main.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013-2014 Jo-Philipp Wich <jow@openwrt.org>
   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
  34
  35 static enum fw3_family print_family = FW3_FAMILY_ANY;
  36
  37 static struct fw3_state *run_state = NULL;
  38 static struct fw3_state *cfg_state = NULL;
  39
  40
  41 static bool
  42 build_state(bool runtime)
  43 {
  44         struct fw3_state *state = NULL;
  45         struct uci_package *p = NULL;
  46         FILE *sf;
  47
  48         state = malloc(sizeof(*state));
  49
  50         if (!state)
  51                 error("Out of memory");
  52
  53         memset(state, 0, sizeof(*state));
  54         state->uci = uci_alloc_context();
  55
  56         if (!state->uci)
  57                 error("Out of memory");
  58
  59         if (runtime)
  60         {
  61                 sf = fopen(FW3_STATEFILE, "r");
  62
  63                 if (sf)
  64                 {
  65                         uci_import(state->uci, sf, "fw3_state", &p, true);
  66                         fclose(sf);
  67                 }
  68
  69                 if (!p)
  70                 {
  71                         uci_free_context(state->uci);
  72                         free(state);
  73
  74                         return false;
  75                 }
  76
  77                 state->statefile = true;
  78
  79                 run_state = state;
  80         }
  81         else
  82         {
  83                 if (!fw3_ubus_connect())
  84                         error("Failed to connect to ubus");
  85
  86                 if (uci_load(state->uci, "firewall", &p))
  87                 {
  88                         uci_perror(state->uci, NULL);
  89                         error("Failed to load /etc/config/firewall");
  90                 }
  91
  92                 if (!fw3_find_command("ipset"))
  93                 {
  94                         warn("Unable to locate ipset utility, disabling ipset support");
  95                         state->disable_ipsets = true;
  96                 }
  97
  98                 cfg_state = state;
  99         }
 100
 101
 102         struct blob_buf b = {NULL, NULL, 0, NULL};
 103         fw3_ubus_rules(&b);
 104
 105         fw3_load_defaults(state, p);
 106         fw3_load_ipsets(state, p);
 107         fw3_load_zones(state, p);
 108         fw3_load_rules(state, p, b.head);
 109         fw3_load_redirects(state, p);
 110         fw3_load_snats(state, p, b.head);
 111         fw3_load_forwards(state, p);
 112         fw3_load_includes(state, p);
 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         uci_free_context(state->uci);
 144
 145         free(state);
 146
 147         fw3_ubus_disconnect();
 148 }
 149
 150
 151 static bool
 152 family_running(enum fw3_family family)
 153 {
 154         return (run_state && has(run_state->defaults.flags, family, family));
 155 }
 156
 157 static void
 158 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 159 {
 160         if (!state)
 161                 return;
 162
 163         if (set)
 164                 set(state->defaults.flags, family, family);
 165         else
 166                 del(state->defaults.flags, family, family);
 167 }
 168
 169 static int
 170 stop(bool complete)
 171 {
 172         FILE *ct;
 173
 174         int rv = 1;
 175         enum fw3_family family;
 176         enum fw3_table table;
 177         struct fw3_ipt_handle *handle;
 178
 179         if (!complete && !run_state)
 180         {
 181                 warn("The firewall appears to be stopped. "
 182                          "Use the 'flush' command to forcefully purge all rules.");
 183
 184                 return rv;
 185         }
 186
 187         if (!print_family && run_state)
 188                 fw3_hotplug_zones(run_state, false);
 189
 190         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 191         {
 192                 if (!complete && !family_running(family))
 193                         continue;
 194
 195                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 196                 {
 197                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 198                                 continue;
 199
 200                         if (!(handle = fw3_ipt_open(family, table)))
 201                                 continue;
 202
 203                         info(" * %sing %s %s table", complete ? "Flush" : "Clear",
 204                              fw3_flag_names[family], fw3_flag_names[table]);
 205
 206                         if (complete)
 207                         {
 208                                 fw3_flush_all(handle);
 209                         }
 210                         else if (run_state)
 211                         {
 212                                 fw3_flush_rules(handle, run_state, false);
 213                                 fw3_flush_zones(handle, run_state, false);
 214                         }
 215
 216                         fw3_ipt_commit(handle);
 217                         fw3_ipt_close(handle);
 218                 }
 219
 220                 family_set(run_state, family, false);
 221                 family_set(cfg_state, family, false);
 222
 223                 rv = 0;
 224         }
 225
 226         if (run_state)
 227                 fw3_destroy_ipsets(run_state);
 228
 229         if (complete && (ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 230         {
 231                 info(" * Flushing conntrack table ...");
 232
 233                 fwrite("f\n", 2, 1, ct);
 234                 fclose(ct);
 235         }
 236
 237         if (!rv && run_state)
 238                 fw3_write_statefile(run_state);
 239
 240         return rv;
 241 }
 242
 243 static int
 244 start(void)
 245 {
 246         int rv = 1;
 247         enum fw3_family family;
 248         enum fw3_table table;
