networking/ifupdown.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *  ifupdown for busybox
   4  *  Copyright (c) 2002 Glenn McGrath <bug1@iinet.net.au>
   5  *  Copyright (c) 2003-2004 Erik Andersen <andersen@codepoet.org>
   6  *
   7  *  Based on ifupdown v 0.6.4 by Anthony Towns
   8  *  Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
   9  *
  10  *  Changes to upstream version
  11  *  Remove checks for kernel version, assume kernel version 2.2.0 or better.
  12  *  Lines in the interfaces file cannot wrap.
  13  *  To adhere to the FHS, the default state file is /var/run/ifstate.
  14  *
  15  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  16  */
  17
  18 #include "busybox.h"
  19 #include <sys/utsname.h>
  20 #include <fnmatch.h>
  21 #include <getopt.h>
  22
  23 #define MAX_OPT_DEPTH 10
  24 #define EUNBALBRACK 10001
  25 #define EUNDEFVAR   10002
  26 #define EUNBALPER   10000
  27
  28 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
  29 #define MAX_INTERFACE_LENGTH 10
  30 #endif
  31
  32 #define debug_noise(fmt, args...)
  33
  34 /* Forward declaration */
  35 struct interface_defn_t;
  36
  37 typedef int (execfn)(char *command);
  38
  39 struct method_t
  40 {
  41         char *name;
  42         int (*up)(struct interface_defn_t *ifd, execfn *e);
  43         int (*down)(struct interface_defn_t *ifd, execfn *e);
  44 };
  45
  46 struct address_family_t
  47 {
  48         char *name;
  49         int n_methods;
  50         const struct method_t *method;
  51 };
  52
  53 struct mapping_defn_t
  54 {
  55         struct mapping_defn_t *next;
  56
  57         int max_matches;
  58         int n_matches;
  59         char **match;
  60
  61         char *script;
  62
  63         int max_mappings;
  64         int n_mappings;
  65         char **mapping;
  66 };
  67
  68 struct variable_t
  69 {
  70         char *name;
  71         char *value;
  72 };
  73
  74 struct interface_defn_t
  75 {
  76         const struct address_family_t *address_family;
  77         const struct method_t *method;
  78
  79         char *iface;
  80         int max_options;
  81         int n_options;
  82         struct variable_t *option;
  83 };
  84
  85 struct interfaces_file_t
  86 {
  87         llist_t *autointerfaces;
  88         llist_t *ifaces;
  89         struct mapping_defn_t *mappings;
  90 };
  91
  92 static unsigned option_mask;
  93 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  94 enum {
  95         OPT_do_all = 0x1,
  96         OPT_no_act = 0x2,
  97         OPT_verbose = 0x4,
  98         OPT_force = 0x8,
  99         OPT_no_mappings = 0x10,
 100 };
 101 #define DO_ALL (option_mask & OPT_do_all)
 102 #define NO_ACT (option_mask & OPT_no_act)
 103 #define VERBOSE (option_mask & OPT_verbose)
 104 #define FORCE (option_mask & OPT_force)
 105 #define NO_MAPPINGS (option_mask & OPT_no_mappings)
 106
 107 static char **__myenviron;
 108
 109 static char *startup_PATH;
 110
 111 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 112
 113 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 114
 115 static unsigned int count_bits(unsigned int a)
 116 {
 117         unsigned int result;
 118         result = (a & 0x55) + ((a >> 1) & 0x55);
 119         result = (result & 0x33) + ((result >> 2) & 0x33);
 120         return ((result & 0x0F) + ((result >> 4) & 0x0F));
 121 }
 122
 123 static int count_netmask_bits(char *dotted_quad)
 124 {
 125         unsigned int result, a, b, c, d;
 126         /* Found a netmask...  Check if it is dotted quad */
 127         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 128                 return -1;
 129         result = count_bits(a);
 130         result += count_bits(b);
 131         result += count_bits(c);
 132         result += count_bits(d);
 133         return (int)result;
 134 }
 135 #endif
 136
 137 static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
 138 {
 139         if (*pos + str_length >= *len) {
 140                 char *newbuf;
 141
 142                 newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
 143                 *buf = newbuf;
 144                 *len = *len * 2 + str_length + 1;
 145         }
 146
 147         while (str_length-- >= 1) {
 148                 (*buf)[(*pos)++] = *str;
 149                 str++;
 150         }
 151         (*buf)[*pos] = '\0';
 152 }
 153
 154 static int strncmpz(char *l, char *r, size_t llen)
 155 {
 156         int i = strncmp(l, r, llen);
 157
 158         if (i == 0) {
 159                 return -r[llen];
 160         } else {
 161                 return i;
 162         }
 163 }
 164
 165 static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
 166 {
 167         int i;
 168
 169         if (strncmpz(id, "iface", idlen) == 0) {
 170                 char *result;
 171                 static char label_buf[20];
 172                 strncpy(label_buf, ifd->iface, 19);
 173                 label_buf[19]=0;
 174                 result = strchr(label_buf, ':');
 175                 if (result) {
 176                         *result=0;
 177                 }
 178                 return label_buf;
 179         } else if (strncmpz(id, "label", idlen) == 0) {
 180                 return ifd->iface;
 181         } else {
 182                 for (i = 0; i < ifd->n_options; i++) {
 183                         if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 184                                 return ifd->option[i].value;
 185                         }
 186                 }
 187         }
 188
 189         return NULL;
 190 }
 191
 192 static char *parse(char *command, struct interface_defn_t *ifd)
 193 {
 194
 195         char *result = NULL;
 196         size_t pos = 0, len = 0;
 197         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 198         int okay[MAX_OPT_DEPTH] = { 1 };
 199         int opt_depth = 1;
 200
 201         while (*command) {
 202                 switch (*command) {
 203                 default:
 204                         addstr(&result, &len, &pos, command, 1);
 205                         command++;
 206                         break;
 207                 case '\\':
