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         if (execute("udhcpc -n -p /var/run/udhcpc.%iface%.pid -i "
 456                         "%iface% [[-H %hostname%]] [[-c %clientid%]]", ifd, exec)) return 1;
 457         if (execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]", ifd, exec)) return 1;
 458         if (execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%", ifd, exec)) return 1;
 459         if (execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 460                         "[[-l %leasetime%]] %iface%", ifd, exec)) return 1;
 461         return 0;
 462 }
 463
 464 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 465 {
 466         /* SIGUSR2 forces udhcpc to release the current lease and go inactive,
 467          * and SIGTERM causes udhcpc to exit.  Signals are queued and processed
 468          * sequentially so we don't need to sleep */
 469         if (execute("kill -USR2 `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec)
 470          || execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec))
 471                 return 1;
 472         if (execute("pump -i %iface% -k", ifd, exec)) return 1;
 473         if (execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null", ifd, exec)) return 1;
 474         if (execute("dhcpcd -k %iface%", ifd, exec)) return 1;
 475         return static_down(ifd, exec);
 476 }
 477
 478 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 479 {
 480         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 481                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 482                         "--returniffail --serverbcast", ifd, exec);
 483 }
 484
 485 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 486 {
 487         return execute("pon [[%provider%]]", ifd, exec);
 488 }
 489
 490 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 491 {
 492         return execute("poff [[%provider%]]", ifd, exec);
 493 }
 494
 495 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 496 {
 497         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 498                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 499 }
 500
 501 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 502 {
 503         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 504                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 505 }
 506
 507 static const struct method_t methods[] = {
 508         { "wvdial", wvdial_up, wvdial_down, },
 509         { "ppp", ppp_up, ppp_down, },
 510         { "static", static_up, static_down, },
 511         { "bootp", bootp_up, static_down, },
 512         { "dhcp", dhcp_up, dhcp_down, },
 513         { "loopback", loopback_up, loopback_down, },
 514 };
 515
 516 static const struct address_family_t addr_inet = {
 517         "inet",
 518         sizeof(methods) / sizeof(struct method_t),
 519         methods
 520 };
 521
 522 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 523
 524 static char *next_word(char **buf)
 525 {
 526         unsigned short length;
 527         char *word;
 528
 529         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 530                 return NULL;
 531         }
 532
 533         /* Skip over leading whitespace */
 534         word = *buf;
 535         while (isspace(*word)) {
 536                 ++word;
 537         }
 538
 539         /* Skip over comments */
 540         if (*word == '#') {
 541                 return NULL;
 542         }
 543
 544         /* Find the length of this word */
 545         length = strcspn(word, " \t\n");
 546         if (length == 0) {
 547                 return NULL;
 548         }
 549         *buf = word + length;
 550         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 551         if (**buf) {
 552                 **buf = '\0';
 553                 (*buf)++;
 554         }
 555
 556         return word;
 557 }
 558
 559 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 560 {
 561         int i;
 562
 563         for (i = 0; af[i]; i++) {
 564                 if (strcmp(af[i]->name, name) == 0) {
 565                         return af[i];
 566                 }
 567         }
 568         return NULL;
 569 }
 570
 571 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 572 {
 573         int i;
 574
 575         for (i = 0; i < af->n_methods; i++) {
 576                 if (strcmp(af->method[i].name, name) == 0) {
 577                         return &af->method[i];
 578                 }
 579         }
 580         return NULL;
 581 }
 582
 583 static const llist_t *find_list_string(const llist_t *list, const char *string)
 584 {
 585         while (list) {
 586                 if (strcmp(list->data, string) == 0) {
 587                         return list;
 588                 }
 589                 list = list->link;
 590         }
 591         return NULL;
 592 }
 593
 594 static struct interfaces_file_t *read_interfaces(const char *filename)
 595 {
 596 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 597         struct mapping_defn_t *currmap = NULL;
 598 #endif
 599         struct interface_defn_t *currif = NULL;
 600         struct interfaces_file_t *defn;
 601         FILE *f;
 602         char *firstword;
 603         char *buf;
 604
 605         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 606
 607         defn = xzalloc(sizeof(struct interfaces_file_t));
 608
 609         f = xfopen(filename, "r");
 610
 611         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 612                 char *buf_ptr = buf;
 613
 614                 firstword = next_word(&buf_ptr);
 615                 if (firstword == NULL) {
 616                         free(buf);
 617                         continue;       /* blank line */
 618                 }
 619
 620                 if (strcmp(firstword, "mapping") == 0) {
 621 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 622                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 623
 624                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 625                                 if (currmap->max_matches == currmap->n_matches) {
 626                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 627                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 628                                 }
 629
 630                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 631                         }
 632                         currmap->max_mappings = 0;
 633                         currmap->n_mappings = 0;
 634                         currmap->mapping = NULL;
 635                         currmap->script = NULL;
 636                         {
 637                                 struct mapping_defn_t **where = &defn->mappings;
