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:       "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] 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      Print out what would happen, but don't do it"
 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 configuration"
 127 //usage:
 128 //usage:#define ifdown_trivial_usage
 129 //usage:       "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] IFACE..."
 130 //usage:#define ifdown_full_usage "\n\n"
 131 //usage:       "        -a      Deconfigure all interfaces"
 132 //usage:     "\n        -i FILE Use FILE for interface definitions"
 133 //usage:     "\n        -n      Print out what would happen, but don't do it"
 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 deconfiguration"
 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         int result;
 310         struct in_addr ip;
 311         unsigned d;
 312
 313         if (inet_aton(dotted_quad, &ip) == 0)
 314                 return -1; /* malformed dotted IP */
 315         d = ntohl(ip.s_addr); /* IP in host order */
 316         d = ~d; /* 11110000 -> 00001111 */
 317         if (d & (d+1)) /* check that it is in 00001111 form */
 318                 return -1; /* no it is not */
 319         result = 32;
 320         while (d) {
 321                 d >>= 1;
 322                 result--;
 323         }
 324         return result;
 325 }
 326 # endif
 327
 328 static char *parse(const char *command, struct interface_defn_t *ifd)
 329 {
 330         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 331         smallint okay[MAX_OPT_DEPTH] = { 1 };
 332         int opt_depth = 1;
 333         char *result = NULL;
 334
 335         while (*command) {
 336                 switch (*command) {
 337                 default:
 338                         addstr(&result, command, 1);
 339                         command++;
 340                         break;
 341                 case '\\':
 342                         if (command[1])
 343                                 command++;
 344                         addstr(&result, command, 1);
 345                         command++;
 346                         break;
 347                 case '[':
 348                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 349                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 350                                 okay[opt_depth] = 1;
 351                                 opt_depth++;
 352                                 command += 2;
 353                         } else {
 354                                 addstr(&result, command, 1);
 355                                 command++;
 356                         }
 357                         break;
 358                 case ']':
 359                         if (command[1] == ']' && opt_depth > 1) {
 360                                 opt_depth--;
 361                                 if (!okay[opt_depth]) {
 362                                         result[old_pos[opt_depth]] = '\0';
 363                                 }
 364                                 command += 2;
 365                         } else {
 366                                 addstr(&result, command, 1);
 367                                 command++;
 368                         }
 369                         break;
 370                 case '%':
 371                         {
 372                                 char *nextpercent;
 373                                 char *varvalue;
 374
 375                                 command++;
 376                                 nextpercent = strchr(command, '%');
 377                                 if (!nextpercent) {
 378                                         /* Unterminated %var% */
 379                                         free(result);
 380                                         return NULL;
 381                                 }
 382
 383                                 varvalue = get_var(command, nextpercent - command, ifd);
 384
 385                                 if (varvalue) {
 386 # if ENABLE_FEATURE_IFUPDOWN_IP
 387                                         /* "hwaddress <class> <address>":
 388                                          * unlike ifconfig, ip doesnt want <class>
 389                                          * (usually "ether" keyword). Skip it. */
 390                                         if (is_prefixed_with(command, "hwaddress")) {
 391                                                 varvalue = skip_whitespace(skip_non_whitespace(varvalue));
 392                                         }
 393 # endif
 394                                         addstr(&result, varvalue, strlen(varvalue));
 395                                 } else {
 396 # if ENABLE_FEATURE_IFUPDOWN_IP
 397                                         /* Sigh...  Add a special case for 'ip' to convert from
 398                                          * dotted quad to bit count style netmasks.  */
 399                                         if (is_prefixed_with(command, "bnmask")) {
 400                                                 unsigned res;
 401                                                 varvalue = get_var("netmask", 7, ifd);
 402                                                 if (varvalue) {
 403                                                         res = count_netmask_bits(varvalue);
 404                                                         if (res > 0) {
 405                                                                 const char *argument = utoa(res);
 406                                                                 addstr(&result, argument, strlen(argument));
 407                                                                 command = nextpercent + 1;
 408                                                                 break;
 409                                                         }
 410                                                 }
 411                                         }
 412 # endif
 413                                         okay[opt_depth - 1] = 0;
 414                                 }
 415
 416                                 command = nextpercent + 1;
 417                         }
 418                         break;
 419                 }
 420         }
 421
 422         if (opt_depth > 1) {
 423                 /* Unbalanced bracket */
 424                 free(result);
 425                 return NULL;
 426         }
 427
 428         if (!okay[0]) {
 429                 /* Undefined variable and we aren't in a bracket */
 430                 free(result);
 431                 return NULL;
 432         }
 433
