networking/ifupdown.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * ifup/ifdown 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 GPLv2 or later, see file LICENSE in this source tree.
  18  */
  19 //config:config IFUP
  20 //config:       bool "ifup (14 kb)"
  21 //config:       default y
  22 //config:       help
  23 //config:       Activate the specified interfaces. This applet makes use
  24 //config:       of either "ifconfig" and "route" or the "ip" command to actually
  25 //config:       configure network interfaces. Therefore, you will probably also want
  26 //config:       to enable either IFCONFIG and ROUTE, or enable
  27 //config:       FEATURE_IFUPDOWN_IP and the various IP options. Of
  28 //config:       course you could use non-busybox versions of these programs, so
  29 //config:       against my better judgement (since this will surely result in plenty
  30 //config:       of support questions on the mailing list), I do not force you to
  31 //config:       enable these additional options. It is up to you to supply either
  32 //config:       "ifconfig", "route" and "run-parts" or the "ip" command, either
  33 //config:       via busybox or via standalone utilities.
  34 //config:
  35 //config:config IFDOWN
  36 //config:       bool "ifdown (13 kb)"
  37 //config:       default y
  38 //config:       help
  39 //config:       Deactivate the specified interfaces.
  40 //config:
  41 //config:config IFUPDOWN_IFSTATE_PATH
  42 //config:       string "Absolute path to ifstate file"
  43 //config:       default "/var/run/ifstate"
  44 //config:       depends on IFUP || IFDOWN
  45 //config:       help
  46 //config:       ifupdown keeps state information in a file called ifstate.
  47 //config:       Typically it is located in /var/run/ifstate, however
  48 //config:       some distributions tend to put it in other places
  49 //config:       (debian, for example, uses /etc/network/run/ifstate).
  50 //config:       This config option defines location of ifstate.
  51 //config:
  52 //config:config FEATURE_IFUPDOWN_IP
  53 //config:       bool "Use ip tool (else ifconfig/route is used)"
  54 //config:       default y
  55 //config:       depends on IFUP || IFDOWN
  56 //config:       help
  57 //config:       Use the iproute "ip" command to implement "ifup" and "ifdown", rather
  58 //config:       than the default of using the older "ifconfig" and "route" utilities.
  59 //config:
  60 //config:       If Y: you must install either the full-blown iproute2 package
  61 //config:       or enable "ip" applet in busybox, or the "ifup" and "ifdown" applets
  62 //config:       will not work.
  63 //config:
  64 //config:       If N: you must install either the full-blown ifconfig and route
  65 //config:       utilities, or enable these applets in busybox.
  66 //config:
  67 //config:config FEATURE_IFUPDOWN_IPV4
  68 //config:       bool "Support IPv4"
  69 //config:       default y
  70 //config:       depends on IFUP || IFDOWN
  71 //config:       help
  72 //config:       If you want ifup/ifdown to talk IPv4, leave this on.
  73 //config:
  74 //config:config FEATURE_IFUPDOWN_IPV6
  75 //config:       bool "Support IPv6"
  76 //config:       default y
  77 //config:       depends on (IFUP || IFDOWN) && FEATURE_IPV6
  78 //config:       help
  79 //config:       If you need support for IPv6, turn this option on.
  80 //config:
  81 //UNUSED:
  82 ////////:config FEATURE_IFUPDOWN_IPX
  83 ////////:       bool "Support IPX"
  84 ////////:       default y
  85 ////////:       depends on IFUP || IFDOWN
  86 ////////:       help
  87 ////////:         If this option is selected you can use busybox to work with IPX
  88 ////////:         networks.
  89 //config:
  90 //config:config FEATURE_IFUPDOWN_MAPPING
  91 //config:       bool "Enable mapping support"
  92 //config:       default y
  93 //config:       depends on IFUP || IFDOWN
  94 //config:       help
  95 //config:       This enables support for the "mapping" stanza, unless you have
  96 //config:       a weird network setup you don't need it.
  97 //config:
  98 //config:config FEATURE_IFUPDOWN_EXTERNAL_DHCP
  99 //config:       bool "Support external DHCP clients"
 100 //config:       default n
 101 //config:       depends on IFUP || IFDOWN
 102 //config:       help
 103 //config:       This enables support for the external dhcp clients. Clients are
 104 //config:       tried in the following order: dhcpcd, dhclient, pump and udhcpc.
 105 //config:       Otherwise, if udhcpc applet is enabled, it is used.
 106 //config:       Otherwise, ifup/ifdown will have no support for DHCP.
 107
 108 //                 APPLET_ODDNAME:name    main      location     suid_type     help
 109 //applet:IF_IFUP(  APPLET_ODDNAME(ifup,   ifupdown, BB_DIR_SBIN, BB_SUID_DROP, ifup))
 110 //applet:IF_IFDOWN(APPLET_ODDNAME(ifdown, ifupdown, BB_DIR_SBIN, BB_SUID_DROP, ifdown))
 111
 112 //kbuild:lib-$(CONFIG_IFUP) += ifupdown.o
 113 //kbuild:lib-$(CONFIG_IFDOWN) += ifupdown.o
 114
 115 //usage:#define ifup_trivial_usage
 116 //usage:       "[-n"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] -a | IFACE..."
 117 //usage:#define ifup_full_usage "\n\n"
 118 //usage:       "        -a      Configure all interfaces"
 119 //usage:     "\n        -i FILE Use FILE instead of /etc/network/interfaces"
 120 //usage:     "\n        -n      Dry run"
 121 //usage:        IF_FEATURE_IFUPDOWN_MAPPING(
 122 //usage:     "\n                (note: doesn't disable mappings)"
 123 //usage:     "\n        -m      Don't run any mappings"
 124 //usage:        )
 125 //usage:     "\n        -v      Print out what would happen before doing it"
 126 //usage:     "\n        -f      Force"
 127 //usage:
 128 //usage:#define ifdown_trivial_usage
 129 //usage:       "[-n"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] -a | IFACE..."
