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> |
88b4a07e MH |
23 | #include "ecryptfs_kernel.h" |
24 | ||
dd2a3b7a MH |
25 | static LIST_HEAD(ecryptfs_msg_ctx_free_list); |
26 | static LIST_HEAD(ecryptfs_msg_ctx_alloc_list); | |
27 | static struct mutex ecryptfs_msg_ctx_lists_mux; | |
88b4a07e | 28 | |
f66e883e MH |
29 | static struct hlist_head *ecryptfs_daemon_hash; |
30 | struct mutex ecryptfs_daemon_hash_mux; | |
dd2a3b7a MH |
31 | static int ecryptfs_hash_buckets; |
32 | #define ecryptfs_uid_hash(uid) \ | |
33 | hash_long((unsigned long)uid, ecryptfs_hash_buckets) | |
88b4a07e | 34 | |
f66e883e | 35 | static u32 ecryptfs_msg_counter; |
dd2a3b7a | 36 | static struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr; |
88b4a07e MH |
37 | |
38 | /** | |
39 | * ecryptfs_acquire_free_msg_ctx | |
40 | * @msg_ctx: The context that was acquired from the free list | |
41 | * | |
42 | * Acquires a context element from the free list and locks the mutex | |
f66e883e MH |
43 | * on the context. Sets the msg_ctx task to current. Returns zero on |
44 | * success; non-zero on error or upon failure to acquire a free | |
45 | * context element. Must be called with ecryptfs_msg_ctx_lists_mux | |
46 | * held. | |
88b4a07e MH |
47 | */ |
48 | static int ecryptfs_acquire_free_msg_ctx(struct ecryptfs_msg_ctx **msg_ctx) | |
49 | { | |
50 | struct list_head *p; | |
51 | int rc; | |
52 | ||
53 | if (list_empty(&ecryptfs_msg_ctx_free_list)) { | |
f66e883e MH |
54 | printk(KERN_WARNING "%s: The eCryptfs free " |
55 | "context list is empty. It may be helpful to " | |
56 | "specify the ecryptfs_message_buf_len " | |
57 | "parameter to be greater than the current " | |
58 | "value of [%d]\n", __func__, ecryptfs_message_buf_len); | |
88b4a07e MH |
59 | rc = -ENOMEM; |
60 | goto out; | |
61 | } | |
62 | list_for_each(p, &ecryptfs_msg_ctx_free_list) { | |
63 | *msg_ctx = list_entry(p, struct ecryptfs_msg_ctx, node); | |
64 | if (mutex_trylock(&(*msg_ctx)->mux)) { | |
65 | (*msg_ctx)->task = current; | |
66 | rc = 0; | |
67 | goto out; | |
68 | } | |
69 | } | |
70 | rc = -ENOMEM; | |
71 | out: | |
72 | return rc; | |
73 | } | |
74 | ||
75 | /** | |
76 | * ecryptfs_msg_ctx_free_to_alloc | |
77 | * @msg_ctx: The context to move from the free list to the alloc list | |
78 | * | |
f66e883e | 79 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
88b4a07e MH |
80 | */ |
81 | static void ecryptfs_msg_ctx_free_to_alloc(struct ecryptfs_msg_ctx *msg_ctx) | |
82 | { | |
83 | list_move(&msg_ctx->node, &ecryptfs_msg_ctx_alloc_list); | |
84 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_PENDING; | |
85 | msg_ctx->counter = ++ecryptfs_msg_counter; | |
86 | } | |
87 | ||
88 | /** | |
89 | * ecryptfs_msg_ctx_alloc_to_free | |
90 | * @msg_ctx: The context to move from the alloc list to the free list | |
91 | * | |
f66e883e | 92 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
88b4a07e | 93 | */ |
f66e883e | 94 | void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx) |
88b4a07e MH |
95 | { |
96 | list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list); | |
97 | if (msg_ctx->msg) | |
98 | kfree(msg_ctx->msg); | |
f66e883e | 99 | msg_ctx->msg = NULL; |
88b4a07e MH |
100 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE; |
101 | } | |
102 | ||
103 | /** | |
f66e883e MH |
104 | * ecryptfs_find_daemon_by_euid |
