diff --git a/src/policy/policy.h b/src/policy/policy.h index 88dae4ab74aa7..be1c0e03ecf10 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 7c4c84c3f9fe6..2c5b5a1a31d0d 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -576,6 +576,12 @@ 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.