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 <sys/utsname.h>
  19 #include <fnmatch.h>
  20 #include <getopt.h>
  21
  22 #include "libbb.h"
  23
  24 #define MAX_OPT_DEPTH 10
  25 #define EUNBALBRACK 10001
  26 #define EUNDEFVAR   10002
  27 #define EUNBALPER   10000
  28
  29 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
  30 #define MAX_INTERFACE_LENGTH 10
  31 #endif
  32
  33 #define debug_noise(args...) /*fprintf(stderr, args)*/
  34
  35 /* Forward declaration */
  36 struct interface_defn_t;
  37
  38 typedef int execfn(char *command);
  39
  40 struct method_t {
  41         const 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         const char *name;
  48         int n_methods;
  49         const struct method_t *method;
  50 };
  51
  52 struct mapping_defn_t {
  53         struct mapping_defn_t *next;
  54
  55         int max_matches;
  56         int n_matches;
  57         char **match;
  58
  59         char *script;
  60
  61         int max_mappings;
  62         int n_mappings;
  63         char **mapping;
  64 };
  65
  66 struct variable_t {
  67         char *name;
  68         char *value;
  69 };
  70
  71 struct interface_defn_t {
  72         const struct address_family_t *address_family;
  73         const struct method_t *method;
  74
  75         char *iface;
  76         int max_options;
  77         int n_options;
  78         struct variable_t *option;
  79 };
  80
  81 struct interfaces_file_t {
  82         llist_t *autointerfaces;
  83         llist_t *ifaces;
  84         struct mapping_defn_t *mappings;
  85 };
  86
  87 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  88 enum {
  89         OPT_do_all = 0x1,
  90         OPT_no_act = 0x2,
  91         OPT_verbose = 0x4,
  92         OPT_force = 0x8,
  93         OPT_no_mappings = 0x10,
  94 };
  95 #define DO_ALL (option_mask32 & OPT_do_all)
  96 #define NO_ACT (option_mask32 & OPT_no_act)
  97 #define VERBOSE (option_mask32 & OPT_verbose)
  98 #define FORCE (option_mask32 & OPT_force)
  99 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 100
 101 static char **my_environ;
 102
 103 static const char *startup_PATH;
 104
 105 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 106
 107 static void addstr(char **bufp, const char *str, size_t str_length)
 108 {
 109         /* xasprintf trick will be smaller, but we are often
 110          * called with str_length == 1 - don't want to have
 111          * THAT much of malloc/freeing! */
 112         char *buf = *bufp;
 113         int len = (buf ? strlen(buf) : 0);
 114         str_length++;
 115         buf = xrealloc(buf, len + str_length);
 116         /* copies at most str_length-1 chars! */
 117         safe_strncpy(buf + len, str, str_length);
 118         *bufp = buf;
 119 }
 120
 121 static int strncmpz(const char *l, const char *r, size_t llen)
 122 {
 123         int i = strncmp(l, r, llen);
 124
 125         if (i == 0)
 126                 return -r[llen];
 127         return i;
 128 }
 129
 130 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 131 {
 132         int i;
 133
 134         if (strncmpz(id, "iface", idlen) == 0) {
 135                 char *result;
 136                 static char label_buf[20];
 137                 safe_strncpy(label_buf, ifd->iface, sizeof(label_buf));
 138                 result = strchr(label_buf, ':');
 139                 if (result) {
 140                         *result = '\0';
 141                 }
 142                 return label_buf;
 143         }
 144         if (strncmpz(id, "label", idlen) == 0) {
 145                 return ifd->iface;
 146         }
 147         for (i = 0; i < ifd->n_options; i++) {
 148                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 149                         return ifd->option[i].value;
 150                 }
 151         }
 152         return NULL;
 153 }
 154
 155 #if ENABLE_FEATURE_IFUPDOWN_IP
 156 static int count_netmask_bits(const char *dotted_quad)
 157 {
 158 //      int result;
 159 //      unsigned a, b, c, d;
 160 //      /* Found a netmask...  Check if it is dotted quad */
 161 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 162 //              return -1;
 163 //      if ((a|b|c|d) >> 8)
 164 //              return -1; /* one of numbers is >= 256 */
 165 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 166 //      d = ~d; /* 11110000 -> 00001111 */
 167
 168         /* Shorter version */
 169         int result;
 170         struct in_addr ip;
 171         unsigned d;
 172
 173         if (inet_aton(dotted_quad, &ip) == 0)
 174                 return -1; /* malformed dotted IP */
 175         d = ntohl(ip.s_addr); /* IP in host order */
 176         d = ~d; /* 11110000 -> 00001111 */
 177         if (d & (d+1)) /* check that it is in 00001111 form */
 178                 return -1; /* no it is not */
 179         result = 32;
 180         while (d) {
 181                 d >>= 1;
 182                 result--;
 183         }
 184         return result;
 185 }
 186 #endif
 187
 188 static char *parse(const char *command, struct interface_defn_t *ifd)
 189 {
 190         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 191         int okay[MAX_OPT_DEPTH] = { 1 };
 192         int opt_depth = 1;
 193         char *result = NULL;
 194
 195         while (*command) {
 196                 switch (*command) {
 197                 default:
 198                         addstr(&result, command, 1);
 199                         command++;
 200                         break;
 201                 case '\\':
 202                         if (command[1]) {
 203                                 addstr(&result, command + 1, 1);
 204                                 command += 2;
 205                         } else {
 206                                 addstr(&result, command, 1);
 207                                 command++;
 208                         }
 209                         break;
 210                 case '[':
 211                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 212                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 213                                 okay[opt_depth] = 1;
