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[project/firewall3.git] / zones.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 "zones.h"
20 #include "ubus.h"
21
22
23 #define C(f, tbl, tgt, fmt) \
24         { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_FLAG_##tgt, fmt }
25
26 static const struct fw3_rule_spec zone_chains[] = {
27         C(ANY, FILTER, UNSPEC,        "zone_%1$s_input"),
28         C(ANY, FILTER, UNSPEC,        "zone_%1$s_output"),
29         C(ANY, FILTER, UNSPEC,        "zone_%1$s_forward"),
30
31         C(ANY, FILTER, SRC_ACCEPT,    "zone_%1$s_src_ACCEPT"),
32         C(ANY, FILTER, SRC_REJECT,    "zone_%1$s_src_REJECT"),
33         C(ANY, FILTER, SRC_DROP,      "zone_%1$s_src_DROP"),
34
35         C(ANY, FILTER, ACCEPT,        "zone_%1$s_dest_ACCEPT"),
36         C(ANY, FILTER, REJECT,        "zone_%1$s_dest_REJECT"),
37         C(ANY, FILTER, DROP,          "zone_%1$s_dest_DROP"),
38
39         C(V4,  NAT,    SNAT,          "zone_%1$s_postrouting"),
40         C(V4,  NAT,    DNAT,          "zone_%1$s_prerouting"),
41
42         C(ANY, FILTER, CUSTOM_CHAINS, "input_%1$s_rule"),
43         C(ANY, FILTER, CUSTOM_CHAINS, "output_%1$s_rule"),
44         C(ANY, FILTER, CUSTOM_CHAINS, "forwarding_%1$s_rule"),
45
46         C(V4,  NAT,    CUSTOM_CHAINS, "prerouting_%1$s_rule"),
47         C(V4,  NAT,    CUSTOM_CHAINS, "postrouting_%1$s_rule"),
48
49         { }
50 };
51
52
53 #define R(dir1, dir2) \
54         "zone_%1$s_" #dir1 " -m comment --comment \"user chain for %1$s " \
55         #dir2 "\" -j " #dir2 "_%1$s_rule"
56
57 static const struct fw3_rule_spec zone_rules[] = {
58         C(ANY, FILTER, CUSTOM_CHAINS, R(input, input)),
59         C(ANY, FILTER, CUSTOM_CHAINS, R(output, output)),
60         C(ANY, FILTER, CUSTOM_CHAINS, R(forward, forwarding)),
61
62         C(V4,  NAT,    CUSTOM_CHAINS, R(prerouting, prerouting)),
63         C(V4,  NAT,    CUSTOM_CHAINS, R(postrouting, postrouting)),
64
65         { }
66 };
67
68 const struct fw3_option fw3_zone_opts[] = {
69         FW3_OPT("enabled",             bool,     zone,     enabled),
70
71         FW3_OPT("name",                string,   zone,     name),
72         FW3_OPT("family",              family,   zone,     family),
73
74         FW3_LIST("network",            device,   zone,     networks),
75         FW3_LIST("device",             device,   zone,     devices),
76         FW3_LIST("subnet",             address,  zone,     subnets),
77
78         FW3_OPT("input",               target,   zone,     policy_input),
79         FW3_OPT("forward",             target,   zone,     policy_forward),
80         FW3_OPT("output",              target,   zone,     policy_output),
81
82         FW3_OPT("masq",                bool,     zone,     masq),
83         FW3_LIST("masq_src",           network,  zone,     masq_src),
84         FW3_LIST("masq_dest",          network,  zone,     masq_dest),
85
86         FW3_OPT("extra",               string,   zone,     extra_src),
87         FW3_OPT("extra_src",           string,   zone,     extra_src),
88         FW3_OPT("extra_dest",          string,   zone,     extra_dest),
89
90         FW3_OPT("conntrack",           bool,     zone,     conntrack),
91         FW3_OPT("mtu_fix",             bool,     zone,     mtu_fix),
92         FW3_OPT("custom_chains",       bool,     zone,     custom_chains),
93
94         FW3_OPT("log",                 bool,     zone,     log),
95         FW3_OPT("log_limit",           limit,    zone,     log_limit),
96
97         { }
98 };
99
100
101 static void
102 check_policy(struct uci_element *e, enum fw3_flag *pol, enum fw3_flag def,
103              const char *name)
104 {
105         if (*pol == FW3_FLAG_UNSPEC)
106         {
107                 warn_elem(e, "has no %s policy specified, using default", name);
108                 *pol = def;
109         }
110         else if (*pol > FW3_FLAG_DROP)
111         {
112                 warn_elem(e, "has invalid %s policy, using default", name);
113                 *pol = def;
114         }
115 }
116
117 static void
118 resolve_networks(struct uci_element *e, struct fw3_zone *zone)
119 {
120         struct fw3_device *net, *tmp;
121
122         list_for_each_entry(net, &zone->networks, list)
123         {
124                 tmp = fw3_ubus_device(net->name);
125
126                 if (!tmp)
127                 {
128                         warn_elem(e, "cannot resolve device of network '%s'", net->name);
