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 "ecryptfs_kernel.h" 39 40 /** 41 * Module parameter that defines the ecryptfs_verbosity level. 42 */ 43 int ecryptfs_verbosity = 0; 44 45 module_param(ecryptfs_verbosity, int, 0); 46 MODULE_PARM_DESC(ecryptfs_verbosity, 47 "Initial verbosity level (0 or 1; defaults to " 48 "0, which is Quiet)"); 49 50 /** 51 * Module parameter that defines the number of message buffer elements 52 */ 53 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 54 55 module_param(ecryptfs_message_buf_len, uint, 0); 56 MODULE_PARM_DESC(ecryptfs_message_buf_len, 57 "Number of message buffer elements"); 58 59 /** 60 * Module parameter that defines the maximum guaranteed amount of time to wait 61 * for a response from ecryptfsd. The actual sleep time will be, more than 62 * likely, a small amount greater than this specified value, but only less if 63 * the message successfully arrives. 64 */ 65 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 66 67 module_param(ecryptfs_message_wait_timeout, long, 0); 68 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 69 "Maximum number of seconds that an operation will " 70 "sleep while waiting for a message response from " 71 "userspace"); 72 73 /** 74 * Module parameter that is an estimate of the maximum number of users 75 * that will be concurrently using eCryptfs. Set this to the right 76 * value to balance performance and memory use. 77 */ 78 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 79 80 module_param(ecryptfs_number_of_users, uint, 0); 81 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 82 "concurrent users of eCryptfs"); 83 84 void __ecryptfs_printk(const char *fmt, ...) 85 { 86 va_list args; 87 va_start(args, fmt); 88 if (fmt[1] == '7') { /* KERN_DEBUG */ 89 if (ecryptfs_verbosity >= 1) 90 vprintk(fmt, args); 91 } else 92 vprintk(fmt, args); 93 va_end(args); 94 } 95 96 /** 97 * ecryptfs_init_persistent_file 98 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 99 * the lower dentry and the lower mount set 100 * 101 * eCryptfs only ever keeps a single open file for every lower 102 * inode. All I/O operations to the lower inode occur through that 103 * file. When the first eCryptfs dentry that interposes with the first 104 * lower dentry for that inode is created, this function creates the 105 * persistent file struct and associates it with the eCryptfs 106 * inode. When the eCryptfs inode is destroyed, the file is closed. 107 * 108 * The persistent file will be opened with read/write permissions, if 109 * possible. Otherwise, it is opened read-only. 110 * 111 * This function does nothing if a lower persistent file is already 112 * associated with the eCryptfs inode. 113 * 114 * Returns zero on success; non-zero otherwise 115 */ 116 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) 117 { 118 const struct cred *cred = current_cred(); 119 struct ecryptfs_inode_info *inode_info = 120 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); 121 int rc = 0; 122 123 mutex_lock(&inode_info->lower_file_mutex); 124 if (!inode_info->lower_file) { 125 struct dentry *lower_dentry; 126 struct vfsmount *lower_mnt = 127 ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); 128 129 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 130 rc = ecryptfs_privileged_open(&inode_info->lower_file, 131 lower_dentry, lower_mnt, cred); 132 if (rc || IS_ERR(inode_info->lower_file)) { 133 printk(KERN_ERR "Error opening lower persistent file " 134 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 135 "rc = [%d]\n", lower_dentry, lower_mnt, rc); 136 rc = PTR_ERR(inode_info->lower_file); 137 inode_info->lower_file = NULL; 138 } 139 } 140 mutex_unlock(&inode_info->lower_file_mutex); 141 return rc; 142 } 143 144 /** 145 * ecryptfs_interpose 146 * @lower_dentry: Existing dentry in the lower filesystem 147 * @dentry: ecryptfs' dentry 148 * @sb: ecryptfs's super_block 149 * @flags: flags to govern behavior of interpose procedure 150 * 151 * Interposes upper and lower dentries. 