src/validation.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 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 #ifndef BITCOIN_VALIDATION_H
   7 #define BITCOIN_VALIDATION_H
   8
   9 #if defined(HAVE_CONFIG_H)
  10 #include "config/bitcoin-config.h"
  11 #endif
  12
  13 #include "amount.h"
  14 #include "chain.h"
  15 #include "coins.h"
  16 #include "protocol.h" // For CMessageHeader::MessageStartChars
  17 #include "script/script_error.h"
  18 #include "sync.h"
  19 #include "versionbits.h"
  20
  21 #include <algorithm>
  22 #include <exception>
  23 #include <map>
  24 #include <set>
  25 #include <stdint.h>
  26 #include <string>
  27 #include <utility>
  28 #include <vector>
  29
  30 #include <atomic>
  31
  32 #include <boost/unordered_map.hpp>
  33 #include <boost/filesystem/path.hpp>
  34
  35 class CBlockIndex;
  36 class CBlockTreeDB;
  37 class CBloomFilter;
  38 class CChainParams;
  39 class CInv;
  40 class CConnman;
  41 class CScriptCheck;
  42 class CTxMemPool;
  43 class CValidationInterface;
  44 class CValidationState;
  45 struct ChainTxData;
  46
  47 struct PrecomputedTransactionData;
  48 struct LockPoints;
  49
  50 /** Default for DEFAULT_WHITELISTRELAY. */
  51 static const bool DEFAULT_WHITELISTRELAY = true;
  52 /** Default for DEFAULT_WHITELISTFORCERELAY. */
  53 static const bool DEFAULT_WHITELISTFORCERELAY = true;
  54 /** Default for -minrelaytxfee, minimum relay fee for transactions */
  55 static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 1000;
  56 //! -maxtxfee default
  57 static const CAmount DEFAULT_TRANSACTION_MAXFEE = 0.1 * COIN;
  58 //! Discourage users to set fees higher than this amount (in satoshis) per kB
  59 static const CAmount HIGH_TX_FEE_PER_KB = 0.01 * COIN;
  60 //! -maxtxfee will warn if called with a higher fee than this amount (in satoshis)
  61 static const CAmount HIGH_MAX_TX_FEE = 100 * HIGH_TX_FEE_PER_KB;
  62 /** Default for -limitancestorcount, max number of in-mempool ancestors */
  63 static const unsigned int DEFAULT_ANCESTOR_LIMIT = 25;
  64 /** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */
  65 static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT = 101;
  66 /** Default for -limitdescendantcount, max number of in-mempool descendants */
  67 static const unsigned int DEFAULT_DESCENDANT_LIMIT = 25;
  68 /** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
  69 static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT = 101;
  70 /** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
  71 static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 336;
  72 /** The maximum size of a blk?????.dat file (since 0.8) */
  73 static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
  74 /** The pre-allocation chunk size for blk?????.dat files (since 0.8) */
  75 static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB
  76 /** The pre-allocation chunk size for rev?????.dat files (since 0.8) */
  77 static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
  78
  79 /** Maximum number of script-checking threads allowed */
  80 static const int MAX_SCRIPTCHECK_THREADS = 16;
  81 /** -par default (number of script-checking threads, 0 = auto) */
  82 static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
  83 /** Number of blocks that can be requested at any given time from a single peer. */
  84 static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 16;
  85 /** Timeout in seconds during which a peer must stall block download progress before being disconnected. */
  86 static const unsigned int BLOCK_STALLING_TIMEOUT = 2;
  87 /** Number of headers sent in one getheaders result. We rely on the assumption that if a peer sends
  88  *  less than this number, we reached its tip. Changing this value is a protocol upgrade. */
  89 static const unsigned int MAX_HEADERS_RESULTS = 2000;
  90 /** Maximum depth of blocks we're willing to serve as compact blocks to peers
  91  *  when requested. For older blocks, a regular BLOCK response will be sent. */
  92 static const int MAX_CMPCTBLOCK_DEPTH = 5;
  93 /** Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests for. */
  94 static const int MAX_BLOCKTXN_DEPTH = 10;
  95 /** Size of the "block download window": how far ahead of our current height do we fetch?
