net: change ConnectSocketDirectly() to take a Sock argument

Change `ConnectSocketDirectly()` to take a `Sock` argument instead of a
bare `SOCKET`. With this, use the `Sock`'s (possibly mocked) methods
`Connect()`, `Wait()` and `GetSockOpt()` instead of calling the OS
functions directly.

Author: vasild

src/i2p.cpp

@@ -279,7 +279,7 @@ Sock Session::Hello() const
         throw std::runtime_error("Cannot create socket");
     }
 
-    if (!ConnectSocketDirectly(m_control_host, sock->Get(), nConnectTimeout, true)) {
+    if (!ConnectSocketDirectly(m_control_host, *sock, nConnectTimeout, true)) {
         throw std::runtime_error(strprintf("Cannot connect to %s", m_control_host.ToString()));
     }
 

src/net.cpp

@@ -448,7 +448,7 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
             if (!sock) {
                 return nullptr;
             }
-            connected = ConnectSocketDirectly(addrConnect, sock->Get(), nConnectTimeout,
+            connected = ConnectSocketDirectly(addrConnect, *sock, nConnectTimeout,
                                               conn_type == ConnectionType::MANUAL);
         }
         if (!proxyConnectionFailed) {

src/netbase.cpp

@@ -537,12 +537,12 @@ static void LogConnectFailure(bool manual_connection, const char* fmt, const Arg
     }
 }
 
-bool ConnectSocketDirectly(const CService &addrConnect, const SOCKET& hSocket, int nTimeout, bool manual_connection)
+bool ConnectSocketDirectly(const CService &addrConnect, const Sock& sock, int nTimeout, bool manual_connection)
 {
     // Create a sockaddr from the specified service.
     struct sockaddr_storage sockaddr;
     socklen_t len = sizeof(sockaddr);
-    if (hSocket == INVALID_SOCKET) {
+    if (sock.Get() == INVALID_SOCKET) {
         LogPrintf("Cannot connect to %s: invalid socket\n", addrConnect.ToString());
         return false;
     }
@@ -552,55 +552,42 @@ bool ConnectSocketDirectly(const CService &addrConnect, const SOCKET& hSocket, i
     }
 
     // Connect to the addrConnect service on the hSocket socket.
-    if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
-    {
+    if (sock.Connect(reinterpret_cast<struct sockaddr*>(&sockaddr), len) == SOCKET_ERROR) {
         int nErr = WSAGetLastError();
         // WSAEINVAL is here because some legacy version of winsock uses it
         if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL)
         {
             // Connection didn't actually fail, but is being established
             // asynchronously. Thus, use async I/O api (select/poll)
             // synchronously to check for successful connection with a timeout.
-#ifdef USE_POLL
-            struct pollfd pollfd = {};
-            pollfd.fd = hSocket;
-            pollfd.events = POLLIN | POLLOUT;
-            int nRet = poll(&pollfd, 1, nTimeout);
-#else
-            struct timeval timeout = MillisToTimeval(nTimeout);
-            fd_set fdset;
-            FD_ZERO(&fdset);
-            FD_SET(hSocket, &fdset);
-            int nRet = select(hSocket + 1, nullptr, &fdset, nullptr, &timeout);
-#endif
-            // Upon successful completion, both select and poll return the total
-            // number of file descriptors that have been selected. A value of 0
-            // indicates that the call timed out and no file descriptors have
-            // been selected.
-            if (nRet == 0)
-            {
-                LogPrint(BCLog::NET, "connection to %s timeout\n", addrConnect.ToString());
+            const Sock::Event requested = Sock::RECV | Sock::SEND;
+            Sock::Event occurred;
+            if (!sock.Wait(std::chrono::milliseconds{nTimeout}, requested, &occurred)) {
+                LogPrintf("wait for connect to %s failed: %s\n",
+                          addrConnect.ToString(),
+                          NetworkErrorString(WSAGetLastError()));
                 return false;
-            }
-            if (nRet == SOCKET_ERROR)
-            {
-                LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
+            } else if (occurred == 0) {
+                LogPrint(BCLog::NET, "connection attempt to %s timed out\n", addrConnect.ToString());
                 return false;
             }
 
-            // Even if the select/poll was successful, the connect might not
+            // Even if the wait was successful, the connect might not
             // have been successful. The reason for this failure is hidden away
             // in the SO_ERROR for the socket in modern systems. We read it into
-            // nRet here.
-            socklen_t nRetSize = sizeof(nRet);
-            if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (sockopt_arg_type)&nRet, &nRetSize) == SOCKET_ERROR)
-            {
+            // sockerr here.
+            int sockerr;
+            socklen_t sockerr_len = sizeof(sockerr);
+            if (sock.GetSockOpt(SOL_SOCKET, SO_ERROR, (sockopt_arg_type)&sockerr, &sockerr_len) ==
+                SOCKET_ERROR) {
                 LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
                 return false;
             }
-            if (nRet != 0)
-            {
-                LogConnectFailure(manual_connection, "connect() to %s failed after select(): %s", addrConnect.ToString(), NetworkErrorString(nRet));
+            if (sockerr != 0) {
+                LogConnectFailure(manual_connection,
+                                  "connect() to %s failed after wait: %s",
+                                  addrConnect.ToString(),
+                                  NetworkErrorString(sockerr));
                 return false;
             }
         }
@@ -668,7 +655,7 @@ bool IsProxy(const CNetAddr &addr) {
 bool ConnectThroughProxy(const proxyType& proxy, const std::string& strDest, int port, const Sock& sock, int nTimeout, bool& outProxyConnectionFailed)
 {
     // first connect to proxy server
-    if (!ConnectSocketDirectly(proxy.proxy, sock.Get(), nTimeout, true)) {
+    if (!ConnectSocketDirectly(proxy.proxy, sock, nTimeout, true)) {
         outProxyConnectionFailed = true;
         return false;
     }

src/netbase.h

@@ -194,15 +194,15 @@ extern std::function<std::unique_ptr<Sock>(const CService&)> CreateSock;
  * Try to connect to the specified service on the specified socket.
  *
  * @param addrConnect The service to which to connect.
- * @param hSocket The socket on which to connect.
+ * @param sock The socket on which to connect.
  * @param nTimeout Wait this many milliseconds for the connection to be
  *                 established.
  * @param manual_connection Whether or not the connection was manually requested
  *                          (e.g. through the addnode RPC)
  *
  * @returns Whether or not a connection was successfully made.
  */
-bool ConnectSocketDirectly(const CService &addrConnect, const SOCKET& hSocket, int nTimeout, bool manual_connection);
+bool ConnectSocketDirectly(const CService &addrConnect, const Sock& sock, int nTimeout, bool manual_connection);
 
 /**
  * Connect to a specified destination service through a SOCKS5 proxy by first