networking/ifupdown.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *  ifupdown for busybox
   4  *  Copyright (c) 2002 Glenn McGrath
   5  *  Copyright (c) 2003-2004 Erik Andersen <andersen@codepoet.org>
   6  *
   7  *  Based on ifupdown v 0.6.4 by Anthony Towns
   8  *  Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
   9  *
  10  *  Changes to upstream version
  11  *  Remove checks for kernel version, assume kernel version 2.2.0 or better.
  12  *  Lines in the interfaces file cannot wrap.
  13  *  To adhere to the FHS, the default state file is /var/run/ifstate
  14  *  (defined via CONFIG_IFUPDOWN_IFSTATE_PATH) and can be overridden by build
  15  *  configuration.
  16  *
  17  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  18  */
  19
  20 #include <sys/utsname.h>
  21 #include <fnmatch.h>
  22
  23 #include "libbb.h"
  24
  25 #define MAX_OPT_DEPTH 10
  26 #define EUNBALBRACK 10001
  27 #define EUNDEFVAR   10002
  28 #define EUNBALPER   10000
  29
  30 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
  31 #define MAX_INTERFACE_LENGTH 10
  32 #endif
  33
  34 #define debug_noise(args...) /*fprintf(stderr, args)*/
  35
  36 /* Forward declaration */
  37 struct interface_defn_t;
  38
  39 typedef int execfn(char *command);
  40
  41 struct method_t {
  42         const char *name;
  43         int (*up)(struct interface_defn_t *ifd, execfn *e);
  44         int (*down)(struct interface_defn_t *ifd, execfn *e);
  45 };
  46
  47 struct address_family_t {
  48         const char *name;
  49         int n_methods;
  50         const struct method_t *method;
  51 };
  52
  53 struct mapping_defn_t {
  54         struct mapping_defn_t *next;
  55
  56         int max_matches;
  57         int n_matches;
  58         char **match;
  59
  60         char *script;
  61
  62         int max_mappings;
  63         int n_mappings;
  64         char **mapping;
  65 };
  66
  67 struct variable_t {
  68         char *name;
  69         char *value;
  70 };
  71
  72 struct interface_defn_t {
  73         const struct address_family_t *address_family;
  74         const struct method_t *method;
  75
  76         char *iface;
  77         int max_options;
  78         int n_options;
  79         struct variable_t *option;
  80 };
  81
  82 struct interfaces_file_t {
  83         llist_t *autointerfaces;
  84         llist_t *ifaces;
  85         struct mapping_defn_t *mappings;
  86 };
  87
  88 #define OPTION_STR "anvf" USE_FEATURE_IFUPDOWN_MAPPING("m") "i:"
  89 enum {
  90         OPT_do_all = 0x1,
  91         OPT_no_act = 0x2,
  92         OPT_verbose = 0x4,
  93         OPT_force = 0x8,
  94         OPT_no_mappings = 0x10,
  95 };
  96 #define DO_ALL (option_mask32 & OPT_do_all)
  97 #define NO_ACT (option_mask32 & OPT_no_act)
  98 #define VERBOSE (option_mask32 & OPT_verbose)
  99 #define FORCE (option_mask32 & OPT_force)
 100 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
 101
 102 static char **my_environ;
 103
 104 static const char *startup_PATH;
 105
 106 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 107
 108 static void addstr(char **bufp, const char *str, size_t str_length)
 109 {
 110         /* xasprintf trick will be smaller, but we are often
 111          * called with str_length == 1 - don't want to have
 112          * THAT much of malloc/freeing! */
 113         char *buf = *bufp;
 114         int len = (buf ? strlen(buf) : 0);
 115         str_length++;
 116         buf = xrealloc(buf, len + str_length);
 117         /* copies at most str_length-1 chars! */
 118         safe_strncpy(buf + len, str, str_length);
 119         *bufp = buf;
 120 }
 121
 122 static int strncmpz(const char *l, const char *r, size_t llen)
 123 {
 124         int i = strncmp(l, r, llen);
 125
 126         if (i == 0)
 127                 return -r[llen];
 128         return i;
 129 }
 130
 131 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 132 {
 133         int i;
 134
 135         if (strncmpz(id, "iface", idlen) == 0) {
 136                 static char *label_buf;
 137                 //char *result;
 138
 139                 free(label_buf);
 140                 label_buf = xstrdup(ifd->iface);
 141                 // Remove virtual iface suffix - why?
