Use fw3_ipt_rule_replace() when setting up reflection
[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 fw3_parse_options(redir, fw3_redirect_opts, s);
251
252 if (!redir->enabled)
253 {
254 fw3_free_redirect(redir);
255 continue;
256 }
257
258 if (redir->src.invert)
259 {
260 warn_elem(e, "must not have an inverted source");
261 fw3_free_redirect(redir);
262 continue;
263 }
264 else if (redir->src.set && !redir->src.any &&
265 !(redir->_src = fw3_lookup_zone(state, redir->src.name)))
266 {
267 warn_elem(e, "refers to not existing zone '%s'", redir->src.name);
268 fw3_free_redirect(redir);
269 continue;
270 }
271 else if (redir->dest.set && !redir->dest.any &&
272 !(redir->_dest = fw3_lookup_zone(state, redir->dest.name)))
273 {
274 warn_elem(e, "refers to not existing zone '%s'", redir->dest.name);
275 fw3_free_redirect(redir);
276 continue;
277 }
278 else if (redir->ipset.set && state->disable_ipsets)
279 {
280 warn_elem(e, "skipped due to disabled ipset support");
281 fw3_free_redirect(redir);
282 continue;
283 }
284 else if (redir->ipset.set &&
285 !(redir->ipset.ptr = fw3_lookup_ipset(state, redir->ipset.name)))
286 {
287 warn_elem(e, "refers to unknown ipset '%s'", redir->ipset.name);
288 fw3_free_redirect(redir);
289 continue;
290 }
291
292 if (!check_families(e, redir))
293 {
294 fw3_free_redirect(redir);
295 continue;
296 }
297
298 if (redir->target == FW3_FLAG_UNSPEC)
299 {
300 warn_elem(e, "has no target specified, defaulting to DNAT");
301 redir->target = FW3_FLAG_DNAT;
302 }
303 else if (redir->target < FW3_FLAG_DNAT)
304 {
305 warn_elem(e, "has invalid target specified, defaulting to DNAT");
306 redir->target = FW3_FLAG_DNAT;
307 }
308
309 if (redir->target == FW3_FLAG_DNAT)
310 {
311 if (redir->src.any)
312 warn_elem(e, "must not have source '*' for DNAT target");
313 else if (!redir->_src)
314 warn_elem(e, "has no source specified");
315 else
316 {
317 set(redir->_src->flags, FW3_FAMILY_V4, redir->target);
318 redir->_src->conntrack = true;
319 valid = true;
320 }
321
322 if (!check_local(e, redir, state) && !redir->dest.set &&
323 resolve_dest(e, redir, state))
324 {
325 warn_elem(e, "does not specify a destination, assuming '%s'",
326 redir->dest.name);
327 }
328
329 if (redir->reflection && redir->_dest && redir->_src->masq)
330 {
331 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_ACCEPT);
332 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_DNAT);
333 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_SNAT);
334 }
335 }
336 else
337 {
338 if (redir->dest.any)
339 warn_elem(e, "must not have destination '*' for SNAT target");
340 else if (!redir->_dest)
341 warn_elem(e, "has no destination specified");
342 else if (!redir->ip_dest.set)
343 warn_elem(e, "has no src_dip option specified");
344 else if (!list_empty(&redir->mac_src))
345 warn_elem(e, "must not use 'src_mac' option for SNAT target");
346 else
347 {
348 set(redir->_dest->flags, FW3_FAMILY_V4, redir->target);
349 redir->_dest->conntrack = true;
350 valid = true;
351 }
352 }
353
354 if (list_empty(&redir->proto))
355 {
356 warn_elem(e, "does not specify a protocol, assuming TCP+UDP");
357 fw3_parse_protocol(&redir->proto, "tcpudp", true);
358 }
359
360 if (!valid)
361 {
362 fw3_free_redirect(redir);
363 continue;
364 }
365
366 if (!redir->port_redir.set)
367 redir->port_redir = redir->port_dest;
368
369 list_add_tail(&redir->list, &state->redirects);
370 }
371 }
372
373 static void
374 append_chain_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
375 {
376 if (redir->target == FW3_FLAG_DNAT)
377 fw3_ipt_rule_append(r, "zone_%s_prerouting", redir->src.name);
378 else
379 fw3_ipt_rule_append(r, "zone_%s_postrouting", redir->dest.name);
380 }
381
382 static void
383 set_snat_dnat(struct fw3_ipt_rule *r, enum fw3_flag target,
384 struct fw3_address *addr, struct fw3_port *port)
385 {
386 char buf[sizeof("255.255.255.255:65535-65535\0")];
387
388 buf[0] = '\0';
389
390 if (addr && addr->set)
391 {
392 inet_ntop(AF_INET, &addr->address.v4, buf, sizeof(buf));
393 }
394
395 if (port && port->set)
396 {
