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
  20 //config:config IFUP
  21 //config:       bool "ifup"
  22 //config:       default y
  23 //config:       help
  24 //config:         Activate the specified interfaces. This applet makes use
  25 //config:         of either "ifconfig" and "route" or the "ip" command to actually
  26 //config:         configure network interfaces. Therefore, you will probably also want
  27 //config:         to enable either IFCONFIG and ROUTE, or enable
  28 //config:         FEATURE_IFUPDOWN_IP and the various IP options. Of
  29 //config:         course you could use non-busybox versions of these programs, so
  30 //config:         against my better judgement (since this will surely result in plenty
  31 //config:         of support questions on the mailing list), I do not force you to
  32 //config:         enable these additional options. It is up to you to supply either
  33 //config:         "ifconfig", "route" and "run-parts" or the "ip" command, either
  34 //config:         via busybox or via standalone utilities.
  35 //config:
  36 //config:config IFDOWN
  37 //config:       bool "ifdown"
  38 //config:       default y
  39 //config:       help
  40 //config:         Deactivate the specified interfaces.
  41 //config:
  42 //config:config IFUPDOWN_IFSTATE_PATH
  43 //config:       string "Absolute path to ifstate file"
  44 //config:       default "/var/run/ifstate"
  45 //config:       depends on IFUP || IFDOWN
  46 //config:       help
  47 //config:         ifupdown keeps state information in a file called ifstate.
  48 //config:         Typically it is located in /var/run/ifstate, however
  49 //config:         some distributions tend to put it in other places
  50 //config:         (debian, for example, uses /etc/network/run/ifstate).
  51 //config:         This config option defines location of ifstate.
  52 //config:
  53 //config:config FEATURE_IFUPDOWN_IP
  54 //config:       bool "Use ip applet"
  55 //config:       default y
  56 //config:       depends on IFUP || IFDOWN
  57 //config:       help
  58 //config:         Use the iproute "ip" command to implement "ifup" and "ifdown", rather
  59 //config:         than the default of using the older 'ifconfig' and 'route' utilities.
  60 //config:
  61 //config:config FEATURE_IFUPDOWN_IP_BUILTIN
  62 //config:       bool "Use busybox ip applet"
  63 //config:       default y
  64 //config:       depends on FEATURE_IFUPDOWN_IP
  65 //config:       select PLATFORM_LINUX
  66 //config:       select IP
  67 //config:       select FEATURE_IP_ADDRESS
  68 //config:       select FEATURE_IP_LINK
  69 //config:       select FEATURE_IP_ROUTE
  70 //config:       help
  71 //config:         Use the busybox iproute "ip" applet to implement "ifupdown".
  72 //config:
  73 //config:         If left disabled, you must install the full-blown iproute2
  74 //config:         utility or the  "ifup" and "ifdown" applets will not work.
  75 //config:
  76 //config:config FEATURE_IFUPDOWN_IFCONFIG_BUILTIN
  77 //config:       bool "Use busybox ifconfig and route applets"
  78 //config:       default n
  79 //config:       depends on (IFUP || IFDOWN) && !FEATURE_IFUPDOWN_IP
  80 //config:       select IFCONFIG
  81 //config:       select ROUTE
  82 //config:       help
  83 //config:         Use the busybox iproute "ifconfig" and "route" applets to
  84 //config:         implement the "ifup" and "ifdown" utilities.
  85 //config:
  86 //config:         If left disabled, you must install the full-blown ifconfig
  87 //config:         and route utilities, or the  "ifup" and "ifdown" applets will not
  88 //config:         work.
  89 //config:
  90 //config:config FEATURE_IFUPDOWN_IPV4
  91 //config:       bool "Support for IPv4"
  92 //config:       default y
  93 //config:       depends on IFUP || IFDOWN
  94 //config:       help
  95 //config:         If you want ifup/ifdown to talk IPv4, leave this on.
  96 //config:
  97 //config:config FEATURE_IFUPDOWN_IPV6
  98 //config:       bool "Support for IPv6"
  99 //config:       default y
 100 //config:       depends on (IFUP || IFDOWN) && FEATURE_IPV6
 101 //config:       help
 102 //config:         If you need support for IPv6, turn this option on.
 103 //config:
 104 //UNUSED:
 105 ////////:config FEATURE_IFUPDOWN_IPX
 106 ////////:       bool "Support for IPX"
 107 ////////:       default y
 108 ////////:       depends on IFUP || IFDOWN
 109 ////////:       help
 110 ////////:         If this option is selected you can use busybox to work with IPX
 111 ////////:         networks.
