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8bf2debd MH |
1 | /** |
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> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
8bf2debd MH |
28 | #include <linux/wait.h> |
29 | #include <linux/module.h> | |
30 | #include "ecryptfs_kernel.h" | |
31 | ||
32 | static atomic_t ecryptfs_num_miscdev_opens; | |
33 | ||
34 | /** | |
35 | * ecryptfs_miscdev_poll | |
2ecaf55d | 36 | * @file: dev file |
8bf2debd MH |
37 | * @pt: dev poll table (ignored) |
38 | * | |
39 | * Returns the poll mask | |
40 | */ | |
076ccb76 | 41 | static __poll_t |
8bf2debd MH |
42 | ecryptfs_miscdev_poll(struct file *file, poll_table *pt) |
43 | { | |
2ecaf55d | 44 | struct ecryptfs_daemon *daemon = file->private_data; |
076ccb76 | 45 | __poll_t mask = 0; |
8bf2debd | 46 | |
8bf2debd | 47 | mutex_lock(&daemon->mux); |
8bf2debd MH |
48 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { |
49 | printk(KERN_WARNING "%s: Attempt to poll on zombified " | |
50 | "daemon\n", __func__); | |
51 | goto out_unlock_daemon; | |
52 | } | |
53 | if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) | |
54 | goto out_unlock_daemon; | |
55 | if (daemon->flags & ECRYPTFS_DAEMON_IN_POLL) | |
56 | goto out_unlock_daemon; | |
57 | daemon->flags |= ECRYPTFS_DAEMON_IN_POLL; | |
58 | mutex_unlock(&daemon->mux); | |
59 | poll_wait(file, &daemon->wait, pt); | |
60 | mutex_lock(&daemon->mux); | |
61 | if (!list_empty(&daemon->msg_ctx_out_queue)) | |
a9a08845 | 62 | mask |= EPOLLIN | EPOLLRDNORM; |
8bf2debd MH |
63 | out_unlock_daemon: |
64 | daemon->flags &= ~ECRYPTFS_DAEMON_IN_POLL; | |
65 | mutex_unlock(&daemon->mux); | |
66 | return mask; | |
67 | } | |
68 | ||
69 | /** | |
70 | * ecryptfs_miscdev_open | |
71 | * @inode: inode of miscdev handle (ignored) | |
2ecaf55d | 72 | * @file: file for miscdev handle |
8bf2debd MH |
73 | * |
74 | * Returns zero on success; non-zero otherwise | |
75 | */ | |
76 | static int | |
77 | ecryptfs_miscdev_open(struct inode *inode, struct file *file) | |
78 | { | |
79 | struct ecryptfs_daemon *daemon = NULL; | |
80 | int rc; | |
81 | ||
82 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
2ecaf55d TH |
83 | rc = ecryptfs_find_daemon_by_euid(&daemon); |
84 | if (!rc) { | |
8bf2debd | 85 | rc = -EINVAL; |
2ecaf55d TH |
86 | goto out_unlock_daemon_list; |
87 | } | |
88 | rc = ecryptfs_spawn_daemon(&daemon, file); | |
89 | if (rc) { | |
90 | printk(KERN_ERR "%s: Error attempting to spawn daemon; " | |
91 | "rc = [%d]\n", __func__, rc); | |
52f21999 | 92 | goto out_unlock_daemon_list; |
8bf2debd | 93 | } |
2ecaf55d | 94 | mutex_lock(&daemon->mux); |
8bf2debd MH |
95 | if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) { |
96 | rc = -EBUSY; | |
8bf2debd MH |
97 | goto out_unlock_daemon; |
98 | } | |
99 | daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN; | |
8dc67805 | 100 | file->private_data = daemon; |
8bf2debd MH |
101 | atomic_inc(&ecryptfs_num_miscdev_opens); |
102 | out_unlock_daemon: | |
103 | mutex_unlock(&daemon->mux); | |
8bf2debd MH |
104 | out_unlock_daemon_list: |
105 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
106 | return rc; | |
107 | } | |
108 | ||
109 | /** | |
110 | * ecryptfs_miscdev_release | |
111 | * @inode: inode of fs/ecryptfs/euid handle (ignored) | |
