zones.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
   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 #include "helpers.h"
  22
  23
  24 #define C(f, tbl, tgt, fmt) \
  25         { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_FLAG_##tgt, fmt }
  26
  27 static const struct fw3_chain_spec zone_chains[] = {
  28         C(ANY, FILTER, UNSPEC,        "zone_?_input"),
  29         C(ANY, FILTER, UNSPEC,        "zone_?_output"),
  30         C(ANY, FILTER, UNSPEC,        "zone_?_forward"),
  31
  32         C(ANY, FILTER, SRC_ACCEPT,    "zone_?_src_ACCEPT"),
  33         C(ANY, FILTER, SRC_REJECT,    "zone_?_src_REJECT"),
  34         C(ANY, FILTER, SRC_DROP,      "zone_?_src_DROP"),
  35
  36         C(ANY, FILTER, ACCEPT,        "zone_?_dest_ACCEPT"),
  37         C(ANY, FILTER, REJECT,        "zone_?_dest_REJECT"),
  38         C(ANY, FILTER, DROP,          "zone_?_dest_DROP"),
  39
  40         C(V4,  NAT,    SNAT,          "zone_?_postrouting"),
  41         C(V4,  NAT,    DNAT,          "zone_?_prerouting"),
  42
  43         C(ANY, RAW,    HELPER,        "zone_?_helper"),
  44         C(ANY, RAW,    NOTRACK,       "zone_?_notrack"),
  45
  46         C(ANY, FILTER, CUSTOM_CHAINS, "input_?_rule"),
  47         C(ANY, FILTER, CUSTOM_CHAINS, "output_?_rule"),
  48         C(ANY, FILTER, CUSTOM_CHAINS, "forwarding_?_rule"),
  49
  50         C(V4,  NAT,    CUSTOM_CHAINS, "prerouting_?_rule"),
  51         C(V4,  NAT,    CUSTOM_CHAINS, "postrouting_?_rule"),
  52
  53         { }
  54 };
  55
  56 enum fw3_zone_logmask {
  57         FW3_ZONE_LOG_FILTER = (1 << 0),
  58         FW3_ZONE_LOG_MANGLE = (1 << 1),
  59 };
  60
  61 const struct fw3_option fw3_zone_opts[] = {
  62         FW3_OPT("enabled",             bool,     zone,     enabled),
  63
  64         FW3_OPT("name",                string,   zone,     name),
  65         FW3_OPT("family",              family,   zone,     family),
  66
  67         FW3_LIST("network",            device,   zone,     networks),
  68         FW3_LIST("device",             device,   zone,     devices),
  69         FW3_LIST("subnet",             network,  zone,     subnets),
  70
  71         FW3_OPT("input",               target,   zone,     policy_input),
  72         FW3_OPT("forward",             target,   zone,     policy_forward),
  73         FW3_OPT("output",              target,   zone,     policy_output),
  74
  75         FW3_OPT("masq",                bool,     zone,     masq),
  76         FW3_OPT("masq_allow_invalid",  bool,     zone,     masq_allow_invalid),
  77         FW3_LIST("masq_src",           network,  zone,     masq_src),
  78         FW3_LIST("masq_dest",          network,  zone,     masq_dest),
  79
  80         FW3_OPT("extra",               string,   zone,     extra_src),
  81         FW3_OPT("extra_src",           string,   zone,     extra_src),
  82         FW3_OPT("extra_dest",          string,   zone,     extra_dest),
  83
  84         FW3_OPT("mtu_fix",             bool,     zone,     mtu_fix),
  85         FW3_OPT("custom_chains",       bool,     zone,     custom_chains),
  86
  87         FW3_OPT("log",                 int,      zone,     log),
  88         FW3_OPT("log_limit",           limit,    zone,     log_limit),
  89
  90         FW3_OPT("auto_helper",         bool,     zone,     auto_helper),
  91         FW3_LIST("helper",             cthelper, zone,     cthelpers),
  92
  93         FW3_OPT("__flags_v4",          int,      zone,     flags[0]),
  94         FW3_OPT("__flags_v6",          int,      zone,     flags[1]),
  95
  96         FW3_LIST("__addrs",            address,  zone,     old_addrs),
  97
  98         { }
  99 };
 100
 101 static void
 102 check_policy(struct uci_element *e, enum fw3_flag *pol, enum fw3_flag def,
 103              const char *name)
 104 {
 105         if (*pol == FW3_FLAG_UNSPEC)
 106         {
 107                 warn_elem(e, "has no %s policy specified, using default", name);
 108                 *pol = def;
 109         }
 110         else if (*pol > FW3_FLAG_DROP)
 111         {
 112                 warn_elem(e, "has invalid %s policy, using default", name);
 113                 *pol = def;
 114         }
 115 }
 116
 117 static bool
 118 check_masq_addrs(struct list_head *head)
 119 {
 120         struct fw3_address *addr;
 121         int n_addr = 0, n_failed = 0;
 122
 123         list_for_each_entry(addr, head, list)
 124         {
 125                 if (addr->invert)
 126                         continue;
 127
 128                 n_addr++;
 129
 130                 if (!addr->set && addr->resolved)
 131                         n_failed++;
 132         }
 133
 134         return (n_addr == 0 || n_failed < n_addr);
 135 }
 136
 137 static void
 138 resolve_networks(struct uci_element *e, struct fw3_zone *zone)
