zones.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include "zones.h"
  20 #include "ubus.h"
  21
  22
  23 #define C(f, tbl, tgt, name) \
  24         { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_TARGET_##tgt, name }
  25
  26 struct chain {
  27         enum fw3_family family;
  28         enum fw3_table table;
  29         enum fw3_target target;
  30         const char *name;
  31 };
  32
  33 static const struct chain src_chains[] = {
  34         C(ANY, FILTER, UNSPEC,  "zone_%s_input"),
  35         C(ANY, FILTER, UNSPEC,  "zone_%s_output"),
  36         C(ANY, FILTER, UNSPEC,  "zone_%s_forward"),
  37
  38         C(ANY, FILTER, ACCEPT,  "zone_%s_src_ACCEPT"),
  39         C(ANY, FILTER, REJECT,  "zone_%s_src_REJECT"),
  40         C(ANY, FILTER, DROP,    "zone_%s_src_DROP"),
  41 };
  42
  43 static const struct chain dst_chains[] = {
  44         C(ANY, FILTER, ACCEPT,  "zone_%s_dest_ACCEPT"),
  45         C(ANY, FILTER, REJECT,  "zone_%s_dest_REJECT"),
  46         C(ANY, FILTER, DROP,    "zone_%s_dest_DROP"),
  47
  48         C(V4,  NAT,    SNAT,    "zone_%s_postrouting"),
  49         C(V4,  NAT,    DNAT,    "zone_%s_prerouting"),
  50
  51         C(ANY, RAW,    NOTRACK, "zone_%s_notrack"),
  52 };
  53
  54 static struct fw3_option zone_opts[] = {
  55         FW3_OPT("name",                string,   zone,     name),
  56
  57         FW3_LIST("network",            device,   zone,     networks),
  58         FW3_LIST("device",             device,   zone,     devices),
  59         FW3_LIST("subnet",             address,  zone,     subnets),
  60
  61         FW3_OPT("input",               target,   zone,     policy_input),
  62         FW3_OPT("forward",             target,   zone,     policy_forward),
  63         FW3_OPT("output",              target,   zone,     policy_output),
  64
  65         FW3_OPT("masq",                bool,     zone,     masq),
  66         FW3_LIST("masq_src",           address,  zone,     masq_src),
  67         FW3_LIST("masq_dest",          address,  zone,     masq_dest),
  68
  69         FW3_OPT("extra",               string,   zone,     extra_src),
  70         FW3_OPT("extra_src",           string,   zone,     extra_src),
  71         FW3_OPT("extra_dest",          string,   zone,     extra_dest),
  72
  73         FW3_OPT("conntrack",           bool,     zone,     conntrack),
  74         FW3_OPT("mtu_fix",             bool,     zone,     mtu_fix),
  75         FW3_OPT("custom_chains",       bool,     zone,     custom_chains),
  76
  77         FW3_OPT("log",                 bool,     zone,     log),
  78         FW3_OPT("log_limit",           limit,    zone,     log_limit),
  79 };
  80
  81
  82 static bool
  83 print_chains(enum fw3_table table, enum fw3_family family,
  84              const char *fmt, const char *name, uint8_t targets,
  85              const struct chain *chains, int n)
  86 {
  87         bool rv = false;
  88         char cn[128] = { 0 };
  89         const struct chain *c;
  90
  91         for (c = chains; n > 0; c++, n--)
  92         {
  93                 if (!fw3_is_family(c, family))
  94                         continue;
  95
  96                 if (c->table != table)
  97                         continue;
  98
  99                 if ((c->target != FW3_TARGET_UNSPEC) && !(targets & (1 << c->target)))
 100                         continue;
 101
 102                 snprintf(cn, sizeof(cn), c->name, name);
 103                 fw3_pr(fmt, cn);
 104
 105                 rv = true;
 106         }
 107
 108         return rv;
 109 }
 110
 111 static void
 112 check_policy(struct uci_element *e, enum fw3_target *pol, enum fw3_target def,
 113              const char *name)
 114 {
 115         if (*pol == FW3_TARGET_UNSPEC)
 116         {
 117                 warn_elem(e, "has no %s policy specified, using default", name);
 118                 *pol = def;
 119         }
 120         else if (*pol > FW3_TARGET_DROP)
 121         {
 122                 warn_elem(e, "has invalid %s policy, using default", name);
 123                 *pol = def;
 124         }
 125 }
 126
 127 static void
 128 resolve_networks(struct uci_element *e, struct fw3_zone *zone)
 129 {
 130         struct fw3_device *net, *tmp;
 131
 132         list_for_each_entry(net, &zone->networks, list)
 133         {
 134                 tmp = fw3_ubus_device(net->name);
 135
 136                 if (!tmp)
 137                 {
 138                         warn_elem(e, "cannot resolve device of network '%s'", net->name);
 139                         continue;
 140                 }
 141
 142                 list_add_tail(&tmp->list, &zone->devices);
 143         }
 144 }
 145
 146 void
 147 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
 148 {
 149         struct uci_section *s;
 150         struct uci_element *e;
