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
  52 const struct fw3_option fw3_zone_opts[] = {
  53         FW3_OPT("name",                string,   zone,     name),
  54         FW3_OPT("family",              family,   zone,     family),
  55
  56         FW3_LIST("network",            device,   zone,     networks),
  57         FW3_LIST("device",             device,   zone,     devices),
  58         FW3_LIST("subnet",             address,  zone,     subnets),
  59
  60         FW3_OPT("input",               target,   zone,     policy_input),
  61         FW3_OPT("forward",             target,   zone,     policy_forward),
  62         FW3_OPT("output",              target,   zone,     policy_output),
  63
  64         FW3_OPT("masq",                bool,     zone,     masq),
  65         FW3_LIST("masq_src",           address,  zone,     masq_src),
  66         FW3_LIST("masq_dest",          address,  zone,     masq_dest),
  67
  68         FW3_OPT("extra",               string,   zone,     extra_src),
  69         FW3_OPT("extra_src",           string,   zone,     extra_src),
  70         FW3_OPT("extra_dest",          string,   zone,     extra_dest),
  71
  72         FW3_OPT("conntrack",           bool,     zone,     conntrack),
  73         FW3_OPT("mtu_fix",             bool,     zone,     mtu_fix),
  74         FW3_OPT("custom_chains",       bool,     zone,     custom_chains),
  75
  76         FW3_OPT("log",                 bool,     zone,     log),
  77         FW3_OPT("log_limit",           limit,    zone,     log_limit),
  78
  79         { }
  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 struct fw3_zone *
 148 fw3_alloc_zone(void)
 149 {
 150         struct fw3_zone *zone;
 151
 152         zone = malloc(sizeof(*zone));
 153
 154         if (!zone)
 155                 return NULL;
 156
 157         memset(zone, 0, sizeof(*zone));
 158
 159         INIT_LIST_HEAD(&zone->networks);
 160         INIT_LIST_HEAD(&zone->devices);
 161         INIT_LIST_HEAD(&zone->subnets);
 162         INIT_LIST_HEAD(&zone->masq_src);
 163         INIT_LIST_HEAD(&zone->masq_dest);
 164
 165         zone->log_limit.rate = 10;
 166
 167         return zone;
 168 }
 169
 170 void
 171 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
 172 {
 173         struct uci_section *s;
 174         struct uci_element *e;
 175         struct fw3_zone *zone;
 176         struct fw3_defaults *defs = &state->defaults;
 177
 178         INIT_LIST_HEAD(&state->zones);
 179
 180         uci_foreach_element(&p->sections, e)
 181         {
 182                 s = uci_to_section(e);
 183
 184                 if (strcmp(s->type, "zone"))
 185                         continue;
 186
 187                 zone = fw3_alloc_zone();
 188
 189                 if (!zone)
 190                         continue;
 191
 192                 fw3_parse_options(zone, fw3_zone_opts, s);
 193
 194                 if (!zone->extra_dest)
 195                         zone->extra_dest = zone->extra_src;
 196
 197                 if (!zone->name || !*zone->name)
 198                 {
 199                         warn_elem(e, "has no name - ignoring");
 200                         fw3_free_zone(zone);
 201                         continue;
 202                 }
 203
 204                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
 205                     list_empty(&zone->subnets) && !zone->extra_src)
 206                 {
 207                         warn_elem(e, "has no device, network, subnet or extra options");
 208                 }
 209
 210                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
 211                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
 212                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
 213
 214                 resolve_networks(e, zone);
 215
 216                 if (zone->masq)
 217                 {
 218                         setbit(zone->dst_flags, FW3_TARGET_SNAT);
 219                         zone->conntrack = true;
 220                 }
 221
 222                 setbit(zone->src_flags, zone->policy_input);
 223                 setbit(zone->dst_flags, zone->policy_output);
 224                 setbit(zone->dst_flags, zone->policy_forward);
 225
 226                 list_add_tail(&zone->list, &state->zones);
 227         }
 228 }
 229
 230
 231 static void
 232 print_zone_chain(enum fw3_table table, enum fw3_family family,
 233                  struct fw3_zone *zone, struct fw3_state *state)
 234 {
 235         bool s, d;
 236
 237         if (!fw3_is_family(zone, family))
 238                 return;
 239
 240         setbit(zone->dst_flags, family);
 241
 242         if (!zone->conntrack && !state->defaults.drop_invalid)
 243                 setbit(zone->dst_flags, FW3_TARGET_NOTRACK);
 244
 245         s = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 246                          zone->src_flags, src_chains, ARRAY_SIZE(src_chains));
 247
 248         d = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 249                          zone->dst_flags, dst_chains, ARRAY_SIZE(dst_chains));
 250
 251         if (s || d)
 252         {
 253                 info("   * Zone '%s'", zone->name);
 254                 fw3_set_running(zone, &state->running_zones);
 255         }
 256 }
 257
 258 static void
