blob: 788995efd1d3247298a3107935a8a54fccd80cfd [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;
45 int rc;
46
47 mutex_lock(&ecryptfs_daemon_hash_mux);
48 /* TODO: Just use file->private_data? */
Michael Halcrow6a3fd922008-04-29 00:59:52 -070049 rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
50 current->nsproxy->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;
86 int rc;
87
88 mutex_lock(&ecryptfs_daemon_hash_mux);
89 rc = try_module_get(THIS_MODULE);
90 if (rc == 0) {
91 rc = -EIO;
92 printk(KERN_ERR "%s: Error attempting to increment module use "
93 "count; rc = [%d]\n", __func__, rc);
94 goto out_unlock_daemon_list;
95 }
Michael Halcrow6a3fd922008-04-29 00:59:52 -070096 rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
97 current->nsproxy->user_ns);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -070098 if (rc || !daemon) {
99 rc = ecryptfs_spawn_daemon(&daemon, current->euid,
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700100 current->nsproxy->user_ns,
101 task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700102 if (rc) {
103 printk(KERN_ERR "%s: Error attempting to spawn daemon; "
104 "rc = [%d]\n", __func__, rc);
105 goto out_module_put_unlock_daemon_list;
106 }
107 }
108 mutex_lock(&daemon->mux);
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700109 if (daemon->pid != task_pid(current)) {
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700110 rc = -EINVAL;
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700111 printk(KERN_ERR "%s: pid [0x%p] has registered with euid [%d], "
112 "but pid [0x%p] has attempted to open the handle "
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700113 "instead\n", __func__, daemon->pid, daemon->euid,
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700114 task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700115 goto out_unlock_daemon;
116 }
117 if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
118 rc = -EBUSY;
119 printk(KERN_ERR "%s: Miscellaneous device handle may only be "
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700120 "opened once per daemon; pid [0x%p] already has this "
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700121 "handle open\n", __func__, daemon->pid);
122 goto out_unlock_daemon;
123 }
124 daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN;
125 atomic_inc(&ecryptfs_num_miscdev_opens);
126out_unlock_daemon:
127 mutex_unlock(&daemon->mux);
128out_module_put_unlock_daemon_list:
129 if (rc)
130 module_put(THIS_MODULE);
131out_unlock_daemon_list:
132 mutex_unlock(&ecryptfs_daemon_hash_mux);
133 return rc;
134}
135
136/**
137 * ecryptfs_miscdev_release
138 * @inode: inode of fs/ecryptfs/euid handle (ignored)
139 * @file: file for fs/ecryptfs/euid handle (ignored)
140 *
141 * This keeps the daemon registered until the daemon sends another
142 * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters.
143 *
144 * Returns zero on success; non-zero otherwise
145 */
146static int
147ecryptfs_miscdev_release(struct inode *inode, struct file *file)
148{
149 struct ecryptfs_daemon *daemon = NULL;
150 int rc;
151
152 mutex_lock(&ecryptfs_daemon_hash_mux);
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700153 rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
154 current->nsproxy->user_ns);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700155 BUG_ON(rc || !daemon);
156 mutex_lock(&daemon->mux);
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700157 BUG_ON(daemon->pid != task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700158 BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN));
159 daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN;
160 atomic_dec(&ecryptfs_num_miscdev_opens);
161 mutex_unlock(&daemon->mux);
162 rc = ecryptfs_exorcise_daemon(daemon);
163 if (rc) {
164 printk(KERN_CRIT "%s: Fatal error whilst attempting to "
165 "shut down daemon; rc = [%d]. Please report this "
166 "bug.\n", __func__, rc);
167 BUG();
168 }
169 module_put(THIS_MODULE);
170 mutex_unlock(&ecryptfs_daemon_hash_mux);
171 return rc;
172}
173
174/**
175 * ecryptfs_send_miscdev
176 * @data: Data to send to daemon; may be NULL
177 * @data_size: Amount of data to send to daemon
178 * @msg_ctx: Message context, which is used to handle the reply. If
179 * this is NULL, then we do not expect a reply.
