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 static unsigned option_mask;
  93 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  94 enum {
  95         OPT_do_all = 0x1,
  96         OPT_no_act = 0x2,
  97         OPT_verbose = 0x4,
  98         OPT_force = 0x8,
  99         OPT_no_mappings = 0x10,
 100 };
 101 #define DO_ALL (option_mask & OPT_do_all)
 102 #define NO_ACT (option_mask & OPT_no_act)
 103 #define VERBOSE (option_mask & OPT_verbose)
 104 #define FORCE (option_mask & OPT_force)
 105 #define NO_MAPPINGS (option_mask & OPT_no_mappings)
 106
 107 static char **__myenviron;
 108
 109 static char *startup_PATH;
 110
 111 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 112
 113 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 114
 115 static unsigned int count_bits(unsigned int a)
 116 {
 117         unsigned int result;
 118         result = (a & 0x55) + ((a >> 1) & 0x55);
 119         result = (result & 0x33) + ((result >> 2) & 0x33);
 120         return ((result & 0x0F) + ((result >> 4) & 0x0F));
 121 }
 122
 123 static int count_netmask_bits(char *dotted_quad)
 124 {
 125         unsigned int result, a, b, c, d;
 126         /* Found a netmask...  Check if it is dotted quad */
 127         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 128                 return -1;
 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 **buf, size_t *len, size_t *pos, char *str, size_t str_length)
 138 {
 139         if (*pos + str_length >= *len) {
 140                 char *newbuf;
 141
 142                 newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
 143                 *buf = newbuf;
 144                 *len = *len * 2 + str_length + 1;
 145         }
 146
 147         while (str_length-- >= 1) {
 148                 (*buf)[(*pos)++] = *str;
 149                 str++;
 150         }
 151         (*buf)[*pos] = '\0';
 152 }
 153
 154 static int strncmpz(char *l, char *r, size_t llen)
 155 {
 156         int i = strncmp(l, r, llen);
 157
 158         if (i == 0) {
 159                 return -r[llen];
 160         } else {
 161                 return i;
 162         }
 163 }
 164
 165 static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
 166 {
 167         int i;
 168
 169         if (strncmpz(id, "iface", idlen) == 0) {
 170                 char *result;
 171                 static char label_buf[20];
 172                 strncpy(label_buf, ifd->iface, 19);
 173                 label_buf[19]=0;
 174                 result = strchr(label_buf, ':');
 175                 if (result) {
 176                         *result=0;
 177                 }
 178                 return label_buf;
 179         } else if (strncmpz(id, "label", idlen) == 0) {
 180                 return ifd->iface;
 181         } else {
 182                 for (i = 0; i < ifd->n_options; i++) {
 183                         if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 184                                 return ifd->option[i].value;
 185                         }
 186                 }
 187         }
 188
 189         return NULL;
 190 }
 191
 192 static char *parse(char *command, struct interface_defn_t *ifd)
 193 {
 194
 195         char *result = NULL;
 196         size_t pos = 0, len = 0;
 197         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 198         int okay[MAX_OPT_DEPTH] = { 1 };
 199         int opt_depth = 1;
 200
 201         while (*command) {
 202                 switch (*command) {
 203                 default:
 204                         addstr(&result, &len, &pos, command, 1);
 205                         command++;
 206                         break;
 207                 case '\\':
 208                         if (command[1]) {
 209                                 addstr(&result, &len, &pos, command + 1, 1);
 210                                 command += 2;
 211                         } else {
 212                                 addstr(&result, &len, &pos, command, 1);
 213                                 command++;
 214                         }
 215                         break;
 216                 case '[':
 217                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 218                                 old_pos[opt_depth] = pos;
 219                                 okay[opt_depth] = 1;
 220                                 opt_depth++;
 221                                 command += 2;
 222                         } else {
 223                                 addstr(&result, &len, &pos, "[", 1);
 224                                 command++;
 225                         }
 226                         break;
 227                 case ']':
 228                         if (command[1] == ']' && opt_depth > 1) {
 229                                 opt_depth--;
 230                                 if (!okay[opt_depth]) {
 231                                         pos = old_pos[opt_depth];
 232                                         result[pos] = '\0';
 233                                 }
 234                                 command += 2;
 235                         } else {
 236                                 addstr(&result, &len, &pos, "]", 1);
 237                                 command++;
 238                         }
 239                         break;
 240                 case '%':
 241                         {
 242                                 char *nextpercent;
 243                                 char *varvalue;
 244
 245                                 command++;
 246                                 nextpercent = strchr(command, '%');
 247                                 if (!nextpercent) {
 248                                         errno = EUNBALPER;
 249                                         free(result);
