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 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  93 enum {
  94         OPT_do_all = 0x1,
  95         OPT_no_act = 0x2,
  96         OPT_verbose = 0x4,
  97         OPT_force = 0x8,
  98         OPT_no_mappings = 0x10,
  99 };
 100 #define DO_ALL (option_mask32 & OPT_do_all)
 101 #define NO_ACT (option_mask32 & OPT_no_act)
 102 #define VERBOSE (option_mask32 & OPT_verbose)
 103 #define FORCE (option_mask32 & OPT_force)
 104 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 105
 106 static char **__myenviron;
 107
 108 static char *startup_PATH;
 109
 110 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 111
 112 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 113
 114 static unsigned int count_bits(unsigned int a)
 115 {
 116         unsigned int result;
 117         result = (a & 0x55) + ((a >> 1) & 0x55);
 118         result = (result & 0x33) + ((result >> 2) & 0x33);
 119         return ((result & 0x0F) + ((result >> 4) & 0x0F));
 120 }
 121
 122 static int count_netmask_bits(char *dotted_quad)
 123 {
 124         unsigned int result, a, b, c, d;
 125         /* Found a netmask...  Check if it is dotted quad */
 126         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 127                 return -1;
 128         result = count_bits(a);
 129         result += count_bits(b);
 130         result += count_bits(c);
 131         result += count_bits(d);
 132         return (int)result;
 133 }
 134 #endif
 135
 136 static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
 137 {
 138         if (*pos + str_length >= *len) {
 139                 char *newbuf;
 140
 141                 newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
 142                 *buf = newbuf;
 143                 *len = *len * 2 + str_length + 1;
 144         }
 145
 146         while (str_length-- >= 1) {
 147                 (*buf)[(*pos)++] = *str;
 148                 str++;
 149         }
 150         (*buf)[*pos] = '\0';
 151 }
 152
 153 static int strncmpz(char *l, char *r, size_t llen)
 154 {
 155         int i = strncmp(l, r, llen);
 156
 157         if (i == 0) {
 158                 return -r[llen];
 159         } else {
 160                 return i;
 161         }
 162 }
 163
 164 static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
 165 {
 166         int i;
 167
 168         if (strncmpz(id, "iface", idlen) == 0) {
 169                 char *result;
 170                 static char label_buf[20];
 171                 strncpy(label_buf, ifd->iface, 19);
 172                 label_buf[19]=0;
 173                 result = strchr(label_buf, ':');
 174                 if (result) {
 175                         *result=0;
 176                 }
 177                 return label_buf;
 178         } else if (strncmpz(id, "label", idlen) == 0) {
 179                 return ifd->iface;
 180         } else {
 181                 for (i = 0; i < ifd->n_options; i++) {
 182                         if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 183                                 return ifd->option[i].value;
 184                         }
 185                 }
 186         }
 187
 188         return NULL;
 189 }
 190
 191 static char *parse(char *command, struct interface_defn_t *ifd)
 192 {
 193
 194         char *result = NULL;
 195         size_t pos = 0, len = 0;
 196         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 197         int okay[MAX_OPT_DEPTH] = { 1 };
 198         int opt_depth = 1;
 199
 200         while (*command) {
 201                 switch (*command) {
 202                 default:
 203                         addstr(&result, &len, &pos, command, 1);
 204                         command++;
 205                         break;
 206                 case '\\':
 207                         if (command[1]) {
 208                                 addstr(&result, &len, &pos, command + 1, 1);
 209                                 command += 2;
 210                         } else {
 211                                 addstr(&result, &len, &pos, command, 1);
 212                                 command++;
 213                         }
 214                         break;
 215                 case '[':
 216                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 217                                 old_pos[opt_depth] = pos;
 218                                 okay[opt_depth] = 1;
 219                                 opt_depth++;
 220                                 command += 2;
 221                         } else {
 222                                 addstr(&result, &len, &pos, "[", 1);
 223                                 command++;
 224                         }
 225                         break;
 226                 case ']':
 227                         if (command[1] == ']' && opt_depth > 1) {
 228                                 opt_depth--;
 229                                 if (!okay[opt_depth]) {
 230                                         pos = old_pos[opt_depth];
 231                                         result[pos] = '\0';
 232                                 }
 233                                 command += 2;
 234                         } else {
 235                                 addstr(&result, &len, &pos, "]", 1);
 236                                 command++;
 237                         }
 238                         break;
 239                 case '%':
 240                         {
 241                                 char *nextpercent;
 242                                 char *varvalue;
 243
 244                                 command++;
 245                                 nextpercent = strchr(command, '%');
 246                                 if (!nextpercent) {
