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.
6 #ifndef BITCOIN_VALIDATION_H
7 #define BITCOIN_VALIDATION_H
9 #if defined(HAVE_CONFIG_H)
10 #include "config/bitcoin-config.h"
16 #include "protocol.h" // For CMessageHeader::MessageStartChars
17 #include "policy/feerate.h"
18 #include "script/script_error.h"
20 #include "versionbits.h"
40 class CBlockPolicyEstimator
;
42 class CValidationState
;
45 struct PrecomputedTransactionData
;
48 /** Default for -whitelistrelay. */
49 static const bool DEFAULT_WHITELISTRELAY
= true;
50 /** Default for -whitelistforcerelay. */
51 static const bool DEFAULT_WHITELISTFORCERELAY
= true;
52 /** Default for -minrelaytxfee, minimum relay fee for transactions */
53 static const unsigned int DEFAULT_MIN_RELAY_TX_FEE
= 1000;
55 static const CAmount DEFAULT_TRANSACTION_MAXFEE
= 0.1 * COIN
;
56 //! Discourage users to set fees higher than this amount (in satoshis) per kB
57 static const CAmount HIGH_TX_FEE_PER_KB
= 0.01 * COIN
;
58 //! -maxtxfee will warn if called with a higher fee than this amount (in satoshis)
59 static const CAmount HIGH_MAX_TX_FEE
= 100 * HIGH_TX_FEE_PER_KB
;
60 /** Default for -limitancestorcount, max number of in-mempool ancestors */
61 static const unsigned int DEFAULT_ANCESTOR_LIMIT
= 25;
62 /** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */
63 static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT
= 101;
64 /** Default for -limitdescendantcount, max number of in-mempool descendants */
65 static const unsigned int DEFAULT_DESCENDANT_LIMIT
= 25;
66 /** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
67 static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT
= 101;
68 /** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
69 static const unsigned int DEFAULT_MEMPOOL_EXPIRY
= 336;
70 /** Maximum kilobytes for transactions to store for processing during reorg */
71 static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE
= 20000;
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
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 pruning harder). We'll probably
98 * 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 * 60 * 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;
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;
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 /** Default for -persistmempool */
135 static const bool DEFAULT_PERSIST_MEMPOOL
= true;
136 /** Default for -mempoolreplacement */
137 static const bool DEFAULT_ENABLE_REPLACEMENT
= true;
138 /** Default for using fee filter */
139 static const bool DEFAULT_FEEFILTER
= true;
141 /** Maximum number of headers to announce when relaying blocks with headers message.*/
142 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE
= 8;
144 /** Maximum number of unconnecting headers announcements before DoS score */
145 static const int MAX_UNCONNECTING_HEADERS
= 10;
147 static const bool DEFAULT_PEERBLOOMFILTERS
= true;
149 /** Default for -stopatheight */
150 static const int DEFAULT_STOPATHEIGHT
= 0;
154 size_t operator()(const uint256
& hash
) const { return hash
.GetCheapHash(); }
157 extern CScript COINBASE_FLAGS
;
158 extern CCriticalSection cs_main
;
159 extern CBlockPolicyEstimator feeEstimator
;
160 extern CTxMemPool mempool
;
161 typedef std::unordered_map
<uint256
, CBlockIndex
*, BlockHasher
> BlockMap
;
162 extern BlockMap mapBlockIndex
;
163 extern uint64_t nLastBlockTx
;
164 extern uint64_t nLastBlockWeight
;
165 extern const std::string strMessageMagic
;
166 extern CWaitableCriticalSection csBestBlock
;
167 extern CConditionVariable cvBlockChange
;
168 extern std::atomic_bool fImporting
;
169 extern std::atomic_bool fReindex
;
170 extern int nScriptCheckThreads
;
171 extern bool fTxIndex
;
172 extern bool fIsBareMultisigStd
;
173 extern bool fRequireStandard
;
174 extern bool fCheckBlockIndex
;
175 extern bool fCheckpointsEnabled
;
176 extern size_t nCoinCacheUsage
;
177 /** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */
178 extern CFeeRate minRelayTxFee
;
179 /** Absolute maximum transaction fee (in satoshis) used by wallet and mempool (rejects high fee in sendrawtransaction) */
180 extern CAmount maxTxFee
;
181 /** If the tip is older than this (in seconds), the node is considered to be in initial block download. */
182 extern int64_t nMaxTipAge
;
183 extern bool fEnableReplacement
;
185 /** Block hash whose ancestors we will assume to have valid scripts without checking them. */
186 extern uint256 hashAssumeValid
;
188 /** Minimum work we will assume exists on some valid chain. */
189 extern arith_uint256 nMinimumChainWork
;
191 /** Best header we've seen so far (used for getheaders queries' starting points). */
192 extern CBlockIndex
*pindexBestHeader
;
194 /** Minimum disk space required - used in CheckDiskSpace() */
195 static const uint64_t nMinDiskSpace
= 52428800;
197 /** Pruning-related variables and constants */
198 /** True if any block files have ever been pruned. */
199 extern bool fHavePruned
;
200 /** True if we're running in -prune mode. */
201 extern bool fPruneMode
;
202 /** Number of MiB of block files that we're trying to stay below. */
203 extern uint64_t nPruneTarget
;
204 /** Block files containing a block-height within MIN_BLOCKS_TO_KEEP of chainActive.Tip() will not be pruned. */
205 static const unsigned int MIN_BLOCKS_TO_KEEP
= 288;
207 static const signed int DEFAULT_CHECKBLOCKS
= 6;
208 static const unsigned int DEFAULT_CHECKLEVEL
= 3;
210 // Require that user allocate at least 550MB for block & undo files (blk???.dat and rev???.dat)
211 // At 1MB per block, 288 blocks = 288MB.
