Don't return nodes with fDisconnect=true in FindNode

FindNode is only interested in active connections, especially when called from OpenNetworkConnection. Connections which are about to get disconnected and removed should be treated as if they are not existent anymore, as otherwise there is a small race between disconnecting and reconnecting nodes, causing OpenNetworkConnection to return early.
dashpay · Apr 22, 2020 · 33bfaff · 33bfaff
1 parent d235364
commit 33bfaff
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Showing 2 changed files with 20 additions and 8 deletions.
diff --git a/src/net.cpp b/src/net.cpp
@@ -323,43 +323,55 @@ bool IsReachable(const CNetAddr& addr)
 }
 
 
-CNode* CConnman::FindNode(const CNetAddr& ip)
+CNode* CConnman::FindNode(const CNetAddr& ip, bool fExcludeDisconnecting)
 {
     LOCK(cs_vNodes);
     for (CNode* pnode : vNodes) {
+        if (fExcludeDisconnecting && pnode->fDisconnect) {
+            continue;
+        }
         if ((CNetAddr)pnode->addr == ip) {
             return pnode;
         }
     }
     return nullptr;
 }
 
-CNode* CConnman::FindNode(const CSubNet& subNet)
+CNode* CConnman::FindNode(const CSubNet& subNet, bool fExcludeDisconnecting)
 {
     LOCK(cs_vNodes);
     for (CNode* pnode : vNodes) {
+        if (fExcludeDisconnecting && pnode->fDisconnect) {
+            continue;
+        }
         if (subNet.Match((CNetAddr)pnode->addr)) {
             return pnode;
         }
     }
     return nullptr;
 }
 
-CNode* CConnman::FindNode(const std::string& addrName)
+CNode* CConnman::FindNode(const std::string& addrName, bool fExcludeDisconnecting)
 {
     LOCK(cs_vNodes);
     for (CNode* pnode : vNodes) {
+        if (fExcludeDisconnecting && pnode->fDisconnect) {
+            continue;
+        }
         if (pnode->GetAddrName() == addrName) {
             return pnode;
         }
     }
     return nullptr;
 }
 
-CNode* CConnman::FindNode(const CService& addr)
+CNode* CConnman::FindNode(const CService& addr, bool fExcludeDisconnecting)
 {
     LOCK(cs_vNodes);
     for (CNode* pnode : vNodes) {
+        if (fExcludeDisconnecting && pnode->fDisconnect) {
+            continue;
+        }
         if ((CService)pnode->addr == addr) {
             return pnode;
         }

diff --git a/src/net.h b/src/net.h
@@ -497,10 +497,10 @@ friend class CNode;
 
     uint64_t CalculateKeyedNetGroup(const CAddress& ad) const;
 
-    CNode* FindNode(const CNetAddr& ip);
-    CNode* FindNode(const CSubNet& subNet);
-    CNode* FindNode(const std::string& addrName);
-    CNode* FindNode(const CService& addr);
+    CNode* FindNode(const CNetAddr& ip, bool fExcludeDisconnecting = true);
+    CNode* FindNode(const CSubNet& subNet, bool fExcludeDisconnecting = true);
+    CNode* FindNode(const std::string& addrName, bool fExcludeDisconnecting = true);
+    CNode* FindNode(const CService& addr, bool fExcludeDisconnecting = true);
 
     bool AttemptToEvictConnection();
     CNode* ConnectNode(CAddress addrConnect, const char *pszDest = nullptr, bool fCountFailure = false);