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 #define warn_rule(r, e, fmt, ...)                                                                       \
 100         do {                                                                                                                    \
 101                 if (e)                                                                                                          \
 102                         warn_elem(e, fmt, ##__VA_ARGS__);                                               \
 103                 else                                                                                                            \
 104                         warn("Warning: ubus rule (%s) " fmt,                                    \
 105                              (r && r->name) ? r->name : "?", ##__VA_ARGS__);    \
 106         } while(0)
 107
 108 static bool
 109 check_rule(struct fw3_state *state, struct fw3_rule *r, struct uci_element *e)
 110 {
 111         if (!r->enabled)
 112                 return false;
 113
 114         if (r->src.invert || r->dest.invert)
 115         {
 116                 warn_rule(r, e, "must not have inverted 'src' or 'dest' options");
 117                 return false;
 118         }
 119         else if (r->src.set && !r->src.any &&
 120                  !(r->_src = fw3_lookup_zone(state, r->src.name)))
 121         {
 122                 warn_rule(r, e, "refers to not existing zone '%s'", r->src.name);
 123                 return false;
 124         }
 125         else if (r->dest.set && !r->dest.any &&
 126                  !(r->_dest = fw3_lookup_zone(state, r->dest.name)))
 127         {
 128                 warn_rule(r, e, "refers to not existing zone '%s'", r->dest.name);
 129                 return false;
 130         }
 131         else if (r->ipset.set && state->disable_ipsets)
 132         {
 133                 warn_rule(r, e, "skipped due to disabled ipset support");
 134                 return false;
 135         }
 136         else if (r->ipset.set &&
 137                  !(r->ipset.ptr = fw3_lookup_ipset(state, r->ipset.name)))
 138         {
 139                 warn_rule(r, e, "refers to unknown ipset '%s'", r->ipset.name);
 140                 return false;
 141         }
 142
 143         if (!r->_src && r->target == FW3_FLAG_NOTRACK)
 144         {
 145                 warn_rule(r, e, "is set to target NOTRACK but has no source assigned");
 146                 return false;
 147         }
 148
 149         if (!r->set_mark.set && !r->set_xmark.set &&
 150             r->target == FW3_FLAG_MARK)
 151         {
 152                 warn_rule(r, e, "is set to target MARK but specifies neither "
 153                                 "'set_mark' nor 'set_xmark' option");
 154                 return false;
 155         }
 156
 157         if (r->_dest && r->target == FW3_FLAG_MARK)
 158         {
 159                 warn_rule(r, e, "must not specify 'dest' for MARK target");
 160                 return false;
 161         }
 162
 163         if (r->set_mark.invert || r->set_xmark.invert)
 164         {
 165                 warn_rule(r, e, "must not have inverted 'set_mark' or 'set_xmark'");
 166                 return false;
 167         }
 168
 169         if (!r->_src && !r->_dest && !r->src.any && !r->dest.any)
 170         {
 171                 warn_rule(r, e, "has neither a source nor a destination zone assigned "
 172                                 "- assuming an output r");
 173         }
 174
 175         if (list_empty(&r->proto))
 176         {
 177                 warn_rule(r, e, "does not specify a protocol, assuming TCP+UDP");
 178                 fw3_parse_protocol(&r->proto, "tcpudp", true);
 179         }
 180
 181         if (r->target == FW3_FLAG_UNSPEC)
 182         {
 183                 warn_rule(r, e, "has no target specified, defaulting to REJECT");
 184                 r->target = FW3_FLAG_REJECT;
 185         }
 186         else if (r->target > FW3_FLAG_MARK)
 187         {
 188                 warn_rule(r, e, "has invalid target specified, defaulting to REJECT");
 189                 r->target = FW3_FLAG_REJECT;
 190         }
 191
 192         /* NB: r family... */
 193         if (r->_dest)
 194         {
 195                 fw3_setbit(r->_dest->flags[0], r->target);
 196                 fw3_setbit(r->_dest->flags[1], r->target);
 197         }
 198         else if (need_src_action_chain(r))
 199         {
 200                 fw3_setbit(r->_src->flags[0], fw3_to_src_target(r->target));
 201                 fw3_setbit(r->_src->flags[1], fw3_to_src_target(r->target));
 202         }
 203
 204         return true;
 205 }
 206
 207 void
 208 fw3_load_rules(struct fw3_state *state, struct uci_package *p,
 209                 struct blob_attr *a)
 210 {
 211         struct uci_section *s;
 212         struct uci_element *e;
 213         struct fw3_rule *rule;
 214         struct blob_attr *entry, *opt;
 215         unsigned rem, orem;
 216
 217         INIT_LIST_HEAD(&state->rules);
 218
 219         blob_for_each_attr(entry, a, rem) {
 220                 const char *type = NULL;
 221                 const char *name = "ubus rule";
 222                 blobmsg_for_each_attr(opt, entry, orem)
 223                         if (!strcmp(blobmsg_name(opt), "type"))
 224                                 type = blobmsg_get_string(opt);
