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 /* TODO: standardise execute() return codes to return 0 for success and 1 for failure */
  19
  20 #include "busybox.h"
  21 #include <sys/utsname.h>
  22 #include <fnmatch.h>
  23 #include <getopt.h>
  24
  25 #define MAX_OPT_DEPTH 10
  26 #define EUNBALBRACK 10001
  27 #define EUNDEFVAR   10002
  28 #define EUNBALPER   10000
  29
  30 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
  31 #define MAX_INTERFACE_LENGTH 10
  32 #endif
  33
  34 #define debug_noise(fmt, args...)
  35
  36 /* Forward declaration */
  37 struct interface_defn_t;
  38
  39 typedef int (execfn)(char *command);
  40
  41 struct method_t
  42 {
  43         char *name;
  44         int (*up)(struct interface_defn_t *ifd, execfn *e);
  45         int (*down)(struct interface_defn_t *ifd, execfn *e);
  46 };
  47
  48 struct address_family_t
  49 {
  50         char *name;
  51         int n_methods;
  52         struct method_t *method;
  53 };
  54
  55 struct mapping_defn_t
  56 {
  57         struct mapping_defn_t *next;
  58
  59         int max_matches;
  60         int n_matches;
  61         char **match;
  62
  63         char *script;
  64
  65         int max_mappings;
  66         int n_mappings;
  67         char **mapping;
  68 };
  69
  70 struct variable_t
  71 {
  72         char *name;
  73         char *value;
  74 };
  75
  76 struct interface_defn_t
  77 {
  78         struct address_family_t *address_family;
  79         struct method_t *method;
  80
  81         char *iface;
  82         int max_options;
  83         int n_options;
  84         struct variable_t *option;
  85 };
  86
  87 struct interfaces_file_t
  88 {
  89         llist_t *autointerfaces;
  90         llist_t *ifaces;
  91         struct mapping_defn_t *mappings;
  92 };
  93
  94 static unsigned option_mask;
  95 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  96 enum {
  97         OPT_do_all = 0x1,
  98         OPT_no_act = 0x2,
  99         OPT_verbose = 0x4,
 100         OPT_force = 0x8,
 101         OPT_no_mappings = 0x10,
 102 };
 103 #define DO_ALL (option_mask & OPT_do_all)
 104 #define NO_ACT (option_mask & OPT_no_act)
 105 #define VERBOSE (option_mask & OPT_verbose)
 106 #define FORCE (option_mask & OPT_force)
 107 #define NO_MAPPINGS (option_mask & OPT_no_mappings)
 108
 109 static char **__myenviron = NULL;
 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
 204                         default:
 205                                 addstr(&result, &len, &pos, command, 1);
 206                                 command++;
 207                                 break;
 208                         case '\\':
 209                                 if (command[1]) {
 210                                         addstr(&result, &len, &pos, command + 1, 1);
 211                                         command += 2;
 212                                 } else {
 213                                         addstr(&result, &len, &pos, command, 1);
 214                                         command++;
 215                                 }
 216                                 break;
 217                         case '[':
 218                                 if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 219                                         old_pos[opt_depth] = pos;
 220                                         okay[opt_depth] = 1;
 221                                         opt_depth++;
 222                                         command += 2;
 223                                 } else {
 224                                         addstr(&result, &len, &pos, "[", 1);
 225                                         command++;
 226                                 }
 227                                 break;
 228                         case ']':
 229                                 if (command[1] == ']' && opt_depth > 1) {
 230                                         opt_depth--;
 231                                         if (!okay[opt_depth]) {
 232                                                 pos = old_pos[opt_depth];
 233                                                 result[pos] = '\0';
 234                                         }
 235                                         command += 2;
 236                                 } else {
 237                                         addstr(&result, &len, &pos, "]", 1);
 238                                         command++;
 239                                 }
 240                                 break;
 241                         case '%':
 242                                 {
 243                                         char *nextpercent;
 244                                         char *varvalue;
 245
 246                                         command++;
 247                                         nextpercent = strchr(command, '%');
 248                                         if (!nextpercent) {
 249                                                 errno = EUNBALPER;
 250                                                 free(result);
 251                                                 return (NULL);
 252                                         }
 253
 254                                         varvalue = get_var(command, nextpercent - command, ifd);
 255
 256                                         if (varvalue) {
 257                                                 addstr(&result, &len, &pos, varvalue, strlen(varvalue));
 258                                         } else {
 259 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 260                                                 /* Sigh...  Add a special case for 'ip' to convert from
 261                                                  * dotted quad to bit count style netmasks.  */
 262                                                 if (strncmp(command, "bnmask", 6)==0) {
 263                                                         int res;
 264                                                         varvalue = get_var("netmask", 7, ifd);
