zones: add zone identifying local traffic in raw OUTPUT chain
[project/firewall3.git] / redirects.c
1 /*
2 * firewall3 - 3rd OpenWrt UCI firewall implementation
3 *
4 * Copyright (C) 2013-2014 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 "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 if (a->family != FW3_FAMILY_V4 || b->family != FW3_FAMILY_V4)
120 return false;
121
122 return ((a->address.v4.s_addr & a->mask.v4.s_addr) ==
123 (b->address.v4.s_addr & a->mask.v4.s_addr));
124 }
125
126 static bool
127 resolve_dest(struct uci_element *e, struct fw3_redirect *redir,
128 struct fw3_state *state)
129 {
130 struct fw3_zone *zone;
131 struct fw3_address *addr;
132 struct list_head *addrs;
133
134 if (!redir->ip_redir.set)
135 return false;
136
137 list_for_each_entry(zone, &state->zones, list)
138 {
139 addrs = fw3_resolve_zone_addresses(zone, NULL);
140
141 if (!addrs)
142 continue;
143
144 list_for_each_entry(addr, addrs, list)
145 {
146 if (!compare_addr(addr, &redir->ip_redir))
147 continue;
148
149 strncpy(redir->dest.name, zone->name, sizeof(redir->dest.name));
150 redir->dest.set = true;
151 redir->_dest = zone;
152
153 break;
154 }
155
156 fw3_free_list(addrs);
157
158 if (redir->_dest)
159 return true;
160 }
161
162 return false;
163 }
164
165 static bool
166 check_local(struct uci_element *e, struct fw3_redirect *redir,
167 struct fw3_state *state)
168 {
169 if (redir->target != FW3_FLAG_DNAT)
170 return false;
171
172 if (!redir->ip_redir.set)
173 redir->local = true;
174
175 return redir->local;
176 }
177
178 static bool
179 check_redirect(struct fw3_state *state, struct fw3_redirect *redir, struct uci_element *e)
180 {
181 bool valid;
182
183 if (!redir->enabled)
184 return false;
185
186 if (redir->src.invert)
187 {
188 warn_section("redirect", redir, e, "must not have an inverted source");
189 return false;
190 }
191 else if (redir->src.set && !redir->src.any &&
192 !(redir->_src = fw3_lookup_zone(state, redir->src.name)))
193 {
194 warn_section("redirect", redir, e, "refers to not existing zone '%s'",
195 redir->src.name);
196 return false;
197 }
198 else if (redir->dest.set && !redir->dest.any &&
199 !(redir->_dest = fw3_lookup_zone(state, redir->dest.name)))
200 {
201 warn_section("redirect", redir, e, "refers to not existing zone '%s'",
202 redir->dest.name);
203 return false;
204 }
205 else if (redir->ipset.set && state->disable_ipsets)
206 {
207 warn_section("redirect", redir, e, "skipped due to disabled ipset support",
208 redir->name);
209 return false;
210 }
211 else if (redir->ipset.set &&
212 !(redir->ipset.ptr = fw3_lookup_ipset(state, redir->ipset.name)))
213 {
214 warn_section("redirect", redir, e, "refers to unknown ipset '%s'", redir->name,
215 redir->ipset.name);
216 return false;
217 }
218
219 if (!check_families(e, redir))
220 return false;
221
222 if (redir->target == FW3_FLAG_UNSPEC)
223 {
224 warn_section("redirect", redir, e, "has no target specified, defaulting to DNAT");
225 redir->target = FW3_FLAG_DNAT;
226 }
227 else if (redir->target < FW3_FLAG_DNAT || redir->target > FW3_FLAG_SNAT)
228 {
229 warn_section("redirect", redir, e, "has invalid target specified, defaulting to DNAT");
230 redir->target = FW3_FLAG_DNAT;
231 }
232
233 valid = false;
234
235 if (redir->target == FW3_FLAG_DNAT)
236 {
237 if (redir->src.any)
238 warn_section("redirect", redir, e, "must not have source '*' for DNAT target");
239 else if (!redir->_src)
240 warn_section("redirect", redir, e, "has no source specified");
241 else
242 {
243 set(redir->_src->flags, FW3_FAMILY_V4, redir->target);
244 valid = true;
245
