rules.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 "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("ipset",               setmatch,  rule,     ipset),
  32
  33         FW3_LIST("proto",              protocol,  rule,     proto),
  34
  35         FW3_LIST("src_ip",             network,   rule,     ip_src),
  36         FW3_LIST("src_mac",            mac,       rule,     mac_src),
  37         FW3_LIST("src_port",           port,      rule,     port_src),
  38
  39         FW3_LIST("dest_ip",            network,   rule,     ip_dest),
  40         FW3_LIST("dest_port",          port,      rule,     port_dest),
  41
  42         FW3_LIST("icmp_type",          icmptype,  rule,     icmp_type),
  43         FW3_OPT("extra",               string,    rule,     extra),
  44
  45         FW3_OPT("limit",               limit,     rule,     limit),
  46         FW3_OPT("limit_burst",         int,       rule,     limit.burst),
  47
  48         FW3_OPT("utc_time",            bool,      rule,     time.utc),
  49         FW3_OPT("start_date",          date,      rule,     time.datestart),
  50         FW3_OPT("stop_date",           date,      rule,     time.datestop),
  51         FW3_OPT("start_time",          time,      rule,     time.timestart),
  52         FW3_OPT("stop_time",           time,      rule,     time.timestop),
  53         FW3_OPT("weekdays",            weekdays,  rule,     time.weekdays),
  54         FW3_OPT("monthdays",           monthdays, rule,     time.monthdays),
  55
  56         FW3_OPT("mark",                mark,      rule,     mark),
  57         FW3_OPT("set_mark",            mark,      rule,     set_mark),
  58         FW3_OPT("set_xmark",           mark,      rule,     set_xmark),
  59
  60         FW3_OPT("target",              target,    rule,     target),
  61
  62         { }
  63 };
  64
  65
  66 static bool
  67 need_src_action_chain(struct fw3_rule *r)
  68 {
  69         return (r->_src && r->_src->log && (r->target > FW3_FLAG_ACCEPT));
  70 }
  71
  72 void
  73 fw3_load_rules(struct fw3_state *state, struct uci_package *p)
  74 {
  75         struct uci_section *s;
  76         struct uci_element *e;
  77         struct fw3_rule *rule;
  78
  79         INIT_LIST_HEAD(&state->rules);
  80
  81         uci_foreach_element(&p->sections, e)
  82         {
  83                 s = uci_to_section(e);
  84
  85                 if (strcmp(s->type, "rule"))
  86                         continue;
  87
  88                 rule = malloc(sizeof(*rule));
  89
  90                 if (!rule)
  91                         continue;
  92
  93                 memset(rule, 0, sizeof(*rule));
  94
  95                 INIT_LIST_HEAD(&rule->proto);
  96
  97                 INIT_LIST_HEAD(&rule->ip_src);
  98                 INIT_LIST_HEAD(&rule->mac_src);
  99                 INIT_LIST_HEAD(&rule->port_src);
 100
 101                 INIT_LIST_HEAD(&rule->ip_dest);
 102                 INIT_LIST_HEAD(&rule->port_dest);
 103
 104                 INIT_LIST_HEAD(&rule->icmp_type);
 105
 106                 rule->enabled = true;
 107
 108                 if (!fw3_parse_options(rule, fw3_rule_opts, s))
 109                 {
 110                         warn_elem(e, "skipped due to invalid options");
 111                         fw3_free_rule(rule);
 112                         continue;
 113                 }
 114
 115                 if (!rule->enabled)
 116                 {
 117                         fw3_free_rule(rule);
 118                         continue;
 119                 }
 120
 121                 if (rule->src.invert || rule->dest.invert)
 122                 {
 123                         warn_elem(e, "must not have inverted 'src' or 'dest' options");
 124                         fw3_free_rule(rule);
 125                         continue;
 126                 }
 127                 else if (rule->src.set && !rule->src.any &&
 128                          !(rule->_src = fw3_lookup_zone(state, rule->src.name)))
 129                 {
 130                         warn_elem(e, "refers to not existing zone '%s'", rule->src.name);
 131                         fw3_free_rule(rule);
 132                         continue;
 133                 }
 134                 else if (rule->dest.set && !rule->dest.any &&
 135                          !(rule->_dest = fw3_lookup_zone(state, rule->dest.name)))
 136                 {
