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 count_bits(unsigned a)
 115 {
 116         unsigned 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 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         // FIXME: will be confused by e.g. 255.0.255.0
 129         result = count_bits(a);
 130         result += count_bits(b);
 131         result += count_bits(c);
 132         result += count_bits(d);
 133         return (int)result;
 134 }
 135 #endif
 136
 137 static void addstr(char **bufp, const char *str, size_t str_length)
 138 {
 139         /* xasprintf trick will be smaller, but we are often
 140          * called with str_length == 1 - don't want to have
 141          * THAT much of malloc/freeing! */
 142         char *buf = *bufp;
 143         int len = (buf ? strlen(buf) : 0);
 144         str_length++;
 145         buf = xrealloc(buf, len + str_length);
 146         /* copies at most str_length-1 chars! */
 147         safe_strncpy(buf + len, str, str_length);
 148         *bufp = buf;
 149 }
 150
 151 static int strncmpz(const char *l, const char *r, size_t llen)
 152 {
 153         int i = strncmp(l, r, llen);
 154
 155         if (i == 0)
 156                 return -r[llen];
 157         return i;
 158 }
 159
 160 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 161 {
 162         int i;
 163
 164         if (strncmpz(id, "iface", idlen) == 0) {
 165                 char *result;
 166                 static char label_buf[20];
 167                 safe_strncpy(label_buf, ifd->iface, sizeof(label_buf));
 168                 result = strchr(label_buf, ':');
 169                 if (result) {
 170                         *result = '\0';
 171                 }
 172                 return label_buf;
 173         }
 174         if (strncmpz(id, "label", idlen) == 0) {
 175                 return ifd->iface;
 176         }
 177         for (i = 0; i < ifd->n_options; i++) {
 178                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 179                         return ifd->option[i].value;
 180                 }
 181         }
 182         return NULL;
 183 }
 184
 185 static char *parse(const char *command, struct interface_defn_t *ifd)
 186 {
 187         char *result = NULL;
 188         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 189         int okay[MAX_OPT_DEPTH] = { 1 };
 190         int opt_depth = 1;
 191
 192         while (*command) {
 193                 switch (*command) {
 194                 default:
 195                         addstr(&result, command, 1);
 196                         command++;
 197                         break;
 198                 case '\\':
 199                         if (command[1]) {
 200                                 addstr(&result, command + 1, 1);
 201                                 command += 2;
 202                         } else {
 203                                 addstr(&result, command, 1);
 204                                 command++;
 205                         }
 206                         break;
 207                 case '[':
 208                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 209                                 old_pos[opt_depth] = strlen(result);
 210                                 okay[opt_depth] = 1;
 211                                 opt_depth++;
 212                                 command += 2;
 213                         } else {
 214                                 addstr(&result, "[", 1);
 215                                 command++;
 216                         }
 217                         break;
 218                 case ']':
 219                         if (command[1] == ']' && opt_depth > 1) {
 220                                 opt_depth--;
 221                                 if (!okay[opt_depth]) {
 222                                         result[old_pos[opt_depth]] = '\0';
 223                                 }
 224                                 command += 2;
 225                         } else {
 226                                 addstr(&result, "]", 1);
 227                                 command++;
 228                         }
 229                         break;
 230                 case '%':
 231                         {
 232                                 char *nextpercent;
 233                                 char *varvalue;
 234
 235                                 command++;
 236                                 nextpercent = strchr(command, '%');
 237                                 if (!nextpercent) {
 238                                         errno = EUNBALPER;
 239                                         free(result);
 240                                         return NULL;
 241                                 }
 242
 243                                 varvalue = get_var(command, nextpercent - command, ifd);
 244
 245                                 if (varvalue) {
 246                                         addstr(&result, varvalue, strlen(varvalue));
 247                                 } else {
 248 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 249                                         /* Sigh...  Add a special case for 'ip' to convert from
 250                                          * dotted quad to bit count style netmasks.  */
 251                                         if (strncmp(command, "bnmask", 6)==0) {
 252                                                 unsigned res;
 253                                                 varvalue = get_var("netmask", 7, ifd);
 254                                                 if (varvalue && (res = count_netmask_bits(varvalue)) > 0) {