 142                 // ubuntu's ifup doesn't do this
 143                 //result = strchrnul(label_buf, ':');
 144                 //*result = '\0';
 145                 return label_buf;
 146         }
 147         if (strncmpz(id, "label", idlen) == 0) {
 148                 return ifd->iface;
 149         }
 150         for (i = 0; i < ifd->n_options; i++) {
 151                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 152                         return ifd->option[i].value;
 153                 }
 154         }
 155         return NULL;
 156 }
 157
 158 #if ENABLE_FEATURE_IFUPDOWN_IP
 159 static int count_netmask_bits(const char *dotted_quad)
 160 {
 161 //      int result;
 162 //      unsigned a, b, c, d;
 163 //      /* Found a netmask...  Check if it is dotted quad */
 164 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 165 //              return -1;
 166 //      if ((a|b|c|d) >> 8)
 167 //              return -1; /* one of numbers is >= 256 */
 168 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
 169 //      d = ~d; /* 11110000 -> 00001111 */
 170
 171         /* Shorter version */
 172         int result;
 173         struct in_addr ip;
 174         unsigned d;
 175
 176         if (inet_aton(dotted_quad, &ip) == 0)
 177                 return -1; /* malformed dotted IP */
 178         d = ntohl(ip.s_addr); /* IP in host order */
 179         d = ~d; /* 11110000 -> 00001111 */
 180         if (d & (d+1)) /* check that it is in 00001111 form */
 181                 return -1; /* no it is not */
 182         result = 32;
 183         while (d) {
 184                 d >>= 1;
 185                 result--;
 186         }
 187         return result;
 188 }
 189 #endif
 190
 191 static char *parse(const char *command, struct interface_defn_t *ifd)
 192 {
 193         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 194         int okay[MAX_OPT_DEPTH] = { 1 };
 195         int opt_depth = 1;
 196         char *result = NULL;
 197
 198         while (*command) {
 199                 switch (*command) {
 200                 default:
 201                         addstr(&result, command, 1);
 202                         command++;
 203                         break;
 204                 case '\\':
 205                         if (command[1]) {
 206                                 addstr(&result, command + 1, 1);
 207                                 command += 2;
 208                         } else {
 209                                 addstr(&result, command, 1);
 210                                 command++;
 211                         }
 212                         break;
 213                 case '[':
 214                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 215                                 old_pos[opt_depth] = result ? strlen(result) : 0;
 216                                 okay[opt_depth] = 1;
 217                                 opt_depth++;
 218                                 command += 2;
 219                         } else {
 220                                 addstr(&result, "[", 1);
 221                                 command++;
 222                         }
 223                         break;
 224                 case ']':
 225                         if (command[1] == ']' && opt_depth > 1) {
 226                                 opt_depth--;
 227                                 if (!okay[opt_depth]) {
 228                                         result[old_pos[opt_depth]] = '\0';
 229                                 }
 230                                 command += 2;
 231                         } else {
 232                                 addstr(&result, "]", 1);
 233                                 command++;
 234                         }
 235                         break;
 236                 case '%':
 237                         {
 238                                 char *nextpercent;
 239                                 char *varvalue;
 240
 241                                 command++;
 242                                 nextpercent = strchr(command, '%');
 243                                 if (!nextpercent) {
 244                                         errno = EUNBALPER;
 245                                         free(result);
 246                                         return NULL;
 247                                 }
 248
 249                                 varvalue = get_var(command, nextpercent - command, ifd);
 250
 251                                 if (varvalue) {
 252                                         addstr(&result, varvalue, strlen(varvalue));
 253                                 } else {
 254 #if ENABLE_FEATURE_IFUPDOWN_IP
 255                                         /* Sigh...  Add a special case for 'ip' to convert from
 256                                          * dotted quad to bit count style netmasks.  */
 257                                         if (strncmp(command, "bnmask", 6) == 0) {
 258                                                 unsigned res;
 259                                                 varvalue = get_var("netmask", 7, ifd);
 260                                                 if (varvalue) {
 261                                                         res = count_netmask_bits(varvalue);
 262                                                         if (res > 0) {
 263                                                                 const char *argument = utoa(res);
 264                                                                 addstr(&result, argument, strlen(argument));
 265                                                                 command = nextpercent + 1;
 266                                                                 break;
 267                                                         }
 268                                                 }
 269                                         }
 270 #endif
 271                                         okay[opt_depth - 1] = 0;
 272                                 }
 273
 274                                 command = nextpercent + 1;
 275                         }
 276                         break;
 277                 }
 278         }
 279
 280         if (opt_depth > 1) {
 281                 errno = EUNBALBRACK;
 282                 free(result);
 283                 return NULL;
 284         }
 285
 286         if (!okay[0]) {
 287                 errno = EUNDEFVAR;
 288                 free(result);
 289                 return NULL;
 290         }
 291
