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 the GPL v2 or later, see the file LICENSE in this tarball.
  18  */
  19
  20 #include <sys/utsname.h>
  21 #include <fnmatch.h>
  22
  23 #include "libbb.h"
  24
  25 #define MAX_OPT_DEPTH 10
  26 #define EUNBALBRACK 10001
  27 #define EUNDEFVAR   10002
  28 #define EUNBALPER   10000
  29
  30 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
  31 #define MAX_INTERFACE_LENGTH 10
  32 #endif
  33
  34 #define UDHCPC_CMD_OPTIONS CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS
  35
  36 #define debug_noise(args...) /*fprintf(stderr, args)*/
  37
  38 /* Forward declaration */
  39 struct interface_defn_t;
  40
  41 typedef int execfn(char *command);
  42
  43 struct method_t {
  44         const char *name;
  45         int (*up)(struct interface_defn_t *ifd, execfn *e);
  46         int (*down)(struct interface_defn_t *ifd, execfn *e);
  47 };
  48
  49 struct address_family_t {
  50         const char *name;
  51         int n_methods;
  52         const struct method_t *method;
  53 };
  54
  55 struct mapping_defn_t {
  56         struct mapping_defn_t *next;
  57
  58         int max_matches;
  59         int n_matches;
  60         char **match;
  61
  62         char *script;
  63
  64         int max_mappings;
  65         int n_mappings;
  66         char **mapping;
  67 };
  68
  69 struct variable_t {
  70         char *name;
  71         char *value;
  72 };
  73
  74 struct interface_defn_t {
  75         const struct address_family_t *address_family;
  76         const struct method_t *method;
  77
  78         char *iface;
  79         int max_options;
  80         int n_options;
  81         struct variable_t *option;
  82 };
  83
  84 struct interfaces_file_t {
  85         llist_t *autointerfaces;
  86         llist_t *ifaces;
  87         struct mapping_defn_t *mappings;
  88 };
  89
  90 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  91 enum {
  92         OPT_do_all = 0x1,
  93         OPT_no_act = 0x2,
  94         OPT_verbose = 0x4,
  95         OPT_force = 0x8,
  96         OPT_no_mappings = 0x10,
  97 };
  98 #define DO_ALL (option_mask32 & OPT_do_all)
  99 #define NO_ACT (option_mask32 & OPT_no_act)
 100 #define VERBOSE (option_mask32 & OPT_verbose)
 101 #define FORCE (option_mask32 & OPT_force)
 102 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 103
 104 static char **my_environ;
 105
 106 static const char *startup_PATH;
 107
 108 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 109
 110 static void addstr(char **bufp, const char *str, size_t str_length)
 111 {
 112         /* xasprintf trick will be smaller, but we are often
 113          * called with str_length == 1 - don't want to have
 114          * THAT much of malloc/freeing! */
 115         char *buf = *bufp;
 116         int len = (buf ? strlen(buf) : 0);
 117         str_length++;
 118         buf = xrealloc(buf, len + str_length);
 119         /* copies at most str_length-1 chars! */
 120         safe_strncpy(buf + len, str, str_length);
 121         *bufp = buf;
 122 }
 123
 124 static int strncmpz(const char *l, const char *r, size_t llen)
 125 {
 126         int i = strncmp(l, r, llen);
 127
 128         if (i == 0)
 129                 return -r[llen];
 130         return i;
 131 }
 132
 133 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 134 {
 135         int i;
 136
 137         if (strncmpz(id, "iface", idlen) == 0) {
 138                 static char *label_buf;
 139                 //char *result;
 140
 141                 free(label_buf);
 142                 label_buf = xstrdup(ifd->iface);
 143                 // Remove virtual iface suffix - why?
