Non-blocking sockets for Windows.

Expands the SetNonBlocking() function in libvncclient/sockets.c to also
work under Windows and also changes it to honour maybe already present
socket flags.

A similar function was introduced for libvncserver as well and
all the #ifdef'ed fnctl calls replaced with calls to that one.
Signed-off-by: Christian Beier <dontmind@freeshell.org>

TODO

@@ -11,7 +11,6 @@ style fixes: use Linux' coding guidelines & ANSIfy tightvnc-filetransfer:
 LibVNCClient cleanup: prefix with "rfbClient", and make sure it does
 	not deliberately die() or exit() anywhere!
 java vncviewer doesn't do colour cursors?
-MinGW32 doesn't do fcntl on sockets; use setsockopt instead...
 make corre work again (libvncclient or libvncserver?)
 teach SDLvncviewer about CopyRect...
 implement "-record" in libvncclient

libvncclient/sockets.c

@@ -551,14 +551,17 @@ AcceptTcpConnection(int listenSock)
 rfbBool
 SetNonBlocking(int sock)
 {
-#ifndef __MINGW32__
-  if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
-    rfbClientErr("AcceptTcpConnection: fcntl\n");
-    return FALSE;
-  }
+#ifdef WIN32
+  unsigned long block=1;
+  if(ioctlsocket(sock, FIONBIO, &block) == SOCKET_ERROR) {
+    errno=WSAGetLastError();
 #else
-  rfbClientErr("O_NONBLOCK on MinGW32 NOT IMPLEMENTED\n");
+  int flags = fcntl(sock, F_GETFL);
+  if(flags < 0 || fcntl(sock, F_SETFL, flags | O_NONBLOCK) < 0) {
 #endif
+    rfbClientErr("Setting socket to non-blocking failed: %s\n",strerror(errno));
+    return FALSE;
+  }
   return TRUE;
 }
 

libvncserver/httpd.c

@@ -181,7 +181,6 @@ rfbHttpCheckFds(rfbScreenInfoPtr rfbScreen)
     }
 
     if (FD_ISSET(rfbScreen->httpListenSock, &fds)) {
-        int flags;
 	if (rfbScreen->httpSock >= 0) close(rfbScreen->httpSock);
 
 	if ((rfbScreen->httpSock = accept(rfbScreen->httpListenSock,
@@ -189,35 +188,21 @@ rfbHttpCheckFds(rfbScreenInfoPtr rfbScreen)
 	    rfbLogPerror("httpCheckFds: accept");
 	    return;
 	}
-#ifdef __MINGW32__
-	rfbErr("O_NONBLOCK on MinGW32 NOT IMPLEMENTED");
-#else
 #ifdef USE_LIBWRAP
 	if(!hosts_ctl("vnc",STRING_UNKNOWN,inet_ntoa(addr.sin_addr),
 		      STRING_UNKNOWN)) {
 	  rfbLog("Rejected HTTP connection from client %s\n",
 		 inet_ntoa(addr.sin_addr));
-#else
-	flags = fcntl(rfbScreen->httpSock, F_GETFL);
-
-	if (flags < 0 || fcntl(rfbScreen->httpSock, F_SETFL, flags | O_NONBLOCK) == -1) {
-	    rfbLogPerror("httpCheckFds: fcntl");
-#endif
-	    close(rfbScreen->httpSock);
-	    rfbScreen->httpSock = -1;
-	    return;
-	}
-
-	flags=fcntl(rfbScreen->httpSock,F_GETFL);
-	if(flags==-1 ||
-	   fcntl(rfbScreen->httpSock,F_SETFL,flags|O_NONBLOCK)==-1) {
-	  rfbLogPerror("httpCheckFds: fcntl");
 	  close(rfbScreen->httpSock);
 	  rfbScreen->httpSock=-1;
 	  return;
 	}
 #endif
-
+        if(!rfbSetNonBlocking(rfbScreen->httpSock)) {
+	    close(rfbScreen->httpSock);
+	    rfbScreen->httpSock=-1;
+	    return;
+	}
 	/*AddEnabledDevice(httpSock);*/
     }
 }

libvncserver/rfbserver.c

@@ -299,13 +299,10 @@ rfbNewTCPOrUDPClient(rfbScreenInfoPtr rfbScreen,
       }
       rfbReleaseClientIterator(iterator);
 
-#ifndef WIN32
-      if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
-	rfbLogPerror("fcntl failed");
+      if(!rfbSetNonBlocking(sock)) {
 	close(sock);
 	return NULL;
       }
-#endif
 
       if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
 		     (char *)&one, sizeof(one)) < 0) {

libvncserver/sockets.c

@@ -116,12 +116,8 @@ rfbInitSockets(rfbScreenInfoPtr rfbScreen)
     if (rfbScreen->inetdSock != -1) {
 	const int one = 1;
 
-#ifndef WIN32
-	if (fcntl(rfbScreen->inetdSock, F_SETFL, O_NONBLOCK) < 0) {
-	    rfbLogPerror("fcntl");
+        if(!rfbSetNonBlocking(rfbScreen->inetdSock))
 	    return;
-	}
-#endif
 
 	if (setsockopt(rfbScreen->inetdSock, IPPROTO_TCP, TCP_NODELAY,
 		       (char *)&one, sizeof(one)) < 0) {
@@ -270,13 +266,10 @@ rfbCheckFds(rfbScreenInfoPtr rfbScreen,long usec)
 		return -1;
 	    }
 
-#ifndef WIN32
-	    if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
-		rfbLogPerror("rfbCheckFds: fcntl");
-		closesocket(sock);
+            if(!rfbSetNonBlocking(sock)) {
+	        closesocket(sock);
 		return -1;
 	    }
-#endif
 
 	    if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
 			(char *)&one, sizeof(one)) < 0) {
@@ -418,13 +411,10 @@ rfbConnect(rfbScreenInfoPtr rfbScreen,
 	return -1;
     }
 
-#ifndef WIN32
-    if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
-	rfbLogPerror("fcntl failed");
-	closesocket(sock);
+    if(!rfbSetNonBlocking(sock)) {
+        closesocket(sock);
 	return -1;
     }
-#endif
 
     if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
 		   (char *)&one, sizeof(one)) < 0) {
@@ -705,3 +695,23 @@ rfbListenOnUDPPort(int port,
 
     return sock;
 }
+
+/*
+ * rfbSetNonBlocking sets a socket into non-blocking mode.
+ */
+rfbBool
+rfbSetNonBlocking(int sock)
+{
+#ifdef WIN32
+  unsigned long block=1;
+  if(ioctlsocket(sock, FIONBIO, &block) == SOCKET_ERROR) {
+    errno=WSAGetLastError();
+#else
+  int flags = fcntl(sock, F_GETFL);
+  if(flags < 0 || fcntl(sock, F_SETFL, flags | O_NONBLOCK) < 0) {
+#endif
+    rfbLogPerror("Setting socket to non-blocking failed");
+    return FALSE;
+  }
+  return TRUE;
+}

rfb/rfb.h

@@ -664,6 +664,7 @@ extern int rfbConnectToTcpAddr(char* host, int port);
 extern int rfbListenOnTCPPort(int port, in_addr_t iface);
 extern int rfbListenOnUDPPort(int port, in_addr_t iface);
 extern int rfbStringToAddr(char* string,in_addr_t* addr);
+extern rfbBool rfbSetNonBlocking(int sock);
 
 /* rfbserver.c */