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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> |
6a3fd92e MH |
23 | #include <linux/user_namespace.h> |
24 | #include <linux/nsproxy.h> | |
88b4a07e MH |
25 | #include "ecryptfs_kernel.h" |
26 | ||
dd2a3b7a MH |
27 | static LIST_HEAD(ecryptfs_msg_ctx_free_list); |
28 | static LIST_HEAD(ecryptfs_msg_ctx_alloc_list); | |
29 | static struct mutex ecryptfs_msg_ctx_lists_mux; | |
88b4a07e | 30 | |
f66e883e MH |
31 | static struct hlist_head *ecryptfs_daemon_hash; |
32 | struct mutex ecryptfs_daemon_hash_mux; | |
dd2a3b7a MH |
33 | static int ecryptfs_hash_buckets; |
34 | #define ecryptfs_uid_hash(uid) \ | |
35 | hash_long((unsigned long)uid, ecryptfs_hash_buckets) | |
88b4a07e | 36 | |
f66e883e | 37 | static u32 ecryptfs_msg_counter; |
dd2a3b7a | 38 | static struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr; |
88b4a07e MH |
39 | |
40 | /** | |
41 | * ecryptfs_acquire_free_msg_ctx | |
42 | * @msg_ctx: The context that was acquired from the free list | |
43 | * | |
44 | * Acquires a context element from the free list and locks the mutex | |
f66e883e MH |
45 | * on the context. Sets the msg_ctx task to current. Returns zero on |
46 | * success; non-zero on error or upon failure to acquire a free | |
47 | * context element. Must be called with ecryptfs_msg_ctx_lists_mux | |
48 | * held. | |
88b4a07e MH |
49 | */ |
50 | static int ecryptfs_acquire_free_msg_ctx(struct ecryptfs_msg_ctx **msg_ctx) | |
51 | { | |
52 | struct list_head *p; | |
53 | int rc; | |
54 | ||
55 | if (list_empty(&ecryptfs_msg_ctx_free_list)) { | |
f66e883e MH |
56 | printk(KERN_WARNING "%s: The eCryptfs free " |
57 | "context list is empty. It may be helpful to " | |
58 | "specify the ecryptfs_message_buf_len " | |
59 | "parameter to be greater than the current " | |
60 | "value of [%d]\n", __func__, ecryptfs_message_buf_len); | |
88b4a07e MH |
61 | rc = -ENOMEM; |
62 | goto out; | |
63 | } | |
64 | list_for_each(p, &ecryptfs_msg_ctx_free_list) { | |
65 | *msg_ctx = list_entry(p, struct ecryptfs_msg_ctx, node); | |
66 | if (mutex_trylock(&(*msg_ctx)->mux)) { | |
67 | (*msg_ctx)->task = current; | |
68 | rc = 0; | |
69 | goto out; | |
70 | } | |
71 | } | |
72 | rc = -ENOMEM; | |
73 | out: | |
74 | return rc; | |
75 | } | |
76 | ||
77 | /** | |
78 | * ecryptfs_msg_ctx_free_to_alloc | |
79 | * @msg_ctx: The context to move from the free list to the alloc list | |
80 | * | |
f66e883e | 81 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
88b4a07e MH |
82 | */ |
83 | static void ecryptfs_msg_ctx_free_to_alloc(struct ecryptfs_msg_ctx *msg_ctx) | |
84 | { | |
85 | list_move(&msg_ctx->node, &ecryptfs_msg_ctx_alloc_list); | |
86 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_PENDING; | |
87 | msg_ctx->counter = ++ecryptfs_msg_counter; | |
88 | } | |
89 | ||
90 | /** | |
91 | * ecryptfs_msg_ctx_alloc_to_free | |
92 | * @msg_ctx: The context to move from the alloc list to the free list | |
93 | * | |
f66e883e | 94 | * Must be called with ecryptfs_msg_ctx_lists_mux held. |
88b4a07e | 95 | */ |
f66e883e | 96 | void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx) |
88b4a07e MH |
97 | { |
98 | list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list); | |
99 | if (msg_ctx->msg) | |
100 | kfree(msg_ctx->msg); | |
f66e883e | 101 | msg_ctx->msg = NULL; |
88b4a07e MH |
102 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE; |
103 | } | |
104 | ||
105 | /** | |
f66e883e MH |
106 | * ecryptfs_find_daemon_by_euid |
107 | * @euid: The effective user id which maps to the desired daemon id | |
