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 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 110
 111 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 112
 113 static unsigned int count_bits(unsigned int a)
 114 {
 115         unsigned int result;
 116         result = (a & 0x55) + ((a >> 1) & 0x55);
 117         result = (result & 0x33) + ((result >> 2) & 0x33);
 118         return ((result & 0x0F) + ((result >> 4) & 0x0F));
 119 }
 120
 121 static int count_netmask_bits(char *dotted_quad)
 122 {
 123         unsigned int result, a, b, c, d;
 124         /* Found a netmask...  Check if it is dotted quad */
 125         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 126                 return -1;
 127         result = count_bits(a);
 128         result += count_bits(b);
 129         result += count_bits(c);
 130         result += count_bits(d);
 131         return (int)result;
 132 }
 133 #endif
 134
 135 static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
 136 {
 137         if (*pos + str_length >= *len) {
 138                 char *newbuf;
 139
 140                 newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
 141                 *buf = newbuf;
 142                 *len = *len * 2 + str_length + 1;
 143         }
 144
 145         while (str_length-- >= 1) {
 146                 (*buf)[(*pos)++] = *str;
 147                 str++;
 148         }
 149         (*buf)[*pos] = '\0';
 150 }
 151
 152 static int strncmpz(char *l, char *r, size_t llen)
 153 {
 154         int i = strncmp(l, r, llen);
 155
 156         if (i == 0) {
 157                 return -r[llen];
 158         } else {
 159                 return i;
 160         }
 161 }
 162
 163 static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
 164 {
 165         int i;
 166
 167         if (strncmpz(id, "iface", idlen) == 0) {
 168                 char *result;
 169                 static char label_buf[20];
 170                 strncpy(label_buf, ifd->iface, 19);
 171                 label_buf[19]=0;
 172                 result = strchr(label_buf, ':');
 173                 if (result) {
 174                         *result=0;
 175                 }
 176                 return label_buf;
 177         } else if (strncmpz(id, "label", idlen) == 0) {
 178                 return ifd->iface;
 179         } else {
 180                 for (i = 0; i < ifd->n_options; i++) {
 181                         if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 182                                 return ifd->option[i].value;
 183                         }
 184                 }
 185         }
 186
 187         return NULL;
 188 }
 189
 190 static char *parse(char *command, struct interface_defn_t *ifd)
 191 {
 192
 193         char *result = NULL;
 194         size_t pos = 0, len = 0;
 195         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 196         int okay[MAX_OPT_DEPTH] = { 1 };
 197         int opt_depth = 1;
 198
 199         while (*command) {
 200                 switch (*command) {
 201                 default:
 202                         addstr(&result, &len, &pos, command, 1);
 203                         command++;
 204                         break;
 205                 case '\\':
 206                         if (command[1]) {
 207                                 addstr(&result, &len, &pos, command + 1, 1);
 208                                 command += 2;
 209                         } else {
 210                                 addstr(&result, &len, &pos, command, 1);
 211                                 command++;
 212                         }
 213                         break;
 214                 case '[':
 215                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 216                                 old_pos[opt_depth] = pos;
 217                                 okay[opt_depth] = 1;
 218                                 opt_depth++;
 219                                 command += 2;
 220                         } else {
 221                                 addstr(&result, &len, &pos, "[", 1);
 222                                 command++;
 223                         }
 224                         break;
 225                 case ']':
 226                         if (command[1] == ']' && opt_depth > 1) {
 227                                 opt_depth--;
 228                                 if (!okay[opt_depth]) {
 229                                         pos = old_pos[opt_depth];
 230                                         result[pos] = '\0';
 231                                 }
 232                                 command += 2;
 233                         } else {
 234                                 addstr(&result, &len, &pos, "]", 1);
 235                                 command++;
 236                         }
 237                         break;
 238                 case '%':
 239                         {
 240                                 char *nextpercent;
 241                                 char *varvalue;
 242
 243                                 command++;
 244                                 nextpercent = strchr(command, '%');
 245                                 if (!nextpercent) {
 246                                         errno = EUNBALPER;
 247                                         free(result);
 248                                         return NULL;
 249                                 }
 250
 251                                 varvalue = get_var(command, nextpercent - command, ifd);
 252
 253                                 if (varvalue) {
 254                                         addstr(&result, &len, &pos, varvalue, strlen(varvalue));
 255                                 } else {
 256 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 257                                         /* Sigh...  Add a special case for 'ip' to convert from
 258                                          * dotted quad to bit count style netmasks.  */
 259                                         if (strncmp(command, "bnmask", 6)==0) {
 260                                                 int res;
 261                                                 varvalue = get_var("netmask", 7, ifd);
 262                                                 if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 263                                                         char argument[255];
