1 /** 2 * eCryptfs: Linux filesystem encryption layer 3 * 4 * Copyright (C) 1997-2003 Erez Zadok 5 * Copyright (C) 2001-2003 Stony Brook University 6 * Copyright (C) 2004-2007 International Business Machines Corp. 7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> 8 * Michael C. Thompson <mcthomps@us.ibm.com> 9 * Tyler Hicks <tyhicks@ou.edu> 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License as 13 * published by the Free Software Foundation; either version 2 of the 14 * License, or (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, but 17 * WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 * General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 24 * 02111-1307, USA. 25 */ 26 27 #include <linux/dcache.h> 28 #include <linux/file.h> 29 #include <linux/module.h> 30 #include <linux/namei.h> 31 #include <linux/skbuff.h> 32 #include <linux/crypto.h> 33 #include <linux/mount.h> 34 #include <linux/pagemap.h> 35 #include <linux/key.h> 36 #include <linux/parser.h> 37 #include <linux/fs_stack.h> 38 #include "ecryptfs_kernel.h" 39 40 /** 41 * Module parameter that defines the ecryptfs_verbosity level. 42 */ 43 int ecryptfs_verbosity = 0; 44 45 module_param(ecryptfs_verbosity, int, 0); 46 MODULE_PARM_DESC(ecryptfs_verbosity, 47 "Initial verbosity level (0 or 1; defaults to " 48 "0, which is Quiet)"); 49 50 /** 51 * Module parameter that defines the number of message buffer elements 52 */ 53 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 54 55 module_param(ecryptfs_message_buf_len, uint, 0); 56 MODULE_PARM_DESC(ecryptfs_message_buf_len, 57 "Number of message buffer elements"); 58 59 /** 60 * Module parameter that defines the maximum guaranteed amount of time to wait 61 * for a response from ecryptfsd. The actual sleep time will be, more than 62 * likely, a small amount greater than this specified value, but only less if 63 * the message successfully arrives. 64 */ 65 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 66 67 module_param(ecryptfs_message_wait_timeout, long, 0); 68 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 69 "Maximum number of seconds that an operation will " 70 "sleep while waiting for a message response from " 71 "userspace"); 72 73 /** 74 * Module parameter that is an estimate of the maximum number of users 75 * that will be concurrently using eCryptfs. Set this to the right 76 * value to balance performance and memory use. 77 */ 78 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 79 80 module_param(ecryptfs_number_of_users, uint, 0); 81 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 82 "concurrent users of eCryptfs"); 83 84 void __ecryptfs_printk(const char *fmt, ...) 85 { 86 va_list args; 87 va_start(args, fmt); 88 if (fmt[1] == '7') { /* KERN_DEBUG */ 89 if (ecryptfs_verbosity >= 1) 90 vprintk(fmt, args); 91 } else 92 vprintk(fmt, args); 93 va_end(args); 94 } 95 96 /** 97 * ecryptfs_init_persistent_file 98 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 99 * the lower dentry and the lower mount set 100 * 101 * eCryptfs only ever keeps a single open file for every lower 102 * inode. All I/O operations to the lower inode occur through that 103 * file. When the first eCryptfs dentry that interposes with the first 104 * lower dentry for that inode is created, this function creates the 105 * persistent file struct and associates it with the eCryptfs 106 * inode. When the eCryptfs inode is destroyed, the file is closed. 107 * 108 * The persistent file will be opened with read/write permissions, if 109 * possible. Otherwise, it is opened read-only. 110 * 111 * This function does nothing if a lower persistent file is already 112 * associated with the eCryptfs inode. 