 259 print_interface_rule(enum fw3_table table, enum fw3_family family,
 260                      struct fw3_zone *zone, struct fw3_device *dev,
 261                      struct fw3_address *sub, bool disable_notrack)
 262 {
 263         enum fw3_target t;
 264
 265 #define jump_target(t) \
 266         ((t == FW3_TARGET_REJECT) ? "reject" : fw3_flag_names[t])
 267
 268         if (table == FW3_TABLE_FILTER)
 269         {
 270                 for (t = FW3_TARGET_ACCEPT; t <= FW3_TARGET_DROP; t++)
 271                 {
 272                         if (hasbit(zone->src_flags, t))
 273                         {
 274                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 275                                 fw3_format_in_out(dev, NULL);
 276                                 fw3_format_src_dest(sub, NULL);
 277                                 fw3_format_extra(zone->extra_src);
 278                                 fw3_pr(" -j %s\n", jump_target(t));
 279                         }
 280
 281                         if (hasbit(zone->dst_flags, t))
 282                         {
 283                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 284                                 fw3_format_in_out(NULL, dev);
 285                                 fw3_format_src_dest(NULL, sub);
 286                                 fw3_format_extra(zone->extra_dest);
 287                                 fw3_pr(" -j %s\n", jump_target(t));
 288                         }
 289                 }
 290
 291                 fw3_pr("-A delegate_input");
 292                 fw3_format_in_out(dev, NULL);
 293                 fw3_format_src_dest(sub, NULL);
 294                 fw3_format_extra(zone->extra_src);
 295                 fw3_pr(" -j zone_%s_input\n", zone->name);
 296
 297                 fw3_pr("-A delegate_forward");
 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_forward\n", zone->name);
 302
 303                 fw3_pr("-A delegate_output");
 304                 fw3_format_in_out(NULL, dev);
 305                 fw3_format_src_dest(NULL, sub);
 306                 fw3_format_extra(zone->extra_dest);
 307                 fw3_pr(" -j zone_%s_output\n", zone->name);
 308         }
 309         else if (table == FW3_TABLE_NAT)
 310         {
 311                 if (hasbit(zone->dst_flags, FW3_TARGET_DNAT))
 312                 {
 313                         fw3_pr("-A delegate_prerouting");
 314                         fw3_format_in_out(dev, NULL);
 315                         fw3_format_src_dest(sub, NULL);
 316                         fw3_format_extra(zone->extra_src);
 317                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
 318                 }
 319
 320                 if (hasbit(zone->dst_flags, FW3_TARGET_SNAT))
 321                 {
 322                         fw3_pr("-A delegate_postrouting");
 323                         fw3_format_in_out(NULL, dev);
 324                         fw3_format_src_dest(NULL, sub);
 325                         fw3_format_extra(zone->extra_dest);
 326                         fw3_pr(" -j zone_%s_postrouting\n", zone->name);
 327                 }
 328         }
 329         else if (table == FW3_TABLE_MANGLE)
 330         {
 331                 if (zone->mtu_fix)
 332                 {
 333                         if (zone->log)
 334                         {
 335                                 fw3_pr("-A mssfix");
 336                                 fw3_format_in_out(NULL, dev);
 337                                 fw3_format_src_dest(NULL, sub);
 338                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 339                                 fw3_format_limit(&zone->log_limit);
 340                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
 341                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
 342                         }
 343
 344                         fw3_pr("-A mssfix");
 345                         fw3_format_in_out(NULL, dev);
 346                         fw3_format_src_dest(NULL, sub);
 347                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 348                         fw3_format_comment(zone->name, " (mtu_fix)");
 349                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
 350                 }
 351         }
 352         else if (table == FW3_TABLE_RAW)
 353         {
 354                 if (!zone->conntrack && !disable_notrack)
 355                 {
 356                         fw3_pr("-A notrack");
 357                         fw3_format_in_out(dev, NULL);
 358                         fw3_format_src_dest(sub, NULL);
 359                         fw3_format_extra(zone->extra_src);
 360                         fw3_format_comment(zone->name, " (notrack)");
 361                         fw3_pr(" -j CT --notrack\n", zone->name);
 362                 }
 363         }
 364 }
 365
 366 static void
 367 print_interface_rules(enum fw3_table table, enum fw3_family family,
 368                       struct fw3_zone *zone, bool disable_notrack)
 369 {
 370         struct fw3_device *dev;
 371         struct fw3_address *sub;
 372
 373         fw3_foreach(dev, &zone->devices)
 374         fw3_foreach(sub, &zone->subnets)
 375         {
 376                 if (!fw3_is_family(sub, family))
 377                         continue;
 378
 379                 if (!dev && !sub)
