1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2015 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_MAIN_H
7 #define BITCOIN_MAIN_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 "net.h"
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 <boost/unordered_map.hpp>
31 
32 class CBlockIndex;
33 class CBlockTreeDB;
34 class CBloomFilter;
35 class CChainParams;
36 class CInv;
37 class CScriptCheck;
38 class CTxMemPool;
39 class CValidationInterface;
40 class CValidationState;
41 
42 struct PrecomputedTransactionData;
43 struct CNodeStateStats;
44 struct LockPoints;
45 
46 /** Default for DEFAULT_WHITELISTRELAY. */
47 static const bool DEFAULT_WHITELISTRELAY = true;
48 /** Default for DEFAULT_WHITELISTFORCERELAY. */
49 static const bool DEFAULT_WHITELISTFORCERELAY = true;
50 /** Default for -minrelaytxfee, minimum relay fee for transactions */
51 static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 5000;
52 //! -maxtxfee default
53 static const CAmount DEFAULT_TRANSACTION_MAXFEE = 0.1 * COIN;
54 //! Discourage users to set fees higher than this amount (in satoshis) per kB
55 static const CAmount HIGH_TX_FEE_PER_KB = 0.01 * COIN;
56 //! -maxtxfee will warn if called with a higher fee than this amount (in satoshis)
57 static const CAmount HIGH_MAX_TX_FEE = 100 * HIGH_TX_FEE_PER_KB;
58 /** Default for -maxorphantx, maximum number of orphan transactions kept in memory */
59 static const unsigned int DEFAULT_MAX_ORPHAN_TRANSACTIONS = 100;
60 /** Expiration time for orphan transactions in seconds */
61 static const int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60;
62 /** Minimum time between orphan transactions expire time checks in seconds */
63 static const int64_t ORPHAN_TX_EXPIRE_INTERVAL = 5 * 60;
64 /** Default for -limitancestorcount, max number of in-mempool ancestors */
65 static const unsigned int DEFAULT_ANCESTOR_LIMIT = 25;
66 /** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */
67 static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT = 101;
68 /** Default for -limitdescendantcount, max number of in-mempool descendants */
69 static const unsigned int DEFAULT_DESCENDANT_LIMIT = 25;
70 /** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
71 static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT = 101;
72 /** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
73 static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 72;
74 /** The maximum size of a blk?????.dat file (since 0.8) */
75 static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
76 /** The pre-allocation chunk size for blk?????.dat files (since 0.8) */
77 static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB
78 /** The pre-allocation chunk size for rev?????.dat files (since 0.8) */
79 static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
80 
81 /** Maximum number of script-checking threads allowed */
82 static const int MAX_SCRIPTCHECK_THREADS = 16;
83 /** -par default (number of script-checking threads, 0 = auto) */
84 static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
85 /** Number of blocks that can be requested at any given time from a single peer. */
86 static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 1024;
87 /** Timeout in seconds during which a peer must stall block download progress before being disconnected. */
88 static const unsigned int BLOCK_STALLING_TIMEOUT = 8;
89 /** Number of headers sent in one getheaders result. We rely on the assumption that if a peer sends
90  *  less than this number, we reached its tip. Changing this value is a protocol upgrade. */
91 static const unsigned int MAX_HEADERS_RESULTS = 2000;
92 /** Maximum depth of blocks we're willing to serve as compact blocks to peers
93  *  when requested. For older blocks, a regular BLOCK response will be sent. */
94 static const int MAX_CMPCTBLOCK_DEPTH = 5;
95 /** Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests for. */
96 static const int MAX_BLOCKTXN_DEPTH = 10;
97 /** Size of the "block download window": how far ahead of our current height do we fetch?