 151         struct fw3_zone *zone;
 152         struct fw3_defaults *defs = &state->defaults;
 153
 154         INIT_LIST_HEAD(&state->zones);
 155
 156         uci_foreach_element(&p->sections, e)
 157         {
 158                 s = uci_to_section(e);
 159
 160                 if (strcmp(s->type, "zone"))
 161                         continue;
 162
 163                 zone = malloc(sizeof(*zone));
 164
 165                 if (!zone)
 166                         continue;
 167
 168                 memset(zone, 0, sizeof(*zone));
 169
 170                 INIT_LIST_HEAD(&zone->networks);
 171                 INIT_LIST_HEAD(&zone->devices);
 172                 INIT_LIST_HEAD(&zone->subnets);
 173                 INIT_LIST_HEAD(&zone->masq_src);
 174                 INIT_LIST_HEAD(&zone->masq_dest);
 175
 176                 zone->log_limit.rate = 10;
 177
 178                 fw3_parse_options(zone, zone_opts, ARRAY_SIZE(zone_opts), s);
 179
 180                 if (!zone->extra_dest)
 181                         zone->extra_dest = zone->extra_src;
 182
 183                 if (!zone->name || !*zone->name)
 184                 {
 185                         warn_elem(e, "has no name - ignoring");
 186                         fw3_free_zone(zone);
 187                         continue;
 188                 }
 189
 190                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
 191                     list_empty(&zone->subnets) && !zone->extra_src)
 192                 {
 193                         warn_elem(e, "has no device, network, subnet or extra options");
 194                 }
 195
 196                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
 197                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
 198                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
 199
 200                 resolve_networks(e, zone);
 201
 202                 if (zone->masq)
 203                 {
 204                         zone->has_dest_target |= (1 << FW3_TARGET_SNAT);
 205                         zone->conntrack = true;
 206                 }
 207
 208                 zone->has_src_target  |= (1 << zone->policy_input);
 209                 zone->has_dest_target |= (1 << zone->policy_output);
 210                 zone->has_dest_target |= (1 << zone->policy_forward);
 211
 212                 list_add_tail(&zone->list, &state->zones);
 213         }
 214 }
 215
 216
 217 static void
 218 print_zone_chain(enum fw3_table table, enum fw3_family family,
 219                  struct fw3_zone *zone, bool disable_notrack)
 220 {
 221         bool s, d;
 222
 223         if (!fw3_is_family(zone, family))
 224                 return;
 225
 226         if (!zone->conntrack && !disable_notrack)
 227                 zone->has_dest_target |= (1 << FW3_TARGET_NOTRACK);
 228
 229         s = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 230                          zone->has_src_target, src_chains, ARRAY_SIZE(src_chains));
 231
 232         d = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 233                          zone->has_dest_target, dst_chains, ARRAY_SIZE(dst_chains));
 234
 235         if (s || d)
 236                 info("   * Zone '%s'", zone->name);
 237 }
 238
 239 static void
 240 print_interface_rule(enum fw3_table table, enum fw3_family family,
 241                      struct fw3_zone *zone, struct fw3_device *dev,
 242                      struct fw3_address *sub, bool disable_notrack)
 243 {
 244         enum fw3_target t;
 245         const char *targets[] = {
 246                 "(bug)",  "(bug)",
 247                 "ACCEPT", "ACCEPT",
 248                 "REJECT", "reject",
 249                 "DROP",   "DROP",
 250         };
 251
 252         if (table == FW3_TABLE_FILTER)
 253         {
 254                 for (t = FW3_TARGET_ACCEPT; t <= FW3_TARGET_DROP; t++)
 255                 {
 256                         if (zone->has_src_target & (1 << t))
 257                         {
 258                                 fw3_pr("-A zone_%s_src_%s", zone->name, targets[t*2]);
 259                                 fw3_format_in_out(dev, NULL);
 260                                 fw3_format_src_dest(sub, NULL);
 261                                 fw3_format_extra(zone->extra_src);
 262                                 fw3_pr(" -j %s\n", targets[t*2+1]);
 263                         }
 264
 265                         if (zone->has_dest_target & (1 << t))
 266                         {
 267                                 fw3_pr("-A zone_%s_dest_%s", zone->name, targets[t*2]);
 268                                 fw3_format_in_out(NULL, dev);
 269                                 fw3_format_src_dest(NULL, sub);
 270                                 fw3_format_extra(zone->extra_dest);
