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, const 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(const char *l, const 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(const 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(const 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(const 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 #ifndef CONFIG_APP_UDHCPC
 453 struct dhcp_client_t
 454 {
 455         const char *name;
 456         const char *startcmd;
 457         const char *stopcmd;
 458 };
 459
 460 static const struct dhcp_client_t ext_dhcp_clients[] = {
 461         { "udhcpc",
 462                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
 463                 "kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 464         },
 465         { "pump",
 466                 "pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
 467                 "pump -i %iface% -k",
 468         },
 469         { "dhclient",
 470                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 471                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 472         },
 473         { "dhcpcd",
 474                 "dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] [[-l %leasetime%]] %iface%",
 475                 "dhcpcd -k %iface%",
 476         },
 477 };
 478 #endif
 479
 480 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 481 {
 482 #ifdef CONFIG_APP_UDHCPC
 483         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 484                         "-i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
 485                         ifd, exec);
 486 #else
 487         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 488         for (i = 0; i < nclients; i++) {
 489                 if (exists_execable(ext_dhcp_clients[i].name))
 490                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 491         }
 492         bb_error_msg("no dhcp clients found");
 493         return 0;
 494 #endif
 495 }
 496
 497 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 498 {
 499 #ifdef CONFIG_APP_UDHCPC
 500         return execute("kill -TERM "
 501                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 502 #else
 503         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 504         for (i = 0; i < nclients; i++) {
 505                 if (exists_execable(ext_dhcp_clients[i].name))
 506                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 507         }
 508         bb_error_msg("no dhcp clients found, using static interface shutdown");
 509         return static_down(ifd, exec);
 510 #endif
 511 }
 512
 513 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 514 {
 515         return 1;
 516 }
 517
 518 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 519 {
 520         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 521                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 522                         "--returniffail --serverbcast", ifd, exec);
 523 }
 524
 525 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 526 {
 527         return execute("pon [[%provider%]]", ifd, exec);
 528 }
 529
 530 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 531 {
 532         return execute("poff [[%provider%]]", ifd, exec);
 533 }
 534
 535 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 536 {
 537         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 538                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 539 }
 540
 541 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 542 {
 543         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 544                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 545 }
 546
 547 static const struct method_t methods[] = {
 548         { "manual", manual_up_down, manual_up_down, },
 549         { "wvdial", wvdial_up, wvdial_down, },
 550         { "ppp", ppp_up, ppp_down, },
 551         { "static", static_up, static_down, },
 552         { "bootp", bootp_up, static_down, },
 553         { "dhcp", dhcp_up, dhcp_down, },
 554         { "loopback", loopback_up, loopback_down, },
 555 };
 556
 557 static const struct address_family_t addr_inet = {
 558         "inet",
 559         sizeof(methods) / sizeof(struct method_t),
 560         methods
 561 };
 562
 563 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 564
 565 static char *next_word(char **buf)
 566 {
 567         unsigned short length;
 568         char *word;
 569
 570         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 571                 return NULL;
 572         }
 573
 574         /* Skip over leading whitespace */
 575         word = skip_whitespace(*buf);
 576
 577         /* Skip over comments */
 578         if (*word == '#') {
 579                 return NULL;
 580         }
 581
 582         /* Find the length of this word */
 583         length = strcspn(word, " \t\n");
 584         if (length == 0) {
 585                 return NULL;
 586         }
 587         *buf = word + length;
 588         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 589         if (**buf) {
 590                 **buf = '\0';
 591                 (*buf)++;
 592         }
 593
 594         return word;
 595 }
 596
 597 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 598 {
 599         int i;
 600
 601         if (!name)
 602                 return NULL;
 603
 604         for (i = 0; af[i]; i++) {
 605                 if (strcmp(af[i]->name, name) == 0) {
 606                         return af[i];
 607                 }
 608         }