 264                                                         sprintf(argument, "%d", res);
 265                                                         addstr(&result, &len, &pos, argument, strlen(argument));
 266                                                         command = nextpercent + 1;
 267                                                         break;
 268                                                 }
 269                                         }
 270 #endif
 271                                         okay[opt_depth - 1] = 0;
 272                                 }
 273
 274                                 command = nextpercent + 1;
 275                         }
 276                         break;
 277                 }
 278         }
 279
 280         if (opt_depth > 1) {
 281                 errno = EUNBALBRACK;
 282                 free(result);
 283                 return NULL;
 284         }
 285
 286         if (!okay[0]) {
 287                 errno = EUNDEFVAR;
 288                 free(result);
 289                 return NULL;
 290         }
 291
 292         return result;
 293 }
 294
 295 /* execute() returns 1 for success and 0 for failure */
 296 static int execute(char *command, struct interface_defn_t *ifd, execfn *exec)
 297 {
 298         char *out;
 299         int ret;
 300
 301         out = parse(command, ifd);
 302         if (!out) {
 303                 return 0;
 304         }
 305         ret = (*exec)(out);
 306
 307         free(out);
 308         if (ret != 1) {
 309                 return 0;
 310         }
 311         return 1;
 312 }
 313 #endif
 314
 315 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 316 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 317 {
 318 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 319         int result;
 320         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 321         result += execute("ip link set %iface% up", ifd, exec);
 322         return ((result == 2) ? 2 : 0);
 323 #else
 324         return execute("ifconfig %iface% add ::1", ifd, exec);
 325 #endif
 326 }
 327
 328 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 329 {
 330 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 331         return execute("ip link set %iface% down", ifd, exec);
 332 #else
 333         return execute("ifconfig %iface% del ::1", ifd, exec);
 334 #endif
 335 }
 336
 337 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 338 {
 339         int result;
 340 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 341         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 342         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 343         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 344 #else
 345         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 346         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 347         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 348 #endif
 349         return ((result == 3) ? 3 : 0);
 350 }
 351
 352 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 353 {
 354 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 355         return execute("ip link set %iface% down", ifd, exec);
 356 #else
 357         return execute("ifconfig %iface% down", ifd, exec);
 358 #endif
 359 }
 360
 361 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 362 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 363 {
 364         int result;
 365         result = execute("ip tunnel add %iface% mode sit remote "
 366                         "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 367         result += execute("ip link set %iface% up", ifd, exec);
 368         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 369         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 370         return ((result == 4) ? 4 : 0);
 371 }
 372
 373 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 374 {
 375         return execute("ip tunnel del %iface%", ifd, exec);
 376 }
 377 #endif
 378
 379 static const struct method_t methods6[] = {
 380 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 381         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 382 #endif
 383         { "static", static_up6, static_down6, },
 384         { "loopback", loopback_up6, loopback_down6, },
 385 };
 386
 387 static const struct address_family_t addr_inet6 = {
 388         "inet6",
 389         sizeof(methods6) / sizeof(struct method_t),
 390         methods6
 391 };
 392 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 393
 394 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 395 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 396 {
 397 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 398         int result;
 399         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 400         result += execute("ip link set %iface% up", ifd, exec);
 401         return ((result == 2) ? 2 : 0);
 402 #else
 403         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 404 #endif
 405 }
 406
 407 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 408 {
 409 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 410         int result;
 411         result = execute("ip addr flush dev %iface%", ifd, exec);
 412         result += execute("ip link set %iface% down", ifd, exec);
 413         return ((result == 2) ? 2 : 0);
 414 #else
 415         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 416 #endif
 417 }
 418
 419 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 420 {
 421         int result;
 422 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 423         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 424                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 425         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 426         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 427         return ((result == 3) ? 3 : 0);
 428 #else
 429         result = execute("ifconfig %iface% %address% netmask %netmask% "
 430                         "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] "
 431                         "[[media %media%]] [[mtu %mtu%]] [[hw %hwaddress%]] up",
 432                         ifd, exec);
 433         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 434         return ((result == 2) ? 2 : 0);
