diff --git a/src/main.cpp b/src/main.cpp index babdff54e..525d9902b 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -794,7 +794,25 @@ bool SequenceLocks(const CTransaction &tx, int flags, std::vector* prevHeig return EvaluateSequenceLocks(block, CalculateSequenceLocks(tx, flags, prevHeights, block)); } -bool CheckSequenceLocks(const CTransaction &tx, int flags) +bool TestLockPointValidity(const LockPoints* lp) +{ + AssertLockHeld(cs_main); + assert(lp); + // If there are relative lock times then the maxInputBlock will be set + // If there are no relative lock times, the LockPoints don't depend on the chain + if (lp->maxInputBlock) { + // Check whether chainActive is an extension of the block at which the LockPoints + // calculation was valid. If not LockPoints are no longer valid + if (!chainActive.Contains(lp->maxInputBlock)) { + return false; + } + } + + // LockPoints still valid + return true; +} + +bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp, bool useExistingLockPoints) { AssertLockHeld(cs_main); AssertLockHeld(mempool.cs); @@ -810,25 +828,57 @@ bool CheckSequenceLocks(const CTransaction &tx, int flags) // *next* block, we need to use one more than chainActive.Height() index.nHeight = tip->nHeight + 1; - // pcoinsTip contains the UTXO set for chainActive.Tip() - CCoinsViewMemPool viewMemPool(pcoinsTip, mempool); - std::vector prevheights; - prevheights.resize(tx.vin.size()); - for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) { - const CTxIn& txin = tx.vin[txinIndex]; - CCoins coins; - if (!viewMemPool.GetCoins(txin.prevout.hash, coins)) { - return error("%s: Missing input", __func__); + std::pair lockPair; + if (useExistingLockPoints) { + assert(lp); + lockPair.first = lp->height; + lockPair.second = lp->time; + } + else { + // pcoinsTip contains the UTXO set for chainActive.Tip() + CCoinsViewMemPool viewMemPool(pcoinsTip, mempool); + std::vector prevheights; + prevheights.resize(tx.vin.size()); + for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) { + const CTxIn& txin = tx.vin[txinIndex]; + CCoins coins; + if (!viewMemPool.GetCoins(txin.prevout.hash, coins)) { + return error("%s: Missing input", __func__); + } + if (coins.nHeight == MEMPOOL_HEIGHT) { + // Assume all mempool transaction confirm in the next block + prevheights[txinIndex] = tip->nHeight + 1; + } else { + prevheights[txinIndex] = coins.nHeight; + } } - if (coins.nHeight == MEMPOOL_HEIGHT) { - // Assume all mempool transaction confirm in the next block - prevheights[txinIndex] = tip->nHeight + 1; - } else { - prevheights[txinIndex] = coins.nHeight; + lockPair = CalculateSequenceLocks(tx, flags, &prevheights, index); + if (lp) { + lp->height = lockPair.first; + lp->time = lockPair.second; + // Also store the hash of the block with the highest height of + // all the blocks which have sequence locked prevouts. + // This hash needs to still be on the chain + // for these LockPoint calculations to be valid + // Note: It is impossible to correctly calculate a maxInputBlock + // if any of the sequence locked inputs depend on unconfirmed txs, + // except in the special case where the relative lock time/height + // is 0, which is equivalent to no sequence lock. Since we assume + // input height of tip+1 for mempool txs and test the resulting + // lockPair from CalculateSequenceLocks against tip+1. We know + // EvaluateSequenceLocks will fail if there was a non-zero sequence + // lock on a mempool input, so we can use the return value of + // CheckSequenceLocks to indicate the LockPoints validity + int maxInputHeight = 0; + BOOST_FOREACH(int height, prevheights) { + // Can ignore mempool inputs since we'll fail if they had non-zero locks + if (height != tip->nHeight+1) { + maxInputHeight = std::max(maxInputHeight, height); + } + } + lp->maxInputBlock = tip->GetAncestor(maxInputHeight); } } - - std::pair lockPair = CalculateSequenceLocks(tx, flags, &prevheights, index); return EvaluateSequenceLocks(index, lockPair); } @@ -1017,6 +1067,7 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C CCoinsViewCache view(&dummy); CAmount nValueIn = 0; + LockPoints lp; { LOCK(pool.cs); CCoinsViewMemPool viewMemPool(pcoinsTip, pool); @@ -1060,7 +1111,7 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C // be mined yet. // Must keep pool.cs for this unless we change CheckSequenceLocks to take a // CoinsViewCache instead of create its own - if (!CheckSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS)) + if (!CheckSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS, &lp)) return state.DoS(0, false, REJECT_NONSTANDARD, "non-BIP68-final"); } @@ -1092,7 +1143,7 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C } } - CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height(), pool.HasNoInputsOf(tx), inChainInputValue, fSpendsCoinbase, nSigOps); + CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height(), pool.HasNoInputsOf(tx), inChainInputValue, fSpendsCoinbase, nSigOps, lp); unsigned int nSize = entry.GetTxSize(); // Check that the transaction doesn't have an excessive number of diff --git a/src/main.h b/src/main.h index 5ba2be251..85ec60ac6 100644 --- a/src/main.h +++ b/src/main.h @@ -39,6 +39,7 @@ class CValidationInterface; class CValidationState; struct CNodeStateStats; +struct LockPoints; /** Default for accepting alerts from the P2P network. */ static const bool DEFAULT_ALERTS = true; @@ -368,6 +369,11 @@ bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime); */ bool CheckFinalTx(const CTransaction &tx, int flags = -1); +/** + * Test whether the LockPoints height and time are still valid on the current chain + */ +bool TestLockPointValidity(const LockPoints* lp); + /** * Check if transaction is final per BIP 68 sequence numbers and can be included in a block. * Consensus critical. Takes as input a list of heights at which tx's inputs (in order) confirmed. @@ -378,10 +384,14 @@ bool SequenceLocks(const CTransaction &tx, int flags, std::vector* prevHeig * Check if transaction will be BIP 68 final in the next block to be created. * * Simulates calling SequenceLocks() with data from the tip of the current active chain. + * Optionally stores in LockPoints the resulting height and time calculated and the hash + * of the block needed for calculation or skips the calculation and uses the LockPoints + * passed in for evaluation. + * The LockPoints should not be considered valid if CheckSequenceLocks returns false. * * See consensus/consensus.h for flag definitions. */ -bool CheckSequenceLocks(const CTransaction &tx, int flags); +bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp = NULL, bool useExistingLockPoints = false); /** * Closure representing one script verification diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp index 0416d0c92..a272018cf 100644 --- a/src/test/test_bitcoin.cpp +++ b/src/test/test_bitcoin.cpp @@ -151,7 +151,7 @@ CTxMemPoolEntry TestMemPoolEntryHelper::FromTx(CMutableTransaction &tx, CTxMemPo CAmount inChainValue = hasNoDependencies ? txn.GetValueOut() : 0; return CTxMemPoolEntry(txn, nFee, nTime, dPriority, nHeight, - hasNoDependencies, inChainValue, spendsCoinbase, sigOpCount); + hasNoDependencies, inChainValue, spendsCoinbase, sigOpCount, lp); } void Shutdown(void* parg) diff --git a/src/test/test_bitcoin.h b/src/test/test_bitcoin.h index c62392088..769ae5a13 100644 --- a/src/test/test_bitcoin.h +++ b/src/test/test_bitcoin.h @@ -9,6 +9,7 @@ #include "key.h" #include "pubkey.h" #include "txdb.h" +#include "txmempool.h" #include #include @@ -71,7 +72,8 @@ struct TestMemPoolEntryHelper bool hadNoDependencies; bool spendsCoinbase; unsigned int sigOpCount; - + LockPoints lp; + TestMemPoolEntryHelper() : nFee(0), nTime(0), dPriority(0.0), nHeight(1), hadNoDependencies(false), spendsCoinbase(false), sigOpCount(1) { } diff --git a/src/txmempool.cpp b/src/txmempool.cpp index 0b0f32e40..5f814749b 100644 --- a/src/txmempool.cpp +++ b/src/txmempool.cpp @@ -22,10 +22,10 @@ using namespace std; CTxMemPoolEntry::CTxMemPoolEntry(const CTransaction& _tx, const CAmount& _nFee, int64_t _nTime, double _entryPriority, unsigned int _entryHeight, bool poolHasNoInputsOf, CAmount _inChainInputValue, - bool _spendsCoinbase, unsigned int _sigOps): + bool _spendsCoinbase, unsigned int _sigOps, LockPoints lp): tx(_tx), nFee(_nFee), nTime(_nTime), entryPriority(_entryPriority), entryHeight(_entryHeight), hadNoDependencies(poolHasNoInputsOf), inChainInputValue(_inChainInputValue), - spendsCoinbase(_spendsCoinbase), sigOpCount(_sigOps) + spendsCoinbase(_spendsCoinbase), sigOpCount(_sigOps), lockPoints(lp) { nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION); nModSize = tx.CalculateModifiedSize(nTxSize); @@ -61,6 +61,11 @@ void