 609         return NULL;
 610 }
 611
 612 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 613 {
 614         int i;
 615
 616         if (!name)
 617                 return NULL;
 618
 619         for (i = 0; i < af->n_methods; i++) {
 620                 if (strcmp(af->method[i].name, name) == 0) {
 621                         return &af->method[i];
 622                 }
 623         }
 624         return NULL;
 625 }
 626
 627 static const llist_t *find_list_string(const llist_t *list, const char *string)
 628 {
 629         if (string == NULL)
 630                 return NULL;
 631
 632         while (list) {
 633                 if (strcmp(list->data, string) == 0) {
 634                         return list;
 635                 }
 636                 list = list->link;
 637         }
 638         return NULL;
 639 }
 640
 641 static struct interfaces_file_t *read_interfaces(const char *filename)
 642 {
 643 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 644         struct mapping_defn_t *currmap = NULL;
 645 #endif
 646         struct interface_defn_t *currif = NULL;
 647         struct interfaces_file_t *defn;
 648         FILE *f;
 649         char *firstword;
 650         char *buf;
 651
 652         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 653
 654         defn = xzalloc(sizeof(struct interfaces_file_t));
 655
 656         f = xfopen(filename, "r");
 657
 658         while ((buf = xmalloc_getline(f)) != NULL) {
 659                 char *buf_ptr = buf;
 660
 661                 firstword = next_word(&buf_ptr);
 662                 if (firstword == NULL) {
 663                         free(buf);
 664                         continue;       /* blank line */
 665                 }
 666
 667                 if (strcmp(firstword, "mapping") == 0) {
 668 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 669                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 670
 671                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 672                                 if (currmap->max_matches == currmap->n_matches) {
 673                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 674                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 675                                 }
 676
 677                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 678                         }
 679                         currmap->max_mappings = 0;
 680                         currmap->n_mappings = 0;
 681                         currmap->mapping = NULL;
 682                         currmap->script = NULL;
 683                         {
 684                                 struct mapping_defn_t **where = &defn->mappings;
 685                                 while (*where != NULL) {
 686                                         where = &(*where)->next;
 687                                 }
 688                                 *where = currmap;
 689                                 currmap->next = NULL;
 690                         }
 691                         debug_noise("Added mapping\n");
 692 #endif
 693                         currently_processing = MAPPING;
 694                 } else if (strcmp(firstword, "iface") == 0) {
 695                         static const struct address_family_t *const addr_fams[] = {
 696 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 697                                 &addr_inet,
 698 #endif
 699 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 700                                 &addr_inet6,
 701 #endif
 702                                 NULL
 703                         };
 704
 705                         char *iface_name;
 706                         char *address_family_name;
 707                         char *method_name;
 708                         llist_t *iface_list;
 709
 710                         currif = xzalloc(sizeof(struct interface_defn_t));
 711                         iface_name = next_word(&buf_ptr);
 712                         address_family_name = next_word(&buf_ptr);
 713                         method_name = next_word(&buf_ptr);
 714
 715                         if (buf_ptr == NULL) {
 716                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 717                                 return NULL;
 718                         }
 719
 720                         /* ship any trailing whitespace */
 721                         buf_ptr = skip_whitespace(buf_ptr);
 722
 723                         if (buf_ptr[0] != '\0') {
 724                                 bb_error_msg("too many parameters \"%s\"", buf);
 725                                 return NULL;
 726                         }
 727
 728                         currif->iface = xstrdup(iface_name);
 729
 730                         currif->address_family = get_address_family(addr_fams, address_family_name);
 731                         if (!currif->address_family) {
 732                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 733                                 return NULL;
 734                         }
 735
 736                         currif->method = get_method(currif->address_family, method_name);
 737                         if (!currif->method) {
 738                                 bb_error_msg("unknown method \"%s\"", method_name);
 739                                 return NULL;
 740                         }
 741
 742                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 743                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 744                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 745                                         (tmp->address_family == currif->address_family)) {
