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 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
  29 #define MAX_INTERFACE_LENGTH 10
  30 #endif
  31
  32 #define debug_noise(args...) /*fprintf(stderr, args)*/
  33
  34 /* Forward declaration */
  35 struct interface_defn_t;
  36
  37 typedef int execfn(char *command);
  38
  39 struct method_t
  40 {
  41         char *name;
  42         int (*up)(struct interface_defn_t *ifd, execfn *e);
  43         int (*down)(struct interface_defn_t *ifd, execfn *e);
  44 };
  45
  46 struct address_family_t
  47 {
  48         char *name;
  49         int n_methods;
  50         const struct method_t *method;
  51 };
  52
  53 struct mapping_defn_t
  54 {
  55         struct mapping_defn_t *next;
  56
  57         int max_matches;
  58         int n_matches;
  59         char **match;
  60
  61         char *script;
  62
  63         int max_mappings;
  64         int n_mappings;
  65         char **mapping;
  66 };
  67
  68 struct variable_t
  69 {
  70         char *name;
  71         char *value;
  72 };
  73
  74 struct interface_defn_t
  75 {
  76         const struct address_family_t *address_family;
  77         const struct method_t *method;
  78
  79         char *iface;
  80         int max_options;
  81         int n_options;
  82         struct variable_t *option;
  83 };
  84
  85 struct interfaces_file_t
  86 {
  87         llist_t *autointerfaces;
  88         llist_t *ifaces;
  89         struct mapping_defn_t *mappings;
  90 };
  91
  92 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  93 enum {
  94         OPT_do_all = 0x1,
  95         OPT_no_act = 0x2,
  96         OPT_verbose = 0x4,
  97         OPT_force = 0x8,
  98         OPT_no_mappings = 0x10,
  99 };
 100 #define DO_ALL (option_mask32 & OPT_do_all)
 101 #define NO_ACT (option_mask32 & OPT_no_act)
 102 #define VERBOSE (option_mask32 & OPT_verbose)
 103 #define FORCE (option_mask32 & OPT_force)
 104 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 105
 106 static char **my_environ;
 107
 108 static char *startup_PATH;
 109
 110 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 111
 112 #if ENABLE_FEATURE_IFUPDOWN_IP
 113
 114 static unsigned count_bits(unsigned a)
 115 {
 116         unsigned result;
 117         result = (a & 0x55) + ((a >> 1) & 0x55);
 118         result = (result & 0x33) + ((result >> 2) & 0x33);
 119         return (result & 0x0F) + ((result >> 4) & 0x0F);
 120 }
 121
 122 static int count_netmask_bits(char *dotted_quad)
 123 {
 124         unsigned result, a, b, c, d;
 125         /* Found a netmask...  Check if it is dotted quad */
 126         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 127                 return -1;
 128         // FIXME: will be confused by e.g. 255.0.255.0
 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 **bufp, const char *str, size_t str_length)
 138 {
 139         /* xasprintf trick will be smaller, but we are often
 140          * called with str_length == 1 - don't want to have
 141          * THAT much of malloc/freeing! */
 142         char *buf = *bufp;
 143         int len = (buf ? strlen(buf) : 0);
 144         str_length++;
 145         buf = xrealloc(buf, len + str_length);
 146         /* copies at most str_length-1 chars! */
 147         safe_strncpy(buf + len, str, str_length);
 148         *bufp = buf;
 149 }
 150
 151 static int strncmpz(const char *l, const char *r, size_t llen)
 152 {
 153         int i = strncmp(l, r, llen);
 154
 155         if (i == 0)
 156                 return -r[llen];
 157         return i;
 158 }
 159
 160 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 161 {
 162         int i;
 163
 164         if (strncmpz(id, "iface", idlen) == 0) {
 165                 char *result;
 166                 static char label_buf[20];
 167                 safe_strncpy(label_buf, ifd->iface, sizeof(label_buf));
 168                 result = strchr(label_buf, ':');
 169                 if (result) {
 170                         *result = '\0';
 171                 }
 172                 return label_buf;
 173         }
 174         if (strncmpz(id, "label", idlen) == 0) {
 175                 return ifd->iface;
 176         }
 177         for (i = 0; i < ifd->n_options; i++) {
 178                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 179                         return ifd->option[i].value;
 180                 }
 181         }
 182         return NULL;
 183 }
 184
 185 static char *parse(const char *command, struct interface_defn_t *ifd)
 186 {
 187         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 188         int okay[MAX_OPT_DEPTH] = { 1 };
 189         int opt_depth = 1;
 190         char *result = NULL;
 191
 192         while (*command) {
 193                 switch (*command) {
 194                 default:
 195                         addstr(&result, command, 1);
 196                         command++;
 197                         break;
 198                 case '\\':
 199                         if (command[1]) {
 200                                 addstr(&result, command + 1, 1);
 201                                 command += 2;
 202                         } else {
 203                                 addstr(&result, command, 1);
 204                                 command++;
 205                         }
 206                         break;
 207                 case '[':
 208                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 209                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 210                                 okay[opt_depth] = 1;
 211                                 opt_depth++;
 212                                 command += 2;
 213                         } else {
 214                                 addstr(&result, "[", 1);
 215                                 command++;
 216                         }
 217                         break;
 218                 case ']':
 219                         if (command[1] == ']' && opt_depth > 1) {
