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                 snprintf(path, sizeof(path), "%.*s/%s", plen, search, cmd);
 195
 196                 if (!stat(path, &s) && S_ISREG(s.st_mode))
 197                         return path;
 198
 199                 search = p + 1;
 200         }
 201         while (*p++);
 202
 203         return NULL;
 204 }
 205
 206 bool
 207 fw3_stdout_pipe(void)
 208 {
 209         pipe_fd = stdout;
 210         return true;
 211 }
 212
 213 bool
 214 __fw3_command_pipe(bool silent, const char *command, ...)
 215 {
 216         pid_t pid;
 217         va_list argp;
 218         int pfds[2];
 219         int argn;
 220         char *arg, **args, **tmp;
 221
 222         command = fw3_find_command(command);
 223
 224         if (!command)
 225                 return false;
 226
 227         if (pipe(pfds))
 228                 return false;
 229
 230         argn = 2;
 231         args = calloc(argn, sizeof(arg));
 232
 233         if (!args)
 234                 return false;
 235
 236         args[0] = (char *)command;
 237         args[1] = NULL;
 238
 239         va_start(argp, command);
 240
 241         while ((arg = va_arg(argp, char *)) != NULL)
 242         {
 243                 tmp = realloc(args, ++argn * sizeof(arg));
 244
 245                 if (!tmp)
 246                         break;
 247
 248                 args = tmp;
 249                 args[argn-2] = arg;
 250                 args[argn-1] = NULL;
 251         }
 252
 253         va_end(argp);
 254
 255         switch ((pid = fork()))
 256         {
 257         case -1:
 258                 free(args);
 259                 return false;
 260
 261         case 0:
 262                 dup2(pfds[0], 0);
 263
 264                 close(pfds[0]);
 265                 close(pfds[1]);
 266
 267                 close(1);
 268
 269                 if (silent)
 270                         close(2);
 271
 272                 execv(command, args);
 273
 274         default:
 275                 signal(SIGPIPE, SIG_IGN);
 276                 pipe_pid = pid;
 277                 close(pfds[0]);
 278                 fcntl(pfds[1], F_SETFD, fcntl(pfds[1], F_GETFD) | FD_CLOEXEC);
 279         }
 280
 281         pipe_fd = fdopen(pfds[1], "w");
 282         free(args);
 283         return true;
 284 }
 285
 286 void
 287 fw3_pr(const char *fmt, ...)
 288 {
 289         va_list args;
 290
 291         if (fw3_pr_debug && pipe_fd != stdout)
 292         {
 293                 va_start(args, fmt);
 294                 vfprintf(stderr, fmt, args);
 295                 va_end(args);
 296         }
 297
 298         va_start(args, fmt);
 299         vfprintf(pipe_fd, fmt, args);
 300         va_end(args);
 301 }
 302
 303 void
 304 fw3_command_close(void)
 305 {
 306         if (pipe_fd && pipe_fd != stdout)
 307                 fclose(pipe_fd);
 308
 309         if (pipe_pid > -1)
 310                 waitpid(pipe_pid, NULL, 0);
 311
 312         signal(SIGPIPE, SIG_DFL);
 313
 314         pipe_fd = NULL;
 315         pipe_pid = -1;
 316 }
 317
 318 static bool
 319 file_contains(const char *path, const char *str)
 320 {
 321         FILE *f;
 322         char line[12];
 323         bool seen = false;
 324
 325         if (!(f = fopen(path, "r")))
 326                 return false;
 327
 328         while (fgets(line, sizeof(line), f))
 329         {
 330                 if (!strncmp(line, str, strlen(str)))
 331                 {
 332                         seen = true;
 333                         break;
 334                 }
 335         }
 336
 337         fclose(f);
 338
 339         return seen;
 340 }
 341
 342 bool
 343 fw3_has_target(const bool ipv6, const char *target)
 344 {
 345         const char *path = ipv6
 346                 ? "/proc/net/ip6_tables_targets" : "/proc/net/ip_tables_targets";
 347
 348         return file_contains(path, target);
 349 }
 350
 351 bool
 352 fw3_lock_path(int *fd, const char *path)
 353 {
 354         int lock_fd = open(path, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 355
 356         if (lock_fd < 0)
 357         {
 358                 warn("Cannot create lock file %s: %s", path, strerror(errno));
 359                 return false;
 360         }
 361
