1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005 Michael Bushkov <[email protected]>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 #include "namespace.h"
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 #include <sys/event.h>
37 #include <sys/uio.h>
38 #include <sys/un.h>
39 #include <assert.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include "un-namespace.h"
46 #include "nscachedcli.h"
47
48 #define NS_DEFAULT_CACHED_IO_TIMEOUT 4
49
50 static int safe_write(struct cached_connection_ *, const void *, size_t);
51 static int safe_read(struct cached_connection_ *, void *, size_t);
52 static int send_credentials(struct cached_connection_ *, int);
53
54 /*
55 * safe_write writes data to the specified connection and tries to do it in
56 * the very safe manner. We ensure, that we can write to the socket with
57 * kevent. If the data_size can't be sent in one piece, then it would be
58 * splitted.
59 */
60 static int
safe_write(struct cached_connection_ * connection,const void * data,size_t data_size)61 safe_write(struct cached_connection_ *connection, const void *data,
62 size_t data_size)
63 {
64 struct kevent eventlist;
65 int nevents;
66 size_t result;
67 ssize_t s_result;
68 struct timespec timeout;
69
70 if (data_size == 0)
71 return (0);
72
73 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
74 timeout.tv_nsec = 0;
75 result = 0;
76 do {
77 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist,
78 1, &timeout);
79 if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) {
80 s_result = _sendto(connection->sockfd, data + result,
81 eventlist.data < data_size - result ?
82 eventlist.data : data_size - result, MSG_NOSIGNAL,
83 NULL, 0);
84 if (s_result == -1)
85 return (-1);
86 else
87 result += s_result;
88
89 if (eventlist.flags & EV_EOF)
90 return (result < data_size ? -1 : 0);
91 } else
92 return (-1);
93 } while (result < data_size);
94
95 return (0);
96 }
97
98 /*
99 * safe_read reads data from connection and tries to do it in the very safe
100 * and stable way. It uses kevent to ensure, that the data are available for
101 * reading. If the amount of data to be read is too large, then they would
102 * be splitted.
103 */
104 static int
safe_read(struct cached_connection_ * connection,void * data,size_t data_size)105 safe_read(struct cached_connection_ *connection, void *data, size_t data_size)
106 {
107 struct kevent eventlist;
108 size_t result;
109 ssize_t s_result;
110 struct timespec timeout;
111 int nevents;
112
113 if (data_size == 0)
114 return (0);
115
116 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT;
117 timeout.tv_nsec = 0;
118 result = 0;
119 do {
120 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist,
121 1, &timeout);
122 if (nevents == 1 && eventlist.filter == EVFILT_READ) {
123 s_result = _read(connection->sockfd, data + result,
124 eventlist.data <= data_size - result ?
125 eventlist.data : data_size - result);
126 if (s_result == -1)
127 return (-1);
128 else
129 result += s_result;
130
131 if (eventlist.flags & EV_EOF)
132 return (result < data_size ? -1 : 0);
133 } else
134 return (-1);
135 } while (result < data_size);
136
137 return (0);
138 }
139
140 /*
141 * Sends the credentials information to the connection along with the
142 * communication element type.
143 */
144 static int
send_credentials(struct cached_connection_ * connection,int type)145 send_credentials(struct cached_connection_ *connection, int type)
146 {
147 union {
148 struct cmsghdr hdr;
149 char pad[CMSG_SPACE(sizeof(struct cmsgcred))];
150 } cmsg;
151 struct msghdr mhdr;
152 struct iovec iov;
153 struct kevent eventlist;
154 int nevents;
155 ssize_t result;
156
157 memset(&cmsg, 0, sizeof(cmsg));
158 cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct cmsgcred));
159 cmsg.hdr.cmsg_level = SOL_SOCKET;
160 cmsg.hdr.cmsg_type = SCM_CREDS;
161
162 memset(&mhdr, 0, sizeof(mhdr));
163 mhdr.msg_iov = &iov;
164 mhdr.msg_iovlen = 1;
165 mhdr.msg_control = &cmsg;
166 mhdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred));
167
168 iov.iov_base = &type;
169 iov.iov_len = sizeof(int);
170
171 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
172 NOTE_LOWAT, sizeof(int), NULL);
173 (void)_kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
174
175 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1,
176 NULL);
177 if (nevents == 1 && eventlist.filter == EVFILT_WRITE) {
178 result = _sendmsg(connection->sockfd, &mhdr,
179 MSG_NOSIGNAL) == -1 ? -1 : 0;
180 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
181 0, 0, NULL);
182 _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
183 return (result);
184 } else
185 return (-1);
186 }
187
188 /*
189 * Opens the connection with the specified params. Initializes all kqueues.
