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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 | |
36 | * @file: dev file (ignored) | |
37 | * @pt: dev poll table (ignored) | |
38 | * | |
39 | * Returns the poll mask | |
40 | */ | |
41 | static unsigned int | |
42 | ecryptfs_miscdev_poll(struct file *file, poll_table *pt) | |
43 | { | |
44 | struct ecryptfs_daemon *daemon; | |
45 | unsigned int mask = 0; | |
4eea0353 | 46 | uid_t euid = current_euid(); |
8bf2debd MH |
47 | int rc; |
48 | ||
49 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
50 | /* TODO: Just use file->private_data? */ | |
18b6e041 | 51 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); |
8dc67805 TH |
52 | if (rc || !daemon) { |
53 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
54 | return -EINVAL; | |
55 | } | |
8bf2debd MH |
56 | mutex_lock(&daemon->mux); |
57 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
58 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { | |
59 | printk(KERN_WARNING "%s: Attempt to poll on zombified " | |
60 | "daemon\n", __func__); | |
61 | goto out_unlock_daemon; | |
62 | } | |
63 | if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) | |
64 | goto out_unlock_daemon; | |
65 | if (daemon->flags & ECRYPTFS_DAEMON_IN_POLL) | |
66 | goto out_unlock_daemon; | |
67 | daemon->flags |= ECRYPTFS_DAEMON_IN_POLL; | |
68 | mutex_unlock(&daemon->mux); | |
69 | poll_wait(file, &daemon->wait, pt); | |
70 | mutex_lock(&daemon->mux); | |
71 | if (!list_empty(&daemon->msg_ctx_out_queue)) | |
72 | mask |= POLLIN | POLLRDNORM; | |
73 | out_unlock_daemon: | |
74 | daemon->flags &= ~ECRYPTFS_DAEMON_IN_POLL; | |
75 | mutex_unlock(&daemon->mux); | |
76 | return mask; | |
77 | } | |
78 | ||
79 | /** | |
80 | * ecryptfs_miscdev_open | |
81 | * @inode: inode of miscdev handle (ignored) | |
82 | * @file: file for miscdev handle (ignored) | |
83 | * | |
84 | * Returns zero on success; non-zero otherwise | |
85 | */ | |
86 | static int | |
87 | ecryptfs_miscdev_open(struct inode *inode, struct file *file) | |
88 | { | |
89 | struct ecryptfs_daemon *daemon = NULL; | |
4eea0353 | 90 | uid_t euid = current_euid(); |
8bf2debd MH |
91 | int rc; |
92 | ||
93 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
94 | rc = try_module_get(THIS_MODULE); | |
95 | if (rc == 0) { | |
96 | rc = -EIO; | |
97 | printk(KERN_ERR "%s: Error attempting to increment module use " | |
98 | "count; rc = [%d]\n", __func__, rc); | |
99 | goto out_unlock_daemon_list; | |
100 | } | |
18b6e041 | 101 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); |
8bf2debd | 102 | if (rc || !daemon) { |
18b6e041 | 103 | rc = ecryptfs_spawn_daemon(&daemon, euid, current_user_ns(), |
6a3fd92e | 104 | task_pid(current)); |
8bf2debd MH |
105 | if (rc) { |
106 | printk(KERN_ERR "%s: Error attempting to spawn daemon; " | |
107 | "rc = [%d]\n", __func__, rc); | |
108 | goto out_module_put_unlock_daemon_list; | |
109 | } | |
110 | } | |
111 | mutex_lock(&daemon->mux); | |
6a3fd92e | 112 | if (daemon->pid != task_pid(current)) { |
8bf2debd | 113 | rc = -EINVAL; |
6a3fd92e MH |
114 | printk(KERN_ERR "%s: pid [0x%p] has registered with euid [%d], " |
115 | "but pid [0x%p] has attempted to open the handle " | |
8bf2debd | 116 | "instead\n", __func__, daemon->pid, daemon->euid, |
6a3fd92e | 117 | task_pid(current)); |
8bf2debd MH |
118 | goto out_unlock_daemon; |
119 | } | |
120 | if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) { | |
121 | rc = -EBUSY; | |
122 | printk(KERN_ERR "%s: Miscellaneous device handle may only be " | |
6a3fd92e | 123 | "opened once per daemon; pid [0x%p] already has this " |
8bf2debd MH |
124 | "handle open\n", __func__, daemon->pid); |
