1 /*-
2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
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 * 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.
13 *
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
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/lib/libc/net/nscachedcli.c,v 1.3 2006/12/04 17:08:43 ume Exp $
27 */
28
29 #include "namespace.h"
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <sys/event.h>
33 #include <sys/time.h>
34 #include <sys/uio.h>
35 #include <sys/un.h>
36 #include <assert.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 #include "un-namespace.h"
43 #include "nscachedcli.h"
44
45 #define NS_DEFAULT_CACHED_IO_TIMEOUT 4
46
47 static int safe_write(struct cached_connection_ *, const void *, size_t);
48 static int safe_read(struct cached_connection_ *, void *, size_t);
49 static int send_credentials(struct cached_connection_ *, int);
50
51 /*
52 * safe_write writes data to the specified connection and tries to do it in
53 * the very safe manner. We ensure, that we can write to the socket with
54 * kevent. If the data_size can't be sent in one piece, then it would be
55 * splitted.
56 */
57 static int
safe_write(struct cached_connection_ * connection,const void * data,size_t data_size)58 safe_write(struct cached_connection_ *connection, const void *data,
59 size_t data_size)
60 {
61 struct kevent eventlist;
62 int nevents;
63 size_t result;
64 ssize_t s_result;
65 struct timespec timeout;
66
67 if (data_size == 0)
68 return (0);
69
70 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
71 timeout.tv_nsec = 0;
72 result = 0;
73 do {
74 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist,
75 1, &timeout);
76 if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) {
77 s_result = _write(connection->sockfd,
78 (char *)data + result,
79 eventlist.data < data_size - result ?
80 eventlist.data : data_size - result);
81 if (s_result == -1)
82 return (-1);
83 else
84 result += s_result;
85
86 if (eventlist.flags & EV_EOF)
87 return (result < data_size ? -1 : 0);
88 } else
89 return (-1);
90 } while (result < data_size);
91
92 return (0);
93 }
94
95 /*
96 * safe_read reads data from connection and tries to do it in the very safe
97 * and stable way. It uses kevent to ensure, that the data are availabe for
98 * reading. If the amount of data to be read is too large, then they would
99 * be splitted.
100 */
101 static int
safe_read(struct cached_connection_ * connection,void * data,size_t data_size)102 safe_read(struct cached_connection_ *connection, void *data, size_t data_size)
103 {
104 struct kevent eventlist;
105 size_t result;
106 ssize_t s_result;
107 struct timespec timeout;
108 int nevents;
109
110 if (data_size == 0)
111 return (0);
112
113 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
114 timeout.tv_nsec = 0;
115 result = 0;
116 do {
117 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist,
118 1, &timeout);
119 if (nevents == 1 && eventlist.filter == EVFILT_READ) {
120 s_result = _read(connection->sockfd,
121 (char *)data + result,
122 eventlist.data <= data_size - result ?
123 eventlist.data : data_size - result);
124 if (s_result == -1)
125 return (-1);
126 else
127 result += s_result;
128
129 if (eventlist.flags & EV_EOF)
130 return (result < data_size ? -1 : 0);
131 } else
132 return (-1);
133 } while (result < data_size);
134
135 return (0);
136 }
137
138 /*
139 * Sends the credentials information to the connection along with the
140 * communication element type.
141 */
142 static int
send_credentials(struct cached_connection_ * connection,int type)143 send_credentials(struct cached_connection_ *connection, int type)
144 {
145 struct kevent eventlist;
146 int nevents;
147 ssize_t result;
148 int res __unused;
149
150 struct msghdr cred_hdr;
151 struct iovec iov;
152
153 struct {
154 struct cmsghdr hdr;
155 char cred[CMSG_SPACE(sizeof(struct cmsgcred))];
156 } cmsg;
157
158 memset(&cmsg, 0, sizeof(cmsg));
159 cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct cmsgcred));
160 cmsg.hdr.cmsg_level = SOL_SOCKET;
161 cmsg.hdr.cmsg_type = SCM_CREDS;
162
163 memset(&cred_hdr, 0, sizeof(struct msghdr));
164 cred_hdr.msg_iov = &iov;
165 cred_hdr.msg_iovlen = 1;
166 cred_hdr.msg_control = (caddr_t)&cmsg;
167 cred_hdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred));
168
169 iov.iov_base = &type;
170 iov.iov_len = sizeof(int);
171
172 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
173 NOTE_LOWAT, sizeof(int), NULL);
174 res = _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
175
176 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1,
177 NULL);
178 if (nevents == 1 && eventlist.filter == EVFILT_WRITE) {
179 result = (_sendmsg(connection->sockfd, &cred_hdr, 0) == -1) ?