 208                         if (command[1]) {
 209                                 addstr(&result, &len, &pos, command + 1, 1);
 210                                 command += 2;
 211                         } else {
 212                                 addstr(&result, &len, &pos, command, 1);
 213                                 command++;
 214                         }
 215                         break;
 216                 case '[':
 217                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 218                                 old_pos[opt_depth] = pos;
 219                                 okay[opt_depth] = 1;
 220                                 opt_depth++;
 221                                 command += 2;
 222                         } else {
 223                                 addstr(&result, &len, &pos, "[", 1);
 224                                 command++;
 225                         }
 226                         break;
 227                 case ']':
 228                         if (command[1] == ']' && opt_depth > 1) {
 229                                 opt_depth--;
 230                                 if (!okay[opt_depth]) {
 231                                         pos = old_pos[opt_depth];
 232                                         result[pos] = '\0';
 233                                 }
 234                                 command += 2;
 235                         } else {
 236                                 addstr(&result, &len, &pos, "]", 1);
 237                                 command++;
 238                         }
 239                         break;
 240                 case '%':
 241                         {
 242                                 char *nextpercent;
 243                                 char *varvalue;
 244
 245                                 command++;
 246                                 nextpercent = strchr(command, '%');
 247                                 if (!nextpercent) {
 248                                         errno = EUNBALPER;
 249                                         free(result);
 250                                         return NULL;
 251                                 }
 252
 253                                 varvalue = get_var(command, nextpercent - command, ifd);
 254
 255                                 if (varvalue) {
 256                                         addstr(&result, &len, &pos, varvalue, strlen(varvalue));
 257                                 } else {
 258 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 259                                         /* Sigh...  Add a special case for 'ip' to convert from
 260                                          * dotted quad to bit count style netmasks.  */
 261                                         if (strncmp(command, "bnmask", 6)==0) {
 262                                                 int res;
 263                                                 varvalue = get_var("netmask", 7, ifd);
 264                                                 if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 265                                                         char argument[255];
 266                                                         sprintf(argument, "%d", res);
 267                                                         addstr(&result, &len, &pos, argument, strlen(argument));
 268                                                         command = nextpercent + 1;
 269                                                         break;
 270                                                 }
 271                                         }
 272 #endif
 273                                         okay[opt_depth - 1] = 0;
 274                                 }
 275
 276                                 command = nextpercent + 1;
 277                         }
 278                         break;
 279                 }
 280         }
 281
 282         if (opt_depth > 1) {
 283                 errno = EUNBALBRACK;
 284                 free(result);
 285                 return NULL;
 286         }
 287
 288         if (!okay[0]) {
 289                 errno = EUNDEFVAR;
 290                 free(result);
 291                 return NULL;
 292         }
 293
 294         return result;
 295 }
 296
 297 /* execute() returns 1 for success and 0 for failure */
 298 static int execute(char *command, struct interface_defn_t *ifd, execfn *exec)
 299 {
 300         char *out;
 301         int ret;
 302
 303         out = parse(command, ifd);
 304         if (!out) {
 305                 return 0;
 306         }
 307         ret = (*exec)(out);
 308
 309         free(out);
 310         if (ret != 1) {
 311                 return 0;
 312         }
 313         return 1;
 314 }
 315 #endif
 316
 317 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 318 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 319 {
 320 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 321         int result;
 322         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 323         result += execute("ip link set %iface% up", ifd, exec);
 324         return ((result == 2) ? 2 : 0);
 325 #else
 326         return execute("ifconfig %iface% add ::1", ifd, exec);
 327 #endif
 328 }
 329
 330 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 331 {
 332 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 333         return execute("ip link set %iface% down", ifd, exec);
 334 #else
 335         return execute("ifconfig %iface% del ::1", ifd, exec);
 336 #endif
 337 }
 338
 339 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 340 {
 341         int result;
 342 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 343         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 344         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 345         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 346 #else
 347         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 348         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 349         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 350 #endif
 351         return ((result == 3) ? 3 : 0);
 352 }
 353
