networking/ifconfig.c

   1 /* ifconfig
   2  *
   3  * Similar to the standard Unix ifconfig, but with only the necessary
   4  * parts for AF_INET, and without any printing of if info (for now).
   5  *
   6  * Bjorn Wesen, Axis Communications AB
   7  *
   8  *
   9  * Authors of the original ifconfig was:
  10  *              Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  11  *
  12  * This program is free software; you can redistribute it
  13  * and/or  modify it under  the terms of  the GNU General
  14  * Public  License as  published  by  the  Free  Software
  15  * Foundation;  either  version 2 of the License, or  (at
  16  * your option) any later version.
  17  *
  18  * $Id: ifconfig.c,v 1.30 2004/03/31 11:30:08 andersen Exp $
  19  *
  20  */
  21
  22 /*
  23  * Heavily modified by Manuel Novoa III       Mar 6, 2001
  24  *
  25  * From initial port to busybox, removed most of the redundancy by
  26  * converting to a table-driven approach.  Added several (optional)
  27  * args missing from initial port.
  28  *
  29  * Still missing:  media, tunnel.
  30  *
  31  * 2002-04-20
  32  * IPV6 support added by Bart Visscher <magick@linux-fan.com>
  33  */
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>             /* strcmp and friends */
  38 #include <ctype.h>              /* isdigit and friends */
  39 #include <stddef.h>             /* offsetof */
  40 #include <unistd.h>
  41 #include <netdb.h>
  42 #include <sys/ioctl.h>
  43 #include <net/if.h>
  44 #include <net/if_arp.h>
  45 #include <netinet/in.h>
  46 #if __GLIBC__ >=2 && __GLIBC_MINOR >= 1
  47 #include <netpacket/packet.h>
  48 #include <net/ethernet.h>
  49 #else
  50 #include <sys/types.h>
  51 #include <netinet/if_ether.h>
  52 #endif
  53 #include "inet_common.h"
  54 #include "busybox.h"
  55
  56 #ifdef CONFIG_FEATURE_IFCONFIG_SLIP
  57 # include <net/if_slip.h>
  58 #endif
  59
  60 /* I don't know if this is needed for busybox or not.  Anyone? */
  61 #define QUESTIONABLE_ALIAS_CASE
  62
  63
  64 /* Defines for glibc2.0 users. */
  65 #ifndef SIOCSIFTXQLEN
  66 # define SIOCSIFTXQLEN      0x8943
  67 # define SIOCGIFTXQLEN      0x8942
  68 #endif
  69
  70 /* ifr_qlen is ifru_ivalue, but it isn't present in 2.0 kernel headers */
  71 #ifndef ifr_qlen
  72 # define ifr_qlen        ifr_ifru.ifru_mtu
  73 #endif
  74
  75 #ifndef IFF_DYNAMIC
  76 # define IFF_DYNAMIC     0x8000 /* dialup device with changing addresses */
  77 #endif
  78
  79 #ifdef CONFIG_FEATURE_IPV6
  80 struct in6_ifreq {
  81         struct in6_addr ifr6_addr;
  82         uint32_t ifr6_prefixlen;
  83         int ifr6_ifindex;
  84 };
  85 #endif
  86
  87 /*
  88  * Here are the bit masks for the "flags" member of struct options below.
  89  * N_ signifies no arg prefix; M_ signifies arg prefixed by '-'.
  90  * CLR clears the flag; SET sets the flag; ARG signifies (optional) arg.
  91  */
  92 #define N_CLR            0x01
  93 #define M_CLR            0x02
  94 #define N_SET            0x04
  95 #define M_SET            0x08
  96 #define N_ARG            0x10
  97 #define M_ARG            0x20
  98
  99 #define M_MASK           (M_CLR | M_SET | M_ARG)
 100 #define N_MASK           (N_CLR | N_SET | N_ARG)
 101 #define SET_MASK         (N_SET | M_SET)
 102 #define CLR_MASK         (N_CLR | M_CLR)
 103 #define SET_CLR_MASK     (SET_MASK | CLR_MASK)
 104 #define ARG_MASK         (M_ARG | N_ARG)
 105
 106 /*
 107  * Here are the bit masks for the "arg_flags" member of struct options below.