 746                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 747                                         return NULL;
 748                                 }
 749                         }
 750                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 751
 752                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 753                         currently_processing = IFACE;
 754                 } else if (strcmp(firstword, "auto") == 0) {
 755                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 756
 757                                 /* Check the interface isnt already listed */
 758                                 if (find_list_string(defn->autointerfaces, firstword)) {
 759                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 760                                 }
 761
 762                                 /* Add the interface to the list */
 763                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 764                                 debug_noise("\nauto %s\n", firstword);
 765                         }
 766                         currently_processing = NONE;
 767                 } else {
 768                         switch (currently_processing) {
 769                         case IFACE:
 770                                 {
 771                                         int i;
 772
 773                                         if (strlen(buf_ptr) == 0) {
 774                                                 bb_error_msg("option with empty value \"%s\"", buf);
 775                                                 return NULL;
 776                                         }
 777
 778                                         if (strcmp(firstword, "up") != 0
 779                                                         && strcmp(firstword, "down") != 0
 780                                                         && strcmp(firstword, "pre-up") != 0
 781                                                         && strcmp(firstword, "post-down") != 0) {
 782                                                 for (i = 0; i < currif->n_options; i++) {
 783                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 784                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 785                                                                 return NULL;
 786                                                         }
 787                                                 }
 788                                         }
 789                                 }
 790                                 if (currif->n_options >= currif->max_options) {
 791                                         struct variable_t *opt;
 792
 793                                         currif->max_options = currif->max_options + 10;
 794                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 795                                         currif->option = opt;
 796                                 }
 797                                 currif->option[currif->n_options].name = xstrdup(firstword);
 798                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 799                                 if (!currif->option[currif->n_options].name) {
 800                                         perror(filename);
 801                                         return NULL;
 802                                 }
 803                                 if (!currif->option[currif->n_options].value) {
 804                                         perror(filename);
 805                                         return NULL;
 806                                 }
 807                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 808                                                 currif->option[currif->n_options].value);
 809                                 currif->n_options++;
 810                                 break;
 811                         case MAPPING:
 812 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 813                                 if (strcmp(firstword, "script") == 0) {
 814                                         if (currmap->script != NULL) {
 815                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 816                                                 return NULL;
 817                                         } else {
 818                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 819                                         }
 820                                 } else if (strcmp(firstword, "map") == 0) {
 821                                         if (currmap->max_mappings == currmap->n_mappings) {
 822                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 823                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 824                                         }
 825                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 826                                         currmap->n_mappings++;
 827                                 } else {
 828                                         bb_error_msg("misplaced option \"%s\"", buf);
 829                                         return NULL;
 830                                 }
 831 #endif
 832                                 break;
 833                         case NONE:
 834                         default:
 835                                 bb_error_msg("misplaced option \"%s\"", buf);
 836                                 return NULL;