 354 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 355 {
 356 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 357         return execute("ip link set %iface% down", ifd, exec);
 358 #else
 359         return execute("ifconfig %iface% down", ifd, exec);
 360 #endif
 361 }
 362
 363 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 364 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 365 {
 366         int result;
 367         result = execute("ip tunnel add %iface% mode sit remote "
 368                         "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 369         result += execute("ip link set %iface% up", ifd, exec);
 370         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 371         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 372         return ((result == 4) ? 4 : 0);
 373 }
 374
 375 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 376 {
 377         return execute("ip tunnel del %iface%", ifd, exec);
 378 }
 379 #endif
 380
 381 static const struct method_t methods6[] = {
 382 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 383         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 384 #endif
 385         { "static", static_up6, static_down6, },
 386         { "loopback", loopback_up6, loopback_down6, },
 387 };
 388
 389 static const struct address_family_t addr_inet6 = {
 390         "inet6",
 391         sizeof(methods6) / sizeof(struct method_t),
 392         methods6
 393 };
 394 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 395
 396 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 397 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 398 {
 399 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 400         int result;
 401         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 402         result += execute("ip link set %iface% up", ifd, exec);
 403         return ((result == 2) ? 2 : 0);
 404 #else
 405         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 406 #endif
 407 }
 408
 409 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 410 {
 411 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 412         int result;
 413         result = execute("ip addr flush dev %iface%", ifd, exec);
 414         result += execute("ip link set %iface% down", ifd, exec);
 415         return ((result == 2) ? 2 : 0);
 416 #else
 417         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 418 #endif
 419 }
 420
 421 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 422 {
 423         int result;
 424 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 425         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 426                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 427         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 428         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 429         return ((result == 3) ? 3 : 0);
 430 #else
 431         result = execute("ifconfig %iface% %address% netmask %netmask% "
 432                         "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] "
 433                         "[[media %media%]] [[mtu %mtu%]] [[hw %hwaddress%]] up",
 434                         ifd, exec);
 435         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 436         return ((result == 2) ? 2 : 0);
 437 #endif
 438 }
 439
 440 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 441 {
 442         int result;
 443 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 444         result = execute("ip addr flush dev %iface%", ifd, exec);
 445         result += execute("ip link set %iface% down", ifd, exec);
 446 #else
 447         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 448         result += execute("ifconfig %iface% down", ifd, exec);
 449 #endif
 450         return ((result == 2) ? 2 : 0);
 451 }
 452
 453 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 454 {
 455         if (execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% "
 456                         "[[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]", ifd, exec))
 457                 return 1;
 458
 459         /* 2006-09-30: The following are deprecated, and should eventually be
 460          * removed. For non-busybox (i.e., other than udhcpc) clients, use
 461          * 'iface foo inet manual' in /etc/network/interfaces, and supply
 462          * start/stop commands explicitly via up/down. */
 463
 464         if (execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
 465                         ifd, exec)) return 1;
 466         if (execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 467                         ifd, exec)) return 1;
 468         if (execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 469                         "[[-l %leasetime%]] %iface%", ifd, exec)) return 1;
 470
 471         return 0;
 472 }
 473
 474 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 475 {
 476         if (execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 477                         ifd, exec)) return 1;
 478
 479         /* 2006-09-30: The following are deprecated, and should eventually be
 480          * removed. For non-busybox (i.e., other than udhcpc) clients, use
 481          * 'iface foo inet manual' in /etc/network/interfaces, and supply
 482          * start/stop commands explicitly via up/down. */
 483
 484         if (execute("pump -i %iface% -k", ifd, exec)) return 1;
 485         if (execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 486                         ifd, exec)) return 1;
 487         if (execute("dhcpcd -k %iface%", ifd, exec)) return 1;
 488
 489         return static_down(ifd, exec);
 490 }
 491
 492 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 493 {
 494         return 1;
 495 }
 496
 497 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 498 {
 499         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 500                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 501                         "--returniffail --serverbcast", ifd, exec);
 502 }
 503
 504 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 505 {