 362         if (flock(lock_fd, LOCK_EX))
 363         {
 364                 warn("Cannot acquire exclusive lock: %s", strerror(errno));
 365                 close(lock_fd);
 366                 return false;
 367         }
 368
 369         *fd = lock_fd;
 370
 371         return true;
 372 }
 373
 374 bool
 375 fw3_lock()
 376 {
 377         return fw3_lock_path(&fw3_lock_fd, FW3_LOCKFILE);
 378 }
 379
 380
 381 void
 382 fw3_unlock_path(int *fd, const char *lockpath)
 383 {
 384         if (*fd < 0)
 385                 return;
 386
 387         if (flock(*fd, LOCK_UN))
 388                 warn("Cannot release exclusive lock: %s", strerror(errno));
 389
 390         close(*fd);
 391
 392         *fd = -1;
 393 }
 394
 395
 396 void
 397 fw3_unlock(void)
 398 {
 399         fw3_unlock_path(&fw3_lock_fd, FW3_LOCKFILE);
 400 }
 401
 402
 403 static void
 404 write_defaults_uci(struct uci_context *ctx, struct fw3_defaults *d,
 405                    struct uci_package *dest)
 406 {
 407         char buf[sizeof("0xffffffff")];
 408         struct uci_ptr ptr = { .p = dest };
 409
 410         uci_add_section(ctx, dest, "defaults", &ptr.s);
 411
 412         ptr.o      = NULL;
 413         ptr.option = "input";
 414         ptr.value  = fw3_flag_names[d->policy_input];
 415         uci_set(ctx, &ptr);
 416
 417         ptr.o      = NULL;
 418         ptr.option = "output";
 419         ptr.value  = fw3_flag_names[d->policy_output];
 420         uci_set(ctx, &ptr);
 421
 422         ptr.o      = NULL;
 423         ptr.option = "forward";
 424         ptr.value  = fw3_flag_names[d->policy_forward];
 425         uci_set(ctx, &ptr);
 426
 427         snprintf(buf, sizeof(buf), "0x%x", d->flags[0]);
 428         ptr.o      = NULL;
 429         ptr.option = "__flags_v4";
 430         ptr.value  = buf;
 431         uci_set(ctx, &ptr);
 432
 433         snprintf(buf, sizeof(buf), "0x%x", d->flags[1]);
 434         ptr.o      = NULL;
 435         ptr.option = "__flags_v6";
 436         ptr.value  = buf;
 437         uci_set(ctx, &ptr);
 438 }
 439
 440 static void
 441 write_zone_uci(struct uci_context *ctx, struct fw3_zone *z,
 442                struct uci_package *dest, struct ifaddrs *ifaddr)
 443 {
 444         struct fw3_device *dev;
 445         struct fw3_address *sub;
 446         struct ifaddrs *ifa;
 447         enum fw3_family fam = FW3_FAMILY_ANY;
 448
 449         char *p, buf[INET6_ADDRSTRLEN];
 450
 451         struct uci_ptr ptr = { .p = dest };
 452
 453         if (!z->enabled)
 454                 return;
 455
 456         if (fw3_no_table(z->flags[0]) && !fw3_no_table(z->flags[1]))
 457                 fam = FW3_FAMILY_V6;
 458         else if (!fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 459                 fam = FW3_FAMILY_V4;
 460         else if (fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 461                 return;
 462
 463         uci_add_section(ctx, dest, "zone", &ptr.s);
 464
 465         ptr.o      = NULL;
 466         ptr.option = "name";
 467         ptr.value  = z->name;
 468         uci_set(ctx, &ptr);
 469
 470         ptr.o      = NULL;
 471         ptr.option = "input";
 472         ptr.value  = fw3_flag_names[z->policy_input];
 473         uci_set(ctx, &ptr);
 474
 475         ptr.o      = NULL;
 476         ptr.option = "output";
 477         ptr.value  = fw3_flag_names[z->policy_output];
 478         uci_set(ctx, &ptr);
 479
 480         ptr.o      = NULL;
 481         ptr.option = "forward";
 482         ptr.value  = fw3_flag_names[z->policy_forward];
 483         uci_set(ctx, &ptr);
 484
 485         ptr.o      = NULL;
 486         ptr.option = "masq";
 487         ptr.value  = z->masq ? "1" : "0";
 488         uci_set(ctx, &ptr);
 489
 490         ptr.o      = NULL;
 491         ptr.option = "mtu_fix";
 492         ptr.value  = z->mtu_fix ? "1" : "0";
 493         uci_set(ctx, &ptr);
 494
 495         ptr.o      = NULL;
 496         ptr.option = "custom_chains";
 497         ptr.value  = z->custom_chains ? "1" : "0";
 498         uci_set(ctx, &ptr);
 499
 500         if (fam != FW3_FAMILY_ANY)
 501         {
 502                 ptr.o      = NULL;
 503                 ptr.option = "family";
 504                 ptr.value  = fw3_flag_names[fam];
