networking/ifupdown.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *  ifupdown for busybox
   4  *  Copyright (c) 2002 Glenn McGrath
   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                 static char *label_buf;
 138                 //char *result;
 139
 140                 free(label_buf);
 141                 label_buf = xstrdup(ifd->iface);
 142                 // Remove virtual iface suffix - why?
 143                 // ubuntu's ifup doesn't do this
 144                 //result = strchrnul(label_buf, ':');
 145                 //*result = '\0';
 146                 return label_buf;
 147         }
 148         if (strncmpz(id, "label", idlen) == 0) {
 149                 return ifd->iface;
 150         }
 151         for (i = 0; i < ifd->n_options; i++) {
 152                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 153                         return ifd->option[i].value;
 154                 }
 155         }
 156         return NULL;
 157 }
 158
 159 #if ENABLE_FEATURE_IFUPDOWN_IP
 160 static int count_netmask_bits(const char *dotted_quad)
 161 {
 162 //      int result;
 163 //      unsigned a, b, c, d;
 164 //      /* Found a netmask...  Check if it is dotted quad */
 165 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 166 //              return -1;
 167 //      if ((a|b|c|d) >> 8)
 168 //              return -1; /* one of numbers is >= 256 */
 169 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 170 //      d = ~d; /* 11110000 -> 00001111 */
 171
 172         /* Shorter version */
 173         int result;
 174         struct in_addr ip;
 175         unsigned d;
 176
 177         if (inet_aton(dotted_quad, &ip) == 0)
 178                 return -1; /* malformed dotted IP */
 179         d = ntohl(ip.s_addr); /* IP in host order */
 180         d = ~d; /* 11110000 -> 00001111 */
 181         if (d & (d+1)) /* check that it is in 00001111 form */
 182                 return -1; /* no it is not */
 183         result = 32;
 184         while (d) {
 185                 d >>= 1;
 186                 result--;
 187         }
 188         return result;
 189 }
 190 #endif
 191
 192 static char *parse(const char *command, struct interface_defn_t *ifd)
 193 {
 194         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 195         int okay[MAX_OPT_DEPTH] = { 1 };
 196         int opt_depth = 1;
 197         char *result = NULL;
 198
 199         while (*command) {
 200                 switch (*command) {
 201                 default:
 202                         addstr(&result, command, 1);
 203                         command++;
 204                         break;
 205                 case '\\':
 206                         if (command[1]) {
 207                                 addstr(&result, command + 1, 1);
 208                                 command += 2;
 209                         } else {
 210                                 addstr(&result, command, 1);
 211                                 command++;
 212                         }
 213                         break;
 214                 case '[':
 215                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 216                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 217                                 okay[opt_depth] = 1;
 218                                 opt_depth++;
 219                                 command += 2;
 220                         } else {
 221                                 addstr(&result, "[", 1);
 222                                 command++;
 223                         }
 224                         break;
 225                 case ']':
 226                         if (command[1] == ']' && opt_depth > 1) {
 227                                 opt_depth--;
 228                                 if (!okay[opt_depth]) {
 229                                         result[old_pos[opt_depth]] = '\0';
 230                                 }
 231                                 command += 2;
 232                         } else {
 233                                 addstr(&result, "]", 1);
 234                                 command++;
 235                         }
 236                         break;
 237                 case '%':
 238                         {
 239                                 char *nextpercent;
 240                                 char *varvalue;
 241
 242                                 command++;
 243                                 nextpercent = strchr(command, '%');
 244                                 if (!nextpercent) {
 245                                         errno = EUNBALPER;
 246                                         free(result);
 247                                         return NULL;
 248                                 }
 249
 250                                 varvalue = get_var(command, nextpercent - command, ifd);
 251
 252                                 if (varvalue) {
 253                                         addstr(&result, varvalue, strlen(varvalue));
 254                                 } else {
 255 #if ENABLE_FEATURE_IFUPDOWN_IP
 256                                         /* Sigh...  Add a special case for 'ip' to convert from
 257                                          * dotted quad to bit count style netmasks.  */
 258                                         if (strncmp(command, "bnmask", 6) == 0) {
 259                                                 unsigned res;
 260                                                 varvalue = get_var("netmask", 7, ifd);