105 | * @euid: The effective user id which maps to the desired daemon id | |
106 | * @daemon: If return value is zero, points to the desired daemon pointer | |
88b4a07e | 107 | * |
f66e883e MH |
108 | * Must be called with ecryptfs_daemon_hash_mux held. |
109 | * | |
110 | * Search the hash list for the given user id. | |
111 | * | |
112 | * Returns zero if the user id exists in the list; non-zero otherwise. | |
88b4a07e | 113 | */ |
f66e883e | 114 | int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid) |
88b4a07e MH |
115 | { |
116 | struct hlist_node *elem; | |
117 | int rc; | |
118 | ||
f66e883e MH |
119 | hlist_for_each_entry(*daemon, elem, |
120 | &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)], | |
121 | euid_chain) { | |
122 | if ((*daemon)->euid == euid) { | |
88b4a07e MH |
123 | rc = 0; |
124 | goto out; | |
125 | } | |
126 | } | |
127 | rc = -EINVAL; | |
128 | out: | |
129 | return rc; | |
130 | } | |
131 | ||
f66e883e MH |
132 | static int |
133 | ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len, | |
134 | u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx); | |
135 | ||
136 | /** | |
137 | * ecryptfs_send_raw_message | |
138 | * @transport: Transport type | |
139 | * @msg_type: Message type | |
140 | * @daemon: Daemon struct for recipient of message | |
141 | * | |
142 | * A raw message is one that does not include an ecryptfs_message | |
143 | * struct. It simply has a type. | |
144 | * | |
145 | * Must be called with ecryptfs_daemon_hash_mux held. | |
146 | * | |
147 | * Returns zero on success; non-zero otherwise | |
148 | */ | |
149 | static int ecryptfs_send_raw_message(unsigned int transport, u8 msg_type, | |
150 | struct ecryptfs_daemon *daemon) | |
88b4a07e | 151 | { |
f66e883e | 152 | struct ecryptfs_msg_ctx *msg_ctx; |
88b4a07e MH |
153 | int rc; |
154 | ||
155 | switch(transport) { | |
156 | case ECRYPTFS_TRANSPORT_NETLINK: | |
f66e883e MH |
157 | rc = ecryptfs_send_netlink(NULL, 0, NULL, msg_type, 0, |
158 | daemon->pid); | |
159 | break; | |
160 | case ECRYPTFS_TRANSPORT_MISCDEV: | |
161 | rc = ecryptfs_send_message_locked(transport, NULL, 0, msg_type, | |
162 | &msg_ctx); | |
163 | if (rc) { | |
164 | printk(KERN_ERR "%s: Error whilst attempting to send " | |
165 | "message via procfs; rc = [%d]\n", __func__, rc); | |
166 | goto out; | |
167 | } | |
168 | /* Raw messages are logically context-free (e.g., no | |
169 | * reply is expected), so we set the state of the | |
170 | * ecryptfs_msg_ctx object to indicate that it should | |
171 | * be freed as soon as the transport sends out the message. */ | |
172 | mutex_lock(&msg_ctx->mux); | |
173 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_NO_REPLY; | |
174 | mutex_unlock(&msg_ctx->mux); | |
88b4a07e MH |
175 | break; |
176 | case ECRYPTFS_TRANSPORT_CONNECTOR: | |
177 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
178 | default: | |
179 | rc = -ENOSYS; | |
180 | } | |
f66e883e MH |
181 | out: |
182 | return rc; | |
183 | } | |
184 | ||
185 | /** | |
186 | * ecryptfs_spawn_daemon - Create and initialize a new daemon struct | |
187 | * @daemon: Pointer to set to newly allocated daemon struct | |
188 | * @euid: Effective user id for the daemon | |
189 | * @pid: Process id for the daemon | |
190 | * | |
191 | * Must be called ceremoniously while in possession of | |