 144                 // ubuntu's ifup doesn't do this
 145                 //result = strchrnul(label_buf, ':');
 146                 //*result = '\0';
 147                 return label_buf;
 148         }
 149         if (strncmpz(id, "label", idlen) == 0) {
 150                 return ifd->iface;
 151         }
 152         for (i = 0; i < ifd->n_options; i++) {
 153                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 154                         return ifd->option[i].value;
 155                 }
 156         }
 157         return NULL;
 158 }
 159
 160 #if ENABLE_FEATURE_IFUPDOWN_IP
 161 static int count_netmask_bits(const char *dotted_quad)
 162 {
 163 //      int result;
 164 //      unsigned a, b, c, d;
 165 //      /* Found a netmask...  Check if it is dotted quad */
 166 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 167 //              return -1;
 168 //      if ((a|b|c|d) >> 8)
 169 //              return -1; /* one of numbers is >= 256 */
 170 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 171 //      d = ~d; /* 11110000 -> 00001111 */
 172
 173         /* Shorter version */
 174         int result;
 175         struct in_addr ip;
 176         unsigned d;
 177
 178         if (inet_aton(dotted_quad, &ip) == 0)
 179                 return -1; /* malformed dotted IP */
 180         d = ntohl(ip.s_addr); /* IP in host order */
 181         d = ~d; /* 11110000 -> 00001111 */
 182         if (d & (d+1)) /* check that it is in 00001111 form */
 183                 return -1; /* no it is not */
 184         result = 32;
 185         while (d) {
 186                 d >>= 1;
 187                 result--;
 188         }
 189         return result;
 190 }
 191 #endif
 192
 193 static char *parse(const char *command, struct interface_defn_t *ifd)
 194 {
 195         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 196         int okay[MAX_OPT_DEPTH] = { 1 };
 197         int opt_depth = 1;
 198         char *result = NULL;
 199
 200         while (*command) {
 201                 switch (*command) {
 202                 default:
 203                         addstr(&result, command, 1);
 204                         command++;
 205                         break;
 206                 case '\\':
 207                         if (command[1]) {
 208                                 addstr(&result, command + 1, 1);
 209                                 command += 2;
 210                         } else {
 211                                 addstr(&result, command, 1);
 212                                 command++;
 213                         }
 214                         break;
 215                 case '[':
 216                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 217                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 218                                 okay[opt_depth] = 1;
 219                                 opt_depth++;
 220                                 command += 2;
 221                         } else {
 222                                 addstr(&result, "[", 1);
 223                                 command++;
 224                         }
 225                         break;
 226                 case ']':
 227                         if (command[1] == ']' && opt_depth > 1) {
 228                                 opt_depth--;
 229                                 if (!okay[opt_depth]) {
 230                                         result[old_pos[opt_depth]] = '\0';
 231                                 }
 232                                 command += 2;
 233                         } else {
 234                                 addstr(&result, "]", 1);
 235                                 command++;
 236                         }
 237                         break;
 238                 case '%':
 239                         {
 240                                 char *nextpercent;
 241                                 char *varvalue;
 242
 243                                 command++;
 244                                 nextpercent = strchr(command, '%');
 245                                 if (!nextpercent) {
 246                                         errno = EUNBALPER;
 247                                         free(result);
 248                                         return NULL;
 249                                 }
 250
 251                                 varvalue = get_var(command, nextpercent - command, ifd);
 252
 253                                 if (varvalue) {
 254 #if ENABLE_FEATURE_IFUPDOWN_IP
 255                                         /* "hwaddress <class> <address>":
 256                                          * unlike ifconfig, ip doesnt want <class>
 257                                          * (usually "ether" keyword). Skip it. */
 258                                         if (strncmp(command, "hwaddress", 9) == 0) {
 259                                                 varvalue = skip_whitespace(skip_non_whitespace(varvalue));
 260                                         }
 261 #endif
 262                                         addstr(&result, varvalue, strlen(varvalue));
 263                                 } else {
 264 #if ENABLE_FEATURE_IFUPDOWN_IP
 265                                         /* Sigh...  Add a special case for 'ip' to convert from
 266                                          * dotted quad to bit count style netmasks.  */
 267                                         if (strncmp(command, "bnmask", 6) == 0) {
 268                                                 unsigned res;
 269                                                 varvalue = get_var("netmask", 7, ifd);
 270                                                 if (varvalue) {
 271                                                         res = count_netmask_bits(varvalue);
 272                                                         if (res > 0) {
 273                                                                 const char *argument = utoa(res);
 274                                                                 addstr(&result, argument, strlen(argument));
 275                                                                 command = nextpercent + 1;
 276                                                                 break;
 277                                                         }
 278                                                 }
 279                                         }
