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