source: branches/samba-3.5.x/source3/libaddns/dnssock.c@ 773

Last change on this file since 773 was 593, checked in by Herwig Bauernfeind, 14 years ago

Samba 3.5: Update trunk to 3.5.7
File size: 9.0 KB
Line 
1/*
2 Linux DNS client library implementation
3
4 Copyright (C) 2006 Krishna Ganugapati <krishnag@centeris.com>
5 Copyright (C) 2006 Gerald Carter <jerry@samba.org>
6
7 ** NOTE! The following LGPL license applies to the libaddns
8 ** library. This does NOT imply that all of Samba is released
9 ** under the LGPL
10
11 This library is free software; you can redistribute it and/or
12 modify it under the terms of the GNU Lesser General Public
13 License as published by the Free Software Foundation; either
14 version 2.1 of the License, or (at your option) any later version.
15
16 This library is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 Lesser General Public License for more details.
20
21 You should have received a copy of the GNU Lesser General Public
22 License along with this library; if not, see <http://www.gnu.org/licenses/>.
23*/
24
25#include "dns.h"
26#include <sys/time.h>
27#include <unistd.h>
28
29static int destroy_dns_connection(struct dns_connection *conn)
30{
31 return close(conn->s);
32}
33
34/********************************************************************
35********************************************************************/
36
37static DNS_ERROR dns_tcp_open( const char *nameserver,
38 TALLOC_CTX *mem_ctx,
39 struct dns_connection **result )
40{
41 uint32_t ulAddress;
42 struct hostent *pHost;
43 struct sockaddr_in s_in;
44 struct dns_connection *conn;
45 int res;
46
47 if (!(conn = talloc(mem_ctx, struct dns_connection))) {
48 return ERROR_DNS_NO_MEMORY;
49 }
50
51 if ( (ulAddress = inet_addr( nameserver )) == INADDR_NONE ) {
52 if ( (pHost = gethostbyname( nameserver )) == NULL ) {
53 TALLOC_FREE(conn);
54 return ERROR_DNS_INVALID_NAME_SERVER;
55 }
56 memcpy( &ulAddress, pHost->h_addr, pHost->h_length );
57 }
58
59 conn->s = socket( PF_INET, SOCK_STREAM, 0 );
60 if (conn->s == -1) {
61 TALLOC_FREE(conn);
62 return ERROR_DNS_CONNECTION_FAILED;
63 }
64
65 talloc_set_destructor(conn, destroy_dns_connection);
66
67 s_in.sin_family = AF_INET;
68 s_in.sin_addr.s_addr = ulAddress;
69 s_in.sin_port = htons( DNS_TCP_PORT );
70
71 res = connect(conn->s, (struct sockaddr*)&s_in, sizeof( s_in ));
72 if (res == -1) {
73 TALLOC_FREE(conn);
74 return ERROR_DNS_CONNECTION_FAILED;
75 }
76
77 conn->hType = DNS_TCP;
78
79 *result = conn;
80 return ERROR_DNS_SUCCESS;
81}
82
83/********************************************************************
84********************************************************************/
85
86static DNS_ERROR dns_udp_open( const char *nameserver,
87 TALLOC_CTX *mem_ctx,
88 struct dns_connection **result )
89{
90 unsigned long ulAddress;
91 struct hostent *pHost;
92 struct sockaddr_in RecvAddr;
93 struct dns_connection *conn;
94
95 if (!(conn = talloc(NULL, struct dns_connection))) {
96 return ERROR_DNS_NO_MEMORY;
97 }
98
99 if ( (ulAddress = inet_addr( nameserver )) == INADDR_NONE ) {
100 if ( (pHost = gethostbyname( nameserver )) == NULL ) {
101 TALLOC_FREE(conn);
102 return ERROR_DNS_INVALID_NAME_SERVER;
103 }
104 memcpy( &ulAddress, pHost->h_addr, pHost->h_length );
