release/src/router/busybox/networking/ifconfig.c

   1 /* vi: set sw=4 ts=4: */
   2 /* ifconfig
   3  *
   4  * Similar to the standard Unix ifconfig, but with only the necessary
   5  * parts for AF_INET, and without any printing of if info (for now).
   6  *
   7  * Bjorn Wesen, Axis Communications AB
   8  *
   9  *
  10  * Authors of the original ifconfig was:
  11  *              Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  12  *
  13  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  14  */
  15
  16 /*
  17  * Heavily modified by Manuel Novoa III       Mar 6, 2001
  18  *
  19  * From initial port to busybox, removed most of the redundancy by
  20  * converting to a table-driven approach.  Added several (optional)
  21  * args missing from initial port.
  22  *
  23  * Still missing:  media, tunnel.
  24  *
  25  * 2002-04-20
  26  * IPV6 support added by Bart Visscher <magick@linux-fan.com>
  27  */
  28
  29 //usage:#define ifconfig_trivial_usage
  30 //usage:        IF_FEATURE_IFCONFIG_STATUS("[-a]") " interface [address]"
  31 //usage:#define ifconfig_full_usage "\n\n"
  32 //usage:       "Configure a network interface\n"
  33 //usage:     "\n"
  34 //usage:        IF_FEATURE_IPV6(
  35 //usage:       "        [add ADDRESS[/PREFIXLEN]]\n")
  36 //usage:        IF_FEATURE_IPV6(
  37 //usage:       "        [del ADDRESS[/PREFIXLEN]]\n")
  38 //usage:       "        [[-]broadcast [ADDRESS]] [[-]pointopoint [ADDRESS]]\n"
  39 //usage:       "        [netmask ADDRESS] [dstaddr ADDRESS]\n"
  40 //usage:        IF_FEATURE_IFCONFIG_SLIP(
  41 //usage:       "        [outfill NN] [keepalive NN]\n")
  42 //usage:       "        " IF_FEATURE_IFCONFIG_HW("[hw ether" IF_FEATURE_HWIB("|infiniband")" ADDRESS] ") "[metric NN] [mtu NN]\n"
  43 //usage:       "        [[-]trailers] [[-]arp] [[-]allmulti]\n"
  44 //usage:       "        [multicast] [[-]promisc] [txqueuelen NN] [[-]dynamic]\n"
  45 //usage:        IF_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ(
  46 //usage:       "        [mem_start NN] [io_addr NN] [irq NN]\n")
  47 //usage:       "        [up|down] ..."
  48
  49 #include "libbb.h"
  50 #include "inet_common.h"
  51 #include <net/if.h>
  52 #include <net/if_arp.h>
  53 #include <netinet/in.h>
  54 #ifdef HAVE_NET_ETHERNET_H
  55 # include <net/ethernet.h>
  56 #endif
  57
  58 #if ENABLE_FEATURE_IFCONFIG_SLIP
  59 # include <net/if_slip.h>
  60 #endif
  61
  62 /* I don't know if this is needed for busybox or not.  Anyone? */
  63 #define QUESTIONABLE_ALIAS_CASE
  64
  65
  66 /* Defines for glibc2.0 users. */
  67 #ifndef SIOCSIFTXQLEN
  68 # define SIOCSIFTXQLEN      0x8943
  69 # define SIOCGIFTXQLEN      0x8942
  70 #endif
  71
  72 /* ifr_qlen is ifru_ivalue, but it isn't present in 2.0 kernel headers */
  73 #ifndef ifr_qlen
  74 # define ifr_qlen        ifr_ifru.ifru_mtu
  75 #endif
  76
  77 #ifndef IFF_DYNAMIC
  78 # define IFF_DYNAMIC     0x8000 /* dialup device with changing addresses */
  79 #endif
  80
  81 #if ENABLE_FEATURE_IPV6
  82 struct in6_ifreq {
  83         struct in6_addr ifr6_addr;
  84         uint32_t ifr6_prefixlen;
  85         int ifr6_ifindex;
  86 };
  87 #endif
  88
  89 /*
  90  * Here are the bit masks for the "flags" member of struct options below.
  91  * N_ signifies no arg prefix; M_ signifies arg prefixed by '-'.
  92  * CLR clears the flag; SET sets the flag; ARG signifies (optional) arg.