98  *  Larger windows tolerate larger download speed differences between peer, but increase the potential
99  *  degree of disordering of blocks on disk (which make reindexing and in the future perhaps pruning
100  *  harder). We'll probably want to make this a per-peer adaptive value at some point. */
101 static const unsigned int BLOCK_DOWNLOAD_WINDOW = 16384;
102 /** Time to wait (in seconds) between writing blocks/block index to disk. */
103 static const unsigned int DATABASE_WRITE_INTERVAL = 60 * 60;
104 /** Time to wait (in seconds) between flushing chainstate to disk. */
105 static const unsigned int DATABASE_FLUSH_INTERVAL = 24 * 60 * 60;
106 /** Maximum length of reject messages. */
107 static const unsigned int MAX_REJECT_MESSAGE_LENGTH = 111;
108 /** Average delay between local address broadcasts in seconds. */
109 static const unsigned int AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL = 24 * 24 * 60;
110 /** Average delay between peer address broadcasts in seconds. */
111 static const unsigned int AVG_ADDRESS_BROADCAST_INTERVAL = 30;
112 /** Average delay between trickled inventory transmissions in seconds.
113  *  Blocks and whitelisted receivers bypass this, outbound peers get half this delay. */
114 static const unsigned int INVENTORY_BROADCAST_INTERVAL = 5;
115 /** Maximum number of inventory items to send per transmission.
116  *  Limits the impact of low-fee transaction floods. */
117 static const unsigned int INVENTORY_BROADCAST_MAX = 7 * INVENTORY_BROADCAST_INTERVAL;
118 /** Average delay between feefilter broadcasts in seconds. */
119 static const unsigned int AVG_FEEFILTER_BROADCAST_INTERVAL = 10 * 60;
120 /** Maximum feefilter broadcast delay after significant change. */
121 static const unsigned int MAX_FEEFILTER_CHANGE_DELAY = 5 * 60;
122 /** Block download timeout base, expressed in millionths of the block interval (i.e. 10 min) */
123 static const int64_t BLOCK_DOWNLOAD_TIMEOUT_BASE = 1000000;
124 /** Additional block download timeout per parallel downloading peer (i.e. 5 min) */
125 static const int64_t BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 500000;
126 
127 static const unsigned int DEFAULT_LIMITFREERELAY = 15;
128 static const bool DEFAULT_RELAYPRIORITY = true;
129 static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;
130 
131 /** Default for -permitbaremultisig */
132 static const bool DEFAULT_PERMIT_BAREMULTISIG = true;
133 static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
134 static const bool DEFAULT_TXINDEX = false;
135 static const unsigned int DEFAULT_BANSCORE_THRESHOLD = 100;
136 
137 static const bool DEFAULT_TESTSAFEMODE = false;
138 /** Default for -mempoolreplacement */
139 static const bool DEFAULT_ENABLE_REPLACEMENT = true;
140 /** Default for using fee filter */
141 static const bool DEFAULT_FEEFILTER = true;
142 
143 /** Maximum number of headers to announce when relaying blocks with headers message.*/
144 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8;
145 
146 /** Maximum number of unconnecting headers announcements before DoS score */
147 static const int MAX_UNCONNECTING_HEADERS = 10;
148 
149 static const bool DEFAULT_PEERBLOOMFILTERS = true;
150 
151 struct BlockHasher
152 {
operatorBlockHasher153     size_t operator()(const uint256& hash) const { return hash.GetCheapHash(); }
154 };
155 
156 extern CScript COINBASE_FLAGS;
157 extern CCriticalSection cs_main;
158 extern CTxMemPool mempool;
159 typedef boost::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
160 extern BlockMap mapBlockIndex;
161 extern uint64_t nLastBlockTx;
162 extern uint64_t nLastBlockSize;
163 extern uint64_t nLastBlockWeight;
164 extern const std::string strMessageMagic;
165 extern CWaitableCriticalSection csBestBlock;
166 extern CConditionVariable cvBlockChange;
167 extern bool fImporting;
168 extern bool fReindex;
169 extern int nScriptCheckThreads;
170 extern bool fTxIndex;
171 extern bool fIsBareMultisigStd;
172 extern bool fRequireStandard;
173 extern bool fCheckBlockIndex;
174 extern bool fCheckpointsEnabled;
175 extern size_t nCoinCacheUsage;
176 /** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */
177 extern CFeeRate minRelayTxFee;
178 /** Absolute maximum transaction fee (in satoshis) used by wallet and mempool (rejects high fee in sendrawtransaction) */
179 extern CAmount maxTxFee;
180 /** If the tip is older than this (in seconds), the node is considered to be in initial block download. */
181 extern int64_t nMaxTipAge;
182 extern bool fEnableReplacement;
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 /** Register with a network node to receive its signals */
214 void RegisterNodeSignals(CNodeSignals& nodeSignals);
215 /** Unregister a network node */
216 void UnregisterNodeSignals(CNodeSignals& nodeSignals);
217 
218 /**
219  * Process an incoming block. This only returns after the best known valid
220  * block is made active. Note that it does not, however, guarantee that the
221  * specific block passed to it has been checked for validity!
