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 <arpa/nameser.h>
31 #include <libubox/usock.h>
32 #include <libubox/uloop.h>
33 #include <libubox/avl-cmp.h>
34 #include <libubox/blobmsg_json.h>
35 #include <libubox/kvlist.h>
41 #include "interface.h"
43 static struct uloop_timeout cache_gc;
44 struct avl_tree services;
45 AVL_TREE(records, avl_strcmp, true, NULL);
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_service_free(struct cache_service *s)
58 DBG(2, "%s\n", s->entry);
59 avl_delete(&services, &s->avl);
64 cache_is_expired(time_t t, uint32_t ttl, int frac)
66 if (monotonic_time() - t >= ttl * frac / 100)
73 cache_gc_timer(struct uloop_timeout *timeout)
75 struct cache_record *r, *p;
76 struct cache_service *s, *t;
78 avl_for_each_element_safe(&records, r, avl, p) {
79 if (!cache_is_expired(r->time, r->ttl, 100))
81 /* Records other and A(AAA) are handled as services */
82 if (r->type != TYPE_A && r->type != TYPE_AAAA) {
86 if (r->refresh >= 100) {
91 dns_send_question(r->iface, r->record, r->type, 0);
94 avl_for_each_element_safe(&services, s, avl, t) {
97 if (!cache_is_expired(s->time, s->ttl, s->refresh))
99 if (s->refresh >= 100) {
100 cache_service_free(s);
104 dns_send_question(s->iface, s->entry, TYPE_PTR, 0);
107 uloop_timeout_set(timeout, 10000);
113 avl_init(&services, avl_strcmp, true, NULL);
115 cache_gc.cb = cache_gc_timer;
116 uloop_timeout_set(&cache_gc, 10000);
121 void cache_cleanup(struct interface *iface)
123 struct cache_record *r, *p;
124 struct cache_service *s, *t;
126 avl_for_each_element_safe(&services, s, avl, t)
127 if (!iface || iface == s->iface)
128 cache_service_free(s);
130 avl_for_each_element_safe(&records, r, avl, p)
131 if (!iface || iface == r->iface)
132 cache_record_free(r);
138 struct interface *iface;
139 struct cache_service *s;
141 vlist_for_each_element(&interfaces, iface, node)
142 avl_for_each_element(&services, s, avl)
143 dns_send_question(iface, s->entry, TYPE_PTR, 0);
146 static struct cache_service*
147 cache_service(struct interface *iface, char *entry, int hlen, int ttl)
149 struct cache_service *s, *t;
154 avl_for_each_element_safe(&services, s, avl, t)
155 if (!strcmp(s->entry, entry)) {
157 s->time = monotonic_time();
162 s = calloc_a(sizeof(*s),
163 &entry_buf, strlen(entry) + 1,
164 &host_buf, hlen ? hlen + 1 : 0);
166 s->avl.key = s->entry = strcpy(entry_buf, entry);
167 s->time = monotonic_time();
173 s->host = strncpy(host_buf, s->entry, hlen);
175 type = strstr(entry_buf, "._");
180 avl_insert(&services, &s->avl);
183 dns_send_question(iface, entry, TYPE_PTR, iface->multicast);
188 static struct cache_record*
189 cache_record_find(char *record, int type, int port, int rdlength, uint8_t *rdata)
191 struct cache_record *l = avl_find_element(&records, record, l, avl);
196 while (l && l->record && !strcmp(l->record, record)) {
197 struct cache_record *r = l;
199 l = avl_next_element(l, avl);
203 if (r->type == TYPE_TXT || (r->type == TYPE_SRV))
209 if (r->rdlength != rdlength)
212 if (!!r->rdata != !!rdata)
215 if (!r->rdata || !rdata || memcmp(r->rdata, rdata, rdlength))
225 cache_host_is_known(char *record)
227 struct cache_record *l = avl_find_element(&records, record, l, avl);
232 while (l && !avl_is_last(&records, &l->avl) && !strcmp(l->record, record)) {
233 struct cache_record *r = l;
235 l = avl_next_element(l, avl);
236 if ((r->type != TYPE_A) && (r->type != TYPE_AAAA))
245 cache_answer(struct interface *iface, uint8_t *base, int blen, char *name, struct dns_answer *a, uint8_t *rdata, int flush)
247 struct dns_srv_data *dsd = (struct dns_srv_data *) rdata;
248 struct cache_record *r;
249 int port = 0, dlen = 0, tlen = 0, nlen, rdlength;
252 void *rdata_ptr, *txt_ptr;
254 static char *rdata_buffer = (char *) mdns_buf;
255 time_t now = monotonic_time();
264 if (dn_expand(base, base + blen, rdata, rdata_buffer, MAX_DATA_LEN) < 0) {
265 perror("process_answer/dn_expand");
269 DBG(1, "A -> %s %s %s ttl:%d\n", dns_type_string(a->type), name, rdata_buffer, a->ttl);
271 rdlength = strlen(rdata_buffer);
273 if (strcmp(C_DNS_SD, name) != 0 &&
