helpers: make the proto field as a list rather than one option
[project/firewall3.git] / rules.c
1 /*
2  * firewall3 - 3rd OpenWrt UCI firewall implementation
3  *
4  *   Copyright (C) 2013-2018 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         FW3_OPT("helper",              cthelper,  rule,     helper),
36         FW3_OPT("set_helper",          cthelper,  rule,     helper),
37
38         FW3_LIST("proto",              protocol,  rule,     proto),
39
40         FW3_LIST("src_ip",             network,   rule,     ip_src),
41         FW3_LIST("src_mac",            mac,       rule,     mac_src),
42         FW3_LIST("src_port",           port,      rule,     port_src),
43
44         FW3_LIST("dest_ip",            network,   rule,     ip_dest),
45         FW3_LIST("dest_port",          port,      rule,     port_dest),
46
47         FW3_LIST("icmp_type",          icmptype,  rule,     icmp_type),
48         FW3_OPT("extra",               string,    rule,     extra),
49
50         FW3_OPT("limit",               limit,     rule,     limit),
51         FW3_OPT("limit_burst",         int,       rule,     limit.burst),
52
53         FW3_OPT("utc_time",            bool,      rule,     time.utc),
54         FW3_OPT("start_date",          date,      rule,     time.datestart),
55         FW3_OPT("stop_date",           date,      rule,     time.datestop),
56         FW3_OPT("start_time",          time,      rule,     time.timestart),
57         FW3_OPT("stop_time",           time,      rule,     time.timestop),
58         FW3_OPT("weekdays",            weekdays,  rule,     time.weekdays),
59         FW3_OPT("monthdays",           monthdays, rule,     time.monthdays),
60
61         FW3_OPT("mark",                mark,      rule,     mark),
62         FW3_OPT("set_mark",            mark,      rule,     set_mark),
63         FW3_OPT("set_xmark",           mark,      rule,     set_xmark),
64
65         FW3_OPT("target",              target,    rule,     target),
66
67         { }
68 };
69
70
71 static bool
72 need_src_action_chain(struct fw3_rule *r)
73 {
74         return (r->_src && r->_src->log && (r->target > FW3_FLAG_ACCEPT));
75 }
76
77 static struct fw3_rule*
78 alloc_rule(struct fw3_state *state)
79 {
80         struct fw3_rule *rule = calloc(1, sizeof(*rule));
81
82         if (rule) {
83                 INIT_LIST_HEAD(&rule->proto);
84
85                 INIT_LIST_HEAD(&rule->ip_src);
86                 INIT_LIST_HEAD(&rule->mac_src);
87                 INIT_LIST_HEAD(&rule->port_src);
88
89                 INIT_LIST_HEAD(&rule->ip_dest);
90                 INIT_LIST_HEAD(&rule->port_dest);
91
92                 INIT_LIST_HEAD(&rule->icmp_type);
93
94                 list_add_tail(&rule->list, &state->rules);
95                 rule->enabled = true;
96         }
97
98         return rule;
99 }
100
101 static bool
102 check_rule(struct fw3_state *state, struct fw3_rule *r, struct uci_element *e)
103 {
104         if (!r->enabled)
105                 return false;
106
107         if (r->src.invert || r->dest.invert)
108         {
109                 warn_section("rule", r, e, "must not have inverted 'src' or 'dest' options");
110                 return false;
111         }
112         else if (r->src.set && !r->src.any &&
113                  !(r->_src = fw3_lookup_zone(state, r->src.name)))
114         {
115                 warn_section("rule", r, e, "refers to not existing zone '%s'", r->src.name);
116                 return false;
117         }
118         else if (r->dest.set && !r->dest.any &&
119                  !(r->_dest = fw3_lookup_zone(state, r->dest.name)))
120         {
121                 warn_section("rule", r, e, "refers to not existing zone '%s'", r->dest.name);
122                 return false;
123         }
124         else if (r->ipset.set && state->disable_ipsets)
125         {
126                 warn_section("rule", r, e, "skipped due to disabled ipset support");
127                 return false;
128         }
129         else if (r->ipset.set &&
130                  !(r->ipset.ptr = fw3_lookup_ipset(state, r->ipset.name)))
131         {
132                 warn_section("rule", r, e, "refers to unknown ipset '%s'", r->ipset.name);
133                 return false;