 255                                                         const char *argument = utoa(res);
 256                                                         addstr(&result, argument, strlen(argument));
 257                                                         command = nextpercent + 1;
 258                                                         break;
 259                                                 }
 260                                         }
 261 #endif
 262                                         okay[opt_depth - 1] = 0;
 263                                 }
 264
 265                                 command = nextpercent + 1;
 266                         }
 267                         break;
 268                 }
 269         }
 270
 271         if (opt_depth > 1) {
 272                 errno = EUNBALBRACK;
 273                 free(result);
 274                 return NULL;
 275         }
 276
 277         if (!okay[0]) {
 278                 errno = EUNDEFVAR;
 279                 free(result);
 280                 return NULL;
 281         }
 282
 283         return result;
 284 }
 285
 286 /* execute() returns 1 for success and 0 for failure */
 287 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 288 {
 289         char *out;
 290         int ret;
 291
 292         out = parse(command, ifd);
 293         if (!out) {
 294                 return 0;
 295         }
 296         ret = (*exec)(out);
 297
 298         free(out);
 299         if (ret != 1) {
 300                 return 0;
 301         }
 302         return 1;
 303 }
 304 #endif
 305
 306 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 307 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 308 {
 309 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 310         int result;
 311         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 312         result += execute("ip link set %iface% up", ifd, exec);
 313         return ((result == 2) ? 2 : 0);
 314 #else
 315         return execute("ifconfig %iface% add ::1", ifd, exec);
 316 #endif
 317 }
 318
 319 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 320 {
 321 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 322         return execute("ip link set %iface% down", ifd, exec);
 323 #else
 324         return execute("ifconfig %iface% del ::1", ifd, exec);
 325 #endif
 326 }
 327
 328 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 329 {
 330         int result;
 331 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 332         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 333         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 334         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 335 #else
 336         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 337         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 338         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 339 #endif
 340         return ((result == 3) ? 3 : 0);
 341 }
 342
 343 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 344 {
 345 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 346         return execute("ip link set %iface% down", ifd, exec);
 347 #else
 348         return execute("ifconfig %iface% down", ifd, exec);
 349 #endif
 350 }
 351
 352 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 353 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 354 {
 355         int result;
 356         result = execute("ip tunnel add %iface% mode sit remote "
 357                         "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 358         result += execute("ip link set %iface% up", ifd, exec);
 359         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 360         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 361         return ((result == 4) ? 4 : 0);
 362 }
 363
 364 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 365 {
 366         return execute("ip tunnel del %iface%", ifd, exec);
 367 }
 368 #endif
 369
 370 static const struct method_t methods6[] = {
 371 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 372         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 373 #endif
 374         { "static", static_up6, static_down6, },
 375         { "loopback", loopback_up6, loopback_down6, },
 376 };
 377
 378 static const struct address_family_t addr_inet6 = {
 379         "inet6",
 380         sizeof(methods6) / sizeof(struct method_t),
 381         methods6
 382 };
 383 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 384
 385 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 386 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 387 {
 388 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 389         int result;
 390         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 391         result += execute("ip link set %iface% up", ifd, exec);
 392         return ((result == 2) ? 2 : 0);
 393 #else
 394         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 395 #endif
 396 }
 397
 398 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 399 {
 400 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 401         int result;
 402         result = execute("ip addr flush dev %iface%", ifd, exec);
 403         result += execute("ip link set %iface% down", ifd, exec);
 404         return ((result == 2) ? 2 : 0);
 405 #else
 406         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 407 #endif
 408 }
 409
 410 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 411 {
 412         int result;