 261                                                 if (varvalue) {
 262                                                         res = count_netmask_bits(varvalue);
 263                                                         if (res > 0) {
 264                                                                 const char *argument = utoa(res);
 265                                                                 addstr(&result, argument, strlen(argument));
 266                                                                 command = nextpercent + 1;
 267                                                                 break;
 268                                                         }
 269                                                 }
 270                                         }
 271 #endif
 272                                         okay[opt_depth - 1] = 0;
 273                                 }
 274
 275                                 command = nextpercent + 1;
 276                         }
 277                         break;
 278                 }
 279         }
 280
 281         if (opt_depth > 1) {
 282                 errno = EUNBALBRACK;
 283                 free(result);
 284                 return NULL;
 285         }
 286
 287         if (!okay[0]) {
 288                 errno = EUNDEFVAR;
 289                 free(result);
 290                 return NULL;
 291         }
 292
 293         return result;
 294 }
 295
 296 /* execute() returns 1 for success and 0 for failure */
 297 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 298 {
 299         char *out;
 300         int ret;
 301
 302         out = parse(command, ifd);
 303         if (!out) {
 304                 /* parse error? */
 305                 return 0;
 306         }
 307         /* out == "": parsed ok but not all needed variables known, skip */
 308         ret = out[0] ? (*exec)(out) : 1;
 309
 310         free(out);
 311         if (ret != 1) {
 312                 return 0;
 313         }
 314         return 1;
 315 }
 316 #endif
 317
 318 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 319 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 320 {
 321 #if ENABLE_FEATURE_IFUPDOWN_IP
 322         int result;
 323         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 324         result += execute("ip link set %iface% up", ifd, exec);
 325         return ((result == 2) ? 2 : 0);
 326 #else
 327         return execute("ifconfig %iface% add ::1", ifd, exec);
 328 #endif
 329 }
 330
 331 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 332 {
 333 #if ENABLE_FEATURE_IFUPDOWN_IP
 334         return execute("ip link set %iface% down", ifd, exec);
 335 #else
 336         return execute("ifconfig %iface% del ::1", ifd, exec);
 337 #endif
 338 }
 339
 340 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 341 {
 342         int result;
 343 #if ENABLE_FEATURE_IFUPDOWN_IP
 344         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 345         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 346         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
 347         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 348 #else
 349         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 350         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 351         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
 352 #endif
 353         return ((result == 3) ? 3 : 0);
 354 }
 355
 356 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 357 {
 358 #if ENABLE_FEATURE_IFUPDOWN_IP
 359         return execute("ip link set %iface% down", ifd, exec);
 360 #else
 361         return execute("ifconfig %iface% down", ifd, exec);
 362 #endif
 363 }
 364
 365 #if ENABLE_FEATURE_IFUPDOWN_IP
 366 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 367 {
 368         int result;
 369         result = execute("ip tunnel add %iface% mode sit remote "
 370                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 371         result += execute("ip link set %iface% up", ifd, exec);
 372         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 373         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 374         return ((result == 4) ? 4 : 0);
 375 }
 376
 377 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 378 {
 379         return execute("ip tunnel del %iface%", ifd, exec);
 380 }
 381 #endif
 382
 383 static const struct method_t methods6[] = {
 384 #if ENABLE_FEATURE_IFUPDOWN_IP
 385         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 386 #endif
 387         { "static", static_up6, static_down6, },
 388         { "loopback", loopback_up6, loopback_down6, },
 389 };
 390
 391 static const struct address_family_t addr_inet6 = {
 392         "inet6",
 393         ARRAY_SIZE(methods6),
 394         methods6
 395 };
 396 #endif /* FEATURE_IFUPDOWN_IPV6 */
 397
 398 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 399 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 400 {
 401 #if ENABLE_FEATURE_IFUPDOWN_IP
 402         int result;
 403         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 404         result += execute("ip link set %iface% up", ifd, exec);
 405         return ((result == 2) ? 2 : 0);
 406 #else
 407         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 408 #endif
 409 }
 410
 411 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 412 {
 413 #if ENABLE_FEATURE_IFUPDOWN_IP
 414         int result;
 415         result = execute("ip addr flush dev %iface%", ifd, exec);
