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, name) \
  24         { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_TARGET_##tgt, name }
  25
  26 struct chain {
  27         enum fw3_family family;
  28         enum fw3_table table;
  29         enum fw3_target target;
  30         const char *name;
  31 };
  32
  33 static const struct chain src_chains[] = {
  34         C(ANY, FILTER, UNSPEC,  "zone_%s_input"),
  35         C(ANY, FILTER, UNSPEC,  "zone_%s_output"),
  36         C(ANY, FILTER, UNSPEC,  "zone_%s_forward"),
  37
  38         C(ANY, FILTER, ACCEPT,  "zone_%s_src_ACCEPT"),
  39         C(ANY, FILTER, REJECT,  "zone_%s_src_REJECT"),
  40         C(ANY, FILTER, DROP,    "zone_%s_src_DROP"),
  41 };
  42
  43 static const struct chain dst_chains[] = {
  44         C(ANY, FILTER, ACCEPT,  "zone_%s_dest_ACCEPT"),
  45         C(ANY, FILTER, REJECT,  "zone_%s_dest_REJECT"),
  46         C(ANY, FILTER, DROP,    "zone_%s_dest_DROP"),
  47
  48         C(V4,  NAT,    SNAT,    "zone_%s_postrouting"),
  49         C(V4,  NAT,    DNAT,    "zone_%s_prerouting"),
  50
  51         C(ANY, RAW,    NOTRACK, "zone_%s_notrack"),
  52 };
  53
  54 const struct fw3_option fw3_zone_opts[] = {
  55         FW3_OPT("name",                string,   zone,     name),
  56         FW3_OPT("family",              family,   zone,     family),
  57
  58         FW3_LIST("network",            device,   zone,     networks),
  59         FW3_LIST("device",             device,   zone,     devices),
  60         FW3_LIST("subnet",             address,  zone,     subnets),
  61
  62         FW3_OPT("input",               target,   zone,     policy_input),
  63         FW3_OPT("forward",             target,   zone,     policy_forward),
  64         FW3_OPT("output",              target,   zone,     policy_output),
  65
  66         FW3_OPT("masq",                bool,     zone,     masq),
  67         FW3_LIST("masq_src",           address,  zone,     masq_src),
  68         FW3_LIST("masq_dest",          address,  zone,     masq_dest),
  69
  70         FW3_OPT("extra",               string,   zone,     extra_src),
  71         FW3_OPT("extra_src",           string,   zone,     extra_src),
  72         FW3_OPT("extra_dest",          string,   zone,     extra_dest),
  73
  74         FW3_OPT("conntrack",           bool,     zone,     conntrack),
  75         FW3_OPT("mtu_fix",             bool,     zone,     mtu_fix),
  76         FW3_OPT("custom_chains",       bool,     zone,     custom_chains),
  77
  78         FW3_OPT("log",                 bool,     zone,     log),
  79         FW3_OPT("log_limit",           limit,    zone,     log_limit),
  80
  81         { }
  82 };
  83
  84
  85 static bool
  86 print_chains(enum fw3_table table, enum fw3_family family,
  87              const char *fmt, const char *name, uint16_t targets,
  88              const struct chain *chains, int n)
  89 {
  90         bool rv = false;
  91         char cn[128] = { 0 };
  92         const struct chain *c;
  93
  94         for (c = chains; n > 0; c++, n--)
  95         {
  96                 if (!fw3_is_family(c, family))
  97                         continue;
  98
  99                 if (c->table != table)
 100                         continue;
 101
 102                 if ((c->target != FW3_TARGET_UNSPEC) && !hasbit(targets, c->target))
 103                         continue;
 104
 105                 snprintf(cn, sizeof(cn), c->name, name);
 106                 fw3_pr(fmt, cn);
 107
 108                 rv = true;
 109         }
 110
 111         return rv;
 112 }
 113
 114 static void
 115 check_policy(struct uci_element *e, enum fw3_target *pol, enum fw3_target def,
 116              const char *name)
 117 {
 118         if (*pol == FW3_TARGET_UNSPEC)
 119         {
 120                 warn_elem(e, "has no %s policy specified, using default", name);
 121                 *pol = def;
 122         }
 123         else if (*pol > FW3_TARGET_DROP)
 124         {
 125                 warn_elem(e, "has invalid %s policy, using default", name);
 126                 *pol = def;
 127         }
 128 }
 129
 130 static void
 131 resolve_networks(struct uci_element *e, struct fw3_zone *zone)
 132 {
 133         struct fw3_device *net, *tmp;
 134
 135         list_for_each_entry(net, &zone->networks, list)
 136         {
 137                 tmp = fw3_ubus_device(net->name);
 138
 139                 if (!tmp)
 140                 {
 141                         warn_elem(e, "cannot resolve device of network '%s'", net->name);
 142                         continue;
 143                 }
 144
 145                 list_add_tail(&tmp->list, &zone->devices);
 146         }
 147 }
 148
 149 struct fw3_zone *
 150 fw3_alloc_zone(void)
 151 {
 152         struct fw3_zone *zone;
