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         unlink(FW3_LOCKFILE);
 401
 402         *fd = -1;
 403 }
 404
 405
 406 void
 407 fw3_unlock(void)
 408 {
 409         fw3_unlock_path(&fw3_lock_fd, FW3_LOCKFILE);
 410 }
 411
 412
 413 static void
 414 write_defaults_uci(struct uci_context *ctx, struct fw3_defaults *d,
 415                    struct uci_package *dest)
 416 {
 417         char buf[sizeof("0xffffffff")];
 418         struct uci_ptr ptr = { .p = dest };
 419
 420         uci_add_section(ctx, dest, "defaults", &ptr.s);
 421
 422         ptr.o      = NULL;
 423         ptr.option = "input";
 424         ptr.value  = fw3_flag_names[d->policy_input];
 425         uci_set(ctx, &ptr);
 426
 427         ptr.o      = NULL;
 428         ptr.option = "output";
 429         ptr.value  = fw3_flag_names[d->policy_output];
 430         uci_set(ctx, &ptr);
 431
 432         ptr.o      = NULL;
 433         ptr.option = "forward";
 434         ptr.value  = fw3_flag_names[d->policy_forward];
 435         uci_set(ctx, &ptr);
 436
 437         snprintf(buf, sizeof(buf), "0x%x", d->flags[0]);
 438         ptr.o      = NULL;
 439         ptr.option = "__flags_v4";
 440         ptr.value  = buf;
 441         uci_set(ctx, &ptr);
 442
 443         snprintf(buf, sizeof(buf), "0x%x", d->flags[1]);
 444         ptr.o      = NULL;
 445         ptr.option = "__flags_v6";
 446         ptr.value  = buf;
 447         uci_set(ctx, &ptr);
 448 }
 449
 450 static void
 451 write_zone_uci(struct uci_context *ctx, struct fw3_zone *z,
 452                struct uci_package *dest, struct ifaddrs *ifaddr)
 453 {
 454         struct fw3_device *dev;
 455         struct fw3_address *sub;
 456         struct ifaddrs *ifa;
 457         enum fw3_family fam = FW3_FAMILY_ANY;
 458
 459         char *p, buf[INET6_ADDRSTRLEN];
 460
 461         struct uci_ptr ptr = { .p = dest };
 462
 463         if (!z->enabled)
 464                 return;
 465
 466         if (fw3_no_table(z->flags[0]) && !fw3_no_table(z->flags[1]))
 467                 fam = FW3_FAMILY_V6;
 468         else if (!fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 469                 fam = FW3_FAMILY_V4;
 470         else if (fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 471                 return;
 472
 473         uci_add_section(ctx, dest, "zone", &ptr.s);
 474
 475         ptr.o      = NULL;
 476         ptr.option = "name";
 477         ptr.value  = z->name;
 478         uci_set(ctx, &ptr);
 479
 480         ptr.o      = NULL;
 481         ptr.option = "input";
 482         ptr.value  = fw3_flag_names[z->policy_input];
 483         uci_set(ctx, &ptr);
 484
 485         ptr.o      = NULL;
 486         ptr.option = "output";
 487         ptr.value  = fw3_flag_names[z->policy_output];
 488         uci_set(ctx, &ptr);
 489
 490         ptr.o      = NULL;
 491         ptr.option = "forward";
 492         ptr.value  = fw3_flag_names[z->policy_forward];
 493         uci_set(ctx, &ptr);
 494
 495         ptr.o      = NULL;
 496         ptr.option = "masq";
 497         ptr.value  = z->masq ? "1" : "0";
 498         uci_set(ctx, &ptr);
 499
 500         ptr.o      = NULL;
 501         ptr.option = "mtu_fix";
 502         ptr.value  = z->mtu_fix ? "1" : "0";
 503         uci_set(ctx, &ptr);
 504
 505         ptr.o      = NULL;
 506         ptr.option = "custom_chains";
 507         ptr.value  = z->custom_chains ? "1" : "0";
 508         uci_set(ctx, &ptr);
 509
 510         if (fam != FW3_FAMILY_ANY)
 511         {
 512                 ptr.o      = NULL;
 513                 ptr.option = "family";
 514                 ptr.value  = fw3_flag_names[fam];
 515                 uci_set(ctx, &ptr);
 516         }
 517
 518         ptr.o      = NULL;
 519         ptr.option = "device";
 520
 521         fw3_foreach(dev, &z->devices)
 522         {
 523                 char *ep;
 524
 525                 if (!dev)
 526                         continue;
 527
 528                 p = buf;
 529                 ep = buf + sizeof(buf);
 530
 531                 if (dev->invert)
 532                         p += snprintf(p, ep - p, "!");
 533