 506         return execute("pon [[%provider%]]", ifd, exec);
 507 }
 508
 509 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 510 {
 511         return execute("poff [[%provider%]]", ifd, exec);
 512 }
 513
 514 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 515 {
 516         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 517                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 518 }
 519
 520 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 521 {
 522         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 523                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 524 }
 525
 526 static const struct method_t methods[] = {
 527         { "manual", manual_up_down, manual_up_down, },
 528         { "wvdial", wvdial_up, wvdial_down, },
 529         { "ppp", ppp_up, ppp_down, },
 530         { "static", static_up, static_down, },
 531         { "bootp", bootp_up, static_down, },
 532         { "dhcp", dhcp_up, dhcp_down, },
 533         { "loopback", loopback_up, loopback_down, },
 534 };
 535
 536 static const struct address_family_t addr_inet = {
 537         "inet",
 538         sizeof(methods) / sizeof(struct method_t),
 539         methods
 540 };
 541
 542 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 543
 544 static char *next_word(char **buf)
 545 {
 546         unsigned short length;
 547         char *word;
 548
 549         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 550                 return NULL;
 551         }
 552
 553         /* Skip over leading whitespace */
 554         word = *buf;
 555         while (isspace(*word)) {
 556                 ++word;
 557         }
 558
 559         /* Skip over comments */
 560         if (*word == '#') {
 561                 return NULL;
 562         }
 563
 564         /* Find the length of this word */
 565         length = strcspn(word, " \t\n");
 566         if (length == 0) {
 567                 return NULL;
 568         }
 569         *buf = word + length;
 570         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 571         if (**buf) {
 572                 **buf = '\0';
 573                 (*buf)++;
 574         }
 575
 576         return word;
 577 }
 578
 579 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 580 {
 581         int i;
 582
 583         for (i = 0; af[i]; i++) {
 584                 if (strcmp(af[i]->name, name) == 0) {
 585                         return af[i];
 586                 }
 587         }
 588         return NULL;
 589 }
 590
 591 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 592 {
 593         int i;
 594
 595         for (i = 0; i < af->n_methods; i++) {
 596                 if (strcmp(af->method[i].name, name) == 0) {
 597                         return &af->method[i];
 598                 }
 599         }
 600         return NULL;
 601 }
 602
 603 static const llist_t *find_list_string(const llist_t *list, const char *string)
 604 {
 605         while (list) {
 606                 if (strcmp(list->data, string) == 0) {
 607                         return list;
 608                 }
 609                 list = list->link;
 610         }
 611         return NULL;
 612 }
 613
 614 static struct interfaces_file_t *read_interfaces(const char *filename)
 615 {
 616 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 617         struct mapping_defn_t *currmap = NULL;
 618 #endif
 619         struct interface_defn_t *currif = NULL;
 620         struct interfaces_file_t *defn;
 621         FILE *f;
 622         char *firstword;
 623         char *buf;
 624
 625         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 626
 627         defn = xzalloc(sizeof(struct interfaces_file_t));
 628
 629         f = xfopen(filename, "r");
 630
 631         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 632                 char *buf_ptr = buf;
 633
 634                 firstword = next_word(&buf_ptr);
 635                 if (firstword == NULL) {
 636                         free(buf);
 637                         continue;       /* blank line */
 638                 }
 639
 640                 if (strcmp(firstword, "mapping") == 0) {
 641 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 642                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 643
 644                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 645                                 if (currmap->max_matches == currmap->n_matches) {
 646                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 647                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 648                                 }
 649
 650                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 651                         }
 652                         currmap->max_mappings = 0;
 653                         currmap->n_mappings = 0;
 654                         currmap->mapping = NULL;
 655                         currmap->script = NULL;
 656                         {
 657                                 struct mapping_defn_t **where = &defn->mappings;
 658                                 while (*where != NULL) {
 659                                         where = &(*where)->next;
 660                                 }
 661                                 *where = currmap;
 662                                 currmap->next = NULL;
 663                         }
 664                         debug_noise("Added mapping\n");
 665 #endif
 666                         currently_processing = MAPPING;
 667                 } else if (strcmp(firstword, "iface") == 0) {
 668                         static const struct address_family_t *const addr_fams[] = {
 669 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 670                                 &addr_inet,
 671 #endif
 672 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 673                                 &addr_inet6,
 674 #endif
 675                                 NULL
 676                         };
 677
 678                         char *iface_name;
 679                         char *address_family_name;
 680                         char *method_name;
 681                         llist_t *iface_list;
