main.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 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 "forwards.h"
  28 #include "ipsets.h"
  29 #include "includes.h"
  30 #include "ubus.h"
  31 #include "iptables.h"
  32
  33
  34 static bool print_rules = false;
  35
  36 static struct fw3_state *run_state = NULL;
  37 static struct fw3_state *cfg_state = NULL;
  38
  39
  40 static bool
  41 build_state(bool runtime)
  42 {
  43         struct fw3_state *state = NULL;
  44         struct uci_package *p = NULL;
  45         FILE *sf;
  46
  47         state = malloc(sizeof(*state));
  48
  49         if (!state)
  50                 error("Out of memory");
  51
  52         memset(state, 0, sizeof(*state));
  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                         error("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         fw3_load_defaults(state, p);
 101         fw3_load_ipsets(state, p);
 102         fw3_load_zones(state, p);
 103         fw3_load_rules(state, p);
 104         fw3_load_redirects(state, p);
 105         fw3_load_forwards(state, p);
 106         fw3_load_includes(state, p);
 107
 108         return true;
 109 }
 110
 111 static void
 112 free_state(struct fw3_state *state)
 113 {
 114         struct list_head *cur, *tmp;
 115
 116         list_for_each_safe(cur, tmp, &state->zones)
 117                 fw3_free_zone((struct fw3_zone *)cur);
 118
 119         list_for_each_safe(cur, tmp, &state->rules)
 120                 fw3_free_rule((struct fw3_rule *)cur);
 121
 122         list_for_each_safe(cur, tmp, &state->redirects)
 123                 fw3_free_redirect((struct fw3_redirect *)cur);
 124
 125         list_for_each_safe(cur, tmp, &state->forwards)
 126                 fw3_free_forward((struct fw3_forward *)cur);
 127
 128         list_for_each_safe(cur, tmp, &state->ipsets)
 129                 fw3_free_ipset((struct fw3_ipset *)cur);
 130
 131         list_for_each_safe(cur, tmp, &state->includes)
 132                 fw3_free_include((struct fw3_include *)cur);
 133
 134         uci_free_context(state->uci);
 135
 136         free(state);
 137
 138         fw3_ubus_disconnect();
 139 }
 140
 141
 142 static bool
 143 restore_pipe(enum fw3_family family, bool silent)
 144 {
 145         const char *cmd;
 146
 147         cmd = (family == FW3_FAMILY_V4) ? "iptables-restore" : "ip6tables-restore";
 148
 149         if (print_rules)
 150                 return fw3_stdout_pipe();
 151
 152         if (!fw3_command_pipe(silent, cmd, "--lenient", "--noflush"))
 153         {
 154                 warn("Unable to execute %s", cmd);
 155                 return false;
 156         }
 157
 158         return true;
 159 }
 160
 161 static bool
 162 family_running(enum fw3_family family)
 163 {
 164         return (run_state && has(run_state->defaults.flags, family, family));
 165 }
 166
 167 static void
 168 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 169 {
 170         if (!state)
 171                 return;
 172
 173         if (set)
 174                 set(state->defaults.flags, family, family);
 175         else
 176                 del(state->defaults.flags, family, family);
 177 }
 178
 179 static int
 180 stop(bool complete)
 181 {
 182         FILE *ct;
 183
 184         int rv = 1;
 185         enum fw3_family family;
 186         enum fw3_table table;
 187         struct fw3_ipt_handle *handle;
 188
 189         if (!complete && !run_state)
 190         {
 191                 warn("The firewall appears to be stopped. "
 192                          "Use the 'flush' command to forcefully purge all rules.");
 193
 194                 return rv;
 195         }
 196
 197         if (!print_rules && run_state)
 198                 fw3_hotplug_zones(run_state, false);
 199
 200         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 201         {
 202                 if (!complete && !family_running(family))
 203                         continue;
 204
 205                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 206                 {
 207                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 208                                 continue;
 209
 210                         if (!(handle = fw3_ipt_open(family, table)))
 211                                 continue;
 212
 213                         info(" * %sing %s %s table", complete ? "Flush" : "Clear",
 214                              fw3_flag_names[family], fw3_flag_names[table]);
 215
 216                         if (complete)
 217                         {
 218                                 fw3_flush_all(handle);
 219                         }
 220                         else if (run_state)
 221                         {
 222                                 fw3_flush_rules(handle, run_state, false);
 223                                 fw3_flush_zones(handle, run_state, false);
 224                         }
 225
 226                         fw3_ipt_commit(handle);
 227                 }
 228
 229                 family_set(run_state, family, false);
 230                 family_set(cfg_state, family, false);
 231
 232                 rv = 0;
 233         }
 234
 235         if (run_state)
 236         {
 237                 if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 238                 {
 239                         fw3_destroy_ipsets(run_state);
 240                         fw3_command_close();
 241                 }
 242         }
 243
 244         if (complete && (ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 245         {
 246                 info(" * Flushing conntrack table ...");
 247
 248                 fwrite("f\n", 2, 1, ct);
 249                 fclose(ct);
 250         }
 251
 252         if (!rv && run_state)
 253                 fw3_write_statefile(run_state);
 254
 255         return rv;
 256 }
 257
 258 static int