 112 //config:
 113 //config:config FEATURE_IFUPDOWN_MAPPING
 114 //config:       bool "Enable mapping support"
 115 //config:       default y
 116 //config:       depends on IFUP || IFDOWN
 117 //config:       help
 118 //config:         This enables support for the "mapping" stanza, unless you have
 119 //config:         a weird network setup you don't need it.
 120 //config:
 121 //config:config FEATURE_IFUPDOWN_EXTERNAL_DHCP
 122 //config:       bool "Support for external dhcp clients"
 123 //config:       default n
 124 //config:       depends on IFUP || IFDOWN
 125 //config:       help
 126 //config:         This enables support for the external dhcp clients. Clients are
 127 //config:         tried in the following order: dhcpcd, dhclient, pump and udhcpc.
 128 //config:         Otherwise, if udhcpc applet is enabled, it is used.
 129 //config:         Otherwise, ifup/ifdown will have no support for DHCP.
 130
 131 //applet:IF_IFUP(APPLET_ODDNAME(ifup, ifupdown, BB_DIR_SBIN, BB_SUID_DROP, ifup))
 132 //applet:IF_IFDOWN(APPLET_ODDNAME(ifdown, ifupdown, BB_DIR_SBIN, BB_SUID_DROP, ifdown))
 133
 134 //kbuild:lib-$(CONFIG_IFUP) += ifupdown.o
 135 //kbuild:lib-$(CONFIG_IFDOWN) += ifupdown.o
 136
 137 //usage:#define ifup_trivial_usage
 138 //usage:       "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] IFACE..."
 139 //usage:#define ifup_full_usage "\n\n"
 140 //usage:       "        -a      Configure all interfaces"
 141 //usage:     "\n        -i FILE Use FILE instead of /etc/network/interfaces"
 142 //usage:     "\n        -n      Print out what would happen, but don't do it"
 143 //usage:        IF_FEATURE_IFUPDOWN_MAPPING(
 144 //usage:     "\n                (note: doesn't disable mappings)"
 145 //usage:     "\n        -m      Don't run any mappings"
 146 //usage:        )
 147 //usage:     "\n        -v      Print out what would happen before doing it"
 148 //usage:     "\n        -f      Force configuration"
 149 //usage:
 150 //usage:#define ifdown_trivial_usage
 151 //usage:       "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] IFACE..."
 152 //usage:#define ifdown_full_usage "\n\n"
 153 //usage:       "        -a      Deconfigure all interfaces"
 154 //usage:     "\n        -i FILE Use FILE for interface definitions"
 155 //usage:     "\n        -n      Print out what would happen, but don't do it"
 156 //usage:        IF_FEATURE_IFUPDOWN_MAPPING(
 157 //usage:     "\n                (note: doesn't disable mappings)"
 158 //usage:     "\n        -m      Don't run any mappings"
 159 //usage:        )
 160 //usage:     "\n        -v      Print out what would happen before doing it"
 161 //usage:     "\n        -f      Force deconfiguration"
 162
 163 #include "libbb.h"
 164 #include "common_bufsiz.h"
 165 /* After libbb.h, since it needs sys/types.h on some systems */
 166 #include <sys/utsname.h>
 167 #include <fnmatch.h>
 168
 169 #define MAX_OPT_DEPTH 10
 170
 171 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 172 #define MAX_INTERFACE_LENGTH 10
 173 #endif
 174
 175 #define UDHCPC_CMD_OPTIONS CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS
 176 #define IFSTATE_FILE_PATH  CONFIG_IFUPDOWN_IFSTATE_PATH
 177
 178 #define debug_noise(args...) /*fprintf(stderr, args)*/
 179
 180 /* Forward declaration */
 181 struct interface_defn_t;
 182
 183 typedef int execfn(char *command);
 184
 185 struct method_t {
 186         const char *name;
 187         int (*up)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
 188         int (*down)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
 189 };
 190
 191 struct address_family_t {
 192         const char *name;
 193         int n_methods;
 194         const struct method_t *method;
 195 };
 196
 197 struct mapping_defn_t {
 198         struct mapping_defn_t *next;
 199
 200         int max_matches;
 201         int n_matches;
 202         char **match;
 203
 204         char *script;
 205
 206         int n_mappings;
 207         char **mapping;
 208 };
 209
 210 struct variable_t {
 211         char *name;
 212         char *value;
 213 };
 214
 215 struct interface_defn_t {
 216         const struct address_family_t *address_family;
 217         const struct method_t *method;
 218
 219         char *iface;
 220         int n_options;
 221         struct variable_t *option;
 222 };
 223
 224 struct interfaces_file_t {
 225         llist_t *autointerfaces;
 226         llist_t *ifaces;
 227         struct mapping_defn_t *mappings;
 228 };
 229
 230
 231 #define OPTION_STR "anvf" IF_FEATURE_IFUPDOWN_MAPPING("m") "i:"
 232 enum {
 233         OPT_do_all      = 0x1,
 234         OPT_no_act      = 0x2,
 235         OPT_verbose     = 0x4,
 236         OPT_force       = 0x8,
 237         OPT_no_mappings = 0x10,
 238 };
 239 #define DO_ALL      (option_mask32 & OPT_do_all)
 240 #define NO_ACT      (option_mask32 & OPT_no_act)
 241 #define VERBOSE     (option_mask32 & OPT_verbose)
 242 #define FORCE       (option_mask32 & OPT_force)
 243 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 244
 245
 246 struct globals {
 247         char **my_environ;
 248         const char *startup_PATH;
