zones.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 "zones.h"
  20 #include "ubus.h"
  21
  22
  23 #define C(f, tbl, tgt, fmt) \
  24         { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_FLAG_##tgt, fmt }
  25
  26 static const struct fw3_rule_spec zone_chains[] = {
  27         C(ANY, FILTER, UNSPEC,        "zone_%1$s_input"),
  28         C(ANY, FILTER, UNSPEC,        "zone_%1$s_output"),
  29         C(ANY, FILTER, UNSPEC,        "zone_%1$s_forward"),
  30
  31         C(ANY, FILTER, SRC_ACCEPT,    "zone_%1$s_src_ACCEPT"),
  32         C(ANY, FILTER, SRC_REJECT,    "zone_%1$s_src_REJECT"),
  33         C(ANY, FILTER, SRC_DROP,      "zone_%1$s_src_DROP"),
  34
  35         C(ANY, FILTER, ACCEPT,        "zone_%1$s_dest_ACCEPT"),
  36         C(ANY, FILTER, REJECT,        "zone_%1$s_dest_REJECT"),
  37         C(ANY, FILTER, DROP,          "zone_%1$s_dest_DROP"),
  38
  39         C(V4,  NAT,    SNAT,          "zone_%1$s_postrouting"),
  40         C(V4,  NAT,    DNAT,          "zone_%1$s_prerouting"),
  41
  42         C(ANY, FILTER, CUSTOM_CHAINS, "input_%1$s_rule"),
  43         C(ANY, FILTER, CUSTOM_CHAINS, "output_%1$s_rule"),
  44         C(ANY, FILTER, CUSTOM_CHAINS, "forwarding_%1$s_rule"),
  45
  46         C(V4,  NAT,    CUSTOM_CHAINS, "prerouting_%1$s_rule"),
  47         C(V4,  NAT,    CUSTOM_CHAINS, "postrouting_%1$s_rule"),
  48
  49         { }
  50 };
  51
  52
  53 #define R(dir1, dir2) \
  54         "zone_%1$s_" #dir1 " -m comment --comment \"user chain for %1$s " \
  55         #dir2 "\" -j " #dir2 "_%1$s_rule"
  56
  57 static const struct fw3_rule_spec zone_rules[] = {
  58         C(ANY, FILTER, CUSTOM_CHAINS, R(input, input)),
  59         C(ANY, FILTER, CUSTOM_CHAINS, R(output, output)),
  60         C(ANY, FILTER, CUSTOM_CHAINS, R(forward, forwarding)),
  61
  62         C(V4,  NAT,    CUSTOM_CHAINS, R(prerouting, prerouting)),
  63         C(V4,  NAT,    CUSTOM_CHAINS, R(postrouting, postrouting)),
  64
  65         { }
  66 };
  67
  68 const struct fw3_option fw3_zone_opts[] = {
  69         FW3_OPT("enabled",             bool,     zone,     enabled),
  70
  71         FW3_OPT("name",                string,   zone,     name),
  72         FW3_OPT("family",              family,   zone,     family),
  73
  74         FW3_LIST("network",            device,   zone,     networks),
  75         FW3_LIST("device",             device,   zone,     devices),
  76         FW3_LIST("subnet",             network,  zone,     subnets),
  77
  78         FW3_OPT("input",               target,   zone,     policy_input),
  79         FW3_OPT("forward",             target,   zone,     policy_forward),
  80         FW3_OPT("output",              target,   zone,     policy_output),
  81
  82         FW3_OPT("masq",                bool,     zone,     masq),
  83         FW3_LIST("masq_src",           network,  zone,     masq_src),
  84         FW3_LIST("masq_dest",          network,  zone,     masq_dest),
  85
  86         FW3_OPT("extra",               string,   zone,     extra_src),
  87         FW3_OPT("extra_src",           string,   zone,     extra_src),
  88         FW3_OPT("extra_dest",          string,   zone,     extra_dest),
  89
  90         FW3_OPT("conntrack",           bool,     zone,     conntrack),
  91         FW3_OPT("mtu_fix",             bool,     zone,     mtu_fix),
  92         FW3_OPT("custom_chains",       bool,     zone,     custom_chains),
  93
  94         FW3_OPT("log",                 bool,     zone,     log),
  95         FW3_OPT("log_limit",           limit,    zone,     log_limit),
  96
  97         FW3_OPT("__flags_v4",          int,      zone,     flags[0]),
  98         FW3_OPT("__flags_v6",          int,      zone,     flags[1]),
  99
 100         { }
 101 };
 102
 103
 104 static void
 105 check_policy(struct uci_element *e, enum fw3_flag *pol, enum fw3_flag def,
 106              const char *name)
 107 {
 108         if (*pol == FW3_FLAG_UNSPEC)
 109         {
 110                 warn_elem(e, "has no %s policy specified, using default", name);
 111                 *pol = def;
 112         }
 113         else if (*pol > FW3_FLAG_DROP)
 114         {
 115                 warn_elem(e, "has invalid %s policy, using default", name);
 116                 *pol = def;
 117         }
 118 }
 119
 120 static void
 121 resolve_networks(struct uci_element *e, struct fw3_zone *zone)
 122 {
 123         struct fw3_device *net, *tmp;
 124