 265                                                         if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 266                                                                 char argument[255];
 267                                                                 sprintf(argument, "%d", res);
 268                                                                 addstr(&result, &len, &pos, argument, strlen(argument));
 269                                                                 command = nextpercent + 1;
 270                                                                 break;
 271                                                         }
 272                                                 }
 273 #endif
 274                                                 okay[opt_depth - 1] = 0;
 275                                         }
 276
 277                                         command = nextpercent + 1;
 278                                 }
 279                                 break;
 280                 }
 281         }
 282
 283         if (opt_depth > 1) {
 284                 errno = EUNBALBRACK;
 285                 free(result);
 286                 return(NULL);
 287         }
 288
 289         if (!okay[0]) {
 290                 errno = EUNDEFVAR;
 291                 free(result);
 292                 return(NULL);
 293         }
 294
 295         return(result);
 296 }
 297
 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 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 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 execable(char *program)
 454 {
 455         struct stat buf;
 456         if (0 == stat(program, &buf)) {
 457                 if (S_ISREG(buf.st_mode) && (S_IXUSR & buf.st_mode)) {
 458                         return(1);
 459                 }
 460         }
 461         return(0);
 462 }
 463
 464 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 465 {
 466         if (execable("/sbin/udhcpc")) {
 467                 return( execute("udhcpc -n -p /var/run/udhcpc.%iface%.pid -i "
 468                                         "%iface% [[-H %hostname%]] [[-c %clientid%]]", ifd, exec));
 469         } else if (execable("/sbin/pump")) {
 470                 return( execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]", ifd, exec));
 471         } else if (execable("/sbin/dhclient")) {
 472                 return( execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%", ifd, exec));
 473         } else if (execable("/sbin/dhcpcd")) {
 474                 return( execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 475                                         "[[-l %leasetime%]] %iface%", ifd, exec));
 476         }
 477         return(0);
 478 }
 479
 480 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 481 {
 482         int result = 0;
 483         if (execable("/sbin/udhcpc")) {
 484                 /* SIGUSR2 forces udhcpc to release the current lease and go inactive,
 485                  * and SIGTERM causes udhcpc to exit.  Signals are queued and processed
 486                  * sequentially so we don't need to sleep */
 487                 result = execute("kill -USR2 `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 488                 result += execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 489         } else if (execable("/sbin/pump")) {
 490                 result = execute("pump -i %iface% -k", ifd, exec);
 491         } else if (execable("/sbin/dhclient")) {
 492                 result = execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null", ifd, exec);
 493         } else if (execable("/sbin/dhcpcd")) {
 494                 result = execute("dhcpcd -k %iface%", ifd, exec);
 495         }
 496         return (result || static_down(ifd, exec));
 497 }
 498
 499 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 500 {
 501         return( execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 502                                 "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 503                                 "--returniffail --serverbcast", ifd, exec));
 504 }
 505
 506 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 507 {
 508         return( execute("pon [[%provider%]]", ifd, exec));
 509 }
 510
 511 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 512 {
 513         return( execute("poff [[%provider%]]", ifd, exec));
 514 }
 515
 516 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 517 {
 518         return( execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 519                                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec));
 520 }
 521
 522 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 523 {
 524         return( execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 525                                 "-p /var/run/wvdial.%iface% -s 2", ifd, exec));
 526 }
 527
 528 static struct method_t methods[] =
 529 {
 530         { "wvdial", wvdial_up, wvdial_down, },
 531         { "ppp", ppp_up, ppp_down, },
 532         { "static", static_up, static_down, },
 533         { "bootp", bootp_up, static_down, },
 534         { "dhcp", dhcp_up, dhcp_down, },
 535         { "loopback", loopback_up, loopback_down, },
 536 };
 537
 538 static struct address_family_t addr_inet =
 539 {
 540         "inet",
 541         sizeof(methods) / sizeof(struct method_t),
 542         methods
 543 };
 544
 545 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 546
 547 static char *next_word(char **buf)
 548 {
 549         unsigned short length;
 550         char *word;
 551
 552         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 553                 return NULL;
 554         }
 555
 556         /* Skip over leading whitespace */
 557         word = *buf;
 558         while (isspace(*word)) {
 559                 ++word;
 560         }
 561
 562         /* Skip over comments */
 563         if (*word == '#') {
 564                 return(NULL);
 565         }
 566
 567         /* Find the length of this word */
 568         length = strcspn(word, " \t\n");