 137                         warn_elem(e, "refers to not existing zone '%s'", rule->dest.name);
 138                         fw3_free_rule(rule);
 139                         continue;
 140                 }
 141                 else if (rule->ipset.set && state->disable_ipsets)
 142                 {
 143                         warn_elem(e, "skipped due to disabled ipset support");
 144                         fw3_free_rule(rule);
 145                         continue;
 146                 }
 147                 else if (rule->ipset.set &&
 148                          !(rule->ipset.ptr = fw3_lookup_ipset(state, rule->ipset.name)))
 149                 {
 150                         warn_elem(e, "refers to unknown ipset '%s'", rule->ipset.name);
 151                         fw3_free_rule(rule);
 152                         continue;
 153                 }
 154
 155                 if (!rule->_src && rule->target == FW3_FLAG_NOTRACK)
 156                 {
 157                         warn_elem(e, "is set to target NOTRACK but has no source assigned");
 158                         fw3_free_rule(rule);
 159                         continue;
 160                 }
 161
 162                 if (!rule->set_mark.set && !rule->set_xmark.set &&
 163                     rule->target == FW3_FLAG_MARK)
 164                 {
 165                         warn_elem(e, "is set to target MARK but specifies neither "
 166                                      "'set_mark' nor 'set_xmark' option");
 167                         fw3_free_rule(rule);
 168                         continue;
 169                 }
 170
 171                 if (rule->_dest && rule->target == FW3_FLAG_MARK)
 172                 {
 173                         warn_elem(e, "must not specify 'dest' for MARK target");
 174                         fw3_free_rule(rule);
 175                         continue;
 176                 }
 177
 178                 if (rule->set_mark.invert || rule->set_xmark.invert)
 179                 {
 180                         warn_elem(e, "must not have inverted 'set_mark' or 'set_xmark'");
 181                         fw3_free_rule(rule);
 182                         continue;
 183                 }
 184
 185                 if (!rule->_src && !rule->_dest && !rule->src.any && !rule->dest.any)
 186                 {
 187                         warn_elem(e, "has neither a source nor a destination zone assigned "
 188                                      "- assuming an output rule");
 189                 }
 190
 191                 if (list_empty(&rule->proto))
 192                 {
 193                         warn_elem(e, "does not specify a protocol, assuming TCP+UDP");
 194                         fw3_parse_protocol(&rule->proto, "tcpudp", true);
 195                 }
 196
 197                 if (rule->target == FW3_FLAG_UNSPEC)
 198                 {
 199                         warn_elem(e, "has no target specified, defaulting to REJECT");
 200                         rule->target = FW3_FLAG_REJECT;
 201                 }
 202                 else if (rule->target > FW3_FLAG_MARK)
 203                 {
 204                         warn_elem(e, "has invalid target specified, defaulting to REJECT");
 205                         rule->target = FW3_FLAG_REJECT;
 206                 }
 207
 208                 /* NB: rule family... */
 209                 if (rule->_dest)
 210                 {
 211                         setbit(rule->_dest->flags[0], rule->target);
 212                         setbit(rule->_dest->flags[1], rule->target);
 213                 }
 214                 else if (need_src_action_chain(rule))
 215                 {
 216                         setbit(rule->_src->flags[0], fw3_to_src_target(rule->target));
 217                         setbit(rule->_src->flags[1], fw3_to_src_target(rule->target));
 218                 }
 219
 220                 list_add_tail(&rule->list, &state->rules);
 221                 continue;
 222         }
 223 }
 224
 225
 226 static void
 227 append_chain(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 228 {
 229         char chain[32];
 230
 231         snprintf(chain, sizeof(chain), "delegate_output");
 232
 233         if (rule->target == FW3_FLAG_NOTRACK)
 234         {
 235                 snprintf(chain, sizeof(chain), "zone_%s_notrack", rule->src.name);
 236         }
