blob: 4ec8f61ccf5a09d82bd84a67a68aa9e1b25c91d1 [file] [log] [blame]
Michael Halcrow8bf2deb2008-04-29 00:59:50 -07001/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 2008 International Business Machines Corp.
5 * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
19 * 02111-1307, USA.
20 */
21
22#include <linux/fs.h>
23#include <linux/hash.h>
24#include <linux/random.h>
25#include <linux/miscdevice.h>
26#include <linux/poll.h>
27#include <linux/wait.h>
28#include <linux/module.h>
29#include "ecryptfs_kernel.h"
30
31static atomic_t ecryptfs_num_miscdev_opens;
32
33/**
34 * ecryptfs_miscdev_poll
35 * @file: dev file (ignored)
36 * @pt: dev poll table (ignored)
37 *
38 * Returns the poll mask
39 */
40static unsigned int
41ecryptfs_miscdev_poll(struct file *file, poll_table *pt)
42{
43 struct ecryptfs_daemon *daemon;
44 unsigned int mask = 0;
David Howells4eea0352008-11-14 10:38:49 +110045 uid_t euid = current_euid();
Michael Halcrow8bf2deb2008-04-29 00:59:50 -070046 int rc;
47
48 mutex_lock(&ecryptfs_daemon_hash_mux);
49 /* TODO: Just use file->private_data? */
Serge Hallyn18b6e042008-10-15 16:38:45 -050050 rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
Michael Halcrow8bf2deb2008-04-29 00:59:50 -070051 BUG_ON(rc || !daemon);
52 mutex_lock(&daemon->mux);
53 mutex_unlock(&ecryptfs_daemon_hash_mux);
54 if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
55 printk(KERN_WARNING "%s: Attempt to poll on zombified "
56 "daemon\n", __func__);
57 goto out_unlock_daemon;
58 }
59 if (daemon->flags & ECRYPTFS_DAEMON_IN_READ)
60 goto out_unlock_daemon;
61 if (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)
62 goto out_unlock_daemon;
63 daemon->flags |= ECRYPTFS_DAEMON_IN_POLL;
64 mutex_unlock(&daemon->mux);
65 poll_wait(file, &daemon->wait, pt);
66 mutex_lock(&daemon->mux);
67 if (!list_empty(&daemon->msg_ctx_out_queue))
68 mask |= POLLIN | POLLRDNORM;
69out_unlock_daemon:
70 daemon->flags &= ~ECRYPTFS_DAEMON_IN_POLL;
71 mutex_unlock(&daemon->mux);
72 return mask;
73}
74
75/**
76 * ecryptfs_miscdev_open
77 * @inode: inode of miscdev handle (ignored)
78 * @file: file for miscdev handle (ignored)
79 *
80 * Returns zero on success; non-zero otherwise
81 */
82static int
83ecryptfs_miscdev_open(struct inode *inode, struct file *file)
84{
85 struct ecryptfs_daemon *daemon = NULL;
David Howells4eea0352008-11-14 10:38:49 +110086 uid_t euid = current_euid();
Michael Halcrow8bf2deb2008-04-29 00:59:50 -070087 int rc;
88
89 mutex_lock(&ecryptfs_daemon_hash_mux);
90 rc = try_module_get(THIS_MODULE);
91 if (rc == 0) {
92 rc = -EIO;
93 printk(KERN_ERR "%s: Error attempting to increment module use "
94 "count; rc = [%d]\n", __func__, rc);
95 goto out_unlock_daemon_list;
96 }
Serge Hallyn18b6e042008-10-15 16:38:45 -050097 rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
Michael Halcrow8bf2deb2008-04-29 00:59:50 -070098 if (rc || !daemon) {
Serge Hallyn18b6e042008-10-15 16:38:45 -050099 rc = ecryptfs_spawn_daemon(&daemon, euid, current_user_ns(),
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700100 task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700101 if (rc) {
102 printk(KERN_ERR "%s: Error attempting to spawn daemon; "
103 "rc = [%d]\n", __func__, rc);
104 goto out_module_put_unlock_daemon_list;
105 }
106 }
107 mutex_lock(&daemon->mux);
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700108 if (daemon->pid != task_pid(current)) {
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700109 rc = -EINVAL;
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700110 printk(KERN_ERR "%s: pid [0x%p] has registered with euid [%d], "
111 "but pid [0x%p] has attempted to open the handle "
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700112 "instead\n", __func__, daemon->pid, daemon->euid,
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700113 task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700114 goto out_unlock_daemon;
115 }
116 if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
117 rc = -EBUSY;
118 printk(KERN_ERR "%s: Miscellaneous device handle may only be "
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700119 "opened once per daemon; pid [0x%p] already has this "
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700120 "handle open\n", __func__, daemon->pid);
121 goto out_unlock_daemon;
122 }
123 daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN;
124 atomic_inc(&ecryptfs_num_miscdev_opens);
125out_unlock_daemon:
126 mutex_unlock(&daemon->mux);
127out_module_put_unlock_daemon_list:
128 if (rc)
129 module_put(THIS_MODULE);
130out_unlock_daemon_list:
131 mutex_unlock(&ecryptfs_daemon_hash_mux);
132 return rc;
133}
134
135/**
136 * ecryptfs_miscdev_release
137 * @inode: inode of fs/ecryptfs/euid handle (ignored)
138 * @file: file for fs/ecryptfs/euid handle (ignored)
139 *
140 * This keeps the daemon registered until the daemon sends another
141 * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters.