222  *
223  * @param[out]  state   This may be set to an Error state if any error occurred processing it, including during validation/connection/etc of otherwise unrelated blocks during reorganization; or it may be set to an Invalid state if pblock is itself invalid (but this is not guaranteed even when the block is checked). If you want to *possibly* get feedback on whether pblock is valid, you must also install a CValidationInterface (see validationinterface.h) - this will have its BlockChecked method called whenever *any* block completes validation.
224  * @param[in]   pfrom   The node which we are receiving the block from; it is added to mapBlockSource and may be penalised if the block is invalid.
225  * @param[in]   pblock  The block we want to process.
226  * @param[in]   fForceProcessing Process this block even if unrequested; used for non-network block sources and whitelisted peers.
227  * @param[out]  dbp     The already known disk position of pblock, or NULL if not yet stored.
228  * @return True if state.IsValid()
229  */
230 bool ProcessNewBlock(CValidationState& state, const CChainParams& chainparams, CNode* pfrom, const CBlock* pblock, bool fForceProcessing, const CDiskBlockPos* dbp, bool fMayBanPeerIfInvalid);
231 /** Check whether enough disk space is available for an incoming block */
232 bool CheckDiskSpace(uint64_t nAdditionalBytes = 0);
233 /** Open a block file (blk?????.dat) */
234 FILE* OpenBlockFile(const CDiskBlockPos &pos, bool fReadOnly = false);
235 /** Open an undo file (rev?????.dat) */
236 FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false);
237 /** Translation to a filesystem path */
238 boost::filesystem::path GetBlockPosFilename(const CDiskBlockPos &pos, const char *prefix);
239 /** Import blocks from an external file */
240 bool LoadExternalBlockFile(const CChainParams& chainparams, FILE* fileIn, CDiskBlockPos *dbp = NULL);
241 /** Initialize a new block tree database + block data on disk */
242 bool InitBlockIndex(const CChainParams& chainparams);
243 /** Load the block tree and coins database from disk */
244 bool LoadBlockIndex();
245 /** Unload database information */
246 void UnloadBlockIndex();
247 /** Process protocol messages received from a given node */
248 bool ProcessMessages(CNode* pfrom);
249 /**
250  * Send queued protocol messages to be sent to a give node.
251  *
252  * @param[in]   pto             The node which we are sending messages to.
253  */
254 bool SendMessages(CNode* pto);
255 /** Run an instance of the script checking thread */
256 void ThreadScriptCheck();
257 /** Check whether we are doing an initial block download (synchronizing from disk or network) */
258 bool IsInitialBlockDownload();
259 /** Format a string that describes several potential problems detected by the core.
260  * strFor can have three values:
261  * - "rpc": get critical warnings, which should put the client in safe mode if non-empty
262  * - "statusbar": get all warnings
263  * - "gui": get all warnings, translated (where possible) for GUI
264  * This function only returns the highest priority warning of the set selected by strFor.
265  */
266 std::string GetWarnings(const std::string& strFor);
267 /** Retrieve a transaction (from memory pool, or from disk, if possible) */
268 bool GetTransaction(const uint256 &hash, CTransaction &tx, const Consensus::Params& params, uint256 &hashBlock, bool fAllowSlow = false);
269 /** Find the best known block, and make it the tip of the block chain */
270 bool ActivateBestChain(CValidationState& state, const CChainParams& chainparams, const CBlock* pblock = NULL);
271 CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams);
272 
273 /**
274  * Prune block and undo files (blk???.dat and undo???.dat) so that the disk space used is less than a user-defined target.