190 */
191 struct cached_connection_ *
__open_cached_connection(struct cached_connection_params const * params)192 __open_cached_connection(struct cached_connection_params const *params)
193 {
194 struct cached_connection_ *retval;
195 struct kevent eventlist;
196 struct sockaddr_un client_address;
197 int client_address_len, client_socket;
198 int res;
199
200 assert(params != NULL);
201
202 client_socket = _socket(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
203 client_address.sun_family = PF_LOCAL;
204 strncpy(client_address.sun_path, params->socket_path,
205 sizeof(client_address.sun_path));
206 client_address_len = sizeof(client_address.sun_family) +
207 strlen(client_address.sun_path) + 1;
208
209 res = _connect(client_socket, (struct sockaddr *)&client_address,
210 client_address_len);
211 if (res == -1) {
212 _close(client_socket);
213 return (NULL);
214 }
215 _fcntl(client_socket, F_SETFL, O_NONBLOCK);
216
217 retval = malloc(sizeof(struct cached_connection_));
218 assert(retval != NULL);
219 memset(retval, 0, sizeof(struct cached_connection_));
220
221 retval->sockfd = client_socket;
222
223 retval->write_queue = kqueue();
224 assert(retval->write_queue != -1);
225
226 EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL);
227 res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL);
228
229 retval->read_queue = kqueue();
230 assert(retval->read_queue != -1);
231
232 EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL);
233 res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL);
234
235 return (retval);
236 }
237
238 void
__close_cached_connection(struct cached_connection_ * connection)239 __close_cached_connection(struct cached_connection_ *connection)
240 {
241 assert(connection != NULL);
242
243 _close(connection->sockfd);
244 _close(connection->read_queue);
245 _close(connection->write_queue);
246 free(connection);
247 }
248
249 /*
250 * This function is very close to the cache_write function of the caching
251 * library, which is used in the caching daemon. It caches the data with the
252 * specified key in the cache entry with entry_name.
253 */
254 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)255 __cached_write(struct cached_connection_ *connection, const char *entry_name,
256 const char *key, size_t key_size, const char *data, size_t data_size)
257 {
258 size_t name_size;
259 int error_code;
260 int result;
261
262 error_code = -1;
263 result = 0;
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
477 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION;
478 (void)safe_write(ws, ¬ification, sizeof(int));
479 __close_cached_connection(ws);
480 return (0);
481 }
482
483 struct cached_connection_ *
__open_cached_mp_read_session(struct cached_connection_params const * params,const char * entry_name)484 __open_cached_mp_read_session(struct cached_connection_params const *params,
485 const char *entry_name)
486 {
487 struct cached_connection_ *connection, *retval;
488 size_t name_size;
489 int error_code;
490 int result;
491
492 retval = NULL;
493 connection = __open_cached_connection(params);
494 if (connection == NULL)
495 return (NULL);
496 connection->mp_flag = 1;
497
498 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST);
499 if (result != 0)
500 goto fin;
501
502 name_size = strlen(entry_name);
503 result = safe_write(connection, &name_size, sizeof(size_t));
504 if (result != 0)
505 goto fin;
506
507 result = safe_write(connection, entry_name, name_size);
508 if (result != 0)
509 goto fin;
510
511 result = safe_read(connection, &error_code, sizeof(int));
512 if (result != 0)
513 goto fin;
514
515 if (error_code != 0)
516 result = error_code;
517
518 fin:
519 if (result != 0)
520 __close_cached_connection(connection);
521 else
522 retval = connection;
523 return (retval);
524 }
525
526 int
__cached_mp_read(struct cached_connection_ * rs,char * data,size_t * data_size)527 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size)
528 {
529 size_t result_size;
530 int error_code, rec_error_code;
531 int request, result;
532
533 error_code = -1;
534 request = CET_MP_READ_SESSION_READ_REQUEST;
535 result = safe_write(rs, &request, sizeof(int));
536 if (result != 0)
537 goto fin;
538
539 result = safe_read(rs, &rec_error_code, sizeof(int));
540 if (result != 0)
541 goto fin;
542
543 if (rec_error_code != 0) {
544 error_code = rec_error_code;
545 goto fin;
546 }
547
548 result = safe_read(rs, &result_size, sizeof(size_t));
549 if (result != 0)
550 goto fin;
551
552 if (result_size > *data_size) {
553 *data_size = result_size;
554 error_code = -2;
555 goto fin;
556 }
557
558 result = safe_read(rs, data, result_size);
559 if (result != 0)
560 goto fin;
561
562 *data_size = result_size;
563 error_code = 0;
564
565 fin:
566 return (error_code);
567 }
568
569 int
__close_cached_mp_read_session(struct cached_connection_ * rs)570 __close_cached_mp_read_session(struct cached_connection_ *rs)
571 {
572
573 __close_cached_connection(rs);
574 return (0);
575 }
576