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         FW3_OPT("family",              family,   zone,     family),
  57
  58         FW3_LIST("network",            device,   zone,     networks),
  59         FW3_LIST("device",             device,   zone,     devices),
  60         FW3_LIST("subnet",             address,  zone,     subnets),
  61
  62         FW3_OPT("input",               target,   zone,     policy_input),
  63         FW3_OPT("forward",             target,   zone,     policy_forward),
  64         FW3_OPT("output",              target,   zone,     policy_output),
  65
  66         FW3_OPT("masq",                bool,     zone,     masq),
  67         FW3_LIST("masq_src",           address,  zone,     masq_src),
  68         FW3_LIST("masq_dest",          address,  zone,     masq_dest),
  69
  70         FW3_OPT("extra",               string,   zone,     extra_src),
  71         FW3_OPT("extra_src",           string,   zone,     extra_src),
  72         FW3_OPT("extra_dest",          string,   zone,     extra_dest),
  73
  74         FW3_OPT("conntrack",           bool,     zone,     conntrack),
  75         FW3_OPT("mtu_fix",             bool,     zone,     mtu_fix),
  76         FW3_OPT("custom_chains",       bool,     zone,     custom_chains),
  77
  78         FW3_OPT("log",                 bool,     zone,     log),
  79         FW3_OPT("log_limit",           limit,    zone,     log_limit),
  80 };
  81
  82
  83 static bool
  84 print_chains(enum fw3_table table, enum fw3_family family,
  85              const char *fmt, const char *name, uint16_t targets,
  86              const struct chain *chains, int n)
  87 {
  88         bool rv = false;
  89         char cn[128] = { 0 };
  90         const struct chain *c;
  91
  92         for (c = chains; n > 0; c++, n--)
  93         {
  94                 if (!fw3_is_family(c, family))
  95                         continue;
  96
  97                 if (c->table != table)
  98                         continue;
  99
 100                 if ((c->target != FW3_TARGET_UNSPEC) && !hasbit(targets, c->target))
 101                         continue;
 102
 103                 snprintf(cn, sizeof(cn), c->name, name);
 104                 fw3_pr(fmt, cn);
 105
 106                 rv = true;
 107         }
 108
 109         return rv;
 110 }
 111
 112 static void
 113 check_policy(struct uci_element *e, enum fw3_target *pol, enum fw3_target def,
 114              const char *name)
 115 {
 116         if (*pol == FW3_TARGET_UNSPEC)
 117         {
 118                 warn_elem(e, "has no %s policy specified, using default", name);
 119                 *pol = def;
 120         }
 121         else if (*pol > FW3_TARGET_DROP)
 122         {
 123                 warn_elem(e, "has invalid %s policy, using default", name);
 124                 *pol = def;
 125         }
 126 }
 127
 128 static void
 129 resolve_networks(struct uci_element *e, struct fw3_zone *zone)
 130 {
 131         struct fw3_device *net, *tmp;
 132
 133         list_for_each_entry(net, &zone->networks, list)
 134         {
 135                 tmp = fw3_ubus_device(net->name);
 136
 137                 if (!tmp)
 138                 {
 139                         warn_elem(e, "cannot resolve device of network '%s'", net->name);
 140                         continue;
 141                 }
 142
 143                 list_add_tail(&tmp->list, &zone->devices);
 144         }
 145 }
 146
 147 void
 148 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
 149 {
 150         struct uci_section *s;
 151         struct uci_element *e;
 152         struct fw3_zone *zone;
 153         struct fw3_defaults *defs = &state->defaults;
 154
 155         INIT_LIST_HEAD(&state->zones);
 156
 157         uci_foreach_element(&p->sections, e)
 158         {
 159                 s = uci_to_section(e);
 160
 161                 if (strcmp(s->type, "zone"))
 162                         continue;
 163
 164                 zone = malloc(sizeof(*zone));
 165
 166                 if (!zone)
 167                         continue;
 168
 169                 memset(zone, 0, sizeof(*zone));
 170
 171                 INIT_LIST_HEAD(&zone->networks);
 172                 INIT_LIST_HEAD(&zone->devices);
 173                 INIT_LIST_HEAD(&zone->subnets);
 174                 INIT_LIST_HEAD(&zone->masq_src);
 175                 INIT_LIST_HEAD(&zone->masq_dest);
 176
 177                 zone->log_limit.rate = 10;
 178
 179                 fw3_parse_options(zone, zone_opts, ARRAY_SIZE(zone_opts), s);
 180
 181                 if (!zone->extra_dest)
 182                         zone->extra_dest = zone->extra_src;
 183
 184                 if (!zone->name || !*zone->name)
 185                 {
 186                         warn_elem(e, "has no name - ignoring");
 187                         fw3_free_zone(zone);
 188                         continue;
 189                 }
 190
 191                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
 192                     list_empty(&zone->subnets) && !zone->extra_src)
 193                 {
 194                         warn_elem(e, "has no device, network, subnet or extra options");
 195                 }
 196
 197                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
 198                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
 199                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
 200
 201                 resolve_networks(e, zone);
 202
 203                 if (zone->masq)
 204                 {
 205                         setbit(zone->dst_flags, FW3_TARGET_SNAT);
 206                         zone->conntrack = true;
 207                 }
 208
 209                 setbit(zone->src_flags, zone->policy_input);
 210                 setbit(zone->dst_flags, zone->policy_output);
 211                 setbit(zone->dst_flags, zone->policy_forward);
 212
 213                 list_add_tail(&zone->list, &state->zones);
 214         }
 215 }
 216
 217
 218 static void
 219 print_zone_chain(enum fw3_table table, enum fw3_family family,
 220                  struct fw3_zone *zone, bool disable_notrack)
 221 {
 222         bool s, d;
 223
 224         if (!fw3_is_family(zone, family))
 225                 return;
 226
 227         setbit(zone->dst_flags, family);
 228
 229         if (!zone->conntrack && !disable_notrack)
 230                 setbit(zone->dst_flags, FW3_TARGET_NOTRACK);
 231
