net: split socket creation out of connection

Also, check for the correct error during socket creation

src/net.cpp

@@ -417,16 +417,30 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
     if (addrConnect.IsValid()) {
         bool proxyConnectionFailed = false;
 
-        if (GetProxy(addrConnect.GetNetwork(), proxy))
+        if (GetProxy(addrConnect.GetNetwork(), proxy)) {
+            hSocket = CreateSocket(proxy.proxy);
+            if (hSocket == INVALID_SOCKET) {
+                return nullptr;
+            }
             connected = ConnectThroughProxy(proxy, addrConnect.ToStringIP(), addrConnect.GetPort(), hSocket, nConnectTimeout, &proxyConnectionFailed);
-        else // no proxy needed (none set for target network)
+        } else {
+            // no proxy needed (none set for target network)
+            hSocket = CreateSocket(addrConnect);
+            if (hSocket == INVALID_SOCKET) {
+                return nullptr;
+            }
             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)) {
+        hSocket = CreateSocket(proxy.proxy);
+        if (hSocket == INVALID_SOCKET) {
+            return nullptr;
+        }
         std::string host;
         int port = default_port;
         SplitHostPort(std::string(pszDest), port, host);

src/netbase.cpp

@@ -452,20 +452,18 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
     return true;
 }
 
-bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
+SOCKET CreateSocket(const CService &addrConnect)
 {
-    hSocketRet = INVALID_SOCKET;
-
     struct sockaddr_storage sockaddr;
     socklen_t len = sizeof(sockaddr);
     if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
-        LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
+        LogPrintf("Cannot create socket for %s: unsupported network\n", addrConnect.ToString());
-        return false;
+        return INVALID_SOCKET;
     }
 
     SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
     if (hSocket == INVALID_SOCKET)
-        return false;
+        return INVALID_SOCKET;
 
 #ifdef SO_NOSIGPIPE
     int set = 1;
@@ -479,9 +477,24 @@ bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int
     // Set to non-blocking
     if (!SetSocketNonBlocking(hSocket, true)) {
         CloseSocket(hSocket);
-        return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
+        LogPrintf("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
     }
+    return hSocket;
+}
 
+bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocket, int nTimeout)
+{
+    struct sockaddr_storage sockaddr;
+    socklen_t len = sizeof(sockaddr);
+    if (hSocket == INVALID_SOCKET) {
+        LogPrintf("Cannot connect to %s: invalid socket\n", addrConnect.ToString());
+        return false;
+    }
+    if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
+        LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
+        CloseSocket(hSocket);
+        return false;
+    }
     if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
     {
         int nErr = WSAGetLastError();
@@ -534,8 +547,6 @@ bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int
             return false;
         }
     }
-
-    hSocketRet = hSocket;
     return true;
 }
 
@@ -587,9 +598,8 @@ bool IsProxy(const CNetAddr &addr) {
     return false;
 }
 
-bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
+bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocket, int nTimeout, bool *outProxyConnectionFailed)
 {
-    SOCKET hSocket = INVALID_SOCKET;
     // first connect to proxy server
     if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) {
         if (outProxyConnectionFailed)
@@ -601,14 +611,16 @@ bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int
         ProxyCredentials random_auth;
         static std::atomic_int counter(0);
         random_auth.username = random_auth.password = strprintf("%i", counter++);
-        if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
+        if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket)) {
+            CloseSocket(hSocket);
             return false;
+        }
     } else {
-        if (!Socks5(strDest, (unsigned short)port, 0, hSocket))
+        if (!Socks5(strDest, (unsigned short)port, 0, hSocket)) {
+            CloseSocket(hSocket);
             return false;
+        }
     }
-
-    hSocketRet = hSocket;
     return true;
 }
 bool LookupSubNet(const char* pszName, CSubNet& ret)

src/netbase.h

@@ -51,6 +51,7 @@ bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLoo
 bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions);
 CService LookupNumeric(const char *pszName, int portDefault = 0);
 bool LookupSubNet(const char *pszName, CSubNet& subnet);
+SOCKET CreateSocket(const CService &addrConnect);
 bool ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout);
 bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed);
 /** Return readable error string for a network error code */