 413 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 414         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 415                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 416         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 417         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 418         return ((result == 3) ? 3 : 0);
 419 #else
 420         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 421          * which then of course fails. Thus we run two separate ifconfig */
 422         result = execute("ifconfig %iface% [[hw %hwaddress%]] [[media %media%]] [[mtu %mtu%]] up",
 423                                 ifd, exec);
 424         result += execute("ifconfig %iface% %address% netmask %netmask% "
 425                                 "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] ",
 426                                 ifd, exec);
 427         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 428         return ((result == 3) ? 3 : 0);
 429 #endif
 430 }
 431
 432 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 433 {
 434         int result;
 435 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 436         result = execute("ip addr flush dev %iface%", ifd, exec);
 437         result += execute("ip link set %iface% down", ifd, exec);
 438 #else
 439         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 440         result += execute("ifconfig %iface% down", ifd, exec);
 441 #endif
 442         return ((result == 2) ? 2 : 0);
 443 }
 444
 445 #ifndef CONFIG_APP_UDHCPC
 446 struct dhcp_client_t
 447 {
 448         const char *name;
 449         const char *startcmd;
 450         const char *stopcmd;
 451 };
 452
 453 static const struct dhcp_client_t ext_dhcp_clients[] = {
 454         { "udhcpc",
 455                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
 456                 "kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 457         },
 458         { "pump",
 459                 "pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
 460                 "pump -i %iface% -k",
 461         },
 462         { "dhclient",
 463                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 464                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 465         },
 466         { "dhcpcd",
 467                 "dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] [[-l %leasetime%]] %iface%",
 468                 "dhcpcd -k %iface%",
 469         },
 470 };
 471 #endif
 472
 473 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 474 {
 475 #ifdef CONFIG_APP_UDHCPC
 476         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 477                         "-i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
 478                         ifd, exec);
 479 #else
 480         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 481         for (i = 0; i < nclients; i++) {
 482                 if (exists_execable(ext_dhcp_clients[i].name))
 483                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 484         }
 485         bb_error_msg("no dhcp clients found");
 486         return 0;
 487 #endif
 488 }
 489
 490 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 491 {
 492 #ifdef CONFIG_APP_UDHCPC
 493         return execute("kill -TERM "
 494                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 495 #else
 496         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 497         for (i = 0; i < nclients; i++) {
 498                 if (exists_execable(ext_dhcp_clients[i].name))
 499                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 500         }
 501         bb_error_msg("no dhcp clients found, using static interface shutdown");
 502         return static_down(ifd, exec);
 503 #endif
 504 }
 505
 506 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 507 {
 508         return 1;
 509 }
 510
 511 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 512 {
 513         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 514                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 515                         "--returniffail --serverbcast", ifd, exec);
 516 }
 517
 518 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 519 {
 520         return execute("pon [[%provider%]]", ifd, exec);
 521 }
 522
 523 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 524 {
 525         return execute("poff [[%provider%]]", ifd, exec);
 526 }
 527
 528 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 529 {
 530         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 531                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 532 }
 533
 534 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 535 {
 536         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 537                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 538 }
 539
 540 static const struct method_t methods[] = {
 541         { "manual", manual_up_down, manual_up_down, },
 542         { "wvdial", wvdial_up, wvdial_down, },
 543         { "ppp", ppp_up, ppp_down, },
 544         { "static", static_up, static_down, },
 545         { "bootp", bootp_up, static_down, },
 546         { "dhcp", dhcp_up, dhcp_down, },
 547         { "loopback", loopback_up, loopback_down, },
 548 };
 549
 550 static const struct address_family_t addr_inet = {
 551         "inet",
 552         sizeof(methods) / sizeof(struct method_t),
 553         methods
 554 };
 555
 556 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 557
 558 static char *next_word(char **buf)
 559 {
 560         unsigned short length;
 561         char *word;
 562
 563         if (!buf || !*buf || !**buf) {
 564                 return NULL;
 565         }
 566
 567         /* Skip over leading whitespace */
