utils.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #define _GNU_SOURCE
  20
  21 #include <net/if.h>
  22 #include <sys/ioctl.h>
  23
  24 #include "utils.h"
  25 #include "options.h"
  26
  27 #include "zones.h"
  28 #include "ipsets.h"
  29
  30
  31 static int fw3_lock_fd = -1;
  32 static pid_t pipe_pid = -1;
  33 static FILE *pipe_fd = NULL;
  34
  35 bool fw3_pr_debug = false;
  36
  37
  38 static void
  39 warn_elem_section_name(struct uci_section *s, bool find_name)
  40 {
  41         int i = 0;
  42         struct uci_option *o;
  43         struct uci_element *tmp;
  44
  45         if (s->anonymous)
  46         {
  47                 uci_foreach_element(&s->package->sections, tmp)
  48                 {
  49                         if (strcmp(uci_to_section(tmp)->type, s->type))
  50                                 continue;
  51
  52                         if (&s->e == tmp)
  53                                 break;
  54
  55                         i++;
  56                 }
  57
  58                 fprintf(stderr, "@%s[%d]", s->type, i);
  59
  60                 if (find_name)
  61                 {
  62                         uci_foreach_element(&s->options, tmp)
  63                         {
  64                                 o = uci_to_option(tmp);
  65
  66                                 if (!strcmp(tmp->name, "name") && (o->type == UCI_TYPE_STRING))
  67                                 {
  68                                         fprintf(stderr, " (%s)", o->v.string);
  69                                         break;
  70                                 }
  71                         }
  72                 }
  73         }
  74         else
  75         {
  76                 fprintf(stderr, "'%s'", s->e.name);
  77         }
  78
  79         if (find_name)
  80                 fprintf(stderr, " ");
  81 }
  82
  83 void
  84 warn_elem(struct uci_element *e, const char *format, ...)
  85 {
  86         if (e->type == UCI_TYPE_SECTION)
  87         {
  88                 fprintf(stderr, "Warning: Section ");
  89                 warn_elem_section_name(uci_to_section(e), true);
  90         }
  91         else if (e->type == UCI_TYPE_OPTION)
  92         {
  93                 fprintf(stderr, "Warning: Option ");
  94                 warn_elem_section_name(uci_to_option(e)->section, false);
  95                 fprintf(stderr, ".%s ", e->name);
  96         }
  97
  98     va_list argptr;
  99     va_start(argptr, format);
 100     vfprintf(stderr, format, argptr);
 101     va_end(argptr);
 102
 103         fprintf(stderr, "\n");
 104 }
 105
 106 void
 107 warn(const char* format, ...)
 108 {
 109         fprintf(stderr, "Warning: ");
 110     va_list argptr;
 111     va_start(argptr, format);
 112     vfprintf(stderr, format, argptr);
 113     va_end(argptr);
 114         fprintf(stderr, "\n");
 115 }
 116
 117 void
 118 error(const char* format, ...)
 119 {
 120         fprintf(stderr, "Error: ");
 121     va_list argptr;
 122     va_start(argptr, format);
 123     vfprintf(stderr, format, argptr);
 124     va_end(argptr);
 125         fprintf(stderr, "\n");
 126
 127         exit(1);
 128 }
 129
 130 void
 131 info(const char* format, ...)
