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 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
 115
 116 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 117
 118 static unsigned int count_bits(unsigned int a)
 119 {
 120         unsigned int result;
 121         result = (a & 0x55) + ((a >> 1) & 0x55);
 122         result = (result & 0x33) + ((result >> 2) & 0x33);
 123         return((result & 0x0F) + ((result >> 4) & 0x0F));
 124 }
 125
 126 static int count_netmask_bits(char *dotted_quad)
 127 {
 128         unsigned int result, a, b, c, d;
 129         /* Found a netmask...  Check if it is dotted quad */
 130         if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
 131                 return -1;
 132         result = count_bits(a);
 133         result += count_bits(b);
 134         result += count_bits(c);
 135         result += count_bits(d);
 136         return ((int)result);
 137 }
 138 #endif
 139
 140 static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
 141 {
 142         if (*pos + str_length >= *len) {
 143                 char *newbuf;
 144
 145                 newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
 146                 *buf = newbuf;
 147                 *len = *len * 2 + str_length + 1;
 148         }
 149
 150         while (str_length-- >= 1) {
 151                 (*buf)[(*pos)++] = *str;
 152                 str++;
 153         }
 154         (*buf)[*pos] = '\0';
 155 }
 156
 157 static int strncmpz(char *l, char *r, size_t llen)
 158 {
 159         int i = strncmp(l, r, llen);
 160
 161         if (i == 0) {
 162                 return(-r[llen]);
 163         } else {
 164                 return(i);
 165         }
 166 }
 167
 168 static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
 169 {
 170         int i;
 171
 172         if (strncmpz(id, "iface", idlen) == 0) {
 173                 char *result;
 174                 static char label_buf[20];
 175                 strncpy(label_buf, ifd->iface, 19);
 176                 label_buf[19]=0;
 177                 result = strchr(label_buf, ':');
 178                 if (result) {
 179                         *result=0;
 180                 }
 181                 return( label_buf);
 182         } else if (strncmpz(id, "label", idlen) == 0) {
 183                 return (ifd->iface);
 184         } else {
 185                 for (i = 0; i < ifd->n_options; i++) {
 186                         if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
 187                                 return (ifd->option[i].value);
 188                         }
 189                 }
 190         }
 191
 192         return(NULL);
 193 }
 194
 195 static char *parse(char *command, struct interface_defn_t *ifd)
 196 {
 197
 198         char *result = NULL;
 199         size_t pos = 0, len = 0;
 200         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
 201         int okay[MAX_OPT_DEPTH] = { 1 };
 202         int opt_depth = 1;
 203
 204         while (*command) {
 205                 switch (*command) {
 206
 207                         default:
 208                                 addstr(&result, &len, &pos, command, 1);
 209                                 command++;
 210                                 break;
 211                         case '\\':
 212                                 if (command[1]) {
 213                                         addstr(&result, &len, &pos, command + 1, 1);
 214                                         command += 2;
 215                                 } else {
 216                                         addstr(&result, &len, &pos, command, 1);
 217                                         command++;
 218                                 }
 219                                 break;
 220                         case '[':
 221                                 if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
 222                                         old_pos[opt_depth] = pos;
 223                                         okay[opt_depth] = 1;
 224                                         opt_depth++;
 225                                         command += 2;
 226                                 } else {
 227                                         addstr(&result, &len, &pos, "[", 1);
 228                                         command++;
 229                                 }
 230                                 break;
 231                         case ']':
 232                                 if (command[1] == ']' && opt_depth > 1) {
 233                                         opt_depth--;
 234                                         if (!okay[opt_depth]) {
 235                                                 pos = old_pos[opt_depth];
 236                                                 result[pos] = '\0';
 237                                         }
 238                                         command += 2;
 239                                 } else {
 240                                         addstr(&result, &len, &pos, "]", 1);
 241                                         command++;
 242                                 }
 243                                 break;
 244                         case '%':
 245                                 {
 246                                         char *nextpercent;
 247                                         char *varvalue;
 248
 249                                         command++;
 250                                         nextpercent = strchr(command, '%');
 251                                         if (!nextpercent) {
 252                                                 errno = EUNBALPER;
 253                                                 free(result);
 254                                                 return (NULL);
 255                                         }
 256
 257                                         varvalue = get_var(command, nextpercent - command, ifd);
 258
 259                                         if (varvalue) {
 260                                                 addstr(&result, &len, &pos, varvalue, strlen(varvalue));
 261                                         } else {