 569         if (length == 0) {
 570                 return(NULL);
 571         }
 572         *buf = word + length;
 573         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 574         if (**buf) {
 575                 **buf = '\0';
 576                 (*buf)++;
 577         }
 578
 579         return word;
 580 }
 581
 582 static struct address_family_t *get_address_family(struct address_family_t *af[], char *name)
 583 {
 584         int i;
 585
 586         for (i = 0; af[i]; i++) {
 587                 if (strcmp(af[i]->name, name) == 0) {
 588                         return af[i];
 589                 }
 590         }
 591         return NULL;
 592 }
 593
 594 static struct method_t *get_method(struct address_family_t *af, char *name)
 595 {
 596         int i;
 597
 598         for (i = 0; i < af->n_methods; i++) {
 599                 if (strcmp(af->method[i].name, name) == 0) {
 600                         return &af->method[i];
 601                 }
 602         }
 603         return(NULL);
 604 }
 605
 606 static const llist_t *find_list_string(const llist_t *list, const char *string)
 607 {
 608         while (list) {
 609                 if (strcmp(list->data, string) == 0) {
 610                         return(list);
 611                 }
 612                 list = list->link;
 613         }
 614         return(NULL);
 615 }
 616
 617 static struct interfaces_file_t *read_interfaces(const char *filename)
 618 {
 619 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 620         struct mapping_defn_t *currmap = NULL;
 621 #endif
 622         struct interface_defn_t *currif = NULL;
 623         struct interfaces_file_t *defn;
 624         FILE *f;
 625         char *firstword;
 626         char *buf;
 627
 628         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 629
 630         defn = xzalloc(sizeof(struct interfaces_file_t));
 631
 632         f = xfopen(filename, "r");
 633
 634         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 635                 char *buf_ptr = buf;
 636
 637                 firstword = next_word(&buf_ptr);
 638                 if (firstword == NULL) {
 639                         free(buf);
 640                         continue;       /* blank line */
 641                 }
 642
 643                 if (strcmp(firstword, "mapping") == 0) {
 644 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 645                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 646
 647                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 648                                 if (currmap->max_matches == currmap->n_matches) {
 649                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 650                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 651                                 }
 652
 653                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 654                         }
 655                         currmap->max_mappings = 0;
 656                         currmap->n_mappings = 0;
 657                         currmap->mapping = NULL;
 658                         currmap->script = NULL;
 659                         {
 660                                 struct mapping_defn_t **where = &defn->mappings;
 661                                 while (*where != NULL) {
 662                                         where = &(*where)->next;
 663                                 }
 664                                 *where = currmap;
 665                                 currmap->next = NULL;
 666                         }
 667                         debug_noise("Added mapping\n");
 668 #endif
 669                         currently_processing = MAPPING;
 670                 } else if (strcmp(firstword, "iface") == 0) {
 671                         {
 672                                 char *iface_name;
 673                                 char *address_family_name;
 674                                 char *method_name;
 675                                 struct address_family_t *addr_fams[] = {
 676 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 677                                         &addr_inet,
 678 #endif
 679 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 680                                         &addr_inet6,
 681 #endif
 682                                         NULL
 683                                 };
 684
 685                                 currif = xzalloc(sizeof(struct interface_defn_t));
 686                                 iface_name = next_word(&buf_ptr);
 687                                 address_family_name = next_word(&buf_ptr);
 688                                 method_name = next_word(&buf_ptr);
 689
 690                                 if (buf_ptr == NULL) {
 691                                         bb_error_msg("too few parameters for line \"%s\"", buf);
 692                                         return NULL;
 693                                 }
 694
 695                                 /* ship any trailing whitespace */
 696                                 while (isspace(*buf_ptr)) {
 697                                         ++buf_ptr;
 698                                 }
 699
 700                                 if (buf_ptr[0] != '\0') {
 701                                         bb_error_msg("too many parameters \"%s\"", buf);
 702                                         return NULL;
 703                                 }
 704
 705                                 currif->iface = xstrdup(iface_name);
 706
 707                                 currif->address_family = get_address_family(addr_fams, address_family_name);
 708                                 if (!currif->address_family) {
 709                                         bb_error_msg("unknown address type \"%s\"", address_family_name);
 710                                         return NULL;
 711                                 }
 712
 713                                 currif->method = get_method(currif->address_family, method_name);
 714                                 if (!currif->method) {