 416         result += execute("ip link set %iface% down", ifd, exec);
 417         return ((result == 2) ? 2 : 0);
 418 #else
 419         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 420 #endif
 421 }
 422
 423 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 424 {
 425         int result;
 426 #if ENABLE_FEATURE_IFUPDOWN_IP
 427         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 428                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 429         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 430         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
 431         return ((result == 3) ? 3 : 0);
 432 #else
 433         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 434          * which then of course fails. Thus we run two separate ifconfig */
 435         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 436                                 ifd, exec);
 437         result += execute("ifconfig %iface% %address% netmask %netmask%"
 438                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 439                                 ifd, exec);
 440         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
 441         return ((result == 3) ? 3 : 0);
 442 #endif
 443 }
 444
 445 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 446 {
 447         int result;
 448 #if ENABLE_FEATURE_IFUPDOWN_IP
 449         result = execute("ip addr flush dev %iface%", ifd, exec);
 450         result += execute("ip link set %iface% down", ifd, exec);
 451 #else
 452         result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec);
 453         result += execute("ifconfig %iface% down", ifd, exec);
 454 #endif
 455         return ((result == 2) ? 2 : 0);
 456 }
 457
 458 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 459 struct dhcp_client_t
 460 {
 461         const char *name;
 462         const char *startcmd;
 463         const char *stopcmd;
 464 };
 465
 466 static const struct dhcp_client_t ext_dhcp_clients[] = {
 467         { "dhcpcd",
 468                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
 469                 "dhcpcd -k %iface%",
 470         },
 471         { "dhclient",
 472                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 473                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 474         },
 475         { "pump",
 476                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 477                 "pump -i %iface% -k",
 478         },
 479         { "udhcpc",
 480                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 481                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 482         },
 483 };
 484 #endif /* ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 485
 486 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 487 {
 488 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 489         int i;
 490 #if ENABLE_FEATURE_IFUPDOWN_IP
 491         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 492         if (!execute("ip link set %iface% up", ifd, exec))
 493                 return 0;
 494 #endif
 495         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 496                 if (exists_execable(ext_dhcp_clients[i].name))
 497                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 498         }
 499         bb_error_msg("no dhcp clients found");
 500         return 0;
 501 #elif ENABLE_APP_UDHCPC
 502 #if ENABLE_FEATURE_IFUPDOWN_IP
 503         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 504         if (!execute("ip link set %iface% up", ifd, exec))
 505                 return 0;
 506 #endif
 507         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 508                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]]",
 509                         ifd, exec);
 510 #else
 511         return 0; /* no dhcp support */
 512 #endif
 513 }
 514
 515 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 516 {
 517 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 518         int i;
 519         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 520                 if (exists_execable(ext_dhcp_clients[i].name))
 521                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 522         }
 523         bb_error_msg("no dhcp clients found, using static interface shutdown");
 524         return static_down(ifd, exec);
 525 #elif ENABLE_APP_UDHCPC
 526         return execute("kill "
 527                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 528 #else
 529         return 0; /* no dhcp support */
 530 #endif
 531 }
 532
 533 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 534 {
 535         return 1;
 536 }
 537
 538 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 539 {
 540         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 541                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 542                         " --returniffail --serverbcast", ifd, exec);
 543 }
 544
 545 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 546 {
 547         return execute("pon[[ %provider%]]", ifd, exec);
 548 }
 549
 550 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 551 {
 552         return execute("poff[[ %provider%]]", ifd, exec);
 553 }
 554
 555 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 556 {
 557         return execute("start-stop-daemon --start -x wvdial "
 558                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 559 }