 139 {
 140         struct fw3_device *net, *dev, *tmp;
 141
 142         list_for_each_entry(net, &zone->networks, list)
 143         {
 144                 tmp = fw3_ubus_device(net->name);
 145
 146                 if (!tmp)
 147                 {
 148                         warn_elem(e, "cannot resolve device of network '%s'", net->name);
 149                         continue;
 150                 }
 151
 152                 list_for_each_entry(dev, &zone->devices, list)
 153                         if (!strcmp(dev->name, tmp->name))
 154                                 goto alias;
 155
 156                 snprintf(tmp->network, sizeof(tmp->network), "%s", net->name);
 157                 list_add_tail(&tmp->list, &zone->devices);
 158                 continue;
 159 alias:
 160                 free(tmp);
 161         }
 162 }
 163
 164 static void
 165 resolve_cthelpers(struct fw3_state *s, struct uci_element *e, struct fw3_zone *zone)
 166 {
 167         struct fw3_cthelpermatch *match;
 168
 169         if (list_empty(&zone->cthelpers))
 170         {
 171                 if (!zone->masq && zone->auto_helper)
 172                 {
 173                         fw3_setbit(zone->flags[0], FW3_FLAG_HELPER);
 174                         fw3_setbit(zone->flags[1], FW3_FLAG_HELPER);
 175                 }
 176
 177                 return;
 178         }
 179
 180         list_for_each_entry(match, &zone->cthelpers, list)
 181         {
 182                 if (match->invert)
 183                 {
 184                         warn_elem(e, "must not use a negated helper match");
 185                         continue;
 186                 }
 187
 188                 match->ptr = fw3_lookup_cthelper(s, match->name);
 189
 190                 if (!match->ptr)
 191                 {
 192                         warn_elem(e, "refers to not existing helper '%s'", match->name);
 193                         continue;
 194                 }
 195
 196                 if (fw3_is_family(match->ptr, FW3_FAMILY_V4))
 197                         fw3_setbit(zone->flags[0], FW3_FLAG_HELPER);
 198
 199                 if (fw3_is_family(match->ptr, FW3_FAMILY_V6))
 200                         fw3_setbit(zone->flags[1], FW3_FLAG_HELPER);
 201         }
 202 }
 203
 204 struct fw3_zone *
 205 fw3_alloc_zone(void)
 206 {
 207         struct fw3_zone *zone;
 208
 209         zone = calloc(1, sizeof(*zone));
 210         if (!zone)
 211                 return NULL;
 212
 213         INIT_LIST_HEAD(&zone->networks);
 214         INIT_LIST_HEAD(&zone->devices);
 215         INIT_LIST_HEAD(&zone->subnets);
 216         INIT_LIST_HEAD(&zone->masq_src);
 217         INIT_LIST_HEAD(&zone->masq_dest);
 218         INIT_LIST_HEAD(&zone->cthelpers);
 219
 220         INIT_LIST_HEAD(&zone->old_addrs);
 221
 222         zone->enabled = true;
 223         zone->auto_helper = true;
 224         zone->custom_chains = true;
 225         zone->log_limit.rate = 10;
 226
 227         return zone;
 228 }
 229
 230 void
 231 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
 232 {
 233         struct uci_section *s;
 234         struct uci_element *e;
 235         struct fw3_zone *zone;
 236         struct fw3_defaults *defs = &state->defaults;
 237
 238         INIT_LIST_HEAD(&state->zones);
 239
 240         uci_foreach_element(&p->sections, e)
 241         {
 242                 s = uci_to_section(e);
 243
 244                 if (strcmp(s->type, "zone"))
 245                         continue;
 246
 247                 zone = fw3_alloc_zone();
 248
 249                 if (!zone)
 250                         continue;
 251
 252                 if (!fw3_parse_options(zone, fw3_zone_opts, s))
 253                         warn_elem(e, "has invalid options");
 254
 255                 if (!zone->enabled)
 256                 {
 257                         fw3_free_zone(zone);
 258                         continue;
 259                 }
 260
 261                 if (!zone->extra_dest)
 262                         zone->extra_dest = zone->extra_src;
 263
 264                 if (!defs->custom_chains && zone->custom_chains)
 265                         zone->custom_chains = false;
 266
 267                 if (!defs->auto_helper && zone->auto_helper)
 268                         zone->auto_helper = false;
 269
 270                 if (!zone->name || !*zone->name)
 271                 {
 272                         warn_elem(e, "has no name - ignoring");
 273                         fw3_free_zone(zone);
 274                         continue;
 275                 }
 276
 277                 if (strlen(zone->name) > FW3_ZONE_MAXNAMELEN)
 278                 {
 279                         warn_elem(e, "must not have a name longer than %u characters",