 435 #endif
 436 }
 437
 438 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 439 {
 440         int result;
 441 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 442         result = execute("ip addr flush dev %iface%", ifd, exec);
 443         result += execute("ip link set %iface% down", ifd, exec);
 444 #else
 445         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 446         result += execute("ifconfig %iface% down", ifd, exec);
 447 #endif
 448         return ((result == 2) ? 2 : 0);
 449 }
 450
 451 static int execable(char *program)
 452 {
 453         struct stat buf;
 454         if (0 == stat(program, &buf)) {
 455                 if (S_ISREG(buf.st_mode) && (S_IXUSR & buf.st_mode)) {
 456                         return(1);
 457                 }
 458         }
 459         return(0);
 460 }
 461
 462 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 463 {
 464         if (execable("/sbin/udhcpc")) {
 465                 return( execute("udhcpc -n -p /var/run/udhcpc.%iface%.pid -i "
 466                                         "%iface% [[-H %hostname%]] [[-c %clientid%]]", ifd, exec));
 467         } else if (execable("/sbin/pump")) {
 468                 return( execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]", ifd, exec));
 469         } else if (execable("/sbin/dhclient")) {
 470                 return( execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%", ifd, exec));
 471         } else if (execable("/sbin/dhcpcd")) {
 472                 return( execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 473                                         "[[-l %leasetime%]] %iface%", ifd, exec));
 474         }
 475         return(0);
 476 }
 477
 478 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 479 {
 480         int result = 0;
 481         if (execable("/sbin/udhcpc")) {
 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                 result = execute("kill -USR2 `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 486                 result += execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 487         } else if (execable("/sbin/pump")) {
 488                 result = execute("pump -i %iface% -k", ifd, exec);
 489         } else if (execable("/sbin/dhclient")) {
 490                 result = execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null", ifd, exec);
 491         } else if (execable("/sbin/dhcpcd")) {
 492                 result = execute("dhcpcd -k %iface%", ifd, exec);
 493         }
 494         return (result || static_down(ifd, exec));
 495 }
 496
 497 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 498 {
 499         return execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 500                         "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 501                         "--returniffail --serverbcast", ifd, exec);
 502 }
 503
 504 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 505 {
 506         return execute("pon [[%provider%]]", ifd, exec);
 507 }
 508
 509 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 510 {
 511         return execute("poff [[%provider%]]", ifd, exec);
 512 }
 513
 514 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 515 {
 516         return execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 517                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec);
 518 }
 519
 520 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 521 {
 522         return execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 523                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 524 }
 525
 526 static const struct method_t methods[] = {
 527         { "wvdial", wvdial_up, wvdial_down, },
 528         { "ppp", ppp_up, ppp_down, },
 529         { "static", static_up, static_down, },
 530         { "bootp", bootp_up, static_down, },
 531         { "dhcp", dhcp_up, dhcp_down, },
 532         { "loopback", loopback_up, loopback_down, },
 533 };
 534
 535 static const struct address_family_t addr_inet = {
 536         "inet",
 537         sizeof(methods) / sizeof(struct method_t),
 538         methods
 539 };
 540
 541 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 542
 543 static char *next_word(char **buf)
 544 {
 545         unsigned short length;
 546         char *word;
 547
 548         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 549                 return NULL;
 550         }
 551
 552         /* Skip over leading whitespace */
 553         word = *buf;
 554         while (isspace(*word)) {
 555                 ++word;
 556         }
 557
 558         /* Skip over comments */
 559         if (*word == '#') {
 560                 return NULL;
 561         }
 562
 563         /* Find the length of this word */
 564         length = strcspn(word, " \t\n");
 565         if (length == 0) {
 566                 return NULL;
 567         }
 568         *buf = word + length;
 569         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 570         if (**buf) {
 571                 **buf = '\0';
 572                 (*buf)++;
 573         }
 574
 575         return word;
 576 }
 577
 578 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 579 {
 580         int i;
 581
 582         for (i = 0; af[i]; i++) {
 583                 if (strcmp(af[i]->name, name) == 0) {
 584                         return af[i];
 585                 }
 586         }
 587         return NULL;
 588 }
 589
 590 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 591 {
 592         int i;
 593
 594         for (i = 0; i < af->n_methods; i++) {
 595                 if (strcmp(af->method[i].name, name) == 0) {
 596                         return &af->method[i];
 597                 }
 598         }
 599         return NULL;
 600 }
 601
 602 static const llist_t *find_list_string(const llist_t *list, const char *string)
 603 {
 604         while (list) {
 605                 if (strcmp(list->data, string) == 0) {
 606                         return list;
 607                 }
 608                 list = list->link;
 609         }
 610         return NULL;
 611 }
 612
 613 static struct interfaces_file_t *read_interfaces(const char *filename)
 614 {
 615 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 616         struct mapping_defn_t *currmap = NULL;
 617 #endif