  93  */
  94 #define N_CLR            0x01
  95 #define M_CLR            0x02
  96 #define N_SET            0x04
  97 #define M_SET            0x08
  98 #define N_ARG            0x10
  99 #define M_ARG            0x20
 100
 101 #define M_MASK           (M_CLR | M_SET | M_ARG)
 102 #define N_MASK           (N_CLR | N_SET | N_ARG)
 103 #define SET_MASK         (N_SET | M_SET)
 104 #define CLR_MASK         (N_CLR | M_CLR)
 105 #define SET_CLR_MASK     (SET_MASK | CLR_MASK)
 106 #define ARG_MASK         (M_ARG | N_ARG)
 107
 108 /*
 109  * Here are the bit masks for the "arg_flags" member of struct options below.
 110  */
 111
 112 /*
 113  * cast type:
 114  *   00 int
 115  *   01 char *
 116  *   02 HOST_COPY in_ether
 117  *   03 HOST_COPY INET_resolve
 118  */
 119 #define A_CAST_TYPE      0x03
 120 /*
 121  * map type:
 122  *   00 not a map type (mem_start, io_addr, irq)
 123  *   04 memstart (unsigned long)
 124  *   08 io_addr  (unsigned short)
 125  *   0C irq      (unsigned char)
 126  */
 127 #define A_MAP_TYPE       0x0C
 128 #define A_ARG_REQ        0x10   /* Set if an arg is required. */
 129 #define A_NETMASK        0x20   /* Set if netmask (check for multiple sets). */
 130 #define A_SET_AFTER      0x40   /* Set a flag at the end. */
 131 #define A_COLON_CHK      0x80   /* Is this needed?  See below. */
 132 #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
 133 #define A_HOSTNAME      0x100   /* Set if it is ip addr. */
 134 #define A_BROADCAST     0x200   /* Set if it is broadcast addr. */
 135 #else
 136 #define A_HOSTNAME          0
 137 #define A_BROADCAST         0
 138 #endif
 139
 140 /*
 141  * These defines are for dealing with the A_CAST_TYPE field.
 142  */
 143 #define A_CAST_CHAR_PTR  0x01
 144 #define A_CAST_RESOLVE   0x01
 145 #define A_CAST_HOST_COPY 0x02
 146 #define A_CAST_HOST_COPY_IN_ETHER    A_CAST_HOST_COPY
 147 #define A_CAST_HOST_COPY_RESOLVE     (A_CAST_HOST_COPY | A_CAST_RESOLVE)
 148
 149 /*
 150  * These defines are for dealing with the A_MAP_TYPE field.
 151  */
 152 #define A_MAP_ULONG      0x04   /* memstart */
 153 #define A_MAP_USHORT     0x08   /* io_addr */
 154 #define A_MAP_UCHAR      0x0C   /* irq */
 155
 156 /*
 157  * Define the bit masks signifying which operations to perform for each arg.
 158  */
 159
 160 #define ARG_METRIC       (A_ARG_REQ /*| A_CAST_INT*/)
 161 #define ARG_MTU          (A_ARG_REQ /*| A_CAST_INT*/)
 162 #define ARG_TXQUEUELEN   (A_ARG_REQ /*| A_CAST_INT*/)
 163 #define ARG_MEM_START    (A_ARG_REQ | A_MAP_ULONG)
 164 #define ARG_IO_ADDR      (A_ARG_REQ | A_MAP_ULONG)
 165 #define ARG_IRQ          (A_ARG_REQ | A_MAP_UCHAR)
 166 #define ARG_DSTADDR      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE)
 167 #define ARG_NETMASK      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_NETMASK)
 168 #define ARG_BROADCAST    (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER | A_BROADCAST)
 169 #define ARG_HW           (A_ARG_REQ | A_CAST_HOST_COPY_IN_ETHER)
 170 #define ARG_POINTOPOINT  (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 171 #define ARG_KEEPALIVE    (A_ARG_REQ | A_CAST_CHAR_PTR)
 172 #define ARG_OUTFILL      (A_ARG_REQ | A_CAST_CHAR_PTR)
 173 #define ARG_HOSTNAME     (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER | A_COLON_CHK | A_HOSTNAME)
 174 #define ARG_ADD_DEL      (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 175
 176
 177 /*
 178  * Set up the tables.  Warning!  They must have corresponding order!