125 | goto out_unlock_daemon; | |
126 | } | |
127 | daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN; | |
8dc67805 | 128 | file->private_data = daemon; |
8bf2debd MH |
129 | atomic_inc(&ecryptfs_num_miscdev_opens); |
130 | out_unlock_daemon: | |
131 | mutex_unlock(&daemon->mux); | |
132 | out_module_put_unlock_daemon_list: | |
133 | if (rc) | |
134 | module_put(THIS_MODULE); | |
135 | out_unlock_daemon_list: | |
136 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
137 | return rc; | |
138 | } | |
139 | ||
140 | /** | |
141 | * ecryptfs_miscdev_release | |
142 | * @inode: inode of fs/ecryptfs/euid handle (ignored) | |
143 | * @file: file for fs/ecryptfs/euid handle (ignored) | |
144 | * | |
145 | * This keeps the daemon registered until the daemon sends another | |
146 | * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters. | |
147 | * | |
148 | * Returns zero on success; non-zero otherwise | |
149 | */ | |
150 | static int | |
151 | ecryptfs_miscdev_release(struct inode *inode, struct file *file) | |
152 | { | |
153 | struct ecryptfs_daemon *daemon = NULL; | |
4eea0353 | 154 | uid_t euid = current_euid(); |
8bf2debd MH |
155 | int rc; |
156 | ||
157 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
18b6e041 | 158 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); |
8dc67805 TH |
159 | if (rc || !daemon) |
160 | daemon = file->private_data; | |
8bf2debd | 161 | mutex_lock(&daemon->mux); |
8bf2debd MH |
162 | BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN)); |
163 | daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN; | |
164 | atomic_dec(&ecryptfs_num_miscdev_opens); | |
165 | mutex_unlock(&daemon->mux); | |
166 | rc = ecryptfs_exorcise_daemon(daemon); | |
167 | if (rc) { | |
168 | printk(KERN_CRIT "%s: Fatal error whilst attempting to " | |
169 | "shut down daemon; rc = [%d]. Please report this " | |
170 | "bug.\n", __func__, rc); | |
171 | BUG(); | |
172 | } | |
173 | module_put(THIS_MODULE); | |
174 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
175 | return rc; | |
176 | } | |
177 | ||
178 | /** | |
179 | * ecryptfs_send_miscdev | |
180 | * @data: Data to send to daemon; may be NULL | |
181 | * @data_size: Amount of data to send to daemon | |
182 | * @msg_ctx: Message context, which is used to handle the reply. If | |
183 | * this is NULL, then we do not expect a reply. | |
184 | * @msg_type: Type of message | |
185 | * @msg_flags: Flags for message | |
186 | * @daemon: eCryptfs daemon object | |
187 | * | |
188 | * Add msg_ctx to queue and then, if it exists, notify the blocked | |
189 | * miscdevess about the data being available. Must be called with | |
190 | * ecryptfs_daemon_hash_mux held. | |
191 | * | |
192 | * Returns zero on success; non-zero otherwise | |
193 | */ | |
194 | int ecryptfs_send_miscdev(char *data, size_t data_size, | |
195 | struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type, | |
196 | u16 msg_flags, struct ecryptfs_daemon *daemon) | |
197 | { | |
60d65f1f | 198 | struct ecryptfs_message *msg; |
8bf2debd | 199 | |
60d65f1f TH |
200 | msg = kmalloc((sizeof(*msg) + data_size), GFP_KERNEL); |
201 | if (!msg) { | |
57ea34d1 TH |
202 | printk(KERN_ERR "%s: Out of memory whilst attempting " |
203 | "to kmalloc(%zd, GFP_KERNEL)\n", __func__, | |
60d65f1f TH |
204 | (sizeof(*msg) + data_size)); |
205 | return -ENOMEM; | |
57ea34d1 | 206 | } |
60d65f1f TH |
207 | |
208 | mutex_lock(&msg_ctx->mux); | |
209 | msg_ctx->msg = msg; | |
8bf2debd MH |
210 | msg_ctx->msg->index = msg_ctx->index; |
211 | msg_ctx->msg->data_len = data_size; | |
212 | msg_ctx->type = msg_type; | |
57ea34d1 TH |
213 | memcpy(msg_ctx->msg->data, data, data_size); |