 262 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 263                                                 /* Sigh...  Add a special case for 'ip' to convert from
 264                                                  * dotted quad to bit count style netmasks.  */
 265                                                 if (strncmp(command, "bnmask", 6)==0) {
 266                                                         int res;
 267                                                         varvalue = get_var("netmask", 7, ifd);
 268                                                         if (varvalue && (res=count_netmask_bits(varvalue)) > 0) {
 269                                                                 char argument[255];
 270                                                                 sprintf(argument, "%d", res);
 271                                                                 addstr(&result, &len, &pos, argument, strlen(argument));
 272                                                                 command = nextpercent + 1;
 273                                                                 break;
 274                                                         }
 275                                                 }
 276 #endif
 277                                                 okay[opt_depth - 1] = 0;
 278                                         }
 279
 280                                         command = nextpercent + 1;
 281                                 }
 282                                 break;
 283                 }
 284         }
 285
 286         if (opt_depth > 1) {
 287                 errno = EUNBALBRACK;
 288                 free(result);
 289                 return(NULL);
 290         }
 291
 292         if (!okay[0]) {
 293                 errno = EUNDEFVAR;
 294                 free(result);
 295                 return(NULL);
 296         }
 297
 298         return(result);
 299 }
 300
 301 static int execute(char *command, struct interface_defn_t *ifd, execfn *exec)
 302 {
 303         char *out;
 304         int ret;
 305
 306         out = parse(command, ifd);
 307         if (!out) {
 308                 return(0);
 309         }
 310         ret = (*exec) (out);
 311
 312         free(out);
 313         if (ret != 1) {
 314                 return(0);
 315         }
 316         return(1);
 317 }
 318 #endif
 319
 320 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 321 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
 322 {
 323 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 324         int result;
 325         result =execute("ip addr add ::1 dev %iface%", ifd, exec);
 326         result += execute("ip link set %iface% up", ifd, exec);
 327         return ((result == 2) ? 2 : 0);
 328 #else
 329         return( execute("ifconfig %iface% add ::1", ifd, exec));
 330 #endif
 331 }
 332
 333 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
 334 {
 335 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 336         return(execute("ip link set %iface% down", ifd, exec));
 337 #else
 338         return(execute("ifconfig %iface% del ::1", ifd, exec));
 339 #endif
 340 }
 341
 342 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
 343 {
 344         int result;
 345 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 346         result = execute("ip addr add %address%/%netmask% dev %iface% [[label %label%]]", ifd, exec);
 347         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 348         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 349 #else
 350         result = execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec);
 351         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
 352         result += execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec);
 353 #endif
 354         return ((result == 3) ? 3 : 0);
 355 }
 356
 357 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
 358 {
 359 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 360         return(execute("ip link set %iface% down", ifd, exec));
 361 #else
 362         return(execute("ifconfig %iface% down", ifd, exec));
 363 #endif
 364 }
 365
 366 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 367 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
 368 {
 369         int result;
 370         result = execute("ip tunnel add %iface% mode sit remote "
 371                                 "%endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec);
 372         result += execute("ip link set %iface% up", ifd, exec);
 373         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
 374         result += execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec);
 375         return ((result == 4) ? 4 : 0);
 376 }
 377
 378 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
 379 {
 380         return( execute("ip tunnel del %iface%", ifd, exec));
 381 }
 382 #endif
 383
 384 static struct method_t methods6[] = {
 385 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 386         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
 387 #endif
 388         { "static", static_up6, static_down6, },
 389         { "loopback", loopback_up6, loopback_down6, },
 390 };
 391
 392 static struct address_family_t addr_inet6 = {
 393         "inet6",
 394         sizeof(methods6) / sizeof(struct method_t),
 395         methods6
 396 };
 397 #endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
 398
 399 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 400 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
 401 {
 402 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 403         int result;
 404         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
 405         result += execute("ip link set %iface% up", ifd, exec);
 406         return ((result == 2) ? 2 : 0);
 407 #else
 408         return( execute("ifconfig %iface% 127.0.0.1 up", ifd, exec));
 409 #endif
 410 }
 411
 412 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
 413 {
 414 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 415         int result;
 416         result = execute("ip addr flush dev %iface%", ifd, exec);
 417         result += execute("ip link set %iface% down", ifd, exec);