 153
 154         zone = malloc(sizeof(*zone));
 155
 156         if (!zone)
 157                 return NULL;
 158
 159         memset(zone, 0, sizeof(*zone));
 160
 161         INIT_LIST_HEAD(&zone->networks);
 162         INIT_LIST_HEAD(&zone->devices);
 163         INIT_LIST_HEAD(&zone->subnets);
 164         INIT_LIST_HEAD(&zone->masq_src);
 165         INIT_LIST_HEAD(&zone->masq_dest);
 166
 167         zone->log_limit.rate = 10;
 168
 169         return zone;
 170 }
 171
 172 void
 173 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
 174 {
 175         struct uci_section *s;
 176         struct uci_element *e;
 177         struct fw3_zone *zone;
 178         struct fw3_defaults *defs = &state->defaults;
 179
 180         INIT_LIST_HEAD(&state->zones);
 181
 182         uci_foreach_element(&p->sections, e)
 183         {
 184                 s = uci_to_section(e);
 185
 186                 if (strcmp(s->type, "zone"))
 187                         continue;
 188
 189                 zone = fw3_alloc_zone();
 190
 191                 if (!zone)
 192                         continue;
 193
 194                 fw3_parse_options(zone, fw3_zone_opts, s);
 195
 196                 if (!zone->extra_dest)
 197                         zone->extra_dest = zone->extra_src;
 198
 199                 if (!zone->name || !*zone->name)
 200                 {
 201                         warn_elem(e, "has no name - ignoring");
 202                         fw3_free_zone(zone);
 203                         continue;
 204                 }
 205
 206                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
 207                     list_empty(&zone->subnets) && !zone->extra_src)
 208                 {
 209                         warn_elem(e, "has no device, network, subnet or extra options");
 210                 }
 211
 212                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
 213                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
 214                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
 215
 216                 resolve_networks(e, zone);
 217
 218                 if (zone->masq)
 219                 {
 220                         setbit(zone->dst_flags, FW3_TARGET_SNAT);
 221                         zone->conntrack = true;
 222                 }
 223
 224                 setbit(zone->src_flags, zone->policy_input);
 225                 setbit(zone->dst_flags, zone->policy_output);
 226                 setbit(zone->dst_flags, zone->policy_forward);
 227
 228                 list_add_tail(&zone->list, &state->zones);
 229         }
 230 }
 231
 232
 233 static void
 234 print_zone_chain(enum fw3_table table, enum fw3_family family,
 235                  struct fw3_zone *zone, struct fw3_state *state)
 236 {
 237         bool s, d;
 238
 239         if (!fw3_is_family(zone, family))
 240                 return;
 241
 242         setbit(zone->dst_flags, family);
 243
 244         if (!zone->conntrack && !state->defaults.drop_invalid)
 245                 setbit(zone->dst_flags, FW3_TARGET_NOTRACK);
 246
 247         s = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 248                          zone->src_flags, src_chains, ARRAY_SIZE(src_chains));
 249
 250         d = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 251                          zone->dst_flags, dst_chains, ARRAY_SIZE(dst_chains));
 252
 253         if (s || d)
 254         {
 255                 info("   * Zone '%s'", zone->name);
 256                 fw3_set_running(zone, &state->running_zones);
 257         }
 258 }
 259
 260 static void
 261 print_interface_rule(enum fw3_table table, enum fw3_family family,
 262                      struct fw3_zone *zone, struct fw3_device *dev,
 263                      struct fw3_address *sub, bool disable_notrack)
 264 {
 265         enum fw3_target t;
 266
 267 #define jump_target(t) \
 268         ((t == FW3_TARGET_REJECT) ? "reject" : fw3_flag_names[t])
 269
 270         if (table == FW3_TABLE_FILTER)
 271         {
 272                 for (t = FW3_TARGET_ACCEPT; t <= FW3_TARGET_DROP; t++)
 273                 {
 274                         if (hasbit(zone->src_flags, t))
 275                         {
 276                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 277                                 fw3_format_in_out(dev, NULL);
 278                                 fw3_format_src_dest(sub, NULL);
 279                                 fw3_format_extra(zone->extra_src);
 280                                 fw3_pr(" -j %s\n", jump_target(t));
 281                         }
 282
 283                         if (hasbit(zone->dst_flags, t))
 284                         {