6a3fd92e | 108 | * @user_ns: The namespace in which @euid applies |
f66e883e | 109 | * @daemon: If return value is zero, points to the desired daemon pointer |
88b4a07e | 110 | * |
f66e883e MH |
111 | * Must be called with ecryptfs_daemon_hash_mux held. |
112 | * | |
113 | * Search the hash list for the given user id. | |
114 | * | |
115 | * Returns zero if the user id exists in the list; non-zero otherwise. | |
88b4a07e | 116 | */ |
6a3fd92e MH |
117 | int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid, |
118 | struct user_namespace *user_ns) | |
88b4a07e MH |
119 | { |
120 | struct hlist_node *elem; | |
121 | int rc; | |
122 | ||
f66e883e MH |
123 | hlist_for_each_entry(*daemon, elem, |
124 | &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)], | |
125 | euid_chain) { | |
6a3fd92e | 126 | if ((*daemon)->euid == euid && (*daemon)->user_ns == user_ns) { |
88b4a07e MH |
127 | rc = 0; |
128 | goto out; | |
129 | } | |
130 | } | |
131 | rc = -EINVAL; | |
132 | out: | |
133 | return rc; | |
134 | } | |
135 | ||
f66e883e MH |
136 | static int |
137 | ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len, | |
138 | u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx); | |
139 | ||
140 | /** | |
141 | * ecryptfs_send_raw_message | |
142 | * @transport: Transport type | |
143 | * @msg_type: Message type | |
144 | * @daemon: Daemon struct for recipient of message | |
145 | * | |
146 | * A raw message is one that does not include an ecryptfs_message | |
147 | * struct. It simply has a type. | |
148 | * | |
149 | * Must be called with ecryptfs_daemon_hash_mux held. | |
150 | * | |
151 | * Returns zero on success; non-zero otherwise | |
152 | */ | |
153 | static int ecryptfs_send_raw_message(unsigned int transport, u8 msg_type, | |
154 | struct ecryptfs_daemon *daemon) | |
88b4a07e | 155 | { |
f66e883e | 156 | struct ecryptfs_msg_ctx *msg_ctx; |
88b4a07e MH |
157 | int rc; |
158 | ||
159 | switch(transport) { | |
160 | case ECRYPTFS_TRANSPORT_NETLINK: | |
f66e883e MH |
161 | rc = ecryptfs_send_netlink(NULL, 0, NULL, msg_type, 0, |
162 | daemon->pid); | |
163 | break; | |
164 | case ECRYPTFS_TRANSPORT_MISCDEV: | |
165 | rc = ecryptfs_send_message_locked(transport, NULL, 0, msg_type, | |
166 | &msg_ctx); | |
167 | if (rc) { | |
168 | printk(KERN_ERR "%s: Error whilst attempting to send " | |
169 | "message via procfs; rc = [%d]\n", __func__, rc); | |
170 | goto out; | |
171 | } | |
172 | /* Raw messages are logically context-free (e.g., no | |
173 | * reply is expected), so we set the state of the | |
174 | * ecryptfs_msg_ctx object to indicate that it should | |
175 | * be freed as soon as the transport sends out the message. */ | |
176 | mutex_lock(&msg_ctx->mux); | |
177 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_NO_REPLY; | |
178 | mutex_unlock(&msg_ctx->mux); | |
88b4a07e MH |
179 | break; |
180 | case ECRYPTFS_TRANSPORT_CONNECTOR: | |
181 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
182 | default: | |
183 | rc = -ENOSYS; | |
184 | } | |
f66e883e MH |
185 | out: |
186 | return rc; | |
187 | } | |
188 | ||
189 | /** | |
190 | * ecryptfs_spawn_daemon - Create and initialize a new daemon struct | |
191 | * @daemon: Pointer to set to newly allocated daemon struct | |
192 | * @euid: Effective user id for the daemon | |
6a3fd92e | 193 | * @user_ns: The namespace in which @euid applies |
f66e883e MH |
194 | * @pid: Process id for the daemon |
195 | * | |
196 | * Must be called ceremoniously while in possession of | |
197 | * ecryptfs_sacred_daemon_hash_mux | |
198 | * | |
199 | * Returns zero on success; non-zero otherwise | |
200 | */ | |
201 | int | |
6a3fd92e MH |