 179  */
 180
 181 struct arg1opt {
 182         const char *name;
 183         unsigned short selector;
 184         unsigned short ifr_offset;
 185 };
 186
 187 struct options {
 188         const char *name;
 189 #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
 190         const unsigned int flags:6;
 191         const unsigned int arg_flags:10;
 192 #else
 193         const unsigned char flags;
 194         const unsigned char arg_flags;
 195 #endif
 196         const unsigned short selector;
 197 };
 198
 199 #define ifreq_offsetof(x)  offsetof(struct ifreq, x)
 200
 201 static const struct arg1opt Arg1Opt[] = {
 202         { "SIFMETRIC",  SIOCSIFMETRIC,  ifreq_offsetof(ifr_metric) },
 203         { "SIFMTU",     SIOCSIFMTU,     ifreq_offsetof(ifr_mtu) },
 204         { "SIFTXQLEN",  SIOCSIFTXQLEN,  ifreq_offsetof(ifr_qlen) },
 205         { "SIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr) },
 206         { "SIFNETMASK", SIOCSIFNETMASK, ifreq_offsetof(ifr_netmask) },
 207         { "SIFBRDADDR", SIOCSIFBRDADDR, ifreq_offsetof(ifr_broadaddr) },
 208 #if ENABLE_FEATURE_IFCONFIG_HW
 209         { "SIFHWADDR",  SIOCSIFHWADDR,  ifreq_offsetof(ifr_hwaddr) },
 210 #endif
 211         { "SIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr) },
 212 #ifdef SIOCSKEEPALIVE
 213         { "SKEEPALIVE", SIOCSKEEPALIVE, ifreq_offsetof(ifr_data) },
 214 #endif
 215 #ifdef SIOCSOUTFILL
 216         { "SOUTFILL",   SIOCSOUTFILL,   ifreq_offsetof(ifr_data) },
 217 #endif
 218 #if ENABLE_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 219         { "SIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.mem_start) },
 220         { "SIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.base_addr) },
 221         { "SIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.irq) },
 222 #endif
 223         /* Last entry if for unmatched (possibly hostname) arg. */
 224 #if ENABLE_FEATURE_IPV6
 225         { "SIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr) }, /* IPv6 version ignores the offset */
 226         { "DIFADDR",    SIOCDIFADDR,    ifreq_offsetof(ifr_addr) }, /* IPv6 version ignores the offset */
 227 #endif
 228         { "SIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr) },
 229 };
 230
 231 static const struct options OptArray[] = {
 232         { "metric",      N_ARG,         ARG_METRIC,      0 },
 233         { "mtu",         N_ARG,         ARG_MTU,         0 },
 234         { "txqueuelen",  N_ARG,         ARG_TXQUEUELEN,  0 },
 235         { "dstaddr",     N_ARG,         ARG_DSTADDR,     0 },
 236         { "netmask",     N_ARG,         ARG_NETMASK,     0 },
 237         { "broadcast",   N_ARG | M_CLR, ARG_BROADCAST,   IFF_BROADCAST },
 238 #if ENABLE_FEATURE_IFCONFIG_HW
 239         { "hw",          N_ARG,         ARG_HW,          0 },
 240 #endif
 241         { "pointopoint", N_ARG | M_CLR, ARG_POINTOPOINT, IFF_POINTOPOINT },
 242 #ifdef SIOCSKEEPALIVE
 243         { "keepalive",   N_ARG,         ARG_KEEPALIVE,   0 },
 244 #endif
 245 #ifdef SIOCSOUTFILL
 246         { "outfill",     N_ARG,         ARG_OUTFILL,     0 },
 247 #endif
 248 #if ENABLE_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 249         { "mem_start",   N_ARG,         ARG_MEM_START,   0 },
 250         { "io_addr",     N_ARG,         ARG_IO_ADDR,     0 },
 251         { "irq",         N_ARG,         ARG_IRQ,         0 },
 252 #endif
 253 #if ENABLE_FEATURE_IPV6
 254         { "add",         N_ARG,         ARG_ADD_DEL,     0 },
 255         { "del",         N_ARG,         ARG_ADD_DEL,     0 },
 256 #endif
 257         { "arp",         N_CLR | M_SET, 0,               IFF_NOARP },
 258         { "trailers",    N_CLR | M_SET, 0,               IFF_NOTRAILERS },
 259         { "promisc",     N_SET | M_CLR, 0,               IFF_PROMISC },
 260         { "multicast",   N_SET | M_CLR, 0,               IFF_MULTICAST },
 261         { "allmulti",    N_SET | M_CLR, 0,               IFF_ALLMULTI },
 262         { "dynamic",     N_SET | M_CLR, 0,               IFF_DYNAMIC },
 263         { "up",          N_SET,         0,               (IFF_UP | IFF_RUNNING) },
 264         { "down",        N_CLR,         0,               IFF_UP },
 265         { NULL,          0,             ARG_HOSTNAME,    (IFF_UP | IFF_RUNNING) }
 266 };
 267
 268 /*
 269  * A couple of prototypes.
