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 filemap_write_and_wait(inode->i_mapping); 166 fput(inode_info->lower_file); 167 inode_info->lower_file = NULL; 168 mutex_unlock(&inode_info->lower_file_mutex); 169 } 170 } 171 172 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 173 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 174 ecryptfs_opt_ecryptfs_key_bytes, 175 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 176 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 177 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 178 ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, 179 ecryptfs_opt_check_dev_ruid, 180 ecryptfs_opt_err }; 181 182 static const match_table_t tokens = { 183 {ecryptfs_opt_sig, "sig=%s"}, 184 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 185 {ecryptfs_opt_cipher, "cipher=%s"}, 186 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 187 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 188 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 189 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 190 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 191 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 192 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 193 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 194 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 195 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 196 {ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"}, 197 {ecryptfs_opt_err, NULL} 198 }; 199 200 static int ecryptfs_init_global_auth_toks( 201 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 202 { 203 struct ecryptfs_global_auth_tok *global_auth_tok; 204 struct ecryptfs_auth_tok *auth_tok; 205 int rc = 0; 206 207 list_for_each_entry(global_auth_tok, 208 &mount_crypt_stat->global_auth_tok_list, 209 mount_crypt_stat_list) { 210 rc = ecryptfs_keyring_auth_tok_for_sig( 211 &global_auth_tok->global_auth_tok_key, &auth_tok, 212 global_auth_tok->sig); 213 if (rc) { 214 printk(KERN_ERR "Could not find valid key in user " 215 "session keyring for sig specified in mount " 216 "option: [%s]\n", global_auth_tok->sig); 217 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 218 goto out; 219 } else { 220 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 221 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 222 } 223 } 224 out: 225 return rc; 226 } 227 228 static void ecryptfs_init_mount_crypt_stat( 229 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 230 { 231 memset((void *)mount_crypt_stat, 0, 232 sizeof(struct ecryptfs_mount_crypt_stat)); 233 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 234 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 235 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 236 } 237 238 /** 239 * ecryptfs_parse_options 240 * @sb: The ecryptfs super block 241 * @options: The options passed to the kernel 242 * @check_ruid: set to 1 if device uid should be checked against the ruid 243 * 244 * Parse mount options: 245 * debug=N - ecryptfs_verbosity level for debug output 246 * sig=XXX - description(signature) of the key to use 247 * 248 * Returns the dentry object of the lower-level (lower/interposed) 249 * directory; We want to mount our stackable file system on top of 250 * that lower directory. 251 * 252 * The signature of the key to use must be the description of a key 253 * already in the keyring. Mounting will fail if the key can not be 254 * found. 255 * 256 * Returns zero on success; non-zero on error 257 */ 258 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, 259 uid_t *check_ruid) 260 { 261 char *p; 262 int rc = 0; 263 int sig_set = 0; 264 int cipher_name_set = 0; 265 int fn_cipher_name_set = 0; 266 int cipher_key_bytes; 267 int cipher_key_bytes_set = 0; 268 int fn_cipher_key_bytes; 269 int fn_cipher_key_bytes_set = 0; 270 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 271 &sbi->mount_crypt_stat; 272 substring_t args[MAX_OPT_ARGS]; 273 int token; 274 char *sig_src; 275 char *cipher_name_dst; 276 char *cipher_name_src; 277 char *fn_cipher_name_dst; 278 char *fn_cipher_name_src; 279 char *fnek_dst; 280 char *fnek_src; 281 char *cipher_key_bytes_src; 282 char *fn_cipher_key_bytes_src; 283 u8 cipher_code; 284 285 *check_ruid = 0; 286 287 if (!options) { 288 rc = -EINVAL; 289 goto out; 290 } 291 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 292 while ((p = strsep(&options, ",")) != NULL) { 293 if (!