 418         return ((result == 2) ? 2 : 0);
 419 #else
 420         return( execute("ifconfig %iface% 127.0.0.1 down", ifd, exec));
 421 #endif
 422 }
 423
 424 static int static_up(struct interface_defn_t *ifd, execfn *exec)
 425 {
 426         int result;
 427 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 428         result = execute("ip addr add %address%/%bnmask% [[broadcast %broadcast%]] "
 429                         "dev %iface% [[peer %pointopoint%]] [[label %label%]]", ifd, exec);
 430         result += execute("ip link set [[mtu %mtu%]] [[address %hwaddress%]] %iface% up", ifd, exec);
 431         result += execute("[[ ip route add default via %gateway% dev %iface% ]]", ifd, exec);
 432         return ((result == 3) ? 3 : 0);
 433 #else
 434         result = execute("ifconfig %iface% %address% netmask %netmask% "
 435                                 "[[broadcast %broadcast%]] [[pointopoint %pointopoint%]] "
 436                                 "[[media %media%]] [[mtu %mtu%]] [[hw %hwaddress%]] up",
 437                                 ifd, exec);
 438         result += execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec);
 439         return ((result == 2) ? 2 : 0);
 440 #endif
 441 }
 442
 443 static int static_down(struct interface_defn_t *ifd, execfn *exec)
 444 {
 445         int result;
 446 #ifdef CONFIG_FEATURE_IFUPDOWN_IP
 447         result = execute("ip addr flush dev %iface%", ifd, exec);
 448         result += execute("ip link set %iface% down", ifd, exec);
 449 #else
 450         result = execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec);
 451         result += execute("ifconfig %iface% down", ifd, exec);
 452 #endif
 453         return ((result == 2) ? 2 : 0);
 454 }
 455
 456 static int execable(char *program)
 457 {
 458         struct stat buf;
 459         if (0 == stat(program, &buf)) {
 460                 if (S_ISREG(buf.st_mode) && (S_IXUSR & buf.st_mode)) {
 461                         return(1);
 462                 }
 463         }
 464         return(0);
 465 }
 466
 467 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 468 {
 469         if (execable("/sbin/udhcpc")) {
 470                 return( execute("udhcpc -n -p /var/run/udhcpc.%iface%.pid -i "
 471                                         "%iface% [[-H %hostname%]] [[-c %clientid%]]", ifd, exec));
 472         } else if (execable("/sbin/pump")) {
 473                 return( execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]", ifd, exec));
 474         } else if (execable("/sbin/dhclient")) {
 475                 return( execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%", ifd, exec));
 476         } else if (execable("/sbin/dhcpcd")) {
 477                 return( execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
 478                                         "[[-l %leasetime%]] %iface%", ifd, exec));
 479         }
 480         return(0);
 481 }
 482
 483 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 484 {
 485         int result = 0;
 486         if (execable("/sbin/udhcpc")) {
 487                 /* SIGUSR2 forces udhcpc to release the current lease and go inactive,
 488                  * and SIGTERM causes udhcpc to exit.  Signals are queued and processed
 489                  * sequentially so we don't need to sleep */
 490                 result = execute("kill -USR2 `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 491                 result += execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
 492         } else if (execable("/sbin/pump")) {
 493                 result = execute("pump -i %iface% -k", ifd, exec);
 494         } else if (execable("/sbin/dhclient")) {
 495                 result = execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null", ifd, exec);
 496         } else if (execable("/sbin/dhcpcd")) {
 497                 result = execute("dhcpcd -k %iface%", ifd, exec);
 498         }
 499         return (result || static_down(ifd, exec));
 500 }
 501
 502 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 503 {
 504         return( execute("bootpc [[--bootfile %bootfile%]] --dev %iface% "
 505                                 "[[--server %server%]] [[--hwaddr %hwaddr%]] "
 506                                 "--returniffail --serverbcast", ifd, exec));
 507 }
 508
 509 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
 510 {
 511         return( execute("pon [[%provider%]]", ifd, exec));
 512 }
 513
 514 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
 515 {
 516         return( execute("poff [[%provider%]]", ifd, exec));
 517 }
 518
 519 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
 520 {
 521         return( execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial "
 522                                 "-p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec));
 523 }
 524
 525 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
 526 {
 527         return( execute("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial "
 528                                 "-p /var/run/wvdial.%iface% -s 2", ifd, exec));
 529 }
 530
 531 static struct method_t methods[] =
 532 {
 533         { "wvdial", wvdial_up, wvdial_down, },
 534         { "ppp", ppp_up, ppp_down, },
 535         { "static", static_up, static_down, },
 536         { "bootp", bootp_up, static_down, },
 537         { "dhcp", dhcp_up, dhcp_down, },
 538         { "loopback", loopback_up, loopback_down, },
 539 };
 540
 541 static struct address_family_t addr_inet =
 542 {
 543         "inet",
 544         sizeof(methods) / sizeof(struct method_t),
 545         methods
 546 };
 547
 548 #endif  /* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
 549
 550 static char *next_word(char **buf)
 551 {
 552         unsigned short length;
 553         char *word;
 554
 555         if ((buf == NULL) || (*buf == NULL) || (**buf == '\0')) {
 556                 return NULL;
 557         }
 558
 559         /* Skip over leading whitespace */
 560         word = *buf;
 561         while (isspace(*word)) {
 562                 ++word;
 563         }
 564
 565         /* Skip over comments */
 566         if (*word == '#') {
 567                 return(NULL);
 568         }
 569