 270  */
 271 #if ENABLE_FEATURE_IFCONFIG_HW
 272 static int in_ether(const char *bufp, struct sockaddr *sap);
 273 #endif
 274
 275 /*
 276  * Our main function.
 277  */
 278 int ifconfig_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 279 int ifconfig_main(int argc UNUSED_PARAM, char **argv)
 280 {
 281         struct ifreq ifr;
 282         struct sockaddr_in sai;
 283 #if ENABLE_FEATURE_IFCONFIG_HW
 284         struct sockaddr sa;
 285 #endif
 286         const struct arg1opt *a1op;
 287         const struct options *op;
 288         int sockfd;                     /* socket fd we use to manipulate stuff with */
 289         int selector;
 290 #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
 291         unsigned int mask;
 292         unsigned int did_flags;
 293         unsigned int sai_hostname, sai_netmask;
 294 #else
 295         unsigned char mask;
 296         unsigned char did_flags;
 297 #endif
 298         char *p;
 299         /*char host[128];*/
 300         const char *host = NULL; /* make gcc happy */
 301
 302         did_flags = 0;
 303 #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
 304         sai_hostname = 0;
 305         sai_netmask = 0;
 306 #endif
 307
 308         /* skip argv[0] */
 309         ++argv;
 310
 311 #if ENABLE_FEATURE_IFCONFIG_STATUS
 312         if (argv[0] && (argv[0][0] == '-' && argv[0][1] == 'a' && !argv[0][2])) {
 313                 interface_opt_a = 1;
 314                 ++argv;
 315         }
 316 #endif
 317
 318         if (!argv[0] || !argv[1]) { /* one or no args */
 319 #if ENABLE_FEATURE_IFCONFIG_STATUS
 320                 return display_interfaces(argv[0] /* can be NULL */);
 321 #else
 322                 bb_error_msg_and_die("no support for status display");
 323 #endif
 324         }
 325
 326         /* Create a channel to the NET kernel. */
 327         sockfd = xsocket(AF_INET, SOCK_DGRAM, 0);
 328
 329         /* get interface name */
 330         strncpy_IFNAMSIZ(ifr.ifr_name, *argv);
 331
 332         /* Process the remaining arguments. */
 333         while (*++argv != (char *) NULL) {
 334                 p = *argv;
 335                 mask = N_MASK;
 336                 if (*p == '-') {        /* If the arg starts with '-'... */
 337                         ++p;            /*    advance past it and */
 338                         mask = M_MASK;  /*    set the appropriate mask. */
 339                 }
 340                 for (op = OptArray; op->name; op++) {   /* Find table entry. */
 341                         if (strcmp(p, op->name) == 0) { /* If name matches... */
 342                                 mask &= op->flags;
 343                                 if (mask)       /* set the mask and go. */
 344                                         goto FOUND_ARG;
 345                                 /* If we get here, there was a valid arg with an */
 346                                 /* invalid '-' prefix. */
 347                                 bb_error_msg_and_die("bad: '%s'", p-1);
 348                         }
 349                 }
 350
 351                 /* We fell through, so treat as possible hostname. */
 352                 a1op = Arg1Opt + ARRAY_SIZE(Arg1Opt) - 1;
 353                 mask = op->arg_flags;
 354                 goto HOSTNAME;
 355
 356  FOUND_ARG:
 357                 if (mask & ARG_MASK) {
 358                         mask = op->arg_flags;
 359                         a1op = Arg1Opt + (op - OptArray);
 360                         if (mask & A_NETMASK & did_flags)
 361                                 bb_show_usage();
 362                         if (*++argv == NULL) {
 363                                 if (mask & A_ARG_REQ)
 364                                         bb_show_usage();
 365                                 --argv;
 366                                 mask &= A_SET_AFTER;    /* just for broadcast */
 367                         } else {        /* got an arg so process it */
 368  HOSTNAME:
 369                                 did_flags |= (mask & (A_NETMASK|A_HOSTNAME));
 370                                 if (mask & A_CAST_HOST_COPY) {
 371 #if ENABLE_FEATURE_IFCONFIG_HW
 372                                         if (mask & A_CAST_RESOLVE) {
 373 #endif
 374 #if ENABLE_FEATURE_IPV6
 375                                                 char *prefix;
 376                                                 int prefix_len = 0;
 377 #endif
 378                                                 /*safe_strncpy(host, *argv, (sizeof host));*/
 379                                                 host = *argv;
 380 #if ENABLE_FEATURE_IPV6
 381                                                 prefix = strchr(host, '/');
 382                                                 if (prefix) {
 383                                                         prefix_len = xatou_range(prefix + 1, 0, 128);
 384                                                         *prefix = '\0';
 385                                                 }
 386 #endif
 387                                                 sai.sin_family = AF_INET;