 250                                         return NULL;
 251                                 }
 252
 253                                 varvalue = get_var(command, nextpercent - command, ifd);
 254
 255                                 if (varvalue) {
 256                                         addstr(&result, &len, &pos, varvalue, strlen(varvalue));
 257                                 } else {
 258 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 259                                         /* Sigh...  Add a special case for 'ip' to convert from
 260                                          * dotted quad to bit count style netmasks.  */
 261                                         if (strncmp(command, "bnmask", 6)==0) {
 262                                                 int res;
 263                                                 varvalue = get_var("netmask", 7, ifd);
 264                                                 if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 265                                                         char argument[255];
 266                                                         sprintf(argument, "%d", res);
 267                                                         addstr(&result, &len, &pos, argument, strlen(argument));
 268                                                         command = nextpercent + 1;
 269                                                         break;
 270                                                 }
 271                                         }
 272 #endif
 273                                         okay[opt_depth - 1] = 0;
 274                                 }
 275
 276                                 command = nextpercent + 1;
 277                         }
 278                         break;
 279                 }
 280         }
 281
 282         if (opt_depth > 1) {
 283                 errno = EUNBALBRACK;
 284                 free(result);
 285                 return NULL;
 286         }
 287
 288         if (!okay[0]) {
 289                 errno = EUNDEFVAR;
 290                 free(result);
 291                 return NULL;
 292         }
 293
 294         return result;
 295 }
 296
 297 /* execute() returns 1 for success and 0 for failure */
 298 static int execute(char *command, struct interface_defn_t *ifd, execfn *exec)
 299 {
 300         char *out;
 301         int ret;
 302
 303         out = parse(command, ifd);
 304         if (!out) {
 305                 return 0;
 306         }
 307         ret = (*exec)(out);
 308
 309         free(out);
 310         if (ret != 1) {
 311                 return 0;
 312         }
 313         return 1;
 314 }
 315 #endif
 316
 317 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 318 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 319 {
 320 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 321         int result;
 322         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 323         result += execute("ip link set %iface% up", ifd, exec);
 324         return ((result == 2) ? 2 : 0);
 325 #else
 326         return execute("ifconfig %iface% add ::1", ifd, exec);
 327 #endif
 328 }
 329
 330 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 331 {
 332 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 333         return execute("ip link set %iface% down", ifd, exec);
 334 #else
 335         return execute("ifconfig %iface% del ::1", ifd, exec);
 336 #endif
 337 }
 338
 339 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 340 {
 341         int result;
 342 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 343         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 344         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 345         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 346 #else
 347         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 348         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 349         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 350 #endif
 351         return ((result == 3) ? 3 : 0);
 352 }
 353
 354 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 355 {
 356 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 357         return execute("ip link set %iface% down", ifd, exec);
 358 #else
 359         return execute("ifconfig %iface% down", ifd, exec);
 360 #endif
 361 }
 362
 363 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 364 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 365 {
 366         int result;
 367         result = execute("ip tunnel add %iface% mode sit remote "
 368                         "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 369         result += execute("ip link set %iface% up", ifd, exec);
 370         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 371         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 372         return ((result == 4) ? 4 : 0);
 373 }
 374
 375 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 376 {
 377         return execute("ip tunnel del %iface%", ifd, exec);
 378 }
 379 #endif
 380
 381 static const struct method_t methods6[] = {
 382 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 383         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 384 #endif
 385         { "static", static_up6, static_down6, },
 386         { "loopback", loopback_up6, loopback_down6, },
 387 };
 388
 389 static const struct address_family_t addr_inet6 = {
 390         "inet6",
 391         sizeof(methods6) / sizeof(struct method_t),
 392         methods6
 393 };
 394 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 395
 396 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 397 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 398 {
