rules.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
   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 static struct fw3_rule*
  76 alloc_rule(struct fw3_state *state)
  77 {
  78         struct fw3_rule *rule = calloc(1, sizeof(*rule));
  79
  80         if (rule) {
  81                 INIT_LIST_HEAD(&rule->proto);
  82
  83                 INIT_LIST_HEAD(&rule->ip_src);
  84                 INIT_LIST_HEAD(&rule->mac_src);
  85                 INIT_LIST_HEAD(&rule->port_src);
  86
  87                 INIT_LIST_HEAD(&rule->ip_dest);
  88                 INIT_LIST_HEAD(&rule->port_dest);
  89
  90                 INIT_LIST_HEAD(&rule->icmp_type);
  91
  92                 list_add_tail(&rule->list, &state->rules);
  93                 rule->enabled = true;
  94         }
  95
  96         return rule;
  97 }
  98
  99 void
 100 fw3_load_rules(struct fw3_state *state, struct uci_package *p,
 101                 struct blob_attr *a)
 102 {
 103         struct uci_section *s;
 104         struct uci_element *e;
 105         struct fw3_rule *rule, *n;
 106         struct blob_attr *entry, *opt;
 107         unsigned rem, orem;
 108
 109         INIT_LIST_HEAD(&state->rules);
 110
 111         blob_for_each_attr(entry, a, rem) {
 112                 const char *type = NULL;
 113                 const char *name = "ubus rule";
 114                 blobmsg_for_each_attr(opt, entry, orem)
 115                         if (!strcmp(blobmsg_name(opt), "type"))
 116                                 type = blobmsg_get_string(opt);
 117                         else if (!strcmp(blobmsg_name(opt), "name"))
 118                                 name = blobmsg_get_string(opt);
 119
 120                 if (!type || strcmp(type, "rule"))
 121                         continue;
 122
 123                 if (!(rule = alloc_rule(state)))
 124                         continue;
 125
 126                 if (!fw3_parse_blob_options(rule, fw3_rule_opts, entry, name))
 127                 {
 128                         fprintf(stderr, "%s skipped due to invalid options\n", name);
 129                         fw3_free_rule(rule);
 130                         continue;
 131                 }
 132         }
 133
 134         uci_foreach_element(&p->sections, e)
 135         {
 136                 s = uci_to_section(e);
 137
 138                 if (strcmp(s->type, "rule"))
 139                         continue;
 140
 141                 if (!(rule = alloc_rule(state)))
 142                         continue;
 143
 144                 if (!fw3_parse_options(rule, fw3_rule_opts, s))
 145                 {
 146                         warn_elem(e, "skipped due to invalid options");
 147                         fw3_free_rule(rule);
 148                         continue;
 149                 }
 150         }
 151
 152         list_for_each_entry_safe(rule, n, &state->rules, list)
 153         {
 154                 if (!rule->enabled)
 155                 {
 156                         fw3_free_rule(rule);
 157                         continue;
 158                 }
 159
 160                 if (rule->src.invert || rule->dest.invert)
 161                 {
 162                         warn_elem(e, "must not have inverted 'src' or 'dest' options");
 163                         fw3_free_rule(rule);
 164                         continue;
 165                 }
 166                 else if (rule->src.set && !rule->src.any &&
 167                          !(rule->_src = fw3_lookup_zone(state, rule->src.name)))
 168                 {
 169                         warn_elem(e, "refers to not existing zone '%s'", rule->src.name);
 170                         fw3_free_rule(rule);
 171                         continue;
 172                 }
 173                 else if (rule->dest.set && !rule->dest.any &&
 174                          !(rule->_dest = fw3_lookup_zone(state, rule->dest.name)))
 175                 {
 176                         warn_elem(e, "refers to not existing zone '%s'", rule->dest.name);
 177                         fw3_free_rule(rule);
 178                         continue;
 179                 }
 180                 else if (rule->ipset.set && state->disable_ipsets)
 181                 {