 132 {
 133         va_list argptr;
 134     va_start(argptr, format);
 135     vfprintf(stderr, format, argptr);
 136     va_end(argptr);
 137         fprintf(stderr, "\n");
 138 }
 139
 140 void *
 141 fw3_alloc(size_t size)
 142 {
 143         void *mem;
 144
 145         mem = calloc(1, size);
 146
 147         if (!mem)
 148                 error("Out of memory while allocating %zd bytes", size);
 149
 150         return mem;
 151 }
 152
 153 char *
 154 fw3_strdup(const char *s)
 155 {
 156         char *ns;
 157
 158         ns = strdup(s);
 159
 160         if (!ns)
 161                 error("Out of memory while duplicating string '%s'", s);
 162
 163         return ns;
 164 }
 165
 166 const char *
 167 fw3_find_command(const char *cmd)
 168 {
 169         struct stat s;
 170         int plen = 0, clen = strlen(cmd) + 1;
 171         char *search, *p;
 172         static char path[PATH_MAX];
 173
 174         if (!stat(cmd, &s) && S_ISREG(s.st_mode))
 175                 return cmd;
 176
 177         search = getenv("PATH");
 178
 179         if (!search)
 180                 search = "/bin:/usr/bin:/sbin:/usr/sbin";
 181
 182         p = search;
 183
 184         do
 185         {
 186                 if (*p != ':' && *p != '\0')
 187                         continue;
 188
 189                 plen = p - search;
 190
 191                 if ((plen + clen) >= sizeof(path))
 192                         continue;
 193
 194                 strncpy(path, search, plen);
 195                 sprintf(path + plen, "/%s", cmd);
 196
 197                 if (!stat(path, &s) && S_ISREG(s.st_mode))
 198                         return path;
 199
 200                 search = p + 1;
 201         }
 202         while (*p++);
 203
 204         return NULL;
 205 }
 206
 207 bool
 208 fw3_stdout_pipe(void)
 209 {
 210         pipe_fd = stdout;
 211         return true;
 212 }
 213
 214 bool
 215 __fw3_command_pipe(bool silent, const char *command, ...)
 216 {
 217         pid_t pid;
 218         va_list argp;
 219         int pfds[2];
 220         int argn;
 221         char *arg, **args, **tmp;
 222
 223         command = fw3_find_command(command);
 224
 225         if (!command)
 226                 return false;
 227
 228         if (pipe(pfds))
 229                 return false;
 230
 231         argn = 2;
 232         args = calloc(argn, sizeof(arg));
 233
 234         if (!args)
 235                 return false;
 236
 237         args[0] = (char *)command;
 238         args[1] = NULL;
 239
 240         va_start(argp, command);
 241
 242         while ((arg = va_arg(argp, char *)) != NULL)
 243         {
 244                 tmp = realloc(args, ++argn * sizeof(arg));
 245
 246                 if (!tmp)
 247                         break;
 248
 249                 args = tmp;
 250                 args[argn-2] = arg;
 251                 args[argn-1] = NULL;
 252         }
 253
 254         va_end(argp);
 255
 256         switch ((pid = fork()))
 257         {
 258         case -1:
 259                 free(args);
 260                 return false;
 261
 262         case 0:
 263                 dup2(pfds[0], 0);
 264
 265                 close(pfds[0]);
 266                 close(pfds[1]);
 267
 268                 close(1);
 269
 270                 if (silent)
 271                         close(2);
 272
 273                 execv(command, args);
 274
 275         default:
 276                 signal(SIGPIPE, SIG_IGN);
 277                 pipe_pid = pid;
 278                 close(pfds[0]);
 279                 fcntl(pfds[1], F_SETFD, fcntl(pfds[1], F_GETFD) | FD_CLOEXEC);
 280         }
 281
 282         pipe_fd = fdopen(pfds[1], "w");
 283         free(args);
 284         return true;
 285 }
 286
 287 void
 288 fw3_pr(const char *fmt, ...)
