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%]][[ -s %script%]][[ -t %retries%]]",
 480                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
 481         },
 482 };
 483 #endif /* ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
 484
 485 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 486 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 487 {
 488         int i;
 489 #if ENABLE_FEATURE_IFUPDOWN_IP
 490         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 491         if (!execute("ip link set %iface% up", ifd, exec))
 492                 return 0;
 493 #endif
 494         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 495                 if (exists_execable(ext_dhcp_clients[i].name))
 496                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
 497         }
 498         bb_error_msg("no dhcp clients found");
 499         return 0;
 500 }
 501 #elif ENABLE_APP_UDHCPC
 502 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 503 {
 504 #if ENABLE_FEATURE_IFUPDOWN_IP
 505         /* ip doesn't up iface when it configures it (unlike ifconfig) */
 506         if (!execute("ip link set %iface% up", ifd, exec))
 507                 return 0;
 508 #endif
 509         return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
 510                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]][[ -t %retries%]]",
 511                         ifd, exec);
 512 }
 513 #else
 514 static int dhcp_up(struct interface_defn_t *ifd ATTRIBUTE_UNUSED,
 515                 execfn *exec ATTRIBUTE_UNUSED)
 516 {
 517         return 0; /* no dhcp support */
 518 }
 519 #endif
 520
 521 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
 522 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 523 {
 524         int i;
 525         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
 526                 if (exists_execable(ext_dhcp_clients[i].name))
 527                         return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
 528         }
 529         bb_error_msg("no dhcp clients found, using static interface shutdown");
 530         return static_down(ifd, exec);
 531 }
 532 #elif ENABLE_APP_UDHCPC
 533 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 534 {
 535         return execute("kill "
 536                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 537 }
 538 #else
 539 static int dhcp_down(struct interface_defn_t *ifd ATTRIBUTE_UNUSED,
 540                 execfn *exec ATTRIBUTE_UNUSED)
 541 {
 542         return 0; /* no dhcp support */
 543 }
 544 #endif
 545
 546 static int manual_up_down(struct interface_defn_t *ifd ATTRIBUTE_UNUSED, execfn *exec ATTRIBUTE_UNUSED)
 547 {
 548         return 1;
 549 }
 550
 551 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 552 {
 553         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
 554                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
 555                         " --returniffail --serverbcast", ifd, exec);
 556 }
 557
 558 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 559 {
 560         return execute("pon[[ %provider%]]", ifd, exec);
 561 }
 562
 563 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 564 {
 565         return execute("poff[[ %provider%]]", ifd, exec);
 566 }
 567
 568 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 569 {
 570         return execute("start-stop-daemon --start -x wvdial "
 571                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
 572 }
 573
 574 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 575 {
 576         return execute("start-stop-daemon --stop -x wvdial "
 577                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
 578 }
 579
 580 static const struct method_t methods[] = {
 581         { "manual", manual_up_down, manual_up_down, },
 582         { "wvdial", wvdial_up, wvdial_down, },
 583         { "ppp", ppp_up, ppp_down, },
 584         { "static", static_up, static_down, },
 585         { "bootp", bootp_up, static_down, },
 586         { "dhcp", dhcp_up, dhcp_down, },
 587         { "loopback", loopback_up, loopback_down, },
 588 };
 589
 590 static const struct address_family_t addr_inet = {
 591         "inet",
 592         ARRAY_SIZE(methods),
 593         methods
 594 };
 595
 596 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
 597
 598 static char *next_word(char **buf)
 599 {
 600         unsigned length;
 601         char *word;
 602
 603         /* Skip over leading whitespace */
 604         word = skip_whitespace(*buf);
 605
 606         /* Stop on EOL */
 607         if (*word == '\0')
 608                 return NULL;
 609
 610         /* Find the length of this word (can't be 0) */
 611         length = strcspn(word, " \t\n");
 612
 613         /* Unless we are already at NUL, store NUL and advance */
 614         if (word[length] != '\0')
 615                 word[length++] = '\0';
 616
 617         *buf = word + length;
 618
 619         return word;
 620 }
 621
 622 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
 623 {
 624         int i;
 625
 626         if (!name)
 627                 return NULL;
 628
 629         for (i = 0; af[i]; i++) {
 630                 if (strcmp(af[i]->name, name) == 0) {
 631                         return af[i];
 632                 }
 633         }
 634         return NULL;
 635 }
 636
 637 static const struct method_t *get_method(const struct address_family_t *af, char *name)
 638 {
 639         int i;
 640
 641         if (!name)
 642                 return NULL;
 643         /* TODO: use index_in_str_array() */
 644         for (i = 0; i < af->n_methods; i++) {
 645                 if (strcmp(af->method[i].name, name) == 0) {
 646                         return &af->method[i];
 647                 }
 648         }
 649         return NULL;
 650 }
 651
 652 static const llist_t *find_list_string(const llist_t *list, const char *string)
 653 {
 654         if (string == NULL)
 655                 return NULL;
 656
 657         while (list) {
 658                 if (strcmp(list->data, string) == 0) {
 659                         return list;
 660                 }
 661                 list = list->link;
 662         }
 663         return NULL;
 664 }
 665
 666 static struct interfaces_file_t *read_interfaces(const char *filename)
 667 {
 668         /* Let's try to be compatible.
