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>
43 static struct uloop_timeout cache_gc
;
44 struct avl_tree records
, entries
, hosts
;
47 cache_record_free(struct cache_record
*r
)
49 DBG(2, "%s %s\n", dns_type_string(r
->type
), r
->record
);
50 avl_delete(&records
, &r
->avl
);
55 cache_entry_free(struct cache_entry
*s
)
57 DBG(2, "%s\n", s
->entry
);
58 avl_delete(&entries
, &s
->avl
);
63 cache_is_expired(time_t t
, uint32_t ttl
)
65 if (time(NULL
) - t
>= ttl
)
72 cache_gc_timer(struct uloop_timeout
*timeout
)
74 struct cache_record
*r
, *p
;
75 struct cache_entry
*s
, *t
;
77 avl_for_each_element_safe(&records
, r
, avl
, p
)
78 if (cache_is_expired(r
->time
, r
->ttl
))
81 avl_for_each_element_safe(&entries
, s
, avl
, t
) {
84 if (cache_is_expired(s
->time
, s
->ttl
))
88 uloop_timeout_set(timeout
, 10000);
94 avl_init(&entries
, avl_strcmp
, true, NULL
);
95 avl_init(&records
, avl_strcmp
, true, NULL
);
97 cache_gc
.cb
= cache_gc_timer
;
98 uloop_timeout_set(&cache_gc
, 10000);
103 void cache_cleanup(void)
105 struct cache_record
*r
, *p
;
106 struct cache_entry
*s
, *t
;
108 avl_for_each_element_safe(&records
, r
, avl
, p
)
109 cache_record_free(r
);
111 avl_for_each_element_safe(&entries
, s
, avl
, t
)
118 struct cache_entry
*s
;
120 avl_for_each_element(&entries
, s
, avl
)
121 dns_send_question(&listener
, s
->entry
, TYPE_PTR
);
124 static struct cache_entry
*
125 cache_entry(struct uloop_fd
*u
, char *entry
, int hlen
, int ttl
)
127 struct cache_entry
*s
;
132 s
= avl_find_element(&entries
, entry
, s
, avl
);
136 s
= calloc_a(sizeof(*s
),
137 &entry_buf
, strlen(entry
) + 1,
138 &host_buf
, hlen
? hlen
+ 1 : 0);
140 s
->avl
.key
= s
->entry
= strcpy(entry_buf
, entry
);
141 s
->time
= time(NULL
);
145 s
->host
= strncpy(host_buf
, s
->entry
, hlen
);
147 type
= strstr(entry_buf
, "._");
152 avl_insert(&entries
, &s
->avl
);
155 dns_send_question(u
, entry
, TYPE_PTR
);
160 static struct cache_record
*
161 cache_record_find(char *record
, int type
, int port
, int rdlength
, uint8_t *rdata
)
163 struct cache_record
*l
= avl_find_element(&records
, record
, l
, avl
);
168 while (l
&& !avl_is_last(&records
, &l
->avl
) && !strcmp(l
->record
, record
)) {
169 struct cache_record
*r
= l
;
171 l
= avl_next_element(l
, avl
);
175 if (r
->type
== TYPE_TXT
|| (r
->type
== TYPE_SRV
))
181 if (r
->rdlength
!= rdlength
)
184 if (!!r
->rdata
!= !!rdata
)
187 if (!r
->rdata
|| !rdata
|| memcmp(r
->rdata
, rdata
, rdlength
))
197 cache_host_is_known(char *record
)
199 struct cache_record
*l
= avl_find_element(&records
, record
, l
, avl
);
204 while (l
&& !avl_is_last(&records
, &l
->avl
) && !strcmp(l
->record
, record
)) {
205 struct cache_record
*r
= l
;
207 l
= avl_next_element(l
, avl
);
208 if ((r
->type
!= TYPE_A
) && (r
->type
!= TYPE_AAAA
))
217 cache_answer(struct uloop_fd
*u
, uint8_t *base
, int blen
, char *name
, struct dns_answer
*a
, uint8_t *rdata
)
219 struct dns_srv_data
*dsd
= (struct dns_srv_data
*) rdata
;
220 struct cache_record
*r
;
221 int port
= 0, dlen
= 0, tlen
= 0, nlen
, rdlength
;
224 void *rdata_ptr
, *txt_ptr
;
227 if (!(a
->class & CLASS_IN
))
237 if (dn_expand(base
, base
+ blen
, rdata
, rdata_buffer
, MAX_DATA_LEN
) < 0) {
238 perror("process_answer/dn_expand");
242 DBG(1, "A -> %s %s %s\n", dns_type_string(a
->type
), name
, rdata_buffer
);
244 rdlength
= strlen(rdata_buffer
);
246 if (strcmp(C_DNS_SD
, name
) != 0 &&
247 nlen
+ 1 < rdlength
&& !strcmp(rdata_buffer
+ rdlength
- nlen
, name
))
248 host_len
= rdlength
- nlen
- 1;
250 cache_entry(u
, rdata_buffer
, host_len
, a
->ttl
);
257 port
= be16_to_cpu(dsd
->port
);
261 rdlength
= a
->rdlength
;
265 memcpy(rdata_buffer
, &rdata
[1], rdlength
);
266 rdata_buffer
[rdlength
] = rdata_buffer
[rdlength
+ 1] = '\0';
268 p
= &rdata_buffer
[*rdata
];
280 cache_entry(u
, name
, strlen(name
), a
->ttl
);
281 if (a
->rdlength
!= 4)
287 cache_entry(u
, name
, strlen(name
), a
->ttl
);
288 if (a
->rdlength
!= 16)
297 r
= cache_record_find(name
, a
->type
, port
, dlen
, rdata
);
300 cache_record_free(r
);
301 DBG(1, "D -> %s %s ttl:%d\n", dns_type_string(r
->type
), r
->record
, r
->ttl
);
304 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r
->type
), r
->record
, r
->ttl
);
312 r
= calloc_a(sizeof(*r
),
313 &name_buf
, strlen(name
) + 1,
317 r
->avl
.key
= r
->record
= strcpy(name_buf
, name
);
322 r
->time
= time(NULL
);
325 r
->txt
= memcpy(txt_ptr
, rdata_buffer
, tlen
);
328 r
->rdata
= memcpy(rdata_ptr
, rdata
, dlen
);
330 if (avl_insert(&records
, &r
->avl
))
333 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r
->type
), r
->record
, r
->ttl
);