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, uint16_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) && !hasbit(targets, 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                         setbit(zone->dst_flags, FW3_TARGET_SNAT);
 205                         zone->conntrack = true;
 206                 }
 207
 208                 setbit(zone->src_flags, zone->policy_input);
 209                 setbit(zone->dst_flags, zone->policy_output);
 210                 setbit(zone->dst_flags, 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                 setbit(zone->dst_flags, FW3_TARGET_NOTRACK);
 228
 229         s = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 230                          zone->src_flags, src_chains, ARRAY_SIZE(src_chains));
 231
 232         d = print_chains(table, family, ":%s - [0:0]\n", zone->name,
 233                          zone->dst_flags, 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
 246 #define jump_target(t) \
 247         ((t == FW3_TARGET_REJECT) ? "reject" : fw3_flag_names[t])
 248
 249         if (table == FW3_TABLE_FILTER)
 250         {
 251                 for (t = FW3_TARGET_ACCEPT; t <= FW3_TARGET_DROP; t++)
 252                 {
 253                         if (hasbit(zone->src_flags, t))
 254                         {
 255                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 256                                 fw3_format_in_out(dev, NULL);
 257                                 fw3_format_src_dest(sub, NULL);
 258                                 fw3_format_extra(zone->extra_src);
 259                                 fw3_pr(" -j %s\n", jump_target(t));
 260                         }
 261
 262                         if (hasbit(zone->dst_flags, t))
 263                         {
 264                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 265                                 fw3_format_in_out(NULL, dev);
 266                                 fw3_format_src_dest(NULL, sub);
 267                                 fw3_format_extra(zone->extra_dest);
 268                                 fw3_pr(" -j %s\n", jump_target(t));
 269                         }
 270                 }
 271
 272                 fw3_pr("-A delegate_input");
 273                 fw3_format_in_out(dev, NULL);
 274                 fw3_format_src_dest(sub, NULL);
 275                 fw3_format_extra(zone->extra_src);
 276                 fw3_pr(" -j zone_%s_input\n", zone->name);
 277
 278                 fw3_pr("-A delegate_forward");
 279                 fw3_format_in_out(dev, NULL);
 280                 fw3_format_src_dest(sub, NULL);
 281                 fw3_format_extra(zone->extra_src);
 282                 fw3_pr(" -j zone_%s_forward\n", zone->name);
 283
 284                 fw3_pr("-A delegate_output");
 285                 fw3_format_in_out(NULL, dev);
 286                 fw3_format_src_dest(NULL, sub);
 287                 fw3_format_extra(zone->extra_dest);
 288                 fw3_pr(" -j zone_%s_output\n", zone->name);
 289         }
 290         else if (table == FW3_TABLE_NAT)
 291         {
 292                 if (hasbit(zone->dst_flags, FW3_TARGET_DNAT))
 293                 {
 294                         fw3_pr("-A delegate_prerouting");
 295                         fw3_format_in_out(dev, NULL);
 296                         fw3_format_src_dest(sub, NULL);
 297                         fw3_format_extra(zone->extra_src);
 298                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
 299                 }
 300
 301                 if (hasbit(zone->dst_flags, FW3_TARGET_SNAT))
 302                 {
 303                         fw3_pr("-A delegate_postrouting");
 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_postrouting\n", zone->name);
 308                 }
 309         }
 310         else if (table == FW3_TABLE_MANGLE)
 311         {
 312                 if (zone->mtu_fix)
 313                 {
 314                         if (zone->log)
 315                         {
 316                                 fw3_pr("-A mssfix");
 317                                 fw3_format_in_out(NULL, dev);
 318                                 fw3_format_src_dest(NULL, sub);
 319                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 320                                 fw3_format_limit(&zone->log_limit);
 321                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
 322                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
 323                         }
 324
 325                         fw3_pr("-A mssfix");
 326                         fw3_format_in_out(NULL, dev);
 327                         fw3_format_src_dest(NULL, sub);
 328                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
 329                         fw3_format_comment(zone->name, " (mtu_fix)");
 330                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
 331                 }
 332         }
 333         else if (table == FW3_TABLE_RAW)
 334         {
 335                 if (!zone->conntrack && !disable_notrack)
 336                 {
 337                         fw3_pr("-A notrack");
 338                         fw3_format_in_out(dev, NULL);
 339                         fw3_format_src_dest(sub, NULL);
 340                         fw3_format_extra(zone->extra_src);
 341                         fw3_format_comment(zone->name, " (notrack)");
 342                         fw3_pr(" -j CT --notrack\n", zone->name);
 343                 }
 344         }
 345 }
 346
 347 static void