 568         word = skip_whitespace(*buf);
 569
 570         /* Skip over comments */
 571         if (*word == '#') {
 572                 return NULL;
 573         }
 574
 575         /* Find the length of this word */
 576         length = strcspn(word, " \t\n");
 577         if (length == 0) {
 578                 return NULL;
 579         }
 580         *buf = word + length;
 581         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 582         if (**buf) {
 583                 **buf = '\0';
 584                 (*buf)++;
 585         }
 586
 587         return word;
 588 }
 589
 590 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 591 {
 592         int i;
 593
 594         if (!name)
 595                 return NULL;
 596
 597         for (i = 0; af[i]; i++) {
 598                 if (strcmp(af[i]->name, name) == 0) {
 599                         return af[i];
 600                 }
 601         }
 602         return NULL;
 603 }
 604
 605 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 606 {
 607         int i;
 608
 609         if (!name)
 610                 return NULL;
 611
 612         for (i = 0; i < af->n_methods; i++) {
 613                 if (strcmp(af->method[i].name, name) == 0) {
 614                         return &af->method[i];
 615                 }
 616         }
 617         return NULL;
 618 }
 619
 620 static const llist_t *find_list_string(const llist_t *list, const char *string)
 621 {
 622         if (string == NULL)
 623                 return NULL;
 624
 625         while (list) {
 626                 if (strcmp(list->data, string) == 0) {
 627                         return list;
 628                 }
 629                 list = list->link;
 630         }
 631         return NULL;
 632 }
 633
 634 static struct interfaces_file_t *read_interfaces(const char *filename)
 635 {
 636 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 637         struct mapping_defn_t *currmap = NULL;
 638 #endif
 639         struct interface_defn_t *currif = NULL;
 640         struct interfaces_file_t *defn;
 641         FILE *f;
 642         char *firstword;
 643         char *buf;
 644
 645         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 646
 647         defn = xzalloc(sizeof(struct interfaces_file_t));
 648
 649         f = xfopen(filename, "r");
 650
 651         while ((buf = xmalloc_getline(f)) != NULL) {
 652                 char *buf_ptr = buf;
 653
 654                 firstword = next_word(&buf_ptr);
 655                 if (firstword == NULL) {
 656                         free(buf);
 657                         continue;       /* blank line */
 658                 }
 659
 660                 if (strcmp(firstword, "mapping") == 0) {
 661 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 662                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 663
 664                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 665                                 if (currmap->max_matches == currmap->n_matches) {
 666                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 667                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 668                                 }
 669
 670                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 671                         }
 672                         currmap->max_mappings = 0;
 673                         currmap->n_mappings = 0;
 674                         currmap->mapping = NULL;
 675                         currmap->script = NULL;
 676                         {
 677                                 struct mapping_defn_t **where = &defn->mappings;
 678                                 while (*where != NULL) {
 679                                         where = &(*where)->next;
 680                                 }
 681                                 *where = currmap;
 682                                 currmap->next = NULL;
 683                         }
 684                         debug_noise("Added mapping\n");
 685 #endif
 686                         currently_processing = MAPPING;
 687                 } else if (strcmp(firstword, "iface") == 0) {
 688                         static const struct address_family_t *const addr_fams[] = {
 689 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 690                                 &addr_inet,
 691 #endif
 692 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 693                                 &addr_inet6,
 694 #endif
 695                                 NULL
 696                         };
 697
 698                         char *iface_name;
 699                         char *address_family_name;
 700                         char *method_name;
 701                         llist_t *iface_list;
 702
 703                         currif = xzalloc(sizeof(struct interface_defn_t));
 704                         iface_name = next_word(&buf_ptr);
 705                         address_family_name = next_word(&buf_ptr);
 706                         method_name = next_word(&buf_ptr);
 707
 708                         if (buf_ptr == NULL) {
 709                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 710                                 return NULL;
 711                         }
 712
 713                         /* ship any trailing whitespace */
 714                         buf_ptr = skip_whitespace(buf_ptr);
 715
 716                         if (buf_ptr[0] != '\0') {
 717                                 bb_error_msg("too many parameters \"%s\"", buf);
 718                                 return NULL;
 719                         }
 720
 721                         currif->iface = xstrdup(iface_name);
 722
