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, 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, 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 = xzalloc(sizeof(struct interfaces_file_t));
 633
 634         f = bb_xfopen(filename, "r");
 635
 636         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 637                 char *buf_ptr = buf;
 638
 639                 firstword = next_word(&buf_ptr);
 640                 if (firstword == NULL) {
 641                         free(buf);
 642                         continue;       /* blank line */
 643                 }
 644
 645                 if (strcmp(firstword, "mapping") == 0) {
 646 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 647                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 648
 649                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 650                                 if (currmap->max_matches == currmap->n_matches) {
 651                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 652                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 653                                 }
 654
 655                                 currmap->match[currmap->n_matches++] = bb_xstrdup(firstword);
 656                         }
 657                         currmap->max_mappings = 0;
 658                         currmap->n_mappings = 0;
 659                         currmap->mapping = NULL;
 660                         currmap->script = NULL;
 661                         {
 662                                 struct mapping_defn_t **where = &defn->mappings;
 663                                 while (*where != NULL) {
 664                                         where = &(*where)->next;
 665                                 }
 666                                 *where = currmap;
 667                                 currmap->next = NULL;
 668                         }
 669                         debug_noise("Added mapping\n");
 670 #endif
 671                         currently_processing = MAPPING;
 672                 } else if (strcmp(firstword, "iface") == 0) {
 673                         {
 674                                 char *iface_name;
 675                                 char *address_family_name;
 676                                 char *method_name;
 677                                 struct address_family_t *addr_fams[] = {
 678 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 679                                         &addr_inet,
 680 #endif
 681 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 682                                         &addr_inet6,
 683 #endif
 684                                         NULL
 685                                 };
 686
 687                                 currif = xzalloc(sizeof(struct interface_defn_t));
 688                                 iface_name = next_word(&buf_ptr);
 689                                 address_family_name = next_word(&buf_ptr);
 690                                 method_name = next_word(&buf_ptr);
 691
 692                                 if (buf_ptr == NULL) {
 693                                         bb_error_msg("too few parameters for line \"%s\"", buf);
 694                                         return NULL;
 695                                 }
 696
 697                                 /* ship any trailing whitespace */
 698                                 while (isspace(*buf_ptr)) {
 699                                         ++buf_ptr;
 700                                 }
 701
 702                                 if (buf_ptr[0] != '\0') {
 703                                         bb_error_msg("too many parameters \"%s\"", buf);
 704                                         return NULL;
 705                                 }
 706
 707                                 currif->iface = bb_xstrdup(iface_name);
 708
 709                                 currif->address_family = get_address_family(addr_fams, address_family_name);
 710                                 if (!currif->address_family) {
 711                                         bb_error_msg("unknown address type \"%s\"", address_family_name);
 712                                         return NULL;
 713                                 }
 714
 715                                 currif->method = get_method(currif->address_family, method_name);
 716                                 if (!currif->method) {
 717                                         bb_error_msg("unknown method \"%s\"", method_name);
 718                                         return NULL;
 719                                 }
 720
 721
 722                                 {
 723                                         llist_t *iface_list;
 724                                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 725                                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 726                                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 727                                                         (tmp->address_family == currif->address_family)) {
 728                                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 729                                                         return NULL;
 730                                                 }
 731                                         }
 732
 733                                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 734                                 }
 735                                 debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 736                         }
 737                         currently_processing = IFACE;
 738                 } else if (strcmp(firstword, "auto") == 0) {
 739                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 740
 741                                 /* Check the interface isnt already listed */
 742                                 if (find_list_string(defn->autointerfaces, firstword)) {
 743                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 744                                 }
