Commit | Line | Data |
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88b4a07e MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * | |
f66e883e | 4 | * Copyright (C) 2004-2008 International Business Machines Corp. |
88b4a07e MH |
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 | */ | |
e8edc6e0 | 22 | #include <linux/sched.h> |
6a3fd92e MH |
23 | #include <linux/user_namespace.h> |
24 | #include <linux/nsproxy.h> | |
88b4a07e MH |
25 | #include "ecryptfs_kernel.h" |
26 | ||
dd2a3b7a MH |
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; | |
88b4a07e | 30 | |
f66e883e MH |
31 | static struct hlist_head *ecryptfs_daemon_hash; |
32 | struct mutex ecryptfs_daemon_hash_mux; | |
dd2a3b7a MH |
33 | static int ecryptfs_hash_buckets; |
34 | #define ecryptfs_uid_hash(uid) \ | |
35 | hash_long((unsigned long)uid, ecryptfs_hash_buckets) | |
88b4a07e | 36 | |
f66e883e | 37 | static u32 ecryptfs_msg_counter; |
dd2a3b7a | 38 | static struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr; |
88b4a07e MH |
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 | |
f66e883e MH |
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. | |
88b4a07e MH |
49 | */ |
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)) { | |
f66e883e MH |
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); | |
88b4a07e MH |
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 | * | |
f66e883e | 81 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
88b4a07e MH |
82 | */ |
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 | * | |
f66e883e | 94 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
88b4a07e | 95 | */ |
f66e883e | 96 | void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx) |
88b4a07e MH |
97 | { |
98 | list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list); | |
99 | if (msg_ctx->msg) | |
100 | kfree(msg_ctx->msg); | |
f66e883e | 101 | msg_ctx->msg = NULL; |
88b4a07e MH |
102 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE; |
103 | } | |
104 | ||
105 | /** | |
f66e883e MH |
106 | * ecryptfs_find_daemon_by_euid |
107 | * @euid: The effective user id which maps to the desired daemon id | |
6a3fd92e | 108 | * @user_ns: The namespace in which @euid applies |
f66e883e | 109 | * @daemon: If return value is zero, points to the desired daemon pointer |
88b4a07e | 110 | * |
f66e883e MH |
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. | |
88b4a07e | 116 | */ |
6a3fd92e MH |
117 | int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid, |
118 | struct user_namespace *user_ns) | |
88b4a07e MH |
119 | { |
120 | struct hlist_node *elem; | |
121 | int rc; | |
122 | ||
f66e883e MH |
123 | hlist_for_each_entry(*daemon, elem, |
124 | &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)], | |
125 | euid_chain) { | |
6a3fd92e | 126 | if ((*daemon)->euid == euid && (*daemon)->user_ns == user_ns) { |
88b4a07e MH |
127 | rc = 0; |
128 | goto out; | |
129 | } | |
130 | } | |
131 | rc = -EINVAL; | |
132 | out: | |
133 | return rc; | |
134 | } | |
135 | ||
f66e883e MH |
136 | /** |
137 | * ecryptfs_spawn_daemon - Create and initialize a new daemon struct | |
138 | * @daemon: Pointer to set to newly allocated daemon struct | |
139 | * @euid: Effective user id for the daemon | |
6a3fd92e | 140 | * @user_ns: The namespace in which @euid applies |
f66e883e MH |
141 | * @pid: Process id for the daemon |
142 | * | |
143 | * Must be called ceremoniously while in possession of | |
144 | * ecryptfs_sacred_daemon_hash_mux | |
145 | * | |
146 | * Returns zero on success; non-zero otherwise | |
147 | */ | |
148 | int | |
6a3fd92e MH |
149 | ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid, |