113 * 114 * Returns zero on success; non-zero otherwise 115 */ 116 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) 117 { 118 struct ecryptfs_inode_info *inode_info = 119 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); 120 int rc = 0; 121 122 mutex_lock(&inode_info->lower_file_mutex); 123 if (!inode_info->lower_file) { 124 struct dentry *lower_dentry; 125 struct vfsmount *lower_mnt = 126 ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); 127 128 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 129 rc = ecryptfs_privileged_open(&inode_info->lower_file, 130 lower_dentry, lower_mnt); 131 if (rc || IS_ERR(inode_info->lower_file)) { 132 printk(KERN_ERR "Error opening lower persistent file " 133 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 134 "rc = [%d]\n", lower_dentry, lower_mnt, rc); 135 rc = PTR_ERR(inode_info->lower_file); 136 inode_info->lower_file = NULL; 137 } 138 } 139 mutex_unlock(&inode_info->lower_file_mutex); 140 return rc; 141 } 142 143 /** 144 * ecryptfs_interpose 145 * @lower_dentry: Existing dentry in the lower filesystem 146 * @dentry: ecryptfs' dentry 147 * @sb: ecryptfs's super_block 148 * @flags: flags to govern behavior of interpose procedure 149 * 150 * Interposes upper and lower dentries. 151 * 152 * Returns zero on success; non-zero otherwise 153 */ 154 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, 155 struct super_block *sb, u32 flags) 156 { 157 struct inode *lower_inode; 158 struct inode *inode; 159 int rc = 0; 160 161 lower_inode = lower_dentry->d_inode; 162 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { 163 rc = -EXDEV; 164 goto out; 165 } 166 if (!igrab(lower_inode)) { 167 rc = -ESTALE; 168 goto out; 169 } 170 inode = iget5_locked(sb, (unsigned long)lower_inode, 171 ecryptfs_inode_test, ecryptfs_inode_set, 172 lower_inode); 173 if (!inode) { 174 rc = -EACCES; 175 iput(lower_inode); 176 goto out; 177 } 178 if (inode->i_state & I_NEW) 179 unlock_new_inode(inode); 180 else 181 iput(lower_inode); 182 if (S_ISLNK(lower_inode->i_mode)) 183 inode->i_op = &ecryptfs_symlink_iops; 184 else if (S_ISDIR(lower_inode->i_mode)) 185 inode->i_op = &ecryptfs_dir_iops; 186 if (S_ISDIR(lower_inode->i_mode)) 187 inode->i_fop = &ecryptfs_dir_fops; 188 if (special_file(lower_inode->i_mode)) 189 init_special_inode(inode, lower_inode->i_mode, 190 lower_inode->i_rdev); 191 dentry->d_op = &ecryptfs_dops; 192 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) 193 d_add(dentry, inode); 194 else 195 d_instantiate(dentry, inode); 196 fsstack_copy_attr_all(inode, lower_inode, NULL); 197 /* This size will be overwritten for real files w/ headers and 198 * other metadata */ 199 fsstack_copy_inode_size(inode, lower_inode); 200 out: 201 return rc; 202 } 203 204 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 205 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 206 ecryptfs_opt_ecryptfs_key_bytes, 207 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 208 ecryptfs_opt_encrypted_view, ecryptfs_opt_err }; 209 210 static const match_table_t tokens = { 211 {ecryptfs_opt_sig, "sig=%s"}, 212 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 213 {ecryptfs_opt_cipher, "cipher=%s"}, 214 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 215 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 216 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 217 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 218 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 219 {ecryptfs_opt_err, NULL} 220 }; 221 222 static int ecryptfs_init_global_auth_toks( 223 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 224 { 225 struct ecryptfs_global_auth_tok *global_auth_tok; 226 int rc = 0; 227 228 list_for_each_entry(global_auth_tok, 229 &mount_crypt_stat->global_auth_tok_list, 230 mount_crypt_stat_list) { 231 rc = ecryptfs_keyring_auth_tok_for_sig( 232 &global_auth_tok->global_auth_tok_key, 233 &global_auth_tok->global_auth_tok, 234 global_auth_tok->sig); 235 if (rc) { 236 printk(KERN_ERR "Could not find valid key in user " 237 "session keyring for sig specified in mount " 238 "option: [%s]\n", global_auth_tok->sig); 239 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 240 goto out; 241 } else 242 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 243 } 244 out: 245 return rc; 246 } 247 248 static void ecryptfs_init_mount_crypt_stat( 249 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 250 { 251 memset((void *)mount_crypt_stat, 0, 252 sizeof(struct ecryptfs_mount_crypt_stat)); 253 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 254 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 255 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 256 } 257 258 /** 259 * ecryptfs_parse_options 260 * @sb: The ecryptfs super block 261 * @options: The options pased to the kernel 262 * 263 * Parse mount options: 264 * debug=N - ecryptfs_verbosity level for debug output 265 * sig=XXX - description(signature) of the key to use 266 * 267 * Returns the dentry object of the lower-level (lower/interposed) 268 * directory; We want to mount our stackable file system on top of 269 * that lower directory. 270 * 271 * The signature of the key to use must be the description of a key 272 * already in the keyring. Mounting will fail if the key can not be 273 * found. 274 * 275 * Returns zero on success; non-zero on error 276 */ 277 static int ecryptfs_parse_options(struct super_block *sb, char *options) 278 { 279 char *p; 280 int rc = 0; 281 int sig_set = 0; 282 int cipher_name_set = 0; 283 int cipher_key_bytes; 284 int cipher_key_bytes_set = 0; 285 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 286 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; 287 substring_t args[MAX_OPT_ARGS]; 288 int token; 289 char *sig_src; 290 char *cipher_name_dst; 291 char *cipher_name_src; 292 char *cipher_key_bytes_src; 293 294 if (!options) { 295 rc = -EINVAL; 296 goto out; 297 } 298 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 299 while ((p = strsep(&options, ",")) != NULL) { 300 if (!*p) 301 continue; 302 token = match_token(p, tokens, args); 303 switch (token) { 304 case ecryptfs_opt_sig: 305 case ecryptfs_opt_ecryptfs_sig: 306 sig_src = args[0].from; 307 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 308 sig_src); 309 if (rc) { 310 printk(KERN_ERR "Error attempting to register " 311 "global sig; rc = [%d]\n", rc); 312 goto out; 313 } 314 sig_set = 1; 315 break; 316 case ecryptfs_opt_cipher: 317 case ecryptfs_opt_ecryptfs_cipher: 318 cipher_name_src = args[0].from; 319 cipher_name_dst = 320 mount_crypt_stat-> 321 global_default_cipher_name; 322 strncpy(cipher_name_dst, cipher_name_src, 323 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 324 ecryptfs_printk(KERN_DEBUG, 325 "The mount_crypt_stat " 326 "global_default_cipher_name set to: " 327 "[%s]\n", cipher_name_dst); 328 cipher_name_set = 1; 329 break; 330 case ecryptfs_opt_ecryptfs_key_bytes: 331 cipher_key_bytes_src = args[0].from; 332 cipher_key_bytes = 333 (int)simple_strtol(cipher_key_bytes_src, 334 &cipher_key_bytes_src, 0); 335 mount_crypt_stat->global_default_cipher_key_size = 336 cipher_key_bytes; 337 ecryptfs_printk(KERN_DEBUG, 338 "The mount_crypt_stat " 339 "global_default_cipher_key_size " 340 "set to: [%d]\n", mount_crypt_stat-> 341 global_default_cipher_key_size); 342 cipher_key_bytes_set = 1; 343 break; 344 case ecryptfs_opt_passthrough: 345 mount_crypt_stat->flags |= 346 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 347 break; 348 case ecryptfs_opt_xattr_metadata: 349 mount_crypt_stat->flags |= 350 ECRYPTFS_XATTR_METADATA_ENABLED; 351 break; 352 case ecryptfs_opt_encrypted_view: 353 mount_crypt_stat->flags |= 354 ECRYPTFS_XATTR_METADATA_ENABLED; 355 mount_crypt_stat->flags |= 356 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 357 break; 358 case ecryptfs_opt_err: 359 default: 360 ecryptfs_printk(KERN_WARNING, 361 "eCryptfs: unrecognized option '%s'\n", 362 p); 363 } 364 } 365 if (!sig_set) { 366 rc = -EINVAL; 367 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 368 "auth tok signature as a mount " 369 "parameter; see the eCryptfs README\n"); 370 goto out; 371 } 372 if (!cipher_name_set) { 373 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 374 375 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 376 377 strcpy(mount_crypt_stat->global_default_cipher_name, 378 ECRYPTFS_DEFAULT_CIPHER); 379 } 380 if (!cipher_key_bytes_set) { 381 mount_crypt_stat->global_default_cipher_key_size = 0; 382 } 383 mutex_lock(&key_tfm_list_mutex); 