1 /**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 2004-2008 International Business Machines Corp.
5 * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
6 * Tyler Hicks <tyhicks@ou.edu>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version
10 * 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
20 * 02111-1307, USA.
21 */
22 #include <linux/sched.h>
23 #include <linux/user_namespace.h>
24 #include <linux/nsproxy.h>
25 #include "ecryptfs_kernel.h"
26
27 static LIST_HEAD(ecryptfs_msg_ctx_free_list);
28 static LIST_HEAD(ecryptfs_msg_ctx_alloc_list);
29 static struct mutex ecryptfs_msg_ctx_lists_mux;
30
31 static struct hlist_head *ecryptfs_daemon_hash;
32 struct mutex ecryptfs_daemon_hash_mux;
33 static int ecryptfs_hash_buckets;
34 #define ecryptfs_uid_hash(uid) \
35 hash_long((unsigned long)uid, ecryptfs_hash_buckets)
36
37 static u32 ecryptfs_msg_counter;
38 static struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr;
39
40 /**
41 * ecryptfs_acquire_free_msg_ctx
42 * @msg_ctx: The context that was acquired from the free list
43 *
44 * Acquires a context element from the free list and locks the mutex
45 * on the context. Sets the msg_ctx task to current. Returns zero on
46 * success; non-zero on error or upon failure to acquire a free
47 * context element. Must be called with ecryptfs_msg_ctx_lists_mux
48 * held.
49 */
ecryptfs_acquire_free_msg_ctx(struct ecryptfs_msg_ctx ** msg_ctx)50 static int ecryptfs_acquire_free_msg_ctx(struct ecryptfs_msg_ctx **msg_ctx)
51 {
52 struct list_head *p;
53 int rc;
54
55 if (list_empty(&ecryptfs_msg_ctx_free_list)) {
56 printk(KERN_WARNING "%s: The eCryptfs free "
57 "context list is empty. It may be helpful to "
58 "specify the ecryptfs_message_buf_len "
59 "parameter to be greater than the current "
60 "value of [%d]\n", __func__, ecryptfs_message_buf_len);
61 rc = -ENOMEM;
62 goto out;
63 }
64 list_for_each(p, &ecryptfs_msg_ctx_free_list) {
65 *msg_ctx = list_entry(p, struct ecryptfs_msg_ctx, node);
66 if (mutex_trylock(&(*msg_ctx)->mux)) {
67 (*msg_ctx)->task = current;
68 rc = 0;
69 goto out;
70 }
71 }
72 rc = -ENOMEM;
73 out:
74 return rc;
75 }
76
77 /**
78 * ecryptfs_msg_ctx_free_to_alloc
79 * @msg_ctx: The context to move from the free list to the alloc list
80 *
81 * Must be called with ecryptfs_msg_ctx_lists_mux held.
82 */
ecryptfs_msg_ctx_free_to_alloc(struct ecryptfs_msg_ctx * msg_ctx)83 static void ecryptfs_msg_ctx_free_to_alloc(struct ecryptfs_msg_ctx *msg_ctx)
84 {
85 list_move(&msg_ctx->node, &ecryptfs_msg_ctx_alloc_list);
86 msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_PENDING;
87 msg_ctx->counter = ++ecryptfs_msg_counter;
88 }
89
90 /**
91 * ecryptfs_msg_ctx_alloc_to_free
92 * @msg_ctx: The context to move from the alloc list to the free list
93 *
94 * Must be called with ecryptfs_msg_ctx_lists_mux held.
95 */
ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx * msg_ctx)96 void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx)
97 {
98 list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list);
99 if (msg_ctx->msg)
100 kfree(msg_ctx->msg);
101 msg_ctx->msg = NULL;
102 msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE;
103 }
104
105 /**
106 * ecryptfs_find_daemon_by_euid
107 * @euid: The effective user id which maps to the desired daemon id
108 * @user_ns: The namespace in which @euid applies
109 * @daemon: If return value is zero, points to the desired daemon pointer
110 *
111 * Must be called with ecryptfs_daemon_hash_mux held.
112 *
113 * Search the hash list for the given user id.
114 *
115 * Returns zero if the user id exists in the list; non-zero otherwise.
