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 struct kevent eventlist;
148 int nevents;
149 ssize_t result;
150 int res;
151
152 struct msghdr cred_hdr;
153 struct iovec iov;
154
155 struct {
156 struct cmsghdr hdr;
157 char cred[CMSG_SPACE(sizeof(struct cmsgcred))];
158 } cmsg;
159
160 memset(&cmsg, 0, sizeof(cmsg));
161 cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct cmsgcred));
162 cmsg.hdr.cmsg_level = SOL_SOCKET;
163 cmsg.hdr.cmsg_type = SCM_CREDS;
164
165 memset(&cred_hdr, 0, sizeof(struct msghdr));
166 cred_hdr.msg_iov = &iov;
167 cred_hdr.msg_iovlen = 1;
168 cred_hdr.msg_control = (caddr_t)&cmsg;
169 cred_hdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred));
170
171 iov.iov_base = &type;
172 iov.iov_len = sizeof(int);
173
174 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
175 NOTE_LOWAT, sizeof(int), NULL);
176 res = _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
177
178 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1,
179 NULL);
180 if (nevents == 1 && eventlist.filter == EVFILT_WRITE) {
181 result = (_sendmsg(connection->sockfd, &cred_hdr,
182 MSG_NOSIGNAL) == -1) ? -1 : 0;
183 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
184 0, 0, NULL);
185 _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
186 return (result);
187 } else
188 return (-1);
189 }
190
191 /*
192 * Opens the connection with the specified params. Initializes all kqueues.
193 */
194 struct cached_connection_ *
__open_cached_connection(struct cached_connection_params const * params)195 __open_cached_connection(struct cached_connection_params const *params)
196 {
197 struct cached_connection_ *retval;
198 struct kevent eventlist;
199 struct sockaddr_un client_address;
200 int client_address_len, client_socket;
201 int res;
202
203 assert(params != NULL);
204
205 client_socket = _socket(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
206 client_address.sun_family = PF_LOCAL;
207 strncpy(client_address.sun_path, params->socket_path,
208 sizeof(client_address.sun_path));
209 client_address_len = sizeof(client_address.sun_family) +
210 strlen(client_address.sun_path) + 1;
211
212 res = _connect(client_socket, (struct sockaddr *)&client_address,
213 client_address_len);
214 if (res == -1) {
215 _close(client_socket);
216 return (NULL);
217 }
218 _fcntl(client_socket, F_SETFL, O_NONBLOCK);
219
220 retval = malloc(sizeof(struct cached_connection_));
221 assert(retval != NULL);
222 memset(retval, 0, sizeof(struct cached_connection_));
223
224 retval->sockfd = client_socket;
225
226 retval->write_queue = kqueue();
227 assert(retval->write_queue != -1);
228
229 EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL);
230 res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL);
231
232 retval->read_queue = kqueue();
233 assert(retval->read_queue != -1);
234
235 EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL);
236 res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL);
237
238 return (retval);
239 }
240
241 void
__close_cached_connection(struct cached_connection_ * connection)242 __close_cached_connection(struct cached_connection_ *connection)
243 {
244 assert(connection != NULL);
245
246 _close(connection->sockfd);
247 _close(connection->read_queue);
248 _close(connection->write_queue);
249 free(connection);
250 }
251
252 /*
253 * This function is very close to the cache_write function of the caching
254 * library, which is used in the caching daemon. It caches the data with the
255 * specified key in the cache entry with entry_name.
256 */
257 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)258 __cached_write(struct cached_connection_ *connection, const char *entry_name,
259 const char *key, size_t key_size, const char *data, size_t data_size)
260 {
261 size_t name_size;
262 int error_code;
263 int result;
264
265 error_code = -1;
266 result = 0;
267 result = send_credentials(connection, CET_WRITE_REQUEST);
268 if (result != 0)
269 goto fin;
270
271 name_size = strlen(entry_name);
272 result = safe_write(connection, &name_size, sizeof(size_t));
273 if (result != 0)
274 goto fin;
275
276 result = safe_write(connection, &key_size, sizeof(size_t));
277 if (result != 0)
278 goto fin;
279
280 result = safe_write(connection, &data_size, sizeof(size_t));
281 if (result != 0)
282 goto fin;
283
284 result = safe_write(connection, entry_name, name_size);
285 if (result != 0)
286 goto fin;
287
288 result = safe_write(connection, key, key_size);
289 if (result != 0)
290 goto fin;
291
292 result = safe_write(connection, data, data_size);
293 if (result != 0)
294 goto fin;
295
296 result = safe_read(connection, &error_code, sizeof(int));
297 if (result != 0)
298 error_code = -1;
299
300 fin:
301 return (error_code);
302 }
303
304 /*
305 * This function is very close to the cache_read function of the caching
306 * library, which is used in the caching daemon. It reads cached data with the
307 * specified key from the cache entry with entry_name.
