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
  32
  33 static bool print_rules = false;
  34
  35 static struct fw3_state *run_state = NULL;
  36 static struct fw3_state *cfg_state = NULL;
  37
  38
  39 static bool
  40 build_state(bool runtime)
  41 {
  42         struct fw3_state *state = NULL;
  43         struct uci_package *p = NULL;
  44         FILE *sf;
  45
  46         state = malloc(sizeof(*state));
  47
  48         if (!state)
  49                 error("Out of memory");
  50
  51         memset(state, 0, sizeof(*state));
  52         state->uci = uci_alloc_context();
  53
  54         if (!state->uci)
  55                 error("Out of memory");
  56
  57         if (runtime)
  58         {
  59                 sf = fopen(FW3_STATEFILE, "r");
  60
  61                 if (sf)
  62                 {
  63                         uci_import(state->uci, sf, "fw3_state", &p, true);
  64                         fclose(sf);
  65                 }
  66
  67                 if (!p)
  68                 {
  69                         uci_free_context(state->uci);
  70                         free(state);
  71
  72                         return false;
  73                 }
  74
  75                 state->statefile = true;
  76
  77                 run_state = state;
  78         }
  79         else
  80         {
  81                 if (!fw3_ubus_connect())
  82                         error("Failed to connect to ubus");
  83
  84                 if (uci_load(state->uci, "firewall", &p))
  85                 {
  86                         uci_perror(state->uci, NULL);
  87                         error("Failed to load /etc/config/firewall");
  88                 }
  89
  90                 if (!fw3_find_command("ipset"))
  91                 {
  92                         warn("Unable to locate ipset utility, disabling ipset support");
  93                         state->disable_ipsets = true;
  94                 }
  95
  96                 cfg_state = state;
  97         }
  98
  99         fw3_load_defaults(state, p);
 100         fw3_load_ipsets(state, p);
 101         fw3_load_zones(state, p);
 102         fw3_load_rules(state, p);
 103         fw3_load_redirects(state, p);
 104         fw3_load_forwards(state, p);
 105         fw3_load_includes(state, p);
 106
 107         return true;
 108 }
 109
 110 static void
 111 free_state(struct fw3_state *state)
 112 {
 113         struct list_head *cur, *tmp;
 114
 115         list_for_each_safe(cur, tmp, &state->zones)
 116                 fw3_free_zone((struct fw3_zone *)cur);
 117
 118         list_for_each_safe(cur, tmp, &state->rules)
 119                 fw3_free_rule((struct fw3_rule *)cur);
 120
 121         list_for_each_safe(cur, tmp, &state->redirects)
 122                 fw3_free_redirect((struct fw3_redirect *)cur);
 123
 124         list_for_each_safe(cur, tmp, &state->forwards)
 125                 fw3_free_forward((struct fw3_forward *)cur);
 126
 127         list_for_each_safe(cur, tmp, &state->ipsets)
 128                 fw3_free_ipset((struct fw3_ipset *)cur);
 129
 130         list_for_each_safe(cur, tmp, &state->includes)
 131                 fw3_free_include((struct fw3_include *)cur);
 132
 133         uci_free_context(state->uci);
 134
 135         free(state);
 136
 137         fw3_ubus_disconnect();
 138 }
 139
 140
 141 static bool
 142 restore_pipe(enum fw3_family family, bool silent)
 143 {
 144         const char *cmd;
 145
 146         cmd = (family == FW3_FAMILY_V4) ? "iptables-restore" : "ip6tables-restore";
 147
 148         if (print_rules)
 149                 return fw3_stdout_pipe();
 150
 151         if (!fw3_command_pipe(silent, cmd, "--lenient", "--noflush"))
 152         {
 153                 warn("Unable to execute %s", cmd);
 154                 return false;
 155         }
 156
 157         return true;
 158 }
 159
 160 static bool
 161 family_running(enum fw3_family family)
 162 {
 163         return (run_state && has(run_state->defaults.flags, family, family));
 164 }
 165
 166 static void
 167 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 168 {
 169         if (!state)
 170                 return;
 171
 172         if (set)
 173                 set(state->defaults.flags, family, family);
 174         else
 175                 del(state->defaults.flags, family, family);
 176 }
 177
 178 static int
 179 stop(bool complete, bool reload)
 180 {
 181         FILE *ct;
 182
 183         int rv = 1;
 184         enum fw3_family family;
 185         enum fw3_table table;
 186
 187         if (!complete && !run_state)
 188         {
 189                 if (!reload)
 190                         warn("The firewall appears to be stopped. "
 191                                  "Use the 'flush' command to forcefully purge all rules.");
 192
 193                 return rv;
 194         }
 195
 196         if (!print_rules && run_state)
 197                 fw3_hotplug_zones(run_state, false);
 198
 199         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 200         {
 201                 if (!complete && !family_running(family))
 202                         continue;
 203
 204                 if (!restore_pipe(family, true))
 205                         continue;
 206
