| 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/wait.h>
|
| 28 | #include <linux/module.h>
|
| 29 | #include "ecryptfs_kernel.h"
|
| 30 |
|
| 31 | static atomic_t ecryptfs_num_miscdev_opens;
|
| 32 |
|
| 33 | |
| 34 | * ecryptfs_miscdev_poll
|
| 35 | * @file: dev file (ignored)
|
| 36 | * @pt: dev poll table (ignored)
|
| 37 | *
|
| 38 | * Returns the poll mask
|
| 39 |
|
| 40 | static unsigned int
|
| 41 | ecryptfs_miscdev_poll(struct file *file, poll_table *pt)
|
| 42 | {
|
| 43 | struct ecryptfs_daemon *daemon;
|
| 44 | unsigned int mask = 0;
|
| 45 | int rc;
|
| 46 |
|
| 47 | mutex_lock(&ecryptfs_daemon_hash_mux);
|
| 48 |
|
| 49 | rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
|
| 50 | current->nsproxy->user_ns);
|
| 51 | BUG_ON(rc || !daemon);
|
| 52 | mutex_lock(&daemon->mux);
|
| 53 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 54 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
|
| 55 | printk(KERN_WARNING "%s: Attempt to poll on zombified "
|
| 56 | "daemon\n", __func__);
|
| 57 | goto out_unlock_daemon;
|
| 58 | }
|
| 59 | if (daemon->flags & ECRYPTFS_DAEMON_IN_READ)
|
| 60 | goto out_unlock_daemon;
|
| 61 | if (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)
|
| 62 | goto out_unlock_daemon;
|
| 63 | daemon->flags |= ECRYPTFS_DAEMON_IN_POLL;
|
| 64 | mutex_unlock(&daemon->mux);
|
| 65 | poll_wait(file, &daemon->wait, pt);
|
| 66 | mutex_lock(&daemon->mux);
|
| 67 | if (!list_empty(&daemon->msg_ctx_out_queue))
|
| 68 | mask |= POLLIN | POLLRDNORM;
|
| 69 | out_unlock_daemon:
|
| 70 | daemon->flags &= ~ECRYPTFS_DAEMON_IN_POLL;
|
| 71 | mutex_unlock(&daemon->mux);
|
| 72 | return mask;
|
| 73 | }
|
| 74 |
|
| 75 | |
| 76 | * ecryptfs_miscdev_open
|
| 77 | * @inode: inode of miscdev handle (ignored)
|
| 78 | * @file: file for miscdev handle (ignored)
|
| 79 | *
|
| 80 | * Returns zero on success; non-zero otherwise
|
| 81 |
|
| 82 | static int
|
| 83 | ecryptfs_miscdev_open(struct inode *inode, struct file *file)
|
| 84 | {
|
| 85 | struct ecryptfs_daemon *daemon = NULL;
|
| 86 | int rc;
|
| 87 |
|
| 88 | mutex_lock(&ecryptfs_daemon_hash_mux);
|
| 89 | rc = try_module_get(THIS_MODULE);
|
| 90 | if (rc == 0) {
|
| 91 | rc = -EIO;
|
| 92 | printk(KERN_ERR "%s: Error attempting to increment module use "
|
| 93 | "count; rc = [%d]\n", __func__, rc);
|
| 94 | goto out_unlock_daemon_list;
|
| 95 | }
|
| 96 | rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
|
| 97 | current->nsproxy->user_ns);
|
| 98 | if (rc || !daemon) {
|
| 99 | rc = ecryptfs_spawn_daemon(&daemon, current->euid,
|
| 100 | current->nsproxy->user_ns,
|
| 101 | task_pid(current));
|
| 102 | if (rc) {
|
| 103 | printk(KERN_ERR "%s: Error attempting to spawn daemon; "
|
| 104 | "rc = [%d]\n", __func__, rc);
|
| 105 | goto out_module_put_unlock_daemon_list;
|
| 106 | }
|
| 107 | }
|
| 108 | mutex_lock(&daemon->mux);
|
| 109 | if (daemon->pid != task_pid(current)) {
|
| 110 | rc = -EINVAL;
|
| 111 | printk(KERN_ERR "%s: pid [0x%p] has registered with euid [%d], "
|
