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_persistent_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 * persistent file struct and associates it with the eCryptfs 108 * inode. When the eCryptfs inode is destroyed, the file is closed. 109 * 110 * The persistent file will be opened with read/write permissions, if 111 * possible. Otherwise, it is opened read-only. 112 * 113 * This function does nothing if a lower persistent file is already 114 * associated with the eCryptfs inode. 115 * 116 * Returns zero on success; non-zero otherwise 117 */ 118 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) 119 { 120 const struct cred *cred = current_cred(); 121 struct ecryptfs_inode_info *inode_info = 122 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); 123 int rc = 0; 124 125 mutex_lock(&inode_info->lower_file_mutex); 126 if (!inode_info->lower_file) { 127 struct dentry *lower_dentry; 128 struct vfsmount *lower_mnt = 129 ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); 130 131 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 132 rc = ecryptfs_privileged_open(&inode_info->lower_file, 133 lower_dentry, lower_mnt, cred); 134 if (rc) { 135 printk(KERN_ERR "Error opening lower persistent file " 136 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 137 "rc = [%d]\n", lower_dentry, lower_mnt, rc); 138 inode_info->lower_file = NULL; 139 } 140 } 141 mutex_unlock(&inode_info->lower_file_mutex); 142 return rc; 143 } 144 145 static struct inode *ecryptfs_get_inode(struct inode *lower_inode, 146 struct super_block *sb) 147 { 148 struct inode *inode; 149 int rc = 0; 150 151 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { 152 rc = -EXDEV; 153 goto out; 154 } 155 if (!igrab(lower_inode)) { 156 rc = -ESTALE; 157 goto out; 158 } 159 inode = iget5_locked(sb, (unsigned long)lower_inode, 160 ecryptfs_inode_test, ecryptfs_inode_set, 161 lower_inode); 162 if (!inode) { 163 rc = -EACCES; 164 iput(lower_inode); 165 goto out; 166 } 167 if (inode->i_state & I_NEW) 168 unlock_new_inode(inode); 169 else 170 iput(lower_inode); 171 if (S_ISLNK(lower_inode->i_mode)) 172 inode->i_op = &ecryptfs_symlink_iops; 173 else if (S_ISDIR(lower_inode->i_mode)) 174 inode->i_op = &ecryptfs_dir_iops; 175 if (S_ISDIR(lower_inode->i_mode)) 176 inode->i_fop = &ecryptfs_dir_fops; 177 if (special_file(lower_inode->i_mode)) 178 init_special_inode(inode, lower_inode->i_mode, 179 lower_inode->i_rdev); 180 fsstack_copy_attr_all(inode, lower_inode); 181 /* This size will be overwritten for real files w/ headers and 182 * other metadata */ 183 fsstack_copy_inode_size(inode, lower_inode); 184 return inode; 185 out: 186 return ERR_PTR(rc); 187 } 188 189 /** 190 * ecryptfs_interpose 191 * @lower_dentry: Existing dentry in the lower filesystem 192 * @dentry: ecryptfs' dentry 193 * @sb: ecryptfs's super_block 194 * @flags: flags to govern behavior of interpose procedure 195 * 196 * Interposes upper and lower dentries. 197 * 198 * Returns zero on success; non-zero otherwise 199 */ 200 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, 201 struct super_block *sb, u32 flags) 202 { 203 struct inode *lower_inode = lower_dentry->d_inode; 204 struct inode *inode = ecryptfs_get_inode(lower_inode, sb); 205 if (IS_ERR(inode)) 206 return PTR_ERR(inode); 207 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) 208 d_add(dentry, inode); 209 else 210 d_instantiate(dentry, inode); 211 return 0; 212 } 213 214 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 215 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 216 ecryptfs_opt_ecryptfs_key_bytes, 217 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 218 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 219 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 220 ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, 221 ecryptfs_opt_err }; 222 223 static const