192 | * ecryptfs_sacred_daemon_hash_mux | |
193 | * | |
194 | * Returns zero on success; non-zero otherwise | |
195 | */ | |
196 | int | |
197 | ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid, pid_t pid) | |
198 | { | |
199 | int rc = 0; | |
200 | ||
201 | (*daemon) = kzalloc(sizeof(**daemon), GFP_KERNEL); | |
202 | if (!(*daemon)) { | |
203 | rc = -ENOMEM; | |
204 | printk(KERN_ERR "%s: Failed to allocate [%Zd] bytes of " | |
205 | "GFP_KERNEL memory\n", __func__, sizeof(**daemon)); | |
206 | goto out; | |
207 | } | |
208 | (*daemon)->euid = euid; | |
209 | (*daemon)->pid = pid; | |
210 | (*daemon)->task = current; | |
211 | mutex_init(&(*daemon)->mux); | |
212 | INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue); | |
213 | init_waitqueue_head(&(*daemon)->wait); | |
214 | (*daemon)->num_queued_msg_ctx = 0; | |
215 | hlist_add_head(&(*daemon)->euid_chain, | |
216 | &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)]); | |
217 | out: | |
88b4a07e MH |
218 | return rc; |
219 | } | |
220 | ||
221 | /** | |
222 | * ecryptfs_process_helo | |
223 | * @transport: The underlying transport (netlink, etc.) | |
f66e883e | 224 | * @euid: The user ID owner of the message |
88b4a07e MH |
225 | * @pid: The process ID for the userspace program that sent the |
226 | * message | |
227 | * | |
f66e883e | 228 | * Adds the euid and pid values to the daemon euid hash. If an euid |
88b4a07e | 229 | * already has a daemon pid registered, the daemon will be |
f66e883e MH |
230 | * unregistered before the new daemon is put into the hash list. |
231 | * Returns zero after adding a new daemon to the hash list; | |
88b4a07e MH |
232 | * non-zero otherwise. |
233 | */ | |
f66e883e | 234 | int ecryptfs_process_helo(unsigned int transport, uid_t euid, pid_t pid) |
88b4a07e | 235 | { |
f66e883e MH |
236 | struct ecryptfs_daemon *new_daemon; |
237 | struct ecryptfs_daemon *old_daemon; | |
88b4a07e MH |
238 | int rc; |
239 | ||
f66e883e MH |
240 | mutex_lock(&ecryptfs_daemon_hash_mux); |
241 | rc = ecryptfs_find_daemon_by_euid(&old_daemon, euid); | |
242 | if (rc != 0) { | |
88b4a07e MH |
243 | printk(KERN_WARNING "Received request from user [%d] " |
244 | "to register daemon [%d]; unregistering daemon " | |
f66e883e MH |
245 | "[%d]\n", euid, pid, old_daemon->pid); |
246 | rc = ecryptfs_send_raw_message(transport, ECRYPTFS_MSG_QUIT, | |
247 | old_daemon); | |
88b4a07e MH |
248 | if (rc) |
249 | printk(KERN_WARNING "Failed to send QUIT " | |
250 | "message to daemon [%d]; rc = [%d]\n", | |
f66e883e MH |
251 | old_daemon->pid, rc); |
252 | hlist_del(&old_daemon->euid_chain); | |
253 | kfree(old_daemon); | |
88b4a07e | 254 | } |
f66e883e MH |
255 | rc = ecryptfs_spawn_daemon(&new_daemon, euid, pid); |
256 | if (rc) | |
257 | printk(KERN_ERR "%s: The gods are displeased with this attempt " | |
258 | "to create a new daemon object for euid [%d]; pid [%d]; " | |
259 | "rc = [%d]\n", __func__, euid, pid, rc); | |
260 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
261 | return rc; | |
262 | } | |
263 | ||
264 | /** | |
265 | * ecryptfs_exorcise_daemon - Destroy the daemon struct | |
266 | * | |
267 | * Must be called ceremoniously while in possession of | |
268 | * ecryptfs_daemon_hash_mux and the daemon's own mux. | |
269 | */ | |
270 | int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon) | |
271 | { | |
