networking/ifupdown.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *  ifupdown for busybox
   4  *  Copyright (c) 2002 Glenn McGrath
   5  *  Copyright (c) 2003-2004 Erik Andersen <andersen@codepoet.org>
   6  *
   7  *  Based on ifupdown v 0.6.4 by Anthony Towns
   8  *  Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
   9  *
  10  *  Changes to upstream version
  11  *  Remove checks for kernel version, assume kernel version 2.2.0 or better.
  12  *  Lines in the interfaces file cannot wrap.
  13  *  To adhere to the FHS, the default state file is /var/run/ifstate
  14  *  (defined via CONFIG_IFUPDOWN_IFSTATE_PATH) and can be overridden by build
  15  *  configuration.
  16  *
  17  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  18  */
  19
  20 //usage:#define ifup_trivial_usage
  21 //usage:       "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] IFACE..."
  22 //usage:#define ifup_full_usage "\n\n"
  23 //usage:       "        -a      De/configure all interfaces automatically"
  24 //usage:     "\n        -i FILE Use FILE for interface definitions"
  25 //usage:     "\n        -n      Print out what would happen, but don't do it"
  26 //usage:        IF_FEATURE_IFUPDOWN_MAPPING(
  27 //usage:     "\n                (note: doesn't disable mappings)"
  28 //usage:     "\n        -m      Don't run any mappings"
  29 //usage:        )
  30 //usage:     "\n        -v      Print out what would happen before doing it"
  31 //usage:     "\n        -f      Force de/configuration"
  32 //usage:
  33 //usage:#define ifdown_trivial_usage
  34 //usage:       "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] IFACE..."
  35 //usage:#define ifdown_full_usage "\n\n"
  36 //usage:       "        -a      De/configure all interfaces automatically"
  37 //usage:     "\n        -i FILE Use FILE for interface definitions"
  38 //usage:     "\n        -n      Print out what would happen, but don't do it"
  39 //usage:        IF_FEATURE_IFUPDOWN_MAPPING(
  40 //usage:     "\n                (note: doesn't disable mappings)"
  41 //usage:     "\n        -m      Don't run any mappings"
  42 //usage:        )
  43 //usage:     "\n        -v      Print out what would happen before doing it"
  44 //usage:     "\n        -f      Force de/configuration"
  45
  46 #include "libbb.h"
  47 #include "common_bufsiz.h"
  48 /* After libbb.h, since it needs sys/types.h on some systems */
  49 #include <sys/utsname.h>
  50 #include <fnmatch.h>
  51
  52 #define MAX_OPT_DEPTH 10
  53
  54 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
  55 #define MAX_INTERFACE_LENGTH 10
  56 #endif
  57
  58 #define UDHCPC_CMD_OPTIONS CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS
  59
  60 #define debug_noise(args...) /*fprintf(stderr, args)*/
  61
  62 /* Forward declaration */
  63 struct interface_defn_t;
  64
  65 typedef int execfn(char *command);
  66
  67 struct method_t {
  68         const char *name;
  69         int (*up)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
  70         int (*down)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
  71 };
  72
  73 struct address_family_t {
  74         const char *name;
  75         int n_methods;
  76         const struct method_t *method;
  77 };
  78
  79 struct mapping_defn_t {
  80         struct mapping_defn_t *next;
  81
  82         int max_matches;
  83         int n_matches;
  84         char **match;
  85
  86         char *script;
  87
  88         int n_mappings;
  89         char **mapping;
  90 };
  91
  92 struct variable_t {
  93         char *name;
  94         char *value;
  95 };
  96
  97 struct interface_defn_t {
  98         const struct address_family_t *address_family;
  99         const struct method_t *method;
 100
 101         char *iface;
 102         int n_options;
 103         struct variable_t *option;
 104 };
 105
 106 struct interfaces_file_t {
 107         llist_t *autointerfaces;
 108         llist_t *ifaces;
 109         struct mapping_defn_t *mappings;
 110 };
 111
 112
 113 #define OPTION_STR "anvf" IF_FEATURE_IFUPDOWN_MAPPING("m") "i:"
 114 enum {
 115         OPT_do_all      = 0x1,
 116         OPT_no_act      = 0x2,
 117         OPT_verbose     = 0x4,
 118         OPT_force       = 0x8,
 119         OPT_no_mappings = 0x10,
 120 };
 121 #define DO_ALL      (option_mask32 & OPT_do_all)
 122 #define NO_ACT      (option_mask32 & OPT_no_act)
 123 #define VERBOSE     (option_mask32 & OPT_verbose)
 124 #define FORCE       (option_mask32 & OPT_force)
 125 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 126
 127
 128 struct globals {
 129         char **my_environ;
 130         const char *startup_PATH;
 131         char *shell;
 132 } FIX_ALIASING;
 133 #define G (*(struct globals*)bb_common_bufsiz1)
 134 #define INIT_G() do { } while (0)
 135
 136
 137 static const char keywords_up_down[] ALIGN1 =
 138         "up\0"
 139         "down\0"
 140         "pre-up\0"
 141         "post-down\0"
 142 ;
 143
 144
 145 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 146
 147 static void addstr(char **bufp, const char *str, size_t str_length)
 148 {
 149         /* xasprintf trick will be smaller, but we are often
 150          * called with str_length == 1 - don't want to have
 151          * THAT much of malloc/freeing! */
 152         char *buf = *bufp;
 153         int len = (buf ? strlen(buf) : 0);
 154         str_length++;
 155         buf = xrealloc(buf, len + str_length);
 156         /* copies at most str_length-1 chars! */
 157         safe_strncpy(buf + len, str, str_length);
 158         *bufp = buf;
 159 }
 160
 161 static int strncmpz(const char *l, const char *r, size_t llen)
 162 {
 163         int i = strncmp(l, r, llen);
 164
 165         if (i == 0)
 166                 return - (unsigned char)r[llen];
 167         return i;
 168 }
 169
 170 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 171 {
 172         int i;
 173
 174         if (strncmpz(id, "iface", idlen) == 0) {
 175                 // ubuntu's ifup doesn't do this:
 176                 //static char *label_buf;
 177                 //char *result;
 178                 //free(label_buf);
 179                 //label_buf = xstrdup(ifd->iface);
 180                 // Remove virtual iface suffix
 181                 //result = strchrnul(label_buf, ':');
 182                 //*result = '\0';
 183                 //return label_buf;
 184
 185                 return ifd->iface;
 186         }
 187         if (strncmpz(id, "label", idlen) == 0) {
 188                 return ifd->iface;
 189         }
 190         for (i = 0; i < ifd->n_options; i++) {
