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 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
  29 #define MAX_INTERFACE_LENGTH 10
  30 #endif
  31
  32 #define debug_noise(args...) /*fprintf(stderr, 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 **my_environ;
 107
 108 static char *startup_PATH;
 109
 110 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 111
 112 #if ENABLE_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         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 188         int okay[MAX_OPT_DEPTH] = { 1 };
 189         int opt_depth = 1;
 190         char *result = NULL;
 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] = result ? strlen(result) : 0;
 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 #if ENABLE_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                 /* parse error? */
 295                 return 0;
 296         }
 297         /* out == "": parsed ok but not all needed variables known, skip */
 298         ret = out[0] ? (*exec)(out) : 1;
 299
 300         free(out);
 301         if (ret != 1) {
 302                 return 0;
 303         }
 304         return 1;
 305 }
 306 #endif
 307
 308 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 309 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 310 {
 311 #if ENABLE_FEATURE_IFUPDOWN_IP
 312         int result;
 313         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 314         result += execute("ip link set %iface% up", ifd, exec);
 315         return ((result == 2) ? 2 : 0);
 316 #else
 317         return execute("ifconfig %iface% add ::1", ifd, exec);
 318 #endif
 319 }
 320
 321 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 322 {
 323 #if ENABLE_FEATURE_IFUPDOWN_IP
 324         return execute("ip link set %iface% down", ifd, exec);
 325 #else
 326         return execute("ifconfig %iface% del ::1", ifd, exec);
 327 #endif
 328 }
 329
 330 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 331 {
 332         int result;
 333 #if ENABLE_FEATURE_IFUPDOWN_IP
 334         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 335         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 336         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
 337         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 338 #else
 339         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 340         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 341         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
 342 #endif
 343         return ((result == 3) ? 3 : 0);
 344 }
 345
 346 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 347 {
 348 #if ENABLE_FEATURE_IFUPDOWN_IP
 349         return execute("ip link set %iface% down", ifd, exec);
 350 #else
 351         return execute("ifconfig %iface% down", ifd, exec);
 352 #endif
 353 }
 354
 355 #if ENABLE_FEATURE_IFUPDOWN_IP
 356 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 357 {
 358         int result;
 359         result = execute("ip tunnel add %iface% mode sit remote "
 360                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 361         result += execute("ip link set %iface% up", ifd, exec);
 362         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 363         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 364         return ((result == 4) ? 4 : 0);
 365 }
 366
 367 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 368 {
 369         return execute("ip tunnel del %iface%", ifd, exec);
 370 }
 371 #endif
 372
 373 static const struct method_t methods6[] = {
 374 #if ENABLE_FEATURE_IFUPDOWN_IP
 375         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 376 #endif
 377         { "static", static_up6, static_down6, },
 378         { "loopback", loopback_up6, loopback_down6, },
 379 };
 380
 381 static const struct address_family_t addr_inet6 = {
 382         "inet6",
 383         sizeof(methods6) / sizeof(struct method_t),
 384         methods6
 385 };
 386 #endif /* FEATURE_IFUPDOWN_IPV6 */
 387
 388 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 389 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 390 {
 391 #if ENABLE_FEATURE_IFUPDOWN_IP
 392         int result;
 393         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 394         result += execute("ip link set %iface% up", ifd, exec);
 395         return ((result == 2) ? 2 : 0);
 396 #else
 397         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 398 #endif
 399 }
 400
 401 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 402 {
 403 #if ENABLE_FEATURE_IFUPDOWN_IP
 404         int result;
 405         result = execute("ip addr flush dev %iface%", ifd, exec);
 406         result += execute("ip link set %iface% down", ifd, exec);
 407         return ((result == 2) ? 2 : 0);
 408 #else
 409         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 410 #endif
 411 }
 412
 413 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 414 {
 415         int result;
 416 #if ENABLE_FEATURE_IFUPDOWN_IP
 417         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 418                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 419         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 420         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
 421         return ((result == 3) ? 3 : 0);
 422 #else
 423         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 424          * which then of course fails. Thus we run two separate ifconfig */
 425         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 426                                 ifd, exec);
 427         result += execute("ifconfig %iface% %address% netmask %netmask%"
 428                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 429                                 ifd, exec);
 430         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
 431         return ((result == 3) ? 3 : 0);
 432 #endif
 433 }
 434
 435 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 436 {
