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 CValidationInterface
;
43 class CValidationState
;
46 struct PrecomputedTransactionData
;
49 /** Default for DEFAULT_WHITELISTRELAY. */
50 static const bool DEFAULT_WHITELISTRELAY
= true;
51 /** Default for DEFAULT_WHITELISTFORCERELAY. */
52 static const bool DEFAULT_WHITELISTFORCERELAY
= true;
53 /** Default for -minrelaytxfee, minimum relay fee for transactions */
54 static const unsigned int DEFAULT_MIN_RELAY_TX_FEE
= 1000;
56 static const CAmount DEFAULT_TRANSACTION_MAXFEE
= 0.1 * COIN
;
57 //! Discourage users to set fees higher than this amount (in satoshis) per kB
58 static const CAmount HIGH_TX_FEE_PER_KB
= 0.01 * COIN
;
59 //! -maxtxfee will warn if called with a higher fee than this amount (in satoshis)
60 static const CAmount HIGH_MAX_TX_FEE
= 100 * HIGH_TX_FEE_PER_KB
;
61 /** Default for -limitancestorcount, max number of in-mempool ancestors */
62 static const unsigned int DEFAULT_ANCESTOR_LIMIT
= 25;
63 /** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */
64 static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT
= 101;
65 /** Default for -limitdescendantcount, max number of in-mempool descendants */
66 static const unsigned int DEFAULT_DESCENDANT_LIMIT
= 25;
67 /** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
68 static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT
= 101;
69 /** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
70 static const unsigned int DEFAULT_MEMPOOL_EXPIRY
= 336;
71 /** Maximum kilobytes for transactions to store for processing during reorg */
72 static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE
= 20000;
73 /** The maximum size of a blk?????.dat file (since 0.8) */
74 static const unsigned int MAX_BLOCKFILE_SIZE
= 0x8000000; // 128 MiB
75 /** The pre-allocation chunk size for blk?????.dat files (since 0.8) */
76 static const unsigned int BLOCKFILE_CHUNK_SIZE
= 0x1000000; // 16 MiB
77 /** The pre-allocation chunk size for rev?????.dat files (since 0.8) */
78 static const unsigned int UNDOFILE_CHUNK_SIZE
= 0x100000; // 1 MiB
80 /** Maximum number of script-checking threads allowed */
81 static const int MAX_SCRIPTCHECK_THREADS
= 16;
82 /** -par default (number of script-checking threads, 0 = auto) */
83 static const int DEFAULT_SCRIPTCHECK_THREADS
= 0;
84 /** Number of blocks that can be requested at any given time from a single peer. */
85 static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER
= 16;
86 /** Timeout in seconds during which a peer must stall block download progress before being disconnected. */
87 static const unsigned int BLOCK_STALLING_TIMEOUT
= 2;
88 /** Number of headers sent in one getheaders result. We rely on the assumption that if a peer sends
89 * less than this number, we reached its tip. Changing this value is a protocol upgrade. */
90 static const unsigned int MAX_HEADERS_RESULTS
= 2000;
91 /** Maximum depth of blocks we're willing to serve as compact blocks to peers
92 * when requested. For older blocks, a regular BLOCK response will be sent. */
93 static const int MAX_CMPCTBLOCK_DEPTH
= 5;
94 /** Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests for. */
95 static const int MAX_BLOCKTXN_DEPTH
= 10;
96 /** Size of the "block download window": how far ahead of our current height do we fetch?