 280 #endif
 281                                         okay[opt_depth - 1] = 0;
 282                                 }
 283
 284                                 command = nextpercent + 1;
 285                         }
 286                         break;
 287                 }
 288         }
 289
 290         if (opt_depth > 1) {
 291                 errno = EUNBALBRACK;
 292                 free(result);
 293                 return NULL;
 294         }
 295
 296         if (!okay[0]) {
 297                 errno = EUNDEFVAR;
 298                 free(result);
 299                 return NULL;
 300         }
 301
 302         return result;
 303 }
 304
 305 /* execute() returns 1 for success and 0 for failure */
 306 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 307 {
 308         char *out;
 309         int ret;
 310
 311         out = parse(command, ifd);
 312         if (!out) {
 313                 /* parse error? */
 314                 return 0;
 315         }
 316         /* out == "": parsed ok but not all needed variables known, skip */
 317         ret = out[0] ? (*exec)(out) : 1;
 318
 319         free(out);
 320         if (ret != 1) {
 321                 return 0;
 322         }
 323         return 1;
 324 }
 325 #endif
 326
 327 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 328 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 329 {
 330 #if ENABLE_FEATURE_IFUPDOWN_IP
 331         int result;
 332         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 333         result += execute("ip link set %iface% up", ifd, exec);
 334         return ((result == 2) ? 2 : 0);
 335 #else
 336         return execute("ifconfig %iface% add ::1", ifd, exec);
 337 #endif
 338 }
 339
 340 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 341 {
 342 #if ENABLE_FEATURE_IFUPDOWN_IP
 343         return execute("ip link set %iface% down", ifd, exec);
 344 #else
 345         return execute("ifconfig %iface% del ::1", ifd, exec);
 346 #endif
 347 }
 348
 349 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 350 {
 351         int result;
 352 #if ENABLE_FEATURE_IFUPDOWN_IP
 353         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 354         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 355         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
 356         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 357 #else
 358         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 359         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 360         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
 361 #endif
 362         return ((result == 3) ? 3 : 0);
 363 }
 364
 365 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 366 {
 367 #if ENABLE_FEATURE_IFUPDOWN_IP
 368         return execute("ip link set %iface% down", ifd, exec);
 369 #else
 370         return execute("ifconfig %iface% down", ifd, exec);
 371 #endif
 372 }
 373
 374 #if ENABLE_FEATURE_IFUPDOWN_IP
 375 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 376 {
 377         int result;
 378         result = execute("ip tunnel add %iface% mode sit remote "
 379                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 380         result += execute("ip link set %iface% up", ifd, exec);
 381         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 382         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 383         return ((result == 4) ? 4 : 0);
 384 }
 385
 386 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 387 {
 388         return execute("ip tunnel del %iface%", ifd, exec);
 389 }
 390 #endif
 391
 392 static const struct method_t methods6[] = {
 393 #if ENABLE_FEATURE_IFUPDOWN_IP
 394         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 395 #endif
 396         { "static", static_up6, static_down6, },
 397         { "loopback", loopback_up6, loopback_down6, },
 398 };
 399
 400 static const struct address_family_t addr_inet6 = {
 401         "inet6",
 402         ARRAY_SIZE(methods6),
 403         methods6
 404 };
 405 #endif /* FEATURE_IFUPDOWN_IPV6 */
 406
 407 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 408 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 409 {
 410 #if ENABLE_FEATURE_IFUPDOWN_IP
 411         int result;
 412         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 413         result += execute("ip link set %iface% up", ifd, exec);
 414         return ((result == 2) ? 2 : 0);
 415 #else
 416         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 417 #endif
 418 }
 419
 420 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 421 {
 422 #if ENABLE_FEATURE_IFUPDOWN_IP
 423         int result;
 424         result = execute("ip addr flush dev %iface%", ifd, exec);
 425         result += execute("ip link set %iface% down", ifd, exec);
 426         return ((result == 2) ? 2 : 0);
 427 #else
 428         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 429 #endif
 430 }
 431
 432 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 433 {
 434         int result;
 435 #if ENABLE_FEATURE_IFUPDOWN_IP
 436         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 437                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 438         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
 439         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
 440         return ((result == 3) ? 3 : 0);
 441 #else
 442         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 443          * which then of course fails. Thus we run two separate ifconfig */
 444         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 445                                 ifd, exec);
 446         result += execute("ifconfig %iface% %address% netmask %netmask%"
 447                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 448                                 ifd, exec);
 449         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
 450         return ((result == 3) ? 3 : 0);
 451 #endif
 452 }
 453
 454 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 455 {
 456         int result;
 457 #if ENABLE_FEATURE_IFUPDOWN_IP
 458         result = execute("ip addr flush dev %iface%", ifd, exec);
 459         result += execute("ip link set %iface% down", ifd, exec);
 460 #else
 461         /* result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec); */
 462         /* Bringing the interface down deletes the routes in itself.