 249         struct fw3_ipt_handle *handle;
 250
 251         if (!print_family)
 252                 fw3_create_ipsets(cfg_state);
 253
 254         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 255         {
 256                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 257                         continue;
 258
 259                 if (print_family && family != print_family)
 260                         continue;
 261
 262                 if (!print_family && family_running(family))
 263                 {
 264                         warn("The %s firewall appears to be started already. "
 265                              "If it is indeed empty, remove the %s file and retry.",
 266                              fw3_flag_names[family], FW3_STATEFILE);
 267
 268                         continue;
 269                 }
 270
 271                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 272                 {
 273                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 274                                 continue;
 275
 276                         if (!(handle = fw3_ipt_open(family, table)))
 277                                 continue;
 278
 279                         info(" * Populating %s %s table",
 280                              fw3_flag_names[family], fw3_flag_names[table]);
 281
 282                         fw3_print_default_chains(handle, cfg_state, false);
 283                         fw3_print_zone_chains(handle, cfg_state, false);
 284                         fw3_print_default_head_rules(handle, cfg_state, false);
 285                         fw3_print_rules(handle, cfg_state);
 286                         fw3_print_redirects(handle, cfg_state);
 287                         fw3_print_snats(handle, cfg_state);
 288                         fw3_print_forwards(handle, cfg_state);
 289                         fw3_print_zone_rules(handle, cfg_state, false);
 290                         fw3_print_default_tail_rules(handle, cfg_state, false);
 291
 292                         if (!print_family)
 293                                 fw3_ipt_commit(handle);
 294
 295                         fw3_ipt_close(handle);
 296                 }
 297
 298                 if (!print_family)
 299                         fw3_print_includes(cfg_state, family, false);
 300
 301                 family_set(run_state, family, true);
 302                 family_set(cfg_state, family, true);
 303
 304                 rv = 0;
 305         }
 306
 307         if (!rv)
 308         {
 309                 fw3_set_defaults(cfg_state);
 310
 311                 if (!print_family)
 312                 {
 313                         fw3_run_includes(cfg_state, false);
 314                         fw3_hotplug_zones(cfg_state, true);
 315                         fw3_write_statefile(cfg_state);
 316                 }
 317         }
 318
 319         return rv;
 320 }
 321
 322
 323 static int
 324 reload(void)
 325 {
 326         int rv = 1;
 327         enum fw3_family family;
 328         enum fw3_table table;
 329         struct fw3_ipt_handle *handle;
 330
 331         if (!run_state)
 332                 return start();
 333
 334         fw3_hotplug_zones(run_state, false);
 335
 336         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 337         {
 338                 if (!family_running(family))
 339                         goto start;
 340
 341                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 342                 {
 343                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 344                                 continue;
 345
 346                         if (!(handle = fw3_ipt_open(family, table)))
 347                                 continue;
 348
 349                         info(" * Clearing %s %s table",
 350                              fw3_flag_names[family], fw3_flag_names[table]);
 351
 352                         fw3_flush_rules(handle, run_state, true);
 353                         fw3_flush_zones(handle, run_state, true);
 354                         fw3_ipt_commit(handle);
 355                         fw3_ipt_close(handle);
 356                 }
 357
 358                 family_set(run_state, family, false);
 359                 family_set(cfg_state, family, false);
 360
 361 start:
 362                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 363                         continue;
 364
 365                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 366                 {
 367                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 368                                 continue;
 369
 370                         if (!(handle = fw3_ipt_open(family, table)))
 371                                 continue;
 372
 373                         info(" * Populating %s %s table",
 374                              fw3_flag_names[family], fw3_flag_names[table]);
 375
 376                         fw3_print_default_chains(handle, cfg_state, true);
 377                         fw3_print_zone_chains(handle, cfg_state, true);
 378                         fw3_print_default_head_rules(handle, cfg_state, true);
 379                         fw3_print_rules(handle, cfg_state);
 380                         fw3_print_redirects(handle, cfg_state);
 381                         fw3_print_snats(handle, cfg_state);
 382                         fw3_print_forwards(handle, cfg_state);
 383                         fw3_print_zone_rules(handle, cfg_state, true);
 384                         fw3_print_default_tail_rules(handle, cfg_state, true);
 385
 386                         fw3_ipt_commit(handle);
 387                         fw3_ipt_close(handle);
 388                 }
 389
 390                 fw3_print_includes(cfg_state, family, true);
 391
 392                 family_set(run_state, family, true);
 393                 family_set(cfg_state, family, true);