2ecaf55d | 112 | * @file: file for fs/ecryptfs/euid handle |
8bf2debd MH |
113 | * |
114 | * This keeps the daemon registered until the daemon sends another | |
115 | * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters. | |
116 | * | |
117 | * Returns zero on success; non-zero otherwise | |
118 | */ | |
119 | static int | |
120 | ecryptfs_miscdev_release(struct inode *inode, struct file *file) | |
121 | { | |
2ecaf55d | 122 | struct ecryptfs_daemon *daemon = file->private_data; |
8bf2debd MH |
123 | int rc; |
124 | ||
8bf2debd | 125 | mutex_lock(&daemon->mux); |
8bf2debd MH |
126 | BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN)); |
127 | daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN; | |
128 | atomic_dec(&ecryptfs_num_miscdev_opens); | |
129 | mutex_unlock(&daemon->mux); | |
2ecaf55d TH |
130 | |
131 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
8bf2debd | 132 | rc = ecryptfs_exorcise_daemon(daemon); |
2ecaf55d | 133 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
8bf2debd MH |
134 | if (rc) { |
135 | printk(KERN_CRIT "%s: Fatal error whilst attempting to " | |
136 | "shut down daemon; rc = [%d]. Please report this " | |
137 | "bug.\n", __func__, rc); | |
138 | BUG(); | |
139 | } | |
8bf2debd MH |
140 | return rc; |
141 | } | |
142 | ||
143 | /** | |
144 | * ecryptfs_send_miscdev | |
145 | * @data: Data to send to daemon; may be NULL | |
146 | * @data_size: Amount of data to send to daemon | |
147 | * @msg_ctx: Message context, which is used to handle the reply. If | |
148 | * this is NULL, then we do not expect a reply. | |
149 | * @msg_type: Type of message | |
150 | * @msg_flags: Flags for message | |
151 | * @daemon: eCryptfs daemon object | |
152 | * | |
153 | * Add msg_ctx to queue and then, if it exists, notify the blocked | |
154 | * miscdevess about the data being available. Must be called with | |
155 | * ecryptfs_daemon_hash_mux held. | |
156 | * | |
157 | * Returns zero on success; non-zero otherwise | |
158 | */ | |
159 | int ecryptfs_send_miscdev(char *data, size_t data_size, | |
160 | struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type, | |
161 | u16 msg_flags, struct ecryptfs_daemon *daemon) | |
162 | { | |
60d65f1f | 163 | struct ecryptfs_message *msg; |
8bf2debd | 164 | |
60d65f1f | 165 | msg = kmalloc((sizeof(*msg) + data_size), GFP_KERNEL); |
1a0bba4f | 166 | if (!msg) |
60d65f1f | 167 | return -ENOMEM; |
60d65f1f TH |
168 | |
169 | mutex_lock(&msg_ctx->mux); | |
170 | msg_ctx->msg = msg; | |
8bf2debd MH |
171 | msg_ctx->msg->index = msg_ctx->index; |
172 | msg_ctx->msg->data_len = data_size; | |
173 | msg_ctx->type = msg_type; | |
57ea34d1 TH |
174 | memcpy(msg_ctx->msg->data, data, data_size); |
175 | msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size); | |
8bf2debd | 176 | list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue); |
60d65f1f TH |
177 | mutex_unlock(&msg_ctx->mux); |
178 | ||
179 | mutex_lock(&daemon->mux); | |
8bf2debd MH |
180 | daemon->num_queued_msg_ctx++; |
181 | wake_up_interruptible(&daemon->wait); | |
182 | mutex_unlock(&daemon->mux); | |
60d65f1f TH |
183 | |
184 | return 0; | |
8bf2debd MH |
185 | } |
186 | ||
48399c0b TH |
187 | /* |
188 | * miscdevfs packet format: | |
189 | * Octet 0: Type | |