 207                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 208                 {
 209                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 210                                 continue;
 211
 212                         info(" * %sing %s %s table", complete ? "Flush" : "Clear",
 213                              fw3_flag_names[family], fw3_flag_names[table]);
 214
 215                         fw3_pr("*%s\n", fw3_flag_names[table]);
 216
 217                         if (complete)
 218                         {
 219                                 fw3_flush_all(table);
 220                         }
 221                         else if (run_state)
 222                         {
 223                                 /* pass 1 */
 224                                 fw3_flush_rules(run_state, family, table, reload, false);
 225                                 fw3_flush_zones(run_state, family, table, reload, false);
 226
 227                                 /* pass 2 */
 228                                 fw3_flush_rules(run_state, family, table, reload, true);
 229                                 fw3_flush_zones(run_state, family, table, reload, true);
 230                         }
 231
 232                         fw3_pr("COMMIT\n");
 233                 }
 234
 235                 fw3_command_close();
 236                 family_set(run_state, family, false);
 237                 family_set(cfg_state, family, false);
 238
 239                 rv = 0;
 240         }
 241
 242         if (!reload && run_state)
 243         {
 244                 if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 245                 {
 246                         fw3_destroy_ipsets(run_state);
 247                         fw3_command_close();
 248                 }
 249         }
 250
 251         if (complete && (ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 252         {
 253                 info(" * Flushing conntrack table ...");
 254
 255                 fwrite("f\n", 2, 1, ct);
 256                 fclose(ct);
 257         }
 258
 259         if (!rv && run_state)
 260                 fw3_write_statefile(run_state);
 261
 262         return rv;
 263 }
 264
 265 static int
 266 start(bool reload)
 267 {
 268         int rv = 1;
 269         enum fw3_family family;
 270         enum fw3_table table;
 271
 272         if (!print_rules && !reload)
 273         {
 274                 if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 275                 {
 276                         fw3_create_ipsets(cfg_state);
 277                         fw3_command_close();
 278                 }
 279         }
 280
 281         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 282         {
 283                 if (family == FW3_FAMILY_V6 && cfg_state->defaults.disable_ipv6)
 284                         continue;
 285
 286                 if (!print_rules && !reload && family_running(family))
 287                 {
 288                         warn("The %s firewall appears to be started already. "
 289                              "If it is indeed empty, remove the %s file and retry.",
 290                              fw3_flag_names[family], FW3_STATEFILE);
 291
 292                         continue;
 293                 }
 294
 295                 if (!restore_pipe(family, false))
 296                         continue;
 297
 298                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 299                 {
 300                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 301                                 continue;
 302
 303                         info(" * Populating %s %s table",
 304                              fw3_flag_names[family], fw3_flag_names[table]);
 305
 306                         fw3_pr("*%s\n", fw3_flag_names[table]);
 307                         fw3_print_default_chains(cfg_state, family, table, reload);
 308                         fw3_print_zone_chains(cfg_state, family, table, reload);
 309                         fw3_print_default_head_rules(cfg_state, family, table, reload);
 310                         fw3_print_rules(cfg_state, family, table);
 311                         fw3_print_redirects(cfg_state, family, table);
 312                         fw3_print_forwards(cfg_state, family, table);
 313                         fw3_print_zone_rules(cfg_state, family, table, reload);
 314                         fw3_print_default_tail_rules(cfg_state, family, table, reload);
 315                         fw3_pr("COMMIT\n");
 316                 }
 317
 318                 fw3_print_includes(cfg_state, family, reload);
 319
 320                 fw3_command_close();
 321                 family_set(run_state, family, true);
 322                 family_set(cfg_state, family, true);
 323
 324                 rv = 0;
 325         }
 326
 327         if (!rv)
 328         {
 329                 fw3_set_defaults(cfg_state);
 330
 331                 if (!print_rules)
 332                 {
 333                         fw3_run_includes(cfg_state, reload);
 334                         fw3_hotplug_zones(cfg_state, true);
 335                         fw3_write_statefile(cfg_state);
 336                 }
 337         }
 338
 339         return rv;
 340 }
 341
 342 static int
