Problen with a little C program

[Tyler T]

hi list, firts sorry for my english.

for hobbye i am trying to write a little program in C lenguage, the
program create a ip header and show the values of ip header whitout
send any data, only create the header, the program is this:

//////BEGIN////////
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <sys/time.h>
#include <arpa/inet.h>

#include <netdb.h>

struct ip *create_iph(char *ips, char *ipd, int sec);
void show_iph(struct ip *iph);

int main(){

   struct ip *iph;

   iph = create_iph("127.0.0.1","127.0.0.1",10);
   showiph(iph);

   free(iph);

   iph=NULL;

   return 0;

}

struct ip *create_iph(char *ips, char *ipd, int sec){

        struct ip *iph;

        iph = malloc(sizeof(struct ip));

        iph->ip_v = 4;
        iph->ip_hl = 5;
        iph->ip_tos = 0;
        iph->ip_len = sizeof(struct ip) + sizeof(struct tcphdr);
        iph->ip_id = htons(sec); //cambiar el id por el numero de port a scanear
        iph->ip_ttl = 255;
        iph->ip_p = 6;
        iph->ip_sum = 0;  //checksum
        iph->ip_src.s_addr = inet_addr(ips);
        iph->ip_dst.s_addr = inet_addr(ipd);

        return iph;
}

void show_iph(struct ip *iph){

        printf("version %d\n",iph->ip_v);
        printf("header leng (ihl) %d\n",iph->ip_hl);
        printf("total leng %d\n",iph->ip_len);
        printf("identification %d\n",iph->ip_id);
        printf("TTL %d\n",iph->ip_ttl);
        printf("protocol %d\n",iph->ip_p);
        printf("checksum %d\n",iph->ip_sum);
        printf("type of service (TOS) %d\n",iph->ip_tos);
        printf("ip source %s\n",inet_ntoa(iph->ip_src));
        printf("ip destination %s\n",inet_ntoa(iph->ip_dst));

}
////////END///////

when i execute:  "gcc -o sock_raw sock_raw.c"  i obtain:

-bash-2.05b$ gcc -o sock_raw sock_raw.c
In file included from sock_raw.c:7:
/usr/include/netinet/ip.h:160: error: syntax error before "n_long"
/usr/include/netinet/ip.h:163: error: syntax error before "n_long"
-bash-2.05b$


my system is: FreeBSD 5.4 STABLE
and my gcc version is: gcc version 3.4.2 [FreeBSD] 20040728

thanks in advance.