 380                         continue;
 381
 382                 print_interface_rule(table, family, zone, dev, sub, disable_notrack);
 383         }
 384 }
 385
 386 static void
 387 print_zone_rule(enum fw3_table table, enum fw3_family family,
 388                 struct fw3_zone *zone, bool disable_notrack)
 389 {
 390         struct fw3_address *msrc;
 391         struct fw3_address *mdest;
 392
 393         enum fw3_target t;
 394
 395         if (!fw3_is_family(zone, family))
 396                 return;
 397
 398         switch (table)
 399         {
 400         case FW3_TABLE_FILTER:
 401                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 402                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
 403
 404                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 405                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
 406
 407                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 408                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
 409
 410                 if (zone->log)
 411                 {
 412                         for (t = FW3_TARGET_REJECT; t <= FW3_TARGET_DROP; t++)
 413                         {
 414                                 if (hasbit(zone->src_flags, t))
 415                                 {
 416                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 417                                         fw3_format_limit(&zone->log_limit);
 418                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 419                                                    fw3_flag_names[t], zone->name);
 420                                 }
 421
 422                                 if (hasbit(zone->dst_flags, t))
 423                                 {
 424                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 425                                         fw3_format_limit(&zone->log_limit);
 426                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 427                                                    fw3_flag_names[t], zone->name);
 428                                 }
 429                         }
 430                 }
 431                 break;
 432
 433         case FW3_TABLE_NAT:
 434                 if (zone->masq && family == FW3_FAMILY_V4)
 435                 {
 436                         fw3_foreach(msrc, &zone->masq_src)
 437                         fw3_foreach(mdest, &zone->masq_dest)
 438                         {
 439                                 fw3_pr("-A zone_%s_postrouting ", zone->name);
 440                                 fw3_format_src_dest(msrc, mdest);
 441                                 fw3_pr("-j MASQUERADE\n");
 442                         }
 443                 }
 444                 break;
 445
 446         case FW3_TABLE_RAW:
 447         case FW3_TABLE_MANGLE:
 448                 break;
 449         }
 450
 451         print_interface_rules(table, family, zone, disable_notrack);
 452 }
 453
 454 void
 455 fw3_print_zone_chains(enum fw3_table table, enum fw3_family family,
 456                       struct fw3_state *state)
 457 {
 458         struct fw3_zone *zone;
 459
 460         list_for_each_entry(zone, &state->zones, list)
 461                 print_zone_chain(table, family, zone, state);
 462 }
 463
 464 void
 465 fw3_print_zone_rules(enum fw3_table table, enum fw3_family family,
 466                      struct fw3_state *state)
 467 {
 468         struct fw3_zone *zone;
 469
 470         list_for_each_entry(zone, &state->zones, list)
 471                 print_zone_rule(table, family, zone, state->defaults.drop_invalid);
 472 }
 473
 474 void
 475 fw3_flush_zones(enum fw3_table table, enum fw3_family family,
 476                             bool pass2, struct fw3_state *state)
 477 {
 478         struct fw3_zone *z, *tmp;
 479         int mask = (1 << FW3_FAMILY_V4) | (1 << FW3_FAMILY_V6);
 480
 481         list_for_each_entry_safe(z, tmp, &state->running_zones, running_list)
 482         {
 483                 if (!hasbit(z->dst_flags, family))
 484                         continue;
 485
 486                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 487                              z->name, z->src_flags, src_chains, ARRAY_SIZE(src_chains));
 488
 489                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 490                              z->name, z->dst_flags, dst_chains, ARRAY_SIZE(dst_chains));
 491
 492                 if (pass2)
 493                 {
 494                         delbit(z->dst_flags, family);
 495
 496                         if (!(z->dst_flags & mask))
 497                                 fw3_set_running(z, NULL);
 498                 }
 499         }
 500 }
 501
 502 struct fw3_zone *
 503 fw3_lookup_zone(struct fw3_state *state, const char *name, bool running)
 504 {
 505         struct fw3_zone *z;
 506
 507         if (list_empty(&state->zones))
 508                 return NULL;
 509
 510         list_for_each_entry(z, &state->zones, list)
 511         {
 512                 if (strcmp(z->name, name))
 513                         continue;
 514
 515                 if (!running || z->running_list.next)
 516                         return z;
 517
 518                 break;
 519         }
 520
 521         return NULL;
 522 }