| 1 | |
| 2 | * eCryptfs: Linux filesystem encryption layer
|
| 3 | *
|
| 4 | * Copyright (C) 2008 International Business Machines Corp.
|
| 5 | * Author(s): Michael A. Halcrow <[email protected]>
|
| 6 | *
|
| 7 | * This program is free software; you can redistribute it and/or
|
| 8 | * modify it under the terms of the GNU General Public License version
|
| 9 | * 2 as published by the Free Software Foundation.
|
| 10 | *
|
| 11 | * This program is distributed in the hope that it will be useful, but
|
| 12 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
| 14 | * General Public License for more details.
|
| 15 | *
|
| 16 | * You should have received a copy of the GNU General Public License
|
| 17 | * along with this program; if not, write to the Free Software
|
| 18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
|
| 19 | * 02111-1307, USA.
|
| 20 |
|
| 21 |
|
| 22 | #include <linux/fs.h>
|
| 23 | #include <linux/hash.h>
|
| 24 | #include <linux/random.h>
|
| 25 | #include <linux/miscdevice.h>
|
| 26 | #include <linux/poll.h>
|
| 27 | #include <linux/slab.h>
|
| 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
|
| 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 = file->private_data;
|
| 45 | unsigned int mask = 0;
|
| 46 |
|
| 47 | mutex_lock(&daemon->mux);
|
| 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))
|
| 62 | mask |= POLLIN | POLLRDNORM;
|
| 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)
|
| 72 | * @file: file for miscdev handle
|
| 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);
|
| 83 | rc = try_module_get(THIS_MODULE);
|
| 84 | if (rc == 0) {
|
| 85 | rc = -EIO;
|
| 86 | printk(KERN_ERR "%s: Error attempting to increment module use "
|
| 87 | "count; rc = [%d]\n", __func__, rc);
|
| 88 | goto out_unlock_daemon_list;
|
| 89 | }
|
| 90 | rc = ecryptfs_find_daemon_by_euid(&daemon);
|
| 91 | if (!rc) {
|
| 92 | rc = -EINVAL;
|
| 93 | goto out_unlock_daemon_list;
|
| 94 | }
|
| 95 | rc = ecryptfs_spawn_daemon(&daemon, file);
|
| 96 | if (rc) {
|
| 97 | printk(KERN_ERR "%s: Error attempting to spawn daemon; "
|
| 98 | "rc = [%d]\n", __func__, rc);
|
| 99 | goto out_module_put_unlock_daemon_list;
|
| 100 | }
|
| 101 | mutex_lock(&daemon->mux);
|
| 102 | if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
|
| 103 | rc = -EBUSY;
|
| 104 | goto out_unlock_daemon;
|
| 105 | }
|
| 106 | daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN;
|
| 107 | file->private_data = daemon;
|
| 108 | atomic_inc(&ecryptfs_num_miscdev_opens);
|
| 109 | out_unlock_daemon:
|
| 110 | mutex_unlock(&daemon->mux);
|
| 111 | out_module_put_unlock_daemon_list:
|
| 112 | if (rc)
|
| 113 | module_put(THIS_MODULE);
|
| 114 | out_unlock_daemon_list:
|
| 115 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 116 | return rc;
|
| 117 | }
|
| 118 |
|
| 119 | |
| 120 | * ecryptfs_miscdev_release
|
| 121 | * @inode: inode of fs/ecryptfs/euid handle (ignored)
|
| 122 | * @file: file for fs/ecryptfs/euid handle
|
| 123 | *
|
| 124 | * This keeps the daemon registered until the daemon sends another
|
| 125 | * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters.