 669          *
 670          * "man 5 interfaces" says:
 671          * Lines starting with "#" are ignored. Note that end-of-line
 672          * comments are NOT supported, comments must be on a line of their own.
 673          * A line may be extended across multiple lines by making
 674          * the last character a backslash.
 675          *
 676          * Seen elsewhere in example config file:
 677          * A "#" character in the very first column makes the rest of the line
 678          * be ignored. Blank lines are ignored. Lines may be indented freely.
 679          * A "\" character at the very end of the line indicates the next line
 680          * should be treated as a continuation of the current one.
 681          */
 682 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 683         struct mapping_defn_t *currmap = NULL;
 684 #endif
 685         struct interface_defn_t *currif = NULL;
 686         struct interfaces_file_t *defn;
 687         FILE *f;
 688         char *buf;
 689         char *first_word;
 690         char *rest_of_line;
 691         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 692
 693         defn = xzalloc(sizeof(*defn));
 694         f = xfopen(filename, "r");
 695
 696         while ((buf = xmalloc_fgetline(f)) != NULL) {
 697 #if ENABLE_DESKTOP
 698                 /* Trailing "\" concatenates lines */
 699                 char *p;
 700                 while ((p = last_char_is(buf, '\\')) != NULL) {
 701                         *p = '\0';
 702                         rest_of_line = xmalloc_fgetline(f);
 703                         if (!rest_of_line)
 704                                 break;
 705                         p = xasprintf("%s%s", buf, rest_of_line);
 706                         free(buf);
 707                         free(rest_of_line);
 708                         buf = p;
 709                 }
 710 #endif
 711                 rest_of_line = buf;
 712                 first_word = next_word(&rest_of_line);
 713                 if (!first_word || *buf == '#') {
 714                         free(buf);
 715                         continue; /* blank/comment line */
 716                 }
 717
 718                 if (strcmp(first_word, "mapping") == 0) {
 719 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 720                         currmap = xzalloc(sizeof(*currmap));
 721
 722                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 723                                 if (currmap->n_matches >= currmap->max_matches) {
 724                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 725                                         currmap->match = xrealloc(currmap->match,
 726                                                 sizeof(*currmap->match) * currmap->max_matches);
 727                                 }
 728                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
 729                         }
 730                         /*currmap->max_mappings = 0; - done by xzalloc */
 731                         /*currmap->n_mappings = 0;*/
 732                         /*currmap->mapping = NULL;*/
 733                         /*currmap->script = NULL;*/
 734                         {
 735                                 struct mapping_defn_t **where = &defn->mappings;
 736                                 while (*where != NULL) {
 737                                         where = &(*where)->next;
 738                                 }
 739                                 *where = currmap;
 740                                 /*currmap->next = NULL;*/
 741                         }
 742                         debug_noise("Added mapping\n");
 743 #endif
 744                         currently_processing = MAPPING;
 745                 } else if (strcmp(first_word, "iface") == 0) {
 746                         static const struct address_family_t *const addr_fams[] = {
 747 #if ENABLE_FEATURE_IFUPDOWN_IPV4
 748                                 &addr_inet,
 749 #endif
 750 #if ENABLE_FEATURE_IFUPDOWN_IPV6
 751                                 &addr_inet6,
 752 #endif
 753                                 NULL
 754                         };
 755                         char *iface_name;
 756                         char *address_family_name;
 757                         char *method_name;
 758                         llist_t *iface_list;
 759
 760                         currif = xzalloc(sizeof(*currif));
 761                         iface_name = next_word(&rest_of_line);
 762                         address_family_name = next_word(&rest_of_line);
 763                         method_name = next_word(&rest_of_line);
 764
 765                         if (method_name == NULL)
 766                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
 767
 768                         /* ship any trailing whitespace */
 769                         rest_of_line = skip_whitespace(rest_of_line);
 770
 771                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
 772                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
 773
 774                         currif->iface = xstrdup(iface_name);
 775
 776                         currif->address_family = get_address_family(addr_fams, address_family_name);
 777                         if (!currif->address_family)
