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Viewing changes to gweb/gresolv.c

  • Committer: Ken VanDine
  • Date: 2010-12-01 18:04:21 UTC
  • mfrom: (23.1.11 connman.u)
  • Revision ID: ken.vandine@canonical.com-20101201180421-44ibz1auwpa05l8c
Tags: 0.64-0ubuntu1
releasing version 0.64-0ubuntu1

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gweb/gresolv.c
 
1
/*
 
2
 *
 
3
 *  Resolver library with GLib integration
 
4
 *
 
5
 *  Copyright (C) 2009-2010  Intel Corporation. All rights reserved.
 
6
 *
 
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.
 
10
 *
 
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.
 
15
 *
 
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
 
19
 *
 
20
 */
 
21
 
 
22
#ifdef HAVE_CONFIG_H
 
23
#include <config.h>
 
24
#endif
 
25
 
 
26
#include <errno.h>
 
27
#include <unistd.h>
 
28
#include <stdarg.h>
 
29
#include <string.h>
 
30
#include <resolv.h>
 
31
#include <sys/socket.h>
 
32
#include <arpa/inet.h>
 
33
#include <arpa/nameser.h>
 
34
 
 
35
#include "gresolv.h"
 
36
 
 
37
struct resolv_query {
 
38
        GResolv *resolv;
 
39
 
 
40
        guint id;
 
41
        guint timeout;
 
42
 
 
43
        uint16_t msgid;
 
44
 
 
45
        GResolvResultFunc result_func;
 
46
        gpointer result_data;
 
47
};
 
48
 
 
49
struct resolv_nameserver {
 
50
        GResolv *resolv;
 
51
 
 
52
        char *address;
 
53
        uint16_t port;
 
54
        unsigned long flags;
 
55
 
 
56
        GIOChannel *udp_channel;
 
57
        guint udp_watch;
 
58
};
 
59
 
 
60
struct _GResolv {
 
61
        gint ref_count;
 
62
 
 
63
        guint next_query_id;
 
64
        GQueue *query_queue;
 
65
 
 
66
        int index;
 
67
        GList *nameserver_list;
 
68
 
 
69
        struct __res_state res;
 
70
 
 
71
        GResolvDebugFunc debug_func;
 
72
        gpointer debug_data;
 
73
};
 
74
 
 
75
static inline void debug(GResolv *resolv, const char *format, ...)
 
76
{
 
77
        char str[256];
 
78
        va_list ap;
 
79
 
 
80
        if (resolv->debug_func == NULL)
 
81
                return;
 
82
 
 
83
        va_start(ap, format);
 
84
 
 
85
        if (vsnprintf(str, sizeof(str), format, ap) > 0)
 
86
                resolv->debug_func(str, resolv->debug_data);
 
87
 
 
88
        va_end(ap);
 
89
}
 
90
 
 
91
static void destroy_query(struct resolv_query *query)
 
92
{
 
93
        if (query->timeout > 0)
 
94
                g_source_remove(query->timeout);
 
95
 
 
96
        g_free(query);
 
97
}
 
98
 
 
99
static gboolean query_timeout(gpointer user_data)
 
100
{
 
101
        struct resolv_query *query = user_data;
 
102
        GResolv *resolv = query->resolv;
 
103
 
 
104
        query->timeout = 0;
 
105
 
 
106
        if (query->result_func != NULL)
 
107
                query->result_func(G_RESOLV_RESULT_STATUS_NO_RESPONSE,
 
108
                                                NULL, query->result_data);
 
109
 
 
110
        destroy_query(query);
 
111
        g_queue_remove(resolv->query_queue, query);
 
112
 
 
113
        return FALSE;
 
114
}
 
115
 
 
116
static void free_nameserver(struct resolv_nameserver *nameserver)
 
117
{
 
118
        if (nameserver == NULL)
 
119
                return;
 
120
 
 
121
        if (nameserver->udp_watch > 0)
 
122
                g_source_remove(nameserver->udp_watch);
 
123
 
 
124
        if (nameserver->udp_channel != NULL)
 
125
                g_io_channel_unref(nameserver->udp_channel);
 
126
 
 
127
        g_free(nameserver->address);
 
128
        g_free(nameserver);
 
