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 "ecryptfs_kernel.h" 40 41 /** 42 * Module parameter that defines the ecryptfs_verbosity level. 43 */ 44 int ecryptfs_verbosity = 0; 45 46 module_param(ecryptfs_verbosity, int, 0); 47 MODULE_PARM_DESC(ecryptfs_verbosity, 48 "Initial verbosity level (0 or 1; defaults to " 49 "0, which is Quiet)"); 50 51 /** 52 * Module parameter that defines the number of message buffer elements 53 */ 54 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 55 56 module_param(ecryptfs_message_buf_len, uint, 0); 57 MODULE_PARM_DESC(ecryptfs_message_buf_len, 58 "Number of message buffer elements"); 59 60 /** 61 * Module parameter that defines the maximum guaranteed amount of time to wait 62 * for a response from ecryptfsd. The actual sleep time will be, more than 63 * likely, a small amount greater than this specified value, but only less if 64 * the message successfully arrives. 65 */ 66 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 67 68 module_param(ecryptfs_message_wait_timeout, long, 0); 69 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 70 "Maximum number of seconds that an operation will " 71 "sleep while waiting for a message response from " 72 "userspace"); 73 74 /** 75 * Module parameter that is an estimate of the maximum number of users 76 * that will be concurrently using eCryptfs. Set this to the right 77 * value to balance performance and memory use. 78 */ 79 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 80 81 module_param(ecryptfs_number_of_users, uint, 0); 82 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 83 "concurrent users of eCryptfs"); 84 85 void __ecryptfs_printk(const char *fmt, ...) 86 { 87 va_list args; 88 va_start(args, fmt); 89 if (fmt[1] == '7') { /* KERN_DEBUG */ 90 if (ecryptfs_verbosity >= 1) 91 vprintk(fmt, args); 92 } else 93 vprintk(fmt, args); 94 va_end(args); 95 } 96 97 /** 98 * ecryptfs_init_persistent_file 99 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 100 * the lower dentry and the lower mount set 101 * 102 * eCryptfs only ever keeps a single open file for every lower 103 * inode. All I/O operations to the lower inode occur through that 104 * file. When the first eCryptfs dentry that interposes with the first 105 * lower dentry for that inode is created, this function creates the 106 * persistent file struct and associates it with the eCryptfs 107 * inode. When the eCryptfs inode is destroyed, the file is closed. 108 * 109 * The persistent file will be opened with read/write permissions, if 110 * possible. Otherwise, it is opened read-only. 111 * 112 * This function does nothing if a lower persistent file is already 113 * associated with the eCryptfs inode. 114 * 115 * Returns zero on success; non-zero otherwise 116 */ 117 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) 118 { 119 const struct cred *cred = current_cred(); 120 struct ecryptfs_inode_info *inode_info = 121 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); 122 int rc = 0; 123 124 mutex_lock(&inode_info->lower_file_mutex); 125 if (!inode_info->lower_file) { 126 struct dentry *lower_dentry; 127 struct vfsmount *lower_mnt = 128 ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); 129 130 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 131 rc = ecryptfs_privileged_open(&inode_info->lower_file, 132 lower_dentry, lower_mnt, cred); 133 if (rc) { 134 printk(KERN_ERR "Error opening lower persistent file " 135 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 136 "rc = [%d]\n", lower_dentry, lower_mnt, rc); 137 inode_info->lower_file = NULL; 138 } 139 } 140 mutex_unlock(&inode_info->lower_file_mutex); 141 return rc; 142 } 143 