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-rw-r--r--src/consensus/consensus.h9
-rw-r--r--src/main.cpp43
-rw-r--r--src/main.h4
-rw-r--r--src/miner.cpp8
4 files changed, 55 insertions, 9 deletions
diff --git a/src/consensus/consensus.h b/src/consensus/consensus.h
index f937844e9f..6195d6a79f 100644
--- a/src/consensus/consensus.h
+++ b/src/consensus/consensus.h
@@ -13,4 +13,13 @@ 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),
+};
+
+/** Used as the flags parameter to CheckFinalTx() in non-consensus code */
+static const unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS = 0;
+
#endif // BITCOIN_CONSENSUS_CONSENSUS_H
diff --git a/src/main.cpp b/src/main.cpp
index 621fd720e6..af907d06bc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -709,10 +709,35 @@ 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);
}
/**
@@ -931,9 +956,8 @@ 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))
- return state.DoS(0, error("AcceptToMemoryPool: non-final"),
- REJECT_NONSTANDARD, "non-final");
+ if (!CheckFinalTx(tx, STANDARD_LOCKTIME_VERIFY_FLAGS))
+ return state.DoS(0, false, REJECT_NONSTANDARD, "non-final");
// is it already in the memory pool?
uint256 hash = tx.GetHash();
@@ -2809,10 +2833,15 @@ 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 58c717c277..74911f6e65 100644
--- a/src/main.h
+++ b/src/main.h
@@ -338,8 +338,10 @@ 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 f5919ca3af..5972f74212 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -139,6 +139,7 @@ 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
@@ -153,7 +154,12 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
mi != mempool.mapTx.end(); ++mi)
{
const CTransaction& tx = mi->second.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;