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