1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2019 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 = 7600000;
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 = 400000;
23 /** The maximum weight for transactions we're willing to relay/mine */
24 static const unsigned int MAX_STANDARD_TX_WEIGHT = 400000;
25 /** The minimum non-witness size for transactions we're willing to relay/mine (1 segwit input + 1 P2WPKH output = 82 bytes) */
26 static const unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE = 82;
27 /** Maximum number of signature check operations in an IsStandard() P2SH script */
28 static const unsigned int MAX_P2SH_SIGOPS = 15;
29 /** The maximum number of sigops we're willing to relay/mine in a single tx */
30 extern unsigned int dgpMaxTxSigOps;
31 /** Default for -maxmempool, maximum megabytes of mempool memory usage */
32 static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
33 /** Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting or BIP 125 replacement **/
34 static const unsigned int DEFAULT_INCREMENTAL_RELAY_FEE = 10000;
35 /** Default for -bytespersigop */
36 static const unsigned int DEFAULT_BYTES_PER_SIGOP = 20;
37 /** Default for -permitbaremultisig */
38 static const bool DEFAULT_PERMIT_BAREMULTISIG = true;
39 /** The maximum number of witness stack items in a standard P2WSH script */
40 static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS = 100;
41 /** The maximum size of each witness stack item in a standard P2WSH script */
42 static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEM_SIZE = 80;
43 /** The maximum size of a standard witnessScript */
44 static const unsigned int MAX_STANDARD_P2WSH_SCRIPT_SIZE = 3600;
45 /** Min feerate for defining dust. Historically this has been based on the
46 * minRelayTxFee, however changing the dust limit changes which transactions are
47 * standard and should be done with care and ideally rarely. It makes sense to
48 * only increase the dust limit after prior releases were already not creating
49 * outputs below the new threshold */
50 static const unsigned int DUST_RELAY_TX_FEE = 400000;
51 /**
52 * Standard script verification flags that standard transactions will comply
53 * with. However scripts violating these flags may still be present in valid
54 * blocks and we must accept those blocks.
55 */
56 static constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS |
57 SCRIPT_VERIFY_DERSIG |
58 SCRIPT_VERIFY_STRICTENC |
59 SCRIPT_VERIFY_MINIMALDATA |
60 SCRIPT_VERIFY_NULLDUMMY |
61 SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS |
62 SCRIPT_VERIFY_CLEANSTACK |
63 SCRIPT_VERIFY_MINIMALIF |
64 SCRIPT_VERIFY_NULLFAIL |
65 SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY |
66 SCRIPT_VERIFY_CHECKSEQUENCEVERIFY |
67 SCRIPT_VERIFY_LOW_S |
68 SCRIPT_VERIFY_WITNESS |
69 SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM |
70 SCRIPT_VERIFY_WITNESS_PUBKEYTYPE |
71 SCRIPT_VERIFY_CONST_SCRIPTCODE;
72
73 /** For convenience, standard but not mandatory verify flags. */
74 static constexpr unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
75
76 /** Used as the flags parameter to sequence and nLocktime checks in non-consensus code. */
77 static constexpr unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS = LOCKTIME_VERIFY_SEQUENCE |
78 LOCKTIME_MEDIAN_TIME_PAST;
79 /** The number of sender stack items in a standard sender signature script */
80 static const unsigned int STANDARD_SENDER_STACK_ITEMS = 2;
81 /** The maximum size of each sender stack item in a standard sender signature script */
82 static const unsigned int MAX_STANDARD_SENDER_STACK_ITEM_SIZE = 80;
83
84 CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFee);
85
86 bool IsDust(const CTxOut& txout, const CFeeRate& dustRelayFee);
87
88 bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
89 /**
90 * Check for standard transaction types
91 * @return True if all outputs (scriptPubKeys) use only standard transaction forms
92 */
93 bool IsStandardTx(const CTransaction& tx, bool permit_bare_multisig, const CFeeRate& dust_relay_fee, std::string& reason);
94 /**
95 * Check for standard transaction types
96 * @param[in] mapInputs Map of previous transactions that have outputs we're spending
97 * @return True if all inputs (scriptSigs) use only standard transaction forms
98 */
99 bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
100 /**
101 * Check if the transaction is over standard P2WSH resources limit:
102 * 3600bytes witnessScript size, 80bytes per witness stack element, 100 witness stack elements
103 * These limits are adequate for multi-signature up to n-of-100 using OP_CHECKSIG, OP_ADD, and OP_EQUAL,
104 */
105 bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
106
107 /** Compute the virtual transaction size (weight reinterpreted as bytes). */
108 int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost, unsigned int bytes_per_sigop);
109 int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost, unsigned int bytes_per_sigop);
110 int64_t GetVirtualTransactionInputSize(const CTxIn& tx, int64_t nSigOpCost, unsigned int bytes_per_sigop);
111
GetVirtualTransactionSize(const CTransaction & tx)112 static inline int64_t GetVirtualTransactionSize(const CTransaction& tx)
113 {
114 return GetVirtualTransactionSize(tx, 0, 0);
115 }
116
GetVirtualTransactionInputSize(const CTxIn & tx)117 static inline int64_t GetVirtualTransactionInputSize(const CTxIn& tx)
118 {
119 return GetVirtualTransactionInputSize(tx, 0, 0);
120 }
121
122 #endif // BITCOIN_POLICY_POLICY_H
123