diff options
Diffstat (limited to 'src/validation.cpp')
| -rw-r--r-- | src/validation.cpp | 195 |
1 files changed, 156 insertions, 39 deletions
diff --git a/src/validation.cpp b/src/validation.cpp index 0fe7f775af..975cbcc79f 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -14,6 +14,7 @@ #include "consensus/merkle.h" #include "consensus/tx_verify.h" #include "consensus/validation.h" +#include "cuckoocache.h" #include "fs.h" #include "hash.h" #include "init.h" @@ -189,7 +190,7 @@ enum FlushStateMode { static bool FlushStateToDisk(const CChainParams& chainParams, CValidationState &state, FlushStateMode mode, int nManualPruneHeight=0); static void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight); static void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight); -static bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks = NULL); +bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks = nullptr); static FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false); bool CheckFinalTx(const CTransaction &tx, int flags) @@ -312,6 +313,9 @@ bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp, bool return EvaluateSequenceLocks(index, lockPair); } +// Returns the script flags which should be checked for a given block +static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& chainparams); + static void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age) { int expired = pool.Expire(GetTime() - age); if (expired != 0) { @@ -395,6 +399,42 @@ void UpdateMempoolForReorg(DisconnectedBlockTransactions &disconnectpool, bool f LimitMempoolSize(mempool, GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60); } +// Used to avoid mempool polluting consensus critical paths if CCoinsViewMempool +// were somehow broken and returning the wrong scriptPubKeys +static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &view, CTxMemPool& pool, + unsigned int flags, bool cacheSigStore, PrecomputedTransactionData& txdata) { + AssertLockHeld(cs_main); + + // pool.cs should be locked already, but go ahead and re-take the lock here + // to enforce that mempool doesn't change between when we check the view + // and when we actually call through to CheckInputs + LOCK(pool.cs); + + assert(!tx.IsCoinBase()); + for (const CTxIn& txin : tx.vin) { + const Coin& coin = view.AccessCoin(txin.prevout); + + // At this point we haven't actually checked if the coins are all + // available (or shouldn't assume we have, since CheckInputs does). + // So we just return failure if the inputs are not available here, + // and then only have to check equivalence for available inputs. + if (coin.IsSpent()) return false; + + const CTransactionRef& txFrom = pool.get(txin.prevout.hash); + if (txFrom) { + assert(txFrom->GetHash() == txin.prevout.hash); + assert(txFrom->vout.size() > txin.prevout.n); + assert(txFrom->vout[txin.prevout.n] == coin.out); + } else { + const Coin& coinFromDisk = pcoinsTip->AccessCoin(txin.prevout); + assert(!coinFromDisk.IsSpent()); + assert(coinFromDisk.out == coin.out); + } + } + + return CheckInputs(tx, state, view, true, flags, cacheSigStore, true, txdata); +} + static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool& pool, CValidationState& state, const CTransactionRef& ptx, bool fLimitFree, bool* pfMissingInputs, int64_t nAcceptTime, std::list<CTransactionRef>* plTxnReplaced, bool fOverrideMempoolLimit, const CAmount& nAbsurdFee, std::vector<COutPoint>& coins_to_uncache) @@ -751,32 +791,51 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool // Check against previous transactions // This is done last to help prevent CPU exhaustion denial-of-service attacks. PrecomputedTransactionData txdata(tx); - if (!CheckInputs(tx, state, view, true, scriptVerifyFlags, true, txdata)) { + if (!CheckInputs(tx, state, view, true, scriptVerifyFlags, true, false, txdata)) { // SCRIPT_VERIFY_CLEANSTACK requires SCRIPT_VERIFY_WITNESS, so we // need to turn both off, and compare against just turning off CLEANSTACK // to see if the failure is specifically due to witness validation. CValidationState stateDummy; // Want reported failures to be from first CheckInputs - if (!tx.HasWitness() && CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, txdata) && - !CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, txdata)) { + if (!tx.HasWitness() && CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, txdata) && + !CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, txdata)) { // Only the witness is missing, so the transaction itself may be fine. state.SetCorruptionPossible(); } return false; // state filled in by CheckInputs } - // Check again against just the consensus-critical mandatory script - // verification flags, in case of bugs in the standard flags that cause + // Check again against the current block tip's script verification + // flags to cache our script execution flags. This is, of course, + // useless if the next block has different script flags from the + // previous one, but because the cache tracks script flags for us it + // will auto-invalidate and we'll just have a few blocks of extra + // misses on soft-fork activation. + // + // This is also useful in case of bugs in the standard flags that cause // transactions to pass as valid when they're actually invalid. For // instance the STRICTENC flag was incorrectly allowing certain // CHECKSIG NOT scripts to pass, even though they were invalid. // // There is a similar check in CreateNewBlock() to prevent creating - // invalid blocks, however allowing such transactions into the mempool - // can be exploited as a DoS attack. - if (!CheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, txdata)) + // invalid blocks (using TestBlockValidity), however allowing such + // transactions into the mempool can be exploited as a DoS attack. + unsigned int currentBlockScriptVerifyFlags = GetBlockScriptFlags(chainActive.Tip(), Params().GetConsensus()); + if (!CheckInputsFromMempoolAndCache(tx, state, view, pool, currentBlockScriptVerifyFlags, true, txdata)) { - return error("%s: BUG! PLEASE REPORT THIS! ConnectInputs failed against MANDATORY but not STANDARD flags %s, %s", - __func__, hash.ToString(), FormatStateMessage(state)); + // If we're using promiscuousmempoolflags, we may hit this normally + // Check if current block has some flags that scriptVerifyFlags + // does not before printing an ominous warning + if (!(~scriptVerifyFlags & currentBlockScriptVerifyFlags)) { + return error("%s: BUG! PLEASE REPORT THIS! ConnectInputs failed against latest-block but not STANDARD flags %s, %s", + __func__, hash.ToString(), FormatStateMessage(state)); + } else { + if (!CheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, false, txdata)) { + return error("%s: ConnectInputs failed against MANDATORY but not STANDARD flags due to promiscuous mempool %s, %s", + __func__, hash.ToString(), FormatStateMessage(state)); + } else { + LogPrintf("Warning: -promiscuousmempool flags set to not include currently enforced soft forks, this may break mining or otherwise cause instability!\n"); + } + } } // Remove conflicting transactions from the mempool @@ -1152,12 +1211,34 @@ int GetSpendHeight(const CCoinsViewCache& inputs) return pindexPrev->nHeight + 1; } + +static CuckooCache::cache<uint256, SignatureCacheHasher> scriptExecutionCache; +static uint256 scriptExecutionCacheNonce(GetRandHash()); + +void InitScriptExecutionCache() { + // nMaxCacheSize is unsigned. If -maxsigcachesize is set to zero, + // setup_bytes creates the minimum possible cache (2 elements). + size_t nMaxCacheSize = std::min(std::max((int64_t)0, GetArg("-maxsigcachesize", DEFAULT_MAX_SIG_CACHE_SIZE) / 2), MAX_MAX_SIG_CACHE_SIZE) * ((size_t) 1 << 20); + size_t nElems = scriptExecutionCache.setup_bytes(nMaxCacheSize); + LogPrintf("Using %zu MiB out of %zu/2 requested for script execution cache, able to store %zu elements\n", + (nElems*sizeof(uint256)) >>20, (nMaxCacheSize*2)>>20, nElems); +} + /** * Check whether all inputs of this transaction are valid (no double spends, scripts & sigs, amounts) - * This does not modify the UTXO set. If pvChecks is not NULL, script checks are pushed onto it - * instead of being performed inline. + * This does not modify the UTXO set. + * + * If pvChecks is not NULL, script checks are pushed onto it instead of being performed inline. Any + * script checks which are not necessary (eg due to script execution cache hits) are, obviously, + * not pushed onto pvChecks/run. + * + * Setting cacheSigStore/cacheFullScriptStore to false will remove elements from the corresponding cache + * which are matched. This is useful for checking blocks where we will likely never need the cache + * entry again. + * + * Non-static (and re-declared) in src/test/txvalidationcache_tests.cpp */ -static bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks) +bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks) { if (!tx.IsCoinBase()) { @@ -1177,6 +1258,21 @@ static bool CheckInputs(const CTransaction& tx, CValidationState &state, const C // Of course, if an assumed valid block is invalid due to false scriptSigs // this optimization would allow an invalid chain to be accepted. if (fScriptChecks) { + // First check if script executions have been cached with the same + // flags. Note that this assumes that the inputs provided are + // correct (ie that the transaction hash which is in tx's prevouts + // properly commits to the scriptPubKey in the inputs view of that + // transaction). + uint256 hashCacheEntry; + // We only use the first 19 bytes of nonce to avoid a second SHA + // round - giving us 19 + 32 + 4 = 55 bytes (+ 8 + 1 = 64) + static_assert(55 - sizeof(flags) - 32 >= 128/8, "Want at least 128 bits of nonce for script execution cache"); + CSHA256().Write(scriptExecutionCacheNonce.begin(), 55 - sizeof(flags) - 32).Write(tx.GetWitnessHash().begin(), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin()); + AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks + if (scriptExecutionCache.contains(hashCacheEntry, !cacheFullScriptStore)) { + return true; + } + for (unsigned int i = 0; i < tx.vin.size(); i++) { const COutPoint &prevout = tx.vin[i].prevout; const Coin& coin = inputs.AccessCoin(prevout); @@ -1191,7 +1287,7 @@ static bool CheckInputs(const CTransaction& tx, CValidationState &state, const C const CAmount amount = coin.out.nValue; // Verify signature - CScriptCheck check(scriptPubKey, amount, tx, i, flags, cacheStore, &txdata); + CScriptCheck check(scriptPubKey, amount, tx, i, flags, cacheSigStore, &txdata); if (pvChecks) { pvChecks->push_back(CScriptCheck()); check.swap(pvChecks->back()); @@ -1204,7 +1300,7 @@ static bool CheckInputs(const CTransaction& tx, CValidationState &state, const C // avoid splitting the network between upgraded and // non-upgraded nodes. CScriptCheck check2(scriptPubKey, amount, tx, i, - flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheStore, &txdata); + flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheSigStore, &txdata); if (check2()) return state.Invalid(false, REJECT_NONSTANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(check.GetScriptError()))); } @@ -1218,6 +1314,12 @@ static bool CheckInputs(const CTransaction& tx, CValidationState &state, const C return state.DoS(100,false, REJECT_INVALID, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(check.GetScriptError()))); } } + + if (cacheFullScriptStore && !pvChecks) { + // We executed all of the provided scripts, and were told to + // cache the result. Do so now. + scriptExecutionCache.insert(hashCacheEntry); + } } } @@ -1481,6 +1583,41 @@ public: // Protected by cs_main static ThresholdConditionCache warningcache[VERSIONBITS_NUM_BITS]; +static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& consensusparams) { + AssertLockHeld(cs_main); + + // BIP16 didn't become active until Apr 1 2012 + int64_t nBIP16SwitchTime = 1333238400; + bool fStrictPayToScriptHash = (pindex->GetBlockTime() >= nBIP16SwitchTime); + + unsigned int flags = fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE; + + // Start enforcing the DERSIG (BIP66) rule + if (pindex->nHeight >= consensusparams.BIP66Height) { + flags |= SCRIPT_VERIFY_DERSIG; + } + + // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule + if (pindex->nHeight >= consensusparams.BIP65Height) { + flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY; + } + + // Start enforcing BIP68 (sequence locks) and BIP112 (CHECKSEQUENCEVERIFY) using versionbits logic. + if (VersionBitsState(pindex->pprev, consensusparams, Consensus::DEPLOYMENT_CSV, versionbitscache) == THRESHOLD_ACTIVE) { + flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY; + } + + // Start enforcing WITNESS rules using versionbits logic. + if (IsWitnessEnabled(pindex->pprev, consensusparams)) { + flags |= SCRIPT_VERIFY_WITNESS; + flags |= SCRIPT_VERIFY_NULLDUMMY; + } + + return flags; +} + + + static int64_t nTimeCheck = 0; static int64_t nTimeForks = 0; static int64_t nTimeVerify = 0; @@ -1584,34 +1721,14 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd } } - // BIP16 didn't become active until Apr 1 2012 - int64_t nBIP16SwitchTime = 1333238400; - bool fStrictPayToScriptHash = (pindex->GetBlockTime() >= nBIP16SwitchTime); - - unsigned int flags = fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE; - - // Start enforcing the DERSIG (BIP66) rule - if (pindex->nHeight >= chainparams.GetConsensus().BIP66Height) { - flags |= SCRIPT_VERIFY_DERSIG; - } - - // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule - if (pindex->nHeight >= chainparams.GetConsensus().BIP65Height) { - flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY; - } - // Start enforcing BIP68 (sequence locks) and BIP112 (CHECKSEQUENCEVERIFY) using versionbits logic. int nLockTimeFlags = 0; if (VersionBitsState(pindex->pprev, chainparams.GetConsensus(), Consensus::DEPLOYMENT_CSV, versionbitscache) == THRESHOLD_ACTIVE) { - flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY; nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE; } - // Start enforcing WITNESS rules using versionbits logic. - if (IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus())) { - flags |= SCRIPT_VERIFY_WITNESS; - flags |= SCRIPT_VERIFY_NULLDUMMY; - } + // Get the script flags for this block + unsigned int flags = GetBlockScriptFlags(pindex, chainparams.GetConsensus()); int64_t nTime2 = GetTimeMicros(); nTimeForks += nTime2 - nTime1; LogPrint(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs]\n", 0.001 * (nTime2 - nTime1), nTimeForks * 0.000001); @@ -1672,7 +1789,7 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd std::vector<CScriptCheck> vChecks; bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */ - if (!CheckInputs(tx, state, view, fScriptChecks, flags, fCacheResults, txdata[i], nScriptCheckThreads ? &vChecks : NULL)) + if (!CheckInputs(tx, state, view, fScriptChecks, flags, fCacheResults, fCacheResults, txdata[i], nScriptCheckThreads ? &vChecks : NULL)) return error("ConnectBlock(): CheckInputs on %s failed with %s", tx.GetHash().ToString(), FormatStateMessage(state)); control.Add(vChecks); |