utils.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #define _GNU_SOURCE
  20
  21 #include <net/if.h>
  22 #include <sys/ioctl.h>
  23
  24 #include "utils.h"
  25 #include "options.h"
  26
  27 #include "zones.h"
  28 #include "ipsets.h"
  29
  30
  31 static int fw3_lock_fd = -1;
  32 static pid_t pipe_pid = -1;
  33 static FILE *pipe_fd = NULL;
  34
  35 bool fw3_pr_debug = false;
  36
  37
  38 static void
  39 warn_elem_section_name(struct uci_section *s, bool find_name)
  40 {
  41         int i = 0;
  42         struct uci_option *o;
  43         struct uci_element *tmp;
  44
  45         if (s->anonymous)
  46         {
  47                 uci_foreach_element(&s->package->sections, tmp)
  48                 {
  49                         if (strcmp(uci_to_section(tmp)->type, s->type))
  50                                 continue;
  51
  52                         if (&s->e == tmp)
  53                                 break;
  54
  55                         i++;
  56                 }
  57
  58                 fprintf(stderr, "@%s[%d]", s->type, i);
  59
  60                 if (find_name)
  61                 {
  62                         uci_foreach_element(&s->options, tmp)
  63                         {
  64                                 o = uci_to_option(tmp);
  65
  66                                 if (!strcmp(tmp->name, "name") && (o->type == UCI_TYPE_STRING))
  67                                 {
  68                                         fprintf(stderr, " (%s)", o->v.string);
  69                                         break;
  70                                 }
  71                         }
  72                 }
  73         }
  74         else
  75         {
  76                 fprintf(stderr, "'%s'", s->e.name);
  77         }
  78
  79         if (find_name)
  80                 fprintf(stderr, " ");
  81 }
  82
  83 void
  84 warn_elem(struct uci_element *e, const char *format, ...)
  85 {
  86         if (e->type == UCI_TYPE_SECTION)
  87         {
  88                 fprintf(stderr, "Warning: Section ");
  89                 warn_elem_section_name(uci_to_section(e), true);
  90         }
  91         else if (e->type == UCI_TYPE_OPTION)
  92         {
  93                 fprintf(stderr, "Warning: Option ");
  94                 warn_elem_section_name(uci_to_option(e)->section, false);
  95                 fprintf(stderr, ".%s ", e->name);
  96         }
  97
  98     va_list argptr;
  99     va_start(argptr, format);
 100     vfprintf(stderr, format, argptr);
 101     va_end(argptr);
 102
 103         fprintf(stderr, "\n");
 104 }
 105
 106 void
 107 warn(const char* format, ...)
 108 {
 109         fprintf(stderr, "Warning: ");
 110     va_list argptr;
 111     va_start(argptr, format);
 112     vfprintf(stderr, format, argptr);
 113     va_end(argptr);
 114         fprintf(stderr, "\n");
 115 }
 116
 117 void
 118 error(const char* format, ...)
 119 {
 120         fprintf(stderr, "Error: ");
 121     va_list argptr;
 122     va_start(argptr, format);
 123     vfprintf(stderr, format, argptr);
 124     va_end(argptr);
 125         fprintf(stderr, "\n");
 126
 127         exit(1);
 128 }
 129
 130 void
 131 info(const char* format, ...)