 534                 if (*dev->network)
 535                         p += snprintf(p, ep - p, "%s@%s", dev->name, dev->network);
 536                 else
 537                         p += snprintf(p, ep - p, "%s", dev->name);
 538
 539                 ptr.value = buf;
 540                 uci_add_list(ctx, &ptr);
 541         }
 542
 543         ptr.o      = NULL;
 544         ptr.option = "subnet";
 545
 546         fw3_foreach(sub, &z->subnets)
 547         {
 548                 if (!sub)
 549                         continue;
 550
 551                 ptr.value = fw3_address_to_string(sub, true, false);
 552                 uci_add_list(ctx, &ptr);
 553         }
 554
 555         ptr.o      = NULL;
 556         ptr.option = "__addrs";
 557
 558         fw3_foreach(dev, &z->devices)
 559         {
 560                 if (!dev)
 561                         continue;
 562
 563                 for (ifa = ifaddr; ifa; ifa = ifa->ifa_next)
 564                 {
 565                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 566                                 continue;
 567
 568                         if (ifa->ifa_addr->sa_family == AF_INET)
 569                                 inet_ntop(AF_INET,
 570                                           &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
 571                                           buf, sizeof(buf));
 572                         else if (ifa->ifa_addr->sa_family == AF_INET6)
 573                                 inet_ntop(AF_INET6,
 574                                           &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
 575                                           buf, sizeof(buf));
 576                         else
 577                                 continue;
 578
 579                         ptr.value = buf;
 580                         uci_add_list(ctx, &ptr);
 581                 }
 582         }
 583
 584         if (z->extra_src)
 585         {
 586                 ptr.o      = NULL;
 587                 ptr.option = "extra_src";
 588                 ptr.value  = z->extra_src;
 589                 uci_set(ctx, &ptr);
 590         }
 591
 592         if (z->extra_dest)
 593         {
 594                 ptr.o      = NULL;
 595                 ptr.option = "extra_dest";
 596                 ptr.value  = z->extra_dest;
 597                 uci_set(ctx, &ptr);
 598         }
 599
 600         snprintf(buf, sizeof(buf), "0x%x", z->flags[0]);
 601         ptr.o      = NULL;
 602         ptr.option = "__flags_v4";
 603         ptr.value  = buf;
 604         uci_set(ctx, &ptr);
 605
 606         snprintf(buf, sizeof(buf), "0x%x", z->flags[1]);
 607         ptr.o      = NULL;
 608         ptr.option = "__flags_v6";
 609         ptr.value  = buf;
 610         uci_set(ctx, &ptr);
 611 }
 612
 613 static void
 614 write_ipset_uci(struct uci_context *ctx, struct fw3_ipset *s,
 615                 struct uci_package *dest)
 616 {
 617         struct fw3_ipset_datatype *type;
 618
 619         char buf[sizeof("65535-65535")];
 620
 621         struct uci_ptr ptr = { .p = dest };
 622
 623         if (!s->enabled || s->external)
 624                 return;
 625
 626         uci_add_section(ctx, dest, "ipset", &ptr.s);
 627
 628         ptr.o      = NULL;
 629         ptr.option = "name";
 630         ptr.value  = s->name;
 631         uci_set(ctx, &ptr);
 632
 633         ptr.o      = NULL;
 634         ptr.option = "family";
 635         if (s->family == FW3_FAMILY_V4)
 636                 ptr.value = "ipv4";
 637         else
 638                 ptr.value = "ipv6";
 639         uci_set(ctx, &ptr);
 640
 641         ptr.o      = NULL;
 642         ptr.option = "storage";
 643         ptr.value  = fw3_ipset_method_names[s->method];
 644         uci_set(ctx, &ptr);
 645
 646         list_for_each_entry(type, &s->datatypes, list)
 647         {
 648                 snprintf(buf, sizeof(buf), "%s_%s", type->dir, fw3_ipset_type_names[type->type]);
 649                 ptr.o      = NULL;
 650                 ptr.option = "match";
 651                 ptr.value  = buf;
 652                 uci_add_list(ctx, &ptr);