 388                                                 sai.sin_port = 0;
 389                                                 if (strcmp(host, "default") == 0) {
 390                                                         /* Default is special, meaning 0.0.0.0. */
 391                                                         sai.sin_addr.s_addr = INADDR_ANY;
 392                                                 }
 393 #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
 394                                                 else if ((host[0] == '+' && !host[1]) && (mask & A_BROADCAST)
 395                                                  && (did_flags & (A_NETMASK|A_HOSTNAME)) == (A_NETMASK|A_HOSTNAME)
 396                                                 ) {
 397                                                         /* + is special, meaning broadcast is derived. */
 398                                                         sai.sin_addr.s_addr = (~sai_netmask) | (sai_hostname & sai_netmask);
 399                                                 }
 400 #endif
 401                                                 else {
 402                                                         len_and_sockaddr *lsa;
 403                                                         if (strcmp(host, "inet") == 0)
 404                                                                 continue; /* compat stuff */
 405                                                         lsa = xhost2sockaddr(host, 0);
 406 #if ENABLE_FEATURE_IPV6
 407                                                         if (lsa->u.sa.sa_family == AF_INET6) {
 408                                                                 int sockfd6;
 409                                                                 struct in6_ifreq ifr6;
 410
 411                                                                 memcpy((char *) &ifr6.ifr6_addr,
 412                                                                                 (char *) &(lsa->u.sin6.sin6_addr),
 413                                                                                 sizeof(struct in6_addr));
 414
 415                                                                 /* Create a channel to the NET kernel. */
 416                                                                 sockfd6 = xsocket(AF_INET6, SOCK_DGRAM, 0);
 417                                                                 xioctl(sockfd6, SIOGIFINDEX, &ifr);
 418                                                                 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
 419                                                                 ifr6.ifr6_prefixlen = prefix_len;
 420                                                                 ioctl_or_perror_and_die(sockfd6, a1op->selector, &ifr6, "SIOC%s", a1op->name);
 421                                                                 if (ENABLE_FEATURE_CLEAN_UP)
 422                                                                         free(lsa);
 423                                                                 continue;
 424                                                         }
 425 #endif
 426                                                         sai.sin_addr = lsa->u.sin.sin_addr;
 427                                                         if (ENABLE_FEATURE_CLEAN_UP)
 428                                                                 free(lsa);
 429                                                 }
 430 #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
 431                                                 if (mask & A_HOSTNAME)
 432                                                         sai_hostname = sai.sin_addr.s_addr;
 433                                                 if (mask & A_NETMASK)
 434                                                         sai_netmask = sai.sin_addr.s_addr;
 435 #endif
 436                                                 p = (char *) &sai;
 437 #if ENABLE_FEATURE_IFCONFIG_HW
 438                                         } else {        /* A_CAST_HOST_COPY_IN_ETHER */
 439                                                 /* This is the "hw" arg case. */
 440                                                 smalluint hw_class= index_in_substrings("ether\0"
 441                                                                 IF_FEATURE_HWIB("infiniband\0"), *argv) + 1;
 442                                                 if (!hw_class || !*++argv)
 443                                                         bb_show_usage();
 444                                                 /*safe_strncpy(host, *argv, sizeof(host));*/
 445                                                 host = *argv;
 446                                                 if (hw_class == 1 ? in_ether(host, &sa) : in_ib(host, &sa))
 447                                                         bb_error_msg_and_die("invalid hw-addr %s", host);
 448                                                 p = (char *) &sa;
 449                                         }
 450 #endif
