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 GResolvDebugFunc debug_func;
73 static inline void debug(GResolv *resolv, const char *format, ...)
78 if (resolv->debug_func == NULL)
83 if (vsnprintf(str, sizeof(str), format, ap) > 0)
84 resolv->debug_func(str, resolv->debug_data);
89 static void destroy_query(struct resolv_query *query)
91 if (query->timeout > 0)
92 g_source_remove(query->timeout);
97 static gboolean query_timeout(gpointer user_data)
99 struct resolv_query *query = user_data;
100 GResolv *resolv = query->resolv;
104 if (query->result_func != NULL)
105 query->result_func(G_RESOLV_RESULT_STATUS_NO_RESPONSE,
106 NULL, query->result_data);
108 destroy_query(query);
109 g_queue_remove(resolv->query_queue, query);
114 static void free_nameserver(struct resolv_nameserver *nameserver)
116 if (nameserver == NULL)
119 if (nameserver->udp_watch > 0)
120 g_source_remove(nameserver->udp_watch);
122 if (nameserver->udp_channel != NULL)
123 g_io_channel_unref(nameserver->udp_channel);
125 g_free(nameserver->address);
129 static void flush_nameservers(GResolv *resolv)
133 for (list = g_list_first(resolv->nameserver_list);
134 list; list = g_list_next(list))
135 free_nameserver(list->data);
137 g_list_free(resolv->nameserver_list);
138 resolv->nameserver_list = NULL;
141 static int send_query(GResolv *resolv, const unsigned char *buf, int len)
145 if (resolv->nameserver_list == NULL)
148 for (list = g_list_first(resolv->nameserver_list);
149 list; list = g_list_next(list)) {
150 struct resolv_nameserver *nameserver = list->data;
153 if (nameserver->udp_channel == NULL)
156 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
158 sent = send(sk, buf, len, 0);
164 static gint compare_query_id(gconstpointer a, gconstpointer b)
166 const struct resolv_query *query = a;
167 guint id = GPOINTER_TO_UINT(b);
178 static gint compare_query_msgid(gconstpointer a, gconstpointer b)
180 const struct resolv_query *query = a;
181 uint16_t msgid = GPOINTER_TO_UINT(b);
183 if (query->msgid < msgid)
186 if (query->msgid > msgid)
192 static void parse_response(struct resolv_nameserver *nameserver,
193 const unsigned char *buf, int len)
195 GResolv *resolv = nameserver->resolv;
196 GResolvResultStatus status;
201 int i, n, rcode, count;
203 debug(resolv, "response from %s", nameserver->address);
205 ns_initparse(buf, len, &msg);
207 rcode = ns_msg_getflag(msg, ns_f_rcode);
208 count = ns_msg_count(msg, ns_s_an);
210 debug(resolv, "msg id: 0x%04x rcode: %d count: %d",
211 ns_msg_id(msg), rcode, count);
215 status = G_RESOLV_RESULT_STATUS_SUCCESS;
218 status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR;
221 status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE;
224 status = G_RESOLV_RESULT_STATUS_NAME_ERROR;
227 status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED;
230 status = G_RESOLV_RESULT_STATUS_REFUSED;
233 status = G_RESOLV_RESULT_STATUS_ERROR;
237 results = g_try_new(char *, count + 1);
241 for (i = 0, n = 0; i < count; i++) {
244 ns_parserr(&msg, ns_s_an, i, &rr);
246 if (ns_rr_class(rr) != ns_c_in)
249 if (ns_rr_type(rr) != ns_t_a)
252 if (ns_rr_rdlen(rr) != NS_INADDRSZ)
255 inet_ntop(AF_INET, ns_rr_rdata(rr), result, sizeof(result));
257 results[n++] = g_strdup(result);
262 list = g_queue_find_custom(resolv->query_queue,
263 GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid);
266 struct resolv_query *query = list->data;
268 if (query->result_func != NULL)
269 query->result_func(status, results,
272 destroy_query(query);
273 g_queue_remove(resolv->query_queue, query);
279 static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond,
282 struct resolv_nameserver *nameserver = user_data;
283 unsigned char buf[4096];
286 if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
287 nameserver->udp_watch = 0;
291 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
293 len = recv(sk, buf, sizeof(buf), 0);
297 parse_response(nameserver, buf, len);
302 static int connect_udp_channel(struct resolv_nameserver *nameserver)
304 struct sockaddr_in sin;
307 sk = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
311 memset(&sin, 0, sizeof(sin));
312 sin.sin_family = AF_INET;
313 sin.sin_port = htons(nameserver->port);
314 sin.sin_addr.s_addr = inet_addr(nameserver->address);
316 if (connect(sk, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
321 nameserver->udp_channel = g_io_channel_unix_new(sk);
322 if (nameserver->udp_channel == NULL) {
327 g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
329 nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
330 G_IO_IN, received_udp_data,
336 GResolv *g_resolv_new(int index)
343 resolv = g_try_new0(GResolv, 1);
347 resolv->ref_count = 1;
349 resolv->next_query_id = 1;
350 resolv->query_queue = g_queue_new();
352 if (resolv->query_queue == NULL) {
357 resolv->index = index;
358 resolv->nameserver_list = NULL;
363 GResolv *g_resolv_ref(GResolv *resolv)
368 g_atomic_int_inc(&resolv->ref_count);
373 void g_resolv_unref(GResolv *resolv)
375 struct resolv_query *query;
380 if (g_atomic_int_dec_and_test(&resolv->ref_count) == FALSE)
383 while ((query = g_queue_pop_head(resolv->query_queue)))
384 destroy_query(query);
386 g_queue_free(resolv->query_queue);
388 flush_nameservers(resolv);
393 void g_resolv_set_debug(GResolv *resolv,
394 GResolvDebugFunc func, gpointer user_data)
399 resolv->debug_func = func;
400 resolv->debug_data = user_data;
403 gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address,
404 uint16_t port, unsigned long flags)
406 struct resolv_nameserver *nameserver;
411 nameserver = g_try_new0(struct resolv_nameserver, 1);
412 if (nameserver == NULL)
415 nameserver->address = g_strdup(address);
416 nameserver->port = port;
417 nameserver->flags = flags;
419 if (connect_udp_channel(nameserver) < 0) {
420 free_nameserver(nameserver);
424 nameserver->resolv = resolv;
426 resolv->nameserver_list = g_list_append(resolv->nameserver_list,
429 debug(resolv, "setting nameserver %s", address);
434 void g_resolv_flush_nameservers(GResolv *resolv)
439 flush_nameservers(resolv);
442 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
443 GResolvResultFunc func, gpointer user_data)
445 struct resolv_query *query;
446 unsigned char buf[4096];
449 debug(resolv, "lookup hostname %s", hostname);
454 query = g_try_new0(struct resolv_query, 1);
458 query->id = resolv->next_query_id++;
460 len = res_mkquery(ns_o_query, hostname, ns_c_in, ns_t_a,
461 NULL, 0, NULL, buf, sizeof(buf));
463 query->msgid = buf[0] << 8 | buf[1];
465 query->result_func = func;
466 query->result_data = user_data;
468 if (send_query(resolv, buf, len) < 0) {
473 query->resolv = resolv;
475 g_queue_push_tail(resolv->query_queue, query);
477 query->timeout = g_timeout_add_seconds(5, query_timeout, query);
482 gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id)
486 list = g_queue_find_custom(resolv->query_queue,
487 GUINT_TO_POINTER(id), compare_query_id);
492 destroy_query(list->data);
493 g_queue_remove(resolv->query_queue, list->data);