 249         char *shell;
 250 } FIX_ALIASING;
 251 #define G (*(struct globals*)bb_common_bufsiz1)
 252 #define INIT_G() do { setup_common_bufsiz(); } while (0)
 253
 254
 255 static const char keywords_up_down[] ALIGN1 =
 256         "up\0"
 257         "down\0"
 258         "pre-up\0"
 259         "post-down\0"
 260 ;
 261
 262
 263 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 264
 265 static void addstr(char **bufp, const char *str, size_t str_length)
 266 {
 267         /* xasprintf trick will be smaller, but we are often
 268          * called with str_length == 1 - don't want to have
 269          * THAT much of malloc/freeing! */
 270         char *buf = *bufp;
 271         int len = (buf ? strlen(buf) : 0);
 272         str_length++;
 273         buf = xrealloc(buf, len + str_length);
 274         /* copies at most str_length-1 chars! */
 275         safe_strncpy(buf + len, str, str_length);
 276         *bufp = buf;
 277 }
 278
 279 static int strncmpz(const char *l, const char *r, size_t llen)
 280 {
 281         int i = strncmp(l, r, llen);
 282
 283         if (i == 0)
 284                 return - (unsigned char)r[llen];
 285         return i;
 286 }
 287
 288 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 289 {
 290         int i;
 291
 292         if (strncmpz(id, "iface", idlen) == 0) {
 293                 // ubuntu's ifup doesn't do this:
 294                 //static char *label_buf;
 295                 //char *result;
 296                 //free(label_buf);
 297                 //label_buf = xstrdup(ifd->iface);
 298                 // Remove virtual iface suffix
 299                 //result = strchrnul(label_buf, ':');
 300                 //*result = '\0';
 301                 //return label_buf;
 302
 303                 return ifd->iface;
 304         }
 305         if (strncmpz(id, "label", idlen) == 0) {
 306                 return ifd->iface;
 307         }
 308         for (i = 0; i < ifd->n_options; i++) {
 309                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 310                         return ifd->option[i].value;
 311                 }
 312         }
 313         return NULL;
 314 }
 315
 316 # if ENABLE_FEATURE_IFUPDOWN_IP
 317 static int count_netmask_bits(const char *dotted_quad)
 318 {
 319 //      int result;
 320 //      unsigned a, b, c, d;
 321 //      /* Found a netmask...  Check if it is dotted quad */
 322 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 323 //              return -1;
 324 //      if ((a|b|c|d) >> 8)
 325 //              return -1; /* one of numbers is >= 256 */
 326 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 327 //      d = ~d; /* 11110000 -> 00001111 */
 328
 329         /* Shorter version */
 330         int result;
 331         struct in_addr ip;
 332         unsigned d;
 333
 334         if (inet_aton(dotted_quad, &ip) == 0)
 335                 return -1; /* malformed dotted IP */
 336         d = ntohl(ip.s_addr); /* IP in host order */
 337         d = ~d; /* 11110000 -> 00001111 */
 338         if (d & (d+1)) /* check that it is in 00001111 form */
 339                 return -1; /* no it is not */
 340         result = 32;
 341         while (d) {
 342                 d >>= 1;
 343                 result--;
 344         }
 345         return result;
 346 }
 347 # endif
 348
 349 static char *parse(const char *command, struct interface_defn_t *ifd)
 350 {
 351         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 352         smallint okay[MAX_OPT_DEPTH] = { 1 };
 353         int opt_depth = 1;
 354         char *result = NULL;
 355
 356         while (*command) {
 357                 switch (*command) {
 358                 default:
 359                         addstr(&result, command, 1);
 360                         command++;
 361                         break;
 362                 case '\\':
 363                         if (command[1])
 364                                 command++;
 365                         addstr(&result, command, 1);
 366                         command++;
 367                         break;
 368                 case '[':
 369                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 370                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 371                                 okay[opt_depth] = 1;
 372                                 opt_depth++;
 373                                 command += 2;
 374                         } else {
 375                                 addstr(&result, command, 1);
 376                                 command++;
 377                         }
 378                         break;
 379                 case ']':
 380                         if (command[1] == ']' && opt_depth > 1) {
 381                                 opt_depth--;
 382                                 if (!okay[opt_depth]) {
 383                                         result[old_pos[opt_depth]] = '\0';
 384                                 }
 385                                 command += 2;
 386                         } else {
 387                                 addstr(&result, command, 1);