 247                                         errno = EUNBALPER;
 248                                         free(result);
 249                                         return NULL;
 250                                 }
 251
 252                                 varvalue = get_var(command, nextpercent - command, ifd);
 253
 254                                 if (varvalue) {
 255                                         addstr(&result, &len, &pos, varvalue, strlen(varvalue));
 256                                 } else {
 257 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 258                                         /* Sigh...  Add a special case for 'ip' to convert from
 259                                          * dotted quad to bit count style netmasks.  */
 260                                         if (strncmp(command, "bnmask", 6)==0) {
 261                                                 int res;
 262                                                 varvalue = get_var("netmask", 7, ifd);
 263                                                 if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 264                                                         char argument[255];
 265                                                         sprintf(argument, "%d", res);
 266                                                         addstr(&result, &len, &pos, argument, strlen(argument));
 267                                                         command = nextpercent + 1;
 268                                                         break;
 269                                                 }
 270                                         }
 271 #endif
 272                                         okay[opt_depth - 1] = 0;
 273                                 }
 274
 275                                 command = nextpercent + 1;
 276                         }
 277                         break;
 278                 }
 279         }
 280
 281         if (opt_depth > 1) {
 282                 errno = EUNBALBRACK;
 283                 free(result);
 284                 return NULL;
 285         }
 286
 287         if (!okay[0]) {
 288                 errno = EUNDEFVAR;
 289                 free(result);
 290                 return NULL;
 291         }
 292
 293         return result;
 294 }
 295
 296 /* execute() returns 1 for success and 0 for failure */
 297 static int execute(char *command, struct interface_defn_t *ifd, execfn *exec)
 298 {
 299         char *out;
 300         int ret;
 301
 302         out = parse(command, ifd);
 303         if (!out) {
 304                 return 0;
 305         }
 306         ret = (*exec)(out);
 307
 308         free(out);
 309         if (ret != 1) {
 310                 return 0;
 311         }
 312         return 1;
 313 }
 314 #endif
 315
 316 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 317 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 318 {
 319 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 320         int result;
 321         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 322         result += execute("ip link set %iface% up", ifd, exec);
 323         return ((result == 2) ? 2 : 0);
 324 #else
 325         return execute("ifconfig %iface% add ::1", ifd, exec);
 326 #endif
 327 }
 328
 329 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 330 {
 331 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 332         return execute("ip link set %iface% down", ifd, exec);
 333 #else
 334         return execute("ifconfig %iface% del ::1", ifd, exec);
 335 #endif
 336 }
 337
 338 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 339 {
 340         int result;
 341 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 342         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 343         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 344         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 345 #else
 346         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 347         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 348         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 349 #endif
 350         return ((result == 3) ? 3 : 0);
 351 }
 352
 353 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 354 {
 355 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 356         return execute("ip link set %iface% down", ifd, exec);
 357 #else
 358         return execute("ifconfig %iface% down", ifd, exec);
 359 #endif
 360 }
 361
 362 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 363 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 364 {
 365         int result;
 366         result = execute("ip tunnel add %iface% mode sit remote "
 367                         "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 368         result += execute("ip link set %iface% up", ifd, exec);
 369         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 370         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 371         return ((result == 4) ? 4 : 0);
 372 }
 373
 374 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 375 {
 376         return execute("ip tunnel del %iface%", ifd, exec);
 377 }
 378 #endif
 379
 380 static const struct method_t methods6[] = {
 381 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 382         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 383 #endif
 384         { "static", static_up6, static_down6, },
 385         { "loopback", loopback_up6, loopback_down6, },
 386 };
 387
 388 static const struct address_family_t addr_inet6 = {
 389         "inet6",
 390         sizeof(methods6) / sizeof(struct method_t),
 391         methods6
 392 };
 393 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 394
