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) 139 { 140 struct ecryptfs_inode_info *inode_info = 141 ecryptfs_inode_to_private(dentry->d_inode); 142 int count, rc = 0; 143 144 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 static struct inode *ecryptfs_get_inode(struct inode *lower_inode, 172 struct super_block *sb) 173 { 174 struct inode *inode; 175 int rc = 0; 176 177 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { 178 rc = -EXDEV; 179 goto out; 180 } 181 if (!igrab(lower_inode)) { 182 rc = -ESTALE; 183 goto out; 184 } 185 inode = iget5_locked(sb, (unsigned long)lower_inode, 186 ecryptfs_inode_test, ecryptfs_inode_set, 187 lower_inode); 188 if (!inode) { 189 rc = -EACCES; 190 iput(lower_inode); 191 goto out; 192 } 193 if (inode->i_state & I_NEW) 194 unlock_new_inode(inode); 195 else 196 iput(lower_inode); 197 if (S_ISLNK(lower_inode->i_mode)) 198 inode->i_op = &ecryptfs_symlink_iops; 199 else if (S_ISDIR(lower_inode->i_mode)) 200 inode->i_op = &ecryptfs_dir_iops; 201 if (S_ISDIR(lower_inode->i_mode)) 202 inode->i_fop = &ecryptfs_dir_fops; 203 if (special_file(lower_inode->i_mode)) 204 init_special_inode(inode, lower_inode->i_mode, 205 lower_inode->i_rdev); 206 fsstack_copy_attr_all(inode, lower_inode); 207 /* This size will be overwritten for real files w/ headers and 208 * other metadata */ 209 fsstack_copy_inode_size(inode, lower_inode); 210 return inode; 211 out: 212 return ERR_PTR(rc); 213 } 214 215 /** 216 * ecryptfs_interpose 217 * @lower_dentry: Existing dentry in the lower filesystem 218 * @dentry: ecryptfs' dentry 219 * @sb: ecryptfs's super_block 220 * @flags: flags to govern behavior of interpose procedure 221 * 222 * Interposes upper and lower dentries. 223 * 224 * Returns zero on success; non-zero otherwise 225 */ 226 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, 227 struct super_block *sb, u32 flags) 228 { 229 struct inode *lower_inode = lower_dentry->d_inode; 230 struct inode *inode = ecryptfs_get_inode(lower_inode, sb); 231 if (IS_ERR(inode)) 232 return PTR_ERR(inode); 233 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) 234 d_add(dentry, inode); 235 else 236 d_instantiate(dentry, inode); 237 return 0; 238 } 239 240 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 241 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 242 ecryptfs_opt_ecryptfs_key_bytes, 243 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 244 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 245 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 246 ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, 247 ecryptfs_opt_err }; 248 249 static const match_table_t tokens = { 250 {ecryptfs_opt_sig, "sig=%s"}, 251 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 252 {ecryptfs_opt_cipher, "cipher=%s"}, 253 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 254 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 255 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 256 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 257 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 258 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 259 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 260 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 261 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 262 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 263 {ecryptfs_opt_err, NULL} 264 }; 265 266 static int ecryptfs_init_global_auth_toks( 267 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 268 { 269 struct ecryptfs_global_auth_tok *global_auth_tok; 270 struct ecryptfs_auth_tok *auth_tok; 271 int rc = 0; 272 273 list_for_each_entry(global_auth_tok, 274 &mount_crypt_stat->global_auth_tok_list, 275 