*p) 294 continue; 295 token = match_token(p, tokens, args); 296 switch (token) { 297 case ecryptfs_opt_sig: 298 case ecryptfs_opt_ecryptfs_sig: 299 sig_src = args[0].from; 300 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 301 sig_src, 0); 302 if (rc) { 303 printk(KERN_ERR "Error attempting to register " 304 "global sig; rc = [%d]\n", rc); 305 goto out; 306 } 307 sig_set = 1; 308 break; 309 case ecryptfs_opt_cipher: 310 case ecryptfs_opt_ecryptfs_cipher: 311 cipher_name_src = args[0].from; 312 cipher_name_dst = 313 mount_crypt_stat-> 314 global_default_cipher_name; 315 strncpy(cipher_name_dst, cipher_name_src, 316 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 317 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 318 cipher_name_set = 1; 319 break; 320 case ecryptfs_opt_ecryptfs_key_bytes: 321 cipher_key_bytes_src = args[0].from; 322 cipher_key_bytes = 323 (int)simple_strtol(cipher_key_bytes_src, 324 &cipher_key_bytes_src, 0); 325 mount_crypt_stat->global_default_cipher_key_size = 326 cipher_key_bytes; 327 cipher_key_bytes_set = 1; 328 break; 329 case ecryptfs_opt_passthrough: 330 mount_crypt_stat->flags |= 331 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 332 break; 333 case ecryptfs_opt_xattr_metadata: 334 mount_crypt_stat->flags |= 335 ECRYPTFS_XATTR_METADATA_ENABLED; 336 break; 337 case ecryptfs_opt_encrypted_view: 338 mount_crypt_stat->flags |= 339 ECRYPTFS_XATTR_METADATA_ENABLED; 340 mount_crypt_stat->flags |= 341 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 342 break; 343 case ecryptfs_opt_fnek_sig: 344 fnek_src = args[0].from; 345 fnek_dst = 346 mount_crypt_stat->global_default_fnek_sig; 347 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 348 mount_crypt_stat->global_default_fnek_sig[ 349 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 350 rc = ecryptfs_add_global_auth_tok( 351 mount_crypt_stat, 352 mount_crypt_stat->global_default_fnek_sig, 353 ECRYPTFS_AUTH_TOK_FNEK); 354 if (rc) { 355 printk(KERN_ERR "Error attempting to register " 356 "global fnek sig [%s]; rc = [%d]\n", 357 mount_crypt_stat->global_default_fnek_sig, 358 rc); 359 goto out; 360 } 361 mount_crypt_stat->flags |= 362 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 363 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 364 break; 365 case ecryptfs_opt_fn_cipher: 366 fn_cipher_name_src = args[0].from; 367 fn_cipher_name_dst = 368 mount_crypt_stat->global_default_fn_cipher_name; 369 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 370 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 371 mount_crypt_stat->global_default_fn_cipher_name[ 372 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 373 fn_cipher_name_set = 1; 374 break; 375 case ecryptfs_opt_fn_cipher_key_bytes: 376 fn_cipher_key_bytes_src = args[0].from; 377 fn_cipher_key_bytes = 378 (int)simple_strtol(fn_cipher_key_bytes_src, 379 &fn_cipher_key_bytes_src, 0); 380 mount_crypt_stat->global_default_fn_cipher_key_bytes = 381 fn_cipher_key_bytes; 382 fn_cipher_key_bytes_set = 1; 383 break; 384 case ecryptfs_opt_unlink_sigs: 385 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 386 break; 387 case ecryptfs_opt_mount_auth_tok_only: 388 mount_crypt_stat->flags |= 389 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 390 break; 391 case ecryptfs_opt_check_dev_ruid: 392 *check_ruid = 1; 393 break; 394 case ecryptfs_opt_err: 395 default: 396 printk(KERN_WARNING 397 "%s: eCryptfs: unrecognized option [%s]\n", 398 __func__, p); 399 } 400 } 401 if (!sig_set) { 402 rc = -EINVAL; 403 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 404 "auth tok signature as a mount " 405 "parameter; see the eCryptfs README\n"); 406 goto out; 407 } 408 if (!cipher_name_set) { 409 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 410 411 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 412 strcpy(mount_crypt_stat->global_default_cipher_name, 413 ECRYPTFS_DEFAULT_CIPHER); 414 } 415 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 416 && !fn_cipher_name_set) 417 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 418 mount_crypt_stat->global_default_cipher_name); 