 399 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 400         int result;
 401         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 402         result += execute("ip link set %iface% up", ifd, exec);
 403         return ((result == 2) ? 2 : 0);
 404 #else
 405         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 406 #endif
 407 }
 408
 409 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 410 {
 411 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 412         int result;
 413         result = execute("ip addr flush dev %iface%", ifd, exec);
 414         result += execute("ip link set %iface% down", ifd, exec);
 415         return ((result == 2) ? 2 : 0);
 416 #else
 417         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 418 #endif
 419 }
 420
 421 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 422 {
 423         int result;
 424 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 425         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 426                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 427         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 428         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 429         return ((result == 3) ? 3 : 0);
 430 #else
 431         result = execute("ifconfig %iface% %address% netmask %netmask% "
 432                         "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] "
 433                         "[[media %media%]] [[mtu %mtu%]] [[hw %hwaddress%]] up",
 434                         ifd, exec);
 435         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 436         return ((result == 2) ? 2 : 0);
 437 #endif
 438 }
 439
 440 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 441 {
 442         int result;
 443 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 444         result = execute("ip addr flush dev %iface%", ifd, exec);
 445         result += execute("ip link set %iface% down", ifd, exec);
 446 #else
 447         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 448         result += execute("ifconfig %iface% down", ifd, exec);
 449 #endif
 450         return ((result == 2) ? 2 : 0);
 451 }
 452
 453 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 454 {
 455         int i;
 456
 457         for (i = 0; i < ifd->n_options; i++) {
 458                 if (strcmp(ifd->option[i].name, "dhcp-start-cmd") == 0) {
 459                         return execute(ifd->option[i].value, ifd, exec);
 460                 }
 461         }
 462
 463         if (execute("udhcpc -n -p /var/run/udhcpc.%iface%.pid -i "
 464                         "%iface% [[-H %hostname%]] [[-c %clientid%]]", ifd, exec)) return 1;
 465         if (execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]", ifd, exec)) return 1;
 466         if (execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%", ifd, exec)) return 1;
 467         if (execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 468                         "[[-l %leasetime%]] %iface%", ifd, exec)) return 1;
 469         return 0;
 470 }
 471
 472 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 473 {
 474         int i;
 475
 476         for (i = 0; i < ifd->n_options; i++) {
 477                 if (strcmp(ifd->option[i].name, "dhcp-stop-cmd") == 0) {
 478                         return execute(ifd->option[i].value, ifd, exec);
 479                 }
 480         }
 481
 482         /* SIGUSR2 forces udhcpc to release the current lease and go inactive,
 483          * and SIGTERM causes udhcpc to exit.  Signals are queued and processed
 484          * sequentially so we don't need to sleep */
 485         if (execute("kill -USR2 `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec)
 486          || execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec))
 487                 return 1;
 488         if (execute("pump -i %iface% -k", ifd, exec)) return 1;
 489         if (execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null", ifd, exec)) return 1;
 490         if (execute("dhcpcd -k %iface%", ifd, exec)) return 1;
 491         return static_down(ifd, exec);
 492 }
 493
 494 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 495 {
 496         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 497                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 498                         "--returniffail --serverbcast", ifd, exec);
 499 }
 500
 501 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 502 {
 503         return execute("pon [[%provider%]]", ifd, exec);
 504 }
 505
 506 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 507 {
 508         return execute("poff [[%provider%]]", ifd, exec);
 509 }
 510
 511 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 512 {
 513         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 514                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 515 }
 516
 517 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 518 {
 519         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 520                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 521 }
 522
 523 static const struct method_t methods[] = {
 524         { "wvdial", wvdial_up, wvdial_down, },
 525         { "ppp", ppp_up, ppp_down, },
 526         { "static", static_up, static_down, },
 527         { "bootp", bootp_up, static_down, },
 528         { "dhcp", dhcp_up, dhcp_down, },
 529         { "loopback", loopback_up, loopback_down, },
 530 };
 531
 532 static const struct address_family_t addr_inet = {
 533         "inet",
 534         sizeof(methods) / sizeof(struct method_t),
 535         methods
 536 };
 537
 538 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 539