mount_crypt_stat_list) { 276 rc = ecryptfs_keyring_auth_tok_for_sig( 277 &global_auth_tok->global_auth_tok_key, &auth_tok, 278 global_auth_tok->sig); 279 if (rc) { 280 printk(KERN_ERR "Could not find valid key in user " 281 "session keyring for sig specified in mount " 282 "option: [%s]\n", global_auth_tok->sig); 283 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 284 goto out; 285 } else { 286 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 287 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 288 } 289 } 290 out: 291 return rc; 292 } 293 294 static void ecryptfs_init_mount_crypt_stat( 295 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 296 { 297 memset((void *)mount_crypt_stat, 0, 298 sizeof(struct ecryptfs_mount_crypt_stat)); 299 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 300 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 301 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 302 } 303 304 /** 305 * ecryptfs_parse_options 306 * @sb: The ecryptfs super block 307 * @options: The options passed to the kernel 308 * 309 * Parse mount options: 310 * debug=N - ecryptfs_verbosity level for debug output 311 * sig=XXX - description(signature) of the key to use 312 * 313 * Returns the dentry object of the lower-level (lower/interposed) 314 * directory; We want to mount our stackable file system on top of 315 * that lower directory. 316 * 317 * The signature of the key to use must be the description of a key 318 * already in the keyring. Mounting will fail if the key can not be 319 * found. 320 * 321 * Returns zero on success; non-zero on error 322 */ 323 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) 324 { 325 char *p; 326 int rc = 0; 327 int sig_set = 0; 328 int cipher_name_set = 0; 329 int fn_cipher_name_set = 0; 330 int cipher_key_bytes; 331 int cipher_key_bytes_set = 0; 332 int fn_cipher_key_bytes; 333 int fn_cipher_key_bytes_set = 0; 334 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 335 &sbi->mount_crypt_stat; 336 substring_t args[MAX_OPT_ARGS]; 337 int token; 338 char *sig_src; 339 char *cipher_name_dst; 340 char *cipher_name_src; 341 char *fn_cipher_name_dst; 342 char *fn_cipher_name_src; 343 char *fnek_dst; 344 char *fnek_src; 345 char *cipher_key_bytes_src; 346 char *fn_cipher_key_bytes_src; 347 348 if (!options) { 349 rc = -EINVAL; 350 goto out; 351 } 352 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 353 while ((p = strsep(&options, ",")) != NULL) { 354 if (!*p) 355 continue; 356 token = match_token(p, tokens, args); 357 switch (token) { 358 case ecryptfs_opt_sig: 359 case ecryptfs_opt_ecryptfs_sig: 360 sig_src = args[0].from; 361 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 362 sig_src, 0); 363 if (rc) { 364 printk(KERN_ERR "Error attempting to register " 365 "global sig; rc = [%d]\n", rc); 366 goto out; 367 } 368 sig_set = 1; 369 break; 370 case ecryptfs_opt_cipher: 371 case ecryptfs_opt_ecryptfs_cipher: 372 cipher_name_src = args[0].from; 373 cipher_name_dst = 374 mount_crypt_stat-> 375 global_default_cipher_name; 376 strncpy(cipher_name_dst, cipher_name_src, 377 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 378 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 379 cipher_name_set = 1; 380 break; 381 case ecryptfs_opt_ecryptfs_key_bytes: 382 cipher_key_bytes_src = args[0].from; 383 cipher_key_bytes = 384 (int)simple_strtol(cipher_key_bytes_src, 385 &cipher_key_bytes_src, 0); 386 mount_crypt_stat->global_default_cipher_key_size = 387 cipher_key_bytes; 388 cipher_key_bytes_set = 1; 389 break; 390 case ecryptfs_opt_passthrough: 391 mount_crypt_stat->flags |= 392 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 393 break; 394 case ecryptfs_opt_xattr_metadata: 395 mount_crypt_stat->flags |= 