275  * The user sets the target (in MB) on the command line or in config file.  This will be run on startup and whenever new
276  * space is allocated in a block or undo file, staying below the target. Changing back to unpruned requires a reindex
277  * (which in this case means the blockchain must be re-downloaded.)
278  *
279  * Pruning functions are called from FlushStateToDisk when the global fCheckForPruning flag has been set.
280  * Block and undo files are deleted in lock-step (when blk00003.dat is deleted, so is rev00003.dat.)
281  * Pruning cannot take place until the longest chain is at least a certain length (100000 on mainnet, 1000 on testnet, 1000 on regtest).
282  * Pruning will never delete a block within a defined distance (currently 288) from the active chain's tip.
283  * The block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any blocks that were stored in the deleted files.
284  * A db flag records the fact that at least some block files have been pruned.
285  *
286  * @param[out]   setFilesToPrune   The set of file indices that can be unlinked will be returned
287  */
288 void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight);
289 
290 /**
291  *  Actually unlink the specified files
292  */
293 void UnlinkPrunedFiles(std::set<int>& setFilesToPrune);
294 
295 /** Create a new block index entry for a given block hash */
296 CBlockIndex * InsertBlockIndex(uint256 hash);
297 /** Get statistics from node state */
298 bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats);
299 /** Increase a node's misbehavior score. */
300 void Misbehaving(NodeId nodeid, int howmuch);
301 /** Flush all state, indexes and buffers to disk. */
302 void FlushStateToDisk();
303 /** Prune block files and flush state to disk. */
304 void PruneAndFlush();
305 
306 /** (try to) add transaction to memory pool **/
307 bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool fLimitFree,
308                         bool* pfMissingInputs, bool fOverrideMempoolLimit=false, const CAmount nAbsurdFee=0);
309 
310 /** Convert CValidationState to a human-readable message for logging */
311 std::string FormatStateMessage(const CValidationState &state);
312 
313 /** Get the BIP9 state for a given deployment at the current tip. */
314 ThresholdState VersionBitsTipState(const Consensus::Params& params, Consensus::DeploymentPos pos);
315 
316 struct CNodeStateStats {
317     int nMisbehavior;
318     int nSyncHeight;
319     int nCommonHeight;
320     std::vector<int> vHeightInFlight;
321 };
322 
323 
324 
325 /**
326  * Count ECDSA signature operations the old-fashioned (pre-0.6) way
327  * @return number of sigops this transaction's outputs will produce when spent
328  * @see CTransaction::FetchInputs
329  */
330 unsigned int GetLegacySigOpCount(const CTransaction& tx);
331 
332 /**
333  * Count ECDSA signature operations in pay-to-script-hash inputs.
334  *
335  * @param[in] mapInputs Map of previous transactions that have outputs we're spending
336  * @return maximum number of sigops required to validate this transaction's inputs
337  * @see CTransaction::FetchInputs
338  */
339 unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& mapInputs);
340 
341 /**
342  * Compute total signature operation cost of a transaction.
343  * @param[in] tx     Transaction for which we are computing the cost
344  * @param[in] inputs Map of previous transactions that have outputs we're spending
345  * @param[out] flags Script verification flags
346  * @return Total signature operation cost of tx
347  */
348 int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags);
349 
350 /**
351  * Check whether all inputs of this transaction are valid (no double spends, scripts & sigs, amounts)
352  * This does not modify the UTXO set. If pvChecks is not NULL, script checks are pushed onto it
353  * instead of being performed inline.
354  */
355 bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &view, bool fScriptChecks,
356                  unsigned int flags, bool cacheStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks = NULL);
357 
358 /** Apply the effects of this transaction on the UTXO set represented by view */
359 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, int nHeight);
360 
361 /** Context-independent validity checks */
362 bool CheckTransaction(const CTransaction& tx, CValidationState& state);
363 
364 /**
365  * Check if transaction is final and can be included in a block with the
366  * specified height and time. Consensus critical.
