ws2_32: Manage shorter length for IPV6_V6ONLY.

dlls/ws2_32/socket.c

@@ -1890,6 +1890,12 @@ int WINAPI getsockopt( SOCKET s, int level, int optname, char *optval, int *optl
             return server_getsockopt( s, IOCTL_AFD_WINE_GET_IPV6_UNICAST_IF, optval, optlen );
 
         case IPV6_V6ONLY:
+            if (*optlen < 1 || !optval)
+            {
+                SetLastError( WSAEFAULT );
+                return SOCKET_ERROR;
+            }
+            *optlen = 1;
             return server_getsockopt( s, IOCTL_AFD_WINE_GET_IPV6_V6ONLY, optval, optlen );
 
         default:
@@ -3277,7 +3283,13 @@ int WINAPI setsockopt( SOCKET s, int level, int optname, const char *optval, int
             return server_setsockopt( s, IOCTL_AFD_WINE_SET_IPV6_UNICAST_IF, optval, optlen );
 
         case IPV6_V6ONLY:
-            return server_setsockopt( s, IOCTL_AFD_WINE_SET_IPV6_V6ONLY, optval, optlen );
+            if (!optlen || !optval)
+            {
+                SetLastError( WSAEFAULT );
+                return SOCKET_ERROR;
+            }
+            value = *optval;
+            return server_setsockopt( s, IOCTL_AFD_WINE_SET_IPV6_V6ONLY, (char *)&value, sizeof(value) );
 
         default:
             FIXME("Unknown IPPROTO_IPV6 optname 0x%08x\n", optname);

dlls/ws2_32/tests/sock.c

@@ -1196,6 +1196,7 @@ static void test_set_getsockopt(void)
         {AF_INET6, SOCK_DGRAM, IPPROTO_IPV6, IPV6_PKTINFO, FALSE, {0, 0, 4}, {0}, TRUE, TRUE},
         {AF_INET6, SOCK_DGRAM, IPPROTO_IPV6, IPV6_RECVTCLASS, FALSE, {0, 0, 4}, {0}, TRUE, TRUE},
         {AF_INET6, SOCK_DGRAM, IPPROTO_IPV6, IPV6_UNICAST_HOPS, TRUE, {1, 1, 4}, {0}, FALSE},
+        {AF_INET6, SOCK_DGRAM, IPPROTO_IPV6, IPV6_V6ONLY, TRUE, {1, 1, 1}, {0}, TRUE},
     };
     SOCKET s, s2;
     int i, j, err, lasterr;