180 * @msg_type: Type of message
181 * @msg_flags: Flags for message
182 * @daemon: eCryptfs daemon object
183 *
184 * Add msg_ctx to queue and then, if it exists, notify the blocked
185 * miscdevess about the data being available. Must be called with
186 * ecryptfs_daemon_hash_mux held.
187 *
188 * Returns zero on success; non-zero otherwise
189 */
190int ecryptfs_send_miscdev(char *data, size_t data_size,
191 struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
192 u16 msg_flags, struct ecryptfs_daemon *daemon)
193{
194 int rc = 0;
195
196 mutex_lock(&msg_ctx->mux);
197 if (data) {
198 msg_ctx->msg = kmalloc((sizeof(*msg_ctx->msg) + data_size),
199 GFP_KERNEL);
200 if (!msg_ctx->msg) {
201 rc = -ENOMEM;
202 printk(KERN_ERR "%s: Out of memory whilst attempting "
Michael Halcrowf66e8832008-04-29 00:59:51 -0700203 "to kmalloc(%Zd, GFP_KERNEL)\n", __func__,
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700204 (sizeof(*msg_ctx->msg) + data_size));
205 goto out_unlock;
206 }
207 } else
208 msg_ctx->msg = NULL;
209 msg_ctx->msg->index = msg_ctx->index;
210 msg_ctx->msg->data_len = data_size;
211 msg_ctx->type = msg_type;
212 if (data) {
213 memcpy(msg_ctx->msg->data, data, data_size);
214 msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size);
215 } else
216 msg_ctx->msg_size = 0;
217 mutex_lock(&daemon->mux);
218 list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue);
219 daemon->num_queued_msg_ctx++;
220 wake_up_interruptible(&daemon->wait);
221 mutex_unlock(&daemon->mux);
222out_unlock:
223 mutex_unlock(&msg_ctx->mux);
224 return rc;
225}
226
227/**
228 * ecryptfs_miscdev_read - format and send message from queue
229 * @file: fs/ecryptfs/euid miscdevfs handle (ignored)
230 * @buf: User buffer into which to copy the next message on the daemon queue
231 * @count: Amount of space available in @buf
232 * @ppos: Offset in file (ignored)
233 *
234 * Pulls the most recent message from the daemon queue, formats it for
235 * being sent via a miscdevfs handle, and copies it into @buf
236 *
237 * Returns the number of bytes copied into the user buffer
238 */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700239static ssize_t
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700240ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
241 loff_t *ppos)
242{
243 struct ecryptfs_daemon *daemon;
244 struct ecryptfs_msg_ctx *msg_ctx;
245 size_t packet_length_size;
246 u32 counter_nbo;
247 char packet_length[3];
248 size_t i;
249 size_t total_length;
250 int rc;
251
252 mutex_lock(&ecryptfs_daemon_hash_mux);
253 /* TODO: Just use file->private_data? */
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700254 rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
255 current->nsproxy->user_ns);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700256 BUG_ON(rc || !daemon);
257 mutex_lock(&daemon->mux);
258 if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
259 rc = 0;
260 printk(KERN_WARNING "%s: Attempt to read from zombified "
261 "daemon\n", __func__);
262 goto out_unlock_daemon;
263 }
264 if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) {
265 rc = 0;
266 goto out_unlock_daemon;
267 }
268 /* This daemon will not go away so long as this flag is set */
269 daemon->flags |= ECRYPTFS_DAEMON_IN_READ;
270 mutex_unlock(&ecryptfs_daemon_hash_mux);
271check_list:
272 if (list_empty(&daemon->msg_ctx_out_queue)) {
273 mutex_unlock(&daemon->mux);
274 rc = wait_event_interruptible(
275 daemon->wait, !list_empty(&daemon->msg_ctx_out_queue));
276 mutex_lock(&daemon->mux);
277 if (rc < 0) {
278 rc = 0;
279 goto out_unlock_daemon;
280 }
281 }
282 if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
283 rc = 0;
284 goto out_unlock_daemon;
285 }
286 if (list_empty(&daemon->msg_ctx_out_queue)) {
