busybox/networking/nameif.c
2007-12-28 17:04:42 +00:00

248 lines
6.3 KiB
C

/* 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
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
#include "libbb.h"
#include <syslog.h>
#include <net/if.h>
#include <netinet/ether.h>
#include <linux/sockios.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 ethtable_s {
struct ethtable_s *next;
struct ethtable_s *prev;
char *ifname;
struct ether_addr *mac;
#if ENABLE_FEATURE_NAMEIF_EXTENDED
char *bus_info;
char *driver;
#endif
} ethtable_t;
#if ENABLE_FEATURE_NAMEIF_EXTENDED
/* Cut'n'paste from ethtool.h */
#define ETHTOOL_BUSINFO_LEN 32
/* these strings are set to whatever the driver author decides... */
struct ethtool_drvinfo {
uint32_t cmd;
char driver[32]; /* driver short name, "tulip", "eepro100" */
char version[32]; /* driver version string */
char fw_version[32]; /* firmware version string, if applicable */
char bus_info[ETHTOOL_BUSINFO_LEN]; /* Bus info for this IF. */
/* For PCI devices, use pci_dev->slot_name. */
char reserved1[32];
char reserved2[16];
uint32_t n_stats; /* number of u64's from ETHTOOL_GSTATS */
uint32_t testinfo_len;
uint32_t eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
uint32_t regdump_len; /* Size of data from ETHTOOL_GREGS (bytes) */
};
#define ETHTOOL_GDRVINFO 0x00000003 /* Get driver info. */
#endif
static void nameif_parse_selector(ethtable_t *ch, char *selector)
{
struct ether_addr *lmac;
#if ENABLE_FEATURE_NAMEIF_EXTENDED
int found_selector = 0;
while (*selector) {
char *next;
#endif
selector = skip_whitespace(selector);
#if ENABLE_FEATURE_NAMEIF_EXTENDED
if (*selector == '\0')
break;
/* Search for the end .... */
next = skip_non_whitespace(selector);
if (*next)
*next++ = '\0';
/* Check for selectors, mac= is assumed */
if (strncmp(selector, "bus=", 4) == 0) {
ch->bus_info = xstrdup(selector + 4);
found_selector++;
} else if (strncmp(selector, "driver=", 7) == 0) {
ch->driver = xstrdup(selector + 7);
found_selector++;
} else {
#endif
lmac = ether_aton(selector + (strncmp(selector, "mac=", 4) == 0 ? 4 : 0));
/* Check ascii selector, convert and copy to *mac */
if (lmac == NULL)
bb_error_msg_and_die("cannot parse %s", selector);
ch->mac = xmalloc(ETH_ALEN);
memcpy(ch->mac, lmac, ETH_ALEN);
#if ENABLE_FEATURE_NAMEIF_EXTENDED
found_selector++;
};
selector = next;
}
if (found_selector == 0)
bb_error_msg_and_die("no selectors found for %s", ch->ifname);
#endif
}
static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
{
ethtable_t *ch;
if (strlen(ifname) >= IF_NAMESIZE)
bb_error_msg_and_die("interface name '%s' too long", ifname);
ch = xzalloc(sizeof(*ch));
ch->ifname = ifname;
nameif_parse_selector(ch, selector);
ch->next = *clist;
if (*clist)
(*clist)->prev = ch;
*clist = ch;
}
int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int nameif_main(int argc, char **argv)
{
ethtable_t *clist = NULL;
FILE *ifh;
const char *fname = "/etc/mactab";
char *line;
char *line_ptr;
int linenum;
int ctl_sk;
ethtable_t *ch;
if (1 & getopt32(argv, "sc:", &fname)) {
openlog(applet_name, 0, LOG_LOCAL0);
logmode = LOGMODE_SYSLOG;
}
argc -= optind;
argv += optind;
if (argc & 1)
bb_show_usage();
if (argc) {
while (*argv) {
char *ifname = xstrdup(*argv++);
prepend_new_eth_table(&clist, ifname, *argv++);
}
} else {
ifh = xfopen(fname, "r");
while ((line = xmalloc_fgets(ifh)) != NULL) {
char *next;
line_ptr = skip_whitespace(line);
if ((line_ptr[0] == '#') || (line_ptr[0] == '\n')) {
free(line);
continue;
}
next = skip_non_whitespace(line_ptr);
if (*next)
*next++ = '\0';
prepend_new_eth_table(&clist, line_ptr, next);
free(line);
}
fclose(ifh);
}
ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
ifh = xfopen("/proc/net/dev", "r");
linenum = 0;
while (clist) {
struct ifreq ifr;
#if ENABLE_FEATURE_NAMEIF_EXTENDED
struct ethtool_drvinfo drvinfo;
#endif
line = xmalloc_fgets(ifh);
if (line == NULL)
break; /* Seems like we're done */
if (linenum++ < 2 )
goto next_line; /* Skip the first two lines */
/* Find the current interface name and copy it to ifr.ifr_name */
line_ptr = skip_whitespace(line);
*skip_non_whitespace(line_ptr) = '\0';
memset(&ifr, 0, sizeof(struct ifreq));
strncpy(ifr.ifr_name, line_ptr, sizeof(ifr.ifr_name));
#if ENABLE_FEATURE_NAMEIF_EXTENDED
/* Check for driver etc. */
memset(&drvinfo, 0, sizeof(struct ethtool_drvinfo));
drvinfo.cmd = ETHTOOL_GDRVINFO;
ifr.ifr_data = (caddr_t) &drvinfo;
/* Get driver and businfo first, so we have it in drvinfo */
ioctl(ctl_sk, SIOCETHTOOL, &ifr);
#endif
ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
/* Search the list for a matching device */
for (ch = clist; ch; ch = ch->next) {
#if ENABLE_FEATURE_NAMEIF_EXTENDED
if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
continue;
if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
continue;
#endif
if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
continue;
/* if we came here, all selectors have matched */
goto found;
}
/* Nothing found for current interface */
goto next_line;
found:
if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
strcpy(ifr.ifr_newname, ch->ifname);
ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
"cannot change ifname %s to %s",
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);
}
next_line:
free(line);
}
if (ENABLE_FEATURE_CLEAN_UP) {
fclose(ifh);
};
return 0;
}