 540 static char *next_word(char **buf)
 541 {
 542         unsigned short length;
 543         char *word;
 544
 545         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 546                 return NULL;
 547         }
 548
 549         /* Skip over leading whitespace */
 550         word = *buf;
 551         while (isspace(*word)) {
 552                 ++word;
 553         }
 554
 555         /* Skip over comments */
 556         if (*word == '#') {
 557                 return NULL;
 558         }
 559
 560         /* Find the length of this word */
 561         length = strcspn(word, " \t\n");
 562         if (length == 0) {
 563                 return NULL;
 564         }
 565         *buf = word + length;
 566         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 567         if (**buf) {
 568                 **buf = '\0';
 569                 (*buf)++;
 570         }
 571
 572         return word;
 573 }
 574
 575 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 576 {
 577         int i;
 578
 579         for (i = 0; af[i]; i++) {
 580                 if (strcmp(af[i]->name, name) == 0) {
 581                         return af[i];
 582                 }
 583         }
 584         return NULL;
 585 }
 586
 587 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 588 {
 589         int i;
 590
 591         for (i = 0; i < af->n_methods; i++) {
 592                 if (strcmp(af->method[i].name, name) == 0) {
 593                         return &af->method[i];
 594                 }
 595         }
 596         return NULL;
 597 }
 598
 599 static const llist_t *find_list_string(const llist_t *list, const char *string)
 600 {
 601         while (list) {
 602                 if (strcmp(list->data, string) == 0) {
 603                         return list;
 604                 }
 605                 list = list->link;
 606         }
 607         return NULL;
 608 }
 609
 610 static struct interfaces_file_t *read_interfaces(const char *filename)
 611 {
 612 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 613         struct mapping_defn_t *currmap = NULL;
 614 #endif
 615         struct interface_defn_t *currif = NULL;
 616         struct interfaces_file_t *defn;
 617         FILE *f;
 618         char *firstword;
 619         char *buf;
 620
 621         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 622
 623         defn = xzalloc(sizeof(struct interfaces_file_t));
 624
 625         f = xfopen(filename, "r");
 626
 627         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 628                 char *buf_ptr = buf;
 629
 630                 firstword = next_word(&buf_ptr);
 631                 if (firstword == NULL) {
 632                         free(buf);
 633                         continue;       /* blank line */
 634                 }
 635
 636                 if (strcmp(firstword, "mapping") == 0) {
 637 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 638                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 639
 640                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 641                                 if (currmap->max_matches == currmap->n_matches) {
 642                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 643                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 644                                 }
 645
 646                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 647                         }
 648                         currmap->max_mappings = 0;
 649                         currmap->n_mappings = 0;
 650                         currmap->mapping = NULL;
 651                         currmap->script = NULL;
 652                         {
 653                                 struct mapping_defn_t **where = &defn->mappings;
 654                                 while (*where != NULL) {
 655                                         where = &(*where)->next;
 656                                 }
 657                                 *where = currmap;
 658                                 currmap->next = NULL;
 659                         }
 660                         debug_noise("Added mapping\n");
 661 #endif
 662                         currently_processing = MAPPING;
 663                 } else if (strcmp(firstword, "iface") == 0) {
 664                         static const struct address_family_t *const addr_fams[] = {
 665 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 666                                 &addr_inet,
 667 #endif
 668 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 669                                 &addr_inet6,
 670 #endif
 671                                 NULL
 672                         };
 673
 674                         char *iface_name;
 675                         char *address_family_name;
 676                         char *method_name;
 677                         llist_t *iface_list;
 678
 679                         currif = xzalloc(sizeof(struct interface_defn_t));
 680                         iface_name = next_word(&buf_ptr);
 681                         address_family_name = next_word(&buf_ptr);
 682                         method_name = next_word(&buf_ptr);
 683
 684                         if (buf_ptr == NULL) {
 685                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 686                                 return NULL;
 687                         }
 688
 689                         /* ship any trailing whitespace */
 690                         while (isspace(*buf_ptr)) {
 691                                 ++buf_ptr;
 692                         }
 693
 694                         if (buf_ptr[0] != '\0') {
 695                                 bb_error_msg("too many parameters \"%s\"", buf);
