networking/ifupdown.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *  ifupdown for busybox
   4  *  Copyright (c) 2002 Glenn McGrath <bug1@iinet.net.au>
   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  *
  15  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  16  */
  17
  18 /* TODO: standardise execute() return codes to return 0 for success and 1 for failure */
  19
  20 #include <sys/stat.h>
  21 #include <sys/utsname.h>
  22 #include <sys/wait.h>
  23
  24 #include <ctype.h>
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <fnmatch.h>
  28 #include <getopt.h>
  29 #include <stdarg.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34
  35 #include "busybox.h"
  36
  37 #define MAX_OPT_DEPTH 10
  38 #define EUNBALBRACK 10001
  39 #define EUNDEFVAR   10002
  40 #define EUNBALPER   10000
  41
  42 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
  43 #define MAX_INTERFACE_LENGTH 10
  44 #endif
  45
  46 #if 0
  47 #define debug_noise(fmt, args...) printf(fmt, ## args)
  48 #else
  49 #define debug_noise(fmt, args...)
  50 #endif
  51
  52 /* Forward declaration */
  53 struct interface_defn_t;
  54
  55 typedef int (execfn)(char *command);
  56
  57 struct method_t
  58 {
  59         char *name;
  60         int (*up)(struct interface_defn_t *ifd, execfn *e);
  61         int (*down)(struct interface_defn_t *ifd, execfn *e);
  62 };
  63
  64 struct address_family_t
  65 {
  66         char *name;
  67         int n_methods;
  68         struct method_t *method;
  69 };
  70
  71 struct mapping_defn_t
  72 {
  73         struct mapping_defn_t *next;
  74
  75         int max_matches;
  76         int n_matches;
  77         char **match;
  78
  79         char *script;
  80
  81         int max_mappings;
  82         int n_mappings;
  83         char **mapping;
  84 };
  85
  86 struct variable_t
  87 {
  88         char *name;
  89         char *value;
  90 };
  91
  92 struct interface_defn_t
  93 {
  94         struct address_family_t *address_family;
  95         struct method_t *method;
  96
  97         char *iface;
  98         int max_options;
  99         int n_options;
 100         struct variable_t *option;
 101 };
 102
 103 struct interfaces_file_t
 104 {
 105         llist_t *autointerfaces;
 106         llist_t *ifaces;
 107         struct mapping_defn_t *mappings;
 108 };
 109
 110 static char no_act = 0;
 111 static char verbose = 0;
 112 static char **__myenviron = NULL;
 113
 114 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 115
 116 static unsigned int count_bits(unsigned int a)
 117 {
 118         unsigned int result;
 119         result = (a & 0x55) + ((a >> 1) & 0x55);
 120         result = (result & 0x33) + ((result >> 2) & 0x33);
 121         return((result & 0x0F) + ((result >> 4) & 0x0F));
 122 }
 123
 124 static int count_netmask_bits(char *dotted_quad)
 125 {
 126         unsigned int result, a, b, c, d;
 127         /* Found a netmask...  Check if it is dotted quad */
 128         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 129                 return -1;
 130         result = count_bits(a);
 131         result += count_bits(b);
 132         result += count_bits(c);
 133         result += count_bits(d);
 134         return ((int)result);
 135 }
 136 #endif
 137
 138 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 139 static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
 140 {
 141         if (*pos + str_length >= *len) {
 142                 char *newbuf;
 143
 144                 newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
 145                 *buf = newbuf;
 146                 *len = *len * 2 + str_length + 1;
 147         }
 148
 149         while (str_length-- >= 1) {
 150                 (*buf)[(*pos)++] = *str;
 151                 str++;
 152         }
 153         (*buf)[*pos] = '\0';
 154 }
 155
 156 static int strncmpz(char *l, char *r, size_t llen)
 157 {
 158         int i = strncmp(l, r, llen);
 159
 160         if (i == 0) {
 161                 return(-r[llen]);
 162         } else {
 163                 return(i);
 164         }
 165 }
 166
 167 static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
 168 {
 169         int i;
 170
 171         if (strncmpz(id, "iface", idlen) == 0) {
 172                 char *result;
 173                 static char label_buf[20];
 174                 strncpy(label_buf, ifd->iface, 19);
 175                 label_buf[19]=0;
 176                 result = strchr(label_buf, ':');
 177                 if (result) {
 178                         *result=0;
 179                 }
 180                 return( label_buf);
 181         } else if (strncmpz(id, "label", idlen) == 0) {
 182                 return (ifd->iface);
 183         } else {
 184                 for (i = 0; i < ifd->n_options; i++) {
 185                         if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 186                                 return (ifd->option[i].value);
 187                         }
 188                 }
 189         }
 190
 191         return(NULL);
 192 }
 193
 194 static char *parse(char *command, struct interface_defn_t *ifd)
 195 {
 196
 197         char *result = NULL;
 198         size_t pos = 0, len = 0;
 199         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 200         int okay[MAX_OPT_DEPTH] = { 1 };
 201         int opt_depth = 1;
 202
 203         while (*command) {
 204                 switch (*command) {
 205
 206                         default:
 207                                 addstr(&result, &len, &pos, command, 1);
 208                                 command++;
 209                                 break;
 210                         case '\\':
 211                                 if (command[1]) {
 212                                         addstr(&result, &len, &pos, command + 1, 1);
 213                                         command += 2;
 214                                 } else {
 215                                         addstr(&result, &len, &pos, command, 1);
 216                                         command++;
 217                                 }
 218                                 break;
 219                         case '[':
 220                                 if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 221                                         old_pos[opt_depth] = pos;
 222                                         okay[opt_depth] = 1;
 223                                         opt_depth++;
 224                                         command += 2;
 225                                 } else {
 226                                         addstr(&result, &len, &pos, "[", 1);
