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  *  (defined via CONFIG_IFUPDOWN_IFSTATE_PATH) and can be overridden by build
  15  *  configuration.
  16  *
  17  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  18  */
  19
  20 #include <sys/utsname.h>
  21 #include <fnmatch.h>
  22 #include <getopt.h>
  23
  24 #include "libbb.h"
  25
  26 #define MAX_OPT_DEPTH 10
  27 #define EUNBALBRACK 10001
  28 #define EUNDEFVAR   10002
  29 #define EUNBALPER   10000
  30
  31 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
  32 #define MAX_INTERFACE_LENGTH 10
  33 #endif
  34
  35 #define debug_noise(args...) /*fprintf(stderr, args)*/
  36
  37 /* Forward declaration */
  38 struct interface_defn_t;
  39
  40 typedef int execfn(char *command);
  41
  42 struct method_t {
  43         const char *name;
  44         int (*up)(struct interface_defn_t *ifd, execfn *e);
  45         int (*down)(struct interface_defn_t *ifd, execfn *e);
  46 };
  47
  48 struct address_family_t {
  49         const char *name;
  50         int n_methods;
  51         const struct method_t *method;
  52 };
  53
  54 struct mapping_defn_t {
  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         char *name;
  70         char *value;
  71 };
  72
  73 struct interface_defn_t {
  74         const struct address_family_t *address_family;
  75         const struct method_t *method;
  76
  77         char *iface;
  78         int max_options;
  79         int n_options;
  80         struct variable_t *option;
  81 };
  82
  83 struct interfaces_file_t {
  84         llist_t *autointerfaces;
  85         llist_t *ifaces;
  86         struct mapping_defn_t *mappings;
  87 };
  88
  89 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  90 enum {
  91         OPT_do_all = 0x1,
  92         OPT_no_act = 0x2,
  93         OPT_verbose = 0x4,
  94         OPT_force = 0x8,
  95         OPT_no_mappings = 0x10,
  96 };
  97 #define DO_ALL (option_mask32 & OPT_do_all)
  98 #define NO_ACT (option_mask32 & OPT_no_act)
  99 #define VERBOSE (option_mask32 & OPT_verbose)
 100 #define FORCE (option_mask32 & OPT_force)
 101 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 102
 103 static char **my_environ;
 104
 105 static const char *startup_PATH;
 106
 107 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 108
 109 static void addstr(char **bufp, const char *str, size_t str_length)
 110 {
 111         /* xasprintf trick will be smaller, but we are often
 112          * called with str_length == 1 - don't want to have
 113          * THAT much of malloc/freeing! */
 114         char *buf = *bufp;
 115         int len = (buf ? strlen(buf) : 0);
 116         str_length++;
 117         buf = xrealloc(buf, len + str_length);
 118         /* copies at most str_length-1 chars! */
 119         safe_strncpy(buf + len, str, str_length);
 120         *bufp = buf;
 121 }
 122
 123 static int strncmpz(const char *l, const char *r, size_t llen)
 124 {
 125         int i = strncmp(l, r, llen);
 126
 127         if (i == 0)
 128                 return -r[llen];
 129         return i;
 130 }
 131
 132 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 133 {
 134         int i;
 135
 136         if (strncmpz(id, "iface", idlen) == 0) {
 137                 char *result;
 138                 static char label_buf[20];
 139                 safe_strncpy(label_buf, ifd->iface, sizeof(label_buf));
 140                 result = strchr(label_buf, ':');
 141                 if (result) {
 142                         *result = '\0';
 143                 }
 144                 return label_buf;
 145         }
 146         if (strncmpz(id, "label", idlen) == 0) {
 147                 return ifd->iface;
 148         }
 149         for (i = 0; i < ifd->n_options; i++) {
 150                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 151                         return ifd->option[i].value;
 152                 }
 153         }
 154         return NULL;
 155 }
 156
 157 #if ENABLE_FEATURE_IFUPDOWN_IP
 158 static int count_netmask_bits(const char *dotted_quad)
 159 {
 160 //      int result;
 161 //      unsigned a, b, c, d;
 162 //      /* Found a netmask...  Check if it is dotted quad */
 163 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 164 //              return -1;
 165 //      if ((a|b|c|d) >> 8)
 166 //              return -1; /* one of numbers is >= 256 */
 167 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 168 //      d = ~d; /* 11110000 -> 00001111 */
 169
 170         /* Shorter version */
 171         int result;
 172         struct in_addr ip;
 173         unsigned d;
 174
 175         if (inet_aton(dotted_quad, &ip) == 0)
 176                 return -1; /* malformed dotted IP */
 177         d = ntohl(ip.s_addr); /* IP in host order */
 178         d = ~d; /* 11110000 -> 00001111 */
 179         if (d & (d+1)) /* check that it is in 00001111 form */
 180                 return -1; /* no it is not */
 181         result = 32;
 182         while (d) {
 183                 d >>= 1;
 184                 result--;
 185         }
 186         return result;
 187 }
 188 #endif
 189
 190 static char *parse(const char *command, struct interface_defn_t *ifd)
 191 {
 192         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 193         int okay[MAX_OPT_DEPTH] = { 1 };
 194         int opt_depth = 1;
 195         char *result = NULL;
 196
 197         while (*command) {
 198                 switch (*command) {
 199                 default:
 200                         addstr(&result, command, 1);
 201                         command++;
 202                         break;
 203                 case '\\':
 204                         if (command[1]) {
 205                                 addstr(&result, command + 1, 1);
 206                                 command += 2;
 207                         } else {
 208                                 addstr(&result, command, 1);
 209                                 command++;
 210                         }
 211                         break;
 212                 case '[':
 213                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 214                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 215                                 okay[opt_depth] = 1;
