2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/lib/libc/net/nscachedcli.c,v 1.3 2006/12/04 17:08:43 ume Exp $
29 #include "namespace.h"
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <sys/event.h>
41 #include "un-namespace.h"
42 #include "nscachedcli.h"
44 #define NS_DEFAULT_CACHED_IO_TIMEOUT 4
46 static int safe_write(struct cached_connection_ *, const void *, size_t);
47 static int safe_read(struct cached_connection_ *, void *, size_t);
48 static int send_credentials(struct cached_connection_ *, int);
51 * safe_write writes data to the specified connection and tries to do it in
52 * the very safe manner. We ensure, that we can write to the socket with
53 * kevent. If the data_size can't be sent in one piece, then it would be
57 safe_write(struct cached_connection_ *connection, const void *data,
60 struct kevent eventlist;
64 struct timespec timeout;
69 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
73 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist,
75 if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) {
76 s_result = _write(connection->sockfd, data + result,
77 eventlist.data < data_size - result ?
78 eventlist.data : data_size - result);
84 if (eventlist.flags & EV_EOF)
85 return (result < data_size ? -1 : 0);
88 } while (result < data_size);
94 * safe_read reads data from connection and tries to do it in the very safe
95 * and stable way. It uses kevent to ensure, that the data are availabe for
96 * reading. If the amount of data to be read is too large, then they would
100 safe_read(struct cached_connection_ *connection, void *data, size_t data_size)
102 struct kevent eventlist;
105 struct timespec timeout;
111 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
115 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist,
117 if (nevents == 1 && eventlist.filter == EVFILT_READ) {
118 s_result = _read(connection->sockfd, data + result,
119 eventlist.data <= data_size - result ?
120 eventlist.data : data_size - result);
126 if (eventlist.flags & EV_EOF)
127 return (result < data_size ? -1 : 0);
130 } while (result < data_size);
136 * Sends the credentials information to the connection along with the
137 * communication element type.
140 send_credentials(struct cached_connection_ *connection, int type)
142 struct kevent eventlist;
147 struct msghdr cred_hdr;
152 char cred[CMSG_SPACE(sizeof(struct cmsgcred))];
155 memset(&cmsg, 0, sizeof(cmsg));
156 cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct cmsgcred));
157 cmsg.hdr.cmsg_level = SOL_SOCKET;
158 cmsg.hdr.cmsg_type = SCM_CREDS;
160 memset(&cred_hdr, 0, sizeof(struct msghdr));
161 cred_hdr.msg_iov = &iov;
162 cred_hdr.msg_iovlen = 1;
163 cred_hdr.msg_control = (caddr_t)&cmsg;
164 cred_hdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred));
166 iov.iov_base = &type;
167 iov.iov_len = sizeof(int);
169 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
170 NOTE_LOWAT, sizeof(int), NULL);
171 res = _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
173 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1,
175 if (nevents == 1 && eventlist.filter == EVFILT_WRITE) {
176 result = (_sendmsg(connection->sockfd, &cred_hdr, 0) == -1) ?
178 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
180 _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
187 * Opens the connection with the specified params. Initializes all kqueues.
189 struct cached_connection_ *
190 __open_cached_connection(struct cached_connection_params const *params)
192 struct cached_connection_ *retval;
193 struct kevent eventlist;
194 struct sockaddr_un client_address;
195 int client_address_len, client_socket;
198 assert(params != NULL);
200 client_socket = _socket(PF_LOCAL, SOCK_STREAM, 0);
201 client_address.sun_family = PF_LOCAL;
202 strncpy(client_address.sun_path, params->socket_path,
203 sizeof(client_address.sun_path));
204 client_address_len = sizeof(client_address.sun_family) +
205 strlen(client_address.sun_path) + 1;
207 res = _connect(client_socket, (struct sockaddr *)&client_address,
210 _close(client_socket);
213 _fcntl(client_socket, F_SETFL, O_NONBLOCK);
215 retval = malloc(sizeof(struct cached_connection_));
216 assert(retval != NULL);
217 memset(retval, 0, sizeof(struct cached_connection_));
219 retval->sockfd = client_socket;
221 retval->write_queue = kqueue();
222 assert(retval->write_queue != -1);
224 EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL);
225 res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL);
227 retval->read_queue = kqueue();
228 assert(retval->read_queue != -1);
230 EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL);
231 res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL);
237 __close_cached_connection(struct cached_connection_ *connection)
239 assert(connection != NULL);
241 _close(connection->sockfd);
242 _close(connection->read_queue);
243 _close(connection->write_queue);
248 * This function is very close to the cache_write function of the caching
249 * library, which is used in the caching daemon. It caches the data with the
250 * specified key in the cache entry with entry_name.