 191                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 192                         return ifd->option[i].value;
 193                 }
 194         }
 195         return NULL;
 196 }
 197
 198 # if ENABLE_FEATURE_IFUPDOWN_IP
 199 static int count_netmask_bits(const char *dotted_quad)
 200 {
 201 //      int result;
 202 //      unsigned a, b, c, d;
 203 //      /* Found a netmask...  Check if it is dotted quad */
 204 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 205 //              return -1;
 206 //      if ((a|b|c|d) >> 8)
 207 //              return -1; /* one of numbers is >= 256 */
 208 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 209 //      d = ~d; /* 11110000 -> 00001111 */
 210
 211         /* Shorter version */
 212         int result;
 213         struct in_addr ip;
 214         unsigned d;
 215
 216         if (inet_aton(dotted_quad, &ip) == 0)
 217                 return -1; /* malformed dotted IP */
 218         d = ntohl(ip.s_addr); /* IP in host order */
 219         d = ~d; /* 11110000 -> 00001111 */
 220         if (d & (d+1)) /* check that it is in 00001111 form */
 221                 return -1; /* no it is not */
 222         result = 32;
 223         while (d) {
 224                 d >>= 1;
 225                 result--;
 226         }
 227         return result;
 228 }
 229 # endif
 230
 231 static char *parse(const char *command, struct interface_defn_t *ifd)
 232 {
 233         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 234         smallint okay[MAX_OPT_DEPTH] = { 1 };
 235         int opt_depth = 1;
 236         char *result = NULL;
 237
 238         while (*command) {
 239                 switch (*command) {
 240                 default:
 241                         addstr(&result, command, 1);
 242                         command++;
 243                         break;
 244                 case '\\':
 245                         if (command[1])
 246                                 command++;
 247                         addstr(&result, command, 1);
 248                         command++;
 249                         break;
 250                 case '[':
 251                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 252                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 253                                 okay[opt_depth] = 1;
 254                                 opt_depth++;
 255                                 command += 2;
 256                         } else {
 257                                 addstr(&result, command, 1);
 258                                 command++;
 259                         }
 260                         break;
 261                 case ']':
 262                         if (command[1] == ']' && opt_depth > 1) {
 263                                 opt_depth--;
 264                                 if (!okay[opt_depth]) {
 265                                         result[old_pos[opt_depth]] = '\0';
 266                                 }
 267                                 command += 2;
 268                         } else {
 269                                 addstr(&result, command, 1);
 270                                 command++;
 271                         }
 272                         break;
 273                 case '%':
 274                         {
 275                                 char *nextpercent;
 276                                 char *varvalue;
 277
 278                                 command++;
 279                                 nextpercent = strchr(command, '%');
 280                                 if (!nextpercent) {
 281                                         /* Unterminated %var% */
 282                                         free(result);
 283                                         return NULL;
 284                                 }
 285
 286                                 varvalue = get_var(command, nextpercent - command, ifd);
 287
 288                                 if (varvalue) {
 289 # if ENABLE_FEATURE_IFUPDOWN_IP
 290                                         /* "hwaddress <class> <address>":
 291                                          * unlike ifconfig, ip doesnt want <class>
 292                                          * (usually "ether" keyword). Skip it. */
 293                                         if (is_prefixed_with(command, "hwaddress")) {
 294                                                 varvalue = skip_whitespace(skip_non_whitespace(varvalue));
 295                                         }
 296 # endif
 297                                         addstr(&result, varvalue, strlen(varvalue));
 298                                 } else {
 299 # if ENABLE_FEATURE_IFUPDOWN_IP
 300                                         /* Sigh...  Add a special case for 'ip' to convert from
 301                                          * dotted quad to bit count style netmasks.  */
 302                                         if (is_prefixed_with(command, "bnmask")) {
 303                                                 unsigned res;
 304                                                 varvalue = get_var("netmask", 7, ifd);
 305                                                 if (varvalue) {
 306                                                         res = count_netmask_bits(varvalue);
 307                                                         if (res > 0) {
 308                                                                 const char *argument = utoa(res);
 309                                                                 addstr(&result, argument, strlen(argument));
 310                                                                 command = nextpercent + 1;
 311                                                                 break;
 312                                                         }
 313                                                 }
 314                                         }
 315 # endif
 316                                         okay[opt_depth - 1] = 0;
 317                                 }
 318
 319                                 command = nextpercent + 1;
 320                         }
 321                         break;
 322                 }
 323         }
 324
 325         if (opt_depth > 1) {
 326                 /* Unbalanced bracket */
 327                 free(result);
 328                 return NULL;
 329         }
 330
 331         if (!okay[0]) {
 332                 /* Undefined variable and we aren't in a bracket */
 333                 free(result);
 334                 return NULL;
 335         }
 336
 337         return result;