 214                                 opt_depth++;
 215                                 command += 2;
 216                         } else {
 217                                 addstr(&result, "[", 1);
 218                                 command++;
 219                         }
 220                         break;
 221                 case ']':
 222                         if (command[1] == ']' && opt_depth > 1) {
 223                                 opt_depth--;
 224                                 if (!okay[opt_depth]) {
 225                                         result[old_pos[opt_depth]] = '\0';
 226                                 }
 227                                 command += 2;
 228                         } else {
 229                                 addstr(&result, "]", 1);
 230                                 command++;
 231                         }
 232                         break;
 233                 case '%':
 234                         {
 235                                 char *nextpercent;
 236                                 char *varvalue;
 237
 238                                 command++;
 239                                 nextpercent = strchr(command, '%');
 240                                 if (!nextpercent) {
 241                                         errno = EUNBALPER;
 242                                         free(result);
 243                                         return NULL;
 244                                 }
 245
 246                                 varvalue = get_var(command, nextpercent - command, ifd);
 247
 248                                 if (varvalue) {
 249                                         addstr(&result, varvalue, strlen(varvalue));
 250                                 } else {
 251 #if ENABLE_FEATURE_IFUPDOWN_IP
 252                                         /* Sigh...  Add a special case for 'ip' to convert from
 253                                          * dotted quad to bit count style netmasks.  */
 254                                         if (strncmp(command, "bnmask", 6) == 0) {
 255                                                 unsigned res;
 256                                                 varvalue = get_var("netmask", 7, ifd);
 257                                                 if (varvalue) {
 258                                                         res = count_netmask_bits(varvalue);
 259                                                         if (res > 0) {
 260                                                                 const char *argument = utoa(res);
 261                                                                 addstr(&result, argument, strlen(argument));
 262                                                                 command = nextpercent + 1;
 263                                                                 break;
 264                                                         }
 265                                                 }
 266                                         }
 267 #endif
 268                                         okay[opt_depth - 1] = 0;
 269                                 }
 270
 271                                 command = nextpercent + 1;
 272                         }
 273                         break;
 274                 }
 275         }
 276
 277         if (opt_depth > 1) {
 278                 errno = EUNBALBRACK;
 279                 free(result);
 280                 return NULL;
 281         }
 282
 283         if (!okay[0]) {
 284                 errno = EUNDEFVAR;
 285                 free(result);
 286                 return NULL;
 287         }
 288
 289         return result;
 290 }
 291
 292 /* execute() returns 1 for success and 0 for failure */
 293 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 294 {
 295         char *out;
 296         int ret;
 297
 298         out = parse(command, ifd);
 299         if (!out) {
 300                 /* parse error? */
 301                 return 0;
 302         }
 303         /* out == "": parsed ok but not all needed variables known, skip */
 304         ret = out[0] ? (*exec)(out) : 1;
 305
 306         free(out);
 307         if (ret != 1) {
 308                 return 0;
 309         }
 310         return 1;
 311 }
 312 #endif
 313
 314 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 315 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 316 {
 317 #if ENABLE_FEATURE_IFUPDOWN_IP
 318         int result;
 319         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 320         result += execute("ip link set %iface% up", ifd, exec);
 321         return ((result == 2) ? 2 : 0);
 322 #else
 323         return execute("ifconfig %iface% add ::1", ifd, exec);
 324 #endif
 325 }
 326
 327 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 328 {
 329 #if ENABLE_FEATURE_IFUPDOWN_IP
 330         return execute("ip link set %iface% down", ifd, exec);
 331 #else
 332         return execute("ifconfig %iface% del ::1", ifd, exec);
 333 #endif
 334 }
 335
 336 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 337 {
 338         int result;
 339 #if ENABLE_FEATURE_IFUPDOWN_IP
 340         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 341         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 342         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
 343         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 344 #else
 345         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 346         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 347         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
 348 #endif
 349         return ((result == 3) ? 3 : 0);
 350 }
 351
 352 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 353 {
 354 #if ENABLE_FEATURE_IFUPDOWN_IP
 355         return execute("ip link set %iface% down", ifd, exec);
 356 #else
 357         return execute("ifconfig %iface% down", ifd, exec);
 358 #endif
 359 }
 360
 361 #if ENABLE_FEATURE_IFUPDOWN_IP
 362 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 363 {
 364         int result;
 365         result = execute("ip tunnel add %iface% mode sit remote "
 366                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 367         result += execute("ip link set %iface% up", ifd, exec);