 778                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
 779
 780                         currif->method = get_method(currif->address_family, method_name);
 781                         if (!currif->method)
 782                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
 783
 784                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 785                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 786                                 if ((strcmp(tmp->iface, currif->iface) == 0)
 787                                  && (tmp->address_family == currif->address_family)
 788                                 ) {
 789                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
 790                                 }
 791                         }
 792                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 793
 794                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 795                         currently_processing = IFACE;
 796                 } else if (strcmp(first_word, "auto") == 0) {
 797                         while ((first_word = next_word(&rest_of_line)) != NULL) {
 798
 799                                 /* Check the interface isnt already listed */
 800                                 if (find_list_string(defn->autointerfaces, first_word)) {
 801                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 802                                 }
 803
 804                                 /* Add the interface to the list */
 805                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
 806                                 debug_noise("\nauto %s\n", first_word);
 807                         }
 808                         currently_processing = NONE;
 809                 } else {
 810                         switch (currently_processing) {
 811                         case IFACE:
 812                                 if (rest_of_line[0] == '\0')
 813                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
 814
 815                                 if (strcmp(first_word, "up") != 0
 816                                  && strcmp(first_word, "down") != 0
 817                                  && strcmp(first_word, "pre-up") != 0
 818                                  && strcmp(first_word, "post-down") != 0
 819                                 ) {
 820                                         int i;
 821                                         for (i = 0; i < currif->n_options; i++) {
 822                                                 if (strcmp(currif->option[i].name, first_word) == 0)
 823                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
 824                                         }
 825                                 }
 826                                 if (currif->n_options >= currif->max_options) {
 827                                         currif->max_options += 10;
 828                                         currif->option = xrealloc(currif->option,
 829                                                 sizeof(*currif->option) * currif->max_options);
 830                                 }
 831                                 debug_noise("\t%s=%s\n", first_word, rest_of_line);
 832                                 currif->option[currif->n_options].name = xstrdup(first_word);
 833                                 currif->option[currif->n_options].value = xstrdup(rest_of_line);
 834                                 currif->n_options++;
 835                                 break;
 836                         case MAPPING:
 837 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
 838                                 if (strcmp(first_word, "script") == 0) {
 839                                         if (currmap->script != NULL)
 840                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
 841                                         currmap->script = xstrdup(next_word(&rest_of_line));
 842                                 } else if (strcmp(first_word, "map") == 0) {
 843                                         if (currmap->n_mappings >= currmap->max_mappings) {
 844                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
 845                                                 currmap->mapping = xrealloc(currmap->mapping,
 846                                                         sizeof(char *) * currmap->max_mappings);
 847                                         }
 848                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
 849                                         currmap->n_mappings++;
 850                                 } else {
 851                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
 852                                 }
 853 #endif
 854                                 break;
 855                         case NONE:
 856                         default:
 857                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
 858                         }
 859                 }
 860                 free(buf);
 861         } /* while (fgets) */
 862
 863         if (ferror(f) != 0) {
 864                 /* ferror does NOT set errno! */
 865                 bb_error_msg_and_die("%s: I/O error", filename);
 866         }
 867         fclose(f);
 868
 869         return defn;
