source: mainline/uspace/srv/net/dnsrsrv/transport.c@ 257feec

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 257feec was 257feec, checked in by Martin Decky <martin@…>, 12 years ago

cstyle (no change in functionality)
  • Property mode set to 100644
File size: 6.4 KB
Line 
1/*
2 * Copyright (c) 2013 Jiri Svoboda
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup dnsres
30 * @{
31 */
32/**
33 * @file
34 */
35
36#include <adt/list.h>
37#include <errno.h>
38#include <fibril_synch.h>
39#include <io/log.h>
40#include <net/in.h>
41#include <net/inet.h>
42#include <net/socket.h>
43#include <stdbool.h>
44#include <stdlib.h>
45
46#include "dns_msg.h"
47#include "dns_type.h"
48#include "transport.h"
49
50#define RECV_BUF_SIZE 4096
51#define DNS_SERVER_PORT 53
52
53/** Request timeout (microseconds) */
54#define REQ_TIMEOUT (5 * 1000 * 1000)
55
56/** Maximum number of retries */
57#define REQ_RETRY_MAX 3
58
59inet_addr_t dns_server_addr;
60
61typedef struct {
62 link_t lreq;
63 dns_message_t *req;
64 dns_message_t *resp;
65
66 bool done;
67 fibril_condvar_t done_cv;
68 fibril_mutex_t done_lock;
69
70 int status;
71} trans_req_t;
72
73static uint8_t recv_buf[RECV_BUF_SIZE];
74static fid_t recv_fid;
75static int transport_fd = -1;
76
77/** Outstanding requests */
78static LIST_INITIALIZE(treq_list);
79static FIBRIL_MUTEX_INITIALIZE(treq_lock);
80
81static int transport_recv_fibril(void *arg);
82
83int transport_init(void)
84{
85 struct sockaddr_in laddr;
86 int fd;
87 fid_t fid;
88 int rc;
89
90 laddr.sin_family = AF_INET;
91 laddr.sin_port = htons(12345);
92 laddr.sin_addr.s_addr = INADDR_ANY;
93
94 fd = -1;
95
96 fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
97 if (fd < 0) {
98 rc = EIO;
99 goto error;
100 }
101
102 rc = bind(fd, (struct sockaddr *)&laddr, sizeof(laddr));
103 if (rc != EOK)
104 goto error;
105
106 transport_fd = fd;
107
108 fid = fibril_create(transport_recv_fibril, NULL);
109 if (fid == 0)
110 goto error;
111
112 fibril_add_ready(fid);
113 recv_fid = fid;
114 return EOK;
115error:
116 log_msg(LOG_DEFAULT, LVL_ERROR, "Failed initializing network socket.");
117 if (fd >= 0)
118 closesocket(fd);
119 return rc;
120}
121
122void transport_fini(void)
123{
124 if (transport_fd >= 0)
125 closesocket(transport_fd);
126}
127
128static trans_req_t *treq_create(dns_message_t *req)
129{
130 trans_req_t *treq;
131
132 treq = calloc(1, sizeof(trans_req_t));
133 if (treq == NULL)
134 return NULL;
135
136 treq->req = req;
137 treq->resp = NULL;
138 treq->done = false;
139 fibril_condvar_initialize(&treq->done_cv);
140 fibril_mutex_initialize(&treq->done_lock);
141
142 fibril_mutex_lock(&treq_lock);
143 list_append(&treq->lreq, &treq_list);
144 fibril_mutex_unlock(&treq_lock);
145
146 return treq;
147}
148
149static void treq_destroy(trans_req_t *treq)
150{
151 if (link_in_use(&treq->lreq))
152 list_remove(&treq->lreq);
153 free(treq);
154}
155
156static trans_req_t *treq_match_resp(dns_message_t *resp)
157{
158 assert(fibril_mutex_is_locked(&treq_lock));
159
160 list_foreach(treq_list, link) {