| 112 | "but pid [0x%p] has attempted to open the handle "
|
| 113 | "instead\n", __func__, daemon->pid, daemon->euid,
|
| 114 | task_pid(current));
|
| 115 | goto out_unlock_daemon;
|
| 116 | }
|
| 117 | if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
|
| 118 | rc = -EBUSY;
|
| 119 | printk(KERN_ERR "%s: Miscellaneous device handle may only be "
|
| 120 | "opened once per daemon; pid [0x%p] already has this "
|
| 121 | "handle open\n", __func__, daemon->pid);
|
| 122 | goto out_unlock_daemon;
|
| 123 | }
|
| 124 | daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN;
|
| 125 | atomic_inc(&ecryptfs_num_miscdev_opens);
|
| 126 | out_unlock_daemon:
|
| 127 | mutex_unlock(&daemon->mux);
|
| 128 | out_module_put_unlock_daemon_list:
|
| 129 | if (rc)
|
| 130 | module_put(THIS_MODULE);
|
| 131 | out_unlock_daemon_list:
|
| 132 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 133 | return rc;
|
| 134 | }
|
| 135 |
|
| 136 | |
| 137 | * ecryptfs_miscdev_release
|
| 138 | * @inode: inode of fs/ecryptfs/euid handle (ignored)
|
| 139 | * @file: file for fs/ecryptfs/euid handle (ignored)
|
| 140 | *
|
| 141 | * This keeps the daemon registered until the daemon sends another
|
| 142 | * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters.
|
| 143 | *
|
| 144 | * Returns zero on success; non-zero otherwise
|
| 145 |
|
| 146 | static int
|
| 147 | ecryptfs_miscdev_release(struct inode *inode, struct file *file)
|
| 148 | {
|
| 149 | struct ecryptfs_daemon *daemon = NULL;
|
| 150 | int rc;
|
| 151 |
|
| 152 | mutex_lock(&ecryptfs_daemon_hash_mux);
|
| 153 | rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
|
| 154 | current->nsproxy->user_ns);
|
| 155 | BUG_ON(rc || !daemon);
|
| 156 | mutex_lock(&daemon->mux);
|
| 157 | BUG_ON(daemon->pid != task_pid(current));
|
| 158 | BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN));
|
| 159 | daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN;
|
| 160 | atomic_dec(&ecryptfs_num_miscdev_opens);
|
| 161 | mutex_unlock(&daemon->mux);
|
| 162 | rc = ecryptfs_exorcise_daemon(daemon);
|
| 163 | if (rc) {
|
| 164 | printk(KERN_CRIT "%s: Fatal error whilst attempting to "
|
| 165 | "shut down daemon; rc = [%d]. Please report this "
|
| 166 | "bug.\n", __func__, rc);
|
| 167 | BUG();
|
| 168 | }
|
| 169 | module_put(THIS_MODULE);
|
| 170 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 171 | return rc;
|
| 172 | }
|
| 173 |
|
| 174 | |
| 175 | * ecryptfs_send_miscdev
|
| 176 | * @data: Data to send to daemon; may be NULL
|
| 177 | * @data_size: Amount of data to send to daemon
|
| 178 | * @msg_ctx: Message context, which is used to handle the reply. If
|
| 179 | * this is NULL, then we do not expect a reply.
|
| 180 | * @msg_type: Type of message
|
| 181 | * @msg_flags: Flags for message
|
| 182 | * @daemon: eCryptfs daemon object
|
| 183 | *
|
| 184 | * Add msg_ctx to queue and then, if it exists, notify the blocked
|
| 185 | * miscdevess about the data being available. Must be called with
|
| 186 | * ecryptfs_daemon_hash_mux held.