384 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 385 NULL)) 386 rc = ecryptfs_add_new_key_tfm( 387 NULL, mount_crypt_stat->global_default_cipher_name, 388 mount_crypt_stat->global_default_cipher_key_size); 389 mutex_unlock(&key_tfm_list_mutex); 390 if (rc) { 391 printk(KERN_ERR "Error attempting to initialize cipher with " 392 "name = [%s] and key size = [%td]; rc = [%d]\n", 393 mount_crypt_stat->global_default_cipher_name, 394 mount_crypt_stat->global_default_cipher_key_size, rc); 395 rc = -EINVAL; 396 goto out; 397 } 398 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 399 if (rc) { 400 printk(KERN_WARNING "One or more global auth toks could not " 401 "properly register; rc = [%d]\n", rc); 402 } 403 out: 404 return rc; 405 } 406 407 struct kmem_cache *ecryptfs_sb_info_cache; 408 409 /** 410 * ecryptfs_fill_super 411 * @sb: The ecryptfs super block 412 * @raw_data: The options passed to mount 413 * @silent: Not used but required by function prototype 414 * 415 * Sets up what we can of the sb, rest is done in ecryptfs_read_super 416 * 417 * Returns zero on success; non-zero otherwise 418 */ 419 static int 420 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) 421 { 422 int rc = 0; 423 424 /* Released in ecryptfs_put_super() */ 425 ecryptfs_set_superblock_private(sb, 426 kmem_cache_zalloc(ecryptfs_sb_info_cache, 427 GFP_KERNEL)); 428 if (!ecryptfs_superblock_to_private(sb)) { 429 ecryptfs_printk(KERN_WARNING, "Out of memory\n"); 430 rc = -ENOMEM; 431 goto out; 432 } 433 sb->s_op = &ecryptfs_sops; 434 /* Released through deactivate_super(sb) from get_sb_nodev */ 435 sb->s_root = d_alloc(NULL, &(const struct qstr) { 436 .hash = 0,.name = "/",.len = 1}); 437 if (!sb->s_root) { 438 ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); 439 rc = -ENOMEM; 440 goto out; 441 } 442 sb->s_root->d_op = &ecryptfs_dops; 443 sb->s_root->d_sb = sb; 444 sb->s_root->d_parent = sb->s_root; 445 /* Released in d_release when dput(sb->s_root) is called */ 446 /* through deactivate_super(sb) from get_sb_nodev() */ 447 ecryptfs_set_dentry_private(sb->s_root, 448 kmem_cache_zalloc(ecryptfs_dentry_info_cache, 449 GFP_KERNEL)); 450 if (!ecryptfs_dentry_to_private(sb->s_root)) { 451 ecryptfs_printk(KERN_ERR, 452 "dentry_info_cache alloc failed\n"); 453 rc = -ENOMEM; 454 goto out; 455 } 456 rc = 0; 457 out: 458 /* Should be able to rely on deactivate_super called from 459 * get_sb_nodev */ 460 return rc; 461 } 462 463 /** 464 * ecryptfs_read_super 465 * @sb: The ecryptfs super block 466 * @dev_name: The path to mount over 467 * 468 * Read the super block of the lower filesystem, and use 469 * ecryptfs_interpose to create our initial inode and super block 470 * struct. 471 */ 472 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) 473 { 474 struct path path; 475 int rc; 476 477 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 478 if (rc) { 479 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); 480 goto out; 481 } 482 ecryptfs_set_superblock_lower(sb, path.dentry->d_sb); 483 sb->s_maxbytes = path.dentry->d_sb->s_maxbytes; 484 sb->s_blocksize = path.dentry->d_sb->s_blocksize; 485 ecryptfs_set_dentry_lower(sb->s_root, path.dentry); 486 ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt); 487 rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0); 488 if (rc) 489 goto out_free; 490 rc = 0; 491 goto out; 492 out_free: 493 path_put(&path); 494 out: 495 return rc; 496 } 497 498 /** 499 * ecryptfs_get_sb 500 * @fs_type 501 * @flags 502 * @dev_name: The path to mount over 503 * @raw_data: The options passed into the kernel 504 * 505 * The whole ecryptfs_get_sb process is broken into 4 functions: 506 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any 507 * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block 508 * with as much information as it can before needing 509 * the lower filesystem. 