 182                         warn_elem(e, "skipped due to disabled ipset support");
 183                         fw3_free_rule(rule);
 184                         continue;
 185                 }
 186                 else if (rule->ipset.set &&
 187                          !(rule->ipset.ptr = fw3_lookup_ipset(state, rule->ipset.name)))
 188                 {
 189                         warn_elem(e, "refers to unknown ipset '%s'", rule->ipset.name);
 190                         fw3_free_rule(rule);
 191                         continue;
 192                 }
 193
 194                 if (!rule->_src && rule->target == FW3_FLAG_NOTRACK)
 195                 {
 196                         warn_elem(e, "is set to target NOTRACK but has no source assigned");
 197                         fw3_free_rule(rule);
 198                         continue;
 199                 }
 200
 201                 if (!rule->set_mark.set && !rule->set_xmark.set &&
 202                     rule->target == FW3_FLAG_MARK)
 203                 {
 204                         warn_elem(e, "is set to target MARK but specifies neither "
 205                                      "'set_mark' nor 'set_xmark' option");
 206                         fw3_free_rule(rule);
 207                         continue;
 208                 }
 209
 210                 if (rule->_dest && rule->target == FW3_FLAG_MARK)
 211                 {
 212                         warn_elem(e, "must not specify 'dest' for MARK target");
 213                         fw3_free_rule(rule);
 214                         continue;
 215                 }
 216
 217                 if (rule->set_mark.invert || rule->set_xmark.invert)
 218                 {
 219                         warn_elem(e, "must not have inverted 'set_mark' or 'set_xmark'");
 220                         fw3_free_rule(rule);
 221                         continue;
 222                 }
 223
 224                 if (!rule->_src && !rule->_dest && !rule->src.any && !rule->dest.any)
 225                 {
 226                         warn_elem(e, "has neither a source nor a destination zone assigned "
 227                                      "- assuming an output rule");
 228                 }
 229
 230                 if (list_empty(&rule->proto))
 231                 {
 232                         warn_elem(e, "does not specify a protocol, assuming TCP+UDP");
 233                         fw3_parse_protocol(&rule->proto, "tcpudp", true);
 234                 }
 235
 236                 if (rule->target == FW3_FLAG_UNSPEC)
 237                 {
 238                         warn_elem(e, "has no target specified, defaulting to REJECT");
 239                         rule->target = FW3_FLAG_REJECT;
 240                 }
 241                 else if (rule->target > FW3_FLAG_MARK)
 242                 {
 243                         warn_elem(e, "has invalid target specified, defaulting to REJECT");
 244                         rule->target = FW3_FLAG_REJECT;
 245                 }
 246
 247                 /* NB: rule family... */
 248                 if (rule->_dest)
 249                 {
 250                         setbit(rule->_dest->flags[0], rule->target);
 251                         setbit(rule->_dest->flags[1], rule->target);
 252                 }
 253                 else if (need_src_action_chain(rule))
 254                 {
 255                         setbit(rule->_src->flags[0], fw3_to_src_target(rule->target));
 256                         setbit(rule->_src->flags[1], fw3_to_src_target(rule->target));
 257                 }
 258         }
 259 }
 260
 261
 262 static void
 263 append_chain(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 264 {
 265         char chain[32];
 266
 267         snprintf(chain, sizeof(chain), "OUTPUT");
 268
 269         if (rule->target == FW3_FLAG_NOTRACK)
 270         {
 271                 snprintf(chain, sizeof(chain), "zone_%s_notrack", rule->src.name);
 272         }
 273         else if (rule->target == FW3_FLAG_MARK && (rule->_src || rule->src.any))
 274         {
 275                 snprintf(chain, sizeof(chain), "PREROUTING");
 276         }
 277         else
 278         {
 279                 if (rule->src.set)
 280                 {
 281                         if (!rule->src.any)
