ifclone.c revision 319265 
1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef lint
31static const char rcsid[] =
32  "$FreeBSD: stable/10/sbin/ifconfig/ifclone.c 319265 2017-05-30 22:45:01Z asomers $";
33#endif /* not lint */
34
35#include <sys/param.h>
36#include <sys/ioctl.h>
37#include <sys/queue.h>
38#include <sys/socket.h>
39#include <net/if.h>
40
41#include <err.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45#include <unistd.h>
46
47#include "ifconfig.h"
48
49static void
50list_cloners(void)
51{
52	struct if_clonereq ifcr;
53	char *cp, *buf;
54	int idx;
55	int s;
56
57	s = socket(AF_LOCAL, SOCK_DGRAM, 0);
58	if (s == -1)
59		err(1, "socket(AF_LOCAL,SOCK_DGRAM)");
60
61	memset(&ifcr, 0, sizeof(ifcr));
62
63	if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
64		err(1, "SIOCIFGCLONERS for count");
65
66	buf = malloc(ifcr.ifcr_total * IFNAMSIZ);
67	if (buf == NULL)
68		err(1, "unable to allocate cloner name buffer");
69
70	ifcr.ifcr_count = ifcr.ifcr_total;
71	ifcr.ifcr_buffer = buf;
72
73	if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
74		err(1, "SIOCIFGCLONERS for names");
75
76	/*
77	 * In case some disappeared in the mean time, clamp it down.
78	 */
79	if (ifcr.ifcr_count > ifcr.ifcr_total)
80		ifcr.ifcr_count = ifcr.ifcr_total;
81
82	for (cp = buf, idx = 0; idx < ifcr.ifcr_count; idx++, cp += IFNAMSIZ) {
83		if (idx > 0)
84			putchar(' ');
85		printf("%s", cp);
86	}
87
88	putchar('\n');
89	free(buf);
90	close(s);
91}
92
93struct clone_defcb {
94	char ifprefix[IFNAMSIZ];
95	clone_callback_func *clone_cb;
96	SLIST_ENTRY(clone_defcb) next;
97};
98
99static SLIST_HEAD(, clone_defcb) clone_defcbh =
100   SLIST_HEAD_INITIALIZER(clone_defcbh);
101
102void
103clone_setdefcallback(const char *ifprefix, clone_callback_func *p)
104{
105	struct clone_defcb *dcp;
106
107	dcp = malloc(sizeof(*dcp));
108	strlcpy(dcp->ifprefix, ifprefix, IFNAMSIZ-1);
109	dcp->clone_cb = p;
110	SLIST_INSERT_HEAD(&clone_defcbh, dcp, next);
111}
112
113/*
114 * Do the actual clone operation.  Any parameters must have been
115 * setup by now.  If a callback has been setup to do the work
116 * then defer to it; otherwise do a simple create operation with
117 * no parameters.
118 */
119static void
120ifclonecreate(int s, void *arg)
121{
122	struct ifreq ifr;
123	struct clone_defcb *dcp;
124	clone_callback_func *clone_cb = NULL;
125
126	memset(&ifr, 0, sizeof(ifr));
127	(void) strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
128
129	if (clone_cb == NULL) {
130		/* Try to find a default callback */
131		SLIST_FOREACH(dcp, &clone_defcbh, next) {
132			if (strncmp(dcp->ifprefix, ifr.ifr_name,
133			    strlen(dcp->ifprefix)) == 0) {
134				clone_cb = dcp->clone_cb;
135				break;
136			}
137		}
138	}
139	if (clone_cb == NULL) {
140		/* NB: no parameters */
141		if (ioctl(s, SIOCIFCREATE2, &ifr) < 0)
142			err(1, "SIOCIFCREATE2");
143	} else {
144		clone_cb(s, &ifr);
145	}
146
147	/*
148	 * If we get a different name back than we put in, update record and
149	 * indicate it should be printed later.
150	 */
151	if (strncmp(name, ifr.ifr_name, sizeof(name)) != 0) {
152		strlcpy(name, ifr.ifr_name, sizeof(name));
153		printifname = 1;
154	}
155}
156
157static
158DECL_CMD_FUNC(clone_create, arg, d)
159{
160	callback_register(ifclonecreate, NULL);
161}
162
163static
164DECL_CMD_FUNC(clone_destroy, arg, d)
165{
166	(void) strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
167	if (ioctl(s, SIOCIFDESTROY, &ifr) < 0)
168		err(1, "SIOCIFDESTROY");
169}
170
171static struct cmd clone_cmds[] = {
172	DEF_CLONE_CMD("create",	0,	clone_create),
173	DEF_CMD("destroy",	0,	clone_destroy),
174	DEF_CLONE_CMD("plumb",	0,	clone_create),
175	DEF_CMD("unplumb",	0,	clone_destroy),
176};
177
178static void
179clone_Copt_cb(const char *optarg __unused)
180{
181	list_cloners();
182	exit(0);
183}
184static struct option clone_Copt = { .opt = "C", .opt_usage = "[-C]", .cb = clone_Copt_cb };
185
186static __constructor void
187clone_ctor(void)
188{
189	size_t i;
190
191	for (i = 0; i < nitems(clone_cmds);  i++)
192		cmd_register(&clone_cmds[i]);
193	opt_register(&clone_Copt);
194}
195