180 -1 : 0;
181 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
182 0, 0, NULL);
183 _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
184 return (result);
185 } else
186 return (-1);
187 }
188
189 /*
190 * Opens the connection with the specified params. Initializes all kqueues.
191 */
192 struct cached_connection_ *
__open_cached_connection(struct cached_connection_params const * params)193 __open_cached_connection(struct cached_connection_params const *params)
194 {
195 struct cached_connection_ *retval;
196 struct kevent eventlist;
197 struct sockaddr_un client_address;
198 int client_address_len, client_socket;
199 int res;
200
201 assert(params != NULL);
202
203 client_socket = _socket(PF_LOCAL, SOCK_STREAM, 0);
204 client_address.sun_family = PF_LOCAL;
205 strncpy(client_address.sun_path, params->socket_path,
206 sizeof(client_address.sun_path));
207 client_address_len = sizeof(client_address.sun_family) +
208 strlen(client_address.sun_path) + 1;
209
210 res = _connect(client_socket, (struct sockaddr *)&client_address,
211 client_address_len);
212 if (res == -1) {
213 _close(client_socket);
214 return (NULL);
215 }
216 _fcntl(client_socket, F_SETFL, O_NONBLOCK);
217
218 retval = malloc(sizeof(struct cached_connection_));
219 assert(retval != NULL);
220 memset(retval, 0, sizeof(struct cached_connection_));
221
222 retval->sockfd = client_socket;
223
224 retval->write_queue = kqueue();
225 assert(retval->write_queue != -1);
226
227 EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL);
228 res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL);
229
230 retval->read_queue = kqueue();
231 assert(retval->read_queue != -1);
232
233 EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL);
234 res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL);
235
236 return (retval);
237 }
238
239 void
__close_cached_connection(struct cached_connection_ * connection)240 __close_cached_connection(struct cached_connection_ *connection)
241 {
242 assert(connection != NULL);
243
244 _close(connection->sockfd);
245 _close(connection->read_queue);
246 _close(connection->write_queue);
247 free(connection);
248 }
249
250 /*
251 * This function is very close to the cache_write function of the caching
252 * library, which is used in the caching daemon. It caches the data with the
253 * specified key in the cache entry with entry_name.
254 */
255 int
__cached_write(struct cached_connection_ * connection,const char * entry_name,const char * key,size_t key_size,const char * data,size_t data_size)256 __cached_write(struct cached_connection_ *connection, const char *entry_name,
257 const char *key, size_t key_size, const char *data, size_t data_size)
258 {
259 size_t name_size;
260 int error_code;
261 int result;
262
263 error_code = -1;
264 result = send_credentials(connection, CET_WRITE_REQUEST);
265 if (result != 0)
266 goto fin;
267
268 name_size = strlen(entry_name);
269 result = safe_write(connection, &name_size, sizeof(size_t));
270 if (result != 0)
271 goto fin;
272
273 result = safe_write(connection, &key_size, sizeof(size_t));
274 if (result != 0)
275 goto fin;
276
277 result = safe_write(connection, &data_size, sizeof(size_t));
278 if (result != 0)
279 goto fin;
280
281 result = safe_write(connection, entry_name, name_size);
282 if (result != 0)
283 goto fin;
284
285 result = safe_write(connection, key, key_size);
286 if (result != 0)
287 goto fin;
288
289 result = safe_write(connection, data, data_size);
290 if (result != 0)
291 goto fin;
292
293 result = safe_read(connection, &error_code, sizeof(int));
294 if (result != 0)
295 error_code = -1;
296
297 fin:
298 return (error_code);
299 }
300
301 /*
302 * This function is very close to the cache_read function of the caching
303 * library, which is used in the caching daemon. It reads cached data with the
304 * specified key from the cache entry with entry_name.