 232         s = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 233                          zone->src_flags, src_chains, ARRAY_SIZE(src_chains));
 234
 235         d = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 236                          zone->dst_flags, dst_chains, ARRAY_SIZE(dst_chains));
 237
 238         if (s || d)
 239                 info("   * Zone '%s'", zone->name);
 240 }
 241
 242 static void
 243 print_interface_rule(enum fw3_table table, enum fw3_family family,
 244                      struct fw3_zone *zone, struct fw3_device *dev,
 245                      struct fw3_address *sub, bool disable_notrack)
 246 {
 247         enum fw3_target t;
 248
 249 #define jump_target(t) \
 250         ((t == FW3_TARGET_REJECT) ? "reject" : fw3_flag_names[t])
 251
 252         if (table == FW3_TABLE_FILTER)
 253         {
 254                 for (t = FW3_TARGET_ACCEPT; t <= FW3_TARGET_DROP; t++)
 255                 {
 256                         if (hasbit(zone->src_flags, t))
 257                         {
 258                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 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", jump_target(t));
 263                         }
 264
 265                         if (hasbit(zone->dst_flags, t))
 266                         {
 267                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 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", jump_target(t));
 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 (hasbit(zone->dst_flags, 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 (hasbit(zone->dst_flags, 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
 379         if (!fw3_is_family(zone, family))
 380                 return;
 381
 382         switch (table)
 383         {
 384         case FW3_TABLE_FILTER:
 385                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 386                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
 387
 388                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 389                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
 390
 391                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 392                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
 393
 394                 if (zone->log)
 395                 {
 396                         for (t = FW3_TARGET_REJECT; t <= FW3_TARGET_DROP; t++)
 397                         {
 398                                 if (hasbit(zone->src_flags, t))
 399                                 {
 400                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 401                                         fw3_format_limit(&zone->log_limit);
 402                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 403                                                    fw3_flag_names[t], zone->name);
 404                                 }
 405
 406                                 if (hasbit(zone->dst_flags, t))
 407                                 {
 408                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 409                                         fw3_format_limit(&zone->log_limit);
 410                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 411                                                    fw3_flag_names[t], zone->name);
 412                                 }
 413                         }
 414                 }
 415                 break;
 416
 417         case FW3_TABLE_NAT:
 418                 if (zone->masq && family == FW3_FAMILY_V4)
 419                 {
 420                         fw3_foreach(msrc, &zone->masq_src)
 421                         fw3_foreach(mdest, &zone->masq_dest)
 422                         {
 423                                 fw3_pr("-A zone_%s_postrouting ", zone->name);
 424                                 fw3_format_src_dest(msrc, mdest);
 425                                 fw3_pr("-j MASQUERADE\n");
 426                         }
 427                 }
 428                 break;
 429
 430         case FW3_TABLE_RAW:
 431         case FW3_TABLE_MANGLE:
 432                 break;
 433         }
 434
 435         print_interface_rules(table, family, zone, disable_notrack);
 436 }
 437
 438 void
 439 fw3_print_zone_chains(enum fw3_table table, enum fw3_family family,
 440                       struct fw3_state *state)
 441 {
 442         struct fw3_zone *zone;
 443
 444         list_for_each_entry(zone, &state->zones, list)
 445                 print_zone_chain(table, family, zone, state->defaults.drop_invalid);
 446 }
 447
 448 void
 449 fw3_print_zone_rules(enum fw3_table table, enum fw3_family family,
 450                      struct fw3_state *state)
 451 {
 452         struct fw3_zone *zone;
 453
 454         list_for_each_entry(zone, &state->zones, list)
 455                 print_zone_rule(table, family, zone, state->defaults.drop_invalid);
 456 }
 457
 458 void
 459 fw3_flush_zones(enum fw3_table table, enum fw3_family family,
 460                             bool pass2, struct list_head *statefile)
 461 {
 462         struct fw3_statefile_entry *e;
 463
 464         list_for_each_entry(e, statefile, list)
 465         {
 466                 if (e->type != FW3_TYPE_ZONE)
 467                         continue;
 468
 469                 if (!hasbit(e->flags[1], family))
 470                         continue;
 471
 472                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 473                              e->name, e->flags[0], src_chains, ARRAY_SIZE(src_chains));
 474
 475                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 476                              e->name, e->flags[1], dst_chains, ARRAY_SIZE(dst_chains));
 477         }
 478 }
 479
 480 struct fw3_zone *
 481 fw3_lookup_zone(struct fw3_state *state, const char *name)
 482 {
 483         struct fw3_zone *z;
 484
 485         if (list_empty(&state->zones))
 486                 return NULL;
 487
 488         list_for_each_entry(z, &state->zones, list)
 489                 if (!strcmp(z->name, name))
 490                         return z;
 491
 492         return NULL;
 493 }
 494
 495 void
 496 fw3_free_zone(struct fw3_zone *zone)
 497 {
 498         fw3_free_list(&zone->networks);
 499         fw3_free_list(&zone->devices);
 500         fw3_free_list(&zone->subnets);
 501
 502         fw3_free_list(&zone->masq_src);
 503         fw3_free_list(&zone->masq_dest);
 504
 505         free(zone);
 506 }