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 %zd 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                 close(lock_fd);
 363                 return false;
 364         }
 365
 366         *fd = lock_fd;
 367
 368         return true;
 369 }
 370
 371 bool
 372 fw3_lock()
 373 {
 374         return fw3_lock_path(&fw3_lock_fd, FW3_LOCKFILE);
 375 }
 376
 377
 378 void
 379 fw3_unlock_path(int *fd, const char *lockpath)
 380 {
 381         if (*fd < 0)
 382                 return;
 383
 384         if (flock(*fd, LOCK_UN))
 385                 warn("Cannot release exclusive lock: %s", strerror(errno));
 386
 387         close(*fd);
 388         unlink(FW3_LOCKFILE);
 389
 390         *fd = -1;
 391 }
 392
 393
 394 void
 395 fw3_unlock(void)
 396 {
 397         fw3_unlock_path(&fw3_lock_fd, FW3_LOCKFILE);
 398 }
 399
 400
 401 static void
 402 write_defaults_uci(struct uci_context *ctx, struct fw3_defaults *d,
 403                    struct uci_package *dest)
 404 {
 405         char buf[sizeof("0xffffffff\0")];
 406         struct uci_ptr ptr = { .p = dest };
 407
 408         uci_add_section(ctx, dest, "defaults", &ptr.s);
 409
 410         ptr.o      = NULL;
 411         ptr.option = "input";
 412         ptr.value  = fw3_flag_names[d->policy_input];
 413         uci_set(ctx, &ptr);
 414
 415         ptr.o      = NULL;
 416         ptr.option = "output";
 417         ptr.value  = fw3_flag_names[d->policy_output];
 418         uci_set(ctx, &ptr);
 419
 420         ptr.o      = NULL;
 421         ptr.option = "forward";
 422         ptr.value  = fw3_flag_names[d->policy_forward];
 423         uci_set(ctx, &ptr);
 424
 425         sprintf(buf, "0x%x", d->flags[0]);
 426         ptr.o      = NULL;
 427         ptr.option = "__flags_v4";
 428         ptr.value  = buf;
 429         uci_set(ctx, &ptr);
 430
 431         sprintf(buf, "0x%x", d->flags[1]);
 432         ptr.o      = NULL;
 433         ptr.option = "__flags_v6";
 434         ptr.value  = buf;
 435         uci_set(ctx, &ptr);
 436 }
 437
 438 static void
 439 write_zone_uci(struct uci_context *ctx, struct fw3_zone *z,
 440                struct uci_package *dest, struct ifaddrs *ifaddr)
 441 {
 442         struct fw3_device *dev;
 443         struct fw3_address *sub;
 444         struct ifaddrs *ifa;
 445         enum fw3_family fam = FW3_FAMILY_ANY;
 446
 447         char *p, buf[INET6_ADDRSTRLEN];
 448
 449         struct uci_ptr ptr = { .p = dest };
 450
 451         if (!z->enabled)
 452                 return;
 453
 454         if (fw3_no_table(z->flags[0]) && !fw3_no_table(z->flags[1]))
 455                 fam = FW3_FAMILY_V6;
 456         else if (!fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 457                 fam = FW3_FAMILY_V4;
 458         else if (fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 459                 return;
 460
 461         uci_add_section(ctx, dest, "zone", &ptr.s);
 462
 463         ptr.o      = NULL;
 464         ptr.option = "name";
 465         ptr.value  = z->name;
 466         uci_set(ctx, &ptr);
 467
 468         ptr.o      = NULL;
 469         ptr.option = "input";
 470         ptr.value  = fw3_flag_names[z->policy_input];
 471         uci_set(ctx, &ptr);
 472
 473         ptr.o      = NULL;
 474         ptr.option = "output";
 475         ptr.value  = fw3_flag_names[z->policy_output];
 476         uci_set(ctx, &ptr);
 477
 478         ptr.o      = NULL;
 479         ptr.option = "forward";
 480         ptr.value  = fw3_flag_names[z->policy_forward];
 481         uci_set(ctx, &ptr);
 482
 483         ptr.o      = NULL;
 484         ptr.option = "masq";
 485         ptr.value  = z->masq ? "1" : "0";
 486         uci_set(ctx, &ptr);
 487
 488         ptr.o      = NULL;
 489         ptr.option = "mtu_fix";
 490         ptr.value  = z->mtu_fix ? "1" : "0";
 491         uci_set(ctx, &ptr);
 492
 493         ptr.o      = NULL;
 494         ptr.option = "custom_chains";
 495         ptr.value  = z->custom_chains ? "1" : "0";
 496         uci_set(ctx, &ptr);
 497
 498         if (fam != FW3_FAMILY_ANY)
 499         {
 500                 ptr.o      = NULL;