397 if (port->port_min == port->port_max)
398 sprintf(buf + strlen(buf), ":%u", port->port_min);
399 else
400 sprintf(buf + strlen(buf), ":%u-%u",
401 port->port_min, port->port_max);
402 }
403
404 if (target == FW3_FLAG_DNAT)
405 {
406 fw3_ipt_rule_target(r, "DNAT");
407 fw3_ipt_rule_addarg(r, false, "--to-destination", buf);
408 }
409 else
410 {
411 fw3_ipt_rule_target(r, "SNAT");
412 fw3_ipt_rule_addarg(r, false, "--to-source", buf);
413 }
414 }
415
416 static void
417 set_target_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
418 {
419 if (redir->target == FW3_FLAG_DNAT)
420 set_snat_dnat(r, redir->target, &redir->ip_redir, &redir->port_redir);
421 else
422 set_snat_dnat(r, redir->target, &redir->ip_dest, &redir->port_dest);
423 }
424
425 static void
426 append_chain_filter(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
427 {
428 if (redir->target == FW3_FLAG_DNAT)
429 {
430 if (redir->local)
431 fw3_ipt_rule_append(r, "zone_%s_input", redir->src.name);
432 else
433 fw3_ipt_rule_append(r, "zone_%s_forward", redir->src.name);
434 }
435 else
436 {
437 if (redir->src.set && !redir->src.any)
438 fw3_ipt_rule_append(r, "zone_%s_forward", redir->src.name);
439 else
440 fw3_ipt_rule_append(r, "delegate_forward");
441 }
442 }
443
444 static void
445 set_target_filter(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
446 {
447 if (redir->local)
448 fw3_ipt_rule_extra(r, "-m conntrack --ctstate DNAT");
449
450 fw3_ipt_rule_target(r, "ACCEPT");
451 }
452
453 static void
454 set_comment(struct fw3_ipt_rule *r, const char *name, int num, bool ref)
455 {
456 if (name)
457 {
458 if (ref)
459 fw3_ipt_rule_comment(r, "%s (reflection)", name);
460 else
461 fw3_ipt_rule_comment(r, name);
462 }
463 else
464 {
465 if (ref)
466 fw3_ipt_rule_comment(r, "@redirect[%u] (reflection)", num);
467 else
468 fw3_ipt_rule_comment(r, "@redirect[%u]", num);
469 }
470 }
471
472 static void
473 print_redirect(struct fw3_ipt_handle *h, struct fw3_state *state,
474 struct fw3_redirect *redir, int num,
475 struct fw3_protocol *proto, struct fw3_mac *mac)
476 {
477 struct fw3_ipt_rule *r;
478 struct fw3_address *src, *dst;
479 struct fw3_port *spt, *dpt;
480
481 switch (h->table)
482 {
483 case FW3_TABLE_NAT:
484 src = &redir->ip_src;
485 dst = &redir->ip_dest;
486 spt = &redir->port_src;
487 dpt = &redir->port_dest;
488
489 if (redir->target == FW3_FLAG_SNAT)
490 {
491 dst = &redir->ip_redir;
492 dpt = &redir->port_redir;
493 }
494
495 r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
496 fw3_ipt_rule_sport_dport(r, spt, dpt);
497 fw3_ipt_rule_mac(r, mac);
498 fw3_ipt_rule_ipset(r, &redir->ipset);
499 fw3_ipt_rule_limit(r, &redir->limit);
500 fw3_ipt_rule_time(r, &redir->time);
501 fw3_ipt_rule_mark(r, &redir->mark);
502 set_target_nat(r, redir);
503 fw3_ipt_rule_extra(r, redir->extra);
504 set_comment(r, redir->name, num, false);
505 append_chain_nat(r, redir);
506 break;
507
508 case FW3_TABLE_FILTER:
509 src = &redir->ip_src;
510 dst = &redir->ip_redir;
511 spt = &redir->port_src;
512 dpt = &redir->port_redir;
513
514 r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
515 fw3_ipt_rule_sport_dport(r, spt, dpt);
516 fw3_ipt_rule_mac(r, mac);
517 fw3_ipt_rule_ipset(r, &redir->ipset);
518 fw3_ipt_rule_limit(r, &redir->limit);
519 fw3_ipt_rule_time(r, &redir->time);
520 fw3_ipt_rule_mark(r, &redir->mark);
521 set_target_filter(r, redir);
522 fw3_ipt_rule_extra(r, redir->extra);
523 set_comment(r, redir->name, num, false);
524 append_chain_filter(r, redir);
525 break;
526
527 default:
528 break;
529 }
530 }
531
532 static void
533 print_reflection(struct fw3_ipt_handle *h, struct fw3_state *state,
534 struct fw3_redirect *redir, int num,
535 struct fw3_protocol *proto, struct fw3_address *ra,
536 struct fw3_address *ia, struct fw3_address *ea)
537 {
538 struct fw3_ipt_rule *r;
539
540 switch (h->table)
541 {
542 case FW3_TABLE_NAT:
543 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, ea);
544 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_dest);
545 fw3_ipt_rule_limit(r, &redir->limit);
546 fw3_ipt_rule_time(r, &redir->time);