 125         list_for_each_entry(net, &zone->networks, list)
 126         {
 127                 tmp = fw3_ubus_device(net->name);
 128
 129                 if (!tmp)
 130                 {
 131                         warn_elem(e, "cannot resolve device of network '%s'", net->name);
 132                         continue;
 133                 }
 134
 135                 tmp->network = net;
 136                 list_add_tail(&tmp->list, &zone->devices);
 137         }
 138 }
 139
 140 struct fw3_zone *
 141 fw3_alloc_zone(void)
 142 {
 143         struct fw3_zone *zone;
 144
 145         zone = malloc(sizeof(*zone));
 146
 147         if (!zone)
 148                 return NULL;
 149
 150         memset(zone, 0, sizeof(*zone));
 151
 152         INIT_LIST_HEAD(&zone->networks);
 153         INIT_LIST_HEAD(&zone->devices);
 154         INIT_LIST_HEAD(&zone->subnets);
 155         INIT_LIST_HEAD(&zone->masq_src);
 156         INIT_LIST_HEAD(&zone->masq_dest);
 157
 158         zone->enabled = true;
 159         zone->custom_chains = true;
 160         zone->log_limit.rate = 10;
 161
 162         return zone;
 163 }
 164
 165 void
 166 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
 167 {
 168         struct uci_section *s;
 169         struct uci_element *e;
 170         struct fw3_zone *zone;
 171         struct fw3_defaults *defs = &state->defaults;
 172
 173         INIT_LIST_HEAD(&state->zones);
 174
 175         uci_foreach_element(&p->sections, e)
 176         {
 177                 s = uci_to_section(e);
 178
 179                 if (strcmp(s->type, "zone"))
 180                         continue;
 181
 182                 zone = fw3_alloc_zone();
 183
 184                 if (!zone)
 185                         continue;
 186
 187                 fw3_parse_options(zone, fw3_zone_opts, s);
 188
 189                 if (!zone->enabled)
 190                 {
 191                         fw3_free_zone(zone);
 192                         continue;
 193                 }
 194
 195                 if (!zone->extra_dest)
 196                         zone->extra_dest = zone->extra_src;
 197
 198                 if (!defs->custom_chains && zone->custom_chains)
 199                         zone->custom_chains = false;
 200
 201                 if (!zone->name || !*zone->name)
 202                 {
 203                         warn_elem(e, "has no name - ignoring");
 204                         fw3_free_zone(zone);
 205                         continue;
 206                 }
 207
 208                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
 209                     list_empty(&zone->subnets) && !zone->extra_src)
 210                 {
 211                         warn_elem(e, "has no device, network, subnet or extra options");
 212                 }
 213
 214                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
 215                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
 216                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
 217
 218                 resolve_networks(e, zone);
 219
 220                 if (zone->masq)
 221                 {
 222                         setbit(zone->flags[0], FW3_FLAG_SNAT);
 223                         zone->conntrack = true;
 224                 }
 225
 226                 if (zone->custom_chains)
 227                 {
 228                         setbit(zone->flags[0], FW3_FLAG_SNAT);
 229                         setbit(zone->flags[0], FW3_FLAG_DNAT);
 230                 }
 231
 232                 setbit(zone->flags[0], fw3_to_src_target(zone->policy_input));
 233                 setbit(zone->flags[0], zone->policy_output);
 234                 setbit(zone->flags[0], zone->policy_forward);
 235
 236                 setbit(zone->flags[1], fw3_to_src_target(zone->policy_input));
 237                 setbit(zone->flags[1], zone->policy_output);
 238                 setbit(zone->flags[1], zone->policy_forward);
 239
 240                 list_add_tail(&zone->list, &state->zones);
 241         }
 242 }
 243
 244
 245 static void
 246 print_zone_chain(struct fw3_state *state, enum fw3_family family,
 247                  enum fw3_table table, bool reload, struct fw3_zone *zone)
 248 {
 249         bool c, r;
 250         uint32_t custom_mask = ~0;
 251
 252         if (!fw3_is_family(zone, family))
 253                 return;
 254
 255         set(zone->flags, family, table);
 256
 257         /* Don't touch user chains on reload */
 258         if (reload)
