diff options
| -rw-r--r-- | src/consensus/consensus.h | 6 | ||||
| -rw-r--r-- | src/main.cpp | 40 | ||||
| -rw-r--r-- | src/main.h | 4 | ||||
| -rw-r--r-- | src/miner.cpp | 8 | ||||
| -rw-r--r-- | src/policy/policy.h | 3 |
5 files changed, 54 insertions, 7 deletions
diff --git a/src/consensus/consensus.h b/src/consensus/consensus.h index f937844e9f..6d6ce7e099 100644 --- a/src/consensus/consensus.h +++ b/src/consensus/consensus.h @@ -13,4 +13,10 @@ static const unsigned int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50; /** Coinbase transaction outputs can only be spent after this number of new blocks (network rule) */ static const int COINBASE_MATURITY = 100; +/** Flags for LockTime() */ +enum { + /* Use GetMedianTimePast() instead of nTime for end point timestamp. */ + LOCKTIME_MEDIAN_TIME_PAST = (1 << 1), +}; + #endif // BITCOIN_CONSENSUS_CONSENSUS_H diff --git a/src/main.cpp b/src/main.cpp index 30df2744a3..499f2c3f76 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -650,10 +650,35 @@ bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime) return true; } -bool CheckFinalTx(const CTransaction &tx) +bool CheckFinalTx(const CTransaction &tx, int flags) { AssertLockHeld(cs_main); - return IsFinalTx(tx, chainActive.Height() + 1, GetAdjustedTime()); + + // By convention a negative value for flags indicates that the + // current network-enforced consensus rules should be used. In + // a future soft-fork scenario that would mean checking which + // rules would be enforced for the next block and setting the + // appropriate flags. At the present time no soft-forks are + // scheduled, so no flags are set. + flags = std::max(flags, 0); + + // CheckFinalTx() uses chainActive.Height()+1 to evaluate + // nLockTime because 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(). + const int nBlockHeight = chainActive.Height() + 1; + + // 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. + // However this changes once median past time-locks are enforced: + const int64_t nBlockTime = (flags & LOCKTIME_MEDIAN_TIME_PAST) + ? chainActive.Tip()->GetMedianTimePast() + : GetAdjustedTime(); + + return IsFinalTx(tx, nBlockHeight, nBlockTime); } unsigned int GetLegacySigOpCount(const CTransaction& tx) @@ -797,7 +822,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa // 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. - if (!CheckFinalTx(tx)) + if (!CheckFinalTx(tx, STANDARD_LOCKTIME_VERIFY_FLAGS)) return state.DoS(0, false, REJECT_NONSTANDARD, "non-final"); // is it already in the memory pool? @@ -2723,10 +2748,15 @@ bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIn const Consensus::Params& consensusParams = Params().GetConsensus(); // Check that all transactions are finalized - BOOST_FOREACH(const CTransaction& tx, block.vtx) - if (!IsFinalTx(tx, nHeight, block.GetBlockTime())) { + BOOST_FOREACH(const CTransaction& tx, block.vtx) { + int nLockTimeFlags = 0; + int64_t nLockTimeCutoff = (nLockTimeFlags & LOCKTIME_MEDIAN_TIME_PAST) + ? pindexPrev->GetMedianTimePast() + : block.GetBlockTime(); + if (!IsFinalTx(tx, nHeight, nLockTimeCutoff)) { return state.DoS(10, error("%s: contains a non-final transaction", __func__), REJECT_INVALID, "bad-txns-nonfinal"); } + } // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height // if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet): diff --git a/src/main.h b/src/main.h index 202d2c772b..65732d770f 100644 --- a/src/main.h +++ b/src/main.h @@ -308,8 +308,10 @@ bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime); * Check if transaction will be final in the next block to be created. * * Calls IsFinalTx() with current block height and appropriate block time. + * + * See consensus/consensus.h for flag definitions. */ -bool CheckFinalTx(const CTransaction &tx); +bool CheckFinalTx(const CTransaction &tx, int flags = -1); /** * Closure representing one script verification diff --git a/src/miner.cpp b/src/miner.cpp index 42c8bb970b..053d9cdbc4 100644 --- a/src/miner.cpp +++ b/src/miner.cpp @@ -148,6 +148,7 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn) CBlockIndex* pindexPrev = chainActive.Tip(); const int nHeight = pindexPrev->nHeight + 1; pblock->nTime = GetAdjustedTime(); + const int64_t nMedianTimePast = pindexPrev->GetMedianTimePast(); CCoinsViewCache view(pcoinsTip); // Priority order to process transactions @@ -162,7 +163,12 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn) mi != mempool.mapTx.end(); ++mi) { const CTransaction& tx = mi->GetTx(); - if (tx.IsCoinBase() || !IsFinalTx(tx, nHeight, pblock->nTime)) + + int64_t nLockTimeCutoff = (STANDARD_LOCKTIME_VERIFY_FLAGS & LOCKTIME_MEDIAN_TIME_PAST) + ? nMedianTimePast + : pblock->GetBlockTime(); + + if (tx.IsCoinBase() || !IsFinalTx(tx, nHeight, nLockTimeCutoff)) continue; COrphan* porphan = NULL; diff --git a/src/policy/policy.h b/src/policy/policy.h index 0ea0d435ad..cfe6a40526 100644 --- a/src/policy/policy.h +++ b/src/policy/policy.h @@ -43,6 +43,9 @@ static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY /** For convenience, standard but not mandatory verify flags. */ static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS; +/** Used as the flags parameter to CheckFinalTx() in non-consensus code */ +static const unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS = 0; + bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType); /** * Check for standard transaction types |