 437         int result;
 438 #if ENABLE_FEATURE_IFUPDOWN_IP
 439         result = execute("ip addr flush dev %iface%", ifd, exec);
 440         result += execute("ip link set %iface% down", ifd, exec);
 441 #else
 442         result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec);
 443         result += execute("ifconfig %iface% down", ifd, exec);
 444 #endif
 445         return ((result == 2) ? 2 : 0);
 446 }
 447
 448 #if !ENABLE_APP_UDHCPC
 449 struct dhcp_client_t
 450 {
 451         const char *name;
 452         const char *startcmd;
 453         const char *stopcmd;
 454 };
 455
 456 static const struct dhcp_client_t ext_dhcp_clients[] = {
 457         { "udhcpc",
 458                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 459                 "kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 460         },
 461         { "pump",
 462                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 463                 "pump -i %iface% -k",
 464         },
 465         { "dhclient",
 466                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 467                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 468         },
 469         { "dhcpcd",
 470                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
 471                 "dhcpcd -k %iface%",
 472         },
 473 };
 474 #endif
 475
 476 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 477 {
 478 #if ENABLE_APP_UDHCPC
 479         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 480                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 481                         ifd, exec);
 482 #else
 483         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 484         for (i = 0; i < nclients; i++) {
 485                 if (exists_execable(ext_dhcp_clients[i].name))
 486                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 487         }
 488         bb_error_msg("no dhcp clients found");
 489         return 0;
 490 #endif
 491 }
 492
 493 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 494 {
 495 #if ENABLE_APP_UDHCPC
 496         return execute("kill -TERM "
 497                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 498 #else
 499         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 500         for (i = 0; i < nclients; i++) {
 501                 if (exists_execable(ext_dhcp_clients[i].name))
 502                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 503         }
 504         bb_error_msg("no dhcp clients found, using static interface shutdown");
 505         return static_down(ifd, exec);
 506 #endif
 507 }
 508
 509 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 510 {
 511         return 1;
 512 }
 513
 514 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 515 {
 516         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 517                         "[[ --server %server%]][[ --hwaddr %hwaddr%]] "
 518                         "--returniffail --serverbcast", ifd, exec);
 519 }
 520
 521 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 522 {
 523         return execute("pon[[ %provider%]]", ifd, exec);
 524 }
 525
 526 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 527 {
 528         return execute("poff[[ %provider%]]", ifd, exec);
 529 }
 530
 531 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 532 {
 533         return execute("start-stop-daemon --start -x wvdial "
 534                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 535 }
 536
 537 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 538 {
 539         return execute("start-stop-daemon --stop -x wvdial "
 540                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 541 }
 542
 543 static const struct method_t methods[] = {
 544         { "manual", manual_up_down, manual_up_down, },
 545         { "wvdial", wvdial_up, wvdial_down, },
 546         { "ppp", ppp_up, ppp_down, },
 547         { "static", static_up, static_down, },
 548         { "bootp", bootp_up, static_down, },
 549         { "dhcp", dhcp_up, dhcp_down, },
 550         { "loopback", loopback_up, loopback_down, },
 551 };
 552
 553 static const struct address_family_t addr_inet = {
 554         "inet",
 555         sizeof(methods) / sizeof(struct method_t),
 556         methods
 557 };
 558
 559 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 560
 561 static char *next_word(char **buf)
 562 {
 563         unsigned short length;
 564         char *word;
 565
 566         if (!buf || !*buf || !**buf) {
 567                 return NULL;
 568         }
 569
 570         /* Skip over leading whitespace */
 571         word = skip_whitespace(*buf);
 572
 573         /* Skip over comments */
 574         if (*word == '#') {
 575                 return NULL;
 576         }
 577
 578         /* Find the length of this word */
 579         length = strcspn(word, " \t\n");
 580         if (length == 0) {
 581                 return NULL;
 582         }
 583         *buf = word + length;
 584         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 585         if (**buf) {
 586                 **buf = '\0';
 587                 (*buf)++;
 588         }
 589
 590         return word;
 591 }
 592
 593 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 594 {
 595         int i;
 596
 597         if (!name)
 598                 return NULL;
 599
 600         for (i = 0; af[i]; i++) {
 601                 if (strcmp(af[i]->name, name) == 0) {
 602                         return af[i];
 603                 }
 604         }
 605         return NULL;
 606 }
 607
 608 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 609 {
 610         int i;
 611
 612         if (!name)
 613                 return NULL;
 614
 615         for (i = 0; i < af->n_methods; i++) {
 616                 if (strcmp(af->method[i].name, name) == 0) {
 617                         return &af->method[i];
 618                 }