 463            Otherwise this fails if we reference 'gateway' when using this from dhcp_down */
 464         result = 1;
 465         result += execute("ifconfig %iface% down", ifd, exec);
 466 #endif
 467         return ((result == 2) ? 2 : 0);
 468 }
 469
 470 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 471 struct dhcp_client_t
 472 {
 473         const char *name;
 474         const char *startcmd;
 475         const char *stopcmd;
 476 };
 477
 478 static const struct dhcp_client_t ext_dhcp_clients[] = {
 479         { "dhcpcd",
 480                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
 481                 "dhcpcd -k %iface%",
 482         },
 483         { "dhclient",
 484                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 485                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 486         },
 487         { "pump",
 488                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 489                 "pump -i %iface% -k",
 490         },
 491         { "udhcpc",
 492                 "udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]]"
 493                                 "[[ -s %script%]][[ %udhcpc_opts%]]",
 494                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 495         },
 496 };
 497 #endif /* ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 498
 499 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 500 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 501 {
 502         unsigned i;
 503 #if ENABLE_FEATURE_IFUPDOWN_IP
 504         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 505         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 506                 return 0;
 507 #else
 508         /* needed if we have hwaddress on dhcp iface */
 509         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 510                 return 0;
 511 #endif
 512         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 513                 if (exists_execable(ext_dhcp_clients[i].name))
 514                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 515         }
 516         bb_error_msg("no dhcp clients found");
 517         return 0;
 518 }
 519 #elif ENABLE_APP_UDHCPC
 520 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 521 {
 522 #if ENABLE_FEATURE_IFUPDOWN_IP
 523         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 524         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
 525                 return 0;
 526 #else
 527         /* needed if we have hwaddress on dhcp iface */
 528         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
 529                 return 0;
 530 #endif
 531         return execute("udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid "
 532                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]][[ %udhcpc_opts%]]",
 533                         ifd, exec);
 534 }
 535 #else
 536 static int dhcp_up(struct interface_defn_t *ifd UNUSED_PARAM,
 537                 execfn *exec UNUSED_PARAM)
 538 {
 539         return 0; /* no dhcp support */
 540 }
 541 #endif
 542
 543 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 544 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 545 {
 546         int result = 0;
 547         unsigned i;
 548
 549         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 550                 if (exists_execable(ext_dhcp_clients[i].name)) {
 551                         result += execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 552                         if (result)
 553                                 break;
 554                 }
 555         }
 556
 557         if (!result)
 558                 bb_error_msg("warning: no dhcp clients found and stopped");
 559
 560         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 561            and it may come back up because udhcpc is still shutting down */
 562         usleep(100000);
 563         result += static_down(ifd, exec);
 564         return ((result == 3) ? 3 : 0);
 565 }
 566 #elif ENABLE_APP_UDHCPC
 567 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 568 {
 569         int result;
 570         result = execute("kill "
 571                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 572         /* Also bring the hardware interface down since
 573            killing the dhcp client alone doesn't do it.
 574            This enables consecutive ifup->ifdown->ifup */
 575         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
 576            and it may come back up because udhcpc is still shutting down */
 577         usleep(100000);
 578         result += static_down(ifd, exec);
 579         return ((result == 3) ? 3 : 0);
 580 }
 581 #else
 582 static int dhcp_down(struct interface_defn_t *ifd UNUSED_PARAM,
 583                 execfn *exec UNUSED_PARAM)
 584 {
 585         return 0; /* no dhcp support */
 586 }
 587 #endif
 588
 589 static int manual_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
 590 {
 591         return 1;
 592 }
 593
 594 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 595 {
 596         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 597                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 598                         " --returniffail --serverbcast", ifd, exec);
 599 }
 600
 601 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 602 {
 603         return execute("pon[[ %provider%]]", ifd, exec);
 604 }
 605
 606 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 607 {
 608         return execute("poff[[ %provider%]]", ifd, exec);
 609 }
 610
 611 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 612 {
 613         return execute("start-stop-daemon --start -x wvdial "
 614                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 615 }
 616
 617 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 618 {
 619         return execute("start-stop-daemon --stop -x wvdial "
 620                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 621 }
 622
 623 static const struct method_t methods[] = {
 624         { "manual", manual_up_down, manual_up_down, },
 625         { "wvdial", wvdial_up, wvdial_down, },
 626         { "ppp", ppp_up, ppp_down, },
 627         { "static", static_up, static_down, },
 628         { "bootp", bootp_up, static_down, },
 629         { "dhcp", dhcp_up, dhcp_down, },
 630         { "loopback", loopback_up, loopback_down, },
 631 };
 632
 633 static const struct address_family_t addr_inet = {
 634         "inet",
 635         ARRAY_SIZE(methods),
 636         methods
 637 };
 638
 639 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 640
 641 static char *next_word(char **buf)
 642 {
 643         unsigned length;
 644         char *word;
 645
 646         /* Skip over leading whitespace */
 647         word = skip_whitespace(*buf);
 648
 649         /* Stop on EOL */
 650         if (*word == '\0')
 651                 return NULL;
 652
 653         /* Find the length of this word (can't be 0) */
 654         length = strcspn(word, " \t\n");
 655
 656         /* Unless we are already at NUL, store NUL and advance */
 657         if (word[length] != '\0')
 658                 word[length++] = '\0';
 659
 660         *buf = word + length;
 661
 662         return word;
 663 }
 664
 665 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 666 {
 667         int i;
 668
 669         if (!name)
 670                 return NULL;
 671
 672         for (i = 0; af[i]; i++) {
 673                 if (strcmp(af[i]->name, name) == 0) {
 674                         return af[i];
 675                 }
 676         }
 677         return NULL;
 678 }
 679
 680 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 681 {
 682         int i;
 683
 684         if (!name)
 685                 return NULL;
 686         /* TODO: use index_in_str_array() */
 687         for (i = 0; i < af->n_methods; i++) {
 688                 if (strcmp(af->method[i].name, name) == 0) {
 689                         return &af->method[i];
 690                 }
 691         }
 692         return NULL;
 693 }
 694
 695 static const llist_t *find_list_string(const llist_t *list, const char *string)
 696 {
 697         if (string == NULL)
 698                 return NULL;
 699
 700         while (list) {
 701                 if (strcmp(list->data, string) == 0) {
 702                         return list;
 703                 }
 704                 list = list->link;
 705         }
 706         return NULL;
 707 }
 708
 709 static struct interfaces_file_t *read_interfaces(const char *filename)
 710 {
 711         /* Let's try to be compatible.