 723                         currif->address_family = get_address_family(addr_fams, address_family_name);
 724                         if (!currif->address_family) {
 725                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 726                                 return NULL;
 727                         }
 728
 729                         currif->method = get_method(currif->address_family, method_name);
 730                         if (!currif->method) {
 731                                 bb_error_msg("unknown method \"%s\"", method_name);
 732                                 return NULL;
 733                         }
 734
 735                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 736                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 737                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 738                                         (tmp->address_family == currif->address_family)) {
 739                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 740                                         return NULL;
 741                                 }
 742                         }
 743                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 744
 745                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 746                         currently_processing = IFACE;
 747                 } else if (strcmp(firstword, "auto") == 0) {
 748                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 749
 750                                 /* Check the interface isnt already listed */
 751                                 if (find_list_string(defn->autointerfaces, firstword)) {
 752                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 753                                 }
 754
 755                                 /* Add the interface to the list */
 756                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 757                                 debug_noise("\nauto %s\n", firstword);
 758                         }
 759                         currently_processing = NONE;
 760                 } else {
 761                         switch (currently_processing) {
 762                         case IFACE:
 763                                 {
 764                                         int i;
 765
 766                                         if (strlen(buf_ptr) == 0) {
 767                                                 bb_error_msg("option with empty value \"%s\"", buf);
 768                                                 return NULL;
 769                                         }
 770
 771                                         if (strcmp(firstword, "up") != 0
 772                                                         && strcmp(firstword, "down") != 0
 773                                                         && strcmp(firstword, "pre-up") != 0
 774                                                         && strcmp(firstword, "post-down") != 0) {
 775                                                 for (i = 0; i < currif->n_options; i++) {
 776                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 777                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 778                                                                 return NULL;
 779                                                         }
 780                                                 }
 781                                         }
 782                                 }
 783                                 if (currif->n_options >= currif->max_options) {
 784                                         struct variable_t *opt;
 785
 786                                         currif->max_options = currif->max_options + 10;
 787                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 788                                         currif->option = opt;
 789                                 }
 790                                 currif->option[currif->n_options].name = xstrdup(firstword);
 791                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 792                                 if (!currif->option[currif->n_options].name) {
 793                                         perror(filename);
 794                                         return NULL;
 795                                 }
 796                                 if (!currif->option[currif->n_options].value) {
 797                                         perror(filename);
 798                                         return NULL;
 799                                 }
 800                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 801                                                 currif->option[currif->n_options].value);
 802                                 currif->n_options++;
 803                                 break;
 804                         case MAPPING:
 805 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 806                                 if (strcmp(firstword, "script") == 0) {
 807                                         if (currmap->script != NULL) {
 808                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 809                                                 return NULL;
 810                                         } else {
 811                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 812                                         }
 813                                 } else if (strcmp(firstword, "map") == 0) {
 814                                         if (currmap->max_mappings == currmap->n_mappings) {