 395 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 396 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 397 {
 398 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 399         int result;
 400         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 401         result += execute("ip link set %iface% up", ifd, exec);
 402         return ((result == 2) ? 2 : 0);
 403 #else
 404         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 405 #endif
 406 }
 407
 408 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 409 {
 410 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 411         int result;
 412         result = execute("ip addr flush dev %iface%", ifd, exec);
 413         result += execute("ip link set %iface% down", ifd, exec);
 414         return ((result == 2) ? 2 : 0);
 415 #else
 416         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 417 #endif
 418 }
 419
 420 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 421 {
 422         int result;
 423 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 424         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 425                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 426         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 427         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 428         return ((result == 3) ? 3 : 0);
 429 #else
 430         result = execute("ifconfig %iface% %address% netmask %netmask% "
 431                         "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] "
 432                         "[[media %media%]] [[mtu %mtu%]] [[hw %hwaddress%]] up",
 433                         ifd, exec);
 434         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 435         return ((result == 2) ? 2 : 0);
 436 #endif
 437 }
 438
 439 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 440 {
 441         int result;
 442 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 443         result = execute("ip addr flush dev %iface%", ifd, exec);
 444         result += execute("ip link set %iface% down", ifd, exec);
 445 #else
 446         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 447         result += execute("ifconfig %iface% down", ifd, exec);
 448 #endif
 449         return ((result == 2) ? 2 : 0);
 450 }
 451
 452 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 453 {
 454         if (execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% "
 455                         "[[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]", ifd, exec))
 456                 return 1;
 457
 458         /* 2006-09-30: The following are deprecated, and should eventually be
 459          * removed. For non-busybox (i.e., other than udhcpc) clients, use
 460          * 'iface foo inet manual' in /etc/network/interfaces, and supply
 461          * start/stop commands explicitly via up/down. */
 462
 463         if (execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
 464                         ifd, exec)) return 1;
 465         if (execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 466                         ifd, exec)) return 1;
 467         if (execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 468                         "[[-l %leasetime%]] %iface%", ifd, exec)) return 1;
 469
 470         return 0;
 471 }
 472
 473 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 474 {
 475         if (execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 476                         ifd, exec)) return 1;
 477
 478         /* 2006-09-30: The following are deprecated, and should eventually be
 479          * removed. For non-busybox (i.e., other than udhcpc) clients, use
 480          * 'iface foo inet manual' in /etc/network/interfaces, and supply
 481          * start/stop commands explicitly via up/down. */
 482
 483         if (execute("pump -i %iface% -k", ifd, exec)) return 1;
 484         if (execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 485                         ifd, exec)) return 1;
 486         if (execute("dhcpcd -k %iface%", ifd, exec)) return 1;
 487
 488         return static_down(ifd, exec);
 489 }
 490
 491 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 492 {
 493         return 1;
 494 }
 495
 496 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 497 {
 498         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 499                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 500                         "--returniffail --serverbcast", ifd, exec);
 501 }
 502
 503 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 504 {
 505         return execute("pon [[%provider%]]", ifd, exec);
 506 }
 507
 508 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 509 {
 510         return execute("poff [[%provider%]]", ifd, exec);
 511 }
 512
 513 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 514 {
 515         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 516                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 517 }
 518
 519 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 520 {
 521         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 522                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 523 }
 524
 525 static const struct method_t methods[] = {
 526         { "manual", manual_up_down, manual_up_down, },
 527         { "wvdial", wvdial_up, wvdial_down, },
 528         { "ppp", ppp_up, ppp_down, },
 529         { "static", static_up, static_down, },
 530         { "bootp", bootp_up, static_down, },
 531         { "dhcp", dhcp_up, dhcp_down, },
 532         { "loopback", loopback_up, loopback_down, },
 533 };
 534
 535 static const struct address_family_t addr_inet = {
 536         "inet",
 537         sizeof(methods) / sizeof(struct method_t),
 538         methods