214 | msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size); | |
8bf2debd | 215 | list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue); |
60d65f1f TH |
216 | mutex_unlock(&msg_ctx->mux); |
217 | ||
218 | mutex_lock(&daemon->mux); | |
8bf2debd MH |
219 | daemon->num_queued_msg_ctx++; |
220 | wake_up_interruptible(&daemon->wait); | |
221 | mutex_unlock(&daemon->mux); | |
60d65f1f TH |
222 | |
223 | return 0; | |
8bf2debd MH |
224 | } |
225 | ||
48399c0b TH |
226 | /* |
227 | * miscdevfs packet format: | |
228 | * Octet 0: Type | |
229 | * Octets 1-4: network byte order msg_ctx->counter | |
230 | * Octets 5-N0: Size of struct ecryptfs_message to follow | |
231 | * Octets N0-N1: struct ecryptfs_message (including data) | |
232 | * | |
233 | * Octets 5-N1 not written if the packet type does not include a message | |
234 | */ | |
235 | #define PKT_TYPE_SIZE 1 | |
236 | #define PKT_CTR_SIZE 4 | |
237 | #define MIN_NON_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE) | |
238 | #define MIN_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \ | |
239 | + ECRYPTFS_MIN_PKT_LEN_SIZE) | |
240 | /* 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES comes from tag 65 packet format */ | |
241 | #define MAX_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \ | |
242 | + ECRYPTFS_MAX_PKT_LEN_SIZE \ | |
243 | + sizeof(struct ecryptfs_message) \ | |
244 | + 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) | |
245 | #define PKT_TYPE_OFFSET 0 | |
246 | #define PKT_CTR_OFFSET PKT_TYPE_SIZE | |
247 | #define PKT_LEN_OFFSET (PKT_TYPE_SIZE + PKT_CTR_SIZE) | |
248 | ||
8bf2debd MH |
249 | /** |
250 | * ecryptfs_miscdev_read - format and send message from queue | |
251 | * @file: fs/ecryptfs/euid miscdevfs handle (ignored) | |
252 | * @buf: User buffer into which to copy the next message on the daemon queue | |
253 | * @count: Amount of space available in @buf | |
254 | * @ppos: Offset in file (ignored) | |
255 | * | |
256 | * Pulls the most recent message from the daemon queue, formats it for | |
257 | * being sent via a miscdevfs handle, and copies it into @buf | |
258 | * | |
259 | * Returns the number of bytes copied into the user buffer | |
260 | */ | |
f66e883e | 261 | static ssize_t |
8bf2debd MH |
262 | ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count, |
263 | loff_t *ppos) | |
264 | { | |
265 | struct ecryptfs_daemon *daemon; | |
266 | struct ecryptfs_msg_ctx *msg_ctx; | |
267 | size_t packet_length_size; | |
48399c0b | 268 | char packet_length[ECRYPTFS_MAX_PKT_LEN_SIZE]; |
8bf2debd MH |
269 | size_t i; |
270 | size_t total_length; | |
4eea0353 | 271 | uid_t euid = current_euid(); |
8bf2debd MH |
272 | int rc; |
273 | ||
274 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
275 | /* TODO: Just use file->private_data? */ | |
18b6e041 | 276 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); |
8dc67805 TH |
277 | if (rc || !daemon) { |
278 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
279 | return -EINVAL; | |
280 | } | |
8bf2debd | 281 | mutex_lock(&daemon->mux); |
8dc67805 TH |
282 | if (task_pid(current) != daemon->pid) { |
283 | mutex_unlock(&daemon->mux); | |
284 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
285 | return -EPERM; | |
286 | } | |
8bf2debd MH |
287 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { |
288 | rc = 0; | |
43f14d85 | 289 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
8bf2debd MH |
290 | printk(KERN_WARNING "%s: Attempt to read from zombified " |
291 | "daemon\n", __func__); | |
292 | goto out_unlock_daemon; | |
293 | } | |
294 | if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) { | |
295 | rc = 0; | |
