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_table(const bool ipv6, const char *table)
 344 {
 345         const char *path = ipv6
 346                 ? "/proc/net/ip6_tables_names" : "/proc/net/ip_tables_names";
 347
 348         return file_contains(path, table);
 349 }
 350
 351 bool
 352 fw3_has_target(const bool ipv6, const char *target)
 353 {
 354         const char *path = ipv6
 355                 ? "/proc/net/ip6_tables_targets" : "/proc/net/ip_tables_targets";
 356
 357         return file_contains(path, target);
 358 }
 359
 360 bool
 361 fw3_lock_path(int *fd, const char *path)
 362 {
 363         int lock_fd = open(path, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 364
 365         if (lock_fd < 0)
 366         {
 367                 warn("Cannot create lock file %s: %s", path, strerror(errno));
 368                 return false;
 369         }
 370
 371         if (flock(lock_fd, LOCK_EX))
 372         {
 373                 warn("Cannot acquire exclusive lock: %s", strerror(errno));
 374                 close(lock_fd);
 375                 return false;
 376         }
 377
 378         *fd = lock_fd;
 379
 380         return true;
 381 }
 382
 383 bool
 384 fw3_lock()
 385 {
 386         return fw3_lock_path(&fw3_lock_fd, FW3_LOCKFILE);
 387 }
 388
 389
 390 void
 391 fw3_unlock_path(int *fd, const char *lockpath)
 392 {
 393         if (*fd < 0)
 394                 return;
 395
 396         if (flock(*fd, LOCK_UN))
 397                 warn("Cannot release exclusive lock: %s", strerror(errno));
 398
 399         close(*fd);
 400
 401         *fd = -1;
 402 }
 403
 404
 405 void
 406 fw3_unlock(void)
 407 {
 408         fw3_unlock_path(&fw3_lock_fd, FW3_LOCKFILE);
 409 }
 410
 411
 412 static void
 413 write_defaults_uci(struct uci_context *ctx, struct fw3_defaults *d,
 414                    struct uci_package *dest)
 415 {
 416         char buf[sizeof("0xffffffff")];
 417         struct uci_ptr ptr = { .p = dest };
 418
 419         uci_add_section(ctx, dest, "defaults", &ptr.s);
 420
 421         ptr.o      = NULL;
 422         ptr.option = "input";
 423         ptr.value  = fw3_flag_names[d->policy_input];
 424         uci_set(ctx, &ptr);
 425
 426         ptr.o      = NULL;
 427         ptr.option = "output";
 428         ptr.value  = fw3_flag_names[d->policy_output];
 429         uci_set(ctx, &ptr);
 430
 431         ptr.o      = NULL;
 432         ptr.option = "forward";
 433         ptr.value  = fw3_flag_names[d->policy_forward];
 434         uci_set(ctx, &ptr);
 435
 436         snprintf(buf, sizeof(buf), "0x%x", d->flags[0]);
 437         ptr.o      = NULL;
 438         ptr.option = "__flags_v4";
 439         ptr.value  = buf;
 440         uci_set(ctx, &ptr);
 441
 442         snprintf(buf, sizeof(buf), "0x%x", d->flags[1]);
 443         ptr.o      = NULL;
 444         ptr.option = "__flags_v6";
 445         ptr.value  = buf;
 446         uci_set(ctx, &ptr);
 447 }
 448
 449 static void
 450 write_zone_uci(struct uci_context *ctx, struct fw3_zone *z,
 451                struct uci_package *dest, struct ifaddrs *ifaddr)
 452 {
 453         struct fw3_device *dev;
 454         struct fw3_address *sub;
 455         struct ifaddrs *ifa;
 456         enum fw3_family fam = FW3_FAMILY_ANY;
 457
 458         char *p, buf[INET6_ADDRSTRLEN];
 459
 460         struct uci_ptr ptr = { .p = dest };
 461
 462         if (!z->enabled)
 463                 return;
 464
 465         if (fw3_no_table(z->flags[0]) && !fw3_no_table(z->flags[1]))
 466                 fam = FW3_FAMILY_V6;
 467         else if (!fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 468                 fam = FW3_FAMILY_V4;
 469         else if (fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 470                 return;
 471
 472         uci_add_section(ctx, dest, "zone", &ptr.s);
 473
 474         ptr.o      = NULL;
 475         ptr.option = "name";
 476         ptr.value  = z->name;
 477         uci_set(ctx, &ptr);
 478
 479         ptr.o      = NULL;
 480         ptr.option = "input";
 481         ptr.value  = fw3_flag_names[z->policy_input];
 482         uci_set(ctx, &ptr);
 483
 484         ptr.o      = NULL;
 485         ptr.option = "output";
 486         ptr.value  = fw3_flag_names[z->policy_output];
 487         uci_set(ctx, &ptr);
 488
 489         ptr.o      = NULL;
 490         ptr.option = "forward";
 491         ptr.value  = fw3_flag_names[z->policy_forward];
