u_char *host_lookup(u_long in, u_short use_name);

       void host_lookup_r(u_long in, u_short use_name, u_char *buf);

       u_long name_resolve(u_char *hostname, u_short use_name);

       int open_raw_sock(int protocol);

       struct link_int *open_link_interface(char *device, char *ebuf);

       u_long get_ipaddr(struct link_int *l, const u_char *device,
                   const u_char *buf);

       struct ether_addr *get_hwaddr(struct link_int *l, const u_char *device,
                   const u_char *buf);

       void build_arp(u_short hrd, u_short pro, u_short hln, u_short pln,
                   u_short op, u_char *sha, u_char *spa, u_char *tha,
                   u_char *tpa, const u_char *payload, int payload_s,
                   u_char *buf);

       void build_dns(u_short id, u_short flags, u_short num_q,
                   u_short num_anws_rr, u_short num_auth_rr,
                   u_short num_addi_rr, const u_char *payload, int payload_s,
                   u_char *buf);

       void build_ethernet(u_char *daddr, u_char *saddr, u_short id,
                   const u_char *payload, int payload_s, u_char *buf);

       void build_icmp_echo(u_char type, u_char code, u_short id, u_short seq,
                   const u_char *payload, int payload_s, u_char *buf);

       void build_icmp_mask(u_char type, u_char code, u_short id, u_short seq,
                   u_long mask, const u_char *payload, int payload_s,
                   u_char *buf);

       void build_igmp(u_char type, u_char code, u_long ip, u_char *buf);

       void build_ip(u_short len, u_char tos, u_short id, u_short frag,
                   u_char ttl, u_char prot, u_long saddr, u_long daddr,
                   const u_char *payload, int payload_s, u_char *buf);

       void build_rip(u_char command, u_char ver, u_short rd, u_short af,
                   u_short rt, u_long addr, u_long mask, u_long next_hop,
                   u_long metric, const u_char *payload, int payload_s,
                   u_char *buf)

       void build_tcp(u_short sport, u_short dport, u_long seq, u_long ack,
                   u_char control, u_short win, u_short urg,
                   const u_char *payload, int payload_s, u_char *buf);

       void build_udp(u_short sport, u_short dport,  const u_char *payload,
                   int payload_s, u_char *buf);

       int insert_ipo(struct ipoption *opt, u_char opt_len, u_char *buf);

       int insert_tcpo(struct tcpoption *opt, u_char opt_len, u_char *buf);

       int write_ip(int sock, const u_char *pak, int len);

       int write_link_layer(struct link_int *l, const u_char *device,
                    const u_char *buf, int len);

       void do_checksum(u_char *buf, int protocol, int len);

       u_short ip_check(u_short *buf, int len)

       u_short tcp_check(struct tcphdr *th, int len, u_long src, u_long dst);

       int seed_prand();

       u_long get_prand(int type);

EOF