rules.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013-2018 Jo-Philipp Wich <jo@mein.io>
   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 "rules.h"
  20
  21
  22 const struct fw3_option fw3_rule_opts[] = {
  23         FW3_OPT("enabled",             bool,      rule,     enabled),
  24
  25         FW3_OPT("name",                string,    rule,     name),
  26         FW3_OPT("family",              family,    rule,     family),
  27
  28         FW3_OPT("src",                 device,    rule,     src),
  29         FW3_OPT("dest",                device,    rule,     dest),
  30
  31         FW3_OPT("device",              string,    rule,     device),
  32         FW3_OPT("direction",           direction, rule,     direction_out),
  33
  34         FW3_OPT("ipset",               setmatch,  rule,     ipset),
  35         FW3_OPT("helper",              cthelper,  rule,     helper),
  36         FW3_OPT("set_helper",          cthelper,  rule,     set_helper),
  37
  38         FW3_LIST("proto",              protocol,  rule,     proto),
  39
  40         FW3_LIST("src_ip",             network,   rule,     ip_src),
  41         FW3_LIST("src_mac",            mac,       rule,     mac_src),
  42         FW3_LIST("src_port",           port,      rule,     port_src),
  43
  44         FW3_LIST("dest_ip",            network,   rule,     ip_dest),
  45         FW3_LIST("dest_port",          port,      rule,     port_dest),
  46
  47         FW3_LIST("icmp_type",          icmptype,  rule,     icmp_type),
  48         FW3_OPT("extra",               string,    rule,     extra),
  49
  50         FW3_OPT("limit",               limit,     rule,     limit),
  51         FW3_OPT("limit_burst",         int,       rule,     limit.burst),
  52
  53         FW3_OPT("utc_time",            bool,      rule,     time.utc),
  54         FW3_OPT("start_date",          date,      rule,     time.datestart),
  55         FW3_OPT("stop_date",           date,      rule,     time.datestop),
  56         FW3_OPT("start_time",          time,      rule,     time.timestart),
  57         FW3_OPT("stop_time",           time,      rule,     time.timestop),
  58         FW3_OPT("weekdays",            weekdays,  rule,     time.weekdays),
  59         FW3_OPT("monthdays",           monthdays, rule,     time.monthdays),
  60
  61         FW3_OPT("mark",                mark,      rule,     mark),
  62         FW3_OPT("set_mark",            mark,      rule,     set_mark),
  63         FW3_OPT("set_xmark",           mark,      rule,     set_xmark),
  64
  65         FW3_OPT("dscp",                dscp,      rule,     dscp),
  66         FW3_OPT("set_dscp",            dscp,      rule,     set_dscp),
  67
  68         FW3_OPT("target",              target,    rule,     target),
  69
  70         { }
  71 };
  72
  73
  74 static bool
  75 need_src_action_chain(struct fw3_rule *r)
  76 {
  77         return (r->_src && r->_src->log && (r->target > FW3_FLAG_ACCEPT));
  78 }
  79
  80 static struct fw3_rule*
  81 alloc_rule(struct fw3_state *state)
  82 {
  83         struct fw3_rule *rule = calloc(1, sizeof(*rule));
  84
  85         if (rule) {
  86                 INIT_LIST_HEAD(&rule->proto);
  87
  88                 INIT_LIST_HEAD(&rule->ip_src);
  89                 INIT_LIST_HEAD(&rule->mac_src);
  90                 INIT_LIST_HEAD(&rule->port_src);
  91
  92                 INIT_LIST_HEAD(&rule->ip_dest);
  93                 INIT_LIST_HEAD(&rule->port_dest);
  94
  95                 INIT_LIST_HEAD(&rule->icmp_type);
  96
  97                 list_add_tail(&rule->list, &state->rules);
  98                 rule->enabled = true;
  99         }
 100
 101         return rule;
 102 }
 103
 104 static bool
 105 check_rule(struct fw3_state *state, struct fw3_rule *r, struct uci_element *e)
 106 {
 107         if (!r->enabled)
 108                 return false;
 109
 110         if (r->src.invert || r->dest.invert)
 111         {
 112                 warn_section("rule", r, e, "must not have inverted 'src' or 'dest' options");
 113                 return false;
 114         }
 115         else if (r->src.set && !r->src.any &&
 116                  !(r->_src = fw3_lookup_zone(state, r->src.name)))
 117         {
 118                 warn_section("rule", r, e, "refers to not existing zone '%s'", r->src.name);
 119                 return false;
 120         }
 121         else if (r->dest.set && !r->dest.any &&
 122                  !(r->_dest = fw3_lookup_zone(state, r->dest.name)))
 123         {
 124                 warn_section("rule", r, e, "refers to not existing zone '%s'", r->dest.name);
 125                 return false;
 126         }
