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_TARGET_##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",             address,  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",           address,  zone,     masq_src),
  84         FW3_LIST("masq_dest",          address,  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         { }
  98 };
  99
 100
 101 static void
 102 check_policy(struct uci_element *e, enum fw3_target *pol, enum fw3_target def,
 103              const char *name)
 104 {
 105         if (*pol == FW3_TARGET_UNSPEC)
 106         {
 107                 warn_elem(e, "has no %s policy specified, using default", name);
 108                 *pol = def;
 109         }
 110         else if (*pol > FW3_TARGET_DROP)
 111         {
 112                 warn_elem(e, "has invalid %s policy, using default", name);
 113                 *pol = def;
 114         }
 115 }
 116
 117 static void
 118 resolve_networks(struct uci_element *e, struct fw3_zone *zone)
 119 {
 120         struct fw3_device *net, *tmp;
 121
 122         list_for_each_entry(net, &zone->networks, list)
 123         {
 124                 tmp = fw3_ubus_device(net->name);
 125
 126                 if (!tmp)
 127                 {
 128                         warn_elem(e, "cannot resolve device of network '%s'", net->name);
 129                         continue;
 130                 }
 131
 132                 list_add_tail(&tmp->list, &zone->devices);
 133         }
 134 }
 135
 136 struct fw3_zone *
 137 fw3_alloc_zone(void)
 138 {
 139         struct fw3_zone *zone;
 140
 141         zone = malloc(sizeof(*zone));
 142
 143         if (!zone)
 144                 return NULL;
 145
 146         memset(zone, 0, sizeof(*zone));
 147
 148         INIT_LIST_HEAD(&zone->networks);
 149         INIT_LIST_HEAD(&zone->devices);
 150         INIT_LIST_HEAD(&zone->subnets);
 151         INIT_LIST_HEAD(&zone->masq_src);
 152         INIT_LIST_HEAD(&zone->masq_dest);
 153
 154         zone->enabled = true;
 155         zone->custom_chains = true;
 156         zone->log_limit.rate = 10;
 157
 158         return zone;
 159 }
 160
 161 void
 162 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
 163 {
 164         struct uci_section *s;
 165         struct uci_element *e;
 166         struct fw3_zone *zone;
 167         struct fw3_defaults *defs = &state->defaults;
 168
 169         INIT_LIST_HEAD(&state->zones);
 170
 171         uci_foreach_element(&p->sections, e)
 172         {
 173                 s = uci_to_section(e);
 174
 175                 if (strcmp(s->type, "zone"))
 176                         continue;
 177
 178                 zone = fw3_alloc_zone();
 179
 180                 if (!zone)
 181                         continue;
 182
 183                 fw3_parse_options(zone, fw3_zone_opts, s);
 184
 185                 if (!zone->enabled)
 186                 {
 187                         fw3_free_zone(zone);
 188                         continue;
 189                 }
 190
 191                 if (!zone->extra_dest)
 192                         zone->extra_dest = zone->extra_src;
 193
 194                 if (!defs->custom_chains && zone->custom_chains)
 195                         zone->custom_chains = false;
 196
 197                 if (!zone->name || !*zone->name)
 198                 {
 199                         warn_elem(e, "has no name - ignoring");
 200                         fw3_free_zone(zone);
 201                         continue;
 202                 }
 203
 204                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
 205                     list_empty(&zone->subnets) && !zone->extra_src)
 206                 {
 207                         warn_elem(e, "has no device, network, subnet or extra options");
 208                 }
 209
 210                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
 211                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
 212                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
 213
 214                 resolve_networks(e, zone);
 215
 216                 if (zone->masq)
 217                 {
 218                         setbit(zone->flags[0], FW3_TARGET_SNAT);
 219                         zone->conntrack = true;
 220                 }
 221
 222                 if (zone->custom_chains)
 223                 {
 224                         setbit(zone->flags[0], FW3_TARGET_SNAT);
 225                         setbit(zone->flags[0], FW3_TARGET_DNAT);
 226                 }
 227
 228                 setbit(zone->flags[0], fw3_to_src_target(zone->policy_input));
 229                 setbit(zone->flags[0], zone->policy_output);
 230                 setbit(zone->flags[0], zone->policy_forward);
 231
 232                 setbit(zone->flags[1], fw3_to_src_target(zone->policy_input));
 233                 setbit(zone->flags[1], zone->policy_output);
 234                 setbit(zone->flags[1], zone->policy_forward);
 235
 236                 list_add_tail(&zone->list, &state->zones);
 237         }
 238 }
 239
 240
 241 static void
 242 print_zone_chain(enum fw3_table table, enum fw3_family family,
 243                  struct fw3_zone *zone, bool reload, struct fw3_state *state)
 244 {
 245         bool c, r;
 246         uint32_t custom_mask = ~0;
 247
 248         if (!fw3_is_family(zone, family))
 249                 return;
 250
 251         set(zone->flags, family, table);
 252
 253         /* Don't touch user chains on reload */
 254         if (reload)
 255                 delbit(custom_mask, FW3_TARGET_CUSTOM_CHAINS);
 256
 257         if (zone->custom_chains)
 258                 set(zone->flags, family, FW3_TARGET_CUSTOM_CHAINS);
 259
 260         if (!zone->conntrack && !state->defaults.drop_invalid)