 501                 ptr.option = "family";
 502                 ptr.value  = fw3_flag_names[fam];
 503                 uci_set(ctx, &ptr);
 504         }
 505
 506         ptr.o      = NULL;
 507         ptr.option = "device";
 508
 509         fw3_foreach(dev, &z->devices)
 510         {
 511                 char *ep;
 512
 513                 if (!dev)
 514                         continue;
 515
 516                 p = buf;
 517                 ep = buf + sizeof(buf);
 518
 519                 if (dev->invert)
 520                         p += snprintf(p, ep - p, "!");
 521
 522                 if (*dev->network)
 523                         p += snprintf(p, ep - p, "%s@%s", dev->name, dev->network);
 524                 else
 525                         p += snprintf(p, ep - p, "%s", dev->name);
 526
 527                 ptr.value = buf;
 528                 uci_add_list(ctx, &ptr);
 529         }
 530
 531         ptr.o      = NULL;
 532         ptr.option = "subnet";
 533
 534         fw3_foreach(sub, &z->subnets)
 535         {
 536                 if (!sub)
 537                         continue;
 538
 539                 ptr.value = fw3_address_to_string(sub, true, false);
 540                 uci_add_list(ctx, &ptr);
 541         }
 542
 543         ptr.o      = NULL;
 544         ptr.option = "__addrs";
 545
 546         fw3_foreach(dev, &z->devices)
 547         {
 548                 if (!dev)
 549                         continue;
 550
 551                 for (ifa = ifaddr; ifa; ifa = ifa->ifa_next)
 552                 {
 553                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 554                                 continue;
 555
 556                         if (ifa->ifa_addr->sa_family == AF_INET)
 557                                 inet_ntop(AF_INET,
 558                                           &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
 559                                           buf, sizeof(buf));
 560                         else if (ifa->ifa_addr->sa_family == AF_INET6)
 561                                 inet_ntop(AF_INET6,
 562                                           &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
 563                                           buf, sizeof(buf));
 564                         else
 565                                 continue;
 566
 567                         ptr.value = buf;
 568                         uci_add_list(ctx, &ptr);
 569                 }
 570         }
 571
 572         sprintf(buf, "0x%x", z->flags[0]);
 573         ptr.o      = NULL;
 574         ptr.option = "__flags_v4";
 575         ptr.value  = buf;
 576         uci_set(ctx, &ptr);
 577
 578         sprintf(buf, "0x%x", z->flags[1]);
 579         ptr.o      = NULL;
 580         ptr.option = "__flags_v6";
 581         ptr.value  = buf;
 582         uci_set(ctx, &ptr);
 583 }
 584
 585 static void
 586 write_ipset_uci(struct uci_context *ctx, struct fw3_ipset *s,
 587                 struct uci_package *dest)
 588 {
 589         struct fw3_ipset_datatype *type;
 590
 591         char buf[sizeof("65535-65535\0")];
 592
 593         struct uci_ptr ptr = { .p = dest };
 594
 595         if (!s->enabled || s->external)
 596                 return;
 597
 598         uci_add_section(ctx, dest, "ipset", &ptr.s);
 599
 600         ptr.o      = NULL;
 601         ptr.option = "name";
 602         ptr.value  = s->name;
 603         uci_set(ctx, &ptr);
 604
 605         ptr.o      = NULL;
 606         ptr.option = "family";
 607         if (s->family == FW3_FAMILY_V4)
 608                 ptr.value = "ipv4";
 609         else
 610                 ptr.value = "ipv6";
 611         uci_set(ctx, &ptr);
 612
 613         ptr.o      = NULL;
 614         ptr.option = "storage";
 615         ptr.value  = fw3_ipset_method_names[s->method];
 616         uci_set(ctx, &ptr);
 617
 618         list_for_each_entry(type, &s->datatypes, list)
 619         {
 620                 sprintf(buf, "%s_%s", type->dir, fw3_ipset_type_names[type->type]);
 621                 ptr.o      = NULL;
 622                 ptr.option = "match";
 623                 ptr.value  = buf;
