Fix endian issue in compare_addr(), solves auto detection of "option dest" for redire...
[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)
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 void
169 fw3_load_redirects(struct fw3_state *state, struct uci_package *p)
170 {
171 struct uci_section *s;
172 struct uci_element *e;
173 struct fw3_redirect *redir;
174
175 bool valid;
176
177 INIT_LIST_HEAD(&state->redirects);
178
179 uci_foreach_element(&p->sections, e)
180 {
181 s = uci_to_section(e);
182
183 if (strcmp(s->type, "redirect"))
184 continue;
185
186 redir = malloc(sizeof(*redir));
187
188 if (!redir)
189 continue;
190
191 memset(redir, 0, sizeof(*redir));
192
193 INIT_LIST_HEAD(&redir->proto);
194 INIT_LIST_HEAD(&redir->mac_src);
195
196 redir->enabled = true;
197 redir->reflection = true;
198
199 valid = false;
200
201 fw3_parse_options(redir, fw3_redirect_opts, s);
202
203 if (!redir->enabled)
204 {
205 fw3_free_redirect(redir);
206 continue;
207 }
208
209 if (redir->src.invert)
210 {
211 warn_elem(e, "must not have an inverted source");
212 fw3_free_redirect(redir);
213 continue;
214 }
215 else if (redir->src.set && !redir->src.any &&
216 !(redir->_src = fw3_lookup_zone(state, redir->src.name)))
217 {
218 warn_elem(e, "refers to not existing zone '%s'", redir->src.name);
219 fw3_free_redirect(redir);
220 continue;
221 }
222 else if (redir->dest.set && !redir->dest.any &&
223 !(redir->_dest = fw3_lookup_zone(state, redir->dest.name)))
224 {
225 warn_elem(e, "refers to not existing zone '%s'", redir->dest.name);
226 fw3_free_redirect(redir);
227 continue;
228 }
229 else if (redir->ipset.set && state->disable_ipsets)
230 {
231 warn_elem(e, "skipped due to disabled ipset support");
232 fw3_free_redirect(redir);
233 continue;
234 }
235 else if (redir->ipset.set &&
236 !(redir->ipset.ptr = fw3_lookup_ipset(state, redir->ipset.name)))
237 {
238 warn_elem(e, "refers to unknown ipset '%s'", redir->ipset.name);
239 fw3_free_redirect(redir);
240 continue;
241 }
242
243 if (!check_families(e, redir))
244 {
245 fw3_free_redirect(redir);
246 continue;
247 }
248
249 if (redir->target == FW3_FLAG_UNSPEC)
250 {
251 warn_elem(e, "has no target specified, defaulting to DNAT");
252 redir->target = FW3_FLAG_DNAT;
253 }
254 else if (redir->target < FW3_FLAG_DNAT)
255 {
256 warn_elem(e, "has invalid target specified, defaulting to DNAT");
257 redir->target = FW3_FLAG_DNAT;
258 }
259
260 if (redir->target == FW3_FLAG_DNAT)
261 {
262 if (redir->src.any)
263 warn_elem(e, "must not have source '*' for DNAT target");
264 else if (!redir->_src)
265 warn_elem(e, "has no source specified");
266 else
267 {
268 set(redir->_src->flags, FW3_FAMILY_V4, redir->target);
269 redir->_src->conntrack = true;
270 valid = true;
271 }
272
273 if (!redir->dest.set && resolve_dest(e, redir, state))
274 {
275 warn_elem(e, "does not specify a destination, assuming '%s'",
276 redir->dest.name);
277 }
278
279 if (redir->reflection && redir->_dest && redir->_src->masq)
280 {
281 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_ACCEPT);
282 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_DNAT);
283 set(redir->_dest->flags, FW3_FAMILY_V4, FW3_FLAG_SNAT);
284 }
285 }
286 else
287 {
288 if (redir->dest.any)
289 warn_elem(e, "must not have destination '*' for SNAT target");