 130 //usage:#define ifdown_full_usage "\n\n"
 131 //usage:       "        -a      Deconfigure all interfaces"
 132 //usage:     "\n        -i FILE Use FILE instead of /etc/network/interfaces"
 133 //usage:     "\n        -n      Dry run"
 134 //usage:        IF_FEATURE_IFUPDOWN_MAPPING(
 135 //usage:     "\n                (note: doesn't disable mappings)"
 136 //usage:     "\n        -m      Don't run any mappings"
 137 //usage:        )
 138 //usage:     "\n        -v      Print out what would happen before doing it"
 139 //usage:     "\n        -f      Force"
 140
 141 #include <net/if.h>
 142 #include "libbb.h"
 143 #include "common_bufsiz.h"
 144 /* After libbb.h, since it needs sys/types.h on some systems */
 145 #include <sys/utsname.h>
 146 #include <fnmatch.h>
 147
 148 #define MAX_OPT_DEPTH 10
 149
 150 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 151 #define MAX_INTERFACE_LENGTH 10
 152 #endif
 153
 154 #define UDHCPC_CMD_OPTIONS CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS
 155 #define IFSTATE_FILE_PATH  CONFIG_IFUPDOWN_IFSTATE_PATH
 156
 157 #define debug_noise(args...) /*fprintf(stderr, args)*/
 158
 159 /* Forward declaration */
 160 struct interface_defn_t;
 161
 162 typedef int execfn(char *command);
 163
 164 struct method_t {
 165         const char *name;
 166         int (*up)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
 167         int (*down)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
 168 };
 169
 170 struct address_family_t {
 171         const char *name;
 172         int n_methods;
 173         const struct method_t *method;
 174 };
 175
 176 struct mapping_defn_t {
 177         struct mapping_defn_t *next;
 178
 179         int max_matches;
 180         int n_matches;
 181         char **match;
 182
 183         char *script;
 184
 185         int n_mappings;
 186         char **mapping;
 187 };
 188
 189 struct variable_t {
 190         char *name;
 191         char *value;
 192 };
 193
 194 struct interface_defn_t {
 195         const struct address_family_t *address_family;
 196         const struct method_t *method;
 197
 198         char *iface;
 199         int n_options;
 200         struct variable_t *option;
 201 };
 202
 203 struct interfaces_file_t {
 204         llist_t *autointerfaces;
 205         llist_t *ifaces;
 206         struct mapping_defn_t *mappings;
 207 };
 208
 209
 210 #define OPTION_STR "anvf" IF_FEATURE_IFUPDOWN_MAPPING("m") "i:"
 211 enum {
 212         OPT_do_all      = 0x1,
 213         OPT_no_act      = 0x2,
 214         OPT_verbose     = 0x4,
 215         OPT_force       = 0x8,
 216         OPT_no_mappings = 0x10,
 217 };
 218 #define DO_ALL      (option_mask32 & OPT_do_all)
 219 #define NO_ACT      (option_mask32 & OPT_no_act)
 220 #define VERBOSE     (option_mask32 & OPT_verbose)
 221 #define FORCE       (option_mask32 & OPT_force)
 222 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 223
 224
 225 struct globals {
 226         char **my_environ;
 227         const char *startup_PATH;
 228         char *shell;
 229 } FIX_ALIASING;
 230 #define G (*(struct globals*)bb_common_bufsiz1)
 231 #define INIT_G() do { setup_common_bufsiz(); } while (0)
 232
 233
 234 static const char keywords_up_down[] ALIGN1 =
 235         "up\0"
 236         "down\0"
 237         "pre-up\0"
 238         "post-down\0"
 239 ;
 240
 241
 242 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 243
 244 static void addstr(char **bufp, const char *str, size_t str_length)
 245 {
 246         /* xasprintf trick will be smaller, but we are often
 247          * called with str_length == 1 - don't want to have
 248          * THAT much of malloc/freeing! */
 249         char *buf = *bufp;
 250         int len = (buf ? strlen(buf) : 0);
 251         str_length++;
 252         buf = xrealloc(buf, len + str_length);
 253         /* copies at most str_length-1 chars! */
 254         safe_strncpy(buf + len, str, str_length);
 255         *bufp = buf;
 256 }
 257
 258 static int strncmpz(const char *l, const char *r, size_t llen)
 259 {
 260         int i = strncmp(l, r, llen);
 261
 262         if (i == 0)
 263                 return - (unsigned char)r[llen];
 264         return i;
 265 }
 266
 267 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 268 {
 269         int i;
 270
 271         if (strncmpz(id, "iface", idlen) == 0) {
 272                 // ubuntu's ifup doesn't do this:
 273                 //static char *label_buf;
 274                 //char *result;
 275                 //free(label_buf);
 276                 //label_buf = xstrdup(ifd->iface);
 277                 // Remove virtual iface suffix
 278                 //result = strchrnul(label_buf, ':');
 279                 //*result = '\0';
 280                 //return label_buf;
 281
 282                 return ifd->iface;
 283         }
 284         if (strncmpz(id, "label", idlen) == 0) {
 285                 return ifd->iface;
 286         }
 287         for (i = 0; i < ifd->n_options; i++) {
 288                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 289                         return ifd->option[i].value;
 290                 }
 291         }
 292         return NULL;
 293 }
 294
 295 # if ENABLE_FEATURE_IFUPDOWN_IP
 296 static int count_netmask_bits(const char *dotted_quad)
 297 {
 298 //      int result;
 299 //      unsigned a, b, c, d;
 300 //      /* Found a netmask...  Check if it is dotted quad */
 301 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 302 //              return -1;
 303 //      if ((a|b|c|d) >> 8)
 304 //              return -1; /* one of numbers is >= 256 */
 305 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 306 //      d = ~d; /* 11110000 -> 00001111 */
 307
 308         /* Shorter version */
 309         struct in_addr ip;
 310         unsigned d;
 311
 312         if (inet_aton(dotted_quad, &ip) == 0)
 313                 return -1; /* malformed dotted IP */
 314         d = ntohl(ip.s_addr); /* IP in host order */
 315         d = ~d; /* 11110000 -> 00001111 */
 316         if (d & (d+1)) /* check that it is in 00001111 form */
 317                 return -1; /* no it is not */
 318         return bb_popcnt_32(~d);
 319 }
 320 # endif
 321
 322 static char *parse(const char *command, struct interface_defn_t *ifd)
 323 {
 324         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 325         smallint okay[MAX_OPT_DEPTH] = { 1 };
 326         int opt_depth = 1;
 327         char *result = NULL;
 328
 329         while (*command) {
 330                 switch (*command) {
 331                 default:
 332                         addstr(&result, command, 1);
 333                         command++;
 334                         break;
 335                 case '\\':
 336                         if (command[1])
 337                                 command++;
 338                         addstr(&result, command, 1);
 339                         command++;
 340                         break;
 341                 case '[':
 342                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 343                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 344                                 okay[opt_depth] = 1;
 345                                 opt_depth++;
 346                                 command += 2;
 347                         } else {
 348                                 addstr(&result, command, 1);
 349                                 command++;
 350                         }
 351                         break;
 352                 case ']':
 353                         if (command[1] == ']' && opt_depth > 1) {
 354                                 opt_depth--;