116 */
ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon ** daemon,uid_t euid,struct user_namespace * user_ns)117 int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid,
118 struct user_namespace *user_ns)
119 {
120 struct hlist_node *elem;
121 int rc;
122
123 hlist_for_each_entry(*daemon, elem,
124 &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)],
125 euid_chain) {
126 if ((*daemon)->euid == euid && (*daemon)->user_ns == user_ns) {
127 rc = 0;
128 goto out;
129 }
130 }
131 rc = -EINVAL;
132 out:
133 return rc;
134 }
135
136 static int
137 ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type,
138 struct ecryptfs_msg_ctx **msg_ctx);
139
140 /**
141 * ecryptfs_send_raw_message
142 * @msg_type: Message type
143 * @daemon: Daemon struct for recipient of message
144 *
145 * A raw message is one that does not include an ecryptfs_message
146 * struct. It simply has a type.
147 *
148 * Must be called with ecryptfs_daemon_hash_mux held.
149 *
150 * Returns zero on success; non-zero otherwise
151 */
ecryptfs_send_raw_message(u8 msg_type,struct ecryptfs_daemon * daemon)152 static int ecryptfs_send_raw_message(u8 msg_type,
153 struct ecryptfs_daemon *daemon)
154 {
155 struct ecryptfs_msg_ctx *msg_ctx;
156 int rc;
157
158 rc = ecryptfs_send_message_locked(NULL, 0, msg_type, &msg_ctx);
159 if (rc) {
160 printk(KERN_ERR "%s: Error whilst attempting to send "
161 "message to ecryptfsd; rc = [%d]\n", __func__, rc);
162 goto out;
163 }
164 /* Raw messages are logically context-free (e.g., no
165 * reply is expected), so we set the state of the
166 * ecryptfs_msg_ctx object to indicate that it should
167 * be freed as soon as the message is sent. */
168 mutex_lock(&msg_ctx->mux);
169 msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_NO_REPLY;
170 mutex_unlock(&msg_ctx->mux);
171 out:
172 return rc;
173 }
174
175 /**
176 * ecryptfs_spawn_daemon - Create and initialize a new daemon struct
177 * @daemon: Pointer to set to newly allocated daemon struct
178 * @euid: Effective user id for the daemon
179 * @user_ns: The namespace in which @euid applies
180 * @pid: Process id for the daemon
181 *
182 * Must be called ceremoniously while in possession of
183 * ecryptfs_sacred_daemon_hash_mux
184 *
185 * Returns zero on success; non-zero otherwise
186 */
187 int
ecryptfs_spawn_daemon(struct ecryptfs_daemon ** daemon,uid_t euid,struct user_namespace * user_ns,struct pid * pid)188 ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid,
189 struct user_namespace *user_ns, struct pid *pid)
190 {
191 int rc = 0;
192
193 (*daemon) = kzalloc(sizeof(**daemon), GFP_KERNEL);
194 if (!(*daemon)) {
195 rc = -ENOMEM;
196 printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of "
197 "GFP_KERNEL memory\n", __func__, sizeof(**daemon));
198 goto out;
199 }
200 (*daemon)->euid = euid;
201 (*daemon)->user_ns = get_user_ns(user_ns);
202 (*daemon)->pid = get_pid(pid);
203 (*daemon)->task = current;
204 mutex_init(&(*daemon)->mux);
205 INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue);
206 init_waitqueue_head(&(*daemon)->wait);
207 (*daemon)->num_queued_msg_ctx = 0;
208 hlist_add_head(&(*daemon)->euid_chain,
209 &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)]);
210 out:
211 return rc;
212 }
213
214 /**
215 * ecryptfs_process_helo
216 * @euid: The user ID owner of the message
217 * @user_ns: The namespace in which @euid applies
218 * @pid: The process ID for the userspace program that sent the
219 * message
220 *
221 * Adds the euid and pid values to the daemon euid hash. If an euid
222 * already has a daemon pid registered, the daemon will be
223 * unregistered before the new daemon is put into the hash list.
224 * Returns zero after adding a new daemon to the hash list;
225 * non-zero otherwise.
