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 restart)
 164 {
 165         int rv = 1;
 166         enum fw3_family family;
 167         enum fw3_table table;
 168
 169         if (!complete && !state->statefile)
 170         {
 171                 if (!restart)
 172                         warn("The firewall appears to be stopped. "
 173                                  "Use the 'flush' command to forcefully purge all rules.");
 174
 175                 return rv;
 176         }
 177
 178         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 179         {
 180                 if (!complete && !family_running(state, family))
 181                         continue;
 182
 183                 if (!family_used(family) || !restore_pipe(family, true))
 184                         continue;
 185
 186                 info("Removing %s rules ...", fw3_flag_names[family]);
 187
 188                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 189                 {
 190                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 191                                 continue;
 192
 193                         info(" * %sing %s table",
 194                              complete ? "Flush" : "Clear", fw3_flag_names[table]);
 195
 196                         fw3_pr("*%s\n", fw3_flag_names[table]);
 197
 198                         if (complete)
 199                         {
 200                                 fw3_flush_all(table);
 201                         }
 202                         else
 203                         {
 204                                 /* pass 1 */
 205                                 fw3_flush_rules(table, family, false, state);
 206                                 fw3_flush_zones(table, family, false, state);
 207
 208                                 /* pass 2 */
 209                                 fw3_flush_rules(table, family, true, state);
 210                                 fw3_flush_zones(table, family, true, state);
 211                         }
 212
 213                         fw3_pr("COMMIT\n");
 214                 }
 215
 216                 fw3_command_close();
 217
 218                 if (!restart)
 219                         family_set(state, family, false);
 220
 221                 rv = 0;
 222         }
 223
 224         if (!restart && fw3_command_pipe(false, "ipset", "-exist", "-"))
 225         {
 226                 fw3_destroy_ipsets(state);
 227                 fw3_command_close();
 228         }
 229
 230         if (!rv)
 231                 fw3_write_statefile(state);
 232
 233         return rv;
 234 }
 235
 236 static int
 237 start(struct fw3_state *state, bool reload)
 238 {
 239         int rv = 1;
 240         enum fw3_family family;
 241         enum fw3_table table;
 242
 243         if (!print_rules && !reload &&
 244             fw3_command_pipe(false, "ipset", "-exist", "-"))
 245         {
 246                 fw3_create_ipsets(state);
 247                 fw3_command_close();
 248         }
 249
 250         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 251         {
 252                 if (!family_used(family))
 253                         continue;
 254
 255                 if (!print_rules && !reload && family_running(state, family))
 256                 {
 257                         warn("The %s firewall appears to be started already. "
 258                              "If it is indeed empty, remove the %s file and retry.",
 259                              fw3_flag_names[family], FW3_STATEFILE);
 260
 261                         continue;
 262                 }
 263
 264                 if (!family_loaded(state, family) || !restore_pipe(family, false))
 265                         continue;
 266
 267                 info("Constructing %s rules ...", fw3_flag_names[family]);
 268
 269                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 270                 {
 271                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 272                                 continue;
 273
 274                         info(" * Populating %s table", fw3_flag_names[table]);
 275
 276                         fw3_pr("*%s\n", fw3_flag_names[table]);
 277                         fw3_print_default_chains(table, family, state);
 278                         fw3_print_zone_chains(table, family, state);
 279                         fw3_print_default_head_rules(table, family, state);
 280                         fw3_print_rules(table, family, state);
 281                         fw3_print_redirects(table, family, state);
 282                         fw3_print_forwards(table, family, state);
 283                         fw3_print_zone_rules(table, family, state);
 284                         fw3_print_default_tail_rules(table, family, state);
 285                         fw3_pr("COMMIT\n");
 286                 }
 287
 288                 if (!reload)
 289                         fw3_print_includes(family, state);