 745
 746                                 /* Add the interface to the list */
 747                                 llist_add_to_end(&(defn->autointerfaces), bb_xstrdup(firstword));
 748                                 debug_noise("\nauto %s\n", firstword);
 749                         }
 750                         currently_processing = NONE;
 751                 } else {
 752                         switch (currently_processing) {
 753                                 case IFACE:
 754                                         {
 755                                                 int i;
 756
 757                                                 if (strlen(buf_ptr) == 0) {
 758                                                         bb_error_msg("option with empty value \"%s\"", buf);
 759                                                         return NULL;
 760                                                 }
 761
 762                                                 if (strcmp(firstword, "up") != 0
 763                                                                 && strcmp(firstword, "down") != 0
 764                                                                 && strcmp(firstword, "pre-up") != 0
 765                                                                 && strcmp(firstword, "post-down") != 0) {
 766                                                         for (i = 0; i < currif->n_options; i++) {
 767                                                                 if (strcmp(currif->option[i].name, firstword) == 0) {
 768                                                                         bb_error_msg("duplicate option \"%s\"", buf);
 769                                                                         return NULL;
 770                                                                 }
 771                                                         }
 772                                                 }
 773                                         }
 774                                         if (currif->n_options >= currif->max_options) {
 775                                                 struct variable_t *opt;
 776
 777                                                 currif->max_options = currif->max_options + 10;
 778                                                 opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 779                                                 currif->option = opt;
 780                                         }
 781                                         currif->option[currif->n_options].name = bb_xstrdup(firstword);
 782                                         currif->option[currif->n_options].value = bb_xstrdup(buf_ptr);
 783                                         if (!currif->option[currif->n_options].name) {
 784                                                 perror(filename);
 785                                                 return NULL;
 786                                         }
 787                                         if (!currif->option[currif->n_options].value) {
 788                                                 perror(filename);
 789                                                 return NULL;
 790                                         }
 791                                         debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 792                                                         currif->option[currif->n_options].value);
 793                                         currif->n_options++;
 794                                         break;
 795                                 case MAPPING:
 796 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 797                                         if (strcmp(firstword, "script") == 0) {
 798                                                 if (currmap->script != NULL) {
 799                                                         bb_error_msg("duplicate script in mapping \"%s\"", buf);
 800                                                         return NULL;
 801                                                 } else {
 802                                                         currmap->script = bb_xstrdup(next_word(&buf_ptr));
 803                                                 }
 804                                         } else if (strcmp(firstword, "map") == 0) {
 805                                                 if (currmap->max_mappings == currmap->n_mappings) {
 806                                                         currmap->max_mappings = currmap->max_mappings * 2 + 1;
 807                                                         currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 808                                                 }
 809                                                 currmap->mapping[currmap->n_mappings] = bb_xstrdup(next_word(&buf_ptr));
 810                                                 currmap->n_mappings++;
 811                                         } else {
 812                                                 bb_error_msg("misplaced option \"%s\"", buf);
 813                                                 return NULL;
 814                                         }
 815 #endif
 816                                         break;
 817                                 case NONE:
 818                                 default:
 819                                         bb_error_msg("misplaced option \"%s\"", buf);
 820                                         return NULL;
 821                         }
 822                 }
 823                 free(buf);
 824         }
 825         if (ferror(f) != 0) {
 826                 bb_perror_msg_and_die("%s", filename);
 827         }
 828         fclose(f);
 829
 830         return defn;
 831 }
 832
 833 static char *setlocalenv(char *format, const char *name, const char *value)
 834 {
 835         char *result;
 836         char *here;
 837         char *there;
 838
 839         result = bb_xasprintf(format, name, value);
 840
