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_err }; 179 180 static const match_table_t tokens = { 181 {ecryptfs_opt_sig, "sig=%s"}, 182 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 183 {ecryptfs_opt_cipher, "cipher=%s"}, 184 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 185 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 186 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 187 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 188 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 189 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 190 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 191 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 192 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 193 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 194 {ecryptfs_opt_err, NULL} 195 }; 196 197 static int ecryptfs_init_global_auth_toks( 198 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 199 { 200 struct ecryptfs_global_auth_tok *global_auth_tok; 201 struct ecryptfs_auth_tok *auth_tok; 202 int rc = 0; 203 204 list_for_each_entry(global_auth_tok, 205 &mount_crypt_stat->global_auth_tok_list, 206 mount_crypt_stat_list) { 207 rc = ecryptfs_keyring_auth_tok_for_sig( 208 &global_auth_tok->global_auth_tok_key, &auth_tok, 209 global_auth_tok->sig); 210 if (rc) { 211 printk(KERN_ERR "Could not find valid key in user " 212 "session keyring for sig specified in mount " 213 "option: [%s]\n", global_auth_tok->sig); 214 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 215 goto out; 216 } else { 217 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 218 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 219 } 220 } 221 out: 222 return rc; 223 } 224 225 static void ecryptfs_init_mount_crypt_stat( 226 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 227 { 228 memset((void *)mount_crypt_stat, 0, 229 sizeof(struct ecryptfs_mount_crypt_stat)); 230 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 231 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 232 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 233 } 234 235 /** 236 * ecryptfs_parse_options 237 * @sb: The ecryptfs super block 238 * @options: The options passed to the kernel 239 * 240 * Parse mount options: 241 * debug=N - ecryptfs_verbosity level for debug output 242 * sig=XXX - description(signature) of the key to use 243 * 244 * Returns the dentry object of the lower-level (lower/interposed) 245 * directory; We want to mount our stackable file system on top of 246 * that lower directory. 247 * 248 * The signature of the key to use must be the description of a key 249 * already in the keyring. Mounting will fail if the key can not be 250 * found. 251 * 252 * Returns zero on success; non-zero on error 253 */ 254 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) 255 { 256 char *p; 257 int rc = 0; 258 int sig_set = 0; 259 int cipher_name_set = 0; 260 int fn_cipher_name_set = 0; 261 int cipher_key_bytes; 262 int cipher_key_bytes_set = 0; 263 int fn_cipher_key_bytes; 264 int fn_cipher_key_bytes_set = 0; 265 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 266 &sbi->mount_crypt_stat; 267 substring_t args[MAX_OPT_ARGS]; 268 int token; 269 char *sig_src; 270 char *cipher_name_dst; 271 char *cipher_name_src; 272 char *fn_cipher_name_dst; 273 char *fn_cipher_name_src; 274 char *fnek_dst; 275 char *fnek_src; 276 char *cipher_key_bytes_src; 277 char *fn_cipher_key_bytes_src; 278 279 if (!options) { 280 rc = -EINVAL; 281 goto out; 282 } 283 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 284 while ((p = strsep(&options, ",")) != NULL) { 285 if (!