 216                                 opt_depth++;
 217                                 command += 2;
 218                         } else {
 219                                 addstr(&result, "[", 1);
 220                                 command++;
 221                         }
 222                         break;
 223                 case ']':
 224                         if (command[1] == ']' && opt_depth > 1) {
 225                                 opt_depth--;
 226                                 if (!okay[opt_depth]) {
 227                                         result[old_pos[opt_depth]] = '\0';
 228                                 }
 229                                 command += 2;
 230                         } else {
 231                                 addstr(&result, "]", 1);
 232                                 command++;
 233                         }
 234                         break;
 235                 case '%':
 236                         {
 237                                 char *nextpercent;
 238                                 char *varvalue;
 239
 240                                 command++;
 241                                 nextpercent = strchr(command, '%');
 242                                 if (!nextpercent) {
 243                                         errno = EUNBALPER;
 244                                         free(result);
 245                                         return NULL;
 246                                 }
 247
 248                                 varvalue = get_var(command, nextpercent - command, ifd);
 249
 250                                 if (varvalue) {
 251                                         addstr(&result, varvalue, strlen(varvalue));
 252                                 } else {
 253 #if ENABLE_FEATURE_IFUPDOWN_IP
 254                                         /* Sigh...  Add a special case for 'ip' to convert from
 255                                          * dotted quad to bit count style netmasks.  */
 256                                         if (strncmp(command, "bnmask", 6) == 0) {
 257                                                 unsigned res;
 258                                                 varvalue = get_var("netmask", 7, ifd);
 259                                                 if (varvalue) {
 260                                                         res = count_netmask_bits(varvalue);
 261                                                         if (res > 0) {
 262                                                                 const char *argument = utoa(res);
 263                                                                 addstr(&result, argument, strlen(argument));
 264                                                                 command = nextpercent + 1;
 265                                                                 break;
 266                                                         }
 267                                                 }
 268                                         }
 269 #endif
 270                                         okay[opt_depth - 1] = 0;
 271                                 }
 272
 273                                 command = nextpercent + 1;
 274                         }
 275                         break;
 276                 }
 277         }
 278
 279         if (opt_depth > 1) {
 280                 errno = EUNBALBRACK;
 281                 free(result);
 282                 return NULL;
 283         }
 284
 285         if (!okay[0]) {
 286                 errno = EUNDEFVAR;
 287                 free(result);
 288                 return NULL;
 289         }
 290
 291         return result;
 292 }
 293
 294 /* execute() returns 1 for success and 0 for failure */
 295 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 296 {
 297         char *out;
 298         int ret;
 299
 300         out = parse(command, ifd);
 301         if (!out) {
 302                 /* parse error? */
 303                 return 0;
 304         }
 305         /* out == "": parsed ok but not all needed variables known, skip */
 306         ret = out[0] ? (*exec)(out) : 1;
 307
 308         free(out);
 309         if (ret != 1) {
 310                 return 0;
 311         }
 312         return 1;
 313 }
 314 #endif
 315
 316 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 317 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 318 {
 319 #if ENABLE_FEATURE_IFUPDOWN_IP
 320         int result;
 321         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 322         result += execute("ip link set %iface% up", ifd, exec);
 323         return ((result == 2) ? 2 : 0);
 324 #else
 325         return execute("ifconfig %iface% add ::1", ifd, exec);
 326 #endif
 327 }
 328
 329 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 330 {
 331 #if ENABLE_FEATURE_IFUPDOWN_IP
 332         return execute("ip link set %iface% down", ifd, exec);
 333 #else
 334         return execute("ifconfig %iface% del ::1", ifd, exec);
 335 #endif
 336 }
 337
 338 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 339 {
 340         int result;
 341 #if ENABLE_FEATURE_IFUPDOWN_IP
 342         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 343         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 344         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
 345         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 346 #else
 347         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 348         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 349         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
 350 #endif
 351         return ((result == 3) ? 3 : 0);
 352 }
 353
 354 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 355 {
 356 #if ENABLE_FEATURE_IFUPDOWN_IP
 357         return execute("ip link set %iface% down", ifd, exec);
 358 #else
 359         return execute("ifconfig %iface% down", ifd, exec);
 360 #endif
 361 }
 362
 363 #if ENABLE_FEATURE_IFUPDOWN_IP
 364 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 365 {
 366         int result;
 367         result = execute("ip tunnel add %iface% mode sit remote "
 368                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 369         result += execute("ip link set %iface% up", ifd, exec);