 715                                         bb_error_msg("unknown method \"%s\"", method_name);
 716                                         return NULL;
 717                                 }
 718
 719
 720                                 {
 721                                         llist_t *iface_list;
 722                                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 723                                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 724                                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 725                                                         (tmp->address_family == currif->address_family)) {
 726                                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 727                                                         return NULL;
 728                                                 }
 729                                         }
 730
 731                                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 732                                 }
 733                                 debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 734                         }
 735                         currently_processing = IFACE;
 736                 } else if (strcmp(firstword, "auto") == 0) {
 737                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 738
 739                                 /* Check the interface isnt already listed */
 740                                 if (find_list_string(defn->autointerfaces, firstword)) {
 741                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 742                                 }
 743
 744                                 /* Add the interface to the list */
 745                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 746                                 debug_noise("\nauto %s\n", firstword);
 747                         }
 748                         currently_processing = NONE;
 749                 } else {
 750                         switch (currently_processing) {
 751                                 case IFACE:
 752                                         {
 753                                                 int i;
 754
 755                                                 if (strlen(buf_ptr) == 0) {
 756                                                         bb_error_msg("option with empty value \"%s\"", buf);
 757                                                         return NULL;
 758                                                 }
 759
 760                                                 if (strcmp(firstword, "up") != 0
 761                                                                 && strcmp(firstword, "down") != 0
 762                                                                 && strcmp(firstword, "pre-up") != 0
 763                                                                 && strcmp(firstword, "post-down") != 0) {
 764                                                         for (i = 0; i < currif->n_options; i++) {
 765                                                                 if (strcmp(currif->option[i].name, firstword) == 0) {
 766                                                                         bb_error_msg("duplicate option \"%s\"", buf);
 767                                                                         return NULL;
 768                                                                 }
 769                                                         }
 770                                                 }
 771                                         }
 772                                         if (currif->n_options >= currif->max_options) {
 773                                                 struct variable_t *opt;
 774
 775                                                 currif->max_options = currif->max_options + 10;
 776                                                 opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 777                                                 currif->option = opt;
 778                                         }
 779                                         currif->option[currif->n_options].name = xstrdup(firstword);
 780                                         currif->option[currif->n_options].value = xstrdup(buf_ptr);
 781                                         if (!currif->option[currif->n_options].name) {
 782                                                 perror(filename);
 783                                                 return NULL;
 784                                         }
 785                                         if (!currif->option[currif->n_options].value) {
 786                                                 perror(filename);
 787                                                 return NULL;
 788                                         }
 789                                         debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 790                                                         currif->option[currif->n_options].value);
 791                                         currif->n_options++;
 792                                         break;
 793                                 case MAPPING:
 794 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 795                                         if (strcmp(firstword, "script") == 0) {
 796                                                 if (currmap->script != NULL) {
 797                                                         bb_error_msg("duplicate script in mapping \"%s\"", buf);
 798                                                         return NULL;
 799                                                 } else {
 800                                                         currmap->script = xstrdup(next_word(&buf_ptr));
 801                                                 }
 802                                         } else if (strcmp(firstword, "map") == 0) {
 803                                                 if (currmap->max_mappings == currmap->n_mappings) {
