/*
 * Copyright (c) 1999, 2000 Seth Kingsley.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgment:
 *    This product includes software developed by Seth Kingsley and
 *    contributors.
 * 4. Neither the author's name, nor any of the contributors names may be
 *    used to endorse or promote products derived from this software without
 *    specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include    <sys/types.h>
#include    <sys/sysctl.h>
#include    <sys/socket.h>

#include    <net/ethernet.h>
#include    <net/route.h>
#include    <net/if_dl.h>
#include    <netinet/in.h>
#include    <arpa/inet.h>
#include    <netinet/if_ether.h>
#include    <netdb.h>

#include    <stdlib.h>
#include    <stdio.h>
#include    <string.h>
#include    <sysexits.h>
#include    <err.h>

#include    "ethcodes.h"

static const char rcsid[] =
	"$Id$";

static void
ping(struct in_addr *inp)
{
    int	    ec = 1;
    char    *fs = "ping -qc 1 %s > /dev/null", *cs,
	    *as = inet_ntoa(*inp);

    cs = malloc(sizeof(fs) + strlen(as));
    sprintf(cs, fs, as);
    ec = system(cs);
    if (ec)
	errx(1, "Error pinging host: command returned error code %d",
		ec);
}

/* Various parts of this stolen were from BSD arp.c */
#define ROUNDUP(a) \
	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
static struct ether_addr
*in2eth(struct in_addr *in, int pf)
{
    static int	mib[6] =
    {
	CTL_NET,
	PF_ROUTE,
	0,
	AF_INET,
	NET_RT_FLAGS,
	RTF_LLINFO
    };
    size_t	s;
    char	*buf, *p;
    struct	rt_msghdr *rtmp;
    struct	sockaddr_inarp *sin;
    struct	sockaddr_dl *sdl;
    struct	ether_addr  *ea;

    if (!in)
	return NULL;
    if (sysctl(mib, 6, NULL, &s, NULL, 0) == -1)
	err(1, "route-sysctl-estimate");
    if (!(buf = malloc(s)))
	err(1, "Cannot allocate memory");
    if (sysctl(mib, 6, buf, &s, NULL, 0) == -1)
	err(1, "Cannot get routing table");
    for (p = buf; (p - buf) < s; p+= rtmp->rtm_msglen)
    {
	rtmp = (struct rt_msghdr *)p;
	sin = (struct sockaddr_inarp *)(rtmp + 1);
	(char *)sdl = (char *)sin + ROUNDUP(sin->sin_len);
	if (in->s_addr == sin->sin_addr.s_addr && sdl->sdl_alen)
	{
	    if (!(ea = malloc(sizeof(struct ether_addr))))
		err(1, "Cannot allocate memory");
	    bcopy(sdl->sdl_data + sdl->sdl_nlen,
		    ea,
		    sizeof(struct ether_addr));
	    return ea;
	}
    }
    free(buf);
    if (!pf)
    {
	fputs("Pinging host\n", stderr);
	ping(in);
	in2eth(in, 1);
    }
    else
	warnx("Ethernet address not found in routing table.");
    return NULL;
}
#undef ROUNDUP

static struct in_addr
*ip2in(char *ip)
{
    struct in_addr  *inp = malloc(sizeof(struct in_addr));

    if (!inp)
	err(1, "Error allocating memory");
    if (!inet_aton(ip, inp))
	return NULL;
    return inp;
}

static struct in_addr
*host2in(char *hn)
{
    struct hostent  *h = gethostbyname(hn);
    struct in_addr  *iap;

    if (!h)
    {
	warnx("Cannot resolve hostname %s: %s", hn, hstrerror(h_errno));
	return NULL;
    }
    if (!(iap = malloc(sizeof(struct in_addr))))
	err(1, "Cannot allocate memory");
    bcopy(h->h_addr_list[0], iap, h->h_length);
    return iap;
}

int
main(int ac, char *av[])
{
    char		*prog;
    register int	i;
    struct ether_addr	*eap;
    u_int32_t		rea;

    prog = strrchr(av[0], '/');
    prog = (prog) ? prog + 1 : av[0];
    if (ac != 2)
    {
	fprintf(stderr, "Usage: %s <ether_addr>|<ip_addr>|<hostname>\n",
		prog);
	return EX_USAGE;
    }
    if (!(eap = ether_aton(av[1])) &&
	    !(eap = in2eth(ip2in(av[1]), 0)) &&
	    !(eap = in2eth(host2in(av[1]), 0)))
	return 1;
    rea = eap->octet[0] << 16 | eap->octet[1] << 8 | eap->octet[2];
    for (i = 0; eth_vend[i].ev_addr; ++i)
    {
	if (rea == eth_vend[i].ev_addr)
	{
	    printf("%s: (%s) Vendor: %s", av[1],
		    ether_ntoa(eap),
		    eth_vend[i].ev_name);
	    if (eth_vend[i].ev_note)
		printf("\t<%s>", eth_vend[i].ev_note);
	    putchar('\n');
	    return EX_OK;
	}
    }
    printf("No matching ethernet vendor found for %s\n",
	    ether_ntoa(eap));
    return 1;
}