274 nlen + 1 < rdlength && !strcmp(rdata_buffer + rdlength - nlen, name))
275 host_len = rdlength - nlen - 1;
278 cache_service(iface, rdata_buffer, host_len, a->ttl);
280 dlen = strlen(rdata_buffer) + 1;
281 rdata = (uint8_t*)rdata_buffer;
288 port = be16_to_cpu(dsd->port);
289 memcpy(rdata_buffer, dsd, sizeof(*dsd));
290 if (dn_expand(base, base + blen, (const uint8_t*)&dsd[1],
291 &rdata_buffer[sizeof(*dsd)], MAX_DATA_LEN - sizeof(*dsd)) < 0) {
292 perror("process_answer/dn_expand");
295 dlen = sizeof(*dsd) + strlen(&rdata_buffer[sizeof(*dsd)]) + 1;
296 rdata = (uint8_t*)rdata_buffer;
300 rdlength = a->rdlength;
304 memcpy(rdata_buffer, &rdata[1], rdlength);
305 rdata_buffer[rdlength] = rdata_buffer[rdlength + 1] = '\0';
307 p = &rdata_buffer[*rdata];
313 if (v && p + v < &rdata_buffer[rdlength])
319 if (a->rdlength != 4)
325 if (a->rdlength != 16)
334 r = cache_record_find(name, a->type, port, dlen, rdata);
337 DBG(1, "D -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
338 r->time = now + 1 - r->ttl;
342 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
350 r = calloc_a(sizeof(*r),
351 &name_buf, strlen(name) + 1,
355 r->avl.key = r->record = strcpy(name_buf, name);
364 r->txt = memcpy(txt_ptr, rdata_buffer, tlen);
367 r->rdata = memcpy(rdata_ptr, rdata, dlen);
369 if (avl_insert(&records, &r->avl))
372 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
376 cache_dump_records(struct blob_buf *buf, const char *name)
378 struct cache_record *r, *last, *next;
380 char buffer[INET6_ADDRSTRLEN];
382 last = avl_last_element(&records, last, avl);
383 for (r = avl_find_element(&records, name, r, avl); r; r = next) {
386 if (r->txt && strlen(r->txt)) {
389 blobmsg_add_string(buf, "txt", txt);
390 txt = &txt[strlen(txt) + 1];
397 blobmsg_add_u32(buf, "port", r->port);
401 if ((r->rdlength == 4) && inet_ntop(AF_INET, r->rdata, buffer, INET6_ADDRSTRLEN))
402 blobmsg_add_string(buf, "ipv4", buffer);
406 if ((r->rdlength == 16) && inet_ntop(AF_INET6, r->rdata, buffer, INET6_ADDRSTRLEN))
407 blobmsg_add_string(buf, "ipv6", buffer);
414 next = avl_next_element(r, avl);
415 if (strcmp(r->record, next->record) != 0)
421 cache_dump_recursive(struct blob_buf *b, const char *name, uint16_t type, struct interface *iface)
423 time_t now = monotonic_time();
424 for (struct cache_record *r = avl_find_ge_element(&records, name, r, avl);
425 r && !strcmp(r->record, name);
426 r = !avl_is_last(&records, &r->avl) ? avl_next_element(r, avl) : NULL) {
427 int32_t ttl = r->ttl - (now - r->time);
428 if (ttl <= 0 || (iface && iface->ifindex != r->iface->ifindex) ||
429 (type != TYPE_ANY && type != r->type))
433 char buf[INET6_ADDRSTRLEN];
434 void *k = blobmsg_open_table(b, NULL), *l;
435 const struct dns_srv_data *dsd = (const struct dns_srv_data*)r->rdata;
437 blobmsg_add_string(b, "name", r->record);
438 blobmsg_add_string(b, "type", dns_type_string(r->type));
439 blobmsg_add_u32(b, "ttl", ttl);
443 if ((txt = r->txt) && strlen(txt)) {
444 l = blobmsg_open_array(b, "data");
446 blobmsg_add_string(b, NULL, txt);
447 txt = &txt[strlen(txt) + 1];
449 blobmsg_close_array(b, l);
454 if (r->rdlength > sizeof(*dsd)) {
455 blobmsg_add_u32(b, "priority", be16_to_cpu(dsd->priority));
456 blobmsg_add_u32(b, "weight", be16_to_cpu(dsd->weight));
457 blobmsg_add_u32(b, "port", be16_to_cpu(dsd->port));
458 blobmsg_add_string(b, "target", (const char*)&dsd[1]);
464 blobmsg_add_string(b, "target", (const char*)r->rdata);
468 if ((r->rdlength == 4) && inet_ntop(AF_INET, r->rdata, buf, sizeof(buf)))
469 blobmsg_add_string(b, "target", buf);
473 if ((r->rdlength == 16) && inet_ntop(AF_INET6, r->rdata, buf, sizeof(buf)))
474 blobmsg_add_string(b, "target", buf);
478 blobmsg_close_table(b, k);
481 if (r->type == TYPE_PTR) {
482 cache_dump_recursive(b, (const char*)r->rdata, TYPE_SRV, iface);
483 cache_dump_recursive(b, (const char*)r->rdata, TYPE_TXT, iface);
486 if (r->type == TYPE_SRV) {
487 cache_dump_recursive(b, (const char*)&dsd[1], TYPE_A, iface);
488 cache_dump_recursive(b, (const char*)&dsd[1], TYPE_AAAA, iface);