 132 {
 133         va_list argptr;
 134     va_start(argptr, format);
 135     vfprintf(stderr, format, argptr);
 136     va_end(argptr);
 137         fprintf(stderr, "\n");
 138 }
 139
 140 void *
 141 fw3_alloc(size_t size)
 142 {
 143         void *mem;
 144
 145         mem = calloc(1, size);
 146
 147         if (!mem)
 148                 error("Out of memory while allocating %d bytes", size);
 149
 150         return mem;
 151 }
 152
 153 char *
 154 fw3_strdup(const char *s)
 155 {
 156         char *ns;
 157
 158         ns = strdup(s);
 159
 160         if (!ns)
 161                 error("Out of memory while duplicating string '%s'", s);
 162
 163         return ns;
 164 }
 165
 166 const char *
 167 fw3_find_command(const char *cmd)
 168 {
 169         struct stat s;
 170         int plen = 0, clen = strlen(cmd) + 1;
 171         char *search, *p;
 172         static char path[PATH_MAX];
 173
 174         if (!stat(cmd, &s) && S_ISREG(s.st_mode))
 175                 return cmd;
 176
 177         search = getenv("PATH");
 178
 179         if (!search)
 180                 search = "/bin:/usr/bin:/sbin:/usr/sbin";
 181
 182         p = search;
 183
 184         do
 185         {
 186                 if (*p != ':' && *p != '\0')
 187                         continue;
 188
 189                 plen = p - search;
 190
 191                 if ((plen + clen) >= sizeof(path))
 192                         continue;
 193
 194                 strncpy(path, search, plen);
 195                 sprintf(path + plen, "/%s", cmd);
 196
 197                 if (!stat(path, &s) && S_ISREG(s.st_mode))
 198                         return path;
 199
 200                 search = p + 1;
 201         }
 202         while (*p++);
 203
 204         return NULL;
 205 }
 206
 207 bool
 208 fw3_stdout_pipe(void)
 209 {
 210         pipe_fd = stdout;
 211         return true;
 212 }
 213
 214 bool
 215 __fw3_command_pipe(bool silent, const char *command, ...)
 216 {
 217         pid_t pid;
 218         va_list argp;
 219         int pfds[2];
 220         int argn;
 221         char *arg, **args, **tmp;
 222
 223         command = fw3_find_command(command);
 224
 225         if (!command)
 226                 return false;
 227
 228         if (pipe(pfds))
 229                 return false;
 230
 231         argn = 2;
 232         args = calloc(argn, sizeof(arg));
 233
 234         if (!args)
 235                 return false;
 236
 237         args[0] = (char *)command;
 238         args[1] = NULL;
 239
 240         va_start(argp, command);
 241
 242         while ((arg = va_arg(argp, char *)) != NULL)
 243         {
 244                 tmp = realloc(args, ++argn * sizeof(arg));
 245
 246                 if (!tmp)
 247                         break;
 248
 249                 args = tmp;
 250                 args[argn-2] = arg;
 251                 args[argn-1] = NULL;
 252         }
 253
 254         va_end(argp);
 255
 256         switch ((pid = fork()))
 257         {
 258         case -1:
 259                 free(args);
 260                 return false;
 261
 262         case 0:
 263                 dup2(pfds[0], 0);
 264
 265                 close(pfds[0]);
 266                 close(pfds[1]);
 267
 268                 close(1);
 269
 270                 if (silent)
 271                         close(2);
 272
 273                 execv(command, args);
 274
 275         default:
 276                 signal(SIGPIPE, SIG_IGN);
 277                 pipe_pid = pid;
 278                 close(pfds[0]);
 279                 fcntl(pfds[1], F_SETFD, fcntl(pfds[1], F_GETFD) | FD_CLOEXEC);
 280         }
 281
 282         pipe_fd = fdopen(pfds[1], "w");
 283         free(args);
 284         return true;
 285 }
 286
 287 void
 288 fw3_pr(const char *fmt, ...)