 638                                 while (*where != NULL) {
 639                                         where = &(*where)->next;
 640                                 }
 641                                 *where = currmap;
 642                                 currmap->next = NULL;
 643                         }
 644                         debug_noise("Added mapping\n");
 645 #endif
 646                         currently_processing = MAPPING;
 647                 } else if (strcmp(firstword, "iface") == 0) {
 648                         static const struct address_family_t *const addr_fams[] = {
 649 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 650                                 &addr_inet,
 651 #endif
 652 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 653                                 &addr_inet6,
 654 #endif
 655                                 NULL
 656                         };
 657
 658                         char *iface_name;
 659                         char *address_family_name;
 660                         char *method_name;
 661                         llist_t *iface_list;
 662
 663                         currif = xzalloc(sizeof(struct interface_defn_t));
 664                         iface_name = next_word(&buf_ptr);
 665                         address_family_name = next_word(&buf_ptr);
 666                         method_name = next_word(&buf_ptr);
 667
 668                         if (buf_ptr == NULL) {
 669                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 670                                 return NULL;
 671                         }
 672
 673                         /* ship any trailing whitespace */
 674                         while (isspace(*buf_ptr)) {
 675                                 ++buf_ptr;
 676                         }
 677
 678                         if (buf_ptr[0] != '\0') {
 679                                 bb_error_msg("too many parameters \"%s\"", buf);
 680                                 return NULL;
 681                         }
 682
 683                         currif->iface = xstrdup(iface_name);
 684
 685                         currif->address_family = get_address_family(addr_fams, address_family_name);
 686                         if (!currif->address_family) {
 687                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 688                                 return NULL;
 689                         }
 690
 691                         currif->method = get_method(currif->address_family, method_name);
 692                         if (!currif->method) {
 693                                 bb_error_msg("unknown method \"%s\"", method_name);
 694                                 return NULL;
 695                         }
 696
 697                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 698                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 699                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 700                                         (tmp->address_family == currif->address_family)) {
 701                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 702                                         return NULL;
 703                                 }
 704                         }
 705                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 706
 707                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 708                         currently_processing = IFACE;
 709                 } else if (strcmp(firstword, "auto") == 0) {
 710                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 711
 712                                 /* Check the interface isnt already listed */
 713                                 if (find_list_string(defn->autointerfaces, firstword)) {
 714                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 715                                 }
 716
 717                                 /* Add the interface to the list */
 718                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 719                                 debug_noise("\nauto %s\n", firstword);
 720                         }
 721                         currently_processing = NONE;
 722                 } else {
 723                         switch (currently_processing) {
 724                         case IFACE:
 725                                 {
 726                                         int i;
 727
 728                                         if (strlen(buf_ptr) == 0) {
 729                                                 bb_error_msg("option with empty value \"%s\"", buf);
 730                                                 return NULL;
 731                                         }
 732
 733                                         if (strcmp(firstword, "up") != 0
 734                                                         && strcmp(firstword, "down") != 0
 735                                                         && strcmp(firstword, "pre-up") != 0
 736                                                         && strcmp(firstword, "post-down") != 0) {
 737                                                 for (i = 0; i < currif->n_options; i++) {
 738                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 739                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 740                                                                 return NULL;
 741                                                         }
 742                                                 }
 743                                         }
 744                                 }
 745                                 if (currif->n_options >= currif->max_options) {
 746                                         struct variable_t *opt;
 747
 748                                         currif->max_options = currif->max_options + 10;
 749                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 750                                         currif->option = opt;
 751                                 }
 752                                 currif->option[currif->n_options].name = xstrdup(firstword);
 753                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 754                                 if (!currif->option[currif->n_options].name) {
 755                                         perror(filename);
 756                                         return NULL;
 757                                 }
 758                                 if (!currif->option[currif->n_options].value) {
 759                                         perror(filename);
 760                                         return NULL;
 761                                 }