 227                                         command++;
 228                                 }
 229                                 break;
 230                         case ']':
 231                                 if (command[1] == ']' && opt_depth > 1) {
 232                                         opt_depth--;
 233                                         if (!okay[opt_depth]) {
 234                                                 pos = old_pos[opt_depth];
 235                                                 result[pos] = '\0';
 236                                         }
 237                                         command += 2;
 238                                 } else {
 239                                         addstr(&result, &len, &pos, "]", 1);
 240                                         command++;
 241                                 }
 242                                 break;
 243                         case '%':
 244                                 {
 245                                         char *nextpercent;
 246                                         char *varvalue;
 247
 248                                         command++;
 249                                         nextpercent = strchr(command, '%');
 250                                         if (!nextpercent) {
 251                                                 errno = EUNBALPER;
 252                                                 free(result);
 253                                                 return (NULL);
 254                                         }
 255
 256                                         varvalue = get_var(command, nextpercent - command, ifd);
 257
 258                                         if (varvalue) {
 259                                                 addstr(&result, &len, &pos, varvalue, bb_strlen(varvalue));
 260                                         } else {
 261 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 262                                                 /* Sigh...  Add a special case for 'ip' to convert from
 263                                                  * dotted quad to bit count style netmasks.  */
 264                                                 if (strncmp(command, "bnmask", 6)==0) {
 265                                                         int res;
 266                                                         varvalue = get_var("netmask", 7, ifd);
 267                                                         if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 268                                                                 char argument[255];
 269                                                                 sprintf(argument, "%d", res);
 270                                                                 addstr(&result, &len, &pos, argument, bb_strlen(argument));
 271                                                                 command = nextpercent + 1;
 272                                                                 break;
 273                                                         }
 274                                                 }
 275 #endif
 276                                                 okay[opt_depth - 1] = 0;
 277                                         }
 278
 279                                         command = nextpercent + 1;
 280                                 }
 281                                 break;
 282                 }
 283         }
 284
 285         if (opt_depth > 1) {
 286                 errno = EUNBALBRACK;
 287                 free(result);
 288                 return(NULL);
 289         }
 290
 291         if (!okay[0]) {
 292                 errno = EUNDEFVAR;
 293                 free(result);
 294                 return(NULL);
 295         }
 296
 297         return(result);
 298 }
 299
 300 static int execute(char *command, struct interface_defn_t *ifd, execfn *exec)
 301 {
 302         char *out;
 303         int ret;
 304
 305         out = parse(command, ifd);
 306         if (!out) {
 307                 return(0);
 308         }
 309         ret = (*exec) (out);
 310
 311         free(out);
 312         if (ret != 1) {
 313                 return(0);
 314         }
 315         return(1);
 316 }
 317 #endif
 318
 319 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 320 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 321 {
 322 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 323         int result;
 324         result =execute("ip addr add ::1 dev %iface%", ifd, exec);
 325         result += execute("ip link set %iface% up", ifd, exec);
 326         return ((result == 2) ? 2 : 0);
 327 #else
 328         return( execute("ifconfig %iface% add ::1", ifd, exec));
 329 #endif
 330 }
 331
 332 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 333 {
 334 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 335         return(execute("ip link set %iface% down", ifd, exec));
 336 #else
 337         return(execute("ifconfig %iface% del ::1", ifd, exec));
 338 #endif
 339 }
 340
 341 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 342 {
 343         int result;
 344 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 345         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 346         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 347         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 348 #else
 349         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 350         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 351         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 352 #endif
 353         return ((result == 3) ? 3 : 0);
 354 }
 355
 356 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 357 {
 358 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 359         return(execute("ip link set %iface% down", ifd, exec));
 360 #else
 361         return(execute("ifconfig %iface% down", ifd, exec));
 362 #endif
 363 }
 364
 365 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 366 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 367 {
 368         int result;
 369         result = execute("ip tunnel add %iface% mode sit remote "
 370                                 "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 371         result += execute("ip link set %iface% up", ifd, exec);
 372         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 373         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 374         return ((result == 4) ? 4 : 0);
 375 }
 376
 377 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 378 {
 379         return( execute("ip tunnel del %iface%", ifd, exec));