 696                                 return NULL;
 697                         }
 698
 699                         currif->iface = xstrdup(iface_name);
 700
 701                         currif->address_family = get_address_family(addr_fams, address_family_name);
 702                         if (!currif->address_family) {
 703                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 704                                 return NULL;
 705                         }
 706
 707                         currif->method = get_method(currif->address_family, method_name);
 708                         if (!currif->method) {
 709                                 bb_error_msg("unknown method \"%s\"", method_name);
 710                                 return NULL;
 711                         }
 712
 713                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 714                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 715                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 716                                         (tmp->address_family == currif->address_family)) {
 717                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 718                                         return NULL;
 719                                 }
 720                         }
 721                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 722
 723                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 724                         currently_processing = IFACE;
 725                 } else if (strcmp(firstword, "auto") == 0) {
 726                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 727
 728                                 /* Check the interface isnt already listed */
 729                                 if (find_list_string(defn->autointerfaces, firstword)) {
 730                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 731                                 }
 732
 733                                 /* Add the interface to the list */
 734                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 735                                 debug_noise("\nauto %s\n", firstword);
 736                         }
 737                         currently_processing = NONE;
 738                 } else {
 739                         switch (currently_processing) {
 740                         case IFACE:
 741                                 {
 742                                         int i;
 743
 744                                         if (strlen(buf_ptr) == 0) {
 745                                                 bb_error_msg("option with empty value \"%s\"", buf);
 746                                                 return NULL;
 747                                         }
 748
 749                                         if (strcmp(firstword, "up") != 0
 750                                                         && strcmp(firstword, "down") != 0
 751                                                         && strcmp(firstword, "pre-up") != 0
 752                                                         && strcmp(firstword, "post-down") != 0) {
 753                                                 for (i = 0; i < currif->n_options; i++) {
 754                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 755                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 756                                                                 return NULL;
 757                                                         }
 758                                                 }
 759                                         }
 760                                 }
 761                                 if (currif->n_options >= currif->max_options) {
 762                                         struct variable_t *opt;
 763
 764                                         currif->max_options = currif->max_options + 10;
 765                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 766                                         currif->option = opt;
 767                                 }
 768                                 currif->option[currif->n_options].name = xstrdup(firstword);
 769                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 770                                 if (!currif->option[currif->n_options].name) {
 771                                         perror(filename);
 772                                         return NULL;
 773                                 }
 774                                 if (!currif->option[currif->n_options].value) {
 775                                         perror(filename);
 776                                         return NULL;
 777                                 }
 778                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 779                                                 currif->option[currif->n_options].value);
 780                                 currif->n_options++;
 781                                 break;
 782                         case MAPPING:
 783 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 784                                 if (strcmp(firstword, "script") == 0) {
 785                                         if (currmap->script != NULL) {
 786                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 787                                                 return NULL;
 788                                         } else {
 789                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 790                                         }
 791                                 } else if (strcmp(firstword, "map") == 0) {
 792                                         if (currmap->max_mappings == currmap->n_mappings) {
