[Socket] Fix Socket.BeginConnect to multiple IPAddress (#4960)

We would previously mix 2 SocketAsyncResult, and in case we would succeed asynchronously, we would return one that would not be updated afterwards.

The solution consists in using only 1 SocketAsyncResult that we ensure to update accordingly.

diff --git a/mcs/class/System/System.Net.Sockets/Socket.cs b/mcs/class/System/System.Net.Sockets/Socket.cs
index 89911c426b4420c4cc944c0dea38db8850a40204..d19756b6c30013be319b87d94a0747081fc47394 100644 (file)
--- a/mcs/class/System/System.Net.Sockets/Socket.cs
+++ b/mcs/class/System/System.Net.Sockets/Socket.cs
@@ -976,60 +976,7 @@ namespace System.Net.Sockets
                                EndPoint = remoteEP,
                        };
 
-                       // Bug #75154: Connect() should not succeed for .Any addresses.
-                       if (remoteEP is IPEndPoint) {
-                               IPEndPoint ep = (IPEndPoint) remoteEP;
-                               if (ep.Address.Equals (IPAddress.Any) || ep.Address.Equals (IPAddress.IPv6Any)) {
-                                       sockares.Complete (new SocketException ((int) SocketError.AddressNotAvailable), true);
-                                       return sockares;
-                               }
-
-                               sockares.EndPoint = remoteEP = RemapIPEndPoint (ep);
-                       }
-
-                       int error = 0;
-
-                       if (connect_in_progress) {
-                               // This could happen when multiple IPs are used
-                               // Calling connect() again will reset the connection attempt and cause
-                               // an error. Better to just close the socket and move on.
-                               connect_in_progress = false;
-                               m_Handle.Dispose ();
-                               m_Handle = new SafeSocketHandle (Socket_internal (addressFamily, socketType, protocolType, out error), true);
-                               if (error != 0)
-                                       throw new SocketException (error);
-                       }
-
-                       bool blk = is_blocking;
-                       if (blk)
-                               Blocking = false;
-                       Connect_internal (m_Handle, remoteEP.Serialize (), out error, false);
-                       if (blk)
-                               Blocking = true;
-
-                       if (error == 0) {
-                               // succeeded synch
-                               is_connected = true;
-                               is_bound = true;
-                               sockares.Complete (true);
-                               return sockares;
-                       }
-
-                       if (error != (int) SocketError.InProgress && error != (int) SocketError.WouldBlock) {
-                               // error synch
-                               is_connected = false;
-                               is_bound = false;
-                               sockares.Complete (new SocketException (error), true);
-                               return sockares;
-                       }
-
-                       // continue asynch
-                       is_connected = false;
-                       is_bound = false;
-                       connect_in_progress = true;
-
-                       IOSelector.Add (sockares.Handle, new IOSelectorJob (IOOperation.Write, BeginConnectCallback, sockares));
-
+                       BeginSConnect (sockares);
                        return sockares;
                }
 
@@ -1055,39 +1002,85 @@ namespace System.Net.Sockets
 
                        is_connected = false;
 
-                       return BeginMConnect (sockares);
+                       BeginMConnect (sockares);
+                       return sockares;
                }
 
-               internal IAsyncResult BeginMConnect (SocketAsyncResult sockares)
+               static void BeginMConnect (SocketAsyncResult sockares)
                {
-                       SocketAsyncResult ares = null;
                        Exception exc = null;
-                       AsyncCallback callback;
 
                        for (int i = sockares.CurrentAddress; i < sockares.Addresses.Length; i++) {
                                try {
                                        sockares.CurrentAddress++;
+                                       sockares.EndPoint = new IPEndPoint (sockares.Addresses [i], sockares.Port);
 
-                                       ares = (SocketAsyncResult) BeginConnect (new IPEndPoint (sockares.Addresses [i], sockares.Port), null, sockares);
-                                       if (ares.IsCompleted && ares.CompletedSynchronously) {
-                                               ares.CheckIfThrowDelayedException ();
-
-                                               callback = ares.AsyncCallback;
-                                               if (callback != null)
-                                                       ThreadPool.UnsafeQueueUserWorkItem (_ => callback (ares), null);
-                                       }
-
-                                       break;
+                                       BeginSConnect (sockares);
+                                       return;
                                } catch (Exception e) {
                                        exc = e;
-                                       ares = null;
                                }
                        }
 
-                       if (ares == null)
-                               throw exc;
+                       throw exc;
+               }
 