 380 }
 381 #endif
 382
 383 static struct method_t methods6[] = {
 384 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 385         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 386 #endif
 387         { "static", static_up6, static_down6, },
 388         { "loopback", loopback_up6, loopback_down6, },
 389 };
 390
 391 static struct address_family_t addr_inet6 = {
 392         "inet6",
 393         sizeof(methods6) / sizeof(struct method_t),
 394         methods6
 395 };
 396 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 397
 398 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 399 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 400 {
 401 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 402         int result;
 403         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 404         result += execute("ip link set %iface% up", ifd, exec);
 405         return ((result == 2) ? 2 : 0);
 406 #else
 407         return( execute("ifconfig %iface% 127.0.0.1 up", ifd, exec));
 408 #endif
 409 }
 410
 411 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 412 {
 413 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 414         int result;
 415         result = execute("ip addr flush dev %iface%", ifd, exec);
 416         result += execute("ip link set %iface% down", ifd, exec);
 417         return ((result == 2) ? 2 : 0);
 418 #else
 419         return( execute("ifconfig %iface% 127.0.0.1 down", ifd, exec));
 420 #endif
 421 }
 422
 423 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 424 {
 425         int result;
 426 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 427         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 428                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 429         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 430         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 431         return ((result == 3) ? 3 : 0);
 432 #else
 433         result = execute("ifconfig %iface% %address% netmask %netmask% "
 434                                 "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] "
 435                                 "[[media %media%]] [[mtu %mtu%]] [[hw %hwaddress%]] up",
 436                                 ifd, exec);
 437         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 438         return ((result == 2) ? 2 : 0);
 439 #endif
 440 }
 441
 442 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 443 {
 444         int result;
 445 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 446         result = execute("ip addr flush dev %iface%", ifd, exec);
 447         result += execute("ip link set %iface% down", ifd, exec);
 448 #else
 449         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 450         result += execute("ifconfig %iface% down", ifd, exec);
 451 #endif
 452         return ((result == 2) ? 2 : 0);
 453 }
 454
 455 static int execable(char *program)
 456 {
 457         struct stat buf;
 458         if (0 == stat(program, &buf)) {
 459                 if (S_ISREG(buf.st_mode) && (S_IXUSR & buf.st_mode)) {
 460                         return(1);
 461                 }
 462         }
 463         return(0);
 464 }
 465
 466 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 467 {
 468         if (execable("/sbin/udhcpc")) {
 469                 return( execute("udhcpc -n -p /var/run/udhcpc.%iface%.pid -i "
 470                                         "%iface% [[-H %hostname%]] [[-c %clientid%]]", ifd, exec));
 471         } else if (execable("/sbin/pump")) {
 472                 return( execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]", ifd, exec));
 473         } else if (execable("/sbin/dhclient")) {
 474                 return( execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%", ifd, exec));
 475         } else if (execable("/sbin/dhcpcd")) {
 476                 return( execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 477                                         "[[-l %leasetime%]] %iface%", ifd, exec));
 478         }
 479         return(0);
 480 }
 481
 482 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 483 {
 484         int result = 0;
 485         if (execable("/sbin/udhcpc")) {
 486                 /* SIGUSR2 forces udhcpc to release the current lease and go inactive,
 487                  * and SIGTERM causes udhcpc to exit.  Signals are queued and processed
 488                  * sequentially so we don't need to sleep */
 489                 result = execute("kill -USR2 `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 490                 result += execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 491         } else if (execable("/sbin/pump")) {
 492                 result = execute("pump -i %iface% -k", ifd, exec);
 493         } else if (execable("/sbin/dhclient")) {
 494                 result = execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null", ifd, exec);
 495         } else if (execable("/sbin/dhcpcd")) {
 496                 result = execute("dhcpcd -k %iface%", ifd, exec);
 497         }
 498         return (result || static_down(ifd, exec));
 499 }
 500
 501 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 502 {
 503         return( execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 504                                 "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 505                                 "--returniffail --serverbcast", ifd, exec));
 506 }
 507
 508 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 509 {
 510         return( execute("pon [[%provider%]]", ifd, exec));
 511 }
 512
 513 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 514 {
 515         return( execute("poff [[%provider%]]", ifd, exec));
 516 }
 517
 518 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 519 {
 520         return( execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 521                                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec));
 522 }
 523
 524 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 525 {
 526         return( execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 527                                 "-p /var/run/wvdial.%iface% -s 2", ifd, exec));
 528 }
 529
 530 static struct method_t methods[] =
 531 {
 532         { "wvdial", wvdial_up, wvdial_down, },
 533         { "ppp", ppp_up, ppp_down, },
 534         { "static", static_up, static_down, },
 535         { "bootp", bootp_up, static_down, },
 536         { "dhcp", dhcp_up, dhcp_down, },
 537         { "loopback", loopback_up, loopback_down, },
 538 };
 539
 540 static struct address_family_t addr_inet =