396 ECRYPTFS_XATTR_METADATA_ENABLED; 397 break; 398 case ecryptfs_opt_encrypted_view: 399 mount_crypt_stat->flags |= 400 ECRYPTFS_XATTR_METADATA_ENABLED; 401 mount_crypt_stat->flags |= 402 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 403 break; 404 case ecryptfs_opt_fnek_sig: 405 fnek_src = args[0].from; 406 fnek_dst = 407 mount_crypt_stat->global_default_fnek_sig; 408 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 409 mount_crypt_stat->global_default_fnek_sig[ 410 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 411 rc = ecryptfs_add_global_auth_tok( 412 mount_crypt_stat, 413 mount_crypt_stat->global_default_fnek_sig, 414 ECRYPTFS_AUTH_TOK_FNEK); 415 if (rc) { 416 printk(KERN_ERR "Error attempting to register " 417 "global fnek sig [%s]; rc = [%d]\n", 418 mount_crypt_stat->global_default_fnek_sig, 419 rc); 420 goto out; 421 } 422 mount_crypt_stat->flags |= 423 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 424 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 425 break; 426 case ecryptfs_opt_fn_cipher: 427 fn_cipher_name_src = args[0].from; 428 fn_cipher_name_dst = 429 mount_crypt_stat->global_default_fn_cipher_name; 430 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 431 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 432 mount_crypt_stat->global_default_fn_cipher_name[ 433 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 434 fn_cipher_name_set = 1; 435 break; 436 case ecryptfs_opt_fn_cipher_key_bytes: 437 fn_cipher_key_bytes_src = args[0].from; 438 fn_cipher_key_bytes = 439 (int)simple_strtol(fn_cipher_key_bytes_src, 440 &fn_cipher_key_bytes_src, 0); 441 mount_crypt_stat->global_default_fn_cipher_key_bytes = 442 fn_cipher_key_bytes; 443 fn_cipher_key_bytes_set = 1; 444 break; 445 case ecryptfs_opt_unlink_sigs: 446 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 447 break; 448 case ecryptfs_opt_mount_auth_tok_only: 449 mount_crypt_stat->flags |= 450 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 451 break; 452 case ecryptfs_opt_err: 453 default: 454 printk(KERN_WARNING 455 "%s: eCryptfs: unrecognized option [%s]\n", 456 __func__, p); 457 } 458 } 459 if (!sig_set) { 460 rc = -EINVAL; 461 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 462 "auth tok signature as a mount " 463 "parameter; see the eCryptfs README\n"); 464 goto out; 465 } 466 if (!cipher_name_set) { 467 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 468 469 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 470 strcpy(mount_crypt_stat->global_default_cipher_name, 471 ECRYPTFS_DEFAULT_CIPHER); 472 } 473 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 474 && !fn_cipher_name_set) 475 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 476 mount_crypt_stat->global_default_cipher_name); 477 if (!cipher_key_bytes_set) 478 mount_crypt_stat->global_default_cipher_key_size = 0; 479 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 480 && !fn_cipher_key_bytes_set) 481 mount_crypt_stat->global_default_fn_cipher_key_bytes = 482 mount_crypt_stat->global_default_cipher_key_size; 483 mutex_lock(&key_tfm_list_mutex); 484 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 485 NULL)) { 486 rc = ecryptfs_add_new_key_tfm( 487 NULL, mount_crypt_stat->global_default_cipher_name, 488 mount_crypt_stat->global_default_cipher_key_size); 489 if (rc) { 490 printk(KERN_ERR "Error attempting to initialize " 491 "cipher with name = [%s] and key size = [%td]; " 492 "rc = [%d]\n", 493 mount_crypt_stat->global_default_cipher_name, 494 mount_crypt_stat->global_default_cipher_key_size, 495 rc); 496 rc = -EINVAL; 497 mutex_unlock(&key_tfm_list_mutex); 498 goto out; 499 } 500 } 501 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 502 && !ecryptfs_tfm_exists( 