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         }
 585         else if (handle->table == FW3_TABLE_RAW)
 586         {
 587                 bool loopback_dev = (dev != NULL && !dev->any &&
 588                                      !dev->invert && fw3_check_loopback_dev(dev->name));
 589                 char *chain = loopback_dev || (sub != NULL && !sub->invert && fw3_check_loopback_addr(sub)) ?
 590                               "OUTPUT" : "PREROUTING";
 591
 592                 if (has(zone->flags, handle->family, FW3_FLAG_HELPER))
 593                 {
 594                         r = fw3_ipt_rule_create(handle, NULL, loopback_dev ? NULL : dev, NULL, sub, NULL);
 595                         fw3_ipt_rule_comment(r, "%s CT helper assignment", zone->name);
 596                         fw3_ipt_rule_target(r, "zone_%s_helper", zone->name);
 597                         fw3_ipt_rule_extra(r, zone->extra_src);
 598                         fw3_ipt_rule_replace(r, chain);
 599                 }
 600
 601                 if (has(zone->flags, handle->family, FW3_FLAG_NOTRACK))
 602                 {
 603                         r = fw3_ipt_rule_create(handle, NULL, loopback_dev ? NULL : dev, NULL, sub, NULL);
 604                         fw3_ipt_rule_comment(r, "%s CT bypass", zone->name);
 605                         fw3_ipt_rule_target(r, "zone_%s_notrack", zone->name);
 606                         fw3_ipt_rule_extra(r, zone->extra_src);
 607                         fw3_ipt_rule_replace(r, chain);
 608                 }
 609         }
 610 }
 611
 612 static void
 613 print_interface_rules(struct fw3_ipt_handle *handle, struct fw3_state *state,
 614                       bool reload, struct fw3_zone *zone)
 615 {
 616         struct fw3_device *dev;
 617         struct fw3_address *sub;
 618
 619         fw3_foreach(dev, &zone->devices)
 620         fw3_foreach(sub, &zone->subnets)
 621         {
 622                 if (!fw3_is_family(sub, handle->family))
 623                         continue;
 624
 625                 if (!dev && !sub && !zone->extra_src && !zone->extra_dest)
 626                         continue;
 627
 628                 print_interface_rule(handle, state, reload, zone, dev, sub);
 629         }
 630 }
 631
 632 static struct fw3_address *
 633 next_addr(struct fw3_address *addr, struct list_head *list,
 634                 enum fw3_family family, bool invert)
 635 {
 636         struct list_head *p;
 637         struct fw3_address *rv;
 638
 639         for (p = addr ? addr->list.next : list->next; p != list; p = p->next)
 640         {
 641                 rv = list_entry(p, struct fw3_address, list);
 642
 643                 if (fw3_is_family(rv, family) && rv->set && rv->invert == invert)
 644                         return rv;
 645         }
 646
 647         return NULL;
 648 }
 649
 650 static void
 651 print_zone_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 652                 bool reload, struct fw3_zone *zone)
 653 {
 654         bool first_src, first_dest;
 655         struct fw3_address *msrc;
 656         struct fw3_address *mdest;
 657         struct fw3_ipt_rule *r;
 658
 659         if (!fw3_is_family(zone, handle->family))
 660                 return;
 661
 662         info("   * Zone '%s'", zone->name);
 663
 664         switch (handle->table)
 665         {
 666         case FW3_TABLE_FILTER:
 667                 if (has(zone->flags, handle->family, FW3_FLAG_DNAT))
 668                 {
 669                         r = fw3_ipt_rule_new(handle);
 670                         fw3_ipt_rule_extra(r, "-m conntrack --ctstate DNAT");
 671                         fw3_ipt_rule_comment(r, "Accept port redirections");
 672                         fw3_ipt_rule_target(r, fw3_flag_names[FW3_FLAG_ACCEPT]);
 673                         fw3_ipt_rule_append(r, "zone_%s_input", zone->name);
 674
 675                         r = fw3_ipt_rule_new(handle);
 676                         fw3_ipt_rule_extra(r, "-m conntrack --ctstate DNAT");
 677                         fw3_ipt_rule_comment(r, "Accept port forwards");
 678                         fw3_ipt_rule_target(r, fw3_flag_names[FW3_FLAG_ACCEPT]);
 679                         fw3_ipt_rule_append(r, "zone_%s_forward", zone->name);
 680                 }
 681
 682                 r = fw3_ipt_rule_new(handle);
 683                 fw3_ipt_rule_target(r, "zone_%s_src_%s", zone->name,