202 | ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid, |
203 | struct user_namespace *user_ns, struct pid *pid) | |
f66e883e MH |
204 | { |
205 | int rc = 0; | |
206 | ||
207 | (*daemon) = kzalloc(sizeof(**daemon), GFP_KERNEL); | |
208 | if (!(*daemon)) { | |
209 | rc = -ENOMEM; | |
210 | printk(KERN_ERR "%s: Failed to allocate [%Zd] bytes of " | |
211 | "GFP_KERNEL memory\n", __func__, sizeof(**daemon)); | |
212 | goto out; | |
213 | } | |
214 | (*daemon)->euid = euid; | |
6a3fd92e MH |
215 | (*daemon)->user_ns = get_user_ns(user_ns); |
216 | (*daemon)->pid = get_pid(pid); | |
f66e883e MH |
217 | (*daemon)->task = current; |
218 | mutex_init(&(*daemon)->mux); | |
219 | INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue); | |
220 | init_waitqueue_head(&(*daemon)->wait); | |
221 | (*daemon)->num_queued_msg_ctx = 0; | |
222 | hlist_add_head(&(*daemon)->euid_chain, | |
223 | &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)]); | |
224 | out: | |
88b4a07e MH |
225 | return rc; |
226 | } | |
227 | ||
228 | /** | |
229 | * ecryptfs_process_helo | |
230 | * @transport: The underlying transport (netlink, etc.) | |
f66e883e | 231 | * @euid: The user ID owner of the message |
6a3fd92e | 232 | * @user_ns: The namespace in which @euid applies |
88b4a07e MH |
233 | * @pid: The process ID for the userspace program that sent the |
234 | * message | |
235 | * | |
f66e883e | 236 | * Adds the euid and pid values to the daemon euid hash. If an euid |
88b4a07e | 237 | * already has a daemon pid registered, the daemon will be |
f66e883e MH |
238 | * unregistered before the new daemon is put into the hash list. |
239 | * Returns zero after adding a new daemon to the hash list; | |
88b4a07e MH |
240 | * non-zero otherwise. |
241 | */ | |
6a3fd92e MH |
242 | int ecryptfs_process_helo(unsigned int transport, uid_t euid, |
243 | struct user_namespace *user_ns, struct pid *pid) | |
88b4a07e | 244 | { |
f66e883e MH |
245 | struct ecryptfs_daemon *new_daemon; |
246 | struct ecryptfs_daemon *old_daemon; | |
88b4a07e MH |
247 | int rc; |
248 | ||
f66e883e | 249 | mutex_lock(&ecryptfs_daemon_hash_mux); |
6a3fd92e | 250 | rc = ecryptfs_find_daemon_by_euid(&old_daemon, euid, user_ns); |
f66e883e | 251 | if (rc != 0) { |
88b4a07e | 252 | printk(KERN_WARNING "Received request from user [%d] " |
6a3fd92e MH |
253 | "to register daemon [0x%p]; unregistering daemon " |
254 | "[0x%p]\n", euid, pid, old_daemon->pid); | |
f66e883e MH |
255 | rc = ecryptfs_send_raw_message(transport, ECRYPTFS_MSG_QUIT, |
256 | old_daemon); | |
88b4a07e MH |
257 | if (rc) |
258 | printk(KERN_WARNING "Failed to send QUIT " | |
6a3fd92e | 259 | "message to daemon [0x%p]; rc = [%d]\n", |
f66e883e MH |
260 | old_daemon->pid, rc); |
261 | hlist_del(&old_daemon->euid_chain); | |
262 | kfree(old_daemon); | |
88b4a07e | 263 | } |
6a3fd92e | 264 | rc = ecryptfs_spawn_daemon(&new_daemon, euid, user_ns, pid); |
f66e883e MH |
265 | if (rc) |
266 | printk(KERN_ERR "%s: The gods are displeased with this attempt " | |
6a3fd92e MH |
267 | "to create a new daemon object for euid [%d]; pid " |
268 | "[0x%p]; rc = [%d]\n", __func__, euid, pid, rc); | |
f66e883e MH |
269 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
270 | return rc; | |
271 | } | |
272 | ||
273 | /** | |
274 | * ecryptfs_exorcise_daemon - Destroy the daemon struct | |
275 | * | |
276 | * Must be called ceremoniously while in possession of | |
277 | * ecryptfs_daemon_hash_mux and the daemon's own mux. | |
278 | */ | |
279 | int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon) | |
280 | { | |
281 | struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp; | |
