networking/ifupdown.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *  ifupdown for busybox
   4  *  Copyright (c) 2002 Glenn McGrath <bug1@iinet.net.au>
   5  *  Copyright (c) 2003-2004 Erik Andersen <andersen@codepoet.org>
   6  *
   7  *  Based on ifupdown v 0.6.4 by Anthony Towns
   8  *  Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
   9  *
  10  *  Changes to upstream version
  11  *  Remove checks for kernel version, assume kernel version 2.2.0 or better.
  12  *  Lines in the interfaces file cannot wrap.
  13  *  To adhere to the FHS, the default state file is /var/run/ifstate.
  14  *
  15  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  16  */
  17
  18 #include "busybox.h"
  19 #include <sys/utsname.h>
  20 #include <fnmatch.h>
  21 #include <getopt.h>
  22
  23 #define MAX_OPT_DEPTH 10
  24 #define EUNBALBRACK 10001
  25 #define EUNDEFVAR   10002
  26 #define EUNBALPER   10000
  27
  28 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
  29 #define MAX_INTERFACE_LENGTH 10
  30 #endif
  31
  32 #define debug_noise(fmt, args...)
  33
  34 /* Forward declaration */
  35 struct interface_defn_t;
  36
  37 typedef int (execfn)(char *command);
  38
  39 struct method_t
  40 {
  41         char *name;
  42         int (*up)(struct interface_defn_t *ifd, execfn *e);
  43         int (*down)(struct interface_defn_t *ifd, execfn *e);
  44 };
  45
  46 struct address_family_t
  47 {
  48         char *name;
  49         int n_methods;
  50         const struct method_t *method;
  51 };
  52
  53 struct mapping_defn_t
  54 {
  55         struct mapping_defn_t *next;
  56
  57         int max_matches;
  58         int n_matches;
  59         char **match;
  60
  61         char *script;
  62
  63         int max_mappings;
  64         int n_mappings;
  65         char **mapping;
  66 };
  67
  68 struct variable_t
  69 {
  70         char *name;
  71         char *value;
  72 };
  73
  74 struct interface_defn_t
  75 {
  76         const struct address_family_t *address_family;
  77         const struct method_t *method;
  78
  79         char *iface;
  80         int max_options;
  81         int n_options;
  82         struct variable_t *option;
  83 };
  84
  85 struct interfaces_file_t
  86 {
  87         llist_t *autointerfaces;
  88         llist_t *ifaces;
  89         struct mapping_defn_t *mappings;
  90 };
  91
  92 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  93 enum {
  94         OPT_do_all = 0x1,
  95         OPT_no_act = 0x2,
  96         OPT_verbose = 0x4,
  97         OPT_force = 0x8,
  98         OPT_no_mappings = 0x10,
  99 };
 100 #define DO_ALL (option_mask32 & OPT_do_all)
 101 #define NO_ACT (option_mask32 & OPT_no_act)
 102 #define VERBOSE (option_mask32 & OPT_verbose)
 103 #define FORCE (option_mask32 & OPT_force)
 104 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 105
 106 static char **__myenviron;
 107
 108 static char *startup_PATH;
 109
 110 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 111
 112 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 113
 114 static unsigned int count_bits(unsigned int a)
 115 {
 116         unsigned int result;
 117         result = (a & 0x55) + ((a >> 1) & 0x55);
 118         result = (result & 0x33) + ((result >> 2) & 0x33);
 119         return ((result & 0x0F) + ((result >> 4) & 0x0F));
 120 }
 121
 122 static int count_netmask_bits(char *dotted_quad)
 123 {
 124         unsigned int result, a, b, c, d;
 125         /* Found a netmask...  Check if it is dotted quad */
 126         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 127                 return -1;
 128         result = count_bits(a);
 129         result += count_bits(b);
 130         result += count_bits(c);
 131         result += count_bits(d);
 132         return (int)result;
 133 }
 134 #endif
 135
 136 static void addstr(char **buf, size_t *len, size_t *pos, const char *str, size_t str_length)
 137 {
 138         if (*pos + str_length >= *len) {
 139                 char *newbuf;
 140
 141                 newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
 142                 *buf = newbuf;
 143                 *len = *len * 2 + str_length + 1;
 144         }
 145
 146         while (str_length-- >= 1) {
 147                 (*buf)[(*pos)++] = *str;
 148                 str++;
 149         }
 150         (*buf)[*pos] = '\0';
 151 }
 152
 153 static int strncmpz(const char *l, const char *r, size_t llen)
 154 {
 155         int i = strncmp(l, r, llen);
 156
 157         if (i == 0) {
 158                 return -r[llen];
 159         } else {
 160                 return i;
 161         }
 162 }
 163
 164 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 165 {
 166         int i;
 167
 168         if (strncmpz(id, "iface", idlen) == 0) {
 169                 char *result;
 170                 static char label_buf[20];
 171                 strncpy(label_buf, ifd->iface, 19);
 172                 label_buf[19]=0;
 173                 result = strchr(label_buf, ':');
 174                 if (result) {
 175                         *result=0;
 176                 }
 177                 return label_buf;
 178         } else if (strncmpz(id, "label", idlen) == 0) {
 179                 return ifd->iface;
 180         } else {
 181                 for (i = 0; i < ifd->n_options; i++) {
 182                         if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 183                                 return ifd->option[i].value;
 184                         }
 185                 }
 186         }
 187
 188         return NULL;
 189 }
 190
 191 static char *parse(const char *command, struct interface_defn_t *ifd)
 192 {
 193
 194         char *result = NULL;
 195         size_t pos = 0, len = 0;
 196         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 197         int okay[MAX_OPT_DEPTH] = { 1 };
 198         int opt_depth = 1;