 682
 683                         currif = xzalloc(sizeof(struct interface_defn_t));
 684                         iface_name = next_word(&buf_ptr);
 685                         address_family_name = next_word(&buf_ptr);
 686                         method_name = next_word(&buf_ptr);
 687
 688                         if (buf_ptr == NULL) {
 689                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 690                                 return NULL;
 691                         }
 692
 693                         /* ship any trailing whitespace */
 694                         while (isspace(*buf_ptr)) {
 695                                 ++buf_ptr;
 696                         }
 697
 698                         if (buf_ptr[0] != '\0') {
 699                                 bb_error_msg("too many parameters \"%s\"", buf);
 700                                 return NULL;
 701                         }
 702
 703                         currif->iface = xstrdup(iface_name);
 704
 705                         currif->address_family = get_address_family(addr_fams, address_family_name);
 706                         if (!currif->address_family) {
 707                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 708                                 return NULL;
 709                         }
 710
 711                         currif->method = get_method(currif->address_family, method_name);
 712                         if (!currif->method) {
 713                                 bb_error_msg("unknown method \"%s\"", method_name);
 714                                 return NULL;
 715                         }
 716
 717                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 718                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 719                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 720                                         (tmp->address_family == currif->address_family)) {
 721                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 722                                         return NULL;
 723                                 }
 724                         }
 725                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 726
 727                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 728                         currently_processing = IFACE;
 729                 } else if (strcmp(firstword, "auto") == 0) {
 730                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 731
 732                                 /* Check the interface isnt already listed */
 733                                 if (find_list_string(defn->autointerfaces, firstword)) {
 734                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 735                                 }
 736
 737                                 /* Add the interface to the list */
 738                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 739                                 debug_noise("\nauto %s\n", firstword);
 740                         }
 741                         currently_processing = NONE;
 742                 } else {
 743                         switch (currently_processing) {
 744                         case IFACE:
 745                                 {
 746                                         int i;
 747
 748                                         if (strlen(buf_ptr) == 0) {
 749                                                 bb_error_msg("option with empty value \"%s\"", buf);
 750                                                 return NULL;
 751                                         }
 752
 753                                         if (strcmp(firstword, "up") != 0
 754                                                         && strcmp(firstword, "down") != 0
 755                                                         && strcmp(firstword, "pre-up") != 0
 756                                                         && strcmp(firstword, "post-down") != 0) {
 757                                                 for (i = 0; i < currif->n_options; i++) {
 758                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 759                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 760                                                                 return NULL;
 761                                                         }
 762                                                 }
 763                                         }
 764                                 }
 765                                 if (currif->n_options >= currif->max_options) {
 766                                         struct variable_t *opt;
 767
 768                                         currif->max_options = currif->max_options + 10;
 769                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 770                                         currif->option = opt;
 771                                 }
 772                                 currif->option[currif->n_options].name = xstrdup(firstword);
 773                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 774                                 if (!currif->option[currif->n_options].name) {
 775                                         perror(filename);
 776                                         return NULL;
 777                                 }
 778                                 if (!currif->option[currif->n_options].value) {
 779                                         perror(filename);
 780                                         return NULL;
 781                                 }
 782                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 783                                                 currif->option[currif->n_options].value);
 784                                 currif->n_options++;
 785                                 break;
 786                         case MAPPING:
 787 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 788                                 if (strcmp(firstword, "script") == 0) {
 789                                         if (currmap->script != NULL) {