 388                                 command++;
 389                         }
 390                         break;
 391                 case '%':
 392                         {
 393                                 char *nextpercent;
 394                                 char *varvalue;
 395
 396                                 command++;
 397                                 nextpercent = strchr(command, '%');
 398                                 if (!nextpercent) {
 399                                         /* Unterminated %var% */
 400                                         free(result);
 401                                         return NULL;
 402                                 }
 403
 404                                 varvalue = get_var(command, nextpercent - command, ifd);
 405
 406                                 if (varvalue) {
 407 # if ENABLE_FEATURE_IFUPDOWN_IP
 408                                         /* "hwaddress <class> <address>":
 409                                          * unlike ifconfig, ip doesnt want <class>
 410                                          * (usually "ether" keyword). Skip it. */
 411                                         if (is_prefixed_with(command, "hwaddress")) {
 412                                                 varvalue = skip_whitespace(skip_non_whitespace(varvalue));
 413                                         }
 414 # endif
 415                                         addstr(&result, varvalue, strlen(varvalue));
 416                                 } else {
 417 # if ENABLE_FEATURE_IFUPDOWN_IP
 418                                         /* Sigh...  Add a special case for 'ip' to convert from
 419                                          * dotted quad to bit count style netmasks.  */
 420                                         if (is_prefixed_with(command, "bnmask")) {
 421                                                 unsigned res;
 422                                                 varvalue = get_var("netmask", 7, ifd);
 423                                                 if (varvalue) {
 424                                                         res = count_netmask_bits(varvalue);
 425                                                         if (res > 0) {
 426                                                                 const char *argument = utoa(res);
 427                                                                 addstr(&result, argument, strlen(argument));
 428                                                                 command = nextpercent + 1;
 429                                                                 break;
 430                                                         }
 431                                                 }
 432                                         }
 433 # endif
 434                                         okay[opt_depth - 1] = 0;
 435                                 }
 436
 437                                 command = nextpercent + 1;
 438                         }
 439                         break;
 440                 }
 441         }
 442
 443         if (opt_depth > 1) {
 444                 /* Unbalanced bracket */
 445                 free(result);
 446                 return NULL;
 447         }
 448
 449         if (!okay[0]) {
 450                 /* Undefined variable and we aren't in a bracket */
 451                 free(result);
 452                 return NULL;
 453         }
 454
 455         return result;
 456 }
 457
 458 /* execute() returns 1 for success and 0 for failure */
 459 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 460 {
 461         char *out;
 462         int ret;
 463
 464         out = parse(command, ifd);
 465         if (!out) {
 466                 /* parse error? */
 467                 return 0;
 468         }
 469         /* out == "": parsed ok but not all needed variables known, skip */
 470         ret = out[0] ? (*exec)(out) : 1;
 471
 472         free(out);
 473         if (ret != 1) {
 474                 return 0;
 475         }
 476         return 1;
 477 }
 478
 479 #endif /* FEATURE_IFUPDOWN_IPV4 || FEATURE_IFUPDOWN_IPV6 */
 480
 481
 482 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 483
 484 static int FAST_FUNC loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 485 {
 486 # if ENABLE_FEATURE_IFUPDOWN_IP
 487         int result;
 488         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 489         result += execute("ip link set %iface% up", ifd, exec);
 490         return ((result == 2) ? 2 : 0);
 491 # else
 492         return execute("ifconfig %iface% add ::1", ifd, exec);
 493 # endif
 494 }
 495
 496 static int FAST_FUNC loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 497 {
 498 # if ENABLE_FEATURE_IFUPDOWN_IP
 499         return execute("ip link set %iface% down", ifd, exec);
 500 # else
 501         return execute("ifconfig %iface% del ::1", ifd, exec);
 502 # endif
 503 }
 504
 505 static int FAST_FUNC manual_up_down6(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 506 {
 507         return 1;
 508 }
 509
 510 static int FAST_FUNC static_up6(struct interface_defn_t *ifd, execfn *exec)