 280                                      FW3_ZONE_MAXNAMELEN);
 281                         fw3_free_zone(zone);
 282                         continue;
 283                 }
 284
 285                 fw3_ubus_zone_devices(zone);
 286
 287                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
 288                     list_empty(&zone->subnets) && !zone->extra_src)
 289                 {
 290                         warn_elem(e, "has no device, network, subnet or extra options");
 291                 }
 292
 293                 if (!check_masq_addrs(&zone->masq_src))
 294                 {
 295                         warn_elem(e, "has unresolved masq_src, disabling masq");
 296                         zone->masq = false;
 297                 }
 298
 299                 if (!check_masq_addrs(&zone->masq_dest))
 300                 {
 301                         warn_elem(e, "has unresolved masq_dest, disabling masq");
 302                         zone->masq = false;
 303                 }
 304
 305                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
 306                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
 307                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
 308
 309                 resolve_networks(e, zone);
 310
 311                 if (zone->masq)
 312                 {
 313                         fw3_setbit(zone->flags[0], FW3_FLAG_SNAT);
 314                 }
 315
 316                 if (zone->custom_chains)
 317                 {
 318                         fw3_setbit(zone->flags[0], FW3_FLAG_SNAT);
 319                         fw3_setbit(zone->flags[0], FW3_FLAG_DNAT);
 320                 }
 321
 322                 resolve_cthelpers(state, e, zone);
 323
 324                 fw3_setbit(zone->flags[0], fw3_to_src_target(zone->policy_input));
 325                 fw3_setbit(zone->flags[0], zone->policy_forward);
 326                 fw3_setbit(zone->flags[0], zone->policy_output);
 327
 328                 fw3_setbit(zone->flags[1], fw3_to_src_target(zone->policy_input));
 329                 fw3_setbit(zone->flags[1], zone->policy_forward);
 330                 fw3_setbit(zone->flags[1], zone->policy_output);
 331
 332                 list_add_tail(&zone->list, &state->zones);
 333         }
 334 }
 335
 336
 337 static char *
 338 format_chain(const char *fmt, const char *zonename)
 339 {
 340         static char chain[32];
 341         size_t rem;
 342         char *p;
 343         int len;
 344
 345         for (p = chain, rem = sizeof(chain); *fmt; fmt++) {
 346                 if (*fmt == '?') {
 347                         len = snprintf(p, rem, "%s", zonename);
 348
 349                         if (len < 0 || len >= rem)
 350                                 break;
 351
 352                         rem -= len;
 353                         p += len;
 354                 }
 355                 else {
 356                         if (rem <= 1)
 357                                 break;
 358
 359                         *p++ = *fmt;
 360                         rem--;
 361                 }
 362         }
 363
 364         *p = 0;
 365
 366         return chain;
 367 }
 368
 369 static void
 370 print_zone_chain(struct fw3_ipt_handle *handle, struct fw3_state *state,
 371                  bool reload, struct fw3_zone *zone)
 372 {
 373         int i;
 374         struct fw3_ipt_rule *r;
 375         const struct fw3_chain_spec *c;
 376
 377         const char *flt_chains[] = {
 378                 "input",   "input",
 379                 "output",  "output",
 380                 "forward", "forwarding",
 381         };
 382
 383         const char *nat_chains[] = {
 384                 "prerouting",  "prerouting",
 385                 "postrouting", "postrouting",
 386         };
 387
 388         if (!fw3_is_family(zone, handle->family))
 389                 return;
 390
 391         set(zone->flags, handle->family, handle->table);
 392
 393         if (zone->custom_chains)
 394                 set(zone->flags, handle->family, FW3_FLAG_CUSTOM_CHAINS);
 395
 396         for (c = zone_chains; c->format; c++)
 397         {
 398                 if (!fw3_is_family(c, handle->family))
 399                         continue;
 400
 401                 if (c->table != handle->table)
 402                         continue;
 403
 404                 if (c->flag &&
 405                     !fw3_hasbit(zone->flags[handle->family == FW3_FAMILY_V6], c->flag))
 406                         continue;
 407
 408                 fw3_ipt_create_chain(handle, reload, format_chain(c->format, zone->name));
 409         }
 410
 411         if (zone->custom_chains)
 412         {
 413                 if (handle->table == FW3_TABLE_FILTER)
 414                 {