 560
 561 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 562 {
 563         return execute("start-stop-daemon --stop -x wvdial "
 564                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 565 }
 566
 567 static const struct method_t methods[] = {
 568         { "manual", manual_up_down, manual_up_down, },
 569         { "wvdial", wvdial_up, wvdial_down, },
 570         { "ppp", ppp_up, ppp_down, },
 571         { "static", static_up, static_down, },
 572         { "bootp", bootp_up, static_down, },
 573         { "dhcp", dhcp_up, dhcp_down, },
 574         { "loopback", loopback_up, loopback_down, },
 575 };
 576
 577 static const struct address_family_t addr_inet = {
 578         "inet",
 579         ARRAY_SIZE(methods),
 580         methods
 581 };
 582
 583 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 584
 585 static char *next_word(char **buf)
 586 {
 587         unsigned length;
 588         char *word;
 589
 590         /* Skip over leading whitespace */
 591         word = skip_whitespace(*buf);
 592
 593         /* Stop on EOL/comments */
 594         if (*word == '#' || *word == '\0')
 595                 return NULL;
 596
 597         /* Find the length of this word (can't be 0) */
 598         length = strcspn(word, " \t\n");
 599
 600         /* Unless we are already at NUL, store NUL and advance */
 601         if (word[length] != '\0')
 602                 word[length++] = '\0';
 603
 604         *buf = word + length;
 605
 606         return word;
 607 }
 608
 609 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 610 {
 611         int i;
 612
 613         if (!name)
 614                 return NULL;
 615
 616         for (i = 0; af[i]; i++) {
 617                 if (strcmp(af[i]->name, name) == 0) {
 618                         return af[i];
 619                 }
 620         }
 621         return NULL;
 622 }
 623
 624 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 625 {
 626         int i;
 627
 628         if (!name)
 629                 return NULL;
 630         /* TODO: use index_in_str_array() */
 631         for (i = 0; i < af->n_methods; i++) {
 632                 if (strcmp(af->method[i].name, name) == 0) {
 633                         return &af->method[i];
 634                 }
 635         }
 636         return NULL;
 637 }
 638
 639 static const llist_t *find_list_string(const llist_t *list, const char *string)
 640 {
 641         if (string == NULL)
 642                 return NULL;
 643
 644         while (list) {
 645                 if (strcmp(list->data, string) == 0) {
 646                         return list;
 647                 }
 648                 list = list->link;
 649         }
 650         return NULL;
 651 }
 652
 653 static struct interfaces_file_t *read_interfaces(const char *filename)
 654 {
 655 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 656         struct mapping_defn_t *currmap = NULL;
 657 #endif
 658         struct interface_defn_t *currif = NULL;
 659         struct interfaces_file_t *defn;
 660         FILE *f;
 661         char *firstword;
 662         char *buf;
 663
 664         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 665
 666         defn = xzalloc(sizeof(struct interfaces_file_t));
 667
 668         f = xfopen(filename, "r");
 669
 670         while ((buf = xmalloc_getline(f)) != NULL) {
 671                 char *buf_ptr = buf;
 672
 673                 firstword = next_word(&buf_ptr);
 674                 if (firstword == NULL) {
 675                         free(buf);
 676                         continue;       /* blank line */
 677                 }
 678
 679                 if (strcmp(firstword, "mapping") == 0) {
 680 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 681                         currmap = xzalloc(sizeof(*currmap));
 682
 683                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 684                                 if (currmap->n_matches >= currmap->max_matches) {
 685                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 686                                         currmap->match = xrealloc(currmap->match, sizeof(*currmap->match) * currmap->max_matches);
 687                                 }
 688                                 currmap->match[currmap->n_matches++] = xstrdup(firstword);
 689                         }
 690                         /*currmap->max_mappings = 0; - done by xzalloc */
 691                         /*currmap->n_mappings = 0;*/
 692                         /*currmap->mapping = NULL;*/
 693                         /*currmap->script = NULL;*/
 694                         {
 695                                 struct mapping_defn_t **where = &defn->mappings;
 696                                 while (*where != NULL) {
 697                                         where = &(*where)->next;
 698                                 }
 699                                 *where = currmap;
 700                                 /*currmap->next = NULL;*/
 701                         }
 702                         debug_noise("Added mapping\n");
 703 #endif
 704                         currently_processing = MAPPING;
 705                 } else if (strcmp(firstword, "iface") == 0) {
 706                         static const struct address_family_t *const addr_fams[] = {
 707 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 708                                 &addr_inet,
 709 #endif
 710 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 711                                 &addr_inet6,