 368         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 369         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 370         return ((result == 4) ? 4 : 0);
 371 }
 372
 373 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 374 {
 375         return execute("ip tunnel del %iface%", ifd, exec);
 376 }
 377 #endif
 378
 379 static const struct method_t methods6[] = {
 380 #if ENABLE_FEATURE_IFUPDOWN_IP
 381         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 382 #endif
 383         { "static", static_up6, static_down6, },
 384         { "loopback", loopback_up6, loopback_down6, },
 385 };
 386
 387 static const struct address_family_t addr_inet6 = {
 388         "inet6",
 389         ARRAY_SIZE(methods6),
 390         methods6
 391 };
 392 #endif /* FEATURE_IFUPDOWN_IPV6 */
 393
 394 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 395 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 396 {
 397 #if ENABLE_FEATURE_IFUPDOWN_IP
 398         int result;
 399         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 400         result += execute("ip link set %iface% up", ifd, exec);
 401         return ((result == 2) ? 2 : 0);
 402 #else
 403         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 404 #endif
 405 }
 406
 407 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 408 {
 409 #if ENABLE_FEATURE_IFUPDOWN_IP
 410         int result;
 411         result = execute("ip addr flush dev %iface%", ifd, exec);
 412         result += execute("ip link set %iface% down", ifd, exec);
 413         return ((result == 2) ? 2 : 0);
 414 #else
 415         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 416 #endif
 417 }
 418
 419 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 420 {
 421         int result;
 422 #if ENABLE_FEATURE_IFUPDOWN_IP
 423         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 424                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 425         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 426         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
 427         return ((result == 3) ? 3 : 0);
 428 #else
 429         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 430          * which then of course fails. Thus we run two separate ifconfig */
 431         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 432                                 ifd, exec);
 433         result += execute("ifconfig %iface% %address% netmask %netmask%"
 434                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 435                                 ifd, exec);
 436         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
 437         return ((result == 3) ? 3 : 0);
 438 #endif
 439 }
 440
 441 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 442 {
 443         int result;
 444 #if ENABLE_FEATURE_IFUPDOWN_IP
 445         result = execute("ip addr flush dev %iface%", ifd, exec);
 446         result += execute("ip link set %iface% down", ifd, exec);
 447 #else
 448         result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec);
 449         result += execute("ifconfig %iface% down", ifd, exec);
 450 #endif
 451         return ((result == 2) ? 2 : 0);
 452 }
 453
 454 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 455 struct dhcp_client_t
 456 {
 457         const char *name;
 458         const char *startcmd;
 459         const char *stopcmd;
 460 };
 461
 462 static const struct dhcp_client_t ext_dhcp_clients[] = {
 463         { "dhcpcd",
 464                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
 465                 "dhcpcd -k %iface%",
 466         },
 467         { "dhclient",
 468                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 469                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 470         },
 471         { "pump",
 472                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 473                 "pump -i %iface% -k",
 474         },
 475         { "udhcpc",
 476                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 477                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 478         },
 479 };
 480 #endif /* ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 481
 482 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 483 {
 484 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 485         int i ;
 486         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 487                 if (exists_execable(ext_dhcp_clients[i].name))
 488                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 489         }
 490         bb_error_msg("no dhcp clients found");
 491         return 0;
 492 #elif ENABLE_APP_UDHCPC
 493         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 494                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 495                         ifd, exec);
 496 #else
 497         return 0; /* no dhcp support */
 498 #endif
 499 }
 500
 501 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 502 {
 503 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 504         int i ;
 505         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 506                 if (exists_execable(ext_dhcp_clients[i].name))
 507                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 508         }
 509         bb_error_msg("no dhcp clients found, using static interface shutdown");
 510         return static_down(ifd, exec);
 511 #elif ENABLE_APP_UDHCPC
 512         return execute("kill "
 513                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 514 #else
 515         return 0; /* no dhcp support */
 516 #endif
 517 }
 518
 519 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 520 {
 521         return 1;
 522 }
 523
 524 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 525 {
 526         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 527                         "[[ --server %server%]][[ --hwaddr %hwaddr%]] "
 528                         "--returniffail --serverbcast", ifd, exec);
 529 }
 530
 531 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 532 {