246 if (!check_local(e, redir, state) && !redir->dest.set &&
247 resolve_dest(e, redir, state))
248 {
249 warn_section("redirect", redir, e,
250 "does not specify a destination, assuming '%s'",
251 redir->dest.name);
252 }
253
254 if (redir->reflection && redir->_dest && redir->_src->masq)
255 {
256 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_ACCEPT);
257 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_DNAT);
258 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_SNAT);
259 }
260 }
261 }
262 else
263 {
264 if (redir->dest.any)
265 warn_section("redirect", redir, e,
266 "must not have destination '*' for SNAT target");
267 else if (!redir->_dest)
268 warn_section("redirect", redir, e, "has no destination specified");
269 else if (!redir->ip_dest.set)
270 warn_section("redirect", redir, e, "has no src_dip option specified");
271 else if (!list_empty(&redir->mac_src))
272 warn_section("redirect", redir, e, "must not use 'src_mac' option for SNAT target");
273 else
274 {
275 set(redir->_dest->flags, FW3_FAMILY_V4, redir->target);
276 valid = true;
277 }
278 }
279
280 if (list_empty(&redir->proto))
281 {
282 warn_section("redirect", redir, e, "does not specify a protocol, assuming TCP+UDP");
283 fw3_parse_protocol(&redir->proto, "tcpudp", true);
284 }
285
286 if (!valid)
287 return false;
288
289 if (!redir->port_redir.set)
290 redir->port_redir = redir->port_dest;
291
292 return true;
293 }
294
295 static struct fw3_redirect *
296 fw3_alloc_redirect(struct fw3_state *state)
297 {
298 struct fw3_redirect *redir;
299
300 redir = calloc(1, sizeof(*redir));
301 if (!redir)
302 return NULL;
303
304 INIT_LIST_HEAD(&redir->proto);
305 INIT_LIST_HEAD(&redir->mac_src);
306
307 redir->enabled = true;
308 redir->reflection = true;
309
310 list_add_tail(&redir->list, &state->redirects);
311
312 return redir;
313 }
314
315 void
316 fw3_load_redirects(struct fw3_state *state, struct uci_package *p,
317 struct blob_attr *a)
318 {
319 struct uci_section *s;
320 struct uci_element *e;
321 struct fw3_redirect *redir;
322 struct blob_attr *entry;
323 unsigned rem;
324
325 INIT_LIST_HEAD(&state->redirects);
326
327 blob_for_each_attr(entry, a, rem)
328 {
329 const char *type;
330 const char *name = "ubus redirect";
331
332 if (!fw3_attr_parse_name_type(entry, &name, &type))
333 continue;
334
335 if (strcmp(type, "redirect"))
336 continue;
337
338 redir = fw3_alloc_redirect(state);
339 if (!redir)
340 continue;
341
342 if (!fw3_parse_blob_options(redir, fw3_redirect_opts, entry, name))
343 {
344 warn_section("redirect", redir, NULL, "skipped due to invalid options");
345 fw3_free_redirect(redir);
346 continue;
347 }
348
349 if (!check_redirect(state, redir, NULL))
350 fw3_free_redirect(redir);
351 }
352
353 uci_foreach_element(&p->sections, e)
354 {
355 s = uci_to_section(e);
356
357 if (strcmp(s->type, "redirect"))
358 continue;
359
360 redir = fw3_alloc_redirect(state);
361 if (!redir)
362 continue;
363
364 if (!fw3_parse_options(redir, fw3_redirect_opts, s))
365 {
366 warn_elem(e, "skipped due to invalid options");
367 fw3_free_redirect(redir);
368 continue;
369 }
370
371 if (!check_redirect(state, redir, e))
372 fw3_free_redirect(redir);
373 }
374 }
375
376 static void
377 append_chain_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
378 {
379 if (redir->target == FW3_FLAG_DNAT)
380 fw3_ipt_rule_append(r, "zone_%s_prerouting", redir->src.name);
381 else
382 fw3_ipt_rule_append(r, "zone_%s_postrouting", redir->dest.name);
383 }
384
385 static void
386 set_redirect(struct fw3_ipt_rule *r, struct fw3_port *port)
387 {
388 char buf[sizeof("65535-65535\0")];