150 | struct user_namespace *user_ns, struct pid *pid) | |
f66e883e MH |
151 | { |
152 | int rc = 0; | |
153 | ||
154 | (*daemon) = kzalloc(sizeof(**daemon), GFP_KERNEL); | |
155 | if (!(*daemon)) { | |
156 | rc = -ENOMEM; | |
df261c52 | 157 | printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of " |
f66e883e MH |
158 | "GFP_KERNEL memory\n", __func__, sizeof(**daemon)); |
159 | goto out; | |
160 | } | |
161 | (*daemon)->euid = euid; | |
6a3fd92e MH |
162 | (*daemon)->user_ns = get_user_ns(user_ns); |
163 | (*daemon)->pid = get_pid(pid); | |
f66e883e MH |
164 | (*daemon)->task = current; |
165 | mutex_init(&(*daemon)->mux); | |
166 | INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue); | |
167 | init_waitqueue_head(&(*daemon)->wait); | |
168 | (*daemon)->num_queued_msg_ctx = 0; | |
169 | hlist_add_head(&(*daemon)->euid_chain, | |
170 | &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)]); | |
171 | out: | |
88b4a07e MH |
172 | return rc; |
173 | } | |
174 | ||
f66e883e MH |
175 | /** |
176 | * ecryptfs_exorcise_daemon - Destroy the daemon struct | |
177 | * | |
178 | * Must be called ceremoniously while in possession of | |
179 | * ecryptfs_daemon_hash_mux and the daemon's own mux. | |
180 | */ | |
181 | int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon) | |
182 | { | |
183 | struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp; | |
184 | int rc = 0; | |
185 | ||
186 | mutex_lock(&daemon->mux); | |
187 | if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ) | |
188 | || (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) { | |
189 | rc = -EBUSY; | |
190 | printk(KERN_WARNING "%s: Attempt to destroy daemon with pid " | |
6a3fd92e | 191 | "[0x%p], but it is in the midst of a read or a poll\n", |
f66e883e MH |
192 | __func__, daemon->pid); |
193 | mutex_unlock(&daemon->mux); | |
194 | goto out; | |
195 | } | |
196 | list_for_each_entry_safe(msg_ctx, msg_ctx_tmp, | |
197 | &daemon->msg_ctx_out_queue, daemon_out_list) { | |
198 | list_del(&msg_ctx->daemon_out_list); | |
199 | daemon->num_queued_msg_ctx--; | |
200 | printk(KERN_WARNING "%s: Warning: dropping message that is in " | |
201 | "the out queue of a dying daemon\n", __func__); | |
202 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
203 | } | |
204 | hlist_del(&daemon->euid_chain); | |
205 | if (daemon->task) | |
206 | wake_up_process(daemon->task); | |
6a3fd92e MH |
207 | if (daemon->pid) |
208 | put_pid(daemon->pid); | |
209 | if (daemon->user_ns) | |
210 | put_user_ns(daemon->user_ns); | |
f66e883e | 211 | mutex_unlock(&daemon->mux); |
00fcf2cb | 212 | kzfree(daemon); |
f66e883e | 213 | out: |
88b4a07e MH |
214 | return rc; |
215 | } | |
216 | ||
217 | /** | |
218 | * ecryptfs_process_quit | |
f66e883e | 219 | * @euid: The user ID owner of the message |
6a3fd92e | 220 | * @user_ns: The namespace in which @euid applies |
88b4a07e MH |
221 | * @pid: The process ID for the userspace program that sent the |
222 | * message | |
223 | * | |
f66e883e | 224 | * Deletes the corresponding daemon for the given euid and pid, if |
88b4a07e | 225 | * it is the registered that is requesting the deletion. Returns zero |
f66e883e | 226 | * after deleting the desired daemon; non-zero otherwise. |
88b4a07e | 227 | */ |
6a3fd92e MH |
228 | int ecryptfs_process_quit(uid_t euid, struct user_namespace *user_ns, |
229 | struct pid *pid) | |
88b4a07e | 230 | { |
f66e883e | 231 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
232 | int rc; |
233 | ||
f66e883e | 234 | mutex_lock(&ecryptfs_daemon_hash_mux); |
6a3fd92e | 235 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid, user_ns); |