 220                                 opt_depth--;
 221                                 if (!okay[opt_depth]) {
 222                                         result[old_pos[opt_depth]] = '\0';
 223                                 }
 224                                 command += 2;
 225                         } else {
 226                                 addstr(&result, "]", 1);
 227                                 command++;
 228                         }
 229                         break;
 230                 case '%':
 231                         {
 232                                 char *nextpercent;
 233                                 char *varvalue;
 234
 235                                 command++;
 236                                 nextpercent = strchr(command, '%');
 237                                 if (!nextpercent) {
 238                                         errno = EUNBALPER;
 239                                         free(result);
 240                                         return NULL;
 241                                 }
 242
 243                                 varvalue = get_var(command, nextpercent - command, ifd);
 244
 245                                 if (varvalue) {
 246                                         addstr(&result, varvalue, strlen(varvalue));
 247                                 } else {
 248 #if ENABLE_FEATURE_IFUPDOWN_IP
 249                                         /* Sigh...  Add a special case for 'ip' to convert from
 250                                          * dotted quad to bit count style netmasks.  */
 251                                         if (strncmp(command, "bnmask", 6) == 0) {
 252                                                 unsigned res;
 253                                                 varvalue = get_var("netmask", 7, ifd);
 254                                                 if (varvalue && (res = count_netmask_bits(varvalue)) > 0) {
 255                                                         const char *argument = utoa(res);
 256                                                         addstr(&result, argument, strlen(argument));
 257                                                         command = nextpercent + 1;
 258                                                         break;
 259                                                 }
 260                                         }
 261 #endif
 262                                         okay[opt_depth - 1] = 0;
 263                                 }
 264
 265                                 command = nextpercent + 1;
 266                         }
 267                         break;
 268                 }
 269         }
 270
 271         if (opt_depth > 1) {
 272                 errno = EUNBALBRACK;
 273                 free(result);
 274                 return NULL;
 275         }
 276
 277         if (!okay[0]) {
 278                 errno = EUNDEFVAR;
 279                 free(result);
 280                 return NULL;
 281         }
 282
 283         return result;
 284 }
 285
 286 /* execute() returns 1 for success and 0 for failure */
 287 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 288 {
 289         char *out;
 290         int ret;
 291
 292         out = parse(command, ifd);
 293         if (!out) {
 294                 return 0;
 295         }
 296         ret = (*exec)(out);
 297
 298         free(out);
 299         if (ret != 1) {
 300                 return 0;
 301         }
 302         return 1;
 303 }
 304 #endif
 305
 306 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 307 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 308 {
 309 #if ENABLE_FEATURE_IFUPDOWN_IP
 310         int result;
 311         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 312         result += execute("ip link set %iface% up", ifd, exec);
 313         return ((result == 2) ? 2 : 0);
 314 #else
 315         return execute("ifconfig %iface% add ::1", ifd, exec);
 316 #endif
 317 }
 318
 319 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 320 {
 321 #if ENABLE_FEATURE_IFUPDOWN_IP
 322         return execute("ip link set %iface% down", ifd, exec);
 323 #else
 324         return execute("ifconfig %iface% del ::1", ifd, exec);
 325 #endif
 326 }
 327
 328 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 329 {
 330         int result;
 331 #if ENABLE_FEATURE_IFUPDOWN_IP
 332         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 333         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 334         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
 335         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 336 #else
 337         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 338         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 339         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
 340 #endif
 341         return ((result == 3) ? 3 : 0);
 342 }
 343
 344 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 345 {
 346 #if ENABLE_FEATURE_IFUPDOWN_IP
 347         return execute("ip link set %iface% down", ifd, exec);
 348 #else
 349         return execute("ifconfig %iface% down", ifd, exec);
 350 #endif
 351 }
 352
 353 #if ENABLE_FEATURE_IFUPDOWN_IP
 354 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 355 {
 356         int result;
 357         result = execute("ip tunnel add %iface% mode sit remote "
 358                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 359         result += execute("ip link set %iface% up", ifd, exec);
 360         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 361         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 362         return ((result == 4) ? 4 : 0);
 363 }
 364
 365 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 366 {
 367         return execute("ip tunnel del %iface%", ifd, exec);
 368 }
 369 #endif
 370
 371 static const struct method_t methods6[] = {
 372 #if ENABLE_FEATURE_IFUPDOWN_IP
 373         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 374 #endif
 375         { "static", static_up6, static_down6, },
