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 print_chain(struct fw3_rule *rule)
 212 {
 213         char chain[256];
 214
 215         sprintf(chain, "delegate_output");
 216
 217         if (rule->target == FW3_FLAG_NOTRACK)
 218         {
 219                 sprintf(chain, "zone_%s_notrack", rule->src.name);
 220         }
 221         else if (rule->target == FW3_FLAG_MARK)
 222         {
 223                 sprintf(chain, "fwmark");
 224         }
 225         else
 226         {
 227                 if (rule->src.set)
 228                 {
 229                         if (!rule->src.any)
 230                         {
 231                                 if (rule->dest.set)
 232                                         sprintf(chain, "zone_%s_forward", rule->src.name);
 233                                 else
 234                                         sprintf(chain, "zone_%s_input", rule->src.name);
 235                         }
 236                         else
 237                         {
 238                                 if (rule->dest.set)
 239                                         sprintf(chain, "delegate_forward");
 240                                 else
 241                                         sprintf(chain, "delegate_input");
 242                         }
 243                 }
 244
 245                 if (rule->dest.set && !rule->src.set)
 246                         sprintf(chain, "zone_%s_output", rule->dest.name);
 247         }
 248
 249         fw3_pr("-A %s", chain);
 250 }
 251
 252 static void print_target(struct fw3_rule *rule)
 253 {
 254         const char *target;
 255
 256         switch(rule->target)
 257         {
 258         case FW3_FLAG_MARK:
 259                 if (rule->set_mark.set)
 260                         fw3_pr(" -j MARK --set-mark 0x%x/0x%x\n",
 261                                rule->set_mark.mark, rule->set_mark.mask);
 262                 else
 263                         fw3_pr(" -j MARK --set-xmark 0x%x/0x%x\n",
 264                                rule->set_xmark.mark, rule->set_xmark.mask);
 265                 return;
 266
 267         case FW3_FLAG_ACCEPT:
 268         case FW3_FLAG_DROP:
 269         case FW3_FLAG_NOTRACK:
 270                 target = fw3_flag_names[rule->target];
 271                 break;
 272
 273         default:
 274                 target = fw3_flag_names[FW3_FLAG_REJECT];
 275                 break;
 276         }
 277
 278         if (rule->dest.set && !rule->dest.any)
 279                 fw3_pr(" -j zone_%s_dest_%s\n", rule->dest.name, target);
 280         else if (rule->target == FW3_FLAG_REJECT)
 281                 fw3_pr(" -j reject\n");
 282         else
 283                 fw3_pr(" -j %s\n", target);
 284 }
 285
 286 static void
 287 print_rule(struct fw3_state *state, enum fw3_family family,
 288            enum fw3_table table, struct fw3_rule *rule,
 289            struct fw3_protocol *proto,
 290            struct fw3_address *sip, struct fw3_address *dip,
 291            struct fw3_port *sport, struct fw3_port *dport,
 292            struct fw3_mac *mac, struct fw3_icmptype *icmptype)
 293 {
 294         if (!fw3_is_family(sip, family) || !fw3_is_family(dip, family))
 295         {
 296                 info("     ! Skipping due to different family of ip address");
 297                 return;
 298         }
 299
 300         if (proto->protocol == 58 && family == FW3_FAMILY_V4)
 301         {
 302                 info("     ! Skipping due to different family of protocol");
 303                 return;
 304         }
 305
 306         print_chain(rule);
 307         fw3_format_ipset(rule->_ipset, rule->ipset.invert);
 308         fw3_format_protocol(proto, family);
 309         fw3_format_src_dest(sip, dip);
 310         fw3_format_sport_dport(sport, dport);
 311         fw3_format_icmptype(icmptype, family);
 312         fw3_format_mac(mac);
 313         fw3_format_limit(&rule->limit);
 314         fw3_format_time(&rule->time);
 315         fw3_format_mark(&rule->mark);
 316         fw3_format_extra(rule->extra);
 317         fw3_format_comment(rule->name);
 318         print_target(rule);
 319 }
 320
 321 static void
 322 expand_rule(struct fw3_state *state, enum fw3_family family,
 323             enum fw3_table table, struct fw3_rule *rule, int num)
 324 {
 325         struct fw3_protocol *proto;
 326         struct fw3_address *sip;
 327         struct fw3_address *dip;
 328         struct fw3_port *sport;
 329         struct fw3_port *dport;
 330         struct fw3_mac *mac;
 331         struct fw3_icmptype *icmptype;
 332
 333         struct list_head *sports = NULL;
 334         struct list_head *dports = NULL;
 335         struct list_head *icmptypes = NULL;
 336
 337         struct list_head empty;
 338         INIT_LIST_HEAD(&empty);
 339
 340         if (!fw3_is_family(rule, family))
 341                 return;
 342
 343         if ((rule->target == FW3_FLAG_NOTRACK && table != FW3_TABLE_RAW) ||
 344             (rule->target == FW3_FLAG_MARK && table != FW3_TABLE_MANGLE) ||
 345                 (rule->target < FW3_FLAG_NOTRACK && table != FW3_TABLE_FILTER))
 346                 return;
 347
 348         if (rule->name)
 349                 info("   * Rule '%s'", rule->name);
 350         else
 351                 info("   * Rule #%u", num);
 352
 353         if (!fw3_is_family(rule->_src, family) ||
 354             !fw3_is_family(rule->_dest, family))
 355         {
 356                 info("     ! Skipping due to different family of zone");
 357                 return;
 358         }
 359
 360         if (rule->_ipset)
 361         {
 362                 if (!fw3_is_family(rule->_ipset, family))
 363                 {
 364                         info("     ! Skipping due to different family in ipset");
 365                         return;
 366                 }
 367
 368                 set(rule->_ipset->flags, family, family);
 369         }
 370
 371         list_for_each_entry(proto, &rule->proto, list)
 372         {
 373                 /* icmp / ipv6-icmp */
 374                 if (proto->protocol == 1 || proto->protocol == 58)
 375                 {
 376                         sports = &empty;
 377                         dports = &empty;
 378                         icmptypes = &rule->icmp_type;
 379                 }
 380                 else
 381                 {
 382                         sports = &rule->port_src;
 383                         dports = &rule->port_dest;
 384                         icmptypes = &empty;
 385                 }
 386
 387                 fw3_foreach(sip, &rule->ip_src)
 388                 fw3_foreach(dip, &rule->ip_dest)
 389                 fw3_foreach(sport, sports)
 390                 fw3_foreach(dport, dports)
 391                 fw3_foreach(mac, &rule->mac_src)
 392                 fw3_foreach(icmptype, icmptypes)
 393                         print_rule(state, family, table, rule, proto, sip, dip,
 394                                    sport, dport, mac, icmptype);
 395         }
 396 }
 397
 398 void
 399 fw3_print_rules(struct fw3_state *state, enum fw3_family family,
 400                 enum fw3_table table)
 401 {
 402         int num = 0;
 403         struct fw3_rule *rule;
 404
 405         list_for_each_entry(rule, &state->rules, list)
 406                 expand_rule(state, family, table, rule, num++);
 407 }