 338 }
 339
 340 /* execute() returns 1 for success and 0 for failure */
 341 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 342 {
 343         char *out;
 344         int ret;
 345
 346         out = parse(command, ifd);
 347         if (!out) {
 348                 /* parse error? */
 349                 return 0;
 350         }
 351         /* out == "": parsed ok but not all needed variables known, skip */
 352         ret = out[0] ? (*exec)(out) : 1;
 353
 354         free(out);
 355         if (ret != 1) {
 356                 return 0;
 357         }
 358         return 1;
 359 }
 360
 361 #endif /* FEATURE_IFUPDOWN_IPV4 || FEATURE_IFUPDOWN_IPV6 */
 362
 363
 364 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 365
 366 static int FAST_FUNC loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 367 {
 368 # if ENABLE_FEATURE_IFUPDOWN_IP
 369         int result;
 370         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 371         result += execute("ip link set %iface% up", ifd, exec);
 372         return ((result == 2) ? 2 : 0);
 373 # else
 374         return execute("ifconfig %iface% add ::1", ifd, exec);
 375 # endif
 376 }
 377
 378 static int FAST_FUNC loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 379 {
 380 # if ENABLE_FEATURE_IFUPDOWN_IP
 381         return execute("ip link set %iface% down", ifd, exec);
 382 # else
 383         return execute("ifconfig %iface% del ::1", ifd, exec);
 384 # endif
 385 }
 386
 387 static int FAST_FUNC manual_up_down6(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 388 {
 389         return 1;
 390 }
 391
 392 static int FAST_FUNC static_up6(struct interface_defn_t *ifd, execfn *exec)
 393 {
 394         int result;
 395 # if ENABLE_FEATURE_IFUPDOWN_IP
 396         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 397         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 398         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 399         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]][[ metric %metric%]]", ifd, exec);
 400 # else
 401         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 402         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 403         result += execute("[[route -A inet6 add ::/0 gw %gateway%[[ metric %metric%]]]]", ifd, exec);
 404 # endif
 405         return ((result == 3) ? 3 : 0);
 406 }
 407
 408 static int FAST_FUNC static_down6(struct interface_defn_t *ifd, execfn *exec)
 409 {
 410 # if ENABLE_FEATURE_IFUPDOWN_IP
 411         return execute("ip link set %iface% down", ifd, exec);
 412 # else
 413         return execute("ifconfig %iface% down", ifd, exec);
 414 # endif
 415 }
 416
 417 # if ENABLE_FEATURE_IFUPDOWN_IP
 418 static int FAST_FUNC v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 419 {
 420         int result;
 421         result = execute("ip tunnel add %iface% mode sit remote "
 422                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 423         result += execute("ip link set %iface% up", ifd, exec);
 424         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 425         /* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
 426         result += execute("[[ip route add ::/0 via %gateway% dev %iface%]]", ifd, exec);
 427         return ((result == 4) ? 4 : 0);
 428 }
 429
 430 static int FAST_FUNC v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 431 {
 432         return execute("ip tunnel del %iface%", ifd, exec);
 433 }
 434 # endif
 435
 436 static const struct method_t methods6[] = {
 437 # if ENABLE_FEATURE_IFUPDOWN_IP
 438         { "v4tunnel" , v4tunnel_up     , v4tunnel_down   , },
 439 # endif
 440         { "static"   , static_up6      , static_down6    , },
 441         { "manual"   , manual_up_down6 , manual_up_down6 , },
 442         { "loopback" , loopback_up6    , loopback_down6  , },
 443 };
 444
 445 static const struct address_family_t addr_inet6 = {
 446         "inet6",
 447         ARRAY_SIZE(methods6),
 448         methods6
 449 };
 450
 451 #endif /* FEATURE_IFUPDOWN_IPV6 */
 452
 453
 454 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 455
 456 static int FAST_FUNC loopback_up(struct interface_defn_t *ifd, execfn *exec)
 457 {
 458 # if ENABLE_FEATURE_IFUPDOWN_IP
 459         int result;
 460         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 461         result += execute("ip link set %iface% up", ifd, exec);
 462         return ((result == 2) ? 2 : 0);
 463 # else
 464         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 465 # endif
 466 }
 467
 468 static int FAST_FUNC loopback_down(struct interface_defn_t *ifd, execfn *exec)
 469 {
 470 # if ENABLE_FEATURE_IFUPDOWN_IP
 471         int result;
 472         result = execute("ip addr flush dev %iface%", ifd, exec);
 473         result += execute("ip link set %iface% down", ifd, exec);
 474         return ((result == 2) ? 2 : 0);
 475 # else
 476         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 477 # endif
 478 }
 479
 480 static int FAST_FUNC static_up(struct interface_defn_t *ifd, execfn *exec)
 481 {
 482         int result;
 483 # if ENABLE_FEATURE_IFUPDOWN_IP
 484         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 485                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 486         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 487         result += execute("[[ip route add default via %gateway% dev %iface%[[ metric %metric%]]]]", ifd, exec);
 488         return ((result == 3) ? 3 : 0);
 489 # else
 490         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 491          * which then of course fails. Thus we run two separate ifconfig */
 492         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 493                                 ifd, exec);
 494         result += execute("ifconfig %iface% %address% netmask %netmask%"
 495                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 496                                 ifd, exec);
 497         result += execute("[[route add default gw %gateway%[[ metric %metric%]] %iface%]]", ifd, exec);
 498         return ((result == 3) ? 3 : 0);
 499 # endif
 500 }
 501
 502 static int FAST_FUNC static_down(struct interface_defn_t *ifd, execfn *exec)
 503 {
 504         int result;
 505 # if ENABLE_FEATURE_IFUPDOWN_IP
 506         result = execute("ip addr flush dev %iface%", ifd, exec);
 507         result += execute("ip link set %iface% down", ifd, exec);
 508 # else
 509         /* result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec); */
 510         /* Bringing the interface down deletes the routes in itself.