144 static struct inode *ecryptfs_get_inode(struct inode *lower_inode, 145 struct super_block *sb) 146 { 147 struct inode *inode; 148 int rc = 0; 149 150 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { 151 rc = -EXDEV; 152 goto out; 153 } 154 if (!igrab(lower_inode)) { 155 rc = -ESTALE; 156 goto out; 157 } 158 inode = iget5_locked(sb, (unsigned long)lower_inode, 159 ecryptfs_inode_test, ecryptfs_inode_set, 160 lower_inode); 161 if (!inode) { 162 rc = -EACCES; 163 iput(lower_inode); 164 goto out; 165 } 166 if (inode->i_state & I_NEW) 167 unlock_new_inode(inode); 168 else 169 iput(lower_inode); 170 if (S_ISLNK(lower_inode->i_mode)) 171 inode->i_op = &ecryptfs_symlink_iops; 172 else if (S_ISDIR(lower_inode->i_mode)) 173 inode->i_op = &ecryptfs_dir_iops; 174 if (S_ISDIR(lower_inode->i_mode)) 175 inode->i_fop = &ecryptfs_dir_fops; 176 if (special_file(lower_inode->i_mode)) 177 init_special_inode(inode, lower_inode->i_mode, 178 lower_inode->i_rdev); 179 fsstack_copy_attr_all(inode, lower_inode); 180 /* This size will be overwritten for real files w/ headers and 181 * other metadata */ 182 fsstack_copy_inode_size(inode, lower_inode); 183 return inode; 184 out: 185 return ERR_PTR(rc); 186 } 187 188 /** 189 * ecryptfs_interpose 190 * @lower_dentry: Existing dentry in the lower filesystem 191 * @dentry: ecryptfs' dentry 192 * @sb: ecryptfs's super_block 193 * @flags: flags to govern behavior of interpose procedure 194 * 195 * Interposes upper and lower dentries. 196 * 197 * Returns zero on success; non-zero otherwise 198 */ 199 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, 200 struct super_block *sb, u32 flags) 201 { 202 struct inode *lower_inode = lower_dentry->d_inode; 203 struct inode *inode = ecryptfs_get_inode(lower_inode, sb); 204 if (IS_ERR(inode)) 205 return PTR_ERR(inode); 206 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) 207 d_add(dentry, inode); 208 else 209 d_instantiate(dentry, inode); 210 return 0; 211 } 212 213 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 214 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 215 ecryptfs_opt_ecryptfs_key_bytes, 216 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 217 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 218 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 219 ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, 220 ecryptfs_opt_err }; 221 222 static const match_table_t tokens = { 223 {ecryptfs_opt_sig, "sig=%s"}, 224 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 225 {ecryptfs_opt_cipher, "cipher=%s"}, 226 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 227 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 228 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 229 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 230 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 231 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 232 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 233 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 234 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 235 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 236 {ecryptfs_opt_err, NULL} 237 }; 238 239 static int ecryptfs_init_global_auth_toks( 240 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 241 { 242 struct ecryptfs_global_auth_tok *global_auth_tok; 243 int rc = 0; 244 245 list_for_each_entry(global_auth_tok, 246 &mount_crypt_stat->global_auth_tok_list, 247 mount_crypt_stat_list) { 248 rc = ecryptfs_keyring_auth_tok_for_sig( 249 &global_auth_tok->global_auth_tok_key, 250 &global_auth_tok->global_auth_tok, 251 global_auth_tok->sig); 252 if (rc) { 253 printk(KERN_ERR "Could not