 451                                         memcpy( (((char *)&ifr) + a1op->ifr_offset),
 452                                                    p, sizeof(struct sockaddr));
 453                                 } else {
 454                                         /* FIXME: error check?? */
 455                                         unsigned long i = strtoul(*argv, NULL, 0);
 456                                         p = ((char *)&ifr) + a1op->ifr_offset;
 457 #if ENABLE_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 458                                         if (mask & A_MAP_TYPE) {
 459                                                 xioctl(sockfd, SIOCGIFMAP, &ifr);
 460                                                 if ((mask & A_MAP_UCHAR) == A_MAP_UCHAR)
 461                                                         *((unsigned char *) p) = i;
 462                                                 else if (mask & A_MAP_USHORT)
 463                                                         *((unsigned short *) p) = i;
 464                                                 else
 465                                                         *((unsigned long *) p) = i;
 466                                         } else
 467 #endif
 468                                         if (mask & A_CAST_CHAR_PTR)
 469                                                 *((caddr_t *) p) = (caddr_t) i;
 470                                         else    /* A_CAST_INT */
 471                                                 *((int *) p) = i;
 472                                 }
 473
 474                                 ioctl_or_perror_and_die(sockfd, a1op->selector, &ifr, "SIOC%s", a1op->name);
 475 #ifdef QUESTIONABLE_ALIAS_CASE
 476                                 if (mask & A_COLON_CHK) {
 477                                         /*
 478                                          * Don't do the set_flag() if the address is an alias with
 479                                          * a '-' at the end, since it's deleted already! - Roman
 480                                          *
 481                                          * Should really use regex.h here, not sure though how well
 482                                          * it'll go with the cross-platform support etc.
 483                                          */
 484                                         char *ptr;
 485                                         short int found_colon = 0;
 486                                         for (ptr = ifr.ifr_name; *ptr; ptr++)
 487                                                 if (*ptr == ':')
 488                                                         found_colon++;
 489                                         if (found_colon && ptr[-1] == '-')
 490                                                 continue;
 491                                 }
 492 #endif
 493                         }
 494                         if (!(mask & A_SET_AFTER))
 495                                 continue;
 496                         mask = N_SET;
 497                 }
 498
 499                 xioctl(sockfd, SIOCGIFFLAGS, &ifr);
 500                 selector = op->selector;
 501                 if (mask & SET_MASK)
 502                         ifr.ifr_flags |= selector;
 503                 else
 504                         ifr.ifr_flags &= ~selector;
 505                 xioctl(sockfd, SIOCSIFFLAGS, &ifr);
 506         } /* while () */
 507
 508         if (ENABLE_FEATURE_CLEAN_UP)
 509                 close(sockfd);
 510         return 0;
 511 }
 512
 513 #if ENABLE_FEATURE_IFCONFIG_HW
 514 /* Input an Ethernet address and convert to binary. */
 515 static int in_ether(const char *bufp, struct sockaddr *sap)
 516 {
 517         char *ptr;
 518         int i, j;
 519         unsigned char val;
 520         unsigned char c;
 521
 522         sap->sa_family = ARPHRD_ETHER;
 523         ptr = (char *) sap->sa_data;
 524
 525         i = 0;
 526         do {
 527                 j = val = 0;
 528
 529                 /* We might get a semicolon here - not required. */
 530                 if (i && (*bufp == ':')) {
 531                         bufp++;
 532                 }
 533
 534                 do {
 535                         c = *bufp;
 536                         if (((unsigned char)(c - '0')) <= 9) {
 537                                 c -= '0';
 538                         } else if (((unsigned char)((c|0x20) - 'a')) <= 5) {
 539                                 c = (c|0x20) - ('a'-10);
 540                         } else if (j && (c == ':' || c == 0)) {
 541                                 break;
 542                         } else {
 543                                 return -1;
 544                         }
 545                         ++bufp;
 546                         val <<= 4;
 547                         val += c;
 548                 } while (++j < 2);
 549                 *ptr++ = val;
 550         } while (++i < ETH_ALEN);
 551
 552         return *bufp; /* Error if we don't end at end of string. */
 553 }
 554 #endif