|
| 187 | *
|
| 188 | * Returns zero on success; non-zero otherwise
|
| 189 |
|
| 190 | int ecryptfs_send_miscdev(char *data, size_t data_size,
|
| 191 | struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
|
| 192 | u16 msg_flags, struct ecryptfs_daemon *daemon)
|
| 193 | {
|
| 194 | int rc = 0;
|
| 195 |
|
| 196 | mutex_lock(&msg_ctx->mux);
|
| 197 | if (data) {
|
| 198 | msg_ctx->msg = kmalloc((sizeof(*msg_ctx->msg) + data_size),
|
| 199 | GFP_KERNEL);
|
| 200 | if (!msg_ctx->msg) {
|
| 201 | rc = -ENOMEM;
|
| 202 | printk(KERN_ERR "%s: Out of memory whilst attempting "
|
| 203 | "to kmalloc(%Zd, GFP_KERNEL)\n", __func__,
|
| 204 | (sizeof(*msg_ctx->msg) + data_size));
|
| 205 | goto out_unlock;
|
| 206 | }
|
| 207 | } else
|
| 208 | msg_ctx->msg = NULL;
|
| 209 | msg_ctx->msg->index = msg_ctx->index;
|
| 210 | msg_ctx->msg->data_len = data_size;
|
| 211 | msg_ctx->type = msg_type;
|
| 212 | if (data) {
|
| 213 | memcpy(msg_ctx->msg->data, data, data_size);
|
| 214 | msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size);
|
| 215 | } else
|
| 216 | msg_ctx->msg_size = 0;
|
| 217 | mutex_lock(&daemon->mux);
|
| 218 | list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue);
|
| 219 | daemon->num_queued_msg_ctx++;
|
| 220 | wake_up_interruptible(&daemon->wait);
|
| 221 | mutex_unlock(&daemon->mux);
|
| 222 | out_unlock:
|
| 223 | mutex_unlock(&msg_ctx->mux);
|
| 224 | return rc;
|
| 225 | }
|
| 226 |
|
| 227 | |
| 228 | * ecryptfs_miscdev_read - format and send message from queue
|
| 229 | * @file: fs/ecryptfs/euid miscdevfs handle (ignored)
|
| 230 | * @buf: User buffer into which to copy the next message on the daemon queue
|
| 231 | * @count: Amount of space available in @buf
|
| 232 | * @ppos: Offset in file (ignored)
|
| 233 | *
|
| 234 | * Pulls the most recent message from the daemon queue, formats it for
|
| 235 | * being sent via a miscdevfs handle, and copies it into @buf
|
| 236 | *
|
| 237 | * Returns the number of bytes copied into the user buffer
|
| 238 |
|
| 239 | static ssize_t
|
| 240 | ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
|
| 241 | loff_t *ppos)
|
| 242 | {
|
| 243 | struct ecryptfs_daemon *daemon;
|
| 244 | struct ecryptfs_msg_ctx *msg_ctx;
|
| 245 | size_t packet_length_size;
|
| 246 | char packet_length[3];
|
| 247 | size_t i;
|
| 248 | size_t total_length;
|
| 249 | int rc;
|
| 250 |
|
| 251 | mutex_lock(&ecryptfs_daemon_hash_mux);
|
| 252 |
|
| 253 | rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
|
| 254 | current->nsproxy->user_ns);
|
| 255 | BUG_ON(rc || !daemon);
|
| 256 | mutex_lock(&daemon->mux);
|
| 257 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
|
| 258 | rc = 0;
|
| 259 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 260 | printk(KERN_WARNING "%s: Attempt to read from zombified "
|
| 261 | "daemon\n", __func__);
|
| 262 | goto out_unlock_daemon;
|
| 263 | }
|
| 264 | if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) {
|
| 265 | rc = 0;
|