 762                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 763                                                 currif->option[currif->n_options].value);
 764                                 currif->n_options++;
 765                                 break;
 766                         case MAPPING:
 767 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 768                                 if (strcmp(firstword, "script") == 0) {
 769                                         if (currmap->script != NULL) {
 770                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 771                                                 return NULL;
 772                                         } else {
 773                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 774                                         }
 775                                 } else if (strcmp(firstword, "map") == 0) {
 776                                         if (currmap->max_mappings == currmap->n_mappings) {
 777                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 778                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 779                                         }
 780                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 781                                         currmap->n_mappings++;
 782                                 } else {
 783                                         bb_error_msg("misplaced option \"%s\"", buf);
 784                                         return NULL;
 785                                 }
 786 #endif
 787                                 break;
 788                         case NONE:
 789                         default:
 790                                 bb_error_msg("misplaced option \"%s\"", buf);
 791                                 return NULL;
 792                         }
 793                 }
 794                 free(buf);
 795         }
 796         if (ferror(f) != 0) {
 797                 bb_perror_msg_and_die("%s", filename);
 798         }
 799         fclose(f);
 800
 801         return defn;
 802 }
 803
 804 static char *setlocalenv(char *format, const char *name, const char *value)
 805 {
 806         char *result;
 807         char *here;
 808         char *there;
 809
 810         result = xasprintf(format, name, value);
 811
 812         for (here = there = result; *there != '=' && *there; there++) {
 813                 if (*there == '-')
 814                         *there = '_';
 815                 if (isalpha(*there))
 816                         *there = toupper(*there);
 817
 818                 if (isalnum(*there) || *there == '_') {
 819                         *here = *there;
 820                         here++;
 821                 }
 822         }
 823         memmove(here, there, strlen(there) + 1);
 824
 825         return result;
 826 }
 827
 828 static void set_environ(struct interface_defn_t *iface, const char *mode)
 829 {
 830         char **environend;
 831         int i;
 832         const int n_env_entries = iface->n_options + 5;
 833         char **ppch;
 834
 835         if (__myenviron != NULL) {
 836                 for (ppch = __myenviron; *ppch; ppch++) {
 837                         free(*ppch);
 838                         *ppch = NULL;
 839                 }
 840                 free(__myenviron);
 841         }
 842         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 843         environend = __myenviron;
 844
 845         for (i = 0; i < iface->n_options; i++) {
 846                 if (strcmp(iface->option[i].name, "up") == 0
 847                                 || strcmp(iface->option[i].name, "down") == 0
 848                                 || strcmp(iface->option[i].name, "pre-up") == 0
 849                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 850                         continue;
 851                 }
 852                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 853         }
 854
 855         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 856         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 857         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 858         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 859         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 860 }
 861
 862 static int doit(char *str)
 863 {
 864         if (option_mask & (OPT_no_act|OPT_verbose)) {
 865                 puts(str);
 866         }
 867         if (!(option_mask & OPT_no_act)) {
 868                 pid_t child;
 869                 int status;
 870
 871                 fflush(NULL);
 872                 switch (child = fork()) {
 873                 case -1:                /* failure */
 874                         return 0;
 875                 case 0:         /* child */
 876                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 877                         exit(127);
 878                 }
 879                 waitpid(child, &status, 0);
 880                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 881                         return 0;
 882                 }
 883         }
 884         return 1;
 885 }
 886
 887 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 888 {
 889         int i;
 890         char *buf;
 891         for (i = 0; i < ifd->n_options; i++) {
 892                 if (strcmp(ifd->option[i].name, opt) == 0) {
 893                         if (!doit(ifd->option[i].value)) {
 894                                 return 0;
 895                         }
 896                 }
 897         }
 898
 899         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 900         if (doit(buf) != 1) {
 901                 return 0;
 902         }
 903         return 1;
 904 }
 905
 906 static int check(char *str) {
 907         return str != NULL;
 908 }
 909
 910 static int iface_up(struct interface_defn_t *iface)
 911 {
 912         if (!iface->method->up(iface,check)) return -1;
 913         set_environ(iface, "start");
 914         if (!execute_all(iface, "pre-up")) return 0;
 915         if (!iface->method->up(iface, doit)) return 0;
 916         if (!execute_all(iface, "up")) return 0;
 917         return 1;
 918 }
 919
 920 static int iface_down(struct interface_defn_t *iface)
 921 {
 922         if (!iface->method->down(iface,check)) return -1;
 923         set_environ(iface, "stop");
 924         if (!execute_all(iface, "down")) return 0;
 925         if (!iface->method->down(iface, doit)) return 0;
 926         if (!execute_all(iface, "post-down")) return 0;
 927         return 1;
 928 }
 929
 930 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 931 static int popen2(FILE **in, FILE **out, char *command, ...)
