Merge #8080: Do not use mempool for GETDATA for tx accepted after the last mempool req.

7e908c7 Do not use mempool for GETDATA for tx accepted after the last mempool req. (Gregory Maxwell)

1 files changed, 5 insertions, 1 deletions

diff --git a/src/main.cpp b/src/main.cpp
index ffc57d48be..c2905784f0 100644
--- 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