| 266 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 267 | goto out_unlock_daemon;
|
| 268 | }
|
| 269 |
|
| 270 | daemon->flags |= ECRYPTFS_DAEMON_IN_READ;
|
| 271 | mutex_unlock(&ecryptfs_daemon_hash_mux);
|
| 272 | check_list:
|
| 273 | if (list_empty(&daemon->msg_ctx_out_queue)) {
|
| 274 | mutex_unlock(&daemon->mux);
|
| 275 | rc = wait_event_interruptible(
|
| 276 | daemon->wait, !list_empty(&daemon->msg_ctx_out_queue));
|
| 277 | mutex_lock(&daemon->mux);
|
| 278 | if (rc < 0) {
|
| 279 | rc = 0;
|
| 280 | goto out_unlock_daemon;
|
| 281 | }
|
| 282 | }
|
| 283 | if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) {
|
| 284 | rc = 0;
|
| 285 | goto out_unlock_daemon;
|
| 286 | }
|
| 287 | if (list_empty(&daemon->msg_ctx_out_queue)) {
|
| 288 | |
| 289 | * wait_event_interruptable() and removed the
|
| 290 | * message from the queue; try again
|
| 291 | goto check_list;
|
| 292 | }
|
| 293 | BUG_ON(current->euid != daemon->euid);
|
| 294 | BUG_ON(current->nsproxy->user_ns != daemon->user_ns);
|
| 295 | BUG_ON(task_pid(current) != daemon->pid);
|
| 296 | msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue,
|
| 297 | struct ecryptfs_msg_ctx, daemon_out_list);
|
| 298 | BUG_ON(!msg_ctx);
|
| 299 | mutex_lock(&msg_ctx->mux);
|
| 300 | if (msg_ctx->msg) {
|
| 301 | rc = ecryptfs_write_packet_length(packet_length,
|
| 302 | msg_ctx->msg_size,
|
| 303 | &packet_length_size);
|
| 304 | if (rc) {
|
| 305 | rc = 0;
|
| 306 | printk(KERN_WARNING "%s: Error writing packet length; "
|
| 307 | "rc = [%d]\n", __func__, rc);
|
| 308 | goto out_unlock_msg_ctx;
|
| 309 | }
|
| 310 | } else {
|
| 311 | packet_length_size = 0;
|
| 312 | msg_ctx->msg_size = 0;
|
| 313 | }
|
| 314 | |
| 315 | * Octet 0: Type
|
| 316 | * Octets 1-4: network byte order msg_ctx->counter
|
| 317 | * Octets 5-N0: Size of struct ecryptfs_message to follow
|
| 318 | * Octets N0-N1: struct ecryptfs_message (including data)
|
| 319 | *
|
| 320 | * Octets 5-N1 not written if the packet type does not
|
| 321 | * include a message
|
| 322 | total_length = (1 + 4 + packet_length_size + msg_ctx->msg_size);
|
| 323 | if (count < total_length) {
|
| 324 | rc = 0;
|
| 325 | printk(KERN_WARNING "%s: Only given user buffer of "
|
| 326 | "size [%Zd], but we need [%Zd] to read the "
|
| 327 | "pending message\n", __func__, count, total_length);
|
| 328 | goto out_unlock_msg_ctx;
|
| 329 | }
|
| 330 | rc = -EFAULT;
|
| 331 | if (put_user(msg_ctx->type, buf))
|
| 332 | goto out_unlock_msg_ctx;
|
| 333 | if (put_user(cpu_to_be32(msg_ctx->counter), (__be32 __user *)(buf + 1)))
|
| 334 | goto out_unlock_msg_ctx;
|
| 335 | i = 5;
|
| 336 | if (msg_ctx->msg) {
|
| 337 | if (copy_to_user(&buf[i], packet_length, packet_length_size))
|
| 338 | goto out_unlock_msg_ctx;
|
| 339 | i += packet_length_size;
|
| 340 | if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size))
|
| 341 | goto out_unlock_msg_ctx;
|
| 342 | i += msg_ctx->msg_size;
|
| 343 | }
|
| 344 | rc = i;
|
| 345 | list_del(&msg_ctx->daemon_out_list);
|
| 346 | kfree(msg_ctx->msg);
|