 684                                      fw3_flag_names[zone->policy_input]);
 685                 fw3_ipt_rule_append(r, "zone_%s_input", zone->name);
 686
 687                 r = fw3_ipt_rule_new(handle);
 688                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", zone->name,
 689                                      fw3_flag_names[zone->policy_forward]);
 690                 fw3_ipt_rule_append(r, "zone_%s_forward", zone->name);
 691
 692                 r = fw3_ipt_rule_new(handle);
 693                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", zone->name,
 694                                      fw3_flag_names[zone->policy_output]);
 695                 fw3_ipt_rule_append(r, "zone_%s_output", zone->name);
 696
 697                 break;
 698
 699         case FW3_TABLE_NAT:
 700                 if (zone->masq && handle->family == FW3_FAMILY_V4)
 701                 {
 702                         /* for any negated masq_src ip, emit -s addr -j RETURN rules */
 703                         for (msrc = NULL;
 704                              (msrc = next_addr(msrc, &zone->masq_src,
 705                                                handle->family, true)) != NULL; )
 706                         {
 707                                 msrc->invert = false;
 708                                 r = fw3_ipt_rule_new(handle);
 709                                 fw3_ipt_rule_src_dest(r, msrc, NULL);
 710                                 fw3_ipt_rule_target(r, "RETURN");
 711                                 fw3_ipt_rule_append(r, "zone_%s_postrouting", zone->name);
 712                                 msrc->invert = true;
 713                         }
 714
 715                         /* for any negated masq_dest ip, emit -d addr -j RETURN rules */
 716                         for (mdest = NULL;
 717                              (mdest = next_addr(mdest, &zone->masq_dest,
 718                                                 handle->family, true)) != NULL; )
 719                         {
 720                                 mdest->invert = false;
 721                                 r = fw3_ipt_rule_new(handle);
 722                                 fw3_ipt_rule_src_dest(r, NULL, mdest);
 723                                 fw3_ipt_rule_target(r, "RETURN");
 724                                 fw3_ipt_rule_append(r, "zone_%s_postrouting", zone->name);
 725                                 mdest->invert = true;
 726                         }
 727
 728                         /* emit masquerading entries for non-negated addresses
 729                            and ensure that both src and dest loops run at least once,
 730                            even if there are no relevant addresses */
 731                         for (first_src = true, msrc = NULL;
 732                              (msrc = next_addr(msrc, &zone->masq_src,
 733                                                    handle->family, false)) || first_src;
 734                              first_src = false)
 735                         {
 736                                 for (first_dest = true, mdest = NULL;
 737                                      (mdest = next_addr(mdest, &zone->masq_dest,
 738                                                             handle->family, false)) || first_dest;
 739                                      first_dest = false)
 740                                 {
 741                                         r = fw3_ipt_rule_new(handle);
 742                                         fw3_ipt_rule_src_dest(r, msrc, mdest);
 743                                         fw3_ipt_rule_target(r, "MASQUERADE");
 744                                         fw3_ipt_rule_append(r, "zone_%s_postrouting", zone->name);
 745                                 }
 746                         }
 747                 }
 748                 break;
 749
 750         case FW3_TABLE_RAW:
 751                 fw3_print_cthelpers(handle, state, zone);
 752                 break;
 753
 754         case FW3_TABLE_MANGLE:
 755                 break;
 756         }
 757
 758         print_interface_rules(handle, state, reload, zone);
 759 }
 760
 761 void
 762 fw3_print_zone_chains(struct fw3_ipt_handle *handle, struct fw3_state *state,
 763                       bool reload)
 764 {
 765         struct fw3_zone *zone;
 766
 767         list_for_each_entry(zone, &state->zones, list)
 768                 print_zone_chain(handle, state, reload, zone);
