Merge #7856: Only send one GetAddr response per connection.

66b0724 Only send one GetAddr response per connection. (Gregory Maxwell)

src/net.cpp

@@ -2708,6 +2708,7 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     nNextAddrSend = 0;
     nNextInvSend = 0;
     fRelayTxes = false;
+    fSentAddr = false;
     pfilter = new CBloomFilter();
     nLastBlockTime = 0;
     nLastTXTime = 0;

src/net.h

@@ -709,6 +709,7 @@ public:
     // b) the peer may tell us in its version message that we should not relay tx invs
     //    unless it loads a bloom filter.
     bool fRelayTxes;
+    bool fSentAddr;
     // If 'true' this node will be disconnected on CMasternodeMan::ProcessMasternodeConnections()
     bool fMasternode;
     CSemaphoreGrant grantOutbound;

src/net_processing.cpp

@@ -1938,6 +1938,14 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
             return true;
         }
 
+        // Only send one GetAddr response per connection to reduce resource waste
+        //  and discourage addr stamping of INV announcements.
+        if (pfrom->fSentAddr) {
+            LogPrint("net", "Ignoring repeated \"getaddr\". peer=%d\n", pfrom->id);
+            return true;
+        }
+        pfrom->fSentAddr = true;
+
         pfrom->vAddrToSend.clear();
         vector<CAddress> vAddr = connman.GetAddresses();
         BOOST_FOREACH(const CAddress &addr, vAddr)