 127         else if (r->ipset.set && state->disable_ipsets)
 128         {
 129                 warn_section("rule", r, e, "skipped due to disabled ipset support");
 130                 return false;
 131         }
 132         else if (r->ipset.set &&
 133                  !(r->ipset.ptr = fw3_lookup_ipset(state, r->ipset.name)))
 134         {
 135                 warn_section("rule", r, e, "refers to unknown ipset '%s'", r->ipset.name);
 136                 return false;
 137         }
 138         else if (r->helper.set &&
 139                  !(r->helper.ptr = fw3_lookup_cthelper(state, r->helper.name)))
 140         {
 141                 warn_section("rule", r, e, "refers to unknown CT helper '%s'", r->helper.name);
 142                 return false;
 143         }
 144         else if (r->set_helper.set &&
 145                  !(r->set_helper.ptr = fw3_lookup_cthelper(state, r->set_helper.name)))
 146         {
 147                 warn_section("rule", r, e, "refers to unknown CT helper '%s'", r->set_helper.name);
 148                 return false;
 149         }
 150
 151         if (!r->_src && (r->target == FW3_FLAG_NOTRACK || r->target == FW3_FLAG_HELPER))
 152         {
 153                 warn_section("rule", r, e, "is set to target %s but has no source assigned",
 154                              fw3_flag_names[r->target]);
 155                 return false;
 156         }
 157
 158         if (!r->set_mark.set && !r->set_xmark.set &&
 159             r->target == FW3_FLAG_MARK)
 160         {
 161                 warn_section("rule", r, e, "is set to target MARK but specifies neither "
 162                                            "'set_mark' nor 'set_xmark' option");
 163                 return false;
 164         }
 165
 166         if (!r->set_dscp.set && r->target == FW3_FLAG_DSCP)
 167         {
 168                 warn_section("rule", r, e, "is set to target DSCP but specifies no "
 169                                            "'set_dscp' option");
 170                 return false;
 171         }
 172
 173         if (r->_dest && (r->target == FW3_FLAG_MARK || r->target == FW3_FLAG_DSCP))
 174         {
 175                 warn_section("rule", r, e, "must not specify 'dest' for %s target",
 176                              fw3_flag_names[r->target]);
 177                 return false;
 178         }
 179
 180         if (r->set_mark.invert || r->set_xmark.invert || r->set_dscp.invert)
 181         {
 182                 warn_section("rule", r, e, "must not have inverted 'set_mark', "
 183                                            "'set_xmark' or 'set_dscp'");
 184                 return false;
 185         }
 186
 187         if (!r->set_helper.set && r->target == FW3_FLAG_HELPER)
 188         {
 189                 warn_section("rule", r, e, "is set to target HELPER but specifies "
 190                                            "no 'set_helper' option");
 191                 return false;
 192         }
 193
 194         if (r->set_helper.invert && r->target == FW3_FLAG_HELPER)
 195         {
 196                 warn_section("rule", r, e, "must not have inverted 'set_helper' option");
 197                 return false;
 198         }
 199
 200         if (!r->_src && !r->_dest && !r->src.any && !r->dest.any)
 201         {
 202                 warn_section("rule", r, e, "has neither a source nor a destination zone assigned "
 203                                 "- assuming an output rule");
 204         }
 205
 206         if (list_empty(&r->proto))
 207         {
 208                 warn_section("rule", r, e, "does not specify a protocol, assuming TCP+UDP");
 209                 fw3_parse_protocol(&r->proto, "tcpudp", true);
 210         }
 211
 212         if (r->target == FW3_FLAG_UNSPEC)
 213         {
 214                 warn_section("rule", r, e, "has no target specified, defaulting to REJECT");
 215                 r->target = FW3_FLAG_REJECT;
 216         }
 217         else if (r->target > FW3_FLAG_DSCP)
 218         {
 219                 warn_section("rule", r, e, "has invalid target specified, defaulting to REJECT");
 220                 r->target = FW3_FLAG_REJECT;
 221         }
 222
 223         /* NB: r family... */
 224         if (r->_dest)
 225         {
 226                 fw3_setbit(r->_dest->flags[0], r->target);
 227                 fw3_setbit(r->_dest->flags[1], r->target);
 228         }
 229         else if (need_src_action_chain(r))
 230         {
 231                 fw3_setbit(r->_src->flags[0], fw3_to_src_target(r->target));
 232                 fw3_setbit(r->_src->flags[1], fw3_to_src_target(r->target));
 233         }
 234
 235         return true;
 236 }
 237
 238 void