 619         }
 620         return NULL;
 621 }
 622
 623 static const llist_t *find_list_string(const llist_t *list, const char *string)
 624 {
 625         if (string == NULL)
 626                 return NULL;
 627
 628         while (list) {
 629                 if (strcmp(list->data, string) == 0) {
 630                         return list;
 631                 }
 632                 list = list->link;
 633         }
 634         return NULL;
 635 }
 636
 637 static struct interfaces_file_t *read_interfaces(const char *filename)
 638 {
 639 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 640         struct mapping_defn_t *currmap = NULL;
 641 #endif
 642         struct interface_defn_t *currif = NULL;
 643         struct interfaces_file_t *defn;
 644         FILE *f;
 645         char *firstword;
 646         char *buf;
 647
 648         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 649
 650         defn = xzalloc(sizeof(struct interfaces_file_t));
 651
 652         f = xfopen(filename, "r");
 653
 654         while ((buf = xmalloc_getline(f)) != NULL) {
 655                 char *buf_ptr = buf;
 656
 657                 firstword = next_word(&buf_ptr);
 658                 if (firstword == NULL) {
 659                         free(buf);
 660                         continue;       /* blank line */
 661                 }
 662
 663                 if (strcmp(firstword, "mapping") == 0) {
 664 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 665                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 666
 667                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 668                                 if (currmap->max_matches == currmap->n_matches) {
 669                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 670                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 671                                 }
 672
 673                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 674                         }
 675                         currmap->max_mappings = 0;
 676                         currmap->n_mappings = 0;
 677                         currmap->mapping = NULL;
 678                         currmap->script = NULL;
 679                         {
 680                                 struct mapping_defn_t **where = &defn->mappings;
 681                                 while (*where != NULL) {
 682                                         where = &(*where)->next;
 683                                 }
 684                                 *where = currmap;
 685                                 currmap->next = NULL;
 686                         }
 687                         debug_noise("Added mapping\n");
 688 #endif
 689                         currently_processing = MAPPING;
 690                 } else if (strcmp(firstword, "iface") == 0) {
 691                         static const struct address_family_t *const addr_fams[] = {
 692 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 693                                 &addr_inet,
 694 #endif
 695 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 696                                 &addr_inet6,
 697 #endif
 698                                 NULL
 699                         };
 700
 701                         char *iface_name;
 702                         char *address_family_name;
 703                         char *method_name;
 704                         llist_t *iface_list;
 705
 706                         currif = xzalloc(sizeof(struct interface_defn_t));
 707                         iface_name = next_word(&buf_ptr);
 708                         address_family_name = next_word(&buf_ptr);
 709                         method_name = next_word(&buf_ptr);
 710
 711                         if (buf_ptr == NULL) {
 712                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 713                                 return NULL;
 714                         }
 715
 716                         /* ship any trailing whitespace */
 717                         buf_ptr = skip_whitespace(buf_ptr);
 718
 719                         if (buf_ptr[0] != '\0') {
 720                                 bb_error_msg("too many parameters \"%s\"", buf);
 721                                 return NULL;
 722                         }
 723
 724                         currif->iface = xstrdup(iface_name);
 725
 726                         currif->address_family = get_address_family(addr_fams, address_family_name);
 727                         if (!currif->address_family) {
 728                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 729                                 return NULL;
 730                         }
 731
 732                         currif->method = get_method(currif->address_family, method_name);
 733                         if (!currif->method) {
 734                                 bb_error_msg("unknown method \"%s\"", method_name);
 735                                 return NULL;
 736                         }
 737
 738                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 739                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 740                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 741                                         (tmp->address_family == currif->address_family)) {
 742                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 743                                         return NULL;
 744                                 }
 745                         }
 746                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 747
 748                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 749                         currently_processing = IFACE;
 750                 } else if (strcmp(firstword, "auto") == 0) {
 751                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 752
 753                                 /* Check the interface isnt already listed */
