/*
* Copyright (c) 2016-2017, Marie Helene Kvello-Aune
* 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,
* thislist 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
*
* $FreeBSD$
*/
#include <err.h>
#include <errno.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libifconfig.h>
int
main(int argc, char *argv[])
{
char *ifname, *ptr;
int mtu;
ifconfig_handle_t *lifh;
if (argc != 3) {
errx(EINVAL, "Invalid number of arguments."
" First argument should be interface name, second argument"
" should be the MTU to set.");
}
/* We have a static number of arguments. Therefore we can do it simple. */
ifname = strdup(argv[1]);
mtu = (int)strtol(argv[2], &ptr, 10);
printf("Interface name: %s\n", ifname);
printf("New MTU: %d", mtu);
lifh = ifconfig_open();
if (lifh == NULL) {
errx(ENOMEM, "Failed to open libifconfig handle.");
return (-1);
}
if (ifconfig_set_mtu(lifh, ifname, mtu) == 0) {
printf("Successfully changed MTU of %s to %d\n", ifname, mtu);
ifconfig_close(lifh);
lifh = NULL;
free(ifname);
return (0);
}
switch (ifconfig_err_errtype(lifh)) {
case SOCKET:
warnx("couldn't create socket. This shouldn't happen.\n");
break;
case IOCTL:
if (ifconfig_err_ioctlreq(lifh) == SIOCSIFMTU) {
warnx("Failed to set MTU (SIOCSIFMTU)\n");
} else {
warnx(
"Failed to set MTU due to error in unexpected ioctl() call %lu. Error code: %i.\n",
ifconfig_err_ioctlreq(lifh),
ifconfig_err_errno(lifh));
}
break;
default:
warnx(
"Should basically never end up here in this example.\n");
break;
}
ifconfig_close(lifh);
lifh = NULL;
free(ifname);
return (-1);
}