 804                                                         currmap->max_mappings = currmap->max_mappings * 2 + 1;
 805                                                         currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 806                                                 }
 807                                                 currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 808                                                 currmap->n_mappings++;
 809                                         } else {
 810                                                 bb_error_msg("misplaced option \"%s\"", buf);
 811                                                 return NULL;
 812                                         }
 813 #endif
 814                                         break;
 815                                 case NONE:
 816                                 default:
 817                                         bb_error_msg("misplaced option \"%s\"", buf);
 818                                         return NULL;
 819                         }
 820                 }
 821                 free(buf);
 822         }
 823         if (ferror(f) != 0) {
 824                 bb_perror_msg_and_die("%s", filename);
 825         }
 826         fclose(f);
 827
 828         return defn;
 829 }
 830
 831 static char *setlocalenv(char *format, const char *name, const char *value)
 832 {
 833         char *result;
 834         char *here;
 835         char *there;
 836
 837         result = xasprintf(format, name, value);
 838
 839         for (here = there = result; *there != '=' && *there; there++) {
 840                 if (*there == '-')
 841                         *there = '_';
 842                 if (isalpha(*there))
 843                         *there = toupper(*there);
 844
 845                 if (isalnum(*there) || *there == '_') {
 846                         *here = *there;
 847                         here++;
 848                 }
 849         }
 850         memmove(here, there, strlen(there) + 1);
 851
 852         return result;
 853 }
 854
 855 static void set_environ(struct interface_defn_t *iface, const char *mode)
 856 {
 857         char **environend;
 858         int i;
 859         const int n_env_entries = iface->n_options + 5;
 860         char **ppch;
 861
 862         if (__myenviron != NULL) {
 863                 for (ppch = __myenviron; *ppch; ppch++) {
 864                         free(*ppch);
 865                         *ppch = NULL;
 866                 }
 867                 free(__myenviron);
 868         }
 869         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 870         environend = __myenviron;
 871
 872         for (i = 0; i < iface->n_options; i++) {
 873                 if (strcmp(iface->option[i].name, "up") == 0
 874                                 || strcmp(iface->option[i].name, "down") == 0
 875                                 || strcmp(iface->option[i].name, "pre-up") == 0
 876                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 877                         continue;
 878                 }
 879                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 880         }
 881
 882         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 883         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 884         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 885         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 886         *(environend++) = setlocalenv("%s=%s", "PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin");
 887 }
 888
 889 static int doit(char *str)
 890 {
 891         if (option_mask & (OPT_no_act|OPT_verbose)) {
 892                 printf("%s\n", str);
 893         }
 894         if (!(option_mask & OPT_no_act)) {
 895                 pid_t child;
 896                 int status;
 897
 898                 fflush(NULL);
 899                 switch (child = fork()) {
 900                         case -1:                /* failure */
 901                                 return 0;
 902                         case 0:         /* child */
 903                                 execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 904                                 exit(127);
 905                 }
 906                 waitpid(child, &status, 0);
 907                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 908                         return 0;
 909                 }
 910         }
 911         return 1;
 912 }
 913
 914 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 915 {
 916         int i;
 917         char *buf;
 918         for (i = 0; i < ifd->n_options; i++) {
 919                 if (strcmp(ifd->option[i].name, opt) == 0) {
 920                         if (!doit(ifd->option[i].value)) {
 921                                 return 0;
 922                         }
 923                 }
 924         }
 925
 926         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 927         if (doit(buf) != 1) {
 928                 return 0;
 929         }
 930         return 1;
 931 }
 932
 933 static int check(char *str) {
 934         return str != NULL;
 935 }
 936
 937 static int iface_up(struct interface_defn_t *iface)
 938 {
 939         if (!iface->method->up(iface,check)) return -1;
 940         set_environ(iface, "start");
 941         if (!execute_all(iface, "pre-up")) return 0;
 942         if (!iface->method->up(iface, doit)) return 0;
 943         if (!execute_all(iface, "up")) return 0;
 944         return 1;
 945 }
 946
 947 static int iface_down(struct interface_defn_t *iface)
 948 {
 949         if (!iface->method->down(iface,check)) return -1;
 950         set_environ(iface, "stop");
 951         if (!execute_all(iface, "down")) return 0;
 952         if (!iface->method->down(iface, doit)) return 0;
 953         if (!execute_all(iface, "post-down")) return 0;
 954         return 1;
 955 }
 956
 957 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 958 static int popen2(FILE **in, FILE **out, char *command, ...)