97 * Larger windows tolerate larger download speed differences between peer, but increase the potential
98 * degree of disordering of blocks on disk (which make reindexing and in the future perhaps pruning
99 * harder). We'll probably want to make this a per-peer adaptive value at some point. */
100 static const unsigned int BLOCK_DOWNLOAD_WINDOW
= 1024;
101 /** Time to wait (in seconds) between writing blocks/block index to disk. */
102 static const unsigned int DATABASE_WRITE_INTERVAL
= 60 * 60;
103 /** Time to wait (in seconds) between flushing chainstate to disk. */
104 static const unsigned int DATABASE_FLUSH_INTERVAL
= 24 * 60 * 60;
105 /** Maximum length of reject messages. */
106 static const unsigned int MAX_REJECT_MESSAGE_LENGTH
= 111;
107 /** Average delay between local address broadcasts in seconds. */
108 static const unsigned int AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL
= 24 * 60 * 60;
109 /** Average delay between peer address broadcasts in seconds. */
110 static const unsigned int AVG_ADDRESS_BROADCAST_INTERVAL
= 30;
111 /** Average delay between trickled inventory transmissions in seconds.
112 * Blocks and whitelisted receivers bypass this, outbound peers get half this delay. */
113 static const unsigned int INVENTORY_BROADCAST_INTERVAL
= 5;
114 /** Maximum number of inventory items to send per transmission.
115 * Limits the impact of low-fee transaction floods. */
116 static const unsigned int INVENTORY_BROADCAST_MAX
= 7 * INVENTORY_BROADCAST_INTERVAL
;
117 /** Average delay between feefilter broadcasts in seconds. */
118 static const unsigned int AVG_FEEFILTER_BROADCAST_INTERVAL
= 10 * 60;
119 /** Maximum feefilter broadcast delay after significant change. */
120 static const unsigned int MAX_FEEFILTER_CHANGE_DELAY
= 5 * 60;
121 /** Block download timeout base, expressed in millionths of the block interval (i.e. 10 min) */
122 static const int64_t BLOCK_DOWNLOAD_TIMEOUT_BASE
= 1000000;
123 /** Additional block download timeout per parallel downloading peer (i.e. 5 min) */
124 static const int64_t BLOCK_DOWNLOAD_TIMEOUT_PER_PEER
= 500000;
126 static const int64_t DEFAULT_MAX_TIP_AGE
= 24 * 60 * 60;
127 /** Maximum age of our tip in seconds for us to be considered current for fee estimation */
128 static const int64_t MAX_FEE_ESTIMATION_TIP_AGE
= 3 * 60 * 60;
130 /** Default for -permitbaremultisig */
131 static const bool DEFAULT_PERMIT_BAREMULTISIG
= true;
132 static const bool DEFAULT_CHECKPOINTS_ENABLED
= true;
133 static const bool DEFAULT_TXINDEX
= false;
134 static const unsigned int DEFAULT_BANSCORE_THRESHOLD
= 100;
135 /** Default for -persistmempool */
136 static const bool DEFAULT_PERSIST_MEMPOOL
= true;
137 /** Default for -mempoolreplacement */
138 static const bool DEFAULT_ENABLE_REPLACEMENT
= true;
139 /** Default for using fee filter */
140 static const bool DEFAULT_FEEFILTER
= true;
142 /** Maximum number of headers to announce when relaying blocks with headers message.*/
143 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE
= 8;
145 /** Maximum number of unconnecting headers announcements before DoS score */
146 static const int MAX_UNCONNECTING_HEADERS
= 10;
148 static const bool DEFAULT_PEERBLOOMFILTERS
= true;
150 /** Default for -stopatheight */
151 static const int DEFAULT_STOPATHEIGHT
= 0;
155 size_t operator()(const uint256
& hash
) const { return hash
.GetCheapHash(); }
158 extern CScript COINBASE_FLAGS
;
159 extern CCriticalSection cs_main
;
160 extern CBlockPolicyEstimator feeEstimator
;
161 extern CTxMemPool mempool
;
162 typedef std::unordered_map
<uint256
, CBlockIndex
*, BlockHasher
> BlockMap
;
163 extern BlockMap mapBlockIndex
;
164 extern uint64_t nLastBlockTx
;
165 extern uint64_t nLastBlockSize
;
166 extern uint64_t nLastBlockWeight