 793                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 794                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 795                                         }
 796                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 797                                         currmap->n_mappings++;
 798                                 } else {
 799                                         bb_error_msg("misplaced option \"%s\"", buf);
 800                                         return NULL;
 801                                 }
 802 #endif
 803                                 break;
 804                         case NONE:
 805                         default:
 806                                 bb_error_msg("misplaced option \"%s\"", buf);
 807                                 return NULL;
 808                         }
 809                 }
 810                 free(buf);
 811         }
 812         if (ferror(f) != 0) {
 813                 bb_perror_msg_and_die("%s", filename);
 814         }
 815         fclose(f);
 816
 817         return defn;
 818 }
 819
 820 static char *setlocalenv(char *format, const char *name, const char *value)
 821 {
 822         char *result;
 823         char *here;
 824         char *there;
 825
 826         result = xasprintf(format, name, value);
 827
 828         for (here = there = result; *there != '=' && *there; there++) {
 829                 if (*there == '-')
 830                         *there = '_';
 831                 if (isalpha(*there))
 832                         *there = toupper(*there);
 833
 834                 if (isalnum(*there) || *there == '_') {
 835                         *here = *there;
 836                         here++;
 837                 }
 838         }
 839         memmove(here, there, strlen(there) + 1);
 840
 841         return result;
 842 }
 843
 844 static void set_environ(struct interface_defn_t *iface, const char *mode)
 845 {
 846         char **environend;
 847         int i;
 848         const int n_env_entries = iface->n_options + 5;
 849         char **ppch;
 850
 851         if (__myenviron != NULL) {
 852                 for (ppch = __myenviron; *ppch; ppch++) {
 853                         free(*ppch);
 854                         *ppch = NULL;
 855                 }
 856                 free(__myenviron);
 857         }
 858         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 859         environend = __myenviron;
 860
 861         for (i = 0; i < iface->n_options; i++) {
 862                 if (strcmp(iface->option[i].name, "up") == 0
 863                                 || strcmp(iface->option[i].name, "down") == 0
 864                                 || strcmp(iface->option[i].name, "pre-up") == 0
 865                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 866                         continue;
 867                 }
 868                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 869         }
 870
 871         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 872         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 873         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 874         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 875         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 876 }
 877
 878 static int doit(char *str)
 879 {
 880         if (option_mask & (OPT_no_act|OPT_verbose)) {
 881                 puts(str);
 882         }
 883         if (!(option_mask & OPT_no_act)) {
 884                 pid_t child;
 885                 int status;
 886
 887                 fflush(NULL);
 888                 switch (child = fork()) {
 889                 case -1:                /* failure */
 890                         return 0;
 891                 case 0:         /* child */
 892                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 893                         exit(127);
 894                 }
 895                 waitpid(child, &status, 0);
 896                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 897                         return 0;
 898                 }
 899         }
 900         return 1;
 901 }
 902
 903 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 904 {
 905         int i;
 906         char *buf;
 907         for (i = 0; i < ifd->n_options; i++) {
 908                 if (strcmp(ifd->option[i].name, opt) == 0) {
 909                         if (!doit(ifd->option[i].value)) {
 910                                 return 0;
 911                         }
 912                 }
 913         }
 914
 915         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 916         if (doit(buf) != 1) {
 917                 return 0;
 918         }
 919         return 1;
 920 }
 921
 922 static int check(char *str) {
 923         return str != NULL;
 924 }
 925
 926 static int iface_up(struct interface_defn_t *iface)
 927 {
 928         if (!iface->method->up(iface,check)) return -1;
 929         set_environ(iface, "start");
 930         if (!execute_all(iface, "pre-up")) return 0;
 931         if (!iface->method->up(iface, doit)) return 0;
 932         if (!execute_all(iface, "up")) return 0;
 933         return 1;
 934 }
 935
 936 static int iface_down(struct interface_defn_t *iface)
 937 {
 938         if (!iface->method->down(iface,check)) return -1;
 939         set_environ(iface, "stop");
 940         if (!execute_all(iface, "down")) return 0;
 941         if (!iface->method->down(iface, doit)) return 0;
 942         if (!execute_all(iface, "post-down")) return 0;
 943         return 1;
 944 }
 945
 946 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 947 static int popen2(FILE **in, FILE **out, char *command, ...)
