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 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) 194 d_add(dentry, inode); 195 else 196 d_instantiate(dentry, inode); 197 fsstack_copy_attr_all(inode, lower_inode, NULL); 198 /* This size will be overwritten for real files w/ headers and 199 * other metadata */ 200 fsstack_copy_inode_size(inode, lower_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_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_err, NULL} 226 }; 227 228 static int ecryptfs_init_global_auth_toks( 229 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 230 { 231 struct ecryptfs_global_auth_tok *global_auth_tok; 232 int rc = 0; 233 234 list_for_each_entry(global_auth_tok, 235 &mount_crypt_stat->global_auth_tok_list, 236 mount_crypt_stat_list) { 237 rc = ecryptfs_keyring_auth_tok_for_sig( 238 &global_auth_tok->global_auth_tok_key, 239 &global_auth_tok->global_auth_tok, 240 global_auth_tok->sig); 241 if (rc) { 242 printk(KERN_ERR "Could not find valid key in user " 243 "session keyring for sig specified in mount " 244 "option: [%s]\n", global_auth_tok->sig); 245 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 246 goto out; 247 } else 248 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 249 } 250 out: 251 return rc; 252 } 253 254 static void ecryptfs_init_mount_crypt_stat( 255 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 256 { 257 memset((void *)mount_crypt_stat, 0, 258 sizeof(struct ecryptfs_mount_crypt_stat)); 259 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 260 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 261 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 262 } 263 264 /** 265 * ecryptfs_parse_options 266 * @sb: The ecryptfs super block 267 * @options: The options pased to the kernel 268 * 269 * Parse mount options: 270 * debug=N - ecryptfs_verbosity level for debug output 271 * sig=XXX - description(signature) of the key to use 272 * 273 * Returns the dentry object of the lower-level (lower/interposed) 274 * directory; We want to mount our stackable file system on top of 275 * that lower directory. 276 * 277 * The signature of the key to use must be the description of a key 278 * already in the keyring. Mounting will fail if the key can not be 279 * found. 280 * 281 * Returns zero on success; non-zero on error 282 */ 283 static int ecryptfs_parse_options(struct super_block *sb, char *options) 284 { 285 char *p; 286 int rc = 0; 287 int sig_set = 0; 288 int cipher_name_set = 0; 289 int fn_cipher_name_set = 0; 290 int cipher_key_bytes; 291 int cipher_key_bytes_set = 0; 292 int fn_cipher_key_bytes; 293 int fn_cipher_key_bytes_set = 0; 294 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 295 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; 296 substring_t args[MAX_OPT_ARGS]; 297 int token; 298 char *sig_src; 299 char *cipher_name_dst; 300 char *cipher_name_src; 301 char *fn_cipher_name_dst; 302 char *fn_cipher_name_src; 303 char *fnek_dst; 304 char *fnek_src; 305 char *cipher_key_bytes_src; 306 char *fn_cipher_key_bytes_src; 307 308 if (!options) { 309 rc = -EINVAL; 310 goto out; 311 } 312 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 313 while ((p = strsep(&options, ",")) != NULL) { 314 if (!*p) 315 continue; 316 token = match_token(p, tokens, args); 317 switch (token) { 318 case ecryptfs_opt_sig: 319 case ecryptfs_opt_ecryptfs_sig: 320 sig_src = args[0].from; 321 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 322 sig_src); 323 if (rc) { 324 printk(KERN_ERR "Error attempting to register " 325 "global sig; rc = [%d]\n", rc); 326 goto out; 327 } 328 sig_set = 1; 329 break; 330 case ecryptfs_opt_cipher: 331 case ecryptfs_opt_ecryptfs_cipher: 332 cipher_name_src = args[0].from; 333 cipher_name_dst = 334 mount_crypt_stat-> 335 global_default_cipher_name; 336 strncpy(cipher_name_dst, cipher_name_src, 337 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 338 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 339 cipher_name_set = 1; 340 break; 341 case