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//config:config NAMEIF
  13//config:       bool "nameif (6.6 kb)"
  14//config:       default y
  15//config:       select PLATFORM_LINUX
  16//config:       select FEATURE_SYSLOG
  17//config:       help
  18//config:       nameif is used to rename network interface by its MAC address.
  19//config:       Renamed interfaces MUST be in the down state.
  20//config:       It is possible to use a file (default: /etc/mactab)
  21//config:       with list of new interface names and MACs.
  22//config:       Maximum interface name length: IFNAMSIZ = 16
  23//config:       File fields are separated by space or tab.
  24//config:       File format:
  25//config:               # Comment
  26//config:               new_interface_name  XX:XX:XX:XX:XX:XX
  27//config:
  28//config:config FEATURE_NAMEIF_EXTENDED
  29//config:       bool "Extended nameif"
  30//config:       default y
  31//config:       depends on NAMEIF
  32//config:       help
  33//config:       This extends the nameif syntax to support the bus_info, driver,
  34//config:       phyaddr selectors. The syntax is compatible to the normal nameif.
  35//config:       File format:
  36//config:               new_interface_name  driver=asix bus=usb-0000:00:08.2-3
  37//config:               new_interface_name  bus=usb-0000:00:08.2-3 00:80:C8:38:91:B5
  38//config:               new_interface_name  phy_address=2 00:80:C8:38:91:B5
  39//config:               new_interface_name  mac=00:80:C8:38:91:B5
  40//config:               new_interface_name  00:80:C8:38:91:B5
  41
  42//applet:IF_NAMEIF(APPLET_NOEXEC(nameif, nameif, BB_DIR_SBIN, BB_SUID_DROP, nameif))
  43
  44//kbuild:lib-$(CONFIG_NAMEIF) += nameif.o
  45
  46//usage:#define nameif_trivial_usage
  47//usage:        IF_NOT_FEATURE_NAMEIF_EXTENDED(
  48//usage:                "[-s] [-c FILE] [IFNAME HWADDR]..."
  49//usage:        )
  50//usage:        IF_FEATURE_NAMEIF_EXTENDED(
  51//usage:                "[-s] [-c FILE] [IFNAME SELECTOR]..."
  52//usage:        )
  53//usage:#define nameif_full_usage "\n\n"
  54//usage:        "Rename network interface while it in the down state."
  55//usage:        IF_NOT_FEATURE_NAMEIF_EXTENDED(
  56//usage:     "\nThe device with address HWADDR is renamed to IFACE."
  57//usage:        )
  58//usage:        IF_FEATURE_NAMEIF_EXTENDED(
  59//usage:     "\nThe device matched by SELECTOR is renamed to IFACE."
  60//usage:     "\nSELECTOR can be a combination of:"
  61//usage:     "\n        driver=STRING"
  62//usage:     "\n        bus=STRING"
  63//usage:     "\n        phy_address=NUM"
  64//usage:     "\n        [mac=]XX:XX:XX:XX:XX:XX"
  65//usage:        )
  66//usage:     "\n"
  67//usage:     "\n        -c FILE Configuration file (default: /etc/mactab)"
  68//usage:     "\n        -s      Log to syslog"
  69//usage:
  70//usage:#define nameif_example_usage
  71//usage:       "$ nameif -s dmz0 00:A0:C9:8C:F6:3F\n"
  72//usage:       " or\n"
  73//usage:       "$ nameif -c /etc/my_mactab_file\n"
  74
  75#include "libbb.h"
  76#include <syslog.h>
  77#include <net/if.h>
  78#include <netinet/ether.h>
  79#include <linux/sockios.h>
  80
  81#ifndef IFNAMSIZ
  82#define IFNAMSIZ 16
  83#endif
  84
  85/* Taken from linux/sockios.h */
  86#define SIOCSIFNAME  0x8923  /* set interface name */
  87
  88/* Octets in one Ethernet addr, from <linux/if_ether.h> */
  89#define ETH_ALEN     6
  90
  91#ifndef ifr_newname
  92#define ifr_newname ifr_ifru.ifru_slave
  93#endif
  94
  95typedef struct ethtable_s {
  96        struct ethtable_s *next;
  97        struct ethtable_s *prev;
  98        char *ifname;
  99        struct ether_addr *mac;
 100#if ENABLE_FEATURE_NAMEIF_EXTENDED
 101        char *bus_info;
 102        char *driver;
 103        int32_t phy_address;
 104#endif
 105} ethtable_t;
 106
 107#if ENABLE_FEATURE_NAMEIF_EXTENDED
 108/* Cut'n'paste from ethtool.h */
 109#define ETHTOOL_BUSINFO_LEN 32
 110/* these strings are set to whatever the driver author decides... */
 111struct ethtool_drvinfo {
 112        uint32_t cmd;
 113        char  driver[32]; /* driver short name, "tulip", "eepro100" */
 114        char  version[32];  /* driver version string */
 115        char  fw_version[32]; /* firmware version string, if applicable */
 116        char  bus_info[ETHTOOL_BUSINFO_LEN];  /* Bus info for this IF. */
 117        /* For PCI devices, use pci_dev->slot_name. */
 118        char  reserved1[32];
 119        char  reserved2[16];