129                         continue;
130                 }
131
132                 tmp->network = net;
133                 list_add_tail(&tmp->list, &zone->devices);
134         }
135 }
136
137 struct fw3_zone *
138 fw3_alloc_zone(void)
139 {
140         struct fw3_zone *zone;
141
142         zone = malloc(sizeof(*zone));
143
144         if (!zone)
145                 return NULL;
146
147         memset(zone, 0, sizeof(*zone));
148
149         INIT_LIST_HEAD(&zone->networks);
150         INIT_LIST_HEAD(&zone->devices);
151         INIT_LIST_HEAD(&zone->subnets);
152         INIT_LIST_HEAD(&zone->masq_src);
153         INIT_LIST_HEAD(&zone->masq_dest);
154
155         INIT_LIST_HEAD(&zone->running_networks);
156         INIT_LIST_HEAD(&zone->running_devices);
157
158         zone->enabled = true;
159         zone->custom_chains = true;
160         zone->log_limit.rate = 10;
161
162         return zone;
163 }
164
165 void
166 fw3_load_zones(struct fw3_state *state, struct uci_package *p)
167 {
168         struct uci_section *s;
169         struct uci_element *e;
170         struct fw3_zone *zone;
171         struct fw3_defaults *defs = &state->defaults;
172
173         INIT_LIST_HEAD(&state->zones);
174
175         uci_foreach_element(&p->sections, e)
176         {
177                 s = uci_to_section(e);
178
179                 if (strcmp(s->type, "zone"))
180                         continue;
181
182                 zone = fw3_alloc_zone();
183
184                 if (!zone)
185                         continue;
186
187                 fw3_parse_options(zone, fw3_zone_opts, s);
188
189                 if (!zone->enabled)
190                 {
191                         fw3_free_zone(zone);
192                         continue;
193                 }
194
195                 if (!zone->extra_dest)
196                         zone->extra_dest = zone->extra_src;
197
198                 if (!defs->custom_chains && zone->custom_chains)
199                         zone->custom_chains = false;
200
201                 if (!zone->name || !*zone->name)
202                 {
203                         warn_elem(e, "has no name - ignoring");
204                         fw3_free_zone(zone);
205                         continue;
206                 }
207
208                 if (list_empty(&zone->networks) && list_empty(&zone->devices) &&
209                     list_empty(&zone->subnets) && !zone->extra_src)
210                 {
211                         warn_elem(e, "has no device, network, subnet or extra options");
212                 }
213
214                 check_policy(e, &zone->policy_input, defs->policy_input, "input");
215                 check_policy(e, &zone->policy_output, defs->policy_output, "output");
216                 check_policy(e, &zone->policy_forward, defs->policy_forward, "forward");
217
218                 resolve_networks(e, zone);
219
220                 if (zone->masq)
221                 {
222                         setbit(zone->flags[0], FW3_FLAG_SNAT);
223                         zone->conntrack = true;
224                 }
225
226                 if (zone->custom_chains)
227                 {
228                         setbit(zone->flags[0], FW3_FLAG_SNAT);
229                         setbit(zone->flags[0], FW3_FLAG_DNAT);
230                 }
231
232                 setbit(zone->flags[0], fw3_to_src_target(zone->policy_input));
233                 setbit(zone->flags[0], zone->policy_output);
234                 setbit(zone->flags[0], zone->policy_forward);
235
236                 setbit(zone->flags[1], fw3_to_src_target(zone->policy_input));
237                 setbit(zone->flags[1], zone->policy_output);
238                 setbit(zone->flags[1], zone->policy_forward);
239
240                 list_add_tail(&zone->list, &state->zones);
241         }
242 }
243
244
245 static void
246 print_zone_chain(struct fw3_state *state, enum fw3_family family,
247                  enum fw3_table table, bool reload, struct fw3_zone *zone)
248 {
249         bool c, r;
250         uint32_t custom_mask = ~0;
251
252         if (!fw3_is_family(zone, family))
253                 return;
254
255         set(zone->flags, family, table);
256
257         /* Don't touch user chains on reload */
258         if (reload)
259                 delbit(custom_mask, FW3_FLAG_CUSTOM_CHAINS);
260
261         if (zone->custom_chains)
262                 set(zone->flags, family, FW3_FLAG_CUSTOM_CHAINS);
263
