Skip redirects with invalid options
[project/firewall3.git] / redirects.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 "redirects.h"
20
21
22 const struct fw3_option fw3_redirect_opts[] = {
23 FW3_OPT("enabled", bool, redirect, enabled),
24
25 FW3_OPT("name", string, redirect, name),
26 FW3_OPT("family", family, redirect, family),
27
28 FW3_OPT("src", device, redirect, src),
29 FW3_OPT("dest", device, redirect, dest),
30
31 FW3_OPT("ipset", setmatch, redirect, ipset),
32
33 FW3_LIST("proto", protocol, redirect, proto),
34
35 FW3_OPT("src_ip", network, redirect, ip_src),
36 FW3_LIST("src_mac", mac, redirect, mac_src),
37 FW3_OPT("src_port", port, redirect, port_src),
38
39 FW3_OPT("src_dip", network, redirect, ip_dest),
40 FW3_OPT("src_dport", port, redirect, port_dest),
41
42 FW3_OPT("dest_ip", network, redirect, ip_redir),
43 FW3_OPT("dest_port", port, redirect, port_redir),
44
45 FW3_OPT("extra", string, redirect, extra),
46
47 FW3_OPT("limit", limit, redirect, limit),
48 FW3_OPT("limit_burst", int, redirect, limit.burst),
49
50 FW3_OPT("utc_time", bool, redirect, time.utc),
51 FW3_OPT("start_date", date, redirect, time.datestart),
52 FW3_OPT("stop_date", date, redirect, time.datestop),
53 FW3_OPT("start_time", time, redirect, time.timestart),
54 FW3_OPT("stop_time", time, redirect, time.timestop),
55 FW3_OPT("weekdays", weekdays, redirect, time.weekdays),
56 FW3_OPT("monthdays", monthdays, redirect, time.monthdays),
57
58 FW3_OPT("mark", mark, redirect, mark),
59
60 FW3_OPT("reflection", bool, redirect, reflection),
61 FW3_OPT("reflection_src", reflection_source,
62 redirect, reflection_src),
63
64 FW3_OPT("target", target, redirect, target),
65
66 { }
67 };
68
69
70 static bool
71 check_families(struct uci_element *e, struct fw3_redirect *r)
72 {
73 if (r->family == FW3_FAMILY_ANY)
74 return true;
75
76 if (r->_src && r->_src->family && r->_src->family != r->family)
77 {
78 warn_elem(e, "refers to source zone with different family");
79 return false;
80 }
81
82 if (r->_dest && r->_dest->family && r->_dest->family != r->family)
83 {
84 warn_elem(e, "refers to destination zone with different family");
85 return false;
86 }
87
88 if (r->ipset.ptr && r->ipset.ptr->family &&
89 r->ipset.ptr->family != r->family)
90 {
91 warn_elem(e, "refers to ipset with different family");
92 return false;
93 }
94
95 if (r->ip_src.family && r->ip_src.family != r->family)
96 {
97 warn_elem(e, "uses source ip with different family");
98 return false;
99 }
100
101 if (r->ip_dest.family && r->ip_dest.family != r->family)
102 {
103 warn_elem(e, "uses destination ip with different family");
104 return false;
105 }
106
107 if (r->ip_redir.family && r->ip_redir.family != r->family)
108 {
109 warn_elem(e, "uses redirect ip with different family");
110 return false;
111 }
112
113 return true;
114 }
115
116 static bool
117 compare_addr(struct fw3_address *a, struct fw3_address *b)
118 {
119 uint32_t mask;
120
121 if (a->family != FW3_FAMILY_V4 || b->family != FW3_FAMILY_V4)
122 return false;
123
124 mask = htonl(~((1 << (32 - a->mask)) - 1));
125
126 return ((a->address.v4.s_addr & mask) == (b->address.v4.s_addr & mask));
127 }
128
129 static bool
130 resolve_dest(struct uci_element *e, struct fw3_redirect *redir,
131 struct fw3_state *state)
132 {
133 struct fw3_zone *zone;
134 struct fw3_address *addr;
135 struct list_head *addrs;
136
137 if (!redir->ip_redir.set)
138 return false;
139
140 list_for_each_entry(zone, &state->zones, list)
141 {
142 addrs = fw3_resolve_zone_addresses(zone);
143
144 if (!addrs)
145 continue;
146
