cmake: Find uci.h
[project/firewall3.git] / snats.c
1 /*
2  * firewall3 - 3rd OpenWrt UCI firewall implementation
3  *
4  *   Copyright (C) 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 "snats.h"
20
21
22 const struct fw3_option fw3_snat_opts[] = {
23         FW3_OPT("enabled",             bool,      snat,     enabled),
24
25         FW3_OPT("name",                string,    snat,     name),
26         FW3_OPT("family",              family,    snat,     family),
27
28         FW3_OPT("src",                 device,    snat,     src),
29         FW3_OPT("device",              string,    snat,     device),
30
31         FW3_OPT("ipset",               setmatch,  snat,     ipset),
32
33         FW3_LIST("proto",              protocol,  snat,     proto),
34
35         FW3_OPT("src_ip",              network,   snat,     ip_src),
36         FW3_OPT("src_port",            port,      snat,     port_src),
37
38         FW3_OPT("snat_ip",             network,   snat,     ip_snat),
39         FW3_OPT("snat_port",           port,      snat,     port_snat),
40
41         FW3_OPT("dest_ip",             network,   snat,     ip_dest),
42         FW3_OPT("dest_port",           port,      snat,     port_dest),
43
44         FW3_OPT("extra",               string,    snat,     extra),
45
46         FW3_OPT("limit",               limit,     snat,     limit),
47         FW3_OPT("limit_burst",         int,       snat,     limit.burst),
48
49         FW3_OPT("connlimit_ports",     bool,      snat,     connlimit_ports),
50
51         FW3_OPT("utc_time",            bool,      snat,     time.utc),
52         FW3_OPT("start_date",          date,      snat,     time.datestart),
53         FW3_OPT("stop_date",           date,      snat,     time.datestop),
54         FW3_OPT("start_time",          time,      snat,     time.timestart),
55         FW3_OPT("stop_time",           time,      snat,     time.timestop),
56         FW3_OPT("weekdays",            weekdays,  snat,     time.weekdays),
57         FW3_OPT("monthdays",           monthdays, snat,     time.monthdays),
58
59         FW3_OPT("mark",                mark,      snat,     mark),
60
61         FW3_OPT("target",              target,    snat,     target),
62
63         { }
64 };
65
66
67 static bool
68 check_families(struct uci_element *e, struct fw3_snat *r)
69 {
70         if (r->family == FW3_FAMILY_ANY)
71                 return true;
72
73         if (r->_src && r->_src->family && r->_src->family != r->family)
74         {
75                 warn_elem(e, "refers to source zone with different family");
76                 return false;
77         }
78
79         if (r->ipset.ptr && r->ipset.ptr->family &&
80             r->ipset.ptr->family != r->family)
81         {
82                 warn_elem(e, "refers to ipset with different family");
83                 return false;
84         }
85
86         if (r->ip_src.family && r->ip_src.family != r->family)
87         {
88                 warn_elem(e, "uses source ip with different family");
89                 return false;
90         }
91
92         if (r->ip_dest.family && r->ip_dest.family != r->family)
93         {
94                 warn_elem(e, "uses destination ip with different family");
95                 return false;
96         }
97
98         if (r->ip_snat.family && r->ip_snat.family != r->family)
99         {
100                 warn_elem(e, "uses snat ip with different family");
101                 return false;
102         }
103
104         return true;
105 }
106
107
108 static struct fw3_snat*
109 alloc_snat(struct fw3_state *state)
110 {
111         struct fw3_snat *snat = calloc(1, sizeof(*snat));
112
113         if (snat) {
114                 INIT_LIST_HEAD(&snat->proto);
115                 list_add_tail(&snat->list, &state->snats);
116                 snat->enabled = true;
117         }
118
119         return snat;
120 }
121
122
123 void
124 fw3_load_snats(struct fw3_state *state, struct uci_package *p, struct blob_attr *a)
125 {
126         struct uci_section *s;
127         struct uci_element *e;
128         struct fw3_snat *snat, *n;
129         struct blob_attr *rule, *opt;
130         unsigned rem, orem;
131
132         INIT_LIST_HEAD(&state->snats);
133
134         blob_for_each_attr(rule, a, rem) {
135                 const char *type = NULL;
136                 const char *name = "ubus rule";
137                 blobmsg_for_each_attr(opt, rule, orem)
138                         if (!strcmp(blobmsg_name(opt), "type"))
139                                 type = blobmsg_get_string(opt);
140                         else if (!strcmp(blobmsg_name(opt), "name"))
141                                 name = blobmsg_get_string(opt);
142
143                 if (!type || strcmp(type, "nat"))
144                         continue;
145
146                 if (!(snat = alloc_snat(state)))
147                         continue;
148
149                 if (!fw3_parse_blob_options(snat, fw3_snat_opts, rule, name))
150                 {
151                         fprintf(stderr, "%s skipped due to invalid options\n", name);
152                         fw3_free_snat(snat);
153                         continue;
154                 }
155         }
156
157         uci_foreach_element(&p->sections, e)
158         {