226 */
ecryptfs_process_helo(uid_t euid,struct user_namespace * user_ns,struct pid * pid)227 int ecryptfs_process_helo(uid_t euid, struct user_namespace *user_ns,
228 struct pid *pid)
229 {
230 struct ecryptfs_daemon *new_daemon;
231 struct ecryptfs_daemon *old_daemon;
232 int rc;
233
234 mutex_lock(&ecryptfs_daemon_hash_mux);
235 rc = ecryptfs_find_daemon_by_euid(&old_daemon, euid, user_ns);
236 if (rc != 0) {
237 printk(KERN_WARNING "Received request from user [%d] "
238 "to register daemon [0x%p]; unregistering daemon "
239 "[0x%p]\n", euid, pid, old_daemon->pid);
240 rc = ecryptfs_send_raw_message(ECRYPTFS_MSG_QUIT, old_daemon);
241 if (rc)
242 printk(KERN_WARNING "Failed to send QUIT "
243 "message to daemon [0x%p]; rc = [%d]\n",
244 old_daemon->pid, rc);
245 hlist_del(&old_daemon->euid_chain);
246 kfree(old_daemon);
247 }
248 rc = ecryptfs_spawn_daemon(&new_daemon, euid, user_ns, pid);
249 if (rc)
250 printk(KERN_ERR "%s: The gods are displeased with this attempt "
251 "to create a new daemon object for euid [%d]; pid "
252 "[0x%p]; rc = [%d]\n", __func__, euid, pid, rc);
253 mutex_unlock(&ecryptfs_daemon_hash_mux);
254 return rc;
255 }
256
257 /**
258 * ecryptfs_exorcise_daemon - Destroy the daemon struct
259 *
260 * Must be called ceremoniously while in possession of
261 * ecryptfs_daemon_hash_mux and the daemon's own mux.
262 */
ecryptfs_exorcise_daemon(struct ecryptfs_daemon * daemon)263 int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon)
264 {
265 struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp;
266 int rc = 0;
267
268 mutex_lock(&daemon->mux);
269 if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ)
270 || (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) {
271 rc = -EBUSY;
272 printk(KERN_WARNING "%s: Attempt to destroy daemon with pid "
273 "[0x%p], but it is in the midst of a read or a poll\n",
274 __func__, daemon->pid);
275 mutex_unlock(&daemon->mux);
276 goto out;
277 }
278 list_for_each_entry_safe(msg_ctx, msg_ctx_tmp,
279 &daemon->msg_ctx_out_queue, daemon_out_list) {
280 list_del(&msg_ctx->daemon_out_list);
281 daemon->num_queued_msg_ctx--;
282 printk(KERN_WARNING "%s: Warning: dropping message that is in "
283 "the out queue of a dying daemon\n", __func__);
284 ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
285 }
286 hlist_del(&daemon->euid_chain);
287 if (daemon->task)
288 wake_up_process(daemon->task);
289 if (daemon->pid)
290 put_pid(daemon->pid);
291 if (daemon->user_ns)
292 put_user_ns(daemon->user_ns);
293 mutex_unlock(&daemon->mux);
294 memset(daemon, 0, sizeof(*daemon));
295 kfree(daemon);
296 out:
297 return rc;
298 }
299
300 /**
301 * ecryptfs_process_quit
302 * @euid: The user ID owner of the message
303 * @user_ns: The namespace in which @euid applies
304 * @pid: The process ID for the userspace program that sent the
305 * message
306 *
307 * Deletes the corresponding daemon for the given euid and pid, if
308 * it is the registered that is requesting the deletion. Returns zero
309 * after deleting the desired daemon; non-zero otherwise.
310 */
ecryptfs_process_quit(uid_t euid,struct user_namespace * user_ns,struct pid * pid)311 int ecryptfs_process_quit(uid_t euid, struct user_namespace *user_ns,
312 struct pid *pid)
313 {
314 struct ecryptfs_daemon *daemon;
315 int rc;
316
317 mutex_lock(&ecryptfs_daemon_hash_mux);
318 rc = ecryptfs_find_daemon_by_euid(&daemon, euid, user_ns);
319 if (rc || !daemon) {
320 rc = -EINVAL;
321 printk(KERN_ERR "Received request from user [%d] to "
322 "unregister unrecognized daemon [0x%p]\n", euid, pid);
323 goto out_unlock;
324 }
325 rc = ecryptfs_exorcise_daemon(daemon);
326 out_unlock:
327 mutex_unlock(&ecryptfs_daemon_hash_mux);
328 return rc;
329 }
330
331 /**
332 * ecryptfs_process_reponse
333 * @msg: The ecryptfs message received; the caller should sanity check
334 * msg->data_len and free the memory
335 * @pid: The process ID of the userspace application that sent the
336 * message
337 * @seq: The sequence number of the message; must match the sequence
338 * number for the existing message context waiting for this
339 * response
340 *
341 * Processes a response message after sending an operation request to
342 * userspace. Some other process is awaiting this response. Before
343 * sending out its first communications, the other process allocated a
344 * msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The
345 * response message contains this index so that we can copy over the
346 * response message into the msg_ctx that the process holds a
347 * reference to. The other process is going to wake up, check to see
348 * that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then
349 * proceed to read off and process the response message. Returns zero
350 * upon delivery to desired context element; non-zero upon delivery
351 * failure or error.
