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 <linux/slab.h> 39 #include <linux/magic.h> 40 #include "ecryptfs_kernel.h" 41 42 /** 43 * Module parameter that defines the ecryptfs_verbosity level. 44 */ 45 int ecryptfs_verbosity = 0; 46 47 module_param(ecryptfs_verbosity, int, 0); 48 MODULE_PARM_DESC(ecryptfs_verbosity, 49 "Initial verbosity level (0 or 1; defaults to " 50 "0, which is Quiet)"); 51 52 /** 53 * Module parameter that defines the number of message buffer elements 54 */ 55 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 56 57 module_param(ecryptfs_message_buf_len, uint, 0); 58 MODULE_PARM_DESC(ecryptfs_message_buf_len, 59 "Number of message buffer elements"); 60 61 /** 62 * Module parameter that defines the maximum guaranteed amount of time to wait 63 * for a response from ecryptfsd. The actual sleep time will be, more than 64 * likely, a small amount greater than this specified value, but only less if 65 * the message successfully arrives. 66 */ 67 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 68 69 module_param(ecryptfs_message_wait_timeout, long, 0); 70 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 71 "Maximum number of seconds that an operation will " 72 "sleep while waiting for a message response from " 73 "userspace"); 74 75 /** 76 * Module parameter that is an estimate of the maximum number of users 77 * that will be concurrently using eCryptfs. Set this to the right 78 * value to balance performance and memory use. 79 */ 80 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 81 82 module_param(ecryptfs_number_of_users, uint, 0); 83 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 84 "concurrent users of eCryptfs"); 85 86 void __ecryptfs_printk(const char *fmt, ...) 87 { 88 va_list args; 89 va_start(args, fmt); 90 if (fmt[1] == '7') { /* KERN_DEBUG */ 91 if (ecryptfs_verbosity >= 1) 92 vprintk(fmt, args); 93 } else 94 vprintk(fmt, args); 95 va_end(args); 96 } 97 98 /** 99 * ecryptfs_init_lower_file 100 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 101 * the lower dentry and the lower mount set 102 * 103 * eCryptfs only ever keeps a single open file for every lower 104 * inode. All I/O operations to the lower inode occur through that 105 * file. When the first eCryptfs dentry that interposes with the first 106 * lower dentry for that inode is created, this function creates the 107 * lower file struct and associates it with the eCryptfs 108 * inode. When all eCryptfs files associated with the inode are released, the 109 * file is closed. 110 * 111 * The lower file will be opened with read/write permissions, if 112 * possible. Otherwise, it is opened read-only. 113 * 114 * This function does nothing if a lower file is already 115 * associated with the eCryptfs inode. 116 * 117 * Returns zero on success; non-zero otherwise 118 */ 119 static int ecryptfs_init_lower_file(struct dentry *dentry, 120 struct file **lower_file) 121 { 122 const struct cred *cred = current_cred(); 123 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); 124 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); 125 int rc; 126 127 rc = ecryptfs_privileged_open(lower_file, lower_dentry, lower_mnt, 128 cred); 129 if (rc) { 130 printk(KERN_ERR "Error opening lower file " 131 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 132 "rc = [%d]\n", lower_dentry, lower_mnt, rc); 133 (*lower_file) = NULL; 134 } 135 return rc; 136 } 137 138 int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) 139 { 140 struct ecryptfs_inode_info *inode_info; 141 int count, rc = 0; 142 143 inode_info = ecryptfs_inode_to_private(inode); 144 mutex_lock(&inode_info->lower_file_mutex); 145 count = atomic_inc_return(&inode_info->lower_file_count); 146 if (WARN_ON_ONCE(count < 1)) 147 rc = -EINVAL; 148 else if (count == 1) { 149 rc = ecryptfs_init_lower_file(dentry, 150 &inode_info->lower_file); 151 if (rc) 152 atomic_set(&inode_info->lower_file_count, 0); 153 } 154 mutex_unlock(&inode_info->lower_file_mutex); 155 return rc; 156 } 157 158 void ecryptfs_put_lower_file(struct inode *inode) 159 { 160 struct ecryptfs_inode_info *inode_info; 161 162 inode_info = ecryptfs_inode_to_private(inode); 163 