 492         uci_set(ctx, &ptr);
 493
 494         ptr.o      = NULL;
 495         ptr.option = "masq";
 496         ptr.value  = z->masq ? "1" : "0";
 497         uci_set(ctx, &ptr);
 498
 499         ptr.o      = NULL;
 500         ptr.option = "mtu_fix";
 501         ptr.value  = z->mtu_fix ? "1" : "0";
 502         uci_set(ctx, &ptr);
 503
 504         ptr.o      = NULL;
 505         ptr.option = "custom_chains";
 506         ptr.value  = z->custom_chains ? "1" : "0";
 507         uci_set(ctx, &ptr);
 508
 509         if (fam != FW3_FAMILY_ANY)
 510         {
 511                 ptr.o      = NULL;
 512                 ptr.option = "family";
 513                 ptr.value  = fw3_flag_names[fam];
 514                 uci_set(ctx, &ptr);
 515         }
 516
 517         ptr.o      = NULL;
 518         ptr.option = "device";
 519
 520         fw3_foreach(dev, &z->devices)
 521         {
 522                 char *ep;
 523
 524                 if (!dev)
 525                         continue;
 526
 527                 p = buf;
 528                 ep = buf + sizeof(buf);
 529
 530                 if (dev->invert)
 531                         p += snprintf(p, ep - p, "!");
 532
 533                 if (*dev->network)
 534                         p += snprintf(p, ep - p, "%s@%s", dev->name, dev->network);
 535                 else
 536                         p += snprintf(p, ep - p, "%s", dev->name);
 537
 538                 ptr.value = buf;
 539                 uci_add_list(ctx, &ptr);
 540         }
 541
 542         ptr.o      = NULL;
 543         ptr.option = "subnet";
 544
 545         fw3_foreach(sub, &z->subnets)
 546         {
 547                 if (!sub)
 548                         continue;
 549
 550                 ptr.value = fw3_address_to_string(sub, true, false);
 551                 uci_add_list(ctx, &ptr);
 552         }
 553
 554         ptr.o      = NULL;
 555         ptr.option = "__addrs";
 556
 557         fw3_foreach(dev, &z->devices)
 558         {
 559                 if (!dev)
 560                         continue;
 561
 562                 for (ifa = ifaddr; ifa; ifa = ifa->ifa_next)
 563                 {
 564                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 565                                 continue;
 566
 567                         if (ifa->ifa_addr->sa_family == AF_INET)
 568                                 inet_ntop(AF_INET,
 569                                           &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
 570                                           buf, sizeof(buf));
 571                         else if (ifa->ifa_addr->sa_family == AF_INET6)
 572                                 inet_ntop(AF_INET6,
 573                                           &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
 574                                           buf, sizeof(buf));
 575                         else
 576                                 continue;
 577
 578                         ptr.value = buf;
 579                         uci_add_list(ctx, &ptr);
 580                 }
 581         }
 582
 583         if (z->extra_src)
 584         {
 585                 ptr.o      = NULL;
 586                 ptr.option = "extra_src";
 587                 ptr.value  = z->extra_src;
 588                 uci_set(ctx, &ptr);
 589         }
 590
 591         if (z->extra_dest)
 592         {
 593                 ptr.o      = NULL;
 594                 ptr.option = "extra_dest";
 595                 ptr.value  = z->extra_dest;
 596                 uci_set(ctx, &ptr);
 597         }
 598
 599         snprintf(buf, sizeof(buf), "0x%x", z->flags[0]);
 600         ptr.o      = NULL;
 601         ptr.option = "__flags_v4";
 602         ptr.value  = buf;
 603         uci_set(ctx, &ptr);
 604
 605         snprintf(buf, sizeof(buf), "0x%x", z->flags[1]);
 606         ptr.o      = NULL;
 607         ptr.option = "__flags_v6";
 608         ptr.value  = buf;
 609         uci_set(ctx, &ptr);
 610 }
 611
 612 static void
 613 write_ipset_uci(struct uci_context *ctx, struct fw3_ipset *s,
 614                 struct uci_package *dest)
 615 {
 616         struct fw3_ipset_datatype *type;
 617
 618         char buf[sizeof("65535-65535")];
 619
 620         struct uci_ptr ptr = { .p = dest };
 621
 622         if (!s->enabled || s->external)
 623                 return;
 624
 625         uci_add_section(ctx, dest, "ipset", &ptr.s);