142 *
143 * Returns zero on success; non-zero otherwise
144 */
145static int
146ecryptfs_miscdev_release(struct inode *inode, struct file *file)
147{
148 struct ecryptfs_daemon *daemon = NULL;
David Howells4eea0352008-11-14 10:38:49 +1100149 uid_t euid = current_euid();
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700150 int rc;
151
152 mutex_lock(&ecryptfs_daemon_hash_mux);
Serge Hallyn18b6e042008-10-15 16:38:45 -0500153 rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700154 BUG_ON(rc || !daemon);
155 mutex_lock(&daemon->mux);
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700156 BUG_ON(daemon->pid != task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700157 BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN));
158 daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN;
159 atomic_dec(&ecryptfs_num_miscdev_opens);
160 mutex_unlock(&daemon->mux);
161 rc = ecryptfs_exorcise_daemon(daemon);
162 if (rc) {
163 printk(KERN_CRIT "%s: Fatal error whilst attempting to "
164 "shut down daemon; rc = [%d]. Please report this "
165 "bug.\n", __func__, rc);
166 BUG();
167 }
168 module_put(THIS_MODULE);
169 mutex_unlock(&ecryptfs_daemon_hash_mux);
170 return rc;
171}
172
173/**
174 * ecryptfs_send_miscdev
175 * @data: Data to send to daemon; may be NULL
176 * @data_size: Amount of data to send to daemon
177 * @msg_ctx: Message context, which is used to handle the reply. If
178 * this is NULL, then we do not expect a reply.
179 * @msg_type: Type of message
180 * @msg_flags: Flags for message
181 * @daemon: eCryptfs daemon object
182 *
183 * Add msg_ctx to queue and then, if it exists, notify the blocked
184 * miscdevess about the data being available. Must be called with
185 * ecryptfs_daemon_hash_mux held.
186 *
187 * Returns zero on success; non-zero otherwise
188 */
189int ecryptfs_send_miscdev(char *data, size_t data_size,
190 struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
191 u16 msg_flags, struct ecryptfs_daemon *daemon)
192{
193 int rc = 0;
194
195 mutex_lock(&msg_ctx->mux);
Tyler Hicks57ea34d2009-03-15 14:17:01 -0500196 msg_ctx->msg = kmalloc((sizeof(*msg_ctx->msg) + data_size),
197 GFP_KERNEL);
198 if (!msg_ctx->msg) {
199 rc = -ENOMEM;
200 printk(KERN_ERR "%s: Out of memory whilst attempting "
201 "to kmalloc(%zd, GFP_KERNEL)\n", __func__,
202 (sizeof(*msg_ctx->msg) + data_size));
203 goto out_unlock;
204 }
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700205 msg_ctx->msg->index = msg_ctx->index;
206 msg_ctx->msg->data_len = data_size;
207 msg_ctx->type = msg_type;
Tyler Hicks57ea34d2009-03-15 14:17:01 -0500208 memcpy(msg_ctx->msg->data, data, data_size);
209 msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700210 mutex_lock(&daemon->mux);
211 list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue);
212 daemon->num_queued_msg_ctx++;
213 wake_up_interruptible(&daemon->wait);
214 mutex_unlock(&daemon->mux);
215out_unlock:
216 mutex_unlock(&msg_ctx->mux);
217 return rc;
218}
219
220/**
221 * ecryptfs_miscdev_read - format and send message from queue
222 * @file: fs/ecryptfs/euid miscdevfs handle (ignored)
223 * @buf: User buffer into which to copy the next message on the daemon queue
224 * @count: Amount of space available in @buf
225 * @ppos: Offset in file (ignored)
226 *
227 * Pulls the most recent message from the daemon queue, formats it for
228 * being sent via a miscdevfs handle, and copies it into @buf
229 *
230 * Returns the number of bytes copied into the user buffer
231 */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700232static ssize_t
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700233ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
234 loff_t *ppos)
235{
236 struct ecryptfs_daemon *daemon;
237 struct ecryptfs_msg_ctx *msg_ctx;
238 size_t packet_length_size;