  96  *  Larger windows tolerate larger download speed differences between peer, but increase the potential
  97  *  degree of disordering of blocks on disk (which make reindexing and in the future perhaps pruning
  98  *  harder). We'll probably want to make this a per-peer adaptive value at some point. */
  99 static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024;
 100 /** Time to wait (in seconds) between writing blocks/block index to disk. */
 101 static const unsigned int DATABASE_WRITE_INTERVAL = 60 * 60;
 102 /** Time to wait (in seconds) between flushing chainstate to disk. */
 103 static const unsigned int DATABASE_FLUSH_INTERVAL = 24 * 60 * 60;
 104 /** Maximum length of reject messages. */
 105 static const unsigned int MAX_REJECT_MESSAGE_LENGTH = 111;
 106 /** Average delay between local address broadcasts in seconds. */
 107 static const unsigned int AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL = 24 * 24 * 60;
 108 /** Average delay between peer address broadcasts in seconds. */
 109 static const unsigned int AVG_ADDRESS_BROADCAST_INTERVAL = 30;
 110 /** Average delay between trickled inventory transmissions in seconds.
 111  *  Blocks and whitelisted receivers bypass this, outbound peers get half this delay. */
 112 static const unsigned int INVENTORY_BROADCAST_INTERVAL = 5;
 113 /** Maximum number of inventory items to send per transmission.
 114  *  Limits the impact of low-fee transaction floods. */
 115 static const unsigned int INVENTORY_BROADCAST_MAX = 7 * INVENTORY_BROADCAST_INTERVAL;
 116 /** Average delay between feefilter broadcasts in seconds. */
 117 static const unsigned int AVG_FEEFILTER_BROADCAST_INTERVAL = 10 * 60;
 118 /** Maximum feefilter broadcast delay after significant change. */
 119 static const unsigned int MAX_FEEFILTER_CHANGE_DELAY = 5 * 60;
 120 /** Block download timeout base, expressed in millionths of the block interval (i.e. 10 min) */
 121 static const int64_t BLOCK_DOWNLOAD_TIMEOUT_BASE = 1000000;
 122 /** Additional block download timeout per parallel downloading peer (i.e. 5 min) */
 123 static const int64_t BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 500000;
 124
 125 static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;
 126 /** Maximum age of our tip in seconds for us to be considered current for fee estimation */
 127 static const int64_t MAX_FEE_ESTIMATION_TIP_AGE = 3 * 60 * 60;
 128
 129 /** Default for -permitbaremultisig */
 130 static const bool DEFAULT_PERMIT_BAREMULTISIG = true;
 131 static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
 132 static const bool DEFAULT_TXINDEX = false;
 133 static const unsigned int DEFAULT_BANSCORE_THRESHOLD = 100;
 134
 135 /** Default for -mempoolreplacement */
 136 static const bool DEFAULT_ENABLE_REPLACEMENT = true;
 137 /** Default for using fee filter */
 138 static const bool DEFAULT_FEEFILTER = true;
 139
 140 /** Maximum number of headers to announce when relaying blocks with headers message.*/
 141 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8;
 142
 143 /** Maximum number of unconnecting headers announcements before DoS score */
 144 static const int MAX_UNCONNECTING_HEADERS = 10;
 145
 146 static const bool DEFAULT_PEERBLOOMFILTERS = true;
 147
 148 struct BlockHasher
 149 {
 150     size_t operator()(const uint256& hash) const { return hash.GetCheapHash(); }
 151 };
 152
 153 extern CScript COINBASE_FLAGS;
 154 extern CCriticalSection cs_main;
 155 extern CTxMemPool mempool;
 156 typedef boost::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
 157 extern BlockMap mapBlockIndex;
 158 extern uint64_t nLastBlockTx;
 159 extern uint64_t nLastBlockSize;
 160 extern uint64_t nLastBlockWeight;
 161 extern const std::string strMessageMagic;
 162 extern CWaitableCriticalSection csBestBlock;
