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 static enum fw3_family use_family = FW3_FAMILY_ANY;
  35
  36
  37 static struct fw3_state *
  38 build_state(void)
  39 {
  40         struct fw3_state *state = NULL;
  41         struct uci_package *p = NULL;
  42
  43         if (!fw3_ubus_connect())
  44                 error("Failed to connect to ubus");
  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 (uci_load(state->uci, "firewall", &p))
  58         {
  59                 uci_perror(state->uci, NULL);
  60                 error("Failed to load /etc/config/firewall");
  61         }
  62
  63         if (!fw3_find_command("ipset"))
  64         {
  65                 warn("Unable to locate ipset utility, disabling ipset support");
  66                 state->disable_ipsets = true;
  67         }
  68
  69         INIT_LIST_HEAD(&state->running_zones);
  70         INIT_LIST_HEAD(&state->running_ipsets);
  71
  72         fw3_load_defaults(state, p);
  73         fw3_load_ipsets(state, p);
  74         fw3_load_zones(state, p);
  75         fw3_load_rules(state, p);
  76         fw3_load_redirects(state, p);
  77         fw3_load_forwards(state, p);
  78         fw3_load_includes(state, p);
  79
  80         state->statefile = fw3_read_statefile(state);
  81
  82         return state;
  83 }
  84
  85 static void
  86 free_state(struct fw3_state *state)
  87 {
  88         struct list_head *cur, *tmp;
  89
  90         list_for_each_safe(cur, tmp, &state->zones)
  91                 fw3_free_zone((struct fw3_zone *)cur);
  92
  93         list_for_each_safe(cur, tmp, &state->rules)
  94                 fw3_free_rule((struct fw3_rule *)cur);
  95
  96         list_for_each_safe(cur, tmp, &state->redirects)
  97                 fw3_free_redirect((struct fw3_redirect *)cur);
  98
  99         list_for_each_safe(cur, tmp, &state->forwards)
 100                 fw3_free_forward((struct fw3_forward *)cur);
 101
 102         list_for_each_safe(cur, tmp, &state->ipsets)
 103                 fw3_free_ipset((struct fw3_ipset *)cur);
 104
 105         list_for_each_safe(cur, tmp, &state->includes)
 106                 fw3_free_include((struct fw3_include *)cur);
 107
 108         uci_free_context(state->uci);
 109
 110         free(state);
 111
 112         fw3_ubus_disconnect();
 113 }
 114
 115
 116 static bool
 117 restore_pipe(enum fw3_family family, bool silent)
 118 {
 119         const char *cmd;
 120
 121         cmd = (family == FW3_FAMILY_V4) ? "iptables-restore" : "ip6tables-restore";
 122
 123         if (print_rules)
 124                 return fw3_stdout_pipe();
 125
 126         if (!fw3_command_pipe(silent, cmd, "--lenient", "--noflush"))
 127         {
 128                 warn("Unable to execute %s", cmd);
 129                 return false;
 130         }
 131
 132         return true;
 133 }
 134
 135 static bool
 136 family_running(struct fw3_state *state, enum fw3_family family)
 137 {
 138         return hasbit(state->defaults.running_flags, family);
 139 }
 140
 141 static bool
 142 family_used(enum fw3_family family)
 143 {
 144         return (use_family == FW3_FAMILY_ANY) || (use_family == family);
 145 }
 146
 147 static bool
 148 family_loaded(struct fw3_state *state, enum fw3_family family)
 149 {
 150         return hasbit(state->defaults.flags, family);
 151 }
 152
 153 static void
 154 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 155 {
 156         if (set)
 157                 setbit(state->defaults.flags, family);
 158         else
 159                 delbit(state->defaults.flags, family);
 160 }
 161
 162 static int
 163 stop(struct fw3_state *state, bool complete, bool reload)
 164 {
 165         FILE *ct;
 166
 167         int rv = 1;
 168         enum fw3_family family;
 169         enum fw3_table table;
 170         enum fw3_target policy = reload ? FW3_TARGET_DROP : FW3_TARGET_ACCEPT;
 171
 172         if (!complete && !state->statefile)
 173         {
 174                 if (!reload)
 175                         warn("The firewall appears to be stopped. "
 176                                  "Use the 'flush' command to forcefully purge all rules.");
 177
 178                 return rv;
 179         }
 180
 181         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 182         {
 183                 if (!complete && !family_running(state, family))
 184                         continue;
 185
 186                 if (!family_used(family) || !restore_pipe(family, true))
 187                         continue;
 188
 189                 info("Removing %s rules ...", fw3_flag_names[family]);
 190
 191                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 192                 {
 193                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 194                                 continue;