|
| 126 | *
|
| 127 | * Returns zero on success; non-zero otherwise
|
| 128 |
|
| 129 | static int
|
| 130 | ecryptfs_miscdev_release(struct inode *inode, struct file *file)
|
| 131 | {
|
| 132 | struct ecryptfs_daemon *daemon = file->private_data;
|
| 133 | int rc;
|
| 134 |
|
| 135 | mutex_lock(&daemon->mux);
|
| 136 | BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN));
|
| 137 | daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN;
|
| 138 | atomic_dec(&ecryptfs_num_miscdev_opens);
|
| 139 | mutex_unlock(&daemon->mux);
|
| 140 |
|
| 141 | mutex_lock(&ecryptfs_daemon_hash_mux);
|
| 142 | rc = ecryptfs_exorcise_daemon(daemon);
|
| 143 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 144 | if (rc) {
|
| 145 | printk(KERN_CRIT "%s: Fatal error whilst attempting to "
|
| 146 | "shut down daemon; rc = [%d]. Please report this "
|
| 147 | "bug.\n", __func__, rc);
|
| 148 | BUG();
|
| 149 | }
|
| 150 | module_put(THIS_MODULE);
|
| 151 | return rc;
|
| 152 | }
|
| 153 |
|
| 154 | |
| 155 | * ecryptfs_send_miscdev
|
| 156 | * @data: Data to send to daemon; may be NULL
|
| 157 | * @data_size: Amount of data to send to daemon
|
| 158 | * @msg_ctx: Message context, which is used to handle the reply. If
|
| 159 | * this is NULL, then we do not expect a reply.
|
| 160 | * @msg_type: Type of message
|
| 161 | * @msg_flags: Flags for message
|
| 162 | * @daemon: eCryptfs daemon object
|
| 163 | *
|
| 164 | * Add msg_ctx to queue and then, if it exists, notify the blocked
|
| 165 | * miscdevess about the data being available. Must be called with
|
| 166 | * ecryptfs_daemon_hash_mux held.
|
| 167 | *
|
| 168 | * Returns zero on success; non-zero otherwise
|
| 169 |
|
| 170 | int ecryptfs_send_miscdev(char *data, size_t data_size,
|
| 171 | struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
|
| 172 | u16 msg_flags, struct ecryptfs_daemon *daemon)
|
| 173 | {
|
| 174 | struct ecryptfs_message *msg;
|
| 175 |
|
| 176 | msg = kmalloc((sizeof(*msg) + data_size), GFP_KERNEL);
|
| 177 | if (!msg) {
|
| 178 | printk(KERN_ERR "%s: Out of memory whilst attempting "
|
| 179 | "to kmalloc(%zd, GFP_KERNEL)\n", __func__,
|
| 180 | (sizeof(*msg) + data_size));
|
| 181 | return -ENOMEM;
|
| 182 | }
|
| 183 |
|
| 184 | mutex_lock(&msg_ctx->mux);
|
| 185 | msg_ctx->msg = msg;
|
| 186 | msg_ctx->msg->index = msg_ctx->index;
|
| 187 | msg_ctx->msg->data_len = data_size;
|
| 188 | msg_ctx->type = msg_type;
|
| 189 | memcpy(msg_ctx->msg->data, data, data_size);
|
| 190 | msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size);
|
| 191 | list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue);
|
| 192 | mutex_unlock(&msg_ctx->mux);
|
| 193 |
|
| 194 | mutex_lock(&daemon->mux);
|
| 195 | daemon->num_queued_msg_ctx++;
|
| 196 | wake_up_interruptible(&daemon->wait);
|
| 197 | mutex_unlock(&daemon->mux);
|
| 198 |
|
| 199 | return 0;
|
| 200 | }
|
| 201 |
|
| 202 | |
| 203 | * miscdevfs packet format:
|
| 204 | * Octet 0: Type
|
| 205 | * Octets 1-4: network byte order msg_ctx->counter
|
| 206 | * Octets 5-N0: Size of struct ecryptfs_message to follow
|
| 207 | * Octets N0-N1: struct ecryptfs_message (including data)
|
| 208 | *
|
| 209 | * Octets 5-N1 not written if the packet type does not include a message
|
| 210 |
|
| 211 | #define PKT_TYPE_SIZE 1
|
| 212 | #define PKT_CTR_SIZE 4
|
| 213 | #define MIN_NON_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE)
