// mapOrphanTransactions
//
-void static AddOrphanTx(const CDataStream& vMsg)
+void AddOrphanTx(const CDataStream& vMsg)
{
CTransaction tx;
CDataStream(vMsg) >> tx;
uint256 hash = tx.GetHash();
if (mapOrphanTransactions.count(hash))
return;
+
CDataStream* pvMsg = mapOrphanTransactions[hash] = new CDataStream(vMsg);
BOOST_FOREACH(const CTxIn& txin, tx.vin)
mapOrphanTransactionsByPrev.insert(make_pair(txin.prevout.hash, pvMsg));
mapOrphanTransactions.erase(hash);
}
+int LimitOrphanTxSize(int nMaxOrphans)
+{
+ int nEvicted = 0;
+ while (mapOrphanTransactions.size() > nMaxOrphans)
+ {
+ // Evict a random orphan:
+ std::vector<unsigned char> randbytes(32);
+ RAND_bytes(&randbytes[0], 32);
+ uint256 randomhash(randbytes);
+ map<uint256, CDataStream*>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
+ if (it == mapOrphanTransactions.end())
+ it = mapOrphanTransactions.begin();
+ EraseOrphanTx(it->first);
+ ++nEvicted;
+ }
+ return nEvicted;
+}
}
// Remove transaction from index
- if (!txdb.EraseTxIndex(*this))
- return error("DisconnectInputs() : EraseTxPos failed");
+ // This can fail if a duplicate of this transaction was in a chain that got
+ // reorganized away. This is only possible if this transaction was completely
+ // spent, so erasing it would be a no-op anway.
+ txdb.EraseTxIndex(*this);
return true;
}
if (!CheckBlock())
return false;
+ // Do not allow blocks that contain transactions which 'overwrite' older transactions,
+ // unless those are already completely spent.
+ // 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.
+ // This logic is not necessary for memory pool transactions, as AcceptToMemoryPool
+ // already refuses previously-known transaction id's entirely.
+ // This rule applies to all blocks whose timestamp is after March 15, 2012, 0:00 UTC.
+ // On testnet it is enabled as of februari 20, 2012, 0:00 UTC.
+ if (pindex->nTime > 1331769600 || (fTestNet && pindex->nTime > 1329696000))
+ BOOST_FOREACH(CTransaction& tx, vtx)
+ {
+ CTxIndex txindexOld;
+ if (txdb.ReadTxIndex(tx.GetHash(), txindexOld))
+ BOOST_FOREACH(CDiskTxPos &pos, txindexOld.vSpent)
+ if (pos.IsNull())
+ return false;
+ }
+
// To avoid being on the short end of a block-chain split,
// don't do secondary validation of pay-to-script-hash transactions
// until blocks with timestamps after paytoscripthashtime (see init.cpp for default).
{
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
+ int nEvicted = LimitOrphanTxSize(MAX_ORPHAN_TRANSACTIONS);
+ if (nEvicted > 0)
+ printf("mapOrphan overflow, removed %d tx\n", nEvicted);
}
if (tx.nDoS) pfrom->Misbehaving(tx.nDoS);
}