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 static 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))
82 avl_for_each_element_safe(&services, s, avl, t) {
85 if (!cache_is_expired(s->time, s->ttl, s->refresh))
87 if (s->refresh >= 100) {
88 cache_service_free(s);
92 dns_send_question(s->iface, s->entry, TYPE_PTR, 0);
95 uloop_timeout_set(timeout, 10000);
101 avl_init(&services, avl_strcmp, true, NULL);
103 cache_gc.cb = cache_gc_timer;
104 uloop_timeout_set(&cache_gc, 10000);
109 void cache_cleanup(struct interface *iface)
111 struct cache_record *r, *p;
112 struct cache_service *s, *t;
114 avl_for_each_element_safe(&services, s, avl, t)
115 if (!iface || iface == s->iface)
116 cache_service_free(s);
118 avl_for_each_element_safe(&records, r, avl, p)
119 if (!iface || iface == r->iface)
120 cache_record_free(r);
126 struct interface *iface;
127 struct cache_service *s;
129 vlist_for_each_element(&interfaces, iface, node)
130 avl_for_each_element(&services, s, avl)
131 dns_send_question(iface, s->entry, TYPE_PTR, 0);
134 static struct cache_service*
135 cache_service(struct interface *iface, char *entry, int hlen, int ttl)
137 struct cache_service *s, *t;
142 avl_for_each_element_safe(&services, s, avl, t)
143 if (!strcmp(s->entry, entry)) {
145 s->time = monotonic_time();
150 s = calloc_a(sizeof(*s),
151 &entry_buf, strlen(entry) + 1,
152 &host_buf, hlen ? hlen + 1 : 0);
154 s->avl.key = s->entry = strcpy(entry_buf, entry);
155 s->time = monotonic_time();
161 s->host = strncpy(host_buf, s->entry, hlen);
163 type = strstr(entry_buf, "._");
168 avl_insert(&services, &s->avl);
171 dns_send_question(iface, entry, TYPE_PTR, iface->multicast);
176 static struct cache_record*
177 cache_record_find(char *record, int type, int port, int rdlength, uint8_t *rdata)
179 struct cache_record *l = avl_find_element(&records, record, l, avl);
184 while (l && l->record && !strcmp(l->record, record)) {
185 struct cache_record *r = l;
187 l = avl_next_element(l, avl);
191 if (r->type == TYPE_TXT || (r->type == TYPE_SRV))
197 if (r->rdlength != rdlength)
200 if (!!r->rdata != !!rdata)
203 if (!r->rdata || !rdata || memcmp(r->rdata, rdata, rdlength))
213 cache_host_is_known(char *record)
215 struct cache_record *l = avl_find_element(&records, record, l, avl);
220 while (l && !avl_is_last(&records, &l->avl) && !strcmp(l->record, record)) {
221 struct cache_record *r = l;
223 l = avl_next_element(l, avl);
224 if ((r->type != TYPE_A) && (r->type != TYPE_AAAA))
233 cache_answer(struct interface *iface, uint8_t *base, int blen, char *name, struct dns_answer *a, uint8_t *rdata, int flush)
235 struct dns_srv_data *dsd = (struct dns_srv_data *) rdata;
236 struct cache_record *r;
237 int port = 0, dlen = 0, tlen = 0, nlen, rdlength;
240 void *rdata_ptr, *txt_ptr;
242 static char *rdata_buffer = (char *) mdns_buf;
243 time_t now = monotonic_time();
252 if (dn_expand(base, base + blen, rdata, rdata_buffer, MAX_DATA_LEN) < 0) {
253 perror("process_answer/dn_expand");
257 DBG(1, "A -> %s %s %s ttl:%d\n", dns_type_string(a->type), name, rdata_buffer, a->ttl);
259 rdlength = strlen(rdata_buffer);
261 if (strcmp(C_DNS_SD, name) != 0 &&
262 nlen + 1 < rdlength && !strcmp(rdata_buffer + rdlength - nlen, name))
263 host_len = rdlength - nlen - 1;
265 cache_service(iface, rdata_buffer, host_len, a->ttl);
267 dlen = strlen(rdata_buffer) + 1;
268 rdata = (uint8_t*)rdata_buffer;
275 port = be16_to_cpu(dsd->port);
276 memcpy(rdata_buffer, dsd, sizeof(*dsd));
277 if (dn_expand(base, base + blen, (const uint8_t*)&dsd[1],
278 &rdata_buffer[sizeof(*dsd)], MAX_DATA_LEN - sizeof(*dsd)) < 0) {
279 perror("process_answer/dn_expand");