147 list_for_each_entry(addr, addrs, list)
148 {
149 if (!compare_addr(addr, &redir->ip_redir))
150 continue;
151
152 strncpy(redir->dest.name, zone->name, sizeof(redir->dest.name));
153 redir->dest.set = true;
154 redir->_dest = zone;
155
156 break;
157 }
158
159 fw3_free_list(addrs);
160
161 if (redir->_dest)
162 return true;
163 }
164
165 return false;
166 }
167
168 static bool
169 check_local(struct uci_element *e, struct fw3_redirect *redir,
170 struct fw3_state *state)
171 {
172 struct fw3_zone *zone;
173 struct fw3_device *net;
174 struct fw3_address *addr;
175 struct list_head *addrs;
176
177 if (redir->target != FW3_FLAG_DNAT)
178 return false;
179
180 if (!redir->ip_redir.set)
181 redir->local = true;
182
183 if (redir->local)
184 return true;
185
186 list_for_each_entry(zone, &state->zones, list)
187 {
188 list_for_each_entry(net, &zone->networks, list)
189 {
190 addrs = fw3_ubus_address(net->name);
191
192 if (!addrs)
193 continue;
194
195 list_for_each_entry(addr, addrs, list)
196 {
197 if (!compare_addr(&redir->ip_redir, addr))
198 continue;
199
200 warn_elem(e, "refers to a destination address on this router, "
201 "assuming port redirection");
202
203 redir->local = true;
204 break;
205 }
206
207 fw3_free_list(addrs);
208
209 if (redir->local)
210 return true;
211 }
212 }
213
214 return false;
215 }
216
217 void
218 fw3_load_redirects(struct fw3_state *state, struct uci_package *p)
219 {
220 struct uci_section *s;
221 struct uci_element *e;
222 struct fw3_redirect *redir;
223
224 bool valid;
225
226 INIT_LIST_HEAD(&state->redirects);
227
228 uci_foreach_element(&p->sections, e)
229 {
230 s = uci_to_section(e);
231
232 if (strcmp(s->type, "redirect"))
233 continue;
234
235 redir = malloc(sizeof(*redir));
236
237 if (!redir)
238 continue;
239
240 memset(redir, 0, sizeof(*redir));
241
242 INIT_LIST_HEAD(&redir->proto);
243 INIT_LIST_HEAD(&redir->mac_src);
244
245 redir->enabled = true;
246 redir->reflection = true;
247
248 valid = false;
249
250 if (!fw3_parse_options(redir, fw3_redirect_opts, s))
251 {
252 warn_elem(e, "skipped due to invalid options");
253 fw3_free_redirect(redir);
254 continue;
255 }
256
257 if (!redir->enabled)
258 {
259 fw3_free_redirect(redir);
260 continue;
261 }
262
263 if (redir->src.invert)
264 {
265 warn_elem(e, "must not have an inverted source");
266 fw3_free_redirect(redir);
267 continue;
268 }
269 else if (redir->src.set && !redir->src.any &&
270 !(redir->_src = fw3_lookup_zone(state, redir->src.name)))
271 {
272 warn_elem(e, "refers to not existing zone '%s'", redir->src.name);
273 fw3_free_redirect(redir);
274 continue;
275 }
276 else if (redir->dest.set && !redir->dest.any &&
277 !(redir->_dest = fw3_lookup_zone(state, redir->dest.name)))
278 {
279 warn_elem(e, "refers to not existing zone '%s'", redir->dest.name);
280 fw3_free_redirect(redir);
281 continue;
282 }
283 else if (redir->ipset.set && state->disable_ipsets)
284 {
285 warn_elem(e, "skipped due to disabled ipset support");
286 fw3_free_redirect(redir);
287 continue;
288 }
289 else if (redir->ipset.set &&
290 !(redir->ipset.ptr = fw3_lookup_ipset(state, redir->ipset.name)))
291 {
292 warn_elem(e, "refers to unknown ipset '%s'", redir->ipset.name);
293 fw3_free_redirect(redir);
294 continue;
295 }
296
297 if (!check_families(e, redir))
298 {
299 fw3_free_redirect(redir);
300 continue;
301 }
302
303 if (redir->target == FW3_FLAG_UNSPEC)
304 {
305 warn_elem(e, "has no target specified, defaulting to DNAT");
306 redir->target = FW3_FLAG_DNAT;
307 }
308 else if (redir->target < FW3_FLAG_DNAT)
309 {
310 warn_elem(e, "has invalid target specified, defaulting to DNAT");
