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 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 return rc; 141 } 142 143 static struct inode *ecryptfs_get_inode(struct inode *lower_inode, 144 struct super_block *sb) 145 { 146 struct inode *inode; 147 int rc = 0; 148 149 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { 150 rc = -EXDEV; 151 goto out; 152 } 153 if (!igrab(lower_inode)) { 154 rc = -ESTALE; 155 goto out; 156 } 157 inode = iget5_locked(sb, (unsigned long)lower_inode, 158 ecryptfs_inode_test, ecryptfs_inode_set, 159 lower_inode); 160 if (!inode) { 161 rc = -EACCES; 162 iput(lower_inode); 163 goto out; 164 } 165 if (inode->i_state & I_NEW) 166 unlock_new_inode(inode); 167 else 168 iput(lower_inode); 169 if (S_ISLNK(lower_inode->i_mode)) 170 inode->i_op = &ecryptfs_symlink_iops; 171 else if (S_ISDIR(lower_inode->i_mode)) 172 inode->i_op = &ecryptfs_dir_iops; 173 if (S_ISDIR(lower_inode->i_mode)) 174 inode->i_fop = &ecryptfs_dir_fops; 175 if (special_file(lower_inode->i_mode)) 176 init_special_inode(inode, lower_inode->i_mode, 177 lower_inode->i_rdev); 178 fsstack_copy_attr_all(inode, lower_inode); 179 /* This size will be overwritten for real files w/ headers and 180 * other metadata */ 181 fsstack_copy_inode_size(inode, lower_inode); 182 return inode; 183 out: 184 return ERR_PTR(rc); 185 } 186 187 /** 188 * ecryptfs_interpose 189 * @lower_dentry: Existing dentry in the lower filesystem 190 * @dentry: ecryptfs' dentry 191 * @sb: ecryptfs's super_block 192 * @flags: flags to govern behavior of interpose procedure 193 * 194 * Interposes upper and lower dentries. 195 * 196 * Returns zero on success; non-zero otherwise 197 */ 198 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, 199 struct super_block *sb, u32 flags) 200 { 201 struct inode *lower_inode = lower_dentry->d_inode; 202 struct inode *inode = ecryptfs_get_inode(lower_inode, sb); 203 if (IS_ERR(inode)) 204 return PTR_ERR(inode); 205 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) 206 d_add(dentry, inode); 207 else 208 d_instantiate(dentry, inode); 209 return 0; 210 } 211 212 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 213 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 214 ecryptfs_opt_ecryptfs_key_bytes, 215 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 216 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 217 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 218 ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, 219 ecryptfs_opt_err }; 220 221 static const match_table_t tokens = { 222 {ecryptfs_opt_sig, "sig=%s"}, 223 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 224 {ecryptfs_opt_cipher, "cipher=%s"}, 225 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 226 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 227 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 228 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 229 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 230 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 231 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 232 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 233 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 234 {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, 235 {ecryptfs_opt_err, NULL} 236 }; 237 238 static int ecryptfs_init_global_auth_toks( 239 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 240 { 241 struct ecryptfs_global_auth_tok *global_auth_tok; 242 int rc = 0; 243 244 list_for_each_entry(global_auth_tok, 245 &mount_crypt_stat->global_auth_tok_list, 246 mount_crypt_stat_list) { 247 rc = ecryptfs_keyring_auth_tok_for_sig( 248 &global_auth_tok->global_auth_tok_key, 249 &global_auth_tok->global_auth_tok, 250 global_auth_tok->sig); 251 if (rc) { 252 printk(KERN_ERR "Could not find valid key in user " 253 "session keyring for sig specified in mount " 254 "option: [%s]\n", global_auth_tok->sig); 255 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 256 goto out; 257 } else 258 