212 // Add 15% for Undo data = 331MB
213 // Add 20% for Orphan block rate = 397MB
214 // We want the low water mark after pruning to be at least 397 MB and since we prune in
215 // full block file chunks, we need the high water mark which triggers the prune to be
216 // one 128MB block file + added 15% undo data = 147MB greater for a total of 545MB
217 // Setting the target to > than 550MB will make it likely we can respect the target.
218 static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES
= 550 * 1024 * 1024;
221 * Process an incoming block. This only returns after the best known valid
222 * block is made active. Note that it does not, however, guarantee that the
223 * specific block passed to it has been checked for validity!
225 * If you want to *possibly* get feedback on whether pblock is valid, you must
226 * install a CValidationInterface (see validationinterface.h) - this will have
227 * its BlockChecked method called whenever *any* block completes validation.
229 * Note that we guarantee that either the proof-of-work is valid on pblock, or
230 * (and possibly also) BlockChecked will have been called.
232 * Call without cs_main held.
234 * @param[in] pblock The block we want to process.
235 * @param[in] fForceProcessing Process this block even if unrequested; used for non-network block sources and whitelisted peers.
236 * @param[out] fNewBlock A boolean which is set to indicate if the block was first received via this call
237 * @return True if state.IsValid()
239 bool ProcessNewBlock(const CChainParams
& chainparams
, const std::shared_ptr
<const CBlock
> pblock
, bool fForceProcessing
, bool* fNewBlock
);
242 * Process incoming block headers.
244 * Call without cs_main held.
246 * @param[in] block The block headers themselves
247 * @param[out] state This may be set to an Error state if any error occurred processing them
248 * @param[in] chainparams The params for the chain we want to connect to
249 * @param[out] ppindex If set, the pointer will be set to point to the last new block index object for the given headers
251 bool ProcessNewBlockHeaders(const std::vector
<CBlockHeader
>& block
, CValidationState
& state
, const CChainParams
& chainparams
, const CBlockIndex
** ppindex
=nullptr);
253 /** Check whether enough disk space is available for an incoming block */
254 bool CheckDiskSpace(uint64_t nAdditionalBytes
= 0);
255 /** Open a block file (blk?????.dat) */
256 FILE* OpenBlockFile(const CDiskBlockPos
&pos
, bool fReadOnly
= false);
257 /** Translation to a filesystem path */
258 fs::path
GetBlockPosFilename(const CDiskBlockPos
&pos
, const char *prefix
);
259 /** Import blocks from an external file */
260 bool LoadExternalBlockFile(const CChainParams
& chainparams
, FILE* fileIn
, CDiskBlockPos
*dbp
= nullptr);
261 /** Ensures we have a genesis block in the block tree, possibly writing one to disk. */
262 bool LoadGenesisBlock(const CChainParams
& chainparams
);
263 /** Load the block tree and coins database from disk,
264 * initializing state if we're running with -reindex. */
265 bool LoadBlockIndex(const CChainParams
& chainparams
);
266 /** Update the chain tip based on database information. */
267 bool LoadChainTip(const CChainParams
& chainparams
);
268 /** Unload database information */
269 void UnloadBlockIndex();
270 /** Run an instance of the script checking thread */
271 void ThreadScriptCheck();
272 /** Check whether we are doing an initial block download (synchronizing from disk or network) */
273 bool IsInitialBlockDownload();
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
);
280 /** Guess verification progress (as a fraction between 0.0=genesis and 1.0=current tip). */
281 double GuessVerificationProgress(const ChainTxData
& data
, CBlockIndex
* pindex
);
284 * Mark one block file as pruned.