*p) 286 continue; 287 token = match_token(p, tokens, args); 288 switch (token) { 289 case ecryptfs_opt_sig: 290 case ecryptfs_opt_ecryptfs_sig: 291 sig_src = args[0].from; 292 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 293 sig_src, 0); 294 if (rc) { 295 printk(KERN_ERR "Error attempting to register " 296 "global sig; rc = [%d]\n", rc); 297 goto out; 298 } 299 sig_set = 1; 300 break; 301 case ecryptfs_opt_cipher: 302 case ecryptfs_opt_ecryptfs_cipher: 303 cipher_name_src = args[0].from; 304 cipher_name_dst = 305 mount_crypt_stat-> 306 global_default_cipher_name; 307 strncpy(cipher_name_dst, cipher_name_src, 308 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 309 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 310 cipher_name_set = 1; 311 break; 312 case ecryptfs_opt_ecryptfs_key_bytes: 313 cipher_key_bytes_src = args[0].from; 314 cipher_key_bytes = 315 (int)simple_strtol(cipher_key_bytes_src, 316 &cipher_key_bytes_src, 0); 317 mount_crypt_stat->global_default_cipher_key_size = 318 cipher_key_bytes; 319 cipher_key_bytes_set = 1; 320 break; 321 case ecryptfs_opt_passthrough: 322 mount_crypt_stat->flags |= 323 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 324 break; 325 case ecryptfs_opt_xattr_metadata: 326 mount_crypt_stat->flags |= 327 ECRYPTFS_XATTR_METADATA_ENABLED; 328 break; 329 case ecryptfs_opt_encrypted_view: 330 mount_crypt_stat->flags |= 331 ECRYPTFS_XATTR_METADATA_ENABLED; 332 mount_crypt_stat->flags |= 333 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 334 break; 335 case ecryptfs_opt_fnek_sig: 336 fnek_src = args[0].from; 337 fnek_dst = 338 mount_crypt_stat->global_default_fnek_sig; 339 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 340 mount_crypt_stat->global_default_fnek_sig[ 341 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 342 rc = ecryptfs_add_global_auth_tok( 343 mount_crypt_stat, 344 mount_crypt_stat->global_default_fnek_sig, 345 ECRYPTFS_AUTH_TOK_FNEK); 346 if (rc) { 347 printk(KERN_ERR "Error attempting to register " 348 "global fnek sig [%s]; rc = [%d]\n", 349 mount_crypt_stat->global_default_fnek_sig, 350 rc); 351 goto out; 352 } 353 mount_crypt_stat->flags |= 354 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 355 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 356 break; 357 case ecryptfs_opt_fn_cipher: 358 fn_cipher_name_src = args[0].from; 359 fn_cipher_name_dst = 360 mount_crypt_stat->global_default_fn_cipher_name; 361 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 362 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 363 mount_crypt_stat->global_default_fn_cipher_name[ 364 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 365 fn_cipher_name_set = 1; 366 break; 367 case ecryptfs_opt_fn_cipher_key_bytes: 368 fn_cipher_key_bytes_src = args[0].from; 369 fn_cipher_key_bytes = 370 (int)simple_strtol(fn_cipher_key_bytes_src, 371 &fn_cipher_key_bytes_src, 0); 372 mount_crypt_stat->global_default_fn_cipher_key_bytes = 373 fn_cipher_key_bytes; 374 fn_cipher_key_bytes_set = 1; 375 break; 376 case ecryptfs_opt_unlink_sigs: 377 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 378 break; 379 case ecryptfs_opt_mount_auth_tok_only: 380 mount_crypt_stat->flags |= 381 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 382 break; 383 case ecryptfs_opt_err: 384 default: 385 printk(KERN_WARNING 386 "%s: eCryptfs: unrecognized option [%s]\n", 387 __func__, p); 388 } 389 } 390 if (!sig_set) { 391 rc = -EINVAL; 392 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 393 "auth tok signature as a mount " 394 "parameter; see the eCryptfs README\n"); 395 goto out; 396 } 397 if (!cipher_name_set) { 398 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 399 400 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 401 strcpy(mount_crypt_stat->global_default_cipher_name, 402 ECRYPTFS_DEFAULT_CIPHER); 403 } 404 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 405 && !fn_cipher_name_set) 406 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 407 mount_crypt_stat->global_default_cipher_name); 408 if (!cipher_key_bytes_set) 409 mount_crypt_stat->global_default_cipher_key_size = 0; 410 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 411 && !fn_cipher_key_bytes_set) 412 