 511            Otherwise this fails if we reference 'gateway' when using this from dhcp_down */
 512         result = 1;
 513         result += execute("ifconfig %iface% down", ifd, exec);
 514 # endif
 515         return ((result == 2) ? 2 : 0);
 516 }
 517
 518 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 519 struct dhcp_client_t {
 520         const char *name;
 521         const char *startcmd;
 522         const char *stopcmd;
 523 };
 524
 525 static const struct dhcp_client_t ext_dhcp_clients[] = {
 526         { "dhcpcd",
 527                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %client%]][[ -l %leasetime%]] %iface%",
 528                 "dhcpcd -k %iface%",
 529         },
 530         { "dhclient",
 531                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 532                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 533         },
 534         { "pump",
 535                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 536                 "pump -i %iface% -k",
 537         },
 538         { "udhcpc",
 539                 "udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -x hostname:%hostname%]][[ -c %client%]]"
 540                                 "[[ -s %script%]][[ %udhcpc_opts%]]",
 541                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 542         },
 543 };
 544 # endif /* FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 545
 546 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 547 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 548 {
 549         unsigned i;
 550 #  if ENABLE_FEATURE_IFUPDOWN_IP
 551         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 552         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 553                 return 0;
 554 #  else
 555         /* needed if we have hwaddress on dhcp iface */
 556         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 557                 return 0;
 558 #  endif
 559         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 560                 if (executable_exists(ext_dhcp_clients[i].name))
 561                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 562         }
 563         bb_error_msg("no dhcp clients found");
 564         return 0;
 565 }
 566 # elif ENABLE_UDHCPC
 567 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 568 {
 569 #  if ENABLE_FEATURE_IFUPDOWN_IP
 570         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 571         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 572                 return 0;
 573 #  else
 574         /* needed if we have hwaddress on dhcp iface */
 575         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 576                 return 0;
 577 #  endif
 578         return execute("udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid "
 579                         "-i %iface%[[ -x hostname:%hostname%]][[ -c %client%]][[ -s %script%]][[ %udhcpc_opts%]]",
 580                         ifd, exec);
 581 }
 582 # else
 583 static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd UNUSED_PARAM,
 584                 execfn *exec UNUSED_PARAM)
 585 {
 586         return 0; /* no dhcp support */
 587 }
 588 # endif
 589
 590 # if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 591 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 592 {
 593         int result = 0;
 594         unsigned i;
 595
 596         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 597                 if (executable_exists(ext_dhcp_clients[i].name)) {
 598                         result = execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 599                         if (result)
 600                                 break;
 601                 }
 602         }
 603
 604         if (!result)
 605                 bb_error_msg("warning: no dhcp clients found and stopped");
 606
 607         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 608            and it may come back up because udhcpc is still shutting down */
 609         usleep(100000);
 610         result += static_down(ifd, exec);
 611         return ((result == 3) ? 3 : 0);
 612 }
 613 # elif ENABLE_UDHCPC
 614 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 615 {
 616         int result;
 617         result = execute(
 618                 "test -f /var/run/udhcpc.%iface%.pid && "
 619                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 620                 ifd, exec);
 621         /* Also bring the hardware interface down since
 622            killing the dhcp client alone doesn't do it.
 623            This enables consecutive ifup->ifdown->ifup */
 624         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 625            and it may come back up because udhcpc is still shutting down */
 626         usleep(100000);
 627         result += static_down(ifd, exec);
 628         return ((result == 3) ? 3 : 0);
 629 }
 630 # else
 631 static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd UNUSED_PARAM,
 632                 execfn *exec UNUSED_PARAM)
 633 {
 634         return 0; /* no dhcp support */
 635 }
 636 # endif
 637
 638 static int FAST_FUNC manual_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 639 {
 640         return 1;
 641 }
 642
 643 static int FAST_FUNC bootp_up(struct interface_defn_t *ifd, execfn *exec)
 644 {
 645         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 646                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 647                         " --returniffail --serverbcast", ifd, exec);
 648 }
 649
 650 static int FAST_FUNC ppp_up(struct interface_defn_t *ifd, execfn *exec)
 651 {
 652         return execute("pon[[ %provider%]]", ifd, exec);
 653 }
 654
 655 static int FAST_FUNC ppp_down(struct interface_defn_t *ifd, execfn *exec)
 656 {
 657         return execute("poff[[ %provider%]]", ifd, exec);
 658 }
 659
 660 static int FAST_FUNC wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 661 {
 662         return execute("start-stop-daemon --start -x wvdial "
 663                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 664 }
 665
 666 static int FAST_FUNC wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 667 {
 668         return execute("start-stop-daemon --stop -x wvdial "
 669                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 670 }
 671
 672 static const struct method_t methods[] = {
 673         { "manual"  , manual_up_down, manual_up_down, },
 674         { "wvdial"  , wvdial_up     , wvdial_down   , },
 675         { "ppp"     , ppp_up        , ppp_down      , },
 676         { "static"  , static_up     , static_down   , },
 677         { "bootp"   , bootp_up      , static_down   , },
 678         { "dhcp"    , dhcp_up       , dhcp_down     , },
 679         { "loopback", loopback_up   , loopback_down , },
 680 };
 681
 682 static const struct address_family_t addr_inet = {
 683         "inet",
 684         ARRAY_SIZE(methods),
 685         methods
 686 };
 687
 688 #endif  /* FEATURE_IFUPDOWN_IPV4 */
 689
 690 static int FAST_FUNC link_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 691 {
 692         return 1;
 693 }
 694
 695 static const struct method_t link_methods[] = {
 696         { "none", link_up_down, link_up_down }
 697 };
 698
 699 static const struct address_family_t addr_link = {
 700         "link", ARRAY_SIZE(link_methods), link_methods
 701 };
 702
 703 /* Returns pointer to the next word, or NULL.
