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  * Extended matching support 2008 by Nico Erfurth <masta@perlgolf.de>
   9  *
  10  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  11  */
  12
  13 //config:config NAMEIF
  14 //config:       bool "nameif"
  15 //config:       default y
  16 //config:       select PLATFORM_LINUX
  17 //config:       select FEATURE_SYSLOG
  18 //config:       help
  19 //config:         nameif is used to rename network interface by its MAC address.
  20 //config:         Renamed interfaces MUST be in the down state.
  21 //config:         It is possible to use a file (default: /etc/mactab)
  22 //config:         with list of new interface names and MACs.
  23 //config:         Maximum interface name length: IFNAMSIZ = 16
  24 //config:         File fields are separated by space or tab.
  25 //config:         File format:
  26 //config:         # Comment
  27 //config:         new_interface_name    XX:XX:XX:XX:XX:XX
  28 //config:
  29 //config:config FEATURE_NAMEIF_EXTENDED
  30 //config:       bool "Extended nameif"
  31 //config:       default y
  32 //config:       depends on NAMEIF
  33 //config:       help
  34 //config:         This extends the nameif syntax to support the bus_info, driver,
  35 //config:         phyaddr selectors. The syntax is compatible to the normal nameif.
  36 //config:         File format:
  37 //config:           new_interface_name  driver=asix bus=usb-0000:00:08.2-3
  38 //config:           new_interface_name  bus=usb-0000:00:08.2-3 00:80:C8:38:91:B5
  39 //config:           new_interface_name  phy_address=2 00:80:C8:38:91:B5
  40 //config:           new_interface_name  mac=00:80:C8:38:91:B5
  41 //config:           new_interface_name  00:80:C8:38:91:B5
  42
  43 //usage:#define nameif_trivial_usage
  44 //usage:        IF_NOT_FEATURE_NAMEIF_EXTENDED(
  45 //usage:                "[-s] [-c FILE] [IFNAME HWADDR]..."
  46 //usage:        )
  47 //usage:        IF_FEATURE_NAMEIF_EXTENDED(
  48 //usage:                "[-s] [-c FILE] [IFNAME SELECTOR]..."
  49 //usage:        )
  50 //usage:#define nameif_full_usage "\n\n"
  51 //usage:        "Rename network interface while it in the down state."
  52 //usage:        IF_NOT_FEATURE_NAMEIF_EXTENDED(
  53 //usage:     "\nThe device with address HWADDR is renamed to IFACE."
  54 //usage:        )
  55 //usage:        IF_FEATURE_NAMEIF_EXTENDED(
  56 //usage:     "\nThe device matched by SELECTOR is renamed to IFACE."
  57 //usage:     "\nSELECTOR can be a combination of:"
  58 //usage:     "\n        driver=STRING"
  59 //usage:     "\n        bus=STRING"
  60 //usage:     "\n        phy_address=NUM"
  61 //usage:     "\n        [mac=]XX:XX:XX:XX:XX:XX"
  62 //usage:        )
  63 //usage:     "\n"
  64 //usage:     "\n        -c FILE Configuration file (default: /etc/mactab)"
  65 //usage:     "\n        -s      Log to syslog"
  66 //usage:
  67 //usage:#define nameif_example_usage
  68 //usage:       "$ nameif -s dmz0 00:A0:C9:8C:F6:3F\n"
  69 //usage:       " or\n"
  70 //usage:       "$ nameif -c /etc/my_mactab_file\n"
  71
  72 #include "libbb.h"
  73 #include <syslog.h>
  74 #include <net/if.h>
  75 #include <netinet/ether.h>
  76 #include <linux/sockios.h>
  77
  78 #ifndef IFNAMSIZ
  79 #define IFNAMSIZ 16
  80 #endif
  81
  82 /* Taken from linux/sockios.h */
  83 #define SIOCSIFNAME  0x8923  /* set interface name */
  84
  85 /* Octets in one Ethernet addr, from <linux/if_ether.h> */
  86 #define ETH_ALEN     6
  87
  88 #ifndef ifr_newname
  89 #define ifr_newname ifr_ifru.ifru_slave
  90 #endif
  91
  92 typedef struct ethtable_s {
  93         struct ethtable_s *next;
  94         struct ethtable_s *prev;
  95         char *ifname;
  96         struct ether_addr *mac;
  97 #if ENABLE_FEATURE_NAMEIF_EXTENDED
  98         char *bus_info;
  99         char *driver;
 100         int32_t phy_address;
 101 #endif
 102 } ethtable_t;
 103
 104 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 105 /* Cut'n'paste from ethtool.h */
 106 #define ETHTOOL_BUSINFO_LEN 32
 107 /* these strings are set to whatever the driver author decides... */
 108 struct ethtool_drvinfo {
 109         uint32_t cmd;
 110         char  driver[32]; /* driver short name, "tulip", "eepro100" */
 111         char  version[32];  /* driver version string */
 112         char  fw_version[32]; /* firmware version string, if applicable */
 113         char  bus_info[ETHTOOL_BUSINFO_LEN];  /* Bus info for this IF. */
 114         /* For PCI devices, use pci_dev->slot_name. */
 115         char  reserved1[32];
 116         char  reserved2[16];