 712 #endif
 713                                 NULL
 714                         };
 715
 716                         char *iface_name;
 717                         char *address_family_name;
 718                         char *method_name;
 719                         llist_t *iface_list;
 720
 721                         currif = xzalloc(sizeof(*currif));
 722                         iface_name = next_word(&buf_ptr);
 723                         address_family_name = next_word(&buf_ptr);
 724                         method_name = next_word(&buf_ptr);
 725
 726                         if (method_name == NULL)
 727                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 728
 729                         /* ship any trailing whitespace */
 730                         buf_ptr = skip_whitespace(buf_ptr);
 731
 732                         if (buf_ptr[0] != '\0' /* && buf_ptr[0] != '#' */)
 733                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 734
 735                         currif->iface = xstrdup(iface_name);
 736
 737                         currif->address_family = get_address_family(addr_fams, address_family_name);
 738                         if (!currif->address_family)
 739                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 740
 741                         currif->method = get_method(currif->address_family, method_name);
 742                         if (!currif->method)
 743                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 744
 745                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 746                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 747                                 if ((strcmp(tmp->iface, currif->iface) == 0)
 748                                  && (tmp->address_family == currif->address_family)
 749                                 ) {
 750                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
 751                                 }
 752                         }
 753                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 754
 755                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 756                         currently_processing = IFACE;
 757                 } else if (strcmp(firstword, "auto") == 0) {
 758                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 759
 760                                 /* Check the interface isnt already listed */
 761                                 if (find_list_string(defn->autointerfaces, firstword)) {
 762                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 763                                 }
 764
 765                                 /* Add the interface to the list */
 766                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(firstword));
 767                                 debug_noise("\nauto %s\n", firstword);
 768                         }
 769                         currently_processing = NONE;
 770                 } else {
 771                         switch (currently_processing) {
 772                         case IFACE:
 773                                 if (buf_ptr[0] == '\0')
 774                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
 775
 776                                 if (strcmp(firstword, "up") != 0
 777                                  && strcmp(firstword, "down") != 0
 778                                  && strcmp(firstword, "pre-up") != 0
 779                                  && strcmp(firstword, "post-down") != 0
 780                                 ) {
 781                                         int i;
 782                                         for (i = 0; i < currif->n_options; i++) {
 783                                                 if (strcmp(currif->option[i].name, firstword) == 0)
 784                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
 785                                         }
 786                                 }
 787                                 if (currif->n_options >= currif->max_options) {
 788                                         currif->max_options += 10;
 789                                         currif->option = xrealloc(currif->option, sizeof(*currif->option) * currif->max_options);
 790                                 }
 791                                 debug_noise("\t%s=%s\n", firstword, buf_ptr);
 792                                 currif->option[currif->n_options].name = xstrdup(firstword);
 793                                 currif->option[currif->n_options].value = xstrdup(buf_ptr);
 794                                 currif->n_options++;
 795                                 break;
 796                         case MAPPING:
 797 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 798                                 if (strcmp(firstword, "script") == 0) {
 799                                         if (currmap->script != NULL)
 800                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
 801                                         currmap->script = xstrdup(next_word(&buf_ptr));
 802                                 } else if (strcmp(firstword, "map") == 0) {
 803                                         if (currmap->n_mappings >= currmap->max_mappings) {
 804                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 805                                                 currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 806                                         }