 195
 196                         info(" * %sing %s table",
 197                              complete ? "Flush" : "Clear", fw3_flag_names[table]);
 198
 199                         fw3_pr("*%s\n", fw3_flag_names[table]);
 200
 201                         if (complete)
 202                         {
 203                                 fw3_flush_all(table);
 204                         }
 205                         else
 206                         {
 207                                 /* pass 1 */
 208                                 fw3_flush_rules(table, family, false, state, policy);
 209                                 fw3_flush_zones(table, family, false, reload, state);
 210
 211                                 /* pass 2 */
 212                                 fw3_flush_rules(table, family, true, state, policy);
 213                                 fw3_flush_zones(table, family, true, reload, state);
 214                         }
 215
 216                         fw3_pr("COMMIT\n");
 217                 }
 218
 219                 fw3_command_close();
 220
 221                 if (!reload)
 222                 {
 223                         if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 224                         {
 225                                 fw3_destroy_ipsets(state, family);
 226                                 fw3_command_close();
 227                         }
 228
 229                         family_set(state, family, false);
 230                 }
 231
 232                 rv = 0;
 233         }
 234
 235         if (complete && (ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 236         {
 237                 info("Flushing conntrack table ...");
 238
 239                 fwrite("f\n", 2, 1, ct);
 240                 fclose(ct);
 241         }
 242
 243         if (!rv)
 244                 fw3_write_statefile(state);
 245
 246         return rv;
 247 }
 248
 249 static int
 250 start(struct fw3_state *state, bool reload)
 251 {
 252         int rv = 1;
 253         enum fw3_family family;
 254         enum fw3_table table;
 255
 256         if (!print_rules && !reload)
 257         {
 258                 if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 259                 {
 260                         fw3_create_ipsets(state);
 261                         fw3_command_close();
 262                 }
 263         }
 264
 265         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 266         {
 267                 if (!family_used(family))
 268                         continue;
 269
 270                 if (!print_rules && !reload && family_running(state, family))
 271                 {
 272                         warn("The %s firewall appears to be started already. "
 273                              "If it is indeed empty, remove the %s file and retry.",
 274                              fw3_flag_names[family], FW3_STATEFILE);
 275
 276                         continue;
 277                 }
 278
 279                 if (!family_loaded(state, family) || !restore_pipe(family, false))
 280                         continue;
 281
 282                 info("Constructing %s rules ...", fw3_flag_names[family]);
 283
 284                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 285                 {
 286                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 287                                 continue;
 288
 289                         info(" * Populating %s table", fw3_flag_names[table]);
 290
 291                         fw3_pr("*%s\n", fw3_flag_names[table]);
 292                         fw3_print_default_chains(table, family, state);
 293                         fw3_print_zone_chains(table, family, state);
 294                         fw3_print_default_head_rules(table, family, state);
 295                         fw3_print_rules(table, family, state);
 296                         fw3_print_redirects(table, family, state);
 297                         fw3_print_forwards(table, family, state);
 298                         fw3_print_zone_rules(table, family, state);
 299                         fw3_print_default_tail_rules(table, family, state);
 300                         fw3_pr("COMMIT\n");
 301                 }
 302
 303                 if (!reload)
 304                         fw3_print_includes(family, state);
 305
 306                 fw3_command_close();
 307                 family_set(state, family, true);
 308
 309                 rv = 0;
 310         }
 311
 312         if (!rv)
 313         {
 314                 fw3_set_defaults(state);
 315
 316                 if (!reload && !print_rules)
 317                         fw3_run_includes(state);
 318
 319                 if (!print_rules)
 320                         fw3_write_statefile(state);
