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 "ecryptfs_kernel.h" 40 41/** 42 * Module parameter that defines the ecryptfs_verbosity level. 43 */ 44int ecryptfs_verbosity = 0; 45 46module_param(ecryptfs_verbosity, int, 0); 47MODULE_PARM_DESC(ecryptfs_verbosity, 48 "Initial verbosity level (0 or 1; defaults to " 49 "0, which is Quiet)"); 50 51/** 52 * Module parameter that defines the number of message buffer elements 53 */ 54unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 55 56module_param(ecryptfs_message_buf_len, uint, 0); 57MODULE_PARM_DESC(ecryptfs_message_buf_len, 58 "Number of message buffer elements"); 59 60/** 61 * Module parameter that defines the maximum guaranteed amount of time to wait 62 * for a response from ecryptfsd. The actual sleep time will be, more than 63 * likely, a small amount greater than this specified value, but only less if 64 * the message successfully arrives. 65 */ 66signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 67 68module_param(ecryptfs_message_wait_timeout, long, 0); 69MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 70 "Maximum number of seconds that an operation will " 71 "sleep while waiting for a message response from " 72 "userspace"); 73 74/** 75 * Module parameter that is an estimate of the maximum number of users 76 * that will be concurrently using eCryptfs. Set this to the right 77 * value to balance performance and memory use. 78 */ 79unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 80 81module_param(ecryptfs_number_of_users, uint, 0); 82MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 83 "concurrent users of eCryptfs"); 84 85void __ecryptfs_printk(const char *fmt, ...) 86{ 87 va_list args; 88 va_start(args, fmt); 89 if (fmt[1] == '7') { /* KERN_DEBUG */ 90 if (ecryptfs_verbosity >= 1) 91 vprintk(fmt, args); 92 } else 93 vprintk(fmt, args); 94 va_end(args); 95} 96 97/** 98 * ecryptfs_init_persistent_file 99 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 100 * the lower dentry and the lower mount set 101 * 102 * eCryptfs only ever keeps a single open file for every lower 103 * inode. All I/O operations to the lower inode occur through that 104 * file. When the first eCryptfs dentry that interposes with the first 105 * lower dentry for that inode is created, this function creates the 106 * persistent file struct and associates it with the eCryptfs 107 * inode. When the eCryptfs inode is destroyed, the file is closed. 108 * 109 * The persistent file will be opened with read/write permissions, if 110 * possible. Otherwise, it is opened read-only. 111 * 112 * This function does nothing if a lower persistent file is already 113 * associated with the eCryptfs inode. 114 * 115 * Returns zero on success; non-zero otherwise 116 */ 117int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) 118{ 119 const struct cred *cred = current_cred(); 120 struct ecryptfs_inode_info *inode_info = 121 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); 122 int rc = 0; 123 124 mutex_lock(&inode_info->lower_file_mutex); 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 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 */ 155int 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); 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); 201out: 202 return rc; 203} 204 205enum { 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 213static 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 229static 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 } 251out: 252 return rc; 253} 254 255static 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 265static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) 266{ 267 char *p; 268 int rc = 0; 269 int sig_set = 0; 270 int cipher_name_set = 0; 271 int fn_cipher_name_set = 0; 272 int cipher_key_bytes; 273 int cipher_key_bytes_set = 0; 274 int fn_cipher_key_bytes; 275 int fn_cipher_key_bytes_set = 0; 276 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 277 &sbi->mount_crypt_stat; 278 substring_t args[MAX_OPT_ARGS]; 279 int token; 280 char *sig_src; 281 char *cipher_name_dst; 282 char *cipher_name_src; 283 char *fn_cipher_name_dst; 284 char *fn_cipher_name_src; 285 char *fnek_dst; 286 char *fnek_src; 287 char *cipher_key_bytes_src; 288 char *fn_cipher_key_bytes_src; 289 290 if (!options) { 291 rc = -EINVAL; 292 goto out; 293 } 294 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 295 while ((p = strsep(&options, ",")) != NULL) { 296 if (!*p) 297 continue; 298 token = match_token(p, tokens, args); 299 switch (token) { 300 case ecryptfs_opt_sig: 301 case ecryptfs_opt_ecryptfs_sig: 302 sig_src = args[0].from; 303 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 304 sig_src, 0); 305 if (rc) { 306 printk(KERN_ERR "Error attempting to register " 307 "global sig; rc = [%d]\n", rc); 308 goto out; 309 } 310 sig_set = 1; 311 break; 312 case ecryptfs_opt_cipher: 313 case ecryptfs_opt_ecryptfs_cipher: 314 cipher_name_src = args[0].from; 315 cipher_name_dst = 316 mount_crypt_stat-> 317 global_default_cipher_name; 318 strncpy(cipher_name_dst, cipher_name_src, 319 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 320 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 321 cipher_name_set = 1; 322 break; 323 case ecryptfs_opt_ecryptfs_key_bytes: 324 cipher_key_bytes_src = args[0].from; 325 cipher_key_bytes = 326 (int)simple_strtol(cipher_key_bytes_src, 327 &cipher_key_bytes_src, 0); 328 mount_crypt_stat->global_default_cipher_key_size = 329 cipher_key_bytes; 330 cipher_key_bytes_set = 1; 331 break; 332 case ecryptfs_opt_passthrough: 333 mount_crypt_stat->flags |= 334 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 335 break; 336 case ecryptfs_opt_xattr_metadata: 337 mount_crypt_stat->flags |= 338 ECRYPTFS_XATTR_METADATA_ENABLED; 339 break; 340 case ecryptfs_opt_encrypted_view: 341 mount_crypt_stat->flags |= 342 ECRYPTFS_XATTR_METADATA_ENABLED; 343 mount_crypt_stat->flags |= 344 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 345 break; 346 case ecryptfs_opt_fnek_sig: 347 fnek_src = args[0].from; 348 fnek_dst = 349 mount_crypt_stat->global_default_fnek_sig; 350 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); 351 mount_crypt_stat->global_default_fnek_sig[ 352 ECRYPTFS_SIG_SIZE_HEX] = '\0'; 353 rc = ecryptfs_add_global_auth_tok( 354 mount_crypt_stat, 355 mount_crypt_stat->global_default_fnek_sig, 356 ECRYPTFS_AUTH_TOK_FNEK); 357 if (rc) { 358 printk(KERN_ERR "Error attempting to register " 359 "global fnek sig [%s]; rc = [%d]\n", 360 mount_crypt_stat->global_default_fnek_sig, 361 rc); 362 goto out; 363 } 364 mount_crypt_stat->flags |= 365 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 366 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 367 break; 368 case ecryptfs_opt_fn_cipher: 369 fn_cipher_name_src = args[0].from; 370 fn_cipher_name_dst = 371 mount_crypt_stat->global_default_fn_cipher_name; 372 strncpy(fn_cipher_name_dst, fn_