 289 {
 290         va_list args;
 291
 292         if (fw3_pr_debug && pipe_fd != stdout)
 293         {
 294                 va_start(args, fmt);
 295                 vfprintf(stderr, fmt, args);
 296                 va_end(args);
 297         }
 298
 299         va_start(args, fmt);
 300         vfprintf(pipe_fd, fmt, args);
 301         va_end(args);
 302 }
 303
 304 void
 305 fw3_command_close(void)
 306 {
 307         if (pipe_fd && pipe_fd != stdout)
 308                 fclose(pipe_fd);
 309
 310         if (pipe_pid > -1)
 311                 waitpid(pipe_pid, NULL, 0);
 312
 313         signal(SIGPIPE, SIG_DFL);
 314
 315         pipe_fd = NULL;
 316         pipe_pid = -1;
 317 }
 318
 319 bool
 320 fw3_has_table(bool ipv6, const char *table)
 321 {
 322         FILE *f;
 323
 324         char line[12];
 325         bool seen = false;
 326
 327         const char *path = ipv6
 328                 ? "/proc/net/ip6_tables_names" : "/proc/net/ip_tables_names";
 329
 330         if (!(f = fopen(path, "r")))
 331                 return false;
 332
 333         while (fgets(line, sizeof(line), f))
 334         {
 335                 if (!strncmp(line, table, strlen(table)))
 336                 {
 337                         seen = true;
 338                         break;
 339                 }
 340         }
 341
 342         fclose(f);
 343
 344         return seen;
 345 }
 346
 347
 348 bool
 349 fw3_lock_path(int *fd, const char *path)
 350 {
 351         int lock_fd = open(path, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 352
 353         if (lock_fd < 0)
 354         {
 355                 warn("Cannot create lock file %s: %s", path, strerror(errno));
 356                 return false;
 357         }
 358
 359         if (flock(lock_fd, LOCK_EX))
 360         {
 361                 warn("Cannot acquire exclusive lock: %s", strerror(errno));
 362                 return false;
 363         }
 364
 365         *fd = lock_fd;
 366
 367         return true;
 368 }
 369
 370 bool
 371 fw3_lock()
 372 {
 373         return fw3_lock_path(&fw3_lock_fd, FW3_LOCKFILE);
 374 }
 375
 376
 377 void
 378 fw3_unlock_path(int *fd, const char *lockpath)
 379 {
 380         if (*fd < 0)
 381                 return;
 382
 383         if (flock(*fd, LOCK_UN))
 384                 warn("Cannot release exclusive lock: %s", strerror(errno));
 385
 386         close(*fd);
 387         unlink(FW3_LOCKFILE);
 388
 389         *fd = -1;
 390 }
 391
 392
 393 void
 394 fw3_unlock(void)
 395 {
 396         fw3_unlock_path(&fw3_lock_fd, FW3_LOCKFILE);
 397 }
 398
 399
 400 static void
 401 write_defaults_uci(struct uci_context *ctx, struct fw3_defaults *d,
 402                    struct uci_package *dest)
 403 {
 404         char buf[sizeof("0xffffffff\0")];
 405         struct uci_ptr ptr = { .p = dest };
 406
 407         uci_add_section(ctx, dest, "defaults", &ptr.s);
 408
 409         ptr.o      = NULL;
 410         ptr.option = "input";
 411         ptr.value  = fw3_flag_names[d->policy_input];
 412         uci_set(ctx, &ptr);
 413
 414         ptr.o      = NULL;
 415         ptr.option = "output";
 416         ptr.value  = fw3_flag_names[d->policy_output];
 417         uci_set(ctx, &ptr);
 418
 419         ptr.o      = NULL;
 420         ptr.option = "forward";
 421         ptr.value  = fw3_flag_names[d->policy_forward];
 422         uci_set(ctx, &ptr);
 423
 424         sprintf(buf, "0x%x", d->flags[0]);
 425         ptr.o      = NULL;
 426         ptr.option = "__flags_v4";
 427         ptr.value  = buf;
 428         uci_set(ctx, &ptr);
 429
 430         sprintf(buf, "0x%x", d->flags[1]);
 431         ptr.o      = NULL;
 432         ptr.option = "__flags_v6";
 433         ptr.value  = buf;
 434         uci_set(ctx, &ptr);
 435 }
 436
 437 static void
 438 write_zone_uci(struct uci_context *ctx, struct fw3_zone *z,
 439                struct uci_package *dest, struct ifaddrs *ifaddr)
 440 {
 441         struct fw3_device *dev;
 442         struct fw3_address *sub;
 443         struct ifaddrs *ifa;
 444         enum fw3_family fam = FW3_FAMILY_ANY;
 445
 446         char *p, buf[INET6_ADDRSTRLEN];
 447
 448         struct uci_ptr ptr = { .p = dest };
 449
 450         if (!z->enabled)
 451                 return;
 452
 453         if (fw3_no_table(z->flags[0]) && !fw3_no_table(z->flags[1]))
 454                 fam = FW3_FAMILY_V6;
 455         else if (!fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 456                 fam = FW3_FAMILY_V4;