105 }
106
107 /* Create a socket for sending data */
108
109 conn->s = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP );
110 if (conn->s == -1) {
111 TALLOC_FREE(conn);
112 return ERROR_DNS_CONNECTION_FAILED;
113 }
114
115 talloc_set_destructor(conn, destroy_dns_connection);
116
117 /* Set up the RecvAddr structure with the IP address of
118 the receiver (in this example case "123.456.789.1")
119 and the specified port number. */
120
121 ZERO_STRUCT(RecvAddr);
122 RecvAddr.sin_family = AF_INET;
123 RecvAddr.sin_port = htons( DNS_UDP_PORT );
124 RecvAddr.sin_addr.s_addr = ulAddress;
125
126 conn->hType = DNS_UDP;
127 memcpy( &conn->RecvAddr, &RecvAddr, sizeof( struct sockaddr_in ) );
128
129 *result = conn;
130 return ERROR_DNS_SUCCESS;
131}
132
133/********************************************************************
134********************************************************************/
135
136DNS_ERROR dns_open_connection( const char *nameserver, int32 dwType,
137 TALLOC_CTX *mem_ctx,
138 struct dns_connection **conn )
139{
140 switch ( dwType ) {
141 case DNS_TCP:
142 return dns_tcp_open( nameserver, mem_ctx, conn );
143 case DNS_UDP:
144 return dns_udp_open( nameserver, mem_ctx, conn );
145 }
146
147 return ERROR_DNS_INVALID_PARAMETER;
148}
149
150static DNS_ERROR write_all(int fd, uint8 *data, size_t len)
151{
152 size_t total = 0;
153
154 while (total < len) {
155
156 ssize_t ret = write(fd, data + total, len - total);
157
158 if (ret <= 0) {
159 /*
160 * EOF or error
161 */
162 return ERROR_DNS_SOCKET_ERROR;
163 }
164
165 total += ret;
166 }
167
168 return ERROR_DNS_SUCCESS;
169}
170
171static DNS_ERROR dns_send_tcp(struct dns_connection *conn,
172 const struct dns_buffer *buf)
173{
174 uint16 len = htons(buf->offset);
175 DNS_ERROR err;
176
177 err = write_all(conn->s, (uint8 *)&len, sizeof(len));
178 if (!ERR_DNS_IS_OK(err)) return err;
179
180 return write_all(conn->s, buf->data, buf->offset);
181}
182
183static DNS_ERROR dns_send_udp(struct dns_connection *conn,
184 const struct dns_buffer *buf)
185{
186 ssize_t ret;
187
188 ret = sendto(conn->s, buf->data, buf->offset, 0,
189 (struct sockaddr *)&conn->RecvAddr,
190 sizeof(conn->RecvAddr));
191
192 if (ret != buf->offset) {
193 return ERROR_DNS_SOCKET_ERROR;
194 }
195
196 return ERROR_DNS_SUCCESS;
197}
198
199DNS_ERROR dns_send(struct dns_connection *conn, const struct dns_buffer *buf)
200{
201 if (conn->hType == DNS_TCP) {
202 return dns_send_tcp(conn, buf);
203 }
204
205 if (conn->hType == DNS_UDP) {
206 return dns_send_udp(conn, buf);
207 }
208
209 return ERROR_DNS_INVALID_PARAMETER;
210}
211
212static DNS_ERROR read_all(int fd, uint8 *data, size_t len)
213{
214 size_t total = 0;
215 fd_set rfds;
216 struct timeval tv;
217
218 while (total < len) {
219 ssize_t ret;
220 int fd_ready;
221
222 if (fd < 0 || fd >= FD_SETSIZE) {
223 /* read timeout */
224 return ERROR_DNS_SOCKET_ERROR;
225 }
226
227 FD_ZERO( &rfds );
228 FD_SET( fd, &rfds );
229
230 /* 10 second timeout */
231 tv.tv_sec = 10;
232 tv.tv_usec = 0;
233
234 fd_ready = select( fd+1, &rfds, NULL, NULL, &tv );
235 if ( fd_ready == 0 ) {
236 /* read timeout */
237 return ERROR_DNS_SOCKET_ERROR;
238 }
239
240 ret = read(fd, data + total, len - total);