 199
 200         while (*command) {
 201                 switch (*command) {
 202                 default:
 203                         addstr(&result, &len, &pos, command, 1);
 204                         command++;
 205                         break;
 206                 case '\\':
 207                         if (command[1]) {
 208                                 addstr(&result, &len, &pos, command + 1, 1);
 209                                 command += 2;
 210                         } else {
 211                                 addstr(&result, &len, &pos, command, 1);
 212                                 command++;
 213                         }
 214                         break;
 215                 case '[':
 216                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 217                                 old_pos[opt_depth] = pos;
 218                                 okay[opt_depth] = 1;
 219                                 opt_depth++;
 220                                 command += 2;
 221                         } else {
 222                                 addstr(&result, &len, &pos, "[", 1);
 223                                 command++;
 224                         }
 225                         break;
 226                 case ']':
 227                         if (command[1] == ']' && opt_depth > 1) {
 228                                 opt_depth--;
 229                                 if (!okay[opt_depth]) {
 230                                         pos = old_pos[opt_depth];
 231                                         result[pos] = '\0';
 232                                 }
 233                                 command += 2;
 234                         } else {
 235                                 addstr(&result, &len, &pos, "]", 1);
 236                                 command++;
 237                         }
 238                         break;
 239                 case '%':
 240                         {
 241                                 char *nextpercent;
 242                                 char *varvalue;
 243
 244                                 command++;
 245                                 nextpercent = strchr(command, '%');
 246                                 if (!nextpercent) {
 247                                         errno = EUNBALPER;
 248                                         free(result);
 249                                         return NULL;
 250                                 }
 251
 252                                 varvalue = get_var(command, nextpercent - command, ifd);
 253
 254                                 if (varvalue) {
 255                                         addstr(&result, &len, &pos, varvalue, strlen(varvalue));
 256                                 } else {
 257 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 258                                         /* Sigh...  Add a special case for 'ip' to convert from
 259                                          * dotted quad to bit count style netmasks.  */
 260                                         if (strncmp(command, "bnmask", 6)==0) {
 261                                                 int res;
 262                                                 varvalue = get_var("netmask", 7, ifd);
 263                                                 if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 264                                                         char argument[255];
 265                                                         sprintf(argument, "%d", res);
 266                                                         addstr(&result, &len, &pos, argument, strlen(argument));
 267                                                         command = nextpercent + 1;
 268                                                         break;
 269                                                 }
 270                                         }
 271 #endif
 272                                         okay[opt_depth - 1] = 0;
 273                                 }
 274
 275                                 command = nextpercent + 1;
 276                         }
 277                         break;
 278                 }
 279         }
 280
 281         if (opt_depth > 1) {
 282                 errno = EUNBALBRACK;
 283                 free(result);
 284                 return NULL;
 285         }
 286
 287         if (!okay[0]) {
 288                 errno = EUNDEFVAR;
 289                 free(result);
 290                 return NULL;
 291         }
 292
 293         return result;
 294 }
 295
 296 /* execute() returns 1 for success and 0 for failure */
 297 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 298 {
 299         char *out;
 300         int ret;
 301
 302         out = parse(command, ifd);
 303         if (!out) {
 304                 return 0;
 305         }
 306         ret = (*exec)(out);
 307
 308         free(out);
 309         if (ret != 1) {
 310                 return 0;
 311         }
 312         return 1;
 313 }
 314 #endif
 315
 316 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 317 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 318 {
 319 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 320         int result;
 321         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 322         result += execute("ip link set %iface% up", ifd, exec);
 323         return ((result == 2) ? 2 : 0);
 324 #else
 325         return execute("ifconfig %iface% add ::1", ifd, exec);
 326 #endif
 327 }
 328
 329 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 330 {
 331 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 332         return execute("ip link set %iface% down", ifd, exec);
 333 #else
 334         return execute("ifconfig %iface% del ::1", ifd, exec);
 335 #endif
 336 }
 337
 338 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 339 {
