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
  36 static struct fw3_state *
  37 build_state(void)
  38 {
  39         struct fw3_state *state = NULL;
  40         struct uci_package *p = NULL;
  41
  42         state = malloc(sizeof(*state));
  43
  44         if (!state)
  45                 error("Out of memory");
  46
  47         memset(state, 0, sizeof(*state));
  48         state->uci = uci_alloc_context();
  49
  50         if (!state->uci)
  51                 error("Out of memory");
  52
  53         if (uci_load(state->uci, "firewall", &p))
  54         {
  55                 uci_perror(state->uci, NULL);
  56                 error("Failed to load /etc/config/firewall");
  57         }
  58
  59         if (!fw3_find_command("ipset"))
  60         {
  61                 warn("Unable to locate ipset utility, disabling ipset support");
  62                 state->disable_ipsets = true;
  63         }
  64
  65         fw3_load_defaults(state, p);
  66         fw3_load_ipsets(state, p);
  67         fw3_load_zones(state, p);
  68         fw3_load_rules(state, p);
  69         fw3_load_redirects(state, p);
  70         fw3_load_forwards(state, p);
  71
  72         return state;
  73 }
  74
  75 static void
  76 free_state(struct fw3_state *state)
  77 {
  78         struct list_head *cur, *tmp;
  79
  80         list_for_each_safe(cur, tmp, &state->zones)
  81                 fw3_free_zone((struct fw3_zone *)cur);
  82
  83         list_for_each_safe(cur, tmp, &state->rules)
  84                 fw3_free_rule((struct fw3_rule *)cur);
  85
  86         list_for_each_safe(cur, tmp, &state->redirects)
  87                 fw3_free_redirect((struct fw3_redirect *)cur);
  88
  89         list_for_each_safe(cur, tmp, &state->forwards)
  90                 fw3_free_forward((struct fw3_forward *)cur);
  91
  92         uci_free_context(state->uci);
  93
  94         free(state);
  95
  96         fw3_ubus_disconnect();
  97 }
  98
  99
 100 static bool
 101 restore_pipe(enum fw3_family family, bool silent)
 102 {
 103         const char *cmd;
 104
 105         cmd = (family == FW3_FAMILY_V4) ? "iptables-restore" : "ip6tables-restore";
 106
 107         if (print_rules)
 108                 return fw3_stdout_pipe();
 109
 110         if (!fw3_command_pipe(silent, cmd, "--lenient", "--noflush"))
 111         {
 112                 warn("Unable to execute %s", cmd);
 113                 return false;
 114         }
 115
 116         return true;
 117 }
 118
 119 static bool
 120 family_running(struct list_head *statefile, enum fw3_family family)
 121 {
 122         struct fw3_statefile_entry *e;
 123
 124         if (statefile)
 125         {
 126                 list_for_each_entry(e, statefile, list)
 127                 {
 128                         if (e->type != FW3_TYPE_DEFAULTS)
 129                                 continue;
 130
 131                         return hasbit(e->flags[0], family);
 132                 }
 133         }
 134
 135         return false;
 136 }
 137
 138 static bool
 139 family_used(enum fw3_family family)
 140 {
 141         return (use_family == FW3_FAMILY_ANY) || (use_family == family);
 142 }
 143
 144 static bool
 145 family_loaded(struct fw3_state *state, enum fw3_family family)
 146 {
 147         return hasbit(state->defaults.flags, family);
 148 }
 149
 150 static void
 151 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 152 {
 153         if (set)
 154                 setbit(state->defaults.flags, family);
 155         else
 156                 delbit(state->defaults.flags, family);
 157 }
 158
 159 static int
 160 stop(struct fw3_state *state, bool complete, bool restart)
 161 {
 162         int rv = 1;
 163         enum fw3_family family;
 164         enum fw3_table table;
 165
 166         struct list_head *statefile = fw3_read_statefile();
 167
 168         if (!complete && !statefile)
 169         {
 170                 if (!restart)
 171                         warn("The firewall appears to be stopped. "
 172                                  "Use the 'flush' command to forcefully purge all rules.");
 173
 174                 return rv;
 175         }
 176
 177         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 178         {
 179                 if (!complete && !family_running(statefile, family))
 180                         continue;
 181
 182                 if (!family_used(family) || !restore_pipe(family, true))
 183                         continue;
 184
 185                 info("Removing %s rules ...", fw3_flag_names[family]);
 186
 187                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 188                 {
 189                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 190                                 continue;
 191
 192                         info(" * %sing %s table",
 193                              complete ? "Flush" : "Clear", fw3_flag_names[table]);
 194
 195                         fw3_pr("*%s\n", fw3_flag_names[table]);
 196
 197                         if (complete)
 198                         {
 199                                 fw3_flush_all(table);
 200                         }
 201                         else
 202                         {
 203                                 /* pass 1 */
 204                                 fw3_flush_rules(table, family, false, statefile);
 205                                 fw3_flush_zones(table, family, false, statefile);
 206
 207                                 /* pass 2 */
 208                                 fw3_flush_rules(table, family, true, statefile);
 209                                 fw3_flush_zones(table, family, true, statefile);
 210                         }
 211
 212                         fw3_pr("COMMIT\n");
 213                 }
 214
 215                 fw3_command_close();
 216
 217                 if (!restart)
 218                         family_set(state, family, false);
 219
 220                 rv = 0;
 221         }
 222
 223         if (!restart &&
 224             !family_loaded(state, FW3_FAMILY_V4) &&
 225             !family_loaded(state, FW3_FAMILY_V6) &&
 226             fw3_command_pipe(false, "ipset", "-exist", "-"))
 227         {
 228                 fw3_destroy_ipsets(statefile);
 229                 fw3_command_close();
 230         }
 231
 232         fw3_free_statefile(statefile);