 292         return result;
 293 }
 294
 295 /* execute() returns 1 for success and 0 for failure */
 296 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 297 {
 298         char *out;
 299         int ret;
 300
 301         out = parse(command, ifd);
 302         if (!out) {
 303                 /* parse error? */
 304                 return 0;
 305         }
 306         /* out == "": parsed ok but not all needed variables known, skip */
 307         ret = out[0] ? (*exec)(out) : 1;
 308
 309         free(out);
 310         if (ret != 1) {
 311                 return 0;
 312         }
 313         return 1;
 314 }
 315 #endif
 316
 317 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 318 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 319 {
 320 #if ENABLE_FEATURE_IFUPDOWN_IP
 321         int result;
 322         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
 323         result += execute("ip link set %iface% up", ifd, exec);
 324         return ((result == 2) ? 2 : 0);
 325 #else
 326         return execute("ifconfig %iface% add ::1", ifd, exec);
 327 #endif
 328 }
 329
 330 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 331 {
 332 #if ENABLE_FEATURE_IFUPDOWN_IP
 333         return execute("ip link set %iface% down", ifd, exec);
 334 #else
 335         return execute("ifconfig %iface% del ::1", ifd, exec);
 336 #endif
 337 }
 338
 339 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 340 {
 341         int result;
 342 #if ENABLE_FEATURE_IFUPDOWN_IP
 343         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
 344         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 345         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
 346         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 347 #else
 348         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
 349         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 350         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
 351 #endif
 352         return ((result == 3) ? 3 : 0);
 353 }
 354
 355 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 356 {
 357 #if ENABLE_FEATURE_IFUPDOWN_IP
 358         return execute("ip link set %iface% down", ifd, exec);
 359 #else
 360         return execute("ifconfig %iface% down", ifd, exec);
 361 #endif
 362 }
 363
 364 #if ENABLE_FEATURE_IFUPDOWN_IP
 365 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 366 {
 367         int result;
 368         result = execute("ip tunnel add %iface% mode sit remote "
 369                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
 370         result += execute("ip link set %iface% up", ifd, exec);
 371         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 372         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
 373         return ((result == 4) ? 4 : 0);
 374 }
 375
 376 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 377 {
 378         return execute("ip tunnel del %iface%", ifd, exec);
 379 }
 380 #endif
 381
 382 static const struct method_t methods6[] = {
 383 #if ENABLE_FEATURE_IFUPDOWN_IP
 384         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 385 #endif
 386         { "static", static_up6, static_down6, },
 387         { "loopback", loopback_up6, loopback_down6, },
 388 };
 389
 390 static const struct address_family_t addr_inet6 = {
 391         "inet6",
 392         ARRAY_SIZE(methods6),
 393         methods6
 394 };
 395 #endif /* FEATURE_IFUPDOWN_IPV6 */
 396
 397 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 398 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 399 {
 400 #if ENABLE_FEATURE_IFUPDOWN_IP
 401         int result;
 402         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 403         result += execute("ip link set %iface% up", ifd, exec);
 404         return ((result == 2) ? 2 : 0);
 405 #else
 406         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
 407 #endif
 408 }
 409
 410 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 411 {
 412 #if ENABLE_FEATURE_IFUPDOWN_IP
 413         int result;
 414         result = execute("ip addr flush dev %iface%", ifd, exec);
 415         result += execute("ip link set %iface% down", ifd, exec);
 416         return ((result == 2) ? 2 : 0);
 417 #else
 418         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
 419 #endif
 420 }
 421
 422 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 423 {
 424         int result;
 425 #if ENABLE_FEATURE_IFUPDOWN_IP
 426         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
 427                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
 428         result += execute("ip link set[[ mtu %mtu%]][[ address %hwaddress%]] %iface% up", ifd, exec);
 429         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
 430         return ((result == 3) ? 3 : 0);
 431 #else
 432         /* ifconfig said to set iface up before it processes hw %hwaddress%,
 433          * which then of course fails. Thus we run two separate ifconfig */
 434         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
 435                                 ifd, exec);
 436         result += execute("ifconfig %iface% %address% netmask %netmask%"
 437                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
 438                                 ifd, exec);
 439         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
 440         return ((result == 3) ? 3 : 0);
 441 #endif
 442 }
 443
 444 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 445 {
 446         int result;
 447 #if ENABLE_FEATURE_IFUPDOWN_IP
 448         result = execute("ip addr flush dev %iface%", ifd, exec);
 449         result += execute("ip link set %iface% down", ifd, exec);
 450 #else
 451         result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec);
 452         result += execute("ifconfig %iface% down", ifd, exec);
 453 #endif
 454         return ((result == 2) ? 2 : 0);
 455 }
 456
 457 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 458 struct dhcp_client_t
 459 {
 460         const char *name;
 461         const char *startcmd;
 462         const char *stopcmd;
 463 };
 464
 465 static const struct dhcp_client_t ext_dhcp_clients[] = {
 466         { "dhcpcd",
 467                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
 468                 "dhcpcd -k %iface%",
 469         },
 470         { "dhclient",
 471                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
 472                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
 473         },
 474         { "pump",