 434         return result;
 435 }
 436
 437 /* execute() returns 1 for success and 0 for failure */
 438 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 439 {
 440         char *out;
 441         int ret;
 442
 443         out = parse(command, ifd);
 444         if (!out) {
 445                 /* parse error? */
 446                 return 0;
 447         }
 448         /* out == "": parsed ok but not all needed variables known, skip */
 449         ret = out[0] ? (*exec)(out) : 1;
 450
 451         free(out);
 452         if (ret != 1) {
 453                 return 0;
 454         }
 455         return 1;
 456 }
 457
 458 #endif /* FEATURE_IFUPDOWN_IPV4 || FEATURE_IFUPDOWN_IPV6 */
 459
 460
 461 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 462
 463 static int FAST_FUNC loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 464 {
 465 # if ENABLE_FEATURE_IFUPDOWN_IP
 466         int result;
 467         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 468         result += execute("ip link set %iface% up", ifd, exec);
 469         return ((result == 2) ? 2 : 0);
 470 # else
 471         return execute("ifconfig %iface% add ::1", ifd, exec);
 472 # endif
 473 }
 474
 475 static int FAST_FUNC loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 476 {
 477 # if ENABLE_FEATURE_IFUPDOWN_IP
 478         return execute("ip link set %iface% down", ifd, exec);
 479 # else
 480         return execute("ifconfig %iface% del ::1", ifd, exec);
 481 # endif
 482 }
 483
 484 static int FAST_FUNC manual_up_down6(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 485 {
 486         return 1;
 487 }
 488
 489 static int FAST_FUNC static_up6(struct interface_defn_t *ifd, execfn *exec)
 490 {
 491         int result;
 492 # if ENABLE_FEATURE_IFUPDOWN_IP
 493         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 494         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 495         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 496         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]][[ metric %metric%]]", ifd, exec);
 497 # else
 498         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 499         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 500         result += execute("[[route -A inet6 add ::/0 gw %gateway%[[ metric %metric%]]]]", ifd, exec);
 501 # endif
 502         return ((result == 3) ? 3 : 0);
 503 }
 504
 505 static int FAST_FUNC static_down6(struct interface_defn_t *ifd, execfn *exec)
 506 {
 507         if (!if_nametoindex(ifd->iface))
 508                 return 1; /* already gone */
 509 # if ENABLE_FEATURE_IFUPDOWN_IP
 510         return execute("ip link set %iface% down", ifd, exec);
 511 # else
 512         return execute("ifconfig %iface% down", ifd, exec);
 513 # endif
 514 }
 515
 516 # if ENABLE_FEATURE_IFUPDOWN_IP
 517 static int FAST_FUNC v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 518 {
 519         int result;
 520         result = execute("ip tunnel add %iface% mode sit remote "
 521                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 522         result += execute("ip link set %iface% up", ifd, exec);
 523         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 524         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 525         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]]", ifd, exec);
 526         return ((result == 4) ? 4 : 0);
 527 }
 528
 529 static int FAST_FUNC v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 530 {
 531         return execute("ip tunnel del %iface%", ifd, exec);
 532 }
 533 # endif
 534
 535 static const struct method_t methods6[] = {
 536 # if ENABLE_FEATURE_IFUPDOWN_IP
 537         { "v4tunnel" , v4tunnel_up     , v4tunnel_down   , },
 538 # endif
 539         { "static"   , static_up6      , static_down6    , },
 540         { "manual"   , manual_up_down6 , manual_up_down6 , },
 541         { "loopback" , loopback_up6    , loopback_down6  , },
 542 };
 543
 544 static const struct address_family_t addr_inet6 = {
 545         "inet6",
 546         ARRAY_SIZE(methods6),
 547         methods6
 548 };
 549
 550 #endif /* FEATURE_IFUPDOWN_IPV6 */
 551
 552
 553 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 554
 555 static int FAST_FUNC loopback_up(struct interface_defn_t *ifd, execfn *exec)
 556 {
 557 # if ENABLE_FEATURE_IFUPDOWN_IP
 558         int result;
 559         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 560         result += execute("ip link set %iface% up", ifd, exec);
 561         return ((result == 2) ? 2 : 0);
 562 # else
 563         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 564 # endif
 565 }
 566
 567 static int FAST_FUNC loopback_down(struct interface_defn_t *ifd, execfn *exec)
 568 {
 569 # if ENABLE_FEATURE_IFUPDOWN_IP
 570         int result;
 571         result = execute("ip addr flush dev %iface%", ifd, exec);
 572         result += execute("ip link set %iface% down", ifd, exec);
 573         return ((result == 2) ? 2 : 0);
 574 # else
 575         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 576 # endif
 577 }
 578
 579 static int FAST_FUNC static_up(struct interface_defn_t *ifd, execfn *exec)
 580 {
 581         int result;
 582 # if ENABLE_FEATURE_IFUPDOWN_IP
 583         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 584                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 585         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 586         result += execute("[[ip route add default via %gateway% dev %iface%[[ metric %metric%]]]]", ifd, exec);
 587         return ((result == 3) ? 3 : 0);
 588 # else
 589         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 590          * which then of course fails. Thus we run two separate ifconfig */
 591         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 592                                 ifd, exec);
 593         result += execute("ifconfig %iface% %address% netmask %netmask%"
 594                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]]",
 595                                 ifd, exec);
 596         result += execute("[[route add default gw %gateway%[[ metric %metric%]] %iface%]]", ifd, exec);
 597         return ((result == 3) ? 3 : 0);
 598 # endif
 599 }
 600
 601 static int FAST_FUNC static_down(struct interface_defn_t *ifd, execfn *exec)
 602 {
 603         int result;
 604
 605         if (!if_nametoindex(ifd->iface))
 606                 return 2; /* already gone */
 607 # if ENABLE_FEATURE_IFUPDOWN_IP
 608         /* Optional "label LBL" is necessary if interface is an alias (eth0:0),
 609          * otherwise "ip addr flush dev eth0:0" flushes all addresses on eth0.