389
390 fw3_ipt_rule_target(r, "REDIRECT");
391
392 if (port && port->set)
393 {
394 if (port->port_min == port->port_max)
395 sprintf(buf, "%u", port->port_min);
396 else
397 sprintf(buf, "%u-%u", port->port_min, port->port_max);
398
399 fw3_ipt_rule_addarg(r, false, "--to-ports", buf);
400 }
401 }
402
403 static void
404 set_snat_dnat(struct fw3_ipt_rule *r, enum fw3_flag target,
405 struct fw3_address *addr, struct fw3_port *port)
406 {
407 char buf[sizeof("255.255.255.255:65535-65535\0")];
408
409 buf[0] = '\0';
410
411 if (addr && addr->set)
412 {
413 inet_ntop(AF_INET, &addr->address.v4, buf, sizeof(buf));
414 }
415
416 if (port && port->set)
417 {
418 if (port->port_min == port->port_max)
419 sprintf(buf + strlen(buf), ":%u", port->port_min);
420 else
421 sprintf(buf + strlen(buf), ":%u-%u",
422 port->port_min, port->port_max);
423 }
424
425 if (target == FW3_FLAG_DNAT)
426 {
427 fw3_ipt_rule_target(r, "DNAT");
428 fw3_ipt_rule_addarg(r, false, "--to-destination", buf);
429 }
430 else
431 {
432 fw3_ipt_rule_target(r, "SNAT");
433 fw3_ipt_rule_addarg(r, false, "--to-source", buf);
434 }
435 }
436
437 static void
438 set_target_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
439 {
440 if (redir->local)
441 set_redirect(r, &redir->port_redir);
442 else if (redir->target == FW3_FLAG_DNAT)
443 set_snat_dnat(r, redir->target, &redir->ip_redir, &redir->port_redir);
444 else
445 set_snat_dnat(r, redir->target, &redir->ip_dest, &redir->port_dest);
446 }
447
448 static void
449 set_comment(struct fw3_ipt_rule *r, const char *name, int num, bool ref)
450 {
451 if (name)
452 {
453 if (ref)
454 fw3_ipt_rule_comment(r, "%s (reflection)", name);
455 else
456 fw3_ipt_rule_comment(r, name);
457 }
458 else
459 {
460 if (ref)
461 fw3_ipt_rule_comment(r, "@redirect[%u] (reflection)", num);
462 else
463 fw3_ipt_rule_comment(r, "@redirect[%u]", num);
464 }
465 }
466
467 static void
468 print_redirect(struct fw3_ipt_handle *h, struct fw3_state *state,
469 struct fw3_redirect *redir, int num,
470 struct fw3_protocol *proto, struct fw3_mac *mac)
471 {
472 struct fw3_ipt_rule *r;
473 struct fw3_address *src, *dst;
474 struct fw3_port *spt, *dpt;
475
476 switch (h->table)
477 {
478 case FW3_TABLE_NAT:
479 src = &redir->ip_src;
480 dst = &redir->ip_dest;
481 spt = &redir->port_src;
482 dpt = &redir->port_dest;
483
484 if (redir->target == FW3_FLAG_SNAT)
485 {
486 dst = &redir->ip_redir;
487 dpt = &redir->port_redir;
488 }
489
490 r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
491 fw3_ipt_rule_sport_dport(r, spt, dpt);
492 fw3_ipt_rule_mac(r, mac);
493 fw3_ipt_rule_ipset(r, &redir->ipset);
494 fw3_ipt_rule_limit(r, &redir->limit);
495 fw3_ipt_rule_time(r, &redir->time);
496 fw3_ipt_rule_mark(r, &redir->mark);
497 set_target_nat(r, redir);
498 fw3_ipt_rule_extra(r, redir->extra);
499 set_comment(r, redir->name, num, false);
500 append_chain_nat(r, redir);
501 break;
502
503 default:
504 break;
505 }
506 }
507
508 static void
509 print_reflection(struct fw3_ipt_handle *h, struct fw3_state *state,
510 struct fw3_redirect *redir, int num,
511 struct fw3_protocol *proto, struct fw3_address *ra,
512 struct fw3_address *ia, struct fw3_address *ea)
513 {
514 struct fw3_ipt_rule *r;
515
516 switch (h->table)
517 {
518 case FW3_TABLE_NAT:
519 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, ea);
520 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_dest);
521 fw3_ipt_rule_limit(r, &redir->limit);
522 fw3_ipt_rule_time(r, &redir->time);
523 set_comment(r, redir->name, num, true);
524 set_snat_dnat(r, FW3_FLAG_DNAT, &redir->ip_redir, &redir->port_redir);