 117         uint32_t n_stats;  /* number of u64's from ETHTOOL_GSTATS */
 118         uint32_t testinfo_len;
 119         uint32_t eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
 120         uint32_t regdump_len;  /* Size of data from ETHTOOL_GREGS (bytes) */
 121 };
 122
 123 struct ethtool_cmd {
 124         uint32_t   cmd;
 125         uint32_t   supported;      /* Features this interface supports */
 126         uint32_t   advertising;    /* Features this interface advertises */
 127         uint16_t   speed;          /* The forced speed, 10Mb, 100Mb, gigabit */
 128         uint8_t    duplex;         /* Duplex, half or full */
 129         uint8_t    port;           /* Which connector port */
 130         uint8_t    phy_address;
 131         uint8_t    transceiver;    /* Which transceiver to use */
 132         uint8_t    autoneg;        /* Enable or disable autonegotiation */
 133         uint32_t   maxtxpkt;       /* Tx pkts before generating tx int */
 134         uint32_t   maxrxpkt;       /* Rx pkts before generating rx int */
 135         uint16_t   speed_hi;
 136         uint16_t   reserved2;
 137         uint32_t   reserved[3];
 138 };
 139
 140 #define ETHTOOL_GSET      0x00000001 /* Get settings. */
 141 #define ETHTOOL_GDRVINFO  0x00000003 /* Get driver info. */
 142 #endif
 143
 144
 145 static void nameif_parse_selector(ethtable_t *ch, char *selector)
 146 {
 147         struct ether_addr *lmac;
 148 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 149         int found_selector = 0;
 150
 151         while (*selector) {
 152                 char *next;
 153 #endif
 154                 selector = skip_whitespace(selector);
 155 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 156                 ch->phy_address = -1;
 157                 if (*selector == '\0')
 158                         break;
 159                 /* Search for the end .... */
 160                 next = skip_non_whitespace(selector);
 161                 if (*next)
 162                         *next++ = '\0';
 163                 /* Check for selectors, mac= is assumed */
 164                 if (strncmp(selector, "bus=", 4) == 0) {
 165                         ch->bus_info = xstrdup(selector + 4);
 166                         found_selector++;
 167                 } else if (strncmp(selector, "driver=", 7) == 0) {
 168                         ch->driver = xstrdup(selector + 7);
 169                         found_selector++;
 170                 } else if (strncmp(selector, "phyaddr=", 8) == 0) {
 171                         ch->phy_address = xatoi_positive(selector + 8);
 172                         found_selector++;
 173                 } else {
 174 #endif
 175                         lmac = xmalloc(ETH_ALEN);
 176                         ch->mac = ether_aton_r(selector + (strncmp(selector, "mac=", 4) != 0 ? 0 : 4), lmac);
 177                         if (ch->mac == NULL)
 178                                 bb_error_msg_and_die("can't parse %s", selector);
 179 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
 180                         found_selector++;
 181                 };
 182                 selector = next;
 183         }
 184         if (found_selector == 0)
 185                 bb_error_msg_and_die("no selectors found for %s", ch->ifname);
 186 #endif
 187 }
 188
 189 static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
 190 {
 191         ethtable_t *ch;
 192         if (strlen(ifname) >= IFNAMSIZ)
 193                 bb_error_msg_and_die("interface name '%s' too long", ifname);
 194         ch = xzalloc(sizeof(*ch));
 195         ch->ifname = xstrdup(ifname);
 196         nameif_parse_selector(ch, selector);
 197         ch->next = *clist;
 198         if (*clist)
 199                 (*clist)->prev = ch;
 200         *clist = ch;
 201 }
 202
 203 #if ENABLE_FEATURE_CLEAN_UP
 204 static void delete_eth_table(ethtable_t *ch)
 205 {
 206         free(ch->ifname);
 207 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 208         free(ch->bus_info);
 209         free(ch->driver);
 210 #endif
 211         free(ch->mac);
 212         free(ch);
 213 };
 214 #else
 215 void delete_eth_table(ethtable_t *ch);
 216 #endif
 217
 218 int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 219 int nameif_main(int argc UNUSED_PARAM, char **argv)
 220 {
 221         ethtable_t *clist = NULL;
 222         const char *fname = "/etc/mactab";
 223         int ctl_sk;
 224         ethtable_t *ch;
 225         parser_t *parser;
 226         char *token[2];
 227
 228         if (1 & getopt32(argv, "sc:", &fname)) {
 229                 openlog(applet_name, 0, LOG_LOCAL0);