286 void PruneOneBlockFile(const int fileNumber
);
289 * Actually unlink the specified files
291 void UnlinkPrunedFiles(const std::set
<int>& setFilesToPrune
);
293 /** Create a new block index entry for a given block hash */
294 CBlockIndex
* InsertBlockIndex(uint256 hash
);
295 /** Flush all state, indexes and buffers to disk. */
296 void FlushStateToDisk();
297 /** Prune block files and flush state to disk. */
298 void PruneAndFlush();
299 /** Prune block files up to a given height */
300 void PruneBlockFilesManual(int nManualPruneHeight
);
302 /** (try to) add transaction to memory pool
303 * plTxnReplaced will be appended to with all transactions replaced from mempool **/
304 bool AcceptToMemoryPool(CTxMemPool
& pool
, CValidationState
&state
, const CTransactionRef
&tx
,
305 bool* pfMissingInputs
, std::list
<CTransactionRef
>* plTxnReplaced
,
306 bool bypass_limits
, const CAmount nAbsurdFee
);
308 /** Convert CValidationState to a human-readable message for logging */
309 std::string
FormatStateMessage(const CValidationState
&state
);
311 /** Get the BIP9 state for a given deployment at the current tip. */
312 ThresholdState
VersionBitsTipState(const Consensus::Params
& params
, Consensus::DeploymentPos pos
);
314 /** Get the numerical statistics for the BIP9 state for a given deployment at the current tip. */
315 BIP9Stats
VersionBitsTipStatistics(const Consensus::Params
& params
, Consensus::DeploymentPos pos
);
317 /** Get the block height at which the BIP9 deployment switched into the state for the block building on the current tip. */
318 int VersionBitsTipStateSinceHeight(const Consensus::Params
& params
, Consensus::DeploymentPos pos
);
321 /** Apply the effects of this transaction on the UTXO set represented by view */
322 void UpdateCoins(const CTransaction
& tx
, CCoinsViewCache
& inputs
, int nHeight
);
324 /** Transaction validation functions */
327 * Check if transaction will be final in the next block to be created.
329 * Calls IsFinalTx() with current block height and appropriate block time.
331 * See consensus/consensus.h for flag definitions.
333 bool CheckFinalTx(const CTransaction
&tx
, int flags
= -1);
336 * Test whether the LockPoints height and time are still valid on the current chain
338 bool TestLockPointValidity(const LockPoints
* lp
);
341 * Check if transaction will be BIP 68 final in the next block to be created.
343 * Simulates calling SequenceLocks() with data from the tip of the current active chain.
344 * Optionally stores in LockPoints the resulting height and time calculated and the hash
345 * of the block needed for calculation or skips the calculation and uses the LockPoints
346 * passed in for evaluation.
347 * The LockPoints should not be considered valid if CheckSequenceLocks returns false.
349 * See consensus/consensus.h for flag definitions.
351 bool CheckSequenceLocks(const CTransaction
&tx
, int flags
, LockPoints
* lp
= nullptr, bool useExistingLockPoints
= false);
354 * Closure representing one script verification
355 * Note that this stores references to the spending transaction
361 const CTransaction
*ptxTo
;
366 PrecomputedTransactionData
*txdata
;
369 CScriptCheck(): ptxTo(nullptr), nIn(0), nFlags(0), cacheStore(false), error(SCRIPT_ERR_UNKNOWN_ERROR
) {}
370 CScriptCheck(const CTxOut
& outIn
, const CTransaction
& txToIn
, unsigned int nInIn
, unsigned int nFlagsIn
, bool cacheIn
, PrecomputedTransactionData
* txdataIn
) :
371 m_tx_out(outIn
), ptxTo(&txToIn
), nIn(nInIn
), nFlags(nFlagsIn
), cacheStore(cacheIn
), error(SCRIPT_ERR_UNKNOWN_ERROR
), txdata(txdataIn
) { }
375 void swap(CScriptCheck
&check
) {
376 std::swap(ptxTo
, check
.ptxTo
);
377 std::swap(m_tx_out
, check
.m_tx_out
);
378 std::swap(nIn
, check
.nIn
);
379 std::swap(nFlags
, check
.nFlags
);
380 std::swap(cacheStore
, check
.cacheStore
);
381 std::swap(error
, check
.error
);
382 std::swap(txdata
, check
.txdata
);
385 ScriptError
GetScriptError() const { return error
; }
388 /** Initializes the script-execution cache */
389 void InitScriptExecutionCache();
392 /** Functions for disk access for blocks */
393 bool ReadBlockFromDisk(CBlock
& block
