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