 932 {
 933         va_list ap;
 934         char *argv[11] = { command };
 935         int argc;
 936         int infd[2], outfd[2];
 937         pid_t pid;
 938
 939         argc = 1;
 940         va_start(ap, command);
 941         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 942                 argc++;
 943         }
 944         argv[argc] = NULL;      /* make sure */
 945         va_end(ap);
 946
 947         if (pipe(infd) != 0) {
 948                 return 0;
 949         }
 950
 951         if (pipe(outfd) != 0) {
 952                 close(infd[0]);
 953                 close(infd[1]);
 954                 return 0;
 955         }
 956
 957         fflush(NULL);
 958         switch (pid = fork()) {
 959         case -1:                        /* failure */
 960                 close(infd[0]);
 961                 close(infd[1]);
 962                 close(outfd[0]);
 963                 close(outfd[1]);
 964                 return 0;
 965         case 0:                 /* child */
 966                 dup2(infd[0], 0);
 967                 dup2(outfd[1], 1);
 968                 close(infd[0]);
 969                 close(infd[1]);
 970                 close(outfd[0]);
 971                 close(outfd[1]);
 972                 execvp(command, argv);
 973                 exit(127);
 974         default:                        /* parent */
 975                 *in = fdopen(infd[1], "w");
 976                 *out = fdopen(outfd[0], "r");
 977                 close(infd[0]);
 978                 close(outfd[1]);
 979                 return pid;
 980         }
 981         /* unreached */
 982 }
 983
 984 static char *run_mapping(char *physical, struct mapping_defn_t * map)
 985 {
 986         FILE *in, *out;
 987         int i, status;
 988         pid_t pid;
 989
 990         char *logical = xstrdup(physical);
 991
 992         /* Run the mapping script. */
 993         pid = popen2(&in, &out, map->script, physical, NULL);
 994
 995         /* popen2() returns 0 on failure. */
 996         if (pid == 0)
 997                 return logical;
 998
 999         /* Write mappings to stdin of mapping script. */
1000         for (i = 0; i < map->n_mappings; i++) {
1001                 fprintf(in, "%s\n", map->mapping[i]);
1002         }
1003         fclose(in);
1004         waitpid(pid, &status, 0);
1005
1006         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1007                 /* If the mapping script exited successfully, try to
1008                  * grab a line of output and use that as the name of the
1009                  * logical interface. */
1010                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1011
1012                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1013                         /* If we are able to read a line of output from the script,
1014                          * remove any trailing whitespace and use this value
1015                          * as the name of the logical interface. */
1016                         char *pch = new_logical + strlen(new_logical) - 1;
1017
1018                         while (pch >= new_logical && isspace(*pch))
1019                                 *(pch--) = '\0';
1020
1021                         free(logical);
1022                         logical = new_logical;
1023                 } else {
1024                         /* If we are UNABLE to read a line of output, discard our
1025                          * freshly allocated memory. */
1026                         free(new_logical);
1027                 }
1028         }
1029
1030         fclose(out);
1031
1032         return logical;
1033 }
1034 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1035
1036 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1037 {
1038         unsigned short iface_len = strlen(iface);
1039         llist_t *search = state_list;
1040
1041         while (search) {
1042                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1043                                 (search->data[iface_len] == '=')) {
1044                         return search;
1045                 }
1046                 search = search->link;
1047         }
1048         return NULL;
1049 }
1050
1051 int ifupdown_main(int argc, char **argv)
1052 {
1053         static const char statefile[] = "/var/run/ifstate";
1054
1055         int (*cmds)(struct interface_defn_t *) = NULL;
1056         struct interfaces_file_t *defn;
1057         llist_t *state_list = NULL;
1058         llist_t *target_list = NULL;
1059         const char *interfaces = "/etc/network/interfaces";
1060         int any_failures = 0;
1061         int i;
1062
1063         if (bb_applet_name[2] == 'u') {
1064                 /* ifup command */
1065                 cmds = iface_up;
1066         } else {
1067                 /* ifdown command */
1068                 cmds = iface_down;
1069         }
1070
1071         option_mask = bb_getopt_ulflags(argc, argv, OPTION_STR, &interfaces);
1072         if (argc - optind > 0) {
1073                 if (DO_ALL) bb_show_usage();
1074         } else
1075                 if (!DO_ALL) bb_show_usage();
1076
1077         debug_noise("reading %s file:\n", interfaces);
1078         defn = read_interfaces(interfaces);
1079         debug_noise("\ndone reading %s\n\n", interfaces);
1080
1081         if (!defn) {
1082                 exit(EXIT_FAILURE);
1083         }
1084
1085         startup_PATH = getenv("PATH");
1086         if (!startup_PATH) startup_PATH = "";
1087
1088         /* Create a list of interfaces to work on */
1089         if (DO_ALL) {
1090                 if (cmds == iface_up) {
1091                         target_list = defn->autointerfaces;
1092                 } else {
1093                         /* iface_down */
1094                         const llist_t *list = state_list;
1095                         while (list) {
1096                                 llist_add_to_end(&target_list, xstrdup(list->data));