 618         struct interface_defn_t *currif = NULL;
 619         struct interfaces_file_t *defn;
 620         FILE *f;
 621         char *firstword;
 622         char *buf;
 623
 624         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 625
 626         defn = xzalloc(sizeof(struct interfaces_file_t));
 627
 628         f = xfopen(filename, "r");
 629
 630         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 631                 char *buf_ptr = buf;
 632
 633                 firstword = next_word(&buf_ptr);
 634                 if (firstword == NULL) {
 635                         free(buf);
 636                         continue;       /* blank line */
 637                 }
 638
 639                 if (strcmp(firstword, "mapping") == 0) {
 640 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 641                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 642
 643                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 644                                 if (currmap->max_matches == currmap->n_matches) {
 645                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 646                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 647                                 }
 648
 649                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 650                         }
 651                         currmap->max_mappings = 0;
 652                         currmap->n_mappings = 0;
 653                         currmap->mapping = NULL;
 654                         currmap->script = NULL;
 655                         {
 656                                 struct mapping_defn_t **where = &defn->mappings;
 657                                 while (*where != NULL) {
 658                                         where = &(*where)->next;
 659                                 }
 660                                 *where = currmap;
 661                                 currmap->next = NULL;
 662                         }
 663                         debug_noise("Added mapping\n");
 664 #endif
 665                         currently_processing = MAPPING;
 666                 } else if (strcmp(firstword, "iface") == 0) {
 667                         static const struct address_family_t *const addr_fams[] = {
 668 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 669                                 &addr_inet,
 670 #endif
 671 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 672                                 &addr_inet6,
 673 #endif
 674                                 NULL
 675                         };
 676
 677                         char *iface_name;
 678                         char *address_family_name;
 679                         char *method_name;
 680                         llist_t *iface_list;
 681
 682                         currif = xzalloc(sizeof(struct interface_defn_t));
 683                         iface_name = next_word(&buf_ptr);
 684                         address_family_name = next_word(&buf_ptr);
 685                         method_name = next_word(&buf_ptr);
 686
 687                         if (buf_ptr == NULL) {
 688                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 689                                 return NULL;
 690                         }
 691
 692                         /* ship any trailing whitespace */
 693                         while (isspace(*buf_ptr)) {
 694                                 ++buf_ptr;
 695                         }
 696
 697                         if (buf_ptr[0] != '\0') {
 698                                 bb_error_msg("too many parameters \"%s\"", buf);
 699                                 return NULL;
 700                         }
 701
 702                         currif->iface = xstrdup(iface_name);
 703
 704                         currif->address_family = get_address_family(addr_fams, address_family_name);
 705                         if (!currif->address_family) {
 706                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 707                                 return NULL;
 708                         }
 709
 710                         currif->method = get_method(currif->address_family, method_name);
 711                         if (!currif->method) {
 712                                 bb_error_msg("unknown method \"%s\"", method_name);
 713                                 return NULL;
 714                         }
 715
 716                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 717                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 718                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 719                                         (tmp->address_family == currif->address_family)) {
 720                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 721                                         return NULL;
 722                                 }
 723                         }
 724                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 725
 726                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 727                         currently_processing = IFACE;
 728                 } else if (strcmp(firstword, "auto") == 0) {
 729                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 730
 731                                 /* Check the interface isnt already listed */
 732                                 if (find_list_string(defn->autointerfaces, firstword)) {
 733                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 734                                 }
 735
 736                                 /* Add the interface to the list */
 737                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 738                                 debug_noise("\nauto %s\n", firstword);
 739                         }
 740                         currently_processing = NONE;
 741                 } else {
 742                         switch (currently_processing) {
 743                         case IFACE:
 744                                 {
 745                                         int i;
 746
 747                                         if (strlen(buf_ptr) == 0) {
 748                                                 bb_error_msg("option with empty value \"%s\"", buf);
 749                                                 return NULL;
