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  * $FreeBSD$
27  */
28 
29 #include <err.h>
30 #include <errno.h>
31 #include <net/if.h>
32 #include <sys/ioctl.h>
33 #include <limits.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <libifconfig.h>
38 
39 #include <net/if_vlan_var.h>
40 
41 int
42 main(int argc, char *argv[])
43 {
44 	char *ifname, *parentif;
45 	unsigned short vlantag;
46 	const char *errstr;
47 	ifconfig_handle_t *lifh;
48 
49 	if (argc != 4) {
50 		errx(EINVAL, "Invalid number of arguments."
51 		    " Should provide exactly three arguments: "
52 		    "INTERFACE, PARENT_INTERFACE and VLAN_TAG.");
53 	}
54 
55 	/* We have a static number of arguments. Therefore we can do it simple. */
56 	ifname = strdup(argv[1]);
57 	parentif = strdup(argv[2]);
58 	vlantag = strtonum(argv[3], 0, USHRT_MAX, &errstr);
59 
60 	if (errstr != NULL) {
61 		errx(1, "VLAN_TAG must be between 0 and %i.\n", USHRT_MAX);
62 	}
63 
64 	printf("Interface: %s\nNew VLAN tag: %i\n", ifname, vlantag);
65 
66 	lifh = ifconfig_open();
67 	if (lifh == NULL) {
68 		errx(ENOMEM, "Failed to open libifconfig handle.");
69 		return (-1);
70 	}
71 
72 	if (ifconfig_set_vlantag(lifh, ifname, parentif, vlantag) == 0) {
73 		printf("Successfully changed vlan tag.\n");
74 		ifconfig_close(lifh);
75 		lifh = NULL;
76 		free(ifname);
77 		free(parentif);
78 		return (0);
79 	}
80 
81 	switch (ifconfig_err_errtype(lifh)) {
82 	case SOCKET:
83 		warnx("couldn't create socket. This shouldn't happen.\n");
84 		break;
85 	case IOCTL:
86 		if (ifconfig_err_ioctlreq(lifh) == SIOCGETVLAN) {
87 			warnx("Target interface isn't a VLAN interface.\n");
88 		}
89 		if (ifconfig_err_ioctlreq(lifh) == SIOCSETVLAN) {
90 			warnx(
91 				"Couldn't change VLAN properties of interface.\n");
92 		}
93 		break;
94 	default:
95 		warnx(
96 			"This is a thorough example accommodating for temporary"
97 			" 'not implemented yet' errors. That's likely what happened"
98 			" now. If not, your guess is as good as mine. ;)"
99 			" Error code: %d\n", ifconfig_err_errno(
100 				lifh));
101 		break;
102 	}
103 
104 	ifconfig_close(lifh);
105 	lifh = NULL;
106 	free(ifname);
107 	free(parentif);
108 	return (-1);
109 }
110