 370         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 371         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 372         return ((result == 4) ? 4 : 0);
 373 }
 374
 375 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 376 {
 377         return execute("ip tunnel del %iface%", ifd, exec);
 378 }
 379 #endif
 380
 381 static const struct method_t methods6[] = {
 382 #if ENABLE_FEATURE_IFUPDOWN_IP
 383         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 384 #endif
 385         { "static", static_up6, static_down6, },
 386         { "loopback", loopback_up6, loopback_down6, },
 387 };
 388
 389 static const struct address_family_t addr_inet6 = {
 390         "inet6",
 391         ARRAY_SIZE(methods6),
 392         methods6
 393 };
 394 #endif /* FEATURE_IFUPDOWN_IPV6 */
 395
 396 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 397 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 398 {
 399 #if ENABLE_FEATURE_IFUPDOWN_IP
 400         int result;
 401         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 402         result += execute("ip link set %iface% up", ifd, exec);
 403         return ((result == 2) ? 2 : 0);
 404 #else
 405         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 406 #endif
 407 }
 408
 409 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 410 {
 411 #if ENABLE_FEATURE_IFUPDOWN_IP
 412         int result;
 413         result = execute("ip addr flush dev %iface%", ifd, exec);
 414         result += execute("ip link set %iface% down", ifd, exec);
 415         return ((result == 2) ? 2 : 0);
 416 #else
 417         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 418 #endif
 419 }
 420
 421 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 422 {
 423         int result;
 424 #if ENABLE_FEATURE_IFUPDOWN_IP
 425         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 426                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 427         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 428         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
 429         return ((result == 3) ? 3 : 0);
 430 #else
 431         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 432          * which then of course fails. Thus we run two separate ifconfig */
 433         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 434                                 ifd, exec);
 435         result += execute("ifconfig %iface% %address% netmask %netmask%"
 436                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 437                                 ifd, exec);
 438         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
 439         return ((result == 3) ? 3 : 0);
 440 #endif
 441 }
 442
 443 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 444 {
 445         int result;
 446 #if ENABLE_FEATURE_IFUPDOWN_IP
 447         result = execute("ip addr flush dev %iface%", ifd, exec);
 448         result += execute("ip link set %iface% down", ifd, exec);
 449 #else
 450         result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec);
 451         result += execute("ifconfig %iface% down", ifd, exec);
 452 #endif
 453         return ((result == 2) ? 2 : 0);
 454 }
 455
 456 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 457 struct dhcp_client_t
 458 {
 459         const char *name;
 460         const char *startcmd;
 461         const char *stopcmd;
 462 };
 463
 464 static const struct dhcp_client_t ext_dhcp_clients[] = {
 465         { "dhcpcd",
 466                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
 467                 "dhcpcd -k %iface%",
 468         },
 469         { "dhclient",
 470                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 471                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 472         },
 473         { "pump",
 474                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 475                 "pump -i %iface% -k",
 476         },
 477         { "udhcpc",
 478                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 479                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 480         },
 481 };
 482 #endif /* ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 483
 484 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 485 {
 486 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 487         int i ;
 488         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 489                 if (exists_execable(ext_dhcp_clients[i].name))
 490                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 491         }
 492         bb_error_msg("no dhcp clients found");
 493         return 0;
 494 #elif ENABLE_APP_UDHCPC
 495         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 496                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 497                         ifd, exec);
 498 #else
 499         return 0; /* no dhcp support */
 500 #endif
 501 }
 502
 503 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 504 {
 505 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 506         int i ;
 507         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 508                 if (exists_execable(ext_dhcp_clients[i].name))
 509                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 510         }
 511         bb_error_msg("no dhcp clients found, using static interface shutdown");
 512         return static_down(ifd, exec);
 513 #elif ENABLE_APP_UDHCPC
 514         return execute("kill "
 515                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 516 #else
 517         return 0; /* no dhcp support */
 518 #endif
 519 }
 520
 521 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 522 {
 523         return 1;
 524 }
 525
 526 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 527 {
 528         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 529                         "[[ --server %server%]][[ --hwaddr %hwaddr%]] "
 530                         "--returniffail --serverbcast", ifd, exec);
 531 }
 532
 533 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 534 {
 535         return execute("pon[[ %provider%]]", ifd, exec);
 536 }
 537