 376         { "loopback", loopback_up6, loopback_down6, },
 377 };
 378
 379 static const struct address_family_t addr_inet6 = {
 380         "inet6",
 381         sizeof(methods6) / sizeof(struct method_t),
 382         methods6
 383 };
 384 #endif /* FEATURE_IFUPDOWN_IPV6 */
 385
 386 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 387 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 388 {
 389 #if ENABLE_FEATURE_IFUPDOWN_IP
 390         int result;
 391         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 392         result += execute("ip link set %iface% up", ifd, exec);
 393         return ((result == 2) ? 2 : 0);
 394 #else
 395         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 396 #endif
 397 }
 398
 399 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 400 {
 401 #if ENABLE_FEATURE_IFUPDOWN_IP
 402         int result;
 403         result = execute("ip addr flush dev %iface%", ifd, exec);
 404         result += execute("ip link set %iface% down", ifd, exec);
 405         return ((result == 2) ? 2 : 0);
 406 #else
 407         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 408 #endif
 409 }
 410
 411 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 412 {
 413         int result;
 414 #if ENABLE_FEATURE_IFUPDOWN_IP
 415         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 416                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 417         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 418         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
 419         return ((result == 3) ? 3 : 0);
 420 #else
 421         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 422          * which then of course fails. Thus we run two separate ifconfig */
 423         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 424                                 ifd, exec);
 425         result += execute("ifconfig %iface% %address% netmask %netmask%"
 426                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 427                                 ifd, exec);
 428         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
 429         return ((result == 3) ? 3 : 0);
 430 #endif
 431 }
 432
 433 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 434 {
 435         int result;
 436 #if ENABLE_FEATURE_IFUPDOWN_IP
 437         result = execute("ip addr flush dev %iface%", ifd, exec);
 438         result += execute("ip link set %iface% down", ifd, exec);
 439 #else
 440         result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec);
 441         result += execute("ifconfig %iface% down", ifd, exec);
 442 #endif
 443         return ((result == 2) ? 2 : 0);
 444 }
 445
 446 #if !ENABLE_APP_UDHCPC
 447 struct dhcp_client_t
 448 {
 449         const char *name;
 450         const char *startcmd;
 451         const char *stopcmd;
 452 };
 453
 454 static const struct dhcp_client_t ext_dhcp_clients[] = {
 455         { "udhcpc",
 456                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 457                 "kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 458         },
 459         { "pump",
 460                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 461                 "pump -i %iface% -k",
 462         },
 463         { "dhclient",
 464                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 465                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 466         },
 467         { "dhcpcd",
 468                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
 469                 "dhcpcd -k %iface%",
 470         },
 471 };
 472 #endif
 473
 474 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 475 {
 476 #if ENABLE_APP_UDHCPC
 477         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 478                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 479                         ifd, exec);
 480 #else
 481         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 482         for (i = 0; i < nclients; i++) {
 483                 if (exists_execable(ext_dhcp_clients[i].name))
 484                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 485         }
 486         bb_error_msg("no dhcp clients found");
 487         return 0;
 488 #endif
 489 }
 490
 491 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 492 {
 493 #if ENABLE_APP_UDHCPC
 494         return execute("kill -TERM "
 495                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 496 #else
 497         int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
 498         for (i = 0; i < nclients; i++) {
 499                 if (exists_execable(ext_dhcp_clients[i].name))
 500                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 501         }
 502         bb_error_msg("no dhcp clients found, using static interface shutdown");
 503         return static_down(ifd, exec);
 504 #endif
 505 }
 506
 507 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 508 {
 509         return 1;
 510 }
 511
 512 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 513 {
 514         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 515                         "[[ --server %server%]][[ --hwaddr %hwaddr%]] "
 516                         "--returniffail --serverbcast", ifd, exec);
 517 }
 518
 519 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 520 {
 521         return execute("pon[[ %provider%]]", ifd, exec);
 522 }
 523
 524 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 525 {
 526         return execute("poff[[ %provider%]]", ifd, exec);
 527 }
 528
 529 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 530 {
 531         return execute("start-stop-daemon --start -x wvdial "
 532                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 533 }
 534
 535 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 536 {
 537         return execute("start-stop-daemon --stop -x wvdial "
 538                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 539 }
 540