;
167 extern const std::string strMessageMagic
;
168 extern CWaitableCriticalSection csBestBlock
;
169 extern CConditionVariable cvBlockChange
;
170 extern std::atomic_bool fImporting
;
171 extern bool fReindex
;
172 extern int nScriptCheckThreads
;
173 extern bool fTxIndex
;
174 extern bool fIsBareMultisigStd
;
175 extern bool fRequireStandard
;
176 extern bool fCheckBlockIndex
;
177 extern bool fCheckpointsEnabled
;
178 extern size_t nCoinCacheUsage
;
179 /** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */
180 extern CFeeRate minRelayTxFee
;
181 /** Absolute maximum transaction fee (in satoshis) used by wallet and mempool (rejects high fee in sendrawtransaction) */
182 extern CAmount maxTxFee
;
183 /** If the tip is older than this (in seconds), the node is considered to be in initial block download. */
184 extern int64_t nMaxTipAge
;
185 extern bool fEnableReplacement
;
187 /** Block hash whose ancestors we will assume to have valid scripts without checking them. */
188 extern uint256 hashAssumeValid
;
190 /** Best header we've seen so far (used for getheaders queries' starting points). */
191 extern CBlockIndex
*pindexBestHeader
;
193 /** Minimum disk space required - used in CheckDiskSpace() */
194 static const uint64_t nMinDiskSpace
= 52428800;
196 /** Pruning-related variables and constants */
197 /** True if any block files have ever been pruned. */
198 extern bool fHavePruned
;
199 /** True if we're running in -prune mode. */
200 extern bool fPruneMode
;
201 /** Number of MiB of block files that we're trying to stay below. */
202 extern uint64_t nPruneTarget
;
203 /** Block files containing a block-height within MIN_BLOCKS_TO_KEEP of chainActive.Tip() will not be pruned. */
204 static const unsigned int MIN_BLOCKS_TO_KEEP
= 288;
206 static const signed int DEFAULT_CHECKBLOCKS
= 6;
207 static const unsigned int DEFAULT_CHECKLEVEL
= 3;
209 // Require that user allocate at least 550MB for block & undo files (blk???.dat and rev???.dat)
210 // At 1MB per block, 288 blocks = 288MB.
211 // Add 15% for Undo data = 331MB
212 // Add 20% for Orphan block rate = 397MB
213 // We want the low water mark after pruning to be at least 397 MB and since we prune in
214 // full block file chunks, we need the high water mark which triggers the prune to be
215 // one 128MB block file + added 15% undo data = 147MB greater for a total of 545MB
216 // Setting the target to > than 550MB will make it likely we can respect the target.
217 static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES
= 550 * 1024 * 1024;
220 * Process an incoming block. This only returns after the best known valid
221 * block is made active. Note that it does not, however, guarantee that the
222 * specific block passed to it has been checked for validity!
224 * If you want to *possibly* get feedback on whether pblock is valid, you must
225 * install a CValidationInterface (see validationinterface.h) - this will have
226 * its BlockChecked method called whenever *any* block completes validation.
228 * Note that we guarantee that either the proof-of-work is valid on pblock, or
229 * (and possibly also) BlockChecked will have been called.
231 * Call without cs_main held.
233 * @param[in] pblock The block we want to process.
234 * @param[in] fForceProcessing Process this block even if unrequested; used for non-network block sources and whitelisted peers.
235 * @param[out] fNewBlock A boolean which is set to indicate if the block was first received via this call
236 * @return True if state.IsValid()
238 bool ProcessNewBlock(const CChainParams
& chainparams
, const std::shared_ptr
<const CBlock
> pblock
, bool fForceProcessing
, bool* fNewBlock
);
241 * Process incoming block headers.
243 * Call without cs_main held.
