/*      $NetBSD: siocXmulti.c,v 1.3 2021/08/19 03:36:42 yamaguchi Exp $ */

/*
* Copyright (c) 2021 Internet Initiative Japan Inc.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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/cdefs.h>
__RCSID("$NetBSD: siocXmulti.c,v 1.3 2021/08/19 03:36:42 yamaguchi Exp $");

#include <sys/socket.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <err.h>

enum{
       ARG_PROG = 0,
       ARG_OP,
       ARG_IFNAME,
       ARG_ADDR,
       ARG_NUM
};

static void
usage(void)
{

       printf("%s <add|del> <ifname> <IPv4 addr>\n",
           getprogname());
       exit(1);
}

int
main(int argc, char *argv[])
{
       int                      fd, rv;
       unsigned long            req;
       struct ifreq             ifr;
       unsigned int             ifidx;
       struct sockaddr_in      *sin;
       struct sockaddr_in6     *sin6;

       bzero(&ifr, sizeof(ifr));

       if (argc != ARG_NUM)
               usage();

       if (strcmp(argv[ARG_OP], "add") == 0)
               req = SIOCADDMULTI;
       else if (strcmp(argv[ARG_OP], "del") == 0)
               req = SIOCDELMULTI;
       else
               usage();

       ifidx = if_nametoindex(argv[ARG_IFNAME]);
       if (ifidx == 0)
               err(1, "if_nametoindex(%s)", argv[ARG_IFNAME]);

       strncpy(ifr.ifr_name, argv[ARG_IFNAME], sizeof(ifr.ifr_name) - 1);
       ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';

       sin = (struct sockaddr_in *)&ifr.ifr_addr;
       sin->sin_family = AF_INET;
       sin->sin_len = sizeof(*sin);
       rv = inet_pton(AF_INET, argv[ARG_ADDR], &sin->sin_addr);

       if (rv != 1) {
               sin6 = (struct sockaddr_in6 *)&ifr.ifr_addr;
               sin6->sin6_family = AF_INET6;
               sin6->sin6_len = sizeof(*sin6);
               rv = inet_pton(AF_INET6, argv[ARG_ADDR], &sin6->sin6_addr);

               if (rv != 1)
                       errx(1, "inet_pton(%s)", argv[ARG_ADDR]);
       }

       fd = socket(AF_INET, SOCK_DGRAM, 0);
       if (fd < 0)
               err(1, "socket");

       if (ioctl(fd, req, (caddr_t)&ifr) < 0) {
               err(1, "ioctl(%s)",
                   (req == SIOCADDMULTI) ? "SIOCADDMULTI" : "SIOCDELMULTI");
       }

       close(fd);

       return 0;
}