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 "ubus.h"
  30
  31
  32 static bool print_rules = false;
  33 static enum fw3_family use_family = FW3_FAMILY_ANY;
  34
  35 static const char *families[] = {
  36         "(bug)",
  37         "IPv4",
  38         "IPv6",
  39 };
  40
  41 static const char *tables[] = {
  42         "filter",
  43         "nat",
  44         "mangle",
  45         "raw",
  46 };
  47
  48
  49 static struct fw3_state *
  50 build_state(void)
  51 {
  52         struct fw3_state *state = NULL;
  53         struct uci_package *p = NULL;
  54
  55         state = malloc(sizeof(*state));
  56
  57         if (!state)
  58                 error("Out of memory");
  59
  60         memset(state, 0, sizeof(*state));
  61         state->uci = uci_alloc_context();
  62
  63         if (!state->uci)
  64                 error("Out of memory");
  65
  66         if (uci_load(state->uci, "firewall", &p))
  67         {
  68                 uci_perror(state->uci, NULL);
  69                 error("Failed to load /etc/config/firewall");
  70         }
  71
  72         if (!fw3_find_command("ipset"))
  73         {
  74                 warn("Unable to locate ipset utility, disabling ipset support");
  75                 state->disable_ipsets = true;
  76         }
  77
  78         fw3_load_defaults(state, p);
  79         fw3_load_ipsets(state, p);
  80         fw3_load_zones(state, p);
  81         fw3_load_rules(state, p);
  82         fw3_load_redirects(state, p);
  83         fw3_load_forwards(state, p);
  84
  85         return state;
  86 }
  87
  88 static void
  89 free_state(struct fw3_state *state)
  90 {
  91         struct list_head *cur, *tmp;
  92
  93         list_for_each_safe(cur, tmp, &state->zones)
  94                 fw3_free_zone((struct fw3_zone *)cur);
  95
  96         list_for_each_safe(cur, tmp, &state->rules)
  97                 fw3_free_rule((struct fw3_rule *)cur);
  98
  99         list_for_each_safe(cur, tmp, &state->redirects)
 100                 fw3_free_redirect((struct fw3_redirect *)cur);
 101
 102         list_for_each_safe(cur, tmp, &state->forwards)
 103                 fw3_free_forward((struct fw3_forward *)cur);
 104
 105         uci_free_context(state->uci);
 106
 107         free(state);
 108
 109         fw3_ubus_disconnect();
 110 }
 111
 112
 113 static bool
 114 restore_pipe(enum fw3_family family, bool silent)
 115 {
 116         const char *cmd[] = {
 117                 "(bug)",
 118                 "iptables-restore",
 119                 "ip6tables-restore",
 120         };
 121
 122         if (print_rules)
 123                 return fw3_stdout_pipe();
 124
 125         if (!fw3_command_pipe(silent, cmd[family], "--lenient", "--noflush"))
 126         {
 127                 warn("Unable to execute %s", cmd[family]);
 128                 return false;
 129         }
 130
 131         return true;
 132 }
 133
 134 #define family_flag(f) \
 135         (f == FW3_FAMILY_V4 ? FW3_DEFAULT_IPV4_LOADED : FW3_DEFAULT_IPV6_LOADED)
 136
 137 static bool
 138 family_running(struct list_head *statefile, enum fw3_family family)
 139 {
 140         struct fw3_statefile_entry *e;
 141
 142         if (statefile)
 143         {
 144                 list_for_each_entry(e, statefile, list)
 145                 {
 146                         if (e->type != FW3_TYPE_DEFAULTS)
 147                                 continue;
 148
 149                         return hasbit(e->flags[0], family_flag(family));
 150                 }
 151         }
 152
 153         return false;
 154 }
 155
 156 static bool
 157 family_used(enum fw3_family family)
 158 {
 159         return (use_family == FW3_FAMILY_ANY) || (use_family == family);
 160 }
 161
 162 static bool
 163 family_loaded(struct fw3_state *state, enum fw3_family family)
 164 {
 165         return hasbit(state->defaults.has_flag, family_flag(family));
 166 }
 167
 168 static void
 169 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 170 {
 171         if (set)
 172                 setbit(state->defaults.has_flag, family_flag(family));
 173         else
 174                 delbit(state->defaults.has_flag, family_flag(family));
 175 }
 176
 177 static int
 178 stop(struct fw3_state *state, bool complete, bool restart)
 179 {
 180         int rv = 1;
 181         enum fw3_family family;
 182         enum fw3_table table;
 183
 184         struct list_head *statefile = fw3_read_statefile();
 185
 186         if (!complete && !statefile)
 187         {
 188                 if (!restart)
 189                         warn("The firewall appears to be stopped. "
 190                                  "Use the 'flush' command to forcefully purge all rules.");
 191
 192                 return rv;
 193         }
 194
 195         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 196         {
 197                 if (!complete && !family_running(statefile, family))
 198                         continue;
 199
 200                 if (!family_used(family) || !restore_pipe(family, true))
 201                         continue;
 202
 203                 info("Removing %s rules ...", families[family]);
 204
 205                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 206                 {
 207                         if (!fw3_has_table(family == FW3_FAMILY_V6, tables[table]))
 208                                 continue;
 209
 210                         info(" * %sing %s table",
 211                              complete ? "Flush" : "Clear", tables[table]);
 212
 213                         fw3_pr("*%s\n", tables[table]);
 214
 215                         if (complete)
 216                         {
 217                                 fw3_flush_all(table);
 218                         }
 219                         else
 220                         {
 221                                 /* pass 1 */
 222                                 fw3_flush_rules(table, family, false, statefile);
 223                                 fw3_flush_zones(table, family, false, statefile);