 457         else if (fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 458                 return;
 459
 460         uci_add_section(ctx, dest, "zone", &ptr.s);
 461
 462         ptr.o      = NULL;
 463         ptr.option = "name";
 464         ptr.value  = z->name;
 465         uci_set(ctx, &ptr);
 466
 467         ptr.o      = NULL;
 468         ptr.option = "input";
 469         ptr.value  = fw3_flag_names[z->policy_input];
 470         uci_set(ctx, &ptr);
 471
 472         ptr.o      = NULL;
 473         ptr.option = "output";
 474         ptr.value  = fw3_flag_names[z->policy_output];
 475         uci_set(ctx, &ptr);
 476
 477         ptr.o      = NULL;
 478         ptr.option = "forward";
 479         ptr.value  = fw3_flag_names[z->policy_forward];
 480         uci_set(ctx, &ptr);
 481
 482         ptr.o      = NULL;
 483         ptr.option = "masq";
 484         ptr.value  = z->masq ? "1" : "0";
 485         uci_set(ctx, &ptr);
 486
 487         ptr.o      = NULL;
 488         ptr.option = "mtu_fix";
 489         ptr.value  = z->mtu_fix ? "1" : "0";
 490         uci_set(ctx, &ptr);
 491
 492         ptr.o      = NULL;
 493         ptr.option = "custom_chains";
 494         ptr.value  = z->custom_chains ? "1" : "0";
 495         uci_set(ctx, &ptr);
 496
 497         if (fam != FW3_FAMILY_ANY)
 498         {
 499                 ptr.o      = NULL;
 500                 ptr.option = "family";
 501                 ptr.value  = fw3_flag_names[fam];
 502                 uci_set(ctx, &ptr);
 503         }
 504
 505         ptr.o      = NULL;
 506         ptr.option = "device";
 507
 508         fw3_foreach(dev, &z->devices)
 509         {
 510                 char *ep;
 511
 512                 if (!dev)
 513                         continue;
 514
 515                 p = buf;
 516                 ep = buf + sizeof(buf);
 517
 518                 if (dev->invert)
 519                         p += snprintf(p, ep - p, "!");
 520
 521                 if (*dev->network)
 522                         p += snprintf(p, ep - p, "%s@%s", dev->name, dev->network);
 523                 else
 524                         p += snprintf(p, ep - p, "%s", dev->name);
 525
 526                 ptr.value = buf;
 527                 uci_add_list(ctx, &ptr);
 528         }
 529
 530         ptr.o      = NULL;
 531         ptr.option = "subnet";
 532
 533         fw3_foreach(sub, &z->subnets)
 534         {
 535                 if (!sub)
 536                         continue;
 537
 538                 ptr.value = fw3_address_to_string(sub, true, false);
 539                 uci_add_list(ctx, &ptr);
 540         }
 541
 542         ptr.o      = NULL;
 543         ptr.option = "__addrs";
 544
 545         fw3_foreach(dev, &z->devices)
 546         {
 547                 if (!dev)
 548                         continue;
 549
 550                 for (ifa = ifaddr; ifa; ifa = ifa->ifa_next)
 551                 {
 552                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 553                                 continue;
 554
 555                         if (ifa->ifa_addr->sa_family == AF_INET)
 556                                 inet_ntop(AF_INET,
 557                                           &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
 558                                           buf, sizeof(buf));
 559                         else if (ifa->ifa_addr->sa_family == AF_INET6)
 560                                 inet_ntop(AF_INET6,
 561                                           &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
 562                                           buf, sizeof(buf));
 563                         else
 564                                 continue;
 565
 566                         ptr.value = buf;
 567                         uci_add_list(ctx, &ptr);
 568                 }
 569         }
 570
 571         sprintf(buf, "0x%x", z->flags[0]);
 572         ptr.o      = NULL;
 573         ptr.option = "__flags_v4";
 574         ptr.value  = buf;
 575         uci_set(ctx, &ptr);
 576
 577         sprintf(buf, "0x%x", z->flags[1]);
 578         ptr.o      = NULL;
 579         ptr.option = "__flags_v6";
 580         ptr.value  = buf;
 581         uci_set(ctx, &ptr);
 582 }
 583
 584 static void
 585 write_ipset_uci(struct uci_context *ctx, struct fw3_ipset *s,
 586                 struct uci_package *dest)
 587 {
 588         struct fw3_ipset_datatype *type;
 589
 590         char buf[sizeof("65535-65535\0")];