308 */
309 int
__cached_read(struct cached_connection_ * connection,const char * entry_name,const char * key,size_t key_size,char * data,size_t * data_size)310 __cached_read(struct cached_connection_ *connection, const char *entry_name,
311 const char *key, size_t key_size, char *data, size_t *data_size)
312 {
313 size_t name_size, result_size;
314 int error_code, rec_error_code;
315 int result;
316
317 assert(connection != NULL);
318 result = 0;
319 error_code = -1;
320
321 result = send_credentials(connection, CET_READ_REQUEST);
322 if (result != 0)
323 goto fin;
324
325 name_size = strlen(entry_name);
326 result = safe_write(connection, &name_size, sizeof(size_t));
327 if (result != 0)
328 goto fin;
329
330 result = safe_write(connection, &key_size, sizeof(size_t));
331 if (result != 0)
332 goto fin;
333
334 result = safe_write(connection, entry_name, name_size);
335 if (result != 0)
336 goto fin;
337
338 result = safe_write(connection, key, key_size);
339 if (result != 0)
340 goto fin;
341
342 result = safe_read(connection, &rec_error_code, sizeof(int));
343 if (result != 0)
344 goto fin;
345
346 if (rec_error_code != 0) {
347 error_code = rec_error_code;
348 goto fin;
349 }
350
351 result = safe_read(connection, &result_size, sizeof(size_t));
352 if (result != 0)
353 goto fin;
354
355 if (result_size > *data_size) {
356 *data_size = result_size;
357 error_code = -2;
358 goto fin;
359 }
360
361 result = safe_read(connection, data, result_size);
362 if (result != 0)
363 goto fin;
364
365 *data_size = result_size;
366 error_code = 0;
367
368 fin:
369 return (error_code);
370 }
371
372 /*
373 * Initializes the mp_write_session. For such a session the new connection
374 * would be opened. The data should be written to the session with
375 * __cached_mp_write function. The __close_cached_mp_write_session function
376 * should be used to submit session and __abandon_cached_mp_write_session - to
377 * abandon it. When the session is submitted, the whole se
378 */
379 struct cached_connection_ *
__open_cached_mp_write_session(struct cached_connection_params const * params,const char * entry_name)380 __open_cached_mp_write_session(struct cached_connection_params const *params,
381 const char *entry_name)
382 {
383 struct cached_connection_ *connection, *retval;
384 size_t name_size;
385 int error_code;
386 int result;
387
388 retval = NULL;
389 connection = __open_cached_connection(params);
390 if (connection == NULL)
391 return (NULL);
392 connection->mp_flag = 1;
393
394 result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST);
395 if (result != 0)
396 goto fin;
397
398 name_size = strlen(entry_name);
399 result = safe_write(connection, &name_size, sizeof(size_t));
400 if (result != 0)
401 goto fin;
402
403 result = safe_write(connection, entry_name, name_size);
404 if (result != 0)
405 goto fin;
406
407 result = safe_read(connection, &error_code, sizeof(int));
408 if (result != 0)
409 goto fin;
410
411 if (error_code != 0)
412 result = error_code;
413
414 fin:
415 if (result != 0)
416 __close_cached_connection(connection);
417 else
418 retval = connection;
419 return (retval);
420 }
421
422 /*
423 * Adds new portion of data to the opened write session
424 */
425 int
__cached_mp_write(struct cached_connection_ * ws,const char * data,size_t data_size)426 __cached_mp_write(struct cached_connection_ *ws, const char *data,
427 size_t data_size)
428 {
429 int request, result;
430 int error_code;
431
432 error_code = -1;
433
434 request = CET_MP_WRITE_SESSION_WRITE_REQUEST;
435 result = safe_write(ws, &request, sizeof(int));
436 if (result != 0)
437 goto fin;
438
439 result = safe_write(ws, &data_size, sizeof(size_t));
440 if (result != 0)
441 goto fin;
442
443 result = safe_write(ws, data, data_size);
444 if (result != 0)
445 goto fin;
446
447 result = safe_read(ws, &error_code, sizeof(int));
448 if (result != 0)
449 error_code = -1;
450
451 fin:
452 return (error_code);
453 }
454
455 /*
456 * Abandons all operations with the write session. All data, that were written
457 * to the session before, are discarded.