1097                                 list = list->link;
1098                         }
1099                         target_list = defn->autointerfaces;
1100                 }
1101         } else {
1102                 llist_add_to_end(&target_list, argv[optind]);
1103         }
1104
1105
1106         /* Update the interfaces */
1107         while (target_list) {
1108                 llist_t *iface_list;
1109                 struct interface_defn_t *currif;
1110                 char *iface;
1111                 char *liface;
1112                 char *pch;
1113                 int okay = 0;
1114                 int cmds_ret;
1115
1116                 iface = xstrdup(target_list->data);
1117                 target_list = target_list->link;
1118
1119                 pch = strchr(iface, '=');
1120                 if (pch) {
1121                         *pch = '\0';
1122                         liface = xstrdup(pch + 1);
1123                 } else {
1124                         liface = xstrdup(iface);
1125                 }
1126
1127                 if (!FORCE) {
1128                         const llist_t *iface_state = find_iface_state(state_list, iface);
1129
1130                         if (cmds == iface_up) {
1131                                 /* ifup */
1132                                 if (iface_state) {
1133                                         bb_error_msg("interface %s already configured", iface);
1134                                         continue;
1135                                 }
1136                         } else {
1137                                 /* ifdown */
1138                                 if (iface_state) {
1139                                         bb_error_msg("interface %s not configured", iface);
1140                                         continue;
1141                                 }
1142                         }
1143                 }
1144
1145 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1146                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1147                         struct mapping_defn_t *currmap;
1148
1149                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1150                                 for (i = 0; i < currmap->n_matches; i++) {
1151                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1152                                                 continue;
1153                                         if (VERBOSE) {
1154                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1155                                         }
1156                                         liface = run_mapping(iface, currmap);
1157                                         break;
1158                                 }
1159                         }
1160                 }
1161 #endif
1162
1163
1164                 iface_list = defn->ifaces;
1165                 while (iface_list) {
1166                         currif = (struct interface_defn_t *) iface_list->data;
1167                         if (strcmp(liface, currif->iface) == 0) {
1168                                 char *oldiface = currif->iface;
1169
1170                                 okay = 1;
1171                                 currif->iface = iface;
1172
1173                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1174
1175                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1176                                 cmds_ret = cmds(currif);
1177                                 if (cmds_ret == -1) {
1178                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1179                                                         liface, currif->address_family->name);
1180                                         any_failures += 1;
1181                                 } else if (cmds_ret == 0) {
1182                                         any_failures += 1;
1183                                 }
1184
1185                                 currif->iface = oldiface;
1186                         }
1187                         iface_list = iface_list->link;
1188                 }
1189                 if (VERBOSE) {
1190                         puts("");
1191                 }
1192
1193                 if (!okay && !FORCE) {
1194                         bb_error_msg("ignoring unknown interface %s", liface);
1195                         any_failures += 1;
1196                 } else {
1197                         llist_t *iface_state = find_iface_state(state_list, iface);
1198
1199                         if (cmds == iface_up) {
1200                                 char *newiface = xasprintf("%s=%s", iface, liface);
1201                                 if (iface_state == NULL) {
1202                                         llist_add_to_end(&state_list, newiface);
1203                                 } else {
1204                                         free(iface_state->data);
1205                                         iface_state->data = newiface;
1206                                 }
1207                         } else {
1208                                 /* Remove an interface from the linked list */
1209                                 free(llist_pop(&iface_state));
1210                         }
1211                 }
1212         }
1213
1214         /* Actually write the new state */
1215         if (!NO_ACT) {
1216                 FILE *state_fp = NULL;
1217
1218                 state_fp = xfopen(statefile, "w");
1219                 while (state_list) {
1220                         if (state_list->data) {
1221                                 fputs(state_list->data, state_fp);
1222                                 fputc('\n', state_fp);
1223                         }
1224                         state_list = state_list->link;
1225                 }
1226                 fclose(state_fp);
1227         }
1228
1229         if (any_failures)
1230                 return 1;
1231         return 0;
1232 }