. void ForceFlushStateToDisk(); //! Prune blockfiles from the disk if necessary and then flush chainstate changes //! if we pruned. void PruneAndFlush(); /** * Find the best known block, and make it the tip of the block chain. The * result is either failure or an activated best chain. pblock is either * nullptr or a pointer to a block that is already loaded (to avoid loading * it again from disk). * * ActivateBestChain is split into steps (see ActivateBestChainStep) so that * we avoid holding cs_main for an extended period of time; the length of this * call may be quite long during reindexing or a substantial reorg. * * May not be called with cs_main held. May not be called in a * validationinterface callback. * * @returns true unless a system error occurred */ bool ActivateBestChain( BlockValidationState& state, std::shared_ptr<const CBlock> pblock = nullptr) LOCKS_EXCLUDED(cs_main); bool AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockValidationState& state, CBlockIndex** ppindex, bool fRequested, const FlatFilePos* dbp, bool* fNewBlock) EXCLUSIVE_LOCKS_REQUIRED(cs_main); // Block (dis)connection on a given view: DisconnectResult DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view); bool ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex, CCoinsViewCache& view, bool fJustCheck = false) EXCLUSIVE_LOCKS_REQUIRED(cs_main); // Apply the effects of a block disconnection on the UTXO set. bool DisconnectTip(BlockValidationState& state, DisconnectedBlockTransactions* disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs); // Manual block validity manipulation: /** Mark a block as precious and reorganize. * * May not be called in a validationinterface callback. */ bool PreciousBlock(BlockValidationState& state, CBlockIndex* pindex) LOCKS_EXCLUDED(cs_main); /** Mark a block as invalid. */ bool InvalidateBlock(BlockValidationState& state, CBlockIndex* pindex) LOCKS_EXCLUDED(cs_main); /** Remove invalidity status from a block and its descendants. */ void ResetBlockFailureFlags(CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Replay blocks that aren't fully applied to the database. */ bool ReplayBlocks(); /** Whether the chain state needs to be redownloaded due to lack of witness data */ [[nodiscard]] bool NeedsRedownload() const EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** Ensures we have a genesis block in the block tree, possibly writing one to disk. */ bool LoadGenesisBlock(); void PruneBlockIndexCandidates(); void UnloadBlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); /** Check whether we are doing an initial block download (synchronizing from disk or network) */ bool IsInitialBlockDownload() const; /** * Make various assertions about the state of the block index. * * By default this only executes fully when using the Regtest chain; see: fCheckBlockIndex. */ void CheckBlockIndex(); /** Load the persisted mempool from disk */ void LoadMempool(const ArgsManager& args); /** Update the chain tip based on database information, i.e. CoinsTip()'s best block. */ bool LoadChainTip() EXCLUSIVE_LOCKS_REQUIRED(cs_main); //! Dictates whether we need to flush the cache to disk or not. //! //! @return the state of the size of the coins cache. CoinsCacheSizeState GetCoinsCacheSizeState() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); CoinsCacheSizeState GetCoinsCacheSizeState( size_t max_coins_cache_size_bytes, size_t max_mempool_size_bytes) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); std::string ToString() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); private: bool ActivateBestChainStep(BlockValidationState& state, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs); bool ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs); void InvalidBlockFound(CBlockIndex* pindex, const BlockValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(cs_main); CBlockIndex* FindMostWorkChain() EXCLUSIVE_LOCKS_REQUIRED(cs_main); void ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos) EXCLUSIVE_LOCKS_REQUIRED(cs_main); bool RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs) EXCLUSIVE_LOCKS_REQUIRED(cs_main); void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main); void InvalidChainFound(CBlockIndex* pindexNew) EXCLUSIVE_LOCKS_REQUIRED(cs_main); //! Indirection necessary to make lock annotations work with an optional mempool. RecursiveMutex* MempoolMutex() const LOCK_RETURNED(m_mempool->cs) { return m_mempool ? &m_mempool->cs : nullptr; } /** * Make mempool consistent after a reorg, by re-adding or recursively erasing * disconnected block transactions from the mempool, and also removing any * other transactions from the mempool that are no longer valid given the new * tip/height. * * Note: we assume that disconnectpool only contains transactions that are NOT * confirmed in the current chain nor already in the mempool (otherwise, * in-mempool descendants of such transactions would be removed). * * Passing fAddToMempool=false will skip trying to add the transactions back, * and instead just erase from the