 754                                 if (find_list_string(defn->autointerfaces, firstword)) {
 755                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 756                                 }
 757
 758                                 /* Add the interface to the list */
 759                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 760                                 debug_noise("\nauto %s\n", firstword);
 761                         }
 762                         currently_processing = NONE;
 763                 } else {
 764                         switch (currently_processing) {
 765                         case IFACE:
 766                                 {
 767                                         int i;
 768
 769                                         if (strlen(buf_ptr) == 0) {
 770                                                 bb_error_msg("option with empty value \"%s\"", buf);
 771                                                 return NULL;
 772                                         }
 773
 774                                         if (strcmp(firstword, "up") != 0
 775                                                         && strcmp(firstword, "down") != 0
 776                                                         && strcmp(firstword, "pre-up") != 0
 777                                                         && strcmp(firstword, "post-down") != 0) {
 778                                                 for (i = 0; i < currif->n_options; i++) {
 779                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 780                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 781                                                                 return NULL;
 782                                                         }
 783                                                 }
 784                                         }
 785                                 }
 786                                 if (currif->n_options >= currif->max_options) {
 787                                         struct variable_t *opt;
 788
 789                                         currif->max_options = currif->max_options + 10;
 790                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 791                                         currif->option = opt;
 792                                 }
 793                                 currif->option[currif->n_options].name = xstrdup(firstword);
 794                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 795                                 if (!currif->option[currif->n_options].name) {
 796                                         perror(filename);
 797                                         return NULL;
 798                                 }
 799                                 if (!currif->option[currif->n_options].value) {
 800                                         perror(filename);
 801                                         return NULL;
 802                                 }
 803                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 804                                                 currif->option[currif->n_options].value);
 805                                 currif->n_options++;
 806                                 break;
 807                         case MAPPING:
 808 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 809                                 if (strcmp(firstword, "script") == 0) {
 810                                         if (currmap->script != NULL) {
 811                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 812                                                 return NULL;
 813                                         } else {
 814                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 815                                         }
 816                                 } else if (strcmp(firstword, "map") == 0) {
 817                                         if (currmap->max_mappings == currmap->n_mappings) {
 818                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 819                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 820                                         }
 821                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 822                                         currmap->n_mappings++;
 823                                 } else {
 824                                         bb_error_msg("misplaced option \"%s\"", buf);
 825                                         return NULL;
 826                                 }
 827 #endif
 828                                 break;
 829                         case NONE:
 830                         default:
 831                                 bb_error_msg("misplaced option \"%s\"", buf);
 832                                 return NULL;
 833                         }
 834                 }
 835                 free(buf);
 836         }
 837         if (ferror(f) != 0) {
 838                 bb_perror_msg_and_die("%s", filename);
 839         }
 840         fclose(f);
 841
 842         return defn;
 843 }
 844
 845 static char *setlocalenv(char *format, const char *name, const char *value)
 846 {
 847         char *result;
 848         char *here;
 849         char *there;
 850
 851         result = xasprintf(format, name, value);
 852
 853         for (here = there = result; *there != '=' && *there; there++) {
 854                 if (*there == '-')
 855                         *there = '_';
 856                 if (isalpha(*there))
 857                         *there = toupper(*there);
 858
 859                 if (isalnum(*there) || *there == '_') {
 860                         *here = *there;
 861                         here++;
 862                 }
 863         }
 864         memmove(here, there, strlen(there) + 1);
 865
 866         return result;
 867 }
 868
 869 static void set_environ(struct interface_defn_t *iface, const char *mode)
 870 {