 415                         for (i = 0; i < sizeof(flt_chains)/sizeof(flt_chains[0]); i += 2)
 416                         {
 417                                 r = fw3_ipt_rule_new(handle);
 418                                 fw3_ipt_rule_comment(r, "Custom %s %s rule chain", zone->name, flt_chains[i+1]);
 419                                 fw3_ipt_rule_target(r, "%s_%s_rule", flt_chains[i+1], zone->name);
 420                                 fw3_ipt_rule_append(r, "zone_%s_%s", zone->name, flt_chains[i]);
 421                         }
 422                 }
 423                 else if (handle->table == FW3_TABLE_NAT)
 424                 {
 425                         for (i = 0; i < sizeof(nat_chains)/sizeof(nat_chains[0]); i += 2)
 426                         {
 427                                 r = fw3_ipt_rule_new(handle);
 428                                 fw3_ipt_rule_comment(r, "Custom %s %s rule chain", zone->name, nat_chains[i+1]);
 429                                 fw3_ipt_rule_target(r, "%s_%s_rule", nat_chains[i+1], zone->name);
 430                                 fw3_ipt_rule_append(r, "zone_%s_%s", zone->name, nat_chains[i]);
 431                         }
 432                 }
 433         }
 434
 435         set(zone->flags, handle->family, handle->table);
 436 }
 437
 438 static void
 439 print_interface_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 440                                          bool reload, struct fw3_zone *zone,
 441                      struct fw3_device *dev, struct fw3_address *sub)
 442 {
 443         struct fw3_protocol tcp = { .protocol = 6 };
 444         struct fw3_ipt_rule *r;
 445         enum fw3_flag t;
 446
 447         char buf[32];
 448
 449         int i;
 450
 451         const char *chains[] = {
 452                 "input", "INPUT",
 453                 "output", "OUTPUT",
 454                 "forward", "FORWARD",
 455         };
 456
 457 #define jump_target(t) \
 458         ((t == FW3_FLAG_REJECT) ? "reject" : fw3_flag_names[t])
 459
 460         if (handle->table == FW3_TABLE_FILTER)
 461         {
 462                 for (t = FW3_FLAG_ACCEPT; t <= FW3_FLAG_DROP; t++)
 463                 {
 464                         if (t > FW3_FLAG_ACCEPT && zone->log & FW3_ZONE_LOG_FILTER)
 465                         {
 466                                 if (has(zone->flags, handle->family, fw3_to_src_target(t)))
 467                                 {
 468                                         r = fw3_ipt_rule_create(handle, NULL, dev, NULL, sub, NULL);
 469
 470                                         snprintf(buf, sizeof(buf) - 1, "%s %s in: ",
 471                                                  fw3_flag_names[t], zone->name);
 472
 473                                         fw3_ipt_rule_limit(r, &zone->log_limit);
 474                                         fw3_ipt_rule_target(r, "LOG");
 475                                         fw3_ipt_rule_addarg(r, false, "--log-prefix", buf);
 476                                         fw3_ipt_rule_replace(r, "zone_%s_src_%s",
 477                                                              zone->name, fw3_flag_names[t]);
 478                                 }
 479
 480                                 if (has(zone->flags, handle->family, t))
 481                                 {
 482                                         r = fw3_ipt_rule_create(handle, NULL, NULL, dev, NULL, sub);
 483
 484                                         snprintf(buf, sizeof(buf) - 1, "%s %s out: ",
 485                                                  fw3_flag_names[t], zone->name);
 486
 487                                         fw3_ipt_rule_limit(r, &zone->log_limit);
 488                                         fw3_ipt_rule_target(r, "LOG");
 489                                         fw3_ipt_rule_addarg(r, false, "--log-prefix", buf);
 490                                         fw3_ipt_rule_replace(r, "zone_%s_dest_%s",
 491                                                              zone->name, fw3_flag_names[t]);
 492                                 }
 493                         }
 494
 495                         if (has(zone->flags, handle->family, fw3_to_src_target(t)))
 496                         {
 497                                 r = fw3_ipt_rule_create(handle, NULL, dev, NULL, sub, NULL);
 498                                 fw3_ipt_rule_target(r, jump_target(t));
 499                                 fw3_ipt_rule_extra(r, zone->extra_src);
 500
 501                                 if (t == FW3_FLAG_ACCEPT && !state->defaults.drop_invalid)
 502                                         fw3_ipt_rule_extra(r,
 503                                                            "-m conntrack --ctstate NEW,UNTRACKED");
 504
