ws2_32: Manage shorter length for IPV6_RECVTCLASS.

dlls/ws2_32/socket.c

@@ -1869,6 +1869,12 @@ int WINAPI getsockopt( SOCKET s, int level, int optname, char *optval, int *optl
             return server_getsockopt( s, IOCTL_AFD_WINE_GET_IPV6_RECVPKTINFO, optval, optlen );
 
         case IPV6_RECVTCLASS:
+            if (*optlen < sizeof(DWORD) || !optval)
+            {
+                if (optlen) *optlen = 0;
+                SetLastError( WSAEFAULT );
+                return SOCKET_ERROR;
+            }
             return server_getsockopt( s, IOCTL_AFD_WINE_GET_IPV6_RECVTCLASS, optval, optlen );
 
         case IPV6_UNICAST_HOPS:
@@ -3245,6 +3251,11 @@ int WINAPI setsockopt( SOCKET s, int level, int optname, const char *optval, int
             return 0;
 
         case IPV6_RECVTCLASS:
+            if (optlen < sizeof(DWORD) || !optval)
+            {
+                SetLastError( WSAEFAULT );
+                return SOCKET_ERROR;
+            }
             return server_setsockopt( s, IOCTL_AFD_WINE_SET_IPV6_RECVTCLASS, optval, optlen );
 
         case IPV6_UNICAST_HOPS:

dlls/ws2_32/tests/sock.c

@@ -1194,6 +1194,7 @@ static void test_set_getsockopt(void)
         {AF_INET6, SOCK_DGRAM, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, TRUE, {1, 1, 4}, {0}, FALSE},
         {AF_INET6, SOCK_DGRAM, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, TRUE, {1, 1, 4}, {0}, TRUE, TRUE},
         {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},
     };
     SOCKET s, s2;
     int i, j, err, lasterr;