 712          *
 713          * "man 5 interfaces" says:
 714          * Lines starting with "#" are ignored. Note that end-of-line
 715          * comments are NOT supported, comments must be on a line of their own.
 716          * A line may be extended across multiple lines by making
 717          * the last character a backslash.
 718          *
 719          * Seen elsewhere in example config file:
 720          * A first non-blank "#" character makes the rest of the line
 721          * be ignored. Blank lines are ignored. Lines may be indented freely.
 722          * A "\" character at the very end of the line indicates the next line
 723          * should be treated as a continuation of the current one.
 724          */
 725 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 726         struct mapping_defn_t *currmap = NULL;
 727 #endif
 728         struct interface_defn_t *currif = NULL;
 729         struct interfaces_file_t *defn;
 730         FILE *f;
 731         char *buf;
 732         char *first_word;
 733         char *rest_of_line;
 734         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 735
 736         defn = xzalloc(sizeof(*defn));
 737         f = xfopen_for_read(filename);
 738
 739         while ((buf = xmalloc_fgetline(f)) != NULL) {
 740 #if ENABLE_DESKTOP
 741                 /* Trailing "\" concatenates lines */
 742                 char *p;
 743                 while ((p = last_char_is(buf, '\\')) != NULL) {
 744                         *p = '\0';
 745                         rest_of_line = xmalloc_fgetline(f);
 746                         if (!rest_of_line)
 747                                 break;
 748                         p = xasprintf("%s%s", buf, rest_of_line);
 749                         free(buf);
 750                         free(rest_of_line);
 751                         buf = p;
 752                 }
 753 #endif
 754                 rest_of_line = buf;
 755                 first_word = next_word(&rest_of_line);
 756                 if (!first_word || *first_word == '#') {
 757                         free(buf);
 758                         continue; /* blank/comment line */
 759                 }
 760
 761                 if (strcmp(first_word, "mapping") == 0) {
 762 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 763                         currmap = xzalloc(sizeof(*currmap));
 764
 765                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 766                                 currmap->match = xrealloc_vector(currmap->match, 4, currmap->n_matches);
 767                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
 768                         }
 769                         /*currmap->max_mappings = 0; - done by xzalloc */
 770                         /*currmap->n_mappings = 0;*/
 771                         /*currmap->mapping = NULL;*/
 772                         /*currmap->script = NULL;*/
 773                         {
 774                                 struct mapping_defn_t **where = &defn->mappings;
 775                                 while (*where != NULL) {
 776                                         where = &(*where)->next;
 777                                 }
 778                                 *where = currmap;
 779                                 /*currmap->next = NULL;*/
 780                         }
 781                         debug_noise("Added mapping\n");
 782 #endif
 783                         currently_processing = MAPPING;
 784                 } else if (strcmp(first_word, "iface") == 0) {
 785                         static const struct address_family_t *const addr_fams[] = {
 786 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 787                                 &addr_inet,
 788 #endif
 789 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 790                                 &addr_inet6,
 791 #endif
 792                                 NULL
 793                         };
 794                         char *iface_name;
 795                         char *address_family_name;
 796                         char *method_name;
 797                         llist_t *iface_list;
 798
 799                         currif = xzalloc(sizeof(*currif));
 800                         iface_name = next_word(&rest_of_line);
 801                         address_family_name = next_word(&rest_of_line);
 802                         method_name = next_word(&rest_of_line);
 803
 804                         if (method_name == NULL)
 805                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 806
 807                         /* ship any trailing whitespace */
 808                         rest_of_line = skip_whitespace(rest_of_line);
 809
 810                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
 811                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 812
 813                         currif->iface = xstrdup(iface_name);
 814
 815                         currif->address_family = get_address_family(addr_fams, address_family_name);
 816                         if (!currif->address_family)
 817                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 818
 819                         currif->method = get_method(currif->address_family, method_name);
 820                         if (!currif->method)
 821                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 822
 823                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 824                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 825                                 if ((strcmp(tmp->iface, currif->iface) == 0)
 826                                  && (tmp->address_family == currif->address_family)
 827                                 ) {
 828                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
 829                                 }
 830                         }
 831                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 832
 833                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 834                         currently_processing = IFACE;
 835                 } else if (strcmp(first_word, "auto") == 0) {
 836                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 837
 838                                 /* Check the interface isnt already listed */
 839                                 if (find_list_string(defn->autointerfaces, first_word)) {
 840                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 841                                 }
 842
 843                                 /* Add the interface to the list */