 750                                         }
 751
 752                                         if (strcmp(firstword, "up") != 0
 753                                                         && strcmp(firstword, "down") != 0
 754                                                         && strcmp(firstword, "pre-up") != 0
 755                                                         && strcmp(firstword, "post-down") != 0) {
 756                                                 for (i = 0; i < currif->n_options; i++) {
 757                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 758                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 759                                                                 return NULL;
 760                                                         }
 761                                                 }
 762                                         }
 763                                 }
 764                                 if (currif->n_options >= currif->max_options) {
 765                                         struct variable_t *opt;
 766
 767                                         currif->max_options = currif->max_options + 10;
 768                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 769                                         currif->option = opt;
 770                                 }
 771                                 currif->option[currif->n_options].name = xstrdup(firstword);
 772                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 773                                 if (!currif->option[currif->n_options].name) {
 774                                         perror(filename);
 775                                         return NULL;
 776                                 }
 777                                 if (!currif->option[currif->n_options].value) {
 778                                         perror(filename);
 779                                         return NULL;
 780                                 }
 781                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 782                                                 currif->option[currif->n_options].value);
 783                                 currif->n_options++;
 784                                 break;
 785                         case MAPPING:
 786 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 787                                 if (strcmp(firstword, "script") == 0) {
 788                                         if (currmap->script != NULL) {
 789                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 790                                                 return NULL;
 791                                         } else {
 792                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 793                                         }
 794                                 } else if (strcmp(firstword, "map") == 0) {
 795                                         if (currmap->max_mappings == currmap->n_mappings) {
 796                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 797                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 798                                         }
 799                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 800                                         currmap->n_mappings++;
 801                                 } else {
 802                                         bb_error_msg("misplaced option \"%s\"", buf);
 803                                         return NULL;
 804                                 }
 805 #endif
 806                                 break;
 807                         case NONE:
 808                         default:
 809                                 bb_error_msg("misplaced option \"%s\"", buf);
 810                                 return NULL;
 811                         }
 812                 }
 813                 free(buf);
 814         }
 815         if (ferror(f) != 0) {
 816                 bb_perror_msg_and_die("%s", filename);
 817         }
 818         fclose(f);
 819
 820         return defn;
 821 }
 822
 823 static char *setlocalenv(char *format, const char *name, const char *value)
 824 {
 825         char *result;
 826         char *here;
 827         char *there;
 828
 829         result = xasprintf(format, name, value);
 830
 831         for (here = there = result; *there != '=' && *there; there++) {
 832                 if (*there == '-')
 833                         *there = '_';
 834                 if (isalpha(*there))
 835                         *there = toupper(*there);
 836
 837                 if (isalnum(*there) || *there == '_') {
 838                         *here = *there;
 839                         here++;
 840                 }
 841         }
 842         memmove(here, there, strlen(there) + 1);
 843
 844         return result;
 845 }
 846
 847 static void set_environ(struct interface_defn_t *iface, const char *mode)
 848 {
 849         char **environend;
 850         int i;
 851         const int n_env_entries = iface->n_options + 5;
 852         char **ppch;
 853
 854         if (__myenviron != NULL) {
 855                 for (ppch = __myenviron; *ppch; ppch++) {
 856                         free(*ppch);
 857                         *ppch = NULL;
 858                 }
 859                 free(__myenviron);
 860         }
 861         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 862         environend = __myenviron;
 863
 864         for (i = 0; i < iface->n_options; i++) {
 865                 if (strcmp(iface->option[i].name, "up") == 0
 866                                 || strcmp(iface->option[i].name, "down") == 0
 867                                 || strcmp(iface->option[i].name, "pre-up") == 0
 868                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 869                         continue;
 870                 }
 871                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 872         }
 873
 874         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 875         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 876         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 877         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 878         /* FIXME: we must not impose our own PATH, it is admin's job!