 475                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
 476                 "pump -i %iface% -k",
 477         },
 478         { "udhcpc",
 479                 "udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]]"
 480                                 "[[ -s %script%]][[ %udhcpc_opts%]]",
 481                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 482         },
 483 };
 484 #endif /* ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 485
 486 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 487 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 488 {
 489         unsigned i;
 490 #if ENABLE_FEATURE_IFUPDOWN_IP
 491         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 492         if (!execute("ip link set %iface% up", ifd, exec))
 493                 return 0;
 494 #endif
 495         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 496                 if (exists_execable(ext_dhcp_clients[i].name))
 497                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 498         }
 499         bb_error_msg("no dhcp clients found");
 500         return 0;
 501 }
 502 #elif ENABLE_APP_UDHCPC
 503 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 504 {
 505 #if ENABLE_FEATURE_IFUPDOWN_IP
 506         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 507         if (!execute("ip link set %iface% up", ifd, exec))
 508                 return 0;
 509 #endif
 510         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 511                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]][[ %udhcpc_opts%]]",
 512                         ifd, exec);
 513 }
 514 #else
 515 static int dhcp_up(struct interface_defn_t *ifd ATTRIBUTE_UNUSED,
 516                 execfn *exec ATTRIBUTE_UNUSED)
 517 {
 518         return 0; /* no dhcp support */
 519 }
 520 #endif
 521
 522 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 523 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 524 {
 525         unsigned i;
 526         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 527                 if (exists_execable(ext_dhcp_clients[i].name))
 528                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 529         }
 530         bb_error_msg("no dhcp clients found, using static interface shutdown");
 531         return static_down(ifd, exec);
 532 }
 533 #elif ENABLE_APP_UDHCPC
 534 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 535 {
 536         return execute("kill "
 537                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 538 }
 539 #else
 540 static int dhcp_down(struct interface_defn_t *ifd ATTRIBUTE_UNUSED,
 541                 execfn *exec ATTRIBUTE_UNUSED)
 542 {
 543         return 0; /* no dhcp support */
 544 }
 545 #endif
 546
 547 static int manual_up_down(struct interface_defn_t *ifd ATTRIBUTE_UNUSED, execfn *exec ATTRIBUTE_UNUSED)
 548 {
 549         return 1;
 550 }
 551
 552 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 553 {
 554         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 555                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 556                         " --returniffail --serverbcast", ifd, exec);
 557 }
 558
 559 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 560 {
 561         return execute("pon[[ %provider%]]", ifd, exec);
 562 }
 563
 564 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 565 {
 566         return execute("poff[[ %provider%]]", ifd, exec);
 567 }
 568
 569 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 570 {
 571         return execute("start-stop-daemon --start -x wvdial "
 572                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 573 }
 574
 575 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 576 {
 577         return execute("start-stop-daemon --stop -x wvdial "
 578                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 579 }
 580
 581 static const struct method_t methods[] = {
 582         { "manual", manual_up_down, manual_up_down, },
 583         { "wvdial", wvdial_up, wvdial_down, },
 584         { "ppp", ppp_up, ppp_down, },
 585         { "static", static_up, static_down, },
 586         { "bootp", bootp_up, static_down, },
 587         { "dhcp", dhcp_up, dhcp_down, },
 588         { "loopback", loopback_up, loopback_down, },
 589 };
 590
 591 static const struct address_family_t addr_inet = {
 592         "inet",
 593         ARRAY_SIZE(methods),
 594         methods
 595 };
 596
 597 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 598
 599 static char *next_word(char **buf)
 600 {
 601         unsigned length;
 602         char *word;
 603
 604         /* Skip over leading whitespace */
 605         word = skip_whitespace(*buf);
 606
 607         /* Stop on EOL */
 608         if (*word == '\0')
 609                 return NULL;
 610
 611         /* Find the length of this word (can't be 0) */
 612         length = strcspn(word, " \t\n");
 613
 614         /* Unless we are already at NUL, store NUL and advance */
 615         if (word[length] != '\0')
 616                 word[length++] = '\0';
 617
 618         *buf = word + length;
 619
 620         return word;
 621 }
 622
 623 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 624 {
 625         int i;
 626
 627         if (!name)
 628                 return NULL;
 629
 630         for (i = 0; af[i]; i++) {
 631                 if (strcmp(af[i]->name, name) == 0) {
 632                         return af[i];
 633                 }
 634         }
 635         return NULL;
 636 }
 637
 638 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 639 {
 640         int i;
 641
 642         if (!name)
 643                 return NULL;
 644         /* TODO: use index_in_str_array() */
 645         for (i = 0; i < af->n_methods; i++) {
 646                 if (strcmp(af->method[i].name, name) == 0) {
 647                         return &af->method[i];
 648                 }
 649         }
 650         return NULL;
 651 }
 652
 653 static const llist_t *find_list_string(const llist_t *list, const char *string)
 654 {
 655         if (string == NULL)
 656                 return NULL;
 657
 658         while (list) {
 659                 if (strcmp(list->data, string) == 0) {
 660                         return list;
 661                 }
 662                 list = list->link;
 663         }
 664         return NULL;
 665 }
 666
 667 static struct interfaces_file_t *read_interfaces(const char *filename)
 668 {
 669         /* Let's try to be compatible.