352 *
353 * Returns zero on success; non-zero otherwise
354 */
ecryptfs_process_response(struct ecryptfs_message * msg,uid_t euid,struct user_namespace * user_ns,struct pid * pid,u32 seq)355 int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
356 struct user_namespace *user_ns, struct pid *pid,
357 u32 seq)
358 {
359 struct ecryptfs_daemon *daemon;
360 struct ecryptfs_msg_ctx *msg_ctx;
361 size_t msg_size;
362 struct nsproxy *nsproxy;
363 struct user_namespace *tsk_user_ns;
364 uid_t ctx_euid;
365 int rc;
366
367 if (msg->index >= ecryptfs_message_buf_len) {
368 rc = -EINVAL;
369 printk(KERN_ERR "%s: Attempt to reference "
370 "context buffer at index [%d]; maximum "
371 "allowable is [%d]\n", __func__, msg->index,
372 (ecryptfs_message_buf_len - 1));
373 goto out;
374 }
375 msg_ctx = &ecryptfs_msg_ctx_arr[msg->index];
376 mutex_lock(&msg_ctx->mux);
377 mutex_lock(&ecryptfs_daemon_hash_mux);
378 rcu_read_lock();
379 nsproxy = task_nsproxy(msg_ctx->task);
380 if (nsproxy == NULL) {
381 rc = -EBADMSG;
382 printk(KERN_ERR "%s: Receiving process is a zombie. Dropping "
383 "message.\n", __func__);
384 rcu_read_unlock();
385 mutex_unlock(&ecryptfs_daemon_hash_mux);
386 goto wake_up;
387 }
388 tsk_user_ns = __task_cred(msg_ctx->task)->user->user_ns;
389 ctx_euid = task_euid(msg_ctx->task);
390 rc = ecryptfs_find_daemon_by_euid(&daemon, ctx_euid, tsk_user_ns);
391 rcu_read_unlock();
392 mutex_unlock(&ecryptfs_daemon_hash_mux);
393 if (rc) {
394 rc = -EBADMSG;
395 printk(KERN_WARNING "%s: User [%d] received a "
396 "message response from process [0x%p] but does "
397 "not have a registered daemon\n", __func__,
398 ctx_euid, pid);
399 goto wake_up;
400 }
401 if (ctx_euid != euid) {
402 rc = -EBADMSG;
403 printk(KERN_WARNING "%s: Received message from user "
404 "[%d]; expected message from user [%d]\n", __func__,
405 euid, ctx_euid);
406 goto unlock;
407 }
408 if (tsk_user_ns != user_ns) {
409 rc = -EBADMSG;
410 printk(KERN_WARNING "%s: Received message from user_ns "
411 "[0x%p]; expected message from user_ns [0x%p]\n",
412 __func__, user_ns, tsk_user_ns);
413 goto unlock;
414 }
415 if (daemon->pid != pid) {
416 rc = -EBADMSG;
417 printk(KERN_ERR "%s: User [%d] sent a message response "
418 "from an unrecognized process [0x%p]\n",
419 __func__, ctx_euid, pid);
420 goto unlock;
421 }
422 if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) {
423 rc = -EINVAL;
424 printk(KERN_WARNING "%s: Desired context element is not "
425 "pending a response\n", __func__);
426 goto unlock;
427 } else if (msg_ctx->counter != seq) {
428 rc = -EINVAL;
429 printk(KERN_WARNING "%s: Invalid message sequence; "
430 "expected [%d]; received [%d]\n", __func__,
431 msg_ctx->counter, seq);
432 goto unlock;
433 }
434 msg_size = (sizeof(*msg) + msg->data_len);
435 msg_ctx->msg = kmalloc(msg_size, GFP_KERNEL);
436 if (!msg_ctx->msg) {
437 rc = -ENOMEM;
438 printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of "
439 "GFP_KERNEL memory\n", __func__, msg_size);
440 goto unlock;
441 }
442 memcpy(msg_ctx->msg, msg, msg_size);
443 msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE;
444 rc = 0;
445 wake_up:
446 wake_up_process(msg_ctx->task);
447 unlock:
448 mutex_unlock(&msg_ctx->mux);
449 out:
450 return rc;
451 }
452
453 /**
454 * ecryptfs_send_message_locked
455 * @data: The data to send
456 * @data_len: The length of data
457 * @msg_ctx: The message context allocated for the send
458 *
459 * Must be called with ecryptfs_daemon_hash_mux held.