 163 extern CConditionVariable cvBlockChange;
 164 extern std::atomic_bool fImporting;
 165 extern bool fReindex;
 166 extern int nScriptCheckThreads;
 167 extern bool fTxIndex;
 168 extern bool fIsBareMultisigStd;
 169 extern bool fRequireStandard;
 170 extern bool fCheckBlockIndex;
 171 extern bool fCheckpointsEnabled;
 172 extern size_t nCoinCacheUsage;
 173 /** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */
 174 extern CFeeRate minRelayTxFee;
 175 /** Absolute maximum transaction fee (in satoshis) used by wallet and mempool (rejects high fee in sendrawtransaction) */
 176 extern CAmount maxTxFee;
 177 /** If the tip is older than this (in seconds), the node is considered to be in initial block download. */
 178 extern int64_t nMaxTipAge;
 179 extern bool fEnableReplacement;
 180
 181 /** Block hash whose ancestors we will assume to have valid scripts without checking them. */
 182 extern uint256 hashAssumeValid;
 183
 184 /** Best header we've seen so far (used for getheaders queries' starting points). */
 185 extern CBlockIndex *pindexBestHeader;
 186
 187 /** Minimum disk space required - used in CheckDiskSpace() */
 188 static const uint64_t nMinDiskSpace = 52428800;
 189
 190 /** Pruning-related variables and constants */
 191 /** True if any block files have ever been pruned. */
 192 extern bool fHavePruned;
 193 /** True if we're running in -prune mode. */
 194 extern bool fPruneMode;
 195 /** Number of MiB of block files that we're trying to stay below. */
 196 extern uint64_t nPruneTarget;
 197 /** Block files containing a block-height within MIN_BLOCKS_TO_KEEP of chainActive.Tip() will not be pruned. */
 198 static const unsigned int MIN_BLOCKS_TO_KEEP = 288;
 199
 200 static const signed int DEFAULT_CHECKBLOCKS = 6;
 201 static const unsigned int DEFAULT_CHECKLEVEL = 3;
 202
 203 // Require that user allocate at least 550MB for block & undo files (blk???.dat and rev???.dat)
 204 // At 1MB per block, 288 blocks = 288MB.
 205 // Add 15% for Undo data = 331MB
 206 // Add 20% for Orphan block rate = 397MB
 207 // We want the low water mark after pruning to be at least 397 MB and since we prune in
 208 // full block file chunks, we need the high water mark which triggers the prune to be
 209 // one 128MB block file + added 15% undo data = 147MB greater for a total of 545MB
 210 // Setting the target to > than 550MB will make it likely we can respect the target.
 211 static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024;
 212
 213 /**
 214  * Process an incoming block. This only returns after the best known valid
 215  * block is made active. Note that it does not, however, guarantee that the
 216  * specific block passed to it has been checked for validity!
 217  *
 218  * If you want to *possibly* get feedback on whether pblock is valid, you must
 219  * install a CValidationInterface (see validationinterface.h) - this will have
 220  * its BlockChecked method called whenever *any* block completes validation.
 221  *
 222  * Note that we guarantee that either the proof-of-work is valid on pblock, or
 223  * (and possibly also) BlockChecked will have been called.
 224  *
 225  * Call without cs_main held.
 226  *
 227  * @param[in]   pblock  The block we want to process.
 228  * @param[in]   fForceProcessing Process this block even if unrequested; used for non-network block sources and whitelisted peers.
 229  * @param[out]  fNewBlock A boolean which is set to indicate if the block was first received via this call
 230  * @return True if state.IsValid()
 231  */
 232 bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<const CBlock> pblock, bool fForceProcessing, bool* fNewBlock);
 233
 234 /**
 235  * Process incoming block headers.
 236  *
 237  * Call without cs_main held.