 355                                 if (!okay[opt_depth]) {
 356                                         result[old_pos[opt_depth]] = '\0';
 357                                 }
 358                                 command += 2;
 359                         } else {
 360                                 addstr(&result, command, 1);
 361                                 command++;
 362                         }
 363                         break;
 364                 case '%':
 365                         {
 366                                 char *nextpercent;
 367                                 char *varvalue;
 368
 369                                 command++;
 370                                 nextpercent = strchr(command, '%');
 371                                 if (!nextpercent) {
 372                                         /* Unterminated %var% */
 373                                         free(result);
 374                                         return NULL;
 375                                 }
 376
 377                                 varvalue = get_var(command, nextpercent - command, ifd);
 378
 379                                 if (varvalue) {
 380 # if ENABLE_FEATURE_IFUPDOWN_IP
 381                                         /* "hwaddress <class> <address>":
 382                                          * unlike ifconfig, ip doesnt want <class>
 383                                          * (usually "ether" keyword). Skip it. */
 384                                         if (is_prefixed_with(command, "hwaddress")) {
 385                                                 varvalue = skip_whitespace(skip_non_whitespace(varvalue));
 386                                         }
 387 # endif
 388                                         addstr(&result, varvalue, strlen(varvalue));
 389                                 } else {
 390 # if ENABLE_FEATURE_IFUPDOWN_IP
 391                                         /* Sigh...  Add a special case for 'ip' to convert from
 392                                          * dotted quad to bit count style netmasks.  */
 393                                         if (is_prefixed_with(command, "bnmask")) {
 394                                                 unsigned res;
 395                                                 varvalue = get_var("netmask", 7, ifd);
 396                                                 if (varvalue) {
 397                                                         res = count_netmask_bits(varvalue);
 398                                                         if (res > 0) {
 399                                                                 const char *argument = utoa(res);
 400                                                                 addstr(&result, argument, strlen(argument));
 401                                                                 command = nextpercent + 1;
 402                                                                 break;
 403                                                         }
 404                                                 }
 405                                         }
 406 # endif
 407                                         okay[opt_depth - 1] = 0;
 408                                 }
 409
 410                                 command = nextpercent + 1;
 411                         }
 412                         break;
 413                 }
 414         }
 415
 416         if (opt_depth > 1) {
 417                 /* Unbalanced bracket */
 418                 free(result);
 419                 return NULL;
 420         }
 421
 422         if (!okay[0]) {
 423                 /* Undefined variable and we aren't in a bracket */
 424                 free(result);
 425                 return NULL;
 426         }
 427
 428         return result;
 429 }
 430
 431 /* execute() returns 1 for success and 0 for failure */
 432 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 433 {
 434         char *out;
 435         int ret;
 436
 437         out = parse(command, ifd);
 438         if (!out) {
 439                 /* parse error? */
 440                 return 0;
 441         }
 442         /* out == "": parsed ok but not all needed variables known, skip */
 443         ret = out[0] ? (*exec)(out) : 1;
 444
 445         free(out);
 446         if (ret != 1) {
 447                 return 0;
 448         }
 449         return 1;
 450 }
 451
 452 #endif /* FEATURE_IFUPDOWN_IPV4 || FEATURE_IFUPDOWN_IPV6 */
 453
 454
 455 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 456
 457 static int FAST_FUNC loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 458 {
 459 # if ENABLE_FEATURE_IFUPDOWN_IP
 460         int result;
 461         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 462         result += execute("ip link set %iface% up", ifd, exec);
 463         return ((result == 2) ? 2 : 0);
 464 # else
 465         return execute("ifconfig %iface% add ::1", ifd, exec);
 466 # endif
 467 }
 468
 469 static int FAST_FUNC loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 470 {
 471 # if ENABLE_FEATURE_IFUPDOWN_IP
 472         return execute("ip link set %iface% down", ifd, exec);
 473 # else
 474         return execute("ifconfig %iface% del ::1", ifd, exec);
 475 # endif
 476 }
 477
 478 static int FAST_FUNC manual_up_down6(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 479 {
 480         return 1;
 481 }
 482
 483 static int FAST_FUNC static_up6(struct interface_defn_t *ifd, execfn *exec)
 484 {
 485         int result;
 486 # if ENABLE_FEATURE_IFUPDOWN_IP
 487         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 488         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 489         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 490         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]][[ metric %metric%]]", ifd, exec);
 491 # else
 492         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 493         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 494         result += execute("[[route -A inet6 add ::/0 gw %gateway%[[ metric %metric%]]]]", ifd, exec);
 495 # endif
 496         return ((result == 3) ? 3 : 0);
 497 }
 498
 499 static int FAST_FUNC static_down6(struct interface_defn_t *ifd, execfn *exec)
 500 {
 501         if (!if_nametoindex(ifd->iface))
 502                 return 1; /* already gone */
 503 # if ENABLE_FEATURE_IFUPDOWN_IP
 504         return execute("ip link set %iface% down", ifd, exec);
 505 # else
 506         return execute("ifconfig %iface% down", ifd, exec);
 507 # endif
 508 }
 509
 510 # if ENABLE_FEATURE_IFUPDOWN_IP
 511 static int FAST_FUNC v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 512 {
 513         int result;
 514         result = execute("ip tunnel add %iface% mode sit remote "
 515                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 516         result += execute("ip link set %iface% up", ifd, exec);
 517         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 518         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 519         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]]", ifd, exec);
 520         return ((result == 4) ? 4 : 0);
 521 }
 522
 523 static int FAST_FUNC v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 524 {
 525         return execute("ip tunnel del %iface%", ifd, exec);
 526 }
 527 # endif
 528
 529 static const struct method_t methods6[] ALIGN_PTR = {
 530 # if ENABLE_FEATURE_IFUPDOWN_IP
 531         { "v4tunnel" , v4tunnel_up     , v4tunnel_down   , },
 532 # endif
 533         { "static"   , static_up6      , static_down6    , },
 534         { "manual"   , manual_up_down6 , manual_up_down6 , },
 535         { "loopback" , loopback_up6    , loopback_down6  , },
