rules.c

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