367  */
368 bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime);
369 
370 /**
371  * Check if transaction will be final in the next block to be created.
372  *
373  * Calls IsFinalTx() with current block height and appropriate block time.
374  *
375  * See consensus/consensus.h for flag definitions.
376  */
377 bool CheckFinalTx(const CTransaction &tx, int flags = -1);
378 
379 /**
380  * Test whether the LockPoints height and time are still valid on the current chain
381  */
382 bool TestLockPointValidity(const LockPoints* lp);
383 
384 /**
385  * Check if transaction is final per BIP 68 sequence numbers and can be included in a block.
386  * Consensus critical. Takes as input a list of heights at which tx's inputs (in order) confirmed.
387  */
388 bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block);
389 
390 /**
391  * Check if transaction will be BIP 68 final in the next block to be created.
392  *
393  * Simulates calling SequenceLocks() with data from the tip of the current active chain.
394  * Optionally stores in LockPoints the resulting height and time calculated and the hash
395  * of the block needed for calculation or skips the calculation and uses the LockPoints
396  * passed in for evaluation.
397  * The LockPoints should not be considered valid if CheckSequenceLocks returns false.
398  *
399  * See consensus/consensus.h for flag definitions.
400  */
401 bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp = NULL, bool useExistingLockPoints = false);
402 
403 /**
404  * Closure representing one script verification
405  * Note that this stores references to the spending transaction
406  */
407 class CScriptCheck
408 {
409 private:
410     CScript scriptPubKey;
411     CAmount amount;
412     const CTransaction *ptxTo;
413     unsigned int nIn;
414     unsigned int nFlags;
415     bool cacheStore;
416     ScriptError error;
417     PrecomputedTransactionData *txdata;
418 
419 public:
CScriptCheck()420     CScriptCheck(): amount(0), ptxTo(0), nIn(0), nFlags(0), cacheStore(false), error(SCRIPT_ERR_UNKNOWN_ERROR) {}
CScriptCheck(const CCoins & txFromIn,const CTransaction & txToIn,unsigned int nInIn,unsigned int nFlagsIn,bool cacheIn,PrecomputedTransactionData * txdataIn)421     CScriptCheck(const CCoins& txFromIn, const CTransaction& txToIn, unsigned int nInIn, unsigned int nFlagsIn, bool cacheIn, PrecomputedTransactionData* txdataIn) :
422         scriptPubKey(txFromIn.vout[txToIn.vin[nInIn].prevout.n].scriptPubKey), amount(txFromIn.vout[txToIn.vin[nInIn].prevout.n].nValue),
423         ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn), cacheStore(cacheIn), error(SCRIPT_ERR_UNKNOWN_ERROR), txdata(txdataIn) { }
424 
425     bool operator()();
426 
swap(CScriptCheck & check)427     void swap(CScriptCheck &check) {
428         scriptPubKey.swap(check.scriptPubKey);
429         std::swap(ptxTo, check.ptxTo);
430         std::swap(amount, check.amount);
431         std::swap(nIn, check.nIn);
432         std::swap(nFlags, check.nFlags);
433         std::swap(cacheStore, check.cacheStore);
434         std::swap(error, check.error);
435         std::swap(txdata, check.txdata);
436     }
437 
GetScriptError()438     ScriptError GetScriptError() const { return error; }
439 };
440 
441 
442 /** Functions for disk access for blocks */
443 bool WriteBlockToDisk(const CBlock& block, CDiskBlockPos& pos, const CMessageHeader::MessageStartChars& messageStart);
444 bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos, const Consensus::Params& consensusParams);
445 bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex, const Consensus::Params& consensusParams);
446 
447 /** Functions for validating blocks and updating the block tree */
448 
449 /** Context-independent validity checks */
450 bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true);
451 bool CheckBlock(const CBlock& block, CValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
452 
453 /** Context-dependent validity checks.
