sbin/ifconfig/ifclone.c

   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  * 3. 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  * $FreeBSD: head/sbin/ifconfig/ifclone.c 194799 2009-06-23 23:49:52Z delphij $
  30  */
  31
  32 #include <sys/queue.h>
  33 #include <sys/types.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/socket.h>
  36 #include <net/if.h>
  37
  38 #include <err.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43
  44 #include "ifconfig.h"
  45
  46 static void
  47 list_cloners(void)
  48 {
  49         struct if_clonereq ifcr;
  50         char *cp, *buf;
  51         int idx;
  52         int s;
  53
  54         s = socket(AF_INET, SOCK_DGRAM, 0);
  55         if (s == -1)
  56                 err(1, "socket(AF_INET,SOCK_DGRAM)");
  57
  58         memset(&ifcr, 0, sizeof(ifcr));
  59
  60         if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
  61                 err(1, "SIOCIFGCLONERS for count");
  62
  63         buf = malloc(ifcr.ifcr_total * IFNAMSIZ);
  64         if (buf == NULL)
  65                 err(1, "unable to allocate cloner name buffer");
  66
  67         ifcr.ifcr_count = ifcr.ifcr_total;
  68         ifcr.ifcr_buffer = buf;
  69
  70         if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
  71                 err(1, "SIOCIFGCLONERS for names");
  72
  73         /*
  74          * In case some disappeared in the mean time, clamp it down.
  75          */
  76         if (ifcr.ifcr_count > ifcr.ifcr_total)
  77                 ifcr.ifcr_count = ifcr.ifcr_total;
  78
  79         for (cp = buf, idx = 0; idx < ifcr.ifcr_count; idx++, cp += IFNAMSIZ) {
  80                 if (idx > 0)
  81                         putchar(' ');
  82                 printf("%s", cp);
  83         }
  84
  85         putchar('\n');
  86         free(buf);
  87 }
  88
  89 struct clone_defcb {
  90         char ifprefix[IFNAMSIZ];
  91         clone_callback_func *clone_cb;
  92         SLIST_ENTRY(clone_defcb) next;
  93 };
  94
  95 static SLIST_HEAD(, clone_defcb) clone_defcbh =
  96    SLIST_HEAD_INITIALIZER(clone_defcbh);
  97
  98 void
  99 clone_setdefcallback(const char *ifprefix, clone_callback_func *p)
 100 {
 101         struct clone_defcb *dcp;
 102
 103         dcp = malloc(sizeof(*dcp));
 104         strlcpy(dcp->ifprefix, ifprefix, IFNAMSIZ-1);
 105         dcp->clone_cb = p;
 106         SLIST_INSERT_HEAD(&clone_defcbh, dcp, next);
 107 }
 108
 109 /*
 110  * Do the actual clone operation.  Any parameters must have been
 111  * setup by now.  If a callback has been setup to do the work
 112  * then defer to it; otherwise do a simple create operation with
 113  * no parameters.
 114  */
 115 static void
 116 ifclonecreate(int s, void *arg)
 117 {
 118         struct ifreq ifr;
 119         struct clone_defcb *dcp;
 120         clone_callback_func *clone_cb = NULL;
 121
 122         memset(&ifr, 0, sizeof(ifr));
 123         (void) strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
 124
 125         if (clone_cb == NULL) {
 126                 /* Try to find a default callback */
 127                 SLIST_FOREACH(dcp, &clone_defcbh, next) {
 128                         if (strncmp(dcp->ifprefix, ifr.ifr_name,
 129                             strlen(dcp->ifprefix)) == 0) {
 130                                 clone_cb = dcp->clone_cb;
 131                                 break;
 132                         }
 133                 }
 134         }
 135         if (clone_cb == NULL) {
 136                 /* NB: no parameters */
 137                 if (ioctl(s, SIOCIFCREATE2, &ifr) < 0)
 138                         err(1, "SIOCIFCREATE2");
 139         } else {
 140                 clone_cb(s, &ifr);
 141         }
 142
 143         /*
 144          * If we get a different name back than we put in, print it.
 145          */
 146         if (strncmp(name, ifr.ifr_name, sizeof(name)) != 0) {
 147                 strlcpy(name, ifr.ifr_name, sizeof(name));
 148                 printf("%s\n", name);
 149         }
 150 }
 151
 152 static
 153 DECL_CMD_FUNC(clone_create, arg, d)
 154 {
 155         callback_register(ifclonecreate, NULL);
 156 }
 157
 158 static
 159 DECL_CMD_FUNC(clone_destroy, arg, d)
 160 {
 161         (void) strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
 162         if (ioctl(s, SIOCIFDESTROY, &ifr) < 0)
 163                 err(1, "SIOCIFDESTROY");
 164 }
 165
 166 static struct cmd clone_cmds[] = {
 167         DEF_CLONE_CMD("create", 0,      clone_create),
 168         DEF_CMD("destroy",      0,      clone_destroy),
 169         DEF_CLONE_CMD("plumb",  0,      clone_create),
 170         DEF_CMD("unplumb",      0,      clone_destroy),
 171 };
 172
 173 static void
 174 clone_Copt_cb(const char *optarg __unused)
 175 {
 176         list_cloners();
 177         exit(0);
 178 }
 179 static struct option clone_Copt = { .opt = "C", .opt_usage = "[-C]", .cb = clone_Copt_cb };
 180
 181 static __constructor(101) void
 182 clone_ctor(void)
 183 {
 184 #define N(a)    (sizeof(a) / sizeof(a[0]))
 185         size_t i;
 186
 187         for (i = 0; i < N(clone_cmds);  i++)
 188                 cmd_register(&clone_cmds[i]);
 189         opt_register(&clone_Copt);
 190 #undef N
 191 }