 807                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&buf_ptr));
 808                                         currmap->n_mappings++;
 809                                 } else {
 810                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
 811                                 }
 812 #endif
 813                                 break;
 814                         case NONE:
 815                         default:
 816                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
 817                         }
 818                 }
 819                 free(buf);
 820         }
 821         if (ferror(f) != 0) {
 822                 /* ferror does NOT set errno! */
 823                 bb_error_msg_and_die("%s: I/O error", filename);
 824         }
 825         fclose(f);
 826
 827         return defn;
 828 }
 829
 830 static char *setlocalenv(const char *format, const char *name, const char *value)
 831 {
 832         char *result;
 833         char *here;
 834         char *there;
 835
 836         result = xasprintf(format, name, value);
 837
 838         for (here = there = result; *there != '=' && *there; there++) {
 839                 if (*there == '-')
 840                         *there = '_';
 841                 if (isalpha(*there))
 842                         *there = toupper(*there);
 843
 844                 if (isalnum(*there) || *there == '_') {
 845                         *here = *there;
 846                         here++;
 847                 }
 848         }
 849         memmove(here, there, strlen(there) + 1);
 850
 851         return result;
 852 }
 853
 854 static void set_environ(struct interface_defn_t *iface, const char *mode)
 855 {
 856         char **environend;
 857         int i;
 858         const int n_env_entries = iface->n_options + 5;
 859         char **ppch;
 860
 861         if (my_environ != NULL) {
 862                 for (ppch = my_environ; *ppch; ppch++) {
 863                         free(*ppch);
 864                         *ppch = NULL;
 865                 }
 866                 free(my_environ);
 867         }
 868         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 869         environend = my_environ;
 870
 871         for (i = 0; i < iface->n_options; i++) {
 872                 if (strcmp(iface->option[i].name, "up") == 0
 873                  || strcmp(iface->option[i].name, "down") == 0
 874                  || strcmp(iface->option[i].name, "pre-up") == 0
 875                  || strcmp(iface->option[i].name, "post-down") == 0
 876                 ) {
 877                         continue;
 878                 }
 879                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 880         }
 881
 882         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 883         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 884         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 885         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 886         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 887 }
 888
 889 static int doit(char *str)
 890 {
 891         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 892                 puts(str);
 893         }
 894         if (!(option_mask32 & OPT_no_act)) {
 895                 pid_t child;
 896                 int status;
 897
 898                 fflush(NULL);
 899                 child = fork();
 900                 switch (child) {
 901                 case -1: /* failure */
 902                         return 0;
 903                 case 0: /* child */
 904                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 905                         exit(127);
 906                 }
 907                 safe_waitpid(child, &status, 0);
 908                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 909                         return 0;
 910                 }
 911         }
 912         return 1;
 913 }
 914
 915 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 916 {
 917         int i;
 918         char *buf;
 919         for (i = 0; i < ifd->n_options; i++) {
 920                 if (strcmp(ifd->option[i].name, opt) == 0) {
 921                         if (!doit(ifd->option[i].value)) {
 922                                 return 0;
 923                         }
 924                 }
 925         }
 926
 927         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 928         /* heh, we don't bother free'ing it */
 929         return doit(buf);
 930 }
 931
 932 static int check(char *str)
 933 {
 934         return str != NULL;
 935 }
 936
 937 static int iface_up(struct interface_defn_t *iface)
 938 {
 939         if (!iface->method->up(iface, check)) return -1;
 940         set_environ(iface, "start");
 941         if (!execute_all(iface, "pre-up")) return 0;
 942         if (!iface->method->up(iface, doit)) return 0;
 943         if (!execute_all(iface, "up")) return 0;
 944         return 1;
 945 }
 946
 947 static int iface_down(struct interface_defn_t *iface)
 948 {
 949         if (!iface->method->down(iface,check)) return -1;
 950         set_environ(iface, "stop");
 951         if (!execute_all(iface, "down")) return 0;
 952         if (!iface->method->down(iface, doit)) return 0;
 953         if (!execute_all(iface, "post-down")) return 0;
 954         return 1;
 955 }
 956
 957 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 958 static int popen2(FILE **in, FILE **out, char *command, ...)