 259                 delbit(custom_mask, FW3_FLAG_CUSTOM_CHAINS);
 260
 261         if (zone->custom_chains)
 262                 set(zone->flags, family, FW3_FLAG_CUSTOM_CHAINS);
 263
 264         if (!zone->conntrack && !state->defaults.drop_invalid)
 265                 set(zone->flags, family, FW3_FLAG_NOTRACK);
 266
 267         c = fw3_pr_rulespec(table, family, zone->flags, custom_mask, zone_chains,
 268                             ":%s - [0:0]\n", zone->name);
 269
 270         r = fw3_pr_rulespec(table, family, zone->flags, 0, zone_rules,
 271                             "-A %s\n", zone->name);
 272
 273         if (c || r)
 274         {
 275                 info("   * Zone '%s'", zone->name);
 276
 277                 set(zone->flags, family, table);
 278         }
 279 }
 280
 281 static void
 282 print_interface_rule(struct fw3_state *state, enum fw3_family family,
 283                      enum fw3_table table, bool reload, struct fw3_zone *zone,
 284                      struct fw3_device *dev, struct fw3_address *sub)
 285 {
 286         bool disable_notrack = state->defaults.drop_invalid;
 287
 288         enum fw3_flag t;
 289
 290 #define jump_target(t) \
 291         ((t == FW3_FLAG_REJECT) ? "reject" : fw3_flag_names[t])
 292
 293         if (table == FW3_TABLE_FILTER)
 294         {
 295                 for (t = FW3_FLAG_ACCEPT; t <= FW3_FLAG_DROP; t++)
 296                 {
 297                         if (has(zone->flags, family, fw3_to_src_target(t)))
 298                         {
 299                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 300                                 fw3_format_in_out(dev, NULL);
 301                                 fw3_format_src_dest(sub, NULL);
 302                                 fw3_format_extra(zone->extra_src);
 303                                 fw3_pr(" -j %s\n", jump_target(t));
 304                         }
 305
 306                         if (has(zone->flags, family, t))
 307                         {
 308                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 309                                 fw3_format_in_out(NULL, dev);
 310                                 fw3_format_src_dest(NULL, sub);
 311                                 fw3_format_extra(zone->extra_dest);
 312                                 fw3_pr(" -j %s\n", jump_target(t));
 313                         }
 314                 }
 315
 316                 fw3_pr("-A delegate_input");
 317                 fw3_format_in_out(dev, NULL);
 318                 fw3_format_src_dest(sub, NULL);
 319                 fw3_format_extra(zone->extra_src);
 320                 fw3_pr(" -j zone_%s_input\n", zone->name);
 321
 322                 fw3_pr("-A delegate_forward");
 323                 fw3_format_in_out(dev, NULL);
 324                 fw3_format_src_dest(sub, NULL);
 325                 fw3_format_extra(zone->extra_src);
 326                 fw3_pr(" -j zone_%s_forward\n", zone->name);
 327
 328                 fw3_pr("-A delegate_output");
 329                 fw3_format_in_out(NULL, dev);
 330                 fw3_format_src_dest(NULL, sub);
 331                 fw3_format_extra(zone->extra_dest);
 332                 fw3_pr(" -j zone_%s_output\n", zone->name);
 333         }
 334         else if (table == FW3_TABLE_NAT)
 335         {
 336                 if (has(zone->flags, family, FW3_FLAG_DNAT))
 337                 {
 338                         fw3_pr("-A delegate_prerouting");
 339                         fw3_format_in_out(dev, NULL);
 340                         fw3_format_src_dest(sub, NULL);
 341                         fw3_format_extra(zone->extra_src);
 342                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
 343                 }
 344
 345                 if (has(zone->flags, family, FW3_FLAG_SNAT))
 346                 {
 347                         fw3_pr("-A delegate_postrouting");
 348                         fw3_format_in_out(NULL, dev);
 349                         fw3_format_src_dest(NULL, sub);
 350                         fw3_format_extra(zone->extra_dest);
 351                         fw3_pr(" -j zone_%s_postrouting\n", zone->name);
 352                 }
 353         }
 354         else if (table == FW3_TABLE_MANGLE)
 355         {
 356                 if (zone->mtu_fix)
 357                 {
 358                         if (zone->log)
 359                         {
 360                                 fw3_pr("-A mssfix");
