diff options
Diffstat (limited to 'src/main.cpp')
| -rw-r--r-- | src/main.cpp | 104 |
1 files changed, 18 insertions, 86 deletions
diff --git a/src/main.cpp b/src/main.cpp index dd9e76378e..84178b16e2 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -7,7 +7,6 @@ #include "addrman.h" #include "alert.h" -#include "bloom.h" #include "chainparams.h" #include "checkpoints.h" #include "checkqueue.h" @@ -126,15 +125,6 @@ namespace { } // anon namespace -// Bloom filter to limit respend relays to one -static const unsigned int MAX_DOUBLESPEND_BLOOM = 1000; -static CBloomFilter doubleSpendFilter; -void InitRespendFilter() { - seed_insecure_rand(); - doubleSpendFilter = CBloomFilter(MAX_DOUBLESPEND_BLOOM, 0.01, insecure_rand(), BLOOM_UPDATE_NONE); -} - - ////////////////////////////////////////////////////////////////////////////// // // dispatching functions @@ -161,7 +151,6 @@ struct CMainSignals { } // anon namespace - void RegisterWallet(CWalletInterface* pwalletIn) { g_signals.SyncTransaction.connect(boost::bind(&CWalletInterface::SyncTransaction, pwalletIn, _1, _2)); g_signals.EraseTransaction.connect(boost::bind(&CWalletInterface::EraseFromWallet, pwalletIn, _1)); @@ -881,60 +870,6 @@ int64_t GetMinRelayFee(const CTransaction& tx, unsigned int nBytes, bool fAllowF return nMinFee; } -// Exponentially limit the rate of nSize flow to nLimit. nLimit unit is thousands-per-minute. -bool RateLimitExceeded(double& dCount, int64_t& nLastTime, int64_t nLimit, unsigned int nSize) -{ - static CCriticalSection csLimiter; - int64_t nNow = GetTime(); - - LOCK(csLimiter); - - dCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime)); - nLastTime = nNow; - if (dCount >= nLimit*10*1000) - return true; - dCount += nSize; - return false; -} - -static bool RelayableRespend(const COutPoint& outPoint, const CTransaction& doubleSpend, bool fInBlock, CBloomFilter& filter) -{ - // Relaying double-spend attempts to our peers lets them detect when - // somebody might be trying to cheat them. However, blindly relaying - // every double-spend across the entire network gives attackers - // a denial-of-service attack: just generate a stream of double-spends - // re-spending the same (limited) set of outpoints owned by the attacker. - // So, we use a bloom filter and only relay (at most) the first double - // spend for each outpoint. False-positives ("we have already relayed") - // are OK, because if the peer doesn't hear about the double-spend - // from us they are very likely to hear about it from another peer, since - // each peer uses a different, randomized bloom filter. - - if (fInBlock || filter.contains(outPoint)) return false; - - // Apply an independent rate limit to double-spend relays - static double dRespendCount; - static int64_t nLastRespendTime; - static int64_t nRespendLimit = GetArg("-limitrespendrelay", 100); - unsigned int nSize = ::GetSerializeSize(doubleSpend, SER_NETWORK, PROTOCOL_VERSION); - - if (RateLimitExceeded(dRespendCount, nLastRespendTime, nRespendLimit, nSize)) - { - LogPrint("mempool", "Double-spend relay rejected by rate limiter\n"); - return false; - } - - LogPrint("mempool", "Rate limit dRespendCount: %g => %g\n", dRespendCount, dRespendCount+nSize); - - // Clear the filter on average every MAX_DOUBLE_SPEND_BLOOM - // insertions - if (insecure_rand()%MAX_DOUBLESPEND_BLOOM == 0) - filter.clear(); - - filter.insert(outPoint); - - return true; -} bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool fLimitFree, bool* pfMissingInputs, bool fRejectInsaneFee) @@ -964,18 +899,15 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa return false; // Check for conflicts with in-memory transactions - bool relayableRespend = false; { LOCK(pool.cs); // protect pool.mapNextTx for (unsigned int i = 0; i < tx.vin.size(); i++) { COutPoint outpoint = tx.vin[i].prevout; - // Does tx conflict with a member of the pool, and is it not equivalent to that member? - if (pool.mapNextTx.count(outpoint) && !tx.IsEquivalentTo(*pool.mapNextTx[outpoint].ptx)) + if (pool.mapNextTx.count(outpoint)) { - relayableRespend = RelayableRespend(outpoint, tx, false, doubleSpendFilter); - if (!relayableRespend) - return false; + // Disable replacement feature for now + return false; } } } @@ -1046,15 +978,23 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa // be annoying or make others' transactions take longer to confirm. if (fLimitFree && nFees < ::minRelayTxFee.GetFee(nSize)) { + static CCriticalSection csFreeLimiter; static double dFreeCount; - static int64_t nLastFreeTime; - static int64_t nFreeLimit = GetArg("-limitfreerelay", 15); + static int64_t nLastTime; + int64_t nNow = GetTime(); - if (RateLimitExceeded(dFreeCount, nLastFreeTime, nFreeLimit, nSize)) + LOCK(csFreeLimiter); + + // Use an exponentially decaying ~10-minute window: + dFreeCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime)); + nLastTime = nNow; + // -limitfreerelay unit is thousand-bytes-per-minute + // At default rate it would take over a month to fill 1GB + if (dFreeCount >= GetArg("-limitfreerelay", 15)*10*1000) return state.DoS(0, error("AcceptToMemoryPool : free transaction rejected by rate limiter"), REJECT_INSUFFICIENTFEE, "insufficient priority"); - LogPrint("mempool", "Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize); + dFreeCount += nSize; } if (fRejectInsaneFee && nFees > ::minRelayTxFee.GetFee(nSize) * 10000) @@ -1068,21 +1008,13 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa { return error("AcceptToMemoryPool: : ConnectInputs failed %s", hash.ToString()); } - - if (relayableRespend) - { - RelayTransaction(tx); - } - else - { - // Store transaction in memory - pool.addUnchecked(hash, entry); - } + // Store transaction in memory + pool.addUnchecked(hash, entry); } g_signals.SyncTransaction(tx, NULL); - return !relayableRespend; + return true; } |