 511 {
 512         int result;
 513 # if ENABLE_FEATURE_IFUPDOWN_IP
 514         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 515         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 516         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 517         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]][[ metric %metric%]]", ifd, exec);
 518 # else
 519         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 520         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 521         result += execute("[[route -A inet6 add ::/0 gw %gateway%[[ metric %metric%]]]]", ifd, exec);
 522 # endif
 523         return ((result == 3) ? 3 : 0);
 524 }
 525
 526 static int FAST_FUNC static_down6(struct interface_defn_t *ifd, execfn *exec)
 527 {
 528 # if ENABLE_FEATURE_IFUPDOWN_IP
 529         return execute("ip link set %iface% down", ifd, exec);
 530 # else
 531         return execute("ifconfig %iface% down", ifd, exec);
 532 # endif
 533 }
 534
 535 # if ENABLE_FEATURE_IFUPDOWN_IP
 536 static int FAST_FUNC v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 537 {
 538         int result;
 539         result = execute("ip tunnel add %iface% mode sit remote "
 540                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 541         result += execute("ip link set %iface% up", ifd, exec);
 542         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 543         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 544         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]]", ifd, exec);
 545         return ((result == 4) ? 4 : 0);
 546 }
 547
 548 static int FAST_FUNC v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 549 {
 550         return execute("ip tunnel del %iface%", ifd, exec);
 551 }
 552 # endif
 553
 554 static const struct method_t methods6[] = {
 555 # if ENABLE_FEATURE_IFUPDOWN_IP
 556         { "v4tunnel" , v4tunnel_up     , v4tunnel_down   , },
 557 # endif
 558         { "static"   , static_up6      , static_down6    , },
 559         { "manual"   , manual_up_down6 , manual_up_down6 , },
 560         { "loopback" , loopback_up6    , loopback_down6  , },
 561 };
 562
 563 static const struct address_family_t addr_inet6 = {
 564         "inet6",
 565         ARRAY_SIZE(methods6),
 566         methods6
 567 };
 568
 569 #endif /* FEATURE_IFUPDOWN_IPV6 */
 570
 571
 572 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 573
 574 static int FAST_FUNC loopback_up(struct interface_defn_t *ifd, execfn *exec)
 575 {
 576 # if ENABLE_FEATURE_IFUPDOWN_IP
 577         int result;
 578         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 579         result += execute("ip link set %iface% up", ifd, exec);
 580         return ((result == 2) ? 2 : 0);
 581 # else
 582         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 583 # endif
 584 }
 585
 586 static int FAST_FUNC loopback_down(struct interface_defn_t *ifd, execfn *exec)
 587 {
 588 # if ENABLE_FEATURE_IFUPDOWN_IP
 589         int result;
 590         result = execute("ip addr flush dev %iface%", ifd, exec);
 591         result += execute("ip link set %iface% down", ifd, exec);
 592         return ((result == 2) ? 2 : 0);
 593 # else
 594         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 595 # endif
 596 }
 597
 598 static int FAST_FUNC static_up(struct interface_defn_t *ifd, execfn *exec)
 599 {
 600         int result;
 601 # if ENABLE_FEATURE_IFUPDOWN_IP
 602         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 603                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 604         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 605         result += execute("[[ip route add default via %gateway% dev %iface%[[ metric %metric%]]]]", ifd, exec);
 606         return ((result == 3) ? 3 : 0);
 607 # else
 608         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 609          * which then of course fails. Thus we run two separate ifconfig */
 610         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 611                                 ifd, exec);
 612         result += execute("ifconfig %iface% %address% netmask %netmask%"
 613                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]]",
 614                                 ifd, exec);
 615         result += execute("[[route add default gw %gateway%[[ metric %metric%]] %iface%]]", ifd, exec);
 616         return ((result == 3) ? 3 : 0);
 617 # endif
 618 }
 619
 620 static int FAST_FUNC static_down(struct interface_defn_t *ifd, execfn *exec)
 621 {
 622         int result;
 623 # if ENABLE_FEATURE_IFUPDOWN_IP
 624         /* Optional "label LBL" is necessary if interface is an alias (eth0:0),
 625          * otherwise "ip addr flush dev eth0:0" flushes all addresses on eth0.
 626          */
 627         result = execute("ip addr flush dev %iface%[[ label %label%]]", ifd, exec);
 628         result += execute("ip link set %iface% down", ifd, exec);
 629 # else
 630         /* result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec); */
 631         /* Bringing the interface down deletes the routes in itself.