282 | int rc = 0; | |
283 | ||
284 | mutex_lock(&daemon->mux); | |
285 | if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ) | |
286 | || (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) { | |
287 | rc = -EBUSY; | |
288 | printk(KERN_WARNING "%s: Attempt to destroy daemon with pid " | |
6a3fd92e | 289 | "[0x%p], but it is in the midst of a read or a poll\n", |
f66e883e MH |
290 | __func__, daemon->pid); |
291 | mutex_unlock(&daemon->mux); | |
292 | goto out; | |
293 | } | |
294 | list_for_each_entry_safe(msg_ctx, msg_ctx_tmp, | |
295 | &daemon->msg_ctx_out_queue, daemon_out_list) { | |
296 | list_del(&msg_ctx->daemon_out_list); | |
297 | daemon->num_queued_msg_ctx--; | |
298 | printk(KERN_WARNING "%s: Warning: dropping message that is in " | |
299 | "the out queue of a dying daemon\n", __func__); | |
300 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
301 | } | |
302 | hlist_del(&daemon->euid_chain); | |
303 | if (daemon->task) | |
304 | wake_up_process(daemon->task); | |
6a3fd92e MH |
305 | if (daemon->pid) |
306 | put_pid(daemon->pid); | |
307 | if (daemon->user_ns) | |
308 | put_user_ns(daemon->user_ns); | |
f66e883e MH |
309 | mutex_unlock(&daemon->mux); |
310 | memset(daemon, 0, sizeof(*daemon)); | |
311 | kfree(daemon); | |
312 | out: | |
88b4a07e MH |
313 | return rc; |
314 | } | |
315 | ||
316 | /** | |
317 | * ecryptfs_process_quit | |
f66e883e | 318 | * @euid: The user ID owner of the message |
6a3fd92e | 319 | * @user_ns: The namespace in which @euid applies |
88b4a07e MH |
320 | * @pid: The process ID for the userspace program that sent the |
321 | * message | |
322 | * | |
f66e883e | 323 | * Deletes the corresponding daemon for the given euid and pid, if |
88b4a07e | 324 | * it is the registered that is requesting the deletion. Returns zero |
f66e883e | 325 | * after deleting the desired daemon; non-zero otherwise. |
88b4a07e | 326 | */ |
6a3fd92e MH |
327 | int ecryptfs_process_quit(uid_t euid, struct user_namespace *user_ns, |
328 | struct pid *pid) | |
88b4a07e | 329 | { |
f66e883e | 330 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
331 | int rc; |
332 | ||
f66e883e | 333 | mutex_lock(&ecryptfs_daemon_hash_mux); |
6a3fd92e | 334 | rc = ecryptfs_find_daemon_by_euid(&daemon, euid, user_ns); |
f66e883e | 335 | if (rc || !daemon) { |
88b4a07e | 336 | rc = -EINVAL; |
f66e883e | 337 | printk(KERN_ERR "Received request from user [%d] to " |
6a3fd92e | 338 | "unregister unrecognized daemon [0x%p]\n", euid, pid); |
f66e883e | 339 | goto out_unlock; |
88b4a07e | 340 | } |
f66e883e MH |
341 | rc = ecryptfs_exorcise_daemon(daemon); |
342 | out_unlock: | |
343 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
344 | return rc; |
345 | } | |
346 | ||
347 | /** | |
348 | * ecryptfs_process_reponse | |
349 | * @msg: The ecryptfs message received; the caller should sanity check | |
f66e883e | 350 | * msg->data_len and free the memory |
88b4a07e MH |
351 | * @pid: The process ID of the userspace application that sent the |
352 | * message | |
f66e883e MH |
353 | * @seq: The sequence number of the message; must match the sequence |
354 | * number for the existing message context waiting for this | |
355 | * response | |
356 | * | |
357 | * Processes a response message after sending an operation request to | |
358 | * userspace. Some other process is awaiting this response. Before | |
359 | * sending out its first communications, the other process allocated a | |
360 | * msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The | |
361 | * response message contains this index so that we can copy over the | |
