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 has(state->defaults.flags, family, 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 void
 148 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 149 {
 150         if (set)
 151                 set(state->defaults.flags, family, family);
 152         else
 153                 del(state->defaults.flags, family, family);
 154 }
 155
 156 static int
 157 stop(struct fw3_state *state, bool complete, bool reload)
 158 {
 159         FILE *ct;
 160
 161         int rv = 1;
 162         enum fw3_family family;
 163         enum fw3_table table;
 164
 165         if (!complete && !state->statefile)
 166         {
 167                 if (!reload)
 168                         warn("The firewall appears to be stopped. "
 169                                  "Use the 'flush' command to forcefully purge all rules.");
 170
 171                 return rv;
 172         }
 173
 174         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 175         {
 176                 if (!complete && !family_running(state, family))
 177                         continue;
 178
 179                 if (!family_used(family) || !restore_pipe(family, true))
 180                         continue;
 181
 182                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 183                 {
 184                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 185                                 continue;
 186
 187                         info(" * %sing %s %s table", complete ? "Flush" : "Clear",
 188                              fw3_flag_names[family], fw3_flag_names[table]);
 189
 190                         fw3_pr("*%s\n", fw3_flag_names[table]);
 191
 192                         if (complete)
 193                         {
 194                                 fw3_flush_all(table);
 195                         }
 196                         else
 197                         {
 198                                 /* pass 1 */
 199                                 fw3_flush_rules(table, family, false, reload, state);
 200                                 fw3_flush_zones(table, family, false, reload, state);
 201
 202                                 /* pass 2 */
 203                                 fw3_flush_rules(table, family, true, reload, state);
 204                                 fw3_flush_zones(table, family, true, reload, state);
 205                         }
 206
 207                         fw3_pr("COMMIT\n");
 208                 }
 209
 210                 fw3_command_close();
 211
 212                 if (!reload)
 213                 {
 214                         if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 215                         {
 216                                 fw3_destroy_ipsets(state, family);
 217                                 fw3_command_close();
 218                         }
 219
 220                         family_set(state, family, false);
 221                 }
 222
 223                 rv = 0;
 224         }
 225
 226         if (complete && (ct = fopen("/proc/net/nf_conntrack", "w")) != NULL)
 227         {
 228                 info(" * Flushing conntrack table ...");
 229
 230                 fwrite("f\n", 2, 1, ct);
 231                 fclose(ct);
 232         }
 233
 234         if (!rv)
 235                 fw3_write_statefile(state);
 236
 237         return rv;
 238 }
 239
 240 static int
 241 start(struct fw3_state *state, bool reload)
 242 {
 243         int rv = 1;
 244         enum fw3_family family;
 245         enum fw3_table table;
 246
 247         if (!print_rules && !reload)
 248         {
 249                 if (fw3_command_pipe(false, "ipset", "-exist", "-"))
 250                 {
 251                         fw3_create_ipsets(state);
 252                         fw3_command_close();
 253                 }
 254         }
 255
 256         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 257         {
 258                 if (!family_used(family))
 259                         continue;
 260
 261                 if (!print_rules && !reload && family_running(state, family))
 262                 {
 263                         warn("The %s firewall appears to be started already. "
 264                              "If it is indeed empty, remove the %s file and retry.",
 265                              fw3_flag_names[family], FW3_STATEFILE);
 266
 267                         continue;
 268                 }
 269
 270                 if (!restore_pipe(family, false))
 271                         continue;
 272
 273                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 274                 {
 275                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 276                                 continue;
 277
 278                         info(" * Populating %s %s table",
 279                              fw3_flag_names[family], fw3_flag_names[table]);
 280
 281                         fw3_pr("*%s\n", fw3_flag_names[table]);
 282                         fw3_print_default_chains(table, family, reload, state);
 283                         fw3_print_zone_chains(table, family, reload, state);
 284                         fw3_print_default_head_rules(table, family, reload, state);
 285                         fw3_print_rules(table, family, state);
 286                         fw3_print_redirects(table, family, state);
 287                         fw3_print_forwards(table, family, state);
 288                         fw3_print_zone_rules(table, family, reload, state);