 790                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 791                                                 return NULL;
 792                                         } else {
 793                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 794                                         }
 795                                 } else if (strcmp(firstword, "map") == 0) {
 796                                         if (currmap->max_mappings == currmap->n_mappings) {
 797                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 798                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 799                                         }
 800                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 801                                         currmap->n_mappings++;
 802                                 } else {
 803                                         bb_error_msg("misplaced option \"%s\"", buf);
 804                                         return NULL;
 805                                 }
 806 #endif
 807                                 break;
 808                         case NONE:
 809                         default:
 810                                 bb_error_msg("misplaced option \"%s\"", buf);
 811                                 return NULL;
 812                         }
 813                 }
 814                 free(buf);
 815         }
 816         if (ferror(f) != 0) {
 817                 bb_perror_msg_and_die("%s", filename);
 818         }
 819         fclose(f);
 820
 821         return defn;
 822 }
 823
 824 static char *setlocalenv(char *format, const char *name, const char *value)
 825 {
 826         char *result;
 827         char *here;
 828         char *there;
 829
 830         result = xasprintf(format, name, value);
 831
 832         for (here = there = result; *there != '=' && *there; there++) {
 833                 if (*there == '-')
 834                         *there = '_';
 835                 if (isalpha(*there))
 836                         *there = toupper(*there);
 837
 838                 if (isalnum(*there) || *there == '_') {
 839                         *here = *there;
 840                         here++;
 841                 }
 842         }
 843         memmove(here, there, strlen(there) + 1);
 844
 845         return result;
 846 }
 847
 848 static void set_environ(struct interface_defn_t *iface, const char *mode)
 849 {
 850         char **environend;
 851         int i;
 852         const int n_env_entries = iface->n_options + 5;
 853         char **ppch;
 854
 855         if (__myenviron != NULL) {
 856                 for (ppch = __myenviron; *ppch; ppch++) {
 857                         free(*ppch);
 858                         *ppch = NULL;
 859                 }
 860                 free(__myenviron);
 861         }
 862         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 863         environend = __myenviron;
 864
 865         for (i = 0; i < iface->n_options; i++) {
 866                 if (strcmp(iface->option[i].name, "up") == 0
 867                                 || strcmp(iface->option[i].name, "down") == 0
 868                                 || strcmp(iface->option[i].name, "pre-up") == 0
 869                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 870                         continue;
 871                 }
 872                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 873         }
 874
 875         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 876         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 877         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 878         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 879         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 880 }
 881
 882 static int doit(char *str)
 883 {
 884         if (option_mask & (OPT_no_act|OPT_verbose)) {
 885                 puts(str);
 886         }
 887         if (!(option_mask & OPT_no_act)) {
 888                 pid_t child;
 889                 int status;
 890
 891                 fflush(NULL);
 892                 switch (child = fork()) {
 893                 case -1:                /* failure */
 894                         return 0;
 895                 case 0:         /* child */
 896                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 897                         exit(127);
 898                 }
 899                 waitpid(child, &status, 0);
 900                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 901                         return 0;
 902                 }
 903         }
 904         return 1;
 905 }
 906
 907 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 908 {
 909         int i;
 910         char *buf;
 911         for (i = 0; i < ifd->n_options; i++) {
 912                 if (strcmp(ifd->option[i].name, opt) == 0) {
 913                         if (!doit(ifd->option[i].value)) {
 914                                 return 0;
 915                         }
 916                 }
 917         }
 918
 919         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 920         if (doit(buf) != 1) {
 921                 return 0;
 922         }
 923         return 1;
 924 }
 925
 926 static int check(char *str) {
 927         return str != NULL;
 928 }
 929
 930 static int iface_up(struct interface_defn_t *iface)
 931 {
 932         if (!iface->method->up(iface,check)) return -1;
 933         set_environ(iface, "start");
 934         if (!execute_all(iface, "pre-up")) return 0;
 935         if (!iface->method->up(iface, doit)) return 0;
 936         if (!execute_all(iface, "up")) return 0;
 937         return 1;
 938 }
 939
 940 static int iface_down(struct interface_defn_t *iface)
 941 {
 942         if (!iface->method->down(iface,check)) return -1;
 943         set_environ(iface, "stop");
 944         if (!execute_all(iface, "down")) return 0;
 945         if (!iface->method->down(iface, doit)) return 0;
 946         if (!execute_all(iface, "post-down")) return 0;
 947         return 1;
 948 }
 949
 950 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 951 static int popen2(FILE **in, FILE **out, char *command, ...)