| 347 | msg_ctx->msg = NULL;
|
| 348 | |
| 349 | * message type other than ECRYPTFS_MSG_REQUEST
|
| 350 | if (msg_ctx->type != ECRYPTFS_MSG_REQUEST)
|
| 351 | ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
|
| 352 | out_unlock_msg_ctx:
|
| 353 | mutex_unlock(&msg_ctx->mux);
|
| 354 | out_unlock_daemon:
|
| 355 | daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ;
|
| 356 | mutex_unlock(&daemon->mux);
|
| 357 | return rc;
|
| 358 | }
|
| 359 |
|
| 360 | |
| 361 | * ecryptfs_miscdev_helo
|
| 362 | * @euid: effective user id of miscdevess sending helo packet
|
| 363 | * @user_ns: The namespace in which @euid applies
|
| 364 | * @pid: miscdevess id of miscdevess sending helo packet
|
| 365 | *
|
| 366 | * Returns zero on success; non-zero otherwise
|
| 367 |
|
| 368 | static int ecryptfs_miscdev_helo(uid_t euid, struct user_namespace *user_ns,
|
| 369 | struct pid *pid)
|
| 370 | {
|
| 371 | int rc;
|
| 372 |
|
| 373 | rc = ecryptfs_process_helo(ECRYPTFS_TRANSPORT_MISCDEV, euid, user_ns,
|
| 374 | pid);
|
| 375 | if (rc)
|
| 376 | printk(KERN_WARNING "Error processing HELO; rc = [%d]\n", rc);
|
| 377 | return rc;
|
| 378 | }
|
| 379 |
|
| 380 | |
| 381 | * ecryptfs_miscdev_quit
|
| 382 | * @euid: effective user id of miscdevess sending quit packet
|
| 383 | * @user_ns: The namespace in which @euid applies
|
| 384 | * @pid: miscdevess id of miscdevess sending quit packet
|
| 385 | *
|
| 386 | * Returns zero on success; non-zero otherwise
|
| 387 |
|
| 388 | static int ecryptfs_miscdev_quit(uid_t euid, struct user_namespace *user_ns,
|
| 389 | struct pid *pid)
|
| 390 | {
|
| 391 | int rc;
|
| 392 |
|
| 393 | rc = ecryptfs_process_quit(euid, user_ns, pid);
|
| 394 | if (rc)
|
| 395 | printk(KERN_WARNING
|
| 396 | "Error processing QUIT message; rc = [%d]\n", rc);
|
| 397 | return rc;
|
| 398 | }
|
| 399 |
|
| 400 | |
| 401 | * ecryptfs_miscdev_response - miscdevess response to message previously sent to daemon
|
| 402 | * @data: Bytes comprising struct ecryptfs_message
|
| 403 | * @data_size: sizeof(struct ecryptfs_message) + data len
|
| 404 | * @euid: Effective user id of miscdevess sending the miscdev response
|
| 405 | * @user_ns: The namespace in which @euid applies
|
| 406 | * @pid: Miscdevess id of miscdevess sending the miscdev response
|
| 407 | * @seq: Sequence number for miscdev response packet
|
| 408 | *
|
| 409 | * Returns zero on success; non-zero otherwise
|
| 410 |
|
| 411 | static int ecryptfs_miscdev_response(char *data, size_t data_size,
|
| 412 | uid_t euid, struct user_namespace *user_ns,
|
| 413 | struct pid *pid, u32 seq)
|
| 414 | {
|
| 415 | struct ecryptfs_message *msg = (struct ecryptfs_message *)data;
|
| 416 | int rc;
|
| 417 |
|
| 418 | if ((sizeof(*msg) + msg->data_len) != data_size) {
|
| 419 | printk(KERN_WARNING "%s: (sizeof(*msg) + msg->data_len) = "
|
| 420 | "[%Zd]; data_size = [%Zd]. Invalid packet.\n", __func__,
|
| 421 | (sizeof(*msg) + msg->data_len), data_size);
|
| 422 | rc = -EINVAL;
|
| 423 | goto out;
|
| 424 | }
|