 610          */
 611         result = execute("ip addr flush dev %iface%[[ label %label%]]", ifd, exec);
 612         result += execute("ip link set %iface% down", ifd, exec);
 613 # else
 614         /* result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec); */
 615         /* Bringing the interface down deletes the routes in itself.
 616            Otherwise this fails if we reference 'gateway' when using this from dhcp_down */
 617         result = 1;
 618         result += execute("ifconfig %iface% down", ifd, exec);
 619 # endif
 620         return ((result == 2) ? 2 : 0);
 621 }
 622
 623 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 624 struct dhcp_client_t {
 625         const char *name;
 626         const char *startcmd;
 627         const char *stopcmd;
 628 };
 629
 630 static const struct dhcp_client_t ext_dhcp_clients[] = {
 631         { "dhcpcd",
 632                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %client%]][[ -l %leasetime%]] %iface%",
 633                 "dhcpcd -k %iface%",
 634         },
 635         { "dhclient",
 636                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 637                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 638         },
 639         { "pump",
 640                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 641                 "pump -i %iface% -k",
 642         },
 643         { "udhcpc",
 644                 "udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -x hostname:%hostname%]][[ -c %client%]]"
 645                                 "[[ -s %script%]][[ %udhcpc_opts%]]",
 646                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 647         },
 648 };
 649 # endif /* FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 650
 651 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 652 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 653 {
 654         unsigned i;
 655 #  if ENABLE_FEATURE_IFUPDOWN_IP
 656         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 657         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 658                 return 0;
 659 #  else
 660         /* needed if we have hwaddress on dhcp iface */
 661         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 662                 return 0;
 663 #  endif
 664         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 665                 if (executable_exists(ext_dhcp_clients[i].name))
 666                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 667         }
 668         bb_simple_error_msg("no dhcp clients found");
 669         return 0;
 670 }
 671 # elif ENABLE_UDHCPC
 672 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 673 {
 674 #  if ENABLE_FEATURE_IFUPDOWN_IP
 675         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 676         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 677                 return 0;
 678 #  else
 679         /* needed if we have hwaddress on dhcp iface */
 680         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 681                 return 0;
 682 #  endif
 683         return execute("udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid "
 684                         "-i %iface%[[ -x hostname:%hostname%]][[ -c %client%]][[ -s %script%]][[ %udhcpc_opts%]]",
 685                         ifd, exec);
 686 }
 687 # else
 688 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd UNUSED_PARAM,
 689                 execfn *exec UNUSED_PARAM)
 690 {
 691         return 0; /* no dhcp support */
 692 }
 693 # endif
 694
 695 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 696 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 697 {
 698         int result = 0;
 699         unsigned i;
 700
 701         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 702                 if (executable_exists(ext_dhcp_clients[i].name)) {
 703                         result = execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 704                         if (result)
 705                                 break;
 706                 }
 707         }
 708
 709         if (!result)
 710                 bb_simple_error_msg("warning: no dhcp clients found and stopped");
 711
 712         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 713            and it may come back up because udhcpc is still shutting down */
 714         usleep(100000);
 715         result += static_down(ifd, exec);
 716         return ((result == 3) ? 3 : 0);
 717 }
 718 # elif ENABLE_UDHCPC
 719 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 720 {
 721         int result;
 722         result = execute(
 723                 "test -f /var/run/udhcpc.%iface%.pid && "
 724                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 725                 ifd, exec);
 726         /* Also bring the hardware interface down since
 727            killing the dhcp client alone doesn't do it.
 728            This enables consecutive ifup->ifdown->ifup */
 729         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 730            and it may come back up because udhcpc is still shutting down */
 731         usleep(100000);
 732         result += static_down(ifd, exec);
 733         return ((result == 3) ? 3 : 0);
 734 }
 735 # else
 736 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd UNUSED_PARAM,
 737                 execfn *exec UNUSED_PARAM)
 738 {
 739         return 0; /* no dhcp support */
 740 }
 741 # endif
 742
 743 static int FAST_FUNC manual_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 744 {
 745         return 1;
 746 }
 747
 748 static int FAST_FUNC bootp_up(struct interface_defn_t *ifd, execfn *exec)
 749 {
 750         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 751                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 752                         " --returniffail --serverbcast", ifd, exec);
 753 }
 754
 755 static int FAST_FUNC ppp_up(struct interface_defn_t *ifd, execfn *exec)
 756 {
 757         return execute("pon[[ %provider%]]", ifd, exec);
 758 }
 759
 760 static int FAST_FUNC ppp_down(struct interface_defn_t *ifd, execfn *exec)
 761 {
 762         return execute("poff[[ %provider%]]", ifd, exec);
 763 }
 764
 765 static int FAST_FUNC wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 766 {
 767         return execute("start-stop-daemon --start -x wvdial "
 768                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 769 }
 770
 771 static int FAST_FUNC wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 772 {
 773         return execute("start-stop-daemon --stop -x wvdial "
 774                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 775 }
 776
 777 static const struct method_t methods[] = {
 778         { "manual"  , manual_up_down, manual_up_down, },
 779         { "wvdial"  , wvdial_up     , wvdial_down   , },
 780         { "ppp"     , ppp_up        , ppp_down      , },
 781         { "static"  , static_up     , static_down   , },
 782         { "bootp"   , bootp_up      , static_down   , },
 783         { "dhcp"    , dhcp_up       , dhcp_down     , },
 784         { "loopback", loopback_up   , loopback_down , },
 785 };
 786
 787 static const struct address_family_t addr_inet = {
 788         "inet",
 789         ARRAY_SIZE(methods),
 790         methods
 791 };
 792
 793 #endif  /* FEATURE_IFUPDOWN_IPV4 */
 794
 795 static int FAST_FUNC link_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 796 {
 797         return 1;
 798 }
 799
 800 static const struct method_t link_methods[] = {
 801         { "none", link_up_down, link_up_down }
 802 };
 803
 804 static const struct address_family_t addr_link = {
 805         "link", ARRAY_SIZE(link_methods), link_methods
 806 };
 807
 808 /* Returns pointer to the next word, or NULL.