 538 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 539 {
 540         return execute("poff[[ %provider%]]", ifd, exec);
 541 }
 542
 543 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 544 {
 545         return execute("start-stop-daemon --start -x wvdial "
 546                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 547 }
 548
 549 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 550 {
 551         return execute("start-stop-daemon --stop -x wvdial "
 552                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 553 }
 554
 555 static const struct method_t methods[] = {
 556         { "manual", manual_up_down, manual_up_down, },
 557         { "wvdial", wvdial_up, wvdial_down, },
 558         { "ppp", ppp_up, ppp_down, },
 559         { "static", static_up, static_down, },
 560         { "bootp", bootp_up, static_down, },
 561         { "dhcp", dhcp_up, dhcp_down, },
 562         { "loopback", loopback_up, loopback_down, },
 563 };
 564
 565 static const struct address_family_t addr_inet = {
 566         "inet",
 567         ARRAY_SIZE(methods),
 568         methods
 569 };
 570
 571 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 572
 573 static char *next_word(char **buf)
 574 {
 575         unsigned short length;
 576         char *word;
 577
 578         if (!buf || !*buf || !**buf) {
 579                 return NULL;
 580         }
 581
 582         /* Skip over leading whitespace */
 583         word = skip_whitespace(*buf);
 584
 585         /* Skip over comments */
 586         if (*word == '#') {
 587                 return NULL;
 588         }
 589
 590         /* Find the length of this word */
 591         length = strcspn(word, " \t\n");
 592         if (length == 0) {
 593                 return NULL;
 594         }
 595         *buf = word + length;
 596         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 597         if (**buf) {
 598                 **buf = '\0';
 599                 (*buf)++;
 600         }
 601
 602         return word;
 603 }
 604
 605 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 606 {
 607         int i;
 608
 609         if (!name)
 610                 return NULL;
 611
 612         for (i = 0; af[i]; i++) {
 613                 if (strcmp(af[i]->name, name) == 0) {
 614                         return af[i];
 615                 }
 616         }
 617         return NULL;
 618 }
 619
 620 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 621 {
 622         int i;
 623
 624         if (!name)
 625                 return NULL;
 626
 627         for (i = 0; i < af->n_methods; i++) {
 628                 if (strcmp(af->method[i].name, name) == 0) {
 629                         return &af->method[i];
 630                 }
 631         }
 632         return NULL;
 633 }
 634
 635 static const llist_t *find_list_string(const llist_t *list, const char *string)
 636 {
 637         if (string == NULL)
 638                 return NULL;
 639
 640         while (list) {
 641                 if (strcmp(list->data, string) == 0) {
 642                         return list;
 643                 }
 644                 list = list->link;
 645         }
 646         return NULL;
 647 }
 648
 649 static struct interfaces_file_t *read_interfaces(const char *filename)
 650 {
 651 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 652         struct mapping_defn_t *currmap = NULL;
 653 #endif
 654         struct interface_defn_t *currif = NULL;
 655         struct interfaces_file_t *defn;
 656         FILE *f;
 657         char *firstword;
 658         char *buf;
 659
 660         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 661
 662         defn = xzalloc(sizeof(struct interfaces_file_t));
 663
 664         f = xfopen(filename, "r");
 665
 666         while ((buf = xmalloc_getline(f)) != NULL) {
 667                 char *buf_ptr = buf;
 668
 669                 firstword = next_word(&buf_ptr);
 670                 if (firstword == NULL) {
 671                         free(buf);
 672                         continue;       /* blank line */
 673                 }
 674
 675                 if (strcmp(firstword, "mapping") == 0) {
 676 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 677                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 678
 679                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 680                                 if (currmap->max_matches == currmap->n_matches) {
 681                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 682                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 683                                 }
 684
 685                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 686                         }
 687                         currmap->max_mappings = 0;
 688                         currmap->n_mappings = 0;
 689                         currmap->mapping = NULL;
 690                         currmap->script = NULL;
 691                         {
 692                                 struct mapping_defn_t **where = &defn->mappings;
 693                                 while (*where != NULL) {
 694                                         where = &(*where)->next;
 695                                 }
 696                                 *where = currmap;
 697                                 currmap->next = NULL;
 698                         }
 699                         debug_noise("Added mapping\n");
 700 #endif
 701                         currently_processing = MAPPING;
 702                 } else if (strcmp(firstword, "iface") == 0) {
 703                         static const struct address_family_t *const addr_fams[] = {
 704 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 705                                 &addr_inet,
 706 #endif
 707 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 708                                 &addr_inet6,
 709 #endif
 710                                 NULL
 711                         };
 712
 713                         char *iface_name;
 714                         char *address_family_name;
 715                         char *method_name;
 716                         llist_t *iface_list;
 717
 718                         currif = xzalloc(sizeof(struct interface_defn_t));