 505                                 fw3_ipt_rule_replace(r, "zone_%s_src_%s", zone->name,
 506                                                      fw3_flag_names[t]);
 507                         }
 508
 509                         if (has(zone->flags, handle->family, t))
 510                         {
 511                                 if (t == FW3_FLAG_ACCEPT &&
 512                                     zone->masq && !zone->masq_allow_invalid)
 513                                 {
 514                                         r = fw3_ipt_rule_create(handle, NULL, NULL, dev, NULL, sub);
 515                                         fw3_ipt_rule_extra(r, "-m conntrack --ctstate INVALID");
 516                                         fw3_ipt_rule_comment(r, "Prevent NAT leakage");
 517                                         fw3_ipt_rule_target(r, fw3_flag_names[FW3_FLAG_DROP]);
 518                                         fw3_ipt_rule_replace(r, "zone_%s_dest_%s", zone->name,
 519                                                              fw3_flag_names[t]);
 520                                 }
 521
 522                                 r = fw3_ipt_rule_create(handle, NULL, NULL, dev, NULL, sub);
 523                                 fw3_ipt_rule_target(r, jump_target(t));
 524                                 fw3_ipt_rule_extra(r, zone->extra_dest);
 525                                 fw3_ipt_rule_replace(r, "zone_%s_dest_%s", zone->name,
 526                                                      fw3_flag_names[t]);
 527                         }
 528                 }
 529
 530                 for (i = 0; i < sizeof(chains)/sizeof(chains[0]); i += 2)
 531                 {
 532                         if (*chains[i] == 'o')
 533                                 r = fw3_ipt_rule_create(handle, NULL, NULL, dev, NULL, sub);
 534                         else
 535                                 r = fw3_ipt_rule_create(handle, NULL, dev, NULL, sub, NULL);
 536
 537                         fw3_ipt_rule_target(r, "zone_%s_%s", zone->name, chains[i]);
 538
 539                         if (*chains[i] == 'o')
 540                                 fw3_ipt_rule_extra(r, zone->extra_dest);
 541                         else
 542                                 fw3_ipt_rule_extra(r, zone->extra_src);
 543
 544                         fw3_ipt_rule_replace(r, chains[i + 1]);
 545                 }
 546         }
 547         else if (handle->table == FW3_TABLE_NAT)
 548         {
 549                 if (has(zone->flags, handle->family, FW3_FLAG_DNAT))
 550                 {
 551                         r = fw3_ipt_rule_create(handle, NULL, dev, NULL, sub, NULL);
 552                         fw3_ipt_rule_target(r, "zone_%s_prerouting", zone->name);
 553                         fw3_ipt_rule_extra(r, zone->extra_src);
 554                         fw3_ipt_rule_replace(r, "PREROUTING");
 555                 }
 556
 557                 if (has(zone->flags, handle->family, FW3_FLAG_SNAT))
 558                 {
 559                         r = fw3_ipt_rule_create(handle, NULL, NULL, dev, NULL, sub);
 560                         fw3_ipt_rule_target(r, "zone_%s_postrouting", zone->name);
 561                         fw3_ipt_rule_extra(r, zone->extra_dest);
 562                         fw3_ipt_rule_replace(r, "POSTROUTING");
 563                 }
 564         }
 565         else if (handle->table == FW3_TABLE_MANGLE)
 566         {
 567                 if (zone->mtu_fix)
 568                 {
 569                         if (zone->log & FW3_ZONE_LOG_MANGLE)
 570                         {
 571                                 snprintf(buf, sizeof(buf) - 1, "MSSFIX %s out: ", zone->name);
 572
 573                                 r = fw3_ipt_rule_create(handle, &tcp, NULL, dev, NULL, sub);
 574                                 fw3_ipt_rule_addarg(r, false, "--tcp-flags", "SYN,RST");
 575                                 fw3_ipt_rule_addarg(r, false, "SYN", NULL);
 576                                 fw3_ipt_rule_limit(r, &zone->log_limit);
 577                                 fw3_ipt_rule_comment(r, "Zone %s MTU fix logging", zone->name);
 578                                 fw3_ipt_rule_target(r, "LOG");
 579                                 fw3_ipt_rule_addarg(r, false, "--log-prefix", buf);
 580                                 fw3_ipt_rule_replace(r, "FORWARD");
 581                         }
 582
 583                         r = fw3_ipt_rule_create(handle, &tcp, NULL, dev, NULL, sub);
 584                         fw3_ipt_rule_addarg(r, false, "--tcp-flags", "SYN,RST");
 585                         fw3_ipt_rule_addarg(r, false, "SYN", NULL);
 586                         fw3_ipt_rule_comment(r, "Zone %s MTU fixing", zone->name);
 587                         fw3_ipt_rule_target(r, "TCPMSS");
