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("target",              target,    rule,     target),
  57
  58         { }
  59 };
  60
  61
  62 void
  63 fw3_load_rules(struct fw3_state *state, struct uci_package *p)
  64 {
  65         struct uci_section *s;
  66         struct uci_element *e;
  67         struct fw3_rule *rule;
  68
  69         INIT_LIST_HEAD(&state->rules);
  70
  71         uci_foreach_element(&p->sections, e)
  72         {
  73                 s = uci_to_section(e);
  74
  75                 if (strcmp(s->type, "rule"))
  76                         continue;
  77
  78                 rule = malloc(sizeof(*rule));
  79
  80                 if (!rule)
  81                         continue;
  82
  83                 memset(rule, 0, sizeof(*rule));
  84
  85                 INIT_LIST_HEAD(&rule->proto);
  86
  87                 INIT_LIST_HEAD(&rule->ip_src);
  88                 INIT_LIST_HEAD(&rule->mac_src);
  89                 INIT_LIST_HEAD(&rule->port_src);
  90
  91                 INIT_LIST_HEAD(&rule->ip_dest);
  92                 INIT_LIST_HEAD(&rule->port_dest);
  93
  94                 INIT_LIST_HEAD(&rule->icmp_type);
  95
  96                 rule->enabled = true;
  97
  98                 fw3_parse_options(rule, fw3_rule_opts, s);
  99
 100                 if (!rule->enabled)
 101                 {
 102                         fw3_free_rule(rule);
 103                         continue;
 104                 }
 105
 106                 if (rule->src.invert || rule->dest.invert)
 107                 {
 108                         warn_elem(e, "must not have inverted 'src' or 'dest' options");
 109                         fw3_free_rule(rule);
 110                         continue;
 111                 }
 112                 else if (rule->src.set && !rule->src.any &&
 113                          !(rule->_src = fw3_lookup_zone(state, rule->src.name, false)))
 114                 {
 115                         warn_elem(e, "refers to not existing zone '%s'", rule->src.name);
 116                         fw3_free_rule(rule);
 117                         continue;
 118                 }
 119                 else if (rule->dest.set && !rule->dest.any &&
 120                          !(rule->_dest = fw3_lookup_zone(state, rule->dest.name, false)))
 121                 {
 122                         warn_elem(e, "refers to not existing zone '%s'", rule->dest.name);
 123                         fw3_free_rule(rule);
 124                         continue;
 125                 }
 126                 else if (rule->ipset.set && state->disable_ipsets)
 127                 {
 128                         warn_elem(e, "skipped due to disabled ipset support");
 129                         fw3_free_rule(rule);
 130                         continue;
 131                 }
 132                 else if (rule->ipset.set && !rule->ipset.any &&
 133                          !(rule->_ipset = fw3_lookup_ipset(state, rule->ipset.name, false)))
 134                 {
 135                         warn_elem(e, "refers to unknown ipset '%s'", rule->ipset.name);
 136                         fw3_free_rule(rule);
 137                         continue;
 138                 }
 139
 140                 if (!rule->_src && rule->target == FW3_FLAG_NOTRACK)
 141                 {
 142                         warn_elem(e, "is set to target NOTRACK but has no source assigned");
 143                         fw3_free_rule(rule);
 144                         continue;
 145                 }
 146
 147                 if (!rule->_src && !rule->_dest && !rule->src.any && !rule->dest.any)
 148                 {
 149                         warn_elem(e, "has neither a source nor a destination zone assigned "
 150                                      "- assuming an output rule");
 151                 }
 152
 153                 if (list_empty(&rule->proto))
 154                 {
 155                         warn_elem(e, "does not specify a protocol, assuming TCP+UDP");
 156                         fw3_parse_protocol(&rule->proto, "tcpudp", true);
 157                 }
 158
 159                 if (rule->target == FW3_FLAG_UNSPEC)
 160                 {
 161                         warn_elem(e, "has no target specified, defaulting to REJECT");
 162                         rule->target = FW3_FLAG_REJECT;
 163                 }
 164                 else if (rule->target > FW3_FLAG_NOTRACK)
 165                 {
 166                         warn_elem(e, "has invalid target specified, defaulting to REJECT");
 167                         rule->target = FW3_FLAG_REJECT;
 168                 }
 169
 170                 /* NB: rule family... */
 171                 if (rule->_dest)
 172                 {
 173                         setbit(rule->_dest->flags[0], rule->target);
 174                         setbit(rule->_dest->flags[1], rule->target);
 175                 }
 176
 177                 list_add_tail(&rule->list, &state->rules);
 178                 continue;
 179         }
 180 }
 181
 182
 183 static void
 184 print_chain(struct fw3_rule *rule)
 185 {
 186         char chain[256];
 187
 188         sprintf(chain, "delegate_output");
 189
 190         if (rule->target == FW3_FLAG_NOTRACK)
 191         {
 192                 sprintf(chain, "zone_%s_notrack", rule->src.name);
 193         }
 194         else
 195         {
 196                 if (rule->src.set)
 197                 {
 198                         if (!rule->src.any)
 199                         {
 200                                 if (rule->dest.set)
 201                                         sprintf(chain, "zone_%s_forward", rule->src.name);
 202                                 else
 203                                         sprintf(chain, "zone_%s_input", rule->src.name);
 204                         }