 361                                 fw3_format_in_out(NULL, dev);
 362                                 fw3_format_src_dest(NULL, sub);
 363                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 364                                 fw3_format_limit(&zone->log_limit);
 365                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
 366                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
 367                         }
 368
 369                         fw3_pr("-A mssfix");
 370                         fw3_format_in_out(NULL, dev);
 371                         fw3_format_src_dest(NULL, sub);
 372                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 373                         fw3_format_comment(zone->name, " (mtu_fix)");
 374                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
 375                 }
 376         }
 377         else if (table == FW3_TABLE_RAW)
 378         {
 379                 if (!zone->conntrack && !disable_notrack)
 380                 {
 381                         fw3_pr("-A notrack");
 382                         fw3_format_in_out(dev, NULL);
 383                         fw3_format_src_dest(sub, NULL);
 384                         fw3_format_extra(zone->extra_src);
 385                         fw3_format_comment(zone->name, " (notrack)");
 386                         fw3_pr(" -j CT --notrack\n", zone->name);
 387                 }
 388         }
 389 }
 390
 391 static void
 392 print_interface_rules(struct fw3_state *state, enum fw3_family family,
 393                       enum fw3_table table, bool reload, struct fw3_zone *zone)
 394 {
 395         struct fw3_device *dev;
 396         struct fw3_address *sub;
 397
 398         fw3_foreach(dev, &zone->devices)
 399         fw3_foreach(sub, &zone->subnets)
 400         {
 401                 if (!fw3_is_family(sub, family))
 402                         continue;
 403
 404                 if (!dev && !sub)
 405                         continue;
 406
 407                 print_interface_rule(state, family, table, reload, zone, dev, sub);
 408         }
 409 }
 410
 411 static void
 412 print_zone_rule(struct fw3_state *state, enum fw3_family family,
 413                 enum fw3_table table, bool reload, struct fw3_zone *zone)
 414 {
 415         struct fw3_address *msrc;
 416         struct fw3_address *mdest;
 417
 418         enum fw3_flag t;
 419
 420         if (!fw3_is_family(zone, family))
 421                 return;
 422
 423         switch (table)
 424         {
 425         case FW3_TABLE_FILTER:
 426                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 427                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
 428
 429                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 430                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
 431
 432                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 433                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
 434
 435                 if (zone->log)
 436                 {
 437                         for (t = FW3_FLAG_REJECT; t <= FW3_FLAG_DROP; t++)
 438                         {
 439                                 if (has(zone->flags, family, fw3_to_src_target(t)))
 440                                 {
 441                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 442                                         fw3_format_limit(&zone->log_limit);
 443                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 444                                                    fw3_flag_names[t], zone->name);
 445                                 }
 446
 447                                 if (has(zone->flags, family, t))
 448                                 {
 449                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 450                                         fw3_format_limit(&zone->log_limit);
 451                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 452                                                    fw3_flag_names[t], zone->name);
 453                                 }
 454                         }
 455                 }
 456                 break;
 457
 458         case FW3_TABLE_NAT:
 459                 if (zone->masq && family == FW3_FAMILY_V4)
 460                 {
 461                         fw3_foreach(msrc, &zone->masq_src)
 462                         fw3_foreach(mdest, &zone->masq_dest)