 238  *
 239  * @param[in]  block The block headers themselves
 240  * @param[out] state This may be set to an Error state if any error occurred processing them
 241  * @param[in]  chainparams The params for the chain we want to connect to
 242  * @param[out] ppindex If set, the pointer will be set to point to the last new block index object for the given headers
 243  */
 244 bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, CValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex=NULL);
 245
 246 /** Check whether enough disk space is available for an incoming block */
 247 bool CheckDiskSpace(uint64_t nAdditionalBytes = 0);
 248 /** Open a block file (blk?????.dat) */
 249 FILE* OpenBlockFile(const CDiskBlockPos &pos, bool fReadOnly = false);
 250 /** Open an undo file (rev?????.dat) */
 251 FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false);
 252 /** Translation to a filesystem path */
 253 boost::filesystem::path GetBlockPosFilename(const CDiskBlockPos &pos, const char *prefix);
 254 /** Import blocks from an external file */
 255 bool LoadExternalBlockFile(const CChainParams& chainparams, FILE* fileIn, CDiskBlockPos *dbp = NULL);
 256 /** Initialize a new block tree database + block data on disk */
 257 bool InitBlockIndex(const CChainParams& chainparams);
 258 /** Load the block tree and coins database from disk */
 259 bool LoadBlockIndex(const CChainParams& chainparams);
 260 /** Unload database information */
 261 void UnloadBlockIndex();
 262 /** Run an instance of the script checking thread */
 263 void ThreadScriptCheck();
 264 /** Check whether we are doing an initial block download (synchronizing from disk or network) */
 265 bool IsInitialBlockDownload();
 266 /** Format a string that describes several potential problems detected by the core.
 267  * strFor can have three values:
 268  * - "rpc": get critical warnings, which should put the client in safe mode if non-empty
 269  * - "statusbar": get all warnings
 270  * - "gui": get all warnings, translated (where possible) for GUI
 271  * This function only returns the highest priority warning of the set selected by strFor.
 272  */
 273 std::string GetWarnings(const std::string& strFor);
 274 /** Retrieve a transaction (from memory pool, or from disk, if possible) */
 275 bool GetTransaction(const uint256 &hash, CTransactionRef &tx, const Consensus::Params& params, uint256 &hashBlock, bool fAllowSlow = false);
 276 /** Find the best known block, and make it the tip of the block chain */
 277 bool ActivateBestChain(CValidationState& state, const CChainParams& chainparams, std::shared_ptr<const CBlock> pblock = std::shared_ptr<const CBlock>());
 278 CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams);
 279
 280 /** Guess verification progress (as a fraction between 0.0=genesis and 1.0=current tip). */
 281 double GuessVerificationProgress(const ChainTxData& data, CBlockIndex* pindex);
 282
 283 /**
 284  * Prune block and undo files (blk???.dat and undo???.dat) so that the disk space used is less than a user-defined target.
 285  * The user sets the target (in MB) on the command line or in config file.  This will be run on startup and whenever new
 286  * space is allocated in a block or undo file, staying below the target. Changing back to unpruned requires a reindex
 287  * (which in this case means the blockchain must be re-downloaded.)
 288  *
 289  * Pruning functions are called from FlushStateToDisk when the global fCheckForPruning flag has been set.
 290  * Block and undo files are deleted in lock-step (when blk00003.dat is deleted, so is rev00003.dat.)
 291  * Pruning cannot take place until the longest chain is at least a certain length (100000 on mainnet, 1000 on testnet, 1000 on regtest).
 292  * Pruning will never delete a block within a defined distance (currently 288) from the active chain's tip.
 293  * The block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any blocks that were stored in the deleted files.
 294  * A db flag records the fact that at least some block files have been pruned.
 295  *
 296  * @param[out]   setFilesToPrune   The set of file indices that can be unlinked will be returned
 297  */
 298 void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight);
 299
 300 /**
 301  *  Mark one block file as pruned.