 704  * In 1st case, advances *buf to the word after this one.
 705  */
 706 static char *next_word(char **buf)
 707 {
 708         unsigned length;
 709         char *word;
 710
 711         /* Skip over leading whitespace */
 712         word = skip_whitespace(*buf);
 713
 714         /* Stop on EOL */
 715         if (*word == '\0')
 716                 return NULL;
 717
 718         /* Find the length of this word (can't be 0) */
 719         length = strcspn(word, " \t\n");
 720
 721         /* Unless we are already at NUL, store NUL and advance */
 722         if (word[length] != '\0')
 723                 word[length++] = '\0';
 724
 725         *buf = skip_whitespace(word + length);
 726
 727         return word;
 728 }
 729
 730 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 731 {
 732         int i;
 733
 734         if (!name)
 735                 return NULL;
 736
 737         for (i = 0; af[i]; i++) {
 738                 if (strcmp(af[i]->name, name) == 0) {
 739                         return af[i];
 740                 }
 741         }
 742         return NULL;
 743 }
 744
 745 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 746 {
 747         int i;
 748
 749         if (!name)
 750                 return NULL;
 751         /* TODO: use index_in_str_array() */
 752         for (i = 0; i < af->n_methods; i++) {
 753                 if (strcmp(af->method[i].name, name) == 0) {
 754                         return &af->method[i];
 755                 }
 756         }
 757         return NULL;
 758 }
 759
 760 static struct interfaces_file_t *read_interfaces(const char *filename, struct interfaces_file_t *defn)
 761 {
 762         /* Let's try to be compatible.
 763          *
 764          * "man 5 interfaces" says:
 765          * Lines starting with "#" are ignored. Note that end-of-line
 766          * comments are NOT supported, comments must be on a line of their own.
 767          * A line may be extended across multiple lines by making
 768          * the last character a backslash.
 769          *
 770          * Seen elsewhere in example config file:
 771          * A first non-blank "#" character makes the rest of the line
 772          * be ignored. Blank lines are ignored. Lines may be indented freely.
 773          * A "\" character at the very end of the line indicates the next line
 774          * should be treated as a continuation of the current one.
 775          *
 776          * Lines  beginning with "source" are used to include stanzas from
 777          * other files, so configuration can be split into many files.
 778          * The word "source" is followed by the path of file to be sourced.
 779          */
 780 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 781         struct mapping_defn_t *currmap = NULL;
 782 #endif
 783         struct interface_defn_t *currif = NULL;
 784         FILE *f;
 785         char *buf;
 786         char *first_word;
 787         char *rest_of_line;
 788         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 789
 790         if (!defn)
 791                 defn = xzalloc(sizeof(*defn));
 792
 793         debug_noise("reading %s file:\n", filename);
 794         f = xfopen_for_read(filename);
 795
 796         while ((buf = xmalloc_fgetline(f)) != NULL) {
 797 #if ENABLE_DESKTOP
 798                 /* Trailing "\" concatenates lines */
 799                 char *p;
 800                 while ((p = last_char_is(buf, '\\')) != NULL) {
 801                         *p = '\0';
 802                         rest_of_line = xmalloc_fgetline(f);
 803                         if (!rest_of_line)
 804                                 break;
 805                         p = xasprintf("%s%s", buf, rest_of_line);
 806                         free(buf);
 807                         free(rest_of_line);
 808                         buf = p;
 809                 }
 810 #endif
 811                 rest_of_line = buf;
 812                 first_word = next_word(&rest_of_line);
 813                 if (!first_word || *first_word == '#') {
 814                         free(buf);
 815                         continue; /* blank/comment line */
 816                 }
 817
 818                 if (strcmp(first_word, "mapping") == 0) {
 819 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 820                         currmap = xzalloc(sizeof(*currmap));
 821
 822                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 823                                 currmap->match = xrealloc_vector(currmap->match, 4, currmap->n_matches);
 824                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
 825                         }
 826                         /*currmap->n_mappings = 0;*/
 827                         /*currmap->mapping = NULL;*/
 828                         /*currmap->script = NULL;*/
 829                         {
 830                                 struct mapping_defn_t **where = &defn->mappings;
 831                                 while (*where != NULL) {
 832                                         where = &(*where)->next;
 833                                 }
 834                                 *where = currmap;
 835                                 /*currmap->next = NULL;*/
 836                         }
 837                         debug_noise("Added mapping\n");
 838 #endif
 839                         currently_processing = MAPPING;
 840                 } else if (strcmp(first_word, "iface") == 0) {
 841                         static const struct address_family_t *const addr_fams[] = {
 842 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 843                                 &addr_inet,
 844 #endif
 845 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 846                                 &addr_inet6,
 847 #endif
 848                                 &addr_link,
 849                                 NULL
 850                         };
 851                         char *iface_name;
 852                         char *address_family_name;
 853                         char *method_name;
 854
 855                         currif = xzalloc(sizeof(*currif));
 856                         iface_name = next_word(&rest_of_line);
 857                         address_family_name = next_word(&rest_of_line);
 858                         method_name = next_word(&rest_of_line);
 859
 860                         if (method_name == NULL)
 861                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 862
 863                         /* ship any trailing whitespace */
 864                         rest_of_line = skip_whitespace(rest_of_line);
 865
 866                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
 867                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 868
 869                         currif->iface = xstrdup(iface_name);
 870
 871                         currif->address_family = get_address_family(addr_fams, address_family_name);
 872                         if (!currif->address_family)
 873                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 874