 224
 225                                 /* pass 2 */
 226                                 fw3_flush_rules(table, family, true, statefile);
 227                                 fw3_flush_zones(table, family, true, statefile);
 228                         }
 229
 230                         fw3_pr("COMMIT\n");
 231                 }
 232
 233                 fw3_command_close();
 234
 235                 if (!restart)
 236                         family_set(state, family, false);
 237
 238                 rv = 0;
 239         }
 240
 241         if (!restart &&
 242             !family_loaded(state, FW3_FAMILY_V4) &&
 243             !family_loaded(state, FW3_FAMILY_V6) &&
 244             fw3_command_pipe(false, "ipset", "-exist", "-"))
 245         {
 246                 fw3_destroy_ipsets(statefile);
 247                 fw3_command_close();
 248         }
 249
 250         fw3_free_statefile(statefile);
 251
 252         if (!rv)
 253                 fw3_write_statefile(state);
 254
 255         return rv;
 256 }
 257
 258 static int
 259 start(struct fw3_state *state, bool restart)
 260 {
 261         int rv = 1;
 262         enum fw3_family family;
 263         enum fw3_table table;
 264
 265         struct list_head *statefile = fw3_read_statefile();
 266
 267         if (!print_rules && !restart &&
 268             fw3_command_pipe(false, "ipset", "-exist", "-"))
 269         {
 270                 fw3_create_ipsets(state);
 271                 fw3_command_close();
 272         }
 273
 274         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 275         {
 276                 if (!family_used(family))
 277                         continue;
 278
 279                 if (!family_loaded(state, family) || !restore_pipe(family, false))
 280                         continue;
 281
 282                 if (!restart && family_running(statefile, family))
 283                 {
 284                         warn("The %s firewall appears to be started already. "
 285                              "If it is indeed empty, remove the %s file and retry.",
 286                              families[family], FW3_STATEFILE);
 287
 288                         continue;
 289                 }
 290
 291                 info("Constructing %s rules ...", families[family]);
 292
 293                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 294                 {
 295                         if (!fw3_has_table(family == FW3_FAMILY_V6, tables[table]))
 296                                 continue;
 297
 298                         info(" * Populating %s table", tables[table]);
 299
 300                         fw3_pr("*%s\n", tables[table]);
 301                         fw3_print_default_chains(table, family, state);
 302                         fw3_print_zone_chains(table, family, state);
 303                         fw3_print_default_head_rules(table, family, state);
 304                         fw3_print_rules(table, family, state);
 305                         fw3_print_redirects(table, family, state);
 306                         fw3_print_forwards(table, family, state);
 307                         fw3_print_zone_rules(table, family, state);
 308                         fw3_print_default_tail_rules(table, family, state);
 309                         fw3_pr("COMMIT\n");
 310                 }
 311
 312                 fw3_command_close();
 313                 family_set(state, family, true);
 314
 315                 rv = 0;
 316         }
 317
 318         fw3_free_statefile(statefile);
 319
 320         if (!rv)
 321                 fw3_write_statefile(state);
 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|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, "46qh")) != -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 'q':
 398                         freopen("/dev/null", "w", stderr);
 399                         break;
 400
 401                 case 'h':
 402                         rv = usage();
 403                         goto out;
 404                 }
 405         }
 406
 407         if (!fw3_ubus_connect())
 408                 error("Failed to connect to ubus");
 409
 410         state = build_state();
 411         defs = &state->defaults;
 412
 413         if (!fw3_lock())
 414                 goto out;
 415
 416         if (optind >= argc)
 417         {
 418                 rv = usage();
 419                 goto out;
 420         }
 421
 422         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 423                 warn("IPv6 rules globally disabled in configuration");
 424
 425         if (!strcmp(argv[optind], "print"))
 426         {
 427                 freopen("/dev/null", "w", stderr);
 428
 429                 state->disable_ipsets = true;
 430                 print_rules = true;
 431
 432                 rv = start(state, false);
 433         }
 434         else if (!strcmp(argv[optind], "start"))
 435         {
 436                 rv = start(state, false);
 437         }
 438         else if (!strcmp(argv[optind], "stop"))
 439         {
 440                 rv = stop(state, false, false);
 441         }
 442         else if (!strcmp(argv[optind], "flush"))
 443         {
 444                 rv = stop(state, true, false);
 445         }
 446         else if (!strcmp(argv[optind], "restart"))
 447         {
 448                 rv = stop(state, false, true);
 449                 rv = start(state, !rv);
 450         }
 451         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 452         {
 453                 rv = lookup_network(state, argv[optind + 1]);
 454         }
 455         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 456         {
 457                 rv = lookup_device(state, argv[optind + 1]);
 458         }
 459         else
 460         {
 461                 rv = usage();
 462         }
 463
 464 out:
 465         if (state)
 466                 free_state(state);
 467
 468         fw3_unlock();
 469
 470         return rv;
 471 }