 282                         {
 283                                 if (rule->dest.set)
 284                                         snprintf(chain, sizeof(chain), "zone_%s_forward",
 285                                                  rule->src.name);
 286                                 else
 287                                         snprintf(chain, sizeof(chain), "zone_%s_input",
 288                                                  rule->src.name);
 289                         }
 290                         else
 291                         {
 292                                 if (rule->dest.set)
 293                                         snprintf(chain, sizeof(chain), "FORWARD");
 294                                 else
 295                                         snprintf(chain, sizeof(chain), "INPUT");
 296                         }
 297                 }
 298
 299                 if (rule->dest.set && !rule->src.set)
 300                 {
 301                         if (rule->dest.any)
 302                                 snprintf(chain, sizeof(chain), "OUTPUT");
 303                         else
 304                                 snprintf(chain, sizeof(chain), "zone_%s_output",
 305                                          rule->dest.name);
 306                 }
 307         }
 308
 309         fw3_ipt_rule_append(r, chain);
 310 }
 311
 312 static void set_target(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 313 {
 314         const char *name;
 315         struct fw3_mark *mark;
 316         char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF\0")];
 317
 318         switch(rule->target)
 319         {
 320         case FW3_FLAG_MARK:
 321                 name = rule->set_mark.set ? "--set-mark" : "--set-xmark";
 322                 mark = rule->set_mark.set ? &rule->set_mark : &rule->set_xmark;
 323                 sprintf(buf, "0x%x/0x%x", mark->mark, mark->mask);
 324
 325                 fw3_ipt_rule_target(r, "MARK");
 326                 fw3_ipt_rule_addarg(r, false, name, buf);
 327                 return;
 328
 329         case FW3_FLAG_NOTRACK:
 330                 fw3_ipt_rule_target(r, "CT");
 331                 fw3_ipt_rule_addarg(r, false, "--notrack", NULL);
 332                 return;
 333
 334         case FW3_FLAG_ACCEPT:
 335         case FW3_FLAG_DROP:
 336                 name = fw3_flag_names[rule->target];
 337                 break;
 338
 339         default:
 340                 name = fw3_flag_names[FW3_FLAG_REJECT];
 341                 break;
 342         }
 343
 344         if (rule->dest.set && !rule->dest.any)
 345                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", rule->dest.name, name);
 346         else if (need_src_action_chain(rule))
 347                 fw3_ipt_rule_target(r, "zone_%s_src_%s", rule->src.name, name);
 348         else if (strcmp(name, "REJECT"))
 349                 fw3_ipt_rule_target(r, name);
 350         else
 351                 fw3_ipt_rule_target(r, "reject");
 352 }
 353
 354 static void
 355 set_comment(struct fw3_ipt_rule *r, const char *name, int num)
 356 {
 357         if (name)
 358                 fw3_ipt_rule_comment(r, name);
 359         else
 360                 fw3_ipt_rule_comment(r, "@rule[%u]", num);
 361 }
 362
 363 static void
 364 print_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 365            struct fw3_rule *rule, int num, struct fw3_protocol *proto,
 366            struct fw3_address *sip, struct fw3_address *dip,
 367            struct fw3_port *sport, struct fw3_port *dport,
 368            struct fw3_mac *mac, struct fw3_icmptype *icmptype)
 369 {
 370         struct fw3_ipt_rule *r;
 371
 372         if (!fw3_is_family(sip, handle->family) ||
 373             !fw3_is_family(dip, handle->family))
 374         {
 375                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
 376                         info("     ! Skipping due to different family of ip address");
 377
 378                 return;
 379         }
 380
 381         if (proto->protocol == 58 && handle->family == FW3_FAMILY_V4)
 382         {
 383                 info("     ! Skipping due to different family of protocol");
 384                 return;
 385         }
 386