525 fw3_ipt_rule_replace(r, "zone_%s_prerouting", redir->dest.name);
526
527 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, &redir->ip_redir);
528 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_redir);
529 fw3_ipt_rule_limit(r, &redir->limit);
530 fw3_ipt_rule_time(r, &redir->time);
531 set_comment(r, redir->name, num, true);
532 set_snat_dnat(r, FW3_FLAG_SNAT, ra, NULL);
533 fw3_ipt_rule_replace(r, "zone_%s_postrouting", redir->dest.name);
534 break;
535
536 default:
537 break;
538 }
539 }
540
541 static void
542 expand_redirect(struct fw3_ipt_handle *handle, struct fw3_state *state,
543 struct fw3_redirect *redir, int num)
544 {
545 struct list_head *ext_addrs, *int_addrs;
546 struct fw3_address *ext_addr, *int_addr, ref_addr;
547 struct fw3_protocol *proto;
548 struct fw3_mac *mac;
549
550 if (redir->name)
551 info(" * Redirect '%s'", redir->name);
552 else
553 info(" * Redirect #%u", num);
554
555 if (!fw3_is_family(redir->_src, handle->family) ||
556 !fw3_is_family(redir->_dest, handle->family))
557 {
558 info(" ! Skipping due to different family of zone");
559 return;
560 }
561
562 if (!fw3_is_family(&redir->ip_src, handle->family) ||
563 !fw3_is_family(&redir->ip_dest, handle->family) ||
564 !fw3_is_family(&redir->ip_redir, handle->family))
565 {
566 if (!redir->ip_src.resolved ||
567 !redir->ip_dest.resolved ||
568 !redir->ip_redir.resolved)
569 info(" ! Skipping due to different family of ip address");
570
571 return;
572 }
573
574 if (redir->ipset.ptr)
575 {
576 if (!fw3_is_family(redir->ipset.ptr, handle->family))
577 {
578 info(" ! Skipping due to different family in ipset");
579 return;
580 }
581
582 if (!fw3_check_ipset(redir->ipset.ptr))
583 {
584 info(" ! Skipping due to missing ipset '%s'",
585 redir->ipset.ptr->external ?
586 redir->ipset.ptr->external : redir->ipset.ptr->name);
587 return;
588 }
589
590 set(redir->ipset.ptr->flags, handle->family, handle->family);
591 }
592
593 fw3_foreach(proto, &redir->proto)
594 fw3_foreach(mac, &redir->mac_src)
595 print_redirect(handle, state, redir, num, proto, mac);
596
597 /* reflection rules */
598 if (redir->target != FW3_FLAG_DNAT || !redir->reflection || redir->local)
599 return;
600
601 if (!redir->_dest || !redir->_src->masq)
602 return;
603
604 ext_addrs = fw3_resolve_zone_addresses(redir->_src, &redir->ip_dest);
605 int_addrs = fw3_resolve_zone_addresses(redir->_dest, NULL);
606
607 if (!ext_addrs || !int_addrs)
608 goto out;
609
610 list_for_each_entry(ext_addr, ext_addrs, list)
611 {
612 if (!fw3_is_family(ext_addr, handle->family))
613 continue;
614
615 list_for_each_entry(int_addr, int_addrs, list)
616 {
617 if (!fw3_is_family(int_addr, handle->family))
618 continue;
619
620 fw3_foreach(proto, &redir->proto)
621 {
622 if (!proto)
623 continue;
624
625 if (redir->reflection_src == FW3_REFLECTION_INTERNAL)
626 ref_addr = *int_addr;
627 else
628 ref_addr = *ext_addr;
629
630 ref_addr.mask.v4.s_addr = 0xFFFFFFFF;
631 ext_addr->mask.v4.s_addr = 0xFFFFFFFF;
632
633 print_reflection(handle, state, redir, num, proto,
634 &ref_addr, int_addr, ext_addr);
635 }
636 }
637 }
638
639 out:
640 fw3_free_list(ext_addrs);
641 fw3_free_list(int_addrs);
642 }
643
644 void
645 fw3_print_redirects(struct fw3_ipt_handle *handle, struct fw3_state *state)
646 {
647 int num = 0;
648 struct fw3_redirect *redir;
649
650 if (handle->family == FW3_FAMILY_V6)
651 return;
652
653 if (handle->table != FW3_TABLE_FILTER && handle->table != FW3_TABLE_NAT)
654 return;
655
656 list_for_each_entry(redir, &state->redirects, list)
657 expand_redirect(handle, state, redir, num++);
658 }