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700239 char packet_length[3];
240 size_t i;
241 size_t total_length;
David Howells4eea0352008-11-14 10:38:49 +1100242 uid_t euid = current_euid();
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700243 int rc;
244
245 mutex_lock(&ecryptfs_daemon_hash_mux);
246 /* TODO: Just use file->private_data? */
Serge Hallyn18b6e042008-10-15 16:38:45 -0500247 rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700248 BUG_ON(rc || !daemon);
249 mutex_lock(&daemon->mux);
250 if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
251 rc = 0;
Cyrill Gorcunov43f14d82008-05-12 14:02:40 -0700252 mutex_unlock(&ecryptfs_daemon_hash_mux);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700253 printk(KERN_WARNING "%s: Attempt to read from zombified "
254 "daemon\n", __func__);
255 goto out_unlock_daemon;
256 }
257 if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) {
258 rc = 0;
Cyrill Gorcunov43f14d82008-05-12 14:02:40 -0700259 mutex_unlock(&ecryptfs_daemon_hash_mux);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700260 goto out_unlock_daemon;
261 }
262 /* This daemon will not go away so long as this flag is set */
263 daemon->flags |= ECRYPTFS_DAEMON_IN_READ;
264 mutex_unlock(&ecryptfs_daemon_hash_mux);
265check_list:
266 if (list_empty(&daemon->msg_ctx_out_queue)) {
267 mutex_unlock(&daemon->mux);
268 rc = wait_event_interruptible(
269 daemon->wait, !list_empty(&daemon->msg_ctx_out_queue));
270 mutex_lock(&daemon->mux);
271 if (rc < 0) {
272 rc = 0;
273 goto out_unlock_daemon;
274 }
275 }
276 if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
277 rc = 0;
278 goto out_unlock_daemon;
279 }
280 if (list_empty(&daemon->msg_ctx_out_queue)) {
281 /* Something else jumped in since the
282 * wait_event_interruptable() and removed the
283 * message from the queue; try again */
284 goto check_list;
285 }
David Howells4eea0352008-11-14 10:38:49 +1100286 BUG_ON(euid != daemon->euid);
Serge Hallyn18b6e042008-10-15 16:38:45 -0500287 BUG_ON(current_user_ns() != daemon->user_ns);
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700288 BUG_ON(task_pid(current) != daemon->pid);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700289 msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue,
290 struct ecryptfs_msg_ctx, daemon_out_list);
291 BUG_ON(!msg_ctx);
292 mutex_lock(&msg_ctx->mux);
293 if (msg_ctx->msg) {
294 rc = ecryptfs_write_packet_length(packet_length,
295 msg_ctx->msg_size,
296 &packet_length_size);
297 if (rc) {
298 rc = 0;
299 printk(KERN_WARNING "%s: Error writing packet length; "
300 "rc = [%d]\n", __func__, rc);
301 goto out_unlock_msg_ctx;
302 }
303 } else {
304 packet_length_size = 0;
305 msg_ctx->msg_size = 0;
306 }
307 /* miscdevfs packet format:
308 * Octet 0: Type
309 * Octets 1-4: network byte order msg_ctx->counter
310 * Octets 5-N0: Size of struct ecryptfs_message to follow
311 * Octets N0-N1: struct ecryptfs_message (including data)
312 *
313 * Octets 5-N1 not written if the packet type does not
314 * include a message */
315 total_length = (1 + 4 + packet_length_size + msg_ctx->msg_size);
316 if (count < total_length) {
317 rc = 0;
318 printk(KERN_WARNING "%s: Only given user buffer of "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800319 "size [%zd], but we need [%zd] to read the "
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700320 "pending message\n", __func__, count, total_length);
321 goto out_unlock_msg_ctx;
322 }
Al Viro79bc12a2008-05-21 06:32:11 +0100323 rc = -EFAULT;
324 if (put_user(msg_ctx->type, buf))
325 goto out_unlock_msg_ctx;
326 if (put_user(cpu_to_be32(msg_ctx->counter), (__be32 __user *)(buf + 1)))
327 goto out_unlock_msg_ctx;
328 i = 5;
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700329 if (msg_ctx->msg) {
Al Viro79bc12a2008-05-21 06:32:11 +0100330 if (copy_to_user(&buf[i], packet_length, packet_length_size))