152 * 153 * Returns zero on success; non-zero otherwise 154 */ 155 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, 156 struct super_block *sb, u32 flags) 157 { 158 struct inode *lower_inode; 159 struct inode *inode; 160 int rc = 0; 161 162 lower_inode = lower_dentry->d_inode; 163 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { 164 rc = -EXDEV; 165 goto out; 166 } 167 if (!igrab(lower_inode)) { 168 rc = -ESTALE; 169 goto out; 170 } 171 inode = iget5_locked(sb, (unsigned long)lower_inode, 172 ecryptfs_inode_test, ecryptfs_inode_set, 173 lower_inode); 174 if (!inode) { 175 rc = -EACCES; 176 iput(lower_inode); 177 goto out; 178 } 179 if (inode->i_state & I_NEW) 180 unlock_new_inode(inode); 181 else 182 iput(lower_inode); 183 if (S_ISLNK(lower_inode->i_mode)) 184 inode->i_op = &ecryptfs_symlink_iops; 185 else if (S_ISDIR(lower_inode->i_mode)) 186 inode->i_op = &ecryptfs_dir_iops; 187 if (S_ISDIR(lower_inode->i_mode)) 188 inode->i_fop = &ecryptfs_dir_fops; 189 if (special_file(lower_inode->i_mode)) 190 init_special_inode(inode, lower_inode->i_mode, 191 lower_inode->i_rdev); 192 dentry->d_op = &ecryptfs_dops; 193 fsstack_copy_attr_all(inode, lower_inode, NULL); 194 /* This size will be overwritten for real files w/ headers and 195 * other metadata */ 196 fsstack_copy_inode_size(inode, lower_inode); 197 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) 198 d_add(dentry, inode); 199 else 200 d_instantiate(dentry, inode); 201 out: 202 return rc; 203 } 204 205 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, 206 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, 207 ecryptfs_opt_ecryptfs_key_bytes, 208 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 209 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, 210 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, 211 ecryptfs_opt_unlink_sigs, ecryptfs_opt_err }; 212 213 static const match_table_t tokens = { 214 {ecryptfs_opt_sig, "sig=%s"}, 215 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 216 {ecryptfs_opt_cipher, "cipher=%s"}, 217 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 218 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 219 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 220 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 221 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 222 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, 223 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, 224 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, 225 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, 226 {ecryptfs_opt_err, NULL} 227 }; 228 229 static int ecryptfs_init_global_auth_toks( 230 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 231 { 232 struct ecryptfs_global_auth_tok *global_auth_tok; 233 int rc = 0; 234 235 list_for_each_entry(global_auth_tok, 236 &mount_crypt_stat->global_auth_tok_list, 237 mount_crypt_stat_list) { 238 rc = ecryptfs_keyring_auth_tok_for_sig( 239 &global_auth_tok->global_auth_tok_key, 240 &global_auth_tok->global_auth_tok, 241 global_auth_tok->sig); 242 if (rc) { 243 printk(KERN_ERR "Could not find valid key in user " 244 "session keyring for sig specified in mount " 245 "option: [%s]\n", global_auth_tok->sig); 246 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 247 goto out; 248 } else 249 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 250 } 251 out: 252 return rc; 253 } 254 255 static void ecryptfs_init_mount_crypt_stat( 256 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 257 { 258 memset((void *)mount_crypt_stat, 