287 /* Something else jumped in since the
288 * wait_event_interruptable() and removed the
289 * message from the queue; try again */
290 goto check_list;
291 }
292 BUG_ON(current->euid != daemon->euid);
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700293 BUG_ON(current->nsproxy->user_ns != daemon->user_ns);
294 BUG_ON(task_pid(current) != daemon->pid);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700295 msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue,
296 struct ecryptfs_msg_ctx, daemon_out_list);
297 BUG_ON(!msg_ctx);
298 mutex_lock(&msg_ctx->mux);
299 if (msg_ctx->msg) {
300 rc = ecryptfs_write_packet_length(packet_length,
301 msg_ctx->msg_size,
302 &packet_length_size);
303 if (rc) {
304 rc = 0;
305 printk(KERN_WARNING "%s: Error writing packet length; "
306 "rc = [%d]\n", __func__, rc);
307 goto out_unlock_msg_ctx;
308 }
309 } else {
310 packet_length_size = 0;
311 msg_ctx->msg_size = 0;
312 }
313 /* miscdevfs packet format:
314 * Octet 0: Type
315 * Octets 1-4: network byte order msg_ctx->counter
316 * Octets 5-N0: Size of struct ecryptfs_message to follow
317 * Octets N0-N1: struct ecryptfs_message (including data)
318 *
319 * Octets 5-N1 not written if the packet type does not
320 * include a message */
321 total_length = (1 + 4 + packet_length_size + msg_ctx->msg_size);
322 if (count < total_length) {
323 rc = 0;
324 printk(KERN_WARNING "%s: Only given user buffer of "
325 "size [%Zd], but we need [%Zd] to read the "
326 "pending message\n", __func__, count, total_length);
327 goto out_unlock_msg_ctx;
328 }
329 i = 0;
330 buf[i++] = msg_ctx->type;
331 counter_nbo = cpu_to_be32(msg_ctx->counter);
332 memcpy(&buf[i], (char *)&counter_nbo, 4);
333 i += 4;
334 if (msg_ctx->msg) {
335 memcpy(&buf[i], packet_length, packet_length_size);
336 i += packet_length_size;
337 rc = copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size);
338 if (rc) {
339 printk(KERN_ERR "%s: copy_to_user returned error "
340 "[%d]\n", __func__, rc);
341 goto out_unlock_msg_ctx;
342 }
343 i += msg_ctx->msg_size;
344 }
345 rc = i;
346 list_del(&msg_ctx->daemon_out_list);
347 kfree(msg_ctx->msg);
348 msg_ctx->msg = NULL;
349 /* We do not expect a reply from the userspace daemon for any
350 * message type other than ECRYPTFS_MSG_REQUEST */
351 if (msg_ctx->type != ECRYPTFS_MSG_REQUEST)
352 ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
353out_unlock_msg_ctx:
354 mutex_unlock(&msg_ctx->mux);
355out_unlock_daemon:
356 daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ;
357 mutex_unlock(&daemon->mux);
358 return rc;
359}
360
361/**
362 * ecryptfs_miscdev_helo
363 * @euid: effective user id of miscdevess sending helo packet
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700364 * @user_ns: The namespace in which @euid applies
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700365 * @pid: miscdevess id of miscdevess sending helo packet
366 *
367 * Returns zero on success; non-zero otherwise
368 */
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700369static int ecryptfs_miscdev_helo(uid_t euid, struct user_namespace *user_ns,
370 struct pid *pid)
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700371{
372 int rc;
373
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700374 rc = ecryptfs_process_helo(ECRYPTFS_TRANSPORT_MISCDEV, euid, user_ns,
375 pid);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700376 if (rc)
377 printk(KERN_WARNING "Error processing HELO; rc = [%d]\n", rc);
378 return rc;
379}
380
381/**
382 * ecryptfs_miscdev_quit
383 * @euid: effective user id of miscdevess sending quit packet
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700384 * @user_ns: The namespace in which @euid applies
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700385 * @pid: miscdevess id of miscdevess sending quit packet