 626
 627         ptr.o      = NULL;
 628         ptr.option = "name";
 629         ptr.value  = s->name;
 630         uci_set(ctx, &ptr);
 631
 632         ptr.o      = NULL;
 633         ptr.option = "family";
 634         if (s->family == FW3_FAMILY_V4)
 635                 ptr.value = "ipv4";
 636         else
 637                 ptr.value = "ipv6";
 638         uci_set(ctx, &ptr);
 639
 640         ptr.o      = NULL;
 641         ptr.option = "storage";
 642         ptr.value  = fw3_ipset_method_names[s->method];
 643         uci_set(ctx, &ptr);
 644
 645         list_for_each_entry(type, &s->datatypes, list)
 646         {
 647                 snprintf(buf, sizeof(buf), "%s_%s", type->dir, fw3_ipset_type_names[type->type]);
 648                 ptr.o      = NULL;
 649                 ptr.option = "match";
 650                 ptr.value  = buf;
 651                 uci_add_list(ctx, &ptr);
 652         }
 653
 654         if (s->iprange.set)
 655         {
 656                 ptr.o      = NULL;
 657                 ptr.option = "iprange";
 658                 ptr.value  = fw3_address_to_string(&s->iprange, false, false);
 659                 uci_set(ctx, &ptr);
 660         }
 661
 662         if (s->portrange.set)
 663         {
 664                 snprintf(buf, sizeof(buf), "%u-%u", s->portrange.port_min, s->portrange.port_max);
 665                 ptr.o      = NULL;
 666                 ptr.option = "portrange";
 667                 ptr.value  = buf;
 668                 uci_set(ctx, &ptr);
 669         }
 670 }
 671
 672 void
 673 fw3_write_statefile(void *state)
 674 {
 675         FILE *sf;
 676         struct fw3_state *s = state;
 677         struct fw3_zone *z;
 678         struct fw3_ipset *i;
 679         struct ifaddrs *ifaddr;
 680
 681         struct uci_package *p;
 682
 683         if (fw3_no_family(s->defaults.flags[0]) &&
 684             fw3_no_family(s->defaults.flags[1]))
 685         {
 686                 unlink(FW3_STATEFILE);
 687         }
 688         else
 689         {
 690                 sf = fopen(FW3_STATEFILE, "w+");
 691
 692                 if (!sf)
 693                 {
 694                         warn("Cannot create state %s: %s", FW3_STATEFILE, strerror(errno));
 695                         return;
 696                 }
 697
 698                 if (getifaddrs(&ifaddr))
 699                 {
 700                         warn("Cannot get interface addresses: %s", strerror(errno));
 701                         ifaddr = NULL;
 702                 }
 703
 704                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 705                         uci_unload(s->uci, p);
 706
 707                 uci_import(s->uci, sf, "fw3_state", NULL, true);
 708
 709                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 710                 {
 711                         write_defaults_uci(s->uci, &s->defaults, p);
 712
 713                         list_for_each_entry(z, &s->zones, list)
 714                                 write_zone_uci(s->uci, z, p, ifaddr);
 715
 716                         list_for_each_entry(i, &s->ipsets, list)
 717                                 write_ipset_uci(s->uci, i, p);
 718
 719                         uci_export(s->uci, sf, p, true);
 720                         uci_unload(s->uci, p);
 721                 }
 722
 723                 fsync(fileno(sf));
 724                 fclose(sf);
 725
 726                 if (ifaddr)
 727                         freeifaddrs(ifaddr);
 728         }
 729 }
 730
 731
 732 void
 733 fw3_free_object(void *obj, const void *opts)
 734 {
 735         const struct fw3_option *ol;
 736         struct list_head *list, *cur, *tmp;
 737
 738         for (ol = opts; ol->name; ol++)
 739         {
 740                 if (!ol->elem_size)
 741                         continue;
 742
 743                 list = (struct list_head *)((char *)obj + ol->offset);
 744                 list_for_each_safe(cur, tmp, list)
 745                 {
 746                         list_del(cur);
 747                         free(cur);
 748                 }
 749         }
 750
 751         free(obj);
 752 }
 753
 754 void
 755 fw3_free_list(struct list_head *head)
 756 {
 757         struct list_head *entry, *tmp;
 758
 759         if (!head)
 760                 return;
 761
 762         list_for_each_safe(entry, tmp, head)
 763         {
 764                 list_del(entry);