 505                 uci_set(ctx, &ptr);
 506         }
 507
 508         ptr.o      = NULL;
 509         ptr.option = "device";
 510
 511         fw3_foreach(dev, &z->devices)
 512         {
 513                 char *ep;
 514
 515                 if (!dev)
 516                         continue;
 517
 518                 p = buf;
 519                 ep = buf + sizeof(buf);
 520
 521                 if (dev->invert)
 522                         p += snprintf(p, ep - p, "!");
 523
 524                 if (*dev->network)
 525                         p += snprintf(p, ep - p, "%s@%s", dev->name, dev->network);
 526                 else
 527                         p += snprintf(p, ep - p, "%s", dev->name);
 528
 529                 ptr.value = buf;
 530                 uci_add_list(ctx, &ptr);
 531         }
 532
 533         ptr.o      = NULL;
 534         ptr.option = "subnet";
 535
 536         fw3_foreach(sub, &z->subnets)
 537         {
 538                 if (!sub)
 539                         continue;
 540
 541                 ptr.value = fw3_address_to_string(sub, true, false);
 542                 uci_add_list(ctx, &ptr);
 543         }
 544
 545         ptr.o      = NULL;
 546         ptr.option = "__addrs";
 547
 548         fw3_foreach(dev, &z->devices)
 549         {
 550                 if (!dev)
 551                         continue;
 552
 553                 for (ifa = ifaddr; ifa; ifa = ifa->ifa_next)
 554                 {
 555                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 556                                 continue;
 557
 558                         if (ifa->ifa_addr->sa_family == AF_INET)
 559                                 inet_ntop(AF_INET,
 560                                           &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
 561                                           buf, sizeof(buf));
 562                         else if (ifa->ifa_addr->sa_family == AF_INET6)
 563                                 inet_ntop(AF_INET6,
 564                                           &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
 565                                           buf, sizeof(buf));
 566                         else
 567                                 continue;
 568
 569                         ptr.value = buf;
 570                         uci_add_list(ctx, &ptr);
 571                 }
 572         }
 573
 574         if (z->extra_src)
 575         {
 576                 ptr.o      = NULL;
 577                 ptr.option = "extra_src";
 578                 ptr.value  = z->extra_src;
 579                 uci_set(ctx, &ptr);
 580         }
 581
 582         if (z->extra_dest)
 583         {
 584                 ptr.o      = NULL;
 585                 ptr.option = "extra_dest";
 586                 ptr.value  = z->extra_dest;
 587                 uci_set(ctx, &ptr);
 588         }
 589
 590         snprintf(buf, sizeof(buf), "0x%x", z->flags[0]);
 591         ptr.o      = NULL;
 592         ptr.option = "__flags_v4";
 593         ptr.value  = buf;
 594         uci_set(ctx, &ptr);
 595
 596         snprintf(buf, sizeof(buf), "0x%x", z->flags[1]);
 597         ptr.o      = NULL;
 598         ptr.option = "__flags_v6";
 599         ptr.value  = buf;
 600         uci_set(ctx, &ptr);
 601 }
 602
 603 static void
 604 write_ipset_uci(struct uci_context *ctx, struct fw3_ipset *s,
 605                 struct uci_package *dest)
 606 {
 607         struct fw3_ipset_datatype *type;
 608
 609         char buf[sizeof("65535-65535")];
 610
 611         struct uci_ptr ptr = { .p = dest };
 612
 613         if (!s->enabled || s->external)
 614                 return;
 615
 616         uci_add_section(ctx, dest, "ipset", &ptr.s);
 617
 618         ptr.o      = NULL;
 619         ptr.option = "name";
 620         ptr.value  = s->name;
 621         uci_set(ctx, &ptr);
 622
 623         ptr.o      = NULL;
 624         ptr.option = "family";
 625         if (s->family == FW3_FAMILY_V4)
 626                 ptr.value = "ipv4";
 627         else
 628                 ptr.value = "ipv6";
 629         uci_set(ctx, &ptr);
 630
 631         ptr.o      = NULL;
 632         ptr.option = "storage";
 633         ptr.value  = fw3_ipset_method_names[s->method];