 959 {
 960         va_list ap;
 961         char *argv[11] = { command };
 962         int argc;
 963         int infd[2], outfd[2];
 964         pid_t pid;
 965
 966         argc = 1;
 967         va_start(ap, command);
 968         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 969                 argc++;
 970         }
 971         argv[argc] = NULL;      /* make sure */
 972         va_end(ap);
 973
 974         if (pipe(infd) != 0) {
 975                 return 0;
 976         }
 977
 978         if (pipe(outfd) != 0) {
 979                 close(infd[0]);
 980                 close(infd[1]);
 981                 return 0;
 982         }
 983
 984         fflush(NULL);
 985         switch (pid = fork()) {
 986                 case -1:                        /* failure */
 987                         close(infd[0]);
 988                         close(infd[1]);
 989                         close(outfd[0]);
 990                         close(outfd[1]);
 991                         return 0;
 992                 case 0:                 /* child */
 993                         dup2(infd[0], 0);
 994                         dup2(outfd[1], 1);
 995                         close(infd[0]);
 996                         close(infd[1]);
 997                         close(outfd[0]);
 998                         close(outfd[1]);
 999                         execvp(command, argv);
1000                         exit(127);
1001                 default:                        /* parent */
1002                         *in = fdopen(infd[1], "w");
1003                         *out = fdopen(outfd[0], "r");
1004                         close(infd[0]);
1005                         close(outfd[1]);
1006                         return pid;
1007         }
1008         /* unreached */
1009 }
1010
1011 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1012 {
1013         FILE *in, *out;
1014         int i, status;
1015         pid_t pid;
1016
1017         char *logical = xstrdup(physical);
1018
1019         /* Run the mapping script. */
1020         pid = popen2(&in, &out, map->script, physical, NULL);
1021
1022         /* popen2() returns 0 on failure. */
1023         if (pid == 0)
1024                 return logical;
1025
1026         /* Write mappings to stdin of mapping script. */
1027         for (i = 0; i < map->n_mappings; i++) {
1028                 fprintf(in, "%s\n", map->mapping[i]);
1029         }
1030         fclose(in);
1031         waitpid(pid, &status, 0);
1032
1033         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1034                 /* If the mapping script exited successfully, try to
1035                  * grab a line of output and use that as the name of the
1036                  * logical interface. */
1037                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1038
1039                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1040                         /* If we are able to read a line of output from the script,
1041                          * remove any trailing whitespace and use this value
1042                          * as the name of the logical interface. */
1043                         char *pch = new_logical + strlen(new_logical) - 1;
1044
1045                         while (pch >= new_logical && isspace(*pch))
1046                                 *(pch--) = '\0';
1047
1048                         free(logical);
1049                         logical = new_logical;
1050                 } else {
1051                         /* If we are UNABLE to read a line of output, discard our
1052                          * freshly allocated memory. */
1053                         free(new_logical);
1054                 }
1055         }
1056
1057         fclose(out);
1058
1059         return logical;
1060 }
1061 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1062
1063 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1064 {
1065         unsigned short iface_len = strlen(iface);
1066         llist_t *search = state_list;
1067
1068         while (search) {
1069                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1070                                 (search->data[iface_len] == '=')) {
1071                         return(search);
1072                 }
1073                 search = search->link;
1074         }
1075         return(NULL);
1076 }
1077
1078 int ifupdown_main(int argc, char **argv)
1079 {
1080         int (*cmds) (struct interface_defn_t *) = NULL;
1081         struct interfaces_file_t *defn;
1082         llist_t *state_list = NULL;
1083         llist_t *target_list = NULL;
1084         const char *interfaces = "/etc/network/interfaces";
1085         const char *statefile = "/var/run/ifstate";
1086         int any_failures = 0;
1087         int i;
1088
1089         if (bb_applet_name[2] == 'u') {
1090                 /* ifup command */
1091                 cmds = iface_up;
1092         } else {
1093                 /* ifdown command */
1094                 cmds = iface_down;
1095         }
1096
1097         option_mask = bb_getopt_ulflags(argc, argv, OPTION_STR, &interfaces);
1098         if (argc - optind > 0) {
1099                 if (DO_ALL) bb_show_usage();
1100         } else
1101                 if (!DO_ALL) bb_show_usage();
1102
1103         debug_noise("reading %s file:\n", interfaces);
1104         defn = read_interfaces(interfaces);
1105         debug_noise("\ndone reading %s\n\n", interfaces);
1106
1107         if (!defn) {
1108                 exit(EXIT_FAILURE);
1109         }
1110
1111         /* Create a list of interfaces to work on */
1112         if (DO_ALL) {
1113                 if (cmds == iface_up) {
1114                         target_list = defn->autointerfaces;
1115                 } else {
1116                         /* iface_down */
1117                         const llist_t *list = state_list;
1118                         while (list) {
1119                                 llist_add_to_end(&target_list, xstrdup(list->data));
