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         if (!zone->conntrack && !disable_notrack)
 228                 setbit(zone->dst_flags, FW3_TARGET_NOTRACK);
 229
 230         s = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 231                          zone->src_flags, src_chains, ARRAY_SIZE(src_chains));
 232
 233         d = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 234                          zone->dst_flags, dst_chains, ARRAY_SIZE(dst_chains));
 235
 236         if (s || d)
 237                 info("   * Zone '%s'", zone->name);
 238 }
 239
 240 static void
 241 print_interface_rule(enum fw3_table table, enum fw3_family family,
 242                      struct fw3_zone *zone, struct fw3_device *dev,
 243                      struct fw3_address *sub, bool disable_notrack)
 244 {
 245         enum fw3_target t;
 246
 247 #define jump_target(t) \
 248         ((t == FW3_TARGET_REJECT) ? "reject" : fw3_flag_names[t])
 249
 250         if (table == FW3_TABLE_FILTER)
 251         {
 252                 for (t = FW3_TARGET_ACCEPT; t <= FW3_TARGET_DROP; t++)
 253                 {
 254                         if (hasbit(zone->src_flags, t))
 255                         {
 256                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 257                                 fw3_format_in_out(dev, NULL);
 258                                 fw3_format_src_dest(sub, NULL);
 259                                 fw3_format_extra(zone->extra_src);
 260                                 fw3_pr(" -j %s\n", jump_target(t));
 261                         }
 262
 263                         if (hasbit(zone->dst_flags, t))
 264                         {
 265                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 266                                 fw3_format_in_out(NULL, dev);
 267                                 fw3_format_src_dest(NULL, sub);
 268                                 fw3_format_extra(zone->extra_dest);
 269                                 fw3_pr(" -j %s\n", jump_target(t));
 270                         }
 271                 }
 272
 273                 fw3_pr("-A delegate_input");
 274                 fw3_format_in_out(dev, NULL);
 275                 fw3_format_src_dest(sub, NULL);
 276                 fw3_format_extra(zone->extra_src);
 277                 fw3_pr(" -j zone_%s_input\n", zone->name);
 278
 279                 fw3_pr("-A delegate_forward");
 280                 fw3_format_in_out(dev, NULL);
 281                 fw3_format_src_dest(sub, NULL);
 282                 fw3_format_extra(zone->extra_src);
 283                 fw3_pr(" -j zone_%s_forward\n", zone->name);
 284
 285                 fw3_pr("-A delegate_output");
 286                 fw3_format_in_out(NULL, dev);
 287                 fw3_format_src_dest(NULL, sub);
 288                 fw3_format_extra(zone->extra_dest);
 289                 fw3_pr(" -j zone_%s_output\n", zone->name);
 290         }
 291         else if (table == FW3_TABLE_NAT)
 292         {
 293                 if (hasbit(zone->dst_flags, FW3_TARGET_DNAT))
 294                 {
 295                         fw3_pr("-A delegate_prerouting");
 296                         fw3_format_in_out(dev, NULL);
 297                         fw3_format_src_dest(sub, NULL);
 298                         fw3_format_extra(zone->extra_src);
 299                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
 300                 }
 301
 302                 if (hasbit(zone->dst_flags, FW3_TARGET_SNAT))
 303                 {
 304                         fw3_pr("-A delegate_postrouting");
 305                         fw3_format_in_out(NULL, dev);
 306                         fw3_format_src_dest(NULL, sub);
 307                         fw3_format_extra(zone->extra_dest);
 308                         fw3_pr(" -j zone_%s_postrouting\n", zone->name);
 309                 }
 310         }
 311         else if (table == FW3_TABLE_MANGLE)
 312         {
 313                 if (zone->mtu_fix)
 314                 {
 315                         if (zone->log)
 316                         {
 317                                 fw3_pr("-A mssfix");
 318                                 fw3_format_in_out(NULL, dev);
 319                                 fw3_format_src_dest(NULL, sub);
 320                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 321                                 fw3_format_limit(&zone->log_limit);
 322                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
 323                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
 324                         }
 325
 326                         fw3_pr("-A mssfix");
 327                         fw3_format_in_out(NULL, dev);
 328                         fw3_format_src_dest(NULL, sub);
 329                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 330                         fw3_format_comment(zone->name, " (mtu_fix)");
 331                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
 332                 }
 333         }
 334         else if (table == FW3_TABLE_RAW)
 335         {
 336                 if (!zone->conntrack && !disable_notrack)
 337                 {
 338                         fw3_pr("-A notrack");
 339                         fw3_format_in_out(dev, NULL);
 340                         fw3_format_src_dest(sub, NULL);
 341                         fw3_format_extra(zone->extra_src);
 342                         fw3_format_comment(zone->name, " (notrack)");
 343                         fw3_pr(" -j CT --notrack\n", zone->name);
 344                 }
 345         }
 346 }
 347
 348 static void