 837                         }
 838                 }
 839                 free(buf);
 840         }
 841         if (ferror(f) != 0) {
 842                 bb_perror_msg_and_die("%s", filename);
 843         }
 844         fclose(f);
 845
 846         return defn;
 847 }
 848
 849 static char *setlocalenv(char *format, const char *name, const char *value)
 850 {
 851         char *result;
 852         char *here;
 853         char *there;
 854
 855         result = xasprintf(format, name, value);
 856
 857         for (here = there = result; *there != '=' && *there; there++) {
 858                 if (*there == '-')
 859                         *there = '_';
 860                 if (isalpha(*there))
 861                         *there = toupper(*there);
 862
 863                 if (isalnum(*there) || *there == '_') {
 864                         *here = *there;
 865                         here++;
 866                 }
 867         }
 868         memmove(here, there, strlen(there) + 1);
 869
 870         return result;
 871 }
 872
 873 static void set_environ(struct interface_defn_t *iface, const char *mode)
 874 {
 875         char **environend;
 876         int i;
 877         const int n_env_entries = iface->n_options + 5;
 878         char **ppch;
 879
 880         if (__myenviron != NULL) {
 881                 for (ppch = __myenviron; *ppch; ppch++) {
 882                         free(*ppch);
 883                         *ppch = NULL;
 884                 }
 885                 free(__myenviron);
 886         }
 887         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 888         environend = __myenviron;
 889
 890         for (i = 0; i < iface->n_options; i++) {
 891                 if (strcmp(iface->option[i].name, "up") == 0
 892                                 || strcmp(iface->option[i].name, "down") == 0
 893                                 || strcmp(iface->option[i].name, "pre-up") == 0
 894                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 895                         continue;
 896                 }
 897                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 898         }
 899
 900         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 901         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 902         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 903         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 904         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 905 }
 906
 907 static int doit(char *str)
 908 {
 909         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 910                 puts(str);
 911         }
 912         if (!(option_mask32 & OPT_no_act)) {
 913                 pid_t child;
 914                 int status;
 915
 916                 fflush(NULL);
 917                 switch (child = fork()) {
 918                 case -1:                /* failure */
 919                         return 0;
 920                 case 0:         /* child */
 921                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 922                         exit(127);
 923                 }
 924                 waitpid(child, &status, 0);
 925                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 926                         return 0;
 927                 }
 928         }
 929         return 1;
 930 }
 931
 932 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 933 {
 934         int i;
 935         char *buf;
 936         for (i = 0; i < ifd->n_options; i++) {
 937                 if (strcmp(ifd->option[i].name, opt) == 0) {
 938                         if (!doit(ifd->option[i].value)) {
 939                                 return 0;
 940                         }
 941                 }
 942         }
 943
 944         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 945         if (doit(buf) != 1) {
 946                 return 0;
 947         }
 948         return 1;
 949 }
 950
 951 static int check(char *str) {
 952         return str != NULL;
 953 }
 954
 955 static int iface_up(struct interface_defn_t *iface)
 956 {
 957         if (!iface->method->up(iface,check)) return -1;
 958         set_environ(iface, "start");
 959         if (!execute_all(iface, "pre-up")) return 0;
 960         if (!iface->method->up(iface, doit)) return 0;
 961         if (!execute_all(iface, "up")) return 0;
 962         return 1;
 963 }
 964
 965 static int iface_down(struct interface_defn_t *iface)
 966 {
 967         if (!iface->method->down(iface,check)) return -1;
 968         set_environ(iface, "stop");
 969         if (!execute_all(iface, "down")) return 0;
 970         if (!iface->method->down(iface, doit)) return 0;
 971         if (!execute_all(iface, "post-down")) return 0;
 972         return 1;
 973 }
 974
 975 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 976 static int popen2(FILE **in, FILE **out, char *command, ...)
 977 {
 978         va_list ap;
 979         char *argv[11] = { command };
 980         int argc;
 981         int infd[2], outfd[2];
 982         pid_t pid;
 983
 984         argc = 1;
 985         va_start(ap, command);
 986         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 987                 argc++;
 988         }
 989         argv[argc] = NULL;      /* make sure */
 990         va_end(ap);
 991
 992         if (pipe(infd) != 0) {
 993                 return 0;
 994         }
 995
 996         if (pipe(outfd) != 0) {
 997                 close(infd[0]);
 998                 close(infd[1]);
 999                 return 0;
1000         }
1001
1002         fflush(NULL);