 348 print_interface_rules(enum fw3_table table, enum fw3_family family,
 349                       struct fw3_zone *zone, bool disable_notrack)
 350 {
 351         struct fw3_device *dev;
 352         struct fw3_address *sub;
 353
 354         fw3_foreach(dev, &zone->devices)
 355         fw3_foreach(sub, &zone->subnets)
 356         {
 357                 if (!fw3_is_family(sub, family))
 358                         continue;
 359
 360                 if (!dev && !sub)
 361                         continue;
 362
 363                 print_interface_rule(table, family, zone, dev, sub, disable_notrack);
 364         }
 365 }
 366
 367 static void
 368 print_zone_rule(enum fw3_table table, enum fw3_family family,
 369                 struct fw3_zone *zone, bool disable_notrack)
 370 {
 371         struct fw3_address *msrc;
 372         struct fw3_address *mdest;
 373
 374         enum fw3_target t;
 375
 376         if (!fw3_is_family(zone, family))
 377                 return;
 378
 379         switch (table)
 380         {
 381         case FW3_TABLE_FILTER:
 382                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
 383                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
 384
 385                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
 386                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
 387
 388                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
 389                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
 390
 391                 if (zone->log)
 392                 {
 393                         for (t = FW3_TARGET_REJECT; t <= FW3_TARGET_DROP; t++)
 394                         {
 395                                 if (hasbit(zone->src_flags, t))
 396                                 {
 397                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
 398                                         fw3_format_limit(&zone->log_limit);
 399                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
 400                                                    fw3_flag_names[t], zone->name);
 401                                 }
 402
 403                                 if (hasbit(zone->dst_flags, t))
 404                                 {
 405                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
 406                                         fw3_format_limit(&zone->log_limit);
 407                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
 408                                                    fw3_flag_names[t], zone->name);
 409                                 }
 410                         }
 411                 }
 412                 break;
 413
 414         case FW3_TABLE_NAT:
 415                 if (zone->masq && family == FW3_FAMILY_V4)
 416                 {
 417                         fw3_foreach(msrc, &zone->masq_src)
 418                         fw3_foreach(mdest, &zone->masq_dest)
 419                         {
 420                                 fw3_pr("-A zone_%s_postrouting ", zone->name);
 421                                 fw3_format_src_dest(msrc, mdest);
 422                                 fw3_pr("-j MASQUERADE\n");
 423                         }
 424                 }
 425                 break;
 426
 427         case FW3_TABLE_RAW:
 428         case FW3_TABLE_MANGLE:
 429                 break;
 430         }
 431
 432         print_interface_rules(table, family, zone, disable_notrack);
 433 }
 434
 435 void
 436 fw3_print_zone_chains(enum fw3_table table, enum fw3_family family,
 437                       struct fw3_state *state)
 438 {
 439         struct fw3_zone *zone;
 440
 441         list_for_each_entry(zone, &state->zones, list)
 442                 print_zone_chain(table, family, zone, state->defaults.drop_invalid);
 443 }
 444
 445 void
 446 fw3_print_zone_rules(enum fw3_table table, enum fw3_family family,
 447                      struct fw3_state *state)
 448 {
 449         struct fw3_zone *zone;
 450
 451         list_for_each_entry(zone, &state->zones, list)
 452                 print_zone_rule(table, family, zone, state->defaults.drop_invalid);
 453 }
 454
 455 void
 456 fw3_flush_zones(enum fw3_table table, enum fw3_family family,
 457                             bool pass2, struct list_head *statefile)
 458 {
 459         struct fw3_statefile_entry *e;
 460
 461         list_for_each_entry(e, statefile, list)
 462         {
 463                 if (e->type != FW3_TYPE_ZONE)
 464                         continue;
 465
 466                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 467                              e->name, e->flags[0], src_chains, ARRAY_SIZE(src_chains));
 468
 469                 print_chains(table, family, pass2 ? "-X %s\n" : "-F %s\n",
 470                              e->name, e->flags[1], dst_chains, ARRAY_SIZE(dst_chains));
 471         }
 472 }
 473
 474 struct fw3_zone *
 475 fw3_lookup_zone(struct fw3_state *state, const char *name)
 476 {
 477         struct fw3_zone *z;
 478
 479         if (list_empty(&state->zones))
 480                 return NULL;
 481
 482         list_for_each_entry(z, &state->zones, list)
 483                 if (!strcmp(z->name, name))
 484                         return z;
 485
 486         return NULL;
 487 }
 488
 489 void
 490 fw3_free_zone(struct fw3_zone *zone)
 491 {
 492         fw3_free_list(&zone->networks);
 493         fw3_free_list(&zone->devices);
 494         fw3_free_list(&zone->subnets);
 495
 496         fw3_free_list(&zone->masq_src);
 497         fw3_free_list(&zone->masq_dest);
 498
 499         free(zone);
 500 }