 289 {
 290         va_list args;
 291
 292         if (fw3_pr_debug && pipe_fd != stdout)
 293         {
 294                 va_start(args, fmt);
 295                 vfprintf(stderr, fmt, args);
 296                 va_end(args);
 297         }
 298
 299         va_start(args, fmt);
 300         vfprintf(pipe_fd, fmt, args);
 301         va_end(args);
 302 }
 303
 304 void
 305 fw3_command_close(void)
 306 {
 307         if (pipe_fd && pipe_fd != stdout)
 308                 fclose(pipe_fd);
 309
 310         if (pipe_pid > -1)
 311                 waitpid(pipe_pid, NULL, 0);
 312
 313         signal(SIGPIPE, SIG_DFL);
 314
 315         pipe_fd = NULL;
 316         pipe_pid = -1;
 317 }
 318
 319 bool
 320 fw3_has_table(bool ipv6, const char *table)
 321 {
 322         FILE *f;
 323
 324         char line[12];
 325         bool seen = false;
 326
 327         const char *path = ipv6
 328                 ? "/proc/net/ip6_tables_names" : "/proc/net/ip_tables_names";
 329
 330         if (!(f = fopen(path, "r")))
 331                 return false;
 332
 333         while (fgets(line, sizeof(line), f))
 334         {
 335                 if (!strncmp(line, table, strlen(table)))
 336                 {
 337                         seen = true;
 338                         break;
 339                 }
 340         }
 341
 342         fclose(f);
 343
 344         return seen;
 345 }
 346
 347 bool
 348 fw3_has_target(const bool ipv6, const char *target)
 349 {
 350         FILE *f;
 351
 352         char line[12];
 353         bool seen = false;
 354
 355         const char *path = ipv6
 356                 ? "/proc/net/ip6_tables_targets" : "/proc/net/ip_tables_targets";
 357
 358         if (!(f = fopen(path, "r")))
 359                 return false;
 360
 361         while (fgets(line, sizeof(line), f))
 362         {
 363                 if (!strcmp(line, target))
 364                 {
 365                         seen = true;
 366                         break;
 367                 }
 368         }
 369
 370         fclose(f);
 371
 372         return seen;
 373 }
 374
 375 bool
 376 fw3_lock_path(int *fd, const char *path)
 377 {
 378         int lock_fd = open(path, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 379
 380         if (lock_fd < 0)
 381         {
 382                 warn("Cannot create lock file %s: %s", path, strerror(errno));
 383                 return false;
 384         }
 385
 386         if (flock(lock_fd, LOCK_EX))
 387         {
 388                 warn("Cannot acquire exclusive lock: %s", strerror(errno));
 389                 close(lock_fd);
 390                 return false;
 391         }
 392
 393         *fd = lock_fd;
 394
 395         return true;
 396 }
 397
 398 bool
 399 fw3_lock()
 400 {
 401         return fw3_lock_path(&fw3_lock_fd, FW3_LOCKFILE);
 402 }
 403
 404
 405 void
 406 fw3_unlock_path(int *fd, const char *lockpath)
 407 {
 408         if (*fd < 0)
 409                 return;
 410
 411         if (flock(*fd, LOCK_UN))
 412                 warn("Cannot release exclusive lock: %s", strerror(errno));
 413
 414         close(*fd);
 415         unlink(FW3_LOCKFILE);
 416
 417         *fd = -1;
 418 }
 419
 420
 421 void
 422 fw3_unlock(void)
 423 {
 424         fw3_unlock_path(&fw3_lock_fd, FW3_LOCKFILE);
 425 }
 426
 427
 428 static void
 429 write_defaults_uci(struct uci_context *ctx, struct fw3_defaults *d,
 430                    struct uci_package *dest)
 431 {
 432         char buf[sizeof("0xffffffff\0")];
 433         struct uci_ptr ptr = { .p = dest };
 434
 435         uci_add_section(ctx, dest, "defaults", &ptr.s);
 436
 437         ptr.o      = NULL;
 438         ptr.option = "input";
 439         ptr.value  = fw3_flag_names[d->policy_input];
 440         uci_set(ctx, &ptr);
 441
 442         ptr.o      = NULL;
 443         ptr.option = "output";
 444         ptr.value  = fw3_flag_names[d->policy_output];
 445         uci_set(ctx, &ptr);