 541 static const struct method_t methods[] = {
 542         { "manual", manual_up_down, manual_up_down, },
 543         { "wvdial", wvdial_up, wvdial_down, },
 544         { "ppp", ppp_up, ppp_down, },
 545         { "static", static_up, static_down, },
 546         { "bootp", bootp_up, static_down, },
 547         { "dhcp", dhcp_up, dhcp_down, },
 548         { "loopback", loopback_up, loopback_down, },
 549 };
 550
 551 static const struct address_family_t addr_inet = {
 552         "inet",
 553         sizeof(methods) / sizeof(struct method_t),
 554         methods
 555 };
 556
 557 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 558
 559 static char *next_word(char **buf)
 560 {
 561         unsigned short length;
 562         char *word;
 563
 564         if (!buf || !*buf || !**buf) {
 565                 return NULL;
 566         }
 567
 568         /* Skip over leading whitespace */
 569         word = skip_whitespace(*buf);
 570
 571         /* Skip over comments */
 572         if (*word == '#') {
 573                 return NULL;
 574         }
 575
 576         /* Find the length of this word */
 577         length = strcspn(word, " \t\n");
 578         if (length == 0) {
 579                 return NULL;
 580         }
 581         *buf = word + length;
 582         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 583         if (**buf) {
 584                 **buf = '\0';
 585                 (*buf)++;
 586         }
 587
 588         return word;
 589 }
 590
 591 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 592 {
 593         int i;
 594
 595         if (!name)
 596                 return NULL;
 597
 598         for (i = 0; af[i]; i++) {
 599                 if (strcmp(af[i]->name, name) == 0) {
 600                         return af[i];
 601                 }
 602         }
 603         return NULL;
 604 }
 605
 606 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 607 {
 608         int i;
 609
 610         if (!name)
 611                 return NULL;
 612
 613         for (i = 0; i < af->n_methods; i++) {
 614                 if (strcmp(af->method[i].name, name) == 0) {
 615                         return &af->method[i];
 616                 }
 617         }
 618         return NULL;
 619 }
 620
 621 static const llist_t *find_list_string(const llist_t *list, const char *string)
 622 {
 623         if (string == NULL)
 624                 return NULL;
 625
 626         while (list) {
 627                 if (strcmp(list->data, string) == 0) {
 628                         return list;
 629                 }
 630                 list = list->link;
 631         }
 632         return NULL;
 633 }
 634
 635 static struct interfaces_file_t *read_interfaces(const char *filename)
 636 {
 637 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 638         struct mapping_defn_t *currmap = NULL;
 639 #endif
 640         struct interface_defn_t *currif = NULL;
 641         struct interfaces_file_t *defn;
 642         FILE *f;
 643         char *firstword;
 644         char *buf;
 645
 646         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 647
 648         defn = xzalloc(sizeof(struct interfaces_file_t));
 649
 650         f = xfopen(filename, "r");
 651
 652         while ((buf = xmalloc_getline(f)) != NULL) {
 653                 char *buf_ptr = buf;
 654
 655                 firstword = next_word(&buf_ptr);
 656                 if (firstword == NULL) {
 657                         free(buf);
 658                         continue;       /* blank line */
 659                 }
 660
 661                 if (strcmp(firstword, "mapping") == 0) {
 662 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 663                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 664
 665                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 666                                 if (currmap->max_matches == currmap->n_matches) {
 667                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 668                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 669                                 }
 670
 671                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 672                         }
 673                         currmap->max_mappings = 0;
 674                         currmap->n_mappings = 0;
 675                         currmap->mapping = NULL;
 676                         currmap->script = NULL;
 677                         {
 678                                 struct mapping_defn_t **where = &defn->mappings;
 679                                 while (*where != NULL) {
 680                                         where = &(*where)->next;
 681                                 }
 682                                 *where = currmap;
 683                                 currmap->next = NULL;
 684                         }
 685                         debug_noise("Added mapping\n");
 686 #endif
 687                         currently_processing = MAPPING;
 688                 } else if (strcmp(firstword, "iface") == 0) {
 689                         static const struct address_family_t *const addr_fams[] = {
 690 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 691                                 &addr_inet,
 692 #endif
 693 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 694                                 &addr_inet6,
 695 #endif
 696                                 NULL
 697                         };
 698
 699                         char *iface_name;
 700                         char *address_family_name;
 701                         char *method_name;
 702                         llist_t *iface_list;
 703
 704                         currif = xzalloc(sizeof(struct interface_defn_t));
 705                         iface_name = next_word(&buf_ptr);
 706                         address_family_name = next_word(&buf_ptr);
 707                         method_name = next_word(&buf_ptr);
 708
 709                         if (buf_ptr == NULL) {