 536 };
 537
 538 static const struct address_family_t addr_inet6 = {
 539         "inet6",
 540         ARRAY_SIZE(methods6),
 541         methods6
 542 };
 543
 544 #endif /* FEATURE_IFUPDOWN_IPV6 */
 545
 546
 547 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 548
 549 static int FAST_FUNC loopback_up(struct interface_defn_t *ifd, execfn *exec)
 550 {
 551 # if ENABLE_FEATURE_IFUPDOWN_IP
 552         int result;
 553         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 554         result += execute("ip link set %iface% up", ifd, exec);
 555         return ((result == 2) ? 2 : 0);
 556 # else
 557         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 558 # endif
 559 }
 560
 561 static int FAST_FUNC loopback_down(struct interface_defn_t *ifd, execfn *exec)
 562 {
 563 # if ENABLE_FEATURE_IFUPDOWN_IP
 564         int result;
 565         result = execute("ip addr flush dev %iface%", ifd, exec);
 566         result += execute("ip link set %iface% down", ifd, exec);
 567         return ((result == 2) ? 2 : 0);
 568 # else
 569         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 570 # endif
 571 }
 572
 573 static int FAST_FUNC static_up(struct interface_defn_t *ifd, execfn *exec)
 574 {
 575         int result;
 576 # if ENABLE_FEATURE_IFUPDOWN_IP
 577         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 578                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 579         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 580         result += execute("[[ip route add default via %gateway% dev %iface%[[ metric %metric%]]]]", ifd, exec);
 581         return ((result == 3) ? 3 : 0);
 582 # else
 583         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 584          * which then of course fails. Thus we run two separate ifconfig */
 585         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 586                                 ifd, exec);
 587         result += execute("ifconfig %iface% %address% netmask %netmask%"
 588                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]]",
 589                                 ifd, exec);
 590         result += execute("[[route add default gw %gateway%[[ metric %metric%]] %iface%]]", ifd, exec);
 591         return ((result == 3) ? 3 : 0);
 592 # endif
 593 }
 594
 595 static int FAST_FUNC static_down(struct interface_defn_t *ifd, execfn *exec)
 596 {
 597         int result;
 598
 599         if (!if_nametoindex(ifd->iface))
 600                 return 2; /* already gone */
 601 # if ENABLE_FEATURE_IFUPDOWN_IP
 602         /* Optional "label LBL" is necessary if interface is an alias (eth0:0),
 603          * otherwise "ip addr flush dev eth0:0" flushes all addresses on eth0.
 604          */
 605         result = execute("ip addr flush dev %iface%[[ label %label%]]", ifd, exec);
 606         result += execute("ip link set %iface% down", ifd, exec);
 607 # else
 608         /* result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec); */
 609         /* Bringing the interface down deletes the routes in itself.
 610            Otherwise this fails if we reference 'gateway' when using this from dhcp_down */
 611         result = 1;
 612         result += execute("ifconfig %iface% down", ifd, exec);
 613 # endif
 614         return ((result == 2) ? 2 : 0);
 615 }
 616
 617 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 618 struct dhcp_client_t {
 619         const char *name;
 620         const char *startcmd;
 621         const char *stopcmd;
 622 };
 623
 624 static const struct dhcp_client_t ext_dhcp_clients[] ALIGN_PTR = {
 625         { "dhcpcd",
 626                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %client%]][[ -l %leasetime%]] %iface%",
 627                 "dhcpcd -k %iface%",
 628         },
 629         { "dhclient",
 630                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 631                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 632         },
 633         { "pump",
 634                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 635                 "pump -i %iface% -k",
 636         },
 637         { "udhcpc",
 638                 "udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -x hostname:%hostname%]][[ -c %client%]]"
 639                                 "[[ -s %script%]][[ %udhcpc_opts%]]",
 640                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 641         },
 642 };
 643 # endif /* FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 644
 645 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 646 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 647 {
 648         unsigned i;
 649 #  if ENABLE_FEATURE_IFUPDOWN_IP
 650         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 651         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 652                 return 0;
 653 #  else
 654         /* needed if we have hwaddress on dhcp iface */
 655         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 656                 return 0;
 657 #  endif
 658         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 659                 if (executable_exists(ext_dhcp_clients[i].name))
 660                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 661         }
 662         bb_simple_error_msg("no dhcp clients found");
 663         return 0;
 664 }
 665 # elif ENABLE_UDHCPC
 666 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 667 {
 668 #  if ENABLE_FEATURE_IFUPDOWN_IP
 669         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 670         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 671                 return 0;
 672 #  else
 673         /* needed if we have hwaddress on dhcp iface */
 674         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 675                 return 0;
 676 #  endif
 677         return execute("udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid "
 678                         "-i %iface%[[ -x hostname:%hostname%]][[ -c %client%]][[ -s %script%]][[ %udhcpc_opts%]]",
 679                         ifd, exec);
 680 }
 681 # else
 682 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd UNUSED_PARAM,
 683                 execfn *exec UNUSED_PARAM)
 684 {
 685         return 0; /* no dhcp support */
 686 }
 687 # endif
 688
 689 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 690 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 691 {
 692         int result = 0;
 693         unsigned i;
 694
 695         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 696                 if (executable_exists(ext_dhcp_clients[i].name)) {
 697                         result = execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 698                         if (result)
 699                                 break;
 700                 }
 701         }
 702
 703         if (!result)
 704                 bb_simple_error_msg("warning: no dhcp clients found and stopped");
 705
 706         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 707            and it may come back up because udhcpc is still shutting down */
 708         usleep(100000);
 709         result += static_down(ifd, exec);
 710         return ((result == 3) ? 3 : 0);
 711 }
 712 # elif ENABLE_UDHCPC
 713 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 714 {
 715         int result;
 716         result = execute(
 717                 "test -f /var/run/udhcpc.%iface%.pid && "
 718                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 719                 ifd, exec);
 720         /* Also bring the hardware interface down since
 721            killing the dhcp client alone doesn't do it.