find valid key in user " 254 "session keyring for sig specified in mount " 255 "option: [%s]\n", global_auth_tok->sig); 256 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 257 goto out; 258 } else 259 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 260 } 261 out: 262 return rc; 263 } 264 265 static void ecryptfs_init_mount_crypt_stat( 266 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 267 { 268 memset((void *)mount_crypt_stat, 0, 269 sizeof(struct ecryptfs_mount_crypt_stat)); 270 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 271 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 272 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 273 } 274 275 /** 276 * ecryptfs_parse_options 277 * @sb: The ecryptfs super block 278 * @options: The options pased to the kernel 279 * 280 * Parse mount options: 281 * debug=N - ecryptfs_verbosity level for debug output 282 * sig=XXX - description(signature) of the key to use 283 * 284 * Returns the dentry object of the lower-level (lower/interposed) 285 * directory; We want to mount our stackable file system on top of 286 * that lower directory. 287 * 288 * The signature of the key to use must be the description of a key 289 * already in the keyring. Mounting will fail if the key can not be 290 * found. 291 * 292 * Returns zero on success; non-zero on error 293 */ 294 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) 295 { 296 char *p; 297 int rc = 0; 298 int sig_set = 0; 299 int cipher_name_set = 0; 300 int fn_cipher_name_set = 0; 301 int cipher_key_bytes; 302 int cipher_key_bytes_set = 0; 303 int fn_cipher_key_bytes; 304 int fn_cipher_key_bytes_set = 0; 305 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 306 &sbi->mount_crypt_stat; 307 substring_t args[MAX_OPT_ARGS]; 308 int token; 309 char *sig_src; 310 char *cipher_name_dst; 311 char *cipher_name_src; 312 char *fn_cipher_name_dst; 313 char *fn_cipher_name_src; 314 char *fnek_dst; 315 char *fnek_src; 316 char *cipher_key_bytes_src; 317 char *fn_cipher_key_bytes_src; 318 319 if (!options) { 320 rc = -EINVAL; 321 goto out; 322 } 323 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 324 while ((p = strsep(&options, ",")) != NULL) { 325 if (!*p) 326 continue; 327 token = match_token(p, tokens, args); 328 switch (token) { 329 case ecryptfs_opt_sig: 330 case ecryptfs_opt_ecryptfs_sig: 331 sig_src = args[0].from; 332 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 333 sig_src, 0); 334 if (rc) { 335 printk(KERN_ERR "Error attempting to register " 336 "global sig; rc = [%d]\n", rc); 337 goto out; 338 } 339 sig_set = 1; 340 break; 341 case ecryptfs_opt_cipher: 342 case ecryptfs_opt_ecryptfs_cipher: 343 cipher_name_src = args[0].from; 344 cipher_name_dst = 345 mount_crypt_stat-> 346 global_default_cipher_name; 347 strncpy(cipher_name_dst, cipher_name_src, 348 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 349 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 350 cipher_name_set = 1; 351 break; 352 case ecryptfs_opt_ecryptfs_key_bytes: 353 cipher_key_bytes_src = args[0].from; 354 cipher_key_bytes = 355 (int)simple_strtol(cipher_key_bytes_src, 356 &cipher_key_bytes_src, 0); 357 mount_crypt_stat->global_default_cipher_key_size = 358 cipher_key_bytes; 359 cipher_key_bytes_set = 1; 360 break; 361 case ecryptfs_opt_passthrough: 362 mount_crypt_stat->flags |= 363 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 364 break; 365 case ecryptfs_opt_xattr_metadata: 366 mount_crypt_stat->flags |= 367 ECRYPTFS_XATTR_METADATA_ENABLED; 368 break; 369 case ecryptfs_opt_encrypted_view: 370 mount_crypt_stat->flags |= 371 ECRYPTFS_XATTR_METADATA_ENABLED; 372 mount_crypt_stat->flags |= 373 