 343 lookup_network(const char *net)
 344 {
 345         struct fw3_zone *z;
 346         struct fw3_device *d;
 347
 348         list_for_each_entry(z, &cfg_state->zones, list)
 349         {
 350                 list_for_each_entry(d, &z->networks, list)
 351                 {
 352                         if (!strcmp(d->name, net))
 353                         {
 354                                 printf("%s\n", z->name);
 355                                 return 0;
 356                         }
 357                 }
 358         }
 359
 360         return 1;
 361 }
 362
 363 static int
 364 lookup_device(const char *dev)
 365 {
 366         struct fw3_zone *z;
 367         struct fw3_device *d;
 368
 369         list_for_each_entry(z, &cfg_state->zones, list)
 370         {
 371                 list_for_each_entry(d, &z->devices, list)
 372                 {
 373                         if (!strcmp(d->name, dev))
 374                         {
 375                                 printf("%s\n", z->name);
 376                                 return 0;
 377                         }
 378                 }
 379         }
 380
 381         return 1;
 382 }
 383
 384 static int
 385 usage(void)
 386 {
 387         fprintf(stderr, "fw3 [-4] [-6] [-q] print\n");
 388         fprintf(stderr, "fw3 [-q] {start|stop|flush|reload|restart}\n");
 389         fprintf(stderr, "fw3 [-q] network {net}\n");
 390         fprintf(stderr, "fw3 [-q] device {dev}\n");
 391
 392         return 1;
 393 }
 394
 395
 396 int main(int argc, char **argv)
 397 {
 398         int ch, rv = 1;
 399         struct fw3_defaults *defs = NULL;
 400         enum fw3_family use_family = FW3_FAMILY_ANY;
 401
 402         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 403         {
 404                 switch (ch)
 405                 {
 406                 case '4':
 407                         use_family = FW3_FAMILY_V4;
 408                         break;
 409
 410                 case '6':
 411                         use_family = FW3_FAMILY_V6;
 412                         break;
 413
 414                 case 'd':
 415                         fw3_pr_debug = true;
 416                         break;
 417
 418                 case 'q':
 419                         freopen("/dev/null", "w", stderr);
 420                         break;
 421
 422                 case 'h':
 423                         rv = usage();
 424                         goto out;
 425                 }
 426         }
 427
 428         build_state(false);
 429         build_state(true);
 430         defs = &cfg_state->defaults;
 431
 432         if (optind >= argc)
 433         {
 434                 rv = usage();
 435                 goto out;
 436         }
 437
 438         if (!strcmp(argv[optind], "print"))
 439         {
 440                 if (use_family == FW3_FAMILY_ANY)
 441                         use_family = FW3_FAMILY_V4;
 442                 else if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 443                         warn("IPv6 rules globally disabled in configuration");
 444
 445                 freopen("/dev/null", "w", stderr);
 446
 447                 cfg_state->disable_ipsets = true;
 448                 print_rules = true;
 449
 450                 rv = start(false);
 451         }
 452         else if (!strcmp(argv[optind], "start"))
 453         {
 454                 if (fw3_lock())
 455                 {
 456                         rv = start(false);
 457                         fw3_unlock();
 458                 }
 459         }
 460         else if (!strcmp(argv[optind], "stop"))
 461         {
 462                 if (fw3_lock())
 463                 {
 464                         rv = stop(false, false);
 465                         fw3_unlock();
 466                 }
 467         }
 468         else if (!strcmp(argv[optind], "flush"))
 469         {
 470                 if (fw3_lock())
 471                 {
 472                         rv = stop(true, false);
 473                         fw3_unlock();
 474                 }
 475         }
 476         else if (!strcmp(argv[optind], "restart"))
 477         {
 478                 if (fw3_lock())
 479                 {
 480                         stop(true, false);
 481                         rv = start(false);
 482
 483                         fw3_unlock();
 484                 }
 485         }
 486         else if (!strcmp(argv[optind], "reload"))
 487         {
 488                 if (fw3_lock())
 489                 {
 490                         rv = stop(false, true);
 491                         rv = start(!rv);
 492
 493                         fw3_unlock();
 494                 }
 495         }
 496         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 497         {
 498                 rv = lookup_network(argv[optind + 1]);
 499         }
 500         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 501         {
 502                 rv = lookup_device(argv[optind + 1]);
 503         }
 504         else
 505         {
 506                 rv = usage();
 507         }
 508
 509 out:
 510         if (cfg_state)
 511                 free_state(cfg_state);
 512
 513         if (run_state)
 514                 free_state(run_state);
 515
 516         return rv;
 517 }