 120        uint32_t n_stats;  /* number of u64's from ETHTOOL_GSTATS */
 121        uint32_t testinfo_len;
 122        uint32_t eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
 123        uint32_t regdump_len;  /* Size of data from ETHTOOL_GREGS (bytes) */
 124};
 125
 126struct ethtool_cmd {
 127        uint32_t   cmd;
 128        uint32_t   supported;      /* Features this interface supports */
 129        uint32_t   advertising;    /* Features this interface advertises */
 130        uint16_t   speed;          /* The forced speed, 10Mb, 100Mb, gigabit */
 131        uint8_t    duplex;         /* Duplex, half or full */
 132        uint8_t    port;           /* Which connector port */
 133        uint8_t    phy_address;
 134        uint8_t    transceiver;    /* Which transceiver to use */
 135        uint8_t    autoneg;        /* Enable or disable autonegotiation */
 136        uint32_t   maxtxpkt;       /* Tx pkts before generating tx int */
 137        uint32_t   maxrxpkt;       /* Rx pkts before generating rx int */
 138        uint16_t   speed_hi;
 139        uint16_t   reserved2;
 140        uint32_t   reserved[3];
 141};
 142
 143#define ETHTOOL_GSET      0x00000001 /* Get settings. */
 144#define ETHTOOL_GDRVINFO  0x00000003 /* Get driver info. */
 145#endif
 146
 147
 148static void nameif_parse_selector(ethtable_t *ch, char *selector)
 149{
 150        struct ether_addr *lmac;
 151#if ENABLE_FEATURE_NAMEIF_EXTENDED
 152        int found_selector = 0;
 153
 154        while (*selector) {
 155                char *next;
 156#endif
 157                selector = skip_whitespace(selector);
 158#if ENABLE_FEATURE_NAMEIF_EXTENDED
 159                ch->phy_address = -1;
 160                if (*selector == '\0')
 161                        break;
 162                /* Search for the end .... */
 163                next = skip_non_whitespace(selector);
 164                if (*next)
 165                        *next++ = '\0';
 166                /* Check for selectors, mac= is assumed */
 167                if (is_prefixed_with(selector, "bus=")) {
 168                        ch->bus_info = xstrdup(selector + 4);
 169                        found_selector++;
 170                } else if (is_prefixed_with(selector, "driver=")) {
 171                        ch->driver = xstrdup(selector + 7);
 172                        found_selector++;
 173                } else if (is_prefixed_with(selector, "phyaddr=")) {
 174                        ch->phy_address = xatoi_positive(selector + 8);
 175                        found_selector++;
 176                } else {
 177#endif
 178                        lmac = xmalloc(ETH_ALEN);
 179                        ch->mac = ether_aton_r(selector + (is_prefixed_with(selector, "mac=") ? 4 : 0), lmac);
 180                        if (ch->mac == NULL)
 181                                bb_error_msg_and_die("can't parse %s", selector);
 182#if  ENABLE_FEATURE_NAMEIF_EXTENDED
 183                        found_selector++;
 184                };
 185                selector = next;
 186        }
 187        if (found_selector == 0)
 188                bb_error_msg_and_die("no selectors found for %s", ch->ifname);
 189#endif
 190}
 191
 192static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
 193{
 194        ethtable_t *ch;
 195        if (strlen(ifname) >= IFNAMSIZ)
 196                bb_error_msg_and_die("interface name '%s' too long", ifname);
 197        ch = xzalloc(sizeof(*ch));
 198        ch->ifname = xstrdup(ifname);
 199        nameif_parse_selector(ch, selector);
 200        ch->next = *clist;
 201        if (*clist)
 202                (*clist)->prev = ch;
 203        *clist = ch;
 204}
 205
 206#if ENABLE_FEATURE_CLEAN_UP
 207static void delete_eth_table(ethtable_t *ch)
 208{
 209        free(ch->ifname);
 210#if ENABLE_FEATURE_NAMEIF_EXTENDED
 211        free(ch->bus_info);
 212        free(ch->driver);
 213#endif
 214        free(ch->mac);
 215        free(ch);
 216};
 217#else
 218void delete_eth_table(ethtable_t *ch);
 219#endif
 220
 221int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 222int nameif_main(int argc UNUSED_PARAM, char **argv)
 223{
 224        ethtable_t *clist = NULL;
 225        const char *fname = "/etc/mactab";
 226        int ctl_sk;
 227        ethtable_t *ch;
 228        parser_t *parser;
 229        char *token[2];
 230
 231        if (1 & getopt32(argv, "sc:", &fname)) {
 232                openlog(applet_name, 0, LOG_LOCAL0);