 570         /* Find the length of this word */
 571         length = strcspn(word, " \t\n");
 572         if (length == 0) {
 573                 return(NULL);
 574         }
 575         *buf = word + length;
 576         /*DBU:[dave@cray.com] if we are already at EOL dont't increment beyond it */
 577         if (**buf) {
 578                 **buf = '\0';
 579                 (*buf)++;
 580         }
 581
 582         return word;
 583 }
 584
 585 static struct address_family_t *get_address_family(struct address_family_t *af[], char *name)
 586 {
 587         int i;
 588
 589         for (i = 0; af[i]; i++) {
 590                 if (strcmp(af[i]->name, name) == 0) {
 591                         return af[i];
 592                 }
 593         }
 594         return NULL;
 595 }
 596
 597 static struct method_t *get_method(struct address_family_t *af, char *name)
 598 {
 599         int i;
 600
 601         for (i = 0; i < af->n_methods; i++) {
 602                 if (strcmp(af->method[i].name, name) == 0) {
 603                         return &af->method[i];
 604                 }
 605         }
 606         return(NULL);
 607 }
 608
 609 static const llist_t *find_list_string(const llist_t *list, const char *string)
 610 {
 611         while (list) {
 612                 if (strcmp(list->data, string) == 0) {
 613                         return(list);
 614                 }
 615                 list = list->link;
 616         }
 617         return(NULL);
 618 }
 619
 620 static struct interfaces_file_t *read_interfaces(const char *filename)
 621 {
 622 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 623         struct mapping_defn_t *currmap = NULL;
 624 #endif
 625         struct interface_defn_t *currif = NULL;
 626         struct interfaces_file_t *defn;
 627         FILE *f;
 628         char *firstword;
 629         char *buf;
 630
 631         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
 632
 633         defn = xzalloc(sizeof(struct interfaces_file_t));
 634
 635         f = bb_xfopen(filename, "r");
 636
 637         while ((buf = bb_get_chomped_line_from_file(f)) != NULL) {
 638                 char *buf_ptr = buf;
 639
 640                 firstword = next_word(&buf_ptr);
 641                 if (firstword == NULL) {
 642                         free(buf);
 643                         continue;       /* blank line */
 644                 }
 645
 646                 if (strcmp(firstword, "mapping") == 0) {
 647 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 648                         currmap = xzalloc(sizeof(struct mapping_defn_t));
 649
 650                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 651                                 if (currmap->max_matches == currmap->n_matches) {
 652                                         currmap->max_matches = currmap->max_matches * 2 + 1;
 653                                         currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
 654                                 }
 655
 656                                 currmap->match[currmap->n_matches++] = bb_xstrdup(firstword);
 657                         }
 658                         currmap->max_mappings = 0;
 659                         currmap->n_mappings = 0;
 660                         currmap->mapping = NULL;
 661                         currmap->script = NULL;
 662                         {
 663                                 struct mapping_defn_t **where = &defn->mappings;
 664                                 while (*where != NULL) {
 665                                         where = &(*where)->next;
 666                                 }
 667                                 *where = currmap;
 668                                 currmap->next = NULL;
 669                         }
 670                         debug_noise("Added mapping\n");
 671 #endif
 672                         currently_processing = MAPPING;
 673                 } else if (strcmp(firstword, "iface") == 0) {
 674                         {
 675                                 char *iface_name;
 676                                 char *address_family_name;
 677                                 char *method_name;
 678                                 struct address_family_t *addr_fams[] = {
 679 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
 680                                         &addr_inet,
 681 #endif
 682 #ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
 683                                         &addr_inet6,
 684 #endif
 685                                         NULL
 686                                 };
 687
 688                                 currif = xzalloc(sizeof(struct interface_defn_t));
 689                                 iface_name = next_word(&buf_ptr);
 690                                 address_family_name = next_word(&buf_ptr);
 691                                 method_name = next_word(&buf_ptr);
 692
 693                                 if (buf_ptr == NULL) {
 694                                         bb_error_msg("too few parameters for line \"%s\"", buf);
 695                                         return NULL;
 696                                 }
 697
 698                                 /* ship any trailing whitespace */
 699                                 while (isspace(*buf_ptr)) {
 700                                         ++buf_ptr;
 701                                 }
 702
 703                                 if (buf_ptr[0] != '\0') {
 704                                         bb_error_msg("too many parameters \"%s\"", buf);
 705                                         return NULL;
 706                                 }
 707
 708                                 currif->iface = bb_xstrdup(iface_name);
 709
 710                                 currif->address_family = get_address_family(addr_fams, address_family_name);
 711                                 if (!currif->address_family) {
 712                                         bb_error_msg("unknown address type \"%s\"", address_family_name);
 713                                         return NULL;
 714                                 }
 715
 716                                 currif->method = get_method(currif->address_family, method_name);