0, 259 sizeof(struct ecryptfs_mount_crypt_stat)); 260 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 261 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 262 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 263 } 264 265 /** 266 * ecryptfs_parse_options 267 * @sb: The ecryptfs super block 268 * @options: The options pased to the kernel 269 * 270 * Parse mount options: 271 * debug=N - ecryptfs_verbosity level for debug output 272 * sig=XXX - description(signature) of the key to use 273 * 274 * Returns the dentry object of the lower-level (lower/interposed) 275 * directory; We want to mount our stackable file system on top of 276 * that lower directory. 277 * 278 * The signature of the key to use must be the description of a key 279 * already in the keyring. Mounting will fail if the key can not be 280 * found. 281 * 282 * Returns zero on success; non-zero on error 283 */ 284 static int ecryptfs_parse_options(struct super_block *sb, char *options) 285 { 286 char *p; 287 int rc = 0; 288 int sig_set = 0; 289 int cipher_name_set = 0; 290 int fn_cipher_name_set = 0; 291 int cipher_key_bytes; 292 int cipher_key_bytes_set = 0; 293 int fn_cipher_key_bytes; 294 int fn_cipher_key_bytes_set = 0; 295 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 296 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; 297 substring_t args[MAX_OPT_ARGS]; 298 int token; 299 char *sig_src; 300 char *cipher_name_dst; 301 char *cipher_name_src; 302 char *fn_cipher_name_dst; 303 char *fn_cipher_name_src; 304 char *fnek_dst; 305 char *fnek_src; 306 char *cipher_key_bytes_src; 307 char *fn_cipher_key_bytes_src; 308 309 if (!options) { 310 rc = -EINVAL; 311 goto out; 312 } 313 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 314 while ((p = strsep(&options, ",")) != NULL) { 315 if (!*p) 316 continue; 317 token = match_token(p, tokens, args); 318 switch (token) { 319 case ecryptfs_opt_sig: 320 case ecryptfs_opt_ecryptfs_sig: 321 sig_src = args[0].from; 322 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 323 sig_src, 0); 324 if (rc) { 325 printk(KERN_ERR "Error attempting to register " 326 "global sig; rc = [%d]\n", rc); 327 goto out; 328 } 329 sig_set = 1; 330 break; 331 case ecryptfs_opt_cipher: 332 case ecryptfs_opt_ecryptfs_cipher: 333 cipher_name_src = args[0].from; 334 cipher_name_dst = 335 mount_crypt_stat-> 336 global_default_cipher_name; 337 strncpy(cipher_name_dst, cipher_name_src, 338 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 339 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 340 cipher_name_set = 1; 341 break; 342 case ecryptfs_opt_ecryptfs_key_bytes: 343 cipher_key_bytes_src = args[0].from; 344 cipher_key_bytes = 345 (int)simple_strtol(cipher_key_bytes_src, 346 &cipher_key_bytes_src, 0); 347 mount_crypt_stat->global_default_cipher_key_size = 348 cipher_key_bytes; 349 cipher_key_bytes_set = 1; 350 break; 351 case ecryptfs_opt_passthrough: 352 mount_crypt_stat->flags |= 353 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 354 break; 355 case ecryptfs_opt_xattr_metadata: 356 mount_crypt_stat->flags |= 357 ECRYPTFS_XATTR_METADATA_ENABLED; 358 break; 359 case ecryptfs_opt_encrypted_view: 360 mount_crypt_stat->flags |= 361 ECRYPTFS_XATTR_METADATA_ENABLED; 362 mount_crypt_stat->flags |= 363 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 364 break; 365 case ecryptfs_opt_fnek_sig: 366 fnek_src = args[0].from; 367 fnek_dst = 368 mount_crypt_stat->global_default_fnek_sig; 369 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 370 mount_crypt_stat->global_default_fnek_sig[ 371 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 372 rc = ecryptfs_add_global_auth_tok( 373 mount_crypt_stat, 374 mount_crypt_stat->global_default_fnek_sig, 375 ECRYPTFS_AUTH_TOK_FNEK); 376 if (rc) { 377 printk(KERN_ERR "Error attempting to register " 378 "global fnek sig [%s]; rc = [%d]\n", 379 mount_crypt_stat->global_default_fnek_sig, 380 rc); 381 goto out; 382 } 383 mount_crypt_stat->flags |= 384 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 385 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 386 break; 387 case ecryptfs_opt_fn_cipher: 388 fn_cipher_name_src = args[0].from; 389 fn_cipher_name_dst = 390 mount_crypt_stat->global_default_fn_cipher_name; 391 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 392 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 393 mount_crypt_stat->global_default_fn_cipher_name[ 394 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 395 fn_cipher_name_set = 1; 396 break; 397 case ecryptfs_opt_fn_cipher_key_bytes: 398 fn_cipher_key_bytes_src = args[0].from; 399 fn_cipher_key_bytes = 400 (int)simple_strtol(fn_cipher_key_bytes_src, 401 &fn_cipher_key_bytes_src, 0); 402 mount_crypt_stat->global_default_fn_cipher_key_bytes = 403 fn_cipher_key_bytes; 404 fn_cipher_key_bytes_set = 1; 405 break; 406 case ecryptfs_opt_unlink_sigs: 407 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 408 break; 409 case ecryptfs_opt_err: 410 default: 411 printk(KERN_WARNING 412 "%s: eCryptfs: unrecognized option [%s]\n", 413 __func__, p); 414 } 415 } 416 if (!sig_set) { 417 rc = -EINVAL; 418 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 419 "auth tok signature as a mount " 420 "parameter; see the eCryptfs README\n"); 421 goto out; 422 } 423 if (!cipher_name_set) { 424 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 425 426 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 427 strcpy(mount_crypt_stat->global_default_cipher_name, 428 ECRYPTFS_DEFAULT_CIPHER); 429 } 430 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 431 && !fn_cipher_name_set) 432 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 433 mount_crypt_stat->global_default_cipher_name); 434 if (!cipher_key_bytes_set) 435 mount_crypt_stat->global_default_cipher_key_size = 0; 436 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 437 && !fn_cipher_key_bytes_set) 438 mount_crypt_stat->global_default_fn_cipher_key_bytes = 439 mount_crypt_stat->global_default_cipher_key_size; 440 mutex_lock(&key_tfm_list_mutex); 441 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 442 NULL)) { 443 rc = ecryptfs_add_new_key_tfm( 444 NULL, mount_crypt_stat->global_default_cipher_name, 445 mount_crypt_stat->global_default_cipher_key_size); 446 if (rc) { 447 printk(KERN_ERR "Error attempting to initialize " 448 "cipher with name = [%s] and key size = [%td]; " 449 "rc = [%d]\n", 450 mount_crypt_stat->global_default_cipher_name, 451 mount_crypt_stat->global_default_cipher_key_size, 452 rc); 453 rc = -EINVAL; 454 mutex_unlock(&key_tfm_list_mutex); 455 goto out; 456 } 457 } 458 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 459 && !ecryptfs_tfm_exists( 460 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 461 rc = ecryptfs_add_new_key_tfm( 462 NULL, mount_crypt_stat->global_default_fn_cipher_name, 463 mount_crypt_stat->global_default_fn_cipher_key_bytes); 464 if (rc) { 465 printk(KERN_ERR "Error attempting to initialize " 466 "cipher with name = [%s] and key size = [%td]; " 467 "rc = [%d]\n", 468 mount_crypt_stat->global_default_fn_cipher_name, 469 mount_crypt_stat->global_default_fn_cipher_key_bytes, 470 rc); 471 rc = -EINVAL; 472 mutex_unlock(&key_tfm_list_mutex); 473 goto out; 474 } 475 } 476 mutex_unlock(&key_tfm_list_mutex); 477 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 478 if (rc) 479 printk(KERN_WARNING "One or more global auth toks could not " 480 "properly register; rc = [%d]\n", rc); 481 out: 482 return rc; 483 } 484 485 struct kmem_cache *ecryptfs_sb_info_cache; 486 487 /** 488 * ecryptfs_fill_super 