highperfocused/bitcoin
1
0
Fork 0
mirror of https://github.com/bitcoin/bitcoin.git synced 2026-01-21 15:50:07 +01:00
Code Issues Packages Projects Releases Wiki Activity

Optimize orphan transaction handling

Browse Source 
Changes suggested by Sergio Demian Lerner to
help prevent potential DoS attacks.
This commit is contained in:
Gavin Andresen
2012-05-15 15:53:30 -04:00
committed by Luke Dashjr
parent b0d9f41cd2
commit c3def40293
1 changed files with 30 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
src/main.cpp
View File

@@ -45,7 +45,7 @@ map<uint256, CBlock*> mapOrphanBlocks;
multimap<uint256, CBlock*> mapOrphanBlocksByPrev;
map<uint256, CDataStream*> mapOrphanTransactions;
multimap<uint256, CDataStream*> mapOrphanTransactionsByPrev;
map<uint256, map<uint256, CDataStream*> > mapOrphanTransactionsByPrev;
double dHashesPerSec;
@@ -160,17 +160,37 @@ void static ResendWalletTransactions()
// mapOrphanTransactions
//
void AddOrphanTx(const CDataStream& vMsg)
bool AddOrphanTx(const CDataStream& vMsg)
{
CTransaction tx;
CDataStream(vMsg) >> tx;
uint256 hash = tx.GetHash();
if (mapOrphanTransactions.count(hash))
return;
return false;
CDataStream* pvMsg = mapOrphanTransactions[hash] = new CDataStream(vMsg);
CDataStream* pvMsg = new CDataStream(vMsg);
// Ignore big transactions, to avoid a
// send-big-orphans memory exhaustion attack. If a peer has a legitimate
// large transaction with a missing parent then we assume
// it will rebroadcast it later, after the parent transaction(s)
// have been mined or received.
// 10,000 orphans, each of which is at most 5,000 bytes big is
// at most 500 megabytes of orphans:
if (pvMsg->size() > 5000)
{
delete pvMsg;
printf("ignoring large orphan tx (size: %u, hash: %s)\n", pvMsg->size(), hash.ToString().substr(0,10).c_str());
return false;
}
mapOrphanTransactions[hash] = pvMsg;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
mapOrphanTransactionsByPrev.insert(make_pair(txin.prevout.hash, pvMsg));
mapOrphanTransactionsByPrev[txin.prevout.hash].insert(make_pair(hash, pvMsg));
printf("stored orphan tx %s (mapsz %u)\n", hash.ToString().substr(0,10).c_str(),
mapOrphanTransactions.size());
return true;
}
void static EraseOrphanTx(uint256 hash)
@@ -182,14 +202,9 @@ void static EraseOrphanTx(uint256 hash)
CDataStream(*pvMsg) >> tx;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
{
for (multimap<uint256, CDataStream*>::iterator mi = mapOrphanTransactionsByPrev.lower_bound(txin.prevout.hash);
mi != mapOrphanTransactionsByPrev.upper_bound(txin.prevout.hash);)
{
if ((*mi).second == pvMsg)
mapOrphanTransactionsByPrev.erase(mi++);
else
mi++;
}
mapOrphanTransactionsByPrev[txin.prevout.hash].erase(hash);
if (mapOrphanTransactionsByPrev[txin.prevout.hash].empty())
mapOrphanTransactionsByPrev.erase(txin.prevout.hash);
}
delete pvMsg;
mapOrphanTransactions.erase(hash);
@@ -2371,8 +2386,8 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
for (unsigned int i = 0; i < vWorkQueue.size(); i++)
{
uint256 hashPrev = vWorkQueue[i];
for (multimap<uint256, CDataStream*>::iterator mi = mapOrphanTransactionsByPrev.lower_bound(hashPrev);
mi != mapOrphanTransactionsByPrev.upper_bound(hashPrev);
for (map<uint256, CDataStream*>::iterator mi = mapOrphanTransactionsByPrev[hashPrev].begin();
mi != mapOrphanTransactionsByPrev[hashPrev].end();
++mi)
{
const CDataStream& vMsg = *((*mi).second);
@@ -2396,7 +2411,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
}
else if (fMissingInputs)
{
printf("storing orphan tx %s\n", inv.hash.ToString().substr(0,10).c_str());
AddOrphanTx(vMsg);
// DoS prevention: do not allow mapOrphanTransactions to grow unbounded