Line data    Source code

       1             : // Copyright (c) 2009-2010 Satoshi Nakamoto
       2             : // Copyright (c) 2009-2021 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_POLICY_POLICY_H
       7             : #define BITCOIN_POLICY_POLICY_H
       8             : 
       9             : #include <consensus/amount.h>
      10             : #include <consensus/consensus.h>
      11             : #include <primitives/transaction.h>
      12             : #include <script/interpreter.h>
      13             : #include <script/standard.h>
      14             : 
      15             : #include <cstdint>
      16             : #include <string>
      17             : 
      18             : class CCoinsViewCache;
      19             : class CFeeRate;
      20             : class CScript;
      21             : 
      22             : /** Default for -blockmaxsize, which controls the maximum size of block the mining code will create **/
      23             : static constexpr unsigned int DEFAULT_BLOCK_MAX_SIZE{2000000};
      24             : /** Default for -blockmintxfee, which sets the minimum feerate for a transaction in blocks created by mining code **/
      25             : static constexpr unsigned int DEFAULT_BLOCK_MIN_TX_FEE{1000};
      26             : /** The maximum size for transactions we're willing to relay/mine */
      27             : static constexpr unsigned int MAX_STANDARD_TX_SIZE{100000};
      28             : /** The minimum size for transactions we're willing to relay/mine (1 empty scriptSig input + 1 P2SH output = 83 bytes) */
      29             : static constexpr unsigned int MIN_STANDARD_TX_SIZE{83};
      30             : /** Maximum number of signature check operations in an IsStandard() P2SH script */
      31             : static constexpr unsigned int MAX_P2SH_SIGOPS{15};
      32             : /** The maximum number of sigops we're willing to relay/mine in a single tx */
      33             : static constexpr unsigned int MAX_STANDARD_TX_SIGOPS{4000};
      34             : /** Default for -maxmempool, maximum megabytes of mempool memory usage */
      35             : static constexpr unsigned int DEFAULT_MAX_MEMPOOL_SIZE{300};
      36             : /** Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting **/
      37             : static constexpr unsigned int DEFAULT_INCREMENTAL_RELAY_FEE{1000};
      38             : /** Default for -bytespersigop */
      39             : static constexpr unsigned int DEFAULT_BYTES_PER_SIGOP{20};
      40             : /** Default for -permitbaremultisig */
      41             : static constexpr bool DEFAULT_PERMIT_BAREMULTISIG{true};
      42             : /** The maximum size of a standard ScriptSig */
      43             : static constexpr unsigned int MAX_STANDARD_SCRIPTSIG_SIZE{1650};
      44             : /** Min feerate for defining dust. Historically this has been based on the
      45             :  * minRelayTxFee, however changing the dust limit changes which transactions are
      46             :  * standard and should be done with care and ideally rarely. It makes sense to
      47             :  * only increase the dust limit after prior releases were already not creating
      48             :  * outputs below the new threshold */
      49             : static constexpr unsigned int DUST_RELAY_TX_FEE{3000};
      50             : /** Default for -minrelaytxfee, minimum relay fee for transactions */
      51             : static constexpr unsigned int DEFAULT_MIN_RELAY_TX_FEE{1000};
      52             : /** Default for -limitancestorcount, max number of in-mempool ancestors */
      53             : static constexpr unsigned int DEFAULT_ANCESTOR_LIMIT{25};
      54             : /** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */
      55             : static constexpr unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT{101};
      56             : /** Default for -limitdescendantcount, max number of in-mempool descendants */
      57             : static constexpr unsigned int DEFAULT_DESCENDANT_LIMIT{25};
      58             : /** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
      59             : static constexpr unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT{101};
      60             : /**
      61             :  * An extra transaction can be added to a package, as long as it only has one
      62             :  * ancestor and is no larger than this. Not really any reason to make this
      63             :  * configurable as it doesn't materially change DoS parameters.
      64             :  */
      65             : static constexpr unsigned int EXTRA_DESCENDANT_TX_SIZE_LIMIT{10000};
      66             : /**
      67             :  * Standard script verification flags that standard transactions will comply
      68             :  * with. However scripts violating these flags may still be present in valid
      69             :  * blocks and we must accept those blocks.
      70             :  */
      71             : static constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS{MANDATORY_SCRIPT_VERIFY_FLAGS |
      72             :                                                              SCRIPT_VERIFY_DERSIG |
      73             :                                                              SCRIPT_VERIFY_STRICTENC |
      74             :                                                              SCRIPT_VERIFY_MINIMALDATA |
      75             :                                                              SCRIPT_VERIFY_NULLDUMMY |
      76             :                                                              SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
      77             :                                                              SCRIPT_VERIFY_CLEANSTACK |
      78             :                                                              SCRIPT_VERIFY_NULLFAIL |
      79             :                                                              SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY |
      80             :                                                              SCRIPT_VERIFY_CHECKSEQUENCEVERIFY |
      81             :                                                              SCRIPT_VERIFY_LOW_S |
      82             :                                                              SCRIPT_VERIFY_CONST_SCRIPTCODE};
      83             : 
      84             : /** For convenience, standard but not mandatory verify flags. */
      85             : static constexpr unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS{STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS};
      86             : 
      87             : /** Used as the flags parameter to sequence and nLocktime checks in non-consensus code. */
      88             : static constexpr unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS{LOCKTIME_VERIFY_SEQUENCE};
      89             : 
      90             : CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFee);
      91             : 
      92             : bool IsDust(const CTxOut& txout, const CFeeRate& dustRelayFee);
      93             : 
      94             : bool IsStandard(const CScript& scriptPubKey, TxoutType& whichType);
      95             : 
      96             : 
      97             : // Changing the default transaction version requires a two step process: first
      98             : // adapting relay policy by bumping TX_MAX_STANDARD_VERSION, and then later
      99             : // allowing the new transaction version in the wallet/RPC.
     100             : static constexpr decltype(CTransaction::nVersion) TX_MAX_STANDARD_VERSION{3};
     101             : 
     102             : /**
     103             : * Check for standard transaction types
     104             : * @return True if all outputs (scriptPubKeys) use only standard transaction forms
     105             : */
     106             : bool IsStandardTx(const CTransaction& tx, bool permit_bare_multisig, const CFeeRate& dust_relay_fee, std::string& reason);
     107             : /**
     108             :  * Check for standard transaction types
     109             :  * @param[in] mapInputs    Map of previous transactions that have outputs we're spending
     110             :  * @return True if all inputs (scriptSigs) use only standard transaction forms
     111             :  */
     112             : bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
     113             : 
     114             : /** Compute the virtual transaction size (taking sigops into account). */
     115             : int64_t GetVirtualTransactionSize(int64_t nSize, int64_t nSigOp, unsigned int bytes_per_sigop);
     116             : int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOp, unsigned int bytes_per_sigop);
     117             : 
     118         115 : static inline int64_t GetVirtualTransactionSize(const CTransaction& tx)
     119             : {
     120         115 :     return GetVirtualTransactionSize(tx, 0, 0);
     121             : }
     122             : 
     123             : #endif // BITCOIN_POLICY_POLICY_H