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
  95 typedef 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... */
 111 struct 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
 126 struct 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
 148 static 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
 192 static 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
 207 static 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
 218 void delete_eth_table(ethtable_t *ch);
 219 #endif
 220
 221 int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 222 int 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 }