#include <stdio.h>
#include <sys/sysctl.h>
#include <net/route.h>

#include <sys/socket.h>
#include <netinet/in.h>

/*
mostly ripped. just outputs routes from KRT on NetBSD.
used to look closer at a difference of output from route and netstat.
*/

get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
{
        int     i;

        for (i = 0; i < RTAX_MAX; i++) {
                if (addrs & (1 << i)) {
                        rti_info[i] = sa;
                        sa = (struct sockaddr *)((char *)(sa) +
                            RT_ROUNDUP(sa->sa_len));
                } else
                        rti_info[i] = NULL;
        }
}


void print_sa6(struct sockaddr *sa) {
 int i=0;
 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa;
 struct in6_addr *in6 = &sa6->sin6_addr;
 if(sa) {
  for(i=0;i<16;i++) {
   printf("%02x",(unsigned char)in6->s6_addr[i]);
   i++;
   printf("%02x",(unsigned char)in6->s6_addr[i]);
   if(i != 15) printf(":");
  }
 } else {
  printf("none");
 }
 printf("\n");
}

void p_rtentry(struct rt_msghdr *rtm) {
 struct sockadrr *sa = (struct sockaddr *)(rtm+1);
 struct sockaddr *rti_info[RTAX_MAX];
 struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa;
 struct in6_addr *in6 = &sa6->sin6_addr;
 get_rtaddrs(rtm->rtm_addrs, sa, rti_info);

 printf("addr: ");
 print_sa6(rti_info[RTAX_DST]);
 printf("mask: ");
 print_sa6(rti_info[RTAX_NETMASK]);
 printf("gate: ");
 print_sa6(rti_info[RTAX_GATEWAY]);
 printf("\n");
}

int main() {
//     sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp, 
//            const void *newp, size_t newlen);
 int needed;
        struct rt_msghdr *rtm;
        struct sockaddr *sa;
 char *buf,*next,*lim;
 int mib[6];
 mib[0]=CTL_NET;
 mib[1]=PF_ROUTE;
 mib[2]=0;
 mib[3]=AF_INET6;
 mib[4]=NET_RT_DUMP;
 mib[5]=0;
 sysctl(mib,6,NULL,&needed,NULL,0);
 buf=malloc(needed);
 sysctl(mib,6,buf,&needed,NULL,0);
 lim=buf+needed;
       if (buf) {
                for (next = buf; next < lim; next += rtm->rtm_msglen) {
                        rtm = (struct rt_msghdr *)next;
                        sa = (struct sockaddr *)(rtm + 1);
                        if (sa->sa_family != AF_INET6)
                                continue;
                        p_rtentry(rtm);
                }
                free(buf);
                buf = NULL;
        }

}