 653         }
 654
 655         if (s->iprange.set)
 656         {
 657                 ptr.o      = NULL;
 658                 ptr.option = "iprange";
 659                 ptr.value  = fw3_address_to_string(&s->iprange, false, false);
 660                 uci_set(ctx, &ptr);
 661         }
 662
 663         if (s->portrange.set)
 664         {
 665                 snprintf(buf, sizeof(buf), "%u-%u", s->portrange.port_min, s->portrange.port_max);
 666                 ptr.o      = NULL;
 667                 ptr.option = "portrange";
 668                 ptr.value  = buf;
 669                 uci_set(ctx, &ptr);
 670         }
 671 }
 672
 673 void
 674 fw3_write_statefile(void *state)
 675 {
 676         FILE *sf;
 677         struct fw3_state *s = state;
 678         struct fw3_zone *z;
 679         struct fw3_ipset *i;
 680         struct ifaddrs *ifaddr;
 681
 682         struct uci_package *p;
 683
 684         if (fw3_no_family(s->defaults.flags[0]) &&
 685             fw3_no_family(s->defaults.flags[1]))
 686         {
 687                 unlink(FW3_STATEFILE);
 688         }
 689         else
 690         {
 691                 sf = fopen(FW3_STATEFILE, "w+");
 692
 693                 if (!sf)
 694                 {
 695                         warn("Cannot create state %s: %s", FW3_STATEFILE, strerror(errno));
 696                         return;
 697                 }
 698
 699                 if (getifaddrs(&ifaddr))
 700                 {
 701                         warn("Cannot get interface addresses: %s", strerror(errno));
 702                         ifaddr = NULL;
 703                 }
 704
 705                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 706                         uci_unload(s->uci, p);
 707
 708                 uci_import(s->uci, sf, "fw3_state", NULL, true);
 709
 710                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 711                 {
 712                         write_defaults_uci(s->uci, &s->defaults, p);
 713
 714                         list_for_each_entry(z, &s->zones, list)
 715                                 write_zone_uci(s->uci, z, p, ifaddr);
 716
 717                         list_for_each_entry(i, &s->ipsets, list)
 718                                 write_ipset_uci(s->uci, i, p);
 719
 720                         uci_export(s->uci, sf, p, true);
 721                         uci_unload(s->uci, p);
 722                 }
 723
 724                 fsync(fileno(sf));
 725                 fclose(sf);
 726
 727                 if (ifaddr)
 728                         freeifaddrs(ifaddr);
 729         }
 730 }
 731
 732
 733 void
 734 fw3_free_object(void *obj, const void *opts)
 735 {
 736         const struct fw3_option *ol;
 737         struct list_head *list, *cur, *tmp;
 738
 739         for (ol = opts; ol->name; ol++)
 740         {
 741                 if (!ol->elem_size)
 742                         continue;
 743
 744                 list = (struct list_head *)((char *)obj + ol->offset);
 745                 list_for_each_safe(cur, tmp, list)
 746                 {
 747                         list_del(cur);
 748                         free(cur);
 749                 }
 750         }
 751
 752         free(obj);
 753 }
 754
 755 void
 756 fw3_free_list(struct list_head *head)
 757 {
 758         struct list_head *entry, *tmp;
 759
 760         if (!head)
 761                 return;
 762
 763         list_for_each_safe(entry, tmp, head)
 764         {
 765                 list_del(entry);
 766                 free(entry);
 767         }
 768
 769         free(head);
 770 }
 771
 772 bool
 773 fw3_hotplug(bool add, void *zone, void *device)
 774 {
 775         struct fw3_zone *z = zone;
 776         struct fw3_device *d = device;
 777
 778         if (!*d->network)
 779                 return false;
 780
 781         switch (fork())
 782         {
 783         case -1:
 784                 warn("Unable to fork(): %s\n", strerror(errno));
 785                 return false;
 786
 787         case 0:
 788                 break;
 789
 790         default:
 791                 return true;