129
}
 
130
 
 
131
static void flush_nameservers(GResolv *resolv)
 
132
{
 
133
        GList *list;
 
134
 
 
135
        for (list = g_list_first(resolv->nameserver_list);
 
136
                                        list; list = g_list_next(list))
 
137
                free_nameserver(list->data);
 
138
 
 
139
        g_list_free(resolv->nameserver_list);
 
140
        resolv->nameserver_list = NULL;
 
141
}
 
142
 
 
143
static int send_query(GResolv *resolv, const unsigned char *buf, int len)
 
144
{
 
145
        GList *list;
 
146
 
 
147
        if (resolv->nameserver_list == NULL)
 
148
                return -ENOENT;
 
149
 
 
150
        for (list = g_list_first(resolv->nameserver_list);
 
151
                                        list; list = g_list_next(list)) {
 
152
                struct resolv_nameserver *nameserver = list->data;
 
153
                int sk, sent;
 
154
 
 
155
                if (nameserver->udp_channel == NULL)
 
156
                        continue;
 
157
 
 
158
                sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 
159
 
 
160
                sent = send(sk, buf, len, 0);
 
161
        }
 
162
 
 
163
        return 0;
 
164
}
 
165
 
 
166
static gint compare_query_id(gconstpointer a, gconstpointer b)
 
167
{
 
168
        const struct resolv_query *query = a;
 
169
        guint id = GPOINTER_TO_UINT(b);
 
170
 
 
171
        if (query->id < id)
 
172
                return -1;
 
173
 
 
174
        if (query->id > id)
 
175
                return 1;
 
176
 
 
177
        return 0;
 
178
}
 
179
 
 
180
static gint compare_query_msgid(gconstpointer a, gconstpointer b)
 
181
{
 
182
        const struct resolv_query *query = a;
 
183
        uint16_t msgid = GPOINTER_TO_UINT(b);
 
184
 
 
185
        if (query->msgid < msgid)
 
186
                return -1;
 
187
 
 
188
        if (query->msgid > msgid)
 
189
                return 1;
 
190
 
 
191
        return 0;
 
192
}
 
193
 
 
194
static void parse_response(struct resolv_nameserver *nameserver,
 
195
                                        const unsigned char *buf, int len)
 
196
{
 
197
        GResolv *resolv = nameserver->resolv;
 
198
        GResolvResultStatus status;
 
199
        GList *list;
 
200
        char **results;
 
201
        ns_msg msg;
 
202
        ns_rr rr;
 
203
        int i, n, rcode, count;
 
204
 
 
205
        debug(resolv, "response from %s", nameserver->address);
 
206
 
 
207
        ns_initparse(buf, len, &msg);
 
208
 
 
209
        rcode = ns_msg_getflag(msg, ns_f_rcode);
 
210
        count = ns_msg_count(msg, ns_s_an);
 
211
 
 
212
        debug(resolv, "msg id: 0x%04x rcode: %d count: %d",
 
213
                                        ns_msg_id(msg), rcode, count);
 
214
 
 
215
        switch (rcode) {
 
216
        case 0:
 
217
                status = G_RESOLV_RESULT_STATUS_SUCCESS;
 
218
                break;
 
219
        case 1:
 
220
                status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR;
 
221
                break;
 
222
        case 2:
 
223
                status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE;
 
224
                break;
 
225
        case 3:
 
226
                status = G_RESOLV_RESULT_STATUS_NAME_ERROR;
 
227
                break;
 
228
        case 4:
 
229
                status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED;
 
230
                break;
 
231
        case 5:
 
232
                status = G_RESOLV_RESULT_STATUS_REFUSED;
 
233
                break;
 
234
        default:
 
235
                status = G_RESOLV_RESULT_STATUS_ERROR;
 
236
                break;
 
237
        }
 
238
 
 
239
        results = g_try_new(char *, count + 1);
 
240
        if (results == NULL)
 
241
                return;
 
242
 
 
243
        for (i = 0, n = 0; i < count; i++) {
 
244
                char result[100];
 
245
 
 
246
                ns_parserr(&msg, ns_s_an, i, &rr);
 
247
 
 
248
                if (ns_rr_class(rr) != ns_c_in)
 
249
                        continue;
 