 765                 free(entry);
 766         }
 767
 768         free(head);
 769 }
 770
 771 bool
 772 fw3_hotplug(bool add, void *zone, void *device)
 773 {
 774         struct fw3_zone *z = zone;
 775         struct fw3_device *d = device;
 776
 777         if (!*d->network)
 778                 return false;
 779
 780         switch (fork())
 781         {
 782         case -1:
 783                 warn("Unable to fork(): %s\n", strerror(errno));
 784                 return false;
 785
 786         case 0:
 787                 break;
 788
 789         default:
 790                 return true;
 791         }
 792
 793         close(0);
 794         close(1);
 795         close(2);
 796         if (chdir("/")) {};
 797
 798         clearenv();
 799         setenv("ACTION",    add ? "add" : "remove", 1);
 800         setenv("ZONE",      z->name,                1);
 801         setenv("INTERFACE", d->network,             1);
 802         setenv("DEVICE",    d->name,                1);
 803
 804         execl(FW3_HOTPLUG, FW3_HOTPLUG, "firewall", NULL);
 805
 806         /* unreached */
 807         return false;
 808 }
 809
 810 int
 811 fw3_netmask2bitlen(int family, void *mask)
 812 {
 813         int bits;
 814         struct in_addr *v4;
 815         struct in6_addr *v6;
 816
 817         if (family == FW3_FAMILY_V6)
 818                 for (bits = 0, v6 = mask;
 819                      bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
 820                      bits++);
 821         else
 822                 for (bits = 0, v4 = mask;
 823                      bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
 824                      bits++);
 825
 826         return bits;
 827 }
 828
 829 bool
 830 fw3_bitlen2netmask(int family, int bits, void *mask)
 831 {
 832         int i;
 833         uint8_t rem, b;
 834         struct in_addr *v4;
 835         struct in6_addr *v6;
 836
 837         if (family == FW3_FAMILY_V6)
 838         {
 839                 if (bits < -128 || bits > 128)
 840                         return false;
 841
 842                 v6 = mask;
 843                 rem = abs(bits);
 844
 845                 for (i = 0; i < sizeof(v6->s6_addr); i++)
 846                 {
 847                         b = (rem > 8) ? 8 : rem;
 848                         v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
 849                         rem -= b;
 850                 }
 851
 852                 if (bits < 0)
 853                         for (i = 0; i < sizeof(v6->s6_addr); i++)
 854                                 v6->s6_addr[i] = ~v6->s6_addr[i];
 855         }
 856         else
 857         {
 858                 if (bits < -32 || bits > 32)
 859                         return false;
 860
 861                 v4 = mask;
 862                 v4->s_addr = bits ? htonl(~((1 << (32 - abs(bits))) - 1)) : 0;
 863
 864                 if (bits < 0)
 865                         v4->s_addr = ~v4->s_addr;
 866         }
 867
 868         return true;
 869 }
 870
 871 void
 872 fw3_flush_conntrack(void *state)
 873 {
 874         bool found;
 875         struct fw3_state *s = state;
 876         struct fw3_address *addr;
 877         struct fw3_device *dev;
 878         struct fw3_zone *zone;
 879         struct ifaddrs *ifaddr, *ifa;
 880         struct sockaddr_in *sin;
 881         struct sockaddr_in6 *sin6;
 882         char buf[INET6_ADDRSTRLEN];
 883         FILE *ct;
 884
 885         if (!state)
 886         {
 887                 if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 888                 {
 889                         info(" * Flushing conntrack table ...");
 890
 891                         fwrite("f\n", 1, 2, ct);
 892                         fclose(ct);
 893                 }
 894
 895                 return;
 896         }
 897
 898         if (getifaddrs(&ifaddr))
 899         {
 900                 warn("Cannot get interface addresses: %s", strerror(errno));
 901                 return;
 902         }
 903
 904         if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 905         {
 906                 list_for_each_entry(zone, &s->zones, list)
 907                 list_for_each_entry(addr, &zone->old_addrs, list)
 908                 {
 909                         found = false;
 910
 911                         list_for_each_entry(dev, &zone->devices, list)
 912                         {