 591
 592         struct uci_ptr ptr = { .p = dest };
 593
 594         if (!s->enabled || s->external)
 595                 return;
 596
 597         uci_add_section(ctx, dest, "ipset", &ptr.s);
 598
 599         ptr.o      = NULL;
 600         ptr.option = "name";
 601         ptr.value  = s->name;
 602         uci_set(ctx, &ptr);
 603
 604         ptr.o      = NULL;
 605         ptr.option = "family";
 606         if (s->family == FW3_FAMILY_V4)
 607                 ptr.value = "ipv4";
 608         else
 609                 ptr.value = "ipv6";
 610         uci_set(ctx, &ptr);
 611
 612         ptr.o      = NULL;
 613         ptr.option = "storage";
 614         ptr.value  = fw3_ipset_method_names[s->method];
 615         uci_set(ctx, &ptr);
 616
 617         list_for_each_entry(type, &s->datatypes, list)
 618         {
 619                 sprintf(buf, "%s_%s", type->dir, fw3_ipset_type_names[type->type]);
 620                 ptr.o      = NULL;
 621                 ptr.option = "match";
 622                 ptr.value  = buf;
 623                 uci_add_list(ctx, &ptr);
 624         }
 625
 626         if (s->iprange.set)
 627         {
 628                 ptr.o      = NULL;
 629                 ptr.option = "iprange";
 630                 ptr.value  = fw3_address_to_string(&s->iprange, false, false);
 631                 uci_set(ctx, &ptr);
 632         }
 633
 634         if (s->portrange.set)
 635         {
 636                 sprintf(buf, "%u-%u", s->portrange.port_min, s->portrange.port_max);
 637                 ptr.o      = NULL;
 638                 ptr.option = "portrange";
 639                 ptr.value  = buf;
 640                 uci_set(ctx, &ptr);
 641         }
 642 }
 643
 644 void
 645 fw3_write_statefile(void *state)
 646 {
 647         FILE *sf;
 648         struct fw3_state *s = state;
 649         struct fw3_zone *z;
 650         struct fw3_ipset *i;
 651         struct ifaddrs *ifaddr;
 652
 653         struct uci_package *p;
 654
 655         if (fw3_no_family(s->defaults.flags[0]) &&
 656             fw3_no_family(s->defaults.flags[1]))
 657         {
 658                 unlink(FW3_STATEFILE);
 659         }
 660         else
 661         {
 662                 sf = fopen(FW3_STATEFILE, "w+");
 663
 664                 if (!sf)
 665                 {
 666                         warn("Cannot create state %s: %s", FW3_STATEFILE, strerror(errno));
 667                         return;
 668                 }
 669
 670                 if (getifaddrs(&ifaddr))
 671                 {
 672                         warn("Cannot get interface addresses: %s", strerror(errno));
 673                         ifaddr = NULL;
 674                 }
 675
 676                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 677                         uci_unload(s->uci, p);
 678
 679                 uci_import(s->uci, sf, "fw3_state", NULL, true);
 680
 681                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 682                 {
 683                         write_defaults_uci(s->uci, &s->defaults, p);
 684
 685                         list_for_each_entry(z, &s->zones, list)
 686                                 write_zone_uci(s->uci, z, p, ifaddr);
 687
 688                         list_for_each_entry(i, &s->ipsets, list)
 689                                 write_ipset_uci(s->uci, i, p);
 690
 691                         uci_export(s->uci, sf, p, true);
 692                         uci_unload(s->uci, p);
 693                 }
 694
 695                 fsync(fileno(sf));
 696                 fclose(sf);
 697
 698                 if (ifaddr)
 699                         freeifaddrs(ifaddr);
 700         }
 701 }
 702
 703
 704 void
 705 fw3_free_object(void *obj, const void *opts)
 706 {
 707         const struct fw3_option *ol;
 708         struct list_head *list, *cur, *tmp;
 709
 710         for (ol = opts; ol->name; ol++)
 711         {
 712                 if (!ol->elem_size)
 713                         continue;
 714
 715                 list = (struct list_head *)((char *)obj + ol->offset);
 716                 list_for_each_safe(cur, tmp, list)
 717                 {
 718                         list_del(cur);
 719                         free(cur);
 720                 }
 721         }
 722
 723         free(obj);
 724 }
 725
 726 void
 727 fw3_free_list(struct list_head *head)
 728 {
 729         struct list_head *entry, *tmp;
 730
 731         if (!head)
 732                 return;