272 | struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp; | |
273 | int rc = 0; | |
274 | ||
275 | mutex_lock(&daemon->mux); | |
276 | if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ) | |
277 | || (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) { | |
278 | rc = -EBUSY; | |
279 | printk(KERN_WARNING "%s: Attempt to destroy daemon with pid " | |
280 | "[%d], but it is in the midst of a read or a poll\n", | |
281 | __func__, daemon->pid); | |
282 | mutex_unlock(&daemon->mux); | |
283 | goto out; | |
284 | } | |
285 | list_for_each_entry_safe(msg_ctx, msg_ctx_tmp, | |
286 | &daemon->msg_ctx_out_queue, daemon_out_list) { | |
287 | list_del(&msg_ctx->daemon_out_list); | |
288 | daemon->num_queued_msg_ctx--; | |
289 | printk(KERN_WARNING "%s: Warning: dropping message that is in " | |
290 | "the out queue of a dying daemon\n", __func__); | |
291 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
292 | } | |
293 | hlist_del(&daemon->euid_chain); | |
294 | if (daemon->task) | |
295 | wake_up_process(daemon->task); | |
296 | mutex_unlock(&daemon->mux); | |
297 | memset(daemon, 0, sizeof(*daemon)); | |
298 | kfree(daemon); | |
299 | out: | |
88b4a07e MH |
300 | return rc; |
301 | } | |
302 | ||
303 | /** | |
304 | * ecryptfs_process_quit | |
f66e883e | 305 | * @euid: The user ID owner of the message |
88b4a07e MH |
306 | * @pid: The process ID for the userspace program that sent the |
307 | * message | |
308 | * | |
f66e883e | 309 | * Deletes the corresponding daemon for the given euid and pid, if |
88b4a07e | 310 | * it is the registered that is requesting the deletion. Returns zero |
f66e883e | 311 | * after deleting the desired daemon; non-zero otherwise. |
88b4a07e | 312 | */ |
f66e883e | 313 | int ecryptfs_process_quit(uid_t euid, pid_t pid) |
88b4a07e | 314 | { |
f66e883e | 315 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
316 | int rc; |
317 | ||
f66e883e MH |
318 | mutex_lock(&ecryptfs_daemon_hash_mux); |
319 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid); | |
320 | if (rc || !daemon) { | |
88b4a07e | 321 | rc = -EINVAL; |
f66e883e MH |
322 | printk(KERN_ERR "Received request from user [%d] to " |
323 | "unregister unrecognized daemon [%d]\n", euid, pid); | |
324 | goto out_unlock; | |
88b4a07e | 325 | } |
f66e883e MH |
326 | rc = ecryptfs_exorcise_daemon(daemon); |
327 | out_unlock: | |
328 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
329 | return rc; |
330 | } | |
331 | ||
332 | /** | |
333 | * ecryptfs_process_reponse | |
334 | * @msg: The ecryptfs message received; the caller should sanity check | |
f66e883e | 335 | * msg->data_len and free the memory |
88b4a07e MH |
336 | * @pid: The process ID of the userspace application that sent the |
337 | * message | |
f66e883e MH |
338 | * @seq: The sequence number of the message; must match the sequence |
339 | * number for the existing message context waiting for this | |
340 | * response | |
341 | * | |
342 | * Processes a response message after sending an operation request to | |
343 | * userspace. Some other process is awaiting this response. Before | |
344 | * sending out its first communications, the other process allocated a | |
345 | * msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The | |
346 | * response message contains this index so that we can copy over the | |
347 | * response message into the msg_ctx that the process holds a | |