 844                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
 845                                 debug_noise("\nauto %s\n", first_word);
 846                         }
 847                         currently_processing = NONE;
 848                 } else {
 849                         switch (currently_processing) {
 850                         case IFACE:
 851                                 if (rest_of_line[0] == '\0')
 852                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
 853
 854                                 if (strcmp(first_word, "up") != 0
 855                                  && strcmp(first_word, "down") != 0
 856                                  && strcmp(first_word, "pre-up") != 0
 857                                  && strcmp(first_word, "post-down") != 0
 858                                 ) {
 859                                         int i;
 860                                         for (i = 0; i < currif->n_options; i++) {
 861                                                 if (strcmp(currif->option[i].name, first_word) == 0)
 862                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
 863                                         }
 864                                 }
 865                                 if (currif->n_options >= currif->max_options) {
 866                                         currif->max_options += 10;
 867                                         currif->option = xrealloc(currif->option,
 868                                                 sizeof(*currif->option) * currif->max_options);
 869                                 }
 870                                 debug_noise("\t%s=%s\n", first_word, rest_of_line);
 871                                 currif->option[currif->n_options].name = xstrdup(first_word);
 872                                 currif->option[currif->n_options].value = xstrdup(rest_of_line);
 873                                 currif->n_options++;
 874                                 break;
 875                         case MAPPING:
 876 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 877                                 if (strcmp(first_word, "script") == 0) {
 878                                         if (currmap->script != NULL)
 879                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
 880                                         currmap->script = xstrdup(next_word(&rest_of_line));
 881                                 } else if (strcmp(first_word, "map") == 0) {
 882                                         if (currmap->n_mappings >= currmap->max_mappings) {
 883                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 884                                                 currmap->mapping = xrealloc(currmap->mapping,
 885                                                         sizeof(char *) * currmap->max_mappings);
 886                                         }
 887                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
 888                                         currmap->n_mappings++;
 889                                 } else {
 890                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
 891                                 }
 892 #endif
 893                                 break;
 894                         case NONE:
 895                         default:
 896                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
 897                         }
 898                 }
 899                 free(buf);
 900         } /* while (fgets) */
 901
 902         if (ferror(f) != 0) {
 903                 /* ferror does NOT set errno! */
 904                 bb_error_msg_and_die("%s: I/O error", filename);
 905         }
 906         fclose(f);
 907
 908         return defn;
 909 }
 910
 911 static char *setlocalenv(const char *format, const char *name, const char *value)
 912 {
 913         char *result;
 914         char *here;
 915         char *there;
 916
 917         result = xasprintf(format, name, value);
 918
 919         for (here = there = result; *there != '=' && *there; there++) {
 920                 if (*there == '-')
 921                         *there = '_';
 922                 if (isalpha(*there))
 923                         *there = toupper(*there);
 924
 925                 if (isalnum(*there) || *there == '_') {
 926                         *here = *there;
 927                         here++;
 928                 }
 929         }
 930         memmove(here, there, strlen(there) + 1);
 931
 932         return result;
 933 }
 934
 935 static void set_environ(struct interface_defn_t *iface, const char *mode)
 936 {
 937         char **environend;
 938         int i;
 939         const int n_env_entries = iface->n_options + 5;
 940         char **ppch;
 941
 942         if (my_environ != NULL) {
 943                 for (ppch = my_environ; *ppch; ppch++) {
 944                         free(*ppch);
 945                         *ppch = NULL;
 946                 }
 947                 free(my_environ);
 948         }
 949         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 950         environend = my_environ;
 951
 952         for (i = 0; i < iface->n_options; i++) {
 953                 if (strcmp(iface->option[i].name, "up") == 0
 954                  || strcmp(iface->option[i].name, "down") == 0
 955                  || strcmp(iface->option[i].name, "pre-up") == 0
 956                  || strcmp(iface->option[i].name, "post-down") == 0
 957                 ) {
 958                         continue;
 959                 }
 960                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 961         }
 962
 963         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 964         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 965         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 966         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 967         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 968 }
 969
 970 static int doit(char *str)
 971 {
 972         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 973                 puts(str);
 974         }
 975         if (!(option_mask32 & OPT_no_act)) {
 976                 pid_t child;
 977                 int status;
 978
 979                 fflush(NULL);
 980                 child = vfork();
 981                 switch (child) {
 982                 case -1: /* failure */
 983                         return 0;
 984                 case 0: /* child */