mount_crypt_stat->global_default_fn_cipher_key_bytes = 413 mount_crypt_stat->global_default_cipher_key_size; 414 mutex_lock(&key_tfm_list_mutex); 415 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 416 NULL)) { 417 rc = ecryptfs_add_new_key_tfm( 418 NULL, mount_crypt_stat->global_default_cipher_name, 419 mount_crypt_stat->global_default_cipher_key_size); 420 if (rc) { 421 printk(KERN_ERR "Error attempting to initialize " 422 "cipher with name = [%s] and key size = [%td]; " 423 "rc = [%d]\n", 424 mount_crypt_stat->global_default_cipher_name, 425 mount_crypt_stat->global_default_cipher_key_size, 426 rc); 427 rc = -EINVAL; 428 mutex_unlock(&key_tfm_list_mutex); 429 goto out; 430 } 431 } 432 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 433 && !ecryptfs_tfm_exists( 434 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 435 rc = ecryptfs_add_new_key_tfm( 436 NULL, mount_crypt_stat->global_default_fn_cipher_name, 437 mount_crypt_stat->global_default_fn_cipher_key_bytes); 438 if (rc) { 439 printk(KERN_ERR "Error attempting to initialize " 440 "cipher with name = [%s] and key size = [%td]; " 441 "rc = [%d]\n", 442 mount_crypt_stat->global_default_fn_cipher_name, 443 mount_crypt_stat->global_default_fn_cipher_key_bytes, 444 rc); 445 rc = -EINVAL; 446 mutex_unlock(&key_tfm_list_mutex); 447 goto out; 448 } 449 } 450 mutex_unlock(&key_tfm_list_mutex); 451 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 452 if (rc) 453 printk(KERN_WARNING "One or more global auth toks could not " 454 "properly register; rc = [%d]\n", rc); 455 out: 456 return rc; 457 } 458 459 struct kmem_cache *ecryptfs_sb_info_cache; 460 static struct file_system_type ecryptfs_fs_type; 461 462 /** 463 * ecryptfs_get_sb 464 * @fs_type 465 * @flags 466 * @dev_name: The path to mount over 467 * @raw_data: The options passed into the kernel 468 */ 469 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 470 const char *dev_name, void *raw_data) 471 { 472 struct super_block *s; 473 struct ecryptfs_sb_info *sbi; 474 struct ecryptfs_dentry_info *root_info; 475 const char *err = "Getting sb failed"; 476 struct inode *inode; 477 struct path path; 478 int rc; 479 480 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 481 if (!sbi) { 482 rc = -ENOMEM; 483 goto out; 484 } 485 486 rc = ecryptfs_parse_options(sbi, raw_data); 487 if (rc) { 488 err = "Error parsing options"; 489 goto out; 490 } 491 492 s = sget(fs_type, NULL, set_anon_super, NULL); 493 if (IS_ERR(s)) { 494 rc = PTR_ERR(s); 495 goto out; 496 } 497 498 s->s_flags = flags; 499 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 500 if (rc) 501 goto out1; 502 503 ecryptfs_set_superblock_private(s, sbi); 504 s->s_bdi = &sbi->bdi; 505 506 /* ->kill_sb() will take care of sbi after that point */ 507 sbi = NULL; 508 s->s_op = &ecryptfs_sops; 509 s->s_d_op = &ecryptfs_dops; 510 511 err = "Reading sb failed"; 512 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 513 if (rc) { 514 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 515 goto out1; 516 } 517 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 518 rc = -EINVAL; 519 printk(KERN_ERR "Mount on filesystem of type " 520 "eCryptfs explicitly disallowed due to " 521 "known incompatibilities\n"); 522 goto out_free; 523 } 524 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 525 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 526 s->s_blocksize = path.dentry->d_sb->s_blocksize; 527 s->s_magic = ECRYPTFS_SUPER_MAGIC; 528 529 inode = ecryptfs_get_inode(path.dentry->d_inode, s); 530 rc = PTR_ERR(inode); 531 if (IS_ERR(inode)) 532 goto out_free; 533 534 s->s_root = d_alloc_root(inode); 535 if (!s->s_root) { 536 iput(inode); 537 rc = -ENOMEM; 538 goto out_free; 539 } 540 541 rc = -ENOMEM; 542 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 543 if (!root_info) 544 goto out_free; 545 546 /* ->kill_sb() will take care of root_info */ 547 ecryptfs_set_dentry_private(s->s_root, root_info); 548 