match_table_t tokens = { 224 {ecryptfs_opt_sig, "sig=%s"}, 225 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 226 {ecryptfs_opt_cipher, "cipher=%s"}, 227 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 228 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 229 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 230 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 231 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 232 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 233 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 234 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 235 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 236 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 237 {ecryptfs_opt_err, NULL} 238 }; 239 240 static int ecryptfs_init_global_auth_toks( 241 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 242 { 243 struct ecryptfs_global_auth_tok *global_auth_tok; 244 int rc = 0; 245 246 list_for_each_entry(global_auth_tok, 247 &mount_crypt_stat->global_auth_tok_list, 248 mount_crypt_stat_list) { 249 rc = ecryptfs_keyring_auth_tok_for_sig( 250 &global_auth_tok->global_auth_tok_key, 251 &global_auth_tok->global_auth_tok, 252 global_auth_tok->sig); 253 if (rc) { 254 printk(KERN_ERR "Could not find valid key in user " 255 "session keyring for sig specified in mount " 256 "option: [%s]\n", global_auth_tok->sig); 257 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 258 goto out; 259 } else 260 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 261 } 262 out: 263 return rc; 264 } 265 266 static void ecryptfs_init_mount_crypt_stat( 267 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 268 { 269 memset((void *)mount_crypt_stat, 0, 270 sizeof(struct ecryptfs_mount_crypt_stat)); 271 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 272 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 273 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 274 } 275 276 /** 277 * ecryptfs_parse_options 278 * @sb: The ecryptfs super block 279 * @options: The options pased to the kernel 280 * 281 * Parse mount options: 282 * debug=N - ecryptfs_verbosity level for debug output 283 * sig=XXX - description(signature) of the key to use 284 * 285 * Returns the dentry object of the lower-level (lower/interposed) 286 * directory; We want to mount our stackable file system on top of 287 * that lower directory. 288 * 289 * The signature of the key to use must be the description of a key 290 * already in the keyring. Mounting will fail if the key can not be 291 * found. 292 * 293 * Returns zero on success; non-zero on error 294 */ 295 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) 296 { 297 char *p; 298 int rc = 0; 299 int sig_set = 0; 300 int cipher_name_set = 0; 301 int fn_cipher_name_set = 0; 302 int cipher_key_bytes; 303 int cipher_key_bytes_set = 0; 304 int fn_cipher_key_bytes; 305 int fn_cipher_key_bytes_set = 0; 306 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 307 &sbi->mount_crypt_stat; 308 substring_t args[MAX_OPT_ARGS]; 309 int token; 310 char *sig_src; 311 char *cipher_name_dst; 312 char *cipher_name_src; 313 char *fn_cipher_name_dst; 314 char *fn_cipher_name_src; 315 char *fnek_dst; 316 char *fnek_src; 317 char *cipher_key_bytes_src; 318 char *fn_cipher_key_bytes_src; 319 320 if (!options) { 321 rc = -EINVAL; 322 goto out; 323 } 324 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 325 while ((p = strsep(&options, ",")) != NULL) { 326 if (!