 670          *
 671          * "man 5 interfaces" says:
 672          * Lines starting with "#" are ignored. Note that end-of-line
 673          * comments are NOT supported, comments must be on a line of their own.
 674          * A line may be extended across multiple lines by making
 675          * the last character a backslash.
 676          *
 677          * Seen elsewhere in example config file:
 678          * A "#" character in the very first column makes the rest of the line
 679          * be ignored. Blank lines are ignored. Lines may be indented freely.
 680          * A "\" character at the very end of the line indicates the next line
 681          * should be treated as a continuation of the current one.
 682          */
 683 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 684         struct mapping_defn_t *currmap = NULL;
 685 #endif
 686         struct interface_defn_t *currif = NULL;
 687         struct interfaces_file_t *defn;
 688         FILE *f;
 689         char *buf;
 690         char *first_word;
 691         char *rest_of_line;
 692         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 693
 694         defn = xzalloc(sizeof(*defn));
 695         f = xfopen(filename, "r");
 696
 697         while ((buf = xmalloc_fgetline(f)) != NULL) {
 698 #if ENABLE_DESKTOP
 699                 /* Trailing "\" concatenates lines */
 700                 char *p;
 701                 while ((p = last_char_is(buf, '\\')) != NULL) {
 702                         *p = '\0';
 703                         rest_of_line = xmalloc_fgetline(f);
 704                         if (!rest_of_line)
 705                                 break;
 706                         p = xasprintf("%s%s", buf, rest_of_line);
 707                         free(buf);
 708                         free(rest_of_line);
 709                         buf = p;
 710                 }
 711 #endif
 712                 rest_of_line = buf;
 713                 first_word = next_word(&rest_of_line);
 714                 if (!first_word || *buf == '#') {
 715                         free(buf);
 716                         continue; /* blank/comment line */
 717                 }
 718
 719                 if (strcmp(first_word, "mapping") == 0) {
 720 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 721                         currmap = xzalloc(sizeof(*currmap));
 722
 723                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 724                                 if (currmap->n_matches >= currmap->max_matches) {
 725                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 726                                         currmap->match = xrealloc(currmap->match,
 727                                                 sizeof(*currmap->match) * currmap->max_matches);
 728                                 }
 729                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
 730                         }
 731                         /*currmap->max_mappings = 0; - done by xzalloc */
 732                         /*currmap->n_mappings = 0;*/
 733                         /*currmap->mapping = NULL;*/
 734                         /*currmap->script = NULL;*/
 735                         {
 736                                 struct mapping_defn_t **where = &defn->mappings;
 737                                 while (*where != NULL) {
 738                                         where = &(*where)->next;
 739                                 }
 740                                 *where = currmap;
 741                                 /*currmap->next = NULL;*/
 742                         }
 743                         debug_noise("Added mapping\n");
 744 #endif
 745                         currently_processing = MAPPING;
 746                 } else if (strcmp(first_word, "iface") == 0) {
 747                         static const struct address_family_t *const addr_fams[] = {
 748 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 749                                 &addr_inet,
 750 #endif
 751 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 752                                 &addr_inet6,
 753 #endif
 754                                 NULL
 755                         };
 756                         char *iface_name;
 757                         char *address_family_name;
 758                         char *method_name;
 759                         llist_t *iface_list;
 760
 761                         currif = xzalloc(sizeof(*currif));
 762                         iface_name = next_word(&rest_of_line);
 763                         address_family_name = next_word(&rest_of_line);
 764                         method_name = next_word(&rest_of_line);
 765
 766                         if (method_name == NULL)
 767                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 768
 769                         /* ship any trailing whitespace */
 770                         rest_of_line = skip_whitespace(rest_of_line);
 771
 772                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
 773                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 774
 775                         currif->iface = xstrdup(iface_name);
 776
 777                         currif->address_family = get_address_family(addr_fams, address_family_name);
 778                         if (!currif->address_family)
 779                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 780
 781                         currif->method = get_method(currif->address_family, method_name);
 782                         if (!currif->method)
 783                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 784
 785                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 786                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 787                                 if ((strcmp(tmp->iface, currif->iface) == 0)
 788                                  && (tmp->address_family == currif->address_family)
 789                                 ) {
 790                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
 791                                 }
 792                         }
 793                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 794
 795                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 796                         currently_processing = IFACE;
 797                 } else if (strcmp(first_word, "auto") == 0) {
 798                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 799
 800                                 /* Check the interface isnt already listed */