 722            This enables consecutive ifup->ifdown->ifup */
 723         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 724            and it may come back up because udhcpc is still shutting down */
 725         usleep(100000);
 726         result += static_down(ifd, exec);
 727         return ((result == 3) ? 3 : 0);
 728 }
 729 # else
 730 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd UNUSED_PARAM,
 731                 execfn *exec UNUSED_PARAM)
 732 {
 733         return 0; /* no dhcp support */
 734 }
 735 # endif
 736
 737 static int FAST_FUNC manual_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 738 {
 739         return 1;
 740 }
 741
 742 static int FAST_FUNC bootp_up(struct interface_defn_t *ifd, execfn *exec)
 743 {
 744         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 745                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 746                         " --returniffail --serverbcast", ifd, exec);
 747 }
 748
 749 static int FAST_FUNC ppp_up(struct interface_defn_t *ifd, execfn *exec)
 750 {
 751         return execute("pon[[ %provider%]]", ifd, exec);
 752 }
 753
 754 static int FAST_FUNC ppp_down(struct interface_defn_t *ifd, execfn *exec)
 755 {
 756         return execute("poff[[ %provider%]]", ifd, exec);
 757 }
 758
 759 static int FAST_FUNC wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 760 {
 761         return execute("start-stop-daemon --start -x wvdial "
 762                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 763 }
 764
 765 static int FAST_FUNC wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 766 {
 767         return execute("start-stop-daemon --stop -x wvdial "
 768                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 769 }
 770
 771 static const struct method_t methods[] ALIGN_PTR = {
 772         { "manual"  , manual_up_down, manual_up_down, },
 773         { "wvdial"  , wvdial_up     , wvdial_down   , },
 774         { "ppp"     , ppp_up        , ppp_down      , },
 775         { "static"  , static_up     , static_down   , },
 776         { "bootp"   , bootp_up      , static_down   , },
 777         { "dhcp"    , dhcp_up       , dhcp_down     , },
 778         { "loopback", loopback_up   , loopback_down , },
 779 };
 780
 781 static const struct address_family_t addr_inet = {
 782         "inet",
 783         ARRAY_SIZE(methods),
 784         methods
 785 };
 786
 787 #endif  /* FEATURE_IFUPDOWN_IPV4 */
 788
 789 static int FAST_FUNC link_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 790 {
 791         return 1;
 792 }
 793
 794 static const struct method_t link_methods[] ALIGN_PTR = {
 795         { "none", link_up_down, link_up_down }
 796 };
 797
 798 static const struct address_family_t addr_link = {
 799         "link", ARRAY_SIZE(link_methods), link_methods
 800 };
 801
 802 /* Returns pointer to the next word, or NULL.
 803  * In 1st case, advances *buf to the word after this one.
 804  */
 805 static char *next_word(char **buf)
 806 {
 807         unsigned length;
 808         char *word;
 809
 810         /* Skip over leading whitespace */
 811         word = skip_whitespace(*buf);
 812
 813         /* Stop on EOL */
 814         if (*word == '\0')
 815                 return NULL;
 816
 817         /* Find the length of this word (can't be 0) */
 818         length = strcspn(word, " \t\n");
 819
 820         /* Unless we are already at NUL, store NUL and advance */
 821         if (word[length] != '\0')
 822                 word[length++] = '\0';
 823
 824         *buf = skip_whitespace(word + length);
 825
 826         return word;
 827 }
 828
 829 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 830 {
 831         int i;
 832
 833         if (!name)
 834                 return NULL;
 835
 836         for (i = 0; af[i]; i++) {
 837                 if (strcmp(af[i]->name, name) == 0) {
 838                         return af[i];
 839                 }
 840         }
 841         return NULL;
 842 }
 843
 844 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 845 {
 846         int i;
 847
 848         if (!name)
 849                 return NULL;
 850         /* TODO: use index_in_str_array() */
 851         for (i = 0; i < af->n_methods; i++) {
 852                 if (strcmp(af->method[i].name, name) == 0) {
 853                         return &af->method[i];
 854                 }
 855         }
 856         return NULL;
 857 }
 858
 859 static struct interfaces_file_t *read_interfaces(const char *filename, struct interfaces_file_t *defn)
 860 {
 861         /* Let's try to be compatible.
 862          *
 863          * "man 5 interfaces" says:
 864          * Lines starting with "#" are ignored. Note that end-of-line
 865          * comments are NOT supported, comments must be on a line of their own.
 866          * A line may be extended across multiple lines by making
 867          * the last character a backslash.
 868          *
 869          * Seen elsewhere in example config file:
 870          * A first non-blank "#" character makes the rest of the line
 871          * be ignored. Blank lines are ignored. Lines may be indented freely.
 872          * A "\" character at the very end of the line indicates the next line
 873          * should be treated as a continuation of the current one.
 874          *
 875          * Lines  beginning with "source" are used to include stanzas from
 876          * other files, so configuration can be split into many files.
 877          * The word "source" is followed by the path of file to be sourced.
 878          */
 879 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 880         struct mapping_defn_t *currmap = NULL;
 881 #endif
 882         struct interface_defn_t *currif = NULL;
 883         FILE *f;
 884         char *buf;
 885         char *first_word;
 886         char *rest_of_line;
 887         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 888
 889         if (!defn)
 890                 defn = xzalloc(sizeof(*defn));
 891
 892         debug_noise("reading %s file:\n", filename);
 893         f = xfopen_for_read(filename);
 894
 895         while ((buf = xmalloc_fgetline(f)) != NULL) {
 896 #if ENABLE_DESKTOP
 897                 /* Trailing "\" concatenates lines */
 898                 char *p;
 899                 while ((p = last_char_is(buf, '\\')) != NULL) {
 900                         *p = '\0';
 901                         rest_of_line = xmalloc_fgetline(f);
 902                         if (!rest_of_line)
 903                                 break;
 904                         p = xasprintf("%s%s", buf, rest_of_line);
 905                         free(buf);
 906                         free(rest_of_line);
 907                         buf = p;
 908                 }
 909 #endif
 910                 rest_of_line = buf;
 911                 first_word = next_word(&rest_of_line);
 912                 if (!first_word || *first_word == '#') {
 913                         free(buf);
 914                         continue; /* blank/comment line */
 915                 }
 916
 917                 if (strcmp(first_word, "mapping") == 0) {
 918 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 919                         currmap = xzalloc(sizeof(*currmap));
 920
 921                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 922                                 currmap->match = xrealloc_vector(currmap->match, 4, currmap->n_matches);
 923                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
 924                         }
 925                         /*currmap->n_mappings = 0;*/
 926                         /*currmap->mapping = NULL;*/
 927                         /*currmap->script = NULL;*/
 928                         {
 929                                 struct mapping_defn_t **where = &defn->mappings;
 930                                 while (*where != NULL) {
 931                                         where = &(*where)->next;
 932                                 }
 933                                 *where = currmap;
 934                                 /*currmap->next = NULL;*/
 935                         }
 936                         debug_noise("Added mapping\n");
 937 #endif
 938                         currently_processing = MAPPING;
 939                 } else if (strcmp(first_word, "iface") == 0) {
 940                         static const struct address_family_t *const addr_fams[] = {
 941 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 942                                 &addr_inet,
 943 #endif
 944 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 945                                 &addr_inet6,
 946 #endif
 947                                 &addr_link,
 948                                 NULL
 949                         };
 950                         char *iface_name;
 951                         char *address_family_name;
 952                         char *method_name;
 953
 954                         currif = xzalloc(sizeof(*currif));
 955                         iface_name = next_word(&rest_of_line);
 956                         address_family_name = next_word(&rest_of_line);
 957                         method_name = next_word(&rest_of_line);
 958
 959                         if (method_name == NULL)
 960                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 961
 962                         /* ship any trailing whitespace */
 963                         rest_of_line = skip_whitespace(rest_of_line);
 964
 965                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
 966                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 967