510 * ecryptfs_read_super(): this accesses the lower filesystem and uses 511 * ecryptfs_interpolate to perform most of the linking 512 * ecryptfs_interpolate(): links the lower filesystem into ecryptfs 513 */ 514 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, 515 const char *dev_name, void *raw_data, 516 struct vfsmount *mnt) 517 { 518 int rc; 519 struct super_block *sb; 520 521 rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); 522 if (rc < 0) { 523 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); 524 goto out; 525 } 526 sb = mnt->mnt_sb; 527 rc = ecryptfs_parse_options(sb, raw_data); 528 if (rc) { 529 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); 530 goto out_abort; 531 } 532 rc = ecryptfs_read_super(sb, dev_name); 533 if (rc) { 534 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); 535 goto out_abort; 536 } 537 goto out; 538 out_abort: 539 dput(sb->s_root); 540 up_write(&sb->s_umount); 541 deactivate_super(sb); 542 out: 543 return rc; 544 } 545 546 /** 547 * ecryptfs_kill_block_super 548 * @sb: The ecryptfs super block 549 * 550 * Used to bring the superblock down and free the private data. 551 * Private data is free'd in ecryptfs_put_super() 552 */ 553 static void ecryptfs_kill_block_super(struct super_block *sb) 554 { 555 generic_shutdown_super(sb); 556 } 557 558 static struct file_system_type ecryptfs_fs_type = { 559 .owner = THIS_MODULE, 560 .name = "ecryptfs", 561 .get_sb = ecryptfs_get_sb, 562 .kill_sb = ecryptfs_kill_block_super, 563 .fs_flags = 0 564 }; 565 566 /** 567 * inode_info_init_once 568 * 569 * Initializes the ecryptfs_inode_info_cache when it is created 570 */ 571 static void 572 inode_info_init_once(void *vptr) 573 { 574 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 575 576 inode_init_once(&ei->vfs_inode); 577 } 578 579 static struct ecryptfs_cache_info { 580 struct kmem_cache **cache; 581 const char *name; 582 size_t size; 583 void (*ctor)(void *obj); 584 } ecryptfs_cache_infos[] = { 585 { 586 .cache = &ecryptfs_auth_tok_list_item_cache, 587 .name = "ecryptfs_auth_tok_list_item", 588 .size = sizeof(struct ecryptfs_auth_tok_list_item), 589 }, 590 { 591 .cache = &ecryptfs_file_info_cache, 592 .name = "ecryptfs_file_cache", 593 .size = sizeof(struct ecryptfs_file_info), 594 }, 595 { 596 .cache = &ecryptfs_dentry_info_cache, 597 .name = "ecryptfs_dentry_info_cache", 598 .size = sizeof(struct ecryptfs_dentry_info), 599 }, 600 { 601 .cache = &ecryptfs_inode_info_cache, 602 .name = "ecryptfs_inode_cache", 603 .size = sizeof(struct ecryptfs_inode_info), 604 .ctor = inode_info_init_once, 605 }, 606 { 607 .cache = &ecryptfs_sb_info_cache, 608 .name = "ecryptfs_sb_cache", 609 .size = sizeof(struct ecryptfs_sb_info), 610 }, 611 { 612 .cache = &ecryptfs_header_cache_1, 613 .name = "ecryptfs_headers_1", 614 .size = PAGE_CACHE_SIZE, 615 }, 616 { 617 .cache = &ecryptfs_header_cache_2, 618 .name = "ecryptfs_headers_2", 619 .size = PAGE_CACHE_SIZE, 620 }, 621 { 622 .cache = &ecryptfs_xattr_cache, 623 .name = "ecryptfs_xattr_cache", 624 .size = PAGE_CACHE_SIZE, 625 }, 626 { 627 .cache = &ecryptfs_key_record_cache, 628 .name = "ecryptfs_key_record_cache", 629 .size = sizeof(struct ecryptfs_key_record), 630 }, 631 { 632 .cache = &ecryptfs_key_sig_cache, 633 .name = "ecryptfs_key_sig_cache", 634 .size = sizeof(struct ecryptfs_key_sig), 635 }, 636 { 637 .cache = &ecryptfs_global_auth_tok_cache, 638 .name = "ecryptfs_global_auth_tok_cache", 639 .size = sizeof(struct ecryptfs_global_auth_tok), 640 }, 641 { 642 .cache = &ecryptfs_key_tfm_cache, 643 .name = "ecryptfs_key_tfm_cache", 644 .size = sizeof(struct ecryptfs_key_tfm), 645 }, 646 { 647 .cache = &ecryptfs_open_req_cache, 648 .name = "ecryptfs_open_req_cache", 649 .size = sizeof(struct ecryptfs_open_req), 650 }, 651 }; 652 653 static void ecryptfs_free_kmem_caches(void) 654 { 655 int i; 656 657 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 658 struct ecryptfs_cache_info *info; 659 660 info = &ecryptfs_cache_infos[i]; 661 if (*(info->cache)) 662 kmem_cache_destroy(*(info->cache)); 663 } 664 } 665 666 /** 667 * ecryptfs_init_kmem_caches 668 * 669 * Returns zero on success; non-zero otherwise 670 */ 671 static int ecryptfs_init_kmem_caches(void) 672 { 673 int i; 674 675 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 676 struct ecryptfs_cache_info *info; 677 678 info = &ecryptfs_cache_infos[i]; 679 *(info->cache) = kmem_cache_create(info->name, info->size, 680 0, SLAB_HWCACHE_ALIGN, info->ctor); 681 if (!