ecryptfs_opt_ecryptfs_key_bytes: 342 cipher_key_bytes_src = args[0].from; 343 cipher_key_bytes = 344 (int)simple_strtol(cipher_key_bytes_src, 345 &cipher_key_bytes_src, 0); 346 mount_crypt_stat->global_default_cipher_key_size = 347 cipher_key_bytes; 348 cipher_key_bytes_set = 1; 349 break; 350 case ecryptfs_opt_passthrough: 351 mount_crypt_stat->flags |= 352 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 353 break; 354 case ecryptfs_opt_xattr_metadata: 355 mount_crypt_stat->flags |= 356 ECRYPTFS_XATTR_METADATA_ENABLED; 357 break; 358 case ecryptfs_opt_encrypted_view: 359 mount_crypt_stat->flags |= 360 ECRYPTFS_XATTR_METADATA_ENABLED; 361 mount_crypt_stat->flags |= 362 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 363 break; 364 case ecryptfs_opt_fnek_sig: 365 fnek_src = args[0].from; 366 fnek_dst = 367 mount_crypt_stat->global_default_fnek_sig; 368 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 369 mount_crypt_stat->global_default_fnek_sig[ 370 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 371 rc = ecryptfs_add_global_auth_tok( 372 mount_crypt_stat, 373 mount_crypt_stat->global_default_fnek_sig); 374 if (rc) { 375 printk(KERN_ERR "Error attempting to register " 376 "global fnek sig [%s]; rc = [%d]\n", 377 mount_crypt_stat->global_default_fnek_sig, 378 rc); 379 goto out; 380 } 381 mount_crypt_stat->flags |= 382 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 383 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 384 break; 385 case ecryptfs_opt_fn_cipher: 386 fn_cipher_name_src = args[0].from; 387 fn_cipher_name_dst = 388 mount_crypt_stat->global_default_fn_cipher_name; 389 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 390 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 391 mount_crypt_stat->global_default_fn_cipher_name[ 392 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 393 fn_cipher_name_set = 1; 394 break; 395 case ecryptfs_opt_fn_cipher_key_bytes: 396 fn_cipher_key_bytes_src = args[0].from; 397 fn_cipher_key_bytes = 398 (int)simple_strtol(fn_cipher_key_bytes_src, 399 &fn_cipher_key_bytes_src, 0); 400 mount_crypt_stat->global_default_fn_cipher_key_bytes = 401 fn_cipher_key_bytes; 402 fn_cipher_key_bytes_set = 1; 403 break; 404 case ecryptfs_opt_err: 405 default: 406 printk(KERN_WARNING 407 "%s: eCryptfs: unrecognized option [%s]\n", 408 __func__, p); 409 } 410 } 411 if (!sig_set) { 412 rc = -EINVAL; 413 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 414 "auth tok signature as a mount " 415 "parameter; see the eCryptfs README\n"); 416 goto out; 417 } 418 if (!cipher_name_set) { 419 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 420 421 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 422 strcpy(mount_crypt_stat->global_default_cipher_name, 423 ECRYPTFS_DEFAULT_CIPHER); 424 } 425 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 426 && !fn_cipher_name_set) 427 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 428 mount_crypt_stat->global_default_cipher_name); 429 if (!cipher_key_bytes_set) 430 mount_crypt_stat->global_default_cipher_key_size = 0; 431 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 432 && !fn_cipher_key_bytes_set) 433 mount_crypt_stat->global_default_fn_cipher_key_bytes = 434 mount_crypt_stat->global_default_cipher_key_size; 435 mutex_lock(&key_tfm_list_mutex); 436 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 437 NULL)) { 438 rc = ecryptfs_add_new_key_tfm( 439 NULL, mount_crypt_stat->global_default_cipher_name, 440 mount_crypt_stat->global_default_cipher_key_size); 441 if (rc) { 442 printk(KERN_ERR "Error attempting to initialize " 443 "cipher with name = [%s] and key size = [%td]; " 444 "rc = [%d]\n", 445 mount_crypt_stat->global_default_cipher_name, 446 mount_crypt_stat->global_default_cipher_key_size, 447 rc); 448 rc = -EINVAL; 449 mutex_unlock(&key_tfm_list_mutex); 450 goto out; 451 } 452 } 453 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 454 && !ecryptfs_tfm_exists( 455 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 