LXR busybox/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//applet:IF_NAMEIF(APPLET(nameif, BB_DIR_SBIN, BB_SUID_DROP))
  44
  45//kbuild:lib-$(CONFIG_NAMEIF) += nameif.o
  46
  47//usage:#define nameif_trivial_usage
  48//usage:        IF_NOT_FEATURE_NAMEIF_EXTENDED(
  49//usage:                "[-s] [-c FILE] [IFNAME HWADDR]..."
  50//usage:        )
  51//usage:        IF_FEATURE_NAMEIF_EXTENDED(
  52//usage:                "[-s] [-c FILE] [IFNAME SELECTOR]..."
  53//usage:        )
  54//usage:#define nameif_full_usage "\n\n"
  55//usage:        "Rename network interface while it in the down state."
  56//usage:        IF_NOT_FEATURE_NAMEIF_EXTENDED(
  57//usage:     "\nThe device with address HWADDR is renamed to IFACE."
  58//usage:        )
  59//usage:        IF_FEATURE_NAMEIF_EXTENDED(
  60//usage:     "\nThe device matched by SELECTOR is renamed to IFACE."
  61//usage:     "\nSELECTOR can be a combination of:"
  62//usage:     "\n        driver=STRING"
  63//usage:     "\n        bus=STRING"
  64//usage:     "\n        phy_address=NUM"
  65//usage:     "\n        [mac=]XX:XX:XX:XX:XX:XX"
  66//usage:        )
  67//usage:     "\n"
  68//usage:     "\n        -c FILE Configuration file (default: /etc/mactab)"
  69//usage:     "\n        -s      Log to syslog"
  70//usage:
  71//usage:#define nameif_example_usage
  72//usage:       "$ nameif -s dmz0 00:A0:C9:8C:F6:3F\n"
  73//usage:       " or\n"
  74//usage:       "$ nameif -c /etc/my_mactab_file\n"
  75
  76#include "libbb.h"
  77#include <syslog.h>
  78#include <net/if.h>
  79#include <netinet/ether.h>
  80#include <linux/sockios.h>
  81
  82#ifndef IFNAMSIZ
  83#define IFNAMSIZ 16
  84#endif
  85
  86/* Taken from linux/sockios.h */
  87#define SIOCSIFNAME  0x8923  /* set interface name */
  88
  89/* Octets in one Ethernet addr, from <linux/if_ether.h> */
  90#define ETH_ALEN     6
  91
  92#ifndef ifr_newname
  93#define ifr_newname ifr_ifru.ifru_slave
  94#endif
  95
  96typedef struct ethtable_s {
  97        struct ethtable_s *next;
  98        struct ethtable_s *prev;
  99        char *ifname;
 100        struct ether_addr *mac;
 101#if ENABLE_FEATURE_NAMEIF_EXTENDED
 102        char *bus_info;
 103        char *driver;
 104        int32_t phy_address;
 105#endif
 106} ethtable_t;
 107
 108#if ENABLE_FEATURE_NAMEIF_EXTENDED
 109/* Cut'n'paste from ethtool.h */
 110#define ETHTOOL_BUSINFO_LEN 32
 111/* these strings are set to whatever the driver author decides... */
 112struct ethtool_drvinfo {
 113        uint32_t cmd;
 114        char  driver[32]; /* driver short name, "tulip", "eepro100" */
 115        char  version[32];  /* driver version string */
 116        char  fw_version[32]; /* firmware version string, if applicable */
 117        char  bus_info[ETHTOOL_BUSINFO_LEN];  /* Bus info for this IF. */
 118        /* For PCI devices, use pci_dev->slot_name. */
 119        char  reserved1[32];
 120        char  reserved2[16];
 121        uint32_t n_stats;  /* number of u64's from ETHTOOL_GSTATS */
 122        uint32_t testinfo_len;
 123        uint32_t eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
 124        uint32_t regdump_len;  /* Size of data from ETHTOOL_GREGS (bytes) */
 125};
 126
 127struct ethtool_cmd {
 128        uint32_t   cmd;
 129        uint32_t   supported;      /* Features this interface supports */
 130        uint32_t   advertising;    /* Features this interface advertises */
 131        uint16_t   speed;          /* The forced speed, 10Mb, 100Mb, gigabit */
 132        uint8_t    duplex;         /* Duplex, half or full */
 133        uint8_t    port;           /* Which connector port */
 134        uint8_t    phy_address;
 135        uint8_t    transceiver;    /* Which transceiver to use */
 136        uint8_t    autoneg;        /* Enable or disable autonegotiation */
 137        uint32_t   maxtxpkt;       /* Tx pkts before generating tx int */
 138        uint32_t   maxrxpkt;       /* Rx pkts before generating rx int */