43f14d85 | 296 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
8bf2debd MH |
297 | goto out_unlock_daemon; |
298 | } | |
299 | /* This daemon will not go away so long as this flag is set */ | |
300 | daemon->flags |= ECRYPTFS_DAEMON_IN_READ; | |
301 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
302 | check_list: | |
303 | if (list_empty(&daemon->msg_ctx_out_queue)) { | |
304 | mutex_unlock(&daemon->mux); | |
305 | rc = wait_event_interruptible( | |
306 | daemon->wait, !list_empty(&daemon->msg_ctx_out_queue)); | |
307 | mutex_lock(&daemon->mux); | |
308 | if (rc < 0) { | |
309 | rc = 0; | |
310 | goto out_unlock_daemon; | |
311 | } | |
312 | } | |
313 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { | |
314 | rc = 0; | |
315 | goto out_unlock_daemon; | |
316 | } | |
317 | if (list_empty(&daemon->msg_ctx_out_queue)) { | |
318 | /* Something else jumped in since the | |
319 | * wait_event_interruptable() and removed the | |
320 | * message from the queue; try again */ | |
321 | goto check_list; | |
322 | } | |
8bf2debd MH |
323 | msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue, |
324 | struct ecryptfs_msg_ctx, daemon_out_list); | |
325 | BUG_ON(!msg_ctx); | |
326 | mutex_lock(&msg_ctx->mux); | |
327 | if (msg_ctx->msg) { | |
328 | rc = ecryptfs_write_packet_length(packet_length, | |
329 | msg_ctx->msg_size, | |
330 | &packet_length_size); | |
331 | if (rc) { | |
332 | rc = 0; | |
333 | printk(KERN_WARNING "%s: Error writing packet length; " | |
334 | "rc = [%d]\n", __func__, rc); | |
335 | goto out_unlock_msg_ctx; | |
336 | } | |
337 | } else { | |
338 | packet_length_size = 0; | |
339 | msg_ctx->msg_size = 0; | |
340 | } | |
48399c0b TH |
341 | total_length = (PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_length_size |
342 | + msg_ctx->msg_size); | |
8bf2debd MH |
343 | if (count < total_length) { |
344 | rc = 0; | |
345 | printk(KERN_WARNING "%s: Only given user buffer of " | |
df261c52 | 346 | "size [%zd], but we need [%zd] to read the " |
8bf2debd MH |
347 | "pending message\n", __func__, count, total_length); |
348 | goto out_unlock_msg_ctx; | |
349 | } | |
79bc12a0 AV |
350 | rc = -EFAULT; |
351 | if (put_user(msg_ctx->type, buf)) | |
352 | goto out_unlock_msg_ctx; | |
48399c0b TH |
353 | if (put_user(cpu_to_be32(msg_ctx->counter), |
354 | (__be32 __user *)(&buf[PKT_CTR_OFFSET]))) | |
79bc12a0 | 355 | goto out_unlock_msg_ctx; |
48399c0b | 356 | i = PKT_TYPE_SIZE + PKT_CTR_SIZE; |
8bf2debd | 357 | if (msg_ctx->msg) { |
79bc12a0 AV |
358 | if (copy_to_user(&buf[i], packet_length, packet_length_size)) |
359 | goto out_unlock_msg_ctx; | |
8bf2debd | 360 | i += packet_length_size; |
79bc12a0 | 361 | if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size)) |
8bf2debd | 362 | goto out_unlock_msg_ctx; |
8bf2debd MH |
363 | i += msg_ctx->msg_size; |
364 | } | |
365 | rc = i; | |
366 | list_del(&msg_ctx->daemon_out_list); | |
367 | kfree(msg_ctx->msg); | |
368 | msg_ctx->msg = NULL; | |
369 | /* We do not expect a reply from the userspace daemon for any | |
370 | * message type other than ECRYPTFS_MSG_REQUEST */ | |
371 | if (msg_ctx->type != ECRYPTFS_MSG_REQUEST) | |
372 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
373 | out_unlock_msg_ctx: | |
374 | mutex_unlock(&msg_ctx->mux); | |
375 | out_unlock_daemon: | |
376 | daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ; | |
377 | mutex_unlock(&daemon->mux); | |
378 | return rc; | |
379 | } | |
380 | ||
8bf2debd MH |
381 | /** |
382 | * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon | |
383 | * @data: Bytes comprising struct ecryptfs_message | |
384 | * @data_size: sizeof(struct ecryptfs_message) + data len | |
