Merge #10663: net: split resolve out of connect

b887676 net: remove now-unused functions (Cory Fields)
45fd754 net: remove now-superfluous numeric resolve (Cory Fields)
2416dd7 net: separate resolving and conecting (Cory Fields)

Pull request description:

  This is a greatly simplified version of #10285, which only aims to address async resolving.

  It essentially breaks up two wrapper functions for things only used in one place (ConnectSocketDirectly/ConnectThroughProxy) in favor of calling them directly. This allows us to fully handle resolves before attempting a connection, as is necessary for async connections.

  As a bonus, I believe the logic is now much easier to follow than before.

Tree-SHA512: f03f618107379edf3efe2a9f3e3677e8f075017ab140a0b4fdc3b8263e6beff148d55256263ab10bc2125ef089ca68e0d8e865beeae176f1eca544e769c976d3

1 files changed, 41 insertions, 23 deletions

diff --git a/src/net.cpp b/src/net.cpp
index c3f16a8f1f..ea3840a708 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -385,19 +385,16 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         pszDest ? pszDest : addrConnect.ToString(),
         pszDest ? 0.0 : (double)(GetAdjustedTime() - addrConnect.nTime)/3600.0);
 
-    // Connect
-    SOCKET hSocket;
-    bool proxyConnectionFailed = false;
-    if (pszDest ? ConnectSocketByName(addrConnect, hSocket, pszDest, Params().GetDefaultPort(), nConnectTimeout, &proxyConnectionFailed) :
-                  ConnectSocket(addrConnect, hSocket, nConnectTimeout, &proxyConnectionFailed))
-    {
-        if (!IsSelectableSocket(hSocket)) {
-            LogPrintf("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n");
-            CloseSocket(hSocket);
-            return nullptr;
-        }
-
-        if (pszDest && addrConnect.IsValid()) {
+    // Resolve
+    const int default_port = Params().GetDefaultPort();
+    if (pszDest) {
+        std::vector<CService> resolved;
+        if (Lookup(pszDest, resolved,  default_port, fNameLookup && !HaveNameProxy(), 256) && !resolved.empty()) {
+            addrConnect = CAddress(resolved[GetRand(resolved.size())], NODE_NONE);
+            if (!addrConnect.IsValid()) {
+                LogPrint(BCLog::NET, "Resolver returned invalid address %s for %s", addrConnect.ToString(), pszDest);
+                return nullptr;
+            }
             // It is possible that we already have a connection to the IP/port pszDest resolved to.
             // In that case, drop the connection that was just created, and return the existing CNode instead.
             // Also store the name we used to connect in that CNode, so that future FindNode() calls to that
@@ -407,13 +404,40 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
             if (pnode)
             {
                 pnode->MaybeSetAddrName(std::string(pszDest));
-                CloseSocket(hSocket);
                 LogPrintf("Failed to open new connection, already connected\n");
                 return nullptr;
             }
         }
+    }
 
-        addrman.Attempt(addrConnect, fCountFailure);
+    // Connect
+    bool connected = false;
+    SOCKET hSocket;
+    proxyType proxy;
+    if (addrConnect.IsValid()) {
+        bool proxyConnectionFailed = false;
+
+        if (GetProxy(addrConnect.GetNetwork(), proxy))
+            connected = ConnectThroughProxy(proxy, addrConnect.ToStringIP(), addrConnect.GetPort(), hSocket, nConnectTimeout, &proxyConnectionFailed);
+        else // no proxy needed (none set for target network)
+            connected = ConnectSocketDirectly(addrConnect, hSocket, nConnectTimeout);
+        if (!proxyConnectionFailed) {
+            // If a connection to the node was attempted, and failure (if any) is not caused by a problem connecting to
+            // the proxy, mark this as an attempt.
+            addrman.Attempt(addrConnect, fCountFailure);
+        }
+    } else if (pszDest && GetNameProxy(proxy)) {
+        std::string host;
+        int port = default_port;
+        SplitHostPort(std::string(pszDest), port, host);
+        connected = ConnectThroughProxy(proxy, host, port, hSocket, nConnectTimeout, nullptr);
+    }
+    if (connected) {
+        if (!IsSelectableSocket(hSocket)) {
+            LogPrintf("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n");
+            CloseSocket(hSocket);
+            return nullptr;
+        }
 
         // Add node
         NodeId id = GetNewNodeId();
@@ -424,10 +448,6 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         pnode->AddRef();
 
         return pnode;
-    } else if (!proxyConnectionFailed) {
-        // If connecting to the node failed, and failure is not caused by a problem connecting to
-        // the proxy, mark this as an attempt.
-        addrman.Attempt(addrConnect, fCountFailure);
     }
 
     return nullptr;
@@ -1912,11 +1932,9 @@ void CConnman::ThreadOpenAddedConnections()
                     // the addednodeinfo state might change.
                     break;
                 }
-                // If strAddedNode is an IP/port, decode it immediately, so
-                // OpenNetworkConnection can detect existing connections to that IP/port.
                 tried = true;
-                CService service(LookupNumeric(info.strAddedNode.c_str(), Params().GetDefaultPort()));
-                OpenNetworkConnection(CAddress(service, NODE_NONE), false, &grant, info.strAddedNode.c_str(), false, false, true);
+                CAddress addr(CService(), NODE_NONE);
+                OpenNetworkConnection(addr, false, &grant, info.strAddedNode.c_str(), false, false, true);
                 if (!interruptNet.sleep_for(std::chrono::milliseconds(500)))
                     return;
             }