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 374 break; 375 case ecryptfs_opt_fnek_sig: 376 fnek_src = args[0].from; 377 fnek_dst = 378 mount_crypt_stat->global_default_fnek_sig; 379 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 380 mount_crypt_stat->global_default_fnek_sig[ 381 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 382 rc = ecryptfs_add_global_auth_tok( 383 mount_crypt_stat, 384 mount_crypt_stat->global_default_fnek_sig, 385 ECRYPTFS_AUTH_TOK_FNEK); 386 if (rc) { 387 printk(KERN_ERR "Error attempting to register " 388 "global fnek sig [%s]; rc = [%d]\n", 389 mount_crypt_stat->global_default_fnek_sig, 390 rc); 391 goto out; 392 } 393 mount_crypt_stat->flags |= 394 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 395 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 396 break; 397 case ecryptfs_opt_fn_cipher: 398 fn_cipher_name_src = args[0].from; 399 fn_cipher_name_dst = 400 mount_crypt_stat->global_default_fn_cipher_name; 401 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 402 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 403 mount_crypt_stat->global_default_fn_cipher_name[ 404 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 405 fn_cipher_name_set = 1; 406 break; 407 case ecryptfs_opt_fn_cipher_key_bytes: 408 fn_cipher_key_bytes_src = args[0].from; 409 fn_cipher_key_bytes = 410 (int)simple_strtol(fn_cipher_key_bytes_src, 411 &fn_cipher_key_bytes_src, 0); 412 mount_crypt_stat->global_default_fn_cipher_key_bytes = 413 fn_cipher_key_bytes; 414 fn_cipher_key_bytes_set = 1; 415 break; 416 case ecryptfs_opt_unlink_sigs: 417 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 418 break; 419 case ecryptfs_opt_mount_auth_tok_only: 420 mount_crypt_stat->flags |= 421 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 422 break; 423 case ecryptfs_opt_err: 424 default: 425 printk(KERN_WARNING 426 "%s: eCryptfs: unrecognized option [%s]\n", 427 __func__, p); 428 } 429 } 430 if (!sig_set) { 431 rc = -EINVAL; 432 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 433 "auth tok signature as a mount " 434 "parameter; see the eCryptfs README\n"); 435 goto out; 436 } 437 if (!cipher_name_set) { 438 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 439 440 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 441 strcpy(mount_crypt_stat->global_default_cipher_name, 442 ECRYPTFS_DEFAULT_CIPHER); 443 } 444 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 445 && !fn_cipher_name_set) 446 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 447 mount_crypt_stat->global_default_cipher_name); 448 if (!cipher_key_bytes_set) 449 mount_crypt_stat->global_default_cipher_key_size = 0; 450 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 451 && !fn_cipher_key_bytes_set) 452 mount_crypt_stat->global_default_fn_cipher_key_bytes = 453 mount_crypt_stat->global_default_cipher_key_size; 454 mutex_lock(&key_tfm_list_mutex); 455 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 456 NULL)) { 457 rc = ecryptfs_add_new_key_tfm( 458 NULL, mount_crypt_stat->global_default_cipher_name, 459 mount_crypt_stat->global_default_cipher_key_size); 460 if (rc) { 461 printk(KERN_ERR "Error attempting to initialize " 462 "cipher with name = [%s] and key size = [%td]; " 463 "rc = [%d]\n", 464 mount_crypt_stat->global_default_cipher_name, 465 mount_crypt_stat->global_default_cipher_key_size, 466 rc); 467 rc = -EINVAL; 468 mutex_unlock(&key_tfm_list_mutex); 469 goto out; 470 } 471 } 472 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 473 && !ecryptfs_tfm_exists( 474 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 475 rc = ecryptfs_add_new_key_tfm( 476 