 349 print_interface_rules(enum fw3_table table, enum fw3_family family,
 350                       struct fw3_zone *zone, bool disable_notrack)
 351 {
 352         struct fw3_device *dev;
 353         struct fw3_address *sub;
 354
 355         fw3_foreach(dev, &zone->devices)
 356         fw3_foreach(sub, &zone->subnets)
 357         {
 358                 if (!fw3_is_family(sub, family))
 359                         continue;
 360
 361                 if (!dev && !sub)
 362                         continue;
 363
 364                 print_interface_rule(table, family, zone, dev, sub, disable_notrack);
 365         }
 366 }
 367
 368 static void
 369 print_zone_rule(enum fw3_table table, enum fw3_family family,
 370                 struct fw3_zone *zone, bool disable_notrack)
 371 {
 372         struct fw3_address *msrc;
 373         struct fw3_address *mdest;
 374
 375         enum fw3_target t;
 376
 377         if (!fw3_is_family(zone, family))
 378                 return;
 379
 380         switch (table)
 381         {
 382         case FW3_TABLE_FILTER:
 383                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 384                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
 385
 386                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 387                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
 388
 389                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 390                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
 391
 392                 if (zone->log)
 393                 {
 394                         for (t = FW3_TARGET_REJECT; t <= FW3_TARGET_DROP; t++)
 395                         {
 396                                 if (hasbit(zone->src_flags, t))
 397                                 {
 398                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 399                                         fw3_format_limit(&zone->log_limit);
 400                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 401                                                    fw3_flag_names[t], zone->name);
 402                                 }
 403
 404                                 if (hasbit(zone->dst_flags, t))
 405                                 {
 406                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 407                                         fw3_format_limit(&zone->log_limit);
 408                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 409                                                    fw3_flag_names[t], zone->name);
 410                                 }
 411                         }
 412                 }
 413                 break;
 414
 415         case FW3_TABLE_NAT:
 416                 if (zone->masq && family == FW3_FAMILY_V4)
 417                 {
 418                         fw3_foreach(msrc, &zone->masq_src)
 419                         fw3_foreach(mdest, &zone->masq_dest)
 420                         {
 421                                 fw3_pr("-A zone_%s_postrouting ", zone->name);
 422                                 fw3_format_src_dest(msrc, mdest);
 423                                 fw3_pr("-j MASQUERADE\n");
 424                         }
 425                 }
 426                 break;
 427
 428         case FW3_TABLE_RAW:
 429         case FW3_TABLE_MANGLE:
 430                 break;
 431         }
 432
 433         print_interface_rules(table, family, zone, disable_notrack);
 434 }
 435
 436 void
 437 fw3_print_zone_chains(enum fw3_table table, enum fw3_family family,
 438                       struct fw3_state *state)
 439 {
 440         struct fw3_zone *zone;
 441
 442         list_for_each_entry(zone, &state->zones, list)
 443                 print_zone_chain(table, family, zone, state->defaults.drop_invalid);
 444 }
 445
 446 void
 447 fw3_print_zone_rules(enum fw3_table table, enum fw3_family family,
 448                      struct fw3_state *state)
 449 {
 450         struct fw3_zone *zone;
 451
 452         list_for_each_entry(zone, &state->zones, list)
 453                 print_zone_rule(table, family, zone, state->defaults.drop_invalid);
 454 }
 455
 456 void
 457 fw3_flush_zones(enum fw3_table table, enum fw3_family family,
 458                             bool pass2, struct list_head *statefile)
 459 {
 460         struct fw3_statefile_entry *e;
 461
 462         list_for_each_entry(e, statefile, list)
 463         {
 464                 if (e->type != FW3_TYPE_ZONE)
 465                         continue;
 466
 467                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 468                              e->name, e->flags[0], src_chains, ARRAY_SIZE(src_chains));
 469
 470                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 471                              e->name, e->flags[1], dst_chains, ARRAY_SIZE(dst_chains));
 472         }
 473 }
 474
 475 struct fw3_zone *
 476 fw3_lookup_zone(struct fw3_state *state, const char *name)
 477 {
 478         struct fw3_zone *z;
 479
 480         if (list_empty(&state->zones))
 481                 return NULL;
 482
 483         list_for_each_entry(z, &state->zones, list)
 484                 if (!strcmp(z->name, name))
 485                         return z;
 486
 487         return NULL;
 488 }
 489
 490 void
 491 fw3_free_zone(struct fw3_zone *zone)
 492 {
 493         fw3_free_list(&zone->networks);
 494         fw3_free_list(&zone->devices);
 495         fw3_free_list(&zone->subnets);
 496
 497         fw3_free_list(&zone->masq_src);
 498         fw3_free_list(&zone->masq_dest);
 499
 500         free(zone);
 501 }