busybox/networking/nameif.c

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/*
* nameif.c - Naming Interfaces based on MAC address for busybox.
*
* Writen 2000 by Andi Kleen.
* Busybox port 2002 by Nick Fedchik <nick@fedchik.org.ua>
* Glenn McGrath <bug1@optushome.com.au>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307 USA
*
*/
#include <sys/syslog.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <net/if.h>
#include <netinet/ether.h>
#include <linux/sockios.h>
#include "busybox.h"
/* Octets in one ethernet addr, from <linux/if_ether.h> */
#define ETH_ALEN 6
#ifndef ifr_newname
#define ifr_newname ifr_ifru.ifru_slave
#endif
typedef struct mactable_s {
struct mactable_s *next;
struct mactable_s *prev;
char *ifname;
struct ether_addr *mac;
} mactable_t;
static void serror(const char use_syslog, const char *s, ...)
{
va_list ap;
va_start(ap, s);
if (use_syslog) {
openlog("nameif", 0, LOG_LOCAL0);
syslog(LOG_ERR, s, ap);
closelog();
} else {
vfprintf(stderr, s, ap);
putc('\n', stderr);
}
va_end(ap);
exit(EXIT_FAILURE);
}
/* Check ascii str_macaddr, convert and copy to *mac */
struct ether_addr *cc_macaddr(char *str_macaddr, unsigned char use_syslog)
{
struct ether_addr *lmac, *mac;
lmac = ether_aton(str_macaddr);
if (lmac == NULL)
serror(use_syslog, "cannot parse MAC %s", str_macaddr);
mac = xcalloc(1, ETH_ALEN);
memcpy(mac, lmac, ETH_ALEN);
return mac;
}
int nameif_main(int argc, char **argv)
{
mactable_t *clist = NULL;
FILE *ifh;
char *fname = "/etc/mactab";
char *line;
unsigned char use_syslog = 0;
int ctl_sk = -1;
int opt;
int if_index = 1;
mactable_t *ch = NULL;
static struct option opts[] = {
{"syslog", 0, NULL, 's'},
{"configfile", 1, NULL, 'c'},
{NULL},
};
while ((opt = getopt_long(argc, argv, "c:s", opts, NULL)) != -1) {
switch (opt) {
case 'c':
fname = optarg;
break;
case 's':
use_syslog = 1;
break;
default:
show_usage();
}
}
if ((argc - optind) & 1)
show_usage();
if (optind < argc) {
while (optind < argc) {
if (strlen(argv[optind]) > IF_NAMESIZE)
serror(use_syslog, "interface name `%s' too long",
argv[optind]);
optind++;
ch = xcalloc(1, sizeof(mactable_t));
ch->next = NULL;
ch->prev = NULL;
ch->ifname = strdup(argv[optind - 1]);
ch->mac = cc_macaddr(argv[optind], use_syslog);
optind++;
if (clist)
clist->prev = ch->next;
ch->next = clist;
ch->prev = clist;
clist = ch;
}
} else {
ifh = xfopen(fname, "r");
while ((line = get_line_from_file(ifh)) != NULL) {
char *line_ptr;
unsigned short name_length;
line_ptr = line + strspn(line, " \t");
if ((line_ptr[0] == '#') || (line_ptr[0] == '\n'))
continue;
name_length = strcspn(line_ptr, " \t");
if (name_length > IF_NAMESIZE)
serror(use_syslog, "interface name `%s' too long",
argv[optind]);
ch = xcalloc(1, sizeof(mactable_t));
ch->next = NULL;
ch->prev = NULL;
ch->ifname = strndup(line_ptr, name_length);
line_ptr += name_length;
line_ptr += strspn(line_ptr, " \t");
name_length = strspn(line_ptr, "0123456789ABCDEFabcdef:");
line_ptr[name_length] = '\0';
ch->mac = cc_macaddr(line_ptr, use_syslog);
if (clist)
clist->prev = ch;
ch->next = clist;
clist = ch;
free(line);
}
fclose(ifh);
}
if ((ctl_sk = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
serror(use_syslog, "socket: %s", strerror(errno));
while (clist) {
struct ifreq ifr;
bzero(&ifr, sizeof(struct ifreq));
if_index++;
ifr.ifr_ifindex = if_index;
/* Get ifname by index or die */
if (ioctl(ctl_sk, SIOCGIFNAME, &ifr))
break;
/* Has this device hwaddr? */
if (ioctl(ctl_sk, SIOCGIFHWADDR, &ifr))
continue;
/* Search for mac like in ifr.ifr_hwaddr.sa_data */
for (ch = clist; ch; ch = ch->next)
if (!memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN))
break;
/* Nothing found for current ifr.ifr_hwaddr.sa_data */
if (ch == NULL)
continue;
strcpy(ifr.ifr_newname, ch->ifname);
if (ioctl(ctl_sk, SIOCSIFNAME, &ifr) < 0)
serror(use_syslog, "cannot change ifname %s to %s: %s",
ifr.ifr_name, ch->ifname, strerror(errno));
/* Remove list entry of renamed interface */
if (ch->prev != NULL) {
(ch->prev)->next = ch->next;
} else {
clist = ch->next;
}
if (ch->next != NULL)
(ch->next)->prev = ch->prev;
free(ch);
}
while (clist) {
ch = clist;
clist = clist->next;
free(ch);
}
return 0;
}