 952 {
 953         va_list ap;
 954         char *argv[11] = { command };
 955         int argc;
 956         int infd[2], outfd[2];
 957         pid_t pid;
 958
 959         argc = 1;
 960         va_start(ap, command);
 961         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 962                 argc++;
 963         }
 964         argv[argc] = NULL;      /* make sure */
 965         va_end(ap);
 966
 967         if (pipe(infd) != 0) {
 968                 return 0;
 969         }
 970
 971         if (pipe(outfd) != 0) {
 972                 close(infd[0]);
 973                 close(infd[1]);
 974                 return 0;
 975         }
 976
 977         fflush(NULL);
 978         switch (pid = fork()) {
 979         case -1:                        /* failure */
 980                 close(infd[0]);
 981                 close(infd[1]);
 982                 close(outfd[0]);
 983                 close(outfd[1]);
 984                 return 0;
 985         case 0:                 /* child */
 986                 dup2(infd[0], 0);
 987                 dup2(outfd[1], 1);
 988                 close(infd[0]);
 989                 close(infd[1]);
 990                 close(outfd[0]);
 991                 close(outfd[1]);
 992                 execvp(command, argv);
 993                 exit(127);
 994         default:                        /* parent */
 995                 *in = fdopen(infd[1], "w");
 996                 *out = fdopen(outfd[0], "r");
 997                 close(infd[0]);
 998                 close(outfd[1]);
 999                 return pid;
1000         }
1001         /* unreached */
1002 }
1003
1004 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1005 {
1006         FILE *in, *out;
1007         int i, status;
1008         pid_t pid;
1009
1010         char *logical = xstrdup(physical);
1011
1012         /* Run the mapping script. */
1013         pid = popen2(&in, &out, map->script, physical, NULL);
1014
1015         /* popen2() returns 0 on failure. */
1016         if (pid == 0)
1017                 return logical;
1018
1019         /* Write mappings to stdin of mapping script. */
1020         for (i = 0; i < map->n_mappings; i++) {
1021                 fprintf(in, "%s\n", map->mapping[i]);
1022         }
1023         fclose(in);
1024         waitpid(pid, &status, 0);
1025
1026         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1027                 /* If the mapping script exited successfully, try to
1028                  * grab a line of output and use that as the name of the
1029                  * logical interface. */
1030                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1031
1032                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1033                         /* If we are able to read a line of output from the script,
1034                          * remove any trailing whitespace and use this value
1035                          * as the name of the logical interface. */
1036                         char *pch = new_logical + strlen(new_logical) - 1;
1037
1038                         while (pch >= new_logical && isspace(*pch))
1039                                 *(pch--) = '\0';
1040
1041                         free(logical);
1042                         logical = new_logical;
1043                 } else {
1044                         /* If we are UNABLE to read a line of output, discard our
1045                          * freshly allocated memory. */
1046                         free(new_logical);
1047                 }
1048         }
1049
1050         fclose(out);
1051
1052         return logical;
1053 }
1054 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1055
1056 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1057 {
1058         unsigned short iface_len = strlen(iface);
1059         llist_t *search = state_list;
1060
1061         while (search) {
1062                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1063                                 (search->data[iface_len] == '=')) {
1064                         return search;
1065                 }
1066                 search = search->link;
1067         }
1068         return NULL;
1069 }
1070
1071 int ifupdown_main(int argc, char **argv)
1072 {
1073         static const char statefile[] = "/var/run/ifstate";
1074
1075         int (*cmds)(struct interface_defn_t *) = NULL;
1076         struct interfaces_file_t *defn;
1077         llist_t *state_list = NULL;
1078         llist_t *target_list = NULL;
1079         const char *interfaces = "/etc/network/interfaces";
1080         int any_failures = 0;
1081         int i;
1082
1083         if (bb_applet_name[2] == 'u') {
1084                 /* ifup command */
1085                 cmds = iface_up;
1086         } else {
1087                 /* ifdown command */
1088                 cmds = iface_down;
1089         }
1090
1091         option_mask = bb_getopt_ulflags(argc, argv, OPTION_STR, &interfaces);
1092         if (argc - optind > 0) {
1093                 if (DO_ALL) bb_show_usage();
1094         } else
1095                 if (!DO_ALL) bb_show_usage();
1096
1097         debug_noise("reading %s file:\n", interfaces);
1098         defn = read_interfaces(interfaces);
1099         debug_noise("\ndone reading %s\n\n", interfaces);
1100
1101         if (!defn) {
1102                 exit(EXIT_FAILURE);
1103         }
1104
1105         startup_PATH = getenv("PATH");
1106         if (!startup_PATH) startup_PATH = "";
1107
1108         /* Create a list of interfaces to work on */
1109         if (DO_ALL) {
1110                 if (cmds == iface_up) {
1111                         target_list = defn->autointerfaces;
1112                 } else {
1113                         /* iface_down */
1114                         const llist_t *list = state_list;
1115                         while (list) {
1116                                 llist_add_to_end(&target_list, xstrdup(list->data));