386 *
387 * Returns zero on success; non-zero otherwise
388 */
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700389static int ecryptfs_miscdev_quit(uid_t euid, struct user_namespace *user_ns,
390 struct pid *pid)
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700391{
392 int rc;
393
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700394 rc = ecryptfs_process_quit(euid, user_ns, pid);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700395 if (rc)
396 printk(KERN_WARNING
397 "Error processing QUIT message; rc = [%d]\n", rc);
398 return rc;
399}
400
401/**
402 * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon
403 * @data: Bytes comprising struct ecryptfs_message
404 * @data_size: sizeof(struct ecryptfs_message) + data len
405 * @euid: Effective user id of miscdevess sending the miscdev response
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700406 * @user_ns: The namespace in which @euid applies
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700407 * @pid: Miscdevess id of miscdevess sending the miscdev response
408 * @seq: Sequence number for miscdev response packet
409 *
410 * Returns zero on success; non-zero otherwise
411 */
412static int ecryptfs_miscdev_response(char *data, size_t data_size,
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700413 uid_t euid, struct user_namespace *user_ns,
414 struct pid *pid, u32 seq)
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700415{
416 struct ecryptfs_message *msg = (struct ecryptfs_message *)data;
417 int rc;
418
419 if ((sizeof(*msg) + msg->data_len) != data_size) {
420 printk(KERN_WARNING "%s: (sizeof(*msg) + msg->data_len) = "
421 "[%Zd]; data_size = [%Zd]. Invalid packet.\n", __func__,
422 (sizeof(*msg) + msg->data_len), data_size);
423 rc = -EINVAL;
424 goto out;
425 }
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700426 rc = ecryptfs_process_response(msg, euid, user_ns, pid, seq);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700427 if (rc)
428 printk(KERN_ERR
429 "Error processing response message; rc = [%d]\n", rc);
430out:
431 return rc;
432}
433
434/**
435 * ecryptfs_miscdev_write - handle write to daemon miscdev handle
436 * @file: File for misc dev handle (ignored)
437 * @buf: Buffer containing user data
438 * @count: Amount of data in @buf
439 * @ppos: Pointer to offset in file (ignored)
440 *
441 * miscdevfs packet format:
442 * Octet 0: Type
443 * Octets 1-4: network byte order msg_ctx->counter (0's for non-response)
444 * Octets 5-N0: Size of struct ecryptfs_message to follow
445 * Octets N0-N1: struct ecryptfs_message (including data)
446 *
447 * Returns the number of bytes read from @buf
448 */
449static ssize_t
450ecryptfs_miscdev_write(struct file *file, const char __user *buf,
451 size_t count, loff_t *ppos)
452{
453 u32 counter_nbo, seq;
454 size_t packet_size, packet_size_length, i;
455 ssize_t sz = 0;
456 char *data;
457 int rc;
458
459 if (count == 0)
460 goto out;
461 data = kmalloc(count, GFP_KERNEL);
462 if (!data) {
463 printk(KERN_ERR "%s: Out of memory whilst attempting to "
464 "kmalloc([%Zd], GFP_KERNEL)\n", __func__, count);
465 goto out;
466 }
467 rc = copy_from_user(data, buf, count);
468 if (rc) {
469 printk(KERN_ERR "%s: copy_from_user returned error [%d]\n",
470 __func__, rc);
471 goto out_free;
472 }
473 sz = count;
474 i = 0;
475 switch (data[i++]) {
476 case ECRYPTFS_MSG_RESPONSE:
477 if (count < (1 + 4 + 1 + sizeof(struct ecryptfs_message))) {
478 printk(KERN_WARNING "%s: Minimum acceptable packet "
479 "size is [%Zd], but amount of data written is "
480 "only [%Zd]. Discarding response packet.\n",
481 __func__,
482 (1 + 4 + 1 + sizeof(struct ecryptfs_message)),
483 count);
484 goto out_free;
485 }
486 memcpy((char *)&counter_nbo, &data[i], 4);
