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