 233                /* Why not just "="? I assume logging to stderr
 234                 * can't hurt. 2>/dev/null if you don't like it: */
 235                logmode |= LOGMODE_SYSLOG;
 236        }
 237        argv += optind;
 238
 239        if (argv[0]) {
 240                do {
 241                        if (!argv[1])
 242                                bb_show_usage();
 243                        prepend_new_eth_table(&clist, argv[0], argv[1]);
 244                        argv += 2;
 245                } while (*argv);
 246        } else {
 247                parser = config_open(fname);
 248                while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL))
 249                        prepend_new_eth_table(&clist, token[0], token[1]);
 250                config_close(parser);
 251        }
 252
 253        ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
 254        parser = config_open2("/proc/net/dev", xfopen_for_read);
 255
 256        while (clist && config_read(parser, token, 2, 2, "\0: \t", PARSE_NORMAL)) {
 257                struct ifreq ifr;
 258#if  ENABLE_FEATURE_NAMEIF_EXTENDED
 259                struct ethtool_drvinfo drvinfo;
 260                struct ethtool_cmd eth_settings;
 261#endif
 262                if (parser->lineno <= 2)
 263                        continue; /* Skip the first two lines */
 264
 265                /* Find the current interface name and copy it to ifr.ifr_name */
 266                memset(&ifr, 0, sizeof(struct ifreq));
 267                strncpy_IFNAMSIZ(ifr.ifr_name, token[0]);
 268
 269#if ENABLE_FEATURE_NAMEIF_EXTENDED
 270                /* Check for phy address */
 271                memset(&eth_settings, 0, sizeof(eth_settings));
 272                eth_settings.cmd = ETHTOOL_GSET;
 273                ifr.ifr_data = (caddr_t) &eth_settings;
 274                ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 275
 276                /* Check for driver etc. */
 277                memset(&drvinfo, 0, sizeof(drvinfo));
 278                drvinfo.cmd = ETHTOOL_GDRVINFO;
 279                ifr.ifr_data = (caddr_t) &drvinfo;
 280                /* Get driver and businfo first, so we have it in drvinfo */
 281                ioctl(ctl_sk, SIOCETHTOOL, &ifr);
 282#endif
 283                ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
 284
 285                /* Search the list for a matching device */
 286                for (ch = clist; ch; ch = ch->next) {
 287#if ENABLE_FEATURE_NAMEIF_EXTENDED
 288                        if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
 289                                continue;
 290                        if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
 291                                continue;
 292                        if (ch->phy_address != -1 && ch->phy_address != eth_settings.phy_address)
 293                                continue;
 294#endif
 295                        if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
 296                                continue;
 297                        /* if we came here, all selectors have matched */
 298                        goto found;
 299                }
 300                /* Nothing found for current interface */
 301                continue;
 302 found:
 303                if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
 304                        strcpy(ifr.ifr_newname, ch->ifname);
 305                        ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
 306                                        "can't change ifname %s to %s",
 307                                        ifr.ifr_name, ch->ifname);
 308                }
 309                /* Remove list entry of renamed interface */
 310                if (ch->prev != NULL)
 311                        ch->prev->next = ch->next;
 312                else
 313                        clist = ch->next;
 314                if (ch->next != NULL)
 315                        ch->next->prev = ch->prev;
 316                if (ENABLE_FEATURE_CLEAN_UP)
 317                        delete_eth_table(ch);
 318        } /* while */
 319
 320        if (ENABLE_FEATURE_CLEAN_UP) {
 321                ethtable_t *next;
 322                for (ch = clist; ch; ch = next) {
 323                        next = ch->next;
 324                        delete_eth_table(ch);
 325                }
 326                config_close(parser);
 327        };
 328
 329        return 0;
 330}
 331