 139        uint16_t   speed_hi;
 140        uint16_t   reserved2;
 141        uint32_t   reserved[3];
 142};
 143
 144#define ETHTOOL_GSET      0x00000001 /* Get settings. */
 145#define ETHTOOL_GDRVINFO  0x00000003 /* Get driver info. */
 146#endif
 147
 148
 149static void nameif_parse_selector(ethtable_t *ch, char *selector)
 150{
 151        struct ether_addr *lmac;
 152#if ENABLE_FEATURE_NAMEIF_EXTENDED
 153        int found_selector = 0;
 154
 155        while (*selector) {
 156                char *next;
 157#endif
 158                selector = skip_whitespace(selector);
 159#if ENABLE_FEATURE_NAMEIF_EXTENDED
 160                ch->phy_address = -1;
 161                if (*selector == '\0')
 162                        break;
 163                /* Search for the end .... */
 164                next = skip_non_whitespace(selector);
 165                if (*next)
 166                        *next++ = '\0';
 167                /* Check for selectors, mac= is assumed */
 168                if (is_prefixed_with(selector, "bus=")) {
 169                        ch->bus_info = xstrdup(selector + 4);
 170                        found_selector++;
 171                } else if (is_prefixed_with(selector, "driver=")) {
 172                        ch->driver = xstrdup(selector + 7);
 173                        found_selector++;
 174                } else if (is_prefixed_with(selector, "phyaddr=")) {
 175                        ch->phy_address = xatoi_positive(selector + 8);
 176                        found_selector++;
 177                } else {
 178#endif
 179                        lmac = xmalloc(ETH_ALEN);
 180                        ch->mac = ether_aton_r(selector + (is_prefixed_with(selector, "mac=") ? 4 : 0), lmac);
 181                        if (ch->mac == NULL)
 182                                bb_error_msg_and_die("can't parse %s", selector);
 183#if  ENABLE_FEATURE_NAMEIF_EXTENDED
 184                        found_selector++;
 185                };
 186                selector = next;
 187        }
 188        if (found_selector == 0)
 189                bb_error_msg_and_die("no selectors found for %s", ch->ifname);
 190#endif
 191}
 192
 193static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
 194{
 195        ethtable_t *ch;
 196        if (strlen(ifname) >= IFNAMSIZ)
 197                bb_error_msg_and_die("interface name '%s' too long", ifname);
 198        ch = xzalloc(sizeof(*ch));
 199        ch->ifname = xstrdup(ifname);
 200        nameif_parse_selector(ch, selector);
 201        ch->next = *clist;
 202        if (*clist)
 203                (*clist)->prev = ch;
 204        *clist = ch;
 205}
 206
 207#if ENABLE_FEATURE_CLEAN_UP
 208static void delete_eth_table(ethtable_t *ch)
 209{
 210        free(ch->ifname);
 211#if ENABLE_FEATURE_NAMEIF_EXTENDED
 212        free(ch->bus_info);
 213        free(ch->driver);
 214#endif
 215        free(ch->mac);
 216        free(ch);
 217};
 218#else
 219void delete_eth_table(ethtable_t *ch);
 220#endif
 221
 222int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 223int nameif_main(int argc UNUSED_PARAM, char **argv)
 224{
 225        ethtable_t *clist = NULL;
 226        const char *fname = "/etc/mactab";
 227        int ctl_sk;
 228        ethtable_t *ch;
 229        parser_t *parser;
 230        char *token[2];
 231
 232        if (1 & getopt32(argv, "sc:", &fname)) {
 233                openlog(applet_name, 0, LOG_LOCAL0);
 234                /* Why not just "="? I assume logging to stderr
 235                 * can't hurt. 2>/dev/null if you don't like it: */
 236                logmode |= LOGMODE_SYSLOG;
 237        }
 238        argv += optind;
 239
 240        if (argv[0]) {
 241                do {
 242                        if (!argv[1])
 243                                bb_show_usage();
 244                        prepend_new_eth_table(&clist, argv[0], argv[1]);
 245                        argv += 2;
 246                } while (*argv);