1003         switch (pid = fork()) {
1004         case -1:                        /* failure */
1005                 close(infd[0]);
1006                 close(infd[1]);
1007                 close(outfd[0]);
1008                 close(outfd[1]);
1009                 return 0;
1010         case 0:                 /* child */
1011                 dup2(infd[0], 0);
1012                 dup2(outfd[1], 1);
1013                 close(infd[0]);
1014                 close(infd[1]);
1015                 close(outfd[0]);
1016                 close(outfd[1]);
1017                 execvp(command, argv);
1018                 exit(127);
1019         default:                        /* parent */
1020                 *in = fdopen(infd[1], "w");
1021                 *out = fdopen(outfd[0], "r");
1022                 close(infd[0]);
1023                 close(outfd[1]);
1024                 return pid;
1025         }
1026         /* unreached */
1027 }
1028
1029 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1030 {
1031         FILE *in, *out;
1032         int i, status;
1033         pid_t pid;
1034
1035         char *logical = xstrdup(physical);
1036
1037         /* Run the mapping script. */
1038         pid = popen2(&in, &out, map->script, physical, NULL);
1039
1040         /* popen2() returns 0 on failure. */
1041         if (pid == 0)
1042                 return logical;
1043
1044         /* Write mappings to stdin of mapping script. */
1045         for (i = 0; i < map->n_mappings; i++) {
1046                 fprintf(in, "%s\n", map->mapping[i]);
1047         }
1048         fclose(in);
1049         waitpid(pid, &status, 0);
1050
1051         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1052                 /* If the mapping script exited successfully, try to
1053                  * grab a line of output and use that as the name of the
1054                  * logical interface. */
1055                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1056
1057                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1058                         /* If we are able to read a line of output from the script,
1059                          * remove any trailing whitespace and use this value
1060                          * as the name of the logical interface. */
1061                         char *pch = new_logical + strlen(new_logical) - 1;
1062
1063                         while (pch >= new_logical && isspace(*pch))
1064                                 *(pch--) = '\0';
1065
1066                         free(logical);
1067                         logical = new_logical;
1068                 } else {
1069                         /* If we are UNABLE to read a line of output, discard our
1070                          * freshly allocated memory. */
1071                         free(new_logical);
1072                 }
1073         }
1074
1075         fclose(out);
1076
1077         return logical;
1078 }
1079 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1080
1081 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1082 {
1083         unsigned short iface_len = strlen(iface);
1084         llist_t *search = state_list;
1085
1086         while (search) {
1087                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1088                                 (search->data[iface_len] == '=')) {
1089                         return search;
1090                 }
1091                 search = search->link;
1092         }
1093         return NULL;
1094 }
1095
1096 int ifupdown_main(int argc, char **argv)
1097 {
1098         static const char statefile[] = "/var/run/ifstate";
1099
1100         int (*cmds)(struct interface_defn_t *) = NULL;
1101         struct interfaces_file_t *defn;
1102         llist_t *state_list = NULL;
1103         llist_t *target_list = NULL;
1104         const char *interfaces = "/etc/network/interfaces";
1105         int any_failures = 0;
1106
1107         if (applet_name[2] == 'u') {
1108                 /* ifup command */
1109                 cmds = iface_up;
1110         } else {
1111                 /* ifdown command */
1112                 cmds = iface_down;
1113         }
1114
1115         getopt32(argc, argv, OPTION_STR, &interfaces);
1116         if (argc - optind > 0) {
1117                 if (DO_ALL) bb_show_usage();
1118         } else
1119                 if (!DO_ALL) bb_show_usage();
1120
1121         debug_noise("reading %s file:\n", interfaces);
1122         defn = read_interfaces(interfaces);
1123         debug_noise("\ndone reading %s\n\n", interfaces);
1124
1125         if (!defn) {
1126                 exit(EXIT_FAILURE);
1127         }
1128
1129         startup_PATH = getenv("PATH");
1130         if (!startup_PATH) startup_PATH = "";
1131
1132         /* Create a list of interfaces to work on */
1133         if (DO_ALL) {
1134                 if (cmds == iface_up) {
1135                         target_list = defn->autointerfaces;
1136                 } else {
1137                         /* iface_down */
1138                         const llist_t *list = state_list;
1139                         while (list) {
1140                                 llist_add_to_end(&target_list, xstrdup(list->data));
1141                                 list = list->link;
1142                         }
1143                         target_list = defn->autointerfaces;
1144                 }
1145         } else {
1146                 llist_add_to_end(&target_list, argv[optind]);
1147         }
1148
1149
1150         /* Update the interfaces */
1151         while (target_list) {
1152                 llist_t *iface_list;