 588                         fw3_ipt_rule_addarg(r, false, "--clamp-mss-to-pmtu", NULL);
 589                         fw3_ipt_rule_replace(r, "FORWARD");
 590
 591                         r = fw3_ipt_rule_create(handle, &tcp, dev, NULL, sub, NULL);
 592                         fw3_ipt_rule_addarg(r, false, "--tcp-flags", "SYN,RST");
 593                         fw3_ipt_rule_addarg(r, false, "SYN", NULL);
 594                         fw3_ipt_rule_comment(r, "Zone %s MTU fixing", zone->name);
 595                         fw3_ipt_rule_target(r, "TCPMSS");
 596                         fw3_ipt_rule_addarg(r, false, "--clamp-mss-to-pmtu", NULL);
 597                         fw3_ipt_rule_replace(r, "FORWARD");
 598                 }
 599         }
 600         else if (handle->table == FW3_TABLE_RAW)
 601         {
 602                 bool loopback_dev = (dev != NULL && !dev->any &&
 603                                      !dev->invert && fw3_check_loopback_dev(dev->name));
 604                 char *chain = loopback_dev || (sub != NULL && !sub->invert && fw3_check_loopback_addr(sub)) ?
 605                               "OUTPUT" : "PREROUTING";
 606
 607                 if (has(zone->flags, handle->family, FW3_FLAG_HELPER))
 608                 {
 609                         r = fw3_ipt_rule_create(handle, NULL, loopback_dev ? NULL : dev, NULL, sub, NULL);
 610                         fw3_ipt_rule_comment(r, "%s CT helper assignment", zone->name);
 611                         fw3_ipt_rule_target(r, "zone_%s_helper", zone->name);
 612                         fw3_ipt_rule_extra(r, zone->extra_src);
 613                         fw3_ipt_rule_replace(r, chain);
 614                 }
 615
 616                 if (has(zone->flags, handle->family, FW3_FLAG_NOTRACK))
 617                 {
 618                         r = fw3_ipt_rule_create(handle, NULL, loopback_dev ? NULL : dev, NULL, sub, NULL);
 619                         fw3_ipt_rule_comment(r, "%s CT bypass", zone->name);
 620                         fw3_ipt_rule_target(r, "zone_%s_notrack", zone->name);
 621                         fw3_ipt_rule_extra(r, zone->extra_src);
 622                         fw3_ipt_rule_replace(r, chain);
 623                 }
 624         }
 625 }
 626
 627 static void
 628 print_interface_rules(struct fw3_ipt_handle *handle, struct fw3_state *state,
 629                       bool reload, struct fw3_zone *zone)
 630 {
 631         struct fw3_device *dev;
 632         struct fw3_address *sub;
 633
 634         fw3_foreach(dev, &zone->devices)
 635         fw3_foreach(sub, &zone->subnets)
 636         {
 637                 if (!fw3_is_family(sub, handle->family))
 638                         continue;
 639
 640                 if (!dev && !sub && !zone->extra_src && !zone->extra_dest)
 641                         continue;
 642
 643                 print_interface_rule(handle, state, reload, zone, dev, sub);
 644         }
 645 }
 646
 647 static struct fw3_address *
 648 next_addr(struct fw3_address *addr, struct list_head *list,
 649                 enum fw3_family family, bool invert)
 650 {
 651         struct list_head *p;
 652         struct fw3_address *rv;
 653
 654         for (p = addr ? addr->list.next : list->next; p != list; p = p->next)
 655         {
 656                 rv = list_entry(p, struct fw3_address, list);
 657
 658                 if (fw3_is_family(rv, family) && rv->set && rv->invert == invert)
 659                         return rv;
 660         }
 661
 662         return NULL;
 663 }
 664
 665 static void
 666 print_zone_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 667                 bool reload, struct fw3_zone *zone)
 668 {
 669         bool first_src, first_dest;
 670         struct fw3_address *msrc;
 671         struct fw3_address *mdest;
 672         struct fw3_ipt_rule *r;
 673
 674         if (!fw3_is_family(zone, handle->family))
 675                 return;
 676
 677         info("   * Zone '%s'", zone->name);
 678
 679         switch (handle->table)
 680         {
 681         case FW3_TABLE_FILTER:
 682                 if (has(zone->flags, handle->family, FW3_FLAG_DNAT))
 683                 {
 684                         r = fw3_ipt_rule_new(handle);
 685                         fw3_ipt_rule_extra(r, "-m conntrack --ctstate DNAT");
 686                         fw3_ipt_rule_comment(r, "Accept port redirections");
 687                         fw3_ipt_rule_target(r, fw3_flag_names[FW3_FLAG_ACCEPT]);
 688                         fw3_ipt_rule_append(r, "zone_%s_input", zone->name);
 689
 690                         r = fw3_ipt_rule_new(handle);
 691                         fw3_ipt_rule_extra(r, "-m conntrack --ctstate DNAT");
 692                         fw3_ipt_rule_comment(r, "Accept port forwards");