 792         }
 793
 794         close(0);
 795         close(1);
 796         close(2);
 797         if (chdir("/")) {};
 798
 799         clearenv();
 800         setenv("ACTION",    add ? "add" : "remove", 1);
 801         setenv("ZONE",      z->name,                1);
 802         setenv("INTERFACE", d->network,             1);
 803         setenv("DEVICE",    d->name,                1);
 804
 805         execl(FW3_HOTPLUG, FW3_HOTPLUG, "firewall", NULL);
 806
 807         /* unreached */
 808         return false;
 809 }
 810
 811 int
 812 fw3_netmask2bitlen(int family, void *mask)
 813 {
 814         int bits;
 815         struct in_addr *v4;
 816         struct in6_addr *v6;
 817
 818         if (family == FW3_FAMILY_V6)
 819                 for (bits = 0, v6 = mask;
 820                      bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
 821                      bits++);
 822         else
 823                 for (bits = 0, v4 = mask;
 824                      bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
 825                      bits++);
 826
 827         return bits;
 828 }
 829
 830 bool
 831 fw3_bitlen2netmask(int family, int bits, void *mask)
 832 {
 833         int i;
 834         uint8_t rem, b;
 835         struct in_addr *v4;
 836         struct in6_addr *v6;
 837
 838         if (family == FW3_FAMILY_V6)
 839         {
 840                 if (bits < -128 || bits > 128)
 841                         return false;
 842
 843                 v6 = mask;
 844                 rem = abs(bits);
 845
 846                 for (i = 0; i < sizeof(v6->s6_addr); i++)
 847                 {
 848                         b = (rem > 8) ? 8 : rem;
 849                         v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
 850                         rem -= b;
 851                 }
 852
 853                 if (bits < 0)
 854                         for (i = 0; i < sizeof(v6->s6_addr); i++)
 855                                 v6->s6_addr[i] = ~v6->s6_addr[i];
 856         }
 857         else
 858         {
 859                 if (bits < -32 || bits > 32)
 860                         return false;
 861
 862                 v4 = mask;
 863                 v4->s_addr = bits ? htonl(~((1 << (32 - abs(bits))) - 1)) : 0;
 864
 865                 if (bits < 0)
 866                         v4->s_addr = ~v4->s_addr;
 867         }
 868
 869         return true;
 870 }
 871
 872 void
 873 fw3_flush_conntrack(void *state)
 874 {
 875         bool found;
 876         struct fw3_state *s = state;
 877         struct fw3_address *addr;
 878         struct fw3_device *dev;
 879         struct fw3_zone *zone;
 880         struct ifaddrs *ifaddr, *ifa;
 881         struct sockaddr_in *sin;
 882         struct sockaddr_in6 *sin6;
 883         char buf[INET6_ADDRSTRLEN];
 884         FILE *ct;
 885
 886         if (!state)
 887         {
 888                 if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 889                 {
 890                         info(" * Flushing conntrack table ...");
 891
 892                         fwrite("f\n", 1, 2, ct);
 893                         fclose(ct);
 894                 }
 895
 896                 return;
 897         }
 898
 899         if (getifaddrs(&ifaddr))
 900         {
 901                 warn("Cannot get interface addresses: %s", strerror(errno));
 902                 return;
 903         }
 904
 905         if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 906         {
 907                 list_for_each_entry(zone, &s->zones, list)
 908                 list_for_each_entry(addr, &zone->old_addrs, list)
 909                 {
 910                         found = false;
 911
 912                         list_for_each_entry(dev, &zone->devices, list)
 913                         {
 914                                 for (ifa = ifaddr; ifa && !found; ifa = ifa->ifa_next)
 915                                 {
 916                                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 917                                                 continue;
 918