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 259 } 260 out: 261 return rc; 262 } 263 264 static void ecryptfs_init_mount_crypt_stat( 265 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 266 { 267 memset((void *)mount_crypt_stat, 0, 268 sizeof(struct ecryptfs_mount_crypt_stat)); 269 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 270 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 271 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 272 } 273 274 /** 275 * ecryptfs_parse_options 276 * @sb: The ecryptfs super block 277 * @options: The options pased to the kernel 278 * 279 * Parse mount options: 280 * debug=N - ecryptfs_verbosity level for debug output 281 * sig=XXX - description(signature) of the key to use 282 * 283 * Returns the dentry object of the lower-level (lower/interposed) 284 * directory; We want to mount our stackable file system on top of 285 * that lower directory. 286 * 287 * The signature of the key to use must be the description of a key 288 * already in the keyring. Mounting will fail if the key can not be 289 * found. 290 * 291 * Returns zero on success; non-zero on error 292 */ 293 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) 294 { 295 char *p; 296 int rc = 0; 297 int sig_set = 0; 298 int cipher_name_set = 0; 299 int fn_cipher_name_set = 0; 300 int cipher_key_bytes; 301 int cipher_key_bytes_set = 0; 302 int fn_cipher_key_bytes; 303 int fn_cipher_key_bytes_set = 0; 304 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 305 &sbi->mount_crypt_stat; 306 substring_t args[MAX_OPT_ARGS]; 307 int token; 308 char *sig_src; 309 char *cipher_name_dst; 310 char *cipher_name_src; 311 char *fn_cipher_name_dst; 312 char *fn_cipher_name_src; 313 char *fnek_dst; 314 char *fnek_src; 315 char *cipher_key_bytes_src; 316 char *fn_cipher_key_bytes_src; 317 318 if (!options) { 319 rc = -EINVAL; 320 goto out; 321 } 322 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 323 while ((p = strsep(&options, ",")) != NULL) { 324 if (!*p) 325 continue; 326 token = match_token(p, tokens, args); 327 switch (token) { 328 case ecryptfs_opt_sig: 329 case ecryptfs_opt_ecryptfs_sig: 330 sig_src = args[0].from; 331 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 332 sig_src, 0); 333 if (rc) { 334 printk(KERN_ERR "Error attempting to register " 335 "global sig; rc = [%d]\n", rc); 336 goto out; 337 } 338 sig_set = 1; 339 break; 340 case ecryptfs_opt_cipher: 341 case ecryptfs_opt_ecryptfs_cipher: 342 cipher_name_src = args[0].from; 343 cipher_name_dst = 344 mount_crypt_stat-> 345 global_default_cipher_name; 346 strncpy(cipher_name_dst, cipher_name_src, 347 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 348 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 349 cipher_name_set = 1; 350 break; 351 case ecryptfs_opt_ecryptfs_key_bytes: 352 cipher_key_bytes_src = args[0].from; 353 cipher_key_bytes = 354 (int)simple_strtol(cipher_key_bytes_src, 355 &cipher_key_bytes_src, 0); 356 mount_crypt_stat->global_default_cipher_key_size = 357 cipher_key_bytes; 358 cipher_key_bytes_set = 1; 359 break; 360 case ecryptfs_opt_passthrough: 361 mount_crypt_stat->flags |= 362 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 363 break; 364 case ecryptfs_opt_xattr_metadata: 365 mount_crypt_stat->flags |= 366 ECRYPTFS_XATTR_METADATA_ENABLED; 367 break; 368 case ecryptfs_opt_encrypted_view: 369 mount_crypt_stat->flags |= 370 ECRYPTFS_XATTR_METADATA_ENABLED; 371 mount_crypt_stat->flags |= 372 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 373 break; 374 case ecryptfs_opt_fnek_sig: 375 fnek_src = args[0].from; 376 fnek_dst = 377 mount_crypt_stat->global_default_fnek_sig; 378 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 379 mount_crypt_stat->global_default_fnek_sig[ 380 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 381 rc = ecryptfs_add_global_auth_tok( 382 mount_crypt_stat, 383 mount_crypt_stat->global_default_fnek_sig, 384 ECRYPTFS_AUTH_TOK_FNEK); 385 if (rc) { 386 printk(KERN_ERR "Error attempting