CTxMemPoolEntry::UpdateFeeDelta(int64_t newFeeDelta) feeDelta = newFeeDelta; } +void CTxMemPoolEntry::UpdateLockPoints(const LockPoints& lp) +{ + lockPoints = lp; +} + // Update the given tx for any in-mempool descendants. // Assumes that setMemPoolChildren is correct for the given tx and all // descendants. @@ -506,7 +511,11 @@ void CTxMemPool::removeForReorg(const CCoinsViewCache *pcoins, unsigned int nMem list transactionsToRemove; for (indexed_transaction_set::const_iterator it = mapTx.begin(); it != mapTx.end(); it++) { const CTransaction& tx = it->GetTx(); - if (!CheckFinalTx(tx, flags) || !CheckSequenceLocks(tx, flags)) { + LockPoints lp = it->GetLockPoints(); + bool validLP = TestLockPointValidity(&lp); + if (!CheckFinalTx(tx, flags) || !CheckSequenceLocks(tx, flags, &lp, validLP)) { + // Note if CheckSequenceLocks fails the LockPoints may still be invalid + // So it's critical that we remove the tx and not depend on the LockPoints. transactionsToRemove.push_back(tx); } else if (it->GetSpendsCoinbase()) { BOOST_FOREACH(const CTxIn& txin, tx.vin) { @@ -521,6 +530,9 @@ void CTxMemPool::removeForReorg(const CCoinsViewCache *pcoins, unsigned int nMem } } } + if (!validLP) { + mapTx.modify(it, update_lock_points(lp)); + } } BOOST_FOREACH(const CTransaction& tx, transactionsToRemove) { list removed; diff --git a/src/txmempool.h b/src/txmempool.h index 386cb26d2..5997346b0 100644 --- a/src/txmempool.h +++ b/src/txmempool.h @@ -19,6 +19,7 @@ #include "boost/multi_index/ordered_index.hpp" class CAutoFile; +class CBlockIndex; inline double AllowFreeThreshold() { @@ -35,6 +36,21 @@ inline bool AllowFree(double dPriority) /** Fake height value used in CCoins to signify they are only in the memory pool (since 0.8) */ static const unsigned int MEMPOOL_HEIGHT = 0x7FFFFFFF; +struct LockPoints +{ + // Will be set to the blockchain height and median time past + // values that would be necessary to satisfy all relative locktime + // constraints (BIP68) of this tx given our view of block chain history + int height; + int64_t time; + // As long as the current chain descends from the highest height block + // containing one of the inputs used in the calculation, then the cached + // values are still valid even after a reorg. + CBlockIndex* maxInputBlock; + + LockPoints() : height(0), time(0), maxInputBlock(NULL) { } +}; + class CTxMemPool; /** \class CTxMemPoolEntry @@ -70,6 +86,7 @@ private: bool spendsCoinbase; //! keep track of transactions that spend a coinbase unsigned int sigOpCount; //! Legacy sig ops plus P2SH sig op count int64_t feeDelta; //! Used for determining the priority of the transaction for mining in a block + LockPoints lockPoints; //! Track the height and time at which tx was final // Information about descendants of this transaction that are in the // mempool; if we remove this transaction we must remove all of these @@ -84,7 +101,7 @@ public: CTxMemPoolEntry(const CTransaction& _tx, const CAmount& _nFee, int64_t _nTime, double _entryPriority, unsigned int _entryHeight, bool poolHasNoInputsOf, CAmount _inChainInputValue, bool spendsCoinbase, - unsigned int nSigOps); + unsigned int nSigOps, LockPoints lp); CTxMemPoolEntry(const CTxMemPoolEntry& other); const CTransaction& GetTx() const { return this->tx; } @@ -101,12 +118,15 @@ public: unsigned int GetSigOpCount() const { return sigOpCount; } int64_t GetModifiedFee() const { return nFee + feeDelta; } size_t DynamicMemoryUsage() const { return nUsageSize; } + const LockPoints& GetLockPoints() const { return lockPoints; } // Adjusts the descendant state, if this entry is not dirty. void UpdateState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount); // Updates the fee delta used for mining priority score, and the // modified fees with descendants. void UpdateFeeDelta(int64_t feeDelta); + // Update the LockPoints after a reorg + void UpdateLockPoints(const LockPoints& lp); /** We can set the entry to be dirty if doing the full calculation of in- * mempool descendants will be too expensive, which can potentially happen @@ -154,6 +174,16 @@ private: int64_t feeDelta; }; +struct update_lock_points +{ + update_lock_points(const LockPoints& _lp) : lp(_lp) { } + + void operator() (CTxMemPoolEntry &e) { e.UpdateLockPoints(lp); } + +private: + const LockPoints& lp; +}; + // extracts a TxMemPoolEntry's transaction hash struct mempoolentry_txid {