1117                                 list = list->link;
1118                         }
1119                         target_list = defn->autointerfaces;
1120                 }
1121         } else {
1122                 llist_add_to_end(&target_list, argv[optind]);
1123         }
1124
1125
1126         /* Update the interfaces */
1127         while (target_list) {
1128                 llist_t *iface_list;
1129                 struct interface_defn_t *currif;
1130                 char *iface;
1131                 char *liface;
1132                 char *pch;
1133                 int okay = 0;
1134                 int cmds_ret;
1135
1136                 iface = xstrdup(target_list->data);
1137                 target_list = target_list->link;
1138
1139                 pch = strchr(iface, '=');
1140                 if (pch) {
1141                         *pch = '\0';
1142                         liface = xstrdup(pch + 1);
1143                 } else {
1144                         liface = xstrdup(iface);
1145                 }
1146
1147                 if (!FORCE) {
1148                         const llist_t *iface_state = find_iface_state(state_list, iface);
1149
1150                         if (cmds == iface_up) {
1151                                 /* ifup */
1152                                 if (iface_state) {
1153                                         bb_error_msg("interface %s already configured", iface);
1154                                         continue;
1155                                 }
1156                         } else {
1157                                 /* ifdown */
1158                                 if (iface_state) {
1159                                         bb_error_msg("interface %s not configured", iface);
1160                                         continue;
1161                                 }
1162                         }
1163                 }
1164
1165 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1166                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1167                         struct mapping_defn_t *currmap;
1168
1169                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1170                                 for (i = 0; i < currmap->n_matches; i++) {
1171                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1172                                                 continue;
1173                                         if (VERBOSE) {
1174                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1175                                         }
1176                                         liface = run_mapping(iface, currmap);
1177                                         break;
1178                                 }
1179                         }
1180                 }
1181 #endif
1182
1183
1184                 iface_list = defn->ifaces;
1185                 while (iface_list) {
1186                         currif = (struct interface_defn_t *) iface_list->data;
1187                         if (strcmp(liface, currif->iface) == 0) {
1188                                 char *oldiface = currif->iface;
1189
1190                                 okay = 1;
1191                                 currif->iface = iface;
1192
1193                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1194
1195                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1196                                 cmds_ret = cmds(currif);
1197                                 if (cmds_ret == -1) {
1198                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1199                                                         liface, currif->address_family->name);
1200                                         any_failures += 1;
1201                                 } else if (cmds_ret == 0) {
1202                                         any_failures += 1;
1203                                 }
1204
1205                                 currif->iface = oldiface;
1206                         }
1207                         iface_list = iface_list->link;
1208                 }
1209                 if (VERBOSE) {
1210                         puts("");
1211                 }
1212
1213                 if (!okay && !FORCE) {
1214                         bb_error_msg("ignoring unknown interface %s", liface);
1215                         any_failures += 1;
1216                 } else {
1217                         llist_t *iface_state = find_iface_state(state_list, iface);
1218
1219                         if (cmds == iface_up) {
1220                                 char *newiface = xasprintf("%s=%s", iface, liface);
1221                                 if (iface_state == NULL) {
1222                                         llist_add_to_end(&state_list, newiface);
1223                                 } else {
1224                                         free(iface_state->data);
1225                                         iface_state->data = newiface;
1226                                 }
1227                         } else {
1228                                 /* Remove an interface from the linked list */
1229                                 free(llist_pop(&iface_state));
1230                         }
1231                 }
1232         }
1233
1234         /* Actually write the new state */
1235         if (!NO_ACT) {
1236                 FILE *state_fp = NULL;
1237
1238                 state_fp = xfopen(statefile, "w");
1239                 while (state_list) {
1240                         if (state_list->data) {
1241                                 fputs(state_list->data, state_fp);
1242                                 fputc('\n', state_fp);
1243                         }
1244                         state_list = state_list->link;
1245                 }
1246                 fclose(state_fp);
1247         }
1248
1249         if (any_failures)
1250                 return 1;
1251         return 0;
1252 }