456 rc = ecryptfs_add_new_key_tfm( 457 NULL, mount_crypt_stat->global_default_fn_cipher_name, 458 mount_crypt_stat->global_default_fn_cipher_key_bytes); 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_fn_cipher_name, 464 mount_crypt_stat->global_default_fn_cipher_key_bytes, 465 rc); 466 rc = -EINVAL; 467 mutex_unlock(&key_tfm_list_mutex); 468 goto out; 469 } 470 } 471 mutex_unlock(&key_tfm_list_mutex); 472 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 473 if (rc) 474 printk(KERN_WARNING "One or more global auth toks could not " 475 "properly register; rc = [%d]\n", rc); 476 out: 477 return rc; 478 } 479 480 struct kmem_cache *ecryptfs_sb_info_cache; 481 482 /** 483 * ecryptfs_fill_super 484 * @sb: The ecryptfs super block 485 * @raw_data: The options passed to mount 486 * @silent: Not used but required by function prototype 487 * 488 * Sets up what we can of the sb, rest is done in ecryptfs_read_super 489 * 490 * Returns zero on success; non-zero otherwise 491 */ 492 static int 493 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) 494 { 495 int rc = 0; 496 497 /* Released in ecryptfs_put_super() */ 498 ecryptfs_set_superblock_private(sb, 499 kmem_cache_zalloc(ecryptfs_sb_info_cache, 500 GFP_KERNEL)); 501 if (!ecryptfs_superblock_to_private(sb)) { 502 ecryptfs_printk(KERN_WARNING, "Out of memory\n"); 503 rc = -ENOMEM; 504 goto out; 505 } 506 sb->s_op = &ecryptfs_sops; 507 /* Released through deactivate_super(sb) from get_sb_nodev */ 508 sb->s_root = d_alloc(NULL, &(const struct qstr) { 509 .hash = 0,.name = "/",.len = 1}); 510 if (!sb->s_root) { 511 ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); 512 rc = -ENOMEM; 513 goto out; 514 } 515 sb->s_root->d_op = &ecryptfs_dops; 516 sb->s_root->d_sb = sb; 517 sb->s_root->d_parent = sb->s_root; 518 /* Released in d_release when dput(sb->s_root) is called */ 519 /* through deactivate_super(sb) from get_sb_nodev() */ 520 ecryptfs_set_dentry_private(sb->s_root, 521 kmem_cache_zalloc(ecryptfs_dentry_info_cache, 522 GFP_KERNEL)); 523 if (!ecryptfs_dentry_to_private(sb->s_root)) { 524 ecryptfs_printk(KERN_ERR, 525 "dentry_info_cache alloc failed\n"); 526 rc = -ENOMEM; 527 goto out; 528 } 529 rc = 0; 530 out: 531 /* Should be able to rely on deactivate_super called from 532 * get_sb_nodev */ 533 return rc; 534 } 535 536 /** 537 * ecryptfs_read_super 538 * @sb: The ecryptfs super block 539 * @dev_name: The path to mount over 540 * 541 * Read the super block of the lower filesystem, and use 542 * ecryptfs_interpose to create our initial inode and super block 543 * struct. 544 */ 545 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) 546 { 547 struct path path; 548 int rc; 549 550 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 551 if (rc) { 552 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); 553 goto out; 554 } 555 ecryptfs_set_superblock_lower(sb, path.dentry->d_sb); 556 sb->s_maxbytes = path.dentry->d_sb->s_maxbytes; 557 sb->s_blocksize = path.dentry->d_sb->s_blocksize; 558 ecryptfs_set_dentry_lower(sb->s_root, path.dentry); 559 ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt); 560 rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0); 561 if (rc) 562 goto out_free; 563 rc = 0; 564 goto out; 565 out_free: 566 path_put(&path); 567 out: 568 return rc; 569 } 570 571 /** 572 * ecryptfs_get_sb 573 * @fs_type 574 * @flags 575 * @dev_name: The path to mount over 576 * @raw_data: The options passed into the kernel 577 * 578 * The whole ecryptfs_get_sb process is broken into 4 functions: 579 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any 580 * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block 581 * with as much information as it can before needing 582 * the lower filesystem. 