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 (!(handle = fw3_ipt_open(family, table)))
 199                                 continue;
 200
 201                         info(" * %sing %s %s table", complete ? "Flush" : "Clear",
 202                              fw3_flag_names[family], fw3_flag_names[table]);
 203
 204                         if (complete)
 205                         {
 206                                 fw3_flush_all(handle);
 207                         }
 208                         else if (run_state)
 209                         {
 210                                 fw3_flush_rules(handle, run_state, false);
 211                                 fw3_flush_zones(handle, run_state, false);
 212                         }
 213
 214                         fw3_ipt_commit(handle);
 215                         fw3_ipt_close(handle);
 216                 }
 217
 218                 family_set(run_state, family, false);
 219                 family_set(cfg_state, family, false);
 220
 221                 rv = 0;
 222         }
 223
 224         if (run_state) {
 225                 for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 226                         fw3_destroy_ipsets(run_state, family, false);
 227         }
 228
 229         if (complete)
 230                 fw3_flush_conntrack(NULL);
 231
 232         if (!rv && run_state)
 233                 fw3_write_statefile(run_state);
 234
 235         return rv;
 236 }
 237
 238 static int
 239 start(void)
 240 {
 241         int rv = 1;
 242         enum fw3_family family;
 243         enum fw3_table table;
 244         struct fw3_ipt_handle *handle;
 245
 246         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 247         {
 248                 if (!print_family)
 249                         fw3_create_ipsets(cfg_state, family, false);
 250
 251                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 252                         continue;
 253
 254                 if (print_family && family != print_family)
 255                         continue;
 256
 257                 if (!print_family && family_running(family))
 258                 {
 259                         warn("The %s firewall appears to be started already. "
 260                              "If it is indeed empty, remove the %s file and retry.",
 261                              fw3_flag_names[family], FW3_STATEFILE);
 262
 263                         continue;
 264                 }
 265
 266                 /* Linux 5.15+: make sure the tables are loaded and
 267                  * /proc/net/ip{,6}_tables_names are thus populated.
 268                  */
 269                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 270                 {
 271                         if (!(handle = fw3_ipt_open(family, table)))
 272                                 continue;
 273
 274                         fw3_ipt_close(handle);
 275                 }
 276
 277                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 278                 {
 279                         if (!(handle = fw3_ipt_open(family, table)))
 280                                 continue;
 281
 282                         info(" * Populating %s %s table",
 283                              fw3_flag_names[family], fw3_flag_names[table]);
 284
 285                         fw3_print_default_chains(handle, cfg_state, false);
 286                         fw3_print_zone_chains(handle, cfg_state, false);
 287                         fw3_print_default_head_rules(handle, cfg_state, false);
 288                         fw3_print_rules(handle, cfg_state);
 289                         fw3_print_redirects(handle, cfg_state);
 290                         fw3_print_snats(handle, cfg_state);
 291                         fw3_print_forwards(handle, cfg_state);
 292                         fw3_print_zone_rules(handle, cfg_state, false);
 293                         fw3_print_default_tail_rules(handle, cfg_state, false);
 294
 295                         if (!print_family)
 296                                 fw3_ipt_commit(handle);
 297
 298                         fw3_ipt_close(handle);
 299                 }
 300
 301                 if (!print_family)
 302                         fw3_print_includes(cfg_state, family, false);
 303
 304                 family_set(run_state, family, true);
 305                 family_set(cfg_state, family, true);
 306
 307                 rv = 0;
 308         }
 309
 310         if (!rv)
 311         {
 312                 fw3_flush_conntrack(run_state);
 313                 fw3_set_defaults(cfg_state);
 314
 315                 if (!print_family)
 316                 {
 317                         fw3_run_includes(cfg_state, false);
 318                         fw3_hotplug_zones(cfg_state, true);
 319                         fw3_write_statefile(cfg_state);
 320                 }
 321         }
 322
 323         return rv;
 324 }
 325
 326
 327 static int
 328 reload(void)
 329 {
 330         int rv = 1;
 331         enum fw3_family family;
 332         enum fw3_table table;
 333         struct fw3_ipt_handle *handle;
 334
 335         if (!run_state)
 336                 return start();
 337
 338         fw3_hotplug_zones(run_state, false);
 339
 340         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 341         {
 342                 if (!family_running(family))
 343                         goto start;
 344
