If USE_NETFILTER is set and not SO_REUSEPORT, we evaluate SO_REUSEADDR,
let's fix that to check that it's defined.
* USE_NETFILTER define.
*/
#if !defined(SO_REUSEPORT) && defined(USE_NETFILTER)
-#if (SO_REUSEADDR == 2)
+#if defined(SO_REUSEADDR) && (SO_REUSEADDR == 2)
#define SO_REUSEPORT 15
-#elif (SO_REUSEADDR == 0x0004)
+#elif defined(SO_REUSEADDR) && (SO_REUSEADDR == 0x0004)
#define SO_REUSEPORT 0x0200
#endif /* SO_REUSEADDR */
#endif /* SO_REUSEPORT */