if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, 164 &inode_info->lower_file_mutex)) { 165 fput(inode_info->lower_file); 166 inode_info->lower_file = NULL; 167 mutex_unlock(&inode_info->lower_file_mutex); 168 } 169 } 170 171 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 172 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 173 ecryptfs_opt_ecryptfs_key_bytes, 174 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 175 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 176 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 177 ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, 178 ecryptfs_opt_check_dev_ruid, 179 ecryptfs_opt_err }; 180 181 static const match_table_t tokens = { 182 {ecryptfs_opt_sig, "sig=%s"}, 183 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 184 {ecryptfs_opt_cipher, "cipher=%s"}, 185 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 186 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 187 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 188 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 189 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 190 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 191 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 192 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 193 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 194 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 195 {ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"}, 196 {ecryptfs_opt_err, NULL} 197 }; 198 199 static int ecryptfs_init_global_auth_toks( 200 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 201 { 202 struct ecryptfs_global_auth_tok *global_auth_tok; 203 struct ecryptfs_auth_tok *auth_tok; 204 int rc = 0; 205 206 list_for_each_entry(global_auth_tok, 207 &mount_crypt_stat->global_auth_tok_list, 208 mount_crypt_stat_list) { 209 rc = ecryptfs_keyring_auth_tok_for_sig( 210 &global_auth_tok->global_auth_tok_key, &auth_tok, 211 global_auth_tok->sig); 212 if (rc) { 213 printk(KERN_ERR "Could not find valid key in user " 214 "session keyring for sig specified in mount " 215 "option: [%s]\n", global_auth_tok->sig); 216 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 217 goto out; 218 } else { 219 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 220 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 221 } 222 } 223 out: 224 return rc; 225 } 226 227 static void ecryptfs_init_mount_crypt_stat( 228 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 229 { 230 memset((void *)mount_crypt_stat, 0, 231 sizeof(struct ecryptfs_mount_crypt_stat)); 232 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 233 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 234 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 235 } 236 237 /** 238 * ecryptfs_parse_options 239 * @sb: The ecryptfs super block 240 * @options: The options passed to the kernel 241 * @check_ruid: set to 1 if device uid should be checked against the ruid 242 * 243 * Parse mount options: 244 * debug=N - ecryptfs_verbosity level for debug output 245 * sig=XXX - description(signature) of the key to use 246 * 247 * Returns the dentry object of the lower-level (lower/interposed) 248 * directory; We want to mount our stackable file system on top of 249 * that lower directory. 250 * 251 * The signature of the key to use must be the description of a key 252 * already in the keyring. Mounting will fail if the key can not be 253 * found. 254 * 255 * Returns zero on success; non-zero on error 256 */ 257 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, 258 uid_t *check_ruid) 259 { 260 char *p; 261 int rc = 0; 262 int sig_set = 0; 263 int cipher_name_set = 0; 264 int fn_cipher_name_set = 0; 265 int cipher_key_bytes; 266 int cipher_key_bytes_set = 0; 267 int fn_cipher_key_bytes; 268 int fn_cipher_key_bytes_set = 0; 269 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 270 &sbi->mount_crypt_stat; 271 substring_t args[MAX_OPT_ARGS]; 272 int token; 273 char *sig_src; 274 char *cipher_name_dst; 275 char *cipher_name_src; 276 char *fn_cipher_name_dst; 277 char *fn_cipher_name_src; 278 char *fnek_dst; 279 char *fnek_src; 280 char *cipher_key_bytes_src; 281 char *fn_cipher_key_bytes_src; 282 283 *check_ruid = 0; 284 285 if (!options) { 286 rc = -EINVAL; 287 goto out; 288 } 289 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 290 while ((p = strsep(&options, ",")) != NULL) { 291 if (!