 710                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 711                                 return NULL;
 712                         }
 713
 714                         /* ship any trailing whitespace */
 715                         buf_ptr = skip_whitespace(buf_ptr);
 716
 717                         if (buf_ptr[0] != '\0') {
 718                                 bb_error_msg("too many parameters \"%s\"", buf);
 719                                 return NULL;
 720                         }
 721
 722                         currif->iface = xstrdup(iface_name);
 723
 724                         currif->address_family = get_address_family(addr_fams, address_family_name);
 725                         if (!currif->address_family) {
 726                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 727                                 return NULL;
 728                         }
 729
 730                         currif->method = get_method(currif->address_family, method_name);
 731                         if (!currif->method) {
 732                                 bb_error_msg("unknown method \"%s\"", method_name);
 733                                 return NULL;
 734                         }
 735
 736                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 737                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 738                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 739                                         (tmp->address_family == currif->address_family)) {
 740                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 741                                         return NULL;
 742                                 }
 743                         }
 744                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 745
 746                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 747                         currently_processing = IFACE;
 748                 } else if (strcmp(firstword, "auto") == 0) {
 749                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 750
 751                                 /* Check the interface isnt already listed */
 752                                 if (find_list_string(defn->autointerfaces, firstword)) {
 753                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 754                                 }
 755
 756                                 /* Add the interface to the list */
 757                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 758                                 debug_noise("\nauto %s\n", firstword);
 759                         }
 760                         currently_processing = NONE;
 761                 } else {
 762                         switch (currently_processing) {
 763                         case IFACE:
 764                                 {
 765                                         int i;
 766
 767                                         if (strlen(buf_ptr) == 0) {
 768                                                 bb_error_msg("option with empty value \"%s\"", buf);
 769                                                 return NULL;
 770                                         }
 771
 772                                         if (strcmp(firstword, "up") != 0
 773                                                         && strcmp(firstword, "down") != 0
 774                                                         && strcmp(firstword, "pre-up") != 0
 775                                                         && strcmp(firstword, "post-down") != 0) {
 776                                                 for (i = 0; i < currif->n_options; i++) {
 777                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 778                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 779                                                                 return NULL;
 780                                                         }
 781                                                 }
 782                                         }
 783                                 }
 784                                 if (currif->n_options >= currif->max_options) {
 785                                         struct variable_t *opt;
 786
 787                                         currif->max_options = currif->max_options + 10;
 788                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 789                                         currif->option = opt;
 790                                 }
 791                                 currif->option[currif->n_options].name = xstrdup(firstword);
 792                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 793                                 if (!currif->option[currif->n_options].name) {
 794                                         perror(filename);
 795                                         return NULL;
 796                                 }
 797                                 if (!currif->option[currif->n_options].value) {
 798                                         perror(filename);
 799                                         return NULL;
 800                                 }
 801                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 802                                                 currif->option[currif->n_options].value);
 803                                 currif->n_options++;
 804                                 break;
 805                         case MAPPING:
 806 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 807                                 if (strcmp(firstword, "script") == 0) {
 808                                         if (currmap->script != NULL) {
 809                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 810                                                 return NULL;
 811                                         } else {
 812                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 813                                         }
 814                                 } else if (strcmp(firstword, "map") == 0) {