 717                                 if (!currif->method) {
 718                                         bb_error_msg("unknown method \"%s\"", method_name);
 719                                         return NULL;
 720                                 }
 721
 722
 723                                 {
 724                                         llist_t *iface_list;
 725                                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
 726                                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
 727                                                 if ((strcmp(tmp->iface, currif->iface) == 0) &&
 728                                                         (tmp->address_family == currif->address_family)) {
 729                                                         bb_error_msg("duplicate interface \"%s\"", tmp->iface);
 730                                                         return NULL;
 731                                                 }
 732                                         }
 733
 734                                         llist_add_to_end(&(defn->ifaces), (char*)currif);
 735                                 }
 736                                 debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
 737                         }
 738                         currently_processing = IFACE;
 739                 } else if (strcmp(firstword, "auto") == 0) {
 740                         while ((firstword = next_word(&buf_ptr)) != NULL) {
 741
 742                                 /* Check the interface isnt already listed */
 743                                 if (find_list_string(defn->autointerfaces, firstword)) {
 744                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
 745                                 }
 746
 747                                 /* Add the interface to the list */
 748                                 llist_add_to_end(&(defn->autointerfaces), bb_xstrdup(firstword));
 749                                 debug_noise("\nauto %s\n", firstword);
 750                         }
 751                         currently_processing = NONE;
 752                 } else {
 753                         switch (currently_processing) {
 754                                 case IFACE:
 755                                         {
 756                                                 int i;
 757
 758                                                 if (strlen(buf_ptr) == 0) {
 759                                                         bb_error_msg("option with empty value \"%s\"", buf);
 760                                                         return NULL;
 761                                                 }
 762
 763                                                 if (strcmp(firstword, "up") != 0
 764                                                                 && strcmp(firstword, "down") != 0
 765                                                                 && strcmp(firstword, "pre-up") != 0
 766                                                                 && strcmp(firstword, "post-down") != 0) {
 767                                                         for (i = 0; i < currif->n_options; i++) {
 768                                                                 if (strcmp(currif->option[i].name, firstword) == 0) {
 769                                                                         bb_error_msg("duplicate option \"%s\"", buf);
 770                                                                         return NULL;
 771                                                                 }
 772                                                         }
 773                                                 }
 774                                         }
 775                                         if (currif->n_options >= currif->max_options) {
 776                                                 struct variable_t *opt;
 777
 778                                                 currif->max_options = currif->max_options + 10;
 779                                                 opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
 780                                                 currif->option = opt;
 781                                         }
 782                                         currif->option[currif->n_options].name = bb_xstrdup(firstword);
 783                                         currif->option[currif->n_options].value = bb_xstrdup(buf_ptr);
 784                                         if (!currif->option[currif->n_options].name) {
 785                                                 perror(filename);
 786                                                 return NULL;
 787                                         }
 788                                         if (!currif->option[currif->n_options].value) {
 789                                                 perror(filename);
 790                                                 return NULL;
 791                                         }
 792                                         debug_noise("\t%s=%s\n", currif->option[currif->n_options].name,
 793                                                         currif->option[currif->n_options].value);
 794                                         currif->n_options++;
 795                                         break;
 796                                 case MAPPING:
 797 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 798                                         if (strcmp(firstword, "script") == 0) {
 799                                                 if (currmap->script != NULL) {
 800                                                         bb_error_msg("duplicate script in mapping \"%s\"", buf);
 801                                                         return NULL;
 802                                                 } else {
 803                                                         currmap->script = bb_xstrdup(next_word(&buf_ptr));
 804                                                 }
 805                                         } else if (strcmp(firstword, "map") == 0) {