NULL, mount_crypt_stat->global_default_fn_cipher_name, 477 mount_crypt_stat->global_default_fn_cipher_key_bytes); 478 if (rc) { 479 printk(KERN_ERR "Error attempting to initialize " 480 "cipher with name = [%s] and key size = [%td]; " 481 "rc = [%d]\n", 482 mount_crypt_stat->global_default_fn_cipher_name, 483 mount_crypt_stat->global_default_fn_cipher_key_bytes, 484 rc); 485 rc = -EINVAL; 486 mutex_unlock(&key_tfm_list_mutex); 487 goto out; 488 } 489 } 490 mutex_unlock(&key_tfm_list_mutex); 491 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 492 if (rc) 493 printk(KERN_WARNING "One or more global auth toks could not " 494 "properly register; rc = [%d]\n", rc); 495 out: 496 return rc; 497 } 498 499 struct kmem_cache *ecryptfs_sb_info_cache; 500 static struct file_system_type ecryptfs_fs_type; 501 502 /** 503 * ecryptfs_get_sb 504 * @fs_type 505 * @flags 506 * @dev_name: The path to mount over 507 * @raw_data: The options passed into the kernel 508 */ 509 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 510 const char *dev_name, void *raw_data) 511 { 512 struct super_block *s; 513 struct ecryptfs_sb_info *sbi; 514 struct ecryptfs_dentry_info *root_info; 515 const char *err = "Getting sb failed"; 516 struct inode *inode; 517 struct path path; 518 int rc; 519 520 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 521 if (!sbi) { 522 rc = -ENOMEM; 523 goto out; 524 } 525 526 rc = ecryptfs_parse_options(sbi, raw_data); 527 if (rc) { 528 err = "Error parsing options"; 529 goto out; 530 } 531 532 s = sget(fs_type, NULL, set_anon_super, NULL); 533 if (IS_ERR(s)) { 534 rc = PTR_ERR(s); 535 goto out; 536 } 537 538 s->s_flags = flags; 539 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 540 if (rc) 541 goto out1; 542 543 ecryptfs_set_superblock_private(s, sbi); 544 s->s_bdi = &sbi->bdi; 545 546 /* ->kill_sb() will take care of sbi after that point */ 547 sbi = NULL; 548 s->s_op = &ecryptfs_sops; 549 s->s_d_op = &ecryptfs_dops; 550 551 err = "Reading sb failed"; 552 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 553 if (rc) { 554 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 555 goto out1; 556 } 557 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 558 rc = -EINVAL; 559 printk(KERN_ERR "Mount on filesystem of type " 560 "eCryptfs explicitly disallowed due to " 561 "known incompatibilities\n"); 562 goto out_free; 563 } 564 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 565 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 566 s->s_blocksize = path.dentry->d_sb->s_blocksize; 567 568 inode = ecryptfs_get_inode(path.dentry->d_inode, s); 569 rc = PTR_ERR(inode); 570 if (IS_ERR(inode)) 571 goto out_free; 572 573 s->s_root = d_alloc_root(inode); 574 if (!s->s_root) { 575 iput(inode); 576 rc = -ENOMEM; 577 goto out_free; 578 } 579 580 rc = -ENOMEM; 581 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 582 if (!root_info) 583 goto out_free; 584 585 /* ->kill_sb() will take care of root_info */ 586 ecryptfs_set_dentry_private(s->s_root, root_info); 587 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 588 ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt); 589 590 s->s_flags |= MS_ACTIVE; 591 return dget(s->s_root); 592 593 out_free: 594 path_put(&path); 595 out1: 596 deactivate_locked_super(s); 597 out: 598 if (sbi) { 599 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 600 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 601 } 602 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 603 return ERR_PTR(rc); 604 } 605 606 /** 607 * ecryptfs_kill_block_super 608 * @sb: The ecryptfs super block 609 * 610 * Used to bring the superblock down and free the private data. 611 */ 612 static