f66e883e | 236 | if (rc || !daemon) { |
88b4a07e | 237 | rc = -EINVAL; |
f66e883e | 238 | printk(KERN_ERR "Received request from user [%d] to " |
6a3fd92e | 239 | "unregister unrecognized daemon [0x%p]\n", euid, pid); |
f66e883e | 240 | goto out_unlock; |
88b4a07e | 241 | } |
f66e883e MH |
242 | rc = ecryptfs_exorcise_daemon(daemon); |
243 | out_unlock: | |
244 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
245 | return rc; |
246 | } | |
247 | ||
248 | /** | |
249 | * ecryptfs_process_reponse | |
250 | * @msg: The ecryptfs message received; the caller should sanity check | |
f66e883e | 251 | * msg->data_len and free the memory |
88b4a07e MH |
252 | * @pid: The process ID of the userspace application that sent the |
253 | * message | |
f66e883e MH |
254 | * @seq: The sequence number of the message; must match the sequence |
255 | * number for the existing message context waiting for this | |
256 | * response | |
257 | * | |
258 | * Processes a response message after sending an operation request to | |
259 | * userspace. Some other process is awaiting this response. Before | |
260 | * sending out its first communications, the other process allocated a | |
261 | * msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The | |
262 | * response message contains this index so that we can copy over the | |
263 | * response message into the msg_ctx that the process holds a | |
264 | * reference to. The other process is going to wake up, check to see | |
265 | * that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then | |
266 | * proceed to read off and process the response message. Returns zero | |
267 | * upon delivery to desired context element; non-zero upon delivery | |
268 | * failure or error. | |
88b4a07e | 269 | * |
f66e883e | 270 | * Returns zero on success; non-zero otherwise |
88b4a07e | 271 | */ |
f66e883e | 272 | int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid, |
6a3fd92e MH |
273 | struct user_namespace *user_ns, struct pid *pid, |
274 | u32 seq) | |
88b4a07e | 275 | { |
f66e883e | 276 | struct ecryptfs_daemon *daemon; |
88b4a07e | 277 | struct ecryptfs_msg_ctx *msg_ctx; |
f66e883e | 278 | size_t msg_size; |
6a3fd92e | 279 | struct nsproxy *nsproxy; |
18b6e041 | 280 | struct user_namespace *tsk_user_ns; |
4eea0353 | 281 | uid_t ctx_euid; |
88b4a07e MH |
282 | int rc; |
283 | ||
284 | if (msg->index >= ecryptfs_message_buf_len) { | |
285 | rc = -EINVAL; | |
f66e883e MH |
286 | printk(KERN_ERR "%s: Attempt to reference " |
287 | "context buffer at index [%d]; maximum " | |
288 | "allowable is [%d]\n", __func__, msg->index, | |
289 | (ecryptfs_message_buf_len - 1)); | |
88b4a07e MH |
290 | goto out; |
291 | } | |
292 | msg_ctx = &ecryptfs_msg_ctx_arr[msg->index]; | |
293 | mutex_lock(&msg_ctx->mux); | |
f66e883e | 294 | mutex_lock(&ecryptfs_daemon_hash_mux); |
6a3fd92e MH |
295 | rcu_read_lock(); |
296 | nsproxy = task_nsproxy(msg_ctx->task); | |
297 | if (nsproxy == NULL) { | |
298 | rc = -EBADMSG; | |
299 | printk(KERN_ERR "%s: Receiving process is a zombie. Dropping " | |
300 | "message.\n", __func__); | |
301 | rcu_read_unlock(); | |
302 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
303 | goto wake_up; | |
304 | } | |
18b6e041 | 305 | tsk_user_ns = __task_cred(msg_ctx->task)->user->user_ns; |
4eea0353 | 306 | ctx_euid = task_euid(msg_ctx->task); |
18b6e041 | 307 | rc = ecryptfs_find_daemon_by_euid(&daemon, ctx_euid, tsk_user_ns); |
6a3fd92e | 308 | rcu_read_unlock(); |
f66e883e MH |
309 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
310 | if (rc) { | |
88b4a07e | 311 | rc = -EBADMSG; |
f66e883e | 312 | printk(KERN_WARNING "%s: User [%d] received a " |