*p) 327 continue; 328 token = match_token(p, tokens, args); 329 switch (token) { 330 case ecryptfs_opt_sig: 331 case ecryptfs_opt_ecryptfs_sig: 332 sig_src = args[0].from; 333 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 334 sig_src, 0); 335 if (rc) { 336 printk(KERN_ERR "Error attempting to register " 337 "global sig; rc = [%d]\n", rc); 338 goto out; 339 } 340 sig_set = 1; 341 break; 342 case ecryptfs_opt_cipher: 343 case ecryptfs_opt_ecryptfs_cipher: 344 cipher_name_src = args[0].from; 345 cipher_name_dst = 346 mount_crypt_stat-> 347 global_default_cipher_name; 348 strncpy(cipher_name_dst, cipher_name_src, 349 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 350 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 351 cipher_name_set = 1; 352 break; 353 case ecryptfs_opt_ecryptfs_key_bytes: 354 cipher_key_bytes_src = args[0].from; 355 cipher_key_bytes = 356 (int)simple_strtol(cipher_key_bytes_src, 357 &cipher_key_bytes_src, 0); 358 mount_crypt_stat->global_default_cipher_key_size = 359 cipher_key_bytes; 360 cipher_key_bytes_set = 1; 361 break; 362 case ecryptfs_opt_passthrough: 363 mount_crypt_stat->flags |= 364 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 365 break; 366 case ecryptfs_opt_xattr_metadata: 367 mount_crypt_stat->flags |= 368 ECRYPTFS_XATTR_METADATA_ENABLED; 369 break; 370 case ecryptfs_opt_encrypted_view: 371 mount_crypt_stat->flags |= 372 ECRYPTFS_XATTR_METADATA_ENABLED; 373 mount_crypt_stat->flags |= 374 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 375 break; 376 case ecryptfs_opt_fnek_sig: 377 fnek_src = args[0].from; 378 fnek_dst = 379 mount_crypt_stat->global_default_fnek_sig; 380 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 381 mount_crypt_stat->global_default_fnek_sig[ 382 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 383 rc = ecryptfs_add_global_auth_tok( 384 mount_crypt_stat, 385 mount_crypt_stat->global_default_fnek_sig, 386 ECRYPTFS_AUTH_TOK_FNEK); 387 if (rc) { 388 printk(KERN_ERR "Error attempting to register " 389 "global fnek sig [%s]; rc = [%d]\n", 390 mount_crypt_stat->global_default_fnek_sig, 391 rc); 392 goto out; 393 } 394 mount_crypt_stat->flags |= 395 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 396 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 397 break; 398 case ecryptfs_opt_fn_cipher: 399 fn_cipher_name_src = args[0].from; 400 fn_cipher_name_dst = 401 mount_crypt_stat->global_default_fn_cipher_name; 402 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 403 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 404 mount_crypt_stat->global_default_fn_cipher_name[ 405 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 406 fn_cipher_name_set = 1; 407 break; 408 case ecryptfs_opt_fn_cipher_key_bytes: 409 fn_cipher_key_bytes_src = args[0].from; 410 fn_cipher_key_bytes = 411 (int)simple_strtol(fn_cipher_key_bytes_src, 412 &fn_cipher_key_bytes_src, 0); 413 mount_crypt_stat->global_default_fn_cipher_key_bytes = 414 fn_cipher_key_bytes; 415 fn_cipher_key_bytes_set = 1; 416 break; 417 case ecryptfs_opt_unlink_sigs: 418 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 419 break; 420 case ecryptfs_opt_mount_auth_tok_only: 421 mount_crypt_stat->flags |= 422 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 423 break; 424 case ecryptfs_opt_err: 425 default: 426 printk(KERN_WARNING 427 "%s: eCryptfs: unrecognized option [%s]\n", 428 __func__, p); 429 } 430 } 431 if (!sig_set) { 432 rc = -EINVAL; 433 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 434 "auth tok signature as a mount " 435 "parameter; see the eCryptfs README\n"); 436 goto out; 437 } 438 if (!cipher_name_set) { 439 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 440 441 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 442 strcpy(mount_crypt_stat->global_default_cipher_name, 443 ECRYPTFS_DEFAULT_CIPHER); 444 } 445 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 446 && !fn_cipher_name_set) 447 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 448 mount_crypt_stat->global_default_cipher_name); 449 if (!cipher_key_bytes_set) 450 mount_crypt_stat->global_default_cipher_key_size = 0; 451 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 452 && !fn_cipher_key_bytes_set) 453 