348 | * reference to. The other process is going to wake up, check to see | |
349 | * that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then | |
350 | * proceed to read off and process the response message. Returns zero | |
351 | * upon delivery to desired context element; non-zero upon delivery | |
352 | * failure or error. | |
88b4a07e | 353 | * |
f66e883e | 354 | * Returns zero on success; non-zero otherwise |
88b4a07e | 355 | */ |
f66e883e | 356 | int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid, |
dddfa461 | 357 | pid_t pid, u32 seq) |
88b4a07e | 358 | { |
f66e883e | 359 | struct ecryptfs_daemon *daemon; |
88b4a07e | 360 | struct ecryptfs_msg_ctx *msg_ctx; |
f66e883e | 361 | size_t msg_size; |
88b4a07e MH |
362 | int rc; |
363 | ||
364 | if (msg->index >= ecryptfs_message_buf_len) { | |
365 | rc = -EINVAL; | |
f66e883e MH |
366 | printk(KERN_ERR "%s: Attempt to reference " |
367 | "context buffer at index [%d]; maximum " | |
368 | "allowable is [%d]\n", __func__, msg->index, | |
369 | (ecryptfs_message_buf_len - 1)); | |
88b4a07e MH |
370 | goto out; |
371 | } | |
372 | msg_ctx = &ecryptfs_msg_ctx_arr[msg->index]; | |
373 | mutex_lock(&msg_ctx->mux); | |
f66e883e MH |
374 | mutex_lock(&ecryptfs_daemon_hash_mux); |
375 | rc = ecryptfs_find_daemon_by_euid(&daemon, msg_ctx->task->euid); | |
376 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
377 | if (rc) { | |
88b4a07e | 378 | rc = -EBADMSG; |
f66e883e MH |
379 | printk(KERN_WARNING "%s: User [%d] received a " |
380 | "message response from process [%d] but does " | |
381 | "not have a registered daemon\n", __func__, | |
382 | msg_ctx->task->euid, pid); | |
88b4a07e MH |
383 | goto wake_up; |
384 | } | |
f66e883e | 385 | if (msg_ctx->task->euid != euid) { |
dddfa461 | 386 | rc = -EBADMSG; |
f66e883e MH |
387 | printk(KERN_WARNING "%s: Received message from user " |
388 | "[%d]; expected message from user [%d]\n", __func__, | |
389 | euid, msg_ctx->task->euid); | |
dddfa461 MH |
390 | goto unlock; |
391 | } | |
f66e883e | 392 | if (daemon->pid != pid) { |
88b4a07e | 393 | rc = -EBADMSG; |
f66e883e MH |
394 | printk(KERN_ERR "%s: User [%d] sent a message response " |
395 | "from an unrecognized process [%d]\n", | |
396 | __func__, msg_ctx->task->euid, pid); | |
88b4a07e MH |
397 | goto unlock; |
398 | } | |
399 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) { | |
400 | rc = -EINVAL; | |
f66e883e MH |
401 | printk(KERN_WARNING "%s: Desired context element is not " |
402 | "pending a response\n", __func__); | |
88b4a07e MH |
403 | goto unlock; |
404 | } else if (msg_ctx->counter != seq) { | |
405 | rc = -EINVAL; | |
f66e883e MH |
406 | printk(KERN_WARNING "%s: Invalid message sequence; " |
407 | "expected [%d]; received [%d]\n", __func__, | |
408 | msg_ctx->counter, seq); | |
88b4a07e MH |
409 | goto unlock; |
410 | } | |
f66e883e | 411 | msg_size = (sizeof(*msg) + msg->data_len); |
88b4a07e MH |
412 | msg_ctx->msg = kmalloc(msg_size, GFP_KERNEL); |
413 | if (!msg_ctx->msg) { | |
414 | rc = -ENOMEM; | |
f66e883e MH |
415 | printk(KERN_ERR "%s: Failed to allocate [%Zd] bytes of " |
416 | "GFP_KERNEL memory\n", __func__, msg_size); | |
88b4a07e MH |
417 | goto unlock; |
418 | } | |
419 | memcpy(msg_ctx->msg, msg, msg_size); | |
420 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE; | |