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 549 ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt); 550 551 s->s_flags |= MS_ACTIVE; 552 return dget(s->s_root); 553 554 out_free: 555 path_put(&path); 556 out1: 557 deactivate_locked_super(s); 558 out: 559 if (sbi) { 560 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 561 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 562 } 563 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 564 return ERR_PTR(rc); 565 } 566 567 /** 568 * ecryptfs_kill_block_super 569 * @sb: The ecryptfs super block 570 * 571 * Used to bring the superblock down and free the private data. 572 */ 573 static void ecryptfs_kill_block_super(struct super_block *sb) 574 { 575 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 576 kill_anon_super(sb); 577 if (!sb_info) 578 return; 579 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 580 bdi_destroy(&sb_info->bdi); 581 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 582 } 583 584 static struct file_system_type ecryptfs_fs_type = { 585 .owner = THIS_MODULE, 586 .name = "ecryptfs", 587 .mount = ecryptfs_mount, 588 .kill_sb = ecryptfs_kill_block_super, 589 .fs_flags = 0 590 }; 591 592 /** 593 * inode_info_init_once 594 * 595 * Initializes the ecryptfs_inode_info_cache when it is created 596 */ 597 static void 598 inode_info_init_once(void *vptr) 599 { 600 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 601 602 inode_init_once(&ei->vfs_inode); 603 } 604 605 static struct ecryptfs_cache_info { 606 struct kmem_cache **cache; 607 const char *name; 608 size_t size; 609 void (*ctor)(void *obj); 610 } ecryptfs_cache_infos[] = { 611 { 612 .cache = &ecryptfs_auth_tok_list_item_cache, 613 .name = "ecryptfs_auth_tok_list_item", 614 .size = sizeof(struct ecryptfs_auth_tok_list_item), 615 }, 616 { 617 .cache = &ecryptfs_file_info_cache, 618 .name = "ecryptfs_file_cache", 619 .size = sizeof(struct ecryptfs_file_info), 620 }, 621 { 622 .cache = &ecryptfs_dentry_info_cache, 623 .name = "ecryptfs_dentry_info_cache", 624 .size = sizeof(struct ecryptfs_dentry_info), 625 }, 626 { 627 .cache = &ecryptfs_inode_info_cache, 628 .name = "ecryptfs_inode_cache", 629 .size = sizeof(struct ecryptfs_inode_info), 630 .ctor = inode_info_init_once, 631 }, 632 { 633 .cache = &ecryptfs_sb_info_cache, 634 .name = "ecryptfs_sb_cache", 635 .size = sizeof(struct ecryptfs_sb_info), 636 }, 637 { 638 .cache = &ecryptfs_header_cache, 639 .name = "ecryptfs_headers", 640 .size = PAGE_CACHE_SIZE, 641 }, 642 { 643 .cache = &ecryptfs_xattr_cache, 644 .name = "ecryptfs_xattr_cache", 645 .size = PAGE_CACHE_SIZE, 646 }, 647 { 648 .cache = &ecryptfs_key_record_cache, 649 .name = "ecryptfs_key_record_cache", 650 .size = sizeof(struct ecryptfs_key_record), 651 }, 652 { 653 .cache = &ecryptfs_key_sig_cache, 654 .name = "ecryptfs_key_sig_cache", 655 .size = sizeof(struct ecryptfs_key_sig), 656 }, 657 { 658 .cache = &ecryptfs_global_auth_tok_cache, 659 .name = "ecryptfs_global_auth_tok_cache", 660 .size = sizeof(struct ecryptfs_global_auth_tok), 661 }, 662 { 663 .cache = &ecryptfs_key_tfm_cache, 664 .name = "ecryptfs_key_tfm_cache", 665 .size = sizeof(struct ecryptfs_key_tfm), 666 }, 667 { 668 .cache = &ecryptfs_open_req_cache, 669 .name = "ecryptfs_open_req_cache", 670 .size = sizeof(struct ecryptfs_open_req), 671 }, 672 }; 673 674 static void ecryptfs_free_kmem_caches(void) 675 { 676 int i; 677 678 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 679 struct ecryptfs_cache_info *info; 680 681 info = &ecryptfs_cache_infos[i]; 682 if (*(info->cache)) 683 kmem_cache_destroy(*(info->cache)); 684 } 685 } 686 687 /** 688 * ecryptfs_init_kmem_caches 689 * 690 * Returns zero on success; non-zero otherwise 691 */ 692 static int ecryptfs_init_kmem_caches(void) 693 { 694 int i; 695 696 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 697 struct ecryptfs_cache_info *info; 698 699 info = &ecryptfs_cache_infos[i]; 700 *(info->cache) = kmem_cache_create(info->name, info->size, 701 0, SLAB_HWCACHE_ALIGN, info->ctor); 702 if (!