 539 };
 540
 541 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 542
 543 static char *next_word(char **buf)
 544 {
 545         unsigned short length;
 546         char *word;
 547
 548         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 549                 return NULL;
 550         }
 551
 552         /* Skip over leading whitespace */
 553         word = *buf;
 554         while (isspace(*word)) {
 555                 ++word;
 556         }
 557
 558         /* Skip over comments */
 559         if (*word == '#') {
 560                 return NULL;
 561         }
 562
 563         /* Find the length of this word */
 564         length = strcspn(word, " \t\n");
 565         if (length == 0) {
 566                 return NULL;
 567         }
 568         *buf = word + length;
 569         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 570         if (**buf) {
 571                 **buf = '\0';
 572                 (*buf)++;
 573         }
 574
 575         return word;
 576 }
 577
 578 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 579 {
 580         int i;
 581
 582         for (i = 0; af[i]; i++) {
 583                 if (strcmp(af[i]->name, name) == 0) {
 584                         return af[i];
 585                 }
 586         }
 587         return NULL;
 588 }
 589
 590 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 591 {
 592         int i;
 593
 594         for (i = 0; i < af->n_methods; i++) {
 595                 if (strcmp(af->method[i].name, name) == 0) {
 596                         return &af->method[i];
 597                 }
 598         }
 599         return NULL;
 600 }
 601
 602 static const llist_t *find_list_string(const llist_t *list, const char *string)
 603 {
 604         while (list) {
 605                 if (strcmp(list->data, string) == 0) {
 606                         return list;
 607                 }
 608                 list = list->link;
 609         }
 610         return NULL;
 611 }
 612
 613 static struct interfaces_file_t *read_interfaces(const char *filename)
 614 {
 615 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 616         struct mapping_defn_t *currmap = NULL;
 617 #endif
 618         struct interface_defn_t *currif = NULL;
 619         struct interfaces_file_t *defn;
 620         FILE *f;
 621         char *firstword;
 622         char *buf;
 623
 624         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 625
 626         defn = xzalloc(sizeof(struct interfaces_file_t));
 627
 628         f = xfopen(filename, "r");
 629
 630         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 631                 char *buf_ptr = buf;
 632
 633                 firstword = next_word(&buf_ptr);
 634                 if (firstword == NULL) {
 635                         free(buf);
 636                         continue;       /* blank line */
 637                 }
 638
 639                 if (strcmp(firstword, "mapping") == 0) {
 640 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 641                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 642
 643                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 644                                 if (currmap->max_matches == currmap->n_matches) {
 645                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 646                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 647                                 }
 648
 649                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 650                         }
 651                         currmap->max_mappings = 0;
 652                         currmap->n_mappings = 0;
 653                         currmap->mapping = NULL;
 654                         currmap->script = NULL;
 655                         {
 656                                 struct mapping_defn_t **where = &defn->mappings;
 657                                 while (*where != NULL) {
 658                                         where = &(*where)->next;
 659                                 }
 660                                 *where = currmap;
 661                                 currmap->next = NULL;
 662                         }
 663                         debug_noise("Added mapping\n");
 664 #endif
 665                         currently_processing = MAPPING;
 666                 } else if (strcmp(firstword, "iface") == 0) {
 667                         static const struct address_family_t *const addr_fams[] = {
 668 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 669                                 &addr_inet,
 670 #endif
 671 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 672                                 &addr_inet6,
 673 #endif
 674                                 NULL
 675                         };
 676
 677                         char *iface_name;
 678                         char *address_family_name;
 679                         char *method_name;
 680                         llist_t *iface_list;
 681
 682                         currif = xzalloc(sizeof(struct interface_defn_t));
 683                         iface_name = next_word(&buf_ptr);
 684                         address_family_name = next_word(&buf_ptr);
 685                         method_name = next_word(&buf_ptr);
 686
 687                         if (buf_ptr == NULL) {
 688                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 689                                 return NULL;
 690                         }
 691
 692                         /* ship any trailing whitespace */
 693                         while (isspace(*buf_ptr)) {
 694                                 ++buf_ptr;
 695                         }
 696
 697                         if (buf_ptr[0] != '\0') {