mempool as needed. */ void MaybeUpdateMempoolForReorg( DisconnectedBlockTransactions& disconnectpool, bool fAddToMempool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs); /** Check warning conditions and do some notifications on new chain tip set. */ void UpdateTip(const CBlockIndex* pindexNew) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); friend ChainstateManager; }; /** * Provides an interface for creating and interacting with one or two * chainstates: an IBD chainstate generated by downloading blocks, and * an optional snapshot chainstate loaded from a UTXO snapshot. Managed * chainstates can be maintained at different heights simultaneously. * * This class provides abstractions that allow the retrieval of the current * most-work chainstate ("Active") as well as chainstates which may be in * background use to validate UTXO snapshots. * * Definitions: * * *IBD chainstate*: a chainstate whose current state has been "fully" * validated by the initial block download process. * * *Snapshot chainstate*: a chainstate populated by loading in an * assumeutxo UTXO snapshot. * * *Active chainstate*: the chainstate containing the current most-work * chain. Consulted by most parts of the system (net_processing, * wallet) as a reflection of the current chain and UTXO set. * This may either be an IBD chainstate or a snapshot chainstate. * * *Background IBD chainstate*: an IBD chainstate for which the * IBD process is happening in the background while use of the * active (snapshot) chainstate allows the rest of the system to function. * * *Validated chainstate*: the most-work chainstate which has been validated * locally via initial block download. This will be the snapshot chainstate * if a snapshot was loaded and all blocks up to the snapshot starting point * have been downloaded and validated (via background validation), otherwise * it will be the IBD chainstate. */ class ChainstateManager { private: //! The chainstate used under normal operation (i.e. "regular" IBD) or, if //! a snapshot is in use, for background validation. //! //! Its contents (including on-disk data) will be deleted *upon shutdown* //! after background validation of the snapshot has completed. We do not //! free the chainstate contents immediately after it finishes validation //! to cautiously avoid a case where some other part of the system is still //! using this pointer (e.g. net_processing). //! //! Once this pointer is set to a corresponding chainstate, it will not //! be reset until init.cpp:Shutdown(). //! //! This is especially important when, e.g., calling ActivateBestChain() //! on all chainstates because we are not able to hold ::cs_main going into //! that call. std::unique_ptr<CChainState> m_ibd_chainstate GUARDED_BY(::cs_main); //! A chainstate initialized on the basis of a UTXO snapshot. If this is //! non-null, it is always our active chainstate. //! //! Once this pointer is set to a corresponding chainstate, it will not //! be reset until init.cpp:Shutdown(). //! //! This is especially important when, e.g., calling ActivateBestChain() //! on all chainstates because we are not able to hold ::cs_main going into //! that call. std::unique_ptr<CChainState> m_snapshot_chainstate GUARDED_BY(::cs_main); //! Points to either the ibd or snapshot chainstate; indicates our //! most-work chain. //! //! Once this pointer is set to a corresponding chainstate, it will not //! be reset until init.cpp:Shutdown(). //! //! This is especially important when, e.g., calling ActivateBestChain() //! on all chainstates because we are not able to hold ::cs_main going into //! that call. CChainState* m_active_chainstate GUARDED_BY(::cs_main) {nullptr}; //! If true, the assumed-valid chainstate has been fully validated //! by the background validation chainstate. bool m_snapshot_validated{false}; //! Internal helper for ActivateSnapshot(). [[nodiscard]] bool PopulateAndValidateSnapshot( CChainState& snapshot_chainstate, CAutoFile& coins_file, const SnapshotMetadata& metadata); public: std::thread m_load_block; //! A single BlockManager instance is shared across each constructed //! chainstate to avoid duplicating block metadata. BlockManager m_blockman GUARDED_BY(::cs_main); //! The total number of bytes available for us to use across all in-memory //! coins caches. This will be split somehow across chainstates. int64_t m_total_coinstip_cache{0}; // //! The total number of bytes available for us to use across all leveldb //! coins databases. This will be split somehow across chainstates. int64_t m_total_coinsdb_cache{0}; //! Instantiate a new chainstate and assign it based upon whether it is //! from a snapshot. //! //! @param[in] mempool The mempool to pass to the chainstate // constructor //! @param[in] snapshot_blockhash If given, signify that this chainstate //! is based on a snapshot. CChainState& InitializeChainstate( CTxMemPool* mempool, const std::optional<uint256>& snapshot_blockhash = std::nullopt) LIFETIMEBOUND EXCLUSIVE_LOCKS_REQUIRED(::cs_main); //! Get all chainstates currently being