487 seq = be32_to_cpu(counter_nbo);
488 i += 4;
489 rc = ecryptfs_parse_packet_length(&data[i], &packet_size,
490 &packet_size_length);
491 if (rc) {
492 printk(KERN_WARNING "%s: Error parsing packet length; "
493 "rc = [%d]\n", __func__, rc);
494 goto out_free;
495 }
496 i += packet_size_length;
497 if ((1 + 4 + packet_size_length + packet_size) != count) {
498 printk(KERN_WARNING "%s: (1 + packet_size_length([%Zd])"
499 " + packet_size([%Zd]))([%Zd]) != "
500 "count([%Zd]). Invalid packet format.\n",
501 __func__, packet_size_length, packet_size,
502 (1 + packet_size_length + packet_size), count);
503 goto out_free;
504 }
505 rc = ecryptfs_miscdev_response(&data[i], packet_size,
506 current->euid,
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700507 current->nsproxy->user_ns,
508 task_pid(current), seq);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700509 if (rc)
510 printk(KERN_WARNING "%s: Failed to deliver miscdev "
511 "response to requesting operation; rc = [%d]\n",
512 __func__, rc);
513 break;
514 case ECRYPTFS_MSG_HELO:
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700515 rc = ecryptfs_miscdev_helo(current->euid,
516 current->nsproxy->user_ns,
517 task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700518 if (rc) {
519 printk(KERN_ERR "%s: Error attempting to process "
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700520 "helo from pid [0x%p]; rc = [%d]\n", __func__,
521 task_pid(current), rc);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700522 goto out_free;
523 }
524 break;
525 case ECRYPTFS_MSG_QUIT:
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700526 rc = ecryptfs_miscdev_quit(current->euid,
527 current->nsproxy->user_ns,
528 task_pid(current));
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700529 if (rc) {
530 printk(KERN_ERR "%s: Error attempting to process "
Michael Halcrow6a3fd922008-04-29 00:59:52 -0700531 "quit from pid [0x%p]; rc = [%d]\n", __func__,
532 task_pid(current), rc);
Michael Halcrow8bf2deb2008-04-29 00:59:50 -0700533 goto out_free;
534 }
535 break;
536 default:
537 ecryptfs_printk(KERN_WARNING, "Dropping miscdev "
538 "message of unrecognized type [%d]\n",
539 data[0]);
540 break;
541 }
542out_free:
543 kfree(data);
544out:
545 return sz;
546}
547
548
549static const struct file_operations ecryptfs_miscdev_fops = {
550 .open = ecryptfs_miscdev_open,
551 .poll = ecryptfs_miscdev_poll,
552 .read = ecryptfs_miscdev_read,
553 .write = ecryptfs_miscdev_write,
554 .release = ecryptfs_miscdev_release,
555};
556
557static struct miscdevice ecryptfs_miscdev = {
558 .minor = MISC_DYNAMIC_MINOR,
559 .name = "ecryptfs",
560 .fops = &ecryptfs_miscdev_fops
561};
562
563/**
564 * ecryptfs_init_ecryptfs_miscdev
565 *
566 * Messages sent to the userspace daemon from the kernel are placed on
567 * a queue associated with the daemon. The next read against the
568 * miscdev handle by that daemon will return the oldest message placed
569 * on the message queue for the daemon.
570 *
571 * Returns zero on success; non-zero otherwise
572 */
573int ecryptfs_init_ecryptfs_miscdev(void)
574{
575 int rc;
576
577 atomic_set(&ecryptfs_num_miscdev_opens, 0);
578 mutex_lock(&ecryptfs_daemon_hash_mux);
579 rc = misc_register(&ecryptfs_miscdev);
580 if (rc)
581 printk(KERN_ERR "%s: Failed to register miscellaneous device "
582 "for communications with userspace daemons; rc = [%d]\n",
583 __func__, rc);
584 mutex_unlock(&ecryptfs_daemon_hash_mux);
585 return rc;
586}
587
588/**
589 * ecryptfs_destroy_ecryptfs_miscdev
590 *
591 * All of the daemons must be exorcised prior to calling this
592 * function.
593 */
594void ecryptfs_destroy_ecryptfs_miscdev(void)
595{
596 BUG_ON(atomic_read(&ecryptfs_num_miscdev_opens) != 0);
597 misc_deregister(&ecryptfs_miscdev);
598}