summaryrefslogtreecommitdiffstats
path: root/lib/libc/net/nscachedcli.c
blob: 1323805d688620525e6dbef59bd7b4f8f72a9876 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
/*-
 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "namespace.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/event.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "un-namespace.h"
#include "nscachedcli.h"

#define NS_DEFAULT_CACHED_IO_TIMEOUT	4

static int safe_write(struct cached_connection_ *, const void *, size_t);
static int safe_read(struct cached_connection_ *, void *, size_t);
static int send_credentials(struct cached_connection_ *, int);

/*
 * safe_write writes data to the specified connection and tries to do it in
 * the very safe manner. We ensure, that we can write to the socket with
 * kevent. If the data_size can't be sent in one piece, then it would be
 * splitted.
 */
static int
safe_write(struct cached_connection_ *connection, const void *data,
    size_t data_size)
{
	struct kevent eventlist;
	int nevents;
	size_t result;
	ssize_t s_result;
	struct timespec timeout;

	if (data_size == 0)
		return (0);

	timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
	timeout.tv_nsec = 0;
	result = 0;
	do {
		nevents = _kevent(connection->write_queue, NULL, 0, &eventlist,
		    1, &timeout);
		if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) {
			s_result = _write(connection->sockfd, data + result,
			    eventlist.data < data_size - result ?
			    eventlist.data : data_size - result);
			if (s_result == -1)
				return (-1);
			else
				result += s_result;

			if (eventlist.flags & EV_EOF)
				return (result < data_size ? -1 : 0);
		} else
			return (-1);
	} while (result < data_size);

	return (0);
}

/*
 * safe_read reads data from connection and tries to do it in the very safe
 * and stable way. It uses kevent to ensure, that the data are availabe for
 * reading. If the amount of data to be read is too large, then they would
 * be splitted.
 */
static int
safe_read(struct cached_connection_ *connection, void *data, size_t data_size)
{
	struct kevent eventlist;
	size_t result;
	ssize_t s_result;
	struct timespec timeout;
	int nevents;

	if (data_size == 0)
		return (0);

	timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
	timeout.tv_nsec = 0;
	result = 0;
	do {
		nevents = _kevent(connection->read_queue, NULL, 0, &eventlist,
		    1, &timeout);
		if (nevents == 1 && eventlist.filter == EVFILT_READ) {
			s_result = _read(connection->sockfd, data + result,
			    eventlist.data <= data_size - result ?
			    eventlist.data : data_size - result);
			if (s_result == -1)
				return (-1);
			else
				result += s_result;

			if (eventlist.flags & EV_EOF)
				return (result < data_size ? -1 : 0);
		} else
			return (-1);
	} while (result < data_size);

	return (0);
}

/*
 * Sends the credentials information to the connection along with the
 * communication element type.
 */
static int
send_credentials(struct cached_connection_ *connection, int type)
{
	struct kevent eventlist;
	int nevents;
	ssize_t result;
	int res;

	struct msghdr cred_hdr;
	struct iovec iov;

	struct {
		struct cmsghdr hdr;
		char cred[CMSG_SPACE(sizeof(struct cmsgcred))];
	} cmsg;

	memset(&cmsg, 0, sizeof(cmsg));
	cmsg.hdr.cmsg_len =  CMSG_LEN(sizeof(struct cmsgcred));
	cmsg.hdr.cmsg_level = SOL_SOCKET;
	cmsg.hdr.cmsg_type = SCM_CREDS;

	memset(&cred_hdr, 0, sizeof(struct msghdr));
	cred_hdr.msg_iov = &iov;
	cred_hdr.msg_iovlen = 1;
	cred_hdr.msg_control = (caddr_t)&cmsg;
	cred_hdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred));

	iov.iov_base = &type;
	iov.iov_len = sizeof(int);

	EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
	    NOTE_LOWAT, sizeof(int), NULL);
	res = _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);

	nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1,
	    NULL);
	if (nevents == 1 && eventlist.filter == EVFILT_WRITE) {
		result = (_sendmsg(connection->sockfd, &cred_hdr, 0) == -1) ?
		    -1 : 0;
		EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
		    0, 0, NULL);
		_kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
		return (result);
	} else
		return (-1);
}