 205                         else
 206                         {
 207                                 if (rule->dest.set)
 208                                         sprintf(chain, "delegate_forward");
 209                                 else
 210                                         sprintf(chain, "delegate_input");
 211                         }
 212                 }
 213
 214                 if (rule->dest.set && !rule->src.set)
 215                         sprintf(chain, "zone_%s_output", rule->dest.name);
 216         }
 217
 218         fw3_pr("-A %s", chain);
 219 }
 220
 221 static void print_target(struct fw3_rule *rule)
 222 {
 223         const char *target;
 224
 225         switch(rule->target)
 226         {
 227         case FW3_FLAG_ACCEPT:
 228         case FW3_FLAG_DROP:
 229         case FW3_FLAG_NOTRACK:
 230                 target = fw3_flag_names[rule->target];
 231                 break;
 232
 233         default:
 234                 target = fw3_flag_names[FW3_FLAG_REJECT];
 235                 break;
 236         }
 237
 238         if (rule->dest.set && !rule->dest.any)
 239                 fw3_pr(" -j zone_%s_dest_%s\n", rule->dest.name, target);
 240         else if (rule->target == FW3_FLAG_REJECT)
 241                 fw3_pr(" -j reject\n");
 242         else
 243                 fw3_pr(" -j %s\n", target);
 244 }
 245
 246 static void
 247 print_rule(struct fw3_state *state, enum fw3_family family,
 248            enum fw3_table table, struct fw3_rule *rule,
 249            struct fw3_protocol *proto,
 250            struct fw3_address *sip, struct fw3_address *dip,
 251            struct fw3_port *sport, struct fw3_port *dport,
 252            struct fw3_mac *mac, struct fw3_icmptype *icmptype)
 253 {
 254         if (!fw3_is_family(sip, family) || !fw3_is_family(dip, family))
 255         {
 256                 info("     ! Skipping due to different family of ip address");
 257                 return;
 258         }
 259
 260         if (proto->protocol == 58 && family == FW3_FAMILY_V4)
 261         {
 262                 info("     ! Skipping due to different family of protocol");
 263                 return;
 264         }
 265
 266         print_chain(rule);
 267         fw3_format_ipset(rule->_ipset, rule->ipset.invert);
 268         fw3_format_protocol(proto, family);
 269         fw3_format_src_dest(sip, dip);
 270         fw3_format_sport_dport(sport, dport);
 271         fw3_format_icmptype(icmptype, family);
 272         fw3_format_mac(mac);
 273         fw3_format_limit(&rule->limit);
 274         fw3_format_time(&rule->time);
 275         fw3_format_extra(rule->extra);
 276         fw3_format_comment(rule->name);
 277         print_target(rule);
 278 }
 279
 280 static void
 281 expand_rule(struct fw3_state *state, enum fw3_family family,
 282             enum fw3_table table, struct fw3_rule *rule, int num)
 283 {
 284         struct fw3_protocol *proto;
 285         struct fw3_address *sip;
 286         struct fw3_address *dip;
 287         struct fw3_port *sport;
 288         struct fw3_port *dport;
 289         struct fw3_mac *mac;
 290         struct fw3_icmptype *icmptype;
 291
 292         struct list_head *sports = NULL;
 293         struct list_head *dports = NULL;
 294         struct list_head *icmptypes = NULL;
 295
 296         struct list_head empty;
 297         INIT_LIST_HEAD(&empty);
 298
 299         if (!fw3_is_family(rule, family))
 300                 return;
 301
 302         if ((table == FW3_TABLE_RAW && rule->target != FW3_FLAG_NOTRACK) ||
 303             (table != FW3_TABLE_FILTER))
 304                 return;
 305
 306         if (rule->name)
 307                 info("   * Rule '%s'", rule->name);
 308         else
 309                 info("   * Rule #%u", num);
 310
 311         if (!fw3_is_family(rule->_src, family) ||
 312             !fw3_is_family(rule->_dest, family))
 313         {
 314                 info("     ! Skipping due to different family of zone");
 315                 return;
 316         }
 317
 318         if (rule->_ipset)
 319         {
 320                 if (!fw3_is_family(rule->_ipset, family))
 321                 {
 322                         info("     ! Skipping due to different family in ipset");
 323                         return;
 324                 }
 325
 326                 set(rule->_ipset->flags, family, family);
 327         }
 328
 329         list_for_each_entry(proto, &rule->proto, list)
 330         {
 331                 /* icmp / ipv6-icmp */
 332                 if (proto->protocol == 1 || proto->protocol == 58)
 333                 {
 334                         sports = &empty;
 335                         dports = &empty;
 336                         icmptypes = &rule->icmp_type;
 337                 }
 338                 else
 339                 {
 340                         sports = &rule->port_src;
 341                         dports = &rule->port_dest;
 342                         icmptypes = &empty;
 343                 }
 344
 345                 fw3_foreach(sip, &rule->ip_src)
 346                 fw3_foreach(dip, &rule->ip_dest)
 347                 fw3_foreach(sport, sports)
 348                 fw3_foreach(dport, dports)
 349                 fw3_foreach(mac, &rule->mac_src)
 350                 fw3_foreach(icmptype, icmptypes)
 351                         print_rule(state, family, table, rule, proto, sip, dip,
 352                                    sport, dport, mac, icmptype);
 353         }
 354 }
 355
 356 void
 357 fw3_print_rules(struct fw3_state *state, enum fw3_family family,
 358                 enum fw3_table table)
 359 {
 360         int num = 0;
 361         struct fw3_rule *rule;
 362
 363         list_for_each_entry(rule, &state->rules, list)
 364                 expand_rule(state, family, table, rule, num++);
 365 }