362 | * response message into the msg_ctx that the process holds a | |
363 | * reference to. The other process is going to wake up, check to see | |
364 | * that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then | |
365 | * proceed to read off and process the response message. Returns zero | |
366 | * upon delivery to desired context element; non-zero upon delivery | |
367 | * failure or error. | |
88b4a07e | 368 | * |
f66e883e | 369 | * Returns zero on success; non-zero otherwise |
88b4a07e | 370 | */ |
f66e883e | 371 | int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid, |
6a3fd92e MH |
372 | struct user_namespace *user_ns, struct pid *pid, |
373 | u32 seq) | |
88b4a07e | 374 | { |
f66e883e | 375 | struct ecryptfs_daemon *daemon; |
88b4a07e | 376 | struct ecryptfs_msg_ctx *msg_ctx; |
f66e883e | 377 | size_t msg_size; |
6a3fd92e MH |
378 | struct nsproxy *nsproxy; |
379 | struct user_namespace *current_user_ns; | |
88b4a07e MH |
380 | int rc; |
381 | ||
382 | if (msg->index >= ecryptfs_message_buf_len) { | |
383 | rc = -EINVAL; | |
f66e883e MH |
384 | printk(KERN_ERR "%s: Attempt to reference " |
385 | "context buffer at index [%d]; maximum " | |
386 | "allowable is [%d]\n", __func__, msg->index, | |
387 | (ecryptfs_message_buf_len - 1)); | |
88b4a07e MH |
388 | goto out; |
389 | } | |
390 | msg_ctx = &ecryptfs_msg_ctx_arr[msg->index]; | |
391 | mutex_lock(&msg_ctx->mux); | |
f66e883e | 392 | mutex_lock(&ecryptfs_daemon_hash_mux); |
6a3fd92e MH |
393 | rcu_read_lock(); |
394 | nsproxy = task_nsproxy(msg_ctx->task); | |
395 | if (nsproxy == NULL) { | |
396 | rc = -EBADMSG; | |
397 | printk(KERN_ERR "%s: Receiving process is a zombie. Dropping " | |
398 | "message.\n", __func__); | |
399 | rcu_read_unlock(); | |
400 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
401 | goto wake_up; | |
402 | } | |
403 | current_user_ns = nsproxy->user_ns; | |
404 | rc = ecryptfs_find_daemon_by_euid(&daemon, msg_ctx->task->euid, | |
405 | current_user_ns); | |
406 | rcu_read_unlock(); | |
f66e883e MH |
407 | mutex_unlock(&ecryptfs_daemon_hash_mux); |
408 | if (rc) { | |
88b4a07e | 409 | rc = -EBADMSG; |
f66e883e | 410 | printk(KERN_WARNING "%s: User [%d] received a " |
6a3fd92e | 411 | "message response from process [0x%p] but does " |
f66e883e MH |
412 | "not have a registered daemon\n", __func__, |
413 | msg_ctx->task->euid, pid); | |
88b4a07e MH |
414 | goto wake_up; |
415 | } | |
f66e883e | 416 | if (msg_ctx->task->euid != euid) { |
dddfa461 | 417 | rc = -EBADMSG; |
f66e883e MH |
418 | printk(KERN_WARNING "%s: Received message from user " |
419 | "[%d]; expected message from user [%d]\n", __func__, | |
420 | euid, msg_ctx->task->euid); | |
dddfa461 MH |
421 | goto unlock; |
422 | } | |
6a3fd92e MH |
423 | if (current_user_ns != user_ns) { |
424 | rc = -EBADMSG; | |
425 | printk(KERN_WARNING "%s: Received message from user_ns " | |
426 | "[0x%p]; expected message from user_ns [0x%p]\n", | |
427 | __func__, user_ns, nsproxy->user_ns); | |
428 | goto unlock; | |
429 | } | |
f66e883e | 430 | if (daemon->pid != pid) { |
88b4a07e | 431 | rc = -EBADMSG; |
f66e883e | 432 | printk(KERN_ERR "%s: User [%d] sent a message response " |
6a3fd92e | 433 | "from an unrecognized process [0x%p]\n", |
f66e883e | 434 | __func__, msg_ctx->task->euid, pid); |
88b4a07e MH |
435 | goto unlock; |
436 | } | |
437 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) { | |
438 | rc = -EINVAL; | |
f66e883e MH |
439 | printk(KERN_WARNING "%s: Desired context element is not " |
440 | "pending a response\n", __func__); | |
88b4a07e MH |
441 | goto unlock; |