 634         uci_set(ctx, &ptr);
 635
 636         list_for_each_entry(type, &s->datatypes, list)
 637         {
 638                 snprintf(buf, sizeof(buf), "%s_%s", type->dir, fw3_ipset_type_names[type->type]);
 639                 ptr.o      = NULL;
 640                 ptr.option = "match";
 641                 ptr.value  = buf;
 642                 uci_add_list(ctx, &ptr);
 643         }
 644
 645         if (s->iprange.set)
 646         {
 647                 ptr.o      = NULL;
 648                 ptr.option = "iprange";
 649                 ptr.value  = fw3_address_to_string(&s->iprange, false, false);
 650                 uci_set(ctx, &ptr);
 651         }
 652
 653         if (s->portrange.set)
 654         {
 655                 snprintf(buf, sizeof(buf), "%u-%u", s->portrange.port_min, s->portrange.port_max);
 656                 ptr.o      = NULL;
 657                 ptr.option = "portrange";
 658                 ptr.value  = buf;
 659                 uci_set(ctx, &ptr);
 660         }
 661 }
 662
 663 void
 664 fw3_write_statefile(void *state)
 665 {
 666         FILE *sf;
 667         struct fw3_state *s = state;
 668         struct fw3_zone *z;
 669         struct fw3_ipset *i;
 670         struct ifaddrs *ifaddr;
 671
 672         struct uci_package *p;
 673
 674         if (fw3_no_family(s->defaults.flags[0]) &&
 675             fw3_no_family(s->defaults.flags[1]))
 676         {
 677                 unlink(FW3_STATEFILE);
 678         }
 679         else
 680         {
 681                 sf = fopen(FW3_STATEFILE, "w+");
 682
 683                 if (!sf)
 684                 {
 685                         warn("Cannot create state %s: %s", FW3_STATEFILE, strerror(errno));
 686                         return;
 687                 }
 688
 689                 if (getifaddrs(&ifaddr))
 690                 {
 691                         warn("Cannot get interface addresses: %s", strerror(errno));
 692                         ifaddr = NULL;
 693                 }
 694
 695                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 696                         uci_unload(s->uci, p);
 697
 698                 uci_import(s->uci, sf, "fw3_state", NULL, true);
 699
 700                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 701                 {
 702                         write_defaults_uci(s->uci, &s->defaults, p);
 703
 704                         list_for_each_entry(z, &s->zones, list)
 705                                 write_zone_uci(s->uci, z, p, ifaddr);
 706
 707                         list_for_each_entry(i, &s->ipsets, list)
 708                                 write_ipset_uci(s->uci, i, p);
 709
 710                         uci_export(s->uci, sf, p, true);
 711                         uci_unload(s->uci, p);
 712                 }
 713
 714                 fsync(fileno(sf));
 715                 fclose(sf);
 716
 717                 if (ifaddr)
 718                         freeifaddrs(ifaddr);
 719         }
 720 }
 721
 722
 723 void
 724 fw3_free_object(void *obj, const void *opts)
 725 {
 726         const struct fw3_option *ol;
 727         struct list_head *list, *cur, *tmp;
 728
 729         for (ol = opts; ol->name; ol++)
 730         {
 731                 if (!ol->elem_size)
 732                         continue;
 733
 734                 list = (struct list_head *)((char *)obj + ol->offset);
 735                 list_for_each_safe(cur, tmp, list)
 736                 {
 737                         list_del(cur);
 738                         free(cur);
 739                 }
 740         }
 741
 742         free(obj);
 743 }
 744
 745 void
 746 fw3_free_list(struct list_head *head)
 747 {
 748         struct list_head *entry, *tmp;
 749
 750         if (!head)
 751                 return;
 752
 753         list_for_each_safe(entry, tmp, head)
 754         {
 755                 list_del(entry);
 756                 free(entry);
 757         }
 758
 759         free(head);
 760 }
 761
 762 bool
 763 fw3_hotplug(bool add, void *zone, void *device)
 764 {
 765         struct fw3_zone *z = zone;
 766         struct fw3_device *d = device;
 767
 768         if (!*d->network)
 769                 return false;
 770
 771         switch (fork())
 772         {
