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->running_defaults.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                         family_set(state, family, false);
 223
 224                 rv = 0;
 225         }
 226
 227         if (!reload && fw3_command_pipe(false, "ipset", "-exist", "-"))
 228         {
 229                 fw3_destroy_ipsets(state);
 230                 fw3_command_close();
 231         }
 232
 233         if (complete && (ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 234         {
 235                 info("Flushing conntrack table ...");
 236
 237                 fwrite("f\n", 2, 1, ct);
 238                 fclose(ct);
 239         }
 240
 241         if (!rv)
 242                 fw3_write_statefile(state);
 243
 244         return rv;
 245 }
 246
 247 static int
 248 start(struct fw3_state *state, bool reload)
 249 {
 250         int rv = 1;
 251         enum fw3_family family;
 252         enum fw3_table table;
 253
 254         if (!print_rules && !reload)
 255         {
 256                 fw3_set_defaults(state);
 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 (!reload && !print_rules)
 313                 fw3_run_includes(state);
 314
 315         if (!rv && !print_rules)
 316                 fw3_write_statefile(state);
 317
 318         return rv;
 319 }
 320
 321 static int
 322 lookup_network(struct fw3_state *state, const char *net)
 323 {
 324         struct fw3_zone *z;
 325         struct fw3_device *d;
 326
 327         list_for_each_entry(z, &state->zones, list)
 328         {
 329                 list_for_each_entry(d, &z->networks, list)
 330                 {
 331                         if (!strcmp(d->name, net))
 332                         {
 333                                 printf("%s\n", z->name);
 334                                 return 0;
 335                         }
 336                 }
 337         }
 338
 339         return 1;
 340 }
 341
 342 static int
 343 lookup_device(struct fw3_state *state, const char *dev)
 344 {
 345         struct fw3_zone *z;
 346         struct fw3_device *d;
 347
 348         list_for_each_entry(z, &state->zones, list)
 349         {
 350                 list_for_each_entry(d, &z->devices, list)
 351                 {
 352                         if (!strcmp(d->name, dev))
 353                         {
 354                                 printf("%s\n", z->name);
 355                                 return 0;
 356                         }
 357                 }
 358         }
 359
 360         return 1;
 361 }
 362
 363 static int
 364 usage(void)
 365 {
 366         fprintf(stderr, "fw3 [-4] [-6] [-q] {start|stop|flush|reload|restart|print}\n");
 367         fprintf(stderr, "fw3 [-q] network {net}\n");
 368         fprintf(stderr, "fw3 [-q] device {dev}\n");
 369
 370         return 1;
 371 }
 372
 373
 374 int main(int argc, char **argv)
 375 {
 376         int ch, rv = 1;
 377         struct fw3_state *state = NULL;
 378         struct fw3_defaults *defs = NULL;
 379
 380         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 381         {
 382                 switch (ch)
 383                 {
 384                 case '4':
 385                         use_family = FW3_FAMILY_V4;
 386                         break;
 387
 388                 case '6':
 389                         use_family = FW3_FAMILY_V6;
 390                         break;
 391
 392                 case 'd':
 393                         fw3_pr_debug = true;
 394                         break;
 395
 396                 case 'q':
 397                         freopen("/dev/null", "w", stderr);
 398                         break;
 399
 400                 case 'h':
 401                         rv = usage();
 402                         goto out;
 403                 }
 404         }
 405
 406         state = build_state();
 407         defs = &state->defaults;
 408
 409         if (!fw3_lock())
 410                 goto out;
 411
 412         if (optind >= argc)
 413         {
 414                 rv = usage();
 415                 goto out;
 416         }
 417
 418         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 419                 warn("IPv6 rules globally disabled in configuration");
 420
 421         if (!strcmp(argv[optind], "print"))
 422         {
 423                 if (use_family == FW3_FAMILY_ANY)
 424                         use_family = FW3_FAMILY_V4;
 425
 426                 freopen("/dev/null", "w", stderr);
 427
 428                 state->disable_ipsets = true;
 429                 print_rules = true;
 430
 431                 rv = start(state, false);
 432         }
 433         else if (!strcmp(argv[optind], "start"))
 434         {
 435                 rv = start(state, false);
 436         }
 437         else if (!strcmp(argv[optind], "stop"))
 438         {
 439                 rv = stop(state, false, false);
 440         }
 441         else if (!strcmp(argv[optind], "flush"))
 442         {
 443                 rv = stop(state, true, false);
 444         }
 445         else if (!strcmp(argv[optind], "restart"))
 446         {
 447                 stop(state, true, false);
 448                 free_state(state);
 449
 450                 state = build_state();
 451                 rv = start(state, false);
 452         }
 453         else if (!strcmp(argv[optind], "reload"))
 454         {
 455                 rv = stop(state, false, true);
 456                 rv = start(state, !rv);
 457         }
 458         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 459         {
 460                 rv = lookup_network(state, argv[optind + 1]);
 461         }
 462         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 463         {
 464                 rv = lookup_device(state, argv[optind + 1]);
 465         }
 466         else
 467         {
 468                 rv = usage();
 469         }
 470
 471 out:
 472         if (state)
 473                 free_state(state);
 474
 475         fw3_unlock();
 476
 477         return rv;
 478 }