503 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 504 rc = ecryptfs_add_new_key_tfm( 505 NULL, mount_crypt_stat->global_default_fn_cipher_name, 506 mount_crypt_stat->global_default_fn_cipher_key_bytes); 507 if (rc) { 508 printk(KERN_ERR "Error attempting to initialize " 509 "cipher with name = [%s] and key size = [%td]; " 510 "rc = [%d]\n", 511 mount_crypt_stat->global_default_fn_cipher_name, 512 mount_crypt_stat->global_default_fn_cipher_key_bytes, 513 rc); 514 rc = -EINVAL; 515 mutex_unlock(&key_tfm_list_mutex); 516 goto out; 517 } 518 } 519 mutex_unlock(&key_tfm_list_mutex); 520 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 521 if (rc) 522 printk(KERN_WARNING "One or more global auth toks could not " 523 "properly register; rc = [%d]\n", rc); 524 out: 525 return rc; 526 } 527 528 struct kmem_cache *ecryptfs_sb_info_cache; 529 static struct file_system_type ecryptfs_fs_type; 530 531 /** 532 * ecryptfs_get_sb 533 * @fs_type 534 * @flags 535 * @dev_name: The path to mount over 536 * @raw_data: The options passed into the kernel 537 */ 538 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 539 const char *dev_name, void *raw_data) 540 { 541 struct super_block *s; 542 struct ecryptfs_sb_info *sbi; 543 struct ecryptfs_dentry_info *root_info; 544 const char *err = "Getting sb failed"; 545 struct inode *inode; 546 struct path path; 547 int rc; 548 549 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 550 if (!sbi) { 551 rc = -ENOMEM; 552 goto out; 553 } 554 555 rc = ecryptfs_parse_options(sbi, raw_data); 556 if (rc) { 557 err = "Error parsing options"; 558 goto out; 559 } 560 561 s = sget(fs_type, NULL, set_anon_super, NULL); 562 if (IS_ERR(s)) { 563 rc = PTR_ERR(s); 564 goto out; 565 } 566 567 s->s_flags = flags; 568 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 569 if (rc) 570 goto out1; 571 572 ecryptfs_set_superblock_private(s, sbi); 573 s->s_bdi = &sbi->bdi; 574 575 /* ->kill_sb() will take care of sbi after that point */ 576 sbi = NULL; 577 s->s_op = &ecryptfs_sops; 578 s->s_d_op = &ecryptfs_dops; 579 580 err = "Reading sb failed"; 581 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 582 if (rc) { 583 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 584 goto out1; 585 } 586 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 587 rc = -EINVAL; 588 printk(KERN_ERR "Mount on filesystem of type " 589 "eCryptfs explicitly disallowed due to " 590 "known incompatibilities\n"); 591 goto out_free; 592 } 593 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 594 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 595 s->s_blocksize = path.dentry->d_sb->s_blocksize; 596 s->s_magic = ECRYPTFS_SUPER_MAGIC; 597 598 inode = ecryptfs_get_inode(path.dentry->d_inode, s); 599 rc = PTR_ERR(inode); 600 if (IS_ERR(inode)) 601 goto out_free; 602 603 s->s_root = d_alloc_root(inode); 604 if (!s->s_root) { 605 iput(inode); 606 rc = -ENOMEM; 607 goto out_free; 608 } 609 610 rc = -ENOMEM; 611 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 612 if (!root_info) 613 goto out_free; 614 615 /* ->kill_sb() will take care of root_info */ 616 ecryptfs_set_dentry_private(s->s_root, root_info); 617 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 618 ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt); 619 620 s->s_flags |= MS_ACTIVE; 621 return dget(s->s_root); 622 623 out_free: 624 path_put(&path); 625 out1: 626 deactivate_locked_super(s); 627 out: 628 if (sbi) { 629 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 630 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 631 } 632 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 633 return ERR_PTR(rc); 634 } 635 636 /** 637 * ecryptfs_kill_block_super 638 * @sb: The