 446
 447         ptr.o      = NULL;
 448         ptr.option = "forward";
 449         ptr.value  = fw3_flag_names[d->policy_forward];
 450         uci_set(ctx, &ptr);
 451
 452         sprintf(buf, "0x%x", d->flags[0]);
 453         ptr.o      = NULL;
 454         ptr.option = "__flags_v4";
 455         ptr.value  = buf;
 456         uci_set(ctx, &ptr);
 457
 458         sprintf(buf, "0x%x", d->flags[1]);
 459         ptr.o      = NULL;
 460         ptr.option = "__flags_v6";
 461         ptr.value  = buf;
 462         uci_set(ctx, &ptr);
 463 }
 464
 465 static void
 466 write_zone_uci(struct uci_context *ctx, struct fw3_zone *z,
 467                struct uci_package *dest, struct ifaddrs *ifaddr)
 468 {
 469         struct fw3_device *dev;
 470         struct fw3_address *sub;
 471         struct ifaddrs *ifa;
 472         enum fw3_family fam = FW3_FAMILY_ANY;
 473
 474         char *p, buf[INET6_ADDRSTRLEN];
 475
 476         struct uci_ptr ptr = { .p = dest };
 477
 478         if (!z->enabled)
 479                 return;
 480
 481         if (fw3_no_table(z->flags[0]) && !fw3_no_table(z->flags[1]))
 482                 fam = FW3_FAMILY_V6;
 483         else if (!fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 484                 fam = FW3_FAMILY_V4;
 485         else if (fw3_no_table(z->flags[0]) && fw3_no_table(z->flags[1]))
 486                 return;
 487
 488         uci_add_section(ctx, dest, "zone", &ptr.s);
 489
 490         ptr.o      = NULL;
 491         ptr.option = "name";
 492         ptr.value  = z->name;
 493         uci_set(ctx, &ptr);
 494
 495         ptr.o      = NULL;
 496         ptr.option = "input";
 497         ptr.value  = fw3_flag_names[z->policy_input];
 498         uci_set(ctx, &ptr);
 499
 500         ptr.o      = NULL;
 501         ptr.option = "output";
 502         ptr.value  = fw3_flag_names[z->policy_output];
 503         uci_set(ctx, &ptr);
 504
 505         ptr.o      = NULL;
 506         ptr.option = "forward";
 507         ptr.value  = fw3_flag_names[z->policy_forward];
 508         uci_set(ctx, &ptr);
 509
 510         ptr.o      = NULL;
 511         ptr.option = "masq";
 512         ptr.value  = z->masq ? "1" : "0";
 513         uci_set(ctx, &ptr);
 514
 515         ptr.o      = NULL;
 516         ptr.option = "mtu_fix";
 517         ptr.value  = z->mtu_fix ? "1" : "0";
 518         uci_set(ctx, &ptr);
 519
 520         ptr.o      = NULL;
 521         ptr.option = "custom_chains";
 522         ptr.value  = z->custom_chains ? "1" : "0";
 523         uci_set(ctx, &ptr);
 524
 525         if (fam != FW3_FAMILY_ANY)
 526         {
 527                 ptr.o      = NULL;
 528                 ptr.option = "family";
 529                 ptr.value  = fw3_flag_names[fam];
 530                 uci_set(ctx, &ptr);
 531         }
 532
 533         ptr.o      = NULL;
 534         ptr.option = "device";
 535
 536         fw3_foreach(dev, &z->devices)
 537         {
 538                 char *ep;
 539
 540                 if (!dev)
 541                         continue;
 542
 543                 p = buf;
 544                 ep = buf + sizeof(buf);
 545
 546                 if (dev->invert)
 547                         p += snprintf(p, ep - p, "!");
 548
 549                 if (*dev->network)
 550                         p += snprintf(p, ep - p, "%s@%s", dev->name, dev->network);
 551                 else
 552                         p += snprintf(p, ep - p, "%s", dev->name);
 553
 554                 ptr.value = buf;
 555                 uci_add_list(ctx, &ptr);
 556         }
 557
 558         ptr.o      = NULL;
 559         ptr.option = "subnet";
 560
 561         fw3_foreach(sub, &z->subnets)
 562         {
 563                 if (!sub)
 564                         continue;
 565
 566                 ptr.value = fw3_address_to_string(sub, true, false);
 567                 uci_add_list(ctx, &ptr);
 568         }
 569
 570         ptr.o      = NULL;
