diff options
| -rw-r--r-- | src/main.cpp | 43 |
1 files changed, 20 insertions, 23 deletions
diff --git a/src/main.cpp b/src/main.cpp index ca2734b766..e1a0973352 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -625,34 +625,11 @@ unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans) bool IsStandardTx(const CTransaction& tx, string& reason) { - AssertLockHeld(cs_main); if (tx.nVersion > CTransaction::CURRENT_VERSION || tx.nVersion < 1) { reason = "version"; return false; } - // Treat non-final transactions as non-standard to prevent a specific type - // of double-spend attack, as well as DoS attacks. (if the transaction - // can't be mined, the attacker isn't expending resources broadcasting it) - // Basically we don't want to propagate transactions that can't be included in - // the next block. - // - // However, IsFinalTx() is confusing... Without arguments, it uses - // chainActive.Height() to evaluate nLockTime; when a block is accepted, chainActive.Height() - // is set to the value of nHeight in the block. However, when IsFinalTx() - // is called within CBlock::AcceptBlock(), the height of the block *being* - // evaluated is what is used. Thus if we want to know if a transaction can - // be part of the *next* block, we need to call IsFinalTx() with one more - // than chainActive.Height(). - // - // Timestamps on the other hand don't get any special treatment, because we - // can't know what timestamp the next block will have, and there aren't - // timestamp applications where it matters. - if (!IsFinalTx(tx, chainActive.Height() + 1)) { - reason = "non-final"; - return false; - } - // Extremely large transactions with lots of inputs can cost the network // almost as much to process as they cost the sender in fees, because // computing signature hashes is O(ninputs*txsize). Limiting transactions @@ -941,6 +918,26 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa error("AcceptToMemoryPool : nonstandard transaction: %s", reason), REJECT_NONSTANDARD, reason); + // 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. + // + // However, IsFinalTx() is confusing... Without arguments, it uses + // chainActive.Height() to evaluate nLockTime; when a block is accepted, + // chainActive.Height() is set to the value of nHeight in the block. + // However, when IsFinalTx() is called within CBlock::AcceptBlock(), the + // height of the block *being* evaluated is what is used. Thus if we want + // to know if a transaction can be part of the *next* block, we need to + // call IsFinalTx() with one more than chainActive.Height(). + // + // Timestamps on the other hand don't get any special treatment, because we + // can't know what timestamp the next block will have, and there aren't + // timestamp applications where it matters. + if (!IsFinalTx(tx, chainActive.Height() + 1)) + return state.DoS(0, + error("AcceptToMemoryPool : non-final"), + REJECT_NONSTANDARD, "non-final"); + // is it already in the memory pool? uint256 hash = tx.GetHash(); if (pool.exists(hash)) |