 871         char **environend;
 872         int i;
 873         const int n_env_entries = iface->n_options + 5;
 874         char **ppch;
 875
 876         if (my_environ != NULL) {
 877                 for (ppch = my_environ; *ppch; ppch++) {
 878                         free(*ppch);
 879                         *ppch = NULL;
 880                 }
 881                 free(my_environ);
 882         }
 883         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 884         environend = my_environ;
 885
 886         for (i = 0; i < iface->n_options; i++) {
 887                 if (strcmp(iface->option[i].name, "up") == 0
 888                                 || strcmp(iface->option[i].name, "down") == 0
 889                                 || strcmp(iface->option[i].name, "pre-up") == 0
 890                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 891                         continue;
 892                 }
 893                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 894         }
 895
 896         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 897         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 898         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 899         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 900         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 901 }
 902
 903 static int doit(char *str)
 904 {
 905         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 906                 puts(str);
 907         }
 908         if (!(option_mask32 & OPT_no_act)) {
 909                 pid_t child;
 910                 int status;
 911
 912                 fflush(NULL);
 913                 child = fork();
 914                 switch (child) {
 915                 case -1: /* failure */
 916                         return 0;
 917                 case 0: /* child */
 918                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 919                         exit(127);
 920                 }
 921                 waitpid(child, &status, 0);
 922                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 923                         return 0;
 924                 }
 925         }
 926         return 1;
 927 }
 928
 929 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 930 {
 931         int i;
 932         char *buf;
 933         for (i = 0; i < ifd->n_options; i++) {
 934                 if (strcmp(ifd->option[i].name, opt) == 0) {
 935                         if (!doit(ifd->option[i].value)) {
 936                                 return 0;
 937                         }
 938                 }
 939         }
 940
 941         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 942         /* heh, we don't bother free'ing it */
 943         return doit(buf);
 944 }
 945
 946 static int check(char *str)
 947 {
 948         return str != NULL;
 949 }
 950
 951 static int iface_up(struct interface_defn_t *iface)
 952 {
 953         if (!iface->method->up(iface, check)) return -1;
 954         set_environ(iface, "start");
 955         if (!execute_all(iface, "pre-up")) return 0;
 956         if (!iface->method->up(iface, doit)) return 0;
 957         if (!execute_all(iface, "up")) return 0;
 958         return 1;
 959 }
 960
 961 static int iface_down(struct interface_defn_t *iface)
 962 {
 963         if (!iface->method->down(iface,check)) return -1;
 964         set_environ(iface, "stop");
 965         if (!execute_all(iface, "down")) return 0;
 966         if (!iface->method->down(iface, doit)) return 0;
 967         if (!execute_all(iface, "post-down")) return 0;
 968         return 1;
 969 }
 970
 971 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 972 static int popen2(FILE **in, FILE **out, char *command, ...)
 973 {
 974         va_list ap;
 975         char *argv[11] = { command };
 976         int argc;
 977         int infd[2], outfd[2];
 978         pid_t pid;
 979
 980         argc = 1;
 981         va_start(ap, command);
 982         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 983                 argc++;
 984         }
 985         argv[argc] = NULL;      /* make sure */
 986         va_end(ap);
 987
 988         if (pipe(infd) != 0) {
 989                 return 0;
 990         }
 991
 992         if (pipe(outfd) != 0) {
 993                 close(infd[0]);
 994                 close(infd[1]);
 995                 return 0;
 996         }
 997
 998         fflush(NULL);
 999         switch (pid = fork()) {
1000         case -1:                        /* failure */
1001                 close(infd[0]);
1002                 close(infd[1]);
1003                 close(outfd[0]);
1004                 close(outfd[1]);
1005                 return 0;
1006         case 0:                 /* child */
1007                 dup2(infd[0], 0);
1008                 dup2(outfd[1], 1);
1009                 close(infd[0]);
1010                 close(infd[1]);
1011                 close(outfd[0]);
1012                 close(outfd[1]);
1013                 execvp(command, argv);
1014                 exit(127);
1015         default:                        /* parent */
1016                 *in = fdopen(infd[1], "w");
1017                 *out = fdopen(outfd[0], "r");
1018                 close(infd[0]);
1019                 close(outfd[1]);
1020                 return pid;
1021         }
1022         /* unreached */
1023 }
1024
1025 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1026 {
1027         FILE *in, *out;
1028         int i, status;
1029         pid_t pid;
1030
1031         char *logical = xstrdup(physical);
1032
1033         /* Run the mapping script. */
1034         pid = popen2(&in, &out, map->script, physical, NULL);
1035
1036         /* popen2() returns 0 on failure. */
1037         if (pid == 0)
1038                 return logical;
1039
1040         /* Write mappings to stdin of mapping script. */
1041         for (i = 0; i < map->n_mappings; i++) {
1042                 fprintf(in, "%s\n", map->mapping[i]);