*p) 292 continue; 293 token = match_token(p, tokens, args); 294 switch (token) { 295 case ecryptfs_opt_sig: 296 case ecryptfs_opt_ecryptfs_sig: 297 sig_src = args[0].from; 298 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 299 sig_src, 0); 300 if (rc) { 301 printk(KERN_ERR "Error attempting to register " 302 "global sig; rc = [%d]\n", rc); 303 goto out; 304 } 305 sig_set = 1; 306 break; 307 case ecryptfs_opt_cipher: 308 case ecryptfs_opt_ecryptfs_cipher: 309 cipher_name_src = args[0].from; 310 cipher_name_dst = 311 mount_crypt_stat-> 312 global_default_cipher_name; 313 strncpy(cipher_name_dst, cipher_name_src, 314 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 315 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 316 cipher_name_set = 1; 317 break; 318 case ecryptfs_opt_ecryptfs_key_bytes: 319 cipher_key_bytes_src = args[0].from; 320 cipher_key_bytes = 321 (int)simple_strtol(cipher_key_bytes_src, 322 &cipher_key_bytes_src, 0); 323 mount_crypt_stat->global_default_cipher_key_size = 324 cipher_key_bytes; 325 cipher_key_bytes_set = 1; 326 break; 327 case ecryptfs_opt_passthrough: 328 mount_crypt_stat->flags |= 329 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 330 break; 331 case ecryptfs_opt_xattr_metadata: 332 mount_crypt_stat->flags |= 333 ECRYPTFS_XATTR_METADATA_ENABLED; 334 break; 335 case ecryptfs_opt_encrypted_view: 336 mount_crypt_stat->flags |= 337 ECRYPTFS_XATTR_METADATA_ENABLED; 338 mount_crypt_stat->flags |= 339 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 340 break; 341 case ecryptfs_opt_fnek_sig: 342 fnek_src = args[0].from; 343 fnek_dst = 344 mount_crypt_stat->global_default_fnek_sig; 345 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 346 mount_crypt_stat->global_default_fnek_sig[ 347 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 348 rc = ecryptfs_add_global_auth_tok( 349 mount_crypt_stat, 350 mount_crypt_stat->global_default_fnek_sig, 351 ECRYPTFS_AUTH_TOK_FNEK); 352 if (rc) { 353 printk(KERN_ERR "Error attempting to register " 354 "global fnek sig [%s]; rc = [%d]\n", 355 mount_crypt_stat->global_default_fnek_sig, 356 rc); 357 goto out; 358 } 359 mount_crypt_stat->flags |= 360 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 361 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 362 break; 363 case ecryptfs_opt_fn_cipher: 364 fn_cipher_name_src = args[0].from; 365 fn_cipher_name_dst = 366 mount_crypt_stat->global_default_fn_cipher_name; 367 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 368 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 369 mount_crypt_stat->global_default_fn_cipher_name[ 370 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 371 fn_cipher_name_set = 1; 372 break; 373 case ecryptfs_opt_fn_cipher_key_bytes: 374 fn_cipher_key_bytes_src = args[0].from; 375 fn_cipher_key_bytes = 376 (int)simple_strtol(fn_cipher_key_bytes_src, 377 &fn_cipher_key_bytes_src, 0); 378 mount_crypt_stat->global_default_fn_cipher_key_bytes = 379 fn_cipher_key_bytes; 380 fn_cipher_key_bytes_set = 1; 381 break; 382 case ecryptfs_opt_unlink_sigs: 383 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 384 break; 385 case ecryptfs_opt_mount_auth_tok_only: 386 mount_crypt_stat->flags |= 387 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 388 break; 389 case ecryptfs_opt_check_dev_ruid: 390 *check_ruid = 1; 391 break; 392 case ecryptfs_opt_err: 393 default: 394 printk(KERN_WARNING 395 "%s: eCryptfs: unrecognized option [%s]\n", 396 __func__, p); 397 } 398 } 399 if (!sig_set) { 400 rc = -EINVAL; 401 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 402 "auth tok signature as a mount " 403 "parameter; see the eCryptfs README\n"); 404 goto out; 405 } 406 if (!cipher_name_set) { 407 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 408 409 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 410 strcpy(mount_crypt_stat->global_default_cipher_name, 411 ECRYPTFS_DEFAULT_CIPHER); 412 } 413 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 414 && !fn_cipher_name_set) 415 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 416 mount_crypt_stat->global_default_cipher_name); 417 if (!cipher_key_bytes_set) 418 mount_crypt_stat->global_default_cipher_key_size = 0; 419 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 420 && !fn_cipher_key_bytes_set) 421 mount_crypt_stat->global_default_fn_cipher_key_bytes = 422 mount_crypt_stat->global_default_cipher_key_size; 423 mutex_lock(&key_tfm_list_mutex); 424 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 425 NULL)) { 426 rc = ecryptfs_add_new_key_tfm( 427 NULL, mount_crypt_stat->global_default_cipher_name, 428 mount_crypt_stat->global_default_cipher_key_size); 429 if (rc) { 430 printk(KERN_ERR "Error attempting to initialize " 431 "cipher with name = [%s] and key size = [%td]; " 432 "rc = [%d]\n", 433 mount_crypt_stat->global_default_cipher_name, 434 mount_crypt_stat->global_default_cipher_key_size, 435 rc); 436 rc = -EINVAL; 437 mutex_unlock(&key_tfm_list_mutex); 438 goto out; 439 } 440 } 441 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 442 && !ecryptfs_tfm_exists( 443 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 444 rc = ecryptfs_add_new_key_tfm( 445 NULL, mount_crypt_stat->global_default_fn_cipher_name, 446 mount_crypt_stat->global_default_fn_cipher_key_bytes); 447 if (rc) { 448 printk(KERN_ERR "Error attempting to initialize " 449 "cipher with name = [%s] and key size = [%td]; " 450 "rc = [%d]\n", 451 mount_crypt_stat->global_default_fn_cipher_name, 452 mount_crypt_stat->global_default_fn_cipher_key_bytes, 453 rc); 454 rc = -EINVAL; 455 mutex_unlock(&key_tfm_list_mutex); 456 goto out; 457 } 458 } 459 mutex_unlock(&key_tfm_list_mutex); 460 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 461 if (rc) 462 printk(KERN_WARNING "One or more global auth toks could not " 463 "properly register; rc = [%d]\n", rc); 464 out: 465 return rc; 466 } 467 468 struct kmem_cache *ecryptfs_sb_info_cache; 469 static struct file_system_type ecryptfs_fs_type; 470 471 /** 472 * ecryptfs_get_sb 473 * @fs_type 474 * @flags 475 * @dev_name: The path to mount over 476 * @raw_data: The options passed into the kernel 477 */ 478 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 479 const char *dev_name, void *raw_data) 480 { 481 struct super_block *s; 482 struct ecryptfs_sb_info *sbi; 483 struct ecryptfs_dentry_info *root_info; 484 const char *err = "Getting sb failed"; 485 struct inode *inode; 486 struct path path; 487 uid_t check_ruid; 488 int rc; 489 490 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 491 if (!sbi) { 492 rc = -ENOMEM; 493 goto out; 494 } 495 496 rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid); 497 if (rc) { 498 err = "Error parsing options"; 499 goto out; 500 } 501 502 s = sget(fs_type, NULL, set_anon_super, NULL); 503 if (IS_ERR(s)) { 504 rc = PTR_ERR(s); 505 goto out; 506 } 507 508 s->s_flags = flags; 509 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 510 if (rc) 511 goto out1; 512 513 ecryptfs_set_superblock_private(s, sbi); 514 s->s_bdi = &sbi->bdi; 515 516 /* ->kill_sb() will take care of sbi after that point */ 517 sbi = NULL; 518 s->s_op = &ecryptfs_sops; 519 s->s_d_op = &ecryptfs_dops; 520 521 err = "Reading sb failed"; 522 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 523 if (rc) { 524 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 525 goto out1; 526 } 527 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 528 rc = -EINVAL; 529 printk(KERN_ERR "Mount on filesystem of type " 530 "eCryptfs explicitly disallowed due to " 531 "known incompatibilities\n"); 532 goto out_free; 533 } 534 535 if (check_ruid && path.dentry->d_inode->i_uid != current_uid()) { 536 rc = -EPERM; 537 printk(KERN_ERR "Mount of device (uid: %d) not owned by " 538 "requested user (uid: %d)\n", 539 path.dentry->d_inode->i_uid, current_uid()); 540 goto out_free; 541 } 542 543 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 544 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 545 s->s_blocksize = path.dentry->d_sb->s_blocksize; 546 s->s_magic = ECRYPTFS_SUPER_MAGIC; 547 548 inode = ecryptfs_get_inode(path.dentry->d_inode, s); 549 rc = PTR_ERR(inode); 550 if (IS_ERR(inode)) 551 goto out_free; 552 553 s->s_root = d_alloc_root(inode); 554 if (!s->s_root) { 555 iput(inode); 556 rc = -ENOMEM; 557 goto out_free; 558 } 559 560 rc = -ENOMEM; 561 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 562 if (!root_info) 563 goto out_free; 564 565 /* ->kill_sb() will take care of root_info */ 566 ecryptfs_set_dentry_private(s->s_root, root_info); 567 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 568 ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt); 569 570 s->s_flags |= MS_ACTIVE; 571 return dget(s->s_root); 572 573 out_free: 574 path_put(&path); 575 out1: 576 deactivate_locked_super(s); 577 out: 578 if (sbi) { 579 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 580 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 581 } 582 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 583 return ERR_PTR(rc); 584 } 585 586 /** 587 * ecryptfs_kill_block_super 588 * @sb: The ecryptfs super block 589 * 590 * Used to bring the superblock down and free the private data. 591 */ 592 static void ecryptfs_kill_block_super(struct super_block *sb) 593 { 594 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 595 kill_anon_super(sb); 596 if (!sb_info) 597 return; 598 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 599 bdi_destroy(&sb_info->bdi); 600 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 601 } 602 603 static struct file_system_type ecryptfs_fs_type = { 604 .owner = THIS_MODULE, 605 .name = "ecryptfs", 606 .mount = ecryptfs_mount, 607 .kill_sb = ecryptfs_kill_block_super, 608 .fs_flags = 0 609 }; 610 611 /** 612 * inode_info_init_once 613 * 614 * Initializes the ecryptfs_inode_info_cache when it is created 615 */ 616 static void 617 inode_info_init_once(void *vptr) 618 { 619 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 620 621 inode_init_once(&ei->vfs_inode); 622 } 623 624 static struct ecryptfs_cache_info { 625 struct kmem_cache **cache; 626 const char *name; 627 size_t size; 628 void (*ctor)(void *obj); 629 } ecryptfs_cache_infos[] = { 630 { 631 .cache = &ecryptfs_auth_tok_list_item_cache, 632 .name = "ecryptfs_auth_tok_list_item", 633 .size = sizeof(struct ecryptfs_auth_tok_list_item), 634 }, 635 { 636 .cache = &ecryptfs_file_info_cache, 637 .name = "ecryptfs_file_cache", 638 .size = sizeof(struct ecryptfs_file_info), 639 }, 640 { 641 .cache = &ecryptfs_dentry_info_cache, 642 .name = "ecryptfs_dentry_info_cache", 643 .size = sizeof(struct ecryptfs_dentry_info), 644 }, 645 { 646 .cache = &ecryptfs_inode_info_cache, 647 .name = "ecryptfs_inode_cache", 648 .size = sizeof(struct ecryptfs_inode_info), 649 .ctor = inode_info_init_once, 650 }, 651 { 652 .cache = &ecryptfs_sb_info_cache, 653 .name = "ecryptfs_sb_cache", 654 .size = sizeof(struct ecryptfs_sb_info), 655 }, 656 { 657 .cache = &ecryptfs_header_cache, 658 .name = "ecryptfs_headers", 659 .size = PAGE_CACHE_SIZE, 660 }, 661 { 662 .cache = &ecryptfs_xattr_cache, 663 .name = "ecryptfs_xattr_cache", 664 .size = PAGE_CACHE_SIZE, 665 }, 666 { 667 .cache = &ecryptfs_key_record_cache, 668 .name = "ecryptfs_key_record_cache", 669 .size = sizeof(struct ecryptfs_key_record), 670 }, 671 { 672 .cache = &ecryptfs_key_sig_cache, 673 .name = "ecryptfs_key_sig_cache", 674 .size = sizeof(struct ecryptfs_key_sig), 675 }, 676 { 677 .cache = &ecryptfs_global_auth_tok_cache, 678 .name = "ecryptfs_global_auth_tok_cache", 679 .size = sizeof(struct ecryptfs_global_auth_tok), 680 }, 681 { 682 .cache = &ecryptfs_key_tfm_cache, 683 .name = "ecryptfs_key_tfm_cache", 684 .size = sizeof(struct ecryptfs_key_tfm), 685 }, 686 { 687 .cache = &ecryptfs_open_req_cache, 688 .name = "ecryptfs_open_req_cache", 689 .size = sizeof(struct ecryptfs_open_req), 690 }, 691 }; 692 693 static void ecryptfs_free_kmem_caches(void) 694 { 695 int i; 696 697 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 698 struct ecryptfs_cache_info *info; 699 700 info = &ecryptfs_cache_infos[i]; 701 if (*(info->cache)) 702 kmem_cache_destroy(*(info->cache)); 703 } 704 } 705 706 /** 707 * ecryptfs_init_kmem_caches 708 * 709 * Returns zero on success; non-zero otherwise 710 */ 711 static int ecryptfs_init_kmem_caches(void) 712 { 713 int i; 714 715 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 716 struct ecryptfs_cache_info *info; 717 718 info = &ecryptfs_cache_infos[i]; 719 *(info->cache) = kmem_cache_create(info->name, info->size, 720 0, SLAB_HWCACHE_ALIGN, info->ctor); 721 if (!