290 else if (!redir->_dest)
291 warn_elem(e, "has no destination specified");
292 else if (!redir->ip_dest.set)
293 warn_elem(e, "has no src_dip option specified");
294 else if (!list_empty(&redir->mac_src))
295 warn_elem(e, "must not use 'src_mac' option for SNAT target");
296 else
297 {
298 set(redir->_dest->flags, FW3_FAMILY_V4, redir->target);
299 redir->_dest->conntrack = true;
300 valid = true;
301 }
302 }
303
304 if (list_empty(&redir->proto))
305 {
306 warn_elem(e, "does not specify a protocol, assuming TCP+UDP");
307 fw3_parse_protocol(&redir->proto, "tcpudp", true);
308 }
309
310 if (!valid)
311 {
312 fw3_free_redirect(redir);
313 continue;
314 }
315
316 if (!redir->port_redir.set)
317 redir->port_redir = redir->port_dest;
318
319 list_add_tail(&redir->list, &state->redirects);
320 }
321 }
322
323 static void
324 append_chain_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
325 {
326 if (redir->target == FW3_FLAG_DNAT)
327 fw3_ipt_rule_append(r, "zone_%s_prerouting", redir->src.name);
328 else
329 fw3_ipt_rule_append(r, "zone_%s_postrouting", redir->dest.name);
330 }
331
332 static void
333 set_snat_dnat(struct fw3_ipt_rule *r, enum fw3_flag target,
334 struct fw3_address *addr, struct fw3_port *port)
335 {
336 char buf[sizeof("255.255.255.255:65535-65535\0")];
337
338 buf[0] = '\0';
339
340 if (addr && addr->set)
341 {
342 inet_ntop(AF_INET, &addr->address.v4, buf, sizeof(buf));
343 }
344
345 if (port && port->set)
346 {
347 if (port->port_min == port->port_max)
348 sprintf(buf + strlen(buf), ":%u", port->port_min);
349 else
350 sprintf(buf + strlen(buf), ":%u-%u",
351 port->port_min, port->port_max);
352 }
353
354 if (target == FW3_FLAG_DNAT)
355 {
356 fw3_ipt_rule_target(r, "DNAT");
357 fw3_ipt_rule_addarg(r, false, "--to-destination", buf);
358 }
359 else
360 {
361 fw3_ipt_rule_target(r, "SNAT");
362 fw3_ipt_rule_addarg(r, false, "--to-source", buf);
363 }
364 }
365
366 static void
367 set_target_nat(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
368 {
369 if (redir->target == FW3_FLAG_DNAT)
370 set_snat_dnat(r, redir->target, &redir->ip_redir, &redir->port_redir);
371 else
372 set_snat_dnat(r, redir->target, &redir->ip_dest, &redir->port_dest);
373 }
374
375 static void
376 append_chain_filter(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
377 {
378 if (redir->target == FW3_FLAG_DNAT)
379 {
380 /* XXX: check for local ip */
381 if (!redir->ip_redir.set)
382 fw3_ipt_rule_append(r, "zone_%s_input", redir->src.name);
383 else
384 fw3_ipt_rule_append(r, "zone_%s_forward", redir->src.name);
385 }
386 else
387 {
388 if (redir->src.set && !redir->src.any)
389 fw3_ipt_rule_append(r, "zone_%s_forward", redir->src.name);
390 else
391 fw3_ipt_rule_append(r, "delegate_forward");
392 }
393 }
394
395 static void
396 set_target_filter(struct fw3_ipt_rule *r, struct fw3_redirect *redir)
397 {
398 /* XXX: check for local ip */
399 if (redir->target == FW3_FLAG_DNAT && !redir->ip_redir.set)
400 fw3_ipt_rule_extra(r, "-m conntrack --ctstate DNAT");
401
402 fw3_ipt_rule_target(r, "ACCEPT");
403 }
404
405 static void
406 set_comment(struct fw3_ipt_rule *r, const char *name, int num, bool ref)
407 {
408 if (name)
409 {
410 if (ref)
411 fw3_ipt_rule_comment(r, "%s (reflection)", name);