 340         int result;
 341 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 342         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 343         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 344         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 345 #else
 346         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 347         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 348         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 349 #endif
 350         return ((result == 3) ? 3 : 0);
 351 }
 352
 353 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 354 {
 355 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 356         return execute("ip link set %iface% down", ifd, exec);
 357 #else
 358         return execute("ifconfig %iface% down", ifd, exec);
 359 #endif
 360 }
 361
 362 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 363 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 364 {
 365         int result;
 366         result = execute("ip tunnel add %iface% mode sit remote "
 367                         "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 368         result += execute("ip link set %iface% up", ifd, exec);
 369         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 370         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 371         return ((result == 4) ? 4 : 0);
 372 }
 373
 374 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 375 {
 376         return execute("ip tunnel del %iface%", ifd, exec);
 377 }
 378 #endif
 379
 380 static const struct method_t methods6[] = {
 381 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 382         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 383 #endif
 384         { "static", static_up6, static_down6, },
 385         { "loopback", loopback_up6, loopback_down6, },
 386 };
 387
 388 static const struct address_family_t addr_inet6 = {
 389         "inet6",
 390         sizeof(methods6) / sizeof(struct method_t),
 391         methods6
 392 };
 393 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 394
 395 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 396 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 397 {
 398 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 399         int result;
 400         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 401         result += execute("ip link set %iface% up", ifd, exec);
 402         return ((result == 2) ? 2 : 0);
 403 #else
 404         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 405 #endif
 406 }
 407
 408 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 409 {
 410 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 411         int result;
 412         result = execute("ip addr flush dev %iface%", ifd, exec);
 413         result += execute("ip link set %iface% down", ifd, exec);
 414         return ((result == 2) ? 2 : 0);
 415 #else
 416         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 417 #endif
 418 }
 419
 420 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 421 {
 422         int result;
 423 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 424         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 425                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 426         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 427         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 428         return ((result == 3) ? 3 : 0);
 429 #else
 430         result = execute("ifconfig %iface% %address% netmask %netmask% "
 431                         "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] "
 432                         "[[media %media%]] [[mtu %mtu%]] [[hw %hwaddress%]] up",
 433                         ifd, exec);
 434         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 435         return ((result == 2) ? 2 : 0);
 436 #endif
 437 }
 438
 439 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 440 {
 441         int result;
 442 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 443         result = execute("ip addr flush dev %iface%", ifd, exec);
 444         result += execute("ip link set %iface% down", ifd, exec);
 445 #else
 446         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 447         result += execute("ifconfig %iface% down", ifd, exec);
 448 #endif
 449         return ((result == 2) ? 2 : 0);
 450 }
 451
 452 #ifndef CONFIG_APP_UDHCPC
 453 struct dhcp_client_t
 454 {
 455         const char *name;
 456         const char *startcmd;
 457         const char *stopcmd;
 458 };
 459
 460 static const struct dhcp_client_t ext_dhcp_clients[] = {
 461         { "udhcpc",
 462                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
 463                 "kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 464         },
 465         { "pump",
 466                 "pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
 467                 "pump -i %iface% -k",
 468         },
 469         { "dhclient",
 470                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 471                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 472         },
 473         { "dhcpcd",
 474                 "dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] [[-l %leasetime%]] %iface%",
 475                 "dhcpcd -k %iface%",
 476         },
 477 };
 478 #endif
 479
 480 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 481 {
 482 #ifdef CONFIG_APP_UDHCPC
 483         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 484                         "-i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
 485                         ifd, exec);
 486 #else
 487         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 488         for (i = 0; i < nclients; i++) {
 489                 if (exists_execable(ext_dhcp_clients[i].name))