 719                         iface_name = next_word(&buf_ptr);
 720                         address_family_name = next_word(&buf_ptr);
 721                         method_name = next_word(&buf_ptr);
 722
 723                         if (buf_ptr == NULL) {
 724                                 bb_error_msg("too few parameters for line \"%s\"", buf);
 725                                 return NULL;
 726                         }
 727
 728                         /* ship any trailing whitespace */
 729                         buf_ptr = skip_whitespace(buf_ptr);
 730
 731                         if (buf_ptr[0] != '\0') {
 732                                 bb_error_msg("too many parameters \"%s\"", buf);
 733                                 return NULL;
 734                         }
 735
 736                         currif->iface = xstrdup(iface_name);
 737
 738                         currif->address_family = get_address_family(addr_fams, address_family_name);
 739                         if (!currif->address_family) {
 740                                 bb_error_msg("unknown address type \"%s\"", address_family_name);
 741                                 return NULL;
 742                         }
 743
 744                         currif->method = get_method(currif->address_family, method_name);
 745                         if (!currif->method) {
 746                                 bb_error_msg("unknown method \"%s\"", method_name);
 747                                 return NULL;
 748                         }
 749
 750                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 751                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 752                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 753                                         (tmp->address_family == currif->address_family)) {
 754                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 755                                         return NULL;
 756                                 }
 757                         }
 758                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 759
 760                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 761                         currently_processing = IFACE;
 762                 } else if (strcmp(firstword, "auto") == 0) {
 763                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 764
 765                                 /* Check the interface isnt already listed */
 766                                 if (find_list_string(defn->autointerfaces, firstword)) {
 767                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 768                                 }
 769
 770                                 /* Add the interface to the list */
 771                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 772                                 debug_noise("\nauto %s\n", firstword);
 773                         }
 774                         currently_processing = NONE;
 775                 } else {
 776                         switch (currently_processing) {
 777                         case IFACE:
 778                                 {
 779                                         int i;
 780
 781                                         if (strlen(buf_ptr) == 0) {
 782                                                 bb_error_msg("option with empty value \"%s\"", buf);
 783                                                 return NULL;
 784                                         }
 785
 786                                         if (strcmp(firstword, "up") != 0
 787                                                         && strcmp(firstword, "down") != 0
 788                                                         && strcmp(firstword, "pre-up") != 0
 789                                                         && strcmp(firstword, "post-down") != 0) {
 790                                                 for (i = 0; i < currif->n_options; i++) {
 791                                                         if (strcmp(currif->option[i].name, firstword) == 0) {
 792                                                                 bb_error_msg("duplicate option \"%s\"", buf);
 793                                                                 return NULL;
 794                                                         }
 795                                                 }
 796                                         }
 797                                 }
 798                                 if (currif->n_options >= currif->max_options) {
 799                                         struct variable_t *opt;
 800
 801                                         currif->max_options = currif->max_options + 10;
 802                                         opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 803                                         currif->option = opt;
 804                                 }
 805                                 currif->option[currif->n_options].name = xstrdup(firstword);
 806                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 807                                 if (!currif->option[currif->n_options].name) {
 808                                         perror(filename);
 809                                         return NULL;
 810                                 }
 811                                 if (!currif->option[currif->n_options].value) {
 812                                         perror(filename);
 813                                         return NULL;
 814                                 }
 815                                 debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 816                                                 currif->option[currif->n_options].value);
 817                                 currif->n_options++;
 818                                 break;
 819                         case MAPPING:
 820 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 821                                 if (strcmp(firstword, "script") == 0) {
 822                                         if (currmap->script != NULL) {
 823                                                 bb_error_msg("duplicate script in mapping \"%s\"", buf);