 870 }
 871
 872 static char *setlocalenv(const char *format, const char *name, const char *value)
 873 {
 874         char *result;
 875         char *here;
 876         char *there;
 877
 878         result = xasprintf(format, name, value);
 879
 880         for (here = there = result; *there != '=' && *there; there++) {
 881                 if (*there == '-')
 882                         *there = '_';
 883                 if (isalpha(*there))
 884                         *there = toupper(*there);
 885
 886                 if (isalnum(*there) || *there == '_') {
 887                         *here = *there;
 888                         here++;
 889                 }
 890         }
 891         memmove(here, there, strlen(there) + 1);
 892
 893         return result;
 894 }
 895
 896 static void set_environ(struct interface_defn_t *iface, const char *mode)
 897 {
 898         char **environend;
 899         int i;
 900         const int n_env_entries = iface->n_options + 5;
 901         char **ppch;
 902
 903         if (my_environ != NULL) {
 904                 for (ppch = my_environ; *ppch; ppch++) {
 905                         free(*ppch);
 906                         *ppch = NULL;
 907                 }
 908                 free(my_environ);
 909         }
 910         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 911         environend = my_environ;
 912
 913         for (i = 0; i < iface->n_options; i++) {
 914                 if (strcmp(iface->option[i].name, "up") == 0
 915                  || strcmp(iface->option[i].name, "down") == 0
 916                  || strcmp(iface->option[i].name, "pre-up") == 0
 917                  || strcmp(iface->option[i].name, "post-down") == 0
 918                 ) {
 919                         continue;
 920                 }
 921                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 922         }
 923
 924         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 925         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 926         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 927         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 928         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
 929 }
 930
 931 static int doit(char *str)
 932 {
 933         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
 934                 puts(str);
 935         }
 936         if (!(option_mask32 & OPT_no_act)) {
 937                 pid_t child;
 938                 int status;
 939
 940                 fflush(NULL);
 941                 child = vfork();
 942                 switch (child) {
 943                 case -1: /* failure */
 944                         return 0;
 945                 case 0: /* child */
 946                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, my_environ);
 947                         _exit(127);
 948                 }
 949                 safe_waitpid(child, &status, 0);
 950                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 951                         return 0;
 952                 }
 953         }
 954         return 1;
 955 }
 956
 957 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 958 {
 959         int i;
 960         char *buf;
 961         for (i = 0; i < ifd->n_options; i++) {
 962                 if (strcmp(ifd->option[i].name, opt) == 0) {
 963                         if (!doit(ifd->option[i].value)) {
 964                                 return 0;
 965                         }
 966                 }
 967         }
 968
 969         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
 970         /* heh, we don't bother free'ing it */
 971         return doit(buf);
 972 }
 973
 974 static int check(char *str)
 975 {
 976         return str != NULL;
 977 }
 978
 979 static int iface_up(struct interface_defn_t *iface)
 980 {
 981         if (!iface->method->up(iface, check)) return -1;
 982         set_environ(iface, "start");
 983         if (!execute_all(iface, "pre-up")) return 0;
 984         if (!iface->method->up(iface, doit)) return 0;
 985         if (!execute_all(iface, "up")) return 0;
 986         return 1;
 987 }
 988
 989 static int iface_down(struct interface_defn_t *iface)
 990 {
 991         if (!iface->method->down(iface,check)) return -1;
 992         set_environ(iface, "stop");
 993         if (!execute_all(iface, "down")) return 0;
 994         if (!iface->method->down(iface, doit)) return 0;
 995         if (!execute_all(iface, "post-down")) return 0;
 996         return 1;
 997 }
 998
 999 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1000 static int popen2(FILE **in, FILE **out, char *command, char *param)
1001 {
1002         char *argv[3] = { command, param, NULL };
1003         struct fd_pair infd, outfd;
1004         pid_t pid;
1005
1006         xpiped_pair(infd);
1007         xpiped_pair(outfd);
1008
1009         fflush(NULL);
1010         pid = vfork();
1011
1012         switch (pid) {
1013         case -1:  /* failure */
1014                 bb_perror_msg_and_die("vfork");
1015         case 0:  /* child */
1016                 /* NB: close _first_, then move fds! */
1017                 close(infd.wr);
1018                 close(outfd.rd);
1019                 xmove_fd(infd.rd, 0);
1020                 xmove_fd(outfd.wr, 1);
1021                 BB_EXECVP(command, argv);