 541 {
 542         "inet",
 543         sizeof(methods) / sizeof(struct method_t),
 544         methods
 545 };
 546
 547 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 548
 549 static char *next_word(char **buf)
 550 {
 551         unsigned short length;
 552         char *word;
 553
 554         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 555                 return NULL;
 556         }
 557
 558         /* Skip over leading whitespace */
 559         word = *buf;
 560         while (isspace(*word)) {
 561                 ++word;
 562         }
 563
 564         /* Skip over comments */
 565         if (*word == '#') {
 566                 return(NULL);
 567         }
 568
 569         /* Find the length of this word */
 570         length = strcspn(word, " \t\n");
 571         if (length == 0) {
 572                 return(NULL);
 573         }
 574         *buf = word + length;
 575         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 576         if (**buf) {
 577                 **buf = '\0';
 578                 (*buf)++;
 579         }
 580
 581         return word;
 582 }
 583
 584 static struct address_family_t *get_address_family(struct address_family_t *af[], char *name)
 585 {
 586         int i;
 587
 588         for (i = 0; af[i]; i++) {
 589                 if (strcmp(af[i]->name, name) == 0) {
 590                         return af[i];
 591                 }
 592         }
 593         return NULL;
 594 }
 595
 596 static struct method_t *get_method(struct address_family_t *af, char *name)
 597 {
 598         int i;
 599
 600         for (i = 0; i < af->n_methods; i++) {
 601                 if (strcmp(af->method[i].name, name) == 0) {
 602                         return &af->method[i];
 603                 }
 604         }
 605         return(NULL);
 606 }
 607
 608 static const llist_t *find_list_string(const llist_t *list, const char *string)
 609 {
 610         while (list) {
 611                 if (strcmp(list->data, string) == 0) {
 612                         return(list);
 613                 }
 614                 list = list->link;
 615         }
 616         return(NULL);
 617 }
 618
 619 static struct interfaces_file_t *read_interfaces(const char *filename)
 620 {
 621 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 622         struct mapping_defn_t *currmap = NULL;
 623 #endif
 624         struct interface_defn_t *currif = NULL;
 625         struct interfaces_file_t *defn;
 626         FILE *f;
 627         char *firstword;
 628         char *buf;
 629
 630         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 631
 632         defn = xmalloc(sizeof(struct interfaces_file_t));
 633         defn->autointerfaces = NULL;
 634         defn->mappings = NULL;
 635         defn->ifaces = NULL;
 636
 637         f = bb_xfopen(filename, "r");
 638
 639         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 640                 char *buf_ptr = buf;
 641
 642                 firstword = next_word(&buf_ptr);
 643                 if (firstword == NULL) {
 644                         free(buf);
 645                         continue;       /* blank line */
 646                 }
 647
 648                 if (strcmp(firstword, "mapping") == 0) {
 649 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 650                         currmap = xmalloc(sizeof(struct mapping_defn_t));
 651                         currmap->max_matches = 0;
 652                         currmap->n_matches = 0;
 653                         currmap->match = NULL;
 654
 655                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 656                                 if (currmap->max_matches == currmap->n_matches) {
 657                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 658                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 659                                 }
 660
 661                                 currmap->match[currmap->n_matches++] = bb_xstrdup(firstword);
 662                         }
 663                         currmap->max_mappings = 0;
 664                         currmap->n_mappings = 0;
 665                         currmap->mapping = NULL;
 666                         currmap->script = NULL;
 667                         {
 668                                 struct mapping_defn_t **where = &defn->mappings;
 669                                 while (*where != NULL) {
 670                                         where = &(*where)->next;
 671                                 }
 672                                 *where = currmap;
 673                                 currmap->next = NULL;
 674                         }
 675                         debug_noise("Added mapping\n");
 676 #endif
 677                         currently_processing = MAPPING;
 678                 } else if (strcmp(firstword, "iface") == 0) {
 679                         {
 680                                 char *iface_name;
 681                                 char *address_family_name;
 682                                 char *method_name;
 683                                 struct address_family_t *addr_fams[] = {
 684 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 685                                         &addr_inet,
 686 #endif
 687 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 688                                         &addr_inet6,
 689 #endif
 690                                         NULL
 691                                 };
 692
 693                                 currif = xmalloc(sizeof(struct interface_defn_t));
 694                                 iface_name = next_word(&buf_ptr);
 695                                 address_family_name = next_word(&buf_ptr);
 696                                 method_name = next_word(&buf_ptr);
 697
 698                                 if (buf_ptr == NULL) {
 699                                         bb_error_msg("too few parameters for line \"%s\"", buf);
 700                                         return NULL;
 701                                 }
 702
 703                                 /* ship any trailing whitespace */
 704                                 while (isspace(*buf_ptr)) {
 705                                         ++buf_ptr;
 706                                 }
 707
 708                                 if (buf_ptr[0] != '\0') {
 709                                         bb_error_msg("too many parameters \"%s\"", buf);
 710                                         return NULL;
 711                                 }
 712
 713                                 currif->iface = bb_xstrdup(iface_name);
 714