 809  * In 1st case, advances *buf to the word after this one.
 810  */
 811 static char *next_word(char **buf)
 812 {
 813         unsigned length;
 814         char *word;
 815
 816         /* Skip over leading whitespace */
 817         word = skip_whitespace(*buf);
 818
 819         /* Stop on EOL */
 820         if (*word == '\0')
 821                 return NULL;
 822
 823         /* Find the length of this word (can't be 0) */
 824         length = strcspn(word, " \t\n");
 825
 826         /* Unless we are already at NUL, store NUL and advance */
 827         if (word[length] != '\0')
 828                 word[length++] = '\0';
 829
 830         *buf = skip_whitespace(word + length);
 831
 832         return word;
 833 }
 834
 835 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 836 {
 837         int i;
 838
 839         if (!name)
 840                 return NULL;
 841
 842         for (i = 0; af[i]; i++) {
 843                 if (strcmp(af[i]->name, name) == 0) {
 844                         return af[i];
 845                 }
 846         }
 847         return NULL;
 848 }
 849
 850 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 851 {
 852         int i;
 853
 854         if (!name)
 855                 return NULL;
 856         /* TODO: use index_in_str_array() */
 857         for (i = 0; i < af->n_methods; i++) {
 858                 if (strcmp(af->method[i].name, name) == 0) {
 859                         return &af->method[i];
 860                 }
 861         }
 862         return NULL;
 863 }
 864
 865 static struct interfaces_file_t *read_interfaces(const char *filename, struct interfaces_file_t *defn)
 866 {
 867         /* Let's try to be compatible.
 868          *
 869          * "man 5 interfaces" says:
 870          * Lines starting with "#" are ignored. Note that end-of-line
 871          * comments are NOT supported, comments must be on a line of their own.
 872          * A line may be extended across multiple lines by making
 873          * the last character a backslash.
 874          *
 875          * Seen elsewhere in example config file:
 876          * A first non-blank "#" character makes the rest of the line
 877          * be ignored. Blank lines are ignored. Lines may be indented freely.
 878          * A "\" character at the very end of the line indicates the next line
 879          * should be treated as a continuation of the current one.
 880          *
 881          * Lines  beginning with "source" are used to include stanzas from
 882          * other files, so configuration can be split into many files.
 883          * The word "source" is followed by the path of file to be sourced.
 884          */
 885 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 886         struct mapping_defn_t *currmap = NULL;
 887 #endif
 888         struct interface_defn_t *currif = NULL;
 889         FILE *f;
 890         char *buf;
 891         char *first_word;
 892         char *rest_of_line;
 893         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 894
 895         if (!defn)
 896                 defn = xzalloc(sizeof(*defn));
 897
 898         debug_noise("reading %s file:\n", filename);
 899         f = xfopen_for_read(filename);
 900
 901         while ((buf = xmalloc_fgetline(f)) != NULL) {
 902 #if ENABLE_DESKTOP
 903                 /* Trailing "\" concatenates lines */
 904                 char *p;
 905                 while ((p = last_char_is(buf, '\\')) != NULL) {
 906                         *p = '\0';
 907                         rest_of_line = xmalloc_fgetline(f);
 908                         if (!rest_of_line)
 909                                 break;
 910                         p = xasprintf("%s%s", buf, rest_of_line);
 911                         free(buf);
 912                         free(rest_of_line);
 913                         buf = p;
 914                 }
 915 #endif
 916                 rest_of_line = buf;
 917                 first_word = next_word(&rest_of_line);
 918                 if (!first_word || *first_word == '#') {
 919                         free(buf);
 920                         continue; /* blank/comment line */
 921                 }
 922
 923                 if (strcmp(first_word, "mapping") == 0) {
 924 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 925                         currmap = xzalloc(sizeof(*currmap));
 926
 927                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 928                                 currmap->match = xrealloc_vector(currmap->match, 4, currmap->n_matches);
 929                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
 930                         }
 931                         /*currmap->n_mappings = 0;*/
 932                         /*currmap->mapping = NULL;*/
 933                         /*currmap->script = NULL;*/
 934                         {
 935                                 struct mapping_defn_t **where = &defn->mappings;
 936                                 while (*where != NULL) {
 937                                         where = &(*where)->next;
 938                                 }
 939                                 *where = currmap;
 940                                 /*currmap->next = NULL;*/
 941                         }
 942                         debug_noise("Added mapping\n");
 943 #endif
 944                         currently_processing = MAPPING;
 945                 } else if (strcmp(first_word, "iface") == 0) {
 946                         static const struct address_family_t *const addr_fams[] = {
 947 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 948                                 &addr_inet,
 949 #endif
 950 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 951                                 &addr_inet6,