421 | rc = 0; | |
422 | wake_up: | |
423 | wake_up_process(msg_ctx->task); | |
424 | unlock: | |
425 | mutex_unlock(&msg_ctx->mux); | |
426 | out: | |
427 | return rc; | |
428 | } | |
429 | ||
430 | /** | |
f66e883e | 431 | * ecryptfs_send_message_locked |
88b4a07e MH |
432 | * @transport: The transport over which to send the message (i.e., |
433 | * netlink) | |
434 | * @data: The data to send | |
435 | * @data_len: The length of data | |
436 | * @msg_ctx: The message context allocated for the send | |
f66e883e MH |
437 | * |
438 | * Must be called with ecryptfs_daemon_hash_mux held. | |
439 | * | |
440 | * Returns zero on success; non-zero otherwise | |
88b4a07e | 441 | */ |
f66e883e MH |
442 | static int |
443 | ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len, | |
444 | u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx) | |
88b4a07e | 445 | { |
f66e883e | 446 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
447 | int rc; |
448 | ||
f66e883e MH |
449 | rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid); |
450 | if (rc || !daemon) { | |
88b4a07e | 451 | rc = -ENOTCONN; |
f66e883e MH |
452 | printk(KERN_ERR "%s: User [%d] does not have a daemon " |
453 | "registered\n", __func__, current->euid); | |
88b4a07e MH |
454 | goto out; |
455 | } | |
88b4a07e MH |
456 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); |
457 | rc = ecryptfs_acquire_free_msg_ctx(msg_ctx); | |
458 | if (rc) { | |
459 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
f66e883e MH |
460 | printk(KERN_WARNING "%s: Could not claim a free " |
461 | "context element\n", __func__); | |
88b4a07e MH |
462 | goto out; |
463 | } | |
464 | ecryptfs_msg_ctx_free_to_alloc(*msg_ctx); | |
465 | mutex_unlock(&(*msg_ctx)->mux); | |
466 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
467 | switch (transport) { | |
468 | case ECRYPTFS_TRANSPORT_NETLINK: | |
f66e883e MH |
469 | rc = ecryptfs_send_netlink(data, data_len, *msg_ctx, msg_type, |
470 | 0, daemon->pid); | |
471 | break; | |
472 | case ECRYPTFS_TRANSPORT_MISCDEV: | |
473 | rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, | |
474 | 0, daemon); | |
88b4a07e MH |
475 | break; |
476 | case ECRYPTFS_TRANSPORT_CONNECTOR: | |
477 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
478 | default: | |
479 | rc = -ENOSYS; | |
480 | } | |
f66e883e MH |
481 | if (rc) |
482 | printk(KERN_ERR "%s: Error attempting to send message to " | |
483 | "userspace daemon; rc = [%d]\n", __func__, rc); | |
88b4a07e MH |
484 | out: |
485 | return rc; | |
486 | } | |
487 | ||
f66e883e MH |
488 | /** |
489 | * ecryptfs_send_message | |
490 | * @transport: The transport over which to send the message (i.e., | |
491 | * netlink) | |
492 | * @data: The data to send | |
493 | * @data_len: The length of data | |
494 | * @msg_ctx: The message context allocated for the send | |
495 | * | |
496 | * Grabs ecryptfs_daemon_hash_mux. | |
497 | * | |
498 | * Returns zero on success; non-zero otherwise | |
499 | */ | |
500 | int ecryptfs_send_message(unsigned int transport, char *data, int data_len, | |
501 | struct ecryptfs_msg_ctx **msg_ctx) | |
502 | { | |
503 | int rc; | |
504 | ||
505 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
506 | rc = ecryptfs_send_message_locked(transport, data, data_len, | |
507 | ECRYPTFS_MSG_REQUEST, msg_ctx); | |