 733
 734         list_for_each_safe(entry, tmp, head)
 735         {
 736                 list_del(entry);
 737                 free(entry);
 738         }
 739
 740         free(head);
 741 }
 742
 743 bool
 744 fw3_hotplug(bool add, void *zone, void *device)
 745 {
 746         struct fw3_zone *z = zone;
 747         struct fw3_device *d = device;
 748
 749         if (!*d->network)
 750                 return false;
 751
 752         switch (fork())
 753         {
 754         case -1:
 755                 warn("Unable to fork(): %s\n", strerror(errno));
 756                 return false;
 757
 758         case 0:
 759                 break;
 760
 761         default:
 762                 return true;
 763         }
 764
 765         close(0);
 766         close(1);
 767         close(2);
 768         if (chdir("/")) {};
 769
 770         clearenv();
 771         setenv("ACTION",    add ? "add" : "remove", 1);
 772         setenv("ZONE",      z->name,                1);
 773         setenv("INTERFACE", d->network,             1);
 774         setenv("DEVICE",    d->name,                1);
 775
 776         execl(FW3_HOTPLUG, FW3_HOTPLUG, "firewall", NULL);
 777
 778         /* unreached */
 779         return false;
 780 }
 781
 782 int
 783 fw3_netmask2bitlen(int family, void *mask)
 784 {
 785         int bits;
 786         struct in_addr *v4;
 787         struct in6_addr *v6;
 788
 789         if (family == FW3_FAMILY_V6)
 790                 for (bits = 0, v6 = mask;
 791                      bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
 792                      bits++);
 793         else
 794                 for (bits = 0, v4 = mask;
 795                      bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
 796                      bits++);
 797
 798         return bits;
 799 }
 800
 801 bool
 802 fw3_bitlen2netmask(int family, int bits, void *mask)
 803 {
 804         int i;
 805         uint8_t rem, b;
 806         struct in_addr *v4;
 807         struct in6_addr *v6;
 808
 809         if (family == FW3_FAMILY_V6)
 810         {
 811                 if (bits < -128 || bits > 128)
 812                         return false;
 813
 814                 v6 = mask;
 815                 rem = abs(bits);
 816
 817                 for (i = 0; i < sizeof(v6->s6_addr); i++)
 818                 {
 819                         b = (rem > 8) ? 8 : rem;
 820                         v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
 821                         rem -= b;
 822                 }
 823
 824                 if (bits < 0)
 825                         for (i = 0; i < sizeof(v6->s6_addr); i++)
 826                                 v6->s6_addr[i] = ~v6->s6_addr[i];
 827         }
 828         else
 829         {
 830                 if (bits < -32 || bits > 32)
 831                         return false;
 832
 833                 v4 = mask;
 834                 v4->s_addr = bits ? htonl(~((1 << (32 - abs(bits))) - 1)) : 0;
 835
 836                 if (bits < 0)
 837                         v4->s_addr = ~v4->s_addr;
 838         }
 839
 840         return true;
 841 }
 842
 843 void
 844 fw3_flush_conntrack(void *state)
 845 {
 846         bool found;
 847         struct fw3_state *s = state;
 848         struct fw3_address *addr;
 849         struct fw3_device *dev;
 850         struct fw3_zone *zone;
 851         struct ifaddrs *ifaddr, *ifa;
 852         struct sockaddr_in *sin;
 853         struct sockaddr_in6 *sin6;
 854         char buf[INET6_ADDRSTRLEN];
 855         FILE *ct;
 856
 857         if (!state)
 858         {
 859                 if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 860                 {
 861                         info(" * Flushing conntrack table ...");
 862
 863                         fwrite("f\n", 1, 2, ct);
 864                         fclose(ct);
 865                 }
 866
 867                 return;
 868         }
 869
 870         if (getifaddrs(&ifaddr))
 871         {
 872                 warn("Cannot get interface addresses: %s", strerror(errno));
 873                 return;
 874         }
 875
 876         if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 877         {
 878                 list_for_each_entry(zone, &s->zones, list)
 879                 list_for_each_entry(addr, &zone->old_addrs, list)
 880                 {
 881                         found = false;
 882
 883                         list_for_each_entry(dev, &zone->devices, list)
