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);