 239 fw3_load_rules(struct fw3_state *state, struct uci_package *p,
 240                 struct blob_attr *a)
 241 {
 242         struct uci_section *s;
 243         struct uci_element *e;
 244         struct fw3_rule *rule;
 245         struct blob_attr *entry;
 246         unsigned rem;
 247
 248         INIT_LIST_HEAD(&state->rules);
 249
 250         blob_for_each_attr(entry, a, rem) {
 251                 const char *type;
 252                 const char *name = "ubus rule";
 253
 254                 if (!fw3_attr_parse_name_type(entry, &name, &type))
 255                         continue;
 256
 257                 if (strcmp(type, "rule"))
 258                         continue;
 259
 260                 if (!(rule = alloc_rule(state)))
 261                         continue;
 262
 263                 if (!fw3_parse_blob_options(rule, fw3_rule_opts, entry, name))
 264                 {
 265                         warn_section("rule", rule, NULL, "skipped due to invalid options");
 266                         fw3_free_rule(rule);
 267                         continue;
 268                 }
 269
 270                 if (!check_rule(state, rule, NULL))
 271                         fw3_free_rule(rule);
 272         }
 273
 274         uci_foreach_element(&p->sections, e)
 275         {
 276                 s = uci_to_section(e);
 277
 278                 if (strcmp(s->type, "rule"))
 279                         continue;
 280
 281                 if (!(rule = alloc_rule(state)))
 282                         continue;
 283
 284                 if (!fw3_parse_options(rule, fw3_rule_opts, s))
 285                 {
 286                         warn_elem(e, "skipped due to invalid options");
 287                         fw3_free_rule(rule);
 288                         continue;
 289                 }
 290
 291                 if (!check_rule(state, rule, e))
 292                         fw3_free_rule(rule);
 293         }
 294 }
 295
 296
 297 static void
 298 append_chain(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 299 {
 300         char chain[32];
 301
 302         snprintf(chain, sizeof(chain), "OUTPUT");
 303
 304         if (rule->target == FW3_FLAG_NOTRACK)
 305         {
 306                 snprintf(chain, sizeof(chain), "zone_%s_notrack", rule->src.name);
 307         }
 308         else if (rule->target == FW3_FLAG_HELPER)
 309         {
 310                 snprintf(chain, sizeof(chain), "zone_%s_helper", rule->src.name);
 311         }
 312         else if ((rule->target == FW3_FLAG_MARK || rule->target == FW3_FLAG_DSCP) &&
 313                  (rule->_src || rule->src.any))
 314         {
 315                 snprintf(chain, sizeof(chain), "PREROUTING");
 316         }
 317         else
 318         {
 319                 if (rule->src.set)
 320                 {
 321                         if (!rule->src.any)
 322                         {
 323                                 if (rule->dest.set)
 324                                         snprintf(chain, sizeof(chain), "zone_%s_forward",
 325                                                  rule->src.name);
 326                                 else
 327                                         snprintf(chain, sizeof(chain), "zone_%s_input",
 328                                                  rule->src.name);
 329                         }
 330                         else
 331                         {
 332                                 if (rule->dest.set)
 333                                         snprintf(chain, sizeof(chain), "FORWARD");
 334                                 else
 335                                         snprintf(chain, sizeof(chain), "INPUT");
 336                         }
 337                 }
 338
 339                 if (rule->dest.set && !rule->src.set)
 340                 {
 341                         if (rule->dest.any)
 342                                 snprintf(chain, sizeof(chain), "OUTPUT");
 343                         else
 344                                 snprintf(chain, sizeof(chain), "zone_%s_output",
 345                                          rule->dest.name);
 346                 }
 347         }
 348
 349         fw3_ipt_rule_append(r, chain);
 350 }
 351
 352 static void set_target(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 353 {
 354         const char *name;
 355         struct fw3_mark *mark;
 356         char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF")];
 357
 358         switch(rule->target)
 359         {
 360         case FW3_FLAG_MARK:
 361                 name = rule->set_mark.set ? "--set-mark" : "--set-xmark";
 362                 mark = rule->set_mark.set ? &rule->set_mark : &rule->set_xmark;