159                 s = uci_to_section(e);
160
161                 if (strcmp(s->type, "nat"))
162                         continue;
163
164                 if (!(snat = alloc_snat(state)))
165                         continue;
166
167                 if (!fw3_parse_options(snat, fw3_snat_opts, s))
168                 {
169                         warn_elem(e, "skipped due to invalid options");
170                         fw3_free_snat(snat);
171                         continue;
172                 }
173         }
174
175         list_for_each_entry_safe(snat, n, &state->snats, list)
176         {
177                 if (!snat->enabled)
178                 {
179                         fw3_free_snat(snat);
180                         continue;
181                 }
182
183                 if (snat->src.invert)
184                 {
185                         warn_elem(e, "must not have an inverted source");
186                         fw3_free_snat(snat);
187                         continue;
188                 }
189                 else if (snat->src.set && !snat->src.any &&
190                          !(snat->_src = fw3_lookup_zone(state, snat->src.name)))
191                 {
192                         warn_elem(e, "refers to not existing zone '%s'", snat->src.name);
193                         fw3_free_snat(snat);
194                         continue;
195                 }
196                 else if (snat->ipset.set && state->disable_ipsets)
197                 {
198                         warn_elem(e, "skipped due to disabled ipset support");
199                         fw3_free_snat(snat);
200                         continue;
201                 }
202                 else if (snat->ipset.set &&
203                          !(snat->ipset.ptr = fw3_lookup_ipset(state, snat->ipset.name)))
204                 {
205                         warn_elem(e, "refers to unknown ipset '%s'", snat->ipset.name);
206                         fw3_free_snat(snat);
207                         continue;
208                 }
209
210                 if (!check_families(e, snat))
211                 {
212                         fw3_free_snat(snat);
213                         continue;
214                 }
215
216                 if (snat->target == FW3_FLAG_UNSPEC)
217                 {
218                         warn_elem(e, "has no target specified, defaulting to MASQUERADE");
219                         snat->target = FW3_FLAG_MASQUERADE;
220                 }
221                 else if (snat->target != FW3_FLAG_ACCEPT && snat->target != FW3_FLAG_SNAT &&
222                                 snat->target != FW3_FLAG_MASQUERADE)
223                 {
224                         warn_elem(e, "has invalid target specified, defaulting to MASQUERADE");
225                         snat->target = FW3_FLAG_MASQUERADE;
226                 }
227
228                 if (snat->target == FW3_FLAG_SNAT &&
229                     !snat->ip_snat.set && !snat->port_snat.set)
230                 {
231                         warn_elem(e, "needs either 'snat_ip' or 'snat_port' for SNAT");
232                         fw3_free_snat(snat);
233                         continue;
234                 }
235                 else if (snat->target != FW3_FLAG_SNAT && snat->ip_snat.set)
236                 {
237                         warn_elem(e, "must not use 'snat_ip' for non-SNAT");
238                         fw3_free_snat(snat);
239                         continue;
240                 }
241                 else if (snat->target != FW3_FLAG_SNAT && snat->port_snat.set)
242                 {
243                         warn_elem(e, "must not use 'snat_port' for non-SNAT");
244                         fw3_free_snat(snat);
245                         continue;
246                 }
247
248                 if (list_empty(&snat->proto))
249                 {
250                         warn_elem(e, "does not specify a protocol, assuming all");
251                         fw3_parse_protocol(&snat->proto, "all", true);
252                 }
253
254                 if (snat->_src)
255                 {
256                         set(snat->_src->flags, FW3_FAMILY_V4, FW3_FLAG_SNAT);
257                         snat->_src->conntrack = true;
258                 }
259         }
260 }
261
262 static void
263 append_chain(struct fw3_ipt_rule *r, struct fw3_snat *snat)
264 {
265         if (snat->_src)
266                 fw3_ipt_rule_append(r, "zone_%s_postrouting", snat->src.name);
267         else
268                 fw3_ipt_rule_append(r, "POSTROUTING");
269 }
270
271 static void
272 set_target(struct fw3_ipt_rule *r, struct fw3_snat *snat,
273            struct fw3_protocol *proto)
274 {
275         char buf[sizeof("255.255.255.255:65535-65535\0")];
276
277         if (snat->target == FW3_FLAG_SNAT)
278         {
279                 buf[0] = '\0';
280
281                 if (snat->ip_snat.set)
282                 {
283                         inet_ntop(AF_INET, &snat->ip_snat.address.v4, buf, sizeof(buf));
284                 }
285
286                 if (snat->port_snat.set && proto && !proto->any &&
287                     (proto->protocol == 6 || proto->protocol == 17 || proto->protocol == 1))
288                 {
