Merge bitcoin#8080: Do not use mempool for GETDATA for tx accepted af…

…ter the last mempool req. 7e908c7 Do not use mempool for GETDATA for tx accepted after the last mempool req. (Gregory Maxwell)
codablock · May 31, 2016 · 862fd24 · 862fd24
2 parents a2df115 + 7e908c7
commit 862fd24
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Showing 5 changed files with 19 additions and 2 deletions.
diff --git a/src/main.cpp b/src/main.cpp
@@ -4513,7 +4513,10 @@ 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;
                     }
@@ -5911,6 +5914,7 @@ bool SendMessages(CNode* pto)
                         vInv.clear();
                     }
                 }
+                pto->timeLastMempoolReq = GetTime();
             }
 
             // Determine transactions to relay

diff --git a/src/net.cpp b/src/net.cpp
@@ -2397,6 +2397,7 @@ 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;

diff --git a/src/net.h b/src/net.h
@@ -17,6 +17,7 @@
 #include "sync.h"
 #include "uint256.h"
 
+#include <atomic>
 #include <deque>
 #include <stdint.h>
 
@@ -414,6 +415,8 @@ class CNode
     // 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;

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
@@ -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);

diff --git a/src/txmempool.h b/src/txmempool.h
@@ -602,6 +602,7 @@ class CTxMemPool
     }
 
     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