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:     "\nOptions:"
  65 //usage:     "\n        -c FILE Configuration file (default: /etc/mactab)"
  66 //usage:     "\n        -s      Log to syslog"
  67 //usage:
  68 //usage:#define nameif_example_usage
  69 //usage:       "$ nameif -s dmz0 00:A0:C9:8C:F6:3F\n"
  70 //usage:       " or\n"
  71 //usage:       "$ nameif -c /etc/my_mactab_file\n"
  72
  73 #include "libbb.h"
  74 #include <syslog.h>
  75 #include <net/if.h>
  76 #include <netinet/ether.h>
  77 #include <linux/sockios.h>
  78
  79 #ifndef IFNAMSIZ
  80 #define IFNAMSIZ 16
  81 #endif
  82
  83 /* Taken from linux/sockios.h */
  84 #define SIOCSIFNAME  0x8923  /* set interface name */
  85
  86 /* Octets in one Ethernet addr, from <linux/if_ether.h> */
  87 #define ETH_ALEN     6
  88
  89 #ifndef ifr_newname
  90 #define ifr_newname ifr_ifru.ifru_slave
  91 #endif
  92
  93 typedef struct ethtable_s {
  94         struct ethtable_s *next;
  95         struct ethtable_s *prev;
  96         char *ifname;
  97         struct ether_addr *mac;
  98 #if ENABLE_FEATURE_NAMEIF_EXTENDED
  99         char *bus_info;
 100         char *driver;
 101         int32_t phy_address;
 102 #endif
 103 } ethtable_t;
 104
 105 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 106 /* Cut'n'paste from ethtool.h */
 107 #define ETHTOOL_BUSINFO_LEN 32
 108 /* these strings are set to whatever the driver author decides... */
 109 struct ethtool_drvinfo {
 110         uint32_t cmd;
 111         char  driver[32]; /* driver short name, "tulip", "eepro100" */
 112         char  version[32];  /* driver version string */
 113         char  fw_version[32]; /* firmware version string, if applicable */
 114         char  bus_info[ETHTOOL_BUSINFO_LEN];  /* Bus info for this IF. */
 115         /* For PCI devices, use pci_dev->slot_name. */
 116         char  reserved1[32];
 117         char  reserved2[16];
 118         uint32_t n_stats;  /* number of u64's from ETHTOOL_GSTATS */
 119         uint32_t testinfo_len;
 120         uint32_t eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
 121         uint32_t regdump_len;  /* Size of data from ETHTOOL_GREGS (bytes) */
 122 };
 123
 124 struct ethtool_cmd {
 125         __u32   cmd;
 126         __u32   supported;      /* Features this interface supports */
 127         __u32   advertising;    /* Features this interface advertises */
 128         __u16   speed;          /* The forced speed, 10Mb, 100Mb, gigabit */
 129         __u8    duplex;         /* Duplex, half or full */
 130         __u8    port;           /* Which connector port */
 131         __u8    phy_address;
 132         __u8    transceiver;    /* Which transceiver to use */
 133         __u8    autoneg;        /* Enable or disable autonegotiation */
 134         __u32   maxtxpkt;       /* Tx pkts before generating tx int */
 135         __u32   maxrxpkt;       /* Rx pkts before generating rx int */
 136         __u16   speed_hi;
 137         __u16   reserved2;
 138         __u32   reserved[3];
 139 };
 140
 141 #define ETHTOOL_GSET      0x00000001 /* Get settings. */
 142 #define ETHTOOL_GDRVINFO  0x00000003 /* Get driver info. */
 143 #endif
 144
 145
 146 static void nameif_parse_selector(ethtable_t *ch, char *selector)
 147 {
 148         struct ether_addr *lmac;
 149 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 150         int found_selector = 0;
 151
 152         while (*selector) {
 153                 char *next;
 154 #endif
 155                 selector = skip_whitespace(selector);
 156 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 157                 ch->phy_address = -1;
 158                 if (*selector == '\0')
 159                         break;
 160                 /* Search for the end .... */
 161                 next = skip_non_whitespace(selector);
 162                 if (*next)
 163                         *next++ = '\0';
 164                 /* Check for selectors, mac= is assumed */
 165                 if (strncmp(selector, "bus=", 4) == 0) {
 166                         ch->bus_info = xstrdup(selector + 4);
 167                         found_selector++;
 168                 } else if (strncmp(selector, "driver=", 7) == 0) {
 169                         ch->driver = xstrdup(selector + 7);
 170                         found_selector++;
 171                 } else if (strncmp(selector, "phyaddr=", 8) == 0) {
 172                         ch->phy_address = xatoi_positive(selector + 8);
 173                         found_selector++;
 174                 } else {
 175 #endif
 176                         lmac = xmalloc(ETH_ALEN);
 177                         ch->mac = ether_aton_r(selector + (strncmp(selector, "mac=", 4) != 0 ? 0 : 4), lmac);
 178                         if (ch->mac == NULL)
 179                                 bb_error_msg_and_die("can't parse %s", selector);
 180 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
 181                         found_selector++;
 182                 };
 183                 selector = next;
 184         }
 185         if (found_selector == 0)
 186                 bb_error_msg_and_die("no selectors found for %s", ch->ifname);
 187 #endif
 188 }
 189
 190 static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
 191 {
 192         ethtable_t *ch;
 193         if (strlen(ifname) >= IFNAMSIZ)
 194                 bb_error_msg_and_die("interface name '%s' too long", ifname);
 195         ch = xzalloc(sizeof(*ch));
 196         ch->ifname = xstrdup(ifname);