311 redir->target = FW3_FLAG_DNAT;
312 }
313
314 if (redir->target == FW3_FLAG_DNAT)
315 {
316 if (redir->src.any)
317 warn_elem(e, "must not have source '*' for DNAT target");
318 else if (!redir->_src)
319 warn_elem(e, "has no source specified");
320 else
321 {
322 set(redir->_src->flags, FW3_FAMILY_V4, redir->target);
323 redir->_src->conntrack = true;
324 valid = true;
325 }
326
327 if (!check_local(e, redir, state) && !redir->dest.set &&
328 resolve_dest(e, redir, state))
329 {
330 warn_elem(e, "does not specify a destination, assuming '%s'",
331 redir->dest.name);
332 }
333
334 if (redir->reflection && redir->_dest && redir->_src->masq)
335 {
336 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_ACCEPT);
337 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_DNAT);
338 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_SNAT);
339 }
340 }
341 else
342 {
343 if (redir->dest.any)
344 warn_elem(e, "must not have destination '*' for SNAT target");
345 else if (!redir->_dest)
346 warn_elem(e, "has no destination specified");
347 else if (!redir->ip_dest.set)
348 warn_elem(e, "has no src_dip option specified");
349 else if (!list_empty(&redir->mac_src))
350 warn_elem(e, "must not use 'src_mac' option for SNAT target");
351 else
352 {
353 set(redir->_dest->flags, FW3_FAMILY_V4, redir->target);
354 redir->_dest->conntrack = true;
355 valid = true;
356 }
357 }
358
359 if (list_empty(&redir->proto))
360 {
361 warn_elem(e, "does not specify a protocol, assuming TCP+UDP");
362 fw3_parse_protocol(&redir->proto, "tcpudp", true);
363 }
364
365 if (!valid)
366 {
367 fw3_free_redirect(redir);
368 continue;
369 }
370
371 if (!redir->port_redir.set)
372 redir->port_redir = redir->port_dest;
373
374 list_add_tail(&redir->list, &state->redirects);
375 }
376 }
377
378 static void
379 append_chain_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
380 {
381 if (redir->target == FW3_FLAG_DNAT)
382 fw3_ipt_rule_append(r, "zone_%s_prerouting", redir->src.name);
383 else
384 fw3_ipt_rule_append(r, "zone_%s_postrouting", redir->dest.name);
385 }
386
387 static void
388 set_snat_dnat(struct fw3_ipt_rule *r, enum fw3_flag target,
389 struct fw3_address *addr, struct fw3_port *port)
390 {
391 char buf[sizeof("255.255.255.255:65535-65535\0")];
392
393 buf[0] = '\0';
394
395 if (addr && addr->set)
396 {
397 inet_ntop(AF_INET, &addr->address.v4, buf, sizeof(buf));
398 }
399
400 if (port && port->set)
401 {
402 if (port->port_min == port->port_max)
403 sprintf(buf + strlen(buf), ":%u", port->port_min);
404 else
405 sprintf(buf + strlen(buf), ":%u-%u",
406 port->port_min, port->port_max);
407 }
408
409 if (target == FW3_FLAG_DNAT)
410 {
411 fw3_ipt_rule_target(r, "DNAT");
412 fw3_ipt_rule_addarg(r, false, "--to-destination", buf);
413 }
414 else
415 {
416 fw3_ipt_rule_target(r, "SNAT");
417 fw3_ipt_rule_addarg(r, false, "--to-source", buf);
418 }
419 }
420
421 static void
422 set_target_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
423 {
424 if (redir->target == FW3_FLAG_DNAT)
425 set_snat_dnat(r, redir->target, &redir->ip_redir, &redir->port_redir);
426 else
427 set_snat_dnat(r, redir->target, &redir->ip_dest, &redir->port_dest);
428 }
429
430 //static void
431 //append_chain_filter(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
432 //{
433 // if (redir->target == FW3_FLAG_DNAT)
434 // {
435 // if (redir->local)
436 // fw3_ipt_rule_append(r, "zone_%s_input", redir->src.name);
437 // else
438 // fw3_ipt_rule_append(r, "zone_%s_forward", redir->src.name);
439 // }
440 // else
441 // {