 632            Otherwise this fails if we reference 'gateway' when using this from dhcp_down */
 633         result = 1;
 634         result += execute("ifconfig %iface% down", ifd, exec);
 635 # endif
 636         return ((result == 2) ? 2 : 0);
 637 }
 638
 639 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 640 struct dhcp_client_t {
 641         const char *name;
 642         const char *startcmd;
 643         const char *stopcmd;
 644 };
 645
 646 static const struct dhcp_client_t ext_dhcp_clients[] = {
 647         { "dhcpcd",
 648                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %client%]][[ -l %leasetime%]] %iface%",
 649                 "dhcpcd -k %iface%",
 650         },
 651         { "dhclient",
 652                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 653                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 654         },
 655         { "pump",
 656                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 657                 "pump -i %iface% -k",
 658         },
 659         { "udhcpc",
 660                 "udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -x hostname:%hostname%]][[ -c %client%]]"
 661                                 "[[ -s %script%]][[ %udhcpc_opts%]]",
 662                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 663         },
 664 };
 665 # endif /* FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 666
 667 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 668 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 669 {
 670         unsigned i;
 671 #  if ENABLE_FEATURE_IFUPDOWN_IP
 672         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 673         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 674                 return 0;
 675 #  else
 676         /* needed if we have hwaddress on dhcp iface */
 677         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 678                 return 0;
 679 #  endif
 680         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 681                 if (executable_exists(ext_dhcp_clients[i].name))
 682                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 683         }
 684         bb_error_msg("no dhcp clients found");
 685         return 0;
 686 }
 687 # elif ENABLE_UDHCPC
 688 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 689 {
 690 #  if ENABLE_FEATURE_IFUPDOWN_IP
 691         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 692         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 693                 return 0;
 694 #  else
 695         /* needed if we have hwaddress on dhcp iface */
 696         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 697                 return 0;
 698 #  endif
 699         return execute("udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid "
 700                         "-i %iface%[[ -x hostname:%hostname%]][[ -c %client%]][[ -s %script%]][[ %udhcpc_opts%]]",
 701                         ifd, exec);
 702 }
 703 # else
 704 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd UNUSED_PARAM,
 705                 execfn *exec UNUSED_PARAM)
 706 {
 707         return 0; /* no dhcp support */
 708 }
 709 # endif
 710
 711 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 712 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 713 {
 714         int result = 0;
 715         unsigned i;
 716
 717         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 718                 if (executable_exists(ext_dhcp_clients[i].name)) {
 719                         result = execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 720                         if (result)
 721                                 break;
 722                 }
 723         }
 724
 725         if (!result)
 726                 bb_error_msg("warning: no dhcp clients found and stopped");
 727
 728         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 729            and it may come back up because udhcpc is still shutting down */
 730         usleep(100000);
 731         result += static_down(ifd, exec);
 732         return ((result == 3) ? 3 : 0);
 733 }
 734 # elif ENABLE_UDHCPC
 735 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 736 {
 737         int result;
 738         result = execute(
 739                 "test -f /var/run/udhcpc.%iface%.pid && "
 740                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 741                 ifd, exec);
 742         /* Also bring the hardware interface down since
 743            killing the dhcp client alone doesn't do it.
 744            This enables consecutive ifup->ifdown->ifup */
 745         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 746            and it may come back up because udhcpc is still shutting down */
 747         usleep(100000);
 748         result += static_down(ifd, exec);
 749         return ((result == 3) ? 3 : 0);
 750 }
 751 # else
 752 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd UNUSED_PARAM,
 753                 execfn *exec UNUSED_PARAM)
 754 {
 755         return 0; /* no dhcp support */
 756 }
 757 # endif
 758
 759 static int FAST_FUNC manual_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 760 {
 761         return 1;
 762 }
 763
 764 static int FAST_FUNC bootp_up(struct interface_defn_t *ifd, execfn *exec)
 765 {
 766         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 767                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 768                         " --returniffail --serverbcast", ifd, exec);
 769 }
 770
 771 static int FAST_FUNC ppp_up(struct interface_defn_t *ifd, execfn *exec)
 772 {
 773         return execute("pon[[ %provider%]]", ifd, exec);
 774 }
 775
 776 static int FAST_FUNC ppp_down(struct interface_defn_t *ifd, execfn *exec)
 777 {
 778         return execute("poff[[ %provider%]]", ifd, exec);
 779 }
 780
 781 static int FAST_FUNC wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 782 {
 783         return execute("start-stop-daemon --start -x wvdial "
 784                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 785 }
 786
 787 static int FAST_FUNC wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 788 {
 789         return execute("start-stop-daemon --stop -x wvdial "
 790                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 791 }
 792
 793 static const struct method_t methods[] = {
 794         { "manual"  , manual_up_down, manual_up_down, },
 795         { "wvdial"  , wvdial_up     , wvdial_down   , },
 796         { "ppp"     , ppp_up        , ppp_down      , },
 797         { "static"  , static_up     , static_down   , },
 798         { "bootp"   , bootp_up      , static_down   , },
 799         { "dhcp"    , dhcp_up       , dhcp_down     , },
 800         { "loopback", loopback_up   , loopback_down , },
 801 };
 802
 803 static const struct address_family_t addr_inet = {
 804         "inet",
 805         ARRAY_SIZE(methods),
 806         methods
 807 };
 808
 809 #endif  /* FEATURE_IFUPDOWN_IPV4 */
 810
 811 static int FAST_FUNC link_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 812 {
 813         return 1;
 814 }
 815
 816 static const struct method_t link_methods[] = {
 817         { "none", link_up_down, link_up_down }
 818 };
 819
 820 static const struct address_family_t addr_link = {
 821         "link", ARRAY_SIZE(link_methods), link_methods
 822 };
 823
 824 /* Returns pointer to the next word, or NULL.