 271                                 fw3_pr(" -j %s\n", targets[t*2+1]);
 272                         }
 273                 }
 274
 275                 fw3_pr("-A delegate_input");
 276                 fw3_format_in_out(dev, NULL);
 277                 fw3_format_src_dest(sub, NULL);
 278                 fw3_format_extra(zone->extra_src);
 279                 fw3_pr(" -j zone_%s_input\n", zone->name);
 280
 281                 fw3_pr("-A delegate_forward");
 282                 fw3_format_in_out(dev, NULL);
 283                 fw3_format_src_dest(sub, NULL);
 284                 fw3_format_extra(zone->extra_src);
 285                 fw3_pr(" -j zone_%s_forward\n", zone->name);
 286
 287                 fw3_pr("-A delegate_output");
 288                 fw3_format_in_out(NULL, dev);
 289                 fw3_format_src_dest(NULL, sub);
 290                 fw3_format_extra(zone->extra_dest);
 291                 fw3_pr(" -j zone_%s_output\n", zone->name);
 292         }
 293         else if (table == FW3_TABLE_NAT)
 294         {
 295                 if (zone->has_dest_target & (1 << FW3_TARGET_DNAT))
 296                 {
 297                         fw3_pr("-A delegate_prerouting");
 298                         fw3_format_in_out(dev, NULL);
 299                         fw3_format_src_dest(sub, NULL);
 300                         fw3_format_extra(zone->extra_src);
 301                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
 302                 }
 303
 304                 if (zone->has_dest_target & (1 << FW3_TARGET_SNAT))
 305                 {
 306                         fw3_pr("-A delegate_postrouting");
 307                         fw3_format_in_out(NULL, dev);
 308                         fw3_format_src_dest(NULL, sub);
 309                         fw3_format_extra(zone->extra_dest);
 310                         fw3_pr(" -j zone_%s_postrouting\n", zone->name);
 311                 }
 312         }
 313         else if (table == FW3_TABLE_MANGLE)
 314         {
 315                 if (zone->mtu_fix)
 316                 {
 317                         if (zone->log)
 318                         {
 319                                 fw3_pr("-A mssfix");
 320                                 fw3_format_in_out(NULL, dev);
 321                                 fw3_format_src_dest(NULL, sub);
 322                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 323                                 fw3_format_limit(&zone->log_limit);
 324                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
 325                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
 326                         }
 327
 328                         fw3_pr("-A mssfix");
 329                         fw3_format_in_out(NULL, dev);
 330                         fw3_format_src_dest(NULL, sub);
 331                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 332                         fw3_format_comment(zone->name, " (mtu_fix)");
 333                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
 334                 }
 335         }
 336         else if (table == FW3_TABLE_RAW)
 337         {
 338                 if (!zone->conntrack && !disable_notrack)
 339                 {
 340                         fw3_pr("-A notrack");
 341                         fw3_format_in_out(dev, NULL);
 342                         fw3_format_src_dest(sub, NULL);
 343                         fw3_format_extra(zone->extra_src);
 344                         fw3_format_comment(zone->name, " (notrack)");
 345                         fw3_pr(" -j CT --notrack\n", zone->name);
 346                 }
 347         }
 348 }
 349
 350 static void
 351 print_interface_rules(enum fw3_table table, enum fw3_family family,
 352                       struct fw3_zone *zone, bool disable_notrack)
 353 {
 354         struct fw3_device *dev;
 355         struct fw3_address *sub;
 356
 357         fw3_foreach(dev, &zone->devices)
 358         fw3_foreach(sub, &zone->subnets)
 359         {
 360                 if (!fw3_is_family(sub, family))
 361                         continue;
 362
 363                 if (!dev && !sub)
 364                         continue;
 365
 366                 print_interface_rule(table, family, zone, dev, sub, disable_notrack);
 367         }
 368 }
 369
 370 static void
 371 print_zone_rule(enum fw3_table table, enum fw3_family family,
 372                 struct fw3_zone *zone, bool disable_notrack)
 373 {
 374         struct fw3_address *msrc;
 375         struct fw3_address *mdest;
 376
 377         enum fw3_target t;
 378         const char *targets[] = {
 379                 "(bug)",
 380                 "ACCEPT",
 381                 "REJECT",
 382                 "DROP",
 383                 "(bug)",
 384                 "(bug)",
 385                 "(bug)",