282 dlen = sizeof(*dsd) + strlen(&rdata_buffer[sizeof(*dsd)]) + 1;
283 rdata = (uint8_t*)rdata_buffer;
287 rdlength = a->rdlength;
291 memcpy(rdata_buffer, &rdata[1], rdlength);
292 rdata_buffer[rdlength] = rdata_buffer[rdlength + 1] = '\0';
294 p = &rdata_buffer[*rdata];
300 if (v && p + v < &rdata_buffer[rdlength])
306 cache_service(iface, name, strlen(name), a->ttl);
307 if (a->rdlength != 4)
313 cache_service(iface, name, strlen(name), a->ttl);
314 if (a->rdlength != 16)
323 r = cache_record_find(name, a->type, port, dlen, rdata);
326 DBG(1, "D -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
327 r->time = now + 1 - r->ttl;
331 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
339 r = calloc_a(sizeof(*r),
340 &name_buf, strlen(name) + 1,
344 r->avl.key = r->record = strcpy(name_buf, name);
353 r->txt = memcpy(txt_ptr, rdata_buffer, tlen);
356 r->rdata = memcpy(rdata_ptr, rdata, dlen);
358 if (avl_insert(&records, &r->avl))
361 DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
365 cache_dump_records(struct blob_buf *buf, const char *name)
367 struct cache_record *r, *last, *next;
369 char buffer[INET6_ADDRSTRLEN];
371 last = avl_last_element(&records, last, avl);
372 for (r = avl_find_element(&records, name, r, avl); r; r = next) {
375 if (r->txt && strlen(r->txt)) {
378 blobmsg_add_string(buf, "txt", txt);
379 txt = &txt[strlen(txt) + 1];
386 blobmsg_add_u32(buf, "port", r->port);
390 if ((r->rdlength == 4) && inet_ntop(AF_INET, r->rdata, buffer, INET6_ADDRSTRLEN))
391 blobmsg_add_string(buf, "ipv4", buffer);
395 if ((r->rdlength == 16) && inet_ntop(AF_INET6, r->rdata, buffer, INET6_ADDRSTRLEN))
396 blobmsg_add_string(buf, "ipv6", buffer);
403 next = avl_next_element(r, avl);
404 if (strcmp(r->record, next->record) != 0)
410 cache_dump_recursive(struct blob_buf *b, const char *name, uint16_t type, struct interface *iface)
412 time_t now = monotonic_time();
413 for (struct cache_record *r = avl_find_ge_element(&records, name, r, avl);
414 r && !strcmp(r->record, name);
415 r = !avl_is_last(&records, &r->avl) ? avl_next_element(r, avl) : NULL) {
416 int32_t ttl = r->ttl - (now - r->time);
417 if (ttl <= 0 || (iface && iface->ifindex != r->iface->ifindex) ||
418 (type != TYPE_ANY && type != r->type))
422 char buf[INET6_ADDRSTRLEN];
423 void *k = blobmsg_open_table(b, NULL), *l;
424 const struct dns_srv_data *dsd = (const struct dns_srv_data*)r->rdata;
426 blobmsg_add_string(b, "name", r->record);
427 blobmsg_add_string(b, "type", dns_type_string(r->type));
428 blobmsg_add_u32(b, "ttl", ttl);
432 if ((txt = r->txt) && strlen(txt)) {
433 l = blobmsg_open_array(b, "data");
435 blobmsg_add_string(b, NULL, txt);
436 txt = &txt[strlen(txt) + 1];
438 blobmsg_close_array(b, l);
443 if (r->rdlength > sizeof(*dsd)) {
444 blobmsg_add_u32(b, "priority", be16_to_cpu(dsd->priority));
445 blobmsg_add_u32(b, "weight", be16_to_cpu(dsd->weight));
446 blobmsg_add_u32(b, "port", be16_to_cpu(dsd->port));
447 blobmsg_add_string(b, "target", (const char*)&dsd[1]);
453 blobmsg_add_string(b, "target", (const char*)r->rdata);
457 if ((r->rdlength == 4) && inet_ntop(AF_INET, r->rdata, buf, sizeof(buf)))
458 blobmsg_add_string(b, "target", buf);
462 if ((r->rdlength == 16) && inet_ntop(AF_INET6, r->rdata, buf, sizeof(buf)))
463 blobmsg_add_string(b, "target", buf);
467 blobmsg_close_table(b, k);
470 if (r->type == TYPE_PTR) {
471 cache_dump_recursive(b, (const char*)r->rdata, TYPE_SRV, iface);
472 cache_dump_recursive(b, (const char*)r->rdata, TYPE_TXT, iface);
475 if (r->type == TYPE_SRV) {
476 cache_dump_recursive(b, (const char*)&dsd[1], TYPE_A, iface);
477 cache_dump_recursive(b, (const char*)&dsd[1], TYPE_AAAA, iface);