ecryptfs super block 639 * 640 * Used to bring the superblock down and free the private data. 641 */ 642 static void ecryptfs_kill_block_super(struct super_block *sb) 643 { 644 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 645 kill_anon_super(sb); 646 if (!sb_info) 647 return; 648 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 649 bdi_destroy(&sb_info->bdi); 650 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 651 } 652 653 static struct file_system_type ecryptfs_fs_type = { 654 .owner = THIS_MODULE, 655 .name = "ecryptfs", 656 .mount = ecryptfs_mount, 657 .kill_sb = ecryptfs_kill_block_super, 658 .fs_flags = 0 659 }; 660 661 /** 662 * inode_info_init_once 663 * 664 * Initializes the ecryptfs_inode_info_cache when it is created 665 */ 666 static void 667 inode_info_init_once(void *vptr) 668 { 669 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 670 671 inode_init_once(&ei->vfs_inode); 672 } 673 674 static struct ecryptfs_cache_info { 675 struct kmem_cache **cache; 676 const char *name; 677 size_t size; 678 void (*ctor)(void *obj); 679 } ecryptfs_cache_infos[] = { 680 { 681 .cache = &ecryptfs_auth_tok_list_item_cache, 682 .name = "ecryptfs_auth_tok_list_item", 683 .size = sizeof(struct ecryptfs_auth_tok_list_item), 684 }, 685 { 686 .cache = &ecryptfs_file_info_cache, 687 .name = "ecryptfs_file_cache", 688 .size = sizeof(struct ecryptfs_file_info), 689 }, 690 { 691 .cache = &ecryptfs_dentry_info_cache, 692 .name = "ecryptfs_dentry_info_cache", 693 .size = sizeof(struct ecryptfs_dentry_info), 694 }, 695 { 696 .cache = &ecryptfs_inode_info_cache, 697 .name = "ecryptfs_inode_cache", 698 .size = sizeof(struct ecryptfs_inode_info), 699 .ctor = inode_info_init_once, 700 }, 701 { 702 .cache = &ecryptfs_sb_info_cache, 703 .name = "ecryptfs_sb_cache", 704 .size = sizeof(struct ecryptfs_sb_info), 705 }, 706 { 707 .cache = &ecryptfs_header_cache_1, 708 .name = "ecryptfs_headers_1", 709 .size = PAGE_CACHE_SIZE, 710 }, 711 { 712 .cache = &ecryptfs_header_cache_2, 713 .name = "ecryptfs_headers_2", 714 .size = PAGE_CACHE_SIZE, 715 }, 716 { 717 .cache = &ecryptfs_xattr_cache, 718 .name = "ecryptfs_xattr_cache", 719 .size = PAGE_CACHE_SIZE, 720 }, 721 { 722 .cache = &ecryptfs_key_record_cache, 723 .name = "ecryptfs_key_record_cache", 724 .size = sizeof(struct ecryptfs_key_record), 725 }, 726 { 727 .cache = &ecryptfs_key_sig_cache, 728 .name = "ecryptfs_key_sig_cache", 729 .size = sizeof(struct ecryptfs_key_sig), 730 }, 731 { 732 .cache = &ecryptfs_global_auth_tok_cache, 733 .name = "ecryptfs_global_auth_tok_cache", 734 .size = sizeof(struct ecryptfs_global_auth_tok), 735 }, 736 { 737 .cache = &ecryptfs_key_tfm_cache, 738 .name = "ecryptfs_key_tfm_cache", 739 .size = sizeof(struct ecryptfs_key_tfm), 740 }, 741 { 742 .cache = &ecryptfs_open_req_cache, 743 .name = "ecryptfs_open_req_cache", 744 .size = sizeof(struct ecryptfs_open_req), 745 }, 746 }; 747 748 static void ecryptfs_free_kmem_caches(void) 749 { 750 int i; 751 752 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 753 struct ecryptfs_cache_info *info; 754 755 info = &ecryptfs_cache_infos[i]; 756 if (*(info->cache)) 757 kmem_cache_destroy(*(info->cache)); 758 } 759 } 760 761 /** 762 * ecryptfs_init_kmem_caches 763 * 764 * Returns zero on success; non-zero otherwise 765 */ 766 static int ecryptfs_init_kmem_caches(void) 767 { 768 int i; 769 770 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 771 struct ecryptfs_cache_info *info; 772 773 info = &ecryptfs_cache_infos[i]; 774 *(info->cache) = kmem_cache_create(info->name, info->size, 775 0, SLAB_HWCACHE_ALIGN, info->ctor); 776 if (!