 693                         fw3_ipt_rule_target(r, fw3_flag_names[FW3_FLAG_ACCEPT]);
 694                         fw3_ipt_rule_append(r, "zone_%s_forward", zone->name);
 695                 }
 696
 697                 r = fw3_ipt_rule_new(handle);
 698                 fw3_ipt_rule_target(r, "zone_%s_src_%s", zone->name,
 699                                      fw3_flag_names[zone->policy_input]);
 700                 fw3_ipt_rule_append(r, "zone_%s_input", zone->name);
 701
 702                 r = fw3_ipt_rule_new(handle);
 703                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", zone->name,
 704                                      fw3_flag_names[zone->policy_forward]);
 705                 fw3_ipt_rule_append(r, "zone_%s_forward", zone->name);
 706
 707                 r = fw3_ipt_rule_new(handle);
 708                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", zone->name,
 709                                      fw3_flag_names[zone->policy_output]);
 710                 fw3_ipt_rule_append(r, "zone_%s_output", zone->name);
 711
 712                 break;
 713
 714         case FW3_TABLE_NAT:
 715                 if (zone->masq && handle->family == FW3_FAMILY_V4)
 716                 {
 717                         /* for any negated masq_src ip, emit -s addr -j RETURN rules */
 718                         for (msrc = NULL;
 719                              (msrc = next_addr(msrc, &zone->masq_src,
 720                                                handle->family, true)) != NULL; )
 721                         {
 722                                 msrc->invert = false;
 723                                 r = fw3_ipt_rule_new(handle);
 724                                 fw3_ipt_rule_src_dest(r, msrc, NULL);
 725                                 fw3_ipt_rule_target(r, "RETURN");
 726                                 fw3_ipt_rule_append(r, "zone_%s_postrouting", zone->name);
 727                                 msrc->invert = true;
 728                         }
 729
 730                         /* for any negated masq_dest ip, emit -d addr -j RETURN rules */
 731                         for (mdest = NULL;
 732                              (mdest = next_addr(mdest, &zone->masq_dest,
 733                                                 handle->family, true)) != NULL; )
 734                         {
 735                                 mdest->invert = false;
 736                                 r = fw3_ipt_rule_new(handle);
 737                                 fw3_ipt_rule_src_dest(r, NULL, mdest);
 738                                 fw3_ipt_rule_target(r, "RETURN");
 739                                 fw3_ipt_rule_append(r, "zone_%s_postrouting", zone->name);
 740                                 mdest->invert = true;
 741                         }
 742
 743                         /* emit masquerading entries for non-negated addresses
 744                            and ensure that both src and dest loops run at least once,
 745                            even if there are no relevant addresses */
 746                         for (first_src = true, msrc = NULL;
 747                              (msrc = next_addr(msrc, &zone->masq_src,
 748                                                    handle->family, false)) || first_src;
 749                              first_src = false)
 750                         {
 751                                 for (first_dest = true, mdest = NULL;
 752                                      (mdest = next_addr(mdest, &zone->masq_dest,
 753                                                             handle->family, false)) || first_dest;
 754                                      first_dest = false)
 755                                 {
 756                                         r = fw3_ipt_rule_new(handle);
 757                                         fw3_ipt_rule_src_dest(r, msrc, mdest);
 758                                         fw3_ipt_rule_target(r, "MASQUERADE");
 759                                         fw3_ipt_rule_append(r, "zone_%s_postrouting", zone->name);
 760                                 }
 761                         }
 762                 }
 763                 break;
 764
 765         case FW3_TABLE_RAW:
 766                 fw3_print_cthelpers(handle, state, zone);
 767                 break;
 768
 769         case FW3_TABLE_MANGLE:
 770                 break;
 771         }
 772
 773         print_interface_rules(handle, state, reload, zone);
 774 }
 775
 776 void
 777 fw3_print_zone_chains(struct fw3_ipt_handle *handle, struct fw3_state *state,
 778                       bool reload)
 779 {
 780         struct fw3_zone *zone;
 781
 782         list_for_each_entry(zone, &state->zones, list)
 783                 print_zone_chain(handle, state, reload, zone);