 363                 snprintf(buf, sizeof(buf), "0x%x/0x%x", mark->mark, mark->mask);
 364
 365                 fw3_ipt_rule_target(r, "MARK");
 366                 fw3_ipt_rule_addarg(r, false, name, buf);
 367                 return;
 368
 369         case FW3_FLAG_DSCP:
 370                 snprintf(buf, sizeof(buf), "0x%x", rule->set_dscp.dscp);
 371
 372                 fw3_ipt_rule_target(r, "DSCP");
 373                 fw3_ipt_rule_addarg(r, false, "--set-dscp", buf);
 374                 return;
 375
 376         case FW3_FLAG_NOTRACK:
 377                 fw3_ipt_rule_target(r, "CT");
 378                 fw3_ipt_rule_addarg(r, false, "--notrack", NULL);
 379                 return;
 380
 381         case FW3_FLAG_HELPER:
 382                 fw3_ipt_rule_target(r, "CT");
 383                 fw3_ipt_rule_addarg(r, false, "--helper", rule->set_helper.ptr->name);
 384                 return;
 385
 386         case FW3_FLAG_ACCEPT:
 387         case FW3_FLAG_DROP:
 388                 name = fw3_flag_names[rule->target];
 389                 break;
 390
 391         default:
 392                 name = fw3_flag_names[FW3_FLAG_REJECT];
 393                 break;
 394         }
 395
 396         if (rule->dest.set && !rule->dest.any)
 397                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", rule->dest.name, name);
 398         else if (need_src_action_chain(rule))
 399                 fw3_ipt_rule_target(r, "zone_%s_src_%s", rule->src.name, name);
 400         else if (strcmp(name, "REJECT"))
 401                 fw3_ipt_rule_target(r, name);
 402         else
 403                 fw3_ipt_rule_target(r, "reject");
 404 }
 405
 406 static void
 407 set_comment(struct fw3_ipt_rule *r, const char *name, int num)
 408 {
 409         if (name)
 410                 fw3_ipt_rule_comment(r, name);
 411         else
 412                 fw3_ipt_rule_comment(r, "@rule[%u]", num);
 413 }
 414
 415 static void
 416 print_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 417            struct fw3_rule *rule, int num, struct fw3_protocol *proto,
 418            struct fw3_address *sip, struct fw3_address *dip,
 419            struct fw3_port *sport, struct fw3_port *dport,
 420            struct fw3_mac *mac, struct fw3_icmptype *icmptype)
 421 {
 422         struct fw3_ipt_rule *r;
 423
 424         if (!fw3_is_family(sip, handle->family) ||
 425             !fw3_is_family(dip, handle->family))
 426         {
 427                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
 428                         info("     ! Skipping due to different family of ip address");
 429
 430                 return;
 431         }
 432
 433         if (!fw3_is_family(sip, handle->family) ||
 434             !fw3_is_family(dip, handle->family))
 435         {
 436                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
 437                         info("     ! Skipping due to different family of ip address");
 438
 439                 return;
 440         }
 441
 442         if (!fw3_is_family(sip, handle->family) ||
 443             !fw3_is_family(dip, handle->family))
 444         {
 445                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
 446                         info("     ! Skipping due to different family of ip address");
 447
 448                 return;
 449         }
 450
 451         if (proto->protocol == 58 && handle->family == FW3_FAMILY_V4)
 452         {
 453                 info("     ! Skipping protocol %s due to different family",
 454                      fw3_protoname(proto));
 455                 return;
 456         }
 457
 458         if (rule->helper.ptr &&
 459             !fw3_cthelper_check_proto(rule->helper.ptr, proto))
 460         {
 461                 info("     ! Skipping protocol %s since helper '%s' does not support it",
 462                      fw3_protoname(proto), rule->helper.ptr->name);
 463                 return;
 464         }
 465
 466         if (rule->set_helper.ptr &&
 467             !fw3_cthelper_check_proto(rule->set_helper.ptr, proto))
 468         {
 469                 info("     ! Skipping protocol %s since helper '%s' does not support it",
 470                      fw3_protoname(proto), rule->helper.ptr->name);
 471                 return;
 472         }
 473
 474         r = fw3_ipt_rule_create(handle, proto, NULL, NULL, sip, dip);
 475         fw3_ipt_rule_sport_dport(r, sport, dport);
 476         fw3_ipt_rule_device(r, rule->device, rule->direction_out);
 477         fw3_ipt_rule_icmptype(r, icmptype);
 478         fw3_ipt_rule_mac(r, mac);
 479         fw3_ipt_rule_ipset(r, &rule->ipset);