| 425 | rc = ecryptfs_process_response(msg, euid, user_ns, pid, seq);
|
| 426 | if (rc)
|
| 427 | printk(KERN_ERR
|
| 428 | "Error processing response message; rc = [%d]\n", rc);
|
| 429 | out:
|
| 430 | return rc;
|
| 431 | }
|
| 432 |
|
| 433 | |
| 434 | * ecryptfs_miscdev_write - handle write to daemon miscdev handle
|
| 435 | * @file: File for misc dev handle (ignored)
|
| 436 | * @buf: Buffer containing user data
|
| 437 | * @count: Amount of data in @buf
|
| 438 | * @ppos: Pointer to offset in file (ignored)
|
| 439 | *
|
| 440 | * miscdevfs packet format:
|
| 441 | * Octet 0: Type
|
| 442 | * Octets 1-4: network byte order msg_ctx->counter (0's for non-response)
|
| 443 | * Octets 5-N0: Size of struct ecryptfs_message to follow
|
| 444 | * Octets N0-N1: struct ecryptfs_message (including data)
|
| 445 | *
|
| 446 | * Returns the number of bytes read from @buf
|
| 447 |
|
| 448 | static ssize_t
|
| 449 | ecryptfs_miscdev_write(struct file *file, const char __user *buf,
|
| 450 | size_t count, loff_t *ppos)
|
| 451 | {
|
| 452 | __be32 counter_nbo;
|
| 453 | u32 seq;
|
| 454 | size_t packet_size, packet_size_length, i;
|
| 455 | ssize_t sz = 0;
|
| 456 | char *data;
|
| 457 | int rc;
|
| 458 |
|
| 459 | if (count == 0)
|
| 460 | goto out;
|
| 461 | data = kmalloc(count, GFP_KERNEL);
|
| 462 | if (!data) {
|
| 463 | printk(KERN_ERR "%s: Out of memory whilst attempting to "
|
| 464 | "kmalloc([%Zd], GFP_KERNEL)\n", __func__, count);
|
| 465 | goto out;
|
| 466 | }
|
| 467 | rc = copy_from_user(data, buf, count);
|
| 468 | if (rc) {
|
| 469 | printk(KERN_ERR "%s: copy_from_user returned error [%d]\n",
|
| 470 | __func__, rc);
|
| 471 | goto out_free;
|
| 472 | }
|
| 473 | sz = count;
|
| 474 | i = 0;
|
| 475 | switch (data[i++]) {
|
| 476 | case ECRYPTFS_MSG_RESPONSE:
|
| 477 | if (count < (1 + 4 + 1 + sizeof(struct ecryptfs_message))) {
|
| 478 | printk(KERN_WARNING "%s: Minimum acceptable packet "
|
| 479 | "size is [%Zd], but amount of data written is "
|
| 480 | "only [%Zd]. Discarding response packet.\n",
|
| 481 | __func__,
|
| 482 | (1 + 4 + 1 + sizeof(struct ecryptfs_message)),
|
| 483 | count);
|
| 484 | goto out_free;
|
| 485 | }
|
| 486 | memcpy(&counter_nbo, &data[i], 4);
|
| 487 | seq = be32_to_cpu(counter_nbo);
|
| 488 | i += 4;
|
| 489 | rc = ecryptfs_parse_packet_length(&data[i], &packet_size,
|
| 490 | &packet_size_length);
|
| 491 | if (rc) {
|
| 492 | printk(KERN_WARNING "%s: Error parsing packet length; "
|
| 493 | "rc = [%d]\n", __func__, rc);
|
| 494 | goto out_free;
|
| 495 | }
|
| 496 | i += packet_size_length;
|
| 497 | if ((1 + 4 + packet_size_length + packet_size) != count) {
|
| 498 | printk(KERN_WARNING "%s: (1 + packet_size_length([%Zd])"
|
| 499 | " + packet_size([%Zd]))([%Zd]) != "
|
| 500 | "count([%Zd]). Invalid packet format.\n",
|
| 501 | __func__, packet_size_length, packet_size,
|
| 502 | (1 + packet_size_length + packet_size), count);
|
| 503 | goto out_free;
|
| 504 | }
|
| 505 | rc = ecryptfs_miscdev_response(&data[i], packet_size,
|