419 if (!cipher_key_bytes_set) 420 mount_crypt_stat->global_default_cipher_key_size = 0; 421 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 422 && !fn_cipher_key_bytes_set) 423 mount_crypt_stat->global_default_fn_cipher_key_bytes = 424 mount_crypt_stat->global_default_cipher_key_size; 425 426 cipher_code = ecryptfs_code_for_cipher_string( 427 mount_crypt_stat->global_default_cipher_name, 428 mount_crypt_stat->global_default_cipher_key_size); 429 if (!cipher_code) { 430 ecryptfs_printk(KERN_ERR, 431 "eCryptfs doesn't support cipher: %s", 432 mount_crypt_stat->global_default_cipher_name); 433 rc = -EINVAL; 434 goto out; 435 } 436 437 mutex_lock(&key_tfm_list_mutex); 438 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 439 NULL)) { 440 rc = ecryptfs_add_new_key_tfm( 441 NULL, mount_crypt_stat->global_default_cipher_name, 442 mount_crypt_stat->global_default_cipher_key_size); 443 if (rc) { 444 printk(KERN_ERR "Error attempting to initialize " 445 "cipher with name = [%s] and key size = [%td]; " 446 "rc = [%d]\n", 447 mount_crypt_stat->global_default_cipher_name, 448 mount_crypt_stat->global_default_cipher_key_size, 449 rc); 450 rc = -EINVAL; 451 mutex_unlock(&key_tfm_list_mutex); 452 goto out; 453 } 454 } 455 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 456 && !ecryptfs_tfm_exists( 457 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 458 rc = ecryptfs_add_new_key_tfm( 459 NULL, mount_crypt_stat->global_default_fn_cipher_name, 460 mount_crypt_stat->global_default_fn_cipher_key_bytes); 461 if (rc) { 462 printk(KERN_ERR "Error attempting to initialize " 463 "cipher with name = [%s] and key size = [%td]; " 464 "rc = [%d]\n", 465 mount_crypt_stat->global_default_fn_cipher_name, 466 mount_crypt_stat->global_default_fn_cipher_key_bytes, 467 rc); 468 rc = -EINVAL; 469 mutex_unlock(&key_tfm_list_mutex); 470 goto out; 471 } 472 } 473 mutex_unlock(&key_tfm_list_mutex); 474 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 475 if (rc) 476 printk(KERN_WARNING "One or more global auth toks could not " 477 "properly register; rc = [%d]\n", rc); 478 out: 479 return rc; 480 } 481 482 struct kmem_cache *ecryptfs_sb_info_cache; 483 static struct file_system_type ecryptfs_fs_type; 484 485 /** 486 * ecryptfs_get_sb 487 * @fs_type 488 * @flags 489 * @dev_name: The path to mount over 490 * @raw_data: The options passed into the kernel 491 */ 492 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 493 const char *dev_name, void *raw_data) 494 { 495 struct super_block *s; 496 struct ecryptfs_sb_info *sbi; 497 struct ecryptfs_dentry_info *root_info; 498 const char *err = "Getting sb failed"; 499 struct inode *inode; 500 struct path path; 501 uid_t check_ruid; 502 int rc; 503 504 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 505 if (!sbi) { 506 rc = -ENOMEM; 507 goto out; 508 } 509 510 rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid); 511 if (rc) { 512 err = "Error parsing options"; 513 goto out; 514 } 515 516 s = sget(fs_type, NULL, set_anon_super, flags, NULL); 517 if (IS_ERR(s)) { 518 rc = PTR_ERR(s); 519 goto out; 520 } 521 522 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 523 if (rc) 524 goto out1; 525 526 ecryptfs_set_superblock_private(s, sbi); 527 s->s_bdi = &sbi->bdi; 528 529 /* ->kill_sb() will take care of sbi after that point */ 530 sbi = NULL; 531 s->s_op = &ecryptfs_sops; 532 s->s_d_op = &ecryptfs_dops; 533 534 err = "Reading sb failed"; 535 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 536 if (rc) { 537 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 538 goto out1; 539 } 540 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 541 rc = -EINVAL; 542 printk(KERN_ERR "Mount on filesystem of type " 543 "eCryptfs explicitly disallowed due to " 544 "known incompatibilities\n"); 545 goto out_free; 546 } 547 548 if (check_ruid && path.dentry->d_inode->i_uid != current_uid()) { 549 rc = -EPERM; 550 printk(KERN_ERR "Mount of device (uid: %d) not owned by " 551 "requested user (uid: %d)\n", 552 path.dentry->d_inode->i_uid, current_uid()); 553 goto out_free; 554 } 555 556 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 557 558 /** 559 * Set the POSIX ACL flag based on whether they're enabled in the lower 560 * mount. Force a read-only eCryptfs mount