 815                                         if (currmap->max_mappings == currmap->n_mappings) {
 816                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 817                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 818                                         }
 819                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 820                                         currmap->n_mappings++;
 821                                 } else {
 822                                         bb_error_msg("misplaced option \"%s\"", buf);
 823                                         return NULL;
 824                                 }
 825 #endif
 826                                 break;
 827                         case NONE:
 828                         default:
 829                                 bb_error_msg("misplaced option \"%s\"", buf);
 830                                 return NULL;
 831                         }
 832                 }
 833                 free(buf);
 834         }
 835         if (ferror(f) != 0) {
 836                 bb_perror_msg_and_die("%s", filename);
 837         }
 838         fclose(f);
 839
 840         return defn;
 841 }
 842
 843 static char *setlocalenv(char *format, const char *name, const char *value)
 844 {
 845         char *result;
 846         char *here;
 847         char *there;
 848
 849         result = xasprintf(format, name, value);
 850
 851         for (here = there = result; *there != '=' && *there; there++) {
 852                 if (*there == '-')
 853                         *there = '_';
 854                 if (isalpha(*there))
 855                         *there = toupper(*there);
 856
 857                 if (isalnum(*there) || *there == '_') {
 858                         *here = *there;
 859                         here++;
 860                 }
 861         }
 862         memmove(here, there, strlen(there) + 1);
 863
 864         return result;
 865 }
 866
 867 static void set_environ(struct interface_defn_t *iface, const char *mode)
 868 {
 869         char **environend;
 870         int i;
 871         const int n_env_entries = iface->n_options + 5;
 872         char **ppch;
 873
 874         if (my_environ != NULL) {
 875                 for (ppch = my_environ; *ppch; ppch++) {
 876                         free(*ppch);
 877                         *ppch = NULL;
 878                 }
 879                 free(my_environ);
 880         }
 881         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 882         environend = my_environ;
 883
 884         for (i = 0; i < iface->n_options; i++) {
 885                 if (strcmp(iface->option[i].name, "up") == 0
 886                                 || strcmp(iface->option[i].name, "down") == 0
 887                                 || strcmp(iface->option[i].name, "pre-up") == 0
 888                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 889                         continue;
 890                 }
 891                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 892         }
 893
 894         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 895         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 896         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 897         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 898         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 899 }
 900
 901 static int doit(char *str)
 902 {
 903         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 904                 puts(str);
 905         }
 906         /* FIXME: is it true that we can reach this place with str = ""? */
 907         /* how? in execute() parse() may return "", then we do (*exec)(""); */
 908         /* Please add a comment... */
 909         if (!(option_mask32 & OPT_no_act)) {
 910                 pid_t child;
 911                 int status;
 912
 913                 fflush(NULL);
 914                 switch (child = fork()) {
 915                 case -1: /* failure */
 916                         return 0;
 917                 case 0: /* child */
 918                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 919                         exit(127);
 920                 }
 921                 waitpid(child, &status, 0);
 922                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 923                         return 0;
 924                 }
 925         }
 926         return 1;
 927 }
 928
 929 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 930 {
 931         int i;
 932         char *buf;
 933         for (i = 0; i < ifd->n_options; i++) {
 934                 if (strcmp(ifd->option[i].name, opt) == 0) {
 935                         if (!doit(ifd->option[i].value)) {
 936                                 return 0;
 937                         }
 938                 }
 939         }
 940
 941         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 942         if (doit(buf) != 1) {
 943                 return 0;
 944         }
 945         return 1;
 946 }
 947
 948 static int check(char *str)
 949 {
 950         return str != NULL;
 951 }
 952
 953 static int iface_up(struct interface_defn_t *iface)
 954 {
 955         if (!iface->method->up(iface, check)) return -1;
 956         set_environ(iface, "start");
 957         if (!execute_all(iface, "pre-up")) return 0;
 958         if (!iface->method->up(iface, doit)) return 0;
 959         if (!execute_all(iface, "up")) return 0;
 960         return 1;
 961 }
 962
 963 static int iface_down(struct interface_defn_t *iface)
 964 {
 965         if (!iface->method->down(iface,check)) return -1;
 966         set_environ(iface, "stop");
 967         if (!execute_all(iface, "down")) return 0;
 968         if (!iface->method->down(iface, doit)) return 0;
 969         if (!execute_all(iface, "post-down")) return 0;
 970         return 1;
 971 }
 972
 973 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 974 static int popen2(FILE **in, FILE **out, char *command, ...)