 490                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 491         }
 492         bb_error_msg("no dhcp clients found");
 493         return 0;
 494 #endif
 495 }
 496
 497 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 498 {
 499 #ifdef CONFIG_APP_UDHCPC
 500         return execute("kill -TERM "
 501                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 502 #else
 503         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 504         for (i = 0; i < nclients; i++) {
 505                 if (exists_execable(ext_dhcp_clients[i].name))
 506                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 507         }
 508         bb_error_msg("no dhcp clients found, using static interface shutdown");
 509         return static_down(ifd, exec);
 510 #endif
 511 }
 512
 513 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 514 {
 515         return 1;
 516 }
 517
 518 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 519 {
 520         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 521                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 522                         "--returniffail --serverbcast", ifd, exec);
 523 }
 524
 525 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 526 {
 527         return execute("pon [[%provider%]]", ifd, exec);
 528 }
 529
 530 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 531 {
 532         return execute("poff [[%provider%]]", ifd, exec);
 533 }
 534
 535 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 536 {
 537         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 538                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 539 }
 540
 541 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 542 {
 543         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 544                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 545 }
 546
 547 static const struct method_t methods[] = {
 548         { "manual", manual_up_down, manual_up_down, },
 549         { "wvdial", wvdial_up, wvdial_down, },
 550         { "ppp", ppp_up, ppp_down, },
 551         { "static", static_up, static_down, },
 552         { "bootp", bootp_up, static_down, },
 553         { "dhcp", dhcp_up, dhcp_down, },
 554         { "loopback", loopback_up, loopback_down, },
 555 };
 556
 557 static const struct address_family_t addr_inet = {
 558         "inet",
 559         sizeof(methods) / sizeof(struct method_t),
 560         methods
 561 };
 562
 563 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 564
 565 static char *next_word(char **buf)
 566 {
 567         unsigned short length;
 568         char *word;
 569
 570         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 571                 return NULL;
 572         }
 573
 574         /* Skip over leading whitespace */
 575         word = *buf;
 576         while (isspace(*word)) {
 577                 ++word;
 578         }
 579
 580         /* Skip over comments */
 581         if (*word == '#') {
 582                 return NULL;
 583         }
 584
 585         /* Find the length of this word */
 586         length = strcspn(word, " \t\n");
 587         if (length == 0) {
 588                 return NULL;
 589         }
 590         *buf = word + length;
 591         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 592         if (**buf) {
 593                 **buf = '\0';
 594                 (*buf)++;
 595         }
 596
 597         return word;
 598 }
 599
 600 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 601 {
 602         int i;
 603
 604         for (i = 0; af[i]; i++) {
 605                 if (strcmp(af[i]->name, name) == 0) {
 606                         return af[i];
 607                 }
 608         }
 609         return NULL;
 610 }
 611
 612 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 613 {
 614         int i;
 615
 616         for (i = 0; i < af->n_methods; i++) {
 617                 if (strcmp(af->method[i].name, name) == 0) {
 618                         return &af->method[i];
 619                 }
 620         }
 621         return NULL;
 622 }
 623
 624 static const llist_t *find_list_string(const llist_t *list, const char *string)
 625 {
 626         while (list) {
 627                 if (strcmp(list->data, string) == 0) {
 628                         return list;
 629                 }
 630                 list = list->link;
 631         }
 632         return NULL;
 633 }
 634
 635 static struct interfaces_file_t *read_interfaces(const char *filename)
 636 {
 637 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 638         struct mapping_defn_t *currmap = NULL;
 639 #endif
 640         struct interface_defn_t *currif = NULL;
 641         struct interfaces_file_t *defn;
 642         FILE *f;
 643         char *firstword;
 644         char *buf;
 645
 646         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 647
 648         defn = xzalloc(sizeof(struct interfaces_file_t));
 649
 650         f = xfopen(filename, "r");
 651
 652         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 653                 char *buf_ptr = buf;
 654
 655                 firstword = next_word(&buf_ptr);
 656                 if (firstword == NULL) {
 657                         free(buf);
 658                         continue;       /* blank line */
 659                 }
 660
 661                 if (strcmp(firstword, "mapping") == 0) {
 662 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 663                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 664
 665                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 666                                 if (currmap->max_matches == currmap->n_matches) {
 667                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 668                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 669                                 }