 237         else if (rule->target == FW3_FLAG_MARK)
 238         {
 239                 snprintf(chain, sizeof(chain), "fwmark");
 240         }
 241         else
 242         {
 243                 if (rule->src.set)
 244                 {
 245                         if (!rule->src.any)
 246                         {
 247                                 if (rule->dest.set)
 248                                         snprintf(chain, sizeof(chain), "zone_%s_forward",
 249                                                  rule->src.name);
 250                                 else
 251                                         snprintf(chain, sizeof(chain), "zone_%s_input",
 252                                                  rule->src.name);
 253                         }
 254                         else
 255                         {
 256                                 if (rule->dest.set)
 257                                         snprintf(chain, sizeof(chain), "delegate_forward");
 258                                 else
 259                                         snprintf(chain, sizeof(chain), "delegate_input");
 260                         }
 261                 }
 262
 263                 if (rule->dest.set && !rule->src.set)
 264                 {
 265                         if (rule->dest.any)
 266                                 snprintf(chain, sizeof(chain), "delegate_output");
 267                         else
 268                                 snprintf(chain, sizeof(chain), "zone_%s_output",
 269                                          rule->dest.name);
 270                 }
 271         }
 272
 273         fw3_ipt_rule_append(r, chain);
 274 }
 275
 276 static void set_target(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 277 {
 278         const char *name;
 279         struct fw3_mark *mark;
 280         char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF\0")];
 281
 282         switch(rule->target)
 283         {
 284         case FW3_FLAG_MARK:
 285                 name = rule->set_mark.set ? "--set-mark" : "--set-xmark";
 286                 mark = rule->set_mark.set ? &rule->set_mark : &rule->set_xmark;
 287                 sprintf(buf, "0x%x/0x%x", mark->mark, mark->mask);
 288
 289                 fw3_ipt_rule_target(r, "MARK");
 290                 fw3_ipt_rule_addarg(r, false, name, buf);
 291                 return;
 292
 293         case FW3_FLAG_NOTRACK:
 294                 fw3_ipt_rule_target(r, "CT");
 295                 fw3_ipt_rule_addarg(r, false, "--notrack", NULL);
 296                 return;
 297
 298         case FW3_FLAG_ACCEPT:
 299         case FW3_FLAG_DROP:
 300                 name = fw3_flag_names[rule->target];
 301                 break;
 302
 303         default:
 304                 name = fw3_flag_names[FW3_FLAG_REJECT];
 305                 break;
 306         }
 307
 308         if (rule->dest.set && !rule->dest.any)
 309                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", rule->dest.name, name);
 310         else if (need_src_action_chain(rule))
 311                 fw3_ipt_rule_target(r, "zone_%s_src_%s", rule->src.name, name);
 312         else if (strcmp(name, "REJECT"))
 313                 fw3_ipt_rule_target(r, name);
 314         else
 315                 fw3_ipt_rule_target(r, "reject");
 316 }
 317
 318 static void
 319 set_comment(struct fw3_ipt_rule *r, const char *name, int num)
 320 {
 321         if (name)
 322                 fw3_ipt_rule_comment(r, name);
 323         else
 324                 fw3_ipt_rule_comment(r, "@rule[%u]", num);
 325 }
 326
 327 static void
 328 print_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 329            struct fw3_rule *rule, int num, struct fw3_protocol *proto,
 330            struct fw3_address *sip, struct fw3_address *dip,
 331            struct fw3_port *sport, struct fw3_port *dport,
 332            struct fw3_mac *mac, struct fw3_icmptype *icmptype)
 333 {
 334         struct fw3_ipt_rule *r;
 335
 336         if (!fw3_is_family(sip, handle->family) ||
 337             !fw3_is_family(dip, handle->family))
 338         {
 339                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
 340                         info("     ! Skipping due to different family of ip address");
 341
 342                 return;
 343         }
 344
 345         if (proto->protocol == 58 && handle->family == FW3_FAMILY_V4)
