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 entries;
46 static AVL_TREE(records, avl_strcmp, true, NULL);
49 cache_record_free(struct cache_record *r)
51 DBG(2, "%s %s\n", dns_type_string(r->type), r->record);
52 avl_delete(&records, &r->avl);
57 cache_entry_free(struct cache_entry *s)
59 DBG(2, "%s\n", s->entry);
60 avl_delete(&entries, &s->avl);
65 cache_is_expired(time_t t, uint32_t ttl)
67 if (time(NULL) - t >= ttl)
74 cache_gc_timer(struct uloop_timeout *timeout)
76 struct cache_record *r, *p;
77 struct cache_entry *s, *t;
79 avl_for_each_element_safe(&records, r, avl, p)
80 if (cache_is_expired(r->time, r->ttl))
83 avl_for_each_element_safe(&entries, s, avl, t) {
86 if (cache_is_expired(s->time, s->ttl))
90 uloop_timeout_set(timeout, 10000);
96 avl_init(&entries, 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 interface *iface;
120 struct cache_entry *s;
122 vlist_for_each_element(&interfaces, iface, node)
123 avl_for_each_element(&entries, s, avl)
124 dns_send_question(iface, s->entry, TYPE_PTR);
127 static struct cache_entry*
128 cache_entry(struct interface *iface, char *entry, int hlen, int ttl)
130 struct cache_entry *s;
135 s = avl_find_element(&entries, entry, s, avl);
139 s = calloc_a(sizeof(*s),
140 &entry_buf, strlen(entry) + 1,
141 &host_buf, hlen ? hlen + 1 : 0);
143 s->avl.key = s->entry = strcpy(entry_buf, entry);
144 s->time = time(NULL);
148 s->host = strncpy(host_buf, s->entry, hlen);
150 type = strstr(entry_buf, "._");
155 avl_insert(&entries, &s->avl);
158 dns_send_question(iface, entry, TYPE_PTR);
163 static struct cache_record*
164 cache_record_find(char *record, int type, int port, int rdlength, uint8_t *rdata)
166 struct cache_record *l = avl_find_element(&records, record, l, avl);
171 while (l && !avl_is_last(&records, &l->avl) && !strcmp(l->record, record)) {
172 struct cache_record *r = l;
174 l = avl_next_element(l, avl);
178 if (r->type == TYPE_TXT || (r->type == TYPE_SRV))
184 if (r->rdlength != rdlength)
187 if (!!r->rdata != !!rdata)
190 if (!r->rdata || !rdata || memcmp(r->rdata, rdata, rdlength))
200 cache_host_is_known(char *record)
202 struct cache_record *l = avl_find_element(&records, record, l, avl);
207 while (l && !avl_is_last(&records, &l->avl) && !strcmp(l->record, record)) {
208 struct cache_record *r = l;
210 l = avl_next_element(l, avl);
211 if ((r->type != TYPE_A) && (r->type != TYPE_AAAA))
220 cache_answer(struct interface *iface, uint8_t *base, int blen, char *name, struct dns_answer *a, uint8_t *rdata)
222 struct dns_srv_data *dsd = (struct dns_srv_data *) rdata;
223 struct cache_record *r;
224 int port = 0, dlen = 0, tlen = 0, nlen, rdlength;
227 void *rdata_ptr, *txt_ptr;
229 static char *rdata_buffer = (char *) mdns_buf;
231 if (!(a->class & CLASS_IN))
241 if (dn_expand(base, base + blen, rdata, rdata_buffer, MAX_DATA_LEN) < 0) {
242 perror("process_answer/dn_expand");
246 DBG(1, "A -> %s %s %s\n", dns_type_string(a->type), name, rdata_buffer);
248 rdlength = strlen(rdata_buffer);
250 if (strcmp(C_DNS_SD, name) != 0 &&
251 nlen + 1 < rdlength && !strcmp(rdata_buffer + rdlength - nlen, name))
252 host_len = rdlength - nlen - 1;
254 cache_entry(iface, rdata_buffer, host_len, a->ttl);
261 port = be16_to_cpu(dsd->port);
265 rdlength = a->rdlength;
269 memcpy(rdata_buffer, &rdata[1], rdlength);
270 rdata_buffer[rdlength] = rdata_buffer[rdlength + 1] = '\0';
272 p = &rdata_buffer[*rdata];
284 cache_entry(iface, name, strlen(name), a->ttl);
285 if (a->rdlength != 4)
291 cache_entry(iface, name, strlen(name), a->ttl);
292 if (a->rdlength != 16)
301 r = cache_record_find(name, a->type, port, dlen, rdata);
304 cache_record_free(r);
305 DBG(1, "D -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
308 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
316 r = calloc_a(sizeof(*r),
317 &name_buf, strlen(name) + 1,
321 r->avl.key = r->record = strcpy(name_buf, name);
326 r->time = time(NULL);
329 r->txt = memcpy(txt_ptr, rdata_buffer, tlen);
332 r->rdata = memcpy(rdata_ptr, rdata, dlen);
334 if (avl_insert(&records, &r->avl))
337 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
341 cache_dump_records(struct blob_buf *buf, const char *name)
343 struct cache_record *r, *last, *next;
345 char buffer[INET6_ADDRSTRLEN];
347 last = avl_last_element(&records, last, avl);
348 for (r = avl_find_element(&records, name, r, avl); r; r = next) {
351 if (r->txt && strlen(r->txt)) {
354 blobmsg_add_string(buf, "txt", txt);
355 txt = &txt[strlen(txt) + 1];
362 blobmsg_add_u32(buf, "port", r->port);
366 if ((r->rdlength == 4) && inet_ntop(AF_INET, r->rdata, buffer, INET6_ADDRSTRLEN))
367 blobmsg_add_string(buf, "ipv4", buffer);
371 if ((r->rdlength == 16) && inet_ntop(AF_INET6, r->rdata, buffer, INET6_ADDRSTRLEN))
372 blobmsg_add_string(buf, "ipv6", buffer);
379 next = avl_next_element(r, avl);
380 if (strcmp(r->record, next->record) != 0)