 670
 671                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 672                         }
 673                         currmap->max_mappings = 0;
 674                         currmap->n_mappings = 0;
 675                         currmap->mapping = NULL;
 676                         currmap->script = NULL;
 677                         {
 678                                 struct mapping_defn_t **where = &defn->mappings;
 679                                 while (*where != NULL) {
 680                                         where = &(*where)->next;
 681                                 }
 682                                 *where = currmap;
 683                                 currmap->next = NULL;
 684                         }
 685                         debug_noise("Added mapping\n");
 686 #endif
 687                         currently_processing = MAPPING;
 688                 } else if (strcmp(firstword, "iface") == 0) {
 689                         static const struct address_family_t *const addr_fams[] = {
 690 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 691                                 &addr_inet,
 692 #endif
 693 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 694                                 &addr_inet6,
 695 #endif
 696                                 NULL
 697                         };
 698
 699                         char *iface_name;
 700                         char *address_family_name;
 701                         char *method_name;
 702                         llist_t *iface_list;
 703
 704                         currif = xzalloc(sizeof(struct interface_defn_t));
 705                         iface_name = next_word(&buf_ptr);
 706                         address_family_name = next_word(&buf_ptr);
 707                         method_name = next_word(&buf_ptr);
 708
 709                         if (buf_ptr == NULL) {
 710                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 711                                 return NULL;
 712                         }
 713
 714                         /* ship any trailing whitespace */
 715                         while (isspace(*buf_ptr)) {
 716                                 ++buf_ptr;
 717                         }
 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 #ifdef CONFIG_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 (__myenviron != NULL) {
 877                 for (ppch = __myenviron; *ppch; ppch++) {
 878                         free(*ppch);
 879                         *ppch = NULL;
 880                 }
 881                 free(__myenviron);
 882         }
 883         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 884         environend = __myenviron;
 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                 switch (child = fork()) {
 914                 case -1:                /* failure */
 915                         return 0;
 916                 case 0:         /* child */
 917                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 918                         exit(127);
 919                 }
 920                 waitpid(child, &status, 0);
 921                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 922                         return 0;
 923                 }
 924         }
 925         return 1;
 926 }
 927
 928 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 929 {
 930         int i;
 931         char *buf;
 932         for (i = 0; i < ifd->n_options; i++) {
 933                 if (strcmp(ifd->option[i].name, opt) == 0) {
 934                         if (!doit(ifd->option[i].value)) {
 935                                 return 0;
 936                         }
 937                 }
 938         }
 939
 940         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 941         if (doit(buf) != 1) {
 942                 return 0;
 943         }
 944         return 1;
 945 }
 946
 947 static int check(char *str) {
 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 #ifdef CONFIG_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 /* CONFIG_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         static const char statefile[] = "/var/run/ifstate";
1095
1096         int (*cmds)(struct interface_defn_t *) = NULL;
1097         struct interfaces_file_t *defn;
1098         llist_t *state_list = NULL;
1099         llist_t *target_list = NULL;
1100         const char *interfaces = "/etc/network/interfaces";
1101         int any_failures = 0;
1102         int i;
1103
1104         if (applet_name[2] == 'u') {
1105                 /* ifup command */
1106                 cmds = iface_up;
1107         } else {
1108                 /* ifdown command */
1109                 cmds = iface_down;
1110         }
1111
1112         getopt32(argc, argv, OPTION_STR, &interfaces);
1113         if (argc - optind > 0) {
1114                 if (DO_ALL) bb_show_usage();
1115         } else
1116                 if (!DO_ALL) bb_show_usage();
1117
1118         debug_noise("reading %s file:\n", interfaces);
1119         defn = read_interfaces(interfaces);
1120         debug_noise("\ndone reading %s\n\n", interfaces);
1121
1122         if (!defn) {
1123                 exit(EXIT_FAILURE);
1124         }
1125
1126         startup_PATH = getenv("PATH");
1127         if (!startup_PATH) startup_PATH = "";
1128
1129         /* Create a list of interfaces to work on */
1130         if (DO_ALL) {
1131                 if (cmds == iface_up) {
1132                         target_list = defn->autointerfaces;
1133                 } else {
1134                         /* iface_down */
1135                         const llist_t *list = state_list;
1136                         while (list) {
1137                                 llist_add_to_end(&target_list, xstrdup(list->data));
1138                                 list = list->link;