1022                 _exit(127);
1023         }
1024         /* parent */
1025         close(infd.rd);
1026         close(outfd.wr);
1027         *in = fdopen(infd.wr, "w");
1028         *out = fdopen(outfd.rd, "r");
1029         return pid;
1030 }
1031
1032 static char *run_mapping(char *physical, struct mapping_defn_t *map)
1033 {
1034         FILE *in, *out;
1035         int i, status;
1036         pid_t pid;
1037
1038         char *logical = xstrdup(physical);
1039
1040         /* Run the mapping script. Never fails. */
1041         pid = popen2(&in, &out, map->script, physical);
1042
1043         /* Write mappings to stdin of mapping script. */
1044         for (i = 0; i < map->n_mappings; i++) {
1045                 fprintf(in, "%s\n", map->mapping[i]);
1046         }
1047         fclose(in);
1048         safe_waitpid(pid, &status, 0);
1049
1050         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1051                 /* If the mapping script exited successfully, try to
1052                  * grab a line of output and use that as the name of the
1053                  * logical interface. */
1054                 char *new_logical = xmalloc_fgetline(out);
1055
1056                 if (new_logical) {
1057                         /* If we are able to read a line of output from the script,
1058                          * remove any trailing whitespace and use this value
1059                          * as the name of the logical interface. */
1060                         char *pch = new_logical + strlen(new_logical) - 1;
1061
1062                         while (pch >= new_logical && isspace(*pch))
1063                                 *(pch--) = '\0';
1064
1065                         free(logical);
1066                         logical = new_logical;
1067                 }
1068         }
1069
1070         fclose(out);
1071
1072         return logical;
1073 }
1074 #endif /* FEATURE_IFUPDOWN_MAPPING */
1075
1076 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1077 {
1078         unsigned iface_len = strlen(iface);
1079         llist_t *search = state_list;
1080
1081         while (search) {
1082                 if ((strncmp(search->data, iface, iface_len) == 0)
1083                  && (search->data[iface_len] == '=')
1084                 ) {
1085                         return search;
1086                 }
1087                 search = search->link;
1088         }
1089         return NULL;
1090 }
1091
1092 /* read the previous state from the state file */
1093 static llist_t *read_iface_state(void)
1094 {
1095         llist_t *state_list = NULL;
1096         FILE *state_fp = fopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "r");
1097
1098         if (state_fp) {
1099                 char *start, *end_ptr;
1100                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1101                         /* We should only need to check for a single character */
1102                         end_ptr = start + strcspn(start, " \t\n");
1103                         *end_ptr = '\0';
1104                         llist_add_to(&state_list, start);
1105                 }
1106                 fclose(state_fp);
1107         }
1108         return state_list;
1109 }
1110
1111
1112 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1113 int ifupdown_main(int argc, char **argv)
1114 {
1115         int (*cmds)(struct interface_defn_t *);
1116         struct interfaces_file_t *defn;
1117         llist_t *target_list = NULL;
1118         const char *interfaces = "/etc/network/interfaces";
1119         bool any_failures = 0;
1120
1121         cmds = iface_down;
1122         if (applet_name[2] == 'u') {
1123                 /* ifup command */
1124                 cmds = iface_up;
1125         }
1126
1127         getopt32(argv, OPTION_STR, &interfaces);
1128         if (argc - optind > 0) {
1129                 if (DO_ALL) bb_show_usage();
1130         } else {
1131                 if (!DO_ALL) bb_show_usage();
1132         }
1133
1134         debug_noise("reading %s file:\n", interfaces);
1135         defn = read_interfaces(interfaces);
1136         debug_noise("\ndone reading %s\n\n", interfaces);
1137
1138         startup_PATH = getenv("PATH");
1139         if (!startup_PATH) startup_PATH = "";
1140
1141         /* Create a list of interfaces to work on */
1142         if (DO_ALL) {
1143                 target_list = defn->autointerfaces;
1144         } else {
1145                 llist_add_to_end(&target_list, argv[optind]);
1146         }
1147
1148         /* Update the interfaces */
1149         while (target_list) {
1150                 llist_t *iface_list;
1151                 struct interface_defn_t *currif;
1152                 char *iface;
1153                 char *liface;
1154                 char *pch;
1155                 bool okay = 0;
1156                 unsigned cmds_ret;
1157
1158                 iface = xstrdup(target_list->data);
1159                 target_list = target_list->link;
1160
1161                 pch = strchr(iface, '=');
1162                 if (pch) {
1163                         *pch = '\0';
1164                         liface = xstrdup(pch + 1);
1165                 } else {
1166                         liface = xstrdup(iface);
1167                 }
1168
1169                 if (!FORCE) {