 841         for (here = there = result; *there != '=' && *there; there++) {
 842                 if (*there == '-')
 843                         *there = '_';
 844                 if (isalpha(*there))
 845                         *there = toupper(*there);
 846
 847                 if (isalnum(*there) || *there == '_') {
 848                         *here = *there;
 849                         here++;
 850                 }
 851         }
 852         memmove(here, there, strlen(there) + 1);
 853
 854         return result;
 855 }
 856
 857 static void set_environ(struct interface_defn_t *iface, const char *mode)
 858 {
 859         char **environend;
 860         int i;
 861         const int n_env_entries = iface->n_options + 5;
 862         char **ppch;
 863
 864         if (__myenviron != NULL) {
 865                 for (ppch = __myenviron; *ppch; ppch++) {
 866                         free(*ppch);
 867                         *ppch = NULL;
 868                 }
 869                 free(__myenviron);
 870         }
 871         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 872         environend = __myenviron;
 873
 874         for (i = 0; i < iface->n_options; i++) {
 875                 if (strcmp(iface->option[i].name, "up") == 0
 876                                 || strcmp(iface->option[i].name, "down") == 0
 877                                 || strcmp(iface->option[i].name, "pre-up") == 0
 878                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 879                         continue;
 880                 }
 881                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 882         }
 883
 884         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 885         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 886         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 887         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 888         *(environend++) = setlocalenv("%s=%s", "PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin");
 889 }
 890
 891 static int doit(char *str)
 892 {
 893         if (verbose || no_act) {
 894                 printf("%s\n", str);
 895         }
 896         if (!no_act) {
 897                 pid_t child;
 898                 int status;
 899
 900                 fflush(NULL);
 901                 switch (child = fork()) {
 902                         case -1:                /* failure */
 903                                 return 0;
 904                         case 0:         /* child */
 905                                 execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 906                                 exit(127);
 907                 }
 908                 waitpid(child, &status, 0);
 909                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 910                         return 0;
 911                 }
 912         }
 913         return (1);
 914 }
 915
 916 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 917 {
 918         int i;
 919         char *buf;
 920         for (i = 0; i < ifd->n_options; i++) {
 921                 if (strcmp(ifd->option[i].name, opt) == 0) {
 922                         if (!doit(ifd->option[i].value)) {
 923                                 return 0;
 924                         }
 925                 }
 926         }
 927
 928         buf = bb_xasprintf("run-parts /etc/network/if-%s.d", opt);
 929         if (doit(buf) != 1) {
 930                 return 0;
 931         }
 932         return 1;
 933 }
 934
 935 static int check(char *str) {
 936         return str != NULL;
 937 }
 938
 939 static int iface_up(struct interface_defn_t *iface)
 940 {
 941         if (!iface->method->up(iface,check)) return -1;
 942         set_environ(iface, "start");
 943         if (!execute_all(iface, "pre-up")) return 0;
 944         if (!iface->method->up(iface, doit)) return 0;
 945         if (!execute_all(iface, "up")) return 0;
 946         return 1;
 947 }
 948
 949 static int iface_down(struct interface_defn_t *iface)
 950 {
 951         if (!iface->method->down(iface,check)) return -1;
 952         set_environ(iface, "stop");
 953         if (!execute_all(iface, "down")) return 0;
 954         if (!iface->method->down(iface, doit)) return 0;
 955         if (!execute_all(iface, "post-down")) return 0;
 956         return 1;
 957 }
 958
 959 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 960 static int popen2(FILE **in, FILE **out, char *command, ...)
 961 {
 962         va_list ap;
 963         char *argv[11] = { command };
 964         int argc;
 965         int infd[2], outfd[2];
 966         pid_t pid;
 967
 968         argc = 1;
 969         va_start(ap, command);
 970         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 971                 argc++;
 972         }
 973         argv[argc] = NULL;      /* make sure */
 974         va_end(ap);
 975
 976         if (pipe(infd) != 0) {
 977                 return 0;
 978         }
 979
 980         if (pipe(outfd) != 0) {
 981                 close(infd[0]);
 982                 close(infd[1]);
 983                 return 0;
 984         }
 985
 986         fflush(NULL);
 987         switch (pid = fork()) {
 988                 case -1:                        /* failure */
 989                         close(infd[0]);
 990                         close(infd[1]);
 991                         close(outfd[0]);
 992                         close(outfd[1]);
 993                         return 0;
 994                 case 0:                 /* child */
 995                         dup2(infd[0], 0);
 996                         dup2(outfd[1], 1);
 997                         close(infd[0]);
 998                         close(infd[1]);
 999                         close(outfd[0]);
1000                         close(outfd[1]);
1001                         execvp(command, argv);
1002                         exit(127);
1003                 default:                        /* parent */
1004                         *in = fdopen(infd[1], "w");
1005                         *out = fdopen(outfd[0], "r");
1006                         close(infd[0]);