 571         ptr.option = "__addrs";
 572
 573         fw3_foreach(dev, &z->devices)
 574         {
 575                 if (!dev)
 576                         continue;
 577
 578                 for (ifa = ifaddr; ifa; ifa = ifa->ifa_next)
 579                 {
 580                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 581                                 continue;
 582
 583                         if (ifa->ifa_addr->sa_family == AF_INET)
 584                                 inet_ntop(AF_INET,
 585                                           &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
 586                                           buf, sizeof(buf));
 587                         else if (ifa->ifa_addr->sa_family == AF_INET6)
 588                                 inet_ntop(AF_INET6,
 589                                           &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr,
 590                                           buf, sizeof(buf));
 591                         else
 592                                 continue;
 593
 594                         ptr.value = buf;
 595                         uci_add_list(ctx, &ptr);
 596                 }
 597         }
 598
 599         if (z->extra_src)
 600         {
 601                 ptr.o      = NULL;
 602                 ptr.option = "extra_src";
 603                 ptr.value  = z->extra_src;
 604                 uci_set(ctx, &ptr);
 605         }
 606
 607         if (z->extra_dest)
 608         {
 609                 ptr.o      = NULL;
 610                 ptr.option = "extra_dest";
 611                 ptr.value  = z->extra_dest;
 612                 uci_set(ctx, &ptr);
 613         }
 614
 615         sprintf(buf, "0x%x", z->flags[0]);
 616         ptr.o      = NULL;
 617         ptr.option = "__flags_v4";
 618         ptr.value  = buf;
 619         uci_set(ctx, &ptr);
 620
 621         sprintf(buf, "0x%x", z->flags[1]);
 622         ptr.o      = NULL;
 623         ptr.option = "__flags_v6";
 624         ptr.value  = buf;
 625         uci_set(ctx, &ptr);
 626 }
 627
 628 static void
 629 write_ipset_uci(struct uci_context *ctx, struct fw3_ipset *s,
 630                 struct uci_package *dest)
 631 {
 632         struct fw3_ipset_datatype *type;
 633
 634         char buf[sizeof("65535-65535\0")];
 635
 636         struct uci_ptr ptr = { .p = dest };
 637
 638         if (!s->enabled || s->external)
 639                 return;
 640
 641         uci_add_section(ctx, dest, "ipset", &ptr.s);
 642
 643         ptr.o      = NULL;
 644         ptr.option = "name";
 645         ptr.value  = s->name;
 646         uci_set(ctx, &ptr);
 647
 648         ptr.o      = NULL;
 649         ptr.option = "family";
 650         if (s->family == FW3_FAMILY_V4)
 651                 ptr.value = "ipv4";
 652         else
 653                 ptr.value = "ipv6";
 654         uci_set(ctx, &ptr);
 655
 656         ptr.o      = NULL;
 657         ptr.option = "storage";
 658         ptr.value  = fw3_ipset_method_names[s->method];
 659         uci_set(ctx, &ptr);
 660
 661         list_for_each_entry(type, &s->datatypes, list)
 662         {
 663                 sprintf(buf, "%s_%s", type->dir, fw3_ipset_type_names[type->type]);
 664                 ptr.o      = NULL;
 665                 ptr.option = "match";
 666                 ptr.value  = buf;
 667                 uci_add_list(ctx, &ptr);
 668         }
 669
 670         if (s->iprange.set)
 671         {
 672                 ptr.o      = NULL;
 673                 ptr.option = "iprange";
 674                 ptr.value  = fw3_address_to_string(&s->iprange, false, false);
 675                 uci_set(ctx, &ptr);
 676         }
 677
 678         if (s->portrange.set)
 679         {
 680                 sprintf(buf, "%u-%u", s->portrange.port_min, s->portrange.port_max);
 681                 ptr.o      = NULL;
 682                 ptr.option = "portrange";
 683                 ptr.value  = buf;