 784 }
 785
 786 void
 787 fw3_print_zone_rules(struct fw3_ipt_handle *handle, struct fw3_state *state,
 788                      bool reload)
 789 {
 790         struct fw3_zone *zone;
 791
 792         list_for_each_entry(zone, &state->zones, list)
 793                 print_zone_rule(handle, state, reload, zone);
 794 }
 795
 796 void
 797 fw3_flush_zones(struct fw3_ipt_handle *handle, struct fw3_state *state,
 798                 bool reload)
 799 {
 800         struct fw3_zone *z, *tmp;
 801         const struct fw3_chain_spec *c;
 802
 803         list_for_each_entry_safe(z, tmp, &state->zones, list)
 804         {
 805                 if (!has(z->flags, handle->family, handle->table))
 806                         continue;
 807
 808                 /* first flush all rules ... */
 809                 for (c = zone_chains; c->format; c++)
 810                 {
 811                         /* don't touch user chains on selective stop */
 812                         if (reload && c->flag == FW3_FLAG_CUSTOM_CHAINS)
 813                                 continue;
 814
 815                         if (!fw3_is_family(c, handle->family))
 816                                 continue;
 817
 818                         if (c->table != handle->table)
 819                                 continue;
 820
 821                         if (c->flag && !has(z->flags, handle->family, c->flag))
 822                                 continue;
 823
 824                         fw3_ipt_flush_chain(handle, format_chain(c->format, z->name));
 825                 }
 826
 827                 /* ... then remove the chains */
 828                 for (c = zone_chains; c->format; c++)
 829                 {
 830                         if (!fw3_is_family(c, handle->family))
 831                                 continue;
 832
 833                         if (c->table != handle->table)
 834                                 continue;
 835
 836                         if (c->flag && !has(z->flags, handle->family, c->flag))
 837                                 continue;
 838
 839                         fw3_ipt_delete_chain(handle, reload,
 840                                              format_chain(c->format, z->name));
 841                 }
 842
 843                 del(z->flags, handle->family, handle->table);
 844         }
 845 }
 846
 847 void
 848 fw3_hotplug_zones(struct fw3_state *state, bool add)
 849 {
 850         struct fw3_zone *z;
 851         struct fw3_device *d;
 852
 853         list_for_each_entry(z, &state->zones, list)
 854         {
 855                 if (add != fw3_hasbit(z->flags[0], FW3_FLAG_HOTPLUG))
 856                 {
 857                         list_for_each_entry(d, &z->devices, list)
 858                                 fw3_hotplug(add, z, d);
 859
 860                         if (add)
 861                                 fw3_setbit(z->flags[0], FW3_FLAG_HOTPLUG);
 862                         else
 863                                 fw3_delbit(z->flags[0], FW3_FLAG_HOTPLUG);
 864                 }
 865         }
 866 }
 867
 868 struct fw3_zone *
 869 fw3_lookup_zone(struct fw3_state *state, const char *name)
 870 {
 871         struct fw3_zone *z;
 872
 873         if (list_empty(&state->zones))
 874                 return NULL;
 875
 876         list_for_each_entry(z, &state->zones, list)
 877         {
 878                 if (strcmp(z->name, name))
 879                         continue;
 880
 881                 return z;
 882         }
 883
 884         return NULL;
 885 }
 886
 887 struct list_head *
 888 fw3_resolve_zone_addresses(struct fw3_zone *zone, struct fw3_address *addr)
 889 {
 890         struct fw3_device *net;
 891         struct fw3_address *cur, *tmp;
 892         struct list_head *all;
 893
 894         all = calloc(1, sizeof(*all));
 895         if (!all)
 896                 return NULL;
 897
 898         INIT_LIST_HEAD(all);
 899
 900         if (addr && addr->set)
 901         {
 902                 tmp = malloc(sizeof(*tmp));
 903
 904                 if (tmp)
 905                 {
 906                         *tmp = *addr;
 907                         list_add_tail(&tmp->list, all);
 908                 }
 909         }
 910         else
 911         {
 912                 list_for_each_entry(net, &zone->networks, list)
 913                         fw3_ubus_address(all, net->name);
 914
 915                 list_for_each_entry(cur, &zone->subnets, list)
 916                 {
 917                         tmp = malloc(sizeof(*tmp));
 918
 919                         if (!tmp)
 920                                 continue;
 921
 922                         *tmp = *cur;
 923                         list_add_tail(&tmp->list, all);
 924                 }
 925         }
 926
 927         return all;
 928 }