 985                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 986                         _exit(127);
 987                 }
 988                 safe_waitpid(child, &status, 0);
 989                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 990                         return 0;
 991                 }
 992         }
 993         return 1;
 994 }
 995
 996 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 997 {
 998         int i;
 999         char *buf;
1000         for (i = 0; i < ifd->n_options; i++) {
1001                 if (strcmp(ifd->option[i].name, opt) == 0) {
1002                         if (!doit(ifd->option[i].value)) {
1003                                 return 0;
1004                         }
1005                 }
1006         }
1007
1008         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
1009         /* heh, we don't bother free'ing it */
1010         return doit(buf);
1011 }
1012
1013 static int check(char *str)
1014 {
1015         return str != NULL;
1016 }
1017
1018 static int iface_up(struct interface_defn_t *iface)
1019 {
1020         if (!iface->method->up(iface, check)) return -1;
1021         set_environ(iface, "start");
1022         if (!execute_all(iface, "pre-up")) return 0;
1023         if (!iface->method->up(iface, doit)) return 0;
1024         if (!execute_all(iface, "up")) return 0;
1025         return 1;
1026 }
1027
1028 static int iface_down(struct interface_defn_t *iface)
1029 {
1030         if (!iface->method->down(iface,check)) return -1;
1031         set_environ(iface, "stop");
1032         if (!execute_all(iface, "down")) return 0;
1033         if (!iface->method->down(iface, doit)) return 0;
1034         if (!execute_all(iface, "post-down")) return 0;
1035         return 1;
1036 }
1037
1038 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1039 static int popen2(FILE **in, FILE **out, char *command, char *param)
1040 {
1041         char *argv[3] = { command, param, NULL };
1042         struct fd_pair infd, outfd;
1043         pid_t pid;
1044
1045         xpiped_pair(infd);
1046         xpiped_pair(outfd);
1047
1048         fflush(NULL);
1049         pid = vfork();
1050
1051         switch (pid) {
1052         case -1:  /* failure */
1053                 bb_perror_msg_and_die("vfork");
1054         case 0:  /* child */
1055                 /* NB: close _first_, then move fds! */
1056                 close(infd.wr);
1057                 close(outfd.rd);
1058                 xmove_fd(infd.rd, 0);
1059                 xmove_fd(outfd.wr, 1);
1060                 BB_EXECVP(command, argv);
1061                 _exit(127);
1062         }
1063         /* parent */
1064         close(infd.rd);
1065         close(outfd.wr);
1066         *in = fdopen(infd.wr, "w");
1067         *out = fdopen(outfd.rd, "r");
1068         return pid;
1069 }
1070
1071 static char *run_mapping(char *physical, struct mapping_defn_t *map)
1072 {
1073         FILE *in, *out;
1074         int i, status;
1075         pid_t pid;
1076
1077         char *logical = xstrdup(physical);
1078
1079         /* Run the mapping script. Never fails. */
1080         pid = popen2(&in, &out, map->script, physical);
1081
1082         /* Write mappings to stdin of mapping script. */
1083         for (i = 0; i < map->n_mappings; i++) {
1084                 fprintf(in, "%s\n", map->mapping[i]);
1085         }
1086         fclose(in);
1087         safe_waitpid(pid, &status, 0);
1088
1089         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1090                 /* If the mapping script exited successfully, try to
1091                  * grab a line of output and use that as the name of the
1092                  * logical interface. */
1093                 char *new_logical = xmalloc_fgetline(out);
1094
1095                 if (new_logical) {
1096                         /* If we are able to read a line of output from the script,
1097                          * remove any trailing whitespace and use this value
1098                          * as the name of the logical interface. */
1099                         char *pch = new_logical + strlen(new_logical) - 1;
1100
1101                         while (pch >= new_logical && isspace(*pch))
1102                                 *(pch--) = '\0';
1103
1104                         free(logical);
1105                         logical = new_logical;
1106                 }
1107         }
1108
1109         fclose(out);
1110
1111         return logical;
1112 }
1113 #endif /* FEATURE_IFUPDOWN_MAPPING */
1114
1115 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1116 {
1117         unsigned iface_len = strlen(iface);
1118         llist_t *search = state_list;
1119
1120         while (search) {
1121                 if ((strncmp(search->data, iface, iface_len) == 0)
1122                  && (search->data[iface_len] == '=')
1123                 ) {
1124                         return search;
1125                 }
1126                 search = search->link;
1127         }
1128         return NULL;
1129 }
1130
1131 /* read the previous state from the state file */
1132 static llist_t *read_iface_state(void)
1133 {
1134         llist_t *state_list = NULL;
1135         FILE *state_fp = fopen_for_read(CONFIG_IFUPDOWN_IFSTATE_PATH);
1136
1137         if (state_fp) {
1138                 char *start, *end_ptr;
1139                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1140                         /* We should only need to check for a single character */
1141                         end_ptr = start + strcspn(start, " \t\n");
1142                         *end_ptr = '\0';
1143                         llist_add_to(&state_list, start);
1144                 }
1145                 fclose(state_fp);
1146         }
1147         return state_list;
1148 }
1149
1150
1151 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1152 int ifupdown_main(int argc, char **argv)
1153 {
1154         int (*cmds)(struct interface_defn_t *);
1155         struct interfaces_file_t *defn;
1156         llist_t *target_list = NULL;
1157         const char *interfaces = "/etc/network/interfaces";
1158         bool any_failures = 0;
1159
1160         cmds = iface_down;
1161         if (applet_name[2] == 'u') {
1162                 /* ifup command */
1163                 cmds = iface_up;
1164         }
1165
1166         getopt32(argv, OPTION_STR, &interfaces);
1167         if (argc - optind > 0) {
1168                 if (DO_ALL) bb_show_usage();
1169         } else {
1170                 if (!DO_ALL) bb_show_usage();
1171         }
1172
1173         debug_noise("reading %s file:\n", interfaces);