264         if (!zone->conntrack && !state->defaults.drop_invalid)
265                 set(zone->flags, family, FW3_FLAG_NOTRACK);
266
267         c = fw3_pr_rulespec(table, family, zone->flags, custom_mask, zone_chains,
268                             ":%s - [0:0]\n", zone->name);
269
270         r = fw3_pr_rulespec(table, family, zone->flags, 0, zone_rules,
271                             "-A %s\n", zone->name);
272
273         if (c || r)
274         {
275                 info("   * Zone '%s'", zone->name);
276                 fw3_set_running(zone, &state->running_zones);
277
278                 set(zone->flags, family, table);
279         }
280 }
281
282 static void
283 print_interface_rule(struct fw3_state *state, enum fw3_family family,
284                      enum fw3_table table, bool reload, struct fw3_zone *zone,
285                      struct fw3_device *dev, struct fw3_address *sub)
286 {
287         bool disable_notrack = state->defaults.drop_invalid;
288
289         enum fw3_flag t;
290
291 #define jump_target(t) \
292         ((t == FW3_FLAG_REJECT) ? "reject" : fw3_flag_names[t])
293
294         if (table == FW3_TABLE_FILTER)
295         {
296                 for (t = FW3_FLAG_ACCEPT; t <= FW3_FLAG_DROP; t++)
297                 {
298                         if (has(zone->flags, family, fw3_to_src_target(t)))
299                         {
300                                 fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
301                                 fw3_format_in_out(dev, NULL);
302                                 fw3_format_src_dest(sub, NULL);
303                                 fw3_format_extra(zone->extra_src);
304                                 fw3_pr(" -j %s\n", jump_target(t));
305                         }
306
307                         if (has(zone->flags, family, t))
308                         {
309                                 fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
310                                 fw3_format_in_out(NULL, dev);
311                                 fw3_format_src_dest(NULL, sub);
312                                 fw3_format_extra(zone->extra_dest);
313                                 fw3_pr(" -j %s\n", jump_target(t));
314                         }
315                 }
316
317                 fw3_pr("-A delegate_input");
318                 fw3_format_in_out(dev, NULL);
319                 fw3_format_src_dest(sub, NULL);
320                 fw3_format_extra(zone->extra_src);
321                 fw3_pr(" -j zone_%s_input\n", zone->name);
322
323                 fw3_pr("-A delegate_forward");
324                 fw3_format_in_out(dev, NULL);
325                 fw3_format_src_dest(sub, NULL);
326                 fw3_format_extra(zone->extra_src);
327                 fw3_pr(" -j zone_%s_forward\n", zone->name);
328
329                 fw3_pr("-A delegate_output");
330                 fw3_format_in_out(NULL, dev);
331                 fw3_format_src_dest(NULL, sub);
332                 fw3_format_extra(zone->extra_dest);
333                 fw3_pr(" -j zone_%s_output\n", zone->name);
334         }
335         else if (table == FW3_TABLE_NAT)
336         {
337                 if (has(zone->flags, family, FW3_FLAG_DNAT))
338                 {
339                         fw3_pr("-A delegate_prerouting");
340                         fw3_format_in_out(dev, NULL);
341                         fw3_format_src_dest(sub, NULL);
342                         fw3_format_extra(zone->extra_src);
343                         fw3_pr(" -j zone_%s_prerouting\n", zone->name);
344                 }
345
346                 if (has(zone->flags, family, FW3_FLAG_SNAT))
347                 {
348                         fw3_pr("-A delegate_postrouting");
349                         fw3_format_in_out(NULL, dev);
350                         fw3_format_src_dest(NULL, sub);
351                         fw3_format_extra(zone->extra_dest);
352                         fw3_pr(" -j zone_%s_postrouting\n", zone->name);
353                 }
354         }
355         else if (table == FW3_TABLE_MANGLE)
356         {
357                 if (zone->mtu_fix)
358                 {
359                         if (zone->log)
360                         {
361                                 fw3_pr("-A mssfix");
362                                 fw3_format_in_out(NULL, dev);
363                                 fw3_format_src_dest(NULL, sub);
364                                 fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
