blob: f13ef1b8b2eddfc9b38104468245cdf32eb66c8d [file] [log] [blame]
/* vi: set sw=4 ts=4: */
/*
* nameif.c - Naming Interfaces based on MAC address for busybox.
*
* Written 2000 by Andi Kleen.
* Busybox port 2002 by Nick Fedchik <nick@fedchik.org.ua>
* Glenn McGrath <bug1@iinet.net.au>
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
#include "busybox.h"
#include <sys/syslog.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <net/if.h>
#include <netinet/ether.h>
/* Older versions of net/if.h do not appear to define IF_NAMESIZE. */
#ifndef IF_NAMESIZE
# ifdef IFNAMSIZ
# define IF_NAMESIZE IFNAMSIZ
# else
# define IF_NAMESIZE 16
# endif
#endif
/* take from linux/sockios.h */
#define SIOCSIFNAME 0x8923 /* set interface name */
/* 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 unsigned long flags;
static void serror(const char *s, ...) ATTRIBUTE_NORETURN;
static void serror(const char *s, ...)
{
va_list ap;
va_start(ap, s);
if (flags & 1) {
openlog(bb_applet_name, 0, LOG_LOCAL0);
vsyslog(LOG_ERR, s, ap);
closelog();
} else {
bb_verror_msg(s, ap);
putc('\n', stderr);
}
va_end(ap);
exit(EXIT_FAILURE);
}
/* Check ascii str_macaddr, convert and copy to *mac */
static struct ether_addr *cc_macaddr(const char *str_macaddr)
{
struct ether_addr *lmac, *mac;
lmac = ether_aton(str_macaddr);
if (lmac == NULL)
serror("cannot parse MAC %s", str_macaddr);
mac = xmalloc(ETH_ALEN);
memcpy(mac, lmac, ETH_ALEN);
return mac;
}
int nameif_main(int argc, char **argv)
{
mactable_t *clist = NULL;
FILE *ifh;
const char *fname = "/etc/mactab";
char *line;
int ctl_sk;
int if_index = 1;
mactable_t *ch;
flags = bb_getopt_ulflags(argc, argv, "sc:", &fname);
if ((argc - optind) & 1)
bb_show_usage();
if (optind < argc) {
char **a = argv + optind;
while (*a) {
if (strlen(*a) > IF_NAMESIZE)
serror("interface name `%s' too long", *a);
ch = xzalloc(sizeof(mactable_t));
ch->ifname = bb_xstrdup(*a++);
ch->mac = cc_macaddr(*a++);
if (clist)
clist->prev = ch;
ch->next = clist;
clist = ch;
}
} else {
ifh = bb_xfopen(fname, "r");
while ((line = bb_get_line_from_file(ifh)) != NULL) {
char *line_ptr;
size_t name_length;
line_ptr = line + strspn(line, " \t");
if ((line_ptr[0] == '#') || (line_ptr[0] == '\n')) {
free(line);
continue;
}
name_length = strcspn(line_ptr, " \t");
ch = xzalloc(sizeof(mactable_t));
ch->ifname = bb_xstrndup(line_ptr, name_length);
if (name_length > IF_NAMESIZE)
serror("interface name `%s' too long", ch->ifname);
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);
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("socket: %m");
while (clist) {
struct ifreq ifr;
memset(&ifr, 0, 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("cannot change ifname %s to %s: %m",
ifr.ifr_name, ch->ifname);
/* 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;
if (ENABLE_FEATURE_CLEAN_UP) {
free(ch->ifname);
free(ch->mac);
free(ch);
}
}
return 0;
}