Randomize message processing peer order

vijaydasmp · Jun 2, 2021 · 79c02c8 · 79c02c8
1 parent 2aab8a6
commit 79c02c8
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/src/net.cpp b/src/net.cpp
@@ -2173,6 +2173,7 @@ void CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFai
 
 void CConnman::ThreadMessageHandler()
 {
+    FastRandomContext rng;
     while (!flagInterruptMsgProc)
     {
         std::vector<CNode*> vNodesCopy;
@@ -2186,6 +2187,11 @@ void CConnman::ThreadMessageHandler()
 
         bool fMoreWork = false;
 
+        // Randomize the order in which we process messages from/to our peers.
+        // This prevents attacks in which an attacker exploits having multiple
+        // consecutive connections in the vNodes list.
+        Shuffle(vNodesCopy.begin(), vNodesCopy.end(), rng);
+
         for (CNode* pnode : vNodesCopy)
         {
             if (pnode->fDisconnect)