 394
 395                 rv = 0;
 396         }
 397
 398         if (!rv)
 399         {
 400                 fw3_set_defaults(cfg_state);
 401                 fw3_run_includes(cfg_state, true);
 402                 fw3_hotplug_zones(cfg_state, true);
 403                 fw3_write_statefile(cfg_state);
 404         }
 405
 406         return rv;
 407 }
 408
 409 static int
 410 lookup_network(const char *net)
 411 {
 412         struct fw3_zone *z;
 413         struct fw3_device *d;
 414
 415         list_for_each_entry(z, &cfg_state->zones, list)
 416         {
 417                 list_for_each_entry(d, &z->networks, list)
 418                 {
 419                         if (!strcmp(d->name, net))
 420                         {
 421                                 printf("%s\n", z->name);
 422                                 return 0;
 423                         }
 424                 }
 425         }
 426
 427         return 1;
 428 }
 429
 430 static int
 431 lookup_device(const char *dev)
 432 {
 433         struct fw3_zone *z;
 434         struct fw3_device *d;
 435
 436         list_for_each_entry(z, &cfg_state->zones, list)
 437         {
 438                 list_for_each_entry(d, &z->devices, list)
 439                 {
 440                         if (!strcmp(d->name, dev))
 441                         {
 442                                 printf("%s\n", z->name);
 443                                 return 0;
 444                         }
 445                 }
 446         }
 447
 448         return 1;
 449 }
 450
 451 static int
 452 usage(void)
 453 {
 454         fprintf(stderr, "fw3 [-4] [-6] [-q] print\n");
 455         fprintf(stderr, "fw3 [-q] {start|stop|flush|reload|restart}\n");
 456         fprintf(stderr, "fw3 [-q] network {net}\n");
 457         fprintf(stderr, "fw3 [-q] device {dev}\n");
 458
 459         return 1;
 460 }
 461
 462
 463 int main(int argc, char **argv)
 464 {
 465         int ch, rv = 1;
 466         enum fw3_family family = FW3_FAMILY_ANY;
 467         struct fw3_defaults *defs = NULL;
 468
 469         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 470         {
 471                 switch (ch)
 472                 {
 473                 case '4':
 474                         family = FW3_FAMILY_V4;
 475                         break;
 476
 477                 case '6':
 478                         family = FW3_FAMILY_V6;
 479                         break;
 480
 481                 case 'd':
 482                         fw3_pr_debug = true;
 483                         break;
 484
 485                 case 'q':
 486                         if (freopen("/dev/null", "w", stderr)) {}
 487                         break;
 488
 489                 case 'h':
 490                         rv = usage();
 491                         goto out;
 492                 }
 493         }
 494
 495         build_state(false);
 496         build_state(true);
 497         defs = &cfg_state->defaults;
 498
 499         if (optind >= argc)
 500         {
 501                 rv = usage();
 502                 goto out;
 503         }
 504
 505         if (!strcmp(argv[optind], "print"))
 506         {
 507                 if (family == FW3_FAMILY_ANY)
 508                 {
 509                         family = FW3_FAMILY_V4;
 510                 }
 511                 else if (family == FW3_FAMILY_V6)
 512                 {
 513                         if (defs->disable_ipv6)
 514                                 warn("IPv6 rules globally disabled in configuration");
 515 #ifdef DISABLE_IPV6
 516                         else
 517                                 warn("IPv6 support is not compiled in");
 518 #endif
 519                 }
 520
 521                 if (freopen("/dev/null", "w", stderr)) {};
 522
 523                 cfg_state->disable_ipsets = true;
 524                 print_family = family;
 525                 fw3_pr_debug = true;
 526
 527                 rv = start();
 528         }
 529         else if (!strcmp(argv[optind], "start"))
 530         {
 531                 if (fw3_lock())
 532                 {
 533                         rv = start();
 534                         fw3_unlock();
 535                 }
 536         }
 537         else if (!strcmp(argv[optind], "stop"))
 538         {
 539                 if (fw3_lock())
 540                 {
 541                         rv = stop(false);
 542                         fw3_unlock();
 543                 }
 544         }
 545         else if (!strcmp(argv[optind], "flush"))
 546         {
 547                 if (fw3_lock())
 548                 {
 549                         rv = stop(true);
 550                         fw3_unlock();
 551                 }
 552         }
 553         else if (!strcmp(argv[optind], "restart"))
 554         {
 555                 if (fw3_lock())
 556                 {
 557                         stop(true);
 558                         rv = start();
 559                         fw3_unlock();
 560                 }
 561         }
 562         else if (!strcmp(argv[optind], "reload"))
 563         {
 564                 if (fw3_lock())
 565                 {
 566                         rv = reload();
 567                         fw3_unlock();
 568                 }
 569         }
 570         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 571         {
 572                 rv = lookup_network(argv[optind + 1]);
 573         }
 574         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 575         {
 576                 rv = lookup_device(argv[optind + 1]);
 577         }
 578         else
 579         {
 580                 rv = usage();
 581         }
 582
 583 out:
 584         if (cfg_state)
 585                 free_state(cfg_state);
 586
 587         if (run_state)
 588                 free_state(run_state);
 589
 590         return rv;
 591 }