 875                         currif->method = get_method(currif->address_family, method_name);
 876                         if (!currif->method)
 877                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 878 #if 0
 879 // Allegedly, Debian allows a duplicate definition:
 880 // iface eth0 inet static
 881 //     address 192.168.0.15
 882 //     netmask 255.255.0.0
 883 //     gateway 192.168.0.1
 884 //
 885 // iface eth0 inet static
 886 //     address 10.0.0.1
 887 //     netmask 255.255.255.0
 888 //
 889 // This adds *two* addresses to eth0 (probably requires use of "ip", not "ifconfig"
 890 //
 891                         llist_t *iface_list;
 892                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 893                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 894                                 if ((strcmp(tmp->iface, currif->iface) == 0)
 895                                  && (tmp->address_family == currif->address_family)
 896                                 ) {
 897                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
 898                                 }
 899                         }
 900 #endif
 901                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 902
 903                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 904                         currently_processing = IFACE;
 905                 } else if (strcmp(first_word, "auto") == 0) {
 906                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 907
 908                                 /* Check the interface isnt already listed */
 909                                 if (llist_find_str(defn->autointerfaces, first_word)) {
 910                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 911                                 }
 912
 913                                 /* Add the interface to the list */
 914                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
 915                                 debug_noise("\nauto %s\n", first_word);
 916                         }
 917                         currently_processing = NONE;
 918                 } else if (strcmp(first_word, "source") == 0) {
 919                         read_interfaces(next_word(&rest_of_line), defn);
 920                 } else {
 921                         switch (currently_processing) {
 922                         case IFACE:
 923                                 if (rest_of_line[0] == '\0')
 924                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
 925
 926                                 if (strcmp(first_word, "post-up") == 0)
 927                                         first_word += 5; /* "up" */
 928                                 else if (strcmp(first_word, "pre-down") == 0)
 929                                         first_word += 4; /* "down" */
 930
 931                                 /* If not one of "up", "down",... words... */
 932                                 if (index_in_strings(keywords_up_down, first_word) < 0) {
 933                                         int i;
 934                                         for (i = 0; i < currif->n_options; i++) {
 935                                                 if (strcmp(currif->option[i].name, first_word) == 0)
 936                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
 937                                         }
 938                                 }
 939                                 debug_noise("\t%s=%s\n", first_word, rest_of_line);
 940                                 currif->option = xrealloc_vector(currif->option, 4, currif->n_options);
 941                                 currif->option[currif->n_options].name = xstrdup(first_word);
 942                                 currif->option[currif->n_options].value = xstrdup(rest_of_line);
 943                                 currif->n_options++;
 944                                 break;
 945                         case MAPPING:
 946 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 947                                 if (strcmp(first_word, "script") == 0) {
 948                                         if (currmap->script != NULL)
 949                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
 950                                         currmap->script = xstrdup(next_word(&rest_of_line));
 951                                 } else if (strcmp(first_word, "map") == 0) {
 952                                         currmap->mapping = xrealloc_vector(currmap->mapping, 2, currmap->n_mappings);
 953                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
 954                                         currmap->n_mappings++;
 955                                 } else {
 956                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
 957                                 }
 958 #endif
 959                                 break;
 960                         case NONE:
 961                         default:
 962                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
 963                         }
 964                 }
 965                 free(buf);
 966         } /* while (fgets) */
 967
 968         if (ferror(f) != 0) {
 969                 /* ferror does NOT set errno! */
 970                 bb_error_msg_and_die("%s: I/O error", filename);
 971         }
 972         fclose(f);
 973         debug_noise("\ndone reading %s\n\n", filename);
 974
 975         return defn;
 976 }
 977
 978 static char *setlocalenv(const char *format, const char *name, const char *value)
 979 {
 980         char *result;
 981         char *dst;
 982         char *src;
 983         char c;
 984
 985         result = xasprintf(format, name, value);
 986
 987         for (dst = src = result; (c = *src) != '=' && c; src++) {
 988                 if (c == '-')
 989                         c = '_';
 990                 if (c >= 'a' && c <= 'z')
 991                         c -= ('a' - 'A');
 992                 if (isalnum(c) || c == '_')
 993                         *dst++ = c;
 994         }
 995         overlapping_strcpy(dst, src);
 996
 997         return result;
 998 }
 999
1000 static void set_environ(struct interface_defn_t *iface, const char *mode, const char *opt)
1001 {
1002         int i;
1003         char **pp;
1004
1005         if (G.my_environ != NULL) {
1006                 for (pp = G.my_environ; *pp; pp++) {
1007                         free(*pp);
1008                 }
1009                 free(G.my_environ);
1010         }
1011
1012         /* note: last element will stay NULL: */
1013         G.my_environ = xzalloc(sizeof(char *) * (iface->n_options + 7));
1014         pp = G.my_environ;
1015
1016         for (i = 0; i < iface->n_options; i++) {
1017                 if (index_in_strings(keywords_up_down, iface->option[i].name) >= 0) {
1018                         continue;
1019                 }
1020                 *pp++ = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
1021         }
1022
1023         *pp++ = setlocalenv("%s=%s", "IFACE", iface->iface);