 302  */
 303 void PruneOneBlockFile(const int fileNumber);
 304
 305 /**
 306  *  Actually unlink the specified files
 307  */
 308 void UnlinkPrunedFiles(const std::set<int>& setFilesToPrune);
 309
 310 /** Create a new block index entry for a given block hash */
 311 CBlockIndex * InsertBlockIndex(uint256 hash);
 312 /** Flush all state, indexes and buffers to disk. */
 313 void FlushStateToDisk();
 314 /** Prune block files and flush state to disk. */
 315 void PruneAndFlush();
 316 /** Prune block files up to a given height */
 317 void PruneBlockFilesManual(int nManualPruneHeight);
 318
 319 /** (try to) add transaction to memory pool
 320  * plTxnReplaced will be appended to with all transactions replaced from mempool **/
 321 bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransactionRef &tx, bool fLimitFree,
 322                         bool* pfMissingInputs, std::list<CTransactionRef>* plTxnReplaced = NULL,
 323                         bool fOverrideMempoolLimit=false, const CAmount nAbsurdFee=0);
 324
 325 /** (try to) add transaction to memory pool with a specified acceptance time **/
 326 bool AcceptToMemoryPoolWithTime(CTxMemPool& pool, CValidationState &state, const CTransactionRef &tx, bool fLimitFree,
 327                         bool* pfMissingInputs, int64_t nAcceptTime, std::list<CTransactionRef>* plTxnReplaced = NULL,
 328                         bool fOverrideMempoolLimit=false, const CAmount nAbsurdFee=0);
 329
 330 /** Convert CValidationState to a human-readable message for logging */
 331 std::string FormatStateMessage(const CValidationState &state);
 332
 333 /** Get the BIP9 state for a given deployment at the current tip. */
 334 ThresholdState VersionBitsTipState(const Consensus::Params& params, Consensus::DeploymentPos pos);
 335
 336 /** Get the block height at which the BIP9 deployment switched into the state for the block building on the current tip. */
 337 int VersionBitsTipStateSinceHeight(const Consensus::Params& params, Consensus::DeploymentPos pos);
 338
 339 /**
 340  * Count ECDSA signature operations the old-fashioned (pre-0.6) way
 341  * @return number of sigops this transaction's outputs will produce when spent
 342  * @see CTransaction::FetchInputs
 343  */
 344 unsigned int GetLegacySigOpCount(const CTransaction& tx);
 345
 346 /**
 347  * Count ECDSA signature operations in pay-to-script-hash inputs.
 348  *
 349  * @param[in] mapInputs Map of previous transactions that have outputs we're spending
 350  * @return maximum number of sigops required to validate this transaction's inputs
 351  * @see CTransaction::FetchInputs
 352  */
 353 unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& mapInputs);
 354
 355 /**
 356  * Compute total signature operation cost of a transaction.
 357  * @param[in] tx     Transaction for which we are computing the cost
 358  * @param[in] inputs Map of previous transactions that have outputs we're spending
 359  * @param[out] flags Script verification flags
 360  * @return Total signature operation cost of tx
 361  */
 362 int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags);
 363
 364 /**
 365  * Check whether all inputs of this transaction are valid (no double spends, scripts & sigs, amounts)
 366  * This does not modify the UTXO set. If pvChecks is not NULL, script checks are pushed onto it
 367  * instead of being performed inline.
 368  */
 369 bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &view, bool fScriptChecks,
 370                  unsigned int flags, bool cacheStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks = NULL);
 371
 372 /** Apply the effects of this transaction on the UTXO set represented by view */
 373 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, int nHeight);
 374
 375 /** Transaction validation functions */
 376
 377 /** Context-independent validity checks */
 378 bool CheckTransaction(const CTransaction& tx, CValidationState& state, bool fCheckDuplicateInputs=true);
 379
 380 namespace Consensus {
 381
 382 /**
 383  * Check whether all inputs of this transaction are valid (no double spends and amounts)
 384  * This does not modify the UTXO set. This does not check scripts and sigs.
 385  * Preconditions: tx.IsCoinBase() is false.
 386  */
 387 bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight);
 388
 389 } // namespace Consensus
 390
 391 /**
 392  * Check if transaction is final and can be included in a block with the
 393  * specified height and time. Consensus critical.
 394  */
 395 bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime);
 396
 397 /**
 398  * Check if transaction will be final in the next block to be created.
 399  *
 400  * Calls IsFinalTx() with current block height and appropriate block time.
 401  *
 402  * See consensus/consensus.h for flag definitions.