 108  */
 109
 110 /*
 111  * cast type:
 112  *   00 int
 113  *   01 char *
 114  *   02 HOST_COPY in_ether
 115  *   03 HOST_COPY INET_resolve
 116  */
 117 #define A_CAST_TYPE      0x03
 118 /*
 119  * map type:
 120  *   00 not a map type (mem_start, io_addr, irq)
 121  *   04 memstart (unsigned long)
 122  *   08 io_addr  (unsigned short)
 123  *   0C irq      (unsigned char)
 124  */
 125 #define A_MAP_TYPE       0x0C
 126 #define A_ARG_REQ        0x10   /* Set if an arg is required. */
 127 #define A_NETMASK        0x20   /* Set if netmask (check for multiple sets). */
 128 #define A_SET_AFTER      0x40   /* Set a flag at the end. */
 129 #define A_COLON_CHK      0x80   /* Is this needed?  See below. */
 130 #ifdef CONFIG_FEATURE_IFCONFIG_BROADCAST_PLUS
 131 #define A_HOSTNAME      0x100   /* Set if it is ip addr. */
 132 #define A_BROADCAST     0x200   /* Set if it is broadcast addr. */
 133 #else
 134 #define A_HOSTNAME          0
 135 #define A_BROADCAST         0
 136 #endif
 137
 138 /*
 139  * These defines are for dealing with the A_CAST_TYPE field.
 140  */
 141 #define A_CAST_CHAR_PTR  0x01
 142 #define A_CAST_RESOLVE   0x01
 143 #define A_CAST_HOST_COPY 0x02
 144 #define A_CAST_HOST_COPY_IN_ETHER    A_CAST_HOST_COPY
 145 #define A_CAST_HOST_COPY_RESOLVE     (A_CAST_HOST_COPY | A_CAST_RESOLVE)
 146
 147 /*
 148  * These defines are for dealing with the A_MAP_TYPE field.
 149  */
 150 #define A_MAP_ULONG      0x04   /* memstart */
 151 #define A_MAP_USHORT     0x08   /* io_addr */
 152 #define A_MAP_UCHAR      0x0C   /* irq */
 153
 154 /*
 155  * Define the bit masks signifying which operations to perform for each arg.
 156  */
 157
 158 #define ARG_METRIC       (A_ARG_REQ /*| A_CAST_INT*/)
 159 #define ARG_MTU          (A_ARG_REQ /*| A_CAST_INT*/)
 160 #define ARG_TXQUEUELEN   (A_ARG_REQ /*| A_CAST_INT*/)
 161 #define ARG_MEM_START    (A_ARG_REQ | A_MAP_ULONG)
 162 #define ARG_IO_ADDR      (A_ARG_REQ | A_MAP_ULONG)
 163 #define ARG_IRQ          (A_ARG_REQ | A_MAP_UCHAR)
 164 #define ARG_DSTADDR      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE)
 165 #define ARG_NETMASK      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_NETMASK)
 166 #define ARG_BROADCAST    (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER | A_BROADCAST)
 167 #define ARG_HW           (A_ARG_REQ | A_CAST_HOST_COPY_IN_ETHER)
 168 #define ARG_POINTOPOINT  (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 169 #define ARG_KEEPALIVE    (A_ARG_REQ | A_CAST_CHAR_PTR)
 170 #define ARG_OUTFILL      (A_ARG_REQ | A_CAST_CHAR_PTR)
 171 #define ARG_HOSTNAME     (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER | A_COLON_CHK | A_HOSTNAME)
 172 #define ARG_ADD_DEL      (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 173
 174
 175 /*
 176  * Set up the tables.  Warning!  They must have corresponding order!