 684                 uci_set(ctx, &ptr);
 685         }
 686 }
 687
 688 void
 689 fw3_write_statefile(void *state)
 690 {
 691         FILE *sf;
 692         struct fw3_state *s = state;
 693         struct fw3_zone *z;
 694         struct fw3_ipset *i;
 695         struct ifaddrs *ifaddr;
 696
 697         struct uci_package *p;
 698
 699         if (fw3_no_family(s->defaults.flags[0]) &&
 700             fw3_no_family(s->defaults.flags[1]))
 701         {
 702                 unlink(FW3_STATEFILE);
 703         }
 704         else
 705         {
 706                 sf = fopen(FW3_STATEFILE, "w+");
 707
 708                 if (!sf)
 709                 {
 710                         warn("Cannot create state %s: %s", FW3_STATEFILE, strerror(errno));
 711                         return;
 712                 }
 713
 714                 if (getifaddrs(&ifaddr))
 715                 {
 716                         warn("Cannot get interface addresses: %s", strerror(errno));
 717                         ifaddr = NULL;
 718                 }
 719
 720                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 721                         uci_unload(s->uci, p);
 722
 723                 uci_import(s->uci, sf, "fw3_state", NULL, true);
 724
 725                 if ((p = uci_lookup_package(s->uci, "fw3_state")) != NULL)
 726                 {
 727                         write_defaults_uci(s->uci, &s->defaults, p);
 728
 729                         list_for_each_entry(z, &s->zones, list)
 730                                 write_zone_uci(s->uci, z, p, ifaddr);
 731
 732                         list_for_each_entry(i, &s->ipsets, list)
 733                                 write_ipset_uci(s->uci, i, p);
 734
 735                         uci_export(s->uci, sf, p, true);
 736                         uci_unload(s->uci, p);
 737                 }
 738
 739                 fsync(fileno(sf));
 740                 fclose(sf);
 741
 742                 if (ifaddr)
 743                         freeifaddrs(ifaddr);
 744         }
 745 }
 746
 747
 748 void
 749 fw3_free_object(void *obj, const void *opts)
 750 {
 751         const struct fw3_option *ol;
 752         struct list_head *list, *cur, *tmp;
 753
 754         for (ol = opts; ol->name; ol++)
 755         {
 756                 if (!ol->elem_size)
 757                         continue;
 758
 759                 list = (struct list_head *)((char *)obj + ol->offset);
 760                 list_for_each_safe(cur, tmp, list)
 761                 {
 762                         list_del(cur);
 763                         free(cur);
 764                 }
 765         }
 766
 767         free(obj);
 768 }
 769
 770 void
 771 fw3_free_list(struct list_head *head)
 772 {
 773         struct list_head *entry, *tmp;
 774
 775         if (!head)
 776                 return;
 777
 778         list_for_each_safe(entry, tmp, head)
 779         {
 780                 list_del(entry);
 781                 free(entry);
 782         }
 783
 784         free(head);
 785 }
 786
 787 bool
 788 fw3_hotplug(bool add, void *zone, void *device)
 789 {
 790         struct fw3_zone *z = zone;
 791         struct fw3_device *d = device;
 792
 793         if (!*d->network)
 794                 return false;
 795
 796         switch (fork())
 797         {
 798         case -1:
 799                 warn("Unable to fork(): %s\n", strerror(errno));
 800                 return false;
 801
 802         case 0:
 803                 break;
 804
 805         default:
 806                 return true;
 807         }
 808
 809         close(0);
 810         close(1);
 811         close(2);
 812         if (chdir("/")) {};
 813
 814         clearenv();
 815         setenv("ACTION",    add ? "add" : "remove", 1);
 816         setenv("ZONE",      z->name,                1);
 817         setenv("INTERFACE", d->network,             1);
 818         setenv("DEVICE",    d->name,                1);
