diff options
Diffstat (limited to 'src/validation.cpp')
| -rw-r--r-- | src/validation.cpp | 871 |
1 files changed, 529 insertions, 342 deletions
diff --git a/src/validation.cpp b/src/validation.cpp index 3498915192..1faaa411c4 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -428,21 +428,134 @@ static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, CValidationSt return CheckInputs(tx, state, view, flags, cacheSigStore, true, txdata); } -/** - * @param[out] coins_to_uncache Return any outpoints which were not previously present in the - * coins cache, but were added as a result of validating the tx - * for mempool acceptance. This allows the caller to optionally - * remove the cache additions if the associated transaction ends - * up being rejected by the mempool. - */ -static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool& pool, CValidationState& state, const CTransactionRef& ptx, - bool* pfMissingInputs, int64_t nAcceptTime, std::list<CTransactionRef>* plTxnReplaced, - bool bypass_limits, const CAmount& nAbsurdFee, std::vector<COutPoint>& coins_to_uncache, bool test_accept) EXCLUSIVE_LOCKS_REQUIRED(cs_main) +namespace { + +class MemPoolAccept { - const CTransaction& tx = *ptx; - const uint256 hash = tx.GetHash(); - AssertLockHeld(cs_main); - LOCK(pool.cs); // mempool "read lock" (held through GetMainSignals().TransactionAddedToMempool()) +public: + MemPoolAccept(CTxMemPool& mempool) : m_pool(mempool), m_view(&m_dummy), m_viewmempool(&::ChainstateActive().CoinsTip(), m_pool), + m_limit_ancestors(gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT)), + m_limit_ancestor_size(gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT)*1000), + m_limit_descendants(gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT)), + m_limit_descendant_size(gArgs.GetArg("-limitdescendantsize", DEFAULT_DESCENDANT_SIZE_LIMIT)*1000) {} + + // We put the arguments we're handed into a struct, so we can pass them + // around easier. + struct ATMPArgs { + const CChainParams& m_chainparams; + CValidationState &m_state; + bool* m_missing_inputs; + const int64_t m_accept_time; + std::list<CTransactionRef>* m_replaced_transactions; + const bool m_bypass_limits; + const CAmount& m_absurd_fee; + /* + * Return any outpoints which were not previously present in the coins + * cache, but were added as a result of validating the tx for mempool + * acceptance. This allows the caller to optionally remove the cache + * additions if the associated transaction ends up being rejected by + * the mempool. + */ + std::vector<COutPoint>& m_coins_to_uncache; + const bool m_test_accept; + }; + + // Single transaction acceptance + bool AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +private: + // All the intermediate state that gets passed between the various levels + // of checking a given transaction. + struct Workspace { + Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {} + std::set<uint256> m_conflicts; + CTxMemPool::setEntries m_all_conflicting; + CTxMemPool::setEntries m_ancestors; + std::unique_ptr<CTxMemPoolEntry> m_entry; + + bool m_replacement_transaction; + CAmount m_modified_fees; + CAmount m_conflicting_fees; + size_t m_conflicting_size; + + const CTransactionRef& m_ptx; + const uint256& m_hash; + }; + + // Run the policy checks on a given transaction, excluding any script checks. + // Looks up inputs, calculates feerate, considers replacement, evaluates + // package limits, etc. As this function can be invoked for "free" by a peer, + // only tests that are fast should be done here (to avoid CPU DoS). + bool PreChecks(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); + + // Run the script checks using our policy flags. As this can be slow, we should + // only invoke this on transactions that have otherwise passed policy checks. + bool PolicyScriptChecks(ATMPArgs& args, Workspace& ws, PrecomputedTransactionData& txdata) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + // Re-run the script checks, using consensus flags, and try to cache the + // result in the scriptcache. This should be done after + // PolicyScriptChecks(). This requires that all inputs either be in our + // utxo set or in the mempool. + bool ConsensusScriptChecks(ATMPArgs& args, Workspace& ws, PrecomputedTransactionData &txdata) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + // Try to add the transaction to the mempool, removing any conflicts first. + // Returns true if the transaction is in the mempool after any size + // limiting is performed, false otherwise. + bool Finalize(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs); + + // Compare a package's feerate against minimum allowed. + bool CheckFeeRate(size_t package_size, CAmount package_fee, CValidationState& state) + { + CAmount mempoolRejectFee = m_pool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFee(package_size); + if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) { + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee)); + } + + if (package_fee < ::minRelayTxFee.GetFee(package_size)) { + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "min relay fee not met", strprintf("%d < %d", package_fee, ::minRelayTxFee.GetFee(package_size))); + } + return true; + } + +private: + CTxMemPool& m_pool; + CCoinsViewCache m_view; + CCoinsViewMemPool m_viewmempool; + CCoinsView m_dummy; + + // The package limits in effect at the time of invocation. + const size_t m_limit_ancestors; + const size_t m_limit_ancestor_size; + // These may be modified while evaluating a transaction (eg to account for + // in-mempool conflicts; see below). + size_t m_limit_descendants; + size_t m_limit_descendant_size; +}; + +bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws) +{ + const CTransactionRef& ptx = ws.m_ptx; + const CTransaction& tx = *ws.m_ptx; + const uint256& hash = ws.m_hash; + + // Copy/alias what we need out of args + CValidationState &state = args.m_state; + bool* pfMissingInputs = args.m_missing_inputs; + const int64_t nAcceptTime = args.m_accept_time; + const bool bypass_limits = args.m_bypass_limits; + const CAmount& nAbsurdFee = args.m_absurd_fee; + std::vector<COutPoint>& coins_to_uncache = args.m_coins_to_uncache; + + // Alias what we need out of ws + std::set<uint256>& setConflicts = ws.m_conflicts; + CTxMemPool::setEntries& allConflicting = ws.m_all_conflicting; + CTxMemPool::setEntries& setAncestors = ws.m_ancestors; + std::unique_ptr<CTxMemPoolEntry>& entry = ws.m_entry; + bool& fReplacementTransaction = ws.m_replacement_transaction; + CAmount& nModifiedFees = ws.m_modified_fees; + CAmount& nConflictingFees = ws.m_conflicting_fees; + size_t& nConflictingSize = ws.m_conflicting_size; + if (pfMissingInputs) { *pfMissingInputs = false; } @@ -461,7 +574,8 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool // Do not work on transactions that are too small. // A transaction with 1 segwit input and 1 P2WPHK output has non-witness size of 82 bytes. - // Transactions smaller than this are not relayed to reduce unnecessary malloc overhead. + // Transactions smaller than this are not relayed to mitigate CVE-2017-12842 by not relaying + // 64-byte transactions. if (::GetSerializeSize(tx, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) < MIN_STANDARD_TX_NONWITNESS_SIZE) return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_NONSTANDARD, "tx-size-small"); @@ -472,15 +586,14 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool return state.Invalid(ValidationInvalidReason::TX_PREMATURE_SPEND, false, REJECT_NONSTANDARD, "non-final"); // is it already in the memory pool? - if (pool.exists(hash)) { + if (m_pool.exists(hash)) { return state.Invalid(ValidationInvalidReason::TX_CONFLICT, false, REJECT_DUPLICATE, "txn-already-in-mempool"); } // Check for conflicts with in-memory transactions - std::set<uint256> setConflicts; for (const CTxIn &txin : tx.vin) { - const CTransaction* ptxConflicting = pool.GetConflictTx(txin.prevout); + const CTransaction* ptxConflicting = m_pool.GetConflictTx(txin.prevout); if (ptxConflicting) { if (!setConflicts.count(ptxConflicting->GetHash())) { @@ -514,353 +627,436 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool } } - { - CCoinsView dummy; - CCoinsViewCache view(&dummy); - - LockPoints lp; - CCoinsViewCache& coins_cache = ::ChainstateActive().CoinsTip(); - CCoinsViewMemPool viewMemPool(&coins_cache, pool); - view.SetBackend(viewMemPool); - - // do all inputs exist? - for (const CTxIn& txin : tx.vin) { - if (!coins_cache.HaveCoinInCache(txin.prevout)) { - coins_to_uncache.push_back(txin.prevout); - } + LockPoints lp; + m_view.SetBackend(m_viewmempool); - // Note: this call may add txin.prevout to the coins cache - // (CoinsTip().cacheCoins) by way of FetchCoin(). It should be removed - // later (via coins_to_uncache) if this tx turns out to be invalid. - if (!view.HaveCoin(txin.prevout)) { - // Are inputs missing because we already have the tx? - for (size_t out = 0; out < tx.vout.size(); out++) { - // Optimistically just do efficient check of cache for outputs - if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) { - return state.Invalid(ValidationInvalidReason::TX_CONFLICT, false, REJECT_DUPLICATE, "txn-already-known"); - } - } - // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet - if (pfMissingInputs) { - *pfMissingInputs = true; + CCoinsViewCache& coins_cache = ::ChainstateActive().CoinsTip(); + // do all inputs exist? + for (const CTxIn& txin : tx.vin) { + if (!coins_cache.HaveCoinInCache(txin.prevout)) { + coins_to_uncache.push_back(txin.prevout); + } + + // Note: this call may add txin.prevout to the coins cache + // (coins_cache.cacheCoins) by way of FetchCoin(). It should be removed + // later (via coins_to_uncache) if this tx turns out to be invalid. + if (!m_view.HaveCoin(txin.prevout)) { + // Are inputs missing because we already have the tx? + for (size_t out = 0; out < tx.vout.size(); out++) { + // Optimistically just do efficient check of cache for outputs + if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) { + return state.Invalid(ValidationInvalidReason::TX_CONFLICT, false, REJECT_DUPLICATE, "txn-already-known"); } - return false; // fMissingInputs and !state.IsInvalid() is used to detect this condition, don't set state.Invalid() } + // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet + if (pfMissingInputs) { + *pfMissingInputs = true; + } + return false; // fMissingInputs and !state.IsInvalid() is used to detect this condition, don't set state.Invalid() } + } - // Bring the best block into scope - view.GetBestBlock(); + // Bring the best block into scope + m_view.GetBestBlock(); - // we have all inputs cached now, so switch back to dummy, so we don't need to keep lock on mempool - view.SetBackend(dummy); + // we have all inputs cached now, so switch back to dummy (to protect + // against bugs where we pull more inputs from disk that miss being added + // to coins_to_uncache) + m_view.SetBackend(m_dummy); - // Only accept BIP68 sequence locked 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. - // Must keep pool.cs for this unless we change CheckSequenceLocks to take a - // CoinsViewCache instead of create its own - if (!CheckSequenceLocks(pool, tx, STANDARD_LOCKTIME_VERIFY_FLAGS, &lp)) - return state.Invalid(ValidationInvalidReason::TX_PREMATURE_SPEND, false, REJECT_NONSTANDARD, "non-BIP68-final"); + // Only accept BIP68 sequence locked 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. + // Must keep pool.cs for this unless we change CheckSequenceLocks to take a + // CoinsViewCache instead of create its own + if (!CheckSequenceLocks(m_pool, tx, STANDARD_LOCKTIME_VERIFY_FLAGS, &lp)) + return state.Invalid(ValidationInvalidReason::TX_PREMATURE_SPEND, false, REJECT_NONSTANDARD, "non-BIP68-final"); - CAmount nFees = 0; - if (!Consensus::CheckTxInputs(tx, state, view, GetSpendHeight(view), nFees)) { - return error("%s: Consensus::CheckTxInputs: %s, %s", __func__, tx.GetHash().ToString(), FormatStateMessage(state)); - } + CAmount nFees = 0; + if (!Consensus::CheckTxInputs(tx, state, m_view, GetSpendHeight(m_view), nFees)) { + return error("%s: Consensus::CheckTxInputs: %s, %s", __func__, tx.GetHash().ToString(), FormatStateMessage(state)); + } - // Check for non-standard pay-to-script-hash in inputs - if (fRequireStandard && !AreInputsStandard(tx, view)) - return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_NONSTANDARD, "bad-txns-nonstandard-inputs"); + // Check for non-standard pay-to-script-hash in inputs + if (fRequireStandard && !AreInputsStandard(tx, m_view)) + return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_NONSTANDARD, "bad-txns-nonstandard-inputs"); - // Check for non-standard witness in P2WSH - if (tx.HasWitness() && fRequireStandard && !IsWitnessStandard(tx, view)) - return state.Invalid(ValidationInvalidReason::TX_WITNESS_MUTATED, false, REJECT_NONSTANDARD, "bad-witness-nonstandard"); + // Check for non-standard witness in P2WSH + if (tx.HasWitness() && fRequireStandard && !IsWitnessStandard(tx, m_view)) + return state.Invalid(ValidationInvalidReason::TX_WITNESS_MUTATED, false, REJECT_NONSTANDARD, "bad-witness-nonstandard"); - int64_t nSigOpsCost = GetTransactionSigOpCost(tx, view, STANDARD_SCRIPT_VERIFY_FLAGS); + int64_t nSigOpsCost = GetTransactionSigOpCost(tx, m_view, STANDARD_SCRIPT_VERIFY_FLAGS); - // nModifiedFees includes any fee deltas from PrioritiseTransaction - CAmount nModifiedFees = nFees; - pool.ApplyDelta(hash, nModifiedFees); + // nModifiedFees includes any fee deltas from PrioritiseTransaction + nModifiedFees = nFees; + m_pool.ApplyDelta(hash, nModifiedFees); - // Keep track of transactions that spend a coinbase, which we re-scan - // during reorgs to ensure COINBASE_MATURITY is still met. - bool fSpendsCoinbase = false; - for (const CTxIn &txin : tx.vin) { - const Coin &coin = view.AccessCoin(txin.prevout); - if (coin.IsCoinBase()) { - fSpendsCoinbase = true; - break; - } + // Keep track of transactions that spend a coinbase, which we re-scan + // during reorgs to ensure COINBASE_MATURITY is still met. + bool fSpendsCoinbase = false; + for (const CTxIn &txin : tx.vin) { + const Coin &coin = m_view.AccessCoin(txin.prevout); + if (coin.IsCoinBase()) { + fSpendsCoinbase = true; + break; } + } - CTxMemPoolEntry entry(ptx, nFees, nAcceptTime, ::ChainActive().Height(), - fSpendsCoinbase, nSigOpsCost, lp); - unsigned int nSize = entry.GetTxSize(); + entry.reset(new CTxMemPoolEntry(ptx, nFees, nAcceptTime, ::ChainActive().Height(), + fSpendsCoinbase, nSigOpsCost, lp)); + unsigned int nSize = entry->GetTxSize(); - if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST) - return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_NONSTANDARD, "bad-txns-too-many-sigops", + if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST) + return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_NONSTANDARD, "bad-txns-too-many-sigops", strprintf("%d", nSigOpsCost)); - CAmount mempoolRejectFee = pool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFee(nSize); - if (!bypass_limits && mempoolRejectFee > 0 && nModifiedFees < mempoolRejectFee) { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "mempool min fee not met", strprintf("%d < %d", nModifiedFees, mempoolRejectFee)); - } - - // No transactions are allowed below minRelayTxFee except from disconnected blocks - if (!bypass_limits && nModifiedFees < ::minRelayTxFee.GetFee(nSize)) { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "min relay fee not met", strprintf("%d < %d", nModifiedFees, ::minRelayTxFee.GetFee(nSize))); - } + // No transactions are allowed below minRelayTxFee except from disconnected + // blocks + if (!bypass_limits && !CheckFeeRate(nSize, nModifiedFees, state)) return false; - if (nAbsurdFee && nFees > nAbsurdFee) - return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, + if (nAbsurdFee && nFees > nAbsurdFee) + return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_HIGHFEE, "absurdly-high-fee", strprintf("%d > %d", nFees, nAbsurdFee)); - // Calculate in-mempool ancestors, up to a limit. - CTxMemPool::setEntries setAncestors; - size_t nLimitAncestors = gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT); - size_t nLimitAncestorSize = gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT)*1000; - size_t nLimitDescendants = gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT); - size_t nLimitDescendantSize = gArgs.GetArg("-limitdescendantsize", DEFAULT_DESCENDANT_SIZE_LIMIT)*1000; - std::string errString; - if (!pool.CalculateMemPoolAncestors(entry, setAncestors, nLimitAncestors, nLimitAncestorSize, nLimitDescendants, nLimitDescendantSize, errString)) { - setAncestors.clear(); - // If CalculateMemPoolAncestors fails second time, we want the original error string. - std::string dummy_err_string; - // If the new transaction is relatively small (up to 40k weight) - // and has at most one ancestor (ie ancestor limit of 2, including - // the new transaction), allow it if its parent has exactly the - // descendant limit descendants. - // - // This allows protocols which rely on distrusting counterparties - // being able to broadcast descendants of an unconfirmed transaction - // to be secure by simply only having two immediately-spendable - // outputs - one for each counterparty. For more info on the uses for - // this, see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html - if (nSize > EXTRA_DESCENDANT_TX_SIZE_LIMIT || - !pool.CalculateMemPoolAncestors(entry, setAncestors, 2, nLimitAncestorSize, nLimitDescendants + 1, nLimitDescendantSize + EXTRA_DESCENDANT_TX_SIZE_LIMIT, dummy_err_string)) { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_NONSTANDARD, "too-long-mempool-chain", errString); - } - } - - // A transaction that spends outputs that would be replaced by it is invalid. Now - // that we have the set of all ancestors we can detect this - // pathological case by making sure setConflicts and setAncestors don't - // intersect. - for (CTxMemPool::txiter ancestorIt : setAncestors) + const CTxMemPool::setEntries setIterConflicting = m_pool.GetIterSet(setConflicts); + // Calculate in-mempool ancestors, up to a limit. + if (setConflicts.size() == 1) { + // In general, when we receive an RBF transaction with mempool conflicts, we want to know whether we + // would meet the chain limits after the conflicts have been removed. However, there isn't a practical + // way to do this short of calculating the ancestor and descendant sets with an overlay cache of + // changed mempool entries. Due to both implementation and runtime complexity concerns, this isn't + // very realistic, thus we only ensure a limited set of transactions are RBF'able despite mempool + // conflicts here. Importantly, we need to ensure that some transactions which were accepted using + // the below carve-out are able to be RBF'ed, without impacting the security the carve-out provides + // for off-chain contract systems (see link in the comment below). + // + // Specifically, the subset of RBF transactions which we allow despite chain limits are those which + // conflict directly with exactly one other transaction (but may evict children of said transaction), + // and which are not adding any new mempool dependencies. Note that the "no new mempool dependencies" + // check is accomplished later, so we don't bother doing anything about it here, but if BIP 125 is + // amended, we may need to move that check to here instead of removing it wholesale. + // + // Such transactions are clearly not merging any existing packages, so we are only concerned with + // ensuring that (a) no package is growing past the package size (not count) limits and (b) we are + // not allowing something to effectively use the (below) carve-out spot when it shouldn't be allowed + // to. + // + // To check these we first check if we meet the RBF criteria, above, and increment the descendant + // limits by the direct conflict and its descendants (as these are recalculated in + // CalculateMempoolAncestors by assuming the new transaction being added is a new descendant, with no + // removals, of each parent's existing dependant set). The ancestor count limits are unmodified (as + // the ancestor limits should be the same for both our new transaction and any conflicts). + // We don't bother incrementing m_limit_descendants by the full removal count as that limit never comes + // into force here (as we're only adding a single transaction). + assert(setIterConflicting.size() == 1); + CTxMemPool::txiter conflict = *setIterConflicting.begin(); + + m_limit_descendants += 1; + m_limit_descendant_size += conflict->GetSizeWithDescendants(); + } + + std::string errString; + if (!m_pool.CalculateMemPoolAncestors(*entry, setAncestors, m_limit_ancestors, m_limit_ancestor_size, m_limit_descendants, m_limit_descendant_size, errString)) { + setAncestors.clear(); + // If CalculateMemPoolAncestors fails second time, we want the original error string. + std::string dummy_err_string; + // Contracting/payment channels CPFP carve-out: + // If the new transaction is relatively small (up to 40k weight) + // and has at most one ancestor (ie ancestor limit of 2, including + // the new transaction), allow it if its parent has exactly the + // descendant limit descendants. + // + // This allows protocols which rely on distrusting counterparties + // being able to broadcast descendants of an unconfirmed transaction + // to be secure by simply only having two immediately-spendable + // outputs - one for each counterparty. For more info on the uses for + // this, see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html + if (nSize > EXTRA_DESCENDANT_TX_SIZE_LIMIT || + !m_pool.CalculateMemPoolAncestors(*entry, setAncestors, 2, m_limit_ancestor_size, m_limit_descendants + 1, m_limit_descendant_size + EXTRA_DESCENDANT_TX_SIZE_LIMIT, dummy_err_string)) { + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_NONSTANDARD, "too-long-mempool-chain", errString); + } + } + + // A transaction that spends outputs that would be replaced by it is invalid. Now + // that we have the set of all ancestors we can detect this + // pathological case by making sure setConflicts and setAncestors don't + // intersect. + for (CTxMemPool::txiter ancestorIt : setAncestors) + { + const uint256 &hashAncestor = ancestorIt->GetTx().GetHash(); + if (setConflicts.count(hashAncestor)) { - const uint256 &hashAncestor = ancestorIt->GetTx().GetHash(); - if (setConflicts.count(hashAncestor)) - { - return state.Invalid(ValidationInvalidReason::CONSENSUS, false, REJECT_INVALID, "bad-txns-spends-conflicting-tx", - strprintf("%s spends conflicting transaction %s", - hash.ToString(), - hashAncestor.ToString())); - } + return state.Invalid(ValidationInvalidReason::CONSENSUS, false, REJECT_INVALID, "bad-txns-spends-conflicting-tx", + strprintf("%s spends conflicting transaction %s", + hash.ToString(), + hashAncestor.ToString())); } + } - // Check if it's economically rational to mine this transaction rather - // than the ones it replaces. - CAmount nConflictingFees = 0; - size_t nConflictingSize = 0; - uint64_t nConflictingCount = 0; - CTxMemPool::setEntries allConflicting; - - // If we don't hold the lock allConflicting might be incomplete; the - // subsequent RemoveStaged() and addUnchecked() calls don't guarantee - // mempool consistency for us. - const bool fReplacementTransaction = setConflicts.size(); - if (fReplacementTransaction) - { - CFeeRate newFeeRate(nModifiedFees, nSize); - std::set<uint256> setConflictsParents; - const int maxDescendantsToVisit = 100; - const CTxMemPool::setEntries setIterConflicting = pool.GetIterSet(setConflicts); - for (const auto& mi : setIterConflicting) { - // Don't allow the replacement to reduce the feerate of the - // mempool. - // - // We usually don't want to accept replacements with lower - // feerates than what they replaced as that would lower the - // feerate of the next block. Requiring that the feerate always - // be increased is also an easy-to-reason about way to prevent - // DoS attacks via replacements. - // - // We only consider the feerates of transactions being directly - // replaced, not their indirect descendants. While that does - // mean high feerate children are ignored when deciding whether - // or not to replace, we do require the replacement to pay more - // overall fees too, mitigating most cases. - CFeeRate oldFeeRate(mi->GetModifiedFee(), mi->GetTxSize()); - if (newFeeRate <= oldFeeRate) - { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "insufficient fee", - strprintf("rejecting replacement %s; new feerate %s <= old feerate %s", - hash.ToString(), - newFeeRate.ToString(), - oldFeeRate.ToString())); - } - - for (const CTxIn &txin : mi->GetTx().vin) - { - setConflictsParents.insert(txin.prevout.hash); - } + // Check if it's economically rational to mine this transaction rather + // than the ones it replaces. + nConflictingFees = 0; + nConflictingSize = 0; + uint64_t nConflictingCount = 0; - nConflictingCount += mi->GetCountWithDescendants(); - } - // This potentially overestimates the number of actual descendants - // but we just want to be conservative to avoid doing too much - // work. - if (nConflictingCount <= maxDescendantsToVisit) { - // If not too many to replace, then calculate the set of - // transactions that would have to be evicted - for (CTxMemPool::txiter it : setIterConflicting) { - pool.CalculateDescendants(it, allConflicting); - } - for (CTxMemPool::txiter it : allConflicting) { - nConflictingFees += it->GetModifiedFee(); - nConflictingSize += it->GetTxSize(); - } - } else { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_NONSTANDARD, "too many potential replacements", - strprintf("rejecting replacement %s; too many potential replacements (%d > %d)\n", + // If we don't hold the lock allConflicting might be incomplete; the + // subsequent RemoveStaged() and addUnchecked() calls don't guarantee + // mempool consistency for us. + fReplacementTransaction = setConflicts.size(); + if (fReplacementTransaction) + { + CFeeRate newFeeRate(nModifiedFees, nSize); + std::set<uint256> setConflictsParents; + const int maxDescendantsToVisit = 100; + for (const auto& mi : setIterConflicting) { + // Don't allow the replacement to reduce the feerate of the + // mempool. + // + // We usually don't want to accept replacements with lower + // feerates than what they replaced as that would lower the + // feerate of the next block. Requiring that the feerate always + // be increased is also an easy-to-reason about way to prevent + // DoS attacks via replacements. + // + // We only consider the feerates of transactions being directly + // replaced, not their indirect descendants. While that does + // mean high feerate children are ignored when deciding whether + // or not to replace, we do require the replacement to pay more + // overall fees too, mitigating most cases. + CFeeRate oldFeeRate(mi->GetModifiedFee(), mi->GetTxSize()); + if (newFeeRate <= oldFeeRate) + { + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "insufficient fee", + strprintf("rejecting replacement %s; new feerate %s <= old feerate %s", hash.ToString(), - nConflictingCount, - maxDescendantsToVisit)); + newFeeRate.ToString(), + oldFeeRate.ToString())); } - for (unsigned int j = 0; j < tx.vin.size(); j++) + for (const CTxIn &txin : mi->GetTx().vin) { - // We don't want to accept replacements that require low - // feerate junk to be mined first. Ideally we'd keep track of - // the ancestor feerates and make the decision based on that, - // but for now requiring all new inputs to be confirmed works. - if (!setConflictsParents.count(tx.vin[j].prevout.hash)) - { - // Rather than check the UTXO set - potentially expensive - - // it's cheaper to just check if the new input refers to a - // tx that's in the mempool. - if (pool.exists(tx.vin[j].prevout.hash)) { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_NONSTANDARD, "replacement-adds-unconfirmed", - strprintf("replacement %s adds unconfirmed input, idx %d", - hash.ToString(), j)); - } - } + setConflictsParents.insert(txin.prevout.hash); } - // The replacement must pay greater fees than the transactions it - // replaces - if we did the bandwidth used by those conflicting - // transactions would not be paid for. - if (nModifiedFees < nConflictingFees) - { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "insufficient fee", - strprintf("rejecting replacement %s, less fees than conflicting txs; %s < %s", - hash.ToString(), FormatMoney(nModifiedFees), FormatMoney(nConflictingFees))); + nConflictingCount += mi->GetCountWithDescendants(); + } + // This potentially overestimates the number of actual descendants + // but we just want to be conservative to avoid doing too much + // work. + if (nConflictingCount <= maxDescendantsToVisit) { + // If not too many to replace, then calculate the set of + // transactions that would have to be evicted + for (CTxMemPool::txiter it : setIterConflicting) { + m_pool.CalculateDescendants(it, allConflicting); } - - // Finally in addition to paying more fees than the conflicts the - // new transaction must pay for its own bandwidth. - CAmount nDeltaFees = nModifiedFees - nConflictingFees; - if (nDeltaFees < ::incrementalRelayFee.GetFee(nSize)) - { - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "insufficient fee", - strprintf("rejecting replacement %s, not enough additional fees to relay; %s < %s", - hash.ToString(), - FormatMoney(nDeltaFees), - FormatMoney(::incrementalRelayFee.GetFee(nSize)))); + for (CTxMemPool::txiter it : allConflicting) { + nConflictingFees += it->GetModifiedFee(); + nConflictingSize += it->GetTxSize(); } + } else { + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_NONSTANDARD, "too many potential replacements", + strprintf("rejecting replacement %s; too many potential replacements (%d > %d)\n", + hash.ToString(), + nConflictingCount, + maxDescendantsToVisit)); } - constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS; - - // Check against previous transactions - // The first loop above does all the inexpensive checks. - // Only if ALL inputs pass do we perform expensive ECDSA signature checks. - // Helps prevent CPU exhaustion denial-of-service attacks. - PrecomputedTransactionData txdata(tx); - if (!CheckInputs(tx, state, view, 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, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, txdata) && - !CheckInputs(tx, stateDummy, view, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, txdata)) { - // Only the witness is missing, so the transaction itself may be fine. - state.Invalid(ValidationInvalidReason::TX_WITNESS_MUTATED, false, - state.GetRejectCode(), state.GetRejectReason(), state.GetDebugMessage()); + for (unsigned int j = 0; j < tx.vin.size(); j++) + { + // We don't want to accept replacements that require low + // feerate junk to be mined first. Ideally we'd keep track of + // the ancestor feerates and make the decision based on that, + // but for now requiring all new inputs to be confirmed works. + // + // Note that if you relax this to make RBF a little more useful, + // this may break the CalculateMempoolAncestors RBF relaxation, + // above. See the comment above the first CalculateMempoolAncestors + // call for more info. + if (!setConflictsParents.count(tx.vin[j].prevout.hash)) + { + // Rather than check the UTXO set - potentially expensive - + // it's cheaper to just check if the new input refers to a + // tx that's in the mempool. + if (m_pool.exists(tx.vin[j].prevout.hash)) { + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_NONSTANDARD, "replacement-adds-unconfirmed", + strprintf("replacement %s adds unconfirmed input, idx %d", + hash.ToString(), j)); + } } - assert(IsTransactionReason(state.GetReason())); - return false; // state filled in by CheckInputs - } - - // 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 (using TestBlockValidity), however allowing such - // transactions into the mempool can be exploited as a DoS attack. - unsigned int currentBlockScriptVerifyFlags = GetBlockScriptFlags(::ChainActive().Tip(), chainparams.GetConsensus()); - if (!CheckInputsFromMempoolAndCache(tx, state, view, pool, currentBlockScriptVerifyFlags, true, txdata)) { - return error("%s: BUG! PLEASE REPORT THIS! CheckInputs failed against latest-block but not STANDARD flags %s, %s", - __func__, hash.ToString(), FormatStateMessage(state)); } - if (test_accept) { - // Tx was accepted, but not added - return true; + // The replacement must pay greater fees than the transactions it + // replaces - if we did the bandwidth used by those conflicting + // transactions would not be paid for. + if (nModifiedFees < nConflictingFees) + { + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "insufficient fee", + strprintf("rejecting replacement %s, less fees than conflicting txs; %s < %s", + hash.ToString(), FormatMoney(nModifiedFees), FormatMoney(nConflictingFees))); } - // Remove conflicting transactions from the mempool - for (CTxMemPool::txiter it : allConflicting) + // Finally in addition to paying more fees than the conflicts the + // new transaction must pay for its own bandwidth. + CAmount nDeltaFees = nModifiedFees - nConflictingFees; + if (nDeltaFees < ::incrementalRelayFee.GetFee(nSize)) { - LogPrint(BCLog::MEMPOOL, "replacing tx %s with %s for %s BTC additional fees, %d delta bytes\n", - it->GetTx().GetHash().ToString(), - hash.ToString(), - FormatMoney(nModifiedFees - nConflictingFees), - (int)nSize - (int)nConflictingSize); - if (plTxnReplaced) - plTxnReplaced->push_back(it->GetSharedTx()); + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "insufficient fee", + strprintf("rejecting replacement %s, not enough additional fees to relay; %s < %s", + hash.ToString(), + FormatMoney(nDeltaFees), + FormatMoney(::incrementalRelayFee.GetFee(nSize)))); } - pool.RemoveStaged(allConflicting, false, MemPoolRemovalReason::REPLACED); + } + return true; +} + +bool MemPoolAccept::PolicyScriptChecks(ATMPArgs& args, Workspace& ws, PrecomputedTransactionData& txdata) +{ + const CTransaction& tx = *ws.m_ptx; - // This transaction should only count for fee estimation if: - // - it isn't a BIP 125 replacement transaction (may not be widely supported) - // - it's not being re-added during a reorg which bypasses typical mempool fee limits - // - the node is not behind - // - the transaction is not dependent on any other transactions in the mempool - bool validForFeeEstimation = !fReplacementTransaction && !bypass_limits && IsCurrentForFeeEstimation() && pool.HasNoInputsOf(tx); + CValidationState &state = args.m_state; - // Store transaction in memory - pool.addUnchecked(entry, setAncestors, validForFeeEstimation); + constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS; - // trim mempool and check if tx was trimmed - if (!bypass_limits) { - LimitMempoolSize(pool, gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60); - if (!pool.exists(hash)) - return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "mempool full"); + // Check against previous transactions + // This is done last to help prevent CPU exhaustion denial-of-service attacks. + if (!CheckInputs(tx, state, m_view, 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, m_view, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, txdata) && + !CheckInputs(tx, stateDummy, m_view, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, txdata)) { + // Only the witness is missing, so the transaction itself may be fine. + state.Invalid(ValidationInvalidReason::TX_WITNESS_MUTATED, false, + state.GetRejectCode(), state.GetRejectReason(), state.GetDebugMessage()); } + assert(IsTransactionReason(state.GetReason())); + return false; // state filled in by CheckInputs } + return true; +} + +bool MemPoolAccept::ConsensusScriptChecks(ATMPArgs& args, Workspace& ws, PrecomputedTransactionData& txdata) +{ + const CTransaction& tx = *ws.m_ptx; + const uint256& hash = ws.m_hash; + + CValidationState &state = args.m_state; + const CChainParams& chainparams = args.m_chainparams; + + // 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 (using TestBlockValidity), however allowing such + // transactions into the mempool can be exploited as a DoS attack. + unsigned int currentBlockScriptVerifyFlags = GetBlockScriptFlags(::ChainActive().Tip(), chainparams.GetConsensus()); + if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags, true, txdata)) { + return error("%s: BUG! PLEASE REPORT THIS! CheckInputs failed against latest-block but not STANDARD flags %s, %s", + __func__, hash.ToString(), FormatStateMessage(state)); + } + + return true; +} + +bool MemPoolAccept::Finalize(ATMPArgs& args, Workspace& ws) +{ + const CTransaction& tx = *ws.m_ptx; + const uint256& hash = ws.m_hash; + CValidationState &state = args.m_state; + const bool bypass_limits = args.m_bypass_limits; + + CTxMemPool::setEntries& allConflicting = ws.m_all_conflicting; + CTxMemPool::setEntries& setAncestors = ws.m_ancestors; + const CAmount& nModifiedFees = ws.m_modified_fees; + const CAmount& nConflictingFees = ws.m_conflicting_fees; + const size_t& nConflictingSize = ws.m_conflicting_size; + const bool fReplacementTransaction = ws.m_replacement_transaction; + std::unique_ptr<CTxMemPoolEntry>& entry = ws.m_entry; + + // Remove conflicting transactions from the mempool + for (CTxMemPool::txiter it : allConflicting) + { + LogPrint(BCLog::MEMPOOL, "replacing tx %s with %s for %s BTC additional fees, %d delta bytes\n", + it->GetTx().GetHash().ToString(), + hash.ToString(), + FormatMoney(nModifiedFees - nConflictingFees), + (int)entry->GetTxSize() - (int)nConflictingSize); + if (args.m_replaced_transactions) + args.m_replaced_transactions->push_back(it->GetSharedTx()); + } + m_pool.RemoveStaged(allConflicting, false, MemPoolRemovalReason::REPLACED); + + // This transaction should only count for fee estimation if: + // - it isn't a BIP 125 replacement transaction (may not be widely supported) + // - it's not being re-added during a reorg which bypasses typical mempool fee limits + // - the node is not behind + // - the transaction is not dependent on any other transactions in the mempool + bool validForFeeEstimation = !fReplacementTransaction && !bypass_limits && IsCurrentForFeeEstimation() && m_pool.HasNoInputsOf(tx); + + // Store transaction in memory + m_pool.addUnchecked(*entry, setAncestors, validForFeeEstimation); + + // trim mempool and check if tx was trimmed + if (!bypass_limits) { + LimitMempoolSize(m_pool, gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60); + if (!m_pool.exists(hash)) + return state.Invalid(ValidationInvalidReason::TX_MEMPOOL_POLICY, false, REJECT_INSUFFICIENTFEE, "mempool full"); + } + return true; +} + +bool MemPoolAccept::AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) +{ + AssertLockHeld(cs_main); + LOCK(m_pool.cs); // mempool "read lock" (held through GetMainSignals().TransactionAddedToMempool()) + + Workspace workspace(ptx); + + if (!PreChecks(args, workspace)) return false; + + // Only compute the precomputed transaction data if we need to verify + // scripts (ie, other policy checks pass). We perform the inexpensive + // checks first and avoid hashing and signature verification unless those + // checks pass, to mitigate CPU exhaustion denial-of-service attacks. + PrecomputedTransactionData txdata(*ptx); + + if (!PolicyScriptChecks(args, workspace, txdata)) return false; + + if (!ConsensusScriptChecks(args, workspace, txdata)) return false; + + // Tx was accepted, but not added + if (args.m_test_accept) return true; + + if (!Finalize(args, workspace)) return false; + GetMainSignals().TransactionAddedToMempool(ptx); return true; } +} // anon namespace + /** (try to) add transaction to memory pool with a specified acceptance time **/ static bool AcceptToMemoryPoolWithTime(const CChainParams& chainparams, CTxMemPool& pool, CValidationState &state, const CTransactionRef &tx, bool* pfMissingInputs, int64_t nAcceptTime, std::list<CTransactionRef>* plTxnReplaced, bool bypass_limits, const CAmount nAbsurdFee, bool test_accept) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { std::vector<COutPoint> coins_to_uncache; - bool res = AcceptToMemoryPoolWorker(chainparams, pool, state, tx, pfMissingInputs, nAcceptTime, plTxnReplaced, bypass_limits, nAbsurdFee, coins_to_uncache, test_accept); + MemPoolAccept::ATMPArgs args { chainparams, state, pfMissingInputs, nAcceptTime, plTxnReplaced, bypass_limits, nAbsurdFee, coins_to_uncache, test_accept }; + bool res = MemPoolAccept(pool).AcceptSingleTransaction(tx, args); if (!res) { // Remove coins that were not present in the coins cache before calling ATMPW; // this is to prevent memory DoS in case we receive a large number of @@ -1787,7 +1983,7 @@ bool CChainState::ConnectBlock(const CBlock& block, CValidationState& state, CBl // If such overwrites are allowed, coinbases and transactions depending upon those // can be duplicated to remove the ability to spend the first instance -- even after // being sent to another address. - // See BIP30 and http://r6.ca/blog/20120206T005236Z.html for more information. + // See BIP30, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html for more information. // This logic is not necessary for memory pool transactions, as AcceptToMemoryPool // already refuses previously-known transaction ids entirely. // This rule was originally applied to all blocks with a timestamp after March 15, 2012, 0:00 UTC. @@ -2199,14 +2395,12 @@ void static UpdateTip(const CBlockIndex* pindexNew, const CChainParams& chainPar if (nUpgraded > 0) AppendWarning(warningMessages, strprintf(_("%d of last 100 blocks have unexpected version").translated, nUpgraded)); } - LogPrintf("%s: new best=%s height=%d version=0x%08x log2_work=%.8g tx=%lu date='%s' progress=%f cache=%.1fMiB(%utxo)", __func__, /* Continued */ + LogPrintf("%s: new best=%s height=%d version=0x%08x log2_work=%.8g tx=%lu date='%s' progress=%f cache=%.1fMiB(%utxo)%s\n", __func__, pindexNew->GetBlockHash().ToString(), pindexNew->nHeight, pindexNew->nVersion, log(pindexNew->nChainWork.getdouble())/log(2.0), (unsigned long)pindexNew->nChainTx, FormatISO8601DateTime(pindexNew->GetBlockTime()), - GuessVerificationProgress(chainParams.TxData(), pindexNew), ::ChainstateActive().CoinsTip().DynamicMemoryUsage() * (1.0 / (1<<20)), ::ChainstateActive().CoinsTip().GetCacheSize()); - if (!warningMessages.empty()) - LogPrintf(" warning='%s'", warningMessages); /* Continued */ - LogPrintf("\n"); + GuessVerificationProgress(chainParams.TxData(), pindexNew), ::ChainstateActive().CoinsTip().DynamicMemoryUsage() * (1.0 / (1<<20)), ::ChainstateActive().CoinsTip().GetCacheSize(), + !warningMessages.empty() ? strprintf(" warning='%s'", warningMessages) : ""); } @@ -2469,6 +2663,8 @@ void CChainState::PruneBlockIndexCandidates() { /** * Try to make some progress towards making pindexMostWork the active block. * pblock is either nullptr or a pointer to a CBlock corresponding to pindexMostWork. + * + * @returns true unless a system error occurred */ bool CChainState::ActivateBestChainStep(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) { @@ -2588,15 +2784,6 @@ static void LimitValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main) { } } -/** - * Make the best chain active, in multiple steps. The result is either failure - * or an activated best chain. pblock is either nullptr or a pointer to a block - * that is already loaded (to avoid loading it again from disk). - * - * ActivateBestChain is split into steps (see ActivateBestChainStep) so that - * we avoid holding cs_main for an extended period of time; the length of this - * call may be quite long during reindexing or a substantial reorg. - */ bool CChainState::ActivateBestChain(CValidationState &state, const CChainParams& chainparams, std::shared_ptr<const CBlock> pblock) { // Note that while we're often called here from ProcessNewBlock, this is // far from a guarantee. Things in the P2P/RPC will often end up calling @@ -2644,8 +2831,10 @@ bool CChainState::ActivateBestChain(CValidationState &state, const CChainParams& bool fInvalidFound = false; std::shared_ptr<const CBlock> nullBlockPtr; - if (!ActivateBestChainStep(state, chainparams, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace)) + if (!ActivateBestChainStep(state, chainparams, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace)) { + // A system error occurred return false; + } blocks_connected = true; if (fInvalidFound) { @@ -3066,6 +3255,7 @@ bool CheckBlock(const CBlock& block, CValidationState& state, const Consensus::P return state.Invalid(ValidationInvalidReason::CONSENSUS, false, REJECT_INVALID, "bad-cb-multiple", "more than one coinbase"); // Check transactions + // Must check for duplicate inputs (see CVE-2018-17144) for (const auto& tx : block.vtx) if (!CheckTransaction(*tx, state, true)) return state.Invalid(state.GetReason(), false, state.GetRejectCode(), state.GetRejectReason(), @@ -3091,9 +3281,7 @@ bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& pa return (height >= params.SegwitHeight); } -// Compute at which vout of the block's coinbase transaction the witness -// commitment occurs, or -1 if not found. -static int GetWitnessCommitmentIndex(const CBlock& block) +int GetWitnessCommitmentIndex(const CBlock& block) { int commitpos = -1; if (!block.vtx.empty()) { @@ -3399,7 +3587,6 @@ bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, CValidatio } } if (NotifyHeaderTip()) { - LOCK(cs_main); if (::ChainstateActive().IsInitialBlockDownload() && ppindex && *ppindex) { LogPrintf("Synchronizing blockheaders, height: %d (~%.2f%%)\n", (*ppindex)->nHeight, 100.0/((*ppindex)->nHeight+(GetAdjustedTime() - (*ppindex)->GetBlockTime()) / Params().GetConsensus().nPowTargetSpacing) * (*ppindex)->nHeight); } @@ -3899,28 +4086,31 @@ bool static LoadBlockIndexDB(const CChainParams& chainparams) EXCLUSIVE_LOCKS_RE return true; } -bool LoadChainTip(const CChainParams& chainparams) +bool CChainState::LoadChainTip(const CChainParams& chainparams) { AssertLockHeld(cs_main); - const CCoinsViewCache& coins_cache = ::ChainstateActive().CoinsTip(); + const CCoinsViewCache& coins_cache = CoinsTip(); assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty + const CBlockIndex* tip = m_chain.Tip(); - if (::ChainActive().Tip() && - ::ChainActive().Tip()->GetBlockHash() == coins_cache.GetBestBlock()) return true; + if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) { + return true; + } // Load pointer to end of best chain CBlockIndex* pindex = LookupBlockIndex(coins_cache.GetBestBlock()); if (!pindex) { return false; } - ::ChainActive().SetTip(pindex); - - ::ChainstateActive().PruneBlockIndexCandidates(); + m_chain.SetTip(pindex); + PruneBlockIndexCandidates(); + tip = m_chain.Tip(); LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n", - ::ChainActive().Tip()->GetBlockHash().ToString(), ::ChainActive().Height(), - FormatISO8601DateTime(::ChainActive().Tip()->GetBlockTime()), - GuessVerificationProgress(chainparams.TxData(), ::ChainActive().Tip())); + tip->GetBlockHash().ToString(), + m_chain.Height(), + FormatISO8601DateTime(tip->GetBlockTime()), + GuessVerificationProgress(chainparams.TxData(), tip)); return true; } @@ -4055,13 +4245,14 @@ bool CChainState::RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& i return true; } -bool CChainState::ReplayBlocks(const CChainParams& params, CCoinsView* view) +bool CChainState::ReplayBlocks(const CChainParams& params) { LOCK(cs_main); - CCoinsViewCache cache(view); + CCoinsView& db = this->CoinsDB(); + CCoinsViewCache cache(&db); - std::vector<uint256> hashHeads = view->GetHeadBlocks(); + std::vector<uint256> hashHeads = db.GetHeadBlocks(); if (hashHeads.empty()) return true; // We're already in a consistent state. if (hashHeads.size() != 2) return error("ReplayBlocks(): unknown inconsistent state"); @@ -4121,10 +4312,6 @@ bool CChainState::ReplayBlocks(const CChainParams& params, CCoinsView* view) return true; } -bool ReplayBlocks(const CChainParams& params, CCoinsView* view) { - return ::ChainstateActive().ReplayBlocks(params, view); -} - //! Helper for CChainState::RewindBlockIndex void CChainState::EraseBlockData(CBlockIndex* index) { |