/*
 * Opens the connection with the specified params. Initializes all kqueues.
 */
struct cached_connection_ *
__open_cached_connection(struct cached_connection_params const *params)
{
	struct cached_connection_ *retval;
	struct kevent eventlist;
	struct sockaddr_un client_address;
	int client_address_len, client_socket;
	int res;

	assert(params != NULL);

	client_socket = _socket(PF_LOCAL, SOCK_STREAM, 0);
	client_address.sun_family = PF_LOCAL;
	strncpy(client_address.sun_path, params->socket_path,
	    sizeof(client_address.sun_path));
	client_address_len = sizeof(client_address.sun_family) +
	    strlen(client_address.sun_path) + 1;

	res = _connect(client_socket, (struct sockaddr *)&client_address,
	    client_address_len);
	if (res == -1) {
		_close(client_socket);
		return (NULL);
	}
	_fcntl(client_socket, F_SETFL, O_NONBLOCK);

	retval = malloc(sizeof(struct cached_connection_));
	assert(retval != NULL);
	memset(retval, 0, sizeof(struct cached_connection_));

	retval->sockfd = client_socket;

	retval->write_queue = kqueue();
	assert(retval->write_queue != -1);

	EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL);
	res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL);

	retval->read_queue = kqueue();
	assert(retval->read_queue != -1);

	EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL);
	res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL);

	return (retval);
}

void
__close_cached_connection(struct cached_connection_ *connection)
{
	assert(connection != NULL);

	_close(connection->sockfd);
	_close(connection->read_queue);
	_close(connection->write_queue);
	free(connection);
}

/*
 * This function is very close to the cache_write function of the caching
 * library, which is used in the caching daemon. It caches the data with the
 * specified key in the cache entry with entry_name.
 */
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)
{
	size_t name_size;
	int error_code;
	int result;

	error_code = -1;
	result = 0;
	result = send_credentials(connection, CET_WRITE_REQUEST);
	if (result != 0)
		goto fin;

	name_size = strlen(entry_name);
	result = safe_write(connection, &name_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(connection, &key_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(connection, &data_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(connection, entry_name, name_size);
	if (result != 0)
		goto fin;

	result = safe_write(connection, key, key_size);
	if (result != 0)
		goto fin;

	result = safe_write(connection, data, data_size);
	if (result != 0)
		goto fin;

	result = safe_read(connection, &error_code, sizeof(int));
	if (result != 0)
		error_code = -1;

fin:
	return (error_code);
}

/*
 * This function is very close to the cache_read function of the caching
 * library, which is used in the caching daemon. It reads cached data with the
 * specified key from the cache entry with entry_name.
 */
int
__cached_read(struct cached_connection_ *connection, const char *entry_name,
    const char *key, size_t key_size, char *data, size_t *data_size)
{
	size_t name_size, result_size;
	int error_code, rec_error_code;
	int result;

	assert(connection != NULL);
	result = 0;
	error_code = -1;

	result = send_credentials(connection, CET_READ_REQUEST);
	if (result != 0)
		goto fin;

	name_size = strlen(entry_name);
	result = safe_write(connection, &name_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(connection, &key_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(connection, entry_name, name_size);
	if (result != 0)
		goto fin;

	result = safe_write(connection, key, key_size);
	if (result != 0)
		goto fin;

	result = safe_read(connection, &rec_error_code, sizeof(int));
	if (result != 0)
		goto fin;

	if (rec_error_code != 0) {
		error_code = rec_error_code;
		goto fin;
	}

	result = safe_read(connection, &result_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	 if (result_size > *data_size) {
		 *data_size = result_size;
		 error_code = -2;
		 goto fin;
	 }

	result = safe_read(connection, data, result_size);
	if (result != 0)
		goto fin;