 403  */
 404 bool CheckFinalTx(const CTransaction &tx, int flags = -1);
 405
 406 /**
 407  * Test whether the LockPoints height and time are still valid on the current chain
 408  */
 409 bool TestLockPointValidity(const LockPoints* lp);
 410
 411 /**
 412  * Check if transaction is final per BIP 68 sequence numbers and can be included in a block.
 413  * Consensus critical. Takes as input a list of heights at which tx's inputs (in order) confirmed.
 414  */
 415 bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block);
 416
 417 /**
 418  * Check if transaction will be BIP 68 final in the next block to be created.
 419  *
 420  * Simulates calling SequenceLocks() with data from the tip of the current active chain.
 421  * Optionally stores in LockPoints the resulting height and time calculated and the hash
 422  * of the block needed for calculation or skips the calculation and uses the LockPoints
 423  * passed in for evaluation.
 424  * The LockPoints should not be considered valid if CheckSequenceLocks returns false.
 425  *
 426  * See consensus/consensus.h for flag definitions.
 427  */
 428 bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp = NULL, bool useExistingLockPoints = false);
 429
 430 /**
 431  * Closure representing one script verification
 432  * Note that this stores references to the spending transaction
 433  */
 434 class CScriptCheck
 435 {
 436 private:
 437     CScript scriptPubKey;
 438     CAmount amount;
 439     const CTransaction *ptxTo;
 440     unsigned int nIn;
 441     unsigned int nFlags;
 442     bool cacheStore;
 443     ScriptError error;
 444     PrecomputedTransactionData *txdata;
 445
 446 public:
 447     CScriptCheck(): amount(0), ptxTo(0), nIn(0), nFlags(0), cacheStore(false), error(SCRIPT_ERR_UNKNOWN_ERROR) {}
 448     CScriptCheck(const CCoins& txFromIn, const CTransaction& txToIn, unsigned int nInIn, unsigned int nFlagsIn, bool cacheIn, PrecomputedTransactionData* txdataIn) :
 449         scriptPubKey(txFromIn.vout[txToIn.vin[nInIn].prevout.n].scriptPubKey), amount(txFromIn.vout[txToIn.vin[nInIn].prevout.n].nValue),
 450         ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn), cacheStore(cacheIn), error(SCRIPT_ERR_UNKNOWN_ERROR), txdata(txdataIn) { }
 451
 452     bool operator()();
 453
 454     void swap(CScriptCheck &check) {
 455         scriptPubKey.swap(check.scriptPubKey);
 456         std::swap(ptxTo, check.ptxTo);
 457         std::swap(amount, check.amount);
 458         std::swap(nIn, check.nIn);
 459         std::swap(nFlags, check.nFlags);
 460         std::swap(cacheStore, check.cacheStore);
 461         std::swap(error, check.error);
 462         std::swap(txdata, check.txdata);
 463     }
 464
 465     ScriptError GetScriptError() const { return error; }
 466 };
 467
 468
 469 /** Functions for disk access for blocks */
 470 bool WriteBlockToDisk(const CBlock& block, CDiskBlockPos& pos, const CMessageHeader::MessageStartChars& messageStart);
 471 bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos, const Consensus::Params& consensusParams);
 472 bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex, const Consensus::Params& consensusParams);
 473
 474 /** Functions for validating blocks and updating the block tree */
 475
 476 /** Context-independent validity checks */
 477 bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true);
 478 bool CheckBlock(const CBlock& block, CValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
 479
 480 /** Context-dependent validity checks.
 481  *  By "context", we mean only the previous block headers, but not the UTXO
 482  *  set; UTXO-related validity checks are done in ConnectBlock(). */
 483 bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev, int64_t nAdjustedTime);
 484 bool ContextualCheckBlock(const CBlock& block, CValidationState& state, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev);
 485
 486 /** Apply the effects of this block (with given index) on the UTXO set represented by coins.