 290
 291                 fw3_command_close();
 292                 family_set(state, family, true);
 293
 294                 rv = 0;
 295         }
 296
 297         if (!reload && !print_rules)
 298                 fw3_run_includes(state);
 299
 300         if (!rv && !print_rules)
 301                 fw3_write_statefile(state);
 302
 303         return rv;
 304 }
 305
 306 static int
 307 lookup_network(struct fw3_state *state, const char *net)
 308 {
 309         struct fw3_zone *z;
 310         struct fw3_device *d;
 311
 312         list_for_each_entry(z, &state->zones, list)
 313         {
 314                 list_for_each_entry(d, &z->networks, list)
 315                 {
 316                         if (!strcmp(d->name, net))
 317                         {
 318                                 printf("%s\n", z->name);
 319                                 return 0;
 320                         }
 321                 }
 322         }
 323
 324         return 1;
 325 }
 326
 327 static int
 328 lookup_device(struct fw3_state *state, const char *dev)
 329 {
 330         struct fw3_zone *z;
 331         struct fw3_device *d;
 332
 333         list_for_each_entry(z, &state->zones, list)
 334         {
 335                 list_for_each_entry(d, &z->devices, list)
 336                 {
 337                         if (!strcmp(d->name, dev))
 338                         {
 339                                 printf("%s\n", z->name);
 340                                 return 0;
 341                         }
 342                 }
 343         }
 344
 345         return 1;
 346 }
 347
 348 static int
 349 usage(void)
 350 {
 351         fprintf(stderr, "fw3 [-4] [-6] [-q] {start|stop|flush|reload|restart|print}\n");
 352         fprintf(stderr, "fw3 [-q] network {net}\n");
 353         fprintf(stderr, "fw3 [-q] device {dev}\n");
 354
 355         return 1;
 356 }
 357
 358
 359 int main(int argc, char **argv)
 360 {
 361         int ch, rv = 1;
 362         struct fw3_state *state = NULL;
 363         struct fw3_defaults *defs = NULL;
 364
 365         while ((ch = getopt(argc, argv, "46qh")) != -1)
 366         {
 367                 switch (ch)
 368                 {
 369                 case '4':
 370                         use_family = FW3_FAMILY_V4;
 371                         break;
 372
 373                 case '6':
 374                         use_family = FW3_FAMILY_V6;
 375                         break;
 376
 377                 case 'q':
 378                         freopen("/dev/null", "w", stderr);
 379                         break;
 380
 381                 case 'h':
 382                         rv = usage();
 383                         goto out;
 384                 }
 385         }
 386
 387         state = build_state();
 388         defs = &state->defaults;
 389
 390         if (!fw3_lock())
 391                 goto out;
 392
 393         if (optind >= argc)
 394         {
 395                 rv = usage();
 396                 goto out;
 397         }
 398
 399         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 400                 warn("IPv6 rules globally disabled in configuration");
 401
 402         if (!strcmp(argv[optind], "print"))
 403         {
 404                 if (use_family == FW3_FAMILY_ANY)
 405                         use_family = FW3_FAMILY_V4;
 406
 407                 freopen("/dev/null", "w", stderr);
 408
 409                 state->disable_ipsets = true;
 410                 print_rules = true;
 411
 412                 rv = start(state, false);
 413         }
 414         else if (!strcmp(argv[optind], "start"))
 415         {
 416                 rv = start(state, false);
 417         }
 418         else if (!strcmp(argv[optind], "stop"))
 419         {
 420                 rv = stop(state, false, false);
 421         }
 422         else if (!strcmp(argv[optind], "flush"))
 423         {
 424                 rv = stop(state, true, false);
 425         }
 426         else if (!strcmp(argv[optind], "restart"))
 427         {
 428                 stop(state, true, false);
 429                 free_state(state);
 430
 431                 state = build_state();
 432                 rv = start(state, false);
 433         }
 434         else if (!strcmp(argv[optind], "reload"))
 435         {
 436                 rv = stop(state, false, true);
 437                 rv = start(state, !rv);
 438         }
 439         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 440         {
 441                 rv = lookup_network(state, argv[optind + 1]);
 442         }
 443         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 444         {
 445                 rv = lookup_device(state, argv[optind + 1]);
 446         }
 447         else
 448         {
 449                 rv = usage();
 450         }
 451
 452 out:
 453         if (state)
 454                 free_state(state);
 455
 456         fw3_unlock();
 457
 458         return rv;
 459 }