 879            Use PATH from parent env */
 880         *(environend++) = setlocalenv("%s=%s", "PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin");
 881 }
 882
 883 static int doit(char *str)
 884 {
 885         if (option_mask & (OPT_no_act|OPT_verbose)) {
 886                 puts(str);
 887         }
 888         if (!(option_mask & OPT_no_act)) {
 889                 pid_t child;
 890                 int status;
 891
 892                 fflush(NULL);
 893                 switch (child = fork()) {
 894                 case -1:                /* failure */
 895                         return 0;
 896                 case 0:         /* child */
 897                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 898                         exit(127);
 899                 }
 900                 waitpid(child, &status, 0);
 901                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 902                         return 0;
 903                 }
 904         }
 905         return 1;
 906 }
 907
 908 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 909 {
 910         int i;
 911         char *buf;
 912         for (i = 0; i < ifd->n_options; i++) {
 913                 if (strcmp(ifd->option[i].name, opt) == 0) {
 914                         if (!doit(ifd->option[i].value)) {
 915                                 return 0;
 916                         }
 917                 }
 918         }
 919
 920         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 921         if (doit(buf) != 1) {
 922                 return 0;
 923         }
 924         return 1;
 925 }
 926
 927 static int check(char *str) {
 928         return str != NULL;
 929 }
 930
 931 static int iface_up(struct interface_defn_t *iface)
 932 {
 933         if (!iface->method->up(iface,check)) return -1;
 934         set_environ(iface, "start");
 935         if (!execute_all(iface, "pre-up")) return 0;
 936         if (!iface->method->up(iface, doit)) return 0;
 937         if (!execute_all(iface, "up")) return 0;
 938         return 1;
 939 }
 940
 941 static int iface_down(struct interface_defn_t *iface)
 942 {
 943         if (!iface->method->down(iface,check)) return -1;
 944         set_environ(iface, "stop");
 945         if (!execute_all(iface, "down")) return 0;
 946         if (!iface->method->down(iface, doit)) return 0;
 947         if (!execute_all(iface, "post-down")) return 0;
 948         return 1;
 949 }
 950
 951 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 952 static int popen2(FILE **in, FILE **out, char *command, ...)