190 | * Octets 1-4: network byte order msg_ctx->counter | |
191 | * Octets 5-N0: Size of struct ecryptfs_message to follow | |
192 | * Octets N0-N1: struct ecryptfs_message (including data) | |
193 | * | |
194 | * Octets 5-N1 not written if the packet type does not include a message | |
195 | */ | |
196 | #define PKT_TYPE_SIZE 1 | |
197 | #define PKT_CTR_SIZE 4 | |
198 | #define MIN_NON_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE) | |
199 | #define MIN_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \ | |
200 | + ECRYPTFS_MIN_PKT_LEN_SIZE) | |
201 | /* 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES comes from tag 65 packet format */ | |
202 | #define MAX_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \ | |
203 | + ECRYPTFS_MAX_PKT_LEN_SIZE \ | |
204 | + sizeof(struct ecryptfs_message) \ | |
205 | + 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) | |
206 | #define PKT_TYPE_OFFSET 0 | |
207 | #define PKT_CTR_OFFSET PKT_TYPE_SIZE | |
208 | #define PKT_LEN_OFFSET (PKT_TYPE_SIZE + PKT_CTR_SIZE) | |
209 | ||
8bf2debd MH |
210 | /** |
211 | * ecryptfs_miscdev_read - format and send message from queue | |
2ecaf55d | 212 | * @file: miscdevfs handle |
8bf2debd MH |
213 | * @buf: User buffer into which to copy the next message on the daemon queue |
214 | * @count: Amount of space available in @buf | |
215 | * @ppos: Offset in file (ignored) | |
216 | * | |
217 | * Pulls the most recent message from the daemon queue, formats it for | |
218 | * being sent via a miscdevfs handle, and copies it into @buf | |
219 | * | |
220 | * Returns the number of bytes copied into the user buffer | |
221 | */ | |
f66e883e | 222 | static ssize_t |
8bf2debd MH |
223 | ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count, |
224 | loff_t *ppos) | |
225 | { | |
2ecaf55d | 226 | struct ecryptfs_daemon *daemon = file->private_data; |
8bf2debd MH |
227 | struct ecryptfs_msg_ctx *msg_ctx; |
228 | size_t packet_length_size; | |
48399c0b | 229 | char packet_length[ECRYPTFS_MAX_PKT_LEN_SIZE]; |
8bf2debd MH |
230 | size_t i; |
231 | size_t total_length; | |
232 | int rc; | |
233 | ||
8bf2debd MH |
234 | mutex_lock(&daemon->mux); |
235 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { | |
236 | rc = 0; | |
237 | printk(KERN_WARNING "%s: Attempt to read from zombified " | |
238 | "daemon\n", __func__); | |
239 | goto out_unlock_daemon; | |
240 | } | |
241 | if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) { | |
242 | rc = 0; | |
243 | goto out_unlock_daemon; | |
244 | } | |
245 | /* This daemon will not go away so long as this flag is set */ | |
246 | daemon->flags |= ECRYPTFS_DAEMON_IN_READ; | |
8bf2debd MH |
247 | check_list: |
248 | if (list_empty(&daemon->msg_ctx_out_queue)) { | |
249 | mutex_unlock(&daemon->mux); | |
250 | rc = wait_event_interruptible( | |
251 | daemon->wait, !list_empty(&daemon->msg_ctx_out_queue)); | |
252 | mutex_lock(&daemon->mux); | |
253 | if (rc < 0) { | |
254 | rc = 0; | |
255 | goto out_unlock_daemon; | |
256 | } | |
257 | } | |
258 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { | |
259 | rc = 0; | |
260 | goto out_unlock_daemon; | |
261 | } | |
262 | if (list_empty(&daemon->msg_ctx_out_queue)) { | |
263 | /* Something else jumped in since the | |
264 | * wait_event_interruptable() and removed the | |
