4182016cbd3e20a6e6382a33be43d8a729097875
2 * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2.1
6 * as published by the Free Software Foundation
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
15 #include <sys/types.h>
23 #include <sys/types.h>
24 #include <sys/socket.h>
25 #include <netinet/in.h>
26 #include <arpa/inet.h>
27 #include <asm/byteorder.h>
28 #include <arpa/nameser.h>
32 #include <libubox/usock.h>
33 #include <libubox/uloop.h>
34 #include <libubox/avl-cmp.h>
35 #include <libubox/blobmsg_json.h>
36 #include <libubox/kvlist.h>
42 #include "interface.h"
44 static struct uloop_timeout cache_gc
;
45 struct avl_tree records
, entries
, hosts
;
48 cache_record_free(struct cache_record
*r
)
50 DBG(2, "%s %s\n", dns_type_string(r
->type
), r
->record
);
51 avl_delete(&records
, &r
->avl
);
56 cache_entry_free(struct cache_entry
*s
)
58 DBG(2, "%s\n", s
->entry
);
59 avl_delete(&entries
, &s
->avl
);
64 cache_is_expired(time_t t
, uint32_t ttl
)
66 if (time(NULL
) - t
>= ttl
)
73 cache_gc_timer(struct uloop_timeout
*timeout
)
75 struct cache_record
*r
, *p
;
76 struct cache_entry
*s
, *t
;
78 avl_for_each_element_safe(&records
, r
, avl
, p
)
79 if (cache_is_expired(r
->time
, r
->ttl
))
82 avl_for_each_element_safe(&entries
, s
, avl
, t
) {
85 if (cache_is_expired(s
->time
, s
->ttl
))
89 uloop_timeout_set(timeout
, 10000);
95 avl_init(&entries
, avl_strcmp
, true, NULL
);
96 avl_init(&records
, avl_strcmp
, true, NULL
);
98 cache_gc
.cb
= cache_gc_timer
;
99 uloop_timeout_set(&cache_gc
, 10000);
104 void cache_cleanup(void)
106 struct cache_record
*r
, *p
;
107 struct cache_entry
*s
, *t
;
109 avl_for_each_element_safe(&records
, r
, avl
, p
)
110 cache_record_free(r
);
112 avl_for_each_element_safe(&entries
, s
, avl
, t
)
119 struct cache_entry
*s
;
121 avl_for_each_element(&entries
, s
, avl
)
122 dns_send_question(cur_iface
, s
->entry
, TYPE_PTR
);
125 static struct cache_entry
*
126 cache_entry(struct uloop_fd
*u
, char *entry
, int hlen
, int ttl
)
128 struct cache_entry
*s
;
133 s
= avl_find_element(&entries
, entry
, s
, avl
);
137 s
= calloc_a(sizeof(*s
),
138 &entry_buf
, strlen(entry
) + 1,
139 &host_buf
, hlen
? hlen
+ 1 : 0);
141 s
->avl
.key
= s
->entry
= strcpy(entry_buf
, entry
);
142 s
->time
= time(NULL
);
146 s
->host
= strncpy(host_buf
, s
->entry
, hlen
);
148 type
= strstr(entry_buf
, "._");
153 avl_insert(&entries
, &s
->avl
);
156 dns_send_question(cur_iface
, entry
, TYPE_PTR
);
161 static struct cache_record
*
162 cache_record_find(char *record
, int type
, int port
, int rdlength
, uint8_t *rdata
)
164 struct cache_record
*l
= avl_find_element(&records
, record
, l
, avl
);
169 while (l
&& !avl_is_last(&records
, &l
->avl
) && !strcmp(l
->record
, record
)) {
170 struct cache_record
*r
= l
;
172 l
= avl_next_element(l
, avl
);
176 if (r
->type
== TYPE_TXT
|| (r
->type
== TYPE_SRV
))
182 if (r
->rdlength
!= rdlength
)
185 if (!!r
->rdata
!= !!rdata
)
188 if (!r
->rdata
|| !rdata
|| memcmp(r
->rdata
, rdata
, rdlength
))
198 cache_host_is_known(char *record
)
200 struct cache_record
*l
= avl_find_element(&records
, record
, l
, avl
);
205 while (l
&& !avl_is_last(&records
, &l
->avl
) && !strcmp(l
->record
, record
)) {
206 struct cache_record
*r
= l
;
208 l
= avl_next_element(l
, avl
);
209 if ((r
->type
!= TYPE_A
) && (r
->type
!= TYPE_AAAA
))
218 cache_answer(struct uloop_fd
*u
, uint8_t *base
, int blen
, char *name
, struct dns_answer
*a
, uint8_t *rdata
)
220 struct dns_srv_data
*dsd
= (struct dns_srv_data
*) rdata
;
221 struct cache_record
*r
;
222 int port
= 0, dlen
= 0, tlen
= 0, nlen
, rdlength
;
225 void *rdata_ptr
, *txt_ptr
;
228 if (!(a
->class & CLASS_IN
))
238 if (dn_expand(base
, base
+ blen
, rdata
, rdata_buffer
, MAX_DATA_LEN
) < 0) {
239 perror("process_answer/dn_expand");
243 DBG(1, "A -> %s %s %s\n", dns_type_string(a
->type
), name
, rdata_buffer
);
245 rdlength
= strlen(rdata_buffer
);
247 if (strcmp(C_DNS_SD
, name
) != 0 &&
248 nlen
+ 1 < rdlength
&& !strcmp(rdata_buffer
+ rdlength
- nlen
, name
))
249 host_len
= rdlength
- nlen
- 1;
251 cache_entry(u
, rdata_buffer
, host_len
, a
->ttl
);
258 port
= be16_to_cpu(dsd
->port
);
262 rdlength
= a
->rdlength
;
266 memcpy(rdata_buffer
, &rdata
[1], rdlength
);
267 rdata_buffer
[rdlength
] = rdata_buffer
[rdlength
+ 1] = '\0';
269 p
= &rdata_buffer
[*rdata
];
281 cache_entry(u
, name
, strlen(name
), a
->ttl
);
282 if (a
->rdlength
!= 4)
288 cache_entry(u
, name
, strlen(name
), a
->ttl
);
289 if (a
->rdlength
!= 16)
298 r
= cache_record_find(name
, a
->type
, port
, dlen
, rdata
);
301 cache_record_free(r
);
302 DBG(1, "D -> %s %s ttl:%d\n", dns_type_string(r
->type
), r
->record
, r
->ttl
);
305 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r
->type
), r
->record
, r
->ttl
);
313 r
= calloc_a(sizeof(*r
),
314 &name_buf
, strlen(name
) + 1,
318 r
->avl
.key
= r
->record
= strcpy(name_buf
, name
);
323 r
->time
= time(NULL
);
326 r
->txt
= memcpy(txt_ptr
, rdata_buffer
, tlen
);
329 r
->rdata
= memcpy(rdata_ptr
, rdata
, dlen
);
331 if (avl_insert(&records
, &r
->avl
))
334 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r
->type
), r
->record
, r
->ttl
);