 261                 set(zone->flags, family, FW3_TARGET_NOTRACK);
 262
 263         c = fw3_pr_rulespec(table, family, zone->flags, custom_mask, zone_chains,
 264                             ":%s - [0:0]\n", zone->name);
 265
 266         r = fw3_pr_rulespec(table, family, zone->flags, 0, zone_rules,
 267                             "-A %s\n", zone->name);
 268
 269         if (c || r)
 270         {
 271                 info("   * Zone '%s'", zone->name);
 272                 fw3_set_running(zone, &state->running_zones);
 273
 274                 set(zone->flags, family, table);
 275         }
 276 }
 277
 278 static void
 279 print_interface_rule(enum fw3_table table, enum fw3_family family,
 280                      struct fw3_zone *zone, struct fw3_device *dev,
 281                      struct fw3_address *sub, bool reload, bool disable_notrack)
 282 {
 283         enum fw3_target t;
 284
 285 #define jump_target(t) \
 286         ((t == FW3_TARGET_REJECT) ? "reject" : fw3_flag_names[t])
 287
 288         if (table == FW3_TABLE_FILTER)
 289         {
 290                 for (t = FW3_TARGET_ACCEPT; t <= FW3_TARGET_DROP; t++)
 291                 {
 292                         if (has(zone->flags, family, fw3_to_src_target(t)))
 293                         {
 294                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 295                                 fw3_format_in_out(dev, NULL);
 296                                 fw3_format_src_dest(sub, NULL);
 297                                 fw3_format_extra(zone->extra_src);
 298                                 fw3_pr(" -j %s\n", jump_target(t));
 299                         }
 300
 301                         if (has(zone->flags, family, t))
 302                         {
 303                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 304                                 fw3_format_in_out(NULL, dev);
 305                                 fw3_format_src_dest(NULL, sub);
 306                                 fw3_format_extra(zone->extra_dest);
 307                                 fw3_pr(" -j %s\n", jump_target(t));
 308                         }
 309                 }
 310
 311                 fw3_pr("-A delegate_input");
 312                 fw3_format_in_out(dev, NULL);
 313                 fw3_format_src_dest(sub, NULL);
 314                 fw3_format_extra(zone->extra_src);
 315                 fw3_pr(" -j zone_%s_input\n", zone->name);
 316
 317                 fw3_pr("-A delegate_forward");
 318                 fw3_format_in_out(dev, NULL);
 319                 fw3_format_src_dest(sub, NULL);
 320                 fw3_format_extra(zone->extra_src);
 321                 fw3_pr(" -j zone_%s_forward\n", zone->name);
 322
 323                 fw3_pr("-A delegate_output");
 324                 fw3_format_in_out(NULL, dev);
 325                 fw3_format_src_dest(NULL, sub);
 326                 fw3_format_extra(zone->extra_dest);
 327                 fw3_pr(" -j zone_%s_output\n", zone->name);
 328         }
 329         else if (table == FW3_TABLE_NAT)
 330         {
 331                 if (has(zone->flags, family, FW3_TARGET_DNAT))
 332                 {
 333                         fw3_pr("-A delegate_prerouting");
 334                         fw3_format_in_out(dev, NULL);
 335                         fw3_format_src_dest(sub, NULL);
 336                         fw3_format_extra(zone->extra_src);
 337                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
 338                 }
 339
 340                 if (has(zone->flags, family, FW3_TARGET_SNAT))
 341                 {
 342                         fw3_pr("-A delegate_postrouting");
 343                         fw3_format_in_out(NULL, dev);
 344                         fw3_format_src_dest(NULL, sub);
 345                         fw3_format_extra(zone->extra_dest);
 346                         fw3_pr(" -j zone_%s_postrouting\n", zone->name);
 347                 }
 348         }
 349         else if (table == FW3_TABLE_MANGLE)
 350         {
 351                 if (zone->mtu_fix)
 352                 {
 353                         if (zone->log)
 354                         {
 355                                 fw3_pr("-A mssfix");
 356                                 fw3_format_in_out(NULL, dev);
 357                                 fw3_format_src_dest(NULL, sub);
 358                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 359                                 fw3_format_limit(&zone->log_limit);
 360                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
 361                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
 362                         }
 363
 364                         fw3_pr("-A mssfix");
 365                         fw3_format_in_out(NULL, dev);
 366                         fw3_format_src_dest(NULL, sub);
 367                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 368                         fw3_format_comment(zone->name, " (mtu_fix)");
 369                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
 370                 }
 371         }
 372         else if (table == FW3_TABLE_RAW)
 373         {
 374                 if (!zone->conntrack && !disable_notrack)
 375                 {
 376                         fw3_pr("-A notrack");
 377                         fw3_format_in_out(dev, NULL);
 378                         fw3_format_src_dest(sub, NULL);
 379                         fw3_format_extra(zone->extra_src);
 380                         fw3_format_comment(zone->name, " (notrack)");
 381                         fw3_pr(" -j CT --notrack\n", zone->name);
 382                 }
 383         }
 384 }
 385
 386 static void