460 *
461 * Returns zero on success; non-zero otherwise
462 */
463 static int
ecryptfs_send_message_locked(char * data,int data_len,u8 msg_type,struct ecryptfs_msg_ctx ** msg_ctx)464 ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type,
465 struct ecryptfs_msg_ctx **msg_ctx)
466 {
467 struct ecryptfs_daemon *daemon;
468 uid_t euid = current_euid();
469 int rc;
470
471 rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
472 if (rc || !daemon) {
473 rc = -ENOTCONN;
474 printk(KERN_ERR "%s: User [%d] does not have a daemon "
475 "registered\n", __func__, euid);
476 goto out;
477 }
478 mutex_lock(&ecryptfs_msg_ctx_lists_mux);
479 rc = ecryptfs_acquire_free_msg_ctx(msg_ctx);
480 if (rc) {
481 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
482 printk(KERN_WARNING "%s: Could not claim a free "
483 "context element\n", __func__);
484 goto out;
485 }
486 ecryptfs_msg_ctx_free_to_alloc(*msg_ctx);
487 mutex_unlock(&(*msg_ctx)->mux);
488 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
489 rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, 0,
490 daemon);
491 if (rc)
492 printk(KERN_ERR "%s: Error attempting to send message to "
493 "userspace daemon; rc = [%d]\n", __func__, rc);
494 out:
495 return rc;
496 }
497
498 /**
499 * ecryptfs_send_message
500 * @data: The data to send
501 * @data_len: The length of data
502 * @msg_ctx: The message context allocated for the send
503 *
504 * Grabs ecryptfs_daemon_hash_mux.
505 *
506 * Returns zero on success; non-zero otherwise
507 */
ecryptfs_send_message(char * data,int data_len,struct ecryptfs_msg_ctx ** msg_ctx)508 int ecryptfs_send_message(char *data, int data_len,
509 struct ecryptfs_msg_ctx **msg_ctx)
510 {
511 int rc;
512
513 mutex_lock(&ecryptfs_daemon_hash_mux);
514 rc = ecryptfs_send_message_locked(data, data_len, ECRYPTFS_MSG_REQUEST,
515 msg_ctx);
516 mutex_unlock(&ecryptfs_daemon_hash_mux);
517 return rc;
518 }
519
520 /**
521 * ecryptfs_wait_for_response
522 * @msg_ctx: The context that was assigned when sending a message
523 * @msg: The incoming message from userspace; not set if rc != 0
524 *
525 * Sleeps until awaken by ecryptfs_receive_message or until the amount
526 * of time exceeds ecryptfs_message_wait_timeout. If zero is
527 * returned, msg will point to a valid message from userspace; a
528 * non-zero value is returned upon failure to receive a message or an
529 * error occurs. Callee must free @msg on success.