 345                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 346                 {
 347                         if (!(handle = fw3_ipt_open(family, table)))
 348                                 continue;
 349
 350                         info(" * Clearing %s %s table",
 351                              fw3_flag_names[family], fw3_flag_names[table]);
 352
 353                         fw3_flush_rules(handle, run_state, true);
 354                         fw3_flush_zones(handle, run_state, true);
 355                         fw3_ipt_commit(handle);
 356                         fw3_ipt_close(handle);
 357                 }
 358
 359                 fw3_ipsets_update_run_state(family, run_state, cfg_state);
 360                 fw3_destroy_ipsets(run_state, family, true);
 361
 362                 family_set(run_state, family, false);
 363                 family_set(cfg_state, family, false);
 364
 365 start:
 366                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 367                         continue;
 368
 369                 fw3_create_ipsets(cfg_state, family, true);
 370
 371                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 372                 {
 373                         if (!(handle = fw3_ipt_open(family, table)))
 374                                 continue;
 375
 376                         info(" * Populating %s %s table",
 377                              fw3_flag_names[family], fw3_flag_names[table]);
 378
 379                         fw3_print_default_chains(handle, cfg_state, true);
 380                         fw3_print_zone_chains(handle, cfg_state, true);
 381                         fw3_print_default_head_rules(handle, cfg_state, true);
 382                         fw3_print_rules(handle, cfg_state);
 383                         fw3_print_redirects(handle, cfg_state);
 384                         fw3_print_snats(handle, cfg_state);
 385                         fw3_print_forwards(handle, cfg_state);
 386                         fw3_print_zone_rules(handle, cfg_state, true);
 387                         fw3_print_default_tail_rules(handle, cfg_state, true);
 388
 389                         fw3_ipt_commit(handle);
 390                         fw3_ipt_close(handle);
 391                 }
 392
 393                 fw3_print_includes(cfg_state, family, true);
 394
 395                 family_set(run_state, family, true);
 396                 family_set(cfg_state, family, true);
 397
 398                 rv = 0;
 399         }
 400
 401         if (!rv)
 402         {
 403                 fw3_flush_conntrack(run_state);
 404
 405                 fw3_set_defaults(cfg_state);
 406                 fw3_run_includes(cfg_state, true);
 407                 fw3_hotplug_zones(cfg_state, true);
 408                 fw3_write_statefile(cfg_state);
 409         }
 410
 411         return rv;
 412 }
 413
 414 static int
 415 gc(void)
 416 {
 417         enum fw3_family family;
 418         enum fw3_table table;
 419         struct fw3_ipt_handle *handle;
 420
 421         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 422         {
 423                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 424                         continue;
 425
 426                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 427                 {
 428                         if (!(handle = fw3_ipt_open(family, table)))
 429                                 continue;
 430
 431                         fw3_ipt_gc(handle);
 432                         fw3_ipt_commit(handle);
 433                         fw3_ipt_close(handle);
 434                 }
 435         }
 436
 437         return 0;
 438 }
 439
 440 static int
 441 lookup_network(const char *net)
 442 {
 443         struct fw3_zone *z;
 444         struct fw3_device *d;
 445
 446         list_for_each_entry(z, &cfg_state->zones, list)
 447         {
 448                 list_for_each_entry(d, &z->networks, list)
 449                 {
 450                         if (!strcmp(d->name, net))
 451                         {
 452                                 printf("%s\n", z->name);
 453                                 return 0;
 454                         }
 455                 }
 456         }
 457
 458         return 1;
 459 }
 460
 461 static int
 462 lookup_device(const char *dev)
 463 {
 464         struct fw3_zone *z;
 465         struct fw3_device *d;
 466
 467         list_for_each_entry(z, &cfg_state->zones, list)
 468         {
 469                 list_for_each_entry(d, &z->devices, list)
 470                 {
 471                         if (!strcmp(d->name, dev))
 472                         {
 473                                 printf("%s\n", z->name);
 474                                 return 0;
 475                         }
 476                 }
 477         }
 478
 479         return 1;
 480 }
 481
 482 static int
 483 lookup_zone(const char *zone, const char *device)
 484 {
 485         struct fw3_zone *z;
 486         struct fw3_device *d;
 487
 488         list_for_each_entry(z, &cfg_state->zones, list)
 489         {
 490                 if (strcmp(z->name, zone))
 491                         continue;
 492
 493                 list_for_each_entry(d, &z->devices, list)
 494                 {
 495                         if (device && strcmp(device, d->name))
 496                                 continue;
 497
 498                         printf("%s\n", d->name);