-                       return sockares;
+               static void BeginSConnect (SocketAsyncResult sockares)
+               {
+                       EndPoint remoteEP = sockares.EndPoint;
+                       // Bug #75154: Connect() should not succeed for .Any addresses.
+                       if (remoteEP is IPEndPoint) {
+                               IPEndPoint ep = (IPEndPoint) remoteEP;
+                               if (ep.Address.Equals (IPAddress.Any) || ep.Address.Equals (IPAddress.IPv6Any)) {
+                                       sockares.Complete (new SocketException ((int) SocketError.AddressNotAvailable), true);
+                                       return;
+                               }
+
+                               sockares.EndPoint = remoteEP = sockares.socket.RemapIPEndPoint (ep);
+                       }
+
+                       int error = 0;
+
+                       if (sockares.socket.connect_in_progress) {
+                               // This could happen when multiple IPs are used
+                               // Calling connect() again will reset the connection attempt and cause
+                               // an error. Better to just close the socket and move on.
+                               sockares.socket.connect_in_progress = false;
+                               sockares.socket.m_Handle.Dispose ();
+                               sockares.socket.m_Handle = new SafeSocketHandle (sockares.socket.Socket_internal (sockares.socket.addressFamily, sockares.socket.socketType, sockares.socket.protocolType, out error), true);
+                               if (error != 0)
+                                       throw new SocketException (error);
+                       }
+
+                       bool blk = sockares.socket.is_blocking;
+                       if (blk)
+                               sockares.socket.Blocking = false;
+                       Connect_internal (sockares.socket.m_Handle, remoteEP.Serialize (), out error, false);
+                       if (blk)
+                               sockares.socket.Blocking = true;
+
+                       if (error == 0) {
+                               // succeeded synch
+                               sockares.socket.is_connected = true;
+                               sockares.socket.is_bound = true;
+                               sockares.Complete (true);
+                               return;
+                       }
+
+                       if (error != (int) SocketError.InProgress && error != (int) SocketError.WouldBlock) {
+                               // error synch
+                               sockares.socket.is_connected = false;
+                               sockares.socket.is_bound = false;
+                               sockares.Complete (new SocketException (error), true);
+                               return;
+                       }
+
+                       // continue asynch
+                       sockares.socket.is_connected = false;
+                       sockares.socket.is_bound = false;
+                       sockares.socket.connect_in_progress = true;
+
+                       IOSelector.Add (sockares.Handle, new IOSelectorJob (IOOperation.Write, BeginConnectCallback, sockares));
                }
 
                static IOAsyncCallback BeginConnectCallback = new IOAsyncCallback (ares => {
@@ -1098,18 +1091,11 @@ namespace System.Net.Sockets
                                return;
                        }
 
-                       SocketAsyncResult mconnect = sockares.AsyncState as SocketAsyncResult;
-                       bool is_mconnect = mconnect != null && mconnect.Addresses != null;
-
                        try {
-                               EndPoint ep = sockares.EndPoint;
-                               int error_code = (int) sockares.socket.GetSocketOption (SocketOptionLevel.Socket, SocketOptionName.Error);
-
-                               if (error_code == 0) {
-                                       if (is_mconnect)
-                                               sockares = mconnect;
+                               int error = (int) sockares.socket.GetSocketOption (SocketOptionLevel.Socket, SocketOptionName.Error);
 
-                                       sockares.socket.seed_endpoint = ep;
+                               if (error == 0) {
+                                       sockares.socket.seed_endpoint = sockares.EndPoint;
                                        sockares.socket.is_connected = true;
                                        sockares.socket.is_bound = true;
                                        sockares.socket.connect_in_progress = false;
@@ -1118,26 +1104,21 @@ namespace System.Net.Sockets
                                        return;
                                }
 
-                               if (!is_mconnect) {
+                               if (sockares.Addresses == null) {
                                        sockares.socket.connect_in_progress = false;
-                                       sockares.Complete (new SocketException (error_code));
+                                       sockares.Complete (new SocketException (error));
                                        return;
                                }
 
-                               if (mconnect.CurrentAddress >= mconnect.Addresses.Length) {
-                                       mconnect.Complete (new SocketException (error_code));
+                               if (sockares.CurrentAddress >= sockares.Addresses.Length) {
+                                       sockares.Complete (new SocketException (error));
                                        return;
                                }
 
-                               mconnect.socket.BeginMConnect (mconnect);
+                               BeginMConnect (sockares);
                        } catch (Exception e) {
                                sockares.socket.connect_in_progress = false;
-
-                               if (is_mconnect)
-                                       sockares = mconnect;
-
                                sockares.Complete (e);
-                               return;
                        }
                });