 487  *  Validity checks that depend on the UTXO set are also done; ConnectBlock()
 488  *  can fail if those validity checks fail (among other reasons). */
 489 bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins,
 490                   const CChainParams& chainparams, bool fJustCheck = false);
 491
 492 /** Undo the effects of this block (with given index) on the UTXO set represented by coins.
 493  *  In case pfClean is provided, operation will try to be tolerant about errors, and *pfClean
 494  *  will be true if no problems were found. Otherwise, the return value will be false in case
 495  *  of problems. Note that in any case, coins may be modified. */
 496 bool DisconnectBlock(const CBlock& block, CValidationState& state, const CBlockIndex* pindex, CCoinsViewCache& coins, bool* pfClean = NULL);
 497
 498 /** Check a block is completely valid from start to finish (only works on top of our current best block, with cs_main held) */
 499 bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams, const CBlock& block, CBlockIndex* pindexPrev, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
 500
 501 /** Check whether witness commitments are required for block. */
 502 bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params);
 503
 504 /** When there are blocks in the active chain with missing data, rewind the chainstate and remove them from the block index */
 505 bool RewindBlockIndex(const CChainParams& params);
 506
 507 /** Update uncommitted block structures (currently: only the witness nonce). This is safe for submitted blocks. */
 508 void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams);
 509
 510 /** Produce the necessary coinbase commitment for a block (modifies the hash, don't call for mined blocks). */
 511 std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams);
 512
 513 /** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */
 514 class CVerifyDB {
 515 public:
 516     CVerifyDB();
 517     ~CVerifyDB();
 518     bool VerifyDB(const CChainParams& chainparams, CCoinsView *coinsview, int nCheckLevel, int nCheckDepth);
 519 };
 520
 521 /** Find the last common block between the parameter chain and a locator. */
 522 CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator);
 523
 524 /** Mark a block as precious and reorganize. */
 525 bool PreciousBlock(CValidationState& state, const CChainParams& params, CBlockIndex *pindex);
 526
 527 /** Mark a block as invalid. */
 528 bool InvalidateBlock(CValidationState& state, const CChainParams& chainparams, CBlockIndex *pindex);
 529
 530 /** Remove invalidity status from a block and its descendants. */
 531 bool ResetBlockFailureFlags(CBlockIndex *pindex);
 532
 533 /** The currently-connected chain of blocks (protected by cs_main). */
 534 extern CChain chainActive;
 535
 536 /** Global variable that points to the active CCoinsView (protected by cs_main) */
 537 extern CCoinsViewCache *pcoinsTip;
 538
 539 /** Global variable that points to the active block tree (protected by cs_main) */
 540 extern CBlockTreeDB *pblocktree;
 541
 542 /**
 543  * Return the spend height, which is one more than the inputs.GetBestBlock().
 544  * While checking, GetBestBlock() refers to the parent block. (protected by cs_main)
 545  * This is also true for mempool checks.
 546  */
 547 int GetSpendHeight(const CCoinsViewCache& inputs);
 548
 549 extern VersionBitsCache versionbitscache;
 550
 551 /**
 552  * Determine what nVersion a new block should use.
 553  */
 554 int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params);
 555
 556 /** Reject codes greater or equal to this can be returned by AcceptToMemPool
 557  * for transactions, to signal internal conditions. They cannot and should not
 558  * be sent over the P2P network.
 559  */
 560 static const unsigned int REJECT_INTERNAL = 0x100;
 561 /** Too high fee. Can not be triggered by P2P transactions */
 562 static const unsigned int REJECT_HIGHFEE = 0x100;
 563 /** Transaction is already known (either in mempool or blockchain) */
 564 static const unsigned int REJECT_ALREADY_KNOWN = 0x101;
 565 /** Transaction conflicts with a transaction already known */
 566 static const unsigned int REJECT_CONFLICT = 0x102;
 567
 568 /** Get block file info entry for one block file */
 569 CBlockFileInfo* GetBlockFileInfo(size_t n);
 570
 571 /** Dump the mempool to disk. */
 572 void DumpMempool();
 573
 574 /** Load the mempool from disk. */
 575 bool LoadMempool();
 576
 577 #endif // BITCOIN_VALIDATION_H