412 else
413 fw3_ipt_rule_comment(r, name);
414 }
415 else
416 {
417 if (ref)
418 fw3_ipt_rule_comment(r, "@redirect[%u] (reflection)", num);
419 else
420 fw3_ipt_rule_comment(r, "@redirect[%u]", num);
421 }
422 }
423
424 static void
425 print_redirect(struct fw3_ipt_handle *h, struct fw3_state *state,
426 struct fw3_redirect *redir, int num,
427 struct fw3_protocol *proto, struct fw3_mac *mac)
428 {
429 struct fw3_ipt_rule *r;
430 struct fw3_address *src, *dst;
431 struct fw3_port *spt, *dpt;
432
433 switch (h->table)
434 {
435 case FW3_TABLE_NAT:
436 src = &redir->ip_src;
437 dst = &redir->ip_dest;
438 spt = &redir->port_src;
439 dpt = &redir->port_dest;
440
441 if (redir->target == FW3_FLAG_SNAT)
442 {
443 dst = &redir->ip_redir;
444 dpt = &redir->port_redir;
445 }
446
447 r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
448 fw3_ipt_rule_sport_dport(r, spt, dpt);
449 fw3_ipt_rule_mac(r, mac);
450 fw3_ipt_rule_ipset(r, &redir->ipset);
451 fw3_ipt_rule_limit(r, &redir->limit);
452 fw3_ipt_rule_time(r, &redir->time);
453 fw3_ipt_rule_mark(r, &redir->mark);
454 set_target_nat(r, redir);
455 fw3_ipt_rule_extra(r, redir->extra);
456 set_comment(r, redir->name, num, false);
457 append_chain_nat(r, redir);
458 break;
459
460 case FW3_TABLE_FILTER:
461 src = &redir->ip_src;
462 dst = &redir->ip_redir;
463 spt = &redir->port_src;
464 dpt = &redir->port_redir;
465
466 r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
467 fw3_ipt_rule_sport_dport(r, spt, dpt);
468 fw3_ipt_rule_mac(r, mac);
469 fw3_ipt_rule_ipset(r, &redir->ipset);
470 fw3_ipt_rule_limit(r, &redir->limit);
471 fw3_ipt_rule_time(r, &redir->time);
472 fw3_ipt_rule_mark(r, &redir->mark);
473 set_target_filter(r, redir);
474 fw3_ipt_rule_extra(r, redir->extra);
475 set_comment(r, redir->name, num, false);
476 append_chain_filter(r, redir);
477 break;
478
479 default:
480 break;
481 }
482 }
483
484 static void
485 print_reflection(struct fw3_ipt_handle *h, struct fw3_state *state,
486 struct fw3_redirect *redir, int num,
487 struct fw3_protocol *proto, struct fw3_address *ra,
488 struct fw3_address *ia, struct fw3_address *ea)
489 {
490 struct fw3_ipt_rule *r;
491
492 switch (h->table)
493 {
494 case FW3_TABLE_NAT:
495 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, ea);
496 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_dest);
497 fw3_ipt_rule_limit(r, &redir->limit);
498 fw3_ipt_rule_time(r, &redir->time);
499 set_comment(r, redir->name, num, true);
500 set_snat_dnat(r, FW3_FLAG_DNAT, &redir->ip_redir, &redir->port_redir);
501 fw3_ipt_rule_append(r, "zone_%s_prerouting", redir->dest.name);
502
503 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, &redir->ip_redir);
504 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_redir);
505 fw3_ipt_rule_limit(r, &redir->limit);
506 fw3_ipt_rule_time(r, &redir->time);
507 set_comment(r, redir->name, num, true);
508 set_snat_dnat(r, FW3_FLAG_SNAT, ra, NULL);
509 fw3_ipt_rule_append(r, "zone_%s_postrouting", redir->dest.name);
510 break;
511
512 case FW3_TABLE_FILTER:
513 r = fw3_ipt_rule_create(h, proto, NULL, NULL, ia, &redir->ip_redir);
514 fw3_ipt_rule_sport_dport(r, NULL, &redir->port_redir);
515 fw3_ipt_rule_limit(r, &redir->limit);
516 fw3_ipt_rule_time(r, &redir->time);