 698                                 bb_error_msg("too many parameters \"%s\"", buf);
 699                                 return NULL;
 700                         }
 701
 702                         currif->iface = xstrdup(iface_name);
 703
 704                         currif->address_family = get_address_family(addr_fams, address_family_name);
 705                         if (!currif->address_family) {
 706                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 707                                 return NULL;
 708                         }
 709
 710                         currif->method = get_method(currif->address_family, method_name);
 711                         if (!currif->method) {
 712                                 bb_error_msg("unknown method \"%s\"", method_name);
 713                                 return NULL;
 714                         }
 715
 716                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 717                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 718                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 719                                         (tmp->address_family == currif->address_family)) {
 720                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 721                                         return NULL;
 722                                 }
 723                         }
 724                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 725
 726                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 727                         currently_processing = IFACE;
 728                 } else if (strcmp(firstword, "auto") == 0) {
 729                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 730
 731                                 /* Check the interface isnt already listed */
 732                                 if (find_list_string(defn->autointerfaces, firstword)) {
 733                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 734                                 }
 735
 736                                 /* Add the interface to the list */
 737                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 738                                 debug_noise("\nauto %s\n", firstword);
 739                         }
 740                         currently_processing = NONE;
 741                 } else {
 742                         switch (currently_processing) {
 743                         case IFACE:
 744                                 {
 745                                         int i;
 746
 747                                         if (strlen(buf_ptr) == 0) {
 748                                                 bb_error_msg("option with empty value \"%s\"", buf);
 749                                                 return NULL;
 750                                         }
 751
 752                                         if (strcmp(firstword, "up") != 0
 753                                                         && strcmp(firstword, "down") != 0
 754                                                         && strcmp(firstword, "pre-up") != 0
 755                                                         && strcmp(firstword, "post-down") != 0) {
 756                                                 for (i = 0; i < currif->n_options; i++) {
 757                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 758                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 759                                                                 return NULL;
 760                                                         }
 761                                                 }
 762                                         }
 763                                 }
 764                                 if (currif->n_options >= currif->max_options) {
 765                                         struct variable_t *opt;
 766
 767                                         currif->max_options = currif->max_options + 10;
 768                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 769                                         currif->option = opt;
 770                                 }
 771                                 currif->option[currif->n_options].name = xstrdup(firstword);
 772                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 773                                 if (!currif->option[currif->n_options].name) {
 774                                         perror(filename);
 775                                         return NULL;
 776                                 }
 777                                 if (!currif->option[currif->n_options].value) {
 778                                         perror(filename);
 779                                         return NULL;
 780                                 }
 781                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 782                                                 currif->option[currif->n_options].value);
 783                                 currif->n_options++;
 784                                 break;
 785                         case MAPPING:
 786 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 787                                 if (strcmp(firstword, "script") == 0) {
 788                                         if (currmap->script != NULL) {
 789                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 790                                                 return NULL;
 791                                         } else {
 792                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 793                                         }
 794                                 } else if (strcmp(firstword, "map") == 0) {
 795                                         if (currmap->max_mappings == currmap->n_mappings) {