 346         {
 347                 info("     ! Skipping due to different family of protocol");
 348                 return;
 349         }
 350
 351         r = fw3_ipt_rule_create(handle, proto, NULL, NULL, sip, dip);
 352         fw3_ipt_rule_sport_dport(r, sport, dport);
 353         fw3_ipt_rule_icmptype(r, icmptype);
 354         fw3_ipt_rule_mac(r, mac);
 355         fw3_ipt_rule_ipset(r, &rule->ipset);
 356         fw3_ipt_rule_limit(r, &rule->limit);
 357         fw3_ipt_rule_time(r, &rule->time);
 358         fw3_ipt_rule_mark(r, &rule->mark);
 359         set_target(r, rule);
 360         fw3_ipt_rule_extra(r, rule->extra);
 361         set_comment(r, rule->name, num);
 362         append_chain(r, rule);
 363 }
 364
 365 static void
 366 expand_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 367             struct fw3_rule *rule, int num)
 368 {
 369         struct fw3_protocol *proto;
 370         struct fw3_address *sip;
 371         struct fw3_address *dip;
 372         struct fw3_port *sport;
 373         struct fw3_port *dport;
 374         struct fw3_mac *mac;
 375         struct fw3_icmptype *icmptype;
 376
 377         struct list_head *sports = NULL;
 378         struct list_head *dports = NULL;
 379         struct list_head *icmptypes = NULL;
 380
 381         struct list_head empty;
 382         INIT_LIST_HEAD(&empty);
 383
 384         if (!fw3_is_family(rule, handle->family))
 385                 return;
 386
 387         if ((rule->target == FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_RAW) ||
 388             (rule->target == FW3_FLAG_MARK && handle->table != FW3_TABLE_MANGLE) ||
 389                 (rule->target < FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_FILTER))
 390                 return;
 391
 392         if (rule->name)
 393                 info("   * Rule '%s'", rule->name);
 394         else
 395                 info("   * Rule #%u", num);
 396
 397         if (!fw3_is_family(rule->_src, handle->family) ||
 398             !fw3_is_family(rule->_dest, handle->family))
 399         {
 400                 info("     ! Skipping due to different family of zone");
 401                 return;
 402         }
 403
 404         if (rule->ipset.ptr)
 405         {
 406                 if (!fw3_is_family(rule->ipset.ptr, handle->family))
 407                 {
 408                         info("     ! Skipping due to different family in ipset");
 409                         return;
 410                 }
 411
 412                 if (!fw3_check_ipset(rule->ipset.ptr))
 413                 {
 414                         info("     ! Skipping due to missing ipset '%s'",
 415                              rule->ipset.ptr->external
 416                                         ? rule->ipset.ptr->external : rule->ipset.ptr->name);
 417                         return;
 418                 }
 419
 420                 set(rule->ipset.ptr->flags, handle->family, handle->family);
 421         }
 422
 423         list_for_each_entry(proto, &rule->proto, list)
 424         {
 425                 /* icmp / ipv6-icmp */
 426                 if (proto->protocol == 1 || proto->protocol == 58)
 427                 {
 428                         sports = &empty;
 429                         dports = &empty;
 430                         icmptypes = &rule->icmp_type;
 431                 }
 432                 else
 433                 {
 434                         sports = &rule->port_src;
 435                         dports = &rule->port_dest;
 436                         icmptypes = &empty;
 437                 }
 438
 439                 fw3_foreach(sip, &rule->ip_src)
 440                 fw3_foreach(dip, &rule->ip_dest)
 441                 fw3_foreach(sport, sports)
 442                 fw3_foreach(dport, dports)
 443                 fw3_foreach(mac, &rule->mac_src)
 444                 fw3_foreach(icmptype, icmptypes)
 445                         print_rule(handle, state, rule, num, proto, sip, dip,
 446                                    sport, dport, mac, icmptype);
 447         }
 448 }
 449
 450 void
 451 fw3_print_rules(struct fw3_ipt_handle *handle, struct fw3_state *state)
 452 {
 453         int num = 0;
 454         struct fw3_rule *rule;
 455
 456         list_for_each_entry(rule, &state->rules, list)
 457                 expand_rule(handle, state, rule, num++);
 458 }