 533         return execute("pon[[ %provider%]]", ifd, exec);
 534 }
 535
 536 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 537 {
 538         return execute("poff[[ %provider%]]", ifd, exec);
 539 }
 540
 541 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 542 {
 543         return execute("start-stop-daemon --start -x wvdial "
 544                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 545 }
 546
 547 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 548 {
 549         return execute("start-stop-daemon --stop -x wvdial "
 550                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 551 }
 552
 553 static const struct method_t methods[] = {
 554         { "manual", manual_up_down, manual_up_down, },
 555         { "wvdial", wvdial_up, wvdial_down, },
 556         { "ppp", ppp_up, ppp_down, },
 557         { "static", static_up, static_down, },
 558         { "bootp", bootp_up, static_down, },
 559         { "dhcp", dhcp_up, dhcp_down, },
 560         { "loopback", loopback_up, loopback_down, },
 561 };
 562
 563 static const struct address_family_t addr_inet = {
 564         "inet",
 565         ARRAY_SIZE(methods),
 566         methods
 567 };
 568
 569 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 570
 571 static char *next_word(char **buf)
 572 {
 573         unsigned short length;
 574         char *word;
 575
 576         if (!buf || !*buf || !**buf) {
 577                 return NULL;
 578         }
 579
 580         /* Skip over leading whitespace */
 581         word = skip_whitespace(*buf);
 582
 583         /* Skip over comments */
 584         if (*word == '#') {
 585                 return NULL;
 586         }
 587
 588         /* Find the length of this word */
 589         length = strcspn(word, " \t\n");
 590         if (length == 0) {
 591                 return NULL;
 592         }
 593         *buf = word + length;
 594         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 595         if (**buf) {
 596                 **buf = '\0';
 597                 (*buf)++;
 598         }
 599
 600         return word;
 601 }
 602
 603 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 604 {
 605         int i;
 606
 607         if (!name)
 608                 return NULL;
 609
 610         for (i = 0; af[i]; i++) {
 611                 if (strcmp(af[i]->name, name) == 0) {
 612                         return af[i];
 613                 }
 614         }
 615         return NULL;
 616 }
 617
 618 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 619 {
 620         int i;
 621
 622         if (!name)
 623                 return NULL;
 624
 625         for (i = 0; i < af->n_methods; i++) {
 626                 if (strcmp(af->method[i].name, name) == 0) {
 627                         return &af->method[i];
 628                 }
 629         }
 630         return NULL;
 631 }
 632
 633 static const llist_t *find_list_string(const llist_t *list, const char *string)
 634 {
 635         if (string == NULL)
 636                 return NULL;
 637
 638         while (list) {
 639                 if (strcmp(list->data, string) == 0) {
 640                         return list;
 641                 }
 642                 list = list->link;
 643         }
 644         return NULL;
 645 }
 646
 647 static struct interfaces_file_t *read_interfaces(const char *filename)
 648 {
 649 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 650         struct mapping_defn_t *currmap = NULL;
 651 #endif
 652         struct interface_defn_t *currif = NULL;
 653         struct interfaces_file_t *defn;
 654         FILE *f;
 655         char *firstword;
 656         char *buf;
 657
 658         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 659
 660         defn = xzalloc(sizeof(struct interfaces_file_t));
 661
 662         f = xfopen(filename, "r");
 663
 664         while ((buf = xmalloc_getline(f)) != NULL) {
 665                 char *buf_ptr = buf;
 666
 667                 firstword = next_word(&buf_ptr);
 668                 if (firstword == NULL) {
 669                         free(buf);
 670                         continue;       /* blank line */
 671                 }
 672
 673                 if (strcmp(firstword, "mapping") == 0) {
 674 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 675                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 676
 677                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 678                                 if (currmap->max_matches == currmap->n_matches) {
 679                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 680                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 681                                 }
 682
 683                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 684                         }
 685                         currmap->max_mappings = 0;
 686                         currmap->n_mappings = 0;
 687                         currmap->mapping = NULL;
 688                         currmap->script = NULL;
 689                         {
 690                                 struct mapping_defn_t **where = &defn->mappings;
 691                                 while (*where != NULL) {
 692                                         where = &(*where)->next;
 693                                 }
 694                                 *where = currmap;
 695                                 currmap->next = NULL;
 696                         }
 697                         debug_noise("Added mapping\n");
 698 #endif
 699                         currently_processing = MAPPING;
 700                 } else if (strcmp(firstword, "iface") == 0) {
 701                         static const struct address_family_t *const addr_fams[] = {
 702 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 703                                 &addr_inet,
 704 #endif
 705 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 706                                 &addr_inet6,
 707 #endif
 708                                 NULL
 709                         };
 710
 711                         char *iface_name;
 712                         char *address_family_name;