583 * ecryptfs_read_super(): this accesses the lower filesystem and uses 584 * ecryptfs_interpolate to perform most of the linking 585 * ecryptfs_interpolate(): links the lower filesystem into ecryptfs 586 */ 587 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, 588 const char *dev_name, void *raw_data, 589 struct vfsmount *mnt) 590 { 591 int rc; 592 struct super_block *sb; 593 594 rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); 595 if (rc < 0) { 596 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); 597 goto out; 598 } 599 sb = mnt->mnt_sb; 600 rc = ecryptfs_parse_options(sb, raw_data); 601 if (rc) { 602 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); 603 goto out_abort; 604 } 605 rc = ecryptfs_read_super(sb, dev_name); 606 if (rc) { 607 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); 608 goto out_abort; 609 } 610 goto out; 611 out_abort: 612 dput(sb->s_root); 613 up_write(&sb->s_umount); 614 deactivate_super(sb); 615 out: 616 return rc; 617 } 618 619 /** 620 * ecryptfs_kill_block_super 621 * @sb: The ecryptfs super block 622 * 623 * Used to bring the superblock down and free the private data. 624 * Private data is free'd in ecryptfs_put_super() 625 */ 626 static void ecryptfs_kill_block_super(struct super_block *sb) 627 { 628 generic_shutdown_super(sb); 629 } 630 631 static struct file_system_type ecryptfs_fs_type = { 632 .owner = THIS_MODULE, 633 .name = "ecryptfs", 634 .get_sb = ecryptfs_get_sb, 635 .kill_sb = ecryptfs_kill_block_super, 636 .fs_flags = 0 637 }; 638 639 /** 640 * inode_info_init_once 641 * 642 * Initializes the ecryptfs_inode_info_cache when it is created 643 */ 644 static void 645 inode_info_init_once(void *vptr) 646 { 647 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 648 649 inode_init_once(&ei->vfs_inode); 650 } 651 652 static struct ecryptfs_cache_info { 653 struct kmem_cache **cache; 654 const char *name; 655 size_t size; 656 void (*ctor)(void *obj); 657 } ecryptfs_cache_infos[] = { 658 { 659 .cache = &ecryptfs_auth_tok_list_item_cache, 660 .name = "ecryptfs_auth_tok_list_item", 661 .size = sizeof(struct ecryptfs_auth_tok_list_item), 662 }, 663 { 664 .cache = &ecryptfs_file_info_cache, 665 .name = "ecryptfs_file_cache", 666 .size = sizeof(struct ecryptfs_file_info), 667 }, 668 { 669 .cache = &ecryptfs_dentry_info_cache, 670 .name = "ecryptfs_dentry_info_cache", 671 .size = sizeof(struct ecryptfs_dentry_info), 672 }, 673 { 674 .cache = &ecryptfs_inode_info_cache, 675 .name = "ecryptfs_inode_cache", 676 .size = sizeof(struct ecryptfs_inode_info), 677 .ctor = inode_info_init_once, 678 }, 679 { 680 .cache = &ecryptfs_sb_info_cache, 681 .name = "ecryptfs_sb_cache", 682 .size = sizeof(struct ecryptfs_sb_info), 683 }, 684 { 685 .cache = &ecryptfs_header_cache_1, 686 .name = "ecryptfs_headers_1", 687 .size = PAGE_CACHE_SIZE, 688 }, 689 { 690 .cache = &ecryptfs_header_cache_2, 691 .name = "ecryptfs_headers_2", 692 .size = PAGE_CACHE_SIZE, 693 }, 694 { 695 .cache = &ecryptfs_xattr_cache, 696 .name = "ecryptfs_xattr_cache", 697 .size = PAGE_CACHE_SIZE, 698 }, 699 { 700 .cache = &ecryptfs_key_record_cache, 701 .name = "ecryptfs_key_record_cache", 702 .size = sizeof(struct ecryptfs_key_record), 703 }, 704 { 705 .cache = &ecryptfs_key_sig_cache, 706 .name = "ecryptfs_key_sig_cache", 707 .size = sizeof(struct ecryptfs_key_sig), 708 }, 709 { 710 .cache = &ecryptfs_global_auth_tok_cache, 711 .name = "ecryptfs_global_auth_tok_cache", 712 .size = sizeof(struct ecryptfs_global_auth_tok), 713 }, 714 { 715 .cache = &ecryptfs_key_tfm_cache, 716 .name = "ecryptfs_key_tfm_cache", 717 .size = sizeof(struct ecryptfs_key_tfm), 718 }, 719 { 720 .cache = &ecryptfs_open_req_cache, 721 .name = "ecryptfs_open_req_cache", 722 .size = sizeof(struct ecryptfs_open_req), 723 }, 724 }; 725 726 static void ecryptfs_free_kmem_caches(void) 727 { 728 int i; 729 730 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 731 struct ecryptfs_cache_info *info; 732 733 info = &ecryptfs_cache_infos[i]; 734 if (*(info->cache)) 735 kmem_cache_destroy(*(info->cache)); 736 } 737 } 738 739 /** 740 * ecryptfs_init_kmem_caches 741 * 742 * Returns zero on success; non-zero otherwise 743 */ 744 static int ecryptfs_init_kmem_caches(void) 745 { 746 int i; 747 748 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 749 struct ecryptfs_cache_info *info; 750 751 info = &ecryptfs_cache_infos[i]; 752 *(info->cache) = kmem_cache_create(info->name, info->size, 753 0, SLAB_HWCACHE_ALIGN, info->ctor); 754 if (!