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