489 * @sb: The ecryptfs super block 490 * @raw_data: The options passed to mount 491 * @silent: Not used but required by function prototype 492 * 493 * Sets up what we can of the sb, rest is done in ecryptfs_read_super 494 * 495 * Returns zero on success; non-zero otherwise 496 */ 497 static int 498 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) 499 { 500 int rc = 0; 501 502 /* Released in ecryptfs_put_super() */ 503 ecryptfs_set_superblock_private(sb, 504 kmem_cache_zalloc(ecryptfs_sb_info_cache, 505 GFP_KERNEL)); 506 if (!ecryptfs_superblock_to_private(sb)) { 507 ecryptfs_printk(KERN_WARNING, "Out of memory\n"); 508 rc = -ENOMEM; 509 goto out; 510 } 511 sb->s_op = &ecryptfs_sops; 512 /* Released through deactivate_super(sb) from get_sb_nodev */ 513 sb->s_root = d_alloc(NULL, &(const struct qstr) { 514 .hash = 0,.name = "/",.len = 1}); 515 if (!sb->s_root) { 516 ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); 517 rc = -ENOMEM; 518 goto out; 519 } 520 sb->s_root->d_op = &ecryptfs_dops; 521 sb->s_root->d_sb = sb; 522 sb->s_root->d_parent = sb->s_root; 523 /* Released in d_release when dput(sb->s_root) is called */ 524 /* through deactivate_super(sb) from get_sb_nodev() */ 525 ecryptfs_set_dentry_private(sb->s_root, 526 kmem_cache_zalloc(ecryptfs_dentry_info_cache, 527 GFP_KERNEL)); 528 if (!ecryptfs_dentry_to_private(sb->s_root)) { 529 ecryptfs_printk(KERN_ERR, 530 "dentry_info_cache alloc failed\n"); 531 rc = -ENOMEM; 532 goto out; 533 } 534 rc = 0; 535 out: 536 /* Should be able to rely on deactivate_super called from 537 * get_sb_nodev */ 538 return rc; 539 } 540 541 /** 542 * ecryptfs_read_super 543 * @sb: The ecryptfs super block 544 * @dev_name: The path to mount over 545 * 546 * Read the super block of the lower filesystem, and use 547 * ecryptfs_interpose to create our initial inode and super block 548 * struct. 549 */ 550 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) 551 { 552 struct path path; 553 int rc; 554 555 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 556 if (rc) { 557 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); 558 goto out; 559 } 560 ecryptfs_set_superblock_lower(sb, path.dentry->d_sb); 561 sb->s_maxbytes = path.dentry->d_sb->s_maxbytes; 562 sb->s_blocksize = path.dentry->d_sb->s_blocksize; 563 ecryptfs_set_dentry_lower(sb->s_root, path.dentry); 564 ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt); 565 rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0); 566 if (rc) 567 goto out_free; 568 rc = 0; 569 goto out; 570 out_free: 571 path_put(&path); 572 out: 573 return rc; 574 } 575 576 /** 577 * ecryptfs_get_sb 578 * @fs_type 579 * @flags 580 * @dev_name: The path to mount over 581 * @raw_data: The options passed into the kernel 582 * 583 * The whole ecryptfs_get_sb process is broken into 4 functions: 584 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any 585 * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block 586 * with as much information as it can before needing 587 * the lower filesystem. 588 * ecryptfs_read_super(): this accesses the lower filesystem and uses 589 * ecryptfs_interpolate to perform most of the linking 590 * ecryptfs_interpolate(): links the lower filesystem into ecryptfs 591 */ 592 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, 593 const char *dev_name, void *raw_data, 594 struct vfsmount *mnt) 595 { 596 int rc; 597 struct super_block *sb; 598 599 rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); 600 if (rc < 0) { 601 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); 602 goto out; 603 } 604 sb = mnt->mnt_sb; 605 rc = ecryptfs_parse_options(sb, raw_data); 606 if (rc) { 607 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); 608 goto out_abort; 609 } 610 rc = ecryptfs_read_super(sb, dev_name); 611 