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700331 goto out_unlock_msg_ctx;
Al Viro79bc12a2008-05-21 06:32:11 +0100332 i += packet_length_size;
333 if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size))
334 goto out_unlock_msg_ctx;
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700335 i += msg_ctx->msg_size;
336 }
337 rc = i;
338 list_del(&msg_ctx->daemon_out_list);
339 kfree(msg_ctx->msg);
340 msg_ctx->msg = NULL;
341 /* We do not expect a reply from the userspace daemon for any
342 * message type other than ECRYPTFS_MSG_REQUEST */
343 if (msg_ctx->type != ECRYPTFS_MSG_REQUEST)
344 ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
345out_unlock_msg_ctx:
346 mutex_unlock(&msg_ctx->mux);
347out_unlock_daemon:
348 daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ;
349 mutex_unlock(&daemon->mux);
350 return rc;
351}
352
353/**
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700354 * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon
355 * @data: Bytes comprising struct ecryptfs_message
356 * @data_size: sizeof(struct ecryptfs_message) + data len
357 * @euid: Effective user id of miscdevess sending the miscdev response
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700358 * @user_ns: The namespace in which @euid applies
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700359 * @pid: Miscdevess id of miscdevess sending the miscdev response
360 * @seq: Sequence number for miscdev response packet
361 *
362 * Returns zero on success; non-zero otherwise
363 */
364static int ecryptfs_miscdev_response(char *data, size_t data_size,
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700365 uid_t euid, struct user_namespace *user_ns,
366 struct pid *pid, u32 seq)
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700367{
368 struct ecryptfs_message *msg = (struct ecryptfs_message *)data;
369 int rc;
370
371 if ((sizeof(*msg) + msg->data_len) != data_size) {
372 printk(KERN_WARNING "%s: (sizeof(*msg) + msg->data_len) = "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800373 "[%zd]; data_size = [%zd]. Invalid packet.\n", __func__,
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700374 (sizeof(*msg) + msg->data_len), data_size);
375 rc = -EINVAL;
376 goto out;
377 }
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700378 rc = ecryptfs_process_response(msg, euid, user_ns, pid, seq);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700379 if (rc)
380 printk(KERN_ERR
381 "Error processing response message; rc = [%d]\n", rc);
382out:
383 return rc;
384}
385
386/**
387 * ecryptfs_miscdev_write - handle write to daemon miscdev handle
388 * @file: File for misc dev handle (ignored)
389 * @buf: Buffer containing user data
390 * @count: Amount of data in @buf
391 * @ppos: Pointer to offset in file (ignored)
392 *
393 * miscdevfs packet format:
394 * Octet 0: Type
395 * Octets 1-4: network byte order msg_ctx->counter (0's for non-response)
396 * Octets 5-N0: Size of struct ecryptfs_message to follow
397 * Octets N0-N1: struct ecryptfs_message (including data)
398 *
399 * Returns the number of bytes read from @buf
400 */
401static ssize_t
402ecryptfs_miscdev_write(struct file *file, const char __user *buf,
403 size_t count, loff_t *ppos)
404{
Al Viro79bc12a2008-05-21 06:32:11 +0100405 __be32 counter_nbo;
406 u32 seq;
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700407 size_t packet_size, packet_size_length, i;
408 ssize_t sz = 0;
409 char *data;
David Howells4eea0352008-11-14 10:38:49 +1100410 uid_t euid = current_euid();
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700411 int rc;
412
413 if (count == 0)
414 goto out;
Li Zefanfd56d242009-04-08 15:09:29 +0800415
416 data = memdup_user(buf, count);
417 if (IS_ERR(data)) {
418 printk(KERN_ERR "%s: memdup_user returned error [%ld]\n",