used. std::vector<CChainState*> GetAll(); //! Construct and activate a Chainstate on the basis of UTXO snapshot data. //! //! Steps: //! //! - Initialize an unused CChainState. //! - Load its `CoinsViews` contents from `coins_file`. //! - Verify that the hash of the resulting coinsdb matches the expected hash //! per assumeutxo chain parameters. //! - Wait for our headers chain to include the base block of the snapshot. //! - "Fast forward" the tip of the new chainstate to the base of the snapshot, //! faking nTx* block index data along the way. //! - Move the new chainstate to `m_snapshot_chainstate` and make it our //! ChainstateActive(). [[nodiscard]] bool ActivateSnapshot( CAutoFile& coins_file, const SnapshotMetadata& metadata, bool in_memory); //! The most-work chain. CChainState& ActiveChainstate() const; CChain& ActiveChain() const { return ActiveChainstate().m_chain; } int ActiveHeight() const { return ActiveChain().Height(); } CBlockIndex* ActiveTip() const { return ActiveChain().Tip(); } BlockMap& BlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { return m_blockman.m_block_index; } //! @returns true if a snapshot-based chainstate is in use. Also implies //! that a background validation chainstate is also in use. bool IsSnapshotActive() const; std::optional<uint256> SnapshotBlockhash() const; //! Is there a snapshot in use and has it been fully validated? bool IsSnapshotValidated() const { return m_snapshot_validated; } //! @returns true if this chainstate is being used to validate an active //! snapshot in the background. bool IsBackgroundIBD(CChainState* chainstate) const; //! Return the most-work chainstate that has been fully validated. //! //! During background validation of a snapshot, this is the IBD chain. After //! background validation has completed, this is the snapshot chain. CChainState& ValidatedChainstate() const; CChain& ValidatedChain() const { return ValidatedChainstate().m_chain; } CBlockIndex* ValidatedTip() const { return ValidatedChain().Tip(); } /** * Process an incoming block. This only returns after the best known valid * block is made active. Note that it does not, however, guarantee that the * specific block passed to it has been checked for validity! * * If you want to *possibly* get feedback on whether block is valid, you must * install a CValidationInterface (see validationinterface.h) - this will have * its BlockChecked method called whenever *any* block completes validation. * * Note that we guarantee that either the proof-of-work is valid on block, or * (and possibly also) BlockChecked will have been called. * * May not be called in a validationinterface callback. * * @param[in] block The block we want to process. * @param[in] force_processing Process this block even if unrequested; used for non-network block sources. * @param[out] new_block A boolean which is set to indicate if the block was first received via this call * @returns If the block was processed, independently of block validity */ bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<const CBlock>& block, bool force_processing, bool* new_block) LOCKS_EXCLUDED(cs_main); /** * Process incoming block headers. * * May not be called in a * validationinterface callback. * * @param[in] block The block headers themselves * @param[out] state This may be set to an Error state if any error occurred processing them * @param[in] chainparams The params for the chain we want to connect to * @param[out] ppindex If set, the pointer will be set to point to the last new block index object for the given headers */ bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, BlockValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex = nullptr) LOCKS_EXCLUDED(cs_main); //! Load the block tree and coins database from disk, initializing state if we're running with -reindex bool LoadBlockIndex() EXCLUSIVE_LOCKS_REQUIRED(cs_main); //! Unload block index and chain data before shutdown. void Unload() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); //! Clear (deconstruct) chainstate data. void Reset(); //! Check to see if caches are out of balance and if so, call //! ResizeCoinsCaches() as needed. void MaybeRebalanceCaches() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); ~ChainstateManager() { LOCK(::cs_main); UnloadBlockIndex(/* mempool */ nullptr, *this); Reset(); } }; using FopenFn = std::function<FILE*(const fs::path&, const char*)>; /** Dump the mempool to disk. */ bool DumpMempool(const CTxMemPool& pool, FopenFn mockable_fopen_function = fsbridge::fopen, bool skip_file_commit = false); /** Load the mempool from disk. */ bool LoadMempool(CTxMemPool& pool, CChainState& active_chainstate, FopenFn mockable_fopen_function = fsbridge::fopen); /** * Return the expected assumeutxo value for a given height, if one exists. * * @param[in] height Get the assumeutxo value for this height. * * @returns empty if no assumeutxo configuration exists for the given height. */ const AssumeutxoData* ExpectedAssumeutxo(const int height, const CChainParams& params); #endif // BITCOIN_VALIDATION_H