 773         case -1:
 774                 warn("Unable to fork(): %s\n", strerror(errno));
 775                 return false;
 776
 777         case 0:
 778                 break;
 779
 780         default:
 781                 return true;
 782         }
 783
 784         close(0);
 785         close(1);
 786         close(2);
 787         if (chdir("/")) {};
 788
 789         clearenv();
 790         setenv("ACTION",    add ? "add" : "remove", 1);
 791         setenv("ZONE",      z->name,                1);
 792         setenv("INTERFACE", d->network,             1);
 793         setenv("DEVICE",    d->name,                1);
 794
 795         execl(FW3_HOTPLUG, FW3_HOTPLUG, "firewall", NULL);
 796
 797         /* unreached */
 798         return false;
 799 }
 800
 801 int
 802 fw3_netmask2bitlen(int family, void *mask)
 803 {
 804         int bits;
 805         struct in_addr *v4;
 806         struct in6_addr *v6;
 807
 808         if (family == FW3_FAMILY_V6)
 809                 for (bits = 0, v6 = mask;
 810                      bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
 811                      bits++);
 812         else
 813                 for (bits = 0, v4 = mask;
 814                      bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
 815                      bits++);
 816
 817         return bits;
 818 }
 819
 820 bool
 821 fw3_bitlen2netmask(int family, int bits, void *mask)
 822 {
 823         int i;
 824         uint8_t rem, b;
 825         struct in_addr *v4;
 826         struct in6_addr *v6;
 827
 828         if (family == FW3_FAMILY_V6)
 829         {
 830                 if (bits < -128 || bits > 128)
 831                         return false;
 832
 833                 v6 = mask;
 834                 rem = abs(bits);
 835
 836                 for (i = 0; i < sizeof(v6->s6_addr); i++)
 837                 {
 838                         b = (rem > 8) ? 8 : rem;
 839                         v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
 840                         rem -= b;
 841                 }
 842
 843                 if (bits < 0)
 844                         for (i = 0; i < sizeof(v6->s6_addr); i++)
 845                                 v6->s6_addr[i] = ~v6->s6_addr[i];
 846         }
 847         else
 848         {
 849                 if (bits < -32 || bits > 32)
 850                         return false;
 851
 852                 v4 = mask;
 853                 v4->s_addr = bits ? htonl(~((1 << (32 - abs(bits))) - 1)) : 0;
 854
 855                 if (bits < 0)
 856                         v4->s_addr = ~v4->s_addr;
 857         }
 858
 859         return true;
 860 }
 861
 862 void
 863 fw3_flush_conntrack(void *state)
 864 {
 865         bool found;
 866         struct fw3_state *s = state;
 867         struct fw3_address *addr;
 868         struct fw3_device *dev;
 869         struct fw3_zone *zone;
 870         struct ifaddrs *ifaddr, *ifa;
 871         struct sockaddr_in *sin;
 872         struct sockaddr_in6 *sin6;
 873         char buf[INET6_ADDRSTRLEN];
 874         FILE *ct;
 875
 876         if (!state)
 877         {
 878                 if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 879                 {
 880                         info(" * Flushing conntrack table ...");
 881
 882                         fwrite("f\n", 1, 2, ct);
 883                         fclose(ct);
 884                 }
 885
 886                 return;
 887         }
 888
 889         if (getifaddrs(&ifaddr))
 890         {
 891                 warn("Cannot get interface addresses: %s", strerror(errno));
 892                 return;
 893         }
 894
 895         if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 896         {
 897                 list_for_each_entry(zone, &s->zones, list)
 898                 list_for_each_entry(addr, &zone->old_addrs, list)
 899                 {
 900                         found = false;
 901
 902                         list_for_each_entry(dev, &zone->devices, list)
 903                         {
 904                                 for (ifa = ifaddr; ifa && !found; ifa = ifa->ifa_next)
 905                                 {
