main.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013-2014 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 #include <stdio.h>
  20 #include <unistd.h>
  21
  22 #include "options.h"
  23 #include "defaults.h"
  24 #include "zones.h"
  25 #include "rules.h"
  26 #include "redirects.h"
  27 #include "snats.h"
  28 #include "forwards.h"
  29 #include "ipsets.h"
  30 #include "includes.h"
  31 #include "ubus.h"
  32 #include "iptables.h"
  33 #include "helpers.h"
  34
  35
  36 static enum fw3_family print_family = FW3_FAMILY_ANY;
  37
  38 static struct fw3_state *run_state = NULL;
  39 static struct fw3_state *cfg_state = NULL;
  40
  41
  42 static bool
  43 build_state(bool runtime)
  44 {
  45         struct fw3_state *state = NULL;
  46         struct uci_package *p = NULL;
  47         FILE *sf;
  48
  49         state = calloc(1, sizeof(*state));
  50         if (!state)
  51                 error("Out of memory");
  52
  53         state->uci = uci_alloc_context();
  54
  55         if (!state->uci)
  56                 error("Out of memory");
  57
  58         if (runtime)
  59         {
  60                 sf = fopen(FW3_STATEFILE, "r");
  61
  62                 if (sf)
  63                 {
  64                         uci_import(state->uci, sf, "fw3_state", &p, true);
  65                         fclose(sf);
  66                 }
  67
  68                 if (!p)
  69                 {
  70                         uci_free_context(state->uci);
  71                         free(state);
  72
  73                         return false;
  74                 }
  75
  76                 state->statefile = true;
  77
  78                 run_state = state;
  79         }
  80         else
  81         {
  82                 if (!fw3_ubus_connect())
  83                         warn("Failed to connect to ubus");
  84
  85                 if (uci_load(state->uci, "firewall", &p))
  86                 {
  87                         uci_perror(state->uci, NULL);
  88                         error("Failed to load /etc/config/firewall");
  89                 }
  90
  91                 if (!fw3_find_command("ipset"))
  92                 {
  93                         warn("Unable to locate ipset utility, disabling ipset support");
  94                         state->disable_ipsets = true;
  95                 }
  96
  97                 cfg_state = state;
  98         }
  99
 100
 101         struct blob_buf b = {NULL, NULL, 0, NULL};
 102         fw3_ubus_rules(&b);
 103
 104         fw3_load_defaults(state, p);
 105         fw3_load_cthelpers(state, p);
 106         fw3_load_ipsets(state, p, b.head);
 107         fw3_load_zones(state, p);
 108         fw3_load_rules(state, p, b.head);
 109         fw3_load_redirects(state, p, b.head);
 110         fw3_load_snats(state, p, b.head);
 111         fw3_load_forwards(state, p, b.head);
 112         fw3_load_includes(state, p, b.head);
 113
 114         return true;
 115 }
 116
 117 static void
 118 free_state(struct fw3_state *state)
 119 {
 120         struct list_head *cur, *tmp;
 121
 122         list_for_each_safe(cur, tmp, &state->zones)
 123                 fw3_free_zone((struct fw3_zone *)cur);
 124
 125         list_for_each_safe(cur, tmp, &state->rules)
 126                 fw3_free_rule((struct fw3_rule *)cur);
 127
 128         list_for_each_safe(cur, tmp, &state->redirects)
 129                 fw3_free_redirect((struct fw3_redirect *)cur);
 130
 131         list_for_each_safe(cur, tmp, &state->snats)
 132                 fw3_free_snat((struct fw3_snat *)cur);
 133
 134         list_for_each_safe(cur, tmp, &state->forwards)
 135                 fw3_free_forward((struct fw3_forward *)cur);
 136
 137         list_for_each_safe(cur, tmp, &state->ipsets)
 138                 fw3_free_ipset((struct fw3_ipset *)cur);
 139
 140         list_for_each_safe(cur, tmp, &state->includes)
 141                 fw3_free_include((struct fw3_include *)cur);
 142
 143         list_for_each_safe(cur, tmp, &state->cthelpers)
 144                 fw3_free_cthelper((struct fw3_cthelper *)cur);
 145
 146         uci_free_context(state->uci);
 147
 148         free(state);
 149
 150         fw3_ubus_disconnect();
 151 }
 152
 153
 154 static bool
 155 family_running(enum fw3_family family)
 156 {
 157         return (run_state && has(run_state->defaults.flags, family, family));
 158 }
 159
 160 static void
 161 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 162 {
 163         if (!state)
 164                 return;
 165
 166         if (set)
 167                 set(state->defaults.flags, family, family);
 168         else
 169                 del(state->defaults.flags, family, family);
 170 }
 171
 172 static int
 173 stop(bool complete)
 174 {
 175         int rv = 1;
 176         enum fw3_family family;
 177         enum fw3_table table;
 178         struct fw3_ipt_handle *handle;
 179
 180         if (!complete && !run_state)
 181         {
 182                 warn("The firewall appears to be stopped. "
 183                          "Use the 'flush' command to forcefully purge all rules.");
 184
 185                 return rv;
 186         }
 187
 188         if (!print_family && run_state)
 189                 fw3_hotplug_zones(run_state, false);
 190
 191         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 192         {
 193                 if (!complete && !family_running(family))
 194                         continue;
 195
 196                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 197                 {
 198                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 199                                 continue;
