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Revert "Remove signal DoubleSpendDetected, use function"

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This reverts commit 0da6b3fd18.
This commit is contained in:
Wladimir J. van der Laan 2014-07-17 14:07:53 +02:00
parent 0de61e7585
commit 67cc8f25c2
3 changed files with 59 additions and 50 deletions
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2
src/init.cpp
View file

@ -1229,7 +1229,7 @@ bool AppInit2(boost::thread_group& threadGroup)
LogPrintf("mapAddressBook.size() = %u\n", pwalletMain ? pwalletMain->mapAddressBook.size() : 0);
#endif
InitRespendFilter();
RegisterInternalSignals();
StartNode(threadGroup);
if (fServer)
StartRPCThreads();

103
src/main.cpp
View file

@ -126,14 +126,9 @@ namespace {
} // anon namespace
// Bloom filter to limit respend relays to one
// Forward reference functions defined here:
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);
}
static bool RelayableRespend(const COutPoint& outPoint, const CTransaction& doubleSpend, bool fInBlock, CBloomFilter& filter);
//////////////////////////////////////////////////////////////////////////////
//
@ -157,10 +152,24 @@ struct CMainSignals {
boost::signals2::signal<void (const uint256 &)> Inventory;
// Tells listeners to broadcast their data.
boost::signals2::signal<void ()> Broadcast;
// Notifies listeners of detection of a double-spent transaction. Arguments are outpoint that is
// double-spent, first transaction seen, double-spend transaction, and whether the second double-spend
// transaction was first seen in a block.
// Note: only notifies if the previous transaction is in the memory pool; if previous transction was in a block,
// then the double-spend simply fails when we try to lookup the inputs in the current UTXO set.
boost::signals2::signal<bool (const COutPoint&, const CTransaction&, bool)> DetectedDoubleSpend;
} g_signals;
} // anon namespace
void RegisterInternalSignals() {
static CBloomFilter doubleSpendFilter;
seed_insecure_rand();
doubleSpendFilter = CBloomFilter(MAX_DOUBLESPEND_BLOOM, 0.01, insecure_rand(), BLOOM_UPDATE_NONE);
g_signals.DetectedDoubleSpend.connect(boost::bind(RelayableRespend, _1, _2, _3, doubleSpendFilter));
}
void RegisterWallet(CWalletInterface* pwalletIn) {
g_signals.SyncTransaction.connect(boost::bind(&CWalletInterface::SyncTransaction, pwalletIn, _1, _2));
@ -897,45 +906,6 @@ bool RateLimitExceeded(double& dCount, int64_t& nLastTime, int64_t nLimit, unsig
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)
{
@ -973,7 +943,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
// 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))
{
relayableRespend = RelayableRespend(outpoint, tx, false, doubleSpendFilter);
relayableRespend = g_signals.DetectedDoubleSpend(outpoint, tx, false);
if (!relayableRespend)
return false;
}
@ -1085,6 +1055,45 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
return !relayableRespend;
}
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;
}
int CMerkleTx::GetDepthInMainChainINTERNAL(CBlockIndex* &pindexRet) const
{

4
src/main.h
View file

@ -112,8 +112,8 @@ struct CNodeStateStats;
struct CBlockTemplate;
/** Initialize respend bloom filter **/
void InitRespendFilter();
/** Set up internal signal handlers **/
void RegisterInternalSignals();
/** Register a wallet to receive updates from core */
void RegisterWallet(CWalletInterface* pwalletIn);