508 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
509 | return rc; | |
510 | } | |
511 | ||
88b4a07e MH |
512 | /** |
513 | * ecryptfs_wait_for_response | |
514 | * @msg_ctx: The context that was assigned when sending a message | |
515 | * @msg: The incoming message from userspace; not set if rc != 0 | |
516 | * | |
517 | * Sleeps until awaken by ecryptfs_receive_message or until the amount | |
518 | * of time exceeds ecryptfs_message_wait_timeout. If zero is | |
519 | * returned, msg will point to a valid message from userspace; a | |
520 | * non-zero value is returned upon failure to receive a message or an | |
f66e883e | 521 | * error occurs. Callee must free @msg on success. |
88b4a07e MH |
522 | */ |
523 | int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, | |
524 | struct ecryptfs_message **msg) | |
525 | { | |
526 | signed long timeout = ecryptfs_message_wait_timeout * HZ; | |
527 | int rc = 0; | |
528 | ||
529 | sleep: | |
530 | timeout = schedule_timeout_interruptible(timeout); | |
531 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
532 | mutex_lock(&msg_ctx->mux); | |
533 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_DONE) { | |
534 | if (timeout) { | |
535 | mutex_unlock(&msg_ctx->mux); | |
536 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
537 | goto sleep; | |
538 | } | |
539 | rc = -ENOMSG; | |
540 | } else { | |
541 | *msg = msg_ctx->msg; | |
542 | msg_ctx->msg = NULL; | |
543 | } | |
544 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
545 | mutex_unlock(&msg_ctx->mux); | |
546 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
547 | return rc; | |
548 | } | |
549 | ||
550 | int ecryptfs_init_messaging(unsigned int transport) | |
551 | { | |
552 | int i; | |
553 | int rc = 0; | |
554 | ||
555 | if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) { | |
556 | ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS; | |
f66e883e MH |
557 | printk(KERN_WARNING "%s: Specified number of users is " |
558 | "too large, defaulting to [%d] users\n", __func__, | |
559 | ecryptfs_number_of_users); | |
88b4a07e | 560 | } |
f66e883e MH |
561 | mutex_init(&ecryptfs_daemon_hash_mux); |
562 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
5dda6992 MH |
563 | ecryptfs_hash_buckets = 1; |
564 | while (ecryptfs_number_of_users >> ecryptfs_hash_buckets) | |
565 | ecryptfs_hash_buckets++; | |
f66e883e MH |
566 | ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head) |
567 | * ecryptfs_hash_buckets), GFP_KERNEL); | |
568 | if (!ecryptfs_daemon_hash) { | |
88b4a07e | 569 | rc = -ENOMEM; |
f66e883e MH |
570 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
571 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
572 | goto out; |
573 | } | |
574 | for (i = 0; i < ecryptfs_hash_buckets; i++) | |
f66e883e MH |
575 | INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]); |
576 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e | 577 | ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx) |
f66e883e MH |
578 | * ecryptfs_message_buf_len), |
579 | GFP_KERNEL); | |
88b4a07e MH |
580 | if (!ecryptfs_msg_ctx_arr) { |
581 | rc = -ENOMEM; | |
f66e883e | 582 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
88b4a07e MH |
583 | goto out; |
584 | } | |
585 | mutex_init(&ecryptfs_msg_ctx_lists_mux); | |
586 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