250
 
 
251
                if (ns_rr_type(rr) != ns_t_a)
 
252
                        continue;
 
253
 
 
254
                if (ns_rr_rdlen(rr) != NS_INADDRSZ)
 
255
                        continue;
 
256
 
 
257
                inet_ntop(AF_INET, ns_rr_rdata(rr), result, sizeof(result));
 
258
 
 
259
                results[n++] = g_strdup(result);
 
260
        }
 
261
 
 
262
        results[n] = NULL;
 
263
 
 
264
        list = g_queue_find_custom(resolv->query_queue,
 
265
                        GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid);
 
266
 
 
267
        if (list != NULL) {
 
268
                struct resolv_query *query = list->data;
 
269
 
 
270
                if (query->result_func != NULL)
 
271
                        query->result_func(status, results,
 
272
                                                query->result_data);
 
273
 
 
274
                destroy_query(query);
 
275
                g_queue_remove(resolv->query_queue, query);
 
276
        }
 
277
 
 
278
        g_strfreev(results);
 
279
}
 
280
 
 
281
static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond,
 
282
                                                        gpointer user_data)
 
283
{
 
284
        struct resolv_nameserver *nameserver = user_data;
 
285
        unsigned char buf[4096];
 
286
        int sk, len;
 
287
 
 
288
        if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
 
289
                nameserver->udp_watch = 0;
 
290
                return FALSE;
 
291
        }
 
292
 
 
293
        sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 
294
 
 
295
        len = recv(sk, buf, sizeof(buf), 0);
 
296
        if (len < 12)
 
297
                return TRUE;
 
298
 
 
299
        parse_response(nameserver, buf, len);
 
300
 
 
301
        return TRUE;
 
302
}
 
303
 
 
304
static int connect_udp_channel(struct resolv_nameserver *nameserver)
 
305
{
 
306
        struct sockaddr_in sin;
 
307
        int sk;
 
308
 
 
309
        sk = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 
310
        if (sk < 0)
 
311
                return -EIO;
 
312
 
 
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);
 
317
 
 
318
        if (connect(sk, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
 
319
                close(sk);
 
320
                return -EIO;
 
321
        }
 
322
 
 
323
        nameserver->udp_channel = g_io_channel_unix_new(sk);
 
324
        if (nameserver->udp_channel == NULL) {
 
325
                close(sk);
 
326
                return -ENOMEM;
 
327
        }
 
328
 
 
329
        g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
 
330
 
 
331
        nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
 
332
                                                G_IO_IN, received_udp_data,
 
333
                                                                nameserver);
 
334
 
 
335
        return 0;
 
336
}
 
337
 
 
338
GResolv *g_resolv_new(int index)
 
339
{
 
340
        GResolv *resolv;
 
341
 
 
342
        if (index < 0)
 
343
                return NULL;
 
344
 
 
345
        resolv = g_try_new0(GResolv, 1);
 
346
        if (resolv == NULL)
 
347
                return NULL;
 
348
 
 
349
        resolv->ref_count = 1;
 
350
 
 
351
        resolv->next_query_id = 1;
 
352
        resolv->query_queue = g_queue_new();
 
353
 
 
354
        if (resolv->query_queue == NULL) {
 
355
                g_free(resolv);
 
356
                return NULL;
 
357
        }
 
358
 
 
359
        resolv->index = index;
 
360
        resolv->nameserver_list = NULL;
 
361
 
 
362
        res_ninit(&resolv->res);
 
363
 
 
364
        return resolv;
 
365
}
 
366
 
 
367
GResolv *g_resolv_ref(GResolv *resolv)
 
368
{
 
369
        if (resolv == NULL)
 
370
                return NULL;
 
371
 
 
372
        g_atomic_int_inc(&resolv->ref_count);
 
373
 
 
374
        return resolv;
 
375
}
 
376
 
 
377
void g_resolv_unref(GResolv *resolv)
 
378
{
 
379
        struct resolv_query *query;
 
380
 
 
381
        if (resolv == NULL)
 
382
                return;
 
383
 
 
384
        if (g_atomic_int_dec_and_test(&resolv->ref_count) == FALSE)
 
385
                return;
 
386
 
 
387
        while ((query = g_queue_pop_head(resolv->query_queue)))
 