 321         }
 322
 323         return rv;
 324 }
 325
 326 static int
 327 lookup_network(struct fw3_state *state, const char *net)
 328 {
 329         struct fw3_zone *z;
 330         struct fw3_device *d;
 331
 332         list_for_each_entry(z, &state->zones, list)
 333         {
 334                 list_for_each_entry(d, &z->networks, list)
 335                 {
 336                         if (!strcmp(d->name, net))
 337                         {
 338                                 printf("%s\n", z->name);
 339                                 return 0;
 340                         }
 341                 }
 342         }
 343
 344         return 1;
 345 }
 346
 347 static int
 348 lookup_device(struct fw3_state *state, const char *dev)
 349 {
 350         struct fw3_zone *z;
 351         struct fw3_device *d;
 352
 353         list_for_each_entry(z, &state->zones, list)
 354         {
 355                 list_for_each_entry(d, &z->devices, list)
 356                 {
 357                         if (!strcmp(d->name, dev))
 358                         {
 359                                 printf("%s\n", z->name);
 360                                 return 0;
 361                         }
 362                 }
 363         }
 364
 365         return 1;
 366 }
 367
 368 static int
 369 usage(void)
 370 {
 371         fprintf(stderr, "fw3 [-4] [-6] [-q] {start|stop|flush|reload|restart|print}\n");
 372         fprintf(stderr, "fw3 [-q] network {net}\n");
 373         fprintf(stderr, "fw3 [-q] device {dev}\n");
 374
 375         return 1;
 376 }
 377
 378
 379 int main(int argc, char **argv)
 380 {
 381         int ch, rv = 1;
 382         struct fw3_state *state = NULL;
 383         struct fw3_defaults *defs = NULL;
 384
 385         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 386         {
 387                 switch (ch)
 388                 {
 389                 case '4':
 390                         use_family = FW3_FAMILY_V4;
 391                         break;
 392
 393                 case '6':
 394                         use_family = FW3_FAMILY_V6;
 395                         break;
 396
 397                 case 'd':
 398                         fw3_pr_debug = true;
 399                         break;
 400
 401                 case 'q':
 402                         freopen("/dev/null", "w", stderr);
 403                         break;
 404
 405                 case 'h':
 406                         rv = usage();
 407                         goto out;
 408                 }
 409         }
 410
 411         state = build_state();
 412         defs = &state->defaults;
 413
 414         if (!fw3_lock())
 415                 goto out;
 416
 417         if (optind >= argc)
 418         {
 419                 rv = usage();
 420                 goto out;
 421         }
 422
 423         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 424                 warn("IPv6 rules globally disabled in configuration");
 425
 426         if (!strcmp(argv[optind], "print"))
 427         {
 428                 if (use_family == FW3_FAMILY_ANY)
 429                         use_family = FW3_FAMILY_V4;
 430
 431                 freopen("/dev/null", "w", stderr);
 432
 433                 state->disable_ipsets = true;
 434                 print_rules = true;
 435
 436                 rv = start(state, false);
 437         }
 438         else if (!strcmp(argv[optind], "start"))
 439         {
 440                 rv = start(state, false);
 441         }
 442         else if (!strcmp(argv[optind], "stop"))
 443         {
 444                 rv = stop(state, false, false);
 445         }
 446         else if (!strcmp(argv[optind], "flush"))
 447         {
 448                 rv = stop(state, true, false);
 449         }
 450         else if (!strcmp(argv[optind], "restart"))
 451         {
 452                 stop(state, true, false);
 453                 free_state(state);
 454
 455                 state = build_state();
 456                 rv = start(state, false);
 457         }
 458         else if (!strcmp(argv[optind], "reload"))
 459         {
 460                 rv = stop(state, false, true);
 461                 rv = start(state, !rv);
 462         }
 463         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 464         {
 465                 rv = lookup_network(state, argv[optind + 1]);
 466         }
 467         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 468         {
 469                 rv = lookup_device(state, argv[optind + 1]);
 470         }
 471         else
 472         {
 473                 rv = usage();
 474         }
 475
 476 out:
 477         if (state)
 478                 free_state(state);
 479
 480         fw3_unlock();
 481
 482         return rv;
 483 }