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/socket.h>
32 #include <arpa/inet.h>
33 #include <arpa/nameser.h>
45 GResolvResultFunc result_func;
49 struct resolv_nameserver {
56 GIOChannel *udp_channel;
67 GList *nameserver_list;
69 struct __res_state res;
71 GResolvDebugFunc debug_func;
75 static inline void debug(GResolv *resolv, const char *format, ...)
80 if (resolv->debug_func == NULL)
85 if (vsnprintf(str, sizeof(str), format, ap) > 0)
86 resolv->debug_func(str, resolv->debug_data);
91 static void destroy_query(struct resolv_query *query)
93 if (query->timeout > 0)
94 g_source_remove(query->timeout);
99 static gboolean query_timeout(gpointer user_data)
101 struct resolv_query *query = user_data;
102 GResolv *resolv = query->resolv;
106 if (query->result_func != NULL)
107 query->result_func(G_RESOLV_RESULT_STATUS_NO_RESPONSE,
108 NULL, query->result_data);
110 destroy_query(query);
111 g_queue_remove(resolv->query_queue, query);
116 static void free_nameserver(struct resolv_nameserver *nameserver)
118 if (nameserver == NULL)
121 if (nameserver->udp_watch > 0)
122 g_source_remove(nameserver->udp_watch);
124 if (nameserver->udp_channel != NULL)
125 g_io_channel_unref(nameserver->udp_channel);
127 g_free(nameserver->address);
131 static void flush_nameservers(GResolv *resolv)
135 for (list = g_list_first(resolv->nameserver_list);
136 list; list = g_list_next(list))
137 free_nameserver(list->data);
139 g_list_free(resolv->nameserver_list);
140 resolv->nameserver_list = NULL;
143 static int send_query(GResolv *resolv, const unsigned char *buf, int len)
147 if (resolv->nameserver_list == NULL)
150 for (list = g_list_first(resolv->nameserver_list);
151 list; list = g_list_next(list)) {
152 struct resolv_nameserver *nameserver = list->data;
155 if (nameserver->udp_channel == NULL)
158 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
160 sent = send(sk, buf, len, 0);
166 static gint compare_query_id(gconstpointer a, gconstpointer b)
168 const struct resolv_query *query = a;
169 guint id = GPOINTER_TO_UINT(b);
180 static gint compare_query_msgid(gconstpointer a, gconstpointer b)
182 const struct resolv_query *query = a;
183 uint16_t msgid = GPOINTER_TO_UINT(b);
185 if (query->msgid < msgid)
188 if (query->msgid > msgid)
194 static void parse_response(struct resolv_nameserver *nameserver,
195 const unsigned char *buf, int len)
197 GResolv *resolv = nameserver->resolv;
198 GResolvResultStatus status;
203 int i, n, rcode, count;
205 debug(resolv, "response from %s", nameserver->address);
207 ns_initparse(buf, len, &msg);
209 rcode = ns_msg_getflag(msg, ns_f_rcode);
210 count = ns_msg_count(msg, ns_s_an);
212 debug(resolv, "msg id: 0x%04x rcode: %d count: %d",
213 ns_msg_id(msg), rcode, count);
217 status = G_RESOLV_RESULT_STATUS_SUCCESS;
220 status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR;
223 status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE;
226 status = G_RESOLV_RESULT_STATUS_NAME_ERROR;
229 status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED;
232 status = G_RESOLV_RESULT_STATUS_REFUSED;
235 status = G_RESOLV_RESULT_STATUS_ERROR;
239 results = g_try_new(char *, count + 1);
243 for (i = 0, n = 0; i < count; i++) {
246 ns_parserr(&msg, ns_s_an, i, &rr);
248 if (ns_rr_class(rr) != ns_c_in)
251 if (ns_rr_type(rr) != ns_t_a)
254 if (ns_rr_rdlen(rr) != NS_INADDRSZ)
257 inet_ntop(AF_INET, ns_rr_rdata(rr), result, sizeof(result));
259 results[n++] = g_strdup(result);
264 list = g_queue_find_custom(resolv->query_queue,
265 GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid);
268 struct resolv_query *query = list->data;
270 if (query->result_func != NULL)
271 query->result_func(status, results,
274 destroy_query(query);
275 g_queue_remove(resolv->query_queue, query);