 387 print_interface_rules(enum fw3_table table, enum fw3_family family,
 388                       struct fw3_zone *zone, bool reload, bool disable_notrack)
 389 {
 390         struct fw3_device *dev;
 391         struct fw3_address *sub;
 392
 393         fw3_foreach(dev, &zone->devices)
 394         fw3_foreach(sub, &zone->subnets)
 395         {
 396                 if (!fw3_is_family(sub, family))
 397                         continue;
 398
 399                 if (!dev && !sub)
 400                         continue;
 401
 402                 print_interface_rule(table, family, zone, dev, sub, reload, disable_notrack);
 403         }
 404 }
 405
 406 static void
 407 print_zone_rule(enum fw3_table table, enum fw3_family family,
 408                 struct fw3_zone *zone, bool reload, bool disable_notrack)
 409 {
 410         struct fw3_address *msrc;
 411         struct fw3_address *mdest;
 412
 413         enum fw3_target t;
 414
 415         if (!fw3_is_family(zone, family))
 416                 return;
 417
 418         switch (table)
 419         {
 420         case FW3_TABLE_FILTER:
 421                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 422                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
 423
 424                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 425                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
 426
 427                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 428                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
 429
 430                 if (zone->log)
 431                 {
 432                         for (t = FW3_TARGET_REJECT; t <= FW3_TARGET_DROP; t++)
 433                         {
 434                                 if (has(zone->flags, family, fw3_to_src_target(t)))
 435                                 {
 436                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 437                                         fw3_format_limit(&zone->log_limit);
 438                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 439                                                    fw3_flag_names[t], zone->name);
 440                                 }
 441
 442                                 if (has(zone->flags, family, t))
 443                                 {
 444                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 445                                         fw3_format_limit(&zone->log_limit);
 446                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 447                                                    fw3_flag_names[t], zone->name);
 448                                 }
 449                         }
 450                 }
 451                 break;
 452
 453         case FW3_TABLE_NAT:
 454                 if (zone->masq && family == FW3_FAMILY_V4)
 455                 {
 456                         fw3_foreach(msrc, &zone->masq_src)
 457                         fw3_foreach(mdest, &zone->masq_dest)
 458                         {
 459                                 fw3_pr("-A zone_%s_postrouting ", zone->name);
 460                                 fw3_format_src_dest(msrc, mdest);
 461                                 fw3_pr("-j MASQUERADE\n");
 462                         }
 463                 }
 464                 break;
 465
 466         case FW3_TABLE_RAW:
 467         case FW3_TABLE_MANGLE:
 468                 break;
 469         }
 470
 471         print_interface_rules(table, family, zone, reload, disable_notrack);
 472 }
 473
 474 void
 475 fw3_print_zone_chains(enum fw3_table table, enum fw3_family family,
 476                       bool reload, struct fw3_state *state)
 477 {
 478         struct fw3_zone *zone;
 479
 480         list_for_each_entry(zone, &state->zones, list)
 481                 print_zone_chain(table, family, zone, reload, state);
 482 }
 483
 484 void
 485 fw3_print_zone_rules(enum fw3_table table, enum fw3_family family,
 486                      bool reload, struct fw3_state *state)
 487 {
 488         struct fw3_zone *zone;
 489
 490         list_for_each_entry(zone, &state->zones, list)
 491                 print_zone_rule(table, family, zone, reload, state->defaults.drop_invalid);
 492 }
 493
 494 void
 495 fw3_flush_zones(enum fw3_table table, enum fw3_family family,
 496                             bool pass2, bool reload, struct fw3_state *state)
 497 {
 498         struct fw3_zone *z, *tmp;
 499         uint32_t custom_mask = ~0;
 500
 501         /* don't touch user chains on selective stop */
 502         if (reload)
 503                 delbit(custom_mask, FW3_TARGET_CUSTOM_CHAINS);
 504
 505         list_for_each_entry_safe(z, tmp, &state->running_zones, running_list)
 506         {
 507                 if (!has(z->flags, family, table))
 508                         continue;
 509
 510                 fw3_pr_rulespec(table, family, z->flags, custom_mask, zone_chains,
 511                                 pass2 ? "-X %s\n" : "-F %s\n", z->name);
 512
 513                 if (pass2)
 514                 {
 515                         del(z->flags, family, table);
 516                 }
 517         }
 518 }
 519
 520 struct fw3_zone *
 521 fw3_lookup_zone(struct fw3_state *state, const char *name, bool running)
 522 {
 523         struct fw3_zone *z;
 524
 525         if (list_empty(&state->zones))
 526                 return NULL;
 527
 528         list_for_each_entry(z, &state->zones, list)
 529         {
 530                 if (strcmp(z->name, name))
 531                         continue;
 532
 533                 if (!running || z->running_list.next)
 534                         return z;
 535
 536                 break;
 537         }
 538
 539         return NULL;
 540 }