134         }
135         else if (r->helper.set &&
136                  !(r->helper.ptr = fw3_lookup_cthelper(state, r->helper.name)))
137         {
138                 warn_section("rule", r, e, "refers to unknown CT helper '%s'", r->helper.name);
139                 return false;
140         }
141         else if (r->set_helper.set &&
142                  !(r->set_helper.ptr = fw3_lookup_cthelper(state, r->set_helper.name)))
143         {
144                 warn_section("rule", r, e, "refers to unknown CT helper '%s'", r->set_helper.name);
145                 return false;
146         }
147
148         if (!r->_src && (r->target == FW3_FLAG_NOTRACK || r->target == FW3_FLAG_HELPER))
149         {
150                 warn_section("rule", r, e, "is set to target %s but has no source assigned",
151                              fw3_flag_names[r->target]);
152                 return false;
153         }
154
155         if (!r->set_mark.set && !r->set_xmark.set &&
156             r->target == FW3_FLAG_MARK)
157         {
158                 warn_section("rule", r, e, "is set to target MARK but specifies neither "
159                                 "'set_mark' nor 'set_xmark' option");
160                 return false;
161         }
162
163         if (r->_dest && r->target == FW3_FLAG_MARK)
164         {
165                 warn_section("rule", r, e, "must not specify 'dest' for MARK target");
166                 return false;
167         }
168
169         if (r->set_mark.invert || r->set_xmark.invert)
170         {
171                 warn_section("rule", r, e, "must not have inverted 'set_mark' or 'set_xmark'");
172                 return false;
173         }
174
175         if (!r->set_helper.set && r->target == FW3_FLAG_HELPER)
176         {
177                 warn_section("rule", r, e, "is set to target HELPER but specifies "
178                                            "no 'set_helper' option");
179                 return false;
180         }
181
182         if (r->set_helper.invert && r->target == FW3_FLAG_HELPER)
183         {
184                 warn_section("rule", r, e, "must not have inverted 'set_helper' option");
185                 return false;
186         }
187
188         if (!r->_src && !r->_dest && !r->src.any && !r->dest.any)
189         {
190                 warn_section("rule", r, e, "has neither a source nor a destination zone assigned "
191                                 "- assuming an output r");
192         }
193
194         if (list_empty(&r->proto))
195         {
196                 warn_section("rule", r, e, "does not specify a protocol, assuming TCP+UDP");
197                 fw3_parse_protocol(&r->proto, "tcpudp", true);
198         }
199
200         if (r->target == FW3_FLAG_UNSPEC)
201         {
202                 warn_section("rule", r, e, "has no target specified, defaulting to REJECT");
203                 r->target = FW3_FLAG_REJECT;
204         }
205         else if (r->target > FW3_FLAG_MARK)
206         {
207                 warn_section("rule", r, e, "has invalid target specified, defaulting to REJECT");
208                 r->target = FW3_FLAG_REJECT;
209         }
210
211         /* NB: r family... */
212         if (r->_dest)
213         {
214                 fw3_setbit(r->_dest->flags[0], r->target);
215                 fw3_setbit(r->_dest->flags[1], r->target);
216         }
217         else if (need_src_action_chain(r))
218         {
219                 fw3_setbit(r->_src->flags[0], fw3_to_src_target(r->target));
220                 fw3_setbit(r->_src->flags[1], fw3_to_src_target(r->target));
221         }
222
223         return true;
224 }
225
226 void
227 fw3_load_rules(struct fw3_state *state, struct uci_package *p,
228                 struct blob_attr *a)
229 {
230         struct uci_section *s;
231         struct uci_element *e;
232         struct fw3_rule *rule;
233         struct blob_attr *entry;
234         unsigned rem;
235
236         INIT_LIST_HEAD(&state->rules);
237
238         blob_for_each_attr(entry, a, rem) {
239                 const char *type;
240                 const char *name = "ubus rule";
241
242                 if (!fw3_attr_parse_name_type(entry, &name, &type))