281 static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond,
284 struct resolv_nameserver *nameserver = user_data;
285 unsigned char buf[4096];
288 if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
289 nameserver->udp_watch = 0;
293 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
295 len = recv(sk, buf, sizeof(buf), 0);
299 parse_response(nameserver, buf, len);
304 static int connect_udp_channel(struct resolv_nameserver *nameserver)
306 struct sockaddr_in sin;
309 sk = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
313 memset(&sin, 0, sizeof(sin));
314 sin.sin_family = AF_INET;
315 sin.sin_port = htons(nameserver->port);
316 sin.sin_addr.s_addr = inet_addr(nameserver->address);
318 if (connect(sk, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
323 nameserver->udp_channel = g_io_channel_unix_new(sk);
324 if (nameserver->udp_channel == NULL) {
329 g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
331 nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
332 G_IO_IN, received_udp_data,
338 GResolv *g_resolv_new(int index)
345 resolv = g_try_new0(GResolv, 1);
349 resolv->ref_count = 1;
351 resolv->next_query_id = 1;
352 resolv->query_queue = g_queue_new();
354 if (resolv->query_queue == NULL) {
359 resolv->index = index;
360 resolv->nameserver_list = NULL;
362 res_ninit(&resolv->res);
367 GResolv *g_resolv_ref(GResolv *resolv)
372 g_atomic_int_inc(&resolv->ref_count);
377 void g_resolv_unref(GResolv *resolv)
379 struct resolv_query *query;
384 if (g_atomic_int_dec_and_test(&resolv->ref_count) == FALSE)
387 while ((query = g_queue_pop_head(resolv->query_queue)))
388 destroy_query(query);
390 g_queue_free(resolv->query_queue);
392 flush_nameservers(resolv);
394 res_nclose(&resolv->res);
399 void g_resolv_set_debug(GResolv *resolv,
400 GResolvDebugFunc func, gpointer user_data)
405 resolv->debug_func = func;
406 resolv->debug_data = user_data;
409 gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address,
410 uint16_t port, unsigned long flags)
412 struct resolv_nameserver *nameserver;
417 nameserver = g_try_new0(struct resolv_nameserver, 1);
418 if (nameserver == NULL)
421 nameserver->address = g_strdup(address);
422 nameserver->port = port;
423 nameserver->flags = flags;
425 if (connect_udp_channel(nameserver) < 0) {
426 free_nameserver(nameserver);
430 nameserver->resolv = resolv;
432 resolv->nameserver_list = g_list_append(resolv->nameserver_list,
435 debug(resolv, "setting nameserver %s", address);
440 void g_resolv_flush_nameservers(GResolv *resolv)
445 flush_nameservers(resolv);
448 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
449 GResolvResultFunc func, gpointer user_data)
451 struct resolv_query *query;
452 unsigned char buf[4096];
455 debug(resolv, "lookup hostname %s", hostname);
460 if (resolv->nameserver_list == NULL) {
463 for (i = 0; i < resolv->res.nscount; i++) {
464 struct sockaddr_in *addr = &resolv->res.nsaddr_list[i];
465 g_resolv_add_nameserver(resolv,
466 inet_ntoa(addr->sin_addr), 53, 0);
469 if (resolv->nameserver_list == NULL)
470 g_resolv_add_nameserver(resolv, "127.0.0.1", 53, 0);
473 query = g_try_new0(struct resolv_query, 1);
477 query->id = resolv->next_query_id++;
479 len = res_mkquery(ns_o_query, hostname, ns_c_in, ns_t_a,
480 NULL, 0, NULL, buf, sizeof(buf));
482 query->msgid = buf[0] << 8 | buf[1];
484 query->result_func = func;
485 query->result_data = user_data;
487 if (send_query(resolv, buf, len) < 0) {
492 query->resolv = resolv;
494 g_queue_push_tail(resolv->query_queue, query);
496 query->timeout = g_timeout_add_seconds(5, query_timeout, query);
501 gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id)
505 list = g_queue_find_custom(resolv->query_queue,
506 GUINT_TO_POINTER(id), compare_query_id);
511 destroy_query(list->data);
512 g_queue_remove(resolv->query_queue, list->data);