 177  */
 178
 179 struct arg1opt {
 180         const char *name;
 181         int selector;
 182         unsigned short ifr_offset;
 183 };
 184
 185 struct options {
 186         const char *name;
 187 #ifdef CONFIG_FEATURE_IFCONFIG_BROADCAST_PLUS
 188         const unsigned int flags:6;
 189         const unsigned int arg_flags:10;
 190 #else
 191         const unsigned char flags;
 192         const unsigned char arg_flags;
 193 #endif
 194         const unsigned short selector;
 195 };
 196
 197 #define ifreq_offsetof(x)  offsetof(struct ifreq, x)
 198
 199 static const struct arg1opt Arg1Opt[] = {
 200         {"SIOCSIFMETRIC",  SIOCSIFMETRIC,  ifreq_offsetof(ifr_metric)},
 201         {"SIOCSIFMTU",     SIOCSIFMTU,     ifreq_offsetof(ifr_mtu)},
 202         {"SIOCSIFTXQLEN",  SIOCSIFTXQLEN,  ifreq_offsetof(ifr_qlen)},
 203         {"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
 204         {"SIOCSIFNETMASK", SIOCSIFNETMASK, ifreq_offsetof(ifr_netmask)},
 205         {"SIOCSIFBRDADDR", SIOCSIFBRDADDR, ifreq_offsetof(ifr_broadaddr)},
 206 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 207         {"SIOCSIFHWADDR",  SIOCSIFHWADDR,  ifreq_offsetof(ifr_hwaddr)},
 208 #endif
 209         {"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
 210 #ifdef SIOCSKEEPALIVE
 211         {"SIOCSKEEPALIVE", SIOCSKEEPALIVE, ifreq_offsetof(ifr_data)},
 212 #endif
 213 #ifdef SIOCSOUTFILL
 214         {"SIOCSOUTFILL",   SIOCSOUTFILL,   ifreq_offsetof(ifr_data)},
 215 #endif
 216 #ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 217         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.mem_start)},
 218         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.base_addr)},
 219         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.irq)},
 220 #endif
 221         /* Last entry if for unmatched (possibly hostname) arg. */
 222 #ifdef CONFIG_FEATURE_IPV6
 223         {"SIOCSIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr)}, /* IPv6 version ignores the offset */
 224         {"SIOCDIFADDR",    SIOCDIFADDR,    ifreq_offsetof(ifr_addr)}, /* IPv6 version ignores the offset */
 225 #endif
 226         {"SIOCSIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr)},
 227 };
 228
 229 static const struct options OptArray[] = {
 230         {"metric",      N_ARG,         ARG_METRIC,      0},
 231         {"mtu",         N_ARG,         ARG_MTU,         0},
 232         {"txqueuelen",  N_ARG,         ARG_TXQUEUELEN,  0},
 233         {"dstaddr",     N_ARG,         ARG_DSTADDR,     0},
 234         {"netmask",     N_ARG,         ARG_NETMASK,     0},
 235         {"broadcast",   N_ARG | M_CLR, ARG_BROADCAST,   IFF_BROADCAST},
 236 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 237         {"hw",          N_ARG, ARG_HW,                  0},
 238 #endif
 239         {"pointopoint", N_ARG | M_CLR, ARG_POINTOPOINT, IFF_POINTOPOINT},
 240 #ifdef SIOCSKEEPALIVE
 241         {"keepalive",   N_ARG,         ARG_KEEPALIVE,   0},
 242 #endif
 243 #ifdef SIOCSOUTFILL
 244         {"outfill",     N_ARG,         ARG_OUTFILL,     0},
 245 #endif
 246 #ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 247         {"mem_start",   N_ARG,         ARG_MEM_START,   0},
 248         {"io_addr",     N_ARG,         ARG_IO_ADDR,     0},
 249         {"irq",         N_ARG,         ARG_IRQ,         0},
 250 #endif
 251 #ifdef CONFIG_FEATURE_IPV6
 252         {"add",         N_ARG,         ARG_ADD_DEL,     0},
 253         {"del",         N_ARG,         ARG_ADD_DEL,     0},
 254 #endif
 255         {"arp",         N_CLR | M_SET, 0,               IFF_NOARP},
 256         {"trailers",    N_CLR | M_SET, 0,               IFF_NOTRAILERS},
 257         {"promisc",     N_SET | M_CLR, 0,               IFF_PROMISC},
 258         {"multicast",   N_SET | M_CLR, 0,               IFF_MULTICAST},
 259         {"allmulti",    N_SET | M_CLR, 0,               IFF_ALLMULTI},
 260         {"dynamic",     N_SET | M_CLR, 0,               IFF_DYNAMIC},
 261         {"up",          N_SET,         0,               (IFF_UP | IFF_RUNNING)},
 262         {"down",        N_CLR,         0,               IFF_UP},
 263         {NULL,          0,             ARG_HOSTNAME,    (IFF_UP | IFF_RUNNING)}
 264 };
 265
 266 /*
 267  * A couple of prototypes.
 268  */
 269
 270 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 271 static int in_ether(char *bufp, struct sockaddr *sap);
 272 #endif
 273
 274 #ifdef CONFIG_FEATURE_IFCONFIG_STATUS
 275 extern int interface_opt_a;
 276 extern int display_interfaces(char *ifname);
 277 #endif
 278
 279 /*
 280  * Our main function.
