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