net: don't run callbacks on nodes that haven't completed the version handshake

Since ForEach* are can be used to send messages to  all nodes, the caller may
end up sending a message before the version handshake is complete. To limit
this, filter out these nodes. While we're at it, may as well filter out
disconnected nodes as well.

Delete unused methods rather than updating them.

src/net.cpp

@@ -2630,6 +2630,11 @@ void CNode::AskFor(const CInv& inv)
     mapAskFor.insert(std::make_pair(nRequestTime, inv));
 }
 
+bool CConnman::NodeFullyConnected(const CNode* pnode)
+{
+    return pnode && pnode->fSuccessfullyConnected && !pnode->fDisconnect;
+}
+
 void CConnman::PushMessage(CNode* pnode, CSerializedNetMsg&& msg)
 {
     size_t nMessageSize = msg.data.size();
@@ -2680,7 +2685,7 @@ bool CConnman::ForNode(NodeId id, std::function<bool(CNode* pnode)> func)
             break;
         }
     }
-    return found != nullptr && func(found);
+    return found != nullptr && NodeFullyConnected(found) && func(found);
 }
 
 int64_t PoissonNextSend(int64_t nNow, int average_interval_seconds) {

src/net.h

@@ -161,76 +161,34 @@ public:
 
     void PushMessage(CNode* pnode, CSerializedNetMsg&& msg);
 
-    template<typename Callable>
-    bool ForEachNodeContinueIf(Callable&& func)
-    {
-        LOCK(cs_vNodes);
-        for (auto&& node : vNodes)
-            if(!func(node))
-                return false;
-        return true;
-    };
-
-    template<typename Callable>
-    bool ForEachNodeContinueIf(Callable&& func) const
-    {
-        LOCK(cs_vNodes);
-        for (const auto& node : vNodes)
-            if(!func(node))
-                return false;
-        return true;
-    };
-
-    template<typename Callable, typename CallableAfter>
-    bool ForEachNodeContinueIfThen(Callable&& pre, CallableAfter&& post)
-    {
-        bool ret = true;
-        LOCK(cs_vNodes);
-        for (auto&& node : vNodes)
-            if(!pre(node)) {
-                ret = false;
-                break;
-            }
-        post();
-        return ret;
-    };
-
-    template<typename Callable, typename CallableAfter>
-    bool ForEachNodeContinueIfThen(Callable&& pre, CallableAfter&& post) const
-    {
-        bool ret = true;
-        LOCK(cs_vNodes);
-        for (const auto& node : vNodes)
-            if(!pre(node)) {
-                ret = false;
-                break;
-            }
-        post();
-        return ret;
-    };
-
     template<typename Callable>
     void ForEachNode(Callable&& func)
     {
         LOCK(cs_vNodes);
-        for (auto&& node : vNodes)
-            func(node);
+        for (auto&& node : vNodes) {
+            if (NodeFullyConnected(node))
+                func(node);
+        }
     };
 
     template<typename Callable>
     void ForEachNode(Callable&& func) const
     {
         LOCK(cs_vNodes);
-        for (const auto& node : vNodes)
-            func(node);
+        for (auto&& node : vNodes) {
+            if (NodeFullyConnected(node))
+                func(node);
+        }
     };
 
     template<typename Callable, typename CallableAfter>
     void ForEachNodeThen(Callable&& pre, CallableAfter&& post)
     {
         LOCK(cs_vNodes);
-        for (auto&& node : vNodes)
-            pre(node);
+        for (auto&& node : vNodes) {
+            if (NodeFullyConnected(node))
+                pre(node);
+        }
         post();
     };
 
@@ -238,8 +196,10 @@ public:
     void ForEachNodeThen(Callable&& pre, CallableAfter&& post) const
     {
         LOCK(cs_vNodes);
-        for (const auto& node : vNodes)
-            pre(node);
+        for (auto&& node : vNodes) {
+            if (NodeFullyConnected(node))
+                pre(node);
+        }
         post();
     };
 
@@ -372,6 +332,9 @@ private:
     void RecordBytesRecv(uint64_t bytes);
     void RecordBytesSent(uint64_t bytes);
 
+    // Whether the node should be passed out in ForEach* callbacks
+    static bool NodeFullyConnected(const CNode* pnode);
+
     // Network usage totals
     CCriticalSection cs_totalBytesRecv;
     CCriticalSection cs_totalBytesSent;