 225                         else if (!strcmp(blobmsg_name(opt), "name"))
 226                                 name = blobmsg_get_string(opt);
 227
 228                 if (!type || strcmp(type, "rule"))
 229                         continue;
 230
 231                 if (!(rule = alloc_rule(state)))
 232                         continue;
 233
 234                 if (!fw3_parse_blob_options(rule, fw3_rule_opts, entry, name))
 235                 {
 236                         warn_rule(rule, NULL, "skipped due to invalid options\n");
 237                         fw3_free_rule(rule);
 238                         continue;
 239                 }
 240
 241                 if (!check_rule(state, rule, NULL))
 242                         fw3_free_rule(rule);
 243         }
 244
 245         uci_foreach_element(&p->sections, e)
 246         {
 247                 s = uci_to_section(e);
 248
 249                 if (strcmp(s->type, "rule"))
 250                         continue;
 251
 252                 if (!(rule = alloc_rule(state)))
 253                         continue;
 254
 255                 if (!fw3_parse_options(rule, fw3_rule_opts, s))
 256                 {
 257                         warn_elem(e, "skipped due to invalid options");
 258                         fw3_free_rule(rule);
 259                         continue;
 260                 }
 261
 262                 if (!check_rule(state, rule, e))
 263                         fw3_free_rule(rule);
 264         }
 265 }
 266
 267
 268 static void
 269 append_chain(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 270 {
 271         char chain[32];
 272
 273         snprintf(chain, sizeof(chain), "OUTPUT");
 274
 275         if (rule->target == FW3_FLAG_NOTRACK)
 276         {
 277                 snprintf(chain, sizeof(chain), "zone_%s_notrack", rule->src.name);
 278         }
 279         else if (rule->target == FW3_FLAG_MARK && (rule->_src || rule->src.any))
 280         {
 281                 snprintf(chain, sizeof(chain), "PREROUTING");
 282         }
 283         else
 284         {
 285                 if (rule->src.set)
 286                 {
 287                         if (!rule->src.any)
 288                         {
 289                                 if (rule->dest.set)
 290                                         snprintf(chain, sizeof(chain), "zone_%s_forward",
 291                                                  rule->src.name);
 292                                 else
 293                                         snprintf(chain, sizeof(chain), "zone_%s_input",
 294                                                  rule->src.name);
 295                         }
 296                         else
 297                         {
 298                                 if (rule->dest.set)
 299                                         snprintf(chain, sizeof(chain), "FORWARD");
 300                                 else
 301                                         snprintf(chain, sizeof(chain), "INPUT");
 302                         }
 303                 }
 304
 305                 if (rule->dest.set && !rule->src.set)
 306                 {
 307                         if (rule->dest.any)
 308                                 snprintf(chain, sizeof(chain), "OUTPUT");
 309                         else
 310                                 snprintf(chain, sizeof(chain), "zone_%s_output",
 311                                          rule->dest.name);
 312                 }
 313         }
 314
 315         fw3_ipt_rule_append(r, chain);
 316 }
 317
 318 static void set_target(struct fw3_ipt_rule *r, struct fw3_rule *rule)
 319 {
 320         const char *name;
 321         struct fw3_mark *mark;
 322         char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF\0")];
 323
 324         switch(rule->target)
 325         {
 326         case FW3_FLAG_MARK:
 327                 name = rule->set_mark.set ? "--set-mark" : "--set-xmark";
 328                 mark = rule->set_mark.set ? &rule->set_mark : &rule->set_xmark;
 329                 sprintf(buf, "0x%x/0x%x", mark->mark, mark->mask);
 330
 331                 fw3_ipt_rule_target(r, "MARK");
 332                 fw3_ipt_rule_addarg(r, false, name, buf);
 333                 return;
 334
 335         case FW3_FLAG_NOTRACK:
 336                 fw3_ipt_rule_target(r, "CT");
 337                 fw3_ipt_rule_addarg(r, false, "--notrack", NULL);
 338                 return;
 339
 340         case FW3_FLAG_ACCEPT:
 341         case FW3_FLAG_DROP:
 342                 name = fw3_flag_names[rule->target];
 343                 break;
 344
 345         default:
 346                 name = fw3_flag_names[FW3_FLAG_REJECT];
 347                 break;
 348         }
 349
 350         if (rule->dest.set && !rule->dest.any)
 351                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", rule->dest.name, name);
 352         else if (need_src_action_chain(rule))
 353                 fw3_ipt_rule_target(r, "zone_%s_src_%s", rule->src.name, name);
 354         else if (strcmp(name, "REJECT"))
 355                 fw3_ipt_rule_target(r, name);
 356         else
 357                 fw3_ipt_rule_target(r, "reject");
 358 }
 359
 360 static void
 361 set_comment(struct fw3_ipt_rule *r, const char *name, int num)
 362 {
 363         if (name)
 364                 fw3_ipt_rule_comment(r, name);