 801                                 if (find_list_string(defn->autointerfaces, first_word)) {
 802                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 803                                 }
 804
 805                                 /* Add the interface to the list */
 806                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
 807                                 debug_noise("\nauto %s\n", first_word);
 808                         }
 809                         currently_processing = NONE;
 810                 } else {
 811                         switch (currently_processing) {
 812                         case IFACE:
 813                                 if (rest_of_line[0] == '\0')
 814                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
 815
 816                                 if (strcmp(first_word, "up") != 0
 817                                  && strcmp(first_word, "down") != 0
 818                                  && strcmp(first_word, "pre-up") != 0
 819                                  && strcmp(first_word, "post-down") != 0
 820                                 ) {
 821                                         int i;
 822                                         for (i = 0; i < currif->n_options; i++) {
 823                                                 if (strcmp(currif->option[i].name, first_word) == 0)
 824                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
 825                                         }
 826                                 }
 827                                 if (currif->n_options >= currif->max_options) {
 828                                         currif->max_options += 10;
 829                                         currif->option = xrealloc(currif->option,
 830                                                 sizeof(*currif->option) * currif->max_options);
 831                                 }
 832                                 debug_noise("\t%s=%s\n", first_word, rest_of_line);
 833                                 currif->option[currif->n_options].name = xstrdup(first_word);
 834                                 currif->option[currif->n_options].value = xstrdup(rest_of_line);
 835                                 currif->n_options++;
 836                                 break;
 837                         case MAPPING:
 838 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 839                                 if (strcmp(first_word, "script") == 0) {
 840                                         if (currmap->script != NULL)
 841                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
 842                                         currmap->script = xstrdup(next_word(&rest_of_line));
 843                                 } else if (strcmp(first_word, "map") == 0) {
 844                                         if (currmap->n_mappings >= currmap->max_mappings) {
 845                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 846                                                 currmap->mapping = xrealloc(currmap->mapping,
 847                                                         sizeof(char *) * currmap->max_mappings);
 848                                         }
 849                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
 850                                         currmap->n_mappings++;
 851                                 } else {
 852                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
 853                                 }
 854 #endif
 855                                 break;
 856                         case NONE:
 857                         default:
 858                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
 859                         }
 860                 }
 861                 free(buf);
 862         } /* while (fgets) */
 863
 864         if (ferror(f) != 0) {
 865                 /* ferror does NOT set errno! */
 866                 bb_error_msg_and_die("%s: I/O error", filename);
 867         }
 868         fclose(f);
 869
 870         return defn;
 871 }
 872
 873 static char *setlocalenv(const char *format, const char *name, const char *value)
 874 {
 875         char *result;
 876         char *here;
 877         char *there;
 878
 879         result = xasprintf(format, name, value);
 880
 881         for (here = there = result; *there != '=' && *there; there++) {
 882                 if (*there == '-')
 883                         *there = '_';
 884                 if (isalpha(*there))
 885                         *there = toupper(*there);
 886
 887                 if (isalnum(*there) || *there == '_') {
 888                         *here = *there;
 889                         here++;
 890                 }
 891         }
 892         memmove(here, there, strlen(there) + 1);
 893
 894         return result;
 895 }
 896
 897 static void set_environ(struct interface_defn_t *iface, const char *mode)
 898 {
 899         char **environend;
 900         int i;
 901         const int n_env_entries = iface->n_options + 5;
 902         char **ppch;
 903
 904         if (my_environ != NULL) {
 905                 for (ppch = my_environ; *ppch; ppch++) {
 906                         free(*ppch);
 907                         *ppch = NULL;
 908                 }
 909                 free(my_environ);
 910         }
 911         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 912         environend = my_environ;
 913
 914         for (i = 0; i < iface->n_options; i++) {
 915                 if (strcmp(iface->option[i].name, "up") == 0
 916                  || strcmp(iface->option[i].name, "down") == 0
 917                  || strcmp(iface->option[i].name, "pre-up") == 0
 918                  || strcmp(iface->option[i].name, "post-down") == 0
 919                 ) {
 920                         continue;
 921                 }
 922                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 923         }
 924
 925         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 926         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 927         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 928         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 929         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 930 }
 931
 932 static int doit(char *str)
 933 {
 934         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 935                 puts(str);
 936         }
 937         if (!(option_mask32 & OPT_no_act)) {
 938                 pid_t child;
 939                 int status;
 940
 941                 fflush(NULL);
 942                 child = vfork();
 943                 switch (child) {