 968                         currif->iface = xstrdup(iface_name);
 969
 970                         currif->address_family = get_address_family(addr_fams, address_family_name);
 971                         if (!currif->address_family)
 972                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 973
 974                         currif->method = get_method(currif->address_family, method_name);
 975                         if (!currif->method)
 976                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 977 #if 0
 978 // Allegedly, Debian allows a duplicate definition:
 979 // iface eth0 inet static
 980 //     address 192.168.0.15
 981 //     netmask 255.255.0.0
 982 //     gateway 192.168.0.1
 983 //
 984 // iface eth0 inet static
 985 //     address 10.0.0.1
 986 //     netmask 255.255.255.0
 987 //
 988 // This adds *two* addresses to eth0 (probably requires use of "ip", not "ifconfig"
 989 //
 990                         llist_t *iface_list;
 991                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 992                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 993                                 if ((strcmp(tmp->iface, currif->iface) == 0)
 994                                  && (tmp->address_family == currif->address_family)
 995                                 ) {
 996                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
 997                                 }
 998                         }
 999 #endif
1000                         llist_add_to_end(&(defn->ifaces), (char*)currif);
1001
1002                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
1003                         currently_processing = IFACE;
1004                 } else if (strcmp(first_word, "auto") == 0) {
1005                         while ((first_word = next_word(&rest_of_line)) != NULL) {
1006
1007                                 /* Check the interface isnt already listed */
1008                                 if (llist_find_str(defn->autointerfaces, first_word)) {
1009                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
1010                                 }
1011
1012                                 /* Add the interface to the list */
1013                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
1014                                 debug_noise("\nauto %s\n", first_word);
1015                         }
1016                         currently_processing = NONE;
1017                 } else if (strcmp(first_word, "source") == 0) {
1018                         read_interfaces(next_word(&rest_of_line), defn);
1019                 } else if (is_prefixed_with(first_word, "source-dir")) {
1020                         const char *dirpath;
1021                         DIR *dir;
1022                         struct dirent *entry;
1023
1024                         dirpath = next_word(&rest_of_line);
1025                         dir = xopendir(dirpath);
1026                         while ((entry = readdir(dir)) != NULL) {
1027                                 char *path;
1028                                 if (entry->d_name[0] == '.')
1029                                         continue;
1030                                 path = concat_path_file(dirpath, entry->d_name);
1031                                 read_interfaces(path, defn);
1032                                 free(path);
1033                         }
1034                         closedir(dir);
1035                 } else {
1036                         switch (currently_processing) {
1037                         case IFACE:
1038                                 if (rest_of_line[0] == '\0')
1039                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
1040
1041                                 if (strcmp(first_word, "post-up") == 0)
1042                                         first_word += 5; /* "up" */
1043                                 else if (strcmp(first_word, "pre-down") == 0)
1044                                         first_word += 4; /* "down" */
1045
1046                                 /* If not one of "up", "down",... words... */
1047                                 if (index_in_strings(keywords_up_down, first_word) < 0) {
1048                                         int i;
1049                                         for (i = 0; i < currif->n_options; i++) {
1050                                                 if (strcmp(currif->option[i].name, first_word) == 0)
1051                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
1052                                         }
1053                                 }
1054                                 debug_noise("\t%s=%s\n", first_word, rest_of_line);
1055                                 currif->option = xrealloc_vector(currif->option, 4, currif->n_options);
1056                                 currif->option[currif->n_options].name = xstrdup(first_word);
1057                                 currif->option[currif->n_options].value = xstrdup(rest_of_line);
1058                                 currif->n_options++;
1059                                 break;
1060                         case MAPPING:
1061 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1062                                 if (strcmp(first_word, "script") == 0) {
1063                                         if (currmap->script != NULL)
1064                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
1065                                         currmap->script = xstrdup(next_word(&rest_of_line));
1066                                 } else if (strcmp(first_word, "map") == 0) {
1067                                         currmap->mapping = xrealloc_vector(currmap->mapping, 2, currmap->n_mappings);
1068                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
1069                                         currmap->n_mappings++;
1070                                 } else {
1071                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
1072                                 }
1073 #endif
1074                                 break;
1075                         case NONE:
1076                         default:
1077                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
1078                         }
1079                 }
1080                 free(buf);
1081         } /* while (fgets) */
1082
1083         if (ferror(f) != 0) {
1084                 /* ferror does NOT set errno! */
1085                 bb_error_msg_and_die("%s: I/O error", filename);
1086         }
1087         fclose(f);
1088         debug_noise("\ndone reading %s\n\n", filename);
1089
1090         return defn;
1091 }
1092
1093 static char *setlocalenv(const char *format, const char *name, const char *value)
1094 {
1095         char *result;
1096         char *dst;
1097         char *src;
1098         char c;
1099
1100         result = xasprintf(format, name, value);
1101
1102         for (dst = src = result; (c = *src) != '=' && c; src++) {
1103                 if (c == '-')
1104                         c = '_';
1105                 if (c >= 'a' && c <= 'z')
1106                         c -= ('a' - 'A');
1107                 if (isalnum(c) || c == '_')
1108                         *dst++ = c;
1109         }
1110         overlapping_strcpy(dst, src);
1111
1112         return result;
1113 }
1114
1115 static void set_environ(struct interface_defn_t *iface, const char *mode, const char *opt)
1116 {
1117         int i;
1118         char **pp;
1119
1120         if (G.my_environ != NULL) {
1121                 for (pp = G.my_environ; *pp; pp++) {
1122                         free(*pp);
1123                 }
1124                 free(G.my_environ);
1125         }
1126
1127         /* note: last element will stay NULL: */
1128         G.my_environ = xzalloc(sizeof(char *) * (iface->n_options + 7));
1129         pp = G.my_environ;
1130
1131         for (i = 0; i < iface->n_options; i++) {
1132                 if (index_in_strings(keywords_up_down, iface->option[i].name) >= 0) {
1133                         continue;
1134                 }
1135                 *pp++ = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
1136         }
1137
1138         *pp++ = setlocalenv("%s=%s", "IFACE", iface->iface);
1139         *pp++ = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
1140         *pp++ = setlocalenv("%s=%s", "METHOD", iface->method->name);
1141         *pp++ = setlocalenv("%s=%s", "MODE", mode);
1142         *pp++ = setlocalenv("%s=%s", "PHASE", opt);
1143         if (G.startup_PATH)
1144                 *pp++ = setlocalenv("%s=%s", "PATH", G.startup_PATH);
1145 }
1146
1147 static int doit(char *str)
1148 {
1149         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
1150                 puts(str);
1151         }
1152         if (!(option_mask32 & OPT_no_act)) {
1153                 pid_t child;
1154                 int status;
1155
1156                 fflush_all();
1157                 child = vfork();
1158                 if (child < 0) /* failure */
1159                         return 0;
1160                 if (child == 0) { /* child */
1161                         execle(G.shell, G.shell, "-c", str, (char *) NULL, G.my_environ);
1162                         _exit(127);
1163                 }
1164                 safe_waitpid(child, &status, 0);
1165                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
1166                         return 0;
1167                 }
1168         }
1169         return 1;
1170 }
1171
1172 static int execute_all(struct interface_defn_t *ifd, const char *opt)
1173 {
1174         /* 'opt' is always short, the longest value is "post-down".