454  *  By "context", we mean only the previous block headers, but not the UTXO
455  *  set; UTXO-related validity checks are done in ConnectBlock(). */
456 bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, const Consensus::Params& consensusParams, CBlockIndex* pindexPrev, int64_t nAdjustedTime);
457 bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIndex *pindexPrev);
458 
459 /** Apply the effects of this block (with given index) on the UTXO set represented by coins.
460  *  Validity checks that depend on the UTXO set are also done; ConnectBlock()
461  *  can fail if those validity checks fail (among other reasons). */
462 bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins,
463                   const CChainParams& chainparams, bool fJustCheck = false);
464 
465 /** Undo the effects of this block (with given index) on the UTXO set represented by coins.
466  *  In case pfClean is provided, operation will try to be tolerant about errors, and *pfClean
467  *  will be true if no problems were found. Otherwise, the return value will be false in case
468  *  of problems. Note that in any case, coins may be modified. */
469 bool DisconnectBlock(const CBlock& block, CValidationState& state, const CBlockIndex* pindex, CCoinsViewCache& coins, bool* pfClean = NULL);
470 
471 /** Check a block is completely valid from start to finish (only works on top of our current best block, with cs_main held) */
472 bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams, const CBlock& block, CBlockIndex* pindexPrev, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
473 
474 /** Check whether witness commitments are required for block. */
475 bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params);
476 
477 /** When there are blocks in the active chain with missing data, rewind the chainstate and remove them from the block index */
478 bool RewindBlockIndex(const CChainParams& params);
479 
480 /** Update uncommitted block structures (currently: only the witness nonce). This is safe for submitted blocks. */
481 void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams);
482 
483 /** Produce the necessary coinbase commitment for a block (modifies the hash, don't call for mined blocks). */
484 std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams);
485 
486 /** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */
487 class CVerifyDB {
488 public:
489     CVerifyDB();
490     ~CVerifyDB();
491     bool VerifyDB(const CChainParams& chainparams, CCoinsView *coinsview, int nCheckLevel, int nCheckDepth);
492 };
493 
494 /** Find the last common block between the parameter chain and a locator. */
495 CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator);
496 
497 /** Mark a block as invalid. */
498 bool InvalidateBlock(CValidationState& state, const CChainParams& chainparams, CBlockIndex *pindex);
499 
500 /** Remove invalidity status from a block and its descendants. */
501 bool ResetBlockFailureFlags(CBlockIndex *pindex);
502 
503 /** The currently-connected chain of blocks (protected by cs_main). */
504 extern CChain chainActive;
505 
506 /** Global variable that points to the active CCoinsView (protected by cs_main) */
507 extern CCoinsViewCache *pcoinsTip;
508 
509 /** Global variable that points to the active block tree (protected by cs_main) */
510 extern CBlockTreeDB *pblocktree;
511 
512 /**
513  * Return the spend height, which is one more than the inputs.GetBestBlock().
514  * While checking, GetBestBlock() refers to the parent block. (protected by cs_main)
515  * This is also true for mempool checks.
516  */
517 int GetSpendHeight(const CCoinsViewCache& inputs);
518 
519 extern VersionBitsCache versionbitscache;
520 
521 /**
522  * Determine what nVersion a new block should use.
523  */
524 int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params);
525 
526 /** Reject codes greater or equal to this can be returned by AcceptToMemPool
527  * for transactions, to signal internal conditions. They cannot and should not
528  * be sent over the P2P network.
529  */
530 static const unsigned int REJECT_INTERNAL = 0x100;
531 /** Too high fee. Can not be triggered by P2P transactions */
532 static const unsigned int REJECT_HIGHFEE = 0x100;
533 /** Transaction is already known (either in mempool or blockchain) */
534 static const unsigned int REJECT_ALREADY_KNOWN = 0x101;
535 /** Transaction conflicts with a transaction already known */
536 static const unsigned int REJECT_CONFLICT = 0x102;
537 
538 #endif // BITCOIN_MAIN_H
539