3 * Resolver library with GLib integration
5 * Copyright (C) 2009-2010 Intel Corporation. All rights reserved.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
31 #include <sys/types.h>
32 #include <sys/socket.h>
34 #include <arpa/inet.h>
35 #include <arpa/nameser.h>
47 GResolvResultFunc result_func;
51 struct resolv_nameserver {
58 GIOChannel *udp_channel;
69 GList *nameserver_list;
71 struct __res_state res;
73 GResolvDebugFunc debug_func;
77 static inline void debug(GResolv *resolv, const char *format, ...)
82 if (resolv->debug_func == NULL)
87 if (vsnprintf(str, sizeof(str), format, ap) > 0)
88 resolv->debug_func(str, resolv->debug_data);
93 static void destroy_query(struct resolv_query *query)
95 if (query->timeout > 0)
96 g_source_remove(query->timeout);
101 static gboolean query_timeout(gpointer user_data)
103 struct resolv_query *query = user_data;
104 GResolv *resolv = query->resolv;
108 if (query->result_func != NULL)
109 query->result_func(G_RESOLV_RESULT_STATUS_NO_RESPONSE,
110 NULL, query->result_data);
112 destroy_query(query);
113 g_queue_remove(resolv->query_queue, query);
118 static void free_nameserver(struct resolv_nameserver *nameserver)
120 if (nameserver == NULL)
123 if (nameserver->udp_watch > 0)
124 g_source_remove(nameserver->udp_watch);
126 if (nameserver->udp_channel != NULL)
127 g_io_channel_unref(nameserver->udp_channel);
129 g_free(nameserver->address);
133 static void flush_nameservers(GResolv *resolv)
137 for (list = g_list_first(resolv->nameserver_list);
138 list; list = g_list_next(list))
139 free_nameserver(list->data);
141 g_list_free(resolv->nameserver_list);
142 resolv->nameserver_list = NULL;
145 static int send_query(GResolv *resolv, const unsigned char *buf, int len)
149 if (resolv->nameserver_list == NULL)
152 for (list = g_list_first(resolv->nameserver_list);
153 list; list = g_list_next(list)) {
154 struct resolv_nameserver *nameserver = list->data;
157 if (nameserver->udp_channel == NULL)
160 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
162 sent = send(sk, buf, len, 0);
168 static gint compare_query_id(gconstpointer a, gconstpointer b)
170 const struct resolv_query *query = a;
171 guint id = GPOINTER_TO_UINT(b);
182 static gint compare_query_msgid(gconstpointer a, gconstpointer b)
184 const struct resolv_query *query = a;
185 uint16_t msgid = GPOINTER_TO_UINT(b);
187 if (query->msgid < msgid)
190 if (query->msgid > msgid)
196 static void parse_response(struct resolv_nameserver *nameserver,
197 const unsigned char *buf, int len)
199 GResolv *resolv = nameserver->resolv;
200 GResolvResultStatus status;
205 int i, n, rcode, count;
207 debug(resolv, "response from %s", nameserver->address);
209 ns_initparse(buf, len, &msg);
211 rcode = ns_msg_getflag(msg, ns_f_rcode);
212 count = ns_msg_count(msg, ns_s_an);
214 debug(resolv, "msg id: 0x%04x rcode: %d count: %d",
215 ns_msg_id(msg), rcode, count);
219 status = G_RESOLV_RESULT_STATUS_SUCCESS;
222 status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR;
225 status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE;
228 status = G_RESOLV_RESULT_STATUS_NAME_ERROR;
231 status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED;
234 status = G_RESOLV_RESULT_STATUS_REFUSED;
237 status = G_RESOLV_RESULT_STATUS_ERROR;
241 results = g_try_new(char *, count + 1);
245 for (i = 0, n = 0; i < count; i++) {
248 ns_parserr(&msg, ns_s_an, i, &rr);
250 if (ns_rr_class(rr) != ns_c_in)
253 if (ns_rr_type(rr) == ns_t_a &&
254 ns_rr_rdlen(rr) == NS_INADDRSZ) {
255 inet_ntop(AF_INET, ns_rr_rdata(rr), result, sizeof(result));
256 } else if (ns_rr_type(rr) == ns_t_aaaa &&
257 ns_rr_rdlen(rr) == NS_IN6ADDRSZ) {
258 inet_ntop(AF_INET6, ns_rr_rdata(rr), result, sizeof(result));
262 results[n++] = g_strdup(result);
267 list = g_queue_find_custom(resolv->query_queue,
268 GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid);
271 struct resolv_query *query = list->data;
273 /* FIXME: This set of results is *only* for a single A or AAAA
274 query; we need to merge both results together and then sort
275 them according to RFC3484. While honouring /etc/gai.conf */
276 if (query->result_func != NULL)
277 query->result_func(status, results,
280 destroy_query(query);
281 g_queue_remove(resolv->query_queue, query);
287 static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond,
290 struct resolv_nameserver *nameserver = user_data;
291 unsigned char buf[4096];