to register " 387 "global fnek sig [%s]; rc = [%d]\n", 388 mount_crypt_stat->global_default_fnek_sig, 389 rc); 390 goto out; 391 } 392 mount_crypt_stat->flags |= 393 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 394 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 395 break; 396 case ecryptfs_opt_fn_cipher: 397 fn_cipher_name_src = args[0].from; 398 fn_cipher_name_dst = 399 mount_crypt_stat->global_default_fn_cipher_name; 400 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 401 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 402 mount_crypt_stat->global_default_fn_cipher_name[ 403 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 404 fn_cipher_name_set = 1; 405 break; 406 case ecryptfs_opt_fn_cipher_key_bytes: 407 fn_cipher_key_bytes_src = args[0].from; 408 fn_cipher_key_bytes = 409 (int)simple_strtol(fn_cipher_key_bytes_src, 410 &fn_cipher_key_bytes_src, 0); 411 mount_crypt_stat->global_default_fn_cipher_key_bytes = 412 fn_cipher_key_bytes; 413 fn_cipher_key_bytes_set = 1; 414 break; 415 case ecryptfs_opt_unlink_sigs: 416 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 417 break; 418 case ecryptfs_opt_mount_auth_tok_only: 419 mount_crypt_stat->flags |= 420 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 421 break; 422 case ecryptfs_opt_err: 423 default: 424 printk(KERN_WARNING 425 "%s: eCryptfs: unrecognized option [%s]\n", 426 __func__, p); 427 } 428 } 429 if (!sig_set) { 430 rc = -EINVAL; 431 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 432 "auth tok signature as a mount " 433 "parameter; see the eCryptfs README\n"); 434 goto out; 435 } 436 if (!cipher_name_set) { 437 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 438 439 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 440 strcpy(mount_crypt_stat->global_default_cipher_name, 441 ECRYPTFS_DEFAULT_CIPHER); 442 } 443 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 444 && !fn_cipher_name_set) 445 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 446 mount_crypt_stat->global_default_cipher_name); 447 if (!cipher_key_bytes_set) 448 mount_crypt_stat->global_default_cipher_key_size = 0; 449 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 450 && !fn_cipher_key_bytes_set) 451 mount_crypt_stat->global_default_fn_cipher_key_bytes = 452 mount_crypt_stat->global_default_cipher_key_size; 453 mutex_lock(&key_tfm_list_mutex); 454 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 455 NULL)) { 456 rc = ecryptfs_add_new_key_tfm( 457 NULL, mount_crypt_stat->global_default_cipher_name, 458 mount_crypt_stat->global_default_cipher_key_size); 459 if (rc) { 460 printk(KERN_ERR "Error attempting to initialize " 461 "cipher with name = [%s] and key size = [%td]; " 462 "rc = [%d]\n", 463 mount_crypt_stat->global_default_cipher_name, 464 mount_crypt_stat->global_default_cipher_key_size, 465 rc); 466 rc = -EINVAL; 467 mutex_unlock(&key_tfm_list_mutex); 468 goto out; 469 } 470 } 471 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 472 && !ecryptfs_tfm_exists( 473 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 474 rc = ecryptfs_add_new_key_tfm( 475 NULL, mount_crypt_stat->global_default_fn_cipher_name, 476 mount_crypt_stat->global_default_fn_cipher_key_bytes); 477 if (rc) { 478 printk(KERN_ERR "Error attempting to initialize " 479 "cipher with name = [%s] and key size = [%td]; " 480 "rc = [%d]\n", 481 mount_crypt_stat->global_default_fn_cipher_name, 482 mount_crypt_stat->global_default_fn_cipher_key_bytes, 483 rc); 484 rc = -EINVAL; 485 mutex_unlock(&key_tfm_list_mutex); 486 goto out; 487 } 488 } 489 mutex_unlock(&key_tfm_list_mutex); 490 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 491 if (rc) 492 printk(KERN_WARNING "One or more global auth toks could not " 493 "properly register; rc = [%d]\n", rc); 494 out: 495 return rc; 496 } 497 498 struct kmem_cache *ecryptfs_sb_info_cache; 499 static struct file_system_type ecryptfs_fs_type; 500 501 /** 502 * ecryptfs_get_sb 503 * @fs_type 504 * @flags 505 * @dev_name: The path