 713                         char *method_name;
 714                         llist_t *iface_list;
 715
 716                         currif = xzalloc(sizeof(struct interface_defn_t));
 717                         iface_name = next_word(&buf_ptr);
 718                         address_family_name = next_word(&buf_ptr);
 719                         method_name = next_word(&buf_ptr);
 720
 721                         if (buf_ptr == NULL) {
 722                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 723                                 return NULL;
 724                         }
 725
 726                         /* ship any trailing whitespace */
 727                         buf_ptr = skip_whitespace(buf_ptr);
 728
 729                         if (buf_ptr[0] != '\0') {
 730                                 bb_error_msg("too many parameters \"%s\"", buf);
 731                                 return NULL;
 732                         }
 733
 734                         currif->iface = xstrdup(iface_name);
 735
 736                         currif->address_family = get_address_family(addr_fams, address_family_name);
 737                         if (!currif->address_family) {
 738                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 739                                 return NULL;
 740                         }
 741
 742                         currif->method = get_method(currif->address_family, method_name);
 743                         if (!currif->method) {
 744                                 bb_error_msg("unknown method \"%s\"", method_name);
 745                                 return NULL;
 746                         }
 747
 748                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 749                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 750                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 751                                         (tmp->address_family == currif->address_family)) {
 752                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 753                                         return NULL;
 754                                 }
 755                         }
 756                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 757
 758                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 759                         currently_processing = IFACE;
 760                 } else if (strcmp(firstword, "auto") == 0) {
 761                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 762
 763                                 /* Check the interface isnt already listed */
 764                                 if (find_list_string(defn->autointerfaces, firstword)) {
 765                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 766                                 }
 767
 768                                 /* Add the interface to the list */
 769                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 770                                 debug_noise("\nauto %s\n", firstword);
 771                         }
 772                         currently_processing = NONE;
 773                 } else {
 774                         switch (currently_processing) {
 775                         case IFACE:
 776                                 {
 777                                         int i;
 778
 779                                         if (strlen(buf_ptr) == 0) {
 780                                                 bb_error_msg("option with empty value \"%s\"", buf);
 781                                                 return NULL;
 782                                         }
 783
 784                                         if (strcmp(firstword, "up") != 0
 785                                                         && strcmp(firstword, "down") != 0
 786                                                         && strcmp(firstword, "pre-up") != 0
 787                                                         && strcmp(firstword, "post-down") != 0) {
 788                                                 for (i = 0; i < currif->n_options; i++) {
 789                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 790                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 791                                                                 return NULL;
 792                                                         }
 793                                                 }
 794                                         }
 795                                 }
 796                                 if (currif->n_options >= currif->max_options) {
 797                                         struct variable_t *opt;
 798
 799                                         currif->max_options = currif->max_options + 10;
 800                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 801                                         currif->option = opt;
 802                                 }
 803                                 currif->option[currif->n_options].name = xstrdup(firstword);
 804                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 805                                 if (!currif->option[currif->n_options].name) {
 806                                         perror(filename);
 807                                         return NULL;
 808                                 }
 809                                 if (!currif->option[currif->n_options].value) {
 810                                         perror(filename);
 811                                         return NULL;
 812                                 }
 813                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 814                                                 currif->option[currif->n_options].value);
 815                                 currif->n_options++;
 816                                 break;
 817                         case MAPPING:
 818 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 819                                 if (strcmp(firstword, "script") == 0) {
 820                                         if (currmap->script != NULL) {
 821                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 822                                                 return NULL;