1007                         close(outfd[1]);
1008                         return pid;
1009         }
1010         /* unreached */
1011 }
1012
1013 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1014 {
1015         FILE *in, *out;
1016         int i, status;
1017         pid_t pid;
1018
1019         char *logical = bb_xstrdup(physical);
1020
1021         /* Run the mapping script. */
1022         pid = popen2(&in, &out, map->script, physical, NULL);
1023
1024         /* popen2() returns 0 on failure. */
1025         if (pid == 0)
1026                 return logical;
1027
1028         /* Write mappings to stdin of mapping script. */
1029         for (i = 0; i < map->n_mappings; i++) {
1030                 fprintf(in, "%s\n", map->mapping[i]);
1031         }
1032         fclose(in);
1033         waitpid(pid, &status, 0);
1034
1035         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1036                 /* If the mapping script exited successfully, try to
1037                  * grab a line of output and use that as the name of the
1038                  * logical interface. */
1039                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1040
1041                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1042                         /* If we are able to read a line of output from the script,
1043                          * remove any trailing whitespace and use this value
1044                          * as the name of the logical interface. */
1045                         char *pch = new_logical + strlen(new_logical) - 1;
1046
1047                         while (pch >= new_logical && isspace(*pch))
1048                                 *(pch--) = '\0';
1049
1050                         free(logical);
1051                         logical = new_logical;
1052                 } else {
1053                         /* If we are UNABLE to read a line of output, discard our
1054                          * freshly allocated memory. */
1055                         free(new_logical);
1056                 }
1057         }
1058
1059         fclose(out);
1060
1061         return logical;
1062 }
1063 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1064
1065 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1066 {
1067         unsigned short iface_len = strlen(iface);
1068         llist_t *search = state_list;
1069
1070         while (search) {
1071                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1072                                 (search->data[iface_len] == '=')) {
1073                         return(search);
1074                 }
1075                 search = search->link;
1076         }
1077         return(NULL);
1078 }
1079
1080 int ifupdown_main(int argc, char **argv)
1081 {
1082         int (*cmds) (struct interface_defn_t *) = NULL;
1083         struct interfaces_file_t *defn;
1084         llist_t *state_list = NULL;
1085         llist_t *target_list = NULL;
1086         const char *interfaces = "/etc/network/interfaces";
1087         const char *statefile = "/var/run/ifstate";
1088
1089 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1090         int run_mappings = 1;
1091 #endif
1092         int do_all = 0;
1093         int force = 0;
1094         int any_failures = 0;
1095         int i;
1096
1097         if (bb_applet_name[2] == 'u') {
1098                 /* ifup command */
1099                 cmds = iface_up;
1100         } else {
1101                 /* ifdown command */
1102                 cmds = iface_down;
1103         }
1104
1105 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1106         while ((i = getopt(argc, argv, "i:hvnamf")) != -1)
1107 #else
1108                 while ((i = getopt(argc, argv, "i:hvnaf")) != -1)
1109 #endif
1110                 {
1111                         switch (i) {
1112                                 case 'i':       /* interfaces */
1113                                         interfaces = optarg;
1114                                         break;
1115                                 case 'v':       /* verbose */
1116                                         verbose = 1;
1117                                         break;
1118                                 case 'a':       /* all */
1119                                         do_all = 1;
1120                                         break;
1121                                 case 'n':       /* no-act */
1122                                         no_act = 1;
1123                                         break;
1124 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1125                                 case 'm':       /* no-mappings */
1126                                         run_mappings = 0;
1127                                         break;
1128 #endif
1129                                 case 'f':       /* force */
1130                                         force = 1;
1131                                         break;
1132                                 default:
1133                                         bb_show_usage();
1134                                         break;
1135                         }
1136                 }
1137
1138         if (argc - optind > 0) {
1139                 if (do_all) {
1140                         bb_show_usage();
1141                 }
1142         } else {
1143                 if (!do_all) {
1144                         bb_show_usage();
1145                 }
1146         }
1147
1148         debug_noise("reading %s file:\n", interfaces);
1149         defn = read_interfaces(interfaces);
1150         debug_noise("\ndone reading %s\n\n", interfaces);
1151
1152         if (!defn) {
1153                 exit(EXIT_FAILURE);
1154         }
1155
1156         /* Create a list of interfaces to work on */
1157         if (do_all) {
1158                 if (cmds == iface_up) {
1159                         target_list = defn->autointerfaces;
1160                 } else {
1161                         /* iface_down */
1162                         const llist_t *list = state_list;
1163                         while (list) {