385 | * @euid: Effective user id of miscdevess sending the miscdev response | |
6a3fd92e | 386 | * @user_ns: The namespace in which @euid applies |
8bf2debd MH |
387 | * @pid: Miscdevess id of miscdevess sending the miscdev response |
388 | * @seq: Sequence number for miscdev response packet | |
389 | * | |
390 | * Returns zero on success; non-zero otherwise | |
391 | */ | |
392 | static int ecryptfs_miscdev_response(char *data, size_t data_size, | |
6a3fd92e MH |
393 | uid_t euid, struct user_namespace *user_ns, |
394 | struct pid *pid, u32 seq) | |
8bf2debd MH |
395 | { |
396 | struct ecryptfs_message *msg = (struct ecryptfs_message *)data; | |
397 | int rc; | |
398 | ||
399 | if ((sizeof(*msg) + msg->data_len) != data_size) { | |
400 | printk(KERN_WARNING "%s: (sizeof(*msg) + msg->data_len) = " | |
df261c52 | 401 | "[%zd]; data_size = [%zd]. Invalid packet.\n", __func__, |
8bf2debd MH |
402 | (sizeof(*msg) + msg->data_len), data_size); |
403 | rc = -EINVAL; | |
404 | goto out; | |
405 | } | |
6a3fd92e | 406 | rc = ecryptfs_process_response(msg, euid, user_ns, pid, seq); |
8bf2debd MH |
407 | if (rc) |
408 | printk(KERN_ERR | |
409 | "Error processing response message; rc = [%d]\n", rc); | |
410 | out: | |
411 | return rc; | |
412 | } | |
413 | ||
414 | /** | |
415 | * ecryptfs_miscdev_write - handle write to daemon miscdev handle | |
416 | * @file: File for misc dev handle (ignored) | |
417 | * @buf: Buffer containing user data | |
418 | * @count: Amount of data in @buf | |
419 | * @ppos: Pointer to offset in file (ignored) | |
420 | * | |
8bf2debd MH |
421 | * Returns the number of bytes read from @buf |
422 | */ | |
423 | static ssize_t | |
424 | ecryptfs_miscdev_write(struct file *file, const char __user *buf, | |
425 | size_t count, loff_t *ppos) | |
426 | { | |
79bc12a0 AV |
427 | __be32 counter_nbo; |
428 | u32 seq; | |
48399c0b | 429 | size_t packet_size, packet_size_length; |
8bf2debd | 430 | char *data; |
4eea0353 | 431 | uid_t euid = current_euid(); |
48399c0b | 432 | unsigned char packet_size_peek[ECRYPTFS_MAX_PKT_LEN_SIZE]; |
7f133504 | 433 | ssize_t rc; |
8bf2debd | 434 | |
db10e556 | 435 | if (count == 0) { |
7f133504 | 436 | return 0; |
48399c0b | 437 | } else if (count == MIN_NON_MSG_PKT_SIZE) { |
db10e556 TH |
438 | /* Likely a harmless MSG_HELO or MSG_QUIT - no packet length */ |
439 | goto memdup; | |
48399c0b | 440 | } else if (count < MIN_MSG_PKT_SIZE || count > MAX_MSG_PKT_SIZE) { |
db10e556 | 441 | printk(KERN_WARNING "%s: Acceptable packet size range is " |
164974a8 | 442 | "[%d-%zu], but amount of data written is [%zu].", |
48399c0b | 443 | __func__, MIN_MSG_PKT_SIZE, MAX_MSG_PKT_SIZE, count); |
db10e556 TH |
444 | return -EINVAL; |
445 | } | |
446 | ||
48399c0b | 447 | if (copy_from_user(packet_size_peek, &buf[PKT_LEN_OFFSET], |
db10e556 TH |
448 | sizeof(packet_size_peek))) { |
449 | printk(KERN_WARNING "%s: Error while inspecting packet size\n", | |
450 | __func__); | |
451 | return -EFAULT; | |
452 | } | |
453 | ||
454 | rc = ecryptfs_parse_packet_length(packet_size_peek, &packet_size, | |
455 | &packet_size_length); | |
456 | if (rc) { | |
457 | printk(KERN_WARNING "%s: Error parsing packet length; " | |
7f133504 | 458 | "rc = [%zd]\n", __func__, rc); |
db10e556 TH |
459 | return rc; |
460 | } | |
461 | ||
48399c0b TH |
462 | if ((PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_size_length + packet_size) |
463 | != count) { | |
db10e556 TH |
464 | printk(KERN_WARNING "%s: Invalid packet size [%zu]\n", __func__, |
465 | packet_size); | |
466 | return -EINVAL; | |
467 | } | |
fd56d242 | 468 | |
db10e556 | 469 | memdup: |
fd56d242 LZ |
470 | data = memdup_user(buf, count); |
471 | if (IS_ERR(data)) { | |