 819
 820         execl(FW3_HOTPLUG, FW3_HOTPLUG, "firewall", NULL);
 821
 822         /* unreached */
 823         return false;
 824 }
 825
 826 int
 827 fw3_netmask2bitlen(int family, void *mask)
 828 {
 829         int bits;
 830         struct in_addr *v4;
 831         struct in6_addr *v6;
 832
 833         if (family == FW3_FAMILY_V6)
 834                 for (bits = 0, v6 = mask;
 835                      bits < 128 && (v6->s6_addr[bits / 8] << (bits % 8)) & 128;
 836                      bits++);
 837         else
 838                 for (bits = 0, v4 = mask;
 839                      bits < 32 && (ntohl(v4->s_addr) << bits) & 0x80000000;
 840                      bits++);
 841
 842         return bits;
 843 }
 844
 845 bool
 846 fw3_bitlen2netmask(int family, int bits, void *mask)
 847 {
 848         int i;
 849         uint8_t rem, b;
 850         struct in_addr *v4;
 851         struct in6_addr *v6;
 852
 853         if (family == FW3_FAMILY_V6)
 854         {
 855                 if (bits < -128 || bits > 128)
 856                         return false;
 857
 858                 v6 = mask;
 859                 rem = abs(bits);
 860
 861                 for (i = 0; i < sizeof(v6->s6_addr); i++)
 862                 {
 863                         b = (rem > 8) ? 8 : rem;
 864                         v6->s6_addr[i] = (uint8_t)(0xFF << (8 - b));
 865                         rem -= b;
 866                 }
 867
 868                 if (bits < 0)
 869                         for (i = 0; i < sizeof(v6->s6_addr); i++)
 870                                 v6->s6_addr[i] = ~v6->s6_addr[i];
 871         }
 872         else
 873         {
 874                 if (bits < -32 || bits > 32)
 875                         return false;
 876
 877                 v4 = mask;
 878                 v4->s_addr = bits ? htonl(~((1 << (32 - abs(bits))) - 1)) : 0;
 879
 880                 if (bits < 0)
 881                         v4->s_addr = ~v4->s_addr;
 882         }
 883
 884         return true;
 885 }
 886
 887 void
 888 fw3_flush_conntrack(void *state)
 889 {
 890         bool found;
 891         struct fw3_state *s = state;
 892         struct fw3_address *addr;
 893         struct fw3_device *dev;
 894         struct fw3_zone *zone;
 895         struct ifaddrs *ifaddr, *ifa;
 896         struct sockaddr_in *sin;
 897         struct sockaddr_in6 *sin6;
 898         char buf[INET6_ADDRSTRLEN];
 899         FILE *ct;
 900
 901         if (!state)
 902         {
 903                 if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 904                 {
 905                         info(" * Flushing conntrack table ...");
 906
 907                         fwrite("f\n", 1, 2, ct);
 908                         fclose(ct);
 909                 }
 910
 911                 return;
 912         }
 913
 914         if (getifaddrs(&ifaddr))
 915         {
 916                 warn("Cannot get interface addresses: %s", strerror(errno));
 917                 return;
 918         }
 919
 920         if ((ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 921         {
 922                 list_for_each_entry(zone, &s->zones, list)
 923                 list_for_each_entry(addr, &zone->old_addrs, list)
 924                 {
 925                         found = false;
 926
 927                         list_for_each_entry(dev, &zone->devices, list)
 928                         {
 929                                 for (ifa = ifaddr; ifa && !found; ifa = ifa->ifa_next)
 930                                 {
 931                                         if (!ifa->ifa_addr || strcmp(dev->name, ifa->ifa_name))
 932                                                 continue;
 933
 934                                         sin = (struct sockaddr_in *)ifa->ifa_addr;
 935                                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 936
 937                                         if (addr->family == FW3_FAMILY_V4 &&