 796                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 797                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 798                                         }
 799                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 800                                         currmap->n_mappings++;
 801                                 } else {
 802                                         bb_error_msg("misplaced option \"%s\"", buf);
 803                                         return NULL;
 804                                 }
 805 #endif
 806                                 break;
 807                         case NONE:
 808                         default:
 809                                 bb_error_msg("misplaced option \"%s\"", buf);
 810                                 return NULL;
 811                         }
 812                 }
 813                 free(buf);
 814         }
 815         if (ferror(f) != 0) {
 816                 bb_perror_msg_and_die("%s", filename);
 817         }
 818         fclose(f);
 819
 820         return defn;
 821 }
 822
 823 static char *setlocalenv(char *format, const char *name, const char *value)
 824 {
 825         char *result;
 826         char *here;
 827         char *there;
 828
 829         result = xasprintf(format, name, value);
 830
 831         for (here = there = result; *there != '=' && *there; there++) {
 832                 if (*there == '-')
 833                         *there = '_';
 834                 if (isalpha(*there))
 835                         *there = toupper(*there);
 836
 837                 if (isalnum(*there) || *there == '_') {
 838                         *here = *there;
 839                         here++;
 840                 }
 841         }
 842         memmove(here, there, strlen(there) + 1);
 843
 844         return result;
 845 }
 846
 847 static void set_environ(struct interface_defn_t *iface, const char *mode)
 848 {
 849         char **environend;
 850         int i;
 851         const int n_env_entries = iface->n_options + 5;
 852         char **ppch;
 853
 854         if (__myenviron != NULL) {
 855                 for (ppch = __myenviron; *ppch; ppch++) {
 856                         free(*ppch);
 857                         *ppch = NULL;
 858                 }
 859                 free(__myenviron);
 860         }
 861         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 862         environend = __myenviron;
 863
 864         for (i = 0; i < iface->n_options; i++) {
 865                 if (strcmp(iface->option[i].name, "up") == 0
 866                                 || strcmp(iface->option[i].name, "down") == 0
 867                                 || strcmp(iface->option[i].name, "pre-up") == 0
 868                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 869                         continue;
 870                 }
 871                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 872         }
 873
 874         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 875         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 876         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 877         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 878         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 879 }
 880
 881 static int doit(char *str)
 882 {
 883         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 884                 puts(str);
 885         }
 886         if (!(option_mask32 & OPT_no_act)) {
 887                 pid_t child;
 888                 int status;
 889
 890                 fflush(NULL);
 891                 switch (child = fork()) {
 892                 case -1:                /* failure */
 893                         return 0;
 894                 case 0:         /* child */
 895                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 896                         exit(127);
 897                 }
 898                 waitpid(child, &status, 0);
 899                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 900                         return 0;
 901                 }
 902         }
 903         return 1;
 904 }
 905
 906 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 907 {
 908         int i;
 909         char *buf;
 910         for (i = 0; i < ifd->n_options; i++) {
 911                 if (strcmp(ifd->option[i].name, opt) == 0) {
 912                         if (!doit(ifd->option[i].value)) {
 913                                 return 0;
 914                         }
 915                 }
 916         }
 917
 918         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 919         if (doit(buf) != 1) {
 920                 return 0;
 921         }
 922         return 1;
 923 }
 924
 925 static int check(char *str) {
 926         return str != NULL;
 927 }
 928
 929 static int iface_up(struct interface_defn_t *iface)
 930 {
 931         if (!iface->method->up(iface,check)) return -1;
 932         set_environ(iface, "start");
 933         if (!execute_all(iface, "pre-up")) return 0;
 934         if (!iface->method->up(iface, doit)) return 0;
 935         if (!execute_all(iface, "up")) return 0;
 936         return 1;
 937 }
 938
 939 static int iface_down(struct interface_defn_t *iface)
 940 {
 941         if (!iface->method->down(iface,check)) return -1;
 942         set_environ(iface, "stop");
 943         if (!execute_all(iface, "down")) return 0;
 944         if (!iface->method->down(iface, doit)) return 0;
 945         if (!execute_all(iface, "post-down")) return 0;
 946         return 1;
 947 }
 948
 949 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 950 static int popen2(FILE **in, FILE **out, char *command, ...)