547 set_comment(r, redir->name, num, true);
548 set_snat_dnat(r, FW3_FLAG_DNAT, &redir->ip_redir, &redir->port_redir);
549 fw3_ipt_rule_replace(r, "zone_%s_prerouting", redir->dest.name);
550
551 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, &redir->ip_redir);
552 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_redir);
553 fw3_ipt_rule_limit(r, &redir->limit);
554 fw3_ipt_rule_time(r, &redir->time);
555 set_comment(r, redir->name, num, true);
556 set_snat_dnat(r, FW3_FLAG_SNAT, ra, NULL);
557 fw3_ipt_rule_replace(r, "zone_%s_postrouting", redir->dest.name);
558 break;
559
560 case FW3_TABLE_FILTER:
561 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, &redir->ip_redir);
562 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_redir);
563 fw3_ipt_rule_limit(r, &redir->limit);
564 fw3_ipt_rule_time(r, &redir->time);
565 set_comment(r, redir->name, num, true);
566 fw3_ipt_rule_target(r, "zone_%s_dest_ACCEPT", redir->dest.name);
567 fw3_ipt_rule_replace(r, "zone_%s_forward", redir->dest.name);
568 break;
569
570 default:
571 break;
572 }
573 }
574
575 static void
576 expand_redirect(struct fw3_ipt_handle *handle, struct fw3_state *state,
577 struct fw3_redirect *redir, int num)
578 {
579 struct list_head *ext_addrs, *int_addrs;
580 struct fw3_address *ext_addr, *int_addr, ref_addr;
581 struct fw3_protocol *proto;
582 struct fw3_mac *mac;
583
584 if (redir->name)
585 info(" * Redirect '%s'", redir->name);
586 else
587 info(" * Redirect #%u", num);
588
589 if (!fw3_is_family(redir->_src, handle->family) ||
590 !fw3_is_family(redir->_dest, handle->family))
591 {
592 info(" ! Skipping due to different family of zone");
593 return;
594 }
595
596 if (!fw3_is_family(&redir->ip_src, handle->family) ||
597 !fw3_is_family(&redir->ip_dest, handle->family) ||
598 !fw3_is_family(&redir->ip_redir, handle->family))
599 {
600 if (!redir->ip_src.resolved ||
601 !redir->ip_dest.resolved ||
602 !redir->ip_redir.resolved)
603 info(" ! Skipping due to different family of ip address");
604
605 return;
606 }
607
608 if (redir->ipset.ptr)
609 {
610 if (!fw3_is_family(redir->ipset.ptr, handle->family))
611 {
612 info(" ! Skipping due to different family in ipset");
613 return;
614 }
615
616 if (!fw3_check_ipset(redir->ipset.ptr))
617 {
618 info(" ! Skipping due to missing ipset '%s'",
619 redir->ipset.ptr->external ?
620 redir->ipset.ptr->external : redir->ipset.ptr->name);
621 return;
622 }
623
624 set(redir->ipset.ptr->flags, handle->family, handle->family);
625 }
626
627 fw3_foreach(proto, &redir->proto)
628 fw3_foreach(mac, &redir->mac_src)
629 print_redirect(handle, state, redir, num, proto, mac);
630
631 /* reflection rules */
632 if (redir->target != FW3_FLAG_DNAT || !redir->reflection)
633 return;
634
635 if (!redir->_dest || !redir->_src->masq)
636 return;
637
638 ext_addrs = fw3_resolve_zone_addresses(redir->_src);
639 int_addrs = fw3_resolve_zone_addresses(redir->_dest);
640
641 if (!ext_addrs || !int_addrs)
642 goto out;
643
644 list_for_each_entry(ext_addr, ext_addrs, list)
645 {
646 if (!fw3_is_family(ext_addr, handle->family))
647 continue;
648
649 list_for_each_entry(int_addr, int_addrs, list)
650 {
651 if (!fw3_is_family(int_addr, handle->family))
652 continue;
653
654 fw3_foreach(proto, &redir->proto)
655 {
656 if (!proto)
657 continue;
658
659 if (redir->reflection_src == FW3_REFLECTION_INTERNAL)
660 ref_addr = *int_addr;
661 else
662 ref_addr = *ext_addr;
663
664 ref_addr.mask = 32;
665 ext_addr->mask = 32;
666
667 print_reflection(handle, state, redir, num, proto,
668 &ref_addr, int_addr, ext_addr);
669 }
670 }
671 }
672
673 out:
674 fw3_free_list(ext_addrs);
675 fw3_free_list(int_addrs);
676 }
677
678 void
679 fw3_print_redirects(struct fw3_ipt_handle *handle, struct fw3_state *state)
680 {
681 int num = 0;
682 struct fw3_redirect *redir;
683
684 if (handle->family == FW3_FAMILY_V6)
685 return;
686
687 if (handle->table != FW3_TABLE_FILTER && handle->table != FW3_TABLE_NAT)
688 return;
689
690 list_for_each_entry(redir, &state->redirects, list)
691 expand_redirect(handle, state, redir, num++);
692 }