161 trans_req_t *treq = list_get_instance(link, trans_req_t, lreq);
162
163 if (treq->req->id == resp->id) {
164 /* Match */
165 return treq;
166 }
167 }
168
169 return NULL;
170}
171
172static void treq_complete(trans_req_t *treq, dns_message_t *resp)
173{
174 fibril_mutex_lock(&treq->done_lock);
175 treq->done = true;
176 treq->status = EOK;
177 treq->resp = resp;
178 fibril_mutex_unlock(&treq->done_lock);
179
180 fibril_condvar_broadcast(&treq->done_cv);
181}
182
183int dns_request(dns_message_t *req, dns_message_t **rresp)
184{
185 int rc;
186 void *req_data;
187 size_t req_size;
188 struct sockaddr_in addr;
189 trans_req_t *treq;
190 int ntry;
191
192 req_data = NULL;
193 treq = NULL;
194
195 addr.sin_family = AF_INET;
196 addr.sin_port = htons(DNS_SERVER_PORT);
197 inet_addr_sockaddr_in(&dns_server_addr, &addr);
198
199 rc = dns_message_encode(req, &req_data, &req_size);
200 if (rc != EOK)
201 goto error;
202
203 ntry = 0;
204
205 while (ntry < REQ_RETRY_MAX) {
206 rc = sendto(transport_fd, req_data, req_size, 0,
207 (struct sockaddr *) &addr, sizeof(addr));
208 if (rc != EOK)
209 goto error;
210
211 treq = treq_create(req);
212 if (treq == NULL) {
213 rc = ENOMEM;
214 goto error;
215 }
216
217 fibril_mutex_lock(&treq->done_lock);
218 while (treq->done != true) {
219 rc = fibril_condvar_wait_timeout(&treq->done_cv, &treq->done_lock,
220 REQ_TIMEOUT);
221 if (rc == ETIMEOUT) {
222 ++ntry;
223 break;
224 }
225 }
226
227 fibril_mutex_unlock(&treq->done_lock);
228
229 if (rc != ETIMEOUT)
230 break;
231 }
232
233 if (ntry >= REQ_RETRY_MAX) {
234 rc = EIO;
235 goto error;
236 }
237
238 if (treq->status != EOK) {
239 rc = treq->status;
240 goto error;
241 }
242
243 *rresp = treq->resp;
244 treq_destroy(treq);
245 free(req_data);
246 return EOK;
247
248error:
249 if (treq != NULL)
250 treq_destroy(treq);
251
252 free(req_data);
253 return rc;
254}
255
256static int transport_recv_msg(dns_message_t **rresp)
257{
258 struct sockaddr_in src_addr;
259 socklen_t src_addr_size;
260 size_t recv_size;
261 dns_message_t *resp;
262 int rc;
263
264 src_addr_size = sizeof(src_addr);
265 rc = recvfrom(transport_fd, recv_buf, RECV_BUF_SIZE, 0,
266 (struct sockaddr *)&src_addr, &src_addr_size);
267 if (rc < 0) {
268 log_msg(LOG_DEFAULT, LVL_ERROR, "recvfrom returns error - %d", rc);
269 goto error;
270 }
271
272 recv_size = (size_t)rc;
273
274 rc = dns_message_decode(recv_buf, recv_size, &resp);
275 if (rc != EOK) {
276 rc = EIO;
277 goto error;
278 }
279
280 *rresp = resp;
281 return EOK;
282
283error:
284 return rc;
285}
286
287static int transport_recv_fibril(void *arg)
288{
289 dns_message_t *resp;
290 trans_req_t *treq;
291 int rc;
292
293 while (true) {
294 rc = transport_recv_msg(&resp);
295 if (rc != EOK)
296 continue;
297
298 fibril_mutex_lock(&treq_lock);
299 treq = treq_match_resp(resp);
300 if (treq == NULL) {
301 fibril_mutex_unlock(&treq_lock);
302 continue;
303 }
304
305 list_remove(&treq->lreq);
306 fibril_mutex_unlock(&treq_lock);
307
308 treq_complete(treq, resp);
309 }
310
311 return 0;
312}
313
314/** @}
315 */
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