1/*
2 * Copyright (c) 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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <err.h>
28#include <errno.h>
29#include <net/if.h>
30#include <sys/ioctl.h>
31#include <limits.h>
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35#include <libifconfig.h>
36
37#include <net/if_vlan_var.h>
38
39int
40main(int argc, char *argv[])
41{
42	char *ifname, *parentif;
43	unsigned short vlantag;
44	const char *errstr;
45	ifconfig_handle_t *lifh;
46
47	if (argc != 4) {
48		errx(EINVAL, "Invalid number of arguments."
49		    " Should provide exactly three arguments: "
50		    "INTERFACE, PARENT_INTERFACE and VLAN_TAG.");
51	}
52
53	/* We have a static number of arguments. Therefore we can do it simple. */
54	ifname = strdup(argv[1]);
55	parentif = strdup(argv[2]);
56	vlantag = strtonum(argv[3], 0, USHRT_MAX, &errstr);
57
58	if (errstr != NULL) {
59		errx(1, "VLAN_TAG must be between 0 and %i.\n", USHRT_MAX);
60	}
61
62	printf("Interface: %s\nNew VLAN tag: %i\n", ifname, vlantag);
63
64	lifh = ifconfig_open();
65	if (lifh == NULL) {
66		errx(ENOMEM, "Failed to open libifconfig handle.");
67		return (-1);
68	}
69
70	if (ifconfig_set_vlantag(lifh, ifname, parentif, vlantag) == 0) {
71		printf("Successfully changed vlan tag.\n");
72		ifconfig_close(lifh);
73		lifh = NULL;
74		free(ifname);
75		free(parentif);
76		return (0);
77	}
78
79	switch (ifconfig_err_errtype(lifh)) {
80	case SOCKET:
81		warnx("couldn't create socket. This shouldn't happen.\n");
82		break;
83	case IOCTL:
84		if (ifconfig_err_ioctlreq(lifh) == SIOCGETVLAN) {
85			warnx("Target interface isn't a VLAN interface.\n");
86		}
87		if (ifconfig_err_ioctlreq(lifh) == SIOCSETVLAN) {
88			warnx(
89				"Couldn't change VLAN properties of interface.\n");
90		}
91		break;
92	default:
93		warnx(
94			"This is a thorough example accommodating for temporary"
95			" 'not implemented yet' errors. That's likely what happened"
96			" now. If not, your guess is as good as mine. ;)"
97			" Error code: %d\n", ifconfig_err_errno(
98				lifh));
99		break;
100	}
101
102	ifconfig_close(lifh);
103	lifh = NULL;
104	free(ifname);
105	free(parentif);
106	return (-1);
107}
108