1120                                 list = list->link;
1121                         }
1122                         target_list = defn->autointerfaces;
1123                 }
1124         } else {
1125                 llist_add_to_end(&target_list, argv[optind]);
1126         }
1127
1128
1129         /* Update the interfaces */
1130         while (target_list) {
1131                 llist_t *iface_list;
1132                 struct interface_defn_t *currif;
1133                 char *iface;
1134                 char *liface;
1135                 char *pch;
1136                 int okay = 0;
1137                 int cmds_ret;
1138
1139                 iface = xstrdup(target_list->data);
1140                 target_list = target_list->link;
1141
1142                 pch = strchr(iface, '=');
1143                 if (pch) {
1144                         *pch = '\0';
1145                         liface = xstrdup(pch + 1);
1146                 } else {
1147                         liface = xstrdup(iface);
1148                 }
1149
1150                 if (!FORCE) {
1151                         const llist_t *iface_state = find_iface_state(state_list, iface);
1152
1153                         if (cmds == iface_up) {
1154                                 /* ifup */
1155                                 if (iface_state) {
1156                                         bb_error_msg("interface %s already configured", iface);
1157                                         continue;
1158                                 }
1159                         } else {
1160                                 /* ifdown */
1161                                 if (iface_state) {
1162                                         bb_error_msg("interface %s not configured", iface);
1163                                         continue;
1164                                 }
1165                         }
1166                 }
1167
1168 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1169                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1170                         struct mapping_defn_t *currmap;
1171
1172                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1173
1174                                 for (i = 0; i < currmap->n_matches; i++) {
1175                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1176                                                 continue;
1177                                         if (VERBOSE) {
1178                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1179                                         }
1180                                         liface = run_mapping(iface, currmap);
1181                                         break;
1182                                 }
1183                         }
1184                 }
1185 #endif
1186
1187
1188                 iface_list = defn->ifaces;
1189                 while (iface_list) {
1190                         currif = (struct interface_defn_t *) iface_list->data;
1191                         if (strcmp(liface, currif->iface) == 0) {
1192                                 char *oldiface = currif->iface;
1193
1194                                 okay = 1;
1195                                 currif->iface = iface;
1196
1197                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1198
1199                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1200                                 cmds_ret = cmds(currif);
1201                                 if (cmds_ret == -1) {
1202                                         bb_error_msg("Don't seem to have all the variables for %s/%s.",
1203                                                         liface, currif->address_family->name);
1204                                         any_failures += 1;
1205                                 } else if (cmds_ret == 0) {
1206                                         any_failures += 1;
1207                                 }
1208
1209                                 currif->iface = oldiface;
1210                         }
1211                         iface_list = iface_list->link;
1212                 }
1213                 if (VERBOSE) {
1214                         printf("\n");
1215                 }
1216
1217                 if (!okay && !FORCE) {
1218                         bb_error_msg("Ignoring unknown interface %s", liface);
1219                         any_failures += 1;
1220                 } else {
1221                         llist_t *iface_state = find_iface_state(state_list, iface);
1222
1223                         if (cmds == iface_up) {
1224                                 char *newiface = xasprintf("%s=%s", iface, liface);
1225                                 if (iface_state == NULL) {
1226                                         llist_add_to_end(&state_list, newiface);
1227                                 } else {
1228                                         free(iface_state->data);
1229                                         iface_state->data = newiface;
1230                                 }
1231                         } else {
1232                                 /* Remove an interface from the linked list */
1233                                 free(llist_pop(&iface_state));
1234                         }
1235                 }
1236         }
1237
1238         /* Actually write the new state */
1239         if (!NO_ACT) {
1240                 FILE *state_fp = NULL;
1241
1242                 state_fp = xfopen(statefile, "w");
1243                 while (state_list) {
1244                         if (state_list->data) {
1245                                 fputs(state_list->data, state_fp);
1246                                 fputc('\n', state_fp);
1247                         }
1248                         state_list = state_list->link;
1249                 }
1250                 fclose(state_fp);
1251         }
1252
1253         if (any_failures)
1254                 return 1;
1255         return 0;
1256 }