 624                 uci_add_list(ctx, &ptr);
 625         }
 626
 627         if (s->iprange.set)
 628         {
 629                 ptr.o      = NULL;
 630                 ptr.option = "iprange";
 631                 ptr.value  = fw3_address_to_string(&s->iprange, false, false);
 632                 uci_set(ctx, &ptr);
 633         }
 634
 635         if (s->portrange.set)
 636         {
 637                 sprintf(buf, "%u-%u", s->portrange.port_min, s->portrange.port_max);
 638                 ptr.o      = NULL;
 639                 ptr.option = "portrange";
 640                 ptr.value  = buf;
 641                 uci_set(ctx, &ptr);
 642         }
 643 }
 644
 645 void
 646 fw3_write_statefile(void *state)
 647 {
 648         FILE *sf;
 649         struct fw3_state *s = state;
 650         struct fw3_zone *z;
 651         struct fw3_ipset *i;
 652         struct ifaddrs *ifaddr;
 653
 654         struct uci_package *p;
 655
 656         if (fw3_no_family(s->defaults.flags[0]) &&
 657             fw3_no_family(s->defaults.flags[1]))
 658         {
 659                 unlink(FW3_STATEFILE);
 660         }
 661         else
 662         {
 663                 sf = fopen(FW3_STATEFILE, "w+");
 664
 665                 if (!sf)
 666                 {
 667                         warn("Cannot create state %s: %s", FW3_STATEFILE, strerror(errno));
 668                         return;
 669                 }
 670
 671                 if (getifaddrs(&ifaddr))
 672                 {
 673                         warn("Cannot get interface addresses: %s", strerror(errno));
 674                         ifaddr = NULL;
 675                 }
 676
 677                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 678                         uci_unload(s->uci, p);
 679
 680                 uci_import(s->uci, sf, "fw3_state", NULL, true);
 681
 682                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 683                 {
 684                         write_defaults_uci(s->uci, &s->defaults, p);
 685
 686                         list_for_each_entry(z, &s->zones, list)
 687                                 write_zone_uci(s->uci, z, p, ifaddr);
 688
 689                         list_for_each_entry(i, &s->ipsets, list)
 690                                 write_ipset_uci(s->uci, i, p);
 691
 692                         uci_export(s->uci, sf, p, true);
 693                         uci_unload(s->uci, p);
 694                 }
 695
 696                 fsync(fileno(sf));
 697                 fclose(sf);
 698
 699                 if (ifaddr)
 700                         freeifaddrs(ifaddr);
 701         }
 702 }
 703
 704
 705 void
 706 fw3_free_object(void *obj, const void *opts)
 707 {
 708         const struct fw3_option *ol;
 709         struct list_head *list, *cur, *tmp;
 710
 711         for (ol = opts; ol->name; ol++)
 712         {
 713                 if (!ol->elem_size)
 714                         continue;
 715
 716                 list = (struct list_head *)((char *)obj + ol->offset);
 717                 list_for_each_safe(cur, tmp, list)
 718                 {
 719                         list_del(cur);
 720                         free(cur);
 721                 }
 722         }
 723
 724         free(obj);
 725 }
 726
 727 void
 728 fw3_free_list(struct list_head *head)
 729 {
 730         struct list_head *entry, *tmp;
 731
 732         if (!head)
 733                 return;
 734
 735         list_for_each_safe(entry, tmp, head)
 736         {
 737                 list_del(entry);
 738                 free(entry);
 739         }
 740
 741         free(head);
 742 }
 743
 744 bool
 745 fw3_hotplug(bool add, void *zone, void *device)
 746 {
 747         struct fw3_zone *z = zone;
 748         struct fw3_device *d = device;
 749
 750         if (!*d->network)
 751                 return false;
 752
 753         switch (fork())
 754         {
 755         case -1:
 756                 warn("Unable to fork(): %s\n", strerror(errno));
 757                 return false;
 758
 759         case 0:
 760                 break;
 761
 762         default:
 763                 return true;