365                                 fw3_format_limit(&zone->log_limit);
366                                 fw3_format_comment(zone->name, " (mtu_fix logging)");
367                                 fw3_pr(" -j LOG --log-prefix \"MSSFIX(%s): \"\n", zone->name);
368                         }
369
370                         fw3_pr("-A mssfix");
371                         fw3_format_in_out(NULL, dev);
372                         fw3_format_src_dest(NULL, sub);
373                         fw3_pr(" -p tcp --tcp-flags SYN,RST SYN");
374                         fw3_format_comment(zone->name, " (mtu_fix)");
375                         fw3_pr(" -j TCPMSS --clamp-mss-to-pmtu\n");
376                 }
377         }
378         else if (table == FW3_TABLE_RAW)
379         {
380                 if (!zone->conntrack && !disable_notrack)
381                 {
382                         fw3_pr("-A notrack");
383                         fw3_format_in_out(dev, NULL);
384                         fw3_format_src_dest(sub, NULL);
385                         fw3_format_extra(zone->extra_src);
386                         fw3_format_comment(zone->name, " (notrack)");
387                         fw3_pr(" -j CT --notrack\n", zone->name);
388                 }
389         }
390 }
391
392 static void
393 print_interface_rules(struct fw3_state *state, enum fw3_family family,
394                       enum fw3_table table, bool reload, struct fw3_zone *zone)
395 {
396         struct fw3_device *dev;
397         struct fw3_address *sub;
398
399         fw3_foreach(dev, &zone->devices)
400         fw3_foreach(sub, &zone->subnets)
401         {
402                 if (!fw3_is_family(sub, family))
403                         continue;
404
405                 if (!dev && !sub)
406                         continue;
407
408                 print_interface_rule(state, family, table, reload, zone, dev, sub);
409         }
410 }
411
412 static void
413 print_zone_rule(struct fw3_state *state, enum fw3_family family,
414                 enum fw3_table table, bool reload, struct fw3_zone *zone)
415 {
416         struct fw3_address *msrc;
417         struct fw3_address *mdest;
418
419         enum fw3_flag t;
420
421         if (!fw3_is_family(zone, family))
422                 return;
423
424         switch (table)
425         {
426         case FW3_TABLE_FILTER:
427                 fw3_pr("-A zone_%s_input -j zone_%s_src_%s\n",
428                            zone->name, zone->name, fw3_flag_names[zone->policy_input]);
429
430                 fw3_pr("-A zone_%s_forward -j zone_%s_dest_%s\n",
431                            zone->name, zone->name, fw3_flag_names[zone->policy_forward]);
432
433                 fw3_pr("-A zone_%s_output -j zone_%s_dest_%s\n",
434                            zone->name, zone->name, fw3_flag_names[zone->policy_output]);
435
436                 if (zone->log)
437                 {
438                         for (t = FW3_FLAG_REJECT; t <= FW3_FLAG_DROP; t++)
439                         {
440                                 if (has(zone->flags, family, fw3_to_src_target(t)))
441                                 {
442                                         fw3_pr("-A zone_%s_src_%s", zone->name, fw3_flag_names[t]);
443                                         fw3_format_limit(&zone->log_limit);
444                                         fw3_pr(" -j LOG --log-prefix \"%s(src %s)\"\n",
445                                                    fw3_flag_names[t], zone->name);
446                                 }
447
448                                 if (has(zone->flags, family, t))
449                                 {
450                                         fw3_pr("-A zone_%s_dest_%s", zone->name, fw3_flag_names[t]);
451                                         fw3_format_limit(&zone->log_limit);
452                                         fw3_pr(" -j LOG --log-prefix \"%s(dest %s)\"\n",
453                                                    fw3_flag_names[t], zone->name);
454                                 }
455                         }
456                 }
457                 break;
458
459         case FW3_TABLE_NAT:
460                 if (zone->masq && family == FW3_FAMILY_V4)
461                 {
462                         fw3_foreach(msrc, &zone->masq_src)
463                         fw3_foreach(mdest, &zone->masq_dest)
464                         {
465                                 if (!fw3_is_family(msrc, family) ||