265 | * message from the queue; try again */ | |
266 | goto check_list; | |
267 | } | |
8bf2debd MH |
268 | msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue, |
269 | struct ecryptfs_msg_ctx, daemon_out_list); | |
270 | BUG_ON(!msg_ctx); | |
271 | mutex_lock(&msg_ctx->mux); | |
272 | if (msg_ctx->msg) { | |
273 | rc = ecryptfs_write_packet_length(packet_length, | |
274 | msg_ctx->msg_size, | |
275 | &packet_length_size); | |
276 | if (rc) { | |
277 | rc = 0; | |
278 | printk(KERN_WARNING "%s: Error writing packet length; " | |
279 | "rc = [%d]\n", __func__, rc); | |
280 | goto out_unlock_msg_ctx; | |
281 | } | |
282 | } else { | |
283 | packet_length_size = 0; | |
284 | msg_ctx->msg_size = 0; | |
285 | } | |
48399c0b TH |
286 | total_length = (PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_length_size |
287 | + msg_ctx->msg_size); | |
8bf2debd MH |
288 | if (count < total_length) { |
289 | rc = 0; | |
290 | printk(KERN_WARNING "%s: Only given user buffer of " | |
df261c52 | 291 | "size [%zd], but we need [%zd] to read the " |
8bf2debd MH |
292 | "pending message\n", __func__, count, total_length); |
293 | goto out_unlock_msg_ctx; | |
294 | } | |
79bc12a0 AV |
295 | rc = -EFAULT; |
296 | if (put_user(msg_ctx->type, buf)) | |
297 | goto out_unlock_msg_ctx; | |
48399c0b TH |
298 | if (put_user(cpu_to_be32(msg_ctx->counter), |
299 | (__be32 __user *)(&buf[PKT_CTR_OFFSET]))) | |
79bc12a0 | 300 | goto out_unlock_msg_ctx; |
48399c0b | 301 | i = PKT_TYPE_SIZE + PKT_CTR_SIZE; |
8bf2debd | 302 | if (msg_ctx->msg) { |
79bc12a0 AV |
303 | if (copy_to_user(&buf[i], packet_length, packet_length_size)) |
304 | goto out_unlock_msg_ctx; | |
8bf2debd | 305 | i += packet_length_size; |
79bc12a0 | 306 | if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size)) |
8bf2debd | 307 | goto out_unlock_msg_ctx; |
8bf2debd MH |
308 | i += msg_ctx->msg_size; |
309 | } | |
310 | rc = i; | |
311 | list_del(&msg_ctx->daemon_out_list); | |
312 | kfree(msg_ctx->msg); | |
313 | msg_ctx->msg = NULL; | |
314 | /* We do not expect a reply from the userspace daemon for any | |
315 | * message type other than ECRYPTFS_MSG_REQUEST */ | |
316 | if (msg_ctx->type != ECRYPTFS_MSG_REQUEST) | |
317 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
318 | out_unlock_msg_ctx: | |
319 | mutex_unlock(&msg_ctx->mux); | |
320 | out_unlock_daemon: | |
321 | daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ; | |
322 | mutex_unlock(&daemon->mux); | |
323 | return rc; | |
324 | } | |
325 | ||
8bf2debd MH |
326 | /** |
327 | * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon | |
328 | * @data: Bytes comprising struct ecryptfs_message | |
329 | * @data_size: sizeof(struct ecryptfs_message) + data len | |
8bf2debd MH |
330 | * @seq: Sequence number for miscdev response packet |
331 | * | |
332 | * Returns zero on success; non-zero otherwise | |
333 | */ | |
2ecaf55d TH |
334 | static int ecryptfs_miscdev_response(struct ecryptfs_daemon *daemon, char *data, |
335 | size_t data_size, u32 seq) | |
8bf2debd MH |
336 | { |
337 | struct ecryptfs_message *msg = (struct ecryptfs_message *)data; | |
338 | int rc; | |
339 | ||
340 | if ((sizeof(*msg) + msg->data_len) != data_size) { | |
341 | printk(KERN_WARNING "%s: (sizeof(*msg) + msg->data_len) = " | |