 480         fw3_ipt_rule_helper(r, &rule->helper);
 481         fw3_ipt_rule_limit(r, &rule->limit);
 482         fw3_ipt_rule_time(r, &rule->time);
 483         fw3_ipt_rule_mark(r, &rule->mark);
 484         fw3_ipt_rule_dscp(r, &rule->dscp);
 485         set_target(r, rule);
 486         fw3_ipt_rule_extra(r, rule->extra);
 487         set_comment(r, rule->name, num);
 488         append_chain(r, rule);
 489 }
 490
 491 static void
 492 expand_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 493             struct fw3_rule *rule, int num)
 494 {
 495         struct fw3_protocol *proto;
 496         struct fw3_address *sip;
 497         struct fw3_address *dip;
 498         struct fw3_port *sport;
 499         struct fw3_port *dport;
 500         struct fw3_mac *mac;
 501         struct fw3_icmptype *icmptype;
 502
 503         struct list_head *sports = NULL;
 504         struct list_head *dports = NULL;
 505         struct list_head *icmptypes = NULL;
 506
 507         struct list_head empty;
 508         INIT_LIST_HEAD(&empty);
 509
 510         if (!fw3_is_family(rule, handle->family))
 511                 return;
 512
 513         if ((rule->target == FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_RAW) ||
 514             (rule->target == FW3_FLAG_HELPER && handle->table != FW3_TABLE_RAW)  ||
 515             (rule->target == FW3_FLAG_MARK && handle->table != FW3_TABLE_MANGLE) ||
 516             (rule->target == FW3_FLAG_DSCP && handle->table != FW3_TABLE_MANGLE) ||
 517                 (rule->target < FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_FILTER))
 518                 return;
 519
 520         if (rule->name)
 521                 info("   * Rule '%s'", rule->name);
 522         else
 523                 info("   * Rule #%u", num);
 524
 525         if (!fw3_is_family(rule->_src, handle->family) ||
 526             !fw3_is_family(rule->_dest, handle->family))
 527         {
 528                 info("     ! Skipping due to different family of zone");
 529                 return;
 530         }
 531
 532         if (rule->ipset.ptr)
 533         {
 534                 if (!fw3_is_family(rule->ipset.ptr, handle->family))
 535                 {
 536                         info("     ! Skipping due to different family in ipset");
 537                         return;
 538                 }
 539
 540                 if (!fw3_check_ipset(rule->ipset.ptr))
 541                 {
 542                         info("     ! Skipping due to missing ipset '%s'",
 543                              rule->ipset.ptr->external
 544                                         ? rule->ipset.ptr->external : rule->ipset.ptr->name);
 545                         return;
 546                 }
 547
 548                 set(rule->ipset.ptr->flags, handle->family, handle->family);
 549         }
 550
 551         if (rule->helper.ptr && !fw3_is_family(rule->helper.ptr, handle->family))
 552         {
 553                 info("     ! Skipping due to unsupported family of CT helper");
 554                 return;
 555         }
 556
 557         if (rule->set_helper.ptr && !fw3_is_family(rule->set_helper.ptr, handle->family))
 558         {
 559                 info("     ! Skipping due to unsupported family of CT helper");
 560                 return;
 561         }
 562
 563         list_for_each_entry(proto, &rule->proto, list)
 564         {
 565                 /* icmp / ipv6-icmp */
 566                 if (proto->protocol == 1 || proto->protocol == 58)
 567                 {
 568                         sports = &empty;
 569                         dports = &empty;
 570                         icmptypes = &rule->icmp_type;
 571                 }
 572                 else
 573                 {
 574                         sports = &rule->port_src;
 575                         dports = &rule->port_dest;
 576                         icmptypes = &empty;
 577                 }
 578
 579                 fw3_foreach(sip, &rule->ip_src)
 580                 fw3_foreach(dip, &rule->ip_dest)
 581                 fw3_foreach(sport, sports)
 582                 fw3_foreach(dport, dports)
 583                 fw3_foreach(mac, &rule->mac_src)
 584                 fw3_foreach(icmptype, icmptypes)
 585                         print_rule(handle, state, rule, num, proto, sip, dip,
 586                                    sport, dport, mac, icmptype);
 587         }
 588 }
 589
 590 void
 591 fw3_print_rules(struct fw3_ipt_handle *handle, struct fw3_state *state)
 592 {
 593         int num = 0;
 594         struct fw3_rule *rule;
 595
 596         list_for_each_entry(rule, &state->rules, list)
 597                 expand_rule(handle, state, rule, num++);
 598 }