mount_crypt_stat->global_default_fn_cipher_key_bytes = 454 mount_crypt_stat->global_default_cipher_key_size; 455 mutex_lock(&key_tfm_list_mutex); 456 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 457 NULL)) { 458 rc = ecryptfs_add_new_key_tfm( 459 NULL, mount_crypt_stat->global_default_cipher_name, 460 mount_crypt_stat->global_default_cipher_key_size); 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_cipher_name, 466 mount_crypt_stat->global_default_cipher_key_size, 467 rc); 468 rc = -EINVAL; 469 mutex_unlock(&key_tfm_list_mutex); 470 goto out; 471 } 472 } 473 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 474 && !ecryptfs_tfm_exists( 475 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 476 rc = ecryptfs_add_new_key_tfm( 477 NULL, mount_crypt_stat->global_default_fn_cipher_name, 478 mount_crypt_stat->global_default_fn_cipher_key_bytes); 479 if (rc) { 480 printk(KERN_ERR "Error attempting to initialize " 481 "cipher with name = [%s] and key size = [%td]; " 482 "rc = [%d]\n", 483 mount_crypt_stat->global_default_fn_cipher_name, 484 mount_crypt_stat->global_default_fn_cipher_key_bytes, 485 rc); 486 rc = -EINVAL; 487 mutex_unlock(&key_tfm_list_mutex); 488 goto out; 489 } 490 } 491 mutex_unlock(&key_tfm_list_mutex); 492 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 493 if (rc) 494 printk(KERN_WARNING "One or more global auth toks could not " 495 "properly register; rc = [%d]\n", rc); 496 out: 497 return rc; 498 } 499 500 struct kmem_cache *ecryptfs_sb_info_cache; 501 static struct file_system_type ecryptfs_fs_type; 502 503 /** 504 * ecryptfs_get_sb 505 * @fs_type 506 * @flags 507 * @dev_name: The path to mount over 508 * @raw_data: The options passed into the kernel 509 */ 510 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 511 const char *dev_name, void *raw_data) 512 { 513 struct super_block *s; 514 struct ecryptfs_sb_info *sbi; 515 struct ecryptfs_dentry_info *root_info; 516 const char *err = "Getting sb failed"; 517 struct inode *inode; 518 struct path path; 519 int rc; 520 521 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 522 if (!sbi) { 523 rc = -ENOMEM; 524 goto out; 525 } 526 527 rc = ecryptfs_parse_options(sbi, raw_data); 528 if (rc) { 529 err = "Error parsing options"; 530 goto out; 531 } 532 533 s = sget(fs_type, NULL, set_anon_super, NULL); 534 if (IS_ERR(s)) { 535 rc = PTR_ERR(s); 536 goto out; 537 } 538 539 s->s_flags = flags; 540 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 541 if (rc) 542 goto out1; 543 544 ecryptfs_set_superblock_private(s, sbi); 545 s->s_bdi = &sbi->bdi; 546 547 /* ->kill_sb() will take care of sbi after that point */ 548 sbi = NULL; 549 s->s_op = &ecryptfs_sops; 550 s->s_d_op = &ecryptfs_dops; 551 552 err = "Reading sb failed"; 553 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 554 if (rc) { 555 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 556 goto out1; 557 } 558 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 559 rc = -EINVAL; 560 printk(KERN_ERR "Mount on filesystem of type " 561 "eCryptfs explicitly disallowed due to " 562 "known incompatibilities\n"); 563 goto out_free; 564 } 565 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 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_alloc_root(inode); 576 if (!s->s_root) { 577 iput(inode); 578 rc = -ENOMEM; 579 goto out_free; 580 } 581 582 rc = -ENOMEM; 583 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 584 if (!root_info) 585 goto out_free; 586 587 /* ->kill_sb() will take care of root_info */ 588 ecryptfs_set_dentry_private(s->s_root, root_info); 589 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 590 ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt); 591 592 s->s_flags |= MS_ACTIVE; 593 return dget(s->s_root); 594 595 out_free: 596 path_put(&path); 597 out1: 598 deactivate_locked_super(s); 599 out: 600 if (sbi) { 601 