 951 {
 952         va_list ap;
 953         char *argv[11] = { command };
 954         int argc;
 955         int infd[2], outfd[2];
 956         pid_t pid;
 957
 958         argc = 1;
 959         va_start(ap, command);
 960         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 961                 argc++;
 962         }
 963         argv[argc] = NULL;      /* make sure */
 964         va_end(ap);
 965
 966         if (pipe(infd) != 0) {
 967                 return 0;
 968         }
 969
 970         if (pipe(outfd) != 0) {
 971                 close(infd[0]);
 972                 close(infd[1]);
 973                 return 0;
 974         }
 975
 976         fflush(NULL);
 977         switch (pid = fork()) {
 978         case -1:                        /* failure */
 979                 close(infd[0]);
 980                 close(infd[1]);
 981                 close(outfd[0]);
 982                 close(outfd[1]);
 983                 return 0;
 984         case 0:                 /* child */
 985                 dup2(infd[0], 0);
 986                 dup2(outfd[1], 1);
 987                 close(infd[0]);
 988                 close(infd[1]);
 989                 close(outfd[0]);
 990                 close(outfd[1]);
 991                 execvp(command, argv);
 992                 exit(127);
 993         default:                        /* parent */
 994                 *in = fdopen(infd[1], "w");
 995                 *out = fdopen(outfd[0], "r");
 996                 close(infd[0]);
 997                 close(outfd[1]);
 998                 return pid;
 999         }
1000         /* unreached */
1001 }
1002
1003 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1004 {
1005         FILE *in, *out;
1006         int i, status;
1007         pid_t pid;
1008
1009         char *logical = xstrdup(physical);
1010
1011         /* Run the mapping script. */
1012         pid = popen2(&in, &out, map->script, physical, NULL);
1013
1014         /* popen2() returns 0 on failure. */
1015         if (pid == 0)
1016                 return logical;
1017
1018         /* Write mappings to stdin of mapping script. */
1019         for (i = 0; i < map->n_mappings; i++) {
1020                 fprintf(in, "%s\n", map->mapping[i]);
1021         }
1022         fclose(in);
1023         waitpid(pid, &status, 0);
1024
1025         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1026                 /* If the mapping script exited successfully, try to
1027                  * grab a line of output and use that as the name of the
1028                  * logical interface. */
1029                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1030
1031                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1032                         /* If we are able to read a line of output from the script,
1033                          * remove any trailing whitespace and use this value
1034                          * as the name of the logical interface. */
1035                         char *pch = new_logical + strlen(new_logical) - 1;
1036
1037                         while (pch >= new_logical && isspace(*pch))
1038                                 *(pch--) = '\0';
1039
1040                         free(logical);
1041                         logical = new_logical;
1042                 } else {
1043                         /* If we are UNABLE to read a line of output, discard our
1044                          * freshly allocated memory. */
1045                         free(new_logical);
1046                 }
1047         }
1048
1049         fclose(out);
1050
1051         return logical;
1052 }
1053 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1054
1055 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1056 {
1057         unsigned short iface_len = strlen(iface);
1058         llist_t *search = state_list;
1059
1060         while (search) {
1061                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1062                                 (search->data[iface_len] == '=')) {
1063                         return search;
1064                 }
1065                 search = search->link;
1066         }
1067         return NULL;
1068 }
1069
1070 int ifupdown_main(int argc, char **argv)
1071 {
1072         static const char statefile[] = "/var/run/ifstate";
1073
1074         int (*cmds)(struct interface_defn_t *) = NULL;
1075         struct interfaces_file_t *defn;
1076         llist_t *state_list = NULL;
1077         llist_t *target_list = NULL;
1078         const char *interfaces = "/etc/network/interfaces";
1079         int any_failures = 0;
1080         int i;
1081
1082         if (applet_name[2] == 'u') {
1083                 /* ifup command */
1084                 cmds = iface_up;
1085         } else {
1086                 /* ifdown command */
1087                 cmds = iface_down;
1088         }
1089
1090         getopt32(argc, argv, OPTION_STR, &interfaces);
1091         if (argc - optind > 0) {
1092                 if (DO_ALL) bb_show_usage();
1093         } else
1094                 if (!DO_ALL) bb_show_usage();
1095
1096         debug_noise("reading %s file:\n", interfaces);
1097         defn = read_interfaces(interfaces);
1098         debug_noise("\ndone reading %s\n\n", interfaces);
1099
1100         if (!defn) {
1101                 exit(EXIT_FAILURE);
1102         }
1103
1104         startup_PATH = getenv("PATH");
1105         if (!startup_PATH) startup_PATH = "";
1106
1107         /* Create a list of interfaces to work on */
1108         if (DO_ALL) {
1109                 if (cmds == iface_up) {
1110                         target_list = defn->autointerfaces;
1111                 } else {
1112                         /* iface_down */
1113                         const llist_t *list = state_list;
1114                         while (list) {
1115                                 llist_add_to_end(&target_list, xstrdup(list->data));