1153                 struct interface_defn_t *currif;
1154                 char *iface;
1155                 char *liface;
1156                 char *pch;
1157                 int okay = 0;
1158                 int cmds_ret;
1159
1160                 iface = xstrdup(target_list->data);
1161                 target_list = target_list->link;
1162
1163                 pch = strchr(iface, '=');
1164                 if (pch) {
1165                         *pch = '\0';
1166                         liface = xstrdup(pch + 1);
1167                 } else {
1168                         liface = xstrdup(iface);
1169                 }
1170
1171                 if (!FORCE) {
1172                         const llist_t *iface_state = find_iface_state(state_list, iface);
1173
1174                         if (cmds == iface_up) {
1175                                 /* ifup */
1176                                 if (iface_state) {
1177                                         bb_error_msg("interface %s already configured", iface);
1178                                         continue;
1179                                 }
1180                         } else {
1181                                 /* ifdown */
1182                                 if (iface_state) {
1183                                         bb_error_msg("interface %s not configured", iface);
1184                                         continue;
1185                                 }
1186                         }
1187                 }
1188
1189 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1190                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1191                         struct mapping_defn_t *currmap;
1192
1193                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1194                                 int i;
1195                                 for (i = 0; i < currmap->n_matches; i++) {
1196                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1197                                                 continue;
1198                                         if (VERBOSE) {
1199                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1200                                         }
1201                                         liface = run_mapping(iface, currmap);
1202                                         break;
1203                                 }
1204                         }
1205                 }
1206 #endif
1207
1208
1209                 iface_list = defn->ifaces;
1210                 while (iface_list) {
1211                         currif = (struct interface_defn_t *) iface_list->data;
1212                         if (strcmp(liface, currif->iface) == 0) {
1213                                 char *oldiface = currif->iface;
1214
1215                                 okay = 1;
1216                                 currif->iface = iface;
1217
1218                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1219
1220                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1221                                 cmds_ret = cmds(currif);
1222                                 if (cmds_ret == -1) {
1223                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1224                                                         liface, currif->address_family->name);
1225                                         any_failures += 1;
1226                                 } else if (cmds_ret == 0) {
1227                                         any_failures += 1;
1228                                 }
1229
1230                                 currif->iface = oldiface;
1231                         }
1232                         iface_list = iface_list->link;
1233                 }
1234                 if (VERBOSE) {
1235                         puts("");
1236                 }
1237
1238                 if (!okay && !FORCE) {
1239                         bb_error_msg("ignoring unknown interface %s", liface);
1240                         any_failures += 1;
1241                 } else {
1242                         llist_t *iface_state = find_iface_state(state_list, iface);
1243
1244                         if (cmds == iface_up) {
1245                                 char *newiface = xasprintf("%s=%s", iface, liface);
1246                                 if (iface_state == NULL) {
1247                                         llist_add_to_end(&state_list, newiface);
1248                                 } else {
1249                                         free(iface_state->data);
1250                                         iface_state->data = newiface;
1251                                 }
1252                         } else {
1253                                 /* Remove an interface from the linked list */
1254                                 free(llist_pop(&iface_state));
1255                         }
1256                 }
1257         }
1258
1259         /* Actually write the new state */
1260         if (!NO_ACT) {
1261                 FILE *state_fp = NULL;
1262
1263                 state_fp = xfopen(statefile, "w");
1264                 while (state_list) {
1265                         if (state_list->data) {
1266                                 fputs(state_list->data, state_fp);
1267                                 fputc('\n', state_fp);
1268                         }
1269                         state_list = state_list->link;
1270                 }
1271                 fclose(state_fp);
1272         }
1273
1274         if (any_failures)
1275                 return 1;
1276         return 0;
1277 }