 259 start(void)
 260 {
 261         int rv = 1;
 262         enum fw3_family family;
 263         enum fw3_table table;
 264
 265         if (!print_rules)
 266         {
 267                 if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 268                 {
 269                         fw3_create_ipsets(cfg_state);
 270                         fw3_command_close();
 271                 }
 272         }
 273
 274         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 275         {
 276                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 277                         continue;
 278
 279                 if (!print_rules && family_running(family))
 280                 {
 281                         warn("The %s firewall appears to be started already. "
 282                              "If it is indeed empty, remove the %s file and retry.",
 283                              fw3_flag_names[family], FW3_STATEFILE);
 284
 285                         continue;
 286                 }
 287
 288                 if (!restore_pipe(family, false))
 289                         continue;
 290
 291                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 292                 {
 293                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 294                                 continue;
 295
 296                         info(" * Populating %s %s table",
 297                              fw3_flag_names[family], fw3_flag_names[table]);
 298
 299                         fw3_pr("*%s\n", fw3_flag_names[table]);
 300                         fw3_print_default_chains(cfg_state, family, table, false);
 301                         fw3_print_zone_chains(cfg_state, family, table, false);
 302                         fw3_print_default_head_rules(cfg_state, family, table, false);
 303                         fw3_print_rules(cfg_state, family, table);
 304                         fw3_print_redirects(cfg_state, family, table);
 305                         fw3_print_forwards(cfg_state, family, table);
 306                         fw3_print_zone_rules(cfg_state, family, table, false);
 307                         fw3_print_default_tail_rules(cfg_state, family, table, false);
 308                         fw3_pr("COMMIT\n");
 309                 }
 310
 311                 fw3_print_includes(cfg_state, family, false);
 312
 313                 fw3_command_close();
 314                 family_set(run_state, family, true);
 315                 family_set(cfg_state, family, true);
 316
 317                 rv = 0;
 318         }
 319
 320         if (!rv)
 321         {
 322                 fw3_set_defaults(cfg_state);
 323
 324                 if (!print_rules)
 325                 {
 326                         fw3_run_includes(cfg_state, false);
 327                         fw3_hotplug_zones(cfg_state, true);
 328                         fw3_write_statefile(cfg_state);
 329                 }
 330         }
 331
 332         return rv;
 333 }
 334
 335
 336 static int
 337 reload(void)
 338 {
 339         int rv = 1;
 340         enum fw3_family family;
 341         enum fw3_table table;
 342         struct fw3_ipt_handle *handle;
 343
 344         if (!print_rules && run_state)
 345                 fw3_hotplug_zones(run_state, false);
 346
 347         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 348         {
 349                 if (!family_running(family))
 350                         goto start;
 351
 352                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 353                 {
 354                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 355                                 continue;
 356
 357                         if (!(handle = fw3_ipt_open(family, table)))
 358                                 continue;
 359
 360                         info(" * Clearing %s %s table",
 361                              fw3_flag_names[family], fw3_flag_names[table]);
 362
 363                         if (run_state)
 364                         {
 365                                 fw3_flush_rules(handle, run_state, true);
 366                                 fw3_flush_zones(handle, run_state, true);
 367                         }
 368
 369                         fw3_ipt_commit(handle);
 370                 }
 371
 372                 family_set(run_state, family, false);
 373                 family_set(cfg_state, family, false);
 374
 375 start:
 376                 if (!restore_pipe(family, true))
 377                         continue;
 378
 379                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 380                         goto skip;
 381
 382                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 383                 {
 384                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 385                                 continue;
 386
 387                         info(" * Populating %s %s table",
 388                              fw3_flag_names[family], fw3_flag_names[table]);
 389
 390                         fw3_pr("*%s\n", fw3_flag_names[table]);
 391                         fw3_print_default_chains(cfg_state, family, table, true);
 392                         fw3_print_zone_chains(cfg_state, family, table, true);
 393                         fw3_print_default_head_rules(cfg_state, family, table, true);
 394                         fw3_print_rules(cfg_state, family, table);
 395                         fw3_print_redirects(cfg_state, family, table);
 396                         fw3_print_forwards(cfg_state, family, table);
 397                         fw3_print_zone_rules(cfg_state, family, table, true);
 398                         fw3_print_default_tail_rules(cfg_state, family, table, true);
 399                         fw3_pr("COMMIT\n");
 400                 }
 401
 402                 fw3_print_includes(cfg_state, family, true);