if (rc) { 612 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); 613 goto out_abort; 614 } 615 goto out; 616 out_abort: 617 dput(sb->s_root); 618 up_write(&sb->s_umount); 619 deactivate_super(sb); 620 out: 621 return rc; 622 } 623 624 /** 625 * ecryptfs_kill_block_super 626 * @sb: The ecryptfs super block 627 * 628 * Used to bring the superblock down and free the private data. 629 * Private data is free'd in ecryptfs_put_super() 630 */ 631 static void ecryptfs_kill_block_super(struct super_block *sb) 632 { 633 generic_shutdown_super(sb); 634 } 635 636 static struct file_system_type ecryptfs_fs_type = { 637 .owner = THIS_MODULE, 638 .name = "ecryptfs", 639 .get_sb = ecryptfs_get_sb, 640 .kill_sb = ecryptfs_kill_block_super, 641 .fs_flags = 0 642 }; 643 644 /** 645 * inode_info_init_once 646 * 647 * Initializes the ecryptfs_inode_info_cache when it is created 648 */ 649 static void 650 inode_info_init_once(void *vptr) 651 { 652 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 653 654 inode_init_once(&ei->vfs_inode); 655 } 656 657 static struct ecryptfs_cache_info { 658 struct kmem_cache **cache; 659 const char *name; 660 size_t size; 661 void (*ctor)(void *obj); 662 } ecryptfs_cache_infos[] = { 663 { 664 .cache = &ecryptfs_auth_tok_list_item_cache, 665 .name = "ecryptfs_auth_tok_list_item", 666 .size = sizeof(struct ecryptfs_auth_tok_list_item), 667 }, 668 { 669 .cache = &ecryptfs_file_info_cache, 670 .name = "ecryptfs_file_cache", 671 .size = sizeof(struct ecryptfs_file_info), 672 }, 673 { 674 .cache = &ecryptfs_dentry_info_cache, 675 .name = "ecryptfs_dentry_info_cache", 676 .size = sizeof(struct ecryptfs_dentry_info), 677 }, 678 { 679 .cache = &ecryptfs_inode_info_cache, 680 .name = "ecryptfs_inode_cache", 681 .size = sizeof(struct ecryptfs_inode_info), 682 .ctor = inode_info_init_once, 683 }, 684 { 685 .cache = &ecryptfs_sb_info_cache, 686 .name = "ecryptfs_sb_cache", 687 .size = sizeof(struct ecryptfs_sb_info), 688 }, 689 { 690 .cache = &ecryptfs_header_cache_1, 691 .name = "ecryptfs_headers_1", 692 .size = PAGE_CACHE_SIZE, 693 }, 694 { 695 .cache = &ecryptfs_header_cache_2, 696 .name = "ecryptfs_headers_2", 697 .size = PAGE_CACHE_SIZE, 698 }, 699 { 700 .cache = &ecryptfs_xattr_cache, 701 .name = "ecryptfs_xattr_cache", 702 .size = PAGE_CACHE_SIZE, 703 }, 704 { 705 .cache = &ecryptfs_key_record_cache, 706 .name = "ecryptfs_key_record_cache", 707 .size = sizeof(struct ecryptfs_key_record), 708 }, 709 { 710 .cache = &ecryptfs_key_sig_cache, 711 .name = "ecryptfs_key_sig_cache", 712 .size = sizeof(struct ecryptfs_key_sig), 713 }, 714 { 715 .cache = &ecryptfs_global_auth_tok_cache, 716 .name = "ecryptfs_global_auth_tok_cache", 717 .size = sizeof(struct ecryptfs_global_auth_tok), 718 }, 719 { 720 .cache = &ecryptfs_key_tfm_cache, 721 .name = "ecryptfs_key_tfm_cache", 722 .size = sizeof(struct ecryptfs_key_tfm), 723 }, 724 { 725 .cache = &ecryptfs_open_req_cache, 726 .name = "ecryptfs_open_req_cache", 727 .size = sizeof(struct ecryptfs_open_req), 728 }, 729 }; 730 731 static void ecryptfs_free_kmem_caches(void) 732 { 733 int i; 734 735 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 736 struct ecryptfs_cache_info *info; 737 738 info = &ecryptfs_cache_infos[i]; 739 if (*(info->cache)) 740 kmem_cache_destroy(*(info->cache)); 741 } 742 } 743 744 /** 745 * ecryptfs_init_kmem_caches 746 * 747 * Returns zero on success; non-zero otherwise 748 */ 749 static int ecryptfs_init_kmem_caches(void) 750 { 751 int i; 752 753 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 754 struct ecryptfs_cache_info *info; 755 756 info = &ecryptfs_cache_infos[i]; 757 *(info->cache) = kmem_cache_create(info->name, info->size, 758 0, SLAB_HWCACHE_ALIGN, info->ctor); 759 if (!