ifclone.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 4. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#ifndef lint
33static const char rcsid[] =
34  "$FreeBSD: stable/11/sbin/ifconfig/ifclone.c 330897 2018-03-14 03:19:51Z eadler $";
35#endif /* not lint */
36
37#include <sys/param.h>
38#include <sys/ioctl.h>
39#include <sys/queue.h>
40#include <sys/socket.h>
41#include <net/if.h>
42
43#include <err.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48
49#include "ifconfig.h"
50
51static void
52list_cloners(void)
53{
54	struct if_clonereq ifcr;
55	char *cp, *buf;
56	int idx;
57	int s;
58
59	s = socket(AF_LOCAL, SOCK_DGRAM, 0);
60	if (s == -1)
61		err(1, "socket(AF_LOCAL,SOCK_DGRAM)");
62
63	memset(&ifcr, 0, sizeof(ifcr));
64
65	if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
66		err(1, "SIOCIFGCLONERS for count");
67
68	buf = malloc(ifcr.ifcr_total * IFNAMSIZ);
69	if (buf == NULL)
70		err(1, "unable to allocate cloner name buffer");
71
72	ifcr.ifcr_count = ifcr.ifcr_total;
73	ifcr.ifcr_buffer = buf;
74
75	if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
76		err(1, "SIOCIFGCLONERS for names");
77
78	/*
79	 * In case some disappeared in the mean time, clamp it down.
80	 */
81	if (ifcr.ifcr_count > ifcr.ifcr_total)
82		ifcr.ifcr_count = ifcr.ifcr_total;
83
84	for (cp = buf, idx = 0; idx < ifcr.ifcr_count; idx++, cp += IFNAMSIZ) {
85		if (idx > 0)
86			putchar(' ');
87		printf("%s", cp);
88	}
89
90	putchar('\n');
91	free(buf);
92	close(s);
93}
94
95struct clone_defcb {
96	char ifprefix[IFNAMSIZ];
97	clone_callback_func *clone_cb;
98	SLIST_ENTRY(clone_defcb) next;
99};
100
101static SLIST_HEAD(, clone_defcb) clone_defcbh =
102   SLIST_HEAD_INITIALIZER(clone_defcbh);
103
104void
105clone_setdefcallback(const char *ifprefix, clone_callback_func *p)
106{
107	struct clone_defcb *dcp;
108
109	dcp = malloc(sizeof(*dcp));
110	strlcpy(dcp->ifprefix, ifprefix, IFNAMSIZ-1);
111	dcp->clone_cb = p;
112	SLIST_INSERT_HEAD(&clone_defcbh, dcp, next);
113}
114
115/*
116 * Do the actual clone operation.  Any parameters must have been
117 * setup by now.  If a callback has been setup to do the work
118 * then defer to it; otherwise do a simple create operation with
119 * no parameters.
120 */
121static void
122ifclonecreate(int s, void *arg)
123{
124	struct ifreq ifr;
125	struct clone_defcb *dcp;
126	clone_callback_func *clone_cb = NULL;
127
128	memset(&ifr, 0, sizeof(ifr));
129	(void) strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
130
131	if (clone_cb == NULL) {
132		/* Try to find a default callback */
133		SLIST_FOREACH(dcp, &clone_defcbh, next) {
134			if (strncmp(dcp->ifprefix, ifr.ifr_name,
135			    strlen(dcp->ifprefix)) == 0) {
136				clone_cb = dcp->clone_cb;
137				break;
138			}
139		}
140	}
141	if (clone_cb == NULL) {
142		/* NB: no parameters */
143		if (ioctl(s, SIOCIFCREATE2, &ifr) < 0)
144			err(1, "SIOCIFCREATE2");
145	} else {
146		clone_cb(s, &ifr);
147	}
148
149	/*
150	 * If we get a different name back than we put in, update record and
151	 * indicate it should be printed later.
152	 */
153	if (strncmp(name, ifr.ifr_name, sizeof(name)) != 0) {
154		strlcpy(name, ifr.ifr_name, sizeof(name));
155		printifname = 1;
156	}
157}
158
159static
160DECL_CMD_FUNC(clone_create, arg, d)
161{
162	callback_register(ifclonecreate, NULL);
163}
164
165static
166DECL_CMD_FUNC(clone_destroy, arg, d)
167{
168	(void) strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
169	if (ioctl(s, SIOCIFDESTROY, &ifr) < 0)
170		err(1, "SIOCIFDESTROY");
171}
172
173static struct cmd clone_cmds[] = {
174	DEF_CLONE_CMD("create",	0,	clone_create),
175	DEF_CMD("destroy",	0,	clone_destroy),
176	DEF_CLONE_CMD("plumb",	0,	clone_create),
177	DEF_CMD("unplumb",	0,	clone_destroy),
178};
179
180static void
181clone_Copt_cb(const char *optarg __unused)
182{
183	list_cloners();
184	exit(0);
185}
186static struct option clone_Copt = { .opt = "C", .opt_usage = "[-C]", .cb = clone_Copt_cb };
187
188static __constructor void
189clone_ctor(void)
190{
191	size_t i;
192
193	for (i = 0; i < nitems(clone_cmds);  i++)
194		cmd_register(&clone_cmds[i]);
195	opt_register(&clone_Copt);
196}
197