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 602 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 603 } 604 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 605 return ERR_PTR(rc); 606 } 607 608 /** 609 * ecryptfs_kill_block_super 610 * @sb: The ecryptfs super block 611 * 612 * Used to bring the superblock down and free the private data. 613 */ 614 static void ecryptfs_kill_block_super(struct super_block *sb) 615 { 616 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 617 kill_anon_super(sb); 618 if (!sb_info) 619 return; 620 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 621 bdi_destroy(&sb_info->bdi); 622 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 623 } 624 625 static struct file_system_type ecryptfs_fs_type = { 626 .owner = THIS_MODULE, 627 .name = "ecryptfs", 628 .mount = ecryptfs_mount, 629 .kill_sb = ecryptfs_kill_block_super, 630 .fs_flags = 0 631 }; 632 633 /** 634 * inode_info_init_once 635 * 636 * Initializes the ecryptfs_inode_info_cache when it is created 637 */ 638 static void 639 inode_info_init_once(void *vptr) 640 { 641 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 642 643 inode_init_once(&ei->vfs_inode); 644 } 645 646 static struct ecryptfs_cache_info { 647 struct kmem_cache **cache; 648 const char *name; 649 size_t size; 650 void (*ctor)(void *obj); 651 } ecryptfs_cache_infos[] = { 652 { 653 .cache = &ecryptfs_auth_tok_list_item_cache, 654 .name = "ecryptfs_auth_tok_list_item", 655 .size = sizeof(struct ecryptfs_auth_tok_list_item), 656 }, 657 { 658 .cache = &ecryptfs_file_info_cache, 659 .name = "ecryptfs_file_cache", 660 .size = sizeof(struct ecryptfs_file_info), 661 }, 662 { 663 .cache = &ecryptfs_dentry_info_cache, 664 .name = "ecryptfs_dentry_info_cache", 665 .size = sizeof(struct ecryptfs_dentry_info), 666 }, 667 { 668 .cache = &ecryptfs_inode_info_cache, 669 .name = "ecryptfs_inode_cache", 670 .size = sizeof(struct ecryptfs_inode_info), 671 .ctor = inode_info_init_once, 672 }, 673 { 674 .cache = &ecryptfs_sb_info_cache, 675 .name = "ecryptfs_sb_cache", 676 .size = sizeof(struct ecryptfs_sb_info), 677 }, 678 { 679 .cache = &ecryptfs_header_cache_1, 680 .name = "ecryptfs_headers_1", 681 .size = PAGE_CACHE_SIZE, 682 }, 683 { 684 .cache = &ecryptfs_header_cache_2, 685 .name = "ecryptfs_headers_2", 686 .size = PAGE_CACHE_SIZE, 687 }, 688 { 689 .cache = &ecryptfs_xattr_cache, 690 .name = "ecryptfs_xattr_cache", 691 .size = PAGE_CACHE_SIZE, 692 }, 693 { 694 .cache = &ecryptfs_key_record_cache, 695 .name = "ecryptfs_key_record_cache", 696 .size = sizeof(struct ecryptfs_key_record), 697 }, 698 { 699 .cache = &ecryptfs_key_sig_cache, 700 .name = "ecryptfs_key_sig_cache", 701 .size = sizeof(struct ecryptfs_key_sig), 702 }, 703 { 704 .cache = &ecryptfs_global_auth_tok_cache, 705 .name = "ecryptfs_global_auth_tok_cache", 706 .size = sizeof(struct ecryptfs_global_auth_tok), 707 }, 708 { 709 .cache = &ecryptfs_key_tfm_cache, 710 .name = "ecryptfs_key_tfm_cache", 711 .size = sizeof(struct ecryptfs_key_tfm), 712 }, 713 { 714 .cache = &ecryptfs_open_req_cache, 715 .name = "ecryptfs_open_req_cache", 716 .size = sizeof(struct ecryptfs_open_req), 717 }, 718 }; 719 720 static void ecryptfs_free_kmem_caches(void) 721 { 722 int i; 723 724 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 725 struct ecryptfs_cache_info *info; 726 727 info = &ecryptfs_cache_infos[i]; 728 if (*(info->cache)) 729 kmem_cache_destroy(*(info->cache)); 730 } 731 } 732 733 /** 734 * ecryptfs_init_kmem_caches 735 * 736 * Returns zero on success; non-zero otherwise 737 */ 738 static int ecryptfs_init_kmem_caches(void) 739 { 740 int i; 741 742 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 743 struct ecryptfs_cache_info *info; 744 745 info = &ecryptfs_cache_infos[i]; 746 *(info->cache) = kmem_cache_create(info->name, info->size, 747 0, SLAB_HWCACHE_ALIGN, info->ctor); 748 if (!