| 506 | current->euid,
|
| 507 | current->nsproxy->user_ns,
|
| 508 | task_pid(current), seq);
|
| 509 | if (rc)
|
| 510 | printk(KERN_WARNING "%s: Failed to deliver miscdev "
|
| 511 | "response to requesting operation; rc = [%d]\n",
|
| 512 | __func__, rc);
|
| 513 | break;
|
| 514 | case ECRYPTFS_MSG_HELO:
|
| 515 | rc = ecryptfs_miscdev_helo(current->euid,
|
| 516 | current->nsproxy->user_ns,
|
| 517 | task_pid(current));
|
| 518 | if (rc) {
|
| 519 | printk(KERN_ERR "%s: Error attempting to process "
|
| 520 | "helo from pid [0x%p]; rc = [%d]\n", __func__,
|
| 521 | task_pid(current), rc);
|
| 522 | goto out_free;
|
| 523 | }
|
| 524 | break;
|
| 525 | case ECRYPTFS_MSG_QUIT:
|
| 526 | rc = ecryptfs_miscdev_quit(current->euid,
|
| 527 | current->nsproxy->user_ns,
|
| 528 | task_pid(current));
|
| 529 | if (rc) {
|
| 530 | printk(KERN_ERR "%s: Error attempting to process "
|
| 531 | "quit from pid [0x%p]; rc = [%d]\n", __func__,
|
| 532 | task_pid(current), rc);
|
| 533 | goto out_free;
|
| 534 | }
|
| 535 | break;
|
| 536 | default:
|
| 537 | ecryptfs_printk(KERN_WARNING, "Dropping miscdev "
|
| 538 | "message of unrecognized type [%d]\n",
|
| 539 | data[0]);
|
| 540 | break;
|
| 541 | }
|
| 542 | out_free:
|
| 543 | kfree(data);
|
| 544 | out:
|
| 545 | return sz;
|
| 546 | }
|
| 547 |
|
| 548 |
|
| 549 | static const struct file_operations ecryptfs_miscdev_fops = {
|
| 550 | .open = ecryptfs_miscdev_open,
|
| 551 | .poll = ecryptfs_miscdev_poll,
|
| 552 | .read = ecryptfs_miscdev_read,
|
| 553 | .write = ecryptfs_miscdev_write,
|
| 554 | .release = ecryptfs_miscdev_release,
|
| 555 | };
|
| 556 |
|
| 557 | static struct miscdevice ecryptfs_miscdev = {
|
| 558 | .minor = MISC_DYNAMIC_MINOR,
|
| 559 | .name = "ecryptfs",
|
| 560 | .fops = &ecryptfs_miscdev_fops
|
| 561 | };
|
| 562 |
|
| 563 | |
| 564 | * ecryptfs_init_ecryptfs_miscdev
|
| 565 | *
|
| 566 | * Messages sent to the userspace daemon from the kernel are placed on
|
| 567 | * a queue associated with the daemon. The next read against the
|
| 568 | * miscdev handle by that daemon will return the oldest message placed
|
| 569 | * on the message queue for the daemon.
|
| 570 | *
|
| 571 | * Returns zero on success; non-zero otherwise
|
| 572 |
|
| 573 | int ecryptfs_init_ecryptfs_miscdev(void)
|
| 574 | {
|
| 575 | int rc;
|
| 576 |
|
| 577 | atomic_set(&ecryptfs_num_miscdev_opens, 0);
|
| 578 | rc = misc_register(&ecryptfs_miscdev);
|
| 579 | if (rc)
|
| 580 | printk(KERN_ERR "%s: Failed to register miscellaneous device "
|
| 581 | "for communications with userspace daemons; rc = [%d]\n",
|
| 582 | __func__, rc);
|
| 583 | return rc;
|
| 584 | }
|
| 585 |
|
| 586 | |
| 587 | * ecryptfs_destroy_ecryptfs_miscdev
|
| 588 | *
|
| 589 | * All of the daemons must be exorcised prior to calling this
|
| 590 | * function.
|
| 591 |
|
| 592 | void ecryptfs_destroy_ecryptfs_miscdev(void)
|
| 593 | {
|
| 594 | BUG_ON(atomic_read(&ecryptfs_num_miscdev_opens) != 0);
|
| 595 | misc_deregister(&ecryptfs_miscdev);
|
| 596 | }
|