 815                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 816                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 817                                         }
 818                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 819                                         currmap->n_mappings++;
 820                                 } else {
 821                                         bb_error_msg("misplaced option \"%s\"", buf);
 822                                         return NULL;
 823                                 }
 824 #endif
 825                                 break;
 826                         case NONE:
 827                         default:
 828                                 bb_error_msg("misplaced option \"%s\"", buf);
 829                                 return NULL;
 830                         }
 831                 }
 832                 free(buf);
 833         }
 834         if (ferror(f) != 0) {
 835                 bb_perror_msg_and_die("%s", filename);
 836         }
 837         fclose(f);
 838
 839         return defn;
 840 }
 841
 842 static char *setlocalenv(char *format, const char *name, const char *value)
 843 {
 844         char *result;
 845         char *here;
 846         char *there;
 847
 848         result = xasprintf(format, name, value);
 849
 850         for (here = there = result; *there != '=' && *there; there++) {
 851                 if (*there == '-')
 852                         *there = '_';
 853                 if (isalpha(*there))
 854                         *there = toupper(*there);
 855
 856                 if (isalnum(*there) || *there == '_') {
 857                         *here = *there;
 858                         here++;
 859                 }
 860         }
 861         memmove(here, there, strlen(there) + 1);
 862
 863         return result;
 864 }
 865
 866 static void set_environ(struct interface_defn_t *iface, const char *mode)
 867 {
 868         char **environend;
 869         int i;
 870         const int n_env_entries = iface->n_options + 5;
 871         char **ppch;
 872
 873         if (__myenviron != NULL) {
 874                 for (ppch = __myenviron; *ppch; ppch++) {
 875                         free(*ppch);
 876                         *ppch = NULL;
 877                 }
 878                 free(__myenviron);
 879         }
 880         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 881         environend = __myenviron;
 882
 883         for (i = 0; i < iface->n_options; i++) {
 884                 if (strcmp(iface->option[i].name, "up") == 0
 885                                 || strcmp(iface->option[i].name, "down") == 0
 886                                 || strcmp(iface->option[i].name, "pre-up") == 0
 887                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 888                         continue;
 889                 }
 890                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 891         }
 892
 893         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 894         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 895         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 896         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 897         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 898 }
 899
 900 static int doit(char *str)
 901 {
 902         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 903                 puts(str);
 904         }
 905         if (!(option_mask32 & OPT_no_act)) {
 906                 pid_t child;
 907                 int status;
 908
 909                 fflush(NULL);
 910                 switch (child = fork()) {
 911                 case -1:                /* failure */
 912                         return 0;
 913                 case 0:         /* child */
 914                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 915                         exit(127);
 916                 }
 917                 waitpid(child, &status, 0);
 918                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 919                         return 0;
 920                 }
 921         }
 922         return 1;
 923 }
 924
 925 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 926 {
 927         int i;
 928         char *buf;
 929         for (i = 0; i < ifd->n_options; i++) {
 930                 if (strcmp(ifd->option[i].name, opt) == 0) {
 931                         if (!doit(ifd->option[i].value)) {
 932                                 return 0;
 933                         }
 934                 }
 935         }
 936
 937         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 938         if (doit(buf) != 1) {
 939                 return 0;
 940         }
 941         return 1;
 942 }
 943
 944 static int check(char *str) {
 945         return str != NULL;
 946 }
 947
 948 static int iface_up(struct interface_defn_t *iface)
 949 {
 950         if (!iface->method->up(iface,check)) return -1;
 951         set_environ(iface, "start");
 952         if (!execute_all(iface, "pre-up")) return 0;
 953         if (!iface->method->up(iface, doit)) return 0;
 954         if (!execute_all(iface, "up")) return 0;
 955         return 1;
 956 }
 957
 958 static int iface_down(struct interface_defn_t *iface)
 959 {
 960         if (!iface->method->down(iface,check)) return -1;
 961         set_environ(iface, "stop");
 962         if (!execute_all(iface, "down")) return 0;
 963         if (!iface->method->down(iface, doit)) return 0;
 964         if (!execute_all(iface, "post-down")) return 0;
 965         return 1;
 966 }
 967
 968 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 969 static int popen2(FILE **in, FILE **out, char *command, ...)