 715                                 currif->address_family = get_address_family(addr_fams, address_family_name);
 716                                 if (!currif->address_family) {
 717                                         bb_error_msg("unknown address type \"%s\"", address_family_name);
 718                                         return NULL;
 719                                 }
 720
 721                                 currif->method = get_method(currif->address_family, method_name);
 722                                 if (!currif->method) {
 723                                         bb_error_msg("unknown method \"%s\"", method_name);
 724                                         return NULL;
 725                                 }
 726
 727                                 currif->max_options = 0;
 728                                 currif->n_options = 0;
 729                                 currif->option = NULL;
 730
 731                                 {
 732                                         llist_t *iface_list;
 733                                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 734                                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 735                                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 736                                                         (tmp->address_family == currif->address_family)) {
 737                                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 738                                                         return NULL;
 739                                                 }
 740                                         }
 741
 742                                         defn->ifaces = llist_add_to_end(defn->ifaces, (char*)currif);
 743                                 }
 744                                 debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 745                         }
 746                         currently_processing = IFACE;
 747                 } else if (strcmp(firstword, "auto") == 0) {
 748                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 749
 750                                 /* Check the interface isnt already listed */
 751                                 if (find_list_string(defn->autointerfaces, firstword)) {
 752                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 753                                 }
 754
 755                                 /* Add the interface to the list */
 756                                 defn->autointerfaces = llist_add_to_end(defn->autointerfaces, bb_xstrdup(firstword));
 757                                 debug_noise("\nauto %s\n", firstword);
 758                         }
 759                         currently_processing = NONE;
 760                 } else {
 761                         switch (currently_processing) {
 762                                 case IFACE:
 763                                         {
 764                                                 int i;
 765
 766                                                 if (bb_strlen(buf_ptr) == 0) {
 767                                                         bb_error_msg("option with empty value \"%s\"", buf);
 768                                                         return NULL;
 769                                                 }
 770
 771                                                 if (strcmp(firstword, "up") != 0
 772                                                                 && strcmp(firstword, "down") != 0
 773                                                                 && strcmp(firstword, "pre-up") != 0
 774                                                                 && strcmp(firstword, "post-down") != 0) {
 775                                                         for (i = 0; i < currif->n_options; i++) {
 776                                                                 if (strcmp(currif->option[i].name, firstword) == 0) {
 777                                                                         bb_error_msg("duplicate option \"%s\"", buf);
 778                                                                         return NULL;
 779                                                                 }
 780                                                         }
 781                                                 }
 782                                         }
 783                                         if (currif->n_options >= currif->max_options) {
 784                                                 struct variable_t *opt;
 785
 786                                                 currif->max_options = currif->max_options + 10;
 787                                                 opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 788                                                 currif->option = opt;
 789                                         }
 790                                         currif->option[currif->n_options].name = bb_xstrdup(firstword);
 791                                         currif->option[currif->n_options].value = bb_xstrdup(buf_ptr);
 792                                         if (!currif->option[currif->n_options].name) {
 793                                                 perror(filename);
 794                                                 return NULL;
 795                                         }
 796                                         if (!currif->option[currif->n_options].value) {
 797                                                 perror(filename);
 798                                                 return NULL;
 799                                         }
 800                                         debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 801                                                         currif->option[currif->n_options].value);
 802                                         currif->n_options++;
 803                                         break;
 804                                 case MAPPING:
 805 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 806                                         if (strcmp(firstword, "script") == 0) {
 807                                                 if (currmap->script != NULL) {
 808                                                         bb_error_msg("duplicate script in mapping \"%s\"", buf);
 809                                                         return NULL;
 810                                                 } else {
 811                                                         currmap->script = bb_xstrdup(next_word(&buf_ptr));