442 | } else if (msg_ctx->counter != seq) { | |
443 | rc = -EINVAL; | |
f66e883e MH |
444 | printk(KERN_WARNING "%s: Invalid message sequence; " |
445 | "expected [%d]; received [%d]\n", __func__, | |
446 | msg_ctx->counter, seq); | |
88b4a07e MH |
447 | goto unlock; |
448 | } | |
f66e883e | 449 | msg_size = (sizeof(*msg) + msg->data_len); |
88b4a07e MH |
450 | msg_ctx->msg = kmalloc(msg_size, GFP_KERNEL); |
451 | if (!msg_ctx->msg) { | |
452 | rc = -ENOMEM; | |
f66e883e MH |
453 | printk(KERN_ERR "%s: Failed to allocate [%Zd] bytes of " |
454 | "GFP_KERNEL memory\n", __func__, msg_size); | |
88b4a07e MH |
455 | goto unlock; |
456 | } | |
457 | memcpy(msg_ctx->msg, msg, msg_size); | |
458 | msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE; | |
459 | rc = 0; | |
460 | wake_up: | |
461 | wake_up_process(msg_ctx->task); | |
462 | unlock: | |
463 | mutex_unlock(&msg_ctx->mux); | |
464 | out: | |
465 | return rc; | |
466 | } | |
467 | ||
468 | /** | |
f66e883e | 469 | * ecryptfs_send_message_locked |
88b4a07e MH |
470 | * @transport: The transport over which to send the message (i.e., |
471 | * netlink) | |
472 | * @data: The data to send | |
473 | * @data_len: The length of data | |
474 | * @msg_ctx: The message context allocated for the send | |
f66e883e MH |
475 | * |
476 | * Must be called with ecryptfs_daemon_hash_mux held. | |
477 | * | |
478 | * Returns zero on success; non-zero otherwise | |
88b4a07e | 479 | */ |
f66e883e MH |
480 | static int |
481 | ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len, | |
482 | u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx) | |
88b4a07e | 483 | { |
f66e883e | 484 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
485 | int rc; |
486 | ||
6a3fd92e MH |
487 | rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid, |
488 | current->nsproxy->user_ns); | |
f66e883e | 489 | if (rc || !daemon) { |
88b4a07e | 490 | rc = -ENOTCONN; |
f66e883e MH |
491 | printk(KERN_ERR "%s: User [%d] does not have a daemon " |
492 | "registered\n", __func__, current->euid); | |
88b4a07e MH |
493 | goto out; |
494 | } | |
88b4a07e MH |
495 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); |
496 | rc = ecryptfs_acquire_free_msg_ctx(msg_ctx); | |
497 | if (rc) { | |
498 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
f66e883e MH |
499 | printk(KERN_WARNING "%s: Could not claim a free " |
500 | "context element\n", __func__); | |
88b4a07e MH |
501 | goto out; |
502 | } | |
503 | ecryptfs_msg_ctx_free_to_alloc(*msg_ctx); | |
504 | mutex_unlock(&(*msg_ctx)->mux); | |
505 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
506 | switch (transport) { | |
507 | case ECRYPTFS_TRANSPORT_NETLINK: | |
f66e883e MH |
508 | rc = ecryptfs_send_netlink(data, data_len, *msg_ctx, msg_type, |
509 | 0, daemon->pid); | |
510 | break; | |
511 | case ECRYPTFS_TRANSPORT_MISCDEV: | |
512 | rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, | |
513 | 0, daemon); | |
88b4a07e MH |
514 | break; |
515 | case ECRYPTFS_TRANSPORT_CONNECTOR: | |
516 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
517 | default: | |
518 | rc = -ENOSYS; | |
519 | } | |
f66e883e MH |
520 | if (rc) |
521 | printk(KERN_ERR "%s: Error attempting to send message to " | |
522 | "userspace daemon; rc = [%d]\n", __func__, rc); | |
88b4a07e MH |
523 | out: |
524 | return rc; | |
525 | } | |
526 | ||
f66e883e MH |
527 | /** |
528 | * ecryptfs_send_message | |
529 | * @transport: The transport over which to send the message (i.e., | |
530 | * netlink) | |
531 | * @data: The data to send | |
532 | * @data_len: The length of data | |