 200
 201                         if (!(handle = fw3_ipt_open(family, table)))
 202                                 continue;
 203
 204                         info(" * %sing %s %s table", complete ? "Flush" : "Clear",
 205                              fw3_flag_names[family], fw3_flag_names[table]);
 206
 207                         if (complete)
 208                         {
 209                                 fw3_flush_all(handle);
 210                         }
 211                         else if (run_state)
 212                         {
 213                                 fw3_flush_rules(handle, run_state, false);
 214                                 fw3_flush_zones(handle, run_state, false);
 215                         }
 216
 217                         fw3_ipt_commit(handle);
 218                         fw3_ipt_close(handle);
 219                 }
 220
 221                 family_set(run_state, family, false);
 222                 family_set(cfg_state, family, false);
 223
 224                 rv = 0;
 225         }
 226
 227         if (run_state) {
 228                 for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 229                         fw3_destroy_ipsets(run_state, family, false);
 230         }
 231
 232         if (complete)
 233                 fw3_flush_conntrack(NULL);
 234
 235         if (!rv && run_state)
 236                 fw3_write_statefile(run_state);
 237
 238         return rv;
 239 }
 240
 241 static int
 242 start(void)
 243 {
 244         int rv = 1;
 245         enum fw3_family family;
 246         enum fw3_table table;
 247         struct fw3_ipt_handle *handle;
 248
 249         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 250         {
 251                 if (!print_family)
 252                         fw3_create_ipsets(cfg_state, family, false);
 253
 254                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 255                         continue;
 256
 257                 if (print_family && family != print_family)
 258                         continue;
 259
 260                 if (!print_family && family_running(family))
 261                 {
 262                         warn("The %s firewall appears to be started already. "
 263                              "If it is indeed empty, remove the %s file and retry.",
 264                              fw3_flag_names[family], FW3_STATEFILE);
 265
 266                         continue;
 267                 }
 268
 269                 /* Linux 5.15+: make sure the tables are loaded and
 270                  * /proc/net/ip{,6}_tables_names are thus populated.
 271                  */
 272                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 273                 {
 274                         if (!(handle = fw3_ipt_open(family, table)))
 275                                 continue;
 276
 277                         fw3_ipt_close(handle);
 278                 }
 279
 280                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 281                 {
 282                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 283                                 continue;
 284
 285                         if (!(handle = fw3_ipt_open(family, table)))
 286                                 continue;
 287
 288                         info(" * Populating %s %s table",
 289                              fw3_flag_names[family], fw3_flag_names[table]);
 290
 291                         fw3_print_default_chains(handle, cfg_state, false);
 292                         fw3_print_zone_chains(handle, cfg_state, false);
 293                         fw3_print_default_head_rules(handle, cfg_state, false);
 294                         fw3_print_rules(handle, cfg_state);
 295                         fw3_print_redirects(handle, cfg_state);
 296                         fw3_print_snats(handle, cfg_state);
 297                         fw3_print_forwards(handle, cfg_state);
 298                         fw3_print_zone_rules(handle, cfg_state, false);
 299                         fw3_print_default_tail_rules(handle, cfg_state, false);
 300
 301                         if (!print_family)
 302                                 fw3_ipt_commit(handle);
 303
 304                         fw3_ipt_close(handle);
 305                 }
 306
 307                 if (!print_family)
 308                         fw3_print_includes(cfg_state, family, false);
 309
 310                 family_set(run_state, family, true);
 311                 family_set(cfg_state, family, true);
 312
 313                 rv = 0;
 314         }
 315
 316         if (!rv)
 317         {
 318                 fw3_flush_conntrack(run_state);
 319                 fw3_set_defaults(cfg_state);
 320
 321                 if (!print_family)
 322                 {
 323                         fw3_run_includes(cfg_state, false);
 324                         fw3_hotplug_zones(cfg_state, true);
 325                         fw3_write_statefile(cfg_state);
 326                 }
 327         }
 328
 329         return rv;
 330 }
 331
 332
 333 static int
 334 reload(void)
 335 {
 336         int rv = 1;
 337         enum fw3_family family;
 338         enum fw3_table table;
 339         struct fw3_ipt_handle *handle;
 340
 341         if (!run_state)
 342                 return start();
 343
 344         fw3_hotplug_zones(run_state, false);
 345
 346         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 347         {
 348                 if (!family_running(family))
 349                         goto start;
 350