 230                 /* Why not just "="? I assume logging to stderr
 231                  * can't hurt. 2>/dev/null if you don't like it: */
 232                 logmode |= LOGMODE_SYSLOG;
 233         }
 234         argv += optind;
 235
 236         if (argv[0]) {
 237                 do {
 238                         if (!argv[1])
 239                                 bb_show_usage();
 240                         prepend_new_eth_table(&clist, argv[0], argv[1]);
 241                         argv += 2;
 242                 } while (*argv);
 243         } else {
 244                 parser = config_open(fname);
 245                 while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL))
 246                         prepend_new_eth_table(&clist, token[0], token[1]);
 247                 config_close(parser);
 248         }
 249
 250         ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
 251         parser = config_open2("/proc/net/dev", xfopen_for_read);
 252
 253         while (clist && config_read(parser, token, 2, 2, "\0: \t", PARSE_NORMAL)) {
 254                 struct ifreq ifr;
 255 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
 256                 struct ethtool_drvinfo drvinfo;
 257                 struct ethtool_cmd eth_settings;
 258 #endif
 259                 if (parser->lineno <= 2)
 260                         continue; /* Skip the first two lines */
 261
 262                 /* Find the current interface name and copy it to ifr.ifr_name */
 263                 memset(&ifr, 0, sizeof(struct ifreq));
 264                 strncpy_IFNAMSIZ(ifr.ifr_name, token[0]);
 265
 266 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 267                 /* Check for phy address */
 268                 memset(&eth_settings, 0, sizeof(eth_settings));
 269                 eth_settings.cmd = ETHTOOL_GSET;
 270                 ifr.ifr_data = (caddr_t) &eth_settings;
 271                 ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 272
 273                 /* Check for driver etc. */
 274                 memset(&drvinfo, 0, sizeof(drvinfo));
 275                 drvinfo.cmd = ETHTOOL_GDRVINFO;
 276                 ifr.ifr_data = (caddr_t) &drvinfo;
 277                 /* Get driver and businfo first, so we have it in drvinfo */
 278                 ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 279 #endif
 280                 ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
 281
 282                 /* Search the list for a matching device */
 283                 for (ch = clist; ch; ch = ch->next) {
 284 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 285                         if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
 286                                 continue;
 287                         if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
 288                                 continue;
 289                         if (ch->phy_address != -1 && ch->phy_address != eth_settings.phy_address)
 290                                 continue;
 291 #endif
 292                         if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
 293                                 continue;
 294                         /* if we came here, all selectors have matched */
 295                         goto found;
 296                 }
 297                 /* Nothing found for current interface */
 298                 continue;
 299  found:
 300                 if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
 301                         strcpy(ifr.ifr_newname, ch->ifname);
 302                         ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
 303                                         "can't change ifname %s to %s",
 304                                         ifr.ifr_name, ch->ifname);
 305                 }
 306                 /* Remove list entry of renamed interface */
 307                 if (ch->prev != NULL)
 308                         ch->prev->next = ch->next;
 309                 else
 310                         clist = ch->next;
 311                 if (ch->next != NULL)
 312                         ch->next->prev = ch->prev;
 313                 if (ENABLE_FEATURE_CLEAN_UP)
 314                         delete_eth_table(ch);
 315         } /* while */
 316
 317         if (ENABLE_FEATURE_CLEAN_UP) {
 318                 ethtable_t *next;
 319                 for (ch = clist; ch; ch = next) {
 320                         next = ch->next;
 321                         delete_eth_table(ch);
 322                 }
 323                 config_close(parser);
 324         };
 325
 326         return 0;
 327 }