/*
 * Based upon 4.4BSD's /usr/sbin/arp
 */
#include <sys/param.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
# include <net/route.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <netdb.h>
#include <errno.h>
#include <nlist.h>
#include <stdio.h>
#include "ipsend.h"
#include "iplang/iplang.h"


/*
 * lookup host and return
 * its IP address in address
 * (4 bytes)
 */
int     resolve(char *host, char *address)
{
        struct  hostent *hp;
        u_long  add;

        add = inet_addr(host);
        if (add == -1)
            {
                if (!(hp = gethostbyname(host)))
                    {
                        fprintf(stderr, "unknown host: %s\n", host);
                        return (-1);
                    }
                bcopy((char *)hp->h_addr, (char *)address, 4);
                return (0);
        }
        bcopy((char*)&add, address, 4);
        return (0);
}


int     arp(char *addr, char *eaddr)
{
        int     mib[6];
        size_t  needed;
        char    *lim, *buf, *next;
        struct  rt_msghdr       *rtm;
        struct  sockaddr_in     *sin;
        struct  sockaddr_dl     *sdl;

#ifdef  IPSEND
        if (arp_getipv4(addr, ether) == 0)
                return (0);
#endif

        if (!addr)
                return (-1);

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = AF_INET;
        mib[4] = NET_RT_FLAGS;
#ifdef RTF_LLINFO
        mib[5] = RTF_LLINFO;
#else
        mib[5] = 0;
#endif  

        if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
            {
                perror("route-sysctl-estimate");
                exit(-1);
            }
        if ((buf = malloc(needed)) == NULL)
            {
                perror("malloc");
                exit(-1);
            }
        if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1)
            {
                perror("actual retrieval of routing table");
                exit(-1);
            }
        lim = buf + needed;
        for (next = buf; next < lim; next += rtm->rtm_msglen)
            {
                rtm = (struct rt_msghdr *)next;
                sin = (struct sockaddr_in *)(rtm + 1);
                sdl = (struct sockaddr_dl *)(sin + 1);
                if (!bcmp(addr, (char *)&sin->sin_addr,
                          sizeof(struct in_addr)))
                    {
                        bcopy(LLADDR(sdl), eaddr, sdl->sdl_alen);
                        return (0);
                    }
            }
        return (-1);
}