 289                         fw3_print_default_tail_rules(table, family, reload, state);
 290                         fw3_pr("COMMIT\n");
 291                 }
 292
 293                 if (!reload)
 294                         fw3_print_includes(family, state);
 295
 296                 fw3_command_close();
 297                 family_set(state, family, true);
 298
 299                 rv = 0;
 300         }
 301
 302         if (!rv)
 303         {
 304                 fw3_set_defaults(state);
 305
 306                 if (!reload && !print_rules)
 307                         fw3_run_includes(state);
 308
 309                 if (!print_rules)
 310                         fw3_write_statefile(state);
 311         }
 312
 313         return rv;
 314 }
 315
 316 static int
 317 lookup_network(struct fw3_state *state, const char *net)
 318 {
 319         struct fw3_zone *z;
 320         struct fw3_device *d;
 321
 322         list_for_each_entry(z, &state->zones, list)
 323         {
 324                 list_for_each_entry(d, &z->networks, list)
 325                 {
 326                         if (!strcmp(d->name, net))
 327                         {
 328                                 printf("%s\n", z->name);
 329                                 return 0;
 330                         }
 331                 }
 332         }
 333
 334         return 1;
 335 }
 336
 337 static int
 338 lookup_device(struct fw3_state *state, const char *dev)
 339 {
 340         struct fw3_zone *z;
 341         struct fw3_device *d;
 342
 343         list_for_each_entry(z, &state->zones, list)
 344         {
 345                 list_for_each_entry(d, &z->devices, list)
 346                 {
 347                         if (!strcmp(d->name, dev))
 348                         {
 349                                 printf("%s\n", z->name);
 350                                 return 0;
 351                         }
 352                 }
 353         }
 354
 355         return 1;
 356 }
 357
 358 static int
 359 usage(void)
 360 {
 361         fprintf(stderr, "fw3 [-4] [-6] [-q] {start|stop|flush|reload|restart|print}\n");
 362         fprintf(stderr, "fw3 [-q] network {net}\n");
 363         fprintf(stderr, "fw3 [-q] device {dev}\n");
 364
 365         return 1;
 366 }
 367
 368
 369 int main(int argc, char **argv)
 370 {
 371         int ch, rv = 1;
 372         struct fw3_state *state = NULL;
 373         struct fw3_defaults *defs = NULL;
 374
 375         while ((ch = getopt(argc, argv, "46dqh")) != -1)
 376         {
 377                 switch (ch)
 378                 {
 379                 case '4':
 380                         use_family = FW3_FAMILY_V4;
 381                         break;
 382
 383                 case '6':
 384                         use_family = FW3_FAMILY_V6;
 385                         break;
 386
 387                 case 'd':
 388                         fw3_pr_debug = true;
 389                         break;
 390
 391                 case 'q':
 392                         freopen("/dev/null", "w", stderr);
 393                         break;
 394
 395                 case 'h':
 396                         rv = usage();
 397                         goto out;
 398                 }
 399         }
 400
 401         state = build_state();
 402         defs = &state->defaults;
 403
 404         if (!fw3_lock())
 405                 goto out;
 406
 407         if (optind >= argc)
 408         {
 409                 rv = usage();
 410                 goto out;
 411         }
 412
 413         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 414                 warn("IPv6 rules globally disabled in configuration");
 415
 416         if (!strcmp(argv[optind], "print"))
 417         {
 418                 if (use_family == FW3_FAMILY_ANY)
 419                         use_family = FW3_FAMILY_V4;
 420
 421                 freopen("/dev/null", "w", stderr);
 422
 423                 state->disable_ipsets = true;
 424                 print_rules = true;
 425
 426                 rv = start(state, false);
 427         }
 428         else if (!strcmp(argv[optind], "start"))
 429         {
 430                 rv = start(state, false);
 431         }
 432         else if (!strcmp(argv[optind], "stop"))
 433         {
 434                 rv = stop(state, false, false);
 435         }
 436         else if (!strcmp(argv[optind], "flush"))
 437         {
 438                 rv = stop(state, true, false);
 439         }
 440         else if (!strcmp(argv[optind], "restart"))
 441         {
 442                 stop(state, true, false);
 443                 free_state(state);
 444
 445                 state = build_state();
 446                 rv = start(state, false);
 447         }
 448         else if (!strcmp(argv[optind], "reload"))
 449         {
 450                 rv = stop(state, false, true);
 451                 rv = start(state, !rv);
 452         }
 453         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 454         {
 455                 rv = lookup_network(state, argv[optind + 1]);
 456         }
 457         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 458         {
 459                 rv = lookup_device(state, argv[optind + 1]);
 460         }
 461         else
 462         {
 463                 rv = usage();
 464         }
 465
 466 out:
 467         if (state)
 468                 free_state(state);
 469
 470         fw3_unlock();
 471
 472         return rv;
 473 }