|
| 214 | #define MIN_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \
|
| 215 | + ECRYPTFS_MIN_PKT_LEN_SIZE)
|
| 216 |
|
| 217 | #define MAX_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \
|
| 218 | + ECRYPTFS_MAX_PKT_LEN_SIZE \
|
| 219 | + sizeof(struct ecryptfs_message) \
|
| 220 | + 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES)
|
| 221 | #define PKT_TYPE_OFFSET 0
|
| 222 | #define PKT_CTR_OFFSET PKT_TYPE_SIZE
|
| 223 | #define PKT_LEN_OFFSET (PKT_TYPE_SIZE + PKT_CTR_SIZE)
|
| 224 |
|
| 225 | |
| 226 | * ecryptfs_miscdev_read - format and send message from queue
|
| 227 | * @file: miscdevfs handle
|
| 228 | * @buf: User buffer into which to copy the next message on the daemon queue
|
| 229 | * @count: Amount of space available in @buf
|
| 230 | * @ppos: Offset in file (ignored)
|
| 231 | *
|
| 232 | * Pulls the most recent message from the daemon queue, formats it for
|
| 233 | * being sent via a miscdevfs handle, and copies it into @buf
|
| 234 | *
|
| 235 | * Returns the number of bytes copied into the user buffer
|
| 236 |
|
| 237 | static ssize_t
|
| 238 | ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
|
| 239 | loff_t *ppos)
|
| 240 | {
|
| 241 | struct ecryptfs_daemon *daemon = file->private_data;
|
| 242 | struct ecryptfs_msg_ctx *msg_ctx;
|
| 243 | size_t packet_length_size;
|
| 244 | char packet_length[ECRYPTFS_MAX_PKT_LEN_SIZE];
|
| 245 | size_t i;
|
| 246 | size_t total_length;
|
| 247 | int rc;
|
| 248 |
|
| 249 | mutex_lock(&daemon->mux);
|
| 250 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
|
| 251 | rc = 0;
|
| 252 | printk(KERN_WARNING "%s: Attempt to read from zombified "
|
| 253 | "daemon\n", __func__);
|
| 254 | goto out_unlock_daemon;
|
| 255 | }
|
| 256 | if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) {
|
| 257 | rc = 0;
|
| 258 | goto out_unlock_daemon;
|
| 259 | }
|
| 260 |
|
| 261 | daemon->flags |= ECRYPTFS_DAEMON_IN_READ;
|
| 262 | check_list:
|
| 263 | if (list_empty(&daemon->msg_ctx_out_queue)) {
|
| 264 | mutex_unlock(&daemon->mux);
|
| 265 | rc = wait_event_interruptible(
|
| 266 | daemon->wait, !list_empty(&daemon->msg_ctx_out_queue));
|
| 267 | mutex_lock(&daemon->mux);
|
| 268 | if (rc < 0) {
|
| 269 | rc = 0;
|
| 270 | goto out_unlock_daemon;
|
| 271 | }
|
| 272 | }
|
| 273 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
|
| 274 | rc = 0;
|
| 275 | goto out_unlock_daemon;
|
| 276 | }
|
| 277 | if (list_empty(&daemon->msg_ctx_out_queue)) {
|
| 278 | |
| 279 | * wait_event_interruptable() and removed the
|
| 280 | * message from the queue; try again
|
| 281 | goto check_list;
|
| 282 | }
|
| 283 | msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue,
|
| 284 | struct ecryptfs_msg_ctx, daemon_out_list);
|
| 285 | BUG_ON(!msg_ctx);
|
| 286 | mutex_lock(&msg_ctx->mux);
|
| 287 | if (msg_ctx->msg) {
|
| 288 | rc = ecryptfs_write_packet_length(packet_length,
|
| 289 | msg_ctx->msg_size,
|
| 290 | &packet_length_size);
|
| 291 | if (rc) {
|
| 292 | rc = 0;
|
| 293 | printk(KERN_WARNING "%s: Error writing packet length; "
|
| 294 | "rc = [%d]\n", __func__, rc);
|
| 295 | goto out_unlock_msg_ctx;
|
| 296 | }
|
| 297 | } else {
|
| 298 | packet_length_size = 0;
|
| 299 | msg_ctx->msg_size = 0;
|
| 300 | }
|
| 301 | total_length = (PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_length_size
|
| 302 | + msg_ctx->msg_size);