 824                                                 return NULL;
 825                                         } else {
 826                                                 currmap->script = xstrdup(next_word(&buf_ptr));
 827                                         }
 828                                 } else if (strcmp(firstword, "map") == 0) {
 829                                         if (currmap->max_mappings == currmap->n_mappings) {
 830                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 831                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 832                                         }
 833                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 834                                         currmap->n_mappings++;
 835                                 } else {
 836                                         bb_error_msg("misplaced option \"%s\"", buf);
 837                                         return NULL;
 838                                 }
 839 #endif
 840                                 break;
 841                         case NONE:
 842                         default:
 843                                 bb_error_msg("misplaced option \"%s\"", buf);
 844                                 return NULL;
 845                         }
 846                 }
 847                 free(buf);
 848         }
 849         if (ferror(f) != 0) {
 850                 /* ferror does NOT set errno! */
 851                 bb_error_msg_and_die("%s: I/O error", filename);
 852         }
 853         fclose(f);
 854
 855         return defn;
 856 }
 857
 858 static char *setlocalenv(const char *format, const char *name, const char *value)
 859 {
 860         char *result;
 861         char *here;
 862         char *there;
 863
 864         result = xasprintf(format, name, value);
 865
 866         for (here = there = result; *there != '=' && *there; there++) {
 867                 if (*there == '-')
 868                         *there = '_';
 869                 if (isalpha(*there))
 870                         *there = toupper(*there);
 871
 872                 if (isalnum(*there) || *there == '_') {
 873                         *here = *there;
 874                         here++;
 875                 }
 876         }
 877         memmove(here, there, strlen(there) + 1);
 878
 879         return result;
 880 }
 881
 882 static void set_environ(struct interface_defn_t *iface, const char *mode)
 883 {
 884         char **environend;
 885         int i;
 886         const int n_env_entries = iface->n_options + 5;
 887         char **ppch;
 888
 889         if (my_environ != NULL) {
 890                 for (ppch = my_environ; *ppch; ppch++) {
 891                         free(*ppch);
 892                         *ppch = NULL;
 893                 }
 894                 free(my_environ);
 895         }
 896         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 897         environend = my_environ;
 898
 899         for (i = 0; i < iface->n_options; i++) {
 900                 if (strcmp(iface->option[i].name, "up") == 0
 901                  || strcmp(iface->option[i].name, "down") == 0
 902                  || strcmp(iface->option[i].name, "pre-up") == 0
 903                  || strcmp(iface->option[i].name, "post-down") == 0
 904                 ) {
 905                         continue;
 906                 }
 907                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 908         }
 909
 910         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 911         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 912         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 913         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 914         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 915 }
 916
 917 static int doit(char *str)
 918 {
 919         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 920                 puts(str);
 921         }
 922         if (!(option_mask32 & OPT_no_act)) {
 923                 pid_t child;
 924                 int status;
 925
 926                 fflush(NULL);
 927                 child = fork();
 928                 switch (child) {
 929                 case -1: /* failure */
 930                         return 0;
 931                 case 0: /* child */
 932                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 933                         exit(127);
 934                 }
 935                 waitpid(child, &status, 0);
 936                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 937                         return 0;
 938                 }
 939         }
 940         return 1;
 941 }
 942
 943 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 944 {
 945         int i;
 946         char *buf;
 947         for (i = 0; i < ifd->n_options; i++) {
 948                 if (strcmp(ifd->option[i].name, opt) == 0) {
 949                         if (!doit(ifd->option[i].value)) {
 950                                 return 0;
 951                         }
 952                 }
 953         }
 954
 955         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 956         /* heh, we don't bother free'ing it */
 957         return doit(buf);
 958 }
 959
 960 static int check(char *str)
 961 {
 962         return str != NULL;
 963 }
 964
 965 static int iface_up(struct interface_defn_t *iface)
 966 {
 967         if (!iface->method->up(iface, check)) return -1;
 968         set_environ(iface, "start");
 969         if (!execute_all(iface, "pre-up")) return 0;
 970         if (!iface->method->up(iface, doit)) return 0;
 971         if (!execute_all(iface, "up")) return 0;
 972         return 1;
 973 }
 974
 975 static int iface_down(struct interface_defn_t *iface)
 976 {
 977         if (!iface->method->down(iface,check)) return -1;
 978         set_environ(iface, "stop");
 979         if (!execute_all(iface, "down")) return 0;
 980         if (!iface->method->down(iface, doit)) return 0;
 981         if (!execute_all(iface, "post-down")) return 0;
 982         return 1;
 983 }
 984
 985 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 986 static int popen2(FILE **in, FILE **out, char *command, ...)