419 __func__, PTR_ERR(data));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700420 goto out;
421 }
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700422 sz = count;
423 i = 0;
424 switch (data[i++]) {
425 case ECRYPTFS_MSG_RESPONSE:
426 if (count < (1 + 4 + 1 + sizeof(struct ecryptfs_message))) {
427 printk(KERN_WARNING "%s: Minimum acceptable packet "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800428 "size is [%zd], but amount of data written is "
429 "only [%zd]. Discarding response packet.\n",
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700430 __func__,
431 (1 + 4 + 1 + sizeof(struct ecryptfs_message)),
432 count);
433 goto out_free;
434 }
Al Viro79bc12a2008-05-21 06:32:11 +0100435 memcpy(&counter_nbo, &data[i], 4);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700436 seq = be32_to_cpu(counter_nbo);
437 i += 4;
438 rc = ecryptfs_parse_packet_length(&data[i], &packet_size,
439 &packet_size_length);
440 if (rc) {
441 printk(KERN_WARNING "%s: Error parsing packet length; "
442 "rc = [%d]\n", __func__, rc);
443 goto out_free;
444 }
445 i += packet_size_length;
446 if ((1 + 4 + packet_size_length + packet_size) != count) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800447 printk(KERN_WARNING "%s: (1 + packet_size_length([%zd])"
448 " + packet_size([%zd]))([%zd]) != "
449 "count([%zd]). Invalid packet format.\n",
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700450 __func__, packet_size_length, packet_size,
451 (1 + packet_size_length + packet_size), count);
452 goto out_free;
453 }
454 rc = ecryptfs_miscdev_response(&data[i], packet_size,
Serge Hallyn18b6e042008-10-15 16:38:45 -0500455 euid, current_user_ns(),
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700456 task_pid(current), seq);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700457 if (rc)
458 printk(KERN_WARNING "%s: Failed to deliver miscdev "
459 "response to requesting operation; rc = [%d]\n",
460 __func__, rc);
461 break;
462 case ECRYPTFS_MSG_HELO:
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700463 case ECRYPTFS_MSG_QUIT:
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700464 break;
465 default:
466 ecryptfs_printk(KERN_WARNING, "Dropping miscdev "
467 "message of unrecognized type [%d]\n",
468 data[0]);
469 break;
470 }
471out_free:
472 kfree(data);
473out:
474 return sz;
475}
476
477
478static const struct file_operations ecryptfs_miscdev_fops = {
479 .open = ecryptfs_miscdev_open,
480 .poll = ecryptfs_miscdev_poll,
481 .read = ecryptfs_miscdev_read,
482 .write = ecryptfs_miscdev_write,
483 .release = ecryptfs_miscdev_release,
484};
485
486static struct miscdevice ecryptfs_miscdev = {
487 .minor = MISC_DYNAMIC_MINOR,
488 .name = "ecryptfs",
489 .fops = &ecryptfs_miscdev_fops
490};
491
492/**
493 * ecryptfs_init_ecryptfs_miscdev
494 *
495 * Messages sent to the userspace daemon from the kernel are placed on
496 * a queue associated with the daemon. The next read against the
497 * miscdev handle by that daemon will return the oldest message placed
498 * on the message queue for the daemon.
499 *
500 * Returns zero on success; non-zero otherwise
501 */
502int ecryptfs_init_ecryptfs_miscdev(void)
503{
504 int rc;
505
506 atomic_set(&ecryptfs_num_miscdev_opens, 0);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700507 rc = misc_register(&ecryptfs_miscdev);
508 if (rc)
509 printk(KERN_ERR "%s: Failed to register miscellaneous device "
510 "for communications with userspace daemons; rc = [%d]\n",
511 __func__, rc);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700512 return rc;
513}
514
515/**
516 * ecryptfs_destroy_ecryptfs_miscdev
517 *
518 * All of the daemons must be exorcised prior to calling this
519 * function.
520 */
521void ecryptfs_destroy_ecryptfs_miscdev(void)
522{
523 BUG_ON(atomic_read(&ecryptfs_num_miscdev_opens) != 0);
524 misc_deregister(&ecryptfs_miscdev);
525}