if the lower mount is ro. 561 * Allow a ro eCryptfs mount even when the lower mount is rw. 562 */ 563 s->s_flags = flags & ~MS_POSIXACL; 564 s->s_flags |= path.dentry->d_sb->s_flags & (MS_RDONLY | MS_POSIXACL); 565 566 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 567 s->s_blocksize = path.dentry->d_sb->s_blocksize; 568 s->s_magic = ECRYPTFS_SUPER_MAGIC; 569 570 inode = ecryptfs_get_inode(path.dentry->d_inode, s); 571 rc = PTR_ERR(inode); 572 if (IS_ERR(inode)) 573 goto out_free; 574 575 s->s_root = d_make_root(inode); 576 if (!s->s_root) { 577 rc = -ENOMEM; 578 goto out_free; 579 } 580 581 rc = -ENOMEM; 582 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 583 if (!root_info) 584 goto out_free; 585 586 /* ->kill_sb() will take care of root_info */ 587 ecryptfs_set_dentry_private(s->s_root, root_info); 588 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 589 ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt); 590 591 s->s_flags |= MS_ACTIVE; 592 return dget(s->s_root); 593 594 out_free: 595 path_put(&path); 596 out1: 597 deactivate_locked_super(s); 598 out: 599 if (sbi) { 600 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 601 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 602 } 603 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 604 return ERR_PTR(rc); 605 } 606 607 /** 608 * ecryptfs_kill_block_super 609 * @sb: The ecryptfs super block 610 * 611 * Used to bring the superblock down and free the private data. 612 */ 613 static void ecryptfs_kill_block_super(struct super_block *sb) 614 { 615 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 616 kill_anon_super(sb); 617 if (!sb_info) 618 return; 619 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 620 bdi_destroy(&sb_info->bdi); 621 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 622 } 623 624 static struct file_system_type ecryptfs_fs_type = { 625 .owner = THIS_MODULE, 626 .name = "ecryptfs", 627 .mount = ecryptfs_mount, 628 .kill_sb = ecryptfs_kill_block_super, 629 .fs_flags = 0 630 }; 631 632 /** 633 * inode_info_init_once 634 * 635 * Initializes the ecryptfs_inode_info_cache when it is created 636 */ 637 static void 638 inode_info_init_once(void *vptr) 639 { 640 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 641 642 inode_init_once(&ei->vfs_inode); 643 } 644 645 static struct ecryptfs_cache_info { 646 struct kmem_cache **cache; 647 const char *name; 648 size_t size; 649 void (*ctor)(void *obj); 650 } ecryptfs_cache_infos[] = { 651 { 652 .cache = &ecryptfs_auth_tok_list_item_cache, 653 .name = "ecryptfs_auth_tok_list_item", 654 .size = sizeof(struct ecryptfs_auth_tok_list_item), 655 }, 656 { 657 .cache = &ecryptfs_file_info_cache, 658 .name = "ecryptfs_file_cache", 659 .size = sizeof(struct ecryptfs_file_info), 660 }, 661 { 662 .cache = &ecryptfs_dentry_info_cache, 663 .name = "ecryptfs_dentry_info_cache", 664 .size = sizeof(struct ecryptfs_dentry_info), 665 }, 666 { 667 .cache = &ecryptfs_inode_info_cache, 668 .name = "ecryptfs_inode_cache", 669 .size = sizeof(struct ecryptfs_inode_info), 670 .ctor = inode_info_init_once, 671 }, 672 { 673 .cache = &ecryptfs_sb_info_cache, 674 .name = "ecryptfs_sb_cache", 675 .size = sizeof(struct ecryptfs_sb_info), 676 }, 677 { 678 .cache = &ecryptfs_header_cache, 679 .name = "ecryptfs_headers", 680 .size = PAGE_CACHE_SIZE, 681 }, 682 { 683 .cache = &ecryptfs_xattr_cache, 684 .name = "ecryptfs_xattr_cache", 685 .size = PAGE_CACHE_SIZE, 686 }, 687 { 688 .cache = &ecryptfs_key_record_cache, 689 .name = "ecryptfs_key_record_cache", 690 .size = sizeof(struct ecryptfs_key_record), 691 }, 692 { 693 .cache = &ecryptfs_key_sig_cache, 694 .name = "ecryptfs_key_sig_cache", 695 .size = sizeof(struct ecryptfs_key_sig), 696 }, 697 { 698 .cache = &ecryptfs_global_auth_tok_cache, 699 .name = "ecryptfs_global_auth_tok_cache", 700 .size = sizeof(struct ecryptfs_global_auth_tok), 701 }, 702 { 703 .cache = &ecryptfs_key_tfm_cache, 704 .name = "ecryptfs_key_tfm_cache", 705 .size = sizeof(struct ecryptfs_key_tfm), 706 }, 707 }; 708 709 static void ecryptfs_free_kmem_caches(void) 710 { 711 int i; 712 713 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 714 struct ecryptfs_cache_info *info; 715 716 info = &ecryptfs_cache_infos[i]; 717 if (*(info->cache)) 718 kmem_cache_destroy(*(info->cache)); 719 } 720 } 721 722 /** 723 * ecryptfs_init_kmem_caches 724 * 725 * Returns zero on success; non-zero otherwise 726 */ 727 static int ecryptfs_init_kmem_caches(void) 728 { 729 int i; 730 731 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 732 struct ecryptfs_cache_info *info; 733 734 info = &ecryptfs_cache_infos[i]; 735 *(info->cache) = kmem_cache_create(info->name, info->size, 736 0, SLAB_HWCACHE_ALIGN, info->ctor); 737 if (!