|
| 303 | if (count < total_length) {
|
| 304 | rc = 0;
|
| 305 | printk(KERN_WARNING "%s: Only given user buffer of "
|
| 306 | "size [%zd], but we need [%zd] to read the "
|
| 307 | "pending message\n", __func__, count, total_length);
|
| 308 | goto out_unlock_msg_ctx;
|
| 309 | }
|
| 310 | rc = -EFAULT;
|
| 311 | if (put_user(msg_ctx->type, buf))
|
| 312 | goto out_unlock_msg_ctx;
|
| 313 | if (put_user(cpu_to_be32(msg_ctx->counter),
|
| 314 | (__be32 __user *)(&buf[PKT_CTR_OFFSET])))
|
| 315 | goto out_unlock_msg_ctx;
|
| 316 | i = PKT_TYPE_SIZE + PKT_CTR_SIZE;
|
| 317 | if (msg_ctx->msg) {
|
| 318 | if (copy_to_user(&buf[i], packet_length, packet_length_size))
|
| 319 | goto out_unlock_msg_ctx;
|
| 320 | i += packet_length_size;
|
| 321 | if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size))
|
| 322 | goto out_unlock_msg_ctx;
|
| 323 | i += msg_ctx->msg_size;
|
| 324 | }
|
| 325 | rc = i;
|
| 326 | list_del(&msg_ctx->daemon_out_list);
|
| 327 | kfree(msg_ctx->msg);
|
| 328 | msg_ctx->msg = NULL;
|
| 329 | |
| 330 | * message type other than ECRYPTFS_MSG_REQUEST
|
| 331 | if (msg_ctx->type != ECRYPTFS_MSG_REQUEST)
|
| 332 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
|
| 333 | out_unlock_msg_ctx:
|
| 334 | mutex_unlock(&msg_ctx->mux);
|
| 335 | out_unlock_daemon:
|
| 336 | daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ;
|
| 337 | mutex_unlock(&daemon->mux);
|
| 338 | return rc;
|
| 339 | }
|
| 340 |
|
| 341 | |
| 342 | * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon
|
| 343 | * @data: Bytes comprising struct ecryptfs_message
|
| 344 | * @data_size: sizeof(struct ecryptfs_message) + data len
|
| 345 | * @seq: Sequence number for miscdev response packet
|
| 346 | *
|
| 347 | * Returns zero on success; non-zero otherwise
|
| 348 |
|
| 349 | static int ecryptfs_miscdev_response(struct ecryptfs_daemon *daemon, char *data,
|
| 350 | size_t data_size, u32 seq)
|
| 351 | {
|
| 352 | struct ecryptfs_message *msg = (struct ecryptfs_message *)data;
|
| 353 | int rc;
|
| 354 |
|
| 355 | if ((sizeof(*msg) + msg->data_len) != data_size) {
|
| 356 | printk(KERN_WARNING "%s: (sizeof(*msg) + msg->data_len) = "
|
| 357 | "[%zd]; data_size = [%zd]. Invalid packet.\n", __func__,
|
| 358 | (sizeof(*msg) + msg->data_len), data_size);
|
| 359 | rc = -EINVAL;
|
| 360 | goto out;
|
| 361 | }
|
| 362 | rc = ecryptfs_process_response(daemon, msg, seq);
|
| 363 | if (rc)
|
| 364 | printk(KERN_ERR
|
| 365 | "Error processing response message; rc = [%d]\n", rc);
|
| 366 | out:
|
| 367 | return rc;
|
| 368 | }
|
| 369 |
|
| 370 | |
| 371 | * ecryptfs_miscdev_write - handle write to daemon miscdev handle
|
| 372 | * @file: File for misc dev handle
|
| 373 | * @buf: Buffer containing user data
|
| 374 | * @count: Amount of data in @buf
|
| 375 | * @ppos: Pointer to offset in file (ignored)
|
| 376 | *
|
| 377 | * Returns the number of bytes read from @buf
|
| 378 |
|
| 379 | static ssize_t
|
| 380 | ecryptfs_miscdev_write(struct file *file, const char __user *buf,
|
| 381 | size_t count, loff_t *ppos)
|
| 382 | {
|
| 383 | __be32 counter_nbo;
|
| 384 | u32 seq;
|
| 385 | size_t packet_size, packet_size_length;
|
| 386 | char *data;
|
| 387 | unsigned char packet_size_peek[ECRYPTFS_MAX_PKT_LEN_SIZE];
|
| 388 | ssize_t rc;
|
| 389 |
|
| 390 | if (count == 0) {
|
| 391 | return 0;
|
| 392 | } else if (count == MIN_NON_MSG_PKT_SIZE) {