 948 {
 949         va_list ap;
 950         char *argv[11] = { command };
 951         int argc;
 952         int infd[2], outfd[2];
 953         pid_t pid;
 954
 955         argc = 1;
 956         va_start(ap, command);
 957         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 958                 argc++;
 959         }
 960         argv[argc] = NULL;      /* make sure */
 961         va_end(ap);
 962
 963         if (pipe(infd) != 0) {
 964                 return 0;
 965         }
 966
 967         if (pipe(outfd) != 0) {
 968                 close(infd[0]);
 969                 close(infd[1]);
 970                 return 0;
 971         }
 972
 973         fflush(NULL);
 974         switch (pid = fork()) {
 975         case -1:                        /* failure */
 976                 close(infd[0]);
 977                 close(infd[1]);
 978                 close(outfd[0]);
 979                 close(outfd[1]);
 980                 return 0;
 981         case 0:                 /* child */
 982                 dup2(infd[0], 0);
 983                 dup2(outfd[1], 1);
 984                 close(infd[0]);
 985                 close(infd[1]);
 986                 close(outfd[0]);
 987                 close(outfd[1]);
 988                 execvp(command, argv);
 989                 exit(127);
 990         default:                        /* parent */
 991                 *in = fdopen(infd[1], "w");
 992                 *out = fdopen(outfd[0], "r");
 993                 close(infd[0]);
 994                 close(outfd[1]);
 995                 return pid;
 996         }
 997         /* unreached */
 998 }
 999
1000 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1001 {
1002         FILE *in, *out;
1003         int i, status;
1004         pid_t pid;
1005
1006         char *logical = xstrdup(physical);
1007
1008         /* Run the mapping script. */
1009         pid = popen2(&in, &out, map->script, physical, NULL);
1010
1011         /* popen2() returns 0 on failure. */
1012         if (pid == 0)
1013                 return logical;
1014
1015         /* Write mappings to stdin of mapping script. */
1016         for (i = 0; i < map->n_mappings; i++) {
1017                 fprintf(in, "%s\n", map->mapping[i]);
1018         }
1019         fclose(in);
1020         waitpid(pid, &status, 0);
1021
1022         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1023                 /* If the mapping script exited successfully, try to
1024                  * grab a line of output and use that as the name of the
1025                  * logical interface. */
1026                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1027
1028                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1029                         /* If we are able to read a line of output from the script,
1030                          * remove any trailing whitespace and use this value
1031                          * as the name of the logical interface. */
1032                         char *pch = new_logical + strlen(new_logical) - 1;
1033
1034                         while (pch >= new_logical && isspace(*pch))
1035                                 *(pch--) = '\0';
1036
1037                         free(logical);
1038                         logical = new_logical;
1039                 } else {
1040                         /* If we are UNABLE to read a line of output, discard our
1041                          * freshly allocated memory. */
1042                         free(new_logical);
1043                 }
1044         }
1045
1046         fclose(out);
1047
1048         return logical;
1049 }
1050 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1051
1052 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1053 {
1054         unsigned short iface_len = strlen(iface);
1055         llist_t *search = state_list;
1056
1057         while (search) {
1058                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1059                                 (search->data[iface_len] == '=')) {
1060                         return search;
1061                 }
1062                 search = search->link;
1063         }
1064         return NULL;
1065 }
1066
1067 int ifupdown_main(int argc, char **argv)
1068 {
1069         static const char statefile[] = "/var/run/ifstate";
1070
1071         int (*cmds)(struct interface_defn_t *) = NULL;
1072         struct interfaces_file_t *defn;
1073         llist_t *state_list = NULL;
1074         llist_t *target_list = NULL;
1075         const char *interfaces = "/etc/network/interfaces";
1076         int any_failures = 0;
1077         int i;
1078
1079         if (bb_applet_name[2] == 'u') {
1080                 /* ifup command */
1081                 cmds = iface_up;
1082         } else {
1083                 /* ifdown command */
1084                 cmds = iface_down;
1085         }
1086
1087         option_mask = bb_getopt_ulflags(argc, argv, OPTION_STR, &interfaces);
1088         if (argc - optind > 0) {
1089                 if (DO_ALL) bb_show_usage();
1090         } else
1091                 if (!DO_ALL) bb_show_usage();
1092
1093         debug_noise("reading %s file:\n", interfaces);
1094         defn = read_interfaces(interfaces);
1095         debug_noise("\ndone reading %s\n\n", interfaces);
1096
1097         if (!defn) {
1098                 exit(EXIT_FAILURE);
1099         }
1100
1101         startup_PATH = getenv("PATH");
1102         if (!startup_PATH) startup_PATH = "";
1103
1104         /* Create a list of interfaces to work on */
1105         if (DO_ALL) {
1106                 if (cmds == iface_up) {
1107                         target_list = defn->autointerfaces;
1108                 } else {
1109                         /* iface_down */
1110                         const llist_t *list = state_list;
1111                         while (list) {
1112                                 llist_add_to_end(&target_list, xstrdup(list->data));