 764         }
 765
 766         close(0);
 767         close(1);
 768         close(2);
 769         if (chdir("/")) {};
 770
 771         clearenv();
 772         setenv("ACTION",    add ? "add" : "remove", 1);
 773         setenv("ZONE",      z->name,                1);
 774         setenv("INTERFACE", d->network,             1);
 775         setenv("DEVICE",    d->name,                1);
 776
 777         execl(FW3_HOTPLUG, FW3_HOTPLUG, "firewall", NULL);
 778
 779         /* unreached */
 780         return false;
 781 }
 782
 783 int
 784 fw3_netmask2bitlen(int family, void *mask)
 785 {
 786         int bits;
 787         struct in_addr *v4;
 788         struct in6_addr *v6;
 789
 790         if (family == FW3_FAMILY_V6)
 791                 for (bits = 0, v6 = mask;
 792                      bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
 793                      bits++);
 794         else
 795                 for (bits = 0, v4 = mask;
 796                      bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
 797                      bits++);
 798
 799         return bits;
 800 }
 801
 802 bool
 803 fw3_bitlen2netmask(int family, int bits, void *mask)
 804 {
 805         int i;
 806         uint8_t rem, b;
 807         struct in_addr *v4;
 808         struct in6_addr *v6;
 809
 810         if (family == FW3_FAMILY_V6)
 811         {
 812                 if (bits < -128 || bits > 128)
 813                         return false;
 814
 815                 v6 = mask;
 816                 rem = abs(bits);
 817
 818                 for (i = 0; i < sizeof(v6->s6_addr); i++)
 819                 {
 820                         b = (rem > 8) ? 8 : rem;
 821                         v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
 822                         rem -= b;
 823                 }
 824
 825                 if (bits < 0)
 826                         for (i = 0; i < sizeof(v6->s6_addr); i++)
 827                                 v6->s6_addr[i] = ~v6->s6_addr[i];
 828         }
 829         else
 830         {
 831                 if (bits < -32 || bits > 32)
 832                         return false;
 833
 834                 v4 = mask;
 835                 v4->s_addr = bits ? htonl(~((1 << (32 - abs(bits))) - 1)) : 0;
 836
 837                 if (bits < 0)
 838                         v4->s_addr = ~v4->s_addr;
 839         }
 840
 841         return true;
 842 }
 843
 844 void
 845 fw3_flush_conntrack(void *state)
 846 {
 847         bool found;
 848         struct fw3_state *s = state;
 849         struct fw3_address *addr;
 850         struct fw3_device *dev;
 851         struct fw3_zone *zone;
 852         struct ifaddrs *ifaddr, *ifa;
 853         struct sockaddr_in *sin;
 854         struct sockaddr_in6 *sin6;
 855         char buf[INET6_ADDRSTRLEN];
 856         FILE *ct;
 857
 858         if (!state)
 859         {
 860                 if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 861                 {
 862                         info(" * Flushing conntrack table ...");
 863
 864                         fwrite("f\n", 1, 2, ct);
 865                         fclose(ct);
 866                 }
 867
 868                 return;
 869         }
 870
 871         if (getifaddrs(&ifaddr))
 872         {
 873                 warn("Cannot get interface addresses: %s", strerror(errno));
 874                 return;
 875         }
 876
 877         if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 878         {
 879                 list_for_each_entry(zone, &s->zones, list)
 880                 list_for_each_entry(addr, &zone->old_addrs, list)
 881                 {
 882                         found = false;
 883
 884                         list_for_each_entry(dev, &zone->devices, list)
 885                         {
 886                                 for (ifa = ifaddr; ifa && !found; ifa = ifa->ifa_next)
 887                                 {
 888                                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 889                                                 continue;
 890
