networking/nameif.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * nameif.c - Naming Interfaces based on MAC address for busybox.
   4  *
   5  * Written 2000 by Andi Kleen.
   6  * Busybox port 2002 by Nick Fedchik <nick@fedchik.org.ua>
   7  *                      Glenn McGrath
   8  *
   9  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  10  */
  11
  12 #include "libbb.h"
  13 #include <syslog.h>
  14 #include <net/if.h>
  15 #include <netinet/ether.h>
  16 #include <linux/sockios.h>
  17
  18 /* Older versions of net/if.h do not appear to define IF_NAMESIZE. */
  19 #ifndef IF_NAMESIZE
  20 #  ifdef IFNAMSIZ
  21 #    define IF_NAMESIZE IFNAMSIZ
  22 #  else
  23 #    define IF_NAMESIZE 16
  24 #  endif
  25 #endif
  26
  27 /* take from linux/sockios.h */
  28 #define SIOCSIFNAME     0x8923  /* set interface name */
  29
  30 /* Octets in one Ethernet addr, from <linux/if_ether.h> */
  31 #define ETH_ALEN        6
  32
  33 #ifndef ifr_newname
  34 #define ifr_newname ifr_ifru.ifru_slave
  35 #endif
  36
  37 typedef struct ethtable_s {
  38         struct ethtable_s *next;
  39         struct ethtable_s *prev;
  40         char *ifname;
  41         struct ether_addr *mac;
  42 #if ENABLE_FEATURE_NAMEIF_EXTENDED
  43         char *bus_info;
  44         char *driver;
  45 #endif
  46 } ethtable_t;
  47
  48 #if ENABLE_FEATURE_NAMEIF_EXTENDED
  49 /* Cut'n'paste from ethtool.h */
  50 #define ETHTOOL_BUSINFO_LEN 32
  51 /* these strings are set to whatever the driver author decides... */
  52 struct ethtool_drvinfo {
  53         __u32 cmd;
  54         char  driver[32]; /* driver short name, "tulip", "eepro100" */
  55         char  version[32];  /* driver version string */
  56         char  fw_version[32]; /* firmware version string, if applicable */
  57         char  bus_info[ETHTOOL_BUSINFO_LEN];  /* Bus info for this IF. */
  58         /* For PCI devices, use pci_dev->slot_name. */
  59         char  reserved1[32];
  60         char  reserved2[16];
  61         __u32 n_stats;  /* number of u64's from ETHTOOL_GSTATS */
  62         __u32 testinfo_len;
  63         __u32 eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
  64         __u32 regdump_len;  /* Size of data from ETHTOOL_GREGS (bytes) */
  65 };
  66 #define ETHTOOL_GDRVINFO  0x00000003 /* Get driver info. */
  67 #endif
  68
  69
  70 static void nameif_parse_selector(ethtable_t *ch, char *selector)
  71 {
  72         struct ether_addr *lmac;
  73 #if ENABLE_FEATURE_NAMEIF_EXTENDED
  74         int found_selector = 0;
  75
  76         while (*selector) {
  77                 char *next;
  78 #endif
  79                 selector = skip_whitespace(selector);
  80 #if ENABLE_FEATURE_NAMEIF_EXTENDED
  81                 if (*selector == '\0')
  82                         break;
  83                 /* Search for the end .... */
  84                 next = skip_non_whitespace(selector);
  85                 if (*next)
  86                         *next++ = '\0';
  87                 /* Check for selectors, mac= is assumed */
  88                 if (strncmp(selector, "bus=", 4) == 0) {
  89                         ch->bus_info = xstrdup(selector + 4);
  90                         found_selector++;
  91                 } else if (strncmp(selector, "driver=", 7) == 0) {
  92                         ch->driver = xstrdup(selector + 7);
  93                         found_selector++;
  94                 } else {
  95 #endif
  96                         lmac = ether_aton(selector + (strncmp(selector, "mac=", 4) == 0 ? 4 : 0));
  97                         /* Check ascii selector, convert and copy to *mac */
  98                         if (lmac == NULL)
  99                                 bb_error_msg_and_die("cannot parse %s", selector);
 100                         ch->mac = xmalloc(ETH_ALEN);
 101                         memcpy(ch->mac, lmac, ETH_ALEN);
 102 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
 103                         found_selector++;
 104                 };
 105                 selector = next;
 106         }
 107         if (found_selector == 0)
 108                 bb_error_msg_and_die("no selectors found for %s", ch->ifname);
 109 #endif
 110 }
 111
 112 static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
 113 {
 114         ethtable_t *ch;
 115         if (strlen(ifname) >= IF_NAMESIZE)
 116                 bb_error_msg_and_die("interface name '%s' too long", ifname);
 117         ch = xzalloc(sizeof(*ch));
 118         ch->ifname = ifname;
 119         nameif_parse_selector(ch, selector);
 120         ch->next = *clist;
 121         if (*clist)
 122                 (*clist)->prev = ch;
 123         *clist = ch;
 124 }
 125
 126 int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 127 int nameif_main(int argc, char **argv)
 128 {
 129         ethtable_t *clist = NULL;
 130         FILE *ifh;
 131         const char *fname = "/etc/mactab";