 499
 500                         if (device)
 501                                 return 0;
 502                 }
 503
 504                 if (!device)
 505                         return 0;
 506         }
 507
 508         return 1;
 509 }
 510
 511 static int
 512 usage(void)
 513 {
 514         fprintf(stderr, "fw3 [-4] [-6] [-q] print\n");
 515         fprintf(stderr, "fw3 [-q] {start|stop|flush|reload|restart}\n");
 516         fprintf(stderr, "fw3 [-q] network {net}\n");
 517         fprintf(stderr, "fw3 [-q] device {dev}\n");
 518         fprintf(stderr, "fw3 [-q] zone {zone} [dev]\n");
 519
 520         return 1;
 521 }
 522
 523
 524 int main(int argc, char **argv)
 525 {
 526         int ch, rv = 1;
 527         enum fw3_family family = FW3_FAMILY_ANY;
 528         struct fw3_defaults *defs = NULL;
 529
 530         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 531         {
 532                 switch (ch)
 533                 {
 534                 case '4':
 535                         family = FW3_FAMILY_V4;
 536                         break;
 537
 538                 case '6':
 539                         family = FW3_FAMILY_V6;
 540                         break;
 541
 542                 case 'd':
 543                         fw3_pr_debug = true;
 544                         break;
 545
 546                 case 'q':
 547                         if (freopen("/dev/null", "w", stderr)) {}
 548                         break;
 549
 550                 case 'h':
 551                         rv = usage();
 552                         goto out;
 553                 }
 554         }
 555
 556         build_state(false);
 557         defs = &cfg_state->defaults;
 558
 559         if (optind >= argc)
 560         {
 561                 rv = usage();
 562                 goto out;
 563         }
 564
 565         if (!strcmp(argv[optind], "print"))
 566         {
 567                 if (family == FW3_FAMILY_ANY)
 568                 {
 569                         family = FW3_FAMILY_V4;
 570                 }
 571                 else if (family == FW3_FAMILY_V6)
 572                 {
 573                         if (defs->disable_ipv6)
 574                                 warn("IPv6 rules globally disabled in configuration");
 575 #ifdef DISABLE_IPV6
 576                         else
 577                                 warn("IPv6 support is not compiled in");
 578 #endif
 579                 }
 580
 581                 if (freopen("/dev/null", "w", stderr)) {};
 582
 583                 cfg_state->disable_ipsets = true;
 584                 print_family = family;
 585                 fw3_pr_debug = true;
 586
 587                 if (fw3_lock())
 588                 {
 589                         build_state(true);
 590                         rv = start();
 591                         fw3_unlock();
 592                 }
 593         }
 594         else if (!strcmp(argv[optind], "start"))
 595         {
 596                 if (fw3_lock())
 597                 {
 598                         build_state(true);
 599                         rv = start();
 600                         fw3_unlock();
 601                 }
 602         }
 603         else if (!strcmp(argv[optind], "stop"))
 604         {
 605                 if (fw3_lock())
 606                 {
 607                         build_state(true);
 608                         rv = stop(false);
 609                         fw3_unlock();
 610                 }
 611         }
 612         else if (!strcmp(argv[optind], "flush"))
 613         {
 614                 if (fw3_lock())
 615                 {
 616                         build_state(true);
 617                         rv = stop(true);
 618                         fw3_unlock();
 619                 }
 620         }
 621         else if (!strcmp(argv[optind], "restart"))
 622         {
 623                 if (fw3_lock())
 624                 {
 625                         build_state(true);
 626                         stop(true);
 627                         rv = start();
 628                         fw3_unlock();
 629                 }
 630         }
 631         else if (!strcmp(argv[optind], "reload"))
 632         {
 633                 if (fw3_lock())
 634                 {
 635                         build_state(true);
 636                         rv = reload();
 637                         fw3_unlock();
 638                 }
 639         }
 640         else if (!strcmp(argv[optind], "gc"))
 641         {
 642                 if (fw3_lock())
 643                 {
 644                         rv = gc();
 645                         fw3_unlock();
 646                 }
 647         }
 648         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 649         {
 650                 rv = lookup_network(argv[optind + 1]);
 651         }
 652         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 653         {
 654                 rv = lookup_device(argv[optind + 1]);
 655         }
 656         else if (!strcmp(argv[optind], "zone") && (optind + 1) < argc)
 657         {
 658                 rv = lookup_zone(argv[optind + 1], argv[optind + 2]);
 659         }
 660         else
 661         {
 662                 rv = usage();
 663         }
 664
 665 out:
 666         if (cfg_state)
 667                 free_state(cfg_state);
 668
 669         if (run_state)
 670                 free_state(run_state);
 671
 672         return rv;
 673 }