289                         if (snat->port_snat.port_min == snat->port_snat.port_max)
290                                 sprintf(buf + strlen(buf), ":%u", snat->port_snat.port_min);
291                         else
292                                 sprintf(buf + strlen(buf), ":%u-%u",
293                                                 snat->port_snat.port_min, snat->port_snat.port_max);
294
295                         if (snat->connlimit_ports) {
296                                 char portcntbuf[6];
297                                 snprintf(portcntbuf, sizeof(portcntbuf), "%u",
298                                                 1 + snat->port_snat.port_max - snat->port_snat.port_min);
299
300                                 fw3_ipt_rule_addarg(r, false, "-m", "connlimit");
301                                 fw3_ipt_rule_addarg(r, false, "--connlimit-daddr", NULL);
302                                 fw3_ipt_rule_addarg(r, false, "--connlimit-upto", portcntbuf);
303                         }
304                 }
305
306                 fw3_ipt_rule_target(r, "SNAT");
307                 fw3_ipt_rule_addarg(r, false, "--to-source", buf);
308         }
309         else if (snat->target == FW3_FLAG_ACCEPT)
310         {
311                 fw3_ipt_rule_target(r, "ACCEPT");
312         }
313         else
314         {
315                 fw3_ipt_rule_target(r, "MASQUERADE");
316         }
317 }
318
319 static void
320 set_comment(struct fw3_ipt_rule *r, const char *name, int num)
321 {
322         if (name)
323                 fw3_ipt_rule_comment(r, name);
324         else
325                 fw3_ipt_rule_comment(r, "@nat[%u]", num);
326 }
327
328 static void
329 print_snat(struct fw3_ipt_handle *h, struct fw3_state *state,
330            struct fw3_snat *snat, int num, struct fw3_protocol *proto)
331 {
332         struct fw3_ipt_rule *r;
333         struct fw3_address *src, *dst;
334         struct fw3_port *spt, *dpt;
335
336         switch (h->table)
337         {
338         case FW3_TABLE_NAT:
339                 src = &snat->ip_src;
340                 dst = &snat->ip_dest;
341                 spt = &snat->port_src;
342                 dpt = &snat->port_dest;
343
344                 r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst);
345                 fw3_ipt_rule_sport_dport(r, spt, dpt);
346                 fw3_ipt_rule_device(r, snat->device, true);
347                 fw3_ipt_rule_ipset(r, &snat->ipset);
348                 fw3_ipt_rule_limit(r, &snat->limit);
349                 fw3_ipt_rule_time(r, &snat->time);
350                 fw3_ipt_rule_mark(r, &snat->mark);
351                 set_target(r, snat, proto);
352                 fw3_ipt_rule_extra(r, snat->extra);
353                 set_comment(r, snat->name, num);
354                 append_chain(r, snat);
355                 break;
356
357         default:
358                 break;
359         }
360 }
361
362 static void
363 expand_snat(struct fw3_ipt_handle *handle, struct fw3_state *state,
364                 struct fw3_snat *snat, int num)
365 {
366         struct fw3_protocol *proto;
367
368         if (snat->name)
369                 info("   * NAT '%s'", snat->name);
370         else
371                 info("   * NAT #%u", num);
372
373         if (!fw3_is_family(snat->_src, handle->family))
374         {
375                 info("     ! Skipping due to different family of zone");
376                 return;
377         }
378
379         if (!fw3_is_family(&snat->ip_src, handle->family) ||
380             !fw3_is_family(&snat->ip_dest, handle->family) ||
381                 !fw3_is_family(&snat->ip_snat, handle->family))
382         {
383                 if (!snat->ip_src.resolved ||
384                     !snat->ip_dest.resolved ||
385                     !snat->ip_snat.resolved)
386                         info("     ! Skipping due to different family of ip address");
387
388                 return;
389         }
390
391         if (snat->ipset.ptr)
392         {
393                 if (!fw3_is_family(snat->ipset.ptr, handle->family))
394                 {
395                         info("     ! Skipping due to different family in ipset");
396                         return;
397                 }
398
399                 if (!fw3_check_ipset(snat->ipset.ptr))
400                 {
401                         info("     ! Skipping due to missing ipset '%s'",
402                              snat->ipset.ptr->external ?
403                                         snat->ipset.ptr->external : snat->ipset.ptr->name);
404                         return;
405                 }
406
407                 set(snat->ipset.ptr->flags, handle->family, handle->family);
408         }
409
410         fw3_foreach(proto, &snat->proto)
411                 print_snat(handle, state, snat, num, proto);
412 }
413
414 void
415 fw3_print_snats(struct fw3_ipt_handle *handle, struct fw3_state *state)
416 {
417         int num = 0;
418         struct fw3_snat *snat;
419
420         if (handle->family == FW3_FAMILY_V6)
421                 return;
422
423         if (handle->table != FW3_TABLE_NAT)
424                 return;
425
426         list_for_each_entry(snat, &state->snats, list)
427                 expand_snat(handle, state, snat, num++);
428 }