 132         char *line;
 133         char *line_ptr;
 134         int linenum;
 135         int ctl_sk;
 136         ethtable_t *ch;
 137
 138         if (1 & getopt32(argv, "sc:", &fname)) {
 139                 openlog(applet_name, 0, LOG_LOCAL0);
 140                 logmode = LOGMODE_SYSLOG;
 141         }
 142         argc -= optind;
 143         argv += optind;
 144
 145         if (argc & 1)
 146                 bb_show_usage();
 147
 148         if (argc) {
 149                 while (*argv) {
 150                         char *ifname = xstrdup(*argv++);
 151                         prepend_new_eth_table(&clist, ifname, *argv++);
 152                 }
 153         } else {
 154                 ifh = xfopen(fname, "r");
 155                 while ((line = xmalloc_fgets(ifh)) != NULL) {
 156                         char *next;
 157
 158                         line_ptr = skip_whitespace(line);
 159                         if ((line_ptr[0] == '#') || (line_ptr[0] == '\n')) {
 160                                 free(line);
 161                                 continue;
 162                         }
 163                         next = skip_non_whitespace(line_ptr);
 164                         if (*next)
 165                                 *next++ = '\0';
 166                         prepend_new_eth_table(&clist, line_ptr, next);
 167                         free(line);
 168                 }
 169                 fclose(ifh);
 170         }
 171
 172         ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
 173         ifh = xfopen("/proc/net/dev", "r");
 174
 175         linenum = 0;
 176         while (clist) {
 177                 struct ifreq ifr;
 178 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
 179                 struct ethtool_drvinfo drvinfo;
 180 #endif
 181
 182                 line = xmalloc_fgets(ifh);
 183                 if (line == NULL)
 184                         break; /* Seems like we're done */
 185                 if (linenum++ < 2 )
 186                         goto next_line; /* Skip the first two lines */
 187
 188                 /* Find the current interface name and copy it to ifr.ifr_name */
 189                 line_ptr = skip_whitespace(line);
 190                 *skip_non_whitespace(line_ptr) = '\0';
 191
 192                 memset(&ifr, 0, sizeof(struct ifreq));
 193                 strncpy(ifr.ifr_name, line_ptr, sizeof(ifr.ifr_name));
 194
 195 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 196                 /* Check for driver etc. */
 197                 memset(&drvinfo, 0, sizeof(struct ethtool_drvinfo));
 198                 drvinfo.cmd = ETHTOOL_GDRVINFO;
 199                 ifr.ifr_data = (caddr_t) &drvinfo;
 200                 /* Get driver and businfo first, so we have it in drvinfo */
 201                 ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 202 #endif
 203                 ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
 204
 205                 /* Search the list for a matching device */
 206                 for (ch = clist; ch; ch = ch->next) {
 207 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 208                         if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
 209                                 continue;
 210                         if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
 211                                 continue;
 212 #endif
 213                         if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
 214                                 continue;
 215                         /* if we came here, all selectors have matched */
 216                         goto found;
 217                 }
 218                 /* Nothing found for current interface */
 219                 goto next_line;
 220  found:
 221                 if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
 222                         strcpy(ifr.ifr_newname, ch->ifname);
 223                         ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
 224                                         "cannot change ifname %s to %s",
 225                                         ifr.ifr_name, ch->ifname);
 226                 }
 227                 /* Remove list entry of renamed interface */
 228                 if (ch->prev != NULL)
 229                         ch->prev->next = ch->next;
 230                 else
 231                         clist = ch->next;
 232                 if (ch->next != NULL)
 233                         ch->next->prev = ch->prev;
 234                 if (ENABLE_FEATURE_CLEAN_UP) {
 235                         free(ch->ifname);
 236                         free(ch->mac);
 237                         free(ch);
 238                 }
 239  next_line:
 240                 free(line);
 241         }
 242         if (ENABLE_FEATURE_CLEAN_UP) {
 243                 fclose(ifh);
 244         };
 245
 246         return 0;
 247 }