6a3fd92e | 313 | "message response from process [0x%p] but does " |
f66e883e | 314 | "not have a registered daemon\n", __func__, |
4eea0353 | 315 | ctx_euid, pid); |
88b4a07e MH |
316 | goto wake_up; |
317 | } | |
4eea0353 | 318 | if (ctx_euid != euid) { |
dddfa461 | 319 | rc = -EBADMSG; |
f66e883e MH |
320 | printk(KERN_WARNING "%s: Received message from user " |
321 | "[%d]; expected message from user [%d]\n", __func__, | |
4eea0353 | 322 | euid, ctx_euid); |
dddfa461 MH |
323 | goto unlock; |
324 | } | |
18b6e041 | 325 | if (tsk_user_ns != user_ns) { |
6a3fd92e MH |
326 | rc = -EBADMSG; |
327 | printk(KERN_WARNING "%s: Received message from user_ns " | |
328 | "[0x%p]; expected message from user_ns [0x%p]\n", | |
18b6e041 | 329 | __func__, user_ns, tsk_user_ns); |
6a3fd92e MH |
330 | goto unlock; |
331 | } | |
f66e883e | 332 | if (daemon->pid != pid) { |
88b4a07e | 333 | rc = -EBADMSG; |
f66e883e | 334 | printk(KERN_ERR "%s: User [%d] sent a message response " |
6a3fd92e | 335 | "from an unrecognized process [0x%p]\n", |
4eea0353 | 336 | __func__, ctx_euid, pid); |
88b4a07e MH |
337 | goto unlock; |
338 | } | |
339 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) { | |
340 | rc = -EINVAL; | |
f66e883e MH |
341 | printk(KERN_WARNING "%s: Desired context element is not " |
342 | "pending a response\n", __func__); | |
88b4a07e MH |
343 | goto unlock; |
344 | } else if (msg_ctx->counter != seq) { | |
345 | rc = -EINVAL; | |
f66e883e MH |
346 | printk(KERN_WARNING "%s: Invalid message sequence; " |
347 | "expected [%d]; received [%d]\n", __func__, | |
348 | msg_ctx->counter, seq); | |
88b4a07e MH |
349 | goto unlock; |
350 | } | |
f66e883e | 351 | msg_size = (sizeof(*msg) + msg->data_len); |
88b4a07e MH |
352 | msg_ctx->msg = kmalloc(msg_size, GFP_KERNEL); |
353 | if (!msg_ctx->msg) { | |
354 | rc = -ENOMEM; | |
df261c52 | 355 | printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of " |
f66e883e | 356 | "GFP_KERNEL memory\n", __func__, msg_size); |
88b4a07e MH |
357 | goto unlock; |
358 | } | |
359 | memcpy(msg_ctx->msg, msg, msg_size); | |
360 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE; | |
361 | rc = 0; | |
362 | wake_up: | |
363 | wake_up_process(msg_ctx->task); | |
364 | unlock: | |
365 | mutex_unlock(&msg_ctx->mux); | |
366 | out: | |
367 | return rc; | |
368 | } | |
369 | ||
370 | /** | |
f66e883e | 371 | * ecryptfs_send_message_locked |
88b4a07e MH |
372 | * @data: The data to send |
373 | * @data_len: The length of data | |
374 | * @msg_ctx: The message context allocated for the send | |
f66e883e MH |
375 | * |
376 | * Must be called with ecryptfs_daemon_hash_mux held. | |
377 | * | |
378 | * Returns zero on success; non-zero otherwise | |
88b4a07e | 379 | */ |
f66e883e | 380 | static int |
624ae528 TH |
381 | ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type, |
382 | struct ecryptfs_msg_ctx **msg_ctx) | |
88b4a07e | 383 | { |
f66e883e | 384 | struct ecryptfs_daemon *daemon; |
4eea0353 | 385 | uid_t euid = current_euid(); |
88b4a07e MH |
386 | int rc; |
387 | ||
18b6e041 | 388 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); |
f66e883e | 389 | if (rc || !daemon) { |
88b4a07e | 390 | rc = -ENOTCONN; |
f66e883e | 391 | printk(KERN_ERR "%s: User [%d] does not have a daemon " |
4eea0353 | 392 | "registered\n", __func__, euid); |
88b4a07e MH |
393 | goto out; |
394 | } | |
88b4a07e MH |
395 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); |
396 | rc = ecryptfs_acquire_free_msg_ctx(msg_ctx); | |
397 | if (rc) { | |
398 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
f66e883e MH |