245 * @param[in] block The block headers themselves
246 * @param[out] state This may be set to an Error state if any error occurred processing them
247 * @param[in] chainparams The params for the chain we want to connect to
248 * @param[out] ppindex If set, the pointer will be set to point to the last new block index object for the given headers
250 bool ProcessNewBlockHeaders(const std::vector
<CBlockHeader
>& block
, CValidationState
& state
, const CChainParams
& chainparams
, const CBlockIndex
** ppindex
=NULL
);
252 /** Check whether enough disk space is available for an incoming block */
253 bool CheckDiskSpace(uint64_t nAdditionalBytes
= 0);
254 /** Open a block file (blk?????.dat) */
255 FILE* OpenBlockFile(const CDiskBlockPos
&pos
, bool fReadOnly
= false);
256 /** Translation to a filesystem path */
257 fs::path
GetBlockPosFilename(const CDiskBlockPos
&pos
, const char *prefix
);
258 /** Import blocks from an external file */
259 bool LoadExternalBlockFile(const CChainParams
& chainparams
, FILE* fileIn
, CDiskBlockPos
*dbp
= NULL
);
260 /** Initialize a new block tree database + block data on disk */
261 bool InitBlockIndex(const CChainParams
& chainparams
);
262 /** Load the block tree and coins database from disk */
263 bool LoadBlockIndex(const CChainParams
& chainparams
);
264 /** Unload database information */
265 void UnloadBlockIndex();
266 /** Run an instance of the script checking thread */
267 void ThreadScriptCheck();
268 /** Check whether we are doing an initial block download (synchronizing from disk or network) */
269 bool IsInitialBlockDownload();
270 /** Format a string that describes several potential problems detected by the core.
271 * strFor can have three values:
272 * - "rpc": get critical warnings, which should put the client in safe mode if non-empty
273 * - "statusbar": get all warnings
274 * - "gui": get all warnings, translated (where possible) for GUI
275 * This function only returns the highest priority warning of the set selected by strFor.
277 std::string
GetWarnings(const std::string
& strFor
);
278 /** Retrieve a transaction (from memory pool, or from disk, if possible) */
279 bool GetTransaction(const uint256
&hash
, CTransactionRef
&tx
, const Consensus::Params
& params
, uint256
&hashBlock
, bool fAllowSlow
= false);
280 /** Find the best known block, and make it the tip of the block chain */
281 bool ActivateBestChain(CValidationState
& state
, const CChainParams
& chainparams
, std::shared_ptr
<const CBlock
> pblock
= std::shared_ptr
<const CBlock
>());
282 CAmount
GetBlockSubsidy(int nHeight
, const Consensus::Params
& consensusParams
);
284 /** Guess verification progress (as a fraction between 0.0=genesis and 1.0=current tip). */
285 double GuessVerificationProgress(const ChainTxData
& data
, CBlockIndex
* pindex
);
288 * Mark one block file as pruned.
290 void PruneOneBlockFile(const int fileNumber
);
293 * Actually unlink the specified files
295 void UnlinkPrunedFiles(const std::set
<int>& setFilesToPrune
);
297 /** Create a new block index entry for a given block hash */
298 CBlockIndex
* InsertBlockIndex(uint256 hash
);
299 /** Flush all state, indexes and buffers to disk. */
300 void FlushStateToDisk();
301 /** Prune block files and flush state to disk. */
302 void PruneAndFlush();
303 /** Prune block files up to a given height */
304 void PruneBlockFilesManual(int nManualPruneHeight
);
306 /** (try to) add transaction to memory pool
307 * plTxnReplaced will be appended to with all transactions replaced from mempool **/
308 bool AcceptToMemoryPool(CTxMemPool
& pool
, CValidationState
&state
, const CTransactionRef
&tx
, bool fLimitFree
,
309 bool* pfMissingInputs
, std::list
<CTransactionRef
>* plTxnReplaced
= NULL
,
310 bool fOverrideMempoolLimit
=false, const CAmount nAbsurdFee
=0);
312 /** Convert CValidationState to a human-readable message for logging */
313 std::string
FormatStateMessage(const CValidationState
&state
);
315 /** Get the BIP9 state for a given deployment at the current tip. */
316 ThresholdState
VersionBitsTipState(const Consensus::Params
& params
, Consensus::DeploymentPos pos
);
318 /** Get the numerical statistics for the BIP9 state for a given deployment at the current tip. */
319 BIP9Stats
VersionBitsTipStatistics(const Consensus::Params
& params
, Consensus::DeploymentPos pos
);
321 /** Get the block height at which the BIP9 deployment switched into the state for the block building on the current tip. */
322 int VersionBitsTipStateSinceHeight(const Consensus::Params
& params
, Consensus::DeploymentPos pos
);
325 /** Apply the effects of this transaction on the UTXO set represented by view */
326 void UpdateCoins(const CTransaction
& tx
, CCoinsViewCache
& inputs
, int nHeight
);
328 /** Transaction validation functions */
331 * Check if transaction will be final in the next block to be created.