294 if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
295 nameserver->udp_watch = 0;
299 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
301 len = recv(sk, buf, sizeof(buf), 0);
305 parse_response(nameserver, buf, len);
310 static int connect_udp_channel(struct resolv_nameserver *nameserver)
312 struct addrinfo hints, *rp;
316 memset(&hints, 0, sizeof(hints));
317 hints.ai_family = AF_UNSPEC;
318 hints.ai_socktype = SOCK_DGRAM;
319 hints.ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_NUMERICHOST;
321 sprintf(portnr, "%d", nameserver->port);
322 err = getaddrinfo(nameserver->address, portnr, &hints, &rp);
326 /* Do not blindly copy this code elsewhere; it doesn't loop over the
327 results using ->ai_next as it should. That's OK in *this* case
328 because it was a numeric lookup; we *know* there's only one. */
332 sk = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
338 if (connect(sk, rp->ai_addr, rp->ai_addrlen) < 0) {
346 nameserver->udp_channel = g_io_channel_unix_new(sk);
347 if (nameserver->udp_channel == NULL) {
352 g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
354 nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
355 G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
356 received_udp_data, nameserver);
361 GResolv *g_resolv_new(int index)
368 resolv = g_try_new0(GResolv, 1);
372 resolv->ref_count = 1;
374 resolv->next_query_id = 1;
375 resolv->query_queue = g_queue_new();
377 if (resolv->query_queue == NULL) {
382 resolv->index = index;
383 resolv->nameserver_list = NULL;
385 res_ninit(&resolv->res);
390 GResolv *g_resolv_ref(GResolv *resolv)
395 g_atomic_int_inc(&resolv->ref_count);
400 void g_resolv_unref(GResolv *resolv)
402 struct resolv_query *query;
407 if (g_atomic_int_dec_and_test(&resolv->ref_count) == FALSE)
410 while ((query = g_queue_pop_head(resolv->query_queue)))
411 destroy_query(query);
413 g_queue_free(resolv->query_queue);
415 flush_nameservers(resolv);
417 res_nclose(&resolv->res);
422 void g_resolv_set_debug(GResolv *resolv,
423 GResolvDebugFunc func, gpointer user_data)
428 resolv->debug_func = func;
429 resolv->debug_data = user_data;
432 gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address,
433 uint16_t port, unsigned long flags)
435 struct resolv_nameserver *nameserver;
440 nameserver = g_try_new0(struct resolv_nameserver, 1);
441 if (nameserver == NULL)
444 nameserver->address = g_strdup(address);
445 nameserver->port = port;
446 nameserver->flags = flags;
448 if (connect_udp_channel(nameserver) < 0) {
449 free_nameserver(nameserver);
453 nameserver->resolv = resolv;
455 resolv->nameserver_list = g_list_append(resolv->nameserver_list,
458 debug(resolv, "setting nameserver %s", address);
463 void g_resolv_flush_nameservers(GResolv *resolv)
468 flush_nameservers(resolv);
471 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
472 GResolvResultFunc func, gpointer user_data)
474 struct resolv_query *query;
475 unsigned char buf[4096];
478 debug(resolv, "lookup hostname %s", hostname);
483 if (resolv->nameserver_list == NULL) {
486 for (i = 0; i < resolv->res.nscount; i++) {
488 int family = resolv->res.nsaddr_list[i].sin_family;
489 void *sa_addr = &resolv->res.nsaddr_list[i].sin_addr;
491 if (family != AF_INET && resolv->res._u._ext.nsaddrs[i]) {
493 sa_addr = &resolv->res._u._ext.nsaddrs[i]->sin6_addr;
495 if (family != AF_INET && family != AF_INET6)
498 if (inet_ntop(family, sa_addr, buf, sizeof(buf)))
499 g_resolv_add_nameserver(resolv, buf, 53, 0);
502 if (resolv->nameserver_list == NULL)
503 g_resolv_add_nameserver(resolv, "127.0.0.1", 53, 0);
506 query = g_try_new0(struct resolv_query, 1);
510 query->id = resolv->next_query_id++;
512 /* FIXME: Send ns_t_aaaa query too, and see the FIXME in
513 parse_response() re merging and sorting the results */
514 len = res_mkquery(ns_o_query, hostname, ns_c_in, ns_t_a,
515 NULL, 0, NULL, buf, sizeof(buf));
517 query->msgid = buf[0] << 8 | buf[1];
519 query->result_func = func;
520 query->result_data = user_data;
522 if (send_query(resolv, buf, len) < 0) {
527 query->resolv = resolv;
529 g_queue_push_tail(resolv->query_queue, query);
531 query->timeout = g_timeout_add_seconds(5, query_timeout, query);
536 gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id)
540 list = g_queue_find_custom(resolv->query_queue,
541 GUINT_TO_POINTER(id), compare_query_id);
546 destroy_query(list->data);
547 g_queue_remove(resolv->query_queue, list->data);