1113                                 list = list->link;
1114                         }
1115                         target_list = defn->autointerfaces;
1116                 }
1117         } else {
1118                 llist_add_to_end(&target_list, argv[optind]);
1119         }
1120
1121
1122         /* Update the interfaces */
1123         while (target_list) {
1124                 llist_t *iface_list;
1125                 struct interface_defn_t *currif;
1126                 char *iface;
1127                 char *liface;
1128                 char *pch;
1129                 int okay = 0;
1130                 int cmds_ret;
1131
1132                 iface = xstrdup(target_list->data);
1133                 target_list = target_list->link;
1134
1135                 pch = strchr(iface, '=');
1136                 if (pch) {
1137                         *pch = '\0';
1138                         liface = xstrdup(pch + 1);
1139                 } else {
1140                         liface = xstrdup(iface);
1141                 }
1142
1143                 if (!FORCE) {
1144                         const llist_t *iface_state = find_iface_state(state_list, iface);
1145
1146                         if (cmds == iface_up) {
1147                                 /* ifup */
1148                                 if (iface_state) {
1149                                         bb_error_msg("interface %s already configured", iface);
1150                                         continue;
1151                                 }
1152                         } else {
1153                                 /* ifdown */
1154                                 if (iface_state) {
1155                                         bb_error_msg("interface %s not configured", iface);
1156                                         continue;
1157                                 }
1158                         }
1159                 }
1160
1161 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1162                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1163                         struct mapping_defn_t *currmap;
1164
1165                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1166                                 for (i = 0; i < currmap->n_matches; i++) {
1167                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1168                                                 continue;
1169                                         if (VERBOSE) {
1170                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1171                                         }
1172                                         liface = run_mapping(iface, currmap);
1173                                         break;
1174                                 }
1175                         }
1176                 }
1177 #endif
1178
1179
1180                 iface_list = defn->ifaces;
1181                 while (iface_list) {
1182                         currif = (struct interface_defn_t *) iface_list->data;
1183                         if (strcmp(liface, currif->iface) == 0) {
1184                                 char *oldiface = currif->iface;
1185
1186                                 okay = 1;
1187                                 currif->iface = iface;
1188
1189                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1190
1191                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1192                                 cmds_ret = cmds(currif);
1193                                 if (cmds_ret == -1) {
1194                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1195                                                         liface, currif->address_family->name);
1196                                         any_failures += 1;
1197                                 } else if (cmds_ret == 0) {
1198                                         any_failures += 1;
1199                                 }
1200
1201                                 currif->iface = oldiface;
1202                         }
1203                         iface_list = iface_list->link;
1204                 }
1205                 if (VERBOSE) {
1206                         puts("");
1207                 }
1208
1209                 if (!okay && !FORCE) {
1210                         bb_error_msg("ignoring unknown interface %s", liface);
1211                         any_failures += 1;
1212                 } else {
1213                         llist_t *iface_state = find_iface_state(state_list, iface);
1214
1215                         if (cmds == iface_up) {
1216                                 char *newiface = xasprintf("%s=%s", iface, liface);
1217                                 if (iface_state == NULL) {
1218                                         llist_add_to_end(&state_list, newiface);
1219                                 } else {
1220                                         free(iface_state->data);
1221                                         iface_state->data = newiface;
1222                                 }
1223                         } else {
1224                                 /* Remove an interface from the linked list */
1225                                 free(llist_pop(&iface_state));
1226                         }
1227                 }
1228         }
1229
1230         /* Actually write the new state */
1231         if (!NO_ACT) {
1232                 FILE *state_fp = NULL;
1233
1234                 state_fp = xfopen(statefile, "w");
1235                 while (state_list) {
1236                         if (state_list->data) {
1237                                 fputs(state_list->data, state_fp);
1238                                 fputc('\n', state_fp);
1239                         }
1240                         state_list = state_list->link;
1241                 }
1242                 fclose(state_fp);
1243         }
1244
1245         if (any_failures)
1246                 return 1;
1247         return 0;
1248 }