1170                         llist_t *state_list = read_iface_state();
1171                         const llist_t *iface_state = find_iface_state(state_list, iface);
1172
1173                         if (cmds == iface_up) {
1174                                 /* ifup */
1175                                 if (iface_state) {
1176                                         bb_error_msg("interface %s already configured", iface);
1177                                         continue;
1178                                 }
1179                         } else {
1180                                 /* ifdown */
1181                                 if (!iface_state) {
1182                                         bb_error_msg("interface %s not configured", iface);
1183                                         continue;
1184                                 }
1185                         }
1186                         llist_free(state_list, free);
1187                 }
1188
1189 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1190                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1191                         struct mapping_defn_t *currmap;
1192
1193                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1194                                 int i;
1195                                 for (i = 0; i < currmap->n_matches; i++) {
1196                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1197                                                 continue;
1198                                         if (VERBOSE) {
1199                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1200                                         }
1201                                         liface = run_mapping(iface, currmap);
1202                                         break;
1203                                 }
1204                         }
1205                 }
1206 #endif
1207
1208                 iface_list = defn->ifaces;
1209                 while (iface_list) {
1210                         currif = (struct interface_defn_t *) iface_list->data;
1211                         if (strcmp(liface, currif->iface) == 0) {
1212                                 char *oldiface = currif->iface;
1213
1214                                 okay = 1;
1215                                 currif->iface = iface;
1216
1217                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1218
1219                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1220                                 cmds_ret = cmds(currif);
1221                                 if (cmds_ret == -1) {
1222                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1223                                                         liface, currif->address_family->name);
1224                                         any_failures = 1;
1225                                 } else if (cmds_ret == 0) {
1226                                         any_failures = 1;
1227                                 }
1228
1229                                 currif->iface = oldiface;
1230                         }
1231                         iface_list = iface_list->link;
1232                 }
1233                 if (VERBOSE) {
1234                         bb_putchar('\n');
1235                 }
1236
1237                 if (!okay && !FORCE) {
1238                         bb_error_msg("ignoring unknown interface %s", liface);
1239                         any_failures = 1;
1240                 } else if (!NO_ACT) {
1241                         /* update the state file */
1242                         FILE *state_fp;
1243                         llist_t *state;
1244                         llist_t *state_list = read_iface_state();
1245                         llist_t *iface_state = find_iface_state(state_list, iface);
1246
1247                         if (cmds == iface_up) {
1248                                 char * const newiface = xasprintf("%s=%s", iface, liface);
1249                                 if (iface_state == NULL) {
1250                                         llist_add_to_end(&state_list, newiface);
1251                                 } else {
1252                                         free(iface_state->data);
1253                                         iface_state->data = newiface;
1254                                 }
1255                         } else {
1256                                 /* Remove an interface from state_list */
1257                                 llist_unlink(&state_list, iface_state);
1258                                 free(llist_pop(&iface_state));
1259                         }
1260
1261                         /* Actually write the new state */
1262                         state_fp = xfopen(CONFIG_IFUPDOWN_IFSTATE_PATH, "w");
1263                         state = state_list;
1264                         while (state) {
1265                                 if (state->data) {
1266                                         fprintf(state_fp, "%s\n", state->data);
1267                                 }
1268                                 state = state->link;
1269                         }
1270                         fclose(state_fp);
1271                         llist_free(state_list, free);
1272                 }
1273         }
1274
1275         return any_failures;
1276 }