 285                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 286                                 fw3_format_in_out(NULL, dev);
 287                                 fw3_format_src_dest(NULL, sub);
 288                                 fw3_format_extra(zone->extra_dest);
 289                                 fw3_pr(" -j %s\n", jump_target(t));
 290                         }
 291                 }
 292
 293                 fw3_pr("-A delegate_input");
 294                 fw3_format_in_out(dev, NULL);
 295                 fw3_format_src_dest(sub, NULL);
 296                 fw3_format_extra(zone->extra_src);
 297                 fw3_pr(" -j zone_%s_input\n", zone->name);
 298
 299                 fw3_pr("-A delegate_forward");
 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 zone_%s_forward\n", zone->name);
 304
 305                 fw3_pr("-A delegate_output");
 306                 fw3_format_in_out(NULL, dev);
 307                 fw3_format_src_dest(NULL, sub);
 308                 fw3_format_extra(zone->extra_dest);
 309                 fw3_pr(" -j zone_%s_output\n", zone->name);
 310         }
 311         else if (table == FW3_TABLE_NAT)
 312         {
 313                 if (hasbit(zone->dst_flags, FW3_TARGET_DNAT))
 314                 {
 315                         fw3_pr("-A delegate_prerouting");
 316                         fw3_format_in_out(dev, NULL);
 317                         fw3_format_src_dest(sub, NULL);
 318                         fw3_format_extra(zone->extra_src);
 319                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
 320                 }
 321
 322                 if (hasbit(zone->dst_flags, FW3_TARGET_SNAT))
 323                 {
 324                         fw3_pr("-A delegate_postrouting");
 325                         fw3_format_in_out(NULL, dev);
 326                         fw3_format_src_dest(NULL, sub);
 327                         fw3_format_extra(zone->extra_dest);
 328                         fw3_pr(" -j zone_%s_postrouting\n", zone->name);
 329                 }
 330         }
 331         else if (table == FW3_TABLE_MANGLE)
 332         {
 333                 if (zone->mtu_fix)
 334                 {
 335                         if (zone->log)
 336                         {
 337                                 fw3_pr("-A mssfix");
 338                                 fw3_format_in_out(NULL, dev);
 339                                 fw3_format_src_dest(NULL, sub);
 340                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 341                                 fw3_format_limit(&zone->log_limit);
 342                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
 343                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
 344                         }
 345
 346                         fw3_pr("-A mssfix");
 347                         fw3_format_in_out(NULL, dev);
 348                         fw3_format_src_dest(NULL, sub);
 349                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 350                         fw3_format_comment(zone->name, " (mtu_fix)");
 351                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
 352                 }
 353         }
 354         else if (table == FW3_TABLE_RAW)
 355         {
 356                 if (!zone->conntrack && !disable_notrack)
 357                 {
 358                         fw3_pr("-A notrack");
 359                         fw3_format_in_out(dev, NULL);
 360                         fw3_format_src_dest(sub, NULL);
 361                         fw3_format_extra(zone->extra_src);
 362                         fw3_format_comment(zone->name, " (notrack)");
 363                         fw3_pr(" -j CT --notrack\n", zone->name);
 364                 }
 365         }
 366 }
 367
 368 static void
 369 print_interface_rules(enum fw3_table table, enum fw3_family family,
 370                       struct fw3_zone *zone, bool disable_notrack)
 371 {
 372         struct fw3_device *dev;
 373         struct fw3_address *sub;
 374
 375         fw3_foreach(dev, &zone->devices)
 376         fw3_foreach(sub, &zone->subnets)
 377         {
 378                 if (!fw3_is_family(sub, family))
 379                         continue;
 380
 381                 if (!dev && !sub)
 382                         continue;
 383
 384                 print_interface_rule(table, family, zone, dev, sub, disable_notrack);
 385         }
 386 }
 387
 388 static void
 389 print_zone_rule(enum fw3_table table, enum fw3_family family,
 390                 struct fw3_zone *zone, bool disable_notrack)
 391 {
 392         struct fw3_address *msrc;
 393         struct fw3_address *mdest;
 394
 395         enum fw3_target t;
 396
 397         if (!fw3_is_family(zone, family))
 398                 return;
 399
 400         switch (table)
 401         {