 769 }
 770
 771 void
 772 fw3_print_zone_rules(struct fw3_ipt_handle *handle, struct fw3_state *state,
 773                      bool reload)
 774 {
 775         struct fw3_zone *zone;
 776
 777         list_for_each_entry(zone, &state->zones, list)
 778                 print_zone_rule(handle, state, reload, zone);
 779 }
 780
 781 void
 782 fw3_flush_zones(struct fw3_ipt_handle *handle, struct fw3_state *state,
 783                 bool reload)
 784 {
 785         struct fw3_zone *z, *tmp;
 786         const struct fw3_chain_spec *c;
 787
 788         list_for_each_entry_safe(z, tmp, &state->zones, list)
 789         {
 790                 if (!has(z->flags, handle->family, handle->table))
 791                         continue;
 792
 793                 /* first flush all rules ... */
 794                 for (c = zone_chains; c->format; c++)
 795                 {
 796                         /* don't touch user chains on selective stop */
 797                         if (reload && c->flag == FW3_FLAG_CUSTOM_CHAINS)
 798                                 continue;
 799
 800                         if (!fw3_is_family(c, handle->family))
 801                                 continue;
 802
 803                         if (c->table != handle->table)
 804                                 continue;
 805
 806                         if (c->flag && !has(z->flags, handle->family, c->flag))
 807                                 continue;
 808
 809                         fw3_ipt_flush_chain(handle, format_chain(c->format, z->name));
 810                 }
 811
 812                 /* ... then remove the chains */
 813                 for (c = zone_chains; c->format; c++)
 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_delete_chain(handle, reload,
 825                                              format_chain(c->format, z->name));
 826                 }
 827
 828                 del(z->flags, handle->family, handle->table);
 829         }
 830 }
 831
 832 void
 833 fw3_hotplug_zones(struct fw3_state *state, bool add)
 834 {
 835         struct fw3_zone *z;
 836         struct fw3_device *d;
 837
 838         list_for_each_entry(z, &state->zones, list)
 839         {
 840                 if (add != fw3_hasbit(z->flags[0], FW3_FLAG_HOTPLUG))
 841                 {
 842                         list_for_each_entry(d, &z->devices, list)
 843                                 fw3_hotplug(add, z, d);
 844
 845                         if (add)
 846                                 fw3_setbit(z->flags[0], FW3_FLAG_HOTPLUG);
 847                         else
 848                                 fw3_delbit(z->flags[0], FW3_FLAG_HOTPLUG);
 849                 }
 850         }
 851 }
 852
 853 struct fw3_zone *
 854 fw3_lookup_zone(struct fw3_state *state, const char *name)
 855 {
 856         struct fw3_zone *z;
 857
 858         if (list_empty(&state->zones))
 859                 return NULL;
 860
 861         list_for_each_entry(z, &state->zones, list)
 862         {
 863                 if (strcmp(z->name, name))
 864                         continue;
 865
 866                 return z;
 867         }
 868
 869         return NULL;
 870 }
 871
 872 struct list_head *
 873 fw3_resolve_zone_addresses(struct fw3_zone *zone, struct fw3_address *addr)
 874 {
 875         struct fw3_device *net;
 876         struct fw3_address *cur, *tmp;
 877         struct list_head *all;
 878
 879         all = calloc(1, sizeof(*all));
 880         if (!all)
 881                 return NULL;
 882
 883         INIT_LIST_HEAD(all);
 884
 885         if (addr && addr->set)
 886         {
 887                 tmp = malloc(sizeof(*tmp));
 888
 889                 if (tmp)
 890                 {
 891                         *tmp = *addr;
 892                         list_add_tail(&tmp->list, all);
 893                 }
 894         }
 895         else
 896         {
 897                 list_for_each_entry(net, &zone->networks, list)
 898                         fw3_ubus_address(all, net->name);
 899
 900                 list_for_each_entry(cur, &zone->subnets, list)
 901                 {
 902                         tmp = malloc(sizeof(*tmp));
 903
 904                         if (!tmp)
 905                                 continue;
 906
 907                         *tmp = *cur;
 908                         list_add_tail(&tmp->list, all);
 909                 }
 910         }
 911
 912         return all;
 913 }