 959 {
 960         va_list ap;
 961         char *argv[11] = { command };
 962         int argc;
 963         int infd[2], outfd[2];
 964         pid_t pid;
 965
 966         argc = 1;
 967         va_start(ap, command);
 968         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 969                 argc++;
 970         }
 971         argv[argc] = NULL;      /* make sure */
 972         va_end(ap);
 973
 974         if (pipe(infd) != 0) {
 975                 return 0;
 976         }
 977
 978         if (pipe(outfd) != 0) {
 979                 close(infd[0]);
 980                 close(infd[1]);
 981                 return 0;
 982         }
 983
 984         fflush(NULL);
 985         switch (pid = fork()) {
 986         case -1:                        /* failure */
 987                 close(infd[0]);
 988                 close(infd[1]);
 989                 close(outfd[0]);
 990                 close(outfd[1]);
 991                 return 0;
 992         case 0:                 /* child */
 993                 dup2(infd[0], 0);
 994                 dup2(outfd[1], 1);
 995                 close(infd[0]);
 996                 close(infd[1]);
 997                 close(outfd[0]);
 998                 close(outfd[1]);
 999                 BB_EXECVP(command, argv);
1000                 exit(127);
1001         default:                        /* parent */
1002                 *in = fdopen(infd[1], "w");
1003                 *out = fdopen(outfd[0], "r");
1004                 close(infd[0]);
1005                 close(outfd[1]);
1006                 return pid;
1007         }
1008         /* unreached */
1009 }
1010
1011 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1012 {
1013         FILE *in, *out;
1014         int i, status;
1015         pid_t pid;
1016
1017         char *logical = xstrdup(physical);
1018
1019         /* Run the mapping script. */
1020         pid = popen2(&in, &out, map->script, physical, NULL);
1021
1022         /* popen2() returns 0 on failure. */
1023         if (pid == 0)
1024                 return logical;
1025
1026         /* Write mappings to stdin of mapping script. */
1027         for (i = 0; i < map->n_mappings; i++) {
1028                 fprintf(in, "%s\n", map->mapping[i]);
1029         }
1030         fclose(in);
1031         safe_waitpid(pid, &status, 0);
1032
1033         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1034                 /* If the mapping script exited successfully, try to
1035                  * grab a line of output and use that as the name of the
1036                  * logical interface. */
1037                 char *new_logical = xmalloc(MAX_INTERFACE_LENGTH);
1038
1039                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1040                         /* If we are able to read a line of output from the script,
1041                          * remove any trailing whitespace and use this value
1042                          * as the name of the logical interface. */
1043                         char *pch = new_logical + strlen(new_logical) - 1;
1044
1045                         while (pch >= new_logical && isspace(*pch))
1046                                 *(pch--) = '\0';
1047
1048                         free(logical);
1049                         logical = new_logical;
1050                 } else {
1051                         /* If we are UNABLE to read a line of output, discard our
1052                          * freshly allocated memory. */
1053                         free(new_logical);
1054                 }
1055         }
1056
1057         fclose(out);
1058
1059         return logical;
1060 }
1061 #endif /* FEATURE_IFUPDOWN_MAPPING */
1062
1063 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1064 {
1065         unsigned short iface_len = strlen(iface);
1066         llist_t *search = state_list;
1067
1068         while (search) {
1069                 if ((strncmp(search->data, iface, iface_len) == 0)
1070                  && (search->data[iface_len] == '=')) {
1071                         return search;
1072                 }
1073                 search = search->link;
1074         }
1075         return NULL;
1076 }
1077
1078 /* read the previous state from the state file */
1079 static llist_t *read_iface_state(void)
1080 {
1081         llist_t *state_list = NULL;
1082         FILE *state_fp = fopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "r");
1083
1084         if (state_fp) {
1085                 char *start, *end_ptr;
1086                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1087                         /* We should only need to check for a single character */
1088                         end_ptr = start + strcspn(start, " \t\n");
1089                         *end_ptr = '\0';
1090                         llist_add_to(&state_list, start);
1091                 }
1092                 fclose(state_fp);
1093         }
1094         return state_list;
1095 }
1096
1097
1098 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1099 int ifupdown_main(int argc, char **argv)
1100 {
1101         int (*cmds)(struct interface_defn_t *);
1102         struct interfaces_file_t *defn;
1103         llist_t *target_list = NULL;
1104         const char *interfaces = "/etc/network/interfaces";
1105         bool any_failures = 0;
1106
1107         cmds = iface_down;
1108         if (applet_name[2] == 'u') {
1109                 /* ifup command */
1110                 cmds = iface_up;
1111         }
1112
1113         getopt32(argv, OPTION_STR, &interfaces);
1114         if (argc - optind > 0) {
1115                 if (DO_ALL) bb_show_usage();
1116         } else {
1117                 if (!DO_ALL) bb_show_usage();
1118         }
1119
1120         debug_noise("reading %s file:\n", interfaces);
1121         defn = read_interfaces(interfaces);
1122         debug_noise("\ndone reading %s\n\n", interfaces);
1123
1124         startup_PATH = getenv("PATH");
1125         if (!startup_PATH) startup_PATH = "";
1126
1127         /* Create a list of interfaces to work on */
1128         if (DO_ALL) {
1129                 target_list = defn->autointerfaces;
1130         } else {
1131                 llist_add_to_end(&target_list, argv[optind]);