 463                         {
 464                                 if (!fw3_is_family(msrc, family) ||
 465                                     !fw3_is_family(mdest, family))
 466                                         continue;
 467
 468                                 fw3_pr("-A zone_%s_postrouting", zone->name);
 469                                 fw3_format_src_dest(msrc, mdest);
 470                                 fw3_pr(" -j MASQUERADE\n");
 471                         }
 472                 }
 473                 break;
 474
 475         case FW3_TABLE_RAW:
 476         case FW3_TABLE_MANGLE:
 477                 break;
 478         }
 479
 480         print_interface_rules(state, family, table, reload, zone);
 481 }
 482
 483 void
 484 fw3_print_zone_chains(struct fw3_state *state, enum fw3_family family,
 485                       enum fw3_table table, bool reload)
 486 {
 487         struct fw3_zone *zone;
 488
 489         list_for_each_entry(zone, &state->zones, list)
 490                 print_zone_chain(state, family, table, reload, zone);
 491 }
 492
 493 void
 494 fw3_print_zone_rules(struct fw3_state *state, enum fw3_family family,
 495                      enum fw3_table table, bool reload)
 496 {
 497         struct fw3_zone *zone;
 498
 499         list_for_each_entry(zone, &state->zones, list)
 500                 print_zone_rule(state, family, table, reload, zone);
 501 }
 502
 503 void
 504 fw3_flush_zones(struct fw3_state *state, enum fw3_family family,
 505                 enum fw3_table table, bool reload, bool pass2)
 506 {
 507         struct fw3_zone *z, *tmp;
 508         uint32_t custom_mask = ~0;
 509
 510         /* don't touch user chains on selective stop */
 511         if (reload)
 512                 delbit(custom_mask, FW3_FLAG_CUSTOM_CHAINS);
 513
 514         list_for_each_entry_safe(z, tmp, &state->zones, list)
 515         {
 516                 if (!has(z->flags, family, table))
 517                         continue;
 518
 519                 fw3_pr_rulespec(table, family, z->flags, custom_mask, zone_chains,
 520                                 pass2 ? "-X %s\n" : "-F %s\n", z->name);
 521
 522                 if (pass2)
 523                         del(z->flags, family, table);
 524         }
 525 }
 526
 527 void
 528 fw3_hotplug_zones(struct fw3_state *state, bool add)
 529 {
 530         struct fw3_zone *z;
 531         struct fw3_device *d;
 532
 533         if (add)
 534         {
 535                 list_for_each_entry(z, &state->zones, list)
 536                 {
 537                         if (!hasbit(z->flags[0], FW3_FLAG_HOTPLUG))
 538                         {
 539                                 list_for_each_entry(d, &z->devices, list)
 540                                         fw3_hotplug(add, z, d);
 541
 542                                 setbit(z->flags[0], FW3_FLAG_HOTPLUG);
 543                         }
 544                 }
 545         }
 546         else
 547         {
 548                 list_for_each_entry(z, &state->zones, list)
 549                 {
 550                         if (hasbit(z->flags[0], FW3_FLAG_HOTPLUG))
 551                         {
 552                                 list_for_each_entry(d, &z->devices, list)
 553                                         fw3_hotplug(add, z, d);
 554
 555                                 delbit(z->flags[0], FW3_FLAG_HOTPLUG);
 556                         }
 557                 }
 558         }
 559 }
 560
 561 struct fw3_zone *
 562 fw3_lookup_zone(struct fw3_state *state, const char *name)
 563 {
 564         struct fw3_zone *z;
 565
 566         if (list_empty(&state->zones))
 567                 return NULL;
 568
 569         list_for_each_entry(z, &state->zones, list)
 570         {
 571                 if (strcmp(z->name, name))
 572                         continue;
 573
 574                 return z;
 575         }
 576
 577         return NULL;
 578 }
 579
 580 void
 581 fw3_free_zone(struct fw3_zone *zone)
 582 {
 583         struct fw3_device *dev, *tmp;
 584
 585         list_for_each_entry_safe(dev, tmp, &zone->devices, list)
 586         {
 587                 list_del(&dev->list);
 588                 free(dev);
 589         }
 590
 591         list_for_each_entry_safe(dev, tmp, &zone->networks, list)
 592         {
 593                 list_del(&dev->list);
 594                 free(dev);
 595         }
 596
 597         fw3_free_object(zone, fw3_zone_opts);
 598 }