 975 {
 976         va_list ap;
 977         char *argv[11] = { command };
 978         int argc;
 979         int infd[2], outfd[2];
 980         pid_t pid;
 981
 982         argc = 1;
 983         va_start(ap, command);
 984         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 985                 argc++;
 986         }
 987         argv[argc] = NULL;      /* make sure */
 988         va_end(ap);
 989
 990         if (pipe(infd) != 0) {
 991                 return 0;
 992         }
 993
 994         if (pipe(outfd) != 0) {
 995                 close(infd[0]);
 996                 close(infd[1]);
 997                 return 0;
 998         }
 999
1000         fflush(NULL);
1001         switch (pid = fork()) {
1002         case -1:                        /* failure */
1003                 close(infd[0]);
1004                 close(infd[1]);
1005                 close(outfd[0]);
1006                 close(outfd[1]);
1007                 return 0;
1008         case 0:                 /* child */
1009                 dup2(infd[0], 0);
1010                 dup2(outfd[1], 1);
1011                 close(infd[0]);
1012                 close(infd[1]);
1013                 close(outfd[0]);
1014                 close(outfd[1]);
1015                 execvp(command, argv);
1016                 exit(127);
1017         default:                        /* parent */
1018                 *in = fdopen(infd[1], "w");
1019                 *out = fdopen(outfd[0], "r");
1020                 close(infd[0]);
1021                 close(outfd[1]);
1022                 return pid;
1023         }
1024         /* unreached */
1025 }
1026
1027 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1028 {
1029         FILE *in, *out;
1030         int i, status;
1031         pid_t pid;
1032
1033         char *logical = xstrdup(physical);
1034
1035         /* Run the mapping script. */
1036         pid = popen2(&in, &out, map->script, physical, NULL);
1037
1038         /* popen2() returns 0 on failure. */
1039         if (pid == 0)
1040                 return logical;
1041
1042         /* Write mappings to stdin of mapping script. */
1043         for (i = 0; i < map->n_mappings; i++) {
1044                 fprintf(in, "%s\n", map->mapping[i]);
1045         }
1046         fclose(in);
1047         waitpid(pid, &status, 0);
1048
1049         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1050                 /* If the mapping script exited successfully, try to
1051                  * grab a line of output and use that as the name of the
1052                  * logical interface. */
1053                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1054
1055                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1056                         /* If we are able to read a line of output from the script,
1057                          * remove any trailing whitespace and use this value
1058                          * as the name of the logical interface. */
1059                         char *pch = new_logical + strlen(new_logical) - 1;
1060
1061                         while (pch >= new_logical && isspace(*pch))
1062                                 *(pch--) = '\0';
1063
1064                         free(logical);
1065                         logical = new_logical;
1066                 } else {
1067                         /* If we are UNABLE to read a line of output, discard our
1068                          * freshly allocated memory. */
1069                         free(new_logical);
1070                 }
1071         }
1072
1073         fclose(out);
1074
1075         return logical;
1076 }
1077 #endif /* FEATURE_IFUPDOWN_MAPPING */
1078
1079 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1080 {
1081         unsigned short iface_len = strlen(iface);
1082         llist_t *search = state_list;
1083
1084         while (search) {
1085                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1086                                 (search->data[iface_len] == '=')) {
1087                         return search;
1088                 }
1089                 search = search->link;
1090         }
1091         return NULL;
1092 }
1093
1094 int ifupdown_main(int argc, char **argv)
1095 {
1096         int (*cmds)(struct interface_defn_t *) = NULL;
1097         struct interfaces_file_t *defn;
1098         llist_t *state_list = NULL;
1099         llist_t *target_list = NULL;
1100         const char *interfaces = "/etc/network/interfaces";
1101         int any_failures = 0;
1102
1103         cmds = iface_down;
1104         if (applet_name[2] == 'u') {
1105                 /* ifup command */
1106                 cmds = iface_up;
1107         }
1108
1109         getopt32(argc, argv, OPTION_STR, &interfaces);
1110         if (argc - optind > 0) {
1111                 if (DO_ALL) bb_show_usage();
1112         } else {
1113                 if (!DO_ALL) bb_show_usage();
1114         }
1115
1116         debug_noise("reading %s file:\n", interfaces);
1117         defn = read_interfaces(interfaces);
1118         debug_noise("\ndone reading %s\n\n", interfaces);
1119
1120         if (!defn) {
1121                 return EXIT_FAILURE;
1122         }
1123
1124         startup_PATH = getenv("PATH");
1125         if (!startup_PATH) startup_PATH = "";
1126
1127         /* Create a list of interfaces to work on */
1128         if (DO_ALL) {
1129                 if (cmds == iface_up) {
1130                         target_list = defn->autointerfaces;
1131                 } else {
1132                         /* iface_down */
1133                         const llist_t *list = state_list;
1134                         while (list) {
1135                                 llist_add_to_end(&target_list, xstrdup(list->data));
1136                                 list = list->link;
1137                         }