1043         }
1044         fclose(in);
1045         waitpid(pid, &status, 0);
1046
1047         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1048                 /* If the mapping script exited successfully, try to
1049                  * grab a line of output and use that as the name of the
1050                  * logical interface. */
1051                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1052
1053                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1054                         /* If we are able to read a line of output from the script,
1055                          * remove any trailing whitespace and use this value
1056                          * as the name of the logical interface. */
1057                         char *pch = new_logical + strlen(new_logical) - 1;
1058
1059                         while (pch >= new_logical && isspace(*pch))
1060                                 *(pch--) = '\0';
1061
1062                         free(logical);
1063                         logical = new_logical;
1064                 } else {
1065                         /* If we are UNABLE to read a line of output, discard our
1066                          * freshly allocated memory. */
1067                         free(new_logical);
1068                 }
1069         }
1070
1071         fclose(out);
1072
1073         return logical;
1074 }
1075 #endif /* FEATURE_IFUPDOWN_MAPPING */
1076
1077 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1078 {
1079         unsigned short iface_len = strlen(iface);
1080         llist_t *search = state_list;
1081
1082         while (search) {
1083                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1084                                 (search->data[iface_len] == '=')) {
1085                         return search;
1086                 }
1087                 search = search->link;
1088         }
1089         return NULL;
1090 }
1091
1092 int ifupdown_main(int argc, char **argv)
1093 {
1094         int (*cmds)(struct interface_defn_t *) = NULL;
1095         struct interfaces_file_t *defn;
1096         llist_t *state_list = NULL;
1097         llist_t *target_list = NULL;
1098         const char *interfaces = "/etc/network/interfaces";
1099         int any_failures = 0;
1100
1101         cmds = iface_down;
1102         if (applet_name[2] == 'u') {
1103                 /* ifup command */
1104                 cmds = iface_up;
1105         }
1106
1107         getopt32(argc, argv, OPTION_STR, &interfaces);
1108         if (argc - optind > 0) {
1109                 if (DO_ALL) bb_show_usage();
1110         } else {
1111                 if (!DO_ALL) bb_show_usage();
1112         }
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                 return 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 #if ENABLE_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                 iface_list = defn->ifaces;
1202                 while (iface_list) {
1203                         currif = (struct interface_defn_t *) iface_list->data;
1204                         if (strcmp(liface, currif->iface) == 0) {
1205                                 char *oldiface = currif->iface;
1206
1207                                 okay = 1;
1208                                 currif->iface = iface;
1209
1210                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1211
1212                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1213                                 cmds_ret = cmds(currif);
1214                                 if (cmds_ret == -1) {
1215                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1216                                                         liface, currif->address_family->name);
1217                                         any_failures = 1;
1218                                 } else if (cmds_ret == 0) {
1219                                         any_failures = 1;
1220                                 }
1221
1222                                 currif->iface = oldiface;
1223                         }
1224                         iface_list = iface_list->link;
1225                 }
1226                 if (VERBOSE) {
1227                         puts("");
1228                 }
1229
1230                 if (!okay && !FORCE) {
1231                         bb_error_msg("ignoring unknown interface %s", liface);
1232                         any_failures = 1;
1233                 } else {
1234                         llist_t *iface_state = find_iface_state(state_list, iface);
1235
1236                         if (cmds == iface_up) {
1237                                 char *newiface = xasprintf("%s=%s", iface, liface);
1238                                 if (iface_state == NULL) {
1239                                         llist_add_to_end(&state_list, newiface);
1240                                 } else {
1241                                         free(iface_state->data);
1242                                         iface_state->data = newiface;
1243                                 }
1244                         } else {
1245                                 /* Remove an interface from the linked list */
1246                                 free(llist_pop(&iface_state));
1247                         }
1248                 }
1249         }
1250
1251         /* Actually write the new state */
1252         if (!NO_ACT) {
1253                 FILE *state_fp;
1254
1255                 state_fp = xfopen("/var/run/ifstate", "w");
1256                 while (state_list) {
1257                         if (state_list->data) {
1258                                 fputs(state_list->data, state_fp);
1259                                 fputc('\n', state_fp);
1260                         }
1261                         state_list = state_list->link;
1262                 }
1263                 fclose(state_fp);
1264         }
1265
1266         return any_failures;
1267 }