void ecryptfs_kill_block_super(struct super_block *sb) 613 { 614 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 615 kill_anon_super(sb); 616 if (!sb_info) 617 return; 618 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 619 bdi_destroy(&sb_info->bdi); 620 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 621 } 622 623 static struct file_system_type ecryptfs_fs_type = { 624 .owner = THIS_MODULE, 625 .name = "ecryptfs", 626 .mount = ecryptfs_mount, 627 .kill_sb = ecryptfs_kill_block_super, 628 .fs_flags = 0 629 }; 630 631 /** 632 * inode_info_init_once 633 * 634 * Initializes the ecryptfs_inode_info_cache when it is created 635 */ 636 static void 637 inode_info_init_once(void *vptr) 638 { 639 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 640 641 inode_init_once(&ei->vfs_inode); 642 } 643 644 static struct ecryptfs_cache_info { 645 struct kmem_cache **cache; 646 const char *name; 647 size_t size; 648 void (*ctor)(void *obj); 649 } ecryptfs_cache_infos[] = { 650 { 651 .cache = &ecryptfs_auth_tok_list_item_cache, 652 .name = "ecryptfs_auth_tok_list_item", 653 .size = sizeof(struct ecryptfs_auth_tok_list_item), 654 }, 655 { 656 .cache = &ecryptfs_file_info_cache, 657 .name = "ecryptfs_file_cache", 658 .size = sizeof(struct ecryptfs_file_info), 659 }, 660 { 661 .cache = &ecryptfs_dentry_info_cache, 662 .name = "ecryptfs_dentry_info_cache", 663 .size = sizeof(struct ecryptfs_dentry_info), 664 }, 665 { 666 .cache = &ecryptfs_inode_info_cache, 667 .name = "ecryptfs_inode_cache", 668 .size = sizeof(struct ecryptfs_inode_info), 669 .ctor = inode_info_init_once, 670 }, 671 { 672 .cache = &ecryptfs_sb_info_cache, 673 .name = "ecryptfs_sb_cache", 674 .size = sizeof(struct ecryptfs_sb_info), 675 }, 676 { 677 .cache = &ecryptfs_header_cache_1, 678 .name = "ecryptfs_headers_1", 679 .size = PAGE_CACHE_SIZE, 680 }, 681 { 682 .cache = &ecryptfs_header_cache_2, 683 .name = "ecryptfs_headers_2", 684 .size = PAGE_CACHE_SIZE, 685 }, 686 { 687 .cache = &ecryptfs_xattr_cache, 688 .name = "ecryptfs_xattr_cache", 689 .size = PAGE_CACHE_SIZE, 690 }, 691 { 692 .cache = &ecryptfs_key_record_cache, 693 .name = "ecryptfs_key_record_cache", 694 .size = sizeof(struct ecryptfs_key_record), 695 }, 696 { 697 .cache = &ecryptfs_key_sig_cache, 698 .name = "ecryptfs_key_sig_cache", 699 .size = sizeof(struct ecryptfs_key_sig), 700 }, 701 { 702 .cache = &ecryptfs_global_auth_tok_cache, 703 .name = "ecryptfs_global_auth_tok_cache", 704 .size = sizeof(struct ecryptfs_global_auth_tok), 705 }, 706 { 707 .cache = &ecryptfs_key_tfm_cache, 708 .name = "ecryptfs_key_tfm_cache", 709 .size = sizeof(struct ecryptfs_key_tfm), 710 }, 711 { 712 .cache = &ecryptfs_open_req_cache, 713 .name = "ecryptfs_open_req_cache", 714 .size = sizeof(struct ecryptfs_open_req), 715 }, 716 }; 717 718 static void ecryptfs_free_kmem_caches(void) 719 { 720 int i; 721 722 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 723 struct ecryptfs_cache_info *info; 724 725 info = &ecryptfs_cache_infos[i]; 726 if (*(info->cache)) 727 kmem_cache_destroy(*(info->cache)); 728 } 729 } 730 731 /** 732 * ecryptfs_init_kmem_caches 733 * 734 * Returns zero on success; non-zero otherwise 735 */ 736 static int ecryptfs_init_kmem_caches(void) 737 { 738 int i; 739 740 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 741 struct ecryptfs_cache_info *info; 742 743 info = &ecryptfs_cache_infos[i]; 744 *(info->cache) = kmem_cache_create(info->name, info->size, 745 0, SLAB_HWCACHE_ALIGN, info->ctor); 746 if (!