 365         else
 366                 fw3_ipt_rule_comment(r, "@rule[%u]", num);
 367 }
 368
 369 static void
 370 print_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 371            struct fw3_rule *rule, int num, struct fw3_protocol *proto,
 372            struct fw3_address *sip, struct fw3_address *dip,
 373            struct fw3_port *sport, struct fw3_port *dport,
 374            struct fw3_mac *mac, struct fw3_icmptype *icmptype)
 375 {
 376         struct fw3_ipt_rule *r;
 377
 378         if (!fw3_is_family(sip, handle->family) ||
 379             !fw3_is_family(dip, handle->family))
 380         {
 381                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
 382                         info("     ! Skipping due to different family of ip address");
 383
 384                 return;
 385         }
 386
 387         if (proto->protocol == 58 && handle->family == FW3_FAMILY_V4)
 388         {
 389                 info("     ! Skipping due to different family of protocol");
 390                 return;
 391         }
 392
 393         r = fw3_ipt_rule_create(handle, proto, NULL, NULL, sip, dip);
 394         fw3_ipt_rule_sport_dport(r, sport, dport);
 395         fw3_ipt_rule_device(r, rule->device, rule->direction_out);
 396         fw3_ipt_rule_icmptype(r, icmptype);
 397         fw3_ipt_rule_mac(r, mac);
 398         fw3_ipt_rule_ipset(r, &rule->ipset);
 399         fw3_ipt_rule_limit(r, &rule->limit);
 400         fw3_ipt_rule_time(r, &rule->time);
 401         fw3_ipt_rule_mark(r, &rule->mark);
 402         set_target(r, rule);
 403         fw3_ipt_rule_extra(r, rule->extra);
 404         set_comment(r, rule->name, num);
 405         append_chain(r, rule);
 406 }
 407
 408 static void
 409 expand_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
 410             struct fw3_rule *rule, int num)
 411 {
 412         struct fw3_protocol *proto;
 413         struct fw3_address *sip;
 414         struct fw3_address *dip;
 415         struct fw3_port *sport;
 416         struct fw3_port *dport;
 417         struct fw3_mac *mac;
 418         struct fw3_icmptype *icmptype;
 419
 420         struct list_head *sports = NULL;
 421         struct list_head *dports = NULL;
 422         struct list_head *icmptypes = NULL;
 423
 424         struct list_head empty;
 425         INIT_LIST_HEAD(&empty);
 426
 427         if (!fw3_is_family(rule, handle->family))
 428                 return;
 429
 430         if ((rule->target == FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_RAW) ||
 431             (rule->target == FW3_FLAG_MARK && handle->table != FW3_TABLE_MANGLE) ||
 432                 (rule->target < FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_FILTER))
 433                 return;
 434
 435         if (rule->name)
 436                 info("   * Rule '%s'", rule->name);
 437         else
 438                 info("   * Rule #%u", num);
 439
 440         if (!fw3_is_family(rule->_src, handle->family) ||
 441             !fw3_is_family(rule->_dest, handle->family))
 442         {
 443                 info("     ! Skipping due to different family of zone");
 444                 return;
 445         }
 446
 447         if (rule->ipset.ptr)
 448         {
 449                 if (!fw3_is_family(rule->ipset.ptr, handle->family))
 450                 {
 451                         info("     ! Skipping due to different family in ipset");
 452                         return;
 453                 }
 454
 455                 if (!fw3_check_ipset(rule->ipset.ptr))
 456                 {
 457                         info("     ! Skipping due to missing ipset '%s'",
 458                              rule->ipset.ptr->external
 459                                         ? rule->ipset.ptr->external : rule->ipset.ptr->name);
 460                         return;
 461                 }
 462
 463                 set(rule->ipset.ptr->flags, handle->family, handle->family);
 464         }
 465
 466         list_for_each_entry(proto, &rule->proto, list)
 467         {
 468                 /* icmp / ipv6-icmp */
 469                 if (proto->protocol == 1 || proto->protocol == 58)
 470                 {
 471                         sports = &empty;
 472                         dports = &empty;
 473                         icmptypes = &rule->icmp_type;
 474                 }
 475                 else
 476                 {
 477                         sports = &rule->port_src;
 478                         dports = &rule->port_dest;
 479                         icmptypes = &empty;
 480                 }
 481
 482                 fw3_foreach(sip, &rule->ip_src)
 483                 fw3_foreach(dip, &rule->ip_dest)
 484                 fw3_foreach(sport, sports)
 485                 fw3_foreach(dport, dports)
 486                 fw3_foreach(mac, &rule->mac_src)
 487                 fw3_foreach(icmptype, icmptypes)
 488                         print_rule(handle, state, rule, num, proto, sip, dip,
 489                                    sport, dport, mac, icmptype);
 490         }
 491 }
 492
 493 void
 494 fw3_print_rules(struct fw3_ipt_handle *handle, struct fw3_state *state)
 495 {
 496         int num = 0;
 497         struct fw3_rule *rule;
 498
 499         list_for_each_entry(rule, &state->rules, list)
 500                 expand_rule(handle, state, rule, num++);
 501 }