 987 {
 988         va_list ap;
 989         char *argv[11] = { command };
 990         int argc;
 991         int infd[2], outfd[2];
 992         pid_t pid;
 993
 994         argc = 1;
 995         va_start(ap, command);
 996         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 997                 argc++;
 998         }
 999         argv[argc] = NULL;      /* make sure */
1000         va_end(ap);
1001
1002         if (pipe(infd) != 0) {
1003                 return 0;
1004         }
1005
1006         if (pipe(outfd) != 0) {
1007                 close(infd[0]);
1008                 close(infd[1]);
1009                 return 0;
1010         }
1011
1012         fflush(NULL);
1013         switch (pid = fork()) {
1014         case -1:                        /* failure */
1015                 close(infd[0]);
1016                 close(infd[1]);
1017                 close(outfd[0]);
1018                 close(outfd[1]);
1019                 return 0;
1020         case 0:                 /* child */
1021                 dup2(infd[0], 0);
1022                 dup2(outfd[1], 1);
1023                 close(infd[0]);
1024                 close(infd[1]);
1025                 close(outfd[0]);
1026                 close(outfd[1]);
1027                 BB_EXECVP(command, argv);
1028                 exit(127);
1029         default:                        /* parent */
1030                 *in = fdopen(infd[1], "w");
1031                 *out = fdopen(outfd[0], "r");
1032                 close(infd[0]);
1033                 close(outfd[1]);
1034                 return pid;
1035         }
1036         /* unreached */
1037 }
1038
1039 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1040 {
1041         FILE *in, *out;
1042         int i, status;
1043         pid_t pid;
1044
1045         char *logical = xstrdup(physical);
1046
1047         /* Run the mapping script. */
1048         pid = popen2(&in, &out, map->script, physical, NULL);
1049
1050         /* popen2() returns 0 on failure. */
1051         if (pid == 0)
1052                 return logical;
1053
1054         /* Write mappings to stdin of mapping script. */
1055         for (i = 0; i < map->n_mappings; i++) {
1056                 fprintf(in, "%s\n", map->mapping[i]);
1057         }
1058         fclose(in);
1059         waitpid(pid, &status, 0);
1060
1061         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1062                 /* If the mapping script exited successfully, try to
1063                  * grab a line of output and use that as the name of the
1064                  * logical interface. */
1065                 char *new_logical = xmalloc(MAX_INTERFACE_LENGTH);
1066
1067                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1068                         /* If we are able to read a line of output from the script,
1069                          * remove any trailing whitespace and use this value
1070                          * as the name of the logical interface. */
1071                         char *pch = new_logical + strlen(new_logical) - 1;
1072
1073                         while (pch >= new_logical && isspace(*pch))
1074                                 *(pch--) = '\0';
1075
1076                         free(logical);
1077                         logical = new_logical;
1078                 } else {
1079                         /* If we are UNABLE to read a line of output, discard our
1080                          * freshly allocated memory. */
1081                         free(new_logical);
1082                 }
1083         }
1084
1085         fclose(out);
1086
1087         return logical;
1088 }
1089 #endif /* FEATURE_IFUPDOWN_MAPPING */
1090
1091 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1092 {
1093         unsigned short iface_len = strlen(iface);
1094         llist_t *search = state_list;
1095
1096         while (search) {
1097                 if ((strncmp(search->data, iface, iface_len) == 0)
1098                  && (search->data[iface_len] == '=')) {
1099                         return search;
1100                 }
1101                 search = search->link;
1102         }
1103         return NULL;
1104 }
1105
1106 /* read the previous state from the state file */
1107 static llist_t *read_iface_state(void)
1108 {
1109         llist_t *state_list = NULL;
1110         FILE *state_fp = fopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "r");
1111
1112         if (state_fp) {
1113                 char *start, *end_ptr;
1114                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1115                         /* We should only need to check for a single character */
1116                         end_ptr = start + strcspn(start, " \t\n");
1117                         *end_ptr = '\0';
1118                         llist_add_to(&state_list, start);
1119                 }
1120                 fclose(state_fp);
1121         }
1122         return state_list;
1123 }
1124
1125
1126 int ifupdown_main(int argc, char **argv);
1127 int ifupdown_main(int argc, char **argv)
1128 {
1129         int (*cmds)(struct interface_defn_t *) = NULL;
1130         struct interfaces_file_t *defn;
1131         llist_t *target_list = NULL;
1132         const char *interfaces = "/etc/network/interfaces";
1133         bool any_failures = 0;
1134
1135         cmds = iface_down;
1136         if (applet_name[2] == 'u') {
1137                 /* ifup command */
1138                 cmds = iface_up;
1139         }
1140
1141         getopt32(argc, argv, OPTION_STR, &interfaces);
1142         if (argc - optind > 0) {
1143                 if (DO_ALL) bb_show_usage();
1144         } else {
1145                 if (!DO_ALL) bb_show_usage();
1146         }
1147
1148         debug_noise("reading %s file:\n", interfaces);
1149         defn = read_interfaces(interfaces);
1150         debug_noise("\ndone reading %s\n\n", interfaces);
1151
1152         if (!defn) {
1153                 return EXIT_FAILURE;
1154         }
1155
1156         startup_PATH = getenv("PATH");
1157         if (!startup_PATH) startup_PATH = "";
1158
1159         /* Create a list of interfaces to work on */
1160         if (DO_ALL) {
1161                 target_list = defn->autointerfaces;
1162         } else {