305 */
306 int
__cached_read(struct cached_connection_ * connection,const char * entry_name,const char * key,size_t key_size,char * data,size_t * data_size)307 __cached_read(struct cached_connection_ *connection, const char *entry_name,
308 const char *key, size_t key_size, char *data, size_t *data_size)
309 {
310 size_t name_size, result_size;
311 int error_code, rec_error_code;
312 int result;
313
314 assert(connection != NULL);
315 result = 0;
316 error_code = -1;
317
318 result = send_credentials(connection, CET_READ_REQUEST);
319 if (result != 0)
320 goto fin;
321
322 name_size = strlen(entry_name);
323 result = safe_write(connection, &name_size, sizeof(size_t));
324 if (result != 0)
325 goto fin;
326
327 result = safe_write(connection, &key_size, sizeof(size_t));
328 if (result != 0)
329 goto fin;
330
331 result = safe_write(connection, entry_name, name_size);
332 if (result != 0)
333 goto fin;
334
335 result = safe_write(connection, key, key_size);
336 if (result != 0)
337 goto fin;
338
339 result = safe_read(connection, &rec_error_code, sizeof(int));
340 if (result != 0)
341 goto fin;
342
343 if (rec_error_code != 0) {
344 error_code = rec_error_code;
345 goto fin;
346 }
347
348 result = safe_read(connection, &result_size, sizeof(size_t));
349 if (result != 0)
350 goto fin;
351
352 if (result_size > *data_size) {
353 *data_size = result_size;
354 error_code = -2;
355 goto fin;
356 }
357
358 result = safe_read(connection, data, result_size);
359 if (result != 0)
360 goto fin;
361
362 *data_size = result_size;
363 error_code = 0;
364
365 fin:
366 return (error_code);
367 }
368
369 /*
370 * Initializes the mp_write_session. For such a session the new connection
371 * would be opened. The data should be written to the session with
372 * __cached_mp_write function. The __close_cached_mp_write_session function
373 * should be used to submit session and __abandon_cached_mp_write_session - to
374 * abandon it. When the session is submitted, the whole se
375 */
376 struct cached_connection_ *
__open_cached_mp_write_session(struct cached_connection_params const * params,const char * entry_name)377 __open_cached_mp_write_session(struct cached_connection_params const *params,
378 const char *entry_name)
379 {
380 struct cached_connection_ *connection, *retval;
381 size_t name_size;
382 int error_code;
383 int result;
384
385 retval = NULL;
386 connection = __open_cached_connection(params);
387 if (connection == NULL)
388 return (NULL);
389 connection->mp_flag = 1;
390
391 result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST);
392 if (result != 0)
393 goto fin;
394
395 name_size = strlen(entry_name);
396 result = safe_write(connection, &name_size, sizeof(size_t));
397 if (result != 0)
398 goto fin;
399
400 result = safe_write(connection, entry_name, name_size);
401 if (result != 0)
402 goto fin;
403
404 result = safe_read(connection, &error_code, sizeof(int));
405 if (result != 0)
406 goto fin;
407
408 if (error_code != 0)
409 result = error_code;
410
411 fin:
412 if (result != 0)
413 __close_cached_connection(connection);
414 else
415 retval = connection;
416 return (retval);
417 }
418
419 /*
420 * Adds new portion of data to the opened write session
421 */
422 int
__cached_mp_write(struct cached_connection_ * ws,const char * data,size_t data_size)423 __cached_mp_write(struct cached_connection_ *ws, const char *data,
424 size_t data_size)
425 {
426 int request, result;
427 int error_code;
428
429 error_code = -1;
430
431 request = CET_MP_WRITE_SESSION_WRITE_REQUEST;
432 result = safe_write(ws, &request, sizeof(int));
433 if (result != 0)
434 goto fin;
435
436 result = safe_write(ws, &data_size, sizeof(size_t));
437 if (result != 0)
438 goto fin;
439
440 result = safe_write(ws, data, data_size);
441 if (result != 0)
442 goto fin;
443
444 result = safe_read(ws, &error_code, sizeof(int));
445 if (result != 0)
446 error_code = -1;
447
448 fin:
449 return (error_code);
450 }
451
452 /*
453 * Abandons all operations with the write session. All data, that were written
454 * to the session before, are discarded.
