Structure ip_addr

struct ip_addr{
    unsigned int af;     /* address family: AF_INET6 or AF_INET */
    unsigned int len;    /* address len, 16 or 4 */
		
    /* 64 bits alligned address */
    union {
        unsigned int   addr32[4];
        unsigned short addr16[8];
        unsigned char  addr[16];
    }u;
};