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