455 */
456 int
__abandon_cached_mp_write_session(struct cached_connection_ * ws)457 __abandon_cached_mp_write_session(struct cached_connection_ *ws)
458 {
459 int notification;
460 int result;
461
462 notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION;
463 result = safe_write(ws, ¬ification, sizeof(int));
464 __close_cached_connection(ws);
465 return (result);
466 }
467
468 /*
469 * Gracefully closes the write session. The data, that were previously written
470 * to the session, are committed.
471 */
472 int
__close_cached_mp_write_session(struct cached_connection_ * ws)473 __close_cached_mp_write_session(struct cached_connection_ *ws)
474 {
475 int notification;
476 int result __unused;
477
478 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION;
479 result = safe_write(ws, ¬ification, sizeof(int));
480 __close_cached_connection(ws);
481 return (0);
482 }
483
484 struct cached_connection_ *
__open_cached_mp_read_session(struct cached_connection_params const * params,const char * entry_name)485 __open_cached_mp_read_session(struct cached_connection_params const *params,
486 const char *entry_name)
487 {
488 struct cached_connection_ *connection, *retval;
489 size_t name_size;
490 int error_code;
491 int result;
492
493 retval = NULL;
494 connection = __open_cached_connection(params);
495 if (connection == NULL)
496 return (NULL);
497 connection->mp_flag = 1;
498
499 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST);
500 if (result != 0)
501 goto fin;
502
503 name_size = strlen(entry_name);
504 result = safe_write(connection, &name_size, sizeof(size_t));
505 if (result != 0)
506 goto fin;
507
508 result = safe_write(connection, entry_name, name_size);
509 if (result != 0)
510 goto fin;
511
512 result = safe_read(connection, &error_code, sizeof(int));
513 if (result != 0)
514 goto fin;
515
516 if (error_code != 0)
517 result = error_code;
518
519 fin:
520 if (result != 0)
521 __close_cached_connection(connection);
522 else
523 retval = connection;
524 return (retval);
525 }
526
527 int
__cached_mp_read(struct cached_connection_ * rs,char * data,size_t * data_size)528 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size)
529 {
530 size_t result_size;
531 int error_code, rec_error_code;
532 int request, result;
533
534 error_code = -1;
535 request = CET_MP_READ_SESSION_READ_REQUEST;
536 result = safe_write(rs, &request, sizeof(int));
537 if (result != 0)
538 goto fin;
539
540 result = safe_read(rs, &rec_error_code, sizeof(int));
541 if (result != 0)
542 goto fin;
543
544 if (rec_error_code != 0) {
545 error_code = rec_error_code;
546 goto fin;
547 }
548
549 result = safe_read(rs, &result_size, sizeof(size_t));
550 if (result != 0)
551 goto fin;
552
553 if (result_size > *data_size) {
554 *data_size = result_size;
555 error_code = -2;
556 goto fin;
557 }
558
559 result = safe_read(rs, data, result_size);
560 if (result != 0)
561 goto fin;
562
563 *data_size = result_size;
564 error_code = 0;
565
566 fin:
567 return (error_code);
568 }
569
570 int
__close_cached_mp_read_session(struct cached_connection_ * rs)571 __close_cached_mp_read_session(struct cached_connection_ *rs)
572 {
573
574 __close_cached_connection(rs);
575 return (0);
576 }
577