1139                         }
1140                         target_list = defn->autointerfaces;
1141                 }
1142         } else {
1143                 llist_add_to_end(&target_list, argv[optind]);
1144         }
1145
1146
1147         /* Update the interfaces */
1148         while (target_list) {
1149                 llist_t *iface_list;
1150                 struct interface_defn_t *currif;
1151                 char *iface;
1152                 char *liface;
1153                 char *pch;
1154                 int okay = 0;
1155                 int cmds_ret;
1156
1157                 iface = xstrdup(target_list->data);
1158                 target_list = target_list->link;
1159
1160                 pch = strchr(iface, '=');
1161                 if (pch) {
1162                         *pch = '\0';
1163                         liface = xstrdup(pch + 1);
1164                 } else {
1165                         liface = xstrdup(iface);
1166                 }
1167
1168                 if (!FORCE) {
1169                         const llist_t *iface_state = find_iface_state(state_list, iface);
1170
1171                         if (cmds == iface_up) {
1172                                 /* ifup */
1173                                 if (iface_state) {
1174                                         bb_error_msg("interface %s already configured", iface);
1175                                         continue;
1176                                 }
1177                         } else {
1178                                 /* ifdown */
1179                                 if (iface_state) {
1180                                         bb_error_msg("interface %s not configured", iface);
1181                                         continue;
1182                                 }
1183                         }
1184                 }
1185
1186 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1187                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1188                         struct mapping_defn_t *currmap;
1189
1190                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1191                                 for (i = 0; i < currmap->n_matches; i++) {
1192                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1193                                                 continue;
1194                                         if (VERBOSE) {
1195                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1196                                         }
1197                                         liface = run_mapping(iface, currmap);
1198                                         break;
1199                                 }
1200                         }
1201                 }
1202 #endif
1203
1204
1205                 iface_list = defn->ifaces;
1206                 while (iface_list) {
1207                         currif = (struct interface_defn_t *) iface_list->data;
1208                         if (strcmp(liface, currif->iface) == 0) {
1209                                 char *oldiface = currif->iface;
1210
1211                                 okay = 1;
1212                                 currif->iface = iface;
1213
1214                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1215
1216                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1217                                 cmds_ret = cmds(currif);
1218                                 if (cmds_ret == -1) {
1219                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1220                                                         liface, currif->address_family->name);
1221                                         any_failures += 1;
1222                                 } else if (cmds_ret == 0) {
1223                                         any_failures += 1;
1224                                 }
1225
1226                                 currif->iface = oldiface;
1227                         }
1228                         iface_list = iface_list->link;
1229                 }
1230                 if (VERBOSE) {
1231                         puts("");
1232                 }
1233
1234                 if (!okay && !FORCE) {
1235                         bb_error_msg("ignoring unknown interface %s", liface);
1236                         any_failures += 1;
1237                 } else {
1238                         llist_t *iface_state = find_iface_state(state_list, iface);
1239
1240                         if (cmds == iface_up) {
1241                                 char *newiface = xasprintf("%s=%s", iface, liface);
1242                                 if (iface_state == NULL) {
1243                                         llist_add_to_end(&state_list, newiface);
1244                                 } else {
1245                                         free(iface_state->data);
1246                                         iface_state->data = newiface;
1247                                 }
1248                         } else {
1249                                 /* Remove an interface from the linked list */
1250                                 free(llist_pop(&iface_state));
1251                         }
1252                 }
1253         }
1254
1255         /* Actually write the new state */
1256         if (!NO_ACT) {
1257                 FILE *state_fp = NULL;
1258
1259                 state_fp = xfopen(statefile, "w");
1260                 while (state_list) {
1261                         if (state_list->data) {
1262                                 fputs(state_list->data, state_fp);
1263                                 fputc('\n', state_fp);
1264                         }
1265                         state_list = state_list->link;
1266                 }
1267                 fclose(state_fp);
1268         }
1269
1270         if (any_failures)
1271                 return 1;
1272         return 0;
1273 }