 919                                         sin = (struct sockaddr_in *)ifa->ifa_addr;
 920                                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 921
 922                                         if (addr->family == FW3_FAMILY_V4 &&
 923                                                 sin->sin_family == AF_INET)
 924                                         {
 925                                                 found = !memcmp(&addr->address.v4, &sin->sin_addr,
 926                                                                                 sizeof(sin->sin_addr));
 927                                         }
 928                                         else if (addr->family == FW3_FAMILY_V6 &&
 929                                                          sin6->sin6_family == AF_INET6)
 930                                         {
 931                                                 found = !memcmp(&addr->address.v6, &sin6->sin6_addr,
 932                                                                                 sizeof(sin6->sin6_addr));
 933                                         }
 934                                 }
 935
 936                                 if (found)
 937                                         break;
 938                         }
 939
 940                         if (!found)
 941                         {
 942                                 inet_ntop(addr->family == FW3_FAMILY_V4 ? AF_INET : AF_INET6,
 943                                                   &addr->address.v4, buf, sizeof(buf));
 944
 945                                 info(" * Flushing conntrack: %s", buf);
 946                                 fprintf(ct, "%s\n", buf);
 947                         }
 948                 }
 949
 950                 fclose(ct);
 951         }
 952
 953         freeifaddrs(ifaddr);
 954 }
 955
 956 bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const char **type)
 957 {
 958         struct blob_attr *opt;
 959         unsigned orem;
 960
 961         if (!type || !name)
 962                 return false;
 963
 964         *type = NULL;
 965
 966         blobmsg_for_each_attr(opt, entry, orem)
 967                 if (!strcmp(blobmsg_name(opt), "type"))
 968                         *type = blobmsg_get_string(opt);
 969                 else if (!strcmp(blobmsg_name(opt), "name"))
 970                         *name = blobmsg_get_string(opt);
 971
 972         return *type != NULL ? true : false;
 973 }
 974
 975 const char *
 976 fw3_protoname(void *proto)
 977 {
 978         static char buf[sizeof("4294967295")];
 979         struct fw3_protocol *p = proto;
 980         struct protoent *pe;
 981
 982         if (!p)
 983                 return "?";
 984
 985         pe = getprotobynumber(p->protocol);
 986
 987         if (!pe)
 988         {
 989                 snprintf(buf, sizeof(buf), "%u", p->protocol);
 990                 return buf;
 991         }
 992
 993         return pe->p_name;
 994 }
 995
 996 bool
 997 fw3_check_loopback_dev(const char *name)
 998 {
 999         struct ifreq ifr;
1000         int s;
1001         bool rv = false;
1002
1003         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
1004
1005         if (s < 0)
1006                 return false;
1007
1008         memset(&ifr, 0, sizeof(ifr));
1009         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", name);
1010
1011         if (ioctl(s, SIOCGIFFLAGS, &ifr) >= 0) {
1012                 if (ifr.ifr_flags & IFF_LOOPBACK)
1013                         rv = true;
1014         }
1015
1016         close(s);
1017
1018         return rv;
1019 }
1020
1021 bool
1022 fw3_check_loopback_addr(struct fw3_address *addr)
1023 {
1024         if (addr->family == FW3_FAMILY_V4 &&
1025             (ntohl(addr->address.v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
1026                 return true;
1027
1028         if (addr->family == FW3_FAMILY_V6 && !addr->range &&
1029             fw3_netmask2bitlen(FW3_FAMILY_V6, &addr->mask.v6) == 128 &&
1030             IN6_IS_ADDR_LOOPBACK(&addr->address.v6))
1031                 return true;
1032
1033         return false;
1034 }