333 * Calls IsFinalTx() with current block height and appropriate block time.
335 * See consensus/consensus.h for flag definitions.
337 bool CheckFinalTx(const CTransaction
&tx
, int flags
= -1);
340 * Test whether the LockPoints height and time are still valid on the current chain
342 bool TestLockPointValidity(const LockPoints
* lp
);
345 * Check if transaction will be BIP 68 final in the next block to be created.
347 * Simulates calling SequenceLocks() with data from the tip of the current active chain.
348 * Optionally stores in LockPoints the resulting height and time calculated and the hash
349 * of the block needed for calculation or skips the calculation and uses the LockPoints
350 * passed in for evaluation.
351 * The LockPoints should not be considered valid if CheckSequenceLocks returns false.
353 * See consensus/consensus.h for flag definitions.
355 bool CheckSequenceLocks(const CTransaction
&tx
, int flags
, LockPoints
* lp
= NULL
, bool useExistingLockPoints
= false);
358 * Closure representing one script verification
359 * Note that this stores references to the spending transaction
364 CScript scriptPubKey
;
366 const CTransaction
*ptxTo
;
371 PrecomputedTransactionData
*txdata
;
374 CScriptCheck(): amount(0), ptxTo(0), nIn(0), nFlags(0), cacheStore(false), error(SCRIPT_ERR_UNKNOWN_ERROR
) {}
375 CScriptCheck(const CScript
& scriptPubKeyIn
, const CAmount amountIn
, const CTransaction
& txToIn
, unsigned int nInIn
, unsigned int nFlagsIn
, bool cacheIn
, PrecomputedTransactionData
* txdataIn
) :
376 scriptPubKey(scriptPubKeyIn
), amount(amountIn
),
377 ptxTo(&txToIn
), nIn(nInIn
), nFlags(nFlagsIn
), cacheStore(cacheIn
), error(SCRIPT_ERR_UNKNOWN_ERROR
), txdata(txdataIn
) { }
381 void swap(CScriptCheck
&check
) {
382 scriptPubKey
.swap(check
.scriptPubKey
);
383 std::swap(ptxTo
, check
.ptxTo
);
384 std::swap(amount
, check
.amount
);
385 std::swap(nIn
, check
.nIn
);
386 std::swap(nFlags
, check
.nFlags
);
387 std::swap(cacheStore
, check
.cacheStore
);
388 std::swap(error
, check
.error
);
389 std::swap(txdata
, check
.txdata
);
392 ScriptError
GetScriptError() const { return error
; }
396 /** Functions for disk access for blocks */
397 bool ReadBlockFromDisk(CBlock
& block
, const CDiskBlockPos
& pos
, const Consensus::Params
& consensusParams
);
398 bool ReadBlockFromDisk(CBlock
& block
, const CBlockIndex
* pindex
, const Consensus::Params
& consensusParams
);
400 /** Functions for validating blocks and updating the block tree */
402 /** Context-independent validity checks */
403 bool CheckBlock(const CBlock
& block
, CValidationState
& state
, const Consensus::Params
& consensusParams
, bool fCheckPOW
= true, bool fCheckMerkleRoot
= true);
405 /** Check a block is completely valid from start to finish (only works on top of our current best block, with cs_main held) */
406 bool TestBlockValidity(CValidationState
& state
, const CChainParams
& chainparams
, const CBlock
& block
, CBlockIndex
* pindexPrev
, bool fCheckPOW
= true, bool fCheckMerkleRoot
= true);
408 /** Check whether witness commitments are required for block. */
409 bool IsWitnessEnabled(const CBlockIndex
* pindexPrev
, const Consensus::Params