 884                         {
 885                                 for (ifa = ifaddr; ifa && !found; ifa = ifa->ifa_next)
 886                                 {
 887                                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 888                                                 continue;
 889
 890                                         sin = (struct sockaddr_in *)ifa->ifa_addr;
 891                                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 892
 893                                         if (addr->family == FW3_FAMILY_V4 &&
 894                                                 sin->sin_family == AF_INET)
 895                                         {
 896                                                 found = !memcmp(&addr->address.v4, &sin->sin_addr,
 897                                                                                 sizeof(sin->sin_addr));
 898                                         }
 899                                         else if (addr->family == FW3_FAMILY_V6 &&
 900                                                          sin6->sin6_family == AF_INET6)
 901                                         {
 902                                                 found = !memcmp(&addr->address.v6, &sin6->sin6_addr,
 903                                                                                 sizeof(sin6->sin6_addr));
 904                                         }
 905                                 }
 906
 907                                 if (found)
 908                                         break;
 909                         }
 910
 911                         if (!found)
 912                         {
 913                                 inet_ntop(addr->family == FW3_FAMILY_V4 ? AF_INET : AF_INET6,
 914                                                   &addr->address.v4, buf, sizeof(buf));
 915
 916                                 info(" * Flushing conntrack: %s", buf);
 917                                 fprintf(ct, "%s\n", buf);
 918                         }
 919                 }
 920
 921                 fclose(ct);
 922         }
 923
 924         freeifaddrs(ifaddr);
 925 }
 926
 927 bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const char **type)
 928 {
 929         struct blob_attr *opt;
 930         unsigned orem;
 931
 932         if (!type || !name)
 933                 return false;
 934
 935         *type = NULL;
 936
 937         blobmsg_for_each_attr(opt, entry, orem)
 938                 if (!strcmp(blobmsg_name(opt), "type"))
 939                         *type = blobmsg_get_string(opt);
 940                 else if (!strcmp(blobmsg_name(opt), "name"))
 941                         *name = blobmsg_get_string(opt);
 942
 943         return *type != NULL ? true : false;
 944 }
 945
 946 const char *
 947 fw3_protoname(void *proto)
 948 {
 949         static char buf[sizeof("4294967295")];
 950         struct fw3_protocol *p = proto;
 951         struct protoent *pe;
 952
 953         if (!p)
 954                 return "?";
 955
 956         pe = getprotobynumber(p->protocol);
 957
 958         if (!pe)
 959         {
 960                 snprintf(buf, sizeof(buf), "%u", p->protocol);
 961                 return buf;
 962         }
 963
 964         return pe->p_name;
 965 }
 966
 967 bool
 968 fw3_check_loopback_dev(const char *name)
 969 {
 970         struct ifreq ifr;
 971         int s;
 972         bool rv = false;
 973
 974         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
 975
 976         if (s < 0)
 977                 return false;
 978
 979         memset(&ifr, 0, sizeof(ifr));
 980         strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name) - 1);
 981
 982         if (ioctl(s, SIOCGIFFLAGS, &ifr) >= 0) {
 983                 if (ifr.ifr_flags & IFF_LOOPBACK)
 984                         rv = true;
 985         }
 986
 987         close(s);
 988
 989         return rv;
 990 }
 991
 992 bool
 993 fw3_check_loopback_addr(struct fw3_address *addr)
 994 {
 995         if (addr->family == FW3_FAMILY_V4 &&
 996             (ntohl(addr->address.v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
 997                 return true;
 998
 999         if (addr->family == FW3_FAMILY_V6 && !addr->range &&
1000             fw3_netmask2bitlen(FW3_FAMILY_V6, &addr->mask.v6) == 128 &&
1001             IN6_IS_ADDR_LOOPBACK(&addr->address.v6))
1002                 return true;
1003
1004         return false;
1005 }