*(info->cache)) { 738 ecryptfs_free_kmem_caches(); 739 ecryptfs_printk(KERN_WARNING, "%s: " 740 "kmem_cache_create failed\n", 741 info->name); 742 return -ENOMEM; 743 } 744 } 745 return 0; 746 } 747 748 static struct kobject *ecryptfs_kobj; 749 750 static ssize_t version_show(struct kobject *kobj, 751 struct kobj_attribute *attr, char *buff) 752 { 753 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 754 } 755 756 static struct kobj_attribute version_attr = __ATTR_RO(version); 757 758 static struct attribute *attributes[] = { 759 &version_attr.attr, 760 NULL, 761 }; 762 763 static struct attribute_group attr_group = { 764 .attrs = attributes, 765 }; 766 767 static int do_sysfs_registration(void) 768 { 769 int rc; 770 771 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 772 if (!ecryptfs_kobj) { 773 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 774 rc = -ENOMEM; 775 goto out; 776 } 777 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 778 if (rc) { 779 printk(KERN_ERR 780 "Unable to create ecryptfs version attributes\n"); 781 kobject_put(ecryptfs_kobj); 782 } 783 out: 784 return rc; 785 } 786 787 static void do_sysfs_unregistration(void) 788 { 789 sysfs_remove_group(ecryptfs_kobj, &attr_group); 790 kobject_put(ecryptfs_kobj); 791 } 792 793 static int __init ecryptfs_init(void) 794 { 795 int rc; 796 797 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 798 rc = -EINVAL; 799 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 800 "larger than the host's page size, and so " 801 "eCryptfs cannot run on this system. The " 802 "default eCryptfs extent size is [%u] bytes; " 803 "the page size is [%lu] bytes.\n", 804 ECRYPTFS_DEFAULT_EXTENT_SIZE, 805 (unsigned long)PAGE_CACHE_SIZE); 806 goto out; 807 } 808 rc = ecryptfs_init_kmem_caches(); 809 if (rc) { 810 printk(KERN_ERR 811 "Failed to allocate one or more kmem_cache objects\n"); 812 goto out; 813 } 814 rc = do_sysfs_registration(); 815 if (rc) { 816 printk(KERN_ERR "sysfs registration failed\n"); 817 goto out_free_kmem_caches; 818 } 819 rc = ecryptfs_init_kthread(); 820 if (rc) { 821 printk(KERN_ERR "%s: kthread initialization failed; " 822 "rc = [%d]\n", __func__, rc); 823 goto out_do_sysfs_unregistration; 824 } 825 rc = ecryptfs_init_messaging(); 826 if (rc) { 827 printk(KERN_ERR "Failure occurred while attempting to " 828 "initialize the communications channel to " 829 "ecryptfsd\n"); 830 goto out_destroy_kthread; 831 } 832 rc = ecryptfs_init_crypto(); 833 if (rc) { 834 printk(KERN_ERR "Failure whilst attempting to init crypto; " 835 "rc = [%d]\n", rc); 836 goto out_release_messaging; 837 } 838 rc = register_filesystem(&ecryptfs_fs_type); 839 if (rc) { 840 printk(KERN_ERR "Failed to register filesystem\n"); 841 goto out_destroy_crypto; 842 } 843 if (ecryptfs_verbosity > 0) 844 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 845 "will be written to the syslog!\n", ecryptfs_verbosity); 846 847 goto out; 848 out_destroy_crypto: 849 ecryptfs_destroy_crypto(); 850 out_release_messaging: 851 ecryptfs_release_messaging(); 852 out_destroy_kthread: 853 ecryptfs_destroy_kthread(); 854 out_do_sysfs_unregistration: 855 do_sysfs_unregistration(); 856 out_free_kmem_caches: 857 ecryptfs_free_kmem_caches(); 858 out: 859 return rc; 860 } 861 862 static void __exit ecryptfs_exit(void) 863 { 864 int rc; 865 866 rc = ecryptfs_destroy_crypto(); 867 if (rc) 868 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 869 "rc = [%d]\n", rc); 870 ecryptfs_release_messaging(); 871 ecryptfs_destroy_kthread(); 872 do_sysfs_unregistration(); 873 unregister_filesystem(&ecryptfs_fs_type); 874 ecryptfs_free_kmem_caches(); 875 } 876 877 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 878 MODULE_DESCRIPTION("eCryptfs"); 879 880 MODULE_LICENSE("GPL"); 881 882 module_init(ecryptfs_init) 883 module_exit(ecryptfs_exit) 884