df261c52 | 342 | "[%zd]; data_size = [%zd]. Invalid packet.\n", __func__, |
8bf2debd MH |
343 | (sizeof(*msg) + msg->data_len), data_size); |
344 | rc = -EINVAL; | |
345 | goto out; | |
346 | } | |
2ecaf55d | 347 | rc = ecryptfs_process_response(daemon, msg, seq); |
8bf2debd MH |
348 | if (rc) |
349 | printk(KERN_ERR | |
350 | "Error processing response message; rc = [%d]\n", rc); | |
351 | out: | |
352 | return rc; | |
353 | } | |
354 | ||
355 | /** | |
356 | * ecryptfs_miscdev_write - handle write to daemon miscdev handle | |
2ecaf55d | 357 | * @file: File for misc dev handle |
8bf2debd MH |
358 | * @buf: Buffer containing user data |
359 | * @count: Amount of data in @buf | |
360 | * @ppos: Pointer to offset in file (ignored) | |
361 | * | |
8bf2debd MH |
362 | * Returns the number of bytes read from @buf |
363 | */ | |
364 | static ssize_t | |
365 | ecryptfs_miscdev_write(struct file *file, const char __user *buf, | |
366 | size_t count, loff_t *ppos) | |
367 | { | |
79bc12a0 AV |
368 | __be32 counter_nbo; |
369 | u32 seq; | |
48399c0b | 370 | size_t packet_size, packet_size_length; |
8bf2debd | 371 | char *data; |
48399c0b | 372 | unsigned char packet_size_peek[ECRYPTFS_MAX_PKT_LEN_SIZE]; |
7f133504 | 373 | ssize_t rc; |
8bf2debd | 374 | |
db10e556 | 375 | if (count == 0) { |
7f133504 | 376 | return 0; |
48399c0b | 377 | } else if (count == MIN_NON_MSG_PKT_SIZE) { |
db10e556 TH |
378 | /* Likely a harmless MSG_HELO or MSG_QUIT - no packet length */ |
379 | goto memdup; | |
48399c0b | 380 | } else if (count < MIN_MSG_PKT_SIZE || count > MAX_MSG_PKT_SIZE) { |
db10e556 | 381 | printk(KERN_WARNING "%s: Acceptable packet size range is " |
0996b67d | 382 | "[%d-%zu], but amount of data written is [%zu].\n", |
48399c0b | 383 | __func__, MIN_MSG_PKT_SIZE, MAX_MSG_PKT_SIZE, count); |
db10e556 TH |
384 | return -EINVAL; |
385 | } | |
386 | ||
48399c0b | 387 | if (copy_from_user(packet_size_peek, &buf[PKT_LEN_OFFSET], |
db10e556 TH |
388 | sizeof(packet_size_peek))) { |
389 | printk(KERN_WARNING "%s: Error while inspecting packet size\n", | |
390 | __func__); | |
391 | return -EFAULT; | |
392 | } | |
393 | ||
394 | rc = ecryptfs_parse_packet_length(packet_size_peek, &packet_size, | |
395 | &packet_size_length); | |
396 | if (rc) { | |
397 | printk(KERN_WARNING "%s: Error parsing packet length; " | |
7f133504 | 398 | "rc = [%zd]\n", __func__, rc); |
db10e556 TH |
399 | return rc; |
400 | } | |
401 | ||
48399c0b TH |
402 | if ((PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_size_length + packet_size) |
403 | != count) { | |
db10e556 TH |
404 | printk(KERN_WARNING "%s: Invalid packet size [%zu]\n", __func__, |
405 | packet_size); | |
406 | return -EINVAL; | |
407 | } | |
fd56d242 | 408 | |
db10e556 | 409 | memdup: |
fd56d242 LZ |
410 | data = memdup_user(buf, count); |
411 | if (IS_ERR(data)) { | |
412 | printk(KERN_ERR "%s: memdup_user returned error [%ld]\n", | |
413 | __func__, PTR_ERR(data)); | |
7f133504 | 414 | return PTR_ERR(data); |
8bf2debd | 415 | } |
48399c0b | 416 | switch (data[PKT_TYPE_OFFSET]) { |
8bf2debd | 417 | case ECRYPTFS_MSG_RESPONSE: |
48399c0b TH |
418 | if (count < (MIN_MSG_PKT_SIZE |
419 | + sizeof(struct ecryptfs_message))) { | |
8bf2debd | 420 | printk(KERN_WARNING "%s: Minimum acceptable packet " |