399 | printk(KERN_WARNING "%s: Could not claim a free " |
400 | "context element\n", __func__); | |
88b4a07e MH |
401 | goto out; |
402 | } | |
403 | ecryptfs_msg_ctx_free_to_alloc(*msg_ctx); | |
404 | mutex_unlock(&(*msg_ctx)->mux); | |
405 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
624ae528 TH |
406 | rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, 0, |
407 | daemon); | |
f66e883e MH |
408 | if (rc) |
409 | printk(KERN_ERR "%s: Error attempting to send message to " | |
410 | "userspace daemon; rc = [%d]\n", __func__, rc); | |
88b4a07e MH |
411 | out: |
412 | return rc; | |
413 | } | |
414 | ||
f66e883e MH |
415 | /** |
416 | * ecryptfs_send_message | |
f66e883e MH |
417 | * @data: The data to send |
418 | * @data_len: The length of data | |
419 | * @msg_ctx: The message context allocated for the send | |
420 | * | |
421 | * Grabs ecryptfs_daemon_hash_mux. | |
422 | * | |
423 | * Returns zero on success; non-zero otherwise | |
424 | */ | |
624ae528 | 425 | int ecryptfs_send_message(char *data, int data_len, |
f66e883e MH |
426 | struct ecryptfs_msg_ctx **msg_ctx) |
427 | { | |
428 | int rc; | |
429 | ||
430 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
624ae528 TH |
431 | rc = ecryptfs_send_message_locked(data, data_len, ECRYPTFS_MSG_REQUEST, |
432 | msg_ctx); | |
f66e883e MH |
433 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
434 | return rc; | |
435 | } | |
436 | ||
88b4a07e MH |
437 | /** |
438 | * ecryptfs_wait_for_response | |
439 | * @msg_ctx: The context that was assigned when sending a message | |
440 | * @msg: The incoming message from userspace; not set if rc != 0 | |
441 | * | |
442 | * Sleeps until awaken by ecryptfs_receive_message or until the amount | |
443 | * of time exceeds ecryptfs_message_wait_timeout. If zero is | |
444 | * returned, msg will point to a valid message from userspace; a | |
445 | * non-zero value is returned upon failure to receive a message or an | |
f66e883e | 446 | * error occurs. Callee must free @msg on success. |
88b4a07e MH |
447 | */ |
448 | int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, | |
449 | struct ecryptfs_message **msg) | |
450 | { | |
451 | signed long timeout = ecryptfs_message_wait_timeout * HZ; | |
452 | int rc = 0; | |
453 | ||
454 | sleep: | |
455 | timeout = schedule_timeout_interruptible(timeout); | |
456 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
457 | mutex_lock(&msg_ctx->mux); | |
458 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_DONE) { | |
459 | if (timeout) { | |
460 | mutex_unlock(&msg_ctx->mux); | |
461 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
462 | goto sleep; | |
463 | } | |
464 | rc = -ENOMSG; | |
465 | } else { | |
466 | *msg = msg_ctx->msg; | |
467 | msg_ctx->msg = NULL; | |
468 | } | |
469 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
470 | mutex_unlock(&msg_ctx->mux); | |
471 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
472 | return rc; | |
473 | } | |
474 | ||
624ae528 | 475 | int ecryptfs_init_messaging(void) |
88b4a07e MH |
476 | { |
477 | int i; | |
478 | int rc = 0; | |
479 | ||
480 | if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) { | |
481 | ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS; | |
f66e883e MH |
482 | printk(KERN_WARNING "%s: Specified number of users is " |
483 | "too large, defaulting to [%d] users\n", __func__, | |
484 | ecryptfs_number_of_users); | |
88b4a07e | 485 | } |
f66e883e MH |
486 | mutex_init(&ecryptfs_daemon_hash_mux); |
487 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
5dda6992 MH |
488 | ecryptfs_hash_buckets = 1; |
489 | while (ecryptfs_number_of_users >> ecryptfs_hash_buckets) | |
