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