1024         *pp++ = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
1025         *pp++ = setlocalenv("%s=%s", "METHOD", iface->method->name);
1026         *pp++ = setlocalenv("%s=%s", "MODE", mode);
1027         *pp++ = setlocalenv("%s=%s", "PHASE", opt);
1028         if (G.startup_PATH)
1029                 *pp++ = setlocalenv("%s=%s", "PATH", G.startup_PATH);
1030 }
1031
1032 static int doit(char *str)
1033 {
1034         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
1035                 puts(str);
1036         }
1037         if (!(option_mask32 & OPT_no_act)) {
1038                 pid_t child;
1039                 int status;
1040
1041                 fflush_all();
1042                 child = vfork();
1043                 if (child < 0) /* failure */
1044                         return 0;
1045                 if (child == 0) { /* child */
1046                         execle(G.shell, G.shell, "-c", str, (char *) NULL, G.my_environ);
1047                         _exit(127);
1048                 }
1049                 safe_waitpid(child, &status, 0);
1050                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
1051                         return 0;
1052                 }
1053         }
1054         return 1;
1055 }
1056
1057 static int execute_all(struct interface_defn_t *ifd, const char *opt)
1058 {
1059         int i;
1060         char *buf;
1061         for (i = 0; i < ifd->n_options; i++) {
1062                 if (strcmp(ifd->option[i].name, opt) == 0) {
1063                         if (!doit(ifd->option[i].value)) {
1064                                 return 0;
1065                         }
1066                 }
1067         }
1068
1069         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
1070         /* heh, we don't bother free'ing it */
1071         return doit(buf);
1072 }
1073
1074 static int check(char *str)
1075 {
1076         return str != NULL;
1077 }
1078
1079 static int iface_up(struct interface_defn_t *iface)
1080 {
1081         if (!iface->method->up(iface, check)) return -1;
1082         set_environ(iface, "start", "pre-up");
1083         if (!execute_all(iface, "pre-up")) return 0;
1084         if (!iface->method->up(iface, doit)) return 0;
1085         set_environ(iface, "start", "post-up");
1086         if (!execute_all(iface, "up")) return 0;
1087         return 1;
1088 }
1089
1090 static int iface_down(struct interface_defn_t *iface)
1091 {
1092         if (!iface->method->down(iface, check)) return -1;
1093         set_environ(iface, "stop", "pre-down");
1094         if (!execute_all(iface, "down")) return 0;
1095         if (!iface->method->down(iface, doit)) return 0;
1096         set_environ(iface, "stop", "post-down");
1097         if (!execute_all(iface, "post-down")) return 0;
1098         return 1;
1099 }
1100
1101 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1102 static int popen2(FILE **in, FILE **out, char *command, char *param)
1103 {
1104         char *argv[3] = { command, param, NULL };
1105         struct fd_pair infd, outfd;
1106         pid_t pid;
1107
1108         xpiped_pair(infd);
1109         xpiped_pair(outfd);
1110
1111         fflush_all();
1112         pid = xvfork();
1113
1114         if (pid == 0) {
1115                 /* Child */
1116                 /* NB: close _first_, then move fds! */
1117                 close(infd.wr);
1118                 close(outfd.rd);
1119                 xmove_fd(infd.rd, 0);
1120                 xmove_fd(outfd.wr, 1);
1121                 BB_EXECVP_or_die(argv);
1122         }
1123         /* parent */
1124         close(infd.rd);
1125         close(outfd.wr);
1126         *in = xfdopen_for_write(infd.wr);
1127         *out = xfdopen_for_read(outfd.rd);
1128         return pid;
1129 }
1130
1131 static char *run_mapping(char *physical, struct mapping_defn_t *map)
1132 {
1133         FILE *in, *out;
1134         int i, status;
1135         pid_t pid;
1136
1137         char *logical = xstrdup(physical);
1138
1139         /* Run the mapping script. Never fails. */
1140         pid = popen2(&in, &out, map->script, physical);
1141
1142         /* Write mappings to stdin of mapping script. */
1143         for (i = 0; i < map->n_mappings; i++) {
1144                 fprintf(in, "%s\n", map->mapping[i]);
1145         }
1146         fclose(in);
1147         safe_waitpid(pid, &status, 0);
1148
1149         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1150                 /* If the mapping script exited successfully, try to
1151                  * grab a line of output and use that as the name of the
1152                  * logical interface. */
1153                 char *new_logical = xmalloc_fgetline(out);
1154
1155                 if (new_logical) {
1156                         /* If we are able to read a line of output from the script,
1157                          * remove any trailing whitespace and use this value
1158                          * as the name of the logical interface. */
1159                         char *pch = new_logical + strlen(new_logical) - 1;
1160
1161                         while (pch >= new_logical && isspace(*pch))
1162                                 *(pch--) = '\0';
1163
1164                         free(logical);
1165                         logical = new_logical;
1166                 }
1167         }
1168
1169         fclose(out);
1170
1171         return logical;
1172 }
1173 #endif /* FEATURE_IFUPDOWN_MAPPING */
1174
1175 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1176 {
1177         llist_t *search = state_list;
1178
1179         while (search) {
1180                 char *after_iface = is_prefixed_with(search->data, iface);
1181                 if (after_iface
1182                  && *after_iface == '='
1183                 ) {
1184                         return search;
1185                 }
1186                 search = search->link;
1187         }
1188         return NULL;
1189 }
1190
1191 /* read the previous state from the state file */
1192 static llist_t *read_iface_state(void)
1193 {
1194         llist_t *state_list = NULL;
1195         FILE *state_fp = fopen_for_read(CONFIG_IFUPDOWN_IFSTATE_PATH);
1196
1197         if (state_fp) {
1198                 char *start, *end_ptr;
1199                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1200                         /* We should only need to check for a single character */
1201                         end_ptr = start + strcspn(start, " \t\n");
1202                         *end_ptr = '\0';
1203                         llist_add_to(&state_list, start);
1204                 }
1205                 fclose(state_fp);
1206         }
1207         return state_list;
1208 }
1209
1210
1211 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1212 int ifupdown_main(int argc UNUSED_PARAM, char **argv)
1213 {
1214         int (*cmds)(struct interface_defn_t *);
1215         struct interfaces_file_t *defn;
1216         llist_t *target_list = NULL;
1217         const char *interfaces = "/etc/network/interfaces";
1218         bool any_failures = 0;
1219
1220         INIT_G();
1221
1222         G.startup_PATH = getenv("PATH");