 386         };
 387
 388         if (!fw3_is_family(zone, family))
 389                 return;
 390
 391         switch (table)
 392         {
 393         case FW3_TABLE_FILTER:
 394                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 395                            zone->name, zone->name, targets[zone->policy_input]);
 396
 397                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 398                            zone->name, zone->name, targets[zone->policy_forward]);
 399
 400                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 401                            zone->name, zone->name, targets[zone->policy_output]);
 402
 403                 if (zone->log)
 404                 {
 405                         for (t = FW3_TARGET_REJECT; t <= FW3_TARGET_DROP; t++)
 406                         {
 407                                 if (zone->has_src_target & (1 << t))
 408                                 {
 409                                         fw3_pr("-A zone_%s_src_%s", zone->name, targets[t]);
 410                                         fw3_format_limit(&zone->log_limit);
 411                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 412                                                    targets[t], zone->name);
 413                                 }
 414
 415                                 if (zone->has_dest_target & (1 << t))
 416                                 {
 417                                         fw3_pr("-A zone_%s_dest_%s", zone->name, targets[t]);
 418                                         fw3_format_limit(&zone->log_limit);
 419                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 420                                                    targets[t], zone->name);
 421                                 }
 422                         }
 423                 }
 424                 break;
 425
 426         case FW3_TABLE_NAT:
 427                 if (zone->masq && family == FW3_FAMILY_V4)
 428                 {
 429                         fw3_foreach(msrc, &zone->masq_src)
 430                         fw3_foreach(mdest, &zone->masq_dest)
 431                         {
 432                                 fw3_pr("-A zone_%s_postrouting ", zone->name);
 433                                 fw3_format_src_dest(msrc, mdest);
 434                                 fw3_pr("-j MASQUERADE\n");
 435                         }
 436                 }
 437                 break;
 438
 439         case FW3_TABLE_RAW:
 440         case FW3_TABLE_MANGLE:
 441                 break;
 442         }
 443
 444         print_interface_rules(table, family, zone, disable_notrack);
 445 }
 446
 447 void
 448 fw3_print_zone_chains(enum fw3_table table, enum fw3_family family,
 449                       struct fw3_state *state)
 450 {
 451         struct fw3_zone *zone;
 452
 453         list_for_each_entry(zone, &state->zones, list)
 454                 print_zone_chain(table, family, zone, state->defaults.drop_invalid);
 455 }
 456
 457 void
 458 fw3_print_zone_rules(enum fw3_table table, enum fw3_family family,
 459                      struct fw3_state *state)
 460 {
 461         struct fw3_zone *zone;
 462
 463         list_for_each_entry(zone, &state->zones, list)
 464                 print_zone_rule(table, family, zone, state->defaults.drop_invalid);
 465 }
 466
 467 void
 468 fw3_flush_zones(enum fw3_table table, enum fw3_family family,
 469                             bool pass2, struct list_head *statefile)
 470 {
 471         struct fw3_statefile_entry *e;
 472
 473         list_for_each_entry(e, statefile, list)
 474         {
 475                 if (e->type != FW3_TYPE_ZONE)
 476                         continue;
 477
 478                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 479                              e->name, e->flags[0], src_chains, ARRAY_SIZE(src_chains));
 480
 481                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 482                              e->name, e->flags[1], dst_chains, ARRAY_SIZE(dst_chains));
 483         }
 484 }
 485
 486 struct fw3_zone *
 487 fw3_lookup_zone(struct fw3_state *state, const char *name)
 488 {
 489         struct fw3_zone *z;
 490
 491         if (list_empty(&state->zones))
 492                 return NULL;
 493
 494         list_for_each_entry(z, &state->zones, list)
 495                 if (!strcmp(z->name, name))
 496                         return z;
 497
 498         return NULL;
 499 }
 500
 501 void
 502 fw3_free_zone(struct fw3_zone *zone)
 503 {
 504         fw3_free_list(&zone->networks);
 505         fw3_free_list(&zone->devices);
 506         fw3_free_list(&zone->subnets);
 507
 508         fw3_free_list(&zone->masq_src);
 509         fw3_free_list(&zone->masq_dest);
 510
 511         free(zone);
 512 }