 906                                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 907                                                 continue;
 908
 909                                         sin = (struct sockaddr_in *)ifa->ifa_addr;
 910                                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 911
 912                                         if (addr->family == FW3_FAMILY_V4 &&
 913                                                 sin->sin_family == AF_INET)
 914                                         {
 915                                                 found = !memcmp(&addr->address.v4, &sin->sin_addr,
 916                                                                                 sizeof(sin->sin_addr));
 917                                         }
 918                                         else if (addr->family == FW3_FAMILY_V6 &&
 919                                                          sin6->sin6_family == AF_INET6)
 920                                         {
 921                                                 found = !memcmp(&addr->address.v6, &sin6->sin6_addr,
 922                                                                                 sizeof(sin6->sin6_addr));
 923                                         }
 924                                 }
 925
 926                                 if (found)
 927                                         break;
 928                         }
 929
 930                         if (!found)
 931                         {
 932                                 inet_ntop(addr->family == FW3_FAMILY_V4 ? AF_INET : AF_INET6,
 933                                                   &addr->address.v4, buf, sizeof(buf));
 934
 935                                 info(" * Flushing conntrack: %s", buf);
 936                                 fprintf(ct, "%s\n", buf);
 937                         }
 938                 }
 939
 940                 fclose(ct);
 941         }
 942
 943         freeifaddrs(ifaddr);
 944 }
 945
 946 bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const char **type)
 947 {
 948         struct blob_attr *opt;
 949         unsigned orem;
 950
 951         if (!type || !name)
 952                 return false;
 953
 954         *type = NULL;
 955
 956         blobmsg_for_each_attr(opt, entry, orem)
 957                 if (!strcmp(blobmsg_name(opt), "type"))
 958                         *type = blobmsg_get_string(opt);
 959                 else if (!strcmp(blobmsg_name(opt), "name"))
 960                         *name = blobmsg_get_string(opt);
 961
 962         return *type != NULL ? true : false;
 963 }
 964
 965 const char *
 966 fw3_protoname(void *proto)
 967 {
 968         static char buf[sizeof("4294967295")];
 969         struct fw3_protocol *p = proto;
 970         struct protoent *pe;
 971
 972         if (!p)
 973                 return "?";
 974
 975         pe = getprotobynumber(p->protocol);
 976
 977         if (!pe)
 978         {
 979                 snprintf(buf, sizeof(buf), "%u", p->protocol);
 980                 return buf;
 981         }
 982
 983         return pe->p_name;
 984 }
 985
 986 bool
 987 fw3_check_loopback_dev(const char *name)
 988 {
 989         struct ifreq ifr;
 990         int s;
 991         bool rv = false;
 992
 993         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
 994
 995         if (s < 0)
 996                 return false;
 997
 998         memset(&ifr, 0, sizeof(ifr));
 999         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", name);
1000
1001         if (ioctl(s, SIOCGIFFLAGS, &ifr) >= 0) {
1002                 if (ifr.ifr_flags & IFF_LOOPBACK)
1003                         rv = true;
1004         }
1005
1006         close(s);
1007
1008         return rv;
1009 }
1010
1011 bool
1012 fw3_check_loopback_addr(struct fw3_address *addr)
1013 {
1014         if (addr->family == FW3_FAMILY_V4 &&
1015             (ntohl(addr->address.v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
1016                 return true;
1017
1018         if (addr->family == FW3_FAMILY_V6 && !addr->range &&
1019             fw3_netmask2bitlen(FW3_FAMILY_V6, &addr->mask.v6) == 128 &&
1020             IN6_IS_ADDR_LOOPBACK(&addr->address.v6))
1021                 return true;
1022
1023         return false;
1024 }