1132         }
1133
1134         /* Update the interfaces */
1135         while (target_list) {
1136                 llist_t *iface_list;
1137                 struct interface_defn_t *currif;
1138                 char *iface;
1139                 char *liface;
1140                 char *pch;
1141                 bool okay = 0;
1142                 unsigned cmds_ret;
1143
1144                 iface = xstrdup(target_list->data);
1145                 target_list = target_list->link;
1146
1147                 pch = strchr(iface, '=');
1148                 if (pch) {
1149                         *pch = '\0';
1150                         liface = xstrdup(pch + 1);
1151                 } else {
1152                         liface = xstrdup(iface);
1153                 }
1154
1155                 if (!FORCE) {
1156                         llist_t *state_list = read_iface_state();
1157                         const llist_t *iface_state = find_iface_state(state_list, iface);
1158
1159                         if (cmds == iface_up) {
1160                                 /* ifup */
1161                                 if (iface_state) {
1162                                         bb_error_msg("interface %s already configured", iface);
1163                                         continue;
1164                                 }
1165                         } else {
1166                                 /* ifdown */
1167                                 if (!iface_state) {
1168                                         bb_error_msg("interface %s not configured", iface);
1169                                         continue;
1170                                 }
1171                         }
1172                         llist_free(state_list, free);
1173                 }
1174
1175 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1176                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1177                         struct mapping_defn_t *currmap;
1178
1179                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1180                                 int i;
1181                                 for (i = 0; i < currmap->n_matches; i++) {
1182                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1183                                                 continue;
1184                                         if (VERBOSE) {
1185                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1186                                         }
1187                                         liface = run_mapping(iface, currmap);
1188                                         break;
1189                                 }
1190                         }
1191                 }
1192 #endif
1193
1194                 iface_list = defn->ifaces;
1195                 while (iface_list) {
1196                         currif = (struct interface_defn_t *) iface_list->data;
1197                         if (strcmp(liface, currif->iface) == 0) {
1198                                 char *oldiface = currif->iface;
1199
1200                                 okay = 1;
1201                                 currif->iface = iface;
1202
1203                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1204
1205                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1206                                 cmds_ret = cmds(currif);
1207                                 if (cmds_ret == -1) {
1208                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1209                                                         liface, currif->address_family->name);
1210                                         any_failures = 1;
1211                                 } else if (cmds_ret == 0) {
1212                                         any_failures = 1;
1213                                 }
1214
1215                                 currif->iface = oldiface;
1216                         }
1217                         iface_list = iface_list->link;
1218                 }
1219                 if (VERBOSE) {
1220                         bb_putchar('\n');
1221                 }
1222
1223                 if (!okay && !FORCE) {
1224                         bb_error_msg("ignoring unknown interface %s", liface);
1225                         any_failures = 1;
1226                 } else if (!NO_ACT) {
1227                         /* update the state file */
1228                         FILE *state_fp;
1229                         llist_t *state;
1230                         llist_t *state_list = read_iface_state();
1231                         llist_t *iface_state = find_iface_state(state_list, iface);
1232
1233                         if (cmds == iface_up) {
1234                                 char * const newiface = xasprintf("%s=%s", iface, liface);
1235                                 if (iface_state == NULL) {
1236                                         llist_add_to_end(&state_list, newiface);
1237                                 } else {
1238                                         free(iface_state->data);
1239                                         iface_state->data = newiface;
1240                                 }
1241                         } else {
1242                                 /* Remove an interface from state_list */
1243                                 llist_unlink(&state_list, iface_state);
1244                                 free(llist_pop(&iface_state));
1245                         }
1246
1247                         /* Actually write the new state */
1248                         state_fp = xfopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "w");
1249                         state = state_list;
1250                         while (state) {
1251                                 if (state->data) {
1252                                         fprintf(state_fp, "%s\n", state->data);
1253                                 }
1254                                 state = state->link;
1255                         }
1256                         fclose(state_fp);
1257                         llist_free(state_list, free);
1258                 }
1259         }
1260
1261         return any_failures;
1262 }