 823                                         } else {
 824                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 825                                         }
 826                                 } else if (strcmp(firstword, "map") == 0) {
 827                                         if (currmap->max_mappings == currmap->n_mappings) {
 828                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 829                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 830                                         }
 831                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 832                                         currmap->n_mappings++;
 833                                 } else {
 834                                         bb_error_msg("misplaced option \"%s\"", buf);
 835                                         return NULL;
 836                                 }
 837 #endif
 838                                 break;
 839                         case NONE:
 840                         default:
 841                                 bb_error_msg("misplaced option \"%s\"", buf);
 842                                 return NULL;
 843                         }
 844                 }
 845                 free(buf);
 846         }
 847         if (ferror(f) != 0) {
 848                 /* ferror does NOT set errno! */
 849                 bb_error_msg_and_die("%s: I/O error", filename);
 850         }
 851         fclose(f);
 852
 853         return defn;
 854 }
 855
 856 static char *setlocalenv(const char *format, const char *name, const char *value)
 857 {
 858         char *result;
 859         char *here;
 860         char *there;
 861
 862         result = xasprintf(format, name, value);
 863
 864         for (here = there = result; *there != '=' && *there; there++) {
 865                 if (*there == '-')
 866                         *there = '_';
 867                 if (isalpha(*there))
 868                         *there = toupper(*there);
 869
 870                 if (isalnum(*there) || *there == '_') {
 871                         *here = *there;
 872                         here++;
 873                 }
 874         }
 875         memmove(here, there, strlen(there) + 1);
 876
 877         return result;
 878 }
 879
 880 static void set_environ(struct interface_defn_t *iface, const char *mode)
 881 {
 882         char **environend;
 883         int i;
 884         const int n_env_entries = iface->n_options + 5;
 885         char **ppch;
 886
 887         if (my_environ != NULL) {
 888                 for (ppch = my_environ; *ppch; ppch++) {
 889                         free(*ppch);
 890                         *ppch = NULL;
 891                 }
 892                 free(my_environ);
 893         }
 894         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 895         environend = my_environ;
 896
 897         for (i = 0; i < iface->n_options; i++) {
 898                 if (strcmp(iface->option[i].name, "up") == 0
 899                  || strcmp(iface->option[i].name, "down") == 0
 900                  || strcmp(iface->option[i].name, "pre-up") == 0
 901                  || strcmp(iface->option[i].name, "post-down") == 0
 902                 ) {
 903                         continue;
 904                 }
 905                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 906         }
 907
 908         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 909         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 910         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 911         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 912         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 913 }
 914
 915 static int doit(char *str)
 916 {
 917         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 918                 puts(str);
 919         }
 920         if (!(option_mask32 & OPT_no_act)) {
 921                 pid_t child;
 922                 int status;
 923
 924                 fflush(NULL);
 925                 child = fork();
 926                 switch (child) {
 927                 case -1: /* failure */
 928                         return 0;
 929                 case 0: /* child */
 930                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 931                         exit(127);
 932                 }
 933                 waitpid(child, &status, 0);
 934                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 935                         return 0;
 936                 }
 937         }
 938         return 1;
 939 }
 940
 941 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 942 {
 943         int i;
 944         char *buf;
 945         for (i = 0; i < ifd->n_options; i++) {
 946                 if (strcmp(ifd->option[i].name, opt) == 0) {
 947                         if (!doit(ifd->option[i].value)) {
 948                                 return 0;
 949                         }
 950                 }
 951         }
 952
 953         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 954         /* heh, we don't bother free'ing it */
 955         return doit(buf);
 956 }
 957
 958 static int check(char *str)
 959 {
 960         return str != NULL;
 961 }
 962
 963 static int iface_up(struct interface_defn_t *iface)
 964 {
 965         if (!iface->method->up(iface, check)) return -1;
 966         set_environ(iface, "start");
 967         if (!execute_all(iface, "pre-up")) return 0;
 968         if (!iface->method->up(iface, doit)) return 0;
 969         if (!execute_all(iface, "up")) return 0;
 970         return 1;
 971 }
 972
 973 static int iface_down(struct interface_defn_t *iface)
 974 {
 975         if (!iface->method->down(iface,check)) return -1;
 976         set_environ(iface, "stop");
 977         if (!execute_all(iface, "down")) return 0;
 978         if (!iface->method->down(iface, doit)) return 0;
 979         if (!execute_all(iface, "post-down")) return 0;
 980         return 1;
 981 }
 982
 983 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 984 static int popen2(FILE **in, FILE **out, char *command, ...)
