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 restart)
 238 {
 239         int rv = 1;
 240         enum fw3_family family;
 241         enum fw3_table table;
 242
 243         if (!print_rules && !restart &&
 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 && !restart && 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                 fw3_command_close();
 289                 family_set(state, family, true);
 290
 291                 rv = 0;
 292         }
 293
 294         if (!rv && !print_rules)
 295                 fw3_write_statefile(state);
 296
 297         return rv;
 298 }
 299
 300 static int
 301 lookup_network(struct fw3_state *state, const char *net)
 302 {
 303         struct fw3_zone *z;
 304         struct fw3_device *d;
 305
 306         list_for_each_entry(z, &state->zones, list)
 307         {
 308                 list_for_each_entry(d, &z->networks, list)
 309                 {
 310                         if (!strcmp(d->name, net))
 311                         {
 312                                 printf("%s\n", z->name);
 313                                 return 0;
 314                         }
 315                 }
 316         }
 317
 318         return 1;
 319 }
 320
 321 static int
 322 lookup_device(struct fw3_state *state, const char *dev)
 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->devices, list)
 330                 {
 331                         if (!strcmp(d->name, dev))
 332                         {
 333                                 printf("%s\n", z->name);
 334                                 return 0;
 335                         }
 336                 }
 337         }
 338
 339         return 1;
 340 }
 341
 342 static int
 343 usage(void)
 344 {
 345         fprintf(stderr, "fw3 [-4] [-6] [-q] {start|stop|flush|reload|restart|print}\n");
 346         fprintf(stderr, "fw3 [-q] network {net}\n");
 347         fprintf(stderr, "fw3 [-q] device {dev}\n");
 348
 349         return 1;
 350 }
 351
 352
 353 int main(int argc, char **argv)
 354 {
 355         int ch, rv = 1;
 356         struct fw3_state *state = NULL;
 357         struct fw3_defaults *defs = NULL;
 358
 359         while ((ch = getopt(argc, argv, "46qh")) != -1)
 360         {
 361                 switch (ch)
 362                 {
 363                 case '4':
 364                         use_family = FW3_FAMILY_V4;
 365                         break;
 366
 367                 case '6':
 368                         use_family = FW3_FAMILY_V6;
 369                         break;
 370
 371                 case 'q':
 372                         freopen("/dev/null", "w", stderr);
 373                         break;
 374
 375                 case 'h':
 376                         rv = usage();
 377                         goto out;
 378                 }
 379         }
 380
 381         state = build_state();
 382         defs = &state->defaults;
 383
 384         if (!fw3_lock())
 385                 goto out;
 386
 387         if (optind >= argc)
 388         {
 389                 rv = usage();
 390                 goto out;
 391         }
 392
 393         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 394                 warn("IPv6 rules globally disabled in configuration");
 395
 396         if (!strcmp(argv[optind], "print"))
 397         {
 398                 if (use_family == FW3_FAMILY_ANY)
 399                         use_family = FW3_FAMILY_V4;
 400
 401                 freopen("/dev/null", "w", stderr);
 402
 403                 state->disable_ipsets = true;
 404                 print_rules = true;
 405
 406                 rv = start(state, false);
 407         }
 408         else if (!strcmp(argv[optind], "start"))
 409         {
 410                 rv = start(state, false);
 411         }
 412         else if (!strcmp(argv[optind], "stop"))
 413         {
 414                 rv = stop(state, false, false);
 415         }
 416         else if (!strcmp(argv[optind], "flush"))
 417         {
 418                 rv = stop(state, true, false);
 419         }
 420         else if (!strcmp(argv[optind], "restart"))
 421         {
 422                 stop(state, true, false);
 423                 free_state(state);
 424
 425                 state = build_state();
 426                 rv = start(state, false);
 427         }
 428         else if (!strcmp(argv[optind], "reload"))
 429         {
 430                 rv = stop(state, false, true);
 431                 rv = start(state, !rv);
 432         }
 433         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 434         {
 435                 rv = lookup_network(state, argv[optind + 1]);
 436         }
 437         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 438         {
 439                 rv = lookup_device(state, argv[optind + 1]);
 440         }
 441         else
 442         {
 443                 rv = usage();
 444         }
 445
 446 out:
 447         if (state)
 448                 free_state(state);
 449
 450         fw3_unlock();
 451
 452         return rv;
 453 }