 247        } else {
 248                parser = config_open(fname);
 249                while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL))
 250                        prepend_new_eth_table(&clist, token[0], token[1]);
 251                config_close(parser);
 252        }
 253
 254        ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
 255        parser = config_open2("/proc/net/dev", xfopen_for_read);
 256
 257        while (clist && config_read(parser, token, 2, 2, "\0: \t", PARSE_NORMAL)) {
 258                struct ifreq ifr;
 259#if  ENABLE_FEATURE_NAMEIF_EXTENDED
 260                struct ethtool_drvinfo drvinfo;
 261                struct ethtool_cmd eth_settings;
 262#endif
 263                if (parser->lineno <= 2)
 264                        continue; /* Skip the first two lines */
 265
 266                /* Find the current interface name and copy it to ifr.ifr_name */
 267                memset(&ifr, 0, sizeof(struct ifreq));
 268                strncpy_IFNAMSIZ(ifr.ifr_name, token[0]);
 269
 270#if ENABLE_FEATURE_NAMEIF_EXTENDED
 271                /* Check for phy address */
 272                memset(&eth_settings, 0, sizeof(eth_settings));
 273                eth_settings.cmd = ETHTOOL_GSET;
 274                ifr.ifr_data = (caddr_t) &eth_settings;
 275                ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 276
 277                /* Check for driver etc. */
 278                memset(&drvinfo, 0, sizeof(drvinfo));
 279                drvinfo.cmd = ETHTOOL_GDRVINFO;
 280                ifr.ifr_data = (caddr_t) &drvinfo;
 281                /* Get driver and businfo first, so we have it in drvinfo */
 282                ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 283#endif
 284                ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
 285
 286                /* Search the list for a matching device */
 287                for (ch = clist; ch; ch = ch->next) {
 288#if ENABLE_FEATURE_NAMEIF_EXTENDED
 289                        if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
 290                                continue;
 291                        if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
 292                                continue;
 293                        if (ch->phy_address != -1 && ch->phy_address != eth_settings.phy_address)
 294                                continue;
 295#endif
 296                        if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
 297                                continue;
 298                        /* if we came here, all selectors have matched */
 299                        goto found;
 300                }
 301                /* Nothing found for current interface */
 302                continue;
 303 found:
 304                if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
 305                        strcpy(ifr.ifr_newname, ch->ifname);
 306                        ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
 307                                        "can't change ifname %s to %s",
 308                                        ifr.ifr_name, ch->ifname);
 309                }
 310                /* Remove list entry of renamed interface */
 311                if (ch->prev != NULL)
 312                        ch->prev->next = ch->next;
 313                else
 314                        clist = ch->next;
 315                if (ch->next != NULL)
 316                        ch->next->prev = ch->prev;
 317                if (ENABLE_FEATURE_CLEAN_UP)
 318                        delete_eth_table(ch);
 319        } /* while */
 320
 321        if (ENABLE_FEATURE_CLEAN_UP) {
 322                ethtable_t *next;
 323                for (ch = clist; ch; ch = next) {
 324                        next = ch->next;
 325                        delete_eth_table(ch);
 326                }
 327                config_close(parser);
 328        };
 329
 330        return 0;
 331}
 332