587 | ecryptfs_msg_counter = 0; | |
588 | for (i = 0; i < ecryptfs_message_buf_len; i++) { | |
589 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].node); | |
f66e883e | 590 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list); |
88b4a07e MH |
591 | mutex_init(&ecryptfs_msg_ctx_arr[i].mux); |
592 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); | |
593 | ecryptfs_msg_ctx_arr[i].index = i; | |
594 | ecryptfs_msg_ctx_arr[i].state = ECRYPTFS_MSG_CTX_STATE_FREE; | |
595 | ecryptfs_msg_ctx_arr[i].counter = 0; | |
596 | ecryptfs_msg_ctx_arr[i].task = NULL; | |
597 | ecryptfs_msg_ctx_arr[i].msg = NULL; | |
598 | list_add_tail(&ecryptfs_msg_ctx_arr[i].node, | |
599 | &ecryptfs_msg_ctx_free_list); | |
600 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); | |
601 | } | |
602 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
603 | switch(transport) { | |
604 | case ECRYPTFS_TRANSPORT_NETLINK: | |
605 | rc = ecryptfs_init_netlink(); | |
606 | if (rc) | |
607 | ecryptfs_release_messaging(transport); | |
608 | break; | |
f66e883e MH |
609 | case ECRYPTFS_TRANSPORT_MISCDEV: |
610 | rc = ecryptfs_init_ecryptfs_miscdev(); | |
611 | if (rc) | |
612 | ecryptfs_release_messaging(transport); | |
613 | break; | |
88b4a07e MH |
614 | case ECRYPTFS_TRANSPORT_CONNECTOR: |
615 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
616 | default: | |
617 | rc = -ENOSYS; | |
618 | } | |
619 | out: | |
620 | return rc; | |
621 | } | |
622 | ||
623 | void ecryptfs_release_messaging(unsigned int transport) | |
624 | { | |
625 | if (ecryptfs_msg_ctx_arr) { | |
626 | int i; | |
627 | ||
628 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
629 | for (i = 0; i < ecryptfs_message_buf_len; i++) { | |
630 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); | |
631 | if (ecryptfs_msg_ctx_arr[i].msg) | |
632 | kfree(ecryptfs_msg_ctx_arr[i].msg); | |
633 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); | |
634 | } | |
635 | kfree(ecryptfs_msg_ctx_arr); | |
636 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
637 | } | |
f66e883e | 638 | if (ecryptfs_daemon_hash) { |
88b4a07e | 639 | struct hlist_node *elem; |
f66e883e | 640 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
641 | int i; |
642 | ||
f66e883e | 643 | mutex_lock(&ecryptfs_daemon_hash_mux); |
88b4a07e | 644 | for (i = 0; i < ecryptfs_hash_buckets; i++) { |
f66e883e MH |
645 | int rc; |
646 | ||
647 | hlist_for_each_entry(daemon, elem, | |
648 | &ecryptfs_daemon_hash[i], | |
649 | euid_chain) { | |
650 | rc = ecryptfs_exorcise_daemon(daemon); | |
651 | if (rc) | |
652 | printk(KERN_ERR "%s: Error whilst " | |
653 | "attempting to destroy daemon; " | |
654 | "rc = [%d]. Dazed and confused, " | |
655 | "but trying to continue.\n", | |
656 | __func__, rc); | |
88b4a07e MH |
657 | } |
658 | } | |
f66e883e MH |
659 | kfree(ecryptfs_daemon_hash); |
660 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
661 | } |
662 | switch(transport) { | |
663 | case ECRYPTFS_TRANSPORT_NETLINK: | |
664 | ecryptfs_release_netlink(); | |
665 | break; | |
f66e883e MH |
666 | case ECRYPTFS_TRANSPORT_MISCDEV: |
667 | ecryptfs_destroy_ecryptfs_miscdev(); | |
668 | break; | |
88b4a07e MH |
669 | case ECRYPTFS_TRANSPORT_CONNECTOR: |
670 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
671 | default: | |
672 | break; | |
673 | } | |
674 | return; | |
675 | } |