*(info->cache)) { 755 ecryptfs_free_kmem_caches(); 756 ecryptfs_printk(KERN_WARNING, "%s: " 757 "kmem_cache_create failed\n", 758 info->name); 759 return -ENOMEM; 760 } 761 } 762 return 0; 763 } 764 765 static struct kobject *ecryptfs_kobj; 766 767 static ssize_t version_show(struct kobject *kobj, 768 struct kobj_attribute *attr, char *buff) 769 { 770 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 771 } 772 773 static struct kobj_attribute version_attr = __ATTR_RO(version); 774 775 static struct attribute *attributes[] = { 776 &version_attr.attr, 777 NULL, 778 }; 779 780 static struct attribute_group attr_group = { 781 .attrs = attributes, 782 }; 783 784 static int do_sysfs_registration(void) 785 { 786 int rc; 787 788 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 789 if (!ecryptfs_kobj) { 790 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 791 rc = -ENOMEM; 792 goto out; 793 } 794 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 795 if (rc) { 796 printk(KERN_ERR 797 "Unable to create ecryptfs version attributes\n"); 798 kobject_put(ecryptfs_kobj); 799 } 800 out: 801 return rc; 802 } 803 804 static void do_sysfs_unregistration(void) 805 { 806 sysfs_remove_group(ecryptfs_kobj, &attr_group); 807 kobject_put(ecryptfs_kobj); 808 } 809 810 static int __init ecryptfs_init(void) 811 { 812 int rc; 813 814 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 815 rc = -EINVAL; 816 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 817 "larger than the host's page size, and so " 818 "eCryptfs cannot run on this system. The " 819 "default eCryptfs extent size is [%d] bytes; " 820 "the page size is [%d] bytes.\n", 821 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); 822 goto out; 823 } 824 rc = ecryptfs_init_kmem_caches(); 825 if (rc) { 826 printk(KERN_ERR 827 "Failed to allocate one or more kmem_cache objects\n"); 828 goto out; 829 } 830 rc = register_filesystem(&ecryptfs_fs_type); 831 if (rc) { 832 printk(KERN_ERR "Failed to register filesystem\n"); 833 goto out_free_kmem_caches; 834 } 835 rc = do_sysfs_registration(); 836 if (rc) { 837 printk(KERN_ERR "sysfs registration failed\n"); 838 goto out_unregister_filesystem; 839 } 840 rc = ecryptfs_init_kthread(); 841 if (rc) { 842 printk(KERN_ERR "%s: kthread initialization failed; " 843 "rc = [%d]\n", __func__, rc); 844 goto out_do_sysfs_unregistration; 845 } 846 rc = ecryptfs_init_messaging(); 847 if (rc) { 848 printk(KERN_ERR "Failure occured while attempting to " 849 "initialize the communications channel to " 850 "ecryptfsd\n"); 851 goto out_destroy_kthread; 852 } 853 rc = ecryptfs_init_crypto(); 854 if (rc) { 855 printk(KERN_ERR "Failure whilst attempting to init crypto; " 856 "rc = [%d]\n", rc); 857 goto out_release_messaging; 858 } 859 if (ecryptfs_verbosity > 0) 860 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 861 "will be written to the syslog!\n", ecryptfs_verbosity); 862 863 goto out; 864 out_release_messaging: 865 ecryptfs_release_messaging(); 866 out_destroy_kthread: 867 ecryptfs_destroy_kthread(); 868 out_do_sysfs_unregistration: 869 do_sysfs_unregistration(); 870 out_unregister_filesystem: 871 unregister_filesystem(&ecryptfs_fs_type); 872 out_free_kmem_caches: 873 ecryptfs_free_kmem_caches(); 874 out: 875 return rc; 876 } 877 878 static void __exit ecryptfs_exit(void) 879 { 880 int rc; 881 882 rc = ecryptfs_destroy_crypto(); 883 if (rc) 884 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 885 "rc = [%d]\n", rc); 886 ecryptfs_release_messaging(); 887 ecryptfs_destroy_kthread(); 888 do_sysfs_unregistration(); 889 unregister_filesystem(&ecryptfs_fs_type); 890 ecryptfs_free_kmem_caches(); 891 } 892 893 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 894 MODULE_DESCRIPTION("eCryptfs"); 895 896 MODULE_LICENSE("GPL"); 897 898 module_init(ecryptfs_init) 899 module_exit(ecryptfs_exit) 900