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 (6.6 kb)"
  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_NOEXEC(nameif, nameif, BB_DIR_SBIN, BB_SUID_DROP, nameif))
  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
  96 typedef 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... */
 112 struct 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
 127 struct 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
 149 static 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
 193 static 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
 208 static 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
 219 void delete_eth_table(ethtable_t *ch);
 220 #endif
 221
 222 int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 223 int 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 }