1175          * Can use on-stack buffer instead of xasprintf'ed one.
1176          */
1177         char buf[sizeof("run-parts /etc/network/if-%s.d")
1178                 + sizeof("post-down")
1179                 /*paranoia:*/ + 8
1180         ];
1181         int i;
1182
1183         for (i = 0; i < ifd->n_options; i++) {
1184                 if (strcmp(ifd->option[i].name, opt) == 0) {
1185                         if (!doit(ifd->option[i].value)) {
1186                                 return 0;
1187                         }
1188                 }
1189         }
1190
1191         /* Tested on Debian Squeeze: "standard" ifup runs this without
1192          * checking that directory exists. If it doesn't, run-parts
1193          * complains, and this message _is_ annoyingly visible.
1194          * Don't "fix" this (unless newer Debian does).
1195          */
1196         sprintf(buf, "run-parts /etc/network/if-%s.d", opt);
1197         return doit(buf);
1198 }
1199
1200 static int check(char *str)
1201 {
1202         return str != NULL;
1203 }
1204
1205 static int iface_up(struct interface_defn_t *iface)
1206 {
1207         if (!iface->method->up(iface, check)) return -1;
1208         set_environ(iface, "start", "pre-up");
1209         if (!execute_all(iface, "pre-up")) return 0;
1210         if (!iface->method->up(iface, doit)) return 0;
1211         set_environ(iface, "start", "post-up");
1212         if (!execute_all(iface, "up")) return 0;
1213         return 1;
1214 }
1215
1216 static int iface_down(struct interface_defn_t *iface)
1217 {
1218         if (!iface->method->down(iface, check)) return -1;
1219         set_environ(iface, "stop", "pre-down");
1220         if (!execute_all(iface, "down")) return 0;
1221         if (!iface->method->down(iface, doit)) return 0;
1222         set_environ(iface, "stop", "post-down");
1223         if (!execute_all(iface, "post-down")) return 0;
1224         return 1;
1225 }
1226
1227 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1228 static int popen2(FILE **in, FILE **out, char *command, char *param)
1229 {
1230         char *argv[3] = { command, param, NULL };
1231         struct fd_pair infd, outfd;
1232         pid_t pid;
1233
1234         xpiped_pair(infd);
1235         xpiped_pair(outfd);
1236
1237         fflush_all();
1238         pid = xvfork();
1239
1240         if (pid == 0) {
1241                 /* Child */
1242                 /* NB: close _first_, then move fds! */
1243                 close(infd.wr);
1244                 close(outfd.rd);
1245                 xmove_fd(infd.rd, 0);
1246                 xmove_fd(outfd.wr, 1);
1247                 BB_EXECVP_or_die(argv);
1248         }
1249         /* parent */
1250         close(infd.rd);
1251         close(outfd.wr);
1252         *in = xfdopen_for_write(infd.wr);
1253         *out = xfdopen_for_read(outfd.rd);
1254         return pid;
1255 }
1256
1257 static char *run_mapping(char *physical, struct mapping_defn_t *map)
1258 {
1259         FILE *in, *out;
1260         int i, status;
1261         pid_t pid;
1262
1263         char *logical = xstrdup(physical);
1264
1265         /* Run the mapping script. Never fails. */
1266         pid = popen2(&in, &out, map->script, physical);
1267
1268         /* Write mappings to stdin of mapping script. */
1269         for (i = 0; i < map->n_mappings; i++) {
1270                 fprintf(in, "%s\n", map->mapping[i]);
1271         }
1272         fclose(in);
1273         safe_waitpid(pid, &status, 0);
1274
1275         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1276                 /* If the mapping script exited successfully, try to
1277                  * grab a line of output and use that as the name of the
1278                  * logical interface. */
1279                 char *new_logical = xmalloc_fgetline(out);
1280
1281                 if (new_logical) {
1282                         /* If we are able to read a line of output from the script,
1283                          * remove any trailing whitespace and use this value
1284                          * as the name of the logical interface. */
1285                         char *pch = new_logical + strlen(new_logical) - 1;
1286
1287                         while (pch >= new_logical && isspace(*pch))
1288                                 *(pch--) = '\0';
1289
1290                         free(logical);
1291                         logical = new_logical;
1292                 }
1293         }
1294
1295         fclose(out);
1296
1297         return logical;
1298 }
1299 #endif /* FEATURE_IFUPDOWN_MAPPING */
1300
1301 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1302 {
1303         llist_t *search = state_list;
1304
1305         while (search) {
1306                 char *after_iface = is_prefixed_with(search->data, iface);
1307                 if (after_iface
1308                  && *after_iface == '='
1309                 ) {
1310                         return search;
1311                 }
1312                 search = search->link;
1313         }
1314         return NULL;
1315 }
1316
1317 /* read the previous state from the state file */
1318 static llist_t *read_iface_state(void)
1319 {
1320         llist_t *state_list = NULL;
1321         FILE *state_fp = fopen_for_read(IFSTATE_FILE_PATH);
1322
1323         if (state_fp) {
1324                 char *start, *end_ptr;
1325                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1326                         /* We should only need to check for a single character */
1327                         end_ptr = start + strcspn(start, " \t\n");
1328                         *end_ptr = '\0';
1329                         llist_add_to(&state_list, start);
1330                 }
1331                 fclose(state_fp);
1332         }
1333         return state_list;
1334 }
1335
1336 /* read the previous state from the state file */
1337 static FILE *open_new_state_file(void)
1338 {
1339         int fd, flags, cnt;
1340
1341         cnt = 0;
1342         flags = (O_WRONLY | O_CREAT | O_EXCL);
1343         for (;;) {
1344                 fd = open(IFSTATE_FILE_PATH".new", flags, 0666);
1345                 if (fd >= 0)
1346                         break;
1347                 if (errno != EEXIST
1348                  || flags == (O_WRONLY | O_CREAT | O_TRUNC)
1349                 ) {
1350                         bb_perror_msg_and_die("can't open '%s'",
1351                                         IFSTATE_FILE_PATH".new");
1352                 }
1353                 /* Someone else created the .new file */
1354                 if (cnt > 30) {
1355                         /* Waited for 30*30/2 = 450 milliseconds, still EEXIST.