388
                destroy_query(query);
 
389
 
 
390
        g_queue_free(resolv->query_queue);
 
391
 
 
392
        flush_nameservers(resolv);
 
393
 
 
394
        res_nclose(&resolv->res);
 
395
 
 
396
        g_free(resolv);
 
397
}
 
398
 
 
399
void g_resolv_set_debug(GResolv *resolv,
 
400
                                GResolvDebugFunc func, gpointer user_data)
 
401
{
 
402
        if (resolv == NULL)
 
403
                return;
 
404
 
 
405
        resolv->debug_func = func;
 
406
        resolv->debug_data = user_data;
 
407
}
 
408
 
 
409
gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address,
 
410
                                        uint16_t port, unsigned long flags)
 
411
{
 
412
        struct resolv_nameserver *nameserver;
 
413
 
 
414
        if (resolv == NULL)
 
415
                return FALSE;
 
416
 
 
417
        nameserver = g_try_new0(struct resolv_nameserver, 1);
 
418
        if (nameserver == NULL)
 
419
                return FALSE;
 
420
 
 
421
        nameserver->address = g_strdup(address);
 
422
        nameserver->port = port;
 
423
        nameserver->flags = flags;
 
424
 
 
425
        if (connect_udp_channel(nameserver) < 0) {
 
426
                free_nameserver(nameserver);
 
427
                return FALSE;
 
428
        }
 
429
 
 
430
        nameserver->resolv = resolv;
 
431
 
 
432
        resolv->nameserver_list = g_list_append(resolv->nameserver_list,
 
433
                                                                nameserver);
 
434
 
 
435
        debug(resolv, "setting nameserver %s", address);
 
436
 
 
437
        return TRUE;
 
438
}
 
439
 
 
440
void g_resolv_flush_nameservers(GResolv *resolv)
 
441
{
 
442
        if (resolv == NULL)
 
443
                return;
 
444
 
 
445
        flush_nameservers(resolv);
 
446
}
 
447
 
 
448
guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
 
449
                                GResolvResultFunc func, gpointer user_data)
 
450
{
 
451
        struct resolv_query *query;
 
452
        unsigned char buf[4096];
 
453
        int len;
 
454
 
 
455
        debug(resolv, "lookup hostname %s", hostname);
 
456
 
 
457
        if (resolv == NULL)
 
458
                return 0;
 
459
 
 
460
        if (resolv->nameserver_list == NULL) {
 
461
                int i;
 
462
 
 
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);
 
467
                }
 
468
 
 
469
                if (resolv->nameserver_list == NULL)
 
470
                        g_resolv_add_nameserver(resolv, "127.0.0.1", 53, 0);
 
471
        }
 
472
 
 
473
        query = g_try_new0(struct resolv_query, 1);
 
474
        if (query == NULL)
 
475
                return 0;
 
476
 
 
477
        query->id = resolv->next_query_id++;
 
478
 
 
479
        len = res_mkquery(ns_o_query, hostname, ns_c_in, ns_t_a,
 
480
                                        NULL, 0, NULL, buf, sizeof(buf));
 
481
 
 
482
        query->msgid = buf[0] << 8 | buf[1];
 
483
 
 
484
        query->result_func = func;
 
485
        query->result_data = user_data;
 
486
 
 
487
        if (send_query(resolv, buf, len) < 0) {
 
488
                g_free(query);
 
489
                return -EIO;
 
490
        }
 
491
 
 
492
        query->resolv = resolv;
 
493
 
 
494
        g_queue_push_tail(resolv->query_queue, query);
 
495
 
 
496
        query->timeout = g_timeout_add_seconds(5, query_timeout, query);
 
497
 
 
498
        return query->id;
 
499
}
 
500
 
 
501
gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id)
 
502
{
 
503
        GList *list;
 
504
 
 
505
        list = g_queue_find_custom(resolv->query_queue,
 
506
                                GUINT_TO_POINTER(id), compare_query_id);
 
507
 
 
508
        if (list == NULL)
 
509
                return FALSE;
 
510
 
 
511
        destroy_query(list->data);
 
512
        g_queue_remove(resolv->query_queue, list->data);
 
513
 
 
514
        return TRUE;
 
515
}