 953 {
 954         va_list ap;
 955         char *argv[11] = { command };
 956         int argc;
 957         int infd[2], outfd[2];
 958         pid_t pid;
 959
 960         argc = 1;
 961         va_start(ap, command);
 962         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 963                 argc++;
 964         }
 965         argv[argc] = NULL;      /* make sure */
 966         va_end(ap);
 967
 968         if (pipe(infd) != 0) {
 969                 return 0;
 970         }
 971
 972         if (pipe(outfd) != 0) {
 973                 close(infd[0]);
 974                 close(infd[1]);
 975                 return 0;
 976         }
 977
 978         fflush(NULL);
 979         switch (pid = fork()) {
 980         case -1:                        /* failure */
 981                 close(infd[0]);
 982                 close(infd[1]);
 983                 close(outfd[0]);
 984                 close(outfd[1]);
 985                 return 0;
 986         case 0:                 /* child */
 987                 dup2(infd[0], 0);
 988                 dup2(outfd[1], 1);
 989                 close(infd[0]);
 990                 close(infd[1]);
 991                 close(outfd[0]);
 992                 close(outfd[1]);
 993                 execvp(command, argv);
 994                 exit(127);
 995         default:                        /* parent */
 996                 *in = fdopen(infd[1], "w");
 997                 *out = fdopen(outfd[0], "r");
 998                 close(infd[0]);
 999                 close(outfd[1]);
1000                 return pid;
1001         }
1002         /* unreached */
1003 }
1004
1005 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1006 {
1007         FILE *in, *out;
1008         int i, status;
1009         pid_t pid;
1010
1011         char *logical = xstrdup(physical);
1012
1013         /* Run the mapping script. */
1014         pid = popen2(&in, &out, map->script, physical, NULL);
1015
1016         /* popen2() returns 0 on failure. */
1017         if (pid == 0)
1018                 return logical;
1019
1020         /* Write mappings to stdin of mapping script. */
1021         for (i = 0; i < map->n_mappings; i++) {
1022                 fprintf(in, "%s\n", map->mapping[i]);
1023         }
1024         fclose(in);
1025         waitpid(pid, &status, 0);
1026
1027         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1028                 /* If the mapping script exited successfully, try to
1029                  * grab a line of output and use that as the name of the
1030                  * logical interface. */
1031                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1032
1033                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1034                         /* If we are able to read a line of output from the script,
1035                          * remove any trailing whitespace and use this value
1036                          * as the name of the logical interface. */
1037                         char *pch = new_logical + strlen(new_logical) - 1;
1038
1039                         while (pch >= new_logical && isspace(*pch))
1040                                 *(pch--) = '\0';
1041
1042                         free(logical);
1043                         logical = new_logical;
1044                 } else {
1045                         /* If we are UNABLE to read a line of output, discard our
1046                          * freshly allocated memory. */
1047                         free(new_logical);
1048                 }
1049         }
1050
1051         fclose(out);
1052
1053         return logical;
1054 }
1055 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1056
1057 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1058 {
1059         unsigned short iface_len = strlen(iface);
1060         llist_t *search = state_list;
1061
1062         while (search) {
1063                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1064                                 (search->data[iface_len] == '=')) {
1065                         return search;
1066                 }
1067                 search = search->link;
1068         }
1069         return NULL;
1070 }
1071
1072 int ifupdown_main(int argc, char **argv)
1073 {
1074         static const char statefile[] = "/var/run/ifstate";
1075
1076         int (*cmds)(struct interface_defn_t *) = NULL;
1077         struct interfaces_file_t *defn;
1078         llist_t *state_list = NULL;
1079         llist_t *target_list = NULL;
1080         const char *interfaces = "/etc/network/interfaces";
1081         int any_failures = 0;
1082         int i;
1083
1084         if (bb_applet_name[2] == 'u') {
1085                 /* ifup command */
1086                 cmds = iface_up;
1087         } else {
1088                 /* ifdown command */
1089                 cmds = iface_down;
1090         }
1091
1092         option_mask = bb_getopt_ulflags(argc, argv, OPTION_STR, &interfaces);
1093         if (argc - optind > 0) {
1094                 if (DO_ALL) bb_show_usage();
1095         } else
1096                 if (!DO_ALL) bb_show_usage();
1097
1098         debug_noise("reading %s file:\n", interfaces);
1099         defn = read_interfaces(interfaces);
1100         debug_noise("\ndone reading %s\n\n", interfaces);
1101
1102         if (!defn) {
1103                 exit(EXIT_FAILURE);
1104         }
1105
1106         /* Create a list of interfaces to work on */
1107         if (DO_ALL) {
1108                 if (cmds == iface_up) {
1109                         target_list = defn->autointerfaces;
1110                 } else {
1111                         /* iface_down */
1112                         const llist_t *list = state_list;
1113                         while (list) {
1114                                 llist_add_to_end(&target_list, xstrdup(list->data));
1115                                 list = list->link;