 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 restart)
 242 {
 243         int rv = 1;
 244         enum fw3_family family;
 245         enum fw3_table table;
 246
 247         struct list_head *statefile = fw3_read_statefile();
 248
 249         if (!print_rules && !restart &&
 250             fw3_command_pipe(false, "ipset", "-exist", "-"))
 251         {
 252                 fw3_create_ipsets(state);
 253                 fw3_command_close();
 254         }
 255
 256         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 257         {
 258                 if (!family_used(family))
 259                         continue;
 260
 261                 if (!family_loaded(state, family) || !restore_pipe(family, false))
 262                         continue;
 263
 264                 if (!restart && family_running(statefile, family))
 265                 {
 266                         warn("The %s firewall appears to be started already. "
 267                              "If it is indeed empty, remove the %s file and retry.",
 268                              fw3_flag_names[family], FW3_STATEFILE);
 269
 270                         continue;
 271                 }
 272
 273                 info("Constructing %s rules ...", fw3_flag_names[family]);
 274
 275                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 276                 {
 277                         if (!fw3_has_table(family == FW3_FAMILY_V6, fw3_flag_names[table]))
 278                                 continue;
 279
 280                         info(" * Populating %s table", fw3_flag_names[table]);
 281
 282                         fw3_pr("*%s\n", fw3_flag_names[table]);
 283                         fw3_print_default_chains(table, family, state);
 284                         fw3_print_zone_chains(table, family, state);
 285                         fw3_print_default_head_rules(table, family, state);
 286                         fw3_print_rules(table, family, state);
 287                         fw3_print_redirects(table, family, state);
 288                         fw3_print_forwards(table, family, state);
 289                         fw3_print_zone_rules(table, family, state);
 290                         fw3_print_default_tail_rules(table, family, state);
 291                         fw3_pr("COMMIT\n");
 292                 }
 293
 294                 fw3_command_close();
 295                 family_set(state, family, true);
 296
 297                 rv = 0;
 298         }
 299
 300         fw3_free_statefile(statefile);
 301
 302         if (!rv)
 303                 fw3_write_statefile(state);
 304
 305         return rv;
 306 }
 307
 308 static int
 309 lookup_network(struct fw3_state *state, const char *net)
 310 {
 311         struct fw3_zone *z;
 312         struct fw3_device *d;
 313
 314         list_for_each_entry(z, &state->zones, list)
 315         {
 316                 list_for_each_entry(d, &z->networks, list)
 317                 {
 318                         if (!strcmp(d->name, net))
 319                         {
 320                                 printf("%s\n", z->name);
 321                                 return 0;
 322                         }
 323                 }
 324         }
 325
 326         return 1;
 327 }
 328
 329 static int
 330 lookup_device(struct fw3_state *state, const char *dev)
 331 {
 332         struct fw3_zone *z;
 333         struct fw3_device *d;
 334
 335         list_for_each_entry(z, &state->zones, list)
 336         {
 337                 list_for_each_entry(d, &z->devices, list)
 338                 {
 339                         if (!strcmp(d->name, dev))
 340                         {
 341                                 printf("%s\n", z->name);
 342                                 return 0;
 343                         }
 344                 }
 345         }
 346
 347         return 1;
 348 }
 349
 350 static int
 351 usage(void)
 352 {
 353         fprintf(stderr, "fw3 [-4] [-6] [-q] {start|stop|flush|restart|print}\n");
 354         fprintf(stderr, "fw3 [-q] network {net}\n");
 355         fprintf(stderr, "fw3 [-q] device {dev}\n");
 356
 357         return 1;
 358 }
 359
 360
 361 int main(int argc, char **argv)
 362 {
 363         int ch, rv = 1;
 364         struct fw3_state *state = NULL;
 365         struct fw3_defaults *defs = NULL;
 366
 367         while ((ch = getopt(argc, argv, "46qh")) != -1)
 368         {
 369                 switch (ch)
 370                 {
 371                 case '4':
 372                         use_family = FW3_FAMILY_V4;
 373                         break;
 374
 375                 case '6':
 376                         use_family = FW3_FAMILY_V6;
 377                         break;
 378
 379                 case 'q':
 380                         freopen("/dev/null", "w", stderr);
 381                         break;
 382
 383                 case 'h':
 384                         rv = usage();
 385                         goto out;
 386                 }
 387         }
 388
 389         if (!fw3_ubus_connect())
 390                 error("Failed to connect to ubus");
 391
 392         state = build_state();
 393         defs = &state->defaults;
 394
 395         if (!fw3_lock())
 396                 goto out;
 397
 398         if (optind >= argc)
 399         {
 400                 rv = usage();
 401                 goto out;
 402         }
 403
 404         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 405                 warn("IPv6 rules globally disabled in configuration");
 406
 407         if (!strcmp(argv[optind], "print"))
 408         {
 409                 freopen("/dev/null", "w", stderr);
 410
 411                 state->disable_ipsets = true;
 412                 print_rules = true;
 413
 414                 rv = start(state, false);
 415         }
 416         else if (!strcmp(argv[optind], "start"))
 417         {
 418                 rv = start(state, false);
 419         }
 420         else if (!strcmp(argv[optind], "stop"))
 421         {
 422                 rv = stop(state, false, false);
 423         }
 424         else if (!strcmp(argv[optind], "flush"))
 425         {
 426                 rv = stop(state, true, false);
 427         }
 428         else if (!strcmp(argv[optind], "restart"))
 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 }