1 /*
2 * Copyright (c) 2016-2017, Marie Helene Kvello-Aune
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * thislist of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation and/or
13 * other materials provided with the distribution.
14 *
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
18 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30 #include <err.h>
31 #include <errno.h>
32 #include <net/if.h>
33 #include <sys/ioctl.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <libifconfig.h>
38
39
40 int
main(int argc,char * argv[])41 main(int argc, char *argv[])
42 {
43 char *ifname, *ptr;
44 int mtu;
45 ifconfig_handle_t *lifh;
46
47 if (argc != 3) {
48 errx(EINVAL, "Invalid number of arguments."
49 " First argument should be interface name, second argument"
50 " should be the MTU to set.");
51 }
52
53 /* We have a static number of arguments. Therefore we can do it simple. */
54 ifname = strdup(argv[1]);
55 mtu = (int)strtol(argv[2], &ptr, 10);
56
57 printf("Interface name: %s\n", ifname);
58 printf("New MTU: %d", mtu);
59
60 lifh = ifconfig_open();
61 if (lifh == NULL) {
62 errx(ENOMEM, "Failed to open libifconfig handle.");
63 return (-1);
64 }
65
66 if (ifconfig_set_mtu(lifh, ifname, mtu) == 0) {
67 printf("Successfully changed MTU of %s to %d\n", ifname, mtu);
68 ifconfig_close(lifh);
69 lifh = NULL;
70 free(ifname);
71 return (0);
72 }
73
74 switch (ifconfig_err_errtype(lifh)) {
75 case SOCKET:
76 warnx("couldn't create socket. This shouldn't happen.\n");
77 break;
78 case IOCTL:
79 if (ifconfig_err_ioctlreq(lifh) == SIOCSIFMTU) {
80 warnx("Failed to set MTU (SIOCSIFMTU)\n");
81 } else {
82 warnx(
83 "Failed to set MTU due to error in unexpected ioctl() call %lu. Error code: %i.\n",
84 ifconfig_err_ioctlreq(lifh),
85 ifconfig_err_errno(lifh));
86 }
87 break;
88 default:
89 warnx(
90 "Should basically never end up here in this example.\n");
91 break;
92 }
93
94 ifconfig_close(lifh);
95 lifh = NULL;
96 free(ifname);
97 return (-1);
98 }
99