517 set_comment(r, redir->name, num, true);
518 fw3_ipt_rule_target(r, "zone_%s_dest_ACCEPT", redir->dest.name);
519 fw3_ipt_rule_append(r, "zone_%s_forward", redir->dest.name);
520 break;
521
522 default:
523 break;
524 }
525 }
526
527 static void
528 expand_redirect(struct fw3_ipt_handle *handle, struct fw3_state *state,
529 struct fw3_redirect *redir, int num)
530 {
531 struct list_head *ext_addrs, *int_addrs;
532 struct fw3_address *ext_addr, *int_addr, ref_addr;
533 struct fw3_protocol *proto;
534 struct fw3_mac *mac;
535
536 if (redir->name)
537 info(" * Redirect '%s'", redir->name);
538 else
539 info(" * Redirect #%u", num);
540
541 if (!fw3_is_family(redir->_src, handle->family) ||
542 !fw3_is_family(redir->_dest, handle->family))
543 {
544 info(" ! Skipping due to different family of zone");
545 return;
546 }
547
548 if (!fw3_is_family(&redir->ip_src, handle->family) ||
549 !fw3_is_family(&redir->ip_dest, handle->family) ||
550 !fw3_is_family(&redir->ip_redir, handle->family))
551 {
552 if (!redir->ip_src.resolved ||
553 !redir->ip_dest.resolved ||
554 !redir->ip_redir.resolved)
555 info(" ! Skipping due to different family of ip address");
556
557 return;
558 }
559
560 if (redir->ipset.ptr)
561 {
562 if (!fw3_is_family(redir->ipset.ptr, handle->family))
563 {
564 info(" ! Skipping due to different family in ipset");
565 return;
566 }
567
568 if (!fw3_check_ipset(redir->ipset.ptr))
569 {
570 info(" ! Skipping due to missing ipset '%s'",
571 redir->ipset.ptr->external ?
572 redir->ipset.ptr->external : redir->ipset.ptr->name);
573 return;
574 }
575
576 set(redir->ipset.ptr->flags, handle->family, handle->family);
577 }
578
579 fw3_foreach(proto, &redir->proto)
580 fw3_foreach(mac, &redir->mac_src)
581 print_redirect(handle, state, redir, num, proto, mac);
582
583 /* reflection rules */
584 if (redir->target != FW3_FLAG_DNAT || !redir->reflection)
585 return;
586
587 if (!redir->_dest || !redir->_src->masq)
588 return;
589
590 ext_addrs = fw3_resolve_zone_addresses(redir->_src);
591 int_addrs = fw3_resolve_zone_addresses(redir->_dest);
592
593 if (!ext_addrs || !int_addrs)
594 goto out;
595
596 list_for_each_entry(ext_addr, ext_addrs, list)
597 {
598 if (!fw3_is_family(ext_addr, handle->family))
599 continue;
600
601 list_for_each_entry(int_addr, int_addrs, list)
602 {
603 if (!fw3_is_family(int_addr, handle->family))
604 continue;
605
606 fw3_foreach(proto, &redir->proto)
607 {
608 if (!proto || (proto->protocol != 6 && proto->protocol != 17))
609 continue;
610
611 if (redir->reflection_src == FW3_REFLECTION_INTERNAL)
612 ref_addr = *int_addr;
613 else
614 ref_addr = *ext_addr;
615
616 ref_addr.mask = 32;
617 ext_addr->mask = 32;
618
619 print_reflection(handle, state, redir, num, proto,
620 &ref_addr, int_addr, ext_addr);
621 }
622 }
623 }
624
625 out:
626 fw3_free_list(ext_addrs);
627 fw3_free_list(int_addrs);
628 }
629
630 void
631 fw3_print_redirects(struct fw3_ipt_handle *handle, struct fw3_state *state)
632 {
633 int num = 0;
634 struct fw3_redirect *redir;
635
636 if (handle->family == FW3_FAMILY_V6)
637 return;
638
639 if (handle->table != FW3_TABLE_FILTER && handle->table != FW3_TABLE_NAT)
640 return;
641
642 list_for_each_entry(redir, &state->redirects, list)
643 expand_redirect(handle, state, redir, num++);
644 }