src/policy/policy.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2017 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/consensus.h>
  10 #include <policy/feerate.h>
  11 #include <script/interpreter.h>
  12 #include <script/standard.h>
  13
  14 #include <string>
  15
  16 class CCoinsViewCache;
  17 class CTxOut;
  18
  19 /** Default for -blockmaxweight, which controls the range of block weights the mining code will create **/
  20 static const unsigned int DEFAULT_BLOCK_MAX_WEIGHT = MAX_BLOCK_WEIGHT - 4000;
  21 /** Default for -blockmintxfee, which sets the minimum feerate for a transaction in blocks created by mining code **/
  22 static const unsigned int DEFAULT_BLOCK_MIN_TX_FEE = 1000;
  23 /** The maximum weight for transactions we're willing to relay/mine */
  24 static const unsigned int MAX_STANDARD_TX_WEIGHT = 400000;
  25 /** Maximum number of signature check operations in an IsStandard() P2SH script */
  26 static const unsigned int MAX_P2SH_SIGOPS = 15;
  27 /** The maximum number of sigops we're willing to relay/mine in a single tx */
  28 static const unsigned int MAX_STANDARD_TX_SIGOPS_COST = MAX_BLOCK_SIGOPS_COST/5;
  29 /** Default for -maxmempool, maximum megabytes of mempool memory usage */
  30 static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
  31 /** Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting or BIP 125 replacement **/
  32 static const unsigned int DEFAULT_INCREMENTAL_RELAY_FEE = 1000;
  33 /** Default for -bytespersigop */
  34 static const unsigned int DEFAULT_BYTES_PER_SIGOP = 20;
  35 /** The maximum number of witness stack items in a standard P2WSH script */
  36 static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS = 100;
  37 /** The maximum size of each witness stack item in a standard P2WSH script */
  38 static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEM_SIZE = 80;
  39 /** The maximum size of a standard witnessScript */
  40 static const unsigned int MAX_STANDARD_P2WSH_SCRIPT_SIZE = 3600;
  41 /** Min feerate for defining dust. Historically this has been based on the
  42  * minRelayTxFee, however changing the dust limit changes which transactions are
  43  * standard and should be done with care and ideally rarely. It makes sense to
  44  * only increase the dust limit after prior releases were already not creating
  45  * outputs below the new threshold */
  46 static const unsigned int DUST_RELAY_TX_FEE = 3000;
  47 /**
  48  * Standard script verification flags that standard transactions will comply
  49  * with. However scripts violating these flags may still be present in valid
  50  * blocks and we must accept those blocks.
  51  */
  52 static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS |
  53                                                          SCRIPT_VERIFY_DERSIG |
  54                                                          SCRIPT_VERIFY_STRICTENC |
  55                                                          SCRIPT_VERIFY_MINIMALDATA |
  56                                                          SCRIPT_VERIFY_NULLDUMMY |
  57                                                          SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
  58                                                          SCRIPT_VERIFY_CLEANSTACK |
  59                                                          SCRIPT_VERIFY_MINIMALIF |
  60                                                          SCRIPT_VERIFY_NULLFAIL |
  61                                                          SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY |
  62                                                          SCRIPT_VERIFY_CHECKSEQUENCEVERIFY |
  63                                                          SCRIPT_VERIFY_LOW_S |
  64                                                          SCRIPT_VERIFY_WITNESS |
  65                                                          SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM |
  66                                                          SCRIPT_VERIFY_WITNESS_PUBKEYTYPE;
  67
  68 /** For convenience, standard but not mandatory verify flags. */
  69 static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
  70
  71 /** Used as the flags parameter to sequence and nLocktime checks in non-consensus code. */
  72 static const unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS = LOCKTIME_VERIFY_SEQUENCE |
  73                                                            LOCKTIME_MEDIAN_TIME_PAST;
  74
  75 CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFee);
  76
  77 bool IsDust(const CTxOut& txout, const CFeeRate& dustRelayFee);
  78
  79 bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType, const bool witnessEnabled = false);
  80     /**
  81      * Check for standard transaction types
  82      * @return True if all outputs (scriptPubKeys) use only standard transaction forms
  83      */
  84 bool IsStandardTx(const CTransaction& tx, std::string& reason, const bool witnessEnabled = false);
  85     /**
  86      * Check for standard transaction types
  87      * @param[in] mapInputs    Map of previous transactions that have outputs we're spending
  88      * @return True if all inputs (scriptSigs) use only standard transaction forms
  89      */
  90 bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
  91     /**
  92      * Check if the transaction is over standard P2WSH resources limit:
  93      * 3600bytes witnessScript size, 80bytes per witness stack element, 100 witness stack elements
  94      * These limits are adequate for multi-signature up to n-of-100 using OP_CHECKSIG, OP_ADD, and OP_EQUAL,
  95      */
  96 bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
  97
  98 extern CFeeRate incrementalRelayFee;
  99 extern CFeeRate dustRelayFee;
 100 extern unsigned int nBytesPerSigOp;
 101
 102 /** Compute the virtual transaction size (weight reinterpreted as bytes). */
 103 int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost);
 104 int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost = 0);
 105
 106 #endif // BITCOIN_POLICY_POLICY_H