 806                                                 if (currmap->max_mappings == currmap->n_mappings) {
 807                                                         currmap->max_mappings = currmap->max_mappings * 2 + 1;
 808                                                         currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
 809                                                 }
 810                                                 currmap->mapping[currmap->n_mappings] = bb_xstrdup(next_word(&buf_ptr));
 811                                                 currmap->n_mappings++;
 812                                         } else {
 813                                                 bb_error_msg("misplaced option \"%s\"", buf);
 814                                                 return NULL;
 815                                         }
 816 #endif
 817                                         break;
 818                                 case NONE:
 819                                 default:
 820                                         bb_error_msg("misplaced option \"%s\"", buf);
 821                                         return NULL;
 822                         }
 823                 }
 824                 free(buf);
 825         }
 826         if (ferror(f) != 0) {
 827                 bb_perror_msg_and_die("%s", filename);
 828         }
 829         fclose(f);
 830
 831         return defn;
 832 }
 833
 834 static char *setlocalenv(char *format, const char *name, const char *value)
 835 {
 836         char *result;
 837         char *here;
 838         char *there;
 839
 840         result = bb_xasprintf(format, name, value);
 841
 842         for (here = there = result; *there != '=' && *there; there++) {
 843                 if (*there == '-')
 844                         *there = '_';
 845                 if (isalpha(*there))
 846                         *there = toupper(*there);
 847
 848                 if (isalnum(*there) || *there == '_') {
 849                         *here = *there;
 850                         here++;
 851                 }
 852         }
 853         memmove(here, there, strlen(there) + 1);
 854
 855         return result;
 856 }
 857
 858 static void set_environ(struct interface_defn_t *iface, const char *mode)
 859 {
 860         char **environend;
 861         int i;
 862         const int n_env_entries = iface->n_options + 5;
 863         char **ppch;
 864
 865         if (__myenviron != NULL) {
 866                 for (ppch = __myenviron; *ppch; ppch++) {
 867                         free(*ppch);
 868                         *ppch = NULL;
 869                 }
 870                 free(__myenviron);
 871         }
 872         __myenviron = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
 873         environend = __myenviron;
 874
 875         for (i = 0; i < iface->n_options; i++) {
 876                 if (strcmp(iface->option[i].name, "up") == 0
 877                                 || strcmp(iface->option[i].name, "down") == 0
 878                                 || strcmp(iface->option[i].name, "pre-up") == 0
 879                                 || strcmp(iface->option[i].name, "post-down") == 0) {
 880                         continue;
 881                 }
 882                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
 883         }
 884
 885         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
 886         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
 887         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
 888         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
 889         *(environend++) = setlocalenv("%s=%s", "PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin");
 890 }
 891
 892 static int doit(char *str)
 893 {
 894         if (verbose || no_act) {
 895                 printf("%s\n", str);
 896         }
 897         if (!no_act) {
 898                 pid_t child;
 899                 int status;
 900
 901                 fflush(NULL);
 902                 switch (child = fork()) {
 903                         case -1:                /* failure */
 904                                 return 0;
 905                         case 0:         /* child */
 906                                 execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, NULL, __myenviron);
 907                                 exit(127);
 908                 }
 909                 waitpid(child, &status, 0);
 910                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 911                         return 0;
 912                 }
 913         }
 914         return (1);
 915 }
 916
 917 static int execute_all(struct interface_defn_t *ifd, const char *opt)
 918 {
 919         int i;
 920         char *buf;
 921         for (i = 0; i < ifd->n_options; i++) {
 922                 if (strcmp(ifd->option[i].name, opt) == 0) {
 923                         if (!doit(ifd->option[i].value)) {
 924                                 return 0;
 925                         }
 926                 }
 927         }
 928
 929         buf = bb_xasprintf("run-parts /etc/network/if-%s.d", opt);
 930         if (doit(buf) != 1) {
 931                 return 0;
 932         }
 933         return 1;
 934 }
 935
 936 static int check(char *str) {
 937         return str != NULL;
 938 }
 939
 940 static int iface_up(struct interface_defn_t *iface)
 941 {
 942         if (!iface->method->up(iface,check)) return -1;
 943         set_environ(iface, "start");
 944         if (!execute_all(iface, "pre-up")) return 0;
 945         if (!iface->method->up(iface, doit)) return 0;
 946         if (!execute_all(iface, "up")) return 0;
 947         return 1;
 948 }
 949
 950 static int iface_down(struct interface_defn_t *iface)
 951 {
 952         if (!iface->method->down(iface,check)) return -1;
 953         set_environ(iface, "stop");
 954         if (!execute_all(iface, "down")) return 0;
 955         if (!iface->method->down(iface, doit)) return 0;
 956         if (!execute_all(iface, "post-down")) return 0;
 957         return 1;
 958 }
 959
 960 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
 961 static int popen2(FILE **in, FILE **out, char *command, ...)