 952 #endif
 953                                 &addr_link,
 954                                 NULL
 955                         };
 956                         char *iface_name;
 957                         char *address_family_name;
 958                         char *method_name;
 959
 960                         currif = xzalloc(sizeof(*currif));
 961                         iface_name = next_word(&rest_of_line);
 962                         address_family_name = next_word(&rest_of_line);
 963                         method_name = next_word(&rest_of_line);
 964
 965                         if (method_name == NULL)
 966                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 967
 968                         /* ship any trailing whitespace */
 969                         rest_of_line = skip_whitespace(rest_of_line);
 970
 971                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
 972                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 973
 974                         currif->iface = xstrdup(iface_name);
 975
 976                         currif->address_family = get_address_family(addr_fams, address_family_name);
 977                         if (!currif->address_family)
 978                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 979
 980                         currif->method = get_method(currif->address_family, method_name);
 981                         if (!currif->method)
 982                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 983 #if 0
 984 // Allegedly, Debian allows a duplicate definition:
 985 // iface eth0 inet static
 986 //     address 192.168.0.15
 987 //     netmask 255.255.0.0
 988 //     gateway 192.168.0.1
 989 //
 990 // iface eth0 inet static
 991 //     address 10.0.0.1
 992 //     netmask 255.255.255.0
 993 //
 994 // This adds *two* addresses to eth0 (probably requires use of "ip", not "ifconfig"
 995 //
 996                         llist_t *iface_list;
 997                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 998                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 999                                 if ((strcmp(tmp->iface, currif->iface) == 0)
1000                                  && (tmp->address_family == currif->address_family)
1001                                 ) {
1002                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
1003                                 }
1004                         }
1005 #endif
1006                         llist_add_to_end(&(defn->ifaces), (char*)currif);
1007
1008                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
1009                         currently_processing = IFACE;
1010                 } else if (strcmp(first_word, "auto") == 0) {
1011                         while ((first_word = next_word(&rest_of_line)) != NULL) {
1012
1013                                 /* Check the interface isnt already listed */
1014                                 if (llist_find_str(defn->autointerfaces, first_word)) {
1015                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
1016                                 }
1017
1018                                 /* Add the interface to the list */
1019                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
1020                                 debug_noise("\nauto %s\n", first_word);
1021                         }
1022                         currently_processing = NONE;
1023                 } else if (strcmp(first_word, "source") == 0) {
1024                         read_interfaces(next_word(&rest_of_line), defn);
1025                 } else if (is_prefixed_with(first_word, "source-dir")) {
1026                         const char *dirpath;
1027                         DIR *dir;
1028                         struct dirent *entry;
1029
1030                         dirpath = next_word(&rest_of_line);
1031                         dir = xopendir(dirpath);
1032                         while ((entry = readdir(dir)) != NULL) {
1033                                 char *path;
1034                                 if (entry->d_name[0] == '.')
1035                                         continue;
1036                                 path = concat_path_file(dirpath, entry->d_name);
1037                                 read_interfaces(path, defn);
1038                                 free(path);
1039                         }
1040                         closedir(dir);
1041                 } else {
1042                         switch (currently_processing) {
1043                         case IFACE:
1044                                 if (rest_of_line[0] == '\0')
1045                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
1046
1047                                 if (strcmp(first_word, "post-up") == 0)
1048                                         first_word += 5; /* "up" */
1049                                 else if (strcmp(first_word, "pre-down") == 0)
1050                                         first_word += 4; /* "down" */
1051
1052                                 /* If not one of "up", "down",... words... */
1053                                 if (index_in_strings(keywords_up_down, first_word) < 0) {
1054                                         int i;
1055                                         for (i = 0; i < currif->n_options; i++) {
1056                                                 if (strcmp(currif->option[i].name, first_word) == 0)
1057                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
1058                                         }
1059                                 }
1060                                 debug_noise("\t%s=%s\n", first_word, rest_of_line);