466                                     !fw3_is_family(mdest, family))
467                                         continue;
468                                 
469                                 fw3_pr("-A zone_%s_postrouting", zone->name);
470                                 fw3_format_src_dest(msrc, mdest);
471                                 fw3_pr(" -j MASQUERADE\n");
472                         }
473                 }
474                 break;
475
476         case FW3_TABLE_RAW:
477         case FW3_TABLE_MANGLE:
478                 break;
479         }
480
481         print_interface_rules(state, family, table, reload, zone);
482 }
483
484 void
485 fw3_print_zone_chains(struct fw3_state *state, enum fw3_family family,
486                       enum fw3_table table, bool reload)
487 {
488         struct fw3_zone *zone;
489
490         list_for_each_entry(zone, &state->zones, list)
491                 print_zone_chain(state, family, table, reload, zone);
492 }
493
494 void
495 fw3_print_zone_rules(struct fw3_state *state, enum fw3_family family,
496                      enum fw3_table table, bool reload)
497 {
498         struct fw3_zone *zone;
499
500         list_for_each_entry(zone, &state->zones, list)
501                 print_zone_rule(state, family, table, reload, zone);
502 }
503
504 void
505 fw3_flush_zones(struct fw3_state *state, enum fw3_family family,
506                 enum fw3_table table, bool reload, bool pass2)
507 {
508         struct fw3_zone *z, *tmp;
509         uint32_t custom_mask = ~0;
510
511         /* don't touch user chains on selective stop */
512         if (reload)
513                 delbit(custom_mask, FW3_FLAG_CUSTOM_CHAINS);
514
515         list_for_each_entry_safe(z, tmp, &state->running_zones, running_list)
516         {
517                 if (!has(z->flags, family, table))
518                         continue;
519
520                 fw3_pr_rulespec(table, family, z->flags, custom_mask, zone_chains,
521                                 pass2 ? "-X %s\n" : "-F %s\n", z->name);
522
523                 if (pass2)
524                         del(z->flags, family, table);
525         }
526 }
527
528 void
529 fw3_hotplug_zones(struct fw3_state *state, bool add)
530 {
531         struct fw3_zone *z;
532         struct fw3_device *d;
533
534         if (add)
535         {
536                 list_for_each_entry(z, &state->running_zones, running_list)
537                 {
538                         if (!hasbit(z->flags[0], FW3_FLAG_HOTPLUG))
539                         {
540                                 list_for_each_entry(d, &z->devices, list)
541                                         fw3_hotplug(add, z, d);
542
543                                 setbit(z->flags[0], FW3_FLAG_HOTPLUG);
544                         }
545                 }
546         }
547         else
548         {
549                 list_for_each_entry(z, &state->running_zones, running_list)
550                 {
551                         if (hasbit(z->flags[0], FW3_FLAG_HOTPLUG))
552                         {
553                                 list_for_each_entry(d, &z->running_devices, list)
554                                         fw3_hotplug(add, z, d);
555
556                                 delbit(z->flags[0], FW3_FLAG_HOTPLUG);
557                         }
558                 }
559         }
560 }
561
562 struct fw3_zone *
563 fw3_lookup_zone(struct fw3_state *state, const char *name, bool running)
564 {
565         struct fw3_zone *z;
566
567         if (list_empty(&state->zones))
568                 return NULL;
569
570         list_for_each_entry(z, &state->zones, list)
571         {
572                 if (strcmp(z->name, name))
573                         continue;
574
575                 if (!running || z->running_list.next)
576                         return z;
577
578                 break;
579         }
580
581         return NULL;
582 }
583
584 void
585 fw3_free_zone(struct fw3_zone *zone)
586 {
587         struct fw3_device *dev, *tmp;
588
589         list_for_each_entry_safe(dev, tmp, &zone->running_devices, list)
590         {
591                 list_del(&dev->list);
592                 free(dev);
593         }
594
595         list_for_each_entry_safe(dev, tmp, &zone->running_networks, list)
596         {
597                 list_del(&dev->list);
598                 free(dev);
599         }
600
601         fw3_free_object(zone, fw3_zone_opts);
602 }