 387         r = fw3_ipt_rule_create(handle, proto, NULL, NULL, sip, dip);
 388         fw3_ipt_rule_sport_dport(r, sport, dport);
 389         fw3_ipt_rule_device(r, rule->device, rule->direction_out);
 390         fw3_ipt_rule_icmptype(r, icmptype);
 391         fw3_ipt_rule_mac(r, mac);
 392         fw3_ipt_rule_ipset(r, &rule->ipset);
 393         fw3_ipt_rule_limit(r, &rule->limit);
 394         fw3_ipt_rule_time(r, &rule->time);
 395         fw3_ipt_rule_mark(r, &rule->mark);
 396         set_target(r, rule);
 397         fw3_ipt_rule_extra(r, rule->extra);
 398         set_comment(r, rule->name, num);
 399         append_chain(r, rule);
 400 }
 401
 402 static void
 403 expand_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 404             struct fw3_rule *rule, int num)
 405 {
 406         struct fw3_protocol *proto;
 407         struct fw3_address *sip;
 408         struct fw3_address *dip;
 409         struct fw3_port *sport;
 410         struct fw3_port *dport;
 411         struct fw3_mac *mac;
 412         struct fw3_icmptype *icmptype;
 413
 414         struct list_head *sports = NULL;
 415         struct list_head *dports = NULL;
 416         struct list_head *icmptypes = NULL;
 417
 418         struct list_head empty;
 419         INIT_LIST_HEAD(&empty);
 420
 421         if (!fw3_is_family(rule, handle->family))
 422                 return;
 423
 424         if ((rule->target == FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_RAW) ||
 425             (rule->target == FW3_FLAG_MARK && handle->table != FW3_TABLE_MANGLE) ||
 426                 (rule->target < FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_FILTER))
 427                 return;
 428
 429         if (rule->name)
 430                 info("   * Rule '%s'", rule->name);
 431         else
 432                 info("   * Rule #%u", num);
 433
 434         if (!fw3_is_family(rule->_src, handle->family) ||
 435             !fw3_is_family(rule->_dest, handle->family))
 436         {
 437                 info("     ! Skipping due to different family of zone");
 438                 return;
 439         }
 440
 441         if (rule->ipset.ptr)
 442         {
 443                 if (!fw3_is_family(rule->ipset.ptr, handle->family))
 444                 {
 445                         info("     ! Skipping due to different family in ipset");
 446                         return;
 447                 }
 448
 449                 if (!fw3_check_ipset(rule->ipset.ptr))
 450                 {
 451                         info("     ! Skipping due to missing ipset '%s'",
 452                              rule->ipset.ptr->external
 453                                         ? rule->ipset.ptr->external : rule->ipset.ptr->name);
 454                         return;
 455                 }
 456
 457                 set(rule->ipset.ptr->flags, handle->family, handle->family);
 458         }
 459
 460         list_for_each_entry(proto, &rule->proto, list)
 461         {
 462                 /* icmp / ipv6-icmp */
 463                 if (proto->protocol == 1 || proto->protocol == 58)
 464                 {
 465                         sports = &empty;
 466                         dports = &empty;
 467                         icmptypes = &rule->icmp_type;
 468                 }
 469                 else
 470                 {
 471                         sports = &rule->port_src;
 472                         dports = &rule->port_dest;
 473                         icmptypes = &empty;
 474                 }
 475
 476                 fw3_foreach(sip, &rule->ip_src)
 477                 fw3_foreach(dip, &rule->ip_dest)
 478                 fw3_foreach(sport, sports)
 479                 fw3_foreach(dport, dports)
 480                 fw3_foreach(mac, &rule->mac_src)
 481                 fw3_foreach(icmptype, icmptypes)
 482                         print_rule(handle, state, rule, num, proto, sip, dip,
 483                                    sport, dport, mac, icmptype);
 484         }
 485 }
 486
 487 void
 488 fw3_print_rules(struct fw3_ipt_handle *handle, struct fw3_state *state)
 489 {
 490         int num = 0;
 491         struct fw3_rule *rule;
 492
 493         list_for_each_entry(rule, &state->rules, list)
 494                 expand_rule(handle, state, rule, num++);
 495 }