530 */
ecryptfs_wait_for_response(struct ecryptfs_msg_ctx * msg_ctx,struct ecryptfs_message ** msg)531 int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
532 struct ecryptfs_message **msg)
533 {
534 signed long timeout = ecryptfs_message_wait_timeout * HZ;
535 int rc = 0;
536
537 sleep:
538 timeout = schedule_timeout_interruptible(timeout);
539 mutex_lock(&ecryptfs_msg_ctx_lists_mux);
540 mutex_lock(&msg_ctx->mux);
541 if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_DONE) {
542 if (timeout) {
543 mutex_unlock(&msg_ctx->mux);
544 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
545 goto sleep;
546 }
547 rc = -ENOMSG;
548 } else {
549 *msg = msg_ctx->msg;
550 msg_ctx->msg = NULL;
551 }
552 ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
553 mutex_unlock(&msg_ctx->mux);
554 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
555 return rc;
556 }
557
ecryptfs_init_messaging(void)558 int ecryptfs_init_messaging(void)
559 {
560 int i;
561 int rc = 0;
562
563 if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) {
564 ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS;
565 printk(KERN_WARNING "%s: Specified number of users is "
566 "too large, defaulting to [%d] users\n", __func__,
567 ecryptfs_number_of_users);
568 }
569 mutex_init(&ecryptfs_daemon_hash_mux);
570 mutex_lock(&ecryptfs_daemon_hash_mux);
571 ecryptfs_hash_buckets = 1;
572 while (ecryptfs_number_of_users >> ecryptfs_hash_buckets)
573 ecryptfs_hash_buckets++;
574 ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head)
575 * ecryptfs_hash_buckets), GFP_KERNEL);
576 if (!ecryptfs_daemon_hash) {
577 rc = -ENOMEM;
578 printk(KERN_ERR "%s: Failed to allocate memory\n", __func__);
579 mutex_unlock(&ecryptfs_daemon_hash_mux);
580 goto out;
581 }
582 for (i = 0; i < ecryptfs_hash_buckets; i++)
583 INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]);
584 mutex_unlock(&ecryptfs_daemon_hash_mux);
585 ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx)
586 * ecryptfs_message_buf_len),
587 GFP_KERNEL);
588 if (!ecryptfs_msg_ctx_arr) {
589 rc = -ENOMEM;
590 printk(KERN_ERR "%s: Failed to allocate memory\n", __func__);
591 goto out;
592 }
593 mutex_init(&ecryptfs_msg_ctx_lists_mux);
594 mutex_lock(&ecryptfs_msg_ctx_lists_mux);
595 ecryptfs_msg_counter = 0;
596 for (i = 0; i < ecryptfs_message_buf_len; i++) {
597 INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].node);
598 INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list);
599 mutex_init(&ecryptfs_msg_ctx_arr[i].mux);
600 mutex_lock(&ecryptfs_msg_ctx_arr[i].mux);
601 ecryptfs_msg_ctx_arr[i].index = i;
602 ecryptfs_msg_ctx_arr[i].state = ECRYPTFS_MSG_CTX_STATE_FREE;
603 ecryptfs_msg_ctx_arr[i].counter = 0;
604 ecryptfs_msg_ctx_arr[i].task = NULL;
605 ecryptfs_msg_ctx_arr[i].msg = NULL;
606 list_add_tail(&ecryptfs_msg_ctx_arr[i].node,
607 &ecryptfs_msg_ctx_free_list);
608 mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux);
609 }
610 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
611 rc = ecryptfs_init_ecryptfs_miscdev();
612 if (rc)
613 ecryptfs_release_messaging();
614 out:
615 return rc;
616 }
617
ecryptfs_release_messaging(void)618 void ecryptfs_release_messaging(void)
619 {
620 if (ecryptfs_msg_ctx_arr) {
621 int i;
622
623 mutex_lock(&ecryptfs_msg_ctx_lists_mux);
624 for (i = 0; i < ecryptfs_message_buf_len; i++) {
625 mutex_lock(&ecryptfs_msg_ctx_arr[i].mux);
626 if (ecryptfs_msg_ctx_arr[i].msg)
627 kfree(ecryptfs_msg_ctx_arr[i].msg);
628 mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux);
629 }
630 kfree(ecryptfs_msg_ctx_arr);
631 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
632 }
633 if (ecryptfs_daemon_hash) {
634 struct hlist_node *elem;
635 struct ecryptfs_daemon *daemon;
636 int i;
637
638 mutex_lock(&ecryptfs_daemon_hash_mux);
639 for (i = 0; i < ecryptfs_hash_buckets; i++) {
640 int rc;
641
642 hlist_for_each_entry(daemon, elem,
643 &ecryptfs_daemon_hash[i],
644 euid_chain) {
645 rc = ecryptfs_exorcise_daemon(daemon);
646 if (rc)
647 printk(KERN_ERR "%s: Error whilst "
648 "attempting to destroy daemon; "
649 "rc = [%d]. Dazed and confused, "
650 "but trying to continue.\n",
651 __func__, rc);
652 }
653 }
654 kfree(ecryptfs_daemon_hash);
655 mutex_unlock(&ecryptfs_daemon_hash_mux);
656 }
657 ecryptfs_destroy_ecryptfs_miscdev();
658 return;
659 }
660