 913                                 for (ifa = ifaddr; ifa && !found; ifa = ifa->ifa_next)
 914                                 {
 915                                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 916                                                 continue;
 917
 918                                         sin = (struct sockaddr_in *)ifa->ifa_addr;
 919                                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 920
 921                                         if (addr->family == FW3_FAMILY_V4 &&
 922                                                 sin->sin_family == AF_INET)
 923                                         {
 924                                                 found = !memcmp(&addr->address.v4, &sin->sin_addr,
 925                                                                                 sizeof(sin->sin_addr));
 926                                         }
 927                                         else if (addr->family == FW3_FAMILY_V6 &&
 928                                                          sin6->sin6_family == AF_INET6)
 929                                         {
 930                                                 found = !memcmp(&addr->address.v6, &sin6->sin6_addr,
 931                                                                                 sizeof(sin6->sin6_addr));
 932                                         }
 933                                 }
 934
 935                                 if (found)
 936                                         break;
 937                         }
 938
 939                         if (!found)
 940                         {
 941                                 inet_ntop(addr->family == FW3_FAMILY_V4 ? AF_INET : AF_INET6,
 942                                                   &addr->address.v4, buf, sizeof(buf));
 943
 944                                 info(" * Flushing conntrack: %s", buf);
 945                                 fprintf(ct, "%s\n", buf);
 946                         }
 947                 }
 948
 949                 fclose(ct);
 950         }
 951
 952         freeifaddrs(ifaddr);
 953 }
 954
 955 bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const char **type)
 956 {
 957         struct blob_attr *opt;
 958         unsigned orem;
 959
 960         if (!type || !name)
 961                 return false;
 962
 963         *type = NULL;
 964
 965         blobmsg_for_each_attr(opt, entry, orem)
 966                 if (!strcmp(blobmsg_name(opt), "type"))
 967                         *type = blobmsg_get_string(opt);
 968                 else if (!strcmp(blobmsg_name(opt), "name"))
 969                         *name = blobmsg_get_string(opt);
 970
 971         return *type != NULL ? true : false;
 972 }
 973
 974 const char *
 975 fw3_protoname(void *proto)
 976 {
 977         static char buf[sizeof("4294967295")];
 978         struct fw3_protocol *p = proto;
 979         struct protoent *pe;
 980
 981         if (!p)
 982                 return "?";
 983
 984         pe = getprotobynumber(p->protocol);
 985
 986         if (!pe)
 987         {
 988                 snprintf(buf, sizeof(buf), "%u", p->protocol);
 989                 return buf;
 990         }
 991
 992         return pe->p_name;
 993 }
 994
 995 bool
 996 fw3_check_loopback_dev(const char *name)
 997 {
 998         struct ifreq ifr;
 999         int s;
1000         bool rv = false;
1001
1002         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
1003
1004         if (s < 0)
1005                 return false;
1006
1007         memset(&ifr, 0, sizeof(ifr));
1008         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", name);
1009
1010         if (ioctl(s, SIOCGIFFLAGS, &ifr) >= 0) {
1011                 if (ifr.ifr_flags & IFF_LOOPBACK)
1012                         rv = true;
1013         }
1014
1015         close(s);
1016
1017         return rv;
1018 }
1019
1020 bool
1021 fw3_check_loopback_addr(struct fw3_address *addr)
1022 {
1023         if (addr->family == FW3_FAMILY_V4 &&
1024             (ntohl(addr->address.v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
1025                 return true;
1026
1027         if (addr->family == FW3_FAMILY_V6 && !addr->range &&
1028             fw3_netmask2bitlen(FW3_FAMILY_V6, &addr->mask.v6) == 128 &&
1029             IN6_IS_ADDR_LOOPBACK(&addr->address.v6))
1030                 return true;
1031
1032         return false;
1033 }