 944                 case -1: /* failure */
 945                         return 0;
 946                 case 0: /* child */
 947                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 948                         _exit(127);
 949                 }
 950                 safe_waitpid(child, &status, 0);
 951                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 952                         return 0;
 953                 }
 954         }
 955         return 1;
 956 }
 957
 958 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 959 {
 960         int i;
 961         char *buf;
 962         for (i = 0; i < ifd->n_options; i++) {
 963                 if (strcmp(ifd->option[i].name, opt) == 0) {
 964                         if (!doit(ifd->option[i].value)) {
 965                                 return 0;
 966                         }
 967                 }
 968         }
 969
 970         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 971         /* heh, we don't bother free'ing it */
 972         return doit(buf);
 973 }
 974
 975 static int check(char *str)
 976 {
 977         return str != NULL;
 978 }
 979
 980 static int iface_up(struct interface_defn_t *iface)
 981 {
 982         if (!iface->method->up(iface, check)) return -1;
 983         set_environ(iface, "start");
 984         if (!execute_all(iface, "pre-up")) return 0;
 985         if (!iface->method->up(iface, doit)) return 0;
 986         if (!execute_all(iface, "up")) return 0;
 987         return 1;
 988 }
 989
 990 static int iface_down(struct interface_defn_t *iface)
 991 {
 992         if (!iface->method->down(iface,check)) return -1;
 993         set_environ(iface, "stop");
 994         if (!execute_all(iface, "down")) return 0;
 995         if (!iface->method->down(iface, doit)) return 0;
 996         if (!execute_all(iface, "post-down")) return 0;
 997         return 1;
 998 }
 999
1000 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1001 static int popen2(FILE **in, FILE **out, char *command, char *param)
1002 {
1003         char *argv[3] = { command, param, NULL };
1004         struct fd_pair infd, outfd;
1005         pid_t pid;
1006
1007         xpiped_pair(infd);
1008         xpiped_pair(outfd);
1009
1010         fflush(NULL);
1011         pid = xvfork();
1012
1013         if (pid == 0) { /* child */
1014                 /* NB: close _first_, then move fds! */
1015                 close(infd.wr);
1016                 close(outfd.rd);
1017                 xmove_fd(infd.rd, 0);
1018                 xmove_fd(outfd.wr, 1);
1019                 BB_EXECVP(command, argv);
1020                 _exit(127);
1021         }
1022         /* parent */
1023         close(infd.rd);
1024         close(outfd.wr);
1025         *in = fdopen(infd.wr, "w");
1026         *out = fdopen(outfd.rd, "r");
1027         return pid;
1028 }
1029
1030 static char *run_mapping(char *physical, struct mapping_defn_t *map)
1031 {
1032         FILE *in, *out;
1033         int i, status;
1034         pid_t pid;
1035
1036         char *logical = xstrdup(physical);
1037
1038         /* Run the mapping script. Never fails. */
1039         pid = popen2(&in, &out, map->script, physical);
1040
1041         /* Write mappings to stdin of mapping script. */
1042         for (i = 0; i < map->n_mappings; i++) {
1043                 fprintf(in, "%s\n", map->mapping[i]);
1044         }
1045         fclose(in);
1046         safe_waitpid(pid, &status, 0);
1047
1048         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1049                 /* If the mapping script exited successfully, try to
1050                  * grab a line of output and use that as the name of the
1051                  * logical interface. */
1052                 char *new_logical = xmalloc_fgetline(out);
1053
1054                 if (new_logical) {
1055                         /* If we are able to read a line of output from the script,
1056                          * remove any trailing whitespace and use this value
1057                          * as the name of the logical interface. */
1058                         char *pch = new_logical + strlen(new_logical) - 1;
1059
1060                         while (pch >= new_logical && isspace(*pch))
1061                                 *(pch--) = '\0';
1062
1063                         free(logical);
1064                         logical = new_logical;
1065                 }
1066         }
1067
1068         fclose(out);
1069
1070         return logical;
1071 }
1072 #endif /* FEATURE_IFUPDOWN_MAPPING */
1073
1074 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1075 {
1076         unsigned iface_len = strlen(iface);
1077         llist_t *search = state_list;
1078
1079         while (search) {
1080                 if ((strncmp(search->data, iface, iface_len) == 0)
1081                  && (search->data[iface_len] == '=')
1082                 ) {
1083                         return search;
1084                 }
1085                 search = search->link;
1086         }
1087         return NULL;
1088 }
1089
1090 /* read the previous state from the state file */
1091 static llist_t *read_iface_state(void)
1092 {
1093         llist_t *state_list = NULL;
1094         FILE *state_fp = fopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "r");
1095
1096         if (state_fp) {
1097                 char *start, *end_ptr;
1098                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1099                         /* We should only need to check for a single character */
1100                         end_ptr = start + strcspn(start, " \t\n");
1101                         *end_ptr = '\0';
1102                         llist_add_to(&state_list, start);
1103                 }
1104                 fclose(state_fp);
1105         }
1106         return state_list;
1107 }
1108
1109
1110 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1111 int ifupdown_main(int argc, char **argv)
1112 {
1113         int (*cmds)(struct interface_defn_t *);
1114         struct interfaces_file_t *defn;
1115         llist_t *target_list = NULL;
1116         const char *interfaces = "/etc/network/interfaces";
1117         bool any_failures = 0;
1118
1119         cmds = iface_down;
1120         if (applet_name[2] == 'u') {
1121                 /* ifup command */
1122                 cmds = iface_up;
1123         }
1124
1125         getopt32(argv, OPTION_STR, &interfaces);
1126         if (argc - optind > 0) {
1127                 if (DO_ALL) bb_show_usage();
1128         } else {
1129                 if (!DO_ALL) bb_show_usage();
1130         }
1131
1132         debug_noise("reading %s file:\n", interfaces);