533 | * @msg_ctx: The message context allocated for the send | |
534 | * | |
535 | * Grabs ecryptfs_daemon_hash_mux. | |
536 | * | |
537 | * Returns zero on success; non-zero otherwise | |
538 | */ | |
539 | int ecryptfs_send_message(unsigned int transport, char *data, int data_len, | |
540 | struct ecryptfs_msg_ctx **msg_ctx) | |
541 | { | |
542 | int rc; | |
543 | ||
544 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
545 | rc = ecryptfs_send_message_locked(transport, data, data_len, | |
546 | ECRYPTFS_MSG_REQUEST, msg_ctx); | |
547 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
548 | return rc; | |
549 | } | |
550 | ||
88b4a07e MH |
551 | /** |
552 | * ecryptfs_wait_for_response | |
553 | * @msg_ctx: The context that was assigned when sending a message | |
554 | * @msg: The incoming message from userspace; not set if rc != 0 | |
555 | * | |
556 | * Sleeps until awaken by ecryptfs_receive_message or until the amount | |
557 | * of time exceeds ecryptfs_message_wait_timeout. If zero is | |
558 | * returned, msg will point to a valid message from userspace; a | |
559 | * non-zero value is returned upon failure to receive a message or an | |
f66e883e | 560 | * error occurs. Callee must free @msg on success. |
88b4a07e MH |
561 | */ |
562 | int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, | |
563 | struct ecryptfs_message **msg) | |
564 | { | |
565 | signed long timeout = ecryptfs_message_wait_timeout * HZ; | |
566 | int rc = 0; | |
567 | ||
568 | sleep: | |
569 | timeout = schedule_timeout_interruptible(timeout); | |
570 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
571 | mutex_lock(&msg_ctx->mux); | |
572 | if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_DONE) { | |
573 | if (timeout) { | |
574 | mutex_unlock(&msg_ctx->mux); | |
575 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
576 | goto sleep; | |
577 | } | |
578 | rc = -ENOMSG; | |
579 | } else { | |
580 | *msg = msg_ctx->msg; | |
581 | msg_ctx->msg = NULL; | |
582 | } | |
583 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx); | |
584 | mutex_unlock(&msg_ctx->mux); | |
585 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
586 | return rc; | |
587 | } | |
588 | ||
589 | int ecryptfs_init_messaging(unsigned int transport) | |
590 | { | |
591 | int i; | |
592 | int rc = 0; | |
593 | ||
594 | if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) { | |
595 | ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS; | |
f66e883e MH |
596 | printk(KERN_WARNING "%s: Specified number of users is " |
597 | "too large, defaulting to [%d] users\n", __func__, | |
598 | ecryptfs_number_of_users); | |
88b4a07e | 599 | } |
f66e883e MH |
600 | mutex_init(&ecryptfs_daemon_hash_mux); |
601 | mutex_lock(&ecryptfs_daemon_hash_mux); | |
5dda6992 MH |
602 | ecryptfs_hash_buckets = 1; |
603 | while (ecryptfs_number_of_users >> ecryptfs_hash_buckets) | |
604 | ecryptfs_hash_buckets++; | |
f66e883e MH |
605 | ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head) |
606 | * ecryptfs_hash_buckets), GFP_KERNEL); | |
607 | if (!ecryptfs_daemon_hash) { | |
88b4a07e | 608 | rc = -ENOMEM; |
f66e883e MH |
609 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
610 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
611 | goto out; |
612 | } | |
613 | for (i = 0; i < ecryptfs_hash_buckets; i++) | |
f66e883e MH |
614 | INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]); |
615 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e | 616 | ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx) |
f66e883e MH |
617 | * ecryptfs_message_buf_len), |
618 | GFP_KERNEL); | |
88b4a07e MH |