*(info->cache)) { 722 ecryptfs_free_kmem_caches(); 723 ecryptfs_printk(KERN_WARNING, "%s: " 724 "kmem_cache_create failed\n", 725 info->name); 726 return -ENOMEM; 727 } 728 } 729 return 0; 730 } 731 732 static struct kobject *ecryptfs_kobj; 733 734 static ssize_t version_show(struct kobject *kobj, 735 struct kobj_attribute *attr, char *buff) 736 { 737 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 738 } 739 740 static struct kobj_attribute version_attr = __ATTR_RO(version); 741 742 static struct attribute *attributes[] = { 743 &version_attr.attr, 744 NULL, 745 }; 746 747 static struct attribute_group attr_group = { 748 .attrs = attributes, 749 }; 750 751 static int do_sysfs_registration(void) 752 { 753 int rc; 754 755 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 756 if (!ecryptfs_kobj) { 757 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 758 rc = -ENOMEM; 759 goto out; 760 } 761 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 762 if (rc) { 763 printk(KERN_ERR 764 "Unable to create ecryptfs version attributes\n"); 765 kobject_put(ecryptfs_kobj); 766 } 767 out: 768 return rc; 769 } 770 771 static void do_sysfs_unregistration(void) 772 { 773 sysfs_remove_group(ecryptfs_kobj, &attr_group); 774 kobject_put(ecryptfs_kobj); 775 } 776 777 static int __init ecryptfs_init(void) 778 { 779 int rc; 780 781 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 782 rc = -EINVAL; 783 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 784 "larger than the host's page size, and so " 785 "eCryptfs cannot run on this system. The " 786 "default eCryptfs extent size is [%u] bytes; " 787 "the page size is [%lu] bytes.\n", 788 ECRYPTFS_DEFAULT_EXTENT_SIZE, 789 (unsigned long)PAGE_CACHE_SIZE); 790 goto out; 791 } 792 rc = ecryptfs_init_kmem_caches(); 793 if (rc) { 794 printk(KERN_ERR 795 "Failed to allocate one or more kmem_cache objects\n"); 796 goto out; 797 } 798 rc = register_filesystem(&ecryptfs_fs_type); 799 if (rc) { 800 printk(KERN_ERR "Failed to register filesystem\n"); 801 goto out_free_kmem_caches; 802 } 803 rc = do_sysfs_registration(); 804 if (rc) { 805 printk(KERN_ERR "sysfs registration failed\n"); 806 goto out_unregister_filesystem; 807 } 808 rc = ecryptfs_init_kthread(); 809 if (rc) { 810 printk(KERN_ERR "%s: kthread initialization failed; " 811 "rc = [%d]\n", __func__, rc); 812 goto out_do_sysfs_unregistration; 813 } 814 rc = ecryptfs_init_messaging(); 815 if (rc) { 816 printk(KERN_ERR "Failure occurred while attempting to " 817 "initialize the communications channel to " 818 "ecryptfsd\n"); 819 goto out_destroy_kthread; 820 } 821 rc = ecryptfs_init_crypto(); 822 if (rc) { 823 printk(KERN_ERR "Failure whilst attempting to init crypto; " 824 "rc = [%d]\n", rc); 825 goto out_release_messaging; 826 } 827 if (ecryptfs_verbosity > 0) 828 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 829 "will be written to the syslog!\n", ecryptfs_verbosity); 830 831 goto out; 832 out_release_messaging: 833 ecryptfs_release_messaging(); 834 out_destroy_kthread: 835 ecryptfs_destroy_kthread(); 836 out_do_sysfs_unregistration: 837 do_sysfs_unregistration(); 838 out_unregister_filesystem: 839 unregister_filesystem(&ecryptfs_fs_type); 840 out_free_kmem_caches: 841 ecryptfs_free_kmem_caches(); 842 out: 843 return rc; 844 } 845 846 static void __exit ecryptfs_exit(void) 847 { 848 int rc; 849 850 rc = ecryptfs_destroy_crypto(); 851 if (rc) 852 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 853 "rc = [%d]\n", rc); 854 ecryptfs_release_messaging(); 855 ecryptfs_destroy_kthread(); 856 do_sysfs_unregistration(); 857 unregister_filesystem(&ecryptfs_fs_type); 858 ecryptfs_free_kmem_caches(); 859 } 860 861 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 862 MODULE_DESCRIPTION("eCryptfs"); 863 864 MODULE_LICENSE("GPL"); 865 866 module_init(ecryptfs_init) 867 module_exit(ecryptfs_exit) 868