243                         continue;
244
245                 if (strcmp(type, "rule"))
246                         continue;
247
248                 if (!(rule = alloc_rule(state)))
249                         continue;
250
251                 if (!fw3_parse_blob_options(rule, fw3_rule_opts, entry, name))
252                 {
253                         warn_section("rule", rule, NULL, "skipped due to invalid options");
254                         fw3_free_rule(rule);
255                         continue;
256                 }
257
258                 if (!check_rule(state, rule, NULL))
259                         fw3_free_rule(rule);
260         }
261
262         uci_foreach_element(&p->sections, e)
263         {
264                 s = uci_to_section(e);
265
266                 if (strcmp(s->type, "rule"))
267                         continue;
268
269                 if (!(rule = alloc_rule(state)))
270                         continue;
271
272                 if (!fw3_parse_options(rule, fw3_rule_opts, s))
273                 {
274                         warn_elem(e, "skipped due to invalid options");
275                         fw3_free_rule(rule);
276                         continue;
277                 }
278
279                 if (!check_rule(state, rule, e))
280                         fw3_free_rule(rule);
281         }
282 }
283
284
285 static void
286 append_chain(struct fw3_ipt_rule *r, struct fw3_rule *rule)
287 {
288         char chain[32];
289
290         snprintf(chain, sizeof(chain), "OUTPUT");
291
292         if (rule->target == FW3_FLAG_NOTRACK)
293         {
294                 snprintf(chain, sizeof(chain), "zone_%s_notrack", rule->src.name);
295         }
296         else if (rule->target == FW3_FLAG_HELPER)
297         {
298                 snprintf(chain, sizeof(chain), "zone_%s_helper", rule->src.name);
299         }
300         else if (rule->target == FW3_FLAG_MARK && (rule->_src || rule->src.any))
301         {
302                 snprintf(chain, sizeof(chain), "PREROUTING");
303         }
304         else
305         {
306                 if (rule->src.set)
307                 {
308                         if (!rule->src.any)
309                         {
310                                 if (rule->dest.set)
311                                         snprintf(chain, sizeof(chain), "zone_%s_forward",
312                                                  rule->src.name);
313                                 else
314                                         snprintf(chain, sizeof(chain), "zone_%s_input",
315                                                  rule->src.name);
316                         }
317                         else
318                         {
319                                 if (rule->dest.set)
320                                         snprintf(chain, sizeof(chain), "FORWARD");
321                                 else
322                                         snprintf(chain, sizeof(chain), "INPUT");
323                         }
324                 }
325
326                 if (rule->dest.set && !rule->src.set)
327                 {
328                         if (rule->dest.any)
329                                 snprintf(chain, sizeof(chain), "OUTPUT");
330                         else
331                                 snprintf(chain, sizeof(chain), "zone_%s_output",
332                                          rule->dest.name);
333                 }
334         }
335
336         fw3_ipt_rule_append(r, chain);
337 }
338
339 static void set_target(struct fw3_ipt_rule *r, struct fw3_rule *rule)
340 {
341         const char *name;
342         struct fw3_mark *mark;
343         char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF\0")];
344
345         switch(rule->target)
346         {
347         case FW3_FLAG_MARK:
348                 name = rule->set_mark.set ? "--set-mark" : "--set-xmark";
349                 mark = rule->set_mark.set ? &rule->set_mark : &rule->set_xmark;
350                 sprintf(buf, "0x%x/0x%x", mark->mark, mark->mask);
351
352                 fw3_ipt_rule_target(r, "MARK");
353                 fw3_ipt_rule_addarg(r, false, name, buf);
354                 return;
355
356         case FW3_FLAG_NOTRACK:
357                 fw3_ipt_rule_target(r, "CT");
358                 fw3_ipt_rule_addarg(r, false, "--notrack", NULL);
359                 return;
360
361         case FW3_FLAG_HELPER:
362                 fw3_ipt_rule_target(r, "CT");
363                 fw3_ipt_rule_addarg(r, false, "--helper", rule->set_helper.ptr->name);
364                 return;
365
366         case FW3_FLAG_ACCEPT:
367         case FW3_FLAG_DROP:
368                 name = fw3_flag_names[rule->target];
369                 break;
370
371         default:
372                 name = fw3_flag_names[FW3_FLAG_REJECT];
373                 break;
374         }
375
376         if (rule->dest.set && !rule->dest.any)
377                 fw3_ipt_rule_target(r, "zone_%s_dest_%s", rule->dest.name, name);
378         else if (need_src_action_chain(rule))
379                 fw3_ipt_rule_target(r, "zone_%s_src_%s", rule->src.name, name);
380         else if (strcmp(name, "REJECT"))
381                 fw3_ipt_rule_target(r, name);
382         else
383                 fw3_ipt_rule_target(r, "reject");
384 }
385
386 static void
387 set_comment(struct fw3_ipt_rule *r, const char *name, int num)
388 {
389         if (name)
390                 fw3_ipt_rule_comment(r, name);
391         else
392                 fw3_ipt_rule_comment(r, "@rule[%u]", num);
393 }
394
395 static void
396 print_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
397            struct fw3_rule *rule, int num, struct fw3_protocol *proto,
398            struct fw3_address *sip, struct fw3_address *dip,
399            struct fw3_port *sport, struct fw3_port *dport,
400            struct fw3_mac *mac, struct fw3_icmptype *icmptype)
401 {
402         struct fw3_ipt_rule *r;
403
404         if (!fw3_is_family(sip, handle->family) ||
405             !fw3_is_family(dip, handle->family))
406         {
407                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
408                         info("     ! Skipping due to different family of ip address");
409
410                 return;
411         }
412
413         if (!fw3_is_family(sip, handle->family) ||
414             !fw3_is_family(dip, handle->family))
415         {
416                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
417                         info("     ! Skipping due to different family of ip address");
418
419                 return;
420         }
421
422         if (!fw3_is_family(sip, handle->family) ||
423             !fw3_is_family(dip, handle->family))
424         {
425                 if ((sip && !sip->resolved) || (dip && !dip->resolved))
426                         info("     ! Skipping due to different family of ip address");
427
428                 return;
429         }
430
431         if (proto->protocol == 58 && handle->family == FW3_FAMILY_V4)
432         {
433                 info("     ! Skipping protocol %s due to different family",
434                      fw3_protoname(proto));
435                 return;
436         }
437
438         if (rule->helper.ptr &&
439             !fw3_cthelper_check_proto(rule->helper.ptr, proto))
440         {
441                 info("     ! Skipping protocol %s since helper '%s' does not support it",
442                      fw3_protoname(proto), rule->helper.ptr->name);
443                 return;
444         }
445
446         if (rule->set_helper.ptr &&
447             !fw3_cthelper_check_proto(rule->set_helper.ptr, proto))
448         {
449                 info("     ! Skipping protocol %s since helper '%s' does not support it",
450                      fw3_protoname(proto), rule->helper.ptr->name);
451                 return;
452         }
453
454         r = fw3_ipt_rule_create(handle, proto, NULL, NULL, sip, dip);
455         fw3_ipt_rule_sport_dport(r, sport, dport);
456         fw3_ipt_rule_device(r, rule->device, rule->direction_out);
457         fw3_ipt_rule_icmptype(r, icmptype);
458         fw3_ipt_rule_mac(r, mac);
459         fw3_ipt_rule_ipset(r, &rule->ipset);
460         fw3_ipt_rule_helper(r, &rule->helper);
461         fw3_ipt_rule_limit(r, &rule->limit);
462         fw3_ipt_rule_time(r, &rule->time);
463         fw3_ipt_rule_mark(r, &rule->mark);
464         set_target(r, rule);