 281  */
 282
 283 int ifconfig_main(int argc, char **argv)
 284 {
 285         struct ifreq ifr;
 286         struct sockaddr_in sai;
 287 #ifdef CONFIG_FEATURE_IPV6
 288         struct sockaddr_in6 sai6;
 289 #endif
 290 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 291         struct sockaddr sa;
 292 #endif
 293         const struct arg1opt *a1op;
 294         const struct options *op;
 295         int sockfd;                     /* socket fd we use to manipulate stuff with */
 296         int goterr;
 297         int selector;
 298 #ifdef CONFIG_FEATURE_IFCONFIG_BROADCAST_PLUS
 299         unsigned int mask;
 300         unsigned int did_flags;
 301         unsigned int sai_hostname, sai_netmask;
 302 #else
 303         unsigned char mask;
 304         unsigned char did_flags;
 305 #endif
 306         char *p;
 307         char host[128];
 308
 309         goterr = 0;
 310         did_flags = 0;
 311 #ifdef CONFIG_FEATURE_IFCONFIG_BROADCAST_PLUS
 312         sai_hostname = 0;
 313         sai_netmask = 0;
 314 #endif
 315
 316         /* skip argv[0] */
 317         ++argv;
 318         --argc;
 319
 320 #ifdef CONFIG_FEATURE_IFCONFIG_STATUS
 321         if ((argc > 0) && (((*argv)[0] == '-') && ((*argv)[1] == 'a') && !(*argv)[2])) {
 322                 interface_opt_a = 1;
 323                 --argc;
 324                 ++argv;
 325         }
 326 #endif
 327
 328         if (argc <= 1) {
 329 #ifdef CONFIG_FEATURE_IFCONFIG_STATUS
 330                 return display_interfaces(argc ? *argv : NULL);
 331 #else
 332                 bb_error_msg_and_die
 333                         ("ifconfig was not compiled with interface status display support.");
 334 #endif
 335         }
 336
 337         /* Create a channel to the NET kernel. */
 338         if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 339                 bb_perror_msg_and_die("socket");
 340         }
 341
 342         /* get interface name */
 343         safe_strncpy(ifr.ifr_name, *argv, IFNAMSIZ);
 344
 345         /* Process the remaining arguments. */
 346         while (*++argv != (char *) NULL) {
 347                 p = *argv;
 348                 mask = N_MASK;
 349                 if (*p == '-') {        /* If the arg starts with '-'... */
 350                         ++p;            /*    advance past it and */
 351                         mask = M_MASK;  /*    set the appropriate mask. */
 352                 }
 353                 for (op = OptArray; op->name; op++) {   /* Find table entry. */
 354                         if (strcmp(p, op->name) == 0) { /* If name matches... */
 355                                 if ((mask &= op->flags)) {      /* set the mask and go. */
 356                                         goto FOUND_ARG;
 357                                 }
 358                                 /* If we get here, there was a valid arg with an */
 359                                 /* invalid '-' prefix. */
 360                                 ++goterr;
 361                                 goto LOOP;
 362                         }
 363                 }
 364
 365                 /* We fell through, so treat as possible hostname. */
 366                 a1op = Arg1Opt + (sizeof(Arg1Opt) / sizeof(Arg1Opt[0])) - 1;
 367                 mask = op->arg_flags;
 368                 goto HOSTNAME;
 369
 370           FOUND_ARG:
 371                 if (mask & ARG_MASK) {
 372                         mask = op->arg_flags;
 373                         a1op = Arg1Opt + (op - OptArray);
 374                         if (mask & A_NETMASK & did_flags) {
 375                                 bb_show_usage();
 376                         }
 377                         if (*++argv == NULL) {
 378                                 if (mask & A_ARG_REQ) {
 379                                         bb_show_usage();
 380                                 } else {
 381                                         --argv;
 382                                         mask &= A_SET_AFTER;    /* just for broadcast */
 383                                 }
 384                         } else {        /* got an arg so process it */
 385                           HOSTNAME:
 386                                 did_flags |= (mask & (A_NETMASK|A_HOSTNAME));
 387                                 if (mask & A_CAST_HOST_COPY) {
 388 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 389                                         if (mask & A_CAST_RESOLVE) {
 390 #endif
 391 #ifdef CONFIG_FEATURE_IPV6
 392                                                 char *prefix;
 393                                                 int prefix_len = 0;
 394 #endif
 395
 396                                                 safe_strncpy(host, *argv, (sizeof host));
 397 #ifdef CONFIG_FEATURE_IPV6
 398                                                 if ((prefix = strchr(host, '/'))) {
 399                                                         if (safe_strtoi(prefix + 1, &prefix_len) ||
 400                                                                 (prefix_len < 0) || (prefix_len > 128))
 401                                                         {
 402                                                                 ++goterr;
 403                                                                 goto LOOP;
 404                                                         }
 405                                                         *prefix = 0;
 406                                                 }
 407 #endif
 408
 409                                                 sai.sin_family = AF_INET;
 410                                                 sai.sin_port = 0;
 411                                                 if (!strcmp(host, bb_INET_default)) {