 825  * In 1st case, advances *buf to the word after this one.
 826  */
 827 static char *next_word(char **buf)
 828 {
 829         unsigned length;
 830         char *word;
 831
 832         /* Skip over leading whitespace */
 833         word = skip_whitespace(*buf);
 834
 835         /* Stop on EOL */
 836         if (*word == '\0')
 837                 return NULL;
 838
 839         /* Find the length of this word (can't be 0) */
 840         length = strcspn(word, " \t\n");
 841
 842         /* Unless we are already at NUL, store NUL and advance */
 843         if (word[length] != '\0')
 844                 word[length++] = '\0';
 845
 846         *buf = skip_whitespace(word + length);
 847
 848         return word;
 849 }
 850
 851 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 852 {
 853         int i;
 854
 855         if (!name)
 856                 return NULL;
 857
 858         for (i = 0; af[i]; i++) {
 859                 if (strcmp(af[i]->name, name) == 0) {
 860                         return af[i];
 861                 }
 862         }
 863         return NULL;
 864 }
 865
 866 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 867 {
 868         int i;
 869
 870         if (!name)
 871                 return NULL;
 872         /* TODO: use index_in_str_array() */
 873         for (i = 0; i < af->n_methods; i++) {
 874                 if (strcmp(af->method[i].name, name) == 0) {
 875                         return &af->method[i];
 876                 }
 877         }
 878         return NULL;
 879 }
 880
 881 static struct interfaces_file_t *read_interfaces(const char *filename, struct interfaces_file_t *defn)
 882 {
 883         /* Let's try to be compatible.
 884          *
 885          * "man 5 interfaces" says:
 886          * Lines starting with "#" are ignored. Note that end-of-line
 887          * comments are NOT supported, comments must be on a line of their own.
 888          * A line may be extended across multiple lines by making
 889          * the last character a backslash.
 890          *
 891          * Seen elsewhere in example config file:
 892          * A first non-blank "#" character makes the rest of the line
 893          * be ignored. Blank lines are ignored. Lines may be indented freely.
 894          * A "\" character at the very end of the line indicates the next line
 895          * should be treated as a continuation of the current one.
 896          *
 897          * Lines  beginning with "source" are used to include stanzas from
 898          * other files, so configuration can be split into many files.
 899          * The word "source" is followed by the path of file to be sourced.