*(info->cache)) { 682 ecryptfs_free_kmem_caches(); 683 ecryptfs_printk(KERN_WARNING, "%s: " 684 "kmem_cache_create failed\n", 685 info->name); 686 return -ENOMEM; 687 } 688 } 689 return 0; 690 } 691 692 static struct kobject *ecryptfs_kobj; 693 694 static ssize_t version_show(struct kobject *kobj, 695 struct kobj_attribute *attr, char *buff) 696 { 697 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 698 } 699 700 static struct kobj_attribute version_attr = __ATTR_RO(version); 701 702 static struct attribute *attributes[] = { 703 &version_attr.attr, 704 NULL, 705 }; 706 707 static struct attribute_group attr_group = { 708 .attrs = attributes, 709 }; 710 711 static int do_sysfs_registration(void) 712 { 713 int rc; 714 715 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 716 if (!ecryptfs_kobj) { 717 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 718 rc = -ENOMEM; 719 goto out; 720 } 721 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 722 if (rc) { 723 printk(KERN_ERR 724 "Unable to create ecryptfs version attributes\n"); 725 kobject_put(ecryptfs_kobj); 726 } 727 out: 728 return rc; 729 } 730 731 static void do_sysfs_unregistration(void) 732 { 733 sysfs_remove_group(ecryptfs_kobj, &attr_group); 734 kobject_put(ecryptfs_kobj); 735 } 736 737 static int __init ecryptfs_init(void) 738 { 739 int rc; 740 741 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 742 rc = -EINVAL; 743 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 744 "larger than the host's page size, and so " 745 "eCryptfs cannot run on this system. The " 746 "default eCryptfs extent size is [%d] bytes; " 747 "the page size is [%d] bytes.\n", 748 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); 749 goto out; 750 } 751 rc = ecryptfs_init_kmem_caches(); 752 if (rc) { 753 printk(KERN_ERR 754 "Failed to allocate one or more kmem_cache objects\n"); 755 goto out; 756 } 757 rc = register_filesystem(&ecryptfs_fs_type); 758 if (rc) { 759 printk(KERN_ERR "Failed to register filesystem\n"); 760 goto out_free_kmem_caches; 761 } 762 rc = do_sysfs_registration(); 763 if (rc) { 764 printk(KERN_ERR "sysfs registration failed\n"); 765 goto out_unregister_filesystem; 766 } 767 rc = ecryptfs_init_kthread(); 768 if (rc) { 769 printk(KERN_ERR "%s: kthread initialization failed; " 770 "rc = [%d]\n", __func__, rc); 771 goto out_do_sysfs_unregistration; 772 } 773 rc = ecryptfs_init_messaging(); 774 if (rc) { 775 printk(KERN_ERR "Failure occured while attempting to " 776 "initialize the communications channel to " 777 "ecryptfsd\n"); 778 goto out_destroy_kthread; 779 } 780 rc = ecryptfs_init_crypto(); 781 if (rc) { 782 printk(KERN_ERR "Failure whilst attempting to init crypto; " 783 "rc = [%d]\n", rc); 784 goto out_release_messaging; 785 } 786 if (ecryptfs_verbosity > 0) 787 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 788 "will be written to the syslog!\n", ecryptfs_verbosity); 789 790 goto out; 791 out_release_messaging: 792 ecryptfs_release_messaging(); 793 out_destroy_kthread: 794 ecryptfs_destroy_kthread(); 795 out_do_sysfs_unregistration: 796 do_sysfs_unregistration(); 797 out_unregister_filesystem: 798 unregister_filesystem(&ecryptfs_fs_type); 799 out_free_kmem_caches: 800 ecryptfs_free_kmem_caches(); 801 out: 802 return rc; 803 } 804 805 static void __exit ecryptfs_exit(void) 806 { 807 int rc; 808 809 rc = ecryptfs_destroy_crypto(); 810 if (rc) 811 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 812 "rc = [%d]\n", rc); 813 ecryptfs_release_messaging(); 814 ecryptfs_destroy_kthread(); 815 do_sysfs_unregistration(); 816 unregister_filesystem(&ecryptfs_fs_type); 817 ecryptfs_free_kmem_caches(); 818 } 819 820 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 821 MODULE_DESCRIPTION("eCryptfs"); 822 823 MODULE_LICENSE("GPL"); 824 825 module_init(ecryptfs_init) 826 module_exit(ecryptfs_exit) 827