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| author | Johnson Lau <jl2012@xbt.hk> | 2018-04-27 03:31:36 +0800 |
|---|---|---|
| committer | Johnson Lau <jl2012@xbt.hk> | 2018-05-05 04:26:13 +0800 |
| commit | 7485488e907e236133a016ba7064c89bf9ab6da3 (patch) | |
| tree | a0a9edf5d749f6f89510b51ece2b152d7d8cf0e2 | |
| parent | 0f8719bb035187076eeac025e2c786feb0f452d7 (diff) | |
| download | bitcoin-7485488e907e236133a016ba7064c89bf9ab6da3.tar.xz | |
Policy to reject extremely small transactions
A transaction with 1 segwit input and 1 P2WPHK output has non-witness size of 82 bytes. Anything smaller than this have unnecessary malloc overhead and are not relayed/mined.
| -rw-r--r-- | src/policy/policy.h | 2 | ||||
| -rw-r--r-- | src/validation.cpp | 6 |
2 files changed, 8 insertions, 0 deletions
diff --git a/src/policy/policy.h b/src/policy/policy.h index 6ba3ba7450..5ce019df4c 100644 --- a/src/policy/policy.h +++ b/src/policy/policy.h @@ -22,6 +22,8 @@ static const unsigned int DEFAULT_BLOCK_MAX_WEIGHT = MAX_BLOCK_WEIGHT - 4000; static const unsigned int DEFAULT_BLOCK_MIN_TX_FEE = 1000; /** The maximum weight for transactions we're willing to relay/mine */ static const unsigned int MAX_STANDARD_TX_WEIGHT = 400000; +/** The minimum non-witness size for transactions we're willing to relay/mine (1 segwit input + 1 P2WPKH output = 82 bytes) */ +static const unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE = 82; /** Maximum number of signature check operations in an IsStandard() P2SH script */ static const unsigned int MAX_P2SH_SIGOPS = 15; /** The maximum number of sigops we're willing to relay/mine in a single tx */ diff --git a/src/validation.cpp b/src/validation.cpp index 1b9e982753..571e764043 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -582,6 +582,12 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool if (fRequireStandard && !IsStandardTx(tx, reason, witnessEnabled)) return state.DoS(0, false, REJECT_NONSTANDARD, reason); + // Do not work on transactions that are too small. + // A transaction with 1 segwit input and 1 P2WPHK output has non-witness size of 82 bytes. + // Transactions smaller than this are not relayed to reduce unnecessary malloc overhead. + if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) < MIN_STANDARD_TX_NONWITNESS_SIZE) + return state.DoS(0, false, REJECT_NONSTANDARD, "tx-size-small"); + // Only accept nLockTime-using transactions that can be mined in the next // block; we don't want our mempool filled up with transactions that can't // be mined yet. |