 900          */
 901 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 902         struct mapping_defn_t *currmap = NULL;
 903 #endif
 904         struct interface_defn_t *currif = NULL;
 905         FILE *f;
 906         char *buf;
 907         char *first_word;
 908         char *rest_of_line;
 909         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 910
 911         if (!defn)
 912                 defn = xzalloc(sizeof(*defn));
 913
 914         debug_noise("reading %s file:\n", filename);
 915         f = xfopen_for_read(filename);
 916
 917         while ((buf = xmalloc_fgetline(f)) != NULL) {
 918 #if ENABLE_DESKTOP
 919                 /* Trailing "\" concatenates lines */
 920                 char *p;
 921                 while ((p = last_char_is(buf, '\\')) != NULL) {
 922                         *p = '\0';
 923                         rest_of_line = xmalloc_fgetline(f);
 924                         if (!rest_of_line)
 925                                 break;
 926                         p = xasprintf("%s%s", buf, rest_of_line);
 927                         free(buf);
 928                         free(rest_of_line);
 929                         buf = p;
 930                 }
 931 #endif
 932                 rest_of_line = buf;
 933                 first_word = next_word(&rest_of_line);
 934                 if (!first_word || *first_word == '#') {
 935                         free(buf);
 936                         continue; /* blank/comment line */
 937                 }
 938
 939                 if (strcmp(first_word, "mapping") == 0) {
 940 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 941                         currmap = xzalloc(sizeof(*currmap));
 942
 943                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 944                                 currmap->match = xrealloc_vector(currmap->match, 4, currmap->n_matches);
 945                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
 946                         }
 947                         /*currmap->n_mappings = 0;*/
 948                         /*currmap->mapping = NULL;*/
 949                         /*currmap->script = NULL;*/
 950                         {
 951                                 struct mapping_defn_t **where = &defn->mappings;
 952                                 while (*where != NULL) {
 953                                         where = &(*where)->next;
 954                                 }
 955                                 *where = currmap;
 956                                 /*currmap->next = NULL;*/
 957                         }
 958                         debug_noise("Added mapping\n");
 959 #endif
 960                         currently_processing = MAPPING;
 961                 } else if (strcmp(first_word, "iface") == 0) {
 962                         static const struct address_family_t *const addr_fams[] = {
 963 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 964                                 &addr_inet,
 965 #endif
 966 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 967                                 &addr_inet6,
 968 #endif
 969                                 &addr_link,
 970                                 NULL
 971                         };
 972                         char *iface_name;
 973                         char *address_family_name;
 974                         char *method_name;
 975
 976                         currif = xzalloc(sizeof(*currif));
 977                         iface_name = next_word(&rest_of_line);
 978                         address_family_name = next_word(&rest_of_line);
 979                         method_name = next_word(&rest_of_line);
 980
 981                         if (method_name == NULL)
 982                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 983
 984                         /* ship any trailing whitespace */
 985                         rest_of_line = skip_whitespace(rest_of_line);
 986
 987                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
 988                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 989
 990                         currif->iface = xstrdup(iface_name);
 991
 992                         currif->address_family = get_address_family(addr_fams, address_family_name);
 993                         if (!currif->address_family)
 994                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 995
 996                         currif->method = get_method(currif->address_family, method_name);
 997                         if (!currif->method)
 998                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 999 #if 0
1000 // Allegedly, Debian allows a duplicate definition:
1001 // iface eth0 inet static
1002 //     address 192.168.0.15
1003 //     netmask 255.255.0.0
1004 //     gateway 192.168.0.1
1005 //
1006 // iface eth0 inet static
1007 //     address 10.0.0.1
1008 //     netmask 255.255.255.0
1009 //
1010 // This adds *two* addresses to eth0 (probably requires use of "ip", not "ifconfig"
1011 //
1012                         llist_t *iface_list;
1013                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
1014                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
1015                                 if ((strcmp(tmp->iface, currif->iface) == 0)
1016                                  && (tmp->address_family == currif->address_family)
1017                                 ) {
1018                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
1019                                 }
1020                         }
1021 #endif
1022                         llist_add_to_end(&(defn->ifaces), (char*)currif);
1023
1024                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
1025                         currently_processing = IFACE;
1026                 } else if (strcmp(first_word, "auto") == 0) {
1027                         while ((first_word = next_word(&rest_of_line)) != NULL) {
1028
1029                                 /* Check the interface isnt already listed */
1030                                 if (llist_find_str(defn->autointerfaces, first_word)) {
1031                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
1032                                 }
1033
1034                                 /* Add the interface to the list */
1035                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
1036                                 debug_noise("\nauto %s\n", first_word);
1037                         }
1038                         currently_processing = NONE;
1039                 } else if (strcmp(first_word, "source") == 0) {
1040                         read_interfaces(next_word(&rest_of_line), defn);
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         int i;
1181         char *buf;
1182         for (i = 0; i < ifd->n_options; i++) {
1183                 if (strcmp(ifd->option[i].name, opt) == 0) {
1184                         if (!doit(ifd->option[i].value)) {
1185                                 return 0;
1186                         }
1187                 }
1188         }
1189
1190         /* Tested on Debian Squeeze: "standard" ifup runs this without
1191          * checking that directory exists. If it doesn't, run-parts
1192          * complains, and this message _is_ annoyingly visible.
1193          * Don't "fix" this (unless newer Debian does).
1194          */
1195         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
1196         /* heh, we don't bother free'ing it */
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 * 1000) {
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                 usleep(cnt);
1362                 cnt += 1000;
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 }