1163                 llist_add_to_end(&target_list, argv[optind]);
1164         }
1165
1166         /* Update the interfaces */
1167         while (target_list) {
1168                 llist_t *iface_list;
1169                 struct interface_defn_t *currif;
1170                 char *iface;
1171                 char *liface;
1172                 char *pch;
1173                 bool okay = 0;
1174                 unsigned cmds_ret;
1175
1176                 iface = xstrdup(target_list->data);
1177                 target_list = target_list->link;
1178
1179                 pch = strchr(iface, '=');
1180                 if (pch) {
1181                         *pch = '\0';
1182                         liface = xstrdup(pch + 1);
1183                 } else {
1184                         liface = xstrdup(iface);
1185                 }
1186
1187                 if (!FORCE) {
1188                         llist_t *state_list = read_iface_state();
1189                         const llist_t *iface_state = find_iface_state(state_list, iface);
1190
1191                         if (cmds == iface_up) {
1192                                 /* ifup */
1193                                 if (iface_state) {
1194                                         bb_error_msg("interface %s already configured", iface);
1195                                         continue;
1196                                 }
1197                         } else {
1198                                 /* ifdown */
1199                                 if (!iface_state) {
1200                                         bb_error_msg("interface %s not configured", iface);
1201                                         continue;
1202                                 }
1203                         }
1204                         llist_free(state_list, free);
1205                 }
1206
1207 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1208                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1209                         struct mapping_defn_t *currmap;
1210
1211                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1212                                 int i;
1213                                 for (i = 0; i < currmap->n_matches; i++) {
1214                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1215                                                 continue;
1216                                         if (VERBOSE) {
1217                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1218                                         }
1219                                         liface = run_mapping(iface, currmap);
1220                                         break;
1221                                 }
1222                         }
1223                 }
1224 #endif
1225
1226                 iface_list = defn->ifaces;
1227                 while (iface_list) {
1228                         currif = (struct interface_defn_t *) iface_list->data;
1229                         if (strcmp(liface, currif->iface) == 0) {
1230                                 char *oldiface = currif->iface;
1231
1232                                 okay = 1;
1233                                 currif->iface = iface;
1234
1235                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1236
1237                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1238                                 cmds_ret = cmds(currif);
1239                                 if (cmds_ret == -1) {
1240                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1241                                                         liface, currif->address_family->name);
1242                                         any_failures = 1;
1243                                 } else if (cmds_ret == 0) {
1244                                         any_failures = 1;
1245                                 }
1246
1247                                 currif->iface = oldiface;
1248                         }
1249                         iface_list = iface_list->link;
1250                 }
1251                 if (VERBOSE) {
1252                         puts("");
1253                 }
1254
1255                 if (!okay && !FORCE) {
1256                         bb_error_msg("ignoring unknown interface %s", liface);
1257                         any_failures = 1;
1258                 } else if (!NO_ACT) {
1259                         /* update the state file */
1260                         FILE *state_fp;
1261                         llist_t *state;
1262                         llist_t *state_list = read_iface_state();
1263                         llist_t *iface_state = find_iface_state(state_list, iface);
1264
1265                         if (cmds == iface_up) {
1266                                 char * const newiface = xasprintf("%s=%s", iface, liface);
1267                                 if (iface_state == NULL) {
1268                                         llist_add_to_end(&state_list, newiface);
1269                                 } else {
1270                                         free(iface_state->data);
1271                                         iface_state->data = newiface;
1272                                 }
1273                         } else {
1274                                 /* Remove an interface from state_list */
1275                                 llist_unlink(&state_list, iface_state);
1276                                 free(llist_pop(&iface_state));
1277                         }
1278
1279                         /* Actually write the new state */
1280                         state_fp = xfopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "w");
1281                         state = state_list;
1282                         while (state) {
1283                                 if (state->data) {
1284                                         fprintf(state_fp, "%s\n", state->data);
1285                                 }
1286                                 state = state->link;
1287                         }
1288                         fclose(state_fp);
1289                         llist_free(state_list, free);
1290                 }
1291         }
1292
1293         return any_failures;
1294 }