*(info->cache)) { 777 ecryptfs_free_kmem_caches(); 778 ecryptfs_printk(KERN_WARNING, "%s: " 779 "kmem_cache_create failed\n", 780 info->name); 781 return -ENOMEM; 782 } 783 } 784 return 0; 785 } 786 787 static struct kobject *ecryptfs_kobj; 788 789 static ssize_t version_show(struct kobject *kobj, 790 struct kobj_attribute *attr, char *buff) 791 { 792 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 793 } 794 795 static struct kobj_attribute version_attr = __ATTR_RO(version); 796 797 static struct attribute *attributes[] = { 798 &version_attr.attr, 799 NULL, 800 }; 801 802 static struct attribute_group attr_group = { 803 .attrs = attributes, 804 }; 805 806 static int do_sysfs_registration(void) 807 { 808 int rc; 809 810 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 811 if (!ecryptfs_kobj) { 812 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 813 rc = -ENOMEM; 814 goto out; 815 } 816 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 817 if (rc) { 818 printk(KERN_ERR 819 "Unable to create ecryptfs version attributes\n"); 820 kobject_put(ecryptfs_kobj); 821 } 822 out: 823 return rc; 824 } 825 826 static void do_sysfs_unregistration(void) 827 { 828 sysfs_remove_group(ecryptfs_kobj, &attr_group); 829 kobject_put(ecryptfs_kobj); 830 } 831 832 static int __init ecryptfs_init(void) 833 { 834 int rc; 835 836 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 837 rc = -EINVAL; 838 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 839 "larger than the host's page size, and so " 840 "eCryptfs cannot run on this system. The " 841 "default eCryptfs extent size is [%u] bytes; " 842 "the page size is [%lu] bytes.\n", 843 ECRYPTFS_DEFAULT_EXTENT_SIZE, 844 (unsigned long)PAGE_CACHE_SIZE); 845 goto out; 846 } 847 rc = ecryptfs_init_kmem_caches(); 848 if (rc) { 849 printk(KERN_ERR 850 "Failed to allocate one or more kmem_cache objects\n"); 851 goto out; 852 } 853 rc = register_filesystem(&ecryptfs_fs_type); 854 if (rc) { 855 printk(KERN_ERR "Failed to register filesystem\n"); 856 goto out_free_kmem_caches; 857 } 858 rc = do_sysfs_registration(); 859 if (rc) { 860 printk(KERN_ERR "sysfs registration failed\n"); 861 goto out_unregister_filesystem; 862 } 863 rc = ecryptfs_init_kthread(); 864 if (rc) { 865 printk(KERN_ERR "%s: kthread initialization failed; " 866 "rc = [%d]\n", __func__, rc); 867 goto out_do_sysfs_unregistration; 868 } 869 rc = ecryptfs_init_messaging(); 870 if (rc) { 871 printk(KERN_ERR "Failure occurred while attempting to " 872 "initialize the communications channel to " 873 "ecryptfsd\n"); 874 goto out_destroy_kthread; 875 } 876 rc = ecryptfs_init_crypto(); 877 if (rc) { 878 printk(KERN_ERR "Failure whilst attempting to init crypto; " 879 "rc = [%d]\n", rc); 880 goto out_release_messaging; 881 } 882 if (ecryptfs_verbosity > 0) 883 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 884 "will be written to the syslog!\n", ecryptfs_verbosity); 885 886 goto out; 887 out_release_messaging: 888 ecryptfs_release_messaging(); 889 out_destroy_kthread: 890 ecryptfs_destroy_kthread(); 891 out_do_sysfs_unregistration: 892 do_sysfs_unregistration(); 893 out_unregister_filesystem: 894 unregister_filesystem(&ecryptfs_fs_type); 895 out_free_kmem_caches: 896 ecryptfs_free_kmem_caches(); 897 out: 898 return rc; 899 } 900 901 static void __exit ecryptfs_exit(void) 902 { 903 int rc; 904 905 rc = ecryptfs_destroy_crypto(); 906 if (rc) 907 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 908 "rc = [%d]\n", rc); 909 ecryptfs_release_messaging(); 910 ecryptfs_destroy_kthread(); 911 do_sysfs_unregistration(); 912 unregister_filesystem(&ecryptfs_fs_type); 913 ecryptfs_free_kmem_caches(); 914 } 915 916 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 917 MODULE_DESCRIPTION("eCryptfs"); 918 919 MODULE_LICENSE("GPL"); 920 921 module_init(ecryptfs_init) 922 module_exit(ecryptfs_exit) 923