 938                                                 sin->sin_family == AF_INET)
 939                                         {
 940                                                 found = !memcmp(&addr->address.v4, &sin->sin_addr,
 941                                                                                 sizeof(sin->sin_addr));
 942                                         }
 943                                         else if (addr->family == FW3_FAMILY_V6 &&
 944                                                          sin6->sin6_family == AF_INET6)
 945                                         {
 946                                                 found = !memcmp(&addr->address.v6, &sin6->sin6_addr,
 947                                                                                 sizeof(sin6->sin6_addr));
 948                                         }
 949                                 }
 950
 951                                 if (found)
 952                                         break;
 953                         }
 954
 955                         if (!found)
 956                         {
 957                                 inet_ntop(addr->family == FW3_FAMILY_V4 ? AF_INET : AF_INET6,
 958                                                   &addr->address.v4, buf, sizeof(buf));
 959
 960                                 info(" * Flushing conntrack: %s", buf);
 961                                 fprintf(ct, "%s\n", buf);
 962                         }
 963                 }
 964
 965                 fclose(ct);
 966         }
 967
 968         freeifaddrs(ifaddr);
 969 }
 970
 971 bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const char **type)
 972 {
 973         struct blob_attr *opt;
 974         unsigned orem;
 975
 976         if (!type || !name)
 977                 return false;
 978
 979         *type = NULL;
 980
 981         blobmsg_for_each_attr(opt, entry, orem)
 982                 if (!strcmp(blobmsg_name(opt), "type"))
 983                         *type = blobmsg_get_string(opt);
 984                 else if (!strcmp(blobmsg_name(opt), "name"))
 985                         *name = blobmsg_get_string(opt);
 986
 987         return *type != NULL ? true : false;
 988 }
 989
 990 const char *
 991 fw3_protoname(void *proto)
 992 {
 993         static char buf[sizeof("4294967295")];
 994         struct fw3_protocol *p = proto;
 995         struct protoent *pe;
 996
 997         if (!p)
 998                 return "?";
 999
1000         pe = getprotobynumber(p->protocol);
1001
1002         if (!pe)
1003         {
1004                 snprintf(buf, sizeof(buf), "%u", p->protocol);
1005                 return buf;
1006         }
1007
1008         return pe->p_name;
1009 }
1010
1011 bool
1012 fw3_check_loopback_dev(const char *name)
1013 {
1014         struct ifreq ifr;
1015         int s;
1016         bool rv = false;
1017
1018         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
1019
1020         if (s < 0)
1021                 return false;
1022
1023         memset(&ifr, 0, sizeof(ifr));
1024         strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name) - 1);
1025
1026         if (ioctl(s, SIOCGIFFLAGS, &ifr) >= 0) {
1027                 if (ifr.ifr_flags & IFF_LOOPBACK)
1028                         rv = true;
1029         }
1030
1031         close(s);
1032
1033         return rv;
1034 }
1035
1036 bool
1037 fw3_check_loopback_addr(struct fw3_address *addr)
1038 {
1039         if (addr->family == FW3_FAMILY_V4 &&
1040             (ntohl(addr->address.v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
1041                 return true;
1042
1043         if (addr->family == FW3_FAMILY_V6 && !addr->range &&
1044             fw3_netmask2bitlen(FW3_FAMILY_V6, &addr->mask.v6) == 128 &&
1045             IN6_IS_ADDR_LOOPBACK(&addr->address.v6))
1046                 return true;
1047
1048         return false;
1049 }