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