 402         case FW3_TABLE_FILTER:
 403                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 404                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
 405
 406                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 407                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
 408
 409                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 410                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
 411
 412                 if (zone->log)
 413                 {
 414                         for (t = FW3_TARGET_REJECT; t <= FW3_TARGET_DROP; t++)
 415                         {
 416                                 if (hasbit(zone->src_flags, t))
 417                                 {
 418                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 419                                         fw3_format_limit(&zone->log_limit);
 420                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 421                                                    fw3_flag_names[t], zone->name);
 422                                 }
 423
 424                                 if (hasbit(zone->dst_flags, t))
 425                                 {
 426                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 427                                         fw3_format_limit(&zone->log_limit);
 428                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 429                                                    fw3_flag_names[t], zone->name);
 430                                 }
 431                         }
 432                 }
 433                 break;
 434
 435         case FW3_TABLE_NAT:
 436                 if (zone->masq && family == FW3_FAMILY_V4)
 437                 {
 438                         fw3_foreach(msrc, &zone->masq_src)
 439                         fw3_foreach(mdest, &zone->masq_dest)
 440                         {
 441                                 fw3_pr("-A zone_%s_postrouting ", zone->name);
 442                                 fw3_format_src_dest(msrc, mdest);
 443                                 fw3_pr("-j MASQUERADE\n");
 444                         }
 445                 }
 446                 break;
 447
 448         case FW3_TABLE_RAW:
 449         case FW3_TABLE_MANGLE:
 450                 break;
 451         }
 452
 453         print_interface_rules(table, family, zone, disable_notrack);
 454 }
 455
 456 void
 457 fw3_print_zone_chains(enum fw3_table table, enum fw3_family family,
 458                       struct fw3_state *state)
 459 {
 460         struct fw3_zone *zone;
 461
 462         list_for_each_entry(zone, &state->zones, list)
 463                 print_zone_chain(table, family, zone, state);
 464 }
 465
 466 void
 467 fw3_print_zone_rules(enum fw3_table table, enum fw3_family family,
 468                      struct fw3_state *state)
 469 {
 470         struct fw3_zone *zone;
 471
 472         list_for_each_entry(zone, &state->zones, list)
 473                 print_zone_rule(table, family, zone, state->defaults.drop_invalid);
 474 }
 475
 476 void
 477 fw3_flush_zones(enum fw3_table table, enum fw3_family family,
 478                             bool pass2, struct fw3_state *state)
 479 {
 480         struct fw3_zone *z, *tmp;
 481         int mask = (1 << FW3_FAMILY_V4) | (1 << FW3_FAMILY_V6);
 482
 483         list_for_each_entry_safe(z, tmp, &state->running_zones, running_list)
 484         {
 485                 if (!hasbit(z->dst_flags, family))
 486                         continue;
 487
 488                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 489                              z->name, z->src_flags, src_chains, ARRAY_SIZE(src_chains));
 490
 491                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 492                              z->name, z->dst_flags, dst_chains, ARRAY_SIZE(dst_chains));
 493
 494                 if (pass2)
 495                 {
 496                         delbit(z->dst_flags, family);
 497
 498                         if (!(z->dst_flags & mask))
 499                                 fw3_set_running(z, NULL);
 500                 }
 501         }
 502 }
 503
 504 struct fw3_zone *
 505 fw3_lookup_zone(struct fw3_state *state, const char *name, bool running)
 506 {
 507         struct fw3_zone *z;
 508
 509         if (list_empty(&state->zones))
 510                 return NULL;
 511
 512         list_for_each_entry(z, &state->zones, list)
 513         {
 514                 if (strcmp(z->name, name))
 515                         continue;
 516
 517                 if (!running || z->running_list.next)
 518                         return z;
 519
 520                 break;
 521         }
 522
 523         return NULL;
 524 }