465         fw3_ipt_rule_extra(r, rule->extra);
466         set_comment(r, rule->name, num);
467         append_chain(r, rule);
468 }
469
470 static void
471 expand_rule(struct fw3_ipt_handle *handle, struct fw3_state *state,
472             struct fw3_rule *rule, int num)
473 {
474         struct fw3_protocol *proto;
475         struct fw3_address *sip;
476         struct fw3_address *dip;
477         struct fw3_port *sport;
478         struct fw3_port *dport;
479         struct fw3_mac *mac;
480         struct fw3_icmptype *icmptype;
481
482         struct list_head *sports = NULL;
483         struct list_head *dports = NULL;
484         struct list_head *icmptypes = NULL;
485
486         struct list_head empty;
487         INIT_LIST_HEAD(&empty);
488
489         if (!fw3_is_family(rule, handle->family))
490                 return;
491
492         if ((rule->target == FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_RAW) ||
493             (rule->target == FW3_FLAG_HELPER && handle->table != FW3_TABLE_RAW)  ||
494             (rule->target == FW3_FLAG_MARK && handle->table != FW3_TABLE_MANGLE) ||
495                 (rule->target < FW3_FLAG_NOTRACK && handle->table != FW3_TABLE_FILTER))
496                 return;
497
498         if (rule->name)
499                 info("   * Rule '%s'", rule->name);
500         else
501                 info("   * Rule #%u", num);
502
503         if (!fw3_is_family(rule->_src, handle->family) ||
504             !fw3_is_family(rule->_dest, handle->family))
505         {
506                 info("     ! Skipping due to different family of zone");
507                 return;
508         }
509
510         if (rule->ipset.ptr)
511         {
512                 if (!fw3_is_family(rule->ipset.ptr, handle->family))
513                 {
514                         info("     ! Skipping due to different family in ipset");
515                         return;
516                 }
517
518                 if (!fw3_check_ipset(rule->ipset.ptr))
519                 {
520                         info("     ! Skipping due to missing ipset '%s'",
521                              rule->ipset.ptr->external
522                                         ? rule->ipset.ptr->external : rule->ipset.ptr->name);
523                         return;
524                 }
525
526                 set(rule->ipset.ptr->flags, handle->family, handle->family);
527         }
528
529         if (rule->helper.ptr && !fw3_is_family(rule->helper.ptr, handle->family))
530         {
531                 info("     ! Skipping due to unsupported family of CT helper");
532                 return;
533         }
534
535         if (rule->set_helper.ptr && !fw3_is_family(rule->set_helper.ptr, handle->family))
536         {
537                 info("     ! Skipping due to unsupported family of CT helper");
538                 return;
539         }
540
541         list_for_each_entry(proto, &rule->proto, list)
542         {
543                 /* icmp / ipv6-icmp */
544                 if (proto->protocol == 1 || proto->protocol == 58)
545                 {
546                         sports = &empty;
547                         dports = &empty;
548                         icmptypes = &rule->icmp_type;
549                 }
550                 else
551                 {
552                         sports = &rule->port_src;
553                         dports = &rule->port_dest;
554                         icmptypes = &empty;
555                 }
556
557                 fw3_foreach(sip, &rule->ip_src)
558                 fw3_foreach(dip, &rule->ip_dest)
559                 fw3_foreach(sport, sports)
560                 fw3_foreach(dport, dports)
561                 fw3_foreach(mac, &rule->mac_src)
562                 fw3_foreach(icmptype, icmptypes)
563                         print_rule(handle, state, rule, num, proto, sip, dip,
564                                    sport, dport, mac, icmptype);
565         }
566 }
567
568 void
569 fw3_print_rules(struct fw3_ipt_handle *handle, struct fw3_state *state)
570 {
571         int num = 0;
572         struct fw3_rule *rule;
573
574         list_for_each_entry(rule, &state->rules, list)
575                 expand_rule(handle, state, rule, num++);
576 }