 412                                                         /* Default is special, meaning 0.0.0.0. */
 413                                                         sai.sin_addr.s_addr = INADDR_ANY;
 414 #ifdef CONFIG_FEATURE_IFCONFIG_BROADCAST_PLUS
 415                                                 } else if (((host[0] == '+') && !host[1]) && (mask & A_BROADCAST) &&
 416                                                                    (did_flags & (A_NETMASK|A_HOSTNAME)) == (A_NETMASK|A_HOSTNAME)) {
 417                                                         /* + is special, meaning broadcast is derived. */
 418                                                         sai.sin_addr.s_addr = (~sai_netmask) | (sai_hostname & sai_netmask);
 419 #endif
 420 #ifdef CONFIG_FEATURE_IPV6
 421                                                 } else if (inet_pton(AF_INET6, host, &sai6.sin6_addr) > 0) {
 422                                                         int sockfd6;
 423                                                         struct in6_ifreq ifr6;
 424
 425                                                         memcpy((char *) &ifr6.ifr6_addr,
 426                                                                    (char *) &sai6.sin6_addr,
 427                                                                    sizeof(struct in6_addr));
 428
 429                                                         /* Create a channel to the NET kernel. */
 430                                                         if ((sockfd6 = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 431                                                                 bb_perror_msg_and_die("socket6");
 432                                                         }
 433                                                         if (ioctl(sockfd6, SIOGIFINDEX, &ifr) < 0) {
 434                                                                 perror("SIOGIFINDEX");
 435                                                                 ++goterr;
 436                                                                 continue;
 437                                                         }
 438                                                         ifr6.ifr6_ifindex = ifr.ifr_ifindex;
 439                                                         ifr6.ifr6_prefixlen = prefix_len;
 440                                                         if (ioctl(sockfd6, a1op->selector, &ifr6) < 0) {
 441                                                                 perror(a1op->name);
 442                                                                 ++goterr;
 443                                                         }
 444                                                         continue;
 445 #endif
 446                                                 } else if (inet_aton(host, &sai.sin_addr) == 0) {
 447                                                         /* It's not a dotted quad. */
 448                                                         struct hostent *hp;
 449                                                         if ((hp = gethostbyname(host)) == (struct hostent *)NULL) {
 450                                                                 ++goterr;
 451                                                                 continue;
 452                                                         }
 453                                                         memcpy((char *) &sai.sin_addr, (char *) hp->h_addr_list[0],
 454                                                         sizeof(struct in_addr));
 455                                                 }
 456 #ifdef CONFIG_FEATURE_IFCONFIG_BROADCAST_PLUS
 457                                                 if (mask & A_HOSTNAME) {
 458                                                         sai_hostname = sai.sin_addr.s_addr;
 459                                                 }
 460                                                 if (mask & A_NETMASK) {
 461                                                         sai_netmask = sai.sin_addr.s_addr;
 462                                                 }
 463 #endif
 464                                                 p = (char *) &sai;
 465 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 466                                         } else {        /* A_CAST_HOST_COPY_IN_ETHER */
 467                                                 /* This is the "hw" arg case. */
 468                                                 if (strcmp("ether", *argv) || (*++argv == NULL)) {
 469                                                         bb_show_usage();
 470                                                 }
 471                                                 safe_strncpy(host, *argv, (sizeof host));
 472                                                 if (in_ether(host, &sa)) {
 473                                                         bb_error_msg("invalid hw-addr %s", host);
 474                                                         ++goterr;
 475                                                         continue;
 476                                                 }
 477                                                 p = (char *) &sa;
 478                                         }
 479 #endif
 480                                         memcpy((((char *) (&ifr)) + a1op->ifr_offset),
 481                                                    p, sizeof(struct sockaddr));
 482                                 } else {
 483                                         unsigned long i = strtoul(*argv, NULL, 0);
 484
 485                                         p = ((char *) (&ifr)) + a1op->ifr_offset;