490 | ecryptfs_hash_buckets++; | |
f66e883e MH |
491 | ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head) |
492 | * ecryptfs_hash_buckets), GFP_KERNEL); | |
493 | if (!ecryptfs_daemon_hash) { | |
88b4a07e | 494 | rc = -ENOMEM; |
f66e883e MH |
495 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
496 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
497 | goto out; |
498 | } | |
499 | for (i = 0; i < ecryptfs_hash_buckets; i++) | |
f66e883e MH |
500 | INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]); |
501 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e | 502 | ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx) |
f66e883e MH |
503 | * ecryptfs_message_buf_len), |
504 | GFP_KERNEL); | |
88b4a07e MH |
505 | if (!ecryptfs_msg_ctx_arr) { |
506 | rc = -ENOMEM; | |
f66e883e | 507 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
88b4a07e MH |
508 | goto out; |
509 | } | |
510 | mutex_init(&ecryptfs_msg_ctx_lists_mux); | |
511 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
512 | ecryptfs_msg_counter = 0; | |
513 | for (i = 0; i < ecryptfs_message_buf_len; i++) { | |
514 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].node); | |
f66e883e | 515 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list); |
88b4a07e MH |
516 | mutex_init(&ecryptfs_msg_ctx_arr[i].mux); |
517 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); | |
518 | ecryptfs_msg_ctx_arr[i].index = i; | |
519 | ecryptfs_msg_ctx_arr[i].state = ECRYPTFS_MSG_CTX_STATE_FREE; | |
520 | ecryptfs_msg_ctx_arr[i].counter = 0; | |
521 | ecryptfs_msg_ctx_arr[i].task = NULL; | |
522 | ecryptfs_msg_ctx_arr[i].msg = NULL; | |
523 | list_add_tail(&ecryptfs_msg_ctx_arr[i].node, | |
524 | &ecryptfs_msg_ctx_free_list); | |
525 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); | |
526 | } | |
527 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
624ae528 TH |
528 | rc = ecryptfs_init_ecryptfs_miscdev(); |
529 | if (rc) | |
530 | ecryptfs_release_messaging(); | |
88b4a07e MH |
531 | out: |
532 | return rc; | |
533 | } | |
534 | ||
624ae528 | 535 | void ecryptfs_release_messaging(void) |
88b4a07e MH |
536 | { |
537 | if (ecryptfs_msg_ctx_arr) { | |
538 | int i; | |
539 | ||
540 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
541 | for (i = 0; i < ecryptfs_message_buf_len; i++) { | |
542 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); | |
543 | if (ecryptfs_msg_ctx_arr[i].msg) | |
544 | kfree(ecryptfs_msg_ctx_arr[i].msg); | |
545 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); | |
546 | } | |
547 | kfree(ecryptfs_msg_ctx_arr); | |
548 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
549 | } | |
f66e883e | 550 | if (ecryptfs_daemon_hash) { |
88b4a07e | 551 | struct hlist_node *elem; |
f66e883e | 552 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
553 | int i; |
554 | ||
f66e883e | 555 | mutex_lock(&ecryptfs_daemon_hash_mux); |
88b4a07e | 556 | for (i = 0; i < ecryptfs_hash_buckets; i++) { |
f66e883e MH |
557 | int rc; |
558 | ||
559 | hlist_for_each_entry(daemon, elem, | |
560 | &ecryptfs_daemon_hash[i], | |
561 | euid_chain) { | |
562 | rc = ecryptfs_exorcise_daemon(daemon); | |
563 | if (rc) | |
564 | printk(KERN_ERR "%s: Error whilst " | |
565 | "attempting to destroy daemon; " | |
566 | "rc = [%d]. Dazed and confused, " | |
567 | "but trying to continue.\n", | |
568 | __func__, rc); | |
88b4a07e MH |
569 | } |
570 | } | |
f66e883e MH |
571 | kfree(ecryptfs_daemon_hash); |
572 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e | 573 | } |
624ae528 | 574 | ecryptfs_destroy_ecryptfs_miscdev(); |
88b4a07e MH |
575 | return; |
576 | } |