1061                                 currif->option = xrealloc_vector(currif->option, 4, currif->n_options);
1062                                 currif->option[currif->n_options].name = xstrdup(first_word);
1063                                 currif->option[currif->n_options].value = xstrdup(rest_of_line);
1064                                 currif->n_options++;
1065                                 break;
1066                         case MAPPING:
1067 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1068                                 if (strcmp(first_word, "script") == 0) {
1069                                         if (currmap->script != NULL)
1070                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
1071                                         currmap->script = xstrdup(next_word(&rest_of_line));
1072                                 } else if (strcmp(first_word, "map") == 0) {
1073                                         currmap->mapping = xrealloc_vector(currmap->mapping, 2, currmap->n_mappings);
1074                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
1075                                         currmap->n_mappings++;
1076                                 } else {
1077                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
1078                                 }
1079 #endif
1080                                 break;
1081                         case NONE:
1082                         default:
1083                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
1084                         }
1085                 }
1086                 free(buf);
1087         } /* while (fgets) */
1088
1089         if (ferror(f) != 0) {
1090                 /* ferror does NOT set errno! */
1091                 bb_error_msg_and_die("%s: I/O error", filename);
1092         }
1093         fclose(f);
1094         debug_noise("\ndone reading %s\n\n", filename);
1095
1096         return defn;
1097 }
1098
1099 static char *setlocalenv(const char *format, const char *name, const char *value)
1100 {
1101         char *result;
1102         char *dst;
1103         char *src;
1104         char c;
1105
1106         result = xasprintf(format, name, value);
1107
1108         for (dst = src = result; (c = *src) != '=' && c; src++) {
1109                 if (c == '-')
1110                         c = '_';
1111                 if (c >= 'a' && c <= 'z')
1112                         c -= ('a' - 'A');
1113                 if (isalnum(c) || c == '_')
1114                         *dst++ = c;
1115         }
1116         overlapping_strcpy(dst, src);
1117
1118         return result;
1119 }
1120
1121 static void set_environ(struct interface_defn_t *iface, const char *mode, const char *opt)
1122 {
1123         int i;
1124         char **pp;
1125
1126         if (G.my_environ != NULL) {
1127                 for (pp = G.my_environ; *pp; pp++) {
1128                         free(*pp);
1129                 }
1130                 free(G.my_environ);
1131         }
1132
1133         /* note: last element will stay NULL: */
1134         G.my_environ = xzalloc(sizeof(char *) * (iface->n_options + 7));
1135         pp = G.my_environ;
1136
1137         for (i = 0; i < iface->n_options; i++) {
1138                 if (index_in_strings(keywords_up_down, iface->option[i].name) >= 0) {
1139                         continue;
1140                 }
1141                 *pp++ = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
1142         }
1143
1144         *pp++ = setlocalenv("%s=%s", "IFACE", iface->iface);
1145         *pp++ = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
1146         *pp++ = setlocalenv("%s=%s", "METHOD", iface->method->name);
1147         *pp++ = setlocalenv("%s=%s", "MODE", mode);
1148         *pp++ = setlocalenv("%s=%s", "PHASE", opt);
1149         if (G.startup_PATH)
1150                 *pp++ = setlocalenv("%s=%s", "PATH", G.startup_PATH);
1151 }
1152
1153 static int doit(char *str)
1154 {
1155         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
1156                 puts(str);
1157         }
1158         if (!(option_mask32 & OPT_no_act)) {
1159                 pid_t child;
1160                 int status;
1161
1162                 fflush_all();
1163                 child = vfork();
1164                 if (child < 0) /* failure */
1165                         return 0;
1166                 if (child == 0) { /* child */
1167                         execle(G.shell, G.shell, "-c", str, (char *) NULL, G.my_environ);
1168                         _exit(127);
1169                 }
1170                 safe_waitpid(child, &status, 0);
1171                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
1172                         return 0;
1173                 }
1174         }
1175         return 1;
1176 }
1177
1178 static int execute_all(struct interface_defn_t *ifd, const char *opt)
1179 {
1180         /* 'opt' is always short, the longest value is "post-down".
1181          * Can use on-stack buffer instead of xasprintf'ed one.
1182          */
1183         char buf[sizeof("run-parts /etc/network/if-%s.d")
1184                 + sizeof("post-down")
1185                 /*paranoia:*/ + 8
1186         ];
1187         int i;
1188
1189         for (i = 0; i < ifd->n_options; i++) {
1190                 if (strcmp(ifd->option[i].name, opt) == 0) {
1191                         if (!doit(ifd->option[i].value)) {
1192                                 return 0;
1193                         }
1194                 }
1195         }
1196
1197         /* Tested on Debian Squeeze: "standard" ifup runs this without
1198          * checking that directory exists. If it doesn't, run-parts
1199          * complains, and this message _is_ annoyingly visible.
1200          * Don't "fix" this (unless newer Debian does).