442 // if (redir->src.set && !redir->src.any)
443 // fw3_ipt_rule_append(r, "zone_%s_forward", redir->src.name);
444 // else
445 // fw3_ipt_rule_append(r, "delegate_forward");
446 // }
447 //}
448 //
449 //static void
450 //set_target_filter(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
451 //{
452 // if (redir->local)
453 // fw3_ipt_rule_extra(r, "-m conntrack --ctstate DNAT");
454 //
455 // fw3_ipt_rule_target(r, "ACCEPT");
456 //}
457
458 static void
459 set_comment(struct fw3_ipt_rule *r, const char *name, int num, bool ref)
460 {
461 if (name)
462 {
463 if (ref)
464 fw3_ipt_rule_comment(r, "%s (reflection)", name);
465 else
466 fw3_ipt_rule_comment(r, name);
467 }
468 else
469 {
470 if (ref)
471 fw3_ipt_rule_comment(r, "@redirect[%u] (reflection)", num);
472 else
473 fw3_ipt_rule_comment(r, "@redirect[%u]", num);
474 }
475 }
476
477 static void
478 print_redirect(struct fw3_ipt_handle *h, struct fw3_state *state,
479 struct fw3_redirect *redir, int num,
480 struct fw3_protocol *proto, struct fw3_mac *mac)
481 {
482 struct fw3_ipt_rule *r;
483 struct fw3_address *src, *dst;
484 struct fw3_port *spt, *dpt;
485
486 switch (h->table)
487 {
488 case FW3_TABLE_NAT:
489 src = &redir->ip_src;
490 dst = &redir->ip_dest;
491 spt = &redir->port_src;
492 dpt = &redir->port_dest;
493
494 if (redir->target == FW3_FLAG_SNAT)
495 {
496 dst = &redir->ip_redir;
497 dpt = &redir->port_redir;
498 }
499
500 r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
501 fw3_ipt_rule_sport_dport(r, spt, dpt);
502 fw3_ipt_rule_mac(r, mac);
503 fw3_ipt_rule_ipset(r, &redir->ipset);
504 fw3_ipt_rule_limit(r, &redir->limit);
505 fw3_ipt_rule_time(r, &redir->time);
506 fw3_ipt_rule_mark(r, &redir->mark);
507 set_target_nat(r, redir);
508 fw3_ipt_rule_extra(r, redir->extra);
509 set_comment(r, redir->name, num, false);
510 append_chain_nat(r, redir);
511 break;
512
513 case FW3_TABLE_FILTER:
514 //src = &redir->ip_src;
515 //dst = &redir->ip_redir;
516 //spt = &redir->port_src;
517 //dpt = &redir->port_redir;
518 //
519 //r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
520 //fw3_ipt_rule_sport_dport(r, spt, dpt);
521 //fw3_ipt_rule_mac(r, mac);
522 //fw3_ipt_rule_ipset(r, &redir->ipset);
523 //fw3_ipt_rule_limit(r, &redir->limit);
524 //fw3_ipt_rule_time(r, &redir->time);
525 //fw3_ipt_rule_mark(r, &redir->mark);
526 //set_target_filter(r, redir);
527 //fw3_ipt_rule_extra(r, redir->extra);
528 //set_comment(r, redir->name, num, false);
529 //append_chain_filter(r, redir);
530 break;
531
532 default:
533 break;
534 }
535 }
536
537 static void
538 print_reflection(struct fw3_ipt_handle *h, struct fw3_state *state,
539 struct fw3_redirect *redir, int num,
540 struct fw3_protocol *proto, struct fw3_address *ra,
541 struct fw3_address *ia, struct fw3_address *ea)
542 {
543 struct fw3_ipt_rule *r;
544
545 switch (h->table)
546 {
547 case FW3_TABLE_NAT:
548 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, ea);
549 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_dest);
550 fw3_ipt_rule_limit(r, &redir->limit);
551 fw3_ipt_rule_time(r, &redir->time);
552 set_comment(r, redir->name, num, true);
553 set_snat_dnat(r, FW3_FLAG_DNAT, &redir->ip_redir, &redir->port_redir);
554 fw3_ipt_rule_replace(r, "zone_%s_prerouting", redir->dest.name);
555
556 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, &redir->ip_redir);
557 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_redir);
558 fw3_ipt_rule_limit(r, &redir->limit);
559 fw3_ipt_rule_time(r, &redir->time);
560 set_comment(r, redir->name, num, true);
561 set_snat_dnat(r, FW3_FLAG_SNAT, ra, NULL);