 962 {
 963         va_list ap;
 964         char *argv[11] = { command };
 965         int argc;
 966         int infd[2], outfd[2];
 967         pid_t pid;
 968
 969         argc = 1;
 970         va_start(ap, command);
 971         while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
 972                 argc++;
 973         }
 974         argv[argc] = NULL;      /* make sure */
 975         va_end(ap);
 976
 977         if (pipe(infd) != 0) {
 978                 return 0;
 979         }
 980
 981         if (pipe(outfd) != 0) {
 982                 close(infd[0]);
 983                 close(infd[1]);
 984                 return 0;
 985         }
 986
 987         fflush(NULL);
 988         switch (pid = fork()) {
 989                 case -1:                        /* failure */
 990                         close(infd[0]);
 991                         close(infd[1]);
 992                         close(outfd[0]);
 993                         close(outfd[1]);
 994                         return 0;
 995                 case 0:                 /* child */
 996                         dup2(infd[0], 0);
 997                         dup2(outfd[1], 1);
 998                         close(infd[0]);
 999                         close(infd[1]);
1000                         close(outfd[0]);
1001                         close(outfd[1]);
1002                         execvp(command, argv);
1003                         exit(127);
1004                 default:                        /* parent */
1005                         *in = fdopen(infd[1], "w");
1006                         *out = fdopen(outfd[0], "r");
1007                         close(infd[0]);
1008                         close(outfd[1]);
1009                         return pid;
1010         }
1011         /* unreached */
1012 }
1013
1014 static char *run_mapping(char *physical, struct mapping_defn_t * map)
1015 {
1016         FILE *in, *out;
1017         int i, status;
1018         pid_t pid;
1019
1020         char *logical = bb_xstrdup(physical);
1021
1022         /* Run the mapping script. */
1023         pid = popen2(&in, &out, map->script, physical, NULL);
1024
1025         /* popen2() returns 0 on failure. */
1026         if (pid == 0)
1027                 return logical;
1028
1029         /* Write mappings to stdin of mapping script. */
1030         for (i = 0; i < map->n_mappings; i++) {
1031                 fprintf(in, "%s\n", map->mapping[i]);
1032         }
1033         fclose(in);
1034         waitpid(pid, &status, 0);
1035
1036         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1037                 /* If the mapping script exited successfully, try to
1038                  * grab a line of output and use that as the name of the
1039                  * logical interface. */
1040                 char *new_logical = (char *)xmalloc(MAX_INTERFACE_LENGTH);
1041
1042                 if (fgets(new_logical, MAX_INTERFACE_LENGTH, out)) {
1043                         /* If we are able to read a line of output from the script,
1044                          * remove any trailing whitespace and use this value
1045                          * as the name of the logical interface. */
1046                         char *pch = new_logical + strlen(new_logical) - 1;
1047
1048                         while (pch >= new_logical && isspace(*pch))
1049                                 *(pch--) = '\0';
1050
1051                         free(logical);
1052                         logical = new_logical;
1053                 } else {
1054                         /* If we are UNABLE to read a line of output, discard our
1055                          * freshly allocated memory. */
1056                         free(new_logical);
1057                 }
1058         }
1059
1060         fclose(out);
1061
1062         return logical;
1063 }
1064 #endif /* CONFIG_FEATURE_IFUPDOWN_MAPPING */
1065
1066 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1067 {
1068         unsigned short iface_len = strlen(iface);
1069         llist_t *search = state_list;
1070
1071         while (search) {
1072                 if ((strncmp(search->data, iface, iface_len) == 0) &&
1073                                 (search->data[iface_len] == '=')) {
1074                         return(search);
1075                 }
1076                 search = search->link;
1077         }
1078         return(NULL);
1079 }
1080
1081 int ifupdown_main(int argc, char **argv)
1082 {
1083         int (*cmds) (struct interface_defn_t *) = NULL;
1084         struct interfaces_file_t *defn;
1085         llist_t *state_list = NULL;
1086         llist_t *target_list = NULL;
1087         const char *interfaces = "/etc/network/interfaces";
1088         const char *statefile = "/var/run/ifstate";
1089
1090 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1091         int run_mappings = 1;
1092 #endif
1093         int do_all = 0;
1094         int force = 0;
1095         int any_failures = 0;
1096         int i;
1097
1098         if (bb_applet_name[2] == 'u') {
1099                 /* ifup command */
1100                 cmds = iface_up;
1101         } else {
1102                 /* ifdown command */
1103                 cmds = iface_down;
1104         }
1105
1106 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1107         while ((i = getopt(argc, argv, "i:hvnamf")) != -1)
1108 #else
1109                 while ((i = getopt(argc, argv, "i:hvnaf")) != -1)
1110 #endif
1111                 {
1112                         switch (i) {
1113                                 case 'i':       /* interfaces */
1114                                         interfaces = optarg;
1115                                         break;
1116                                 case 'v':       /* verbose */
1117                                         verbose = 1;
1118                                         break;
1119                                 case 'a':       /* all */
1120                                         do_all = 1;
1121                                         break;
1122                                 case 'n':       /* no-act */
1123                                         no_act = 1;
1124                                         break;
1125 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1126                                 case 'm':       /* no-mappings */
1127                                         run_mappings = 0;
1128                                         break;
1129 #endif
1130                                 case 'f':       /* force */
1131                                         force = 1;
1132                                         break;
1133                                 default:
1134                                         bb_show_usage();
1135                                         break;
1136                         }
1137                 }
1138
1139         if (argc - optind > 0) {
1140                 if (do_all) {