1201          */
1202         sprintf(buf, "run-parts /etc/network/if-%s.d", opt);
1203         return doit(buf);
1204 }
1205
1206 static int check(char *str)
1207 {
1208         return str != NULL;
1209 }
1210
1211 static int iface_up(struct interface_defn_t *iface)
1212 {
1213         if (!iface->method->up(iface, check)) return -1;
1214         set_environ(iface, "start", "pre-up");
1215         if (!execute_all(iface, "pre-up")) return 0;
1216         if (!iface->method->up(iface, doit)) return 0;
1217         set_environ(iface, "start", "post-up");
1218         if (!execute_all(iface, "up")) return 0;
1219         return 1;
1220 }
1221
1222 static int iface_down(struct interface_defn_t *iface)
1223 {
1224         if (!iface->method->down(iface, check)) return -1;
1225         set_environ(iface, "stop", "pre-down");
1226         if (!execute_all(iface, "down")) return 0;
1227         if (!iface->method->down(iface, doit)) return 0;
1228         set_environ(iface, "stop", "post-down");
1229         if (!execute_all(iface, "post-down")) return 0;
1230         return 1;
1231 }
1232
1233 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1234 static int popen2(FILE **in, FILE **out, char *command, char *param)
1235 {
1236         char *argv[3] = { command, param, NULL };
1237         struct fd_pair infd, outfd;
1238         pid_t pid;
1239
1240         xpiped_pair(infd);
1241         xpiped_pair(outfd);
1242
1243         fflush_all();
1244         pid = xvfork();
1245
1246         if (pid == 0) {
1247                 /* Child */
1248                 /* NB: close _first_, then move fds! */
1249                 close(infd.wr);
1250                 close(outfd.rd);
1251                 xmove_fd(infd.rd, 0);
1252                 xmove_fd(outfd.wr, 1);
1253                 BB_EXECVP_or_die(argv);
1254         }
1255         /* parent */
1256         close(infd.rd);
1257         close(outfd.wr);
1258         *in = xfdopen_for_write(infd.wr);
1259         *out = xfdopen_for_read(outfd.rd);
1260         return pid;
1261 }
1262
1263 static char *run_mapping(char *physical, struct mapping_defn_t *map)
1264 {
1265         FILE *in, *out;
1266         int i, status;
1267         pid_t pid;
1268
1269         char *logical = xstrdup(physical);
1270
1271         /* Run the mapping script. Never fails. */
1272         pid = popen2(&in, &out, map->script, physical);
1273
1274         /* Write mappings to stdin of mapping script. */
1275         for (i = 0; i < map->n_mappings; i++) {
1276                 fprintf(in, "%s\n", map->mapping[i]);
1277         }
1278         fclose(in);
1279         safe_waitpid(pid, &status, 0);
1280
1281         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1282                 /* If the mapping script exited successfully, try to
1283                  * grab a line of output and use that as the name of the
1284                  * logical interface. */
1285                 char *new_logical = xmalloc_fgetline(out);
1286
1287                 if (new_logical) {
1288                         /* If we are able to read a line of output from the script,
1289                          * remove any trailing whitespace and use this value
1290                          * as the name of the logical interface. */
1291                         char *pch = new_logical + strlen(new_logical) - 1;
1292
1293                         while (pch >= new_logical && isspace(*pch))
1294                                 *(pch--) = '\0';
1295
1296                         free(logical);
1297                         logical = new_logical;
1298                 }
1299         }
1300
1301         fclose(out);
1302
1303         return logical;
1304 }
1305 #endif /* FEATURE_IFUPDOWN_MAPPING */
1306
1307 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1308 {
1309         llist_t *search = state_list;
1310
1311         while (search) {
1312                 char *after_iface = is_prefixed_with(search->data, iface);
1313                 if (after_iface
1314                  && *after_iface == '='
1315                 ) {
1316                         return search;
1317                 }
1318                 search = search->link;
1319         }
1320         return NULL;
1321 }
1322
1323 /* read the previous state from the state file */
1324 static llist_t *read_iface_state(void)
1325 {
1326         llist_t *state_list = NULL;
1327         FILE *state_fp = fopen_for_read(IFSTATE_FILE_PATH);
1328
1329         if (state_fp) {
1330                 char *start, *end_ptr;
1331                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1332                         /* We should only need to check for a single character */
1333                         end_ptr = start + strcspn(start, " \t\n");
1334                         *end_ptr = '\0';
1335                         llist_add_to(&state_list, start);
1336                 }
1337                 fclose(state_fp);
1338         }
1339         return state_list;
1340 }
1341
1342 /* read the previous state from the state file */
1343 static FILE *open_new_state_file(void)
1344 {
1345         int fd, flags, cnt;
1346
1347         cnt = 0;
1348         flags = (O_WRONLY | O_CREAT | O_EXCL);
1349         for (;;) {
1350                 fd = open(IFSTATE_FILE_PATH".new", flags, 0666);
1351                 if (fd >= 0)
1352                         break;
1353                 if (errno != EEXIST
1354                  || flags == (O_WRONLY | O_CREAT | O_TRUNC)
1355                 ) {
1356                         bb_perror_msg_and_die("can't open '%s'",
1357                                         IFSTATE_FILE_PATH".new");
1358                 }
1359                 /* Someone else created the .new file */
1360                 if (cnt > 30 * 1000) {
1361                         /* Waited for 30*30/2 = 450 milliseconds, still EEXIST.
1362                          * Assuming a stale file, rewriting it.