1116                                 list = list->link;
1117                         }
1118                         target_list = defn->autointerfaces;
1119                 }
1120         } else {
1121                 llist_add_to_end(&target_list, argv[optind]);
1122         }
1123
1124
1125         /* Update the interfaces */
1126         while (target_list) {
1127                 llist_t *iface_list;
1128                 struct interface_defn_t *currif;
1129                 char *iface;
1130                 char *liface;
1131                 char *pch;
1132                 int okay = 0;
1133                 int cmds_ret;
1134
1135                 iface = xstrdup(target_list->data);
1136                 target_list = target_list->link;
1137
1138                 pch = strchr(iface, '=');
1139                 if (pch) {
1140                         *pch = '\0';
1141                         liface = xstrdup(pch + 1);
1142                 } else {
1143                         liface = xstrdup(iface);
1144                 }
1145
1146                 if (!FORCE) {
1147                         const llist_t *iface_state = find_iface_state(state_list, iface);
1148
1149                         if (cmds == iface_up) {
1150                                 /* ifup */
1151                                 if (iface_state) {
1152                                         bb_error_msg("interface %s already configured", iface);
1153                                         continue;
1154                                 }
1155                         } else {
1156                                 /* ifdown */
1157                                 if (iface_state) {
1158                                         bb_error_msg("interface %s not configured", iface);
1159                                         continue;
1160                                 }
1161                         }
1162                 }
1163
1164 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1165                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1166                         struct mapping_defn_t *currmap;
1167
1168                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1169                                 for (i = 0; i < currmap->n_matches; i++) {
1170                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1171                                                 continue;
1172                                         if (VERBOSE) {
1173                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1174                                         }
1175                                         liface = run_mapping(iface, currmap);
1176                                         break;
1177                                 }
1178                         }
1179                 }
1180 #endif
1181
1182
1183                 iface_list = defn->ifaces;
1184                 while (iface_list) {
1185                         currif = (struct interface_defn_t *) iface_list->data;
1186                         if (strcmp(liface, currif->iface) == 0) {
1187                                 char *oldiface = currif->iface;
1188
1189                                 okay = 1;
1190                                 currif->iface = iface;
1191
1192                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1193
1194                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1195                                 cmds_ret = cmds(currif);
1196                                 if (cmds_ret == -1) {
1197                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1198                                                         liface, currif->address_family->name);
1199                                         any_failures += 1;
1200                                 } else if (cmds_ret == 0) {
1201                                         any_failures += 1;
1202                                 }
1203
1204                                 currif->iface = oldiface;
1205                         }
1206                         iface_list = iface_list->link;
1207                 }
1208                 if (VERBOSE) {
1209                         puts("");
1210                 }
1211
1212                 if (!okay && !FORCE) {
1213                         bb_error_msg("ignoring unknown interface %s", liface);
1214                         any_failures += 1;
1215                 } else {
1216                         llist_t *iface_state = find_iface_state(state_list, iface);
1217
1218                         if (cmds == iface_up) {
1219                                 char *newiface = xasprintf("%s=%s", iface, liface);
1220                                 if (iface_state == NULL) {
1221                                         llist_add_to_end(&state_list, newiface);
1222                                 } else {
1223                                         free(iface_state->data);
1224                                         iface_state->data = newiface;
1225                                 }
1226                         } else {
1227                                 /* Remove an interface from the linked list */
1228                                 free(llist_pop(&iface_state));
1229                         }
1230                 }
1231         }
1232
1233         /* Actually write the new state */
1234         if (!NO_ACT) {
1235                 FILE *state_fp = NULL;
1236
1237                 state_fp = xfopen(statefile, "w");
1238                 while (state_list) {
1239                         if (state_list->data) {
1240                                 fputs(state_list->data, state_fp);
1241                                 fputc('\n', state_fp);
1242                         }
1243                         state_list = state_list->link;
1244                 }
1245                 fclose(state_fp);
1246         }
1247
1248         if (any_failures)
1249                 return 1;
1250         return 0;
1251 }