458 */
459 int
__abandon_cached_mp_write_session(struct cached_connection_ * ws)460 __abandon_cached_mp_write_session(struct cached_connection_ *ws)
461 {
462 int notification;
463 int result;
464
465 notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION;
466 result = safe_write(ws, ¬ification, sizeof(int));
467 __close_cached_connection(ws);
468 return (result);
469 }
470
471 /*
472 * Gracefully closes the write session. The data, that were previously written
473 * to the session, are committed.
474 */
475 int
__close_cached_mp_write_session(struct cached_connection_ * ws)476 __close_cached_mp_write_session(struct cached_connection_ *ws)
477 {
478 int notification;
479 int result;
480
481 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION;
482 result = safe_write(ws, ¬ification, sizeof(int));
483 __close_cached_connection(ws);
484 return (0);
485 }
486
487 struct cached_connection_ *
__open_cached_mp_read_session(struct cached_connection_params const * params,const char * entry_name)488 __open_cached_mp_read_session(struct cached_connection_params const *params,
489 const char *entry_name)
490 {
491 struct cached_connection_ *connection, *retval;
492 size_t name_size;
493 int error_code;
494 int result;
495
496 retval = NULL;
497 connection = __open_cached_connection(params);
498 if (connection == NULL)
499 return (NULL);
500 connection->mp_flag = 1;
501
502 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST);
503 if (result != 0)
504 goto fin;
505
506 name_size = strlen(entry_name);
507 result = safe_write(connection, &name_size, sizeof(size_t));
508 if (result != 0)
509 goto fin;
510
511 result = safe_write(connection, entry_name, name_size);
512 if (result != 0)
513 goto fin;
514
515 result = safe_read(connection, &error_code, sizeof(int));
516 if (result != 0)
517 goto fin;
518
519 if (error_code != 0)
520 result = error_code;
521
522 fin:
523 if (result != 0)
524 __close_cached_connection(connection);
525 else
526 retval = connection;
527 return (retval);
528 }
529
530 int
__cached_mp_read(struct cached_connection_ * rs,char * data,size_t * data_size)531 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size)
532 {
533 size_t result_size;
534 int error_code, rec_error_code;
535 int request, result;
536
537 error_code = -1;
538 request = CET_MP_READ_SESSION_READ_REQUEST;
539 result = safe_write(rs, &request, sizeof(int));
540 if (result != 0)
541 goto fin;
542
543 result = safe_read(rs, &rec_error_code, sizeof(int));
544 if (result != 0)
545 goto fin;
546
547 if (rec_error_code != 0) {
548 error_code = rec_error_code;
549 goto fin;
550 }
551
552 result = safe_read(rs, &result_size, sizeof(size_t));
553 if (result != 0)
554 goto fin;
555
556 if (result_size > *data_size) {
557 *data_size = result_size;
558 error_code = -2;
559 goto fin;
560 }
561
562 result = safe_read(rs, data, result_size);
563 if (result != 0)
564 goto fin;
565
566 *data_size = result_size;
567 error_code = 0;
568
569 fin:
570 return (error_code);
571 }
572
573 int
__close_cached_mp_read_session(struct cached_connection_ * rs)574 __close_cached_mp_read_session(struct cached_connection_ *rs)
575 {
576
577 __close_cached_connection(rs);
578 return (0);
579 }
580