|
| 393 |
|
| 394 | goto memdup;
|
| 395 | } else if (count < MIN_MSG_PKT_SIZE || count > MAX_MSG_PKT_SIZE) {
|
| 396 | printk(KERN_WARNING "%s: Acceptable packet size range is "
|
| 397 | "[%d-%zu], but amount of data written is [%zu].",
|
| 398 | __func__, MIN_MSG_PKT_SIZE, MAX_MSG_PKT_SIZE, count);
|
| 399 | return -EINVAL;
|
| 400 | }
|
| 401 |
|
| 402 | if (copy_from_user(packet_size_peek, &buf[PKT_LEN_OFFSET],
|
| 403 | sizeof(packet_size_peek))) {
|
| 404 | printk(KERN_WARNING "%s: Error while inspecting packet size\n",
|
| 405 | __func__);
|
| 406 | return -EFAULT;
|
| 407 | }
|
| 408 |
|
| 409 | rc = ecryptfs_parse_packet_length(packet_size_peek, &packet_size,
|
| 410 | &packet_size_length);
|
| 411 | if (rc) {
|
| 412 | printk(KERN_WARNING "%s: Error parsing packet length; "
|
| 413 | "rc = [%zd]\n", __func__, rc);
|
| 414 | return rc;
|
| 415 | }
|
| 416 |
|
| 417 | if ((PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_size_length + packet_size)
|
| 418 | != count) {
|
| 419 | printk(KERN_WARNING "%s: Invalid packet size [%zu]\n", __func__,
|
| 420 | packet_size);
|
| 421 | return -EINVAL;
|
| 422 | }
|
| 423 |
|
| 424 | memdup:
|
| 425 | data = memdup_user(buf, count);
|
| 426 | if (IS_ERR(data)) {
|
| 427 | printk(KERN_ERR "%s: memdup_user returned error [%ld]\n",
|
| 428 | __func__, PTR_ERR(data));
|
| 429 | return PTR_ERR(data);
|
| 430 | }
|
| 431 | switch (data[PKT_TYPE_OFFSET]) {
|
| 432 | case ECRYPTFS_MSG_RESPONSE:
|
| 433 | if (count < (MIN_MSG_PKT_SIZE
|
| 434 | + sizeof(struct ecryptfs_message))) {
|
| 435 | printk(KERN_WARNING "%s: Minimum acceptable packet "
|
| 436 | "size is [%zd], but amount of data written is "
|
| 437 | "only [%zd]. Discarding response packet.\n",
|
| 438 | __func__,
|
| 439 | (MIN_MSG_PKT_SIZE
|
| 440 | + sizeof(struct ecryptfs_message)), count);
|
| 441 | rc = -EINVAL;
|
| 442 | goto out_free;
|
| 443 | }
|
| 444 | memcpy(&counter_nbo, &data[PKT_CTR_OFFSET], PKT_CTR_SIZE);
|
| 445 | seq = be32_to_cpu(counter_nbo);
|
| 446 | rc = ecryptfs_miscdev_response(file->private_data,
|
| 447 | &data[PKT_LEN_OFFSET + packet_size_length],
|
| 448 | packet_size, seq);
|
| 449 | if (rc) {
|
| 450 | printk(KERN_WARNING "%s: Failed to deliver miscdev "
|
| 451 | "response to requesting operation; rc = [%zd]\n",
|
| 452 | __func__, rc);
|
| 453 | goto out_free;
|
| 454 | }
|
| 455 | break;
|
| 456 | case ECRYPTFS_MSG_HELO:
|
| 457 | case ECRYPTFS_MSG_QUIT:
|
| 458 | break;
|
| 459 | default:
|
| 460 | ecryptfs_printk(KERN_WARNING, "Dropping miscdev "
|
| 461 | "message of unrecognized type [%d]\n",
|
| 462 | data[0]);
|
| 463 | rc = -EINVAL;
|
| 464 | goto out_free;
|
| 465 | }
|
| 466 | rc = count;
|
| 467 | out_free:
|
| 468 | kfree(data);
|
| 469 | return rc;
|
| 470 | }
|
| 471 |
|
| 472 |
|
| 473 | static const struct file_operations ecryptfs_miscdev_fops = {
|
| 474 | .open = ecryptfs_miscdev_open,
|
| 475 | .poll = ecryptfs_miscdev_poll,
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| 476 | .read = ecryptfs_miscdev_read,
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| 477 | .write = ecryptfs_miscdev_write,
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| 478 | .release = ecryptfs_miscdev_release,
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| 479 | .llseek = noop_llseek,
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| 480 | };