1174         defn = read_interfaces(interfaces);
1175         debug_noise("\ndone reading %s\n\n", interfaces);
1176
1177         startup_PATH = getenv("PATH");
1178         if (!startup_PATH) startup_PATH = "";
1179
1180         /* Create a list of interfaces to work on */
1181         if (DO_ALL) {
1182                 target_list = defn->autointerfaces;
1183         } else {
1184                 llist_add_to_end(&target_list, argv[optind]);
1185         }
1186
1187         /* Update the interfaces */
1188         while (target_list) {
1189                 llist_t *iface_list;
1190                 struct interface_defn_t *currif;
1191                 char *iface;
1192                 char *liface;
1193                 char *pch;
1194                 bool okay = 0;
1195                 int cmds_ret;
1196
1197                 iface = xstrdup(target_list->data);
1198                 target_list = target_list->link;
1199
1200                 pch = strchr(iface, '=');
1201                 if (pch) {
1202                         *pch = '\0';
1203                         liface = xstrdup(pch + 1);
1204                 } else {
1205                         liface = xstrdup(iface);
1206                 }
1207
1208                 if (!FORCE) {
1209                         llist_t *state_list = read_iface_state();
1210                         const llist_t *iface_state = find_iface_state(state_list, iface);
1211
1212                         if (cmds == iface_up) {
1213                                 /* ifup */
1214                                 if (iface_state) {
1215                                         bb_error_msg("interface %s already configured", iface);
1216                                         continue;
1217                                 }
1218                         } else {
1219                                 /* ifdown */
1220                                 if (!iface_state) {
1221                                         bb_error_msg("interface %s not configured", iface);
1222                                         continue;
1223                                 }
1224                         }
1225                         llist_free(state_list, free);
1226                 }
1227
1228 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1229                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1230                         struct mapping_defn_t *currmap;
1231
1232                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1233                                 int i;
1234                                 for (i = 0; i < currmap->n_matches; i++) {
1235                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1236                                                 continue;
1237                                         if (VERBOSE) {
1238                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1239                                         }
1240                                         liface = run_mapping(iface, currmap);
1241                                         break;
1242                                 }
1243                         }
1244                 }
1245 #endif
1246
1247                 iface_list = defn->ifaces;
1248                 while (iface_list) {
1249                         currif = (struct interface_defn_t *) iface_list->data;
1250                         if (strcmp(liface, currif->iface) == 0) {
1251                                 char *oldiface = currif->iface;
1252
1253                                 okay = 1;
1254                                 currif->iface = iface;
1255
1256                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1257
1258                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1259                                 cmds_ret = cmds(currif);
1260                                 if (cmds_ret == -1) {
1261                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1262                                                         liface, currif->address_family->name);
1263                                         any_failures = 1;
1264                                 } else if (cmds_ret == 0) {
1265                                         any_failures = 1;
1266                                 }
1267
1268                                 currif->iface = oldiface;
1269                         }
1270                         iface_list = iface_list->link;
1271                 }
1272                 if (VERBOSE) {
1273                         bb_putchar('\n');
1274                 }
1275
1276                 if (!okay && !FORCE) {
1277                         bb_error_msg("ignoring unknown interface %s", liface);
1278                         any_failures = 1;
1279                 } else if (!NO_ACT) {
1280                         /* update the state file */
1281                         FILE *state_fp;
1282                         llist_t *state;
1283                         llist_t *state_list = read_iface_state();
1284                         llist_t *iface_state = find_iface_state(state_list, iface);
1285
1286                         if (cmds == iface_up) {
1287                                 char * const newiface = xasprintf("%s=%s", iface, liface);
1288                                 if (iface_state == NULL) {
1289                                         llist_add_to_end(&state_list, newiface);
1290                                 } else {
1291                                         free(iface_state->data);
1292                                         iface_state->data = newiface;
1293                                 }
1294                         } else {
1295                                 /* Remove an interface from state_list */
1296                                 llist_unlink(&state_list, iface_state);
1297                                 free(llist_pop(&iface_state));
1298                         }
1299
1300                         /* Actually write the new state */
1301                         state_fp = xfopen_for_write(CONFIG_IFUPDOWN_IFSTATE_PATH);
1302                         state = state_list;
1303                         while (state) {
1304                                 if (state->data) {
1305                                         fprintf(state_fp, "%s\n", state->data);
1306                                 }
1307                                 state = state->link;
1308                         }
1309                         fclose(state_fp);
1310                         llist_free(state_list, free);
1311                 }
1312         }
1313
1314         return any_failures;
1315 }