*(info->cache)) { 760 ecryptfs_free_kmem_caches(); 761 ecryptfs_printk(KERN_WARNING, "%s: " 762 "kmem_cache_create failed\n", 763 info->name); 764 return -ENOMEM; 765 } 766 } 767 return 0; 768 } 769 770 static struct kobject *ecryptfs_kobj; 771 772 static ssize_t version_show(struct kobject *kobj, 773 struct kobj_attribute *attr, char *buff) 774 { 775 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 776 } 777 778 static struct kobj_attribute version_attr = __ATTR_RO(version); 779 780 static struct attribute *attributes[] = { 781 &version_attr.attr, 782 NULL, 783 }; 784 785 static struct attribute_group attr_group = { 786 .attrs = attributes, 787 }; 788 789 static int do_sysfs_registration(void) 790 { 791 int rc; 792 793 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 794 if (!ecryptfs_kobj) { 795 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 796 rc = -ENOMEM; 797 goto out; 798 } 799 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 800 if (rc) { 801 printk(KERN_ERR 802 "Unable to create ecryptfs version attributes\n"); 803 kobject_put(ecryptfs_kobj); 804 } 805 out: 806 return rc; 807 } 808 809 static void do_sysfs_unregistration(void) 810 { 811 sysfs_remove_group(ecryptfs_kobj, &attr_group); 812 kobject_put(ecryptfs_kobj); 813 } 814 815 static int __init ecryptfs_init(void) 816 { 817 int rc; 818 819 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 820 rc = -EINVAL; 821 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 822 "larger than the host's page size, and so " 823 "eCryptfs cannot run on this system. The " 824 "default eCryptfs extent size is [%d] bytes; " 825 "the page size is [%d] bytes.\n", 826 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); 827 goto out; 828 } 829 rc = ecryptfs_init_kmem_caches(); 830 if (rc) { 831 printk(KERN_ERR 832 "Failed to allocate one or more kmem_cache objects\n"); 833 goto out; 834 } 835 rc = register_filesystem(&ecryptfs_fs_type); 836 if (rc) { 837 printk(KERN_ERR "Failed to register filesystem\n"); 838 goto out_free_kmem_caches; 839 } 840 rc = do_sysfs_registration(); 841 if (rc) { 842 printk(KERN_ERR "sysfs registration failed\n"); 843 goto out_unregister_filesystem; 844 } 845 rc = ecryptfs_init_kthread(); 846 if (rc) { 847 printk(KERN_ERR "%s: kthread initialization failed; " 848 "rc = [%d]\n", __func__, rc); 849 goto out_do_sysfs_unregistration; 850 } 851 rc = ecryptfs_init_messaging(); 852 if (rc) { 853 printk(KERN_ERR "Failure occured while attempting to " 854 "initialize the communications channel to " 855 "ecryptfsd\n"); 856 goto out_destroy_kthread; 857 } 858 rc = ecryptfs_init_crypto(); 859 if (rc) { 860 printk(KERN_ERR "Failure whilst attempting to init crypto; " 861 "rc = [%d]\n", rc); 862 goto out_release_messaging; 863 } 864 if (ecryptfs_verbosity > 0) 865 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 866 "will be written to the syslog!\n", ecryptfs_verbosity); 867 868 goto out; 869 out_release_messaging: 870 ecryptfs_release_messaging(); 871 out_destroy_kthread: 872 ecryptfs_destroy_kthread(); 873 out_do_sysfs_unregistration: 874 do_sysfs_unregistration(); 875 out_unregister_filesystem: 876 unregister_filesystem(&ecryptfs_fs_type); 877 out_free_kmem_caches: 878 ecryptfs_free_kmem_caches(); 879 out: 880 return rc; 881 } 882 883 static void __exit ecryptfs_exit(void) 884 { 885 int rc; 886 887 rc = ecryptfs_destroy_crypto(); 888 if (rc) 889 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 890 "rc = [%d]\n", rc); 891 ecryptfs_release_messaging(); 892 ecryptfs_destroy_kthread(); 893 do_sysfs_unregistration(); 894 unregister_filesystem(&ecryptfs_fs_type); 895 ecryptfs_free_kmem_caches(); 896 } 897 898 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 899 MODULE_DESCRIPTION("eCryptfs"); 900 901 MODULE_LICENSE("GPL"); 902 903 module_init(ecryptfs_init) 904 module_exit(ecryptfs_exit) 905