 970 {
 971         va_list ap;
 972         char *argv[11] = { command };
 973         int argc;
 974         int infd[2], outfd[2];
 975         pid_t pid;
 976
 977         argc = 1;
 978         va_start(ap, command);
 979         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 980                 argc++;
 981         }
 982         argv[argc] = NULL;      /* make sure */
 983         va_end(ap);
 984
 985         if (pipe(infd) != 0) {
 986                 return 0;
 987         }
 988
 989         if (pipe(outfd) != 0) {
 990                 close(infd[0]);
 991                 close(infd[1]);
 992                 return 0;
 993         }
 994
 995         fflush(NULL);
 996         switch (pid = fork()) {
 997         case -1:                        /* failure */
 998                 close(infd[0]);
 999                 close(infd[1]);
1000                 close(outfd[0]);
1001                 close(outfd[1]);
1002                 return 0;
1003         case 0:                 /* child */
1004                 dup2(infd[0], 0);
1005                 dup2(outfd[1], 1);
1006                 close(infd[0]);
1007                 close(infd[1]);
1008                 close(outfd[0]);
1009                 close(outfd[1]);
1010                 execvp(command, argv);
1011                 exit(127);
1012         default:                        /* parent */
1013                 *in = fdopen(infd[1], "w");
1014                 *out = fdopen(outfd[0], "r");
1015                 close(infd[0]);
1016                 close(outfd[1]);
1017                 return pid;
1018         }
1019         /* unreached */
1020 }
1021
1022 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1023 {
1024         FILE *in, *out;
1025         int i, status;
1026         pid_t pid;
1027
1028         char *logical = xstrdup(physical);
1029
1030         /* Run the mapping script. */
1031         pid = popen2(&in, &out, map->script, physical, NULL);
1032
1033         /* popen2() returns 0 on failure. */
1034         if (pid == 0)
1035                 return logical;
1036
1037         /* Write mappings to stdin of mapping script. */
1038         for (i = 0; i < map->n_mappings; i++) {
1039                 fprintf(in, "%s\n", map->mapping[i]);
1040         }
1041         fclose(in);
1042         waitpid(pid, &status, 0);
1043
1044         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1045                 /* If the mapping script exited successfully, try to
1046                  * grab a line of output and use that as the name of the
1047                  * logical interface. */
1048                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1049
1050                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1051                         /* If we are able to read a line of output from the script,
1052                          * remove any trailing whitespace and use this value
1053                          * as the name of the logical interface. */
1054                         char *pch = new_logical + strlen(new_logical) - 1;
1055
1056                         while (pch >= new_logical && isspace(*pch))
1057                                 *(pch--) = '\0';
1058
1059                         free(logical);
1060                         logical = new_logical;
1061                 } else {
1062                         /* If we are UNABLE to read a line of output, discard our
1063                          * freshly allocated memory. */
1064                         free(new_logical);
1065                 }
1066         }
1067
1068         fclose(out);
1069
1070         return logical;
1071 }
1072 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1073
1074 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1075 {
1076         unsigned short iface_len = strlen(iface);
1077         llist_t *search = state_list;
1078
1079         while (search) {
1080                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1081                                 (search->data[iface_len] == '=')) {
1082                         return search;
1083                 }
1084                 search = search->link;
1085         }
1086         return NULL;
1087 }
1088
1089 int ifupdown_main(int argc, char **argv)
1090 {
1091         static const char statefile[] = "/var/run/ifstate";
1092
1093         int (*cmds)(struct interface_defn_t *) = NULL;
1094         struct interfaces_file_t *defn;
1095         llist_t *state_list = NULL;
1096         llist_t *target_list = NULL;
1097         const char *interfaces = "/etc/network/interfaces";
1098         int any_failures = 0;
1099
1100         if (applet_name[2] == 'u') {
1101                 /* ifup command */
1102                 cmds = iface_up;
1103         } else {
1104                 /* ifdown command */
1105                 cmds = iface_down;
1106         }
1107
1108         getopt32(argc, argv, OPTION_STR, &interfaces);
1109         if (argc - optind > 0) {
1110                 if (DO_ALL) bb_show_usage();
1111         } else
1112                 if (!DO_ALL) bb_show_usage();
1113
1114         debug_noise("reading %s file:\n", interfaces);
1115         defn = read_interfaces(interfaces);
1116         debug_noise("\ndone reading %s\n\n", interfaces);
1117
1118         if (!defn) {
1119                 exit(EXIT_FAILURE);
1120         }
1121
1122         startup_PATH = getenv("PATH");
1123         if (!startup_PATH) startup_PATH = "";
1124
1125         /* Create a list of interfaces to work on */
1126         if (DO_ALL) {
1127                 if (cmds == iface_up) {
1128                         target_list = defn->autointerfaces;
1129                 } else {
1130                         /* iface_down */
1131                         const llist_t *list = state_list;
1132                         while (list) {
1133                                 llist_add_to_end(&target_list, xstrdup(list->data));
1134                                 list = list->link;