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| 481 |
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| 482 | static struct miscdevice ecryptfs_miscdev = {
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| 483 | .minor = MISC_DYNAMIC_MINOR,
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| 484 | .name = "ecryptfs",
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| 485 | .fops = &ecryptfs_miscdev_fops
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| 486 | };
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| 487 |
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| 488 | |
| 489 | * ecryptfs_init_ecryptfs_miscdev
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| 490 | *
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| 491 | * Messages sent to the userspace daemon from the kernel are placed on
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| 492 | * a queue associated with the daemon. The next read against the
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| 493 | * miscdev handle by that daemon will return the oldest message placed
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| 494 | * on the message queue for the daemon.
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| 495 | *
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| 496 | * Returns zero on success; non-zero otherwise
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| 497 |
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| 498 | int __init ecryptfs_init_ecryptfs_miscdev(void)
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| 499 | {
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| 500 | int rc;
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| 501 |
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| 502 | atomic_set(&ecryptfs_num_miscdev_opens, 0);
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| 503 | rc = misc_register(&ecryptfs_miscdev);
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| 504 | if (rc)
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| 505 | printk(KERN_ERR "%s: Failed to register miscellaneous device "
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| 506 | "for communications with userspace daemons; rc = [%d]\n",
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| 507 | __func__, rc);
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| 508 | return rc;
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| 509 | }
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| 510 |
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| 511 | |
| 512 | * ecryptfs_destroy_ecryptfs_miscdev
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| 513 | *
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| 514 | * All of the daemons must be exorcised prior to calling this
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| 515 | * function.
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| 516 |
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| 517 | void ecryptfs_destroy_ecryptfs_miscdev(void)
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| 518 | {
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| 519 | BUG_ON(atomic_read(&ecryptfs_num_miscdev_opens) != 0);
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| 520 | misc_deregister(&ecryptfs_miscdev);
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| 521 | }
|