	*data_size = result_size;
	error_code = 0;

fin:
	return (error_code);
}

/*
 * Initializes the mp_write_session. For such a session the new connection
 * would be opened. The data should be written to the session with
 * __cached_mp_write function. The __close_cached_mp_write_session function
 * should be used to submit session and __abandon_cached_mp_write_session - to
 * abandon it. When the session is submitted, the whole se
 */
struct cached_connection_ *
__open_cached_mp_write_session(struct cached_connection_params const *params,
    const char *entry_name)
{
	struct cached_connection_ *connection, *retval;
	size_t name_size;
	int error_code;
	int result;

	retval = NULL;
	connection = __open_cached_connection(params);
	if (connection == NULL)
		return (NULL);
	connection->mp_flag = 1;

	result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST);
	if (result != 0)
		goto fin;

	name_size = strlen(entry_name);
	result = safe_write(connection, &name_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(connection, entry_name, name_size);
	if (result != 0)
		goto fin;

	result = safe_read(connection, &error_code, sizeof(int));
	if (result != 0)
		goto fin;

	if (error_code != 0)
		result = error_code;

fin:
	if (result != 0)
		__close_cached_connection(connection);
	else
		retval = connection;
	return (retval);
}

/*
 * Adds new portion of data to the opened write session
 */
int
__cached_mp_write(struct cached_connection_ *ws, const char *data,
    size_t data_size)
{
	int request, result;
	int error_code;

	error_code = -1;

	request = CET_MP_WRITE_SESSION_WRITE_REQUEST;
	result = safe_write(ws, &request, sizeof(int));
	if (result != 0)
		goto fin;

	result = safe_write(ws, &data_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(ws, data, data_size);
	if (result != 0)
		goto fin;

	result = safe_read(ws, &error_code, sizeof(int));
	if (result != 0)
		error_code = -1;

fin:
	return (error_code);
}

/*
 * Abandons all operations with the write session. All data, that were written
 * to the session before, are discarded.
 */
int
__abandon_cached_mp_write_session(struct cached_connection_ *ws)
{
	int notification;
	int result;

	notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION;
	result = safe_write(ws, &notification, sizeof(int));
	__close_cached_connection(ws);
	return (result);
}

/*
 * Gracefully closes the write session. The data, that were previously written
 * to the session, are committed.
 */
int
__close_cached_mp_write_session(struct cached_connection_ *ws)
{
	int notification;
	int result;

	notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION;
	result = safe_write(ws, &notification, sizeof(int));
	__close_cached_connection(ws);
	return (0);
}

struct cached_connection_ *
__open_cached_mp_read_session(struct cached_connection_params const *params,
	const char *entry_name)
{
	struct cached_connection_ *connection, *retval;
	size_t name_size;
	int error_code;
	int result;

	retval = NULL;
	connection = __open_cached_connection(params);
	if (connection == NULL)
		return (NULL);
	connection->mp_flag = 1;

	result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST);
	if (result != 0)
		goto fin;

	name_size = strlen(entry_name);
	result = safe_write(connection, &name_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	result = safe_write(connection, entry_name, name_size);
	if (result != 0)
		goto fin;

	result = safe_read(connection, &error_code, sizeof(int));
	if (result != 0)
		goto fin;

	if (error_code != 0)
		result = error_code;

fin:
	if (result != 0)
		__close_cached_connection(connection);
	else
		retval = connection;
	return (retval);
}

int
__cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size)
{
	size_t result_size;
	int error_code, rec_error_code;
	int request, result;

	error_code = -1;
	request = CET_MP_READ_SESSION_READ_REQUEST;
	result = safe_write(rs, &request, sizeof(int));
	if (result != 0)
		goto fin;

	result = safe_read(rs, &rec_error_code, sizeof(int));
	if (result != 0)
		goto fin;

	if (rec_error_code != 0) {
		error_code = rec_error_code;
		goto fin;
	}

	result = safe_read(rs, &result_size, sizeof(size_t));
	if (result != 0)
		goto fin;

	if (result_size > *data_size) {
		*data_size = result_size;
		error_code = -2;
		goto fin;
	}

	result = safe_read(rs, data, result_size);
	if (result != 0)
		goto fin;

	*data_size = result_size;
	error_code = 0;

fin:
	return (error_code);
}

int
__close_cached_mp_read_session(struct cached_connection_ *rs)
{

	__close_cached_connection(rs);
	return (0);
}
OpenPOWER on IntegriCloud