*(info->cache)) { 747 ecryptfs_free_kmem_caches(); 748 ecryptfs_printk(KERN_WARNING, "%s: " 749 "kmem_cache_create failed\n", 750 info->name); 751 return -ENOMEM; 752 } 753 } 754 return 0; 755 } 756 757 static struct kobject *ecryptfs_kobj; 758 759 static ssize_t version_show(struct kobject *kobj, 760 struct kobj_attribute *attr, char *buff) 761 { 762 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 763 } 764 765 static struct kobj_attribute version_attr = __ATTR_RO(version); 766 767 static struct attribute *attributes[] = { 768 &version_attr.attr, 769 NULL, 770 }; 771 772 static struct attribute_group attr_group = { 773 .attrs = attributes, 774 }; 775 776 static int do_sysfs_registration(void) 777 { 778 int rc; 779 780 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 781 if (!ecryptfs_kobj) { 782 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 783 rc = -ENOMEM; 784 goto out; 785 } 786 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 787 if (rc) { 788 printk(KERN_ERR 789 "Unable to create ecryptfs version attributes\n"); 790 kobject_put(ecryptfs_kobj); 791 } 792 out: 793 return rc; 794 } 795 796 static void do_sysfs_unregistration(void) 797 { 798 sysfs_remove_group(ecryptfs_kobj, &attr_group); 799 kobject_put(ecryptfs_kobj); 800 } 801 802 static int __init ecryptfs_init(void) 803 { 804 int rc; 805 806 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 807 rc = -EINVAL; 808 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 809 "larger than the host's page size, and so " 810 "eCryptfs cannot run on this system. The " 811 "default eCryptfs extent size is [%d] bytes; " 812 "the page size is [%d] bytes.\n", 813 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); 814 goto out; 815 } 816 rc = ecryptfs_init_kmem_caches(); 817 if (rc) { 818 printk(KERN_ERR 819 "Failed to allocate one or more kmem_cache objects\n"); 820 goto out; 821 } 822 rc = register_filesystem(&ecryptfs_fs_type); 823 if (rc) { 824 printk(KERN_ERR "Failed to register filesystem\n"); 825 goto out_free_kmem_caches; 826 } 827 rc = do_sysfs_registration(); 828 if (rc) { 829 printk(KERN_ERR "sysfs registration failed\n"); 830 goto out_unregister_filesystem; 831 } 832 rc = ecryptfs_init_kthread(); 833 if (rc) { 834 printk(KERN_ERR "%s: kthread initialization failed; " 835 "rc = [%d]\n", __func__, rc); 836 goto out_do_sysfs_unregistration; 837 } 838 rc = ecryptfs_init_messaging(); 839 if (rc) { 840 printk(KERN_ERR "Failure occured while attempting to " 841 "initialize the communications channel to " 842 "ecryptfsd\n"); 843 goto out_destroy_kthread; 844 } 845 rc = ecryptfs_init_crypto(); 846 if (rc) { 847 printk(KERN_ERR "Failure whilst attempting to init crypto; " 848 "rc = [%d]\n", rc); 849 goto out_release_messaging; 850 } 851 if (ecryptfs_verbosity > 0) 852 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 853 "will be written to the syslog!\n", ecryptfs_verbosity); 854 855 goto out; 856 out_release_messaging: 857 ecryptfs_release_messaging(); 858 out_destroy_kthread: 859 ecryptfs_destroy_kthread(); 860 out_do_sysfs_unregistration: 861 do_sysfs_unregistration(); 862 out_unregister_filesystem: 863 unregister_filesystem(&ecryptfs_fs_type); 864 out_free_kmem_caches: 865 ecryptfs_free_kmem_caches(); 866 out: 867 return rc; 868 } 869 870 static void __exit ecryptfs_exit(void) 871 { 872 int rc; 873 874 rc = ecryptfs_destroy_crypto(); 875 if (rc) 876 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 877 "rc = [%d]\n", rc); 878 ecryptfs_release_messaging(); 879 ecryptfs_destroy_kthread(); 880 do_sysfs_unregistration(); 881 unregister_filesystem(&ecryptfs_fs_type); 882 ecryptfs_free_kmem_caches(); 883 } 884 885 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 886 MODULE_DESCRIPTION("eCryptfs"); 887 888 MODULE_LICENSE("GPL"); 889 890 module_init(ecryptfs_init) 891 module_exit(ecryptfs_exit) 892