1116                         }
1117                         target_list = defn->autointerfaces;
1118                 }
1119         } else {
1120                 llist_add_to_end(&target_list, argv[optind]);
1121         }
1122
1123
1124         /* Update the interfaces */
1125         while (target_list) {
1126                 llist_t *iface_list;
1127                 struct interface_defn_t *currif;
1128                 char *iface;
1129                 char *liface;
1130                 char *pch;
1131                 int okay = 0;
1132                 int cmds_ret;
1133
1134                 iface = xstrdup(target_list->data);
1135                 target_list = target_list->link;
1136
1137                 pch = strchr(iface, '=');
1138                 if (pch) {
1139                         *pch = '\0';
1140                         liface = xstrdup(pch + 1);
1141                 } else {
1142                         liface = xstrdup(iface);
1143                 }
1144
1145                 if (!FORCE) {
1146                         const llist_t *iface_state = find_iface_state(state_list, iface);
1147
1148                         if (cmds == iface_up) {
1149                                 /* ifup */
1150                                 if (iface_state) {
1151                                         bb_error_msg("interface %s already configured", iface);
1152                                         continue;
1153                                 }
1154                         } else {
1155                                 /* ifdown */
1156                                 if (iface_state) {
1157                                         bb_error_msg("interface %s not configured", iface);
1158                                         continue;
1159                                 }
1160                         }
1161                 }
1162
1163 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1164                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1165                         struct mapping_defn_t *currmap;
1166
1167                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1168                                 for (i = 0; i < currmap->n_matches; i++) {
1169                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1170                                                 continue;
1171                                         if (VERBOSE) {
1172                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1173                                         }
1174                                         liface = run_mapping(iface, currmap);
1175                                         break;
1176                                 }
1177                         }
1178                 }
1179 #endif
1180
1181
1182                 iface_list = defn->ifaces;
1183                 while (iface_list) {
1184                         currif = (struct interface_defn_t *) iface_list->data;
1185                         if (strcmp(liface, currif->iface) == 0) {
1186                                 char *oldiface = currif->iface;
1187
1188                                 okay = 1;
1189                                 currif->iface = iface;
1190
1191                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1192
1193                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1194                                 cmds_ret = cmds(currif);
1195                                 if (cmds_ret == -1) {
1196                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1197                                                         liface, currif->address_family->name);
1198                                         any_failures += 1;
1199                                 } else if (cmds_ret == 0) {
1200                                         any_failures += 1;
1201                                 }
1202
1203                                 currif->iface = oldiface;
1204                         }
1205                         iface_list = iface_list->link;
1206                 }
1207                 if (VERBOSE) {
1208                         puts("");
1209                 }
1210
1211                 if (!okay && !FORCE) {
1212                         bb_error_msg("ignoring unknown interface %s", liface);
1213                         any_failures += 1;
1214                 } else {
1215                         llist_t *iface_state = find_iface_state(state_list, iface);
1216
1217                         if (cmds == iface_up) {
1218                                 char *newiface = xasprintf("%s=%s", iface, liface);
1219                                 if (iface_state == NULL) {
1220                                         llist_add_to_end(&state_list, newiface);
1221                                 } else {
1222                                         free(iface_state->data);
1223                                         iface_state->data = newiface;
1224                                 }
1225                         } else {
1226                                 /* Remove an interface from the linked list */
1227                                 free(llist_pop(&iface_state));
1228                         }
1229                 }
1230         }
1231
1232         /* Actually write the new state */
1233         if (!NO_ACT) {
1234                 FILE *state_fp = NULL;
1235
1236                 state_fp = xfopen(statefile, "w");
1237                 while (state_list) {
1238                         if (state_list->data) {
1239                                 fputs(state_list->data, state_fp);
1240                                 fputc('\n', state_fp);
1241                         }
1242                         state_list = state_list->link;
1243                 }
1244                 fclose(state_fp);
1245         }
1246
1247         if (any_failures)
1248                 return 1;
1249         return 0;
1250 }