Do not use mempool for GETDATA for tx accepted after the last mempool req.

The ability to GETDATA a transaction which has not (yet) been relayed
 is a privacy loss vector.

The use of the mempool for this was added as part of the mempool p2p
 message and is only needed to fetch transactions returned by it.
This commit is contained in:
Gregory Maxwell 2016-05-20 16:19:26 +00:00
parent 8844ef15de
commit 7e908c7b82
5 changed files with 19 additions and 2 deletions

View File

@ -4503,7 +4503,10 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam
}
if (!pushed && inv.type == MSG_TX) {
CTransaction tx;
if (mempool.lookup(inv.hash, tx)) {
int64_t txtime;
// To protect privacy, do not answer getdata using the mempool when
// that TX couldn't have been INVed in reply to a MEMPOOL request.
if (mempool.lookup(inv.hash, tx, txtime) && txtime <= pfrom->timeLastMempoolReq) {
pfrom->PushMessage(NetMsgType::TX, tx);
pushed = true;
}
@ -5902,6 +5905,7 @@ bool SendMessages(CNode* pto)
vInv.clear();
}
}
pto->timeLastMempoolReq = GetTime();
}
// Determine transactions to relay

View File

@ -2396,6 +2396,7 @@ CNode::CNode(SOCKET hSocketIn, const CAddress& addrIn, const std::string& addrNa
fRelayTxes = false;
fSentAddr = false;
pfilter = new CBloomFilter();
timeLastMempoolReq = 0;
nPingNonceSent = 0;
nPingUsecStart = 0;
nPingUsecTime = 0;

View File

@ -17,6 +17,7 @@
#include "sync.h"
#include "uint256.h"
#include <atomic>
#include <deque>
#include <stdint.h>
@ -413,6 +414,8 @@ public:
// Used for BIP35 mempool sending, also protected by cs_inventory
bool fSendMempool;
// Last time a "MEMPOOL" request was serviced.
std::atomic<int64_t> timeLastMempoolReq;
// Ping time measurement:
// The pong reply we're expecting, or 0 if no pong expected.
uint64_t nPingNonceSent;

View File

@ -789,15 +789,23 @@ void CTxMemPool::queryHashes(vector<uint256>& vtxid)
std::sort(vtxid.begin(), vtxid.end(), DepthAndScoreComparator(this));
}
bool CTxMemPool::lookup(uint256 hash, CTransaction& result) const
bool CTxMemPool::lookup(uint256 hash, CTransaction& result, int64_t& time) const
{
LOCK(cs);
indexed_transaction_set::const_iterator i = mapTx.find(hash);
if (i == mapTx.end()) return false;
result = i->GetTx();
time = i->GetTime();
return true;
}
bool CTxMemPool::lookup(uint256 hash, CTransaction& result) const
{
int64_t time;
return CTxMemPool::lookup(hash, result, time);
}
bool CTxMemPool::lookupFeeRate(const uint256& hash, CFeeRate& feeRate) const
{
LOCK(cs);

View File

@ -602,6 +602,7 @@ public:
}
bool lookup(uint256 hash, CTransaction& result) const;
bool lookup(uint256 hash, CTransaction& result, int64_t& time) const;
bool lookupFeeRate(const uint256& hash, CFeeRate& feeRate) const;
/** Estimate fee rate needed to get into the next nBlocks