1133         defn = read_interfaces(interfaces);
1134         debug_noise("\ndone reading %s\n\n", interfaces);
1135
1136         startup_PATH = getenv("PATH");
1137         if (!startup_PATH) startup_PATH = "";
1138
1139         /* Create a list of interfaces to work on */
1140         if (DO_ALL) {
1141                 target_list = defn->autointerfaces;
1142         } else {
1143                 llist_add_to_end(&target_list, argv[optind]);
1144         }
1145
1146         /* Update the interfaces */
1147         while (target_list) {
1148                 llist_t *iface_list;
1149                 struct interface_defn_t *currif;
1150                 char *iface;
1151                 char *liface;
1152                 char *pch;
1153                 bool okay = 0;
1154                 int cmds_ret;
1155
1156                 iface = xstrdup(target_list->data);
1157                 target_list = target_list->link;
1158
1159                 pch = strchr(iface, '=');
1160                 if (pch) {
1161                         *pch = '\0';
1162                         liface = xstrdup(pch + 1);
1163                 } else {
1164                         liface = xstrdup(iface);
1165                 }
1166
1167                 if (!FORCE) {
1168                         llist_t *state_list = read_iface_state();
1169                         const llist_t *iface_state = find_iface_state(state_list, iface);
1170
1171                         if (cmds == iface_up) {
1172                                 /* ifup */
1173                                 if (iface_state) {
1174                                         bb_error_msg("interface %s already configured", iface);
1175                                         continue;
1176                                 }
1177                         } else {
1178                                 /* ifdown */
1179                                 if (!iface_state) {
1180                                         bb_error_msg("interface %s not configured", iface);
1181                                         continue;
1182                                 }
1183                         }
1184                         llist_free(state_list, free);
1185                 }
1186
1187 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1188                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1189                         struct mapping_defn_t *currmap;
1190
1191                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1192                                 int i;
1193                                 for (i = 0; i < currmap->n_matches; i++) {
1194                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1195                                                 continue;
1196                                         if (VERBOSE) {
1197                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1198                                         }
1199                                         liface = run_mapping(iface, currmap);
1200                                         break;
1201                                 }
1202                         }
1203                 }
1204 #endif
1205
1206                 iface_list = defn->ifaces;
1207                 while (iface_list) {
1208                         currif = (struct interface_defn_t *) iface_list->data;
1209                         if (strcmp(liface, currif->iface) == 0) {
1210                                 char *oldiface = currif->iface;
1211
1212                                 okay = 1;
1213                                 currif->iface = iface;
1214
1215                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1216
1217                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1218                                 cmds_ret = cmds(currif);
1219                                 if (cmds_ret == -1) {
1220                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1221                                                         liface, currif->address_family->name);
1222                                         any_failures = 1;
1223                                 } else if (cmds_ret == 0) {
1224                                         any_failures = 1;
1225                                 }
1226
1227                                 currif->iface = oldiface;
1228                         }
1229                         iface_list = iface_list->link;
1230                 }
1231                 if (VERBOSE) {
1232                         bb_putchar('\n');
1233                 }
1234
1235                 if (!okay && !FORCE) {
1236                         bb_error_msg("ignoring unknown interface %s", liface);
1237                         any_failures = 1;
1238                 } else if (!NO_ACT) {
1239                         /* update the state file */
1240                         FILE *state_fp;
1241                         llist_t *state;
1242                         llist_t *state_list = read_iface_state();
1243                         llist_t *iface_state = find_iface_state(state_list, iface);
1244
1245                         if (cmds == iface_up) {
1246                                 char * const newiface = xasprintf("%s=%s", iface, liface);
1247                                 if (iface_state == NULL) {
1248                                         llist_add_to_end(&state_list, newiface);
1249                                 } else {
1250                                         free(iface_state->data);
1251                                         iface_state->data = newiface;
1252                                 }
1253                         } else {
1254                                 /* Remove an interface from state_list */
1255                                 llist_unlink(&state_list, iface_state);
1256                                 free(llist_pop(&iface_state));
1257                         }
1258
1259                         /* Actually write the new state */
1260                         state_fp = xfopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "w");
1261                         state = state_list;
1262                         while (state) {
1263                                 if (state->data) {
1264                                         fprintf(state_fp, "%s\n", state->data);
1265                                 }
1266                                 state = state->link;
1267                         }
1268                         fclose(state_fp);
1269                         llist_free(state_list, free);
1270                 }
1271         }
1272
1273         return any_failures;
1274 }