 486 #ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 487                                         if (mask & A_MAP_TYPE) {
 488                                                 if (ioctl(sockfd, SIOCGIFMAP, &ifr) < 0) {
 489                                                         ++goterr;
 490                                                         continue;
 491                                                 }
 492                                                 if ((mask & A_MAP_UCHAR) == A_MAP_UCHAR) {
 493                                                         *((unsigned char *) p) = i;
 494                                                 } else if (mask & A_MAP_USHORT) {
 495                                                         *((unsigned short *) p) = i;
 496                                                 } else {
 497                                                         *((unsigned long *) p) = i;
 498                                                 }
 499                                         } else
 500 #endif
 501                                         if (mask & A_CAST_CHAR_PTR) {
 502                                                 *((caddr_t *) p) = (caddr_t) i;
 503                                         } else {        /* A_CAST_INT */
 504                                                 *((int *) p) = i;
 505                                         }
 506                                 }
 507
 508                                 if (ioctl(sockfd, a1op->selector, &ifr) < 0) {
 509                                         perror(a1op->name);
 510                                         ++goterr;
 511                                         continue;
 512                                 }
 513 #ifdef QUESTIONABLE_ALIAS_CASE
 514                                 if (mask & A_COLON_CHK) {
 515                                         /*
 516                                          * Don't do the set_flag() if the address is an alias with
 517                                          * a - at the end, since it's deleted already! - Roman
 518                                          *
 519                                          * Should really use regex.h here, not sure though how well
 520                                          * it'll go with the cross-platform support etc.
 521                                          */
 522                                         char *ptr;
 523                                         short int found_colon = 0;
 524
 525                                         for (ptr = ifr.ifr_name; *ptr; ptr++) {
 526                                                 if (*ptr == ':') {
 527                                                         found_colon++;
 528                                                 }
 529                                         }
 530
 531                                         if (found_colon && *(ptr - 1) == '-') {
 532                                                 continue;
 533                                         }
 534                                 }
 535 #endif
 536                         }
 537                         if (!(mask & A_SET_AFTER)) {
 538                                 continue;
 539                         }
 540                         mask = N_SET;
 541                 }
 542
 543                 if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) < 0) {
 544                         perror("SIOCGIFFLAGS");
 545                         ++goterr;
 546                 } else {
 547                         selector = op->selector;
 548                         if (mask & SET_MASK) {
 549                                 ifr.ifr_flags |= selector;
 550                         } else {
 551                                 ifr.ifr_flags &= ~selector;
 552                         }
 553                         if (ioctl(sockfd, SIOCSIFFLAGS, &ifr) < 0) {
 554                                 perror("SIOCSIFFLAGS");
 555                                 ++goterr;
 556                         }
 557                 }
 558           LOOP:
 559                 continue;
 560         }                                       /* end of while-loop */
 561
 562         if (ENABLE_FEATURE_CLEAN_UP) close(sockfd);
 563         return goterr;
 564 }
 565
 566 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 567 /* Input an Ethernet address and convert to binary. */
 568 static int in_ether(char *bufp, struct sockaddr *sap)
 569 {
 570         char *ptr;
 571         int i, j;
 572         unsigned char val;
 573         unsigned char c;
 574
 575         sap->sa_family = ARPHRD_ETHER;
 576         ptr = sap->sa_data;
 577
 578         i = 0;
 579         do {
 580                 j = val = 0;
 581
 582                 /* We might get a semicolon here - not required. */
 583                 if (i && (*bufp == ':')) {
 584                         bufp++;
 585                 }
 586
 587                 do {
 588                         c = *bufp;
 589                         if (((unsigned char)(c - '0')) <= 9) {
 590                                 c -= '0';
 591                         } else if (((unsigned char)((c|0x20) - 'a')) <= 5) {
 592                                 c = (c|0x20) - ('a'-10);
 593                         } else if (j && (c == ':' || c == 0)) {
 594                                 break;
 595                         } else {
 596                                 return -1;
 597                         }
 598                         ++bufp;
 599                         val <<= 4;
 600                         val += c;
 601                 } while (++j < 2);
 602                 *ptr++ = val;
 603         } while (++i < ETH_ALEN);
 604
 605         return (int) (*bufp);   /* Error if we don't end at end of string. */
 606 }
 607 #endif