253 __cached_write(struct cached_connection_ *connection, const char *entry_name,
254 const char *key, size_t key_size, const char *data, size_t data_size)
262 result = send_credentials(connection, CET_WRITE_REQUEST);
266 name_size = strlen(entry_name);
267 result = safe_write(connection, &name_size, sizeof(size_t));
271 result = safe_write(connection, &key_size, sizeof(size_t));
275 result = safe_write(connection, &data_size, sizeof(size_t));
279 result = safe_write(connection, entry_name, name_size);
283 result = safe_write(connection, key, key_size);
287 result = safe_write(connection, data, data_size);
291 result = safe_read(connection, &error_code, sizeof(int));
300 * This function is very close to the cache_read function of the caching
301 * library, which is used in the caching daemon. It reads cached data with the
302 * specified key from the cache entry with entry_name.
305 __cached_read(struct cached_connection_ *connection, const char *entry_name,
306 const char *key, size_t key_size, char *data, size_t *data_size)
308 size_t name_size, result_size;
309 int error_code, rec_error_code;
312 assert(connection != NULL);
316 result = send_credentials(connection, CET_READ_REQUEST);
320 name_size = strlen(entry_name);
321 result = safe_write(connection, &name_size, sizeof(size_t));
325 result = safe_write(connection, &key_size, sizeof(size_t));
329 result = safe_write(connection, entry_name, name_size);
333 result = safe_write(connection, key, key_size);
337 result = safe_read(connection, &rec_error_code, sizeof(int));
341 if (rec_error_code != 0) {
342 error_code = rec_error_code;
346 result = safe_read(connection, &result_size, sizeof(size_t));
350 if (result_size > *data_size) {
351 *data_size = result_size;
356 result = safe_read(connection, data, result_size);
360 *data_size = result_size;
368 * Initializes the mp_write_session. For such a session the new connection
369 * would be opened. The data should be written to the session with
370 * __cached_mp_write function. The __close_cached_mp_write_session function
371 * should be used to submit session and __abandon_cached_mp_write_session - to
372 * abandon it. When the session is submitted, the whole se
374 struct cached_connection_ *
375 __open_cached_mp_write_session(struct cached_connection_params const *params,
376 const char *entry_name)
378 struct cached_connection_ *connection, *retval;
384 connection = __open_cached_connection(params);
385 if (connection == NULL)
387 connection->mp_flag = 1;
389 result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST);
393 name_size = strlen(entry_name);
394 result = safe_write(connection, &name_size, sizeof(size_t));
398 result = safe_write(connection, entry_name, name_size);
402 result = safe_read(connection, &error_code, sizeof(int));
411 __close_cached_connection(connection);
418 * Adds new portion of data to the opened write session
421 __cached_mp_write(struct cached_connection_ *ws, const char *data,
429 request = CET_MP_WRITE_SESSION_WRITE_REQUEST;
430 result = safe_write(ws, &request, sizeof(int));
434 result = safe_write(ws, &data_size, sizeof(size_t));
438 result = safe_write(ws, data, data_size);
442 result = safe_read(ws, &error_code, sizeof(int));
451 * Abandons all operations with the write session. All data, that were written
452 * to the session before, are discarded.
455 __abandon_cached_mp_write_session(struct cached_connection_ *ws)
460 notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION;
461 result = safe_write(ws, ¬ification, sizeof(int));
462 __close_cached_connection(ws);
467 * Gracefully closes the write session. The data, that were previously written
468 * to the session, are committed.
471 __close_cached_mp_write_session(struct cached_connection_ *ws)
476 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION;
477 result = safe_write(ws, ¬ification, sizeof(int));
478 __close_cached_connection(ws);
482 struct cached_connection_ *
483 __open_cached_mp_read_session(struct cached_connection_params const *params,
484 const char *entry_name)
486 struct cached_connection_ *connection, *retval;
492 connection = __open_cached_connection(params);
493 if (connection == NULL)
495 connection->mp_flag = 1;
497 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST);
501 name_size = strlen(entry_name);
502 result = safe_write(connection, &name_size, sizeof(size_t));
506 result = safe_write(connection, entry_name, name_size);
510 result = safe_read(connection, &error_code, sizeof(int));
519 __close_cached_connection(connection);
526 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size)
529 int error_code, rec_error_code;
533 request = CET_MP_READ_SESSION_READ_REQUEST;
534 result = safe_write(rs, &request, sizeof(int));
538 result = safe_read(rs, &rec_error_code, sizeof(int));
542 if (rec_error_code != 0) {
543 error_code = rec_error_code;
547 result = safe_read(rs, &result_size, sizeof(size_t));
551 if (result_size > *data_size) {
552 *data_size = result_size;
557 result = safe_read(rs, data, result_size);
561 *data_size = result_size;
569 __close_cached_mp_read_session(struct cached_connection_ *rs)
572 __close_cached_connection(rs);