to mount over 506 * @raw_data: The options passed into the kernel 507 */ 508 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, 509 const char *dev_name, void *raw_data) 510 { 511 struct super_block *s; 512 struct ecryptfs_sb_info *sbi; 513 struct ecryptfs_dentry_info *root_info; 514 const char *err = "Getting sb failed"; 515 struct inode *inode; 516 struct path path; 517 int rc; 518 519 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 520 if (!sbi) { 521 rc = -ENOMEM; 522 goto out; 523 } 524 525 rc = ecryptfs_parse_options(sbi, raw_data); 526 if (rc) { 527 err = "Error parsing options"; 528 goto out; 529 } 530 531 s = sget(fs_type, NULL, set_anon_super, NULL); 532 if (IS_ERR(s)) { 533 rc = PTR_ERR(s); 534 goto out; 535 } 536 537 s->s_flags = flags; 538 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 539 if (rc) 540 goto out1; 541 542 ecryptfs_set_superblock_private(s, sbi); 543 s->s_bdi = &sbi->bdi; 544 545 /* ->kill_sb() will take care of sbi after that point */ 546 sbi = NULL; 547 s->s_op = &ecryptfs_sops; 548 s->s_d_op = &ecryptfs_dops; 549 550 err = "Reading sb failed"; 551 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 552 if (rc) { 553 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 554 goto out1; 555 } 556 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 557 rc = -EINVAL; 558 printk(KERN_ERR "Mount on filesystem of type " 559 "eCryptfs explicitly disallowed due to " 560 "known incompatibilities\n"); 561 goto out_free; 562 } 563 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 564 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 565 s->s_blocksize = path.dentry->d_sb->s_blocksize; 566 s->s_magic = ECRYPTFS_SUPER_MAGIC; 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 [%u] bytes; " 812 "the page size is [%lu] bytes.\n", 813 ECRYPTFS_DEFAULT_EXTENT_SIZE, 814 (unsigned long)PAGE_CACHE_SIZE); 815 goto out; 816 } 817 rc = ecryptfs_init_kmem_caches(); 818 if (rc) { 819 printk(KERN_ERR 820 "Failed to allocate one or more kmem_cache objects\n"); 821 goto out; 822 } 823 rc = register_filesystem(&ecryptfs_fs_type); 824 if (rc) { 825 printk(KERN_ERR "Failed to register filesystem\n"); 826 goto out_free_kmem_caches; 827 } 828 rc = do_sysfs_registration(); 829 if (rc) { 830 printk(KERN_ERR "sysfs registration failed\n"); 831 goto out_unregister_filesystem; 832 } 833 rc = ecryptfs_init_kthread(); 834 if (rc) { 835 printk(KERN_ERR "%s: kthread initialization failed; " 836 "rc = [%d]\n", __func__, rc); 837 goto out_do_sysfs_unregistration; 838 } 839 rc = ecryptfs_init_messaging(); 840 if (rc) { 841 printk(KERN_ERR "Failure occured while attempting to " 842 "initialize the communications channel to " 843 "ecryptfsd\n"); 844 goto out_destroy_kthread; 845 } 846 rc = ecryptfs_init_crypto(); 847 if (rc) { 848 printk(KERN_ERR "Failure whilst attempting to init crypto; " 849 "rc = [%d]\n", rc); 850 goto out_release_messaging; 851 } 852 if (ecryptfs_verbosity > 0) 853 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 854 "will be written to the syslog!\n", ecryptfs_verbosity); 855 856 goto out; 857 out_release_messaging: 858 ecryptfs_release_messaging(); 859 out_destroy_kthread: 860 ecryptfs_destroy_kthread(); 861 out_do_sysfs_unregistration: 862 do_sysfs_unregistration(); 863 out_unregister_filesystem: 864 unregister_filesystem(&ecryptfs_fs_type); 865 out_free_kmem_caches: 866 ecryptfs_free_kmem_caches(); 867 out: 868 return rc; 869 } 870 871 static void __exit ecryptfs_exit(void) 872 { 873 int rc; 874 875 rc = ecryptfs_destroy_crypto(); 876 if (rc) 877 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 878 "rc = [%d]\n", rc); 879 ecryptfs_release_messaging(); 880 ecryptfs_destroy_kthread(); 881 do_sysfs_unregistration(); 882 unregister_filesystem(&ecryptfs_fs_type); 883 ecryptfs_free_kmem_caches(); 884 } 885 886 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 887 MODULE_DESCRIPTION("eCryptfs"); 888 889 MODULE_LICENSE("GPL"); 890 891 module_init(ecryptfs_init) 892 module_exit(ecryptfs_exit) 893