562 fw3_ipt_rule_replace(r, "zone_%s_postrouting", redir->dest.name);
563 break;
564
565 //case FW3_TABLE_FILTER:
566 // r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, &redir->ip_redir);
567 // fw3_ipt_rule_sport_dport(r, NULL, &redir->port_redir);
568 // fw3_ipt_rule_limit(r, &redir->limit);
569 // fw3_ipt_rule_time(r, &redir->time);
570 // set_comment(r, redir->name, num, true);
571 // fw3_ipt_rule_target(r, "zone_%s_dest_ACCEPT", redir->dest.name);
572 // fw3_ipt_rule_replace(r, "zone_%s_forward", redir->dest.name);
573 // break;
574
575 default:
576 break;
577 }
578 }
579
580 static void
581 expand_redirect(struct fw3_ipt_handle *handle, struct fw3_state *state,
582 struct fw3_redirect *redir, int num)
583 {
584 struct list_head *ext_addrs, *int_addrs;
585 struct fw3_address *ext_addr, *int_addr, ref_addr;
586 struct fw3_protocol *proto;
587 struct fw3_mac *mac;
588
589 if (redir->name)
590 info(" * Redirect '%s'", redir->name);
591 else
592 info(" * Redirect #%u", num);
593
594 if (!fw3_is_family(redir->_src, handle->family) ||
595 !fw3_is_family(redir->_dest, handle->family))
596 {
597 info(" ! Skipping due to different family of zone");
598 return;
599 }
600
601 if (!fw3_is_family(&redir->ip_src, handle->family) ||
602 !fw3_is_family(&redir->ip_dest, handle->family) ||
603 !fw3_is_family(&redir->ip_redir, handle->family))
604 {
605 if (!redir->ip_src.resolved ||
606 !redir->ip_dest.resolved ||
607 !redir->ip_redir.resolved)
608 info(" ! Skipping due to different family of ip address");
609
610 return;
611 }
612
613 if (redir->ipset.ptr)
614 {
615 if (!fw3_is_family(redir->ipset.ptr, handle->family))
616 {
617 info(" ! Skipping due to different family in ipset");
618 return;
619 }
620
621 if (!fw3_check_ipset(redir->ipset.ptr))
622 {
623 info(" ! Skipping due to missing ipset '%s'",
624 redir->ipset.ptr->external ?
625 redir->ipset.ptr->external : redir->ipset.ptr->name);
626 return;
627 }
628
629 set(redir->ipset.ptr->flags, handle->family, handle->family);
630 }
631
632 fw3_foreach(proto, &redir->proto)
633 fw3_foreach(mac, &redir->mac_src)
634 print_redirect(handle, state, redir, num, proto, mac);
635
636 /* reflection rules */
637 if (redir->target != FW3_FLAG_DNAT || !redir->reflection)
638 return;
639
640 if (!redir->_dest || !redir->_src->masq)
641 return;
642
643 ext_addrs = fw3_resolve_zone_addresses(redir->_src);
644 int_addrs = fw3_resolve_zone_addresses(redir->_dest);
645
646 if (!ext_addrs || !int_addrs)
647 goto out;
648
649 list_for_each_entry(ext_addr, ext_addrs, list)
650 {
651 if (!fw3_is_family(ext_addr, handle->family))
652 continue;
653
654 list_for_each_entry(int_addr, int_addrs, list)
655 {
656 if (!fw3_is_family(int_addr, handle->family))
657 continue;
658
659 fw3_foreach(proto, &redir->proto)
660 {
661 if (!proto)
662 continue;
663
664 if (redir->reflection_src == FW3_REFLECTION_INTERNAL)
665 ref_addr = *int_addr;
666 else
667 ref_addr = *ext_addr;
668
669 ref_addr.mask = 32;
670 ext_addr->mask = 32;
671
672 print_reflection(handle, state, redir, num, proto,
673 &ref_addr, int_addr, ext_addr);
674 }
675 }
676 }
677
678 out:
679 fw3_free_list(ext_addrs);
680 fw3_free_list(int_addrs);
681 }
682
683 void
684 fw3_print_redirects(struct fw3_ipt_handle *handle, struct fw3_state *state)
685 {
686 int num = 0;
687 struct fw3_redirect *redir;
688
689 if (handle->family == FW3_FAMILY_V6)
690 return;
691
692 if (handle->table != FW3_TABLE_FILTER && handle->table != FW3_TABLE_NAT)
693 return;
694
695 list_for_each_entry(redir, &state->redirects, list)
696 expand_redirect(handle, state, redir, num++);
697 }