Permalink
Browse files

Merge pull request #6934

d1c3762 Revert "Revert "Enable policy enforcing GetMedianTimePast as the end point of lock-time constraints"" (Gregory Maxwell)
e4e5334 Restore MedianTimePast for locktime. (Gregory Maxwell)
  • Loading branch information...
laanwj committed Nov 5, 2015
2 parents 3694b74 + d1c3762 commit 3038eb63e8a674b4818cb5d5e461f1ccf4b2932f
Showing with 58 additions and 10 deletions.
  1. +6 −0 src/consensus/consensus.h
  2. +35 −5 src/main.cpp
  3. +3 −1 src/main.h
  4. +7 −1 src/miner.cpp
  5. +3 −0 src/policy/policy.h
  6. +4 −3 src/test/miner_tests.cpp
@@ -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
View
@@ -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):
View
@@ -311,8 +311,10 @@ 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
View
@@ -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;
View
@@ -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 = LOCKTIME_MEDIAN_TIME_PAST;
bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
/**
* Check for standard transaction types
View
@@ -4,6 +4,7 @@
#include "chainparams.h"
#include "coins.h"
#include "consensus/consensus.h"
#include "consensus/validation.h"
#include "main.h"
#include "miner.h"
@@ -229,7 +230,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
tx.nLockTime = chainActive.Tip()->nHeight+1;
hash = tx.GetHash();
mempool.addUnchecked(hash, CTxMemPoolEntry(tx, 11, GetTime(), 111.0, 11));
BOOST_CHECK(!CheckFinalTx(tx));
BOOST_CHECK(!CheckFinalTx(tx, LOCKTIME_MEDIAN_TIME_PAST));
// time locked
tx2.vin.resize(1);
@@ -243,7 +244,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
tx2.nLockTime = chainActive.Tip()->GetMedianTimePast()+1;
hash = tx2.GetHash();
mempool.addUnchecked(hash, CTxMemPoolEntry(tx2, 11, GetTime(), 111.0, 11));
BOOST_CHECK(!CheckFinalTx(tx2));
BOOST_CHECK(!CheckFinalTx(tx2, LOCKTIME_MEDIAN_TIME_PAST));
BOOST_CHECK(pblocktemplate = CreateNewBlock(scriptPubKey));
@@ -261,7 +262,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
//BOOST_CHECK(CheckFinalTx(tx2));
BOOST_CHECK(pblocktemplate = CreateNewBlock(scriptPubKey));
BOOST_CHECK_EQUAL(pblocktemplate->block.vtx.size(), 3);
BOOST_CHECK_EQUAL(pblocktemplate->block.vtx.size(), 2);
delete pblocktemplate;
chainActive.Tip()->nHeight--;

0 comments on commit 3038eb6

Please sign in to comment.