1356                          * Assuming a stale file, rewriting it.
1357                          */
1358                         flags = (O_WRONLY | O_CREAT | O_TRUNC);
1359                         continue;
1360                 }
1361                 msleep(cnt);
1362                 cnt++;
1363         }
1364
1365         return xfdopen_for_write(fd);
1366 }
1367
1368 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1369 int ifupdown_main(int argc UNUSED_PARAM, char **argv)
1370 {
1371         int (*cmds)(struct interface_defn_t *);
1372         struct interfaces_file_t *defn;
1373         llist_t *target_list = NULL;
1374         const char *interfaces = "/etc/network/interfaces";
1375         bool any_failures = 0;
1376
1377         INIT_G();
1378
1379         G.startup_PATH = getenv("PATH");
1380         G.shell = xstrdup(get_shell_name());
1381
1382         if (ENABLE_IFUP
1383          && (!ENABLE_IFDOWN || applet_name[2] == 'u')
1384         ) {
1385                 /* ifup command */
1386                 cmds = iface_up;
1387         } else {
1388                 cmds = iface_down;
1389         }
1390
1391         getopt32(argv, OPTION_STR, &interfaces);
1392         argv += optind;
1393         if (argv[0]) {
1394                 if (DO_ALL) bb_show_usage();
1395         } else {
1396                 if (!DO_ALL) bb_show_usage();
1397         }
1398
1399         defn = read_interfaces(interfaces, NULL);
1400
1401         /* Create a list of interfaces to work on */
1402         if (DO_ALL) {
1403                 target_list = defn->autointerfaces;
1404         } else {
1405                 llist_add_to_end(&target_list, argv[0]);
1406         }
1407
1408         /* Update the interfaces */
1409         while (target_list) {
1410                 llist_t *iface_list;
1411                 struct interface_defn_t *currif;
1412                 char *iface;
1413                 char *liface;
1414                 char *pch;
1415                 bool okay = 0;
1416                 int cmds_ret;
1417                 bool curr_failure = 0;
1418
1419                 iface = xstrdup(target_list->data);
1420                 target_list = target_list->link;
1421
1422                 pch = strchr(iface, '=');
1423                 if (pch) {
1424                         *pch = '\0';
1425                         liface = xstrdup(pch + 1);
1426                 } else {
1427                         liface = xstrdup(iface);
1428                 }
1429
1430                 if (!FORCE) {
1431                         llist_t *state_list = read_iface_state();
1432                         const llist_t *iface_state = find_iface_state(state_list, iface);
1433
1434                         if (cmds == iface_up) {
1435                                 /* ifup */
1436                                 if (iface_state) {
1437                                         bb_error_msg("interface %s already configured", iface);
1438                                         goto next;
1439                                 }
1440                         } else {
1441                                 /* ifdown */
1442                                 if (!iface_state) {
1443                                         bb_error_msg("interface %s not configured", iface);
1444                                         goto next;
1445                                 }
1446                         }
1447                         llist_free(state_list, free);
1448                 }
1449
1450 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1451                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1452                         struct mapping_defn_t *currmap;
1453
1454                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1455                                 int i;
1456                                 for (i = 0; i < currmap->n_matches; i++) {
1457                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1458                                                 continue;
1459                                         if (VERBOSE) {
1460                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1461                                         }
1462                                         liface = run_mapping(iface, currmap);
1463                                         break;
1464                                 }
1465                         }
1466                 }
1467 #endif
1468
1469                 iface_list = defn->ifaces;
1470                 while (iface_list) {
1471                         currif = (struct interface_defn_t *) iface_list->data;
1472                         if (strcmp(liface, currif->iface) == 0) {
1473                                 char *oldiface = currif->iface;
1474
1475                                 okay = 1;
1476                                 currif->iface = iface;
1477
1478                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1479
1480                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1481                                 cmds_ret = cmds(currif);
1482                                 if (cmds_ret == -1) {
1483                                         bb_error_msg("don't have all variables for %s/%s",
1484                                                         liface, currif->address_family->name);
1485                                         any_failures = curr_failure = 1;
1486                                 } else if (cmds_ret == 0) {
1487                                         any_failures = curr_failure = 1;
1488                                 }
1489
1490                                 currif->iface = oldiface;
1491                         }
1492                         iface_list = iface_list->link;
1493                 }
1494                 if (VERBOSE) {
1495                         bb_putchar('\n');
1496                 }
1497
1498                 if (!okay && !FORCE) {
1499                         bb_error_msg("ignoring unknown interface %s", liface);
1500                         any_failures = 1;
1501                 } else if (!NO_ACT) {
1502                         /* update the state file */
1503                         FILE *new_state_fp = open_new_state_file();
1504                         llist_t *state;
1505                         llist_t *state_list = read_iface_state();
1506                         llist_t *iface_state = find_iface_state(state_list, iface);
1507
1508                         if (cmds == iface_up && !curr_failure) {
1509                                 char *newiface = xasprintf("%s=%s", iface, liface);
1510                                 if (!iface_state) {
1511                                         llist_add_to_end(&state_list, newiface);
1512                                 } else {
1513                                         free(iface_state->data);
1514                                         iface_state->data = newiface;
1515                                 }
1516                         } else {
1517                                 /* Remove an interface from state_list */
1518                                 llist_unlink(&state_list, iface_state);
1519                                 free(llist_pop(&iface_state));
1520                         }
1521
1522                         /* Actually write the new state */
1523                         state = state_list;
1524                         while (state) {
1525                                 if (state->data) {
1526                                         fprintf(new_state_fp, "%s\n", state->data);
1527                                 }
1528                                 state = state->link;
1529                         }
1530                         fclose(new_state_fp);
1531                         xrename(IFSTATE_FILE_PATH".new", IFSTATE_FILE_PATH);
1532                         llist_free(state_list, free);
1533                 }
1534  next:
1535                 free(iface);
1536                 free(liface);
1537         }
1538
1539         return any_failures;
1540 }