472 | printk(KERN_ERR "%s: memdup_user returned error [%ld]\n", | |
473 | __func__, PTR_ERR(data)); | |
7f133504 | 474 | return PTR_ERR(data); |
8bf2debd | 475 | } |
48399c0b | 476 | switch (data[PKT_TYPE_OFFSET]) { |
8bf2debd | 477 | case ECRYPTFS_MSG_RESPONSE: |
48399c0b TH |
478 | if (count < (MIN_MSG_PKT_SIZE |
479 | + sizeof(struct ecryptfs_message))) { | |
8bf2debd | 480 | printk(KERN_WARNING "%s: Minimum acceptable packet " |
df261c52 MH |
481 | "size is [%zd], but amount of data written is " |
482 | "only [%zd]. Discarding response packet.\n", | |
8bf2debd | 483 | __func__, |
48399c0b TH |
484 | (MIN_MSG_PKT_SIZE |
485 | + sizeof(struct ecryptfs_message)), count); | |
7f133504 | 486 | rc = -EINVAL; |
8bf2debd MH |
487 | goto out_free; |
488 | } | |
48399c0b | 489 | memcpy(&counter_nbo, &data[PKT_CTR_OFFSET], PKT_CTR_SIZE); |
8bf2debd | 490 | seq = be32_to_cpu(counter_nbo); |
48399c0b TH |
491 | rc = ecryptfs_miscdev_response( |
492 | &data[PKT_LEN_OFFSET + packet_size_length], | |
493 | packet_size, euid, current_user_ns(), | |
494 | task_pid(current), seq); | |
7f133504 | 495 | if (rc) { |
8bf2debd | 496 | printk(KERN_WARNING "%s: Failed to deliver miscdev " |
7f133504 | 497 | "response to requesting operation; rc = [%zd]\n", |
8bf2debd | 498 | __func__, rc); |
7f133504 TH |
499 | goto out_free; |
500 | } | |
8bf2debd MH |
501 | break; |
502 | case ECRYPTFS_MSG_HELO: | |
8bf2debd | 503 | case ECRYPTFS_MSG_QUIT: |
8bf2debd MH |
504 | break; |
505 | default: | |
506 | ecryptfs_printk(KERN_WARNING, "Dropping miscdev " | |
507 | "message of unrecognized type [%d]\n", | |
508 | data[0]); | |
7f133504 TH |
509 | rc = -EINVAL; |
510 | goto out_free; | |
8bf2debd | 511 | } |
7f133504 | 512 | rc = count; |
8bf2debd MH |
513 | out_free: |
514 | kfree(data); | |
7f133504 | 515 | return rc; |
8bf2debd MH |
516 | } |
517 | ||
518 | ||
519 | static const struct file_operations ecryptfs_miscdev_fops = { | |
520 | .open = ecryptfs_miscdev_open, | |
521 | .poll = ecryptfs_miscdev_poll, | |
522 | .read = ecryptfs_miscdev_read, | |
523 | .write = ecryptfs_miscdev_write, | |
524 | .release = ecryptfs_miscdev_release, | |
6038f373 | 525 | .llseek = noop_llseek, |
8bf2debd MH |
526 | }; |
527 | ||
528 | static struct miscdevice ecryptfs_miscdev = { | |
529 | .minor = MISC_DYNAMIC_MINOR, | |
530 | .name = "ecryptfs", | |
531 | .fops = &ecryptfs_miscdev_fops | |
532 | }; | |
533 | ||
534 | /** | |
535 | * ecryptfs_init_ecryptfs_miscdev | |
536 | * | |
537 | * Messages sent to the userspace daemon from the kernel are placed on | |
538 | * a queue associated with the daemon. The next read against the | |
539 | * miscdev handle by that daemon will return the oldest message placed | |
540 | * on the message queue for the daemon. | |
541 | * | |
542 | * Returns zero on success; non-zero otherwise | |
543 | */ | |
7371a382 | 544 | int __init ecryptfs_init_ecryptfs_miscdev(void) |
8bf2debd MH |
545 | { |
546 | int rc; | |
547 | ||
548 | atomic_set(&ecryptfs_num_miscdev_opens, 0); | |
8bf2debd MH |
549 | rc = misc_register(&ecryptfs_miscdev); |
550 | if (rc) | |
551 | printk(KERN_ERR "%s: Failed to register miscellaneous device " | |
552 | "for communications with userspace daemons; rc = [%d]\n", | |
553 | __func__, rc); | |
8bf2debd MH |
554 | return rc; |
555 | } | |
556 | ||
557 | /** | |
558 | * ecryptfs_destroy_ecryptfs_miscdev | |
559 | * | |
560 | * All of the daemons must be exorcised prior to calling this | |
561 | * function. | |
562 | */ | |
563 | void ecryptfs_destroy_ecryptfs_miscdev(void) | |
564 | { | |
565 | BUG_ON(atomic_read(&ecryptfs_num_miscdev_opens) != 0); | |
566 | misc_deregister(&ecryptfs_miscdev); | |
567 | } |