1164                                 llist_add_to_end(&target_list, bb_xstrdup(list->data));
1165                                 list = list->link;
1166                         }
1167                         target_list = defn->autointerfaces;
1168                 }
1169         } else {
1170                 llist_add_to_end(&target_list, argv[optind]);
1171         }
1172
1173
1174         /* Update the interfaces */
1175         while (target_list) {
1176                 llist_t *iface_list;
1177                 struct interface_defn_t *currif;
1178                 char *iface;
1179                 char *liface;
1180                 char *pch;
1181                 int okay = 0;
1182                 int cmds_ret;
1183
1184                 iface = bb_xstrdup(target_list->data);
1185                 target_list = target_list->link;
1186
1187                 pch = strchr(iface, '=');
1188                 if (pch) {
1189                         *pch = '\0';
1190                         liface = bb_xstrdup(pch + 1);
1191                 } else {
1192                         liface = bb_xstrdup(iface);
1193                 }
1194
1195                 if (!force) {
1196                         const llist_t *iface_state = find_iface_state(state_list, iface);
1197
1198                         if (cmds == iface_up) {
1199                                 /* ifup */
1200                                 if (iface_state) {
1201                                         bb_error_msg("interface %s already configured", iface);
1202                                         continue;
1203                                 }
1204                         } else {
1205                                 /* ifdown */
1206                                 if (iface_state) {
1207                                         bb_error_msg("interface %s not configured", iface);
1208                                         continue;
1209                                 }
1210                         }
1211                 }
1212
1213 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1214                 if ((cmds == iface_up) && run_mappings) {
1215                         struct mapping_defn_t *currmap;
1216
1217                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1218
1219                                 for (i = 0; i < currmap->n_matches; i++) {
1220                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1221                                                 continue;
1222                                         if (verbose) {
1223                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1224                                         }
1225                                         liface = run_mapping(iface, currmap);
1226                                         break;
1227                                 }
1228                         }
1229                 }
1230 #endif
1231
1232
1233                 iface_list = defn->ifaces;
1234                 while (iface_list) {
1235                         currif = (struct interface_defn_t *) iface_list->data;
1236                         if (strcmp(liface, currif->iface) == 0) {
1237                                 char *oldiface = currif->iface;
1238
1239                                 okay = 1;
1240                                 currif->iface = iface;
1241
1242                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1243
1244                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1245                                 cmds_ret = cmds(currif);
1246                                 if (cmds_ret == -1) {
1247                                         bb_error_msg("Don't seem to have all the variables for %s/%s.",
1248                                                         liface, currif->address_family->name);
1249                                         any_failures += 1;
1250                                 } else if (cmds_ret == 0) {
1251                                         any_failures += 1;
1252                                 }
1253
1254                                 currif->iface = oldiface;
1255                         }
1256                         iface_list = iface_list->link;
1257                 }
1258                 if (verbose) {
1259                         printf("\n");
1260                 }
1261
1262                 if (!okay && !force) {
1263                         bb_error_msg("Ignoring unknown interface %s", liface);
1264                         any_failures += 1;
1265                 } else {
1266                         llist_t *iface_state = find_iface_state(state_list, iface);
1267
1268                         if (cmds == iface_up) {
1269                                 char *newiface = bb_xasprintf("%s=%s", iface, liface);
1270                                 if (iface_state == NULL) {
1271                                         llist_add_to_end(&state_list, newiface);
1272                                 } else {
1273                                         free(iface_state->data);
1274                                         iface_state->data = newiface;
1275                                 }
1276                         } else {
1277                                 /* Remove an interface from the linked list */
1278                                 free(llist_pop(&iface_state));
1279                         }
1280                 }
1281         }
1282
1283         /* Actually write the new state */
1284         if (!no_act) {
1285                 FILE *state_fp = NULL;
1286
1287                 state_fp = bb_xfopen(statefile, "w");
1288                 while (state_list) {
1289                         if (state_list->data) {
1290                                 fputs(state_list->data, state_fp);
1291                                 fputc('\n', state_fp);
1292                         }
1293                         state_list = state_list->link;
1294                 }
1295                 fclose(state_fp);
1296         }
1297
1298         if (any_failures)
1299                 return 1;
1300         return 0;
1301 }