1141                         bb_show_usage();
1142                 }
1143         } else {
1144                 if (!do_all) {
1145                         bb_show_usage();
1146                 }
1147         }
1148
1149         debug_noise("reading %s file:\n", interfaces);
1150         defn = read_interfaces(interfaces);
1151         debug_noise("\ndone reading %s\n\n", interfaces);
1152
1153         if (!defn) {
1154                 exit(EXIT_FAILURE);
1155         }
1156
1157         /* Create a list of interfaces to work on */
1158         if (do_all) {
1159                 if (cmds == iface_up) {
1160                         target_list = defn->autointerfaces;
1161                 } else {
1162                         /* iface_down */
1163                         const llist_t *list = state_list;
1164                         while (list) {
1165                                 llist_add_to_end(&target_list, bb_xstrdup(list->data));
1166                                 list = list->link;
1167                         }
1168                         target_list = defn->autointerfaces;
1169                 }
1170         } else {
1171                 llist_add_to_end(&target_list, argv[optind]);
1172         }
1173
1174
1175         /* Update the interfaces */
1176         while (target_list) {
1177                 llist_t *iface_list;
1178                 struct interface_defn_t *currif;
1179                 char *iface;
1180                 char *liface;
1181                 char *pch;
1182                 int okay = 0;
1183                 int cmds_ret;
1184
1185                 iface = bb_xstrdup(target_list->data);
1186                 target_list = target_list->link;
1187
1188                 pch = strchr(iface, '=');
1189                 if (pch) {
1190                         *pch = '\0';
1191                         liface = bb_xstrdup(pch + 1);
1192                 } else {
1193                         liface = bb_xstrdup(iface);
1194                 }
1195
1196                 if (!force) {
1197                         const llist_t *iface_state = find_iface_state(state_list, iface);
1198
1199                         if (cmds == iface_up) {
1200                                 /* ifup */
1201                                 if (iface_state) {
1202                                         bb_error_msg("interface %s already configured", iface);
1203                                         continue;
1204                                 }
1205                         } else {
1206                                 /* ifdown */
1207                                 if (iface_state) {
1208                                         bb_error_msg("interface %s not configured", iface);
1209                                         continue;
1210                                 }
1211                         }
1212                 }
1213
1214 #ifdef CONFIG_FEATURE_IFUPDOWN_MAPPING
1215                 if ((cmds == iface_up) && run_mappings) {
1216                         struct mapping_defn_t *currmap;
1217
1218                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1219
1220                                 for (i = 0; i < currmap->n_matches; i++) {
1221                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1222                                                 continue;
1223                                         if (verbose) {
1224                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1225                                         }
1226                                         liface = run_mapping(iface, currmap);
1227                                         break;
1228                                 }
1229                         }
1230                 }
1231 #endif
1232
1233
1234                 iface_list = defn->ifaces;
1235                 while (iface_list) {
1236                         currif = (struct interface_defn_t *) iface_list->data;
1237                         if (strcmp(liface, currif->iface) == 0) {
1238                                 char *oldiface = currif->iface;
1239
1240                                 okay = 1;
1241                                 currif->iface = iface;
1242
1243                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1244
1245                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1246                                 cmds_ret = cmds(currif);
1247                                 if (cmds_ret == -1) {
1248                                         bb_error_msg("Don't seem to have all the variables for %s/%s.",
1249                                                         liface, currif->address_family->name);
1250                                         any_failures += 1;
1251                                 } else if (cmds_ret == 0) {
1252                                         any_failures += 1;
1253                                 }
1254
1255                                 currif->iface = oldiface;
1256                         }
1257                         iface_list = iface_list->link;
1258                 }
1259                 if (verbose) {
1260                         printf("\n");
1261                 }
1262
1263                 if (!okay && !force) {
1264                         bb_error_msg("Ignoring unknown interface %s", liface);
1265                         any_failures += 1;
1266                 } else {
1267                         llist_t *iface_state = find_iface_state(state_list, iface);
1268
1269                         if (cmds == iface_up) {
1270                                 char *newiface = bb_xasprintf("%s=%s", iface, liface);
1271                                 if (iface_state == NULL) {
1272                                         llist_add_to_end(&state_list, newiface);
1273                                 } else {
1274                                         free(iface_state->data);
1275                                         iface_state->data = newiface;
1276                                 }
1277                         } else {
1278                                 /* Remove an interface from the linked list */
1279                                 free(llist_pop(&iface_state));
1280                         }
1281                 }
1282         }
1283
1284         /* Actually write the new state */
1285         if (!no_act) {
1286                 FILE *state_fp = NULL;
1287
1288                 state_fp = bb_xfopen(statefile, "w");
1289                 while (state_list) {
1290                         if (state_list->data) {
1291                                 fputs(state_list->data, state_fp);
1292                                 fputc('\n', state_fp);
1293                         }
1294                         state_list = state_list->link;
1295                 }
1296                 fclose(state_fp);
1297         }
1298
1299         if (any_failures)
1300                 return 1;
1301         return 0;
1302 }