619 | if (!ecryptfs_msg_ctx_arr) { |
620 | rc = -ENOMEM; | |
f66e883e | 621 | printk(KERN_ERR "%s: Failed to allocate memory\n", __func__); |
88b4a07e MH |
622 | goto out; |
623 | } | |
624 | mutex_init(&ecryptfs_msg_ctx_lists_mux); | |
625 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
626 | ecryptfs_msg_counter = 0; | |
627 | for (i = 0; i < ecryptfs_message_buf_len; i++) { | |
628 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].node); | |
f66e883e | 629 | INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list); |
88b4a07e MH |
630 | mutex_init(&ecryptfs_msg_ctx_arr[i].mux); |
631 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); | |
632 | ecryptfs_msg_ctx_arr[i].index = i; | |
633 | ecryptfs_msg_ctx_arr[i].state = ECRYPTFS_MSG_CTX_STATE_FREE; | |
634 | ecryptfs_msg_ctx_arr[i].counter = 0; | |
635 | ecryptfs_msg_ctx_arr[i].task = NULL; | |
636 | ecryptfs_msg_ctx_arr[i].msg = NULL; | |
637 | list_add_tail(&ecryptfs_msg_ctx_arr[i].node, | |
638 | &ecryptfs_msg_ctx_free_list); | |
639 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); | |
640 | } | |
641 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
642 | switch(transport) { | |
643 | case ECRYPTFS_TRANSPORT_NETLINK: | |
644 | rc = ecryptfs_init_netlink(); | |
645 | if (rc) | |
646 | ecryptfs_release_messaging(transport); | |
647 | break; | |
f66e883e MH |
648 | case ECRYPTFS_TRANSPORT_MISCDEV: |
649 | rc = ecryptfs_init_ecryptfs_miscdev(); | |
650 | if (rc) | |
651 | ecryptfs_release_messaging(transport); | |
652 | break; | |
88b4a07e MH |
653 | case ECRYPTFS_TRANSPORT_CONNECTOR: |
654 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
655 | default: | |
656 | rc = -ENOSYS; | |
657 | } | |
658 | out: | |
659 | return rc; | |
660 | } | |
661 | ||
662 | void ecryptfs_release_messaging(unsigned int transport) | |
663 | { | |
664 | if (ecryptfs_msg_ctx_arr) { | |
665 | int i; | |
666 | ||
667 | mutex_lock(&ecryptfs_msg_ctx_lists_mux); | |
668 | for (i = 0; i < ecryptfs_message_buf_len; i++) { | |
669 | mutex_lock(&ecryptfs_msg_ctx_arr[i].mux); | |
670 | if (ecryptfs_msg_ctx_arr[i].msg) | |
671 | kfree(ecryptfs_msg_ctx_arr[i].msg); | |
672 | mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux); | |
673 | } | |
674 | kfree(ecryptfs_msg_ctx_arr); | |
675 | mutex_unlock(&ecryptfs_msg_ctx_lists_mux); | |
676 | } | |
f66e883e | 677 | if (ecryptfs_daemon_hash) { |
88b4a07e | 678 | struct hlist_node *elem; |
f66e883e | 679 | struct ecryptfs_daemon *daemon; |
88b4a07e MH |
680 | int i; |
681 | ||
f66e883e | 682 | mutex_lock(&ecryptfs_daemon_hash_mux); |
88b4a07e | 683 | for (i = 0; i < ecryptfs_hash_buckets; i++) { |
f66e883e MH |
684 | int rc; |
685 | ||
686 | hlist_for_each_entry(daemon, elem, | |
687 | &ecryptfs_daemon_hash[i], | |
688 | euid_chain) { | |
689 | rc = ecryptfs_exorcise_daemon(daemon); | |
690 | if (rc) | |
691 | printk(KERN_ERR "%s: Error whilst " | |
692 | "attempting to destroy daemon; " | |
693 | "rc = [%d]. Dazed and confused, " | |
694 | "but trying to continue.\n", | |
695 | __func__, rc); | |
88b4a07e MH |
696 | } |
697 | } | |
f66e883e MH |
698 | kfree(ecryptfs_daemon_hash); |
699 | mutex_unlock(&ecryptfs_daemon_hash_mux); | |
88b4a07e MH |
700 | } |
701 | switch(transport) { | |
702 | case ECRYPTFS_TRANSPORT_NETLINK: | |
703 | ecryptfs_release_netlink(); | |
704 | break; | |
f66e883e MH |
705 | case ECRYPTFS_TRANSPORT_MISCDEV: |
706 | ecryptfs_destroy_ecryptfs_miscdev(); | |
707 | break; | |
88b4a07e MH |
708 | case ECRYPTFS_TRANSPORT_CONNECTOR: |
709 | case ECRYPTFS_TRANSPORT_RELAYFS: | |
710 | default: | |
711 | break; | |
712 | } | |
713 | return; | |
714 | } |