, const CDiskBlockPos
& pos
, const Consensus::Params
& consensusParams
);
394 bool ReadBlockFromDisk(CBlock
& block
, const CBlockIndex
* pindex
, const Consensus::Params
& consensusParams
);
396 /** Functions for validating blocks and updating the block tree */
398 /** Context-independent validity checks */
399 bool CheckBlock(const CBlock
& block
, CValidationState
& state
, const Consensus::Params
& consensusParams
, bool fCheckPOW
= true, bool fCheckMerkleRoot
= true);
401 /** Check a block is completely valid from start to finish (only works on top of our current best block, with cs_main held) */
402 bool TestBlockValidity(CValidationState
& state
, const CChainParams
& chainparams
, const CBlock
& block
, CBlockIndex
* pindexPrev
, bool fCheckPOW
= true, bool fCheckMerkleRoot
= true);
404 /** Check whether witness commitments are required for block. */
405 bool IsWitnessEnabled(const CBlockIndex
* pindexPrev
, const Consensus::Params
& params
);
407 /** When there are blocks in the active chain with missing data, rewind the chainstate and remove them from the block index */
408 bool RewindBlockIndex(const CChainParams
& params
);
410 /** Update uncommitted block structures (currently: only the witness nonce). This is safe for submitted blocks. */
411 void UpdateUncommittedBlockStructures(CBlock
& block
, const CBlockIndex
* pindexPrev
, const Consensus::Params
& consensusParams
);
413 /** Produce the necessary coinbase commitment for a block (modifies the hash, don't call for mined blocks). */
414 std::vector
<unsigned char> GenerateCoinbaseCommitment(CBlock
& block
, const CBlockIndex
* pindexPrev
, const Consensus::Params
& consensusParams
);
416 /** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */
421 bool VerifyDB(const CChainParams
& chainparams
, CCoinsView
*coinsview
, int nCheckLevel
, int nCheckDepth
);
424 /** Replay blocks that aren't fully applied to the database. */
425 bool ReplayBlocks(const CChainParams
& params
, CCoinsView
* view
);
427 /** Find the last common block between the parameter chain and a locator. */
428 CBlockIndex
* FindForkInGlobalIndex(const CChain
& chain
, const CBlockLocator
& locator
);
430 /** Mark a block as precious and reorganize. */
431 bool PreciousBlock(CValidationState
& state
, const CChainParams
& params
, CBlockIndex
*pindex
);
433 /** Mark a block as invalid. */
434 bool InvalidateBlock(CValidationState
& state
, const CChainParams
& chainparams
, CBlockIndex
*pindex
);
436 /** Remove invalidity status from a block and its descendants. */
437 bool ResetBlockFailureFlags(CBlockIndex
*pindex
);
439 /** The currently-connected chain of blocks (protected by cs_main). */
440 extern CChain chainActive
;
442 /** Global variable that points to the coins database (protected by cs_main) */
443 extern CCoinsViewDB
*pcoinsdbview
;
445 /** Global variable that points to the active CCoinsView (protected by cs_main) */
446 extern CCoinsViewCache
*pcoinsTip
;
448 /** Global variable that points to the active block tree (protected by cs_main) */
449 extern CBlockTreeDB
*pblocktree
;
452 * Return the spend height, which is one more than the inputs.GetBestBlock().
453 * While checking, GetBestBlock() refers to the parent block. (protected by cs_main)
454 * This is also true for mempool checks.
456 int GetSpendHeight(const CCoinsViewCache
& inputs
);
458 extern VersionBitsCache versionbitscache
;
461 * Determine what nVersion a new block should use.
463 int32_t ComputeBlockVersion(const CBlockIndex
* pindexPrev
, const Consensus::Params
& params
);
465 /** Reject codes greater or equal to this can be returned by AcceptToMemPool
466 * for transactions, to signal internal conditions. They cannot and should not
467 * be sent over the P2P network.
469 static const unsigned int REJECT_INTERNAL
= 0x100;
470 /** Too high fee. Can not be triggered by P2P transactions */
471 static const unsigned int REJECT_HIGHFEE
= 0x100;
473 /** Get block file info entry for one block file */
474 CBlockFileInfo
* GetBlockFileInfo(size_t n
);
476 /** Dump the mempool to disk. */
479 /** Load the mempool from disk. */
482 #endif // BITCOIN_VALIDATION_H