 985 {
 986         va_list ap;
 987         char *argv[11] = { command };
 988         int argc;
 989         int infd[2], outfd[2];
 990         pid_t pid;
 991
 992         argc = 1;
 993         va_start(ap, command);
 994         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 995                 argc++;
 996         }
 997         argv[argc] = NULL;      /* make sure */
 998         va_end(ap);
 999
1000         if (pipe(infd) != 0) {
1001                 return 0;
1002         }
1003
1004         if (pipe(outfd) != 0) {
1005                 close(infd[0]);
1006                 close(infd[1]);
1007                 return 0;
1008         }
1009
1010         fflush(NULL);
1011         switch (pid = fork()) {
1012         case -1:                        /* failure */
1013                 close(infd[0]);
1014                 close(infd[1]);
1015                 close(outfd[0]);
1016                 close(outfd[1]);
1017                 return 0;
1018         case 0:                 /* child */
1019                 dup2(infd[0], 0);
1020                 dup2(outfd[1], 1);
1021                 close(infd[0]);
1022                 close(infd[1]);
1023                 close(outfd[0]);
1024                 close(outfd[1]);
1025                 BB_EXECVP(command, argv);
1026                 exit(127);
1027         default:                        /* parent */
1028                 *in = fdopen(infd[1], "w");
1029                 *out = fdopen(outfd[0], "r");
1030                 close(infd[0]);
1031                 close(outfd[1]);
1032                 return pid;
1033         }
1034         /* unreached */
1035 }
1036
1037 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1038 {
1039         FILE *in, *out;
1040         int i, status;
1041         pid_t pid;
1042
1043         char *logical = xstrdup(physical);
1044
1045         /* Run the mapping script. */
1046         pid = popen2(&in, &out, map->script, physical, NULL);
1047
1048         /* popen2() returns 0 on failure. */
1049         if (pid == 0)
1050                 return logical;
1051
1052         /* Write mappings to stdin of mapping script. */
1053         for (i = 0; i < map->n_mappings; i++) {
1054                 fprintf(in, "%s\n", map->mapping[i]);
1055         }
1056         fclose(in);
1057         waitpid(pid, &status, 0);
1058
1059         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1060                 /* If the mapping script exited successfully, try to
1061                  * grab a line of output and use that as the name of the
1062                  * logical interface. */
1063                 char *new_logical = xmalloc(MAX_INTERFACE_LENGTH);
1064
1065                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1066                         /* If we are able to read a line of output from the script,
1067                          * remove any trailing whitespace and use this value
1068                          * as the name of the logical interface. */
1069                         char *pch = new_logical + strlen(new_logical) - 1;
1070
1071                         while (pch >= new_logical && isspace(*pch))
1072                                 *(pch--) = '\0';
1073
1074                         free(logical);
1075                         logical = new_logical;
1076                 } else {
1077                         /* If we are UNABLE to read a line of output, discard our
1078                          * freshly allocated memory. */
1079                         free(new_logical);
1080                 }
1081         }
1082
1083         fclose(out);
1084
1085         return logical;
1086 }
1087 #endif /* FEATURE_IFUPDOWN_MAPPING */
1088
1089 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1090 {
1091         unsigned short iface_len = strlen(iface);
1092         llist_t *search = state_list;
1093
1094         while (search) {
1095                 if ((strncmp(search->data, iface, iface_len) == 0)
1096                  && (search->data[iface_len] == '=')) {
1097                         return search;
1098                 }
1099                 search = search->link;
1100         }
1101         return NULL;
1102 }
1103
1104 /* read the previous state from the state file */
1105 static llist_t *read_iface_state(void)
1106 {
1107         llist_t *state_list = NULL;
1108         FILE *state_fp = fopen("/var/run/ifstate", "r");
1109
1110         if (state_fp) {
1111                 char *start, *end_ptr;
1112                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1113                         /* We should only need to check for a single character */
1114                         end_ptr = start + strcspn(start, " \t\n");
1115                         *end_ptr = '\0';
1116                         llist_add_to(&state_list, start);
1117                 }
1118                 fclose(state_fp);
1119         }
1120         return state_list;
1121 }
1122
1123
1124 int ifupdown_main(int argc, char **argv);
1125 int ifupdown_main(int argc, char **argv)
1126 {
1127         int (*cmds)(struct interface_defn_t *) = NULL;
1128         struct interfaces_file_t *defn;
1129         llist_t *target_list = NULL;
1130         const char *interfaces = "/etc/network/interfaces";
1131         bool any_failures = 0;
1132
1133         cmds = iface_down;
1134         if (applet_name[2] == 'u') {
1135                 /* ifup command */
1136                 cmds = iface_up;
1137         }
1138
1139         getopt32(argc, argv, OPTION_STR, &interfaces);
1140         if (argc - optind > 0) {
1141                 if (DO_ALL) bb_show_usage();
1142         } else {
1143                 if (!DO_ALL) bb_show_usage();
1144         }
1145
1146         debug_noise("reading %s file:\n", interfaces);
1147         defn = read_interfaces(interfaces);
1148         debug_noise("\ndone reading %s\n\n", interfaces);
1149
1150         if (!defn) {
1151                 return EXIT_FAILURE;
1152         }
1153
1154         startup_PATH = getenv("PATH");
1155         if (!startup_PATH) startup_PATH = "";
1156
1157         /* Create a list of interfaces to work on */
1158         if (DO_ALL) {
1159                 target_list = defn->autointerfaces;
1160         } else {