1363                          */
1364                         flags = (O_WRONLY | O_CREAT | O_TRUNC);
1365                         continue;
1366                 }
1367                 usleep(cnt);
1368                 cnt += 1000;
1369         }
1370
1371         return xfdopen_for_write(fd);
1372 }
1373
1374 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1375 int ifupdown_main(int argc UNUSED_PARAM, char **argv)
1376 {
1377         int (*cmds)(struct interface_defn_t *);
1378         struct interfaces_file_t *defn;
1379         llist_t *target_list = NULL;
1380         const char *interfaces = "/etc/network/interfaces";
1381         bool any_failures = 0;
1382
1383         INIT_G();
1384
1385         G.startup_PATH = getenv("PATH");
1386         G.shell = xstrdup(get_shell_name());
1387
1388         if (ENABLE_IFUP
1389          && (!ENABLE_IFDOWN || applet_name[2] == 'u')
1390         ) {
1391                 /* ifup command */
1392                 cmds = iface_up;
1393         } else {
1394                 cmds = iface_down;
1395         }
1396
1397         getopt32(argv, OPTION_STR, &interfaces);
1398         argv += optind;
1399         if (argv[0]) {
1400                 if (DO_ALL) bb_show_usage();
1401         } else {
1402                 if (!DO_ALL) bb_show_usage();
1403         }
1404
1405         defn = read_interfaces(interfaces, NULL);
1406
1407         /* Create a list of interfaces to work on */
1408         if (DO_ALL) {
1409                 target_list = defn->autointerfaces;
1410         } else {
1411                 llist_add_to_end(&target_list, argv[0]);
1412         }
1413
1414         /* Update the interfaces */
1415         while (target_list) {
1416                 llist_t *iface_list;
1417                 struct interface_defn_t *currif;
1418                 char *iface;
1419                 char *liface;
1420                 char *pch;
1421                 bool okay = 0;
1422                 int cmds_ret;
1423                 bool curr_failure = 0;
1424
1425                 iface = xstrdup(target_list->data);
1426                 target_list = target_list->link;
1427
1428                 pch = strchr(iface, '=');
1429                 if (pch) {
1430                         *pch = '\0';
1431                         liface = xstrdup(pch + 1);
1432                 } else {
1433                         liface = xstrdup(iface);
1434                 }
1435
1436                 if (!FORCE) {
1437                         llist_t *state_list = read_iface_state();
1438                         const llist_t *iface_state = find_iface_state(state_list, iface);
1439
1440                         if (cmds == iface_up) {
1441                                 /* ifup */
1442                                 if (iface_state) {
1443                                         bb_error_msg("interface %s already configured", iface);
1444                                         goto next;
1445                                 }
1446                         } else {
1447                                 /* ifdown */
1448                                 if (!iface_state) {
1449                                         bb_error_msg("interface %s not configured", iface);
1450                                         goto next;
1451                                 }
1452                         }
1453                         llist_free(state_list, free);
1454                 }
1455
1456 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1457                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1458                         struct mapping_defn_t *currmap;
1459
1460                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1461                                 int i;
1462                                 for (i = 0; i < currmap->n_matches; i++) {
1463                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1464                                                 continue;
1465                                         if (VERBOSE) {
1466                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1467                                         }
1468                                         liface = run_mapping(iface, currmap);
1469                                         break;
1470                                 }
1471                         }
1472                 }
1473 #endif
1474
1475                 iface_list = defn->ifaces;
1476                 while (iface_list) {
1477                         currif = (struct interface_defn_t *) iface_list->data;
1478                         if (strcmp(liface, currif->iface) == 0) {
1479                                 char *oldiface = currif->iface;
1480
1481                                 okay = 1;
1482                                 currif->iface = iface;
1483
1484                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1485
1486                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1487                                 cmds_ret = cmds(currif);
1488                                 if (cmds_ret == -1) {
1489                                         bb_error_msg("don't have all variables for %s/%s",
1490                                                         liface, currif->address_family->name);
1491                                         any_failures = curr_failure = 1;
1492                                 } else if (cmds_ret == 0) {
1493                                         any_failures = curr_failure = 1;
1494                                 }
1495
1496                                 currif->iface = oldiface;
1497                         }
1498                         iface_list = iface_list->link;
1499                 }
1500                 if (VERBOSE) {
1501                         bb_putchar('\n');
1502                 }
1503
1504                 if (!okay && !FORCE) {
1505                         bb_error_msg("ignoring unknown interface %s", liface);
1506                         any_failures = 1;
1507                 } else if (!NO_ACT) {
1508                         /* update the state file */
1509                         FILE *new_state_fp = open_new_state_file();
1510                         llist_t *state;
1511                         llist_t *state_list = read_iface_state();
1512                         llist_t *iface_state = find_iface_state(state_list, iface);
1513
1514                         if (cmds == iface_up && !curr_failure) {
1515                                 char *newiface = xasprintf("%s=%s", iface, liface);
1516                                 if (!iface_state) {
1517                                         llist_add_to_end(&state_list, newiface);
1518                                 } else {
1519                                         free(iface_state->data);
1520                                         iface_state->data = newiface;
1521                                 }
1522                         } else {
1523                                 /* Remove an interface from state_list */
1524                                 llist_unlink(&state_list, iface_state);
1525                                 free(llist_pop(&iface_state));
1526                         }
1527
1528                         /* Actually write the new state */
1529                         state = state_list;
1530                         while (state) {
1531                                 if (state->data) {
1532                                         fprintf(new_state_fp, "%s\n", state->data);
1533                                 }
1534                                 state = state->link;
1535                         }
1536                         fclose(new_state_fp);
1537                         xrename(IFSTATE_FILE_PATH".new", IFSTATE_FILE_PATH);
1538                         llist_free(state_list, free);
1539                 }
1540  next:
1541                 free(iface);
1542                 free(liface);
1543         }
1544
1545         return any_failures;
1546 }