 351                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 352                 {
 353                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 354                                 continue;
 355
 356                         if (!(handle = fw3_ipt_open(family, table)))
 357                                 continue;
 358
 359                         info(" * Clearing %s %s table",
 360                              fw3_flag_names[family], fw3_flag_names[table]);
 361
 362                         fw3_flush_rules(handle, run_state, true);
 363                         fw3_flush_zones(handle, run_state, true);
 364                         fw3_ipt_commit(handle);
 365                         fw3_ipt_close(handle);
 366                 }
 367
 368                 fw3_ipsets_update_run_state(family, run_state, cfg_state);
 369                 fw3_destroy_ipsets(run_state, family, true);
 370
 371                 family_set(run_state, family, false);
 372                 family_set(cfg_state, family, false);
 373
 374 start:
 375                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 376                         continue;
 377
 378                 fw3_create_ipsets(cfg_state, family, true);
 379
 380                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 381                 {
 382                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 383                                 continue;
 384
 385                         if (!(handle = fw3_ipt_open(family, table)))
 386                                 continue;
 387
 388                         info(" * Populating %s %s table",
 389                              fw3_flag_names[family], fw3_flag_names[table]);
 390
 391                         fw3_print_default_chains(handle, cfg_state, true);
 392                         fw3_print_zone_chains(handle, cfg_state, true);
 393                         fw3_print_default_head_rules(handle, cfg_state, true);
 394                         fw3_print_rules(handle, cfg_state);
 395                         fw3_print_redirects(handle, cfg_state);
 396                         fw3_print_snats(handle, cfg_state);
 397                         fw3_print_forwards(handle, cfg_state);
 398                         fw3_print_zone_rules(handle, cfg_state, true);
 399                         fw3_print_default_tail_rules(handle, cfg_state, true);
 400
 401                         fw3_ipt_commit(handle);
 402                         fw3_ipt_close(handle);
 403                 }
 404
 405                 fw3_print_includes(cfg_state, family, true);
 406
 407                 family_set(run_state, family, true);
 408                 family_set(cfg_state, family, true);
 409
 410                 rv = 0;
 411         }
 412
 413         if (!rv)
 414         {
 415                 fw3_flush_conntrack(run_state);
 416
 417                 fw3_set_defaults(cfg_state);
 418                 fw3_run_includes(cfg_state, true);
 419                 fw3_hotplug_zones(cfg_state, true);
 420                 fw3_write_statefile(cfg_state);
 421         }
 422
 423         return rv;
 424 }
 425
 426 static int
 427 gc(void)
 428 {
 429         enum fw3_family family;
 430         enum fw3_table table;
 431         struct fw3_ipt_handle *handle;
 432
 433         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 434         {
 435                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 436                         continue;
 437
 438                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 439                 {
 440                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 441                                 continue;
 442
 443                         if (!(handle = fw3_ipt_open(family, table)))
 444                                 continue;
 445
 446                         fw3_ipt_gc(handle);
 447                         fw3_ipt_commit(handle);
 448                         fw3_ipt_close(handle);
 449                 }
 450         }
 451
 452         return 0;
 453 }
 454
 455 static int
 456 lookup_network(const char *net)
 457 {
 458         struct fw3_zone *z;
 459         struct fw3_device *d;
 460
 461         list_for_each_entry(z, &cfg_state->zones, list)
 462         {
 463                 list_for_each_entry(d, &z->networks, list)
 464                 {
 465                         if (!strcmp(d->name, net))
 466                         {
 467                                 printf("%s\n", z->name);
 468                                 return 0;
 469                         }
 470                 }
 471         }
 472
 473         return 1;
 474 }
 475
 476 static int
 477 lookup_device(const char *dev)
 478 {
 479         struct fw3_zone *z;
 480         struct fw3_device *d;
 481
 482         list_for_each_entry(z, &cfg_state->zones, list)
 483         {
 484                 list_for_each_entry(d, &z->devices, list)
 485                 {
 486                         if (!strcmp(d->name, dev))
 487                         {
 488                                 printf("%s\n", z->name);
 489                                 return 0;
 490                         }
 491                 }
 492         }
 493
 494         return 1;
 495 }
 496
 497 static int
 498 lookup_zone(const char *zone, const char *device)
 499 {
 500         struct fw3_zone *z;
 501         struct fw3_device *d;
 502
 503         list_for_each_entry(z, &cfg_state->zones, list)
 504         {
 505                 if (strcmp(z->name, zone))
 506                         continue;
 507
 508                 list_for_each_entry(d, &z->devices, list)
 509                 {
