+#define INADDR_ANY 0x00000000
+#define INADDR_BROADCAST 0xFFFFFFFF
+
+#define IPPORT_RESERVED 1024
+#define IPPORT_UNRESERVED 0xC000
+
+// getsockopt/setsockopt(level)
+enum {
+ IPPROTO_IP = 1,
+ IPPROTO_ICMP,
+ IPPROTO_TCP,
+ IPPROTO_UDP
+};
+
+#define INET_ADDRSTRLEN 16
+#define INET6_ADDRSTRLEN 48 // linux
+