*(info->cache)) { 749 ecryptfs_free_kmem_caches(); 750 ecryptfs_printk(KERN_WARNING, "%s: " 751 "kmem_cache_create failed\n", 752 info->name); 753 return -ENOMEM; 754 } 755 } 756 return 0; 757 } 758 759 static struct kobject *ecryptfs_kobj; 760 761 static ssize_t version_show(struct kobject *kobj, 762 struct kobj_attribute *attr, char *buff) 763 { 764 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 765 } 766 767 static struct kobj_attribute version_attr = __ATTR_RO(version); 768 769 static struct attribute *attributes[] = { 770 &version_attr.attr, 771 NULL, 772 }; 773 774 static struct attribute_group attr_group = { 775 .attrs = attributes, 776 }; 777 778 static int do_sysfs_registration(void) 779 { 780 int rc; 781 782 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 783 if (!ecryptfs_kobj) { 784 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 785 rc = -ENOMEM; 786 goto out; 787 } 788 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 789 if (rc) { 790 printk(KERN_ERR 791 "Unable to create ecryptfs version attributes\n"); 792 kobject_put(ecryptfs_kobj); 793 } 794 out: 795 return rc; 796 } 797 798 static void do_sysfs_unregistration(void) 799 { 800 sysfs_remove_group(ecryptfs_kobj, &attr_group); 801 kobject_put(ecryptfs_kobj); 802 } 803 804 static int __init ecryptfs_init(void) 805 { 806 int rc; 807 808 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 809 rc = -EINVAL; 810 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 811 "larger than the host's page size, and so " 812 "eCryptfs cannot run on this system. The " 813 "default eCryptfs extent size is [%u] bytes; " 814 "the page size is [%lu] bytes.\n", 815 ECRYPTFS_DEFAULT_EXTENT_SIZE, 816 (unsigned long)PAGE_CACHE_SIZE); 817 goto out; 818 } 819 rc = ecryptfs_init_kmem_caches(); 820 if (rc) { 821 printk(KERN_ERR 822 "Failed to allocate one or more kmem_cache objects\n"); 823 goto out; 824 } 825 rc = register_filesystem(&ecryptfs_fs_type); 826 if (rc) { 827 printk(KERN_ERR "Failed to register filesystem\n"); 828 goto out_free_kmem_caches; 829 } 830 rc = do_sysfs_registration(); 831 if (rc) { 832 printk(KERN_ERR "sysfs registration failed\n"); 833 goto out_unregister_filesystem; 834 } 835 rc = ecryptfs_init_kthread(); 836 if (rc) { 837 printk(KERN_ERR "%s: kthread initialization failed; " 838 "rc = [%d]\n", __func__, rc); 839 goto out_do_sysfs_unregistration; 840 } 841 rc = ecryptfs_init_messaging(); 842 if (rc) { 843 printk(KERN_ERR "Failure occured while attempting to " 844 "initialize the communications channel to " 845 "ecryptfsd\n"); 846 goto out_destroy_kthread; 847 } 848 rc = ecryptfs_init_crypto(); 849 if (rc) { 850 printk(KERN_ERR "Failure whilst attempting to init crypto; " 851 "rc = [%d]\n", rc); 852 goto out_release_messaging; 853 } 854 if (ecryptfs_verbosity > 0) 855 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 856 "will be written to the syslog!\n", ecryptfs_verbosity); 857 858 goto out; 859 out_release_messaging: 860 ecryptfs_release_messaging(); 861 out_destroy_kthread: 862 ecryptfs_destroy_kthread(); 863 out_do_sysfs_unregistration: 864 do_sysfs_unregistration(); 865 out_unregister_filesystem: 866 unregister_filesystem(&ecryptfs_fs_type); 867 out_free_kmem_caches: 868 ecryptfs_free_kmem_caches(); 869 out: 870 return rc; 871 } 872 873 static void __exit ecryptfs_exit(void) 874 { 875 int rc; 876 877 rc = ecryptfs_destroy_crypto(); 878 if (rc) 879 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 880 "rc = [%d]\n", rc); 881 ecryptfs_release_messaging(); 882 ecryptfs_destroy_kthread(); 883 do_sysfs_unregistration(); 884 unregister_filesystem(&ecryptfs_fs_type); 885 ecryptfs_free_kmem_caches(); 886 } 887 888 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 889 MODULE_DESCRIPTION("eCryptfs"); 890 891 MODULE_LICENSE("GPL"); 892 893 module_init(ecryptfs_init) 894 module_exit(ecryptfs_exit) 895