*(info->cache)) { 703 ecryptfs_free_kmem_caches(); 704 ecryptfs_printk(KERN_WARNING, "%s: " 705 "kmem_cache_create failed\n", 706 info->name); 707 return -ENOMEM; 708 } 709 } 710 return 0; 711 } 712 713 static struct kobject *ecryptfs_kobj; 714 715 static ssize_t version_show(struct kobject *kobj, 716 struct kobj_attribute *attr, char *buff) 717 { 718 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 719 } 720 721 static struct kobj_attribute version_attr = __ATTR_RO(version); 722 723 static struct attribute *attributes[] = { 724 &version_attr.attr, 725 NULL, 726 }; 727 728 static struct attribute_group attr_group = { 729 .attrs = attributes, 730 }; 731 732 static int do_sysfs_registration(void) 733 { 734 int rc; 735 736 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 737 if (!ecryptfs_kobj) { 738 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 739 rc = -ENOMEM; 740 goto out; 741 } 742 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 743 if (rc) { 744 printk(KERN_ERR 745 "Unable to create ecryptfs version attributes\n"); 746 kobject_put(ecryptfs_kobj); 747 } 748 out: 749 return rc; 750 } 751 752 static void do_sysfs_unregistration(void) 753 { 754 sysfs_remove_group(ecryptfs_kobj, &attr_group); 755 kobject_put(ecryptfs_kobj); 756 } 757 758 static int __init ecryptfs_init(void) 759 { 760 int rc; 761 762 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 763 rc = -EINVAL; 764 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 765 "larger than the host's page size, and so " 766 "eCryptfs cannot run on this system. The " 767 "default eCryptfs extent size is [%u] bytes; " 768 "the page size is [%lu] bytes.\n", 769 ECRYPTFS_DEFAULT_EXTENT_SIZE, 770 (unsigned long)PAGE_CACHE_SIZE); 771 goto out; 772 } 773 rc = ecryptfs_init_kmem_caches(); 774 if (rc) { 775 printk(KERN_ERR 776 "Failed to allocate one or more kmem_cache objects\n"); 777 goto out; 778 } 779 rc = register_filesystem(&ecryptfs_fs_type); 780 if (rc) { 781 printk(KERN_ERR "Failed to register filesystem\n"); 782 goto out_free_kmem_caches; 783 } 784 rc = do_sysfs_registration(); 785 if (rc) { 786 printk(KERN_ERR "sysfs registration failed\n"); 787 goto out_unregister_filesystem; 788 } 789 rc = ecryptfs_init_kthread(); 790 if (rc) { 791 printk(KERN_ERR "%s: kthread initialization failed; " 792 "rc = [%d]\n", __func__, rc); 793 goto out_do_sysfs_unregistration; 794 } 795 rc = ecryptfs_init_messaging(); 796 if (rc) { 797 printk(KERN_ERR "Failure occurred while attempting to " 798 "initialize the communications channel to " 799 "ecryptfsd\n"); 800 goto out_destroy_kthread; 801 } 802 rc = ecryptfs_init_crypto(); 803 if (rc) { 804 printk(KERN_ERR "Failure whilst attempting to init crypto; " 805 "rc = [%d]\n", rc); 806 goto out_release_messaging; 807 } 808 if (ecryptfs_verbosity > 0) 809 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 810 "will be written to the syslog!\n", ecryptfs_verbosity); 811 812 goto out; 813 out_release_messaging: 814 ecryptfs_release_messaging(); 815 out_destroy_kthread: 816 ecryptfs_destroy_kthread(); 817 out_do_sysfs_unregistration: 818 do_sysfs_unregistration(); 819 out_unregister_filesystem: 820 unregister_filesystem(&ecryptfs_fs_type); 821 out_free_kmem_caches: 822 ecryptfs_free_kmem_caches(); 823 out: 824 return rc; 825 } 826 827 static void __exit ecryptfs_exit(void) 828 { 829 int rc; 830 831 rc = ecryptfs_destroy_crypto(); 832 if (rc) 833 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 834 "rc = [%d]\n", rc); 835 ecryptfs_release_messaging(); 836 ecryptfs_destroy_kthread(); 837 do_sysfs_unregistration(); 838 unregister_filesystem(&ecryptfs_fs_type); 839 ecryptfs_free_kmem_caches(); 840 } 841 842 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 843 MODULE_DESCRIPTION("eCryptfs"); 844 845 MODULE_LICENSE("GPL"); 846 847 module_init(ecryptfs_init) 848 module_exit(ecryptfs_exit) 849