 891                                         sin = (struct sockaddr_in *)ifa->ifa_addr;
 892                                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 893
 894                                         if (addr->family == FW3_FAMILY_V4 &&
 895                                                 sin->sin_family == AF_INET)
 896                                         {
 897                                                 found = !memcmp(&addr->address.v4, &sin->sin_addr,
 898                                                                                 sizeof(sin->sin_addr));
 899                                         }
 900                                         else if (addr->family == FW3_FAMILY_V6 &&
 901                                                          sin6->sin6_family == AF_INET6)
 902                                         {
 903                                                 found = !memcmp(&addr->address.v6, &sin6->sin6_addr,
 904                                                                                 sizeof(sin6->sin6_addr));
 905                                         }
 906                                 }
 907
 908                                 if (found)
 909                                         break;
 910                         }
 911
 912                         if (!found)
 913                         {
 914                                 inet_ntop(addr->family == FW3_FAMILY_V4 ? AF_INET : AF_INET6,
 915                                                   &addr->address.v4, buf, sizeof(buf));
 916
 917                                 info(" * Flushing conntrack: %s", buf);
 918                                 fprintf(ct, "%s\n", buf);
 919                         }
 920                 }
 921
 922                 fclose(ct);
 923         }
 924
 925         freeifaddrs(ifaddr);
 926 }
 927
 928 bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const char **type)
 929 {
 930         struct blob_attr *opt;
 931         unsigned orem;
 932
 933         if (!type || !name)
 934                 return false;
 935
 936         *type = NULL;
 937
 938         blobmsg_for_each_attr(opt, entry, orem)
 939                 if (!strcmp(blobmsg_name(opt), "type"))
 940                         *type = blobmsg_get_string(opt);
 941                 else if (!strcmp(blobmsg_name(opt), "name"))
 942                         *name = blobmsg_get_string(opt);
 943
 944         return *type != NULL ? true : false;
 945 }
 946
 947 const char *
 948 fw3_protoname(void *proto)
 949 {
 950         static char buf[sizeof("4294967295")];
 951         struct fw3_protocol *p = proto;
 952         struct protoent *pe;
 953
 954         if (!p)
 955                 return "?";
 956
 957         pe = getprotobynumber(p->protocol);
 958
 959         if (!pe)
 960         {
 961                 snprintf(buf, sizeof(buf), "%u", p->protocol);
 962                 return buf;
 963         }
 964
 965         return pe->p_name;
 966 }
 967
 968 bool
 969 fw3_check_loopback_dev(const char *name)
 970 {
 971         struct ifreq ifr;
 972         int s;
 973         bool rv = false;
 974
 975         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
 976
 977         if (s < 0)
 978                 return false;
 979
 980         memset(&ifr, 0, sizeof(ifr));
 981         strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name) - 1);
 982
 983         if (ioctl(s, SIOCGIFFLAGS, &ifr) >= 0) {
 984                 if (ifr.ifr_flags & IFF_LOOPBACK)
 985                         rv = true;
 986         }
 987
 988         close(s);
 989
 990         return rv;
 991 }
 992
 993 bool
 994 fw3_check_loopback_addr(struct fw3_address *addr)
 995 {
 996         if (addr->family == FW3_FAMILY_V4 &&
 997             (ntohl(addr->address.v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
 998                 return true;
 999
1000         if (addr->family == FW3_FAMILY_V6 && !addr->range &&
1001             fw3_netmask2bitlen(FW3_FAMILY_V6, &addr->mask.v6) == 128 &&
1002             IN6_IS_ADDR_LOOPBACK(&addr->address.v6))
1003                 return true;
1004
1005         return false;
1006 }