& params
);
411 /** When there are blocks in the active chain with missing data, rewind the chainstate and remove them from the block index */
412 bool RewindBlockIndex(const CChainParams
& params
);
414 /** Update uncommitted block structures (currently: only the witness nonce). This is safe for submitted blocks. */
415 void UpdateUncommittedBlockStructures(CBlock
& block
, const CBlockIndex
* pindexPrev
, const Consensus::Params
& consensusParams
);
417 /** Produce the necessary coinbase commitment for a block (modifies the hash, don't call for mined blocks). */
418 std::vector
<unsigned char> GenerateCoinbaseCommitment(CBlock
& block
, const CBlockIndex
* pindexPrev
, const Consensus::Params
& consensusParams
);
420 /** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */
425 bool VerifyDB(const CChainParams
& chainparams
, CCoinsView
*coinsview
, int nCheckLevel
, int nCheckDepth
);
428 /** Find the last common block between the parameter chain and a locator. */
429 CBlockIndex
* FindForkInGlobalIndex(const CChain
& chain
, const CBlockLocator
& locator
);
431 /** Mark a block as precious and reorganize. */
432 bool PreciousBlock(CValidationState
& state
, const CChainParams
& params
, CBlockIndex
*pindex
);
434 /** Mark a block as invalid. */
435 bool InvalidateBlock(CValidationState
& state
, const CChainParams
& chainparams
, CBlockIndex
*pindex
);
437 /** Remove invalidity status from a block and its descendants. */
438 bool ResetBlockFailureFlags(CBlockIndex
*pindex
);
440 /** The currently-connected chain of blocks (protected by cs_main). */
441 extern CChain chainActive
;
443 /** Global variable that points to the active CCoinsView (protected by cs_main) */
444 extern CCoinsViewCache
*pcoinsTip
;
446 /** Global variable that points to the active block tree (protected by cs_main) */
447 extern CBlockTreeDB
*pblocktree
;
450 * Return the spend height, which is one more than the inputs.GetBestBlock().
451 * While checking, GetBestBlock() refers to the parent block. (protected by cs_main)
452 * This is also true for mempool checks.
454 int GetSpendHeight(const CCoinsViewCache
& inputs
);
456 extern VersionBitsCache versionbitscache
;
459 * Determine what nVersion a new block should use.
461 int32_t ComputeBlockVersion(const CBlockIndex
* pindexPrev
, const Consensus::Params
& params
);
463 /** Reject codes greater or equal to this can be returned by AcceptToMemPool
464 * for transactions, to signal internal conditions. They cannot and should not
465 * be sent over the P2P network.
467 static const unsigned int REJECT_INTERNAL
= 0x100;
468 /** Too high fee. Can not be triggered by P2P transactions */
469 static const unsigned int REJECT_HIGHFEE
= 0x100;
470 /** Transaction is already known (either in mempool or blockchain) */
471 static const unsigned int REJECT_ALREADY_KNOWN
= 0x101;
472 /** Transaction conflicts with a transaction already known */
473 static const unsigned int REJECT_CONFLICT
= 0x102;
475 /** Get block file info entry for one block file */
476 CBlockFileInfo
* GetBlockFileInfo(size_t n
);
478 /** Dump the mempool to disk. */
481 /** Load the mempool from disk. */
484 #endif // BITCOIN_VALIDATION_H