241 if (ret <= 0) {
242 /* EOF or error */
243 return ERROR_DNS_SOCKET_ERROR;
244 }
245
246 total += ret;
247 }
248
249 return ERROR_DNS_SUCCESS;
250}
251
252static DNS_ERROR dns_receive_tcp(TALLOC_CTX *mem_ctx,
253 struct dns_connection *conn,
254 struct dns_buffer **presult)
255{
256 struct dns_buffer *buf;
257 DNS_ERROR err;
258 uint16 len;
259
260 if (!(buf = TALLOC_ZERO_P(mem_ctx, struct dns_buffer))) {
261 return ERROR_DNS_NO_MEMORY;
262 }
263
264 err = read_all(conn->s, (uint8 *)&len, sizeof(len));
265 if (!ERR_DNS_IS_OK(err)) {
266 return err;
267 }
268
269 buf->size = ntohs(len);
270
271 if (buf->size) {
272 if (!(buf->data = TALLOC_ARRAY(buf, uint8, buf->size))) {
273 TALLOC_FREE(buf);
274 return ERROR_DNS_NO_MEMORY;
275 }
276 } else {
277 buf->data = NULL;
278 }
279
280 err = read_all(conn->s, buf->data, buf->size);
281 if (!ERR_DNS_IS_OK(err)) {
282 TALLOC_FREE(buf);
283 return err;
284 }
285
286 *presult = buf;
287 return ERROR_DNS_SUCCESS;
288}
289
290static DNS_ERROR dns_receive_udp(TALLOC_CTX *mem_ctx,
291 struct dns_connection *conn,
292 struct dns_buffer **presult)
293{
294 struct dns_buffer *buf;
295 ssize_t received;
296
297 if (!(buf = TALLOC_ZERO_P(mem_ctx, struct dns_buffer))) {
298 return ERROR_DNS_NO_MEMORY;
299 }
300
301 /*
302 * UDP based DNS can only be 512 bytes
303 */
304
305 if (!(buf->data = TALLOC_ARRAY(buf, uint8, 512))) {
306 TALLOC_FREE(buf);
307 return ERROR_DNS_NO_MEMORY;
308 }
309
310 received = recv(conn->s, (void *)buf->data, 512, 0);
311
312 if (received == -1) {
313 TALLOC_FREE(buf);
314 return ERROR_DNS_SOCKET_ERROR;
315 }
316
317 if (received > 512) {
318 TALLOC_FREE(buf);
319 return ERROR_DNS_BAD_RESPONSE;
320 }
321
322 buf->size = received;
323 buf->offset = 0;
324
325 *presult = buf;
326 return ERROR_DNS_SUCCESS;
327}
328
329DNS_ERROR dns_receive(TALLOC_CTX *mem_ctx, struct dns_connection *conn,
330 struct dns_buffer **presult)
331{
332 if (conn->hType == DNS_TCP) {
333 return dns_receive_tcp(mem_ctx, conn, presult);
334 }
335
336 if (conn->hType == DNS_UDP) {
337 return dns_receive_udp(mem_ctx, conn, presult);
338 }
339
340 return ERROR_DNS_INVALID_PARAMETER;
341}
342
343DNS_ERROR dns_transaction(TALLOC_CTX *mem_ctx, struct dns_connection *conn,
344 const struct dns_request *req,
345 struct dns_request **resp)
346{
347 struct dns_buffer *buf = NULL;
348 DNS_ERROR err;
349
350 err = dns_marshall_request(conn, req, &buf);
351 if (!ERR_DNS_IS_OK(err)) goto error;
352
353 err = dns_send(conn, buf);
354 if (!ERR_DNS_IS_OK(err)) goto error;
355 TALLOC_FREE(buf);
356
357 err = dns_receive(mem_ctx, conn, &buf);
358 if (!ERR_DNS_IS_OK(err)) goto error;
359
360 err = dns_unmarshall_request(mem_ctx, buf, resp);
361
362 error:
363 TALLOC_FREE(buf);
364 return err;
365}
366
367DNS_ERROR dns_update_transaction(TALLOC_CTX *mem_ctx,
368 struct dns_connection *conn,
369 struct dns_update_request *up_req,
370 struct dns_update_request **up_resp)
371{
372 struct dns_request *resp;
373 DNS_ERROR err;
374
375 err = dns_transaction(mem_ctx, conn, dns_update2request(up_req),
376 &resp);
377
378 if (!ERR_DNS_IS_OK(err)) return err;
379
380 *up_resp = dns_request2update(resp);
381 return ERROR_DNS_SUCCESS;
382}
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