df261c52 MH |
421 | "size is [%zd], but amount of data written is " |
422 | "only [%zd]. Discarding response packet.\n", | |
8bf2debd | 423 | __func__, |
48399c0b TH |
424 | (MIN_MSG_PKT_SIZE |
425 | + sizeof(struct ecryptfs_message)), count); | |
7f133504 | 426 | rc = -EINVAL; |
8bf2debd MH |
427 | goto out_free; |
428 | } | |
48399c0b | 429 | memcpy(&counter_nbo, &data[PKT_CTR_OFFSET], PKT_CTR_SIZE); |
8bf2debd | 430 | seq = be32_to_cpu(counter_nbo); |
2ecaf55d | 431 | rc = ecryptfs_miscdev_response(file->private_data, |
48399c0b | 432 | &data[PKT_LEN_OFFSET + packet_size_length], |
2ecaf55d | 433 | packet_size, seq); |
7f133504 | 434 | if (rc) { |
8bf2debd | 435 | printk(KERN_WARNING "%s: Failed to deliver miscdev " |
7f133504 | 436 | "response to requesting operation; rc = [%zd]\n", |
8bf2debd | 437 | __func__, rc); |
7f133504 TH |
438 | goto out_free; |
439 | } | |
8bf2debd MH |
440 | break; |
441 | case ECRYPTFS_MSG_HELO: | |
8bf2debd | 442 | case ECRYPTFS_MSG_QUIT: |
8bf2debd MH |
443 | break; |
444 | default: | |
445 | ecryptfs_printk(KERN_WARNING, "Dropping miscdev " | |
446 | "message of unrecognized type [%d]\n", | |
447 | data[0]); | |
7f133504 TH |
448 | rc = -EINVAL; |
449 | goto out_free; | |
8bf2debd | 450 | } |
7f133504 | 451 | rc = count; |
8bf2debd MH |
452 | out_free: |
453 | kfree(data); | |
7f133504 | 454 | return rc; |
8bf2debd MH |
455 | } |
456 | ||
457 | ||
458 | static const struct file_operations ecryptfs_miscdev_fops = { | |
52f21999 | 459 | .owner = THIS_MODULE, |
8bf2debd MH |
460 | .open = ecryptfs_miscdev_open, |
461 | .poll = ecryptfs_miscdev_poll, | |
462 | .read = ecryptfs_miscdev_read, | |
463 | .write = ecryptfs_miscdev_write, | |
464 | .release = ecryptfs_miscdev_release, | |
6038f373 | 465 | .llseek = noop_llseek, |
8bf2debd MH |
466 | }; |
467 | ||
468 | static struct miscdevice ecryptfs_miscdev = { | |
469 | .minor = MISC_DYNAMIC_MINOR, | |
470 | .name = "ecryptfs", | |
471 | .fops = &ecryptfs_miscdev_fops | |
472 | }; | |
473 | ||
474 | /** | |
475 | * ecryptfs_init_ecryptfs_miscdev | |
476 | * | |
477 | * Messages sent to the userspace daemon from the kernel are placed on | |
478 | * a queue associated with the daemon. The next read against the | |
479 | * miscdev handle by that daemon will return the oldest message placed | |
480 | * on the message queue for the daemon. | |
481 | * | |
482 | * Returns zero on success; non-zero otherwise | |
483 | */ | |
7371a382 | 484 | int __init ecryptfs_init_ecryptfs_miscdev(void) |
8bf2debd MH |
485 | { |
486 | int rc; | |
487 | ||
488 | atomic_set(&ecryptfs_num_miscdev_opens, 0); | |
8bf2debd MH |
489 | rc = misc_register(&ecryptfs_miscdev); |
490 | if (rc) | |
491 | printk(KERN_ERR "%s: Failed to register miscellaneous device " | |
492 | "for communications with userspace daemons; rc = [%d]\n", | |
493 | __func__, rc); | |
8bf2debd MH |
494 | return rc; |
495 | } | |
496 | ||
497 | /** | |
498 | * ecryptfs_destroy_ecryptfs_miscdev | |
499 | * | |
500 | * All of the daemons must be exorcised prior to calling this | |
501 | * function. | |
502 | */ | |
503 | void ecryptfs_destroy_ecryptfs_miscdev(void) | |
504 | { | |
505 | BUG_ON(atomic_read(&ecryptfs_num_miscdev_opens) != 0); | |
506 | misc_deregister(&ecryptfs_miscdev); | |
507 | } |