1223         G.shell = xstrdup(get_shell_name());
1224
1225         cmds = iface_down;
1226         if (applet_name[2] == 'u') {
1227                 /* ifup command */
1228                 cmds = iface_up;
1229         }
1230
1231         getopt32(argv, OPTION_STR, &interfaces);
1232         argv += optind;
1233         if (argv[0]) {
1234                 if (DO_ALL) bb_show_usage();
1235         } else {
1236                 if (!DO_ALL) bb_show_usage();
1237         }
1238
1239         defn = read_interfaces(interfaces, NULL);
1240
1241         /* Create a list of interfaces to work on */
1242         if (DO_ALL) {
1243                 target_list = defn->autointerfaces;
1244         } else {
1245                 llist_add_to_end(&target_list, argv[0]);
1246         }
1247
1248         /* Update the interfaces */
1249         while (target_list) {
1250                 llist_t *iface_list;
1251                 struct interface_defn_t *currif;
1252                 char *iface;
1253                 char *liface;
1254                 char *pch;
1255                 bool okay = 0;
1256                 int cmds_ret;
1257                 bool curr_failure = 0;
1258
1259                 iface = xstrdup(target_list->data);
1260                 target_list = target_list->link;
1261
1262                 pch = strchr(iface, '=');
1263                 if (pch) {
1264                         *pch = '\0';
1265                         liface = xstrdup(pch + 1);
1266                 } else {
1267                         liface = xstrdup(iface);
1268                 }
1269
1270                 if (!FORCE) {
1271                         llist_t *state_list = read_iface_state();
1272                         const llist_t *iface_state = find_iface_state(state_list, iface);
1273
1274                         if (cmds == iface_up) {
1275                                 /* ifup */
1276                                 if (iface_state) {
1277                                         bb_error_msg("interface %s already configured", iface);
1278                                         goto next;
1279                                 }
1280                         } else {
1281                                 /* ifdown */
1282                                 if (!iface_state) {
1283                                         bb_error_msg("interface %s not configured", iface);
1284                                         goto next;
1285                                 }
1286                         }
1287                         llist_free(state_list, free);
1288                 }
1289
1290 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1291                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1292                         struct mapping_defn_t *currmap;
1293
1294                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1295                                 int i;
1296                                 for (i = 0; i < currmap->n_matches; i++) {
1297                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1298                                                 continue;
1299                                         if (VERBOSE) {
1300                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1301                                         }
1302                                         liface = run_mapping(iface, currmap);
1303                                         break;
1304                                 }
1305                         }
1306                 }
1307 #endif
1308
1309                 iface_list = defn->ifaces;
1310                 while (iface_list) {
1311                         currif = (struct interface_defn_t *) iface_list->data;
1312                         if (strcmp(liface, currif->iface) == 0) {
1313                                 char *oldiface = currif->iface;
1314
1315                                 okay = 1;
1316                                 currif->iface = iface;
1317
1318                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1319
1320                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1321                                 cmds_ret = cmds(currif);
1322                                 if (cmds_ret == -1) {
1323                                         bb_error_msg("don't have all variables for %s/%s",
1324                                                         liface, currif->address_family->name);
1325                                         any_failures = curr_failure = 1;
1326                                 } else if (cmds_ret == 0) {
1327                                         any_failures = curr_failure = 1;
1328                                 }
1329
1330                                 currif->iface = oldiface;
1331                         }
1332                         iface_list = iface_list->link;
1333                 }
1334                 if (VERBOSE) {
1335                         bb_putchar('\n');
1336                 }
1337
1338                 if (!okay && !FORCE) {
1339                         bb_error_msg("ignoring unknown interface %s", liface);
1340                         any_failures = 1;
1341                 } else if (!NO_ACT) {
1342                         /* update the state file */
1343                         FILE *state_fp;
1344                         llist_t *state;
1345                         llist_t *state_list = read_iface_state();
1346                         llist_t *iface_state = find_iface_state(state_list, iface);
1347
1348                         if (cmds == iface_up && !curr_failure) {
1349                                 char *newiface = xasprintf("%s=%s", iface, liface);
1350                                 if (!iface_state) {
1351                                         llist_add_to_end(&state_list, newiface);
1352                                 } else {
1353                                         free(iface_state->data);
1354                                         iface_state->data = newiface;
1355                                 }
1356                         } else {
1357                                 /* Remove an interface from state_list */
1358                                 llist_unlink(&state_list, iface_state);
1359                                 free(llist_pop(&iface_state));
1360                         }
1361
1362                         /* Actually write the new state */
1363                         state_fp = xfopen_for_write(CONFIG_IFUPDOWN_IFSTATE_PATH);
1364                         state = state_list;
1365                         while (state) {
1366                                 if (state->data) {
1367                                         fprintf(state_fp, "%s\n", state->data);
1368                                 }
1369                                 state = state->link;
1370                         }
1371                         fclose(state_fp);
1372                         llist_free(state_list, free);
1373                 }
1374  next:
1375                 free(iface);
1376                 free(liface);
1377         }
1378
1379         return any_failures;
1380 }