1135                         }
1136                         target_list = defn->autointerfaces;
1137                 }
1138         } else {
1139                 llist_add_to_end(&target_list, argv[optind]);
1140         }
1141
1142
1143         /* Update the interfaces */
1144         while (target_list) {
1145                 llist_t *iface_list;
1146                 struct interface_defn_t *currif;
1147                 char *iface;
1148                 char *liface;
1149                 char *pch;
1150                 int okay = 0;
1151                 int cmds_ret;
1152
1153                 iface = xstrdup(target_list->data);
1154                 target_list = target_list->link;
1155
1156                 pch = strchr(iface, '=');
1157                 if (pch) {
1158                         *pch = '\0';
1159                         liface = xstrdup(pch + 1);
1160                 } else {
1161                         liface = xstrdup(iface);
1162                 }
1163
1164                 if (!FORCE) {
1165                         const llist_t *iface_state = find_iface_state(state_list, iface);
1166
1167                         if (cmds == iface_up) {
1168                                 /* ifup */
1169                                 if (iface_state) {
1170                                         bb_error_msg("interface %s already configured", iface);
1171                                         continue;
1172                                 }
1173                         } else {
1174                                 /* ifdown */
1175                                 if (iface_state) {
1176                                         bb_error_msg("interface %s not configured", iface);
1177                                         continue;
1178                                 }
1179                         }
1180                 }
1181
1182 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1183                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1184                         struct mapping_defn_t *currmap;
1185
1186                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1187                                 int i;
1188                                 for (i = 0; i < currmap->n_matches; i++) {
1189                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1190                                                 continue;
1191                                         if (VERBOSE) {
1192                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1193                                         }
1194                                         liface = run_mapping(iface, currmap);
1195                                         break;
1196                                 }
1197                         }
1198                 }
1199 #endif
1200
1201
1202                 iface_list = defn->ifaces;
1203                 while (iface_list) {
1204                         currif = (struct interface_defn_t *) iface_list->data;
1205                         if (strcmp(liface, currif->iface) == 0) {
1206                                 char *oldiface = currif->iface;
1207
1208                                 okay = 1;
1209                                 currif->iface = iface;
1210
1211                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1212
1213                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1214                                 cmds_ret = cmds(currif);
1215                                 if (cmds_ret == -1) {
1216                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1217                                                         liface, currif->address_family->name);
1218                                         any_failures += 1;
1219                                 } else if (cmds_ret == 0) {
1220                                         any_failures += 1;
1221                                 }
1222
1223                                 currif->iface = oldiface;
1224                         }
1225                         iface_list = iface_list->link;
1226                 }
1227                 if (VERBOSE) {
1228                         puts("");
1229                 }
1230
1231                 if (!okay && !FORCE) {
1232                         bb_error_msg("ignoring unknown interface %s", liface);
1233                         any_failures += 1;
1234                 } else {
1235                         llist_t *iface_state = find_iface_state(state_list, iface);
1236
1237                         if (cmds == iface_up) {
1238                                 char *newiface = xasprintf("%s=%s", iface, liface);
1239                                 if (iface_state == NULL) {
1240                                         llist_add_to_end(&state_list, newiface);
1241                                 } else {
1242                                         free(iface_state->data);
1243                                         iface_state->data = newiface;
1244                                 }
1245                         } else {
1246                                 /* Remove an interface from the linked list */
1247                                 free(llist_pop(&iface_state));
1248                         }
1249                 }
1250         }
1251
1252         /* Actually write the new state */
1253         if (!NO_ACT) {
1254                 FILE *state_fp = NULL;
1255
1256                 state_fp = xfopen(statefile, "w");
1257                 while (state_list) {
1258                         if (state_list->data) {
1259                                 fputs(state_list->data, state_fp);
1260                                 fputc('\n', state_fp);
1261                         }
1262                         state_list = state_list->link;
1263                 }
1264                 fclose(state_fp);
1265         }
1266
1267         if (any_failures)
1268                 return 1;
1269         return 0;
1270 }