 510                         if (device && strcmp(device, d->name))
 511                                 continue;
 512
 513                         printf("%s\n", d->name);
 514
 515                         if (device)
 516                                 return 0;
 517                 }
 518
 519                 if (!device)
 520                         return 0;
 521         }
 522
 523         return 1;
 524 }
 525
 526 static int
 527 usage(void)
 528 {
 529         fprintf(stderr, "fw3 [-4] [-6] [-q] print\n");
 530         fprintf(stderr, "fw3 [-q] {start|stop|flush|reload|restart}\n");
 531         fprintf(stderr, "fw3 [-q] network {net}\n");
 532         fprintf(stderr, "fw3 [-q] device {dev}\n");
 533         fprintf(stderr, "fw3 [-q] zone {zone} [dev]\n");
 534
 535         return 1;
 536 }
 537
 538
 539 int main(int argc, char **argv)
 540 {
 541         int ch, rv = 1;
 542         enum fw3_family family = FW3_FAMILY_ANY;
 543         struct fw3_defaults *defs = NULL;
 544
 545         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 546         {
 547                 switch (ch)
 548                 {
 549                 case '4':
 550                         family = FW3_FAMILY_V4;
 551                         break;
 552
 553                 case '6':
 554                         family = FW3_FAMILY_V6;
 555                         break;
 556
 557                 case 'd':
 558                         fw3_pr_debug = true;
 559                         break;
 560
 561                 case 'q':
 562                         if (freopen("/dev/null", "w", stderr)) {}
 563                         break;
 564
 565                 case 'h':
 566                         rv = usage();
 567                         goto out;
 568                 }
 569         }
 570
 571         build_state(false);
 572         defs = &cfg_state->defaults;
 573
 574         if (optind >= argc)
 575         {
 576                 rv = usage();
 577                 goto out;
 578         }
 579
 580         if (!strcmp(argv[optind], "print"))
 581         {
 582                 if (family == FW3_FAMILY_ANY)
 583                 {
 584                         family = FW3_FAMILY_V4;
 585                 }
 586                 else if (family == FW3_FAMILY_V6)
 587                 {
 588                         if (defs->disable_ipv6)
 589                                 warn("IPv6 rules globally disabled in configuration");
 590 #ifdef DISABLE_IPV6
 591                         else
 592                                 warn("IPv6 support is not compiled in");
 593 #endif
 594                 }
 595
 596                 if (freopen("/dev/null", "w", stderr)) {};
 597
 598                 cfg_state->disable_ipsets = true;
 599                 print_family = family;
 600                 fw3_pr_debug = true;
 601
 602                 if (fw3_lock())
 603                 {
 604                         build_state(true);
 605                         rv = start();
 606                         fw3_unlock();
 607                 }
 608         }
 609         else if (!strcmp(argv[optind], "start"))
 610         {
 611                 if (fw3_lock())
 612                 {
 613                         build_state(true);
 614                         rv = start();
 615                         fw3_unlock();
 616                 }
 617         }
 618         else if (!strcmp(argv[optind], "stop"))
 619         {
 620                 if (fw3_lock())
 621                 {
 622                         build_state(true);
 623                         rv = stop(false);
 624                         fw3_unlock();
 625                 }
 626         }
 627         else if (!strcmp(argv[optind], "flush"))
 628         {
 629                 if (fw3_lock())
 630                 {
 631                         build_state(true);
 632                         rv = stop(true);
 633                         fw3_unlock();
 634                 }
 635         }
 636         else if (!strcmp(argv[optind], "restart"))
 637         {
 638                 if (fw3_lock())
 639                 {
 640                         build_state(true);
 641                         stop(true);
 642                         rv = start();
 643                         fw3_unlock();
 644                 }
 645         }
 646         else if (!strcmp(argv[optind], "reload"))
 647         {
 648                 if (fw3_lock())
 649                 {
 650                         build_state(true);
 651                         rv = reload();
 652                         fw3_unlock();
 653                 }
 654         }
 655         else if (!strcmp(argv[optind], "gc"))
 656         {
 657                 if (fw3_lock())
 658                 {
 659                         rv = gc();
 660                         fw3_unlock();
 661                 }
 662         }
 663         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 664         {
 665                 rv = lookup_network(argv[optind + 1]);
 666         }
 667         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 668         {
 669                 rv = lookup_device(argv[optind + 1]);
 670         }
 671         else if (!strcmp(argv[optind], "zone") && (optind + 1) < argc)
 672         {
 673                 rv = lookup_zone(argv[optind + 1], argv[optind + 2]);
 674         }
 675         else
 676         {
 677                 rv = usage();
 678         }
 679
 680 out:
 681         if (cfg_state)
 682                 free_state(cfg_state);
 683
 684         if (run_state)
 685                 free_state(run_state);
 686
 687         return rv;
 688 }