 403
 404                 family_set(run_state, family, true);
 405                 family_set(cfg_state, family, true);
 406
 407                 rv = 0;
 408
 409 skip:
 410                 fw3_command_close();
 411         }
 412
 413         if (!rv)
 414         {
 415                 fw3_set_defaults(cfg_state);
 416
 417                 if (!print_rules)
 418                 {
 419                         fw3_run_includes(cfg_state, true);
 420                         fw3_hotplug_zones(cfg_state, true);
 421                         fw3_write_statefile(cfg_state);
 422                 }
 423         }
 424
 425         return rv;
 426 }
 427
 428 static int
 429 lookup_network(const char *net)
 430 {
 431         struct fw3_zone *z;
 432         struct fw3_device *d;
 433
 434         list_for_each_entry(z, &cfg_state->zones, list)
 435         {
 436                 list_for_each_entry(d, &z->networks, list)
 437                 {
 438                         if (!strcmp(d->name, net))
 439                         {
 440                                 printf("%s\n", z->name);
 441                                 return 0;
 442                         }
 443                 }
 444         }
 445
 446         return 1;
 447 }
 448
 449 static int
 450 lookup_device(const char *dev)
 451 {
 452         struct fw3_zone *z;
 453         struct fw3_device *d;
 454
 455         list_for_each_entry(z, &cfg_state->zones, list)
 456         {
 457                 list_for_each_entry(d, &z->devices, list)
 458                 {
 459                         if (!strcmp(d->name, dev))
 460                         {
 461                                 printf("%s\n", z->name);
 462                                 return 0;
 463                         }
 464                 }
 465         }
 466
 467         return 1;
 468 }
 469
 470 static int
 471 usage(void)
 472 {
 473         fprintf(stderr, "fw3 [-4] [-6] [-q] print\n");
 474         fprintf(stderr, "fw3 [-q] {start|stop|flush|reload|restart}\n");
 475         fprintf(stderr, "fw3 [-q] network {net}\n");
 476         fprintf(stderr, "fw3 [-q] device {dev}\n");
 477
 478         return 1;
 479 }
 480
 481
 482 int main(int argc, char **argv)
 483 {
 484         int ch, rv = 1;
 485         struct fw3_defaults *defs = NULL;
 486         enum fw3_family use_family = FW3_FAMILY_ANY;
 487
 488         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 489         {
 490                 switch (ch)
 491                 {
 492                 case '4':
 493                         use_family = FW3_FAMILY_V4;
 494                         break;
 495
 496                 case '6':
 497                         use_family = FW3_FAMILY_V6;
 498                         break;
 499
 500                 case 'd':
 501                         fw3_pr_debug = true;
 502                         break;
 503
 504                 case 'q':
 505                         freopen("/dev/null", "w", stderr);
 506                         break;
 507
 508                 case 'h':
 509                         rv = usage();
 510                         goto out;
 511                 }
 512         }
 513
 514         build_state(false);
 515         build_state(true);
 516         defs = &cfg_state->defaults;
 517
 518         if (optind >= argc)
 519         {
 520                 rv = usage();
 521                 goto out;
 522         }
 523
 524         if (!strcmp(argv[optind], "print"))
 525         {
 526                 if (use_family == FW3_FAMILY_ANY)
 527                         use_family = FW3_FAMILY_V4;
 528                 else if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 529                         warn("IPv6 rules globally disabled in configuration");
 530
 531                 freopen("/dev/null", "w", stderr);
 532
 533                 cfg_state->disable_ipsets = true;
 534                 print_rules = true;
 535
 536                 rv = start();
 537         }
 538         else if (!strcmp(argv[optind], "start"))
 539         {
 540                 if (fw3_lock())
 541                 {
 542                         rv = start();
 543                         fw3_unlock();
 544                 }
 545         }
 546         else if (!strcmp(argv[optind], "stop"))
 547         {
 548                 if (fw3_lock())
 549                 {
 550                         rv = stop(false);
 551                         fw3_unlock();
 552                 }
 553         }
 554         else if (!strcmp(argv[optind], "flush"))
 555         {
 556                 if (fw3_lock())
 557                 {
 558                         rv = stop(true);
 559                         fw3_unlock();
 560                 }
 561         }
 562         else if (!strcmp(argv[optind], "restart"))
 563         {
 564                 if (fw3_lock())
 565                 {
 566                         stop(true);
 567                         rv = start();
 568                         fw3_unlock();
 569                 }
 570         }
 571         else if (!strcmp(argv[optind], "reload"))
 572         {
 573                 if (fw3_lock())
 574                 {
 575                         rv = reload();
 576                         fw3_unlock();
 577                 }
 578         }
 579         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 580         {
 581                 rv = lookup_network(argv[optind + 1]);
 582         }
 583         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 584         {
 585                 rv = lookup_device(argv[optind + 1]);
 586         }
 587         else
 588         {
 589                 rv = usage();
 590         }
 591
 592 out:
 593         if (cfg_state)
 594                 free_state(cfg_state);
 595
 596         if (run_state)
 597                 free_state(run_state);
 598
 599         return rv;
 600 }