1138                         target_list = defn->autointerfaces;
1139                 }
1140         } else {
1141                 llist_add_to_end(&target_list, argv[optind]);
1142         }
1143
1144
1145         /* Update the interfaces */
1146         while (target_list) {
1147                 llist_t *iface_list;
1148                 struct interface_defn_t *currif;
1149                 char *iface;
1150                 char *liface;
1151                 char *pch;
1152                 int okay = 0;
1153                 int cmds_ret;
1154
1155                 iface = xstrdup(target_list->data);
1156                 target_list = target_list->link;
1157
1158                 pch = strchr(iface, '=');
1159                 if (pch) {
1160                         *pch = '\0';
1161                         liface = xstrdup(pch + 1);
1162                 } else {
1163                         liface = xstrdup(iface);
1164                 }
1165
1166                 if (!FORCE) {
1167                         const llist_t *iface_state = find_iface_state(state_list, iface);
1168
1169                         if (cmds == iface_up) {
1170                                 /* ifup */
1171                                 if (iface_state) {
1172                                         bb_error_msg("interface %s already configured", iface);
1173                                         continue;
1174                                 }
1175                         } else {
1176                                 /* ifdown */
1177                                 if (iface_state) {
1178                                         bb_error_msg("interface %s not configured", iface);
1179                                         continue;
1180                                 }
1181                         }
1182                 }
1183
1184 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1185                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1186                         struct mapping_defn_t *currmap;
1187
1188                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1189                                 int i;
1190                                 for (i = 0; i < currmap->n_matches; i++) {
1191                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1192                                                 continue;
1193                                         if (VERBOSE) {
1194                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1195                                         }
1196                                         liface = run_mapping(iface, currmap);
1197                                         break;
1198                                 }
1199                         }
1200                 }
1201 #endif
1202
1203                 iface_list = defn->ifaces;
1204                 while (iface_list) {
1205                         currif = (struct interface_defn_t *) iface_list->data;
1206                         if (strcmp(liface, currif->iface) == 0) {
1207                                 char *oldiface = currif->iface;
1208
1209                                 okay = 1;
1210                                 currif->iface = iface;
1211
1212                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1213
1214                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1215                                 cmds_ret = cmds(currif);
1216                                 if (cmds_ret == -1) {
1217                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1218                                                         liface, currif->address_family->name);
1219                                         any_failures = 1;
1220                                 } else if (cmds_ret == 0) {
1221                                         any_failures = 1;
1222                                 }
1223
1224                                 currif->iface = oldiface;
1225                         }
1226                         iface_list = iface_list->link;
1227                 }
1228                 if (VERBOSE) {
1229                         puts("");
1230                 }
1231
1232                 if (!okay && !FORCE) {
1233                         bb_error_msg("ignoring unknown interface %s", liface);
1234                         any_failures = 1;
1235                 } else {
1236                         llist_t *iface_state = find_iface_state(state_list, iface);
1237
1238                         if (cmds == iface_up) {
1239                                 char *newiface = xasprintf("%s=%s", iface, liface);
1240                                 if (iface_state == NULL) {
1241                                         llist_add_to_end(&state_list, newiface);
1242                                 } else {
1243                                         free(iface_state->data);
1244                                         iface_state->data = newiface;
1245                                 }
1246                         } else {
1247                                 /* Remove an interface from the linked list */
1248                                 free(llist_pop(&iface_state));
1249                         }
1250                 }
1251         }
1252
1253         /* Actually write the new state */
1254         if (!NO_ACT) {
1255                 FILE *state_fp;
1256
1257                 state_fp = xfopen("/var/run/ifstate", "w");
1258                 while (state_list) {
1259                         if (state_list->data) {
1260                                 fputs(state_list->data, state_fp);
1261                                 fputc('\n', state_fp);
1262                         }
1263                         state_list = state_list->link;
1264                 }
1265                 fclose(state_fp);
1266         }
1267
1268         return any_failures;
1269 }