1161                 llist_add_to_end(&target_list, argv[optind]);
1162         }
1163
1164         /* Update the interfaces */
1165         while (target_list) {
1166                 llist_t *iface_list;
1167                 struct interface_defn_t *currif;
1168                 char *iface;
1169                 char *liface;
1170                 char *pch;
1171                 bool okay = 0;
1172                 unsigned cmds_ret;
1173
1174                 iface = xstrdup(target_list->data);
1175                 target_list = target_list->link;
1176
1177                 pch = strchr(iface, '=');
1178                 if (pch) {
1179                         *pch = '\0';
1180                         liface = xstrdup(pch + 1);
1181                 } else {
1182                         liface = xstrdup(iface);
1183                 }
1184
1185                 if (!FORCE) {
1186                         llist_t *state_list = read_iface_state();
1187                         const llist_t *iface_state = find_iface_state(state_list, iface);
1188
1189                         if (cmds == iface_up) {
1190                                 /* ifup */
1191                                 if (iface_state) {
1192                                         bb_error_msg("interface %s already configured", iface);
1193                                         continue;
1194                                 }
1195                         } else {
1196                                 /* ifdown */
1197                                 if (!iface_state) {
1198                                         bb_error_msg("interface %s not configured", iface);
1199                                         continue;
1200                                 }
1201                         }
1202                         llist_free(state_list, free);
1203                 }
1204
1205 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1206                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1207                         struct mapping_defn_t *currmap;
1208
1209                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1210                                 int i;
1211                                 for (i = 0; i < currmap->n_matches; i++) {
1212                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1213                                                 continue;
1214                                         if (VERBOSE) {
1215                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1216                                         }
1217                                         liface = run_mapping(iface, currmap);
1218                                         break;
1219                                 }
1220                         }
1221                 }
1222 #endif
1223
1224                 iface_list = defn->ifaces;
1225                 while (iface_list) {
1226                         currif = (struct interface_defn_t *) iface_list->data;
1227                         if (strcmp(liface, currif->iface) == 0) {
1228                                 char *oldiface = currif->iface;
1229
1230                                 okay = 1;
1231                                 currif->iface = iface;
1232
1233                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1234
1235                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1236                                 cmds_ret = cmds(currif);
1237                                 if (cmds_ret == -1) {
1238                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1239                                                         liface, currif->address_family->name);
1240                                         any_failures = 1;
1241                                 } else if (cmds_ret == 0) {
1242                                         any_failures = 1;
1243                                 }
1244
1245                                 currif->iface = oldiface;
1246                         }
1247                         iface_list = iface_list->link;
1248                 }
1249                 if (VERBOSE) {
1250                         puts("");
1251                 }
1252
1253                 if (!okay && !FORCE) {
1254                         bb_error_msg("ignoring unknown interface %s", liface);
1255                         any_failures = 1;
1256                 } else if (!NO_ACT) {
1257                         /* update the state file */
1258                         FILE *state_fp;
1259                         llist_t *state;
1260                         llist_t *state_list = read_iface_state();
1261                         llist_t *iface_state = find_iface_state(state_list, iface);
1262
1263                         if (cmds == iface_up) {
1264                                 char * const newiface = xasprintf("%s=%s", iface, liface);
1265                                 if (iface_state == NULL) {
1266                                         llist_add_to_end(&state_list, newiface);
1267                                 } else {
1268                                         free(iface_state->data);
1269                                         iface_state->data = newiface;
1270                                 }
1271                         } else {
1272                                 /* Remove an interface from state_list */
1273                                 llist_unlink(&state_list, iface_state);
1274                                 free(llist_pop(&iface_state));
1275                         }
1276
1277                         /* Actually write the new state */
1278                         state_fp = xfopen("/var/run/ifstate", "w");
1279                         state = state_list;
1280                         while (state) {
1281                                 if (state->data) {
1282                                         fprintf(state_fp, "%s\n", state->data);
1283                                 }
1284                                 state = state->link;
1285                         }
1286                         fclose(state_fp);
1287                         llist_free(state_list, free);
1288                 }
1289         }
1290
1291         return any_failures;
1292 }