 197         nameif_parse_selector(ch, selector);
 198         ch->next = *clist;
 199         if (*clist)
 200                 (*clist)->prev = ch;
 201         *clist = ch;
 202 }
 203
 204 #if ENABLE_FEATURE_CLEAN_UP
 205 static void delete_eth_table(ethtable_t *ch)
 206 {
 207         free(ch->ifname);
 208 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 209         free(ch->bus_info);
 210         free(ch->driver);
 211 #endif
 212         free(ch->mac);
 213         free(ch);
 214 };
 215 #else
 216 void delete_eth_table(ethtable_t *ch);
 217 #endif
 218
 219 int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 220 int nameif_main(int argc UNUSED_PARAM, char **argv)
 221 {
 222         ethtable_t *clist = NULL;
 223         const char *fname = "/etc/mactab";
 224         int ctl_sk;
 225         ethtable_t *ch;
 226         parser_t *parser;
 227         char *token[2];
 228
 229         if (1 & getopt32(argv, "sc:", &fname)) {
 230                 openlog(applet_name, 0, LOG_LOCAL0);
 231                 /* Why not just "="? I assume logging to stderr
 232                  * can't hurt. 2>/dev/null if you don't like it: */
 233                 logmode |= LOGMODE_SYSLOG;
 234         }
 235         argv += optind;
 236
 237         if (argv[0]) {
 238                 do {
 239                         if (!argv[1])
 240                                 bb_show_usage();
 241                         prepend_new_eth_table(&clist, argv[0], argv[1]);
 242                         argv += 2;
 243                 } while (*argv);
 244         } else {
 245                 parser = config_open(fname);
 246                 while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL))
 247                         prepend_new_eth_table(&clist, token[0], token[1]);
 248                 config_close(parser);
 249         }
 250
 251         ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
 252         parser = config_open2("/proc/net/dev", xfopen_for_read);
 253
 254         while (clist && config_read(parser, token, 2, 2, "\0: \t", PARSE_NORMAL)) {
 255                 struct ifreq ifr;
 256 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
 257                 struct ethtool_drvinfo drvinfo;
 258                 struct ethtool_cmd eth_settings;
 259 #endif
 260                 if (parser->lineno <= 2)
 261                         continue; /* Skip the first two lines */
 262
 263                 /* Find the current interface name and copy it to ifr.ifr_name */
 264                 memset(&ifr, 0, sizeof(struct ifreq));
 265                 strncpy_IFNAMSIZ(ifr.ifr_name, token[0]);
 266
 267 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 268                 /* Check for phy address */
 269                 memset(&eth_settings, 0, sizeof(eth_settings));
 270                 eth_settings.cmd = ETHTOOL_GSET;
 271                 ifr.ifr_data = (caddr_t) &eth_settings;
 272                 ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 273
 274                 /* Check for driver etc. */
 275                 memset(&drvinfo, 0, sizeof(drvinfo));
 276                 drvinfo.cmd = ETHTOOL_GDRVINFO;
 277                 ifr.ifr_data = (caddr_t) &drvinfo;
 278                 /* Get driver and businfo first, so we have it in drvinfo */
 279                 ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 280 #endif
 281                 ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
 282
 283                 /* Search the list for a matching device */
 284                 for (ch = clist; ch; ch = ch->next) {
 285 #if ENABLE_FEATURE_NAMEIF_EXTENDED
 286                         if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
 287                                 continue;
 288                         if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
 289                                 continue;
 290                         if (ch->phy_address != -1 && ch->phy_address != eth_settings.phy_address)
 291                                 continue;
 292 #endif
 293                         if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
 294                                 continue;
 295                         /* if we came here, all selectors have matched */
 296                         break;
 297                 }
 298                 /* Nothing found for current interface */
 299                 if (!ch)
 300                         continue;
 301
 302                 if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
 303                         strcpy(ifr.ifr_newname, ch->ifname);
 304                         ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
 305                                         "can't change ifname %s to %s",
 306                                         ifr.ifr_name, ch->ifname);
 307                 }
 308                 /* Remove list entry of renamed interface */
 309                 if (ch->prev != NULL)
 310                         ch->prev->next = ch->next;
 311                 else
 312                         clist = ch->next;
 313                 if (ch->next != NULL)
 314                         ch->next->prev = ch->prev;
 315                 if (ENABLE_FEATURE_CLEAN_UP)
 316                         delete_eth_table(ch);
 317         }
 318         if (ENABLE_FEATURE_CLEAN_UP) {
 319                 for (ch = clist; ch; ch = ch->next)
 320                         delete_eth_table(ch);
 321                 config_close(parser);
 322         };
 323
 324         return 0;
 325 }