 812                                                 }
 813                                         } else if (strcmp(firstword, "map") == 0) {
 814                                                 if (currmap->max_mappings == currmap->n_mappings) {
 815                                                         currmap->max_mappings = currmap->max_mappings * 2 + 1;
 816                                                         currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 817                                                 }
 818                                                 currmap->mapping[currmap->n_mappings] = bb_xstrdup(next_word(&buf_ptr));
 819                                                 currmap->n_mappings++;
 820                                         } else {
 821                                                 bb_error_msg("misplaced option \"%s\"", buf);
 822                                                 return NULL;
 823                                         }
 824 #endif
 825                                         break;
 826                                 case NONE:
 827                                 default:
 828                                         bb_error_msg("misplaced option \"%s\"", buf);
 829                                         return NULL;
 830                         }
 831                 }
 832                 free(buf);
 833         }
 834         if (ferror(f) != 0) {
 835                 bb_perror_msg_and_die("%s", filename);
 836         }
 837         fclose(f);
 838
 839         return defn;
 840 }
 841
 842 static char *setlocalenv(char *format, const char *name, const char *value)
 843 {
 844         char *result;
 845         char *here;
 846         char *there;
 847
 848         result = xmalloc(bb_strlen(format) + bb_strlen(name) + bb_strlen(value) + 1);
 849
 850         sprintf(result, format, name, value);
 851
 852         for (here = there = result; *there != '=' && *there; there++) {
 853                 if (*there == '-')
 854                         *there = '_';
 855                 if (isalpha(*there))
 856                         *there = toupper(*there);
 857
 858                 if (isalnum(*there) || *there == '_') {
 859                         *here = *there;
 860                         here++;
 861                 }
 862         }
 863         memmove(here, there, bb_strlen(there) + 1);
 864
 865         return result;
 866 }
 867
 868 static void set_environ(struct interface_defn_t *iface, const char *mode)
 869 {
 870         char **environend;
 871         int i;
 872         const int n_env_entries = iface->n_options + 5;
 873         char **ppch;
 874
 875         if (__myenviron != NULL) {
 876                 for (ppch = __myenviron; *ppch; ppch++) {
 877                         free(*ppch);
 878                         *ppch = NULL;
 879                 }
 880                 free(__myenviron);
 881                 __myenviron = NULL;
 882         }
 883         __myenviron = xmalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 884         environend = __myenviron;
 885         *environend = NULL;
 886
 887         for (i = 0; i < iface->n_options; i++) {
 888                 if (strcmp(iface->option[i].name, "up") == 0
 889                                 || strcmp(iface->option[i].name, "down") == 0
 890                                 || strcmp(iface->option[i].name, "pre-up") == 0
 891                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 892                         continue;
 893                 }
 894                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 895                 *environend = NULL;
 896         }
 897
 898         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 899         *environend = NULL;
 900         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 901         *environend = NULL;
 902         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 903         *environend = NULL;
 904         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 905         *environend = NULL;
 906         *(environend++) = setlocalenv("%s=%s", "PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin");
 907         *environend = NULL;
 908 }
 909
 910 static int doit(char *str)
 911 {
 912         if (verbose || no_act) {
 913                 printf("%s\n", str);
 914         }
 915         if (!no_act) {
 916                 pid_t child;
 917                 int status;
 918
 919                 fflush(NULL);
 920                 switch (child = fork()) {
 921                         case -1:                /* failure */
 922                                 return 0;
 923                         case 0:         /* child */
 924                                 execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 925                                 exit(127);
 926                 }
 927                 waitpid(child, &status, 0);
 928                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 929                         return 0;
 930                 }
 931         }
 932         return (1);
 933 }
 934
 935 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 936 {
 937         int i;
 938         char *buf;
 939         for (i = 0; i < ifd->n_options; i++) {
 940                 if (strcmp(ifd->option[i].name, opt) == 0) {
 941                         if (!doit(ifd->option[i].value)) {
 942                                 return 0;
 943                         }
 944                 }
 945         }
 946
 947         buf = bb_xasprintf("run-parts /etc/network/if-%s.d", opt);
 948         if (doit(buf) != 1) {
 949                 return 0;
 950         }
 951         return 1;
 952 }
 953
 954 static int check(char *str) {
 955         return str != NULL;
 956 }
 957
 958 static int iface_up(struct interface_defn_t *iface)
 959 {
 960         if (!iface->method->up(iface,check)) return -1;
 961         set_environ(iface, "start");
 962         if (!execute_all(iface, "pre-up")) return 0;
 963         if (!iface->method->up(iface, doit)) return 0;
 964         if (!execute_all(iface, "up")) return 0;
 965         return 1;
 966 }
 967
 968 static int iface_down(struct interface_defn_t *iface)
 969 {
 970         if (!iface->method->down(iface,check)) return -1;
 971         set_environ(iface, "stop");
 972         if (!execute_all(iface, "down")) return 0;
 973         if (!iface->method->down(iface, doit)) return 0;
 974         if (!execute_all(iface, "post-down")) return 0;
 975         return 1;
 976 }
 977
 978 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 979 static int popen2(FILE **in, FILE **out, char *command, ...)
 980 {
 981         va_list ap;
 982         char *argv[11] = { command };
 983         int argc;
 984         int infd[2], outfd[2];
 985         pid_t pid;
 986
 987         argc = 1;
 988         va_start(ap, command);
 989         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 990                 argc++;
 991         }
 992         argv[argc] = NULL;      /* make sure */
 993         va_end(ap);
 994
 995         if (pipe(infd) != 0) {
 996                 return 0;
 997         }
 998
 999         if (pipe(outfd) != 0) {
1000                 close(infd[0]);
1001                 close(infd[1]);
1002                 return 0;
1003         }
1004
1005         fflush(NULL);
1006         switch (pid = fork()) {
1007                 case -1:                        /* failure */
1008                         close(infd[0]);
1009                         close(infd[1]);
1010                         close(outfd[0]);
1011                         close(outfd[1]);
1012                         return 0;
1013                 case 0:                 /* child */
1014                         dup2(infd[0], 0);
1015                         dup2(outfd[1], 1);
1016                         close(infd[0]);
1017                         close(infd[1]);
1018                         close(outfd[0]);
1019                         close(outfd[1]);
1020                         execvp(command, argv);
1021                         exit(127);
1022                 default:                        /* parent */
1023                         *in = fdopen(infd[1], "w");
1024                         *out = fdopen(outfd[0], "r");
1025                         close(infd[0]);
1026                         close(outfd[1]);
1027                         return pid;
1028         }
1029         /* unreached */
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 = bb_xstrdup(physical);
1039
1040         /* Run the mapping script. */
1041         pid = popen2(&in, &out, map->script, physical, NULL);
1042
1043         /* popen2() returns 0 on failure. */
1044         if (pid == 0)
1045                 return logical;
1046
1047         /* Write mappings to stdin of mapping script. */
1048         for (i = 0; i < map->n_mappings; i++) {
1049                 fprintf(in, "%s\n", map->mapping[i]);
1050         }
1051         fclose(in);
1052         waitpid(pid, &status, 0);
1053
1054         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1055                 /* If the mapping script exited successfully, try to
1056                  * grab a line of output and use that as the name of the
1057                  * logical interface. */
1058                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1059
1060                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1061                         /* If we are able to read a line of output from the script,
1062                          * remove any trailing whitespace and use this value
1063                          * as the name of the logical interface. */
1064                         char *pch = new_logical + bb_strlen(new_logical) - 1;
1065
1066                         while (pch >= new_logical && isspace(*pch))
1067                                 *(pch--) = '\0';
1068
1069                         free(logical);
1070                         logical = new_logical;
1071                 } else {
1072                         /* If we are UNABLE to read a line of output, discard are
1073                          * freshly allocated memory. */
1074                         free(new_logical);
1075                 }
1076         }
1077
1078         fclose(out);
1079
1080         return logical;
1081 }
1082 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1083
1084 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1085 {
1086         unsigned short iface_len = bb_strlen(iface);
1087         llist_t *search = state_list;
1088
1089         while (search) {
1090                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1091                                 (search->data[iface_len] == '=')) {
1092                         return(search);
1093                 }
1094                 search = search->link;
1095         }
1096         return(NULL);
1097 }
1098
1099 int ifupdown_main(int argc, char **argv)
1100 {
1101         int (*cmds) (struct interface_defn_t *) = NULL;
1102         struct interfaces_file_t *defn;
1103         llist_t *state_list = NULL;
1104         llist_t *target_list = NULL;
1105         const char *interfaces = "/etc/network/interfaces";
1106         const char *statefile = "/var/run/ifstate";
1107
1108 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1109         int run_mappings = 1;
1110 #endif
1111         int do_all = 0;
1112         int force = 0;
1113         int any_failures = 0;
1114         int i;
1115
1116         if (bb_applet_name[2] == 'u') {
1117                 /* ifup command */
1118                 cmds = iface_up;
1119         } else {
1120                 /* ifdown command */
1121                 cmds = iface_down;
1122         }
1123
1124 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1125         while ((i = getopt(argc, argv, "i:hvnamf")) != -1)
1126 #else
1127                 while ((i = getopt(argc, argv, "i:hvnaf")) != -1)
1128 #endif
1129                 {
1130                         switch (i) {
1131                                 case 'i':       /* interfaces */
1132                                         interfaces = optarg;
1133                                         break;
1134                                 case 'v':       /* verbose */
1135                                         verbose = 1;
1136                                         break;
1137                                 case 'a':       /* all */
1138                                         do_all = 1;
1139                                         break;
1140                                 case 'n':       /* no-act */
1141                                         no_act = 1;
1142                                         break;
1143 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1144                                 case 'm':       /* no-mappings */
1145                                         run_mappings = 0;
1146                                         break;
1147 #endif
1148                                 case 'f':       /* force */
1149                                         force = 1;
1150                                         break;
1151                                 default:
1152                                         bb_show_usage();
1153                                         break;
1154                         }
1155                 }
1156
1157         if (argc - optind > 0) {
1158                 if (do_all) {
1159                         bb_show_usage();
1160                 }
1161         } else {
1162                 if (!do_all) {
1163                         bb_show_usage();
1164                 }
1165         }
1166
1167         debug_noise("reading %s file:\n", interfaces);
1168         defn = read_interfaces(interfaces);
1169         debug_noise("\ndone reading %s\n\n", interfaces);
1170
1171         if (!defn) {
1172                 exit(EXIT_FAILURE);
1173         }
1174
1175         /* Create a list of interfaces to work on */
1176         if (do_all) {
1177                 if (cmds == iface_up) {
1178                         target_list = defn->autointerfaces;
1179                 } else {
1180 #if 0
1181                         /* iface_down */
1182                         llist_t *new_item;
1183                         const llist_t *list = state_list;
1184                         while (list) {
1185                                 new_item = xmalloc(sizeof(llist_t));
1186                                 new_item->data = bb_xstrdup(list->data);
1187                                 new_item->link = NULL;
1188                                 list = target_list;
1189                                 if (list == NULL)
1190                                         target_list = new_item;
1191                                 else {
1192                                         while (list->link) {
1193                                                 list = list->link;
1194                                         }
1195                                         list = new_item;
1196                                 }
1197                                 list = list->link;
1198                         }
1199                         target_list = defn->autointerfaces;
1200 #else
1201
1202                         /* iface_down */
1203                         const llist_t *list = state_list;
1204                         while (list) {
1205                                 target_list = llist_add_to_end(target_list, bb_xstrdup(list->data));
1206                                 list = list->link;
1207                         }
1208                         target_list = defn->autointerfaces;
1209 #endif
1210                 }
1211         } else {
1212                 target_list = llist_add_to_end(target_list, argv[optind]);
1213         }
1214
1215
1216         /* Update the interfaces */
1217         while (target_list) {
1218                 llist_t *iface_list;
1219                 struct interface_defn_t *currif;
1220                 char *iface;
1221                 char *liface;
1222                 char *pch;
1223                 int okay = 0;
1224                 int cmds_ret;
1225
1226                 iface = bb_xstrdup(target_list->data);
1227                 target_list = target_list->link;
1228
1229                 pch = strchr(iface, '=');
1230                 if (pch) {
1231                         *pch = '\0';
1232                         liface = bb_xstrdup(pch + 1);
1233                 } else {
1234                         liface = bb_xstrdup(iface);
1235                 }
1236
1237                 if (!force) {
1238                         const llist_t *iface_state = find_iface_state(state_list, iface);
1239
1240                         if (cmds == iface_up) {
1241                                 /* ifup */
1242                                 if (iface_state) {
1243                                         bb_error_msg("interface %s already configured", iface);
1244                                         continue;
1245                                 }
1246                         } else {
1247                                 /* ifdown */
1248                                 if (iface_state) {
1249                                         bb_error_msg("interface %s not configured", iface);
1250                                         continue;
1251                                 }
1252                         }
1253                 }
1254
1255 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1256                 if ((cmds == iface_up) && run_mappings) {
1257                         struct mapping_defn_t *currmap;
1258
1259                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1260
1261                                 for (i = 0; i < currmap->n_matches; i++) {
1262                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1263                                                 continue;
1264                                         if (verbose) {
1265                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1266                                         }
1267                                         liface = run_mapping(iface, currmap);
1268                                         break;
1269                                 }
1270                         }
1271                 }
1272 #endif
1273
1274
1275                 iface_list = defn->ifaces;
1276                 while (iface_list) {
1277                         currif = (struct interface_defn_t *) iface_list->data;
1278                         if (strcmp(liface, currif->iface) == 0) {
1279                                 char *oldiface = currif->iface;
1280
1281                                 okay = 1;
1282                                 currif->iface = iface;
1283
1284                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1285
1286                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1287                                 cmds_ret = cmds(currif);
1288                                 if (cmds_ret == -1) {
1289                                         bb_error_msg("Don't seem to have all the variables for %s/%s.",
1290                                                         liface, currif->address_family->name);
1291                                         any_failures += 1;
1292                                 } else if (cmds_ret == 0) {
1293                                         any_failures += 1;
1294                                 }
1295
1296                                 currif->iface = oldiface;
1297                         }
1298                         iface_list = iface_list->link;
1299                 }
1300                 if (verbose) {
1301                         printf("\n");
1302                 }
1303
1304                 if (!okay && !force) {
1305                         bb_error_msg("Ignoring unknown interface %s", liface);
1306                         any_failures += 1;
1307                 } else {
1308                         llist_t *iface_state = find_iface_state(state_list, iface);
1309
1310                         if (cmds == iface_up) {
1311                                 char *newiface = xmalloc(bb_strlen(iface) + 1 + bb_strlen(liface) + 1);
1312                                 sprintf(newiface, "%s=%s", iface, liface);
1313                                 if (iface_state == NULL) {
1314                                         state_list = llist_add_to_end(state_list, newiface);
1315                                 } else {
1316                                         free(iface_state->data);
1317                                         iface_state->data = newiface;
1318                                 }
1319                         } else {
1320                                 /* Remove an interface from the linked list */
1321                                 if (iface_state) {
1322                                         llist_t *l = iface_state->link;
1323                                         free(iface_state->data);
1324                                         iface_state->data = NULL;
1325                                         iface_state->link = NULL;
1326                                         if (l) {
1327                                                 iface_state->data = l->data;
1328                                                 iface_state->link = l->link;
1329                                         }
1330                                         free(l);
1331                                 }
1332                         }
1333                 }
1334         }
1335
1336         /* Actually write the new state */
1337         if (!no_act) {
1338                 FILE *state_fp = NULL;
1339
1340                 state_fp = bb_xfopen(statefile, "w");
1341                 while (state_list) {
1342                         if (state_list->data) {
1343                                 fputs(state_list->data, state_fp);
1344                                 fputc('\n', state_fp);
1345                         }
1346                         state_list = state_list->link;
1347                 }
1348                 fclose(state_fp);
1349         }
1350
1351         if (any_failures)
1352                 return 1;
1353         return 0;
1354 }