diff options
Diffstat (limited to 'src/main.cpp')
-rw-r--r-- | src/main.cpp | 267 |
1 files changed, 102 insertions, 165 deletions
diff --git a/src/main.cpp b/src/main.cpp index 4bf5883692..79cc606856 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -11,17 +11,27 @@ #include "chainparams.h" #include "checkpoints.h" #include "checkqueue.h" +#include "consensus/consensus.h" #include "consensus/validation.h" +#include "hash.h" #include "init.h" #include "merkleblock.h" #include "net.h" +#include "policy/policy.h" #include "pow.h" +#include "primitives/block.h" +#include "primitives/transaction.h" +#include "script/script.h" +#include "script/sigcache.h" +#include "script/standard.h" +#include "tinyformat.h" #include "txdb.h" #include "txmempool.h" #include "ui_interface.h" #include "undo.h" #include "util.h" #include "utilmoneystr.h" +#include "utilstrencodings.h" #include "validationinterface.h" #include <sstream> @@ -57,6 +67,7 @@ bool fTxIndex = false; bool fHavePruned = false; bool fPruneMode = false; bool fIsBareMultisigStd = true; +bool fRequireStandard = true; bool fCheckBlockIndex = false; bool fCheckpointsEnabled = true; size_t nCoinCacheUsage = 5000 * 300; @@ -72,9 +83,9 @@ struct COrphanTx { CTransaction tx; NodeId fromPeer; }; -map<uint256, COrphanTx> mapOrphanTransactions; -map<uint256, set<uint256> > mapOrphanTransactionsByPrev; -void EraseOrphansFor(NodeId peer); +map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(cs_main);; +map<uint256, set<uint256> > mapOrphanTransactionsByPrev GUARDED_BY(cs_main);; +void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main); /** * Returns true if there are nRequired or more blocks of minVersion or above @@ -151,6 +162,29 @@ namespace { */ map<uint256, NodeId> mapBlockSource; + /** + * Filter for transactions that were recently rejected by + * AcceptToMemoryPool. These are not rerequested until the chain tip + * changes, at which point the entire filter is reset. Protected by + * cs_main. + * + * Without this filter we'd be re-requesting txs from each of our peers, + * increasing bandwidth consumption considerably. For instance, with 100 + * peers, half of which relay a tx we don't accept, that might be a 50x + * bandwidth increase. A flooding attacker attempting to roll-over the + * filter using minimum-sized, 60byte, transactions might manage to send + * 1000/sec if we have fast peers, so we pick 120,000 to give our peers a + * two minute window to send invs to us. + * + * Decreasing the false positive rate is fairly cheap, so we pick one in a + * million to make it highly unlikely for users to have issues with this + * filter. + * + * Memory used: 1.7MB + */ + boost::scoped_ptr<CRollingBloomFilter> recentRejects; + uint256 hashRecentRejectsChainTip; + /** Blocks that are in flight, and that are in the queue to be downloaded. Protected by cs_main. */ struct QueuedBlock { uint256 hash; @@ -524,7 +558,7 @@ CBlockTreeDB *pblocktree = NULL; // mapOrphanTransactions // -bool AddOrphanTx(const CTransaction& tx, NodeId peer) +bool AddOrphanTx(const CTransaction& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { uint256 hash = tx.GetHash(); if (mapOrphanTransactions.count(hash)) @@ -554,7 +588,7 @@ bool AddOrphanTx(const CTransaction& tx, NodeId peer) return true; } -void static EraseOrphanTx(uint256 hash) +void static EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.find(hash); if (it == mapOrphanTransactions.end()) @@ -588,7 +622,7 @@ void EraseOrphansFor(NodeId peer) } -unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans) +unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { unsigned int nEvicted = 0; while (mapOrphanTransactions.size() > nMaxOrphans) @@ -604,76 +638,6 @@ unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans) return nEvicted; } - - - - - - -bool IsStandardTx(const CTransaction& tx, string& reason) -{ - if (tx.nVersion > CTransaction::CURRENT_VERSION || tx.nVersion < 1) { - reason = "version"; - return false; - } - - // Extremely large transactions with lots of inputs can cost the network - // almost as much to process as they cost the sender in fees, because - // computing signature hashes is O(ninputs*txsize). Limiting transactions - // to MAX_STANDARD_TX_SIZE mitigates CPU exhaustion attacks. - unsigned int sz = tx.GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION); - if (sz >= MAX_STANDARD_TX_SIZE) { - reason = "tx-size"; - return false; - } - - BOOST_FOREACH(const CTxIn& txin, tx.vin) - { - // Biggest 'standard' txin is a 15-of-15 P2SH multisig with compressed - // keys. (remember the 520 byte limit on redeemScript size) That works - // out to a (15*(33+1))+3=513 byte redeemScript, 513+1+15*(73+1)+3=1627 - // bytes of scriptSig, which we round off to 1650 bytes for some minor - // future-proofing. That's also enough to spend a 20-of-20 - // CHECKMULTISIG scriptPubKey, though such a scriptPubKey is not - // considered standard) - if (txin.scriptSig.size() > 1650) { - reason = "scriptsig-size"; - return false; - } - if (!txin.scriptSig.IsPushOnly()) { - reason = "scriptsig-not-pushonly"; - return false; - } - } - - unsigned int nDataOut = 0; - txnouttype whichType; - BOOST_FOREACH(const CTxOut& txout, tx.vout) { - if (!::IsStandard(txout.scriptPubKey, whichType)) { - reason = "scriptpubkey"; - return false; - } - - if (whichType == TX_NULL_DATA) - nDataOut++; - else if ((whichType == TX_MULTISIG) && (!fIsBareMultisigStd)) { - reason = "bare-multisig"; - return false; - } else if (txout.IsDust(::minRelayTxFee)) { - reason = "dust"; - return false; - } - } - - // only one OP_RETURN txout is permitted - if (nDataOut > 1) { - reason = "multi-op-return"; - return false; - } - - return true; -} - bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime) { if (tx.nLockTime == 0) @@ -692,74 +656,6 @@ bool CheckFinalTx(const CTransaction &tx) return IsFinalTx(tx, chainActive.Height() + 1, GetAdjustedTime()); } -/** - * Check transaction inputs to mitigate two - * potential denial-of-service attacks: - * - * 1. scriptSigs with extra data stuffed into them, - * not consumed by scriptPubKey (or P2SH script) - * 2. P2SH scripts with a crazy number of expensive - * CHECKSIG/CHECKMULTISIG operations - */ -bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs) -{ - if (tx.IsCoinBase()) - return true; // Coinbases don't use vin normally - - for (unsigned int i = 0; i < tx.vin.size(); i++) - { - const CTxOut& prev = mapInputs.GetOutputFor(tx.vin[i]); - - vector<vector<unsigned char> > vSolutions; - txnouttype whichType; - // get the scriptPubKey corresponding to this input: - const CScript& prevScript = prev.scriptPubKey; - if (!Solver(prevScript, whichType, vSolutions)) - return false; - int nArgsExpected = ScriptSigArgsExpected(whichType, vSolutions); - if (nArgsExpected < 0) - return false; - - // Transactions with extra stuff in their scriptSigs are - // non-standard. Note that this EvalScript() call will - // be quick, because if there are any operations - // beside "push data" in the scriptSig - // IsStandardTx() will have already returned false - // and this method isn't called. - vector<vector<unsigned char> > stack; - if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE, BaseSignatureChecker())) - return false; - - if (whichType == TX_SCRIPTHASH) - { - if (stack.empty()) - return false; - CScript subscript(stack.back().begin(), stack.back().end()); - vector<vector<unsigned char> > vSolutions2; - txnouttype whichType2; - if (Solver(subscript, whichType2, vSolutions2)) - { - int tmpExpected = ScriptSigArgsExpected(whichType2, vSolutions2); - if (tmpExpected < 0) - return false; - nArgsExpected += tmpExpected; - } - else - { - // Any other Script with less than 15 sigops OK: - unsigned int sigops = subscript.GetSigOpCount(true); - // ... extra data left on the stack after execution is OK, too: - return (sigops <= MAX_P2SH_SIGOPS); - } - } - - if (stack.size() != (unsigned int)nArgsExpected) - return false; - } - - return true; -} - unsigned int GetLegacySigOpCount(const CTransaction& tx) { unsigned int nSigOps = 0; @@ -900,7 +796,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa // Rather not work on nonstandard transactions (unless -testnet/-regtest) string reason; - if (Params().RequireStandard() && !IsStandardTx(tx, reason)) + if (fRequireStandard && !IsStandardTx(tx, reason)) return state.DoS(0, error("AcceptToMemoryPool: nonstandard transaction: %s", reason), REJECT_NONSTANDARD, reason); @@ -971,7 +867,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa } // Check for non-standard pay-to-script-hash in inputs - if (Params().RequireStandard() && !AreInputsStandard(tx, view)) + if (fRequireStandard && !AreInputsStandard(tx, view)) return error("AcceptToMemoryPool: nonstandard transaction input"); // Check that the transaction doesn't have an excessive number of @@ -2196,7 +2092,6 @@ bool static ConnectTip(CValidationState &state, CBlockIndex *pindexNew, CBlock * LogPrint("bench", " - Load block from disk: %.2fms [%.2fs]\n", (nTime2 - nTime1) * 0.001, nTimeReadFromDisk * 0.000001); { CCoinsViewCache view(pcoinsTip); - CInv inv(MSG_BLOCK, pindexNew->GetBlockHash()); bool rv = ConnectBlock(*pblock, state, pindexNew, view); GetMainSignals().BlockChecked(*pblock, state); if (!rv) { @@ -2204,7 +2099,7 @@ bool static ConnectTip(CValidationState &state, CBlockIndex *pindexNew, CBlock * InvalidBlockFound(pindexNew, state); return error("ConnectTip(): ConnectBlock %s failed", pindexNew->GetBlockHash().ToString()); } - mapBlockSource.erase(inv.hash); + mapBlockSource.erase(pindexNew->GetBlockHash()); nTime3 = GetTimeMicros(); nTimeConnectTotal += nTime3 - nTime2; LogPrint("bench", " - Connect total: %.2fms [%.2fs]\n", (nTime3 - nTime2) * 0.001, nTimeConnectTotal * 0.000001); assert(view.Flush()); @@ -2864,9 +2759,15 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex, // Try to process all requested blocks that we don't have, but only // process an unrequested block if it's new and has enough work to - // advance our tip. + // advance our tip, and isn't too many blocks ahead. bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA; bool fHasMoreWork = (chainActive.Tip() ? pindex->nChainWork > chainActive.Tip()->nChainWork : true); + // Blocks that are too out-of-order needlessly limit the effectiveness of + // pruning, because pruning will not delete block files that contain any + // blocks which are too close in height to the tip. Apply this test + // regardless of whether pruning is enabled; it should generally be safe to + // not process unrequested blocks. + bool fTooFarAhead = (pindex->nHeight > int(chainActive.Height() + MIN_BLOCKS_TO_KEEP)); // TODO: deal better with return value and error conditions for duplicate // and unrequested blocks. @@ -2874,6 +2775,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex, if (!fRequested) { // If we didn't ask for it: if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned if (!fHasMoreWork) return true; // Don't process less-work chains + if (fTooFarAhead) return true; // Block height is too high } if ((!CheckBlock(block, state)) || !ContextualCheckBlock(block, state, pindex->pprev)) { @@ -3371,6 +3273,7 @@ void UnloadBlockIndex() setDirtyBlockIndex.clear(); setDirtyFileInfo.clear(); mapNodeState.clear(); + recentRejects.reset(NULL); BOOST_FOREACH(BlockMap::value_type& entry, mapBlockIndex) { delete entry.second; @@ -3391,6 +3294,10 @@ bool LoadBlockIndex() bool InitBlockIndex() { const CChainParams& chainparams = Params(); LOCK(cs_main); + + // Initialize global variables that cannot be constructed at startup. + recentRejects.reset(new CRollingBloomFilter(120000, 0.000001)); + // Check whether we're already initialized if (chainActive.Genesis() != NULL) return true; @@ -3521,7 +3428,7 @@ bool LoadExternalBlockFile(FILE* fileIn, CDiskBlockPos *dbp) } } } catch (const std::exception& e) { - LogPrintf("%s: Deserialize or I/O error - %s", __func__, e.what()); + LogPrintf("%s: Deserialize or I/O error - %s\n", __func__, e.what()); } } } catch (const std::runtime_error& e) { @@ -3787,16 +3694,27 @@ std::string GetWarnings(const std::string& strFor) // -bool static AlreadyHave(const CInv& inv) +bool static AlreadyHave(const CInv& inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { switch (inv.type) { case MSG_TX: { - bool txInMap = false; - txInMap = mempool.exists(inv.hash); - return txInMap || mapOrphanTransactions.count(inv.hash) || - pcoinsTip->HaveCoins(inv.hash); + assert(recentRejects); + if (chainActive.Tip()->GetBlockHash() != hashRecentRejectsChainTip) + { + // If the chain tip has changed previously rejected transactions + // might be now valid, e.g. due to a nLockTime'd tx becoming valid, + // or a double-spend. Reset the rejects filter and give those + // txs a second chance. + hashRecentRejectsChainTip = chainActive.Tip()->GetBlockHash(); + recentRejects->reset(); + } + + return recentRejects->contains(inv.hash) || + mempool.exists(inv.hash) || + mapOrphanTransactions.count(inv.hash) || + pcoinsTip->HaveCoins(inv.hash); } case MSG_BLOCK: return mapBlockIndex.count(inv.hash); @@ -3982,7 +3900,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, if (!vRecv.empty()) vRecv >> addrFrom >> nNonce; if (!vRecv.empty()) { - vRecv >> LIMITED_STRING(pfrom->strSubVer, 256); + vRecv >> LIMITED_STRING(pfrom->strSubVer, MAX_SUBVERSION_LENGTH); pfrom->cleanSubVer = SanitizeString(pfrom->strSubVer); } if (!vRecv.empty()) @@ -4396,6 +4314,8 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, // Probably non-standard or insufficient fee/priority LogPrint("mempool", " removed orphan tx %s\n", orphanHash.ToString()); vEraseQueue.push_back(orphanHash); + assert(recentRejects); + recentRejects->insert(orphanHash); } mempool.check(pcoinsTip); } @@ -4413,11 +4333,24 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, unsigned int nEvicted = LimitOrphanTxSize(nMaxOrphanTx); if (nEvicted > 0) LogPrint("mempool", "mapOrphan overflow, removed %u tx\n", nEvicted); - } else if (pfrom->fWhitelisted) { - // Always relay transactions received from whitelisted peers, even - // if they are already in the mempool (allowing the node to function - // as a gateway for nodes hidden behind it). - RelayTransaction(tx); + } else { + // AcceptToMemoryPool() returned false, possibly because the tx is + // already in the mempool; if the tx isn't in the mempool that + // means it was rejected and we shouldn't ask for it again. + if (!mempool.exists(tx.GetHash())) { + assert(recentRejects); + recentRejects->insert(tx.GetHash()); + } + if (pfrom->fWhitelisted) { + // Always relay transactions received from whitelisted peers, even + // if they were rejected from the mempool, allowing the node to + // function as a gateway for nodes hidden behind it. + // + // FIXME: This includes invalid transactions, which means a + // whitelisted peer could get us banned! We may want to change + // that. + RelayTransaction(tx); + } } int nDoS = 0; if (state.IsInvalid(nDoS)) @@ -4498,8 +4431,12 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, pfrom->AddInventoryKnown(inv); CValidationState state; - // Process all blocks from whitelisted peers, even if not requested. - ProcessNewBlock(state, pfrom, &block, pfrom->fWhitelisted, NULL); + // Process all blocks from whitelisted peers, even if not requested, + // unless we're still syncing with the network. + // Such an unrequested block may still be processed, subject to the + // conditions in AcceptBlock(). + bool forceProcessing = pfrom->fWhitelisted && !IsInitialBlockDownload(); + ProcessNewBlock(state, pfrom, &block, forceProcessing, NULL); int nDoS; if (state.IsInvalid(nDoS)) { pfrom->PushMessage("reject", strCommand, state.GetRejectCode(), @@ -4916,7 +4853,7 @@ bool SendMessages(CNode* pto, bool fSendTrickle) { // Periodically clear addrKnown to allow refresh broadcasts if (nLastRebroadcast) - pnode->addrKnown.clear(); + pnode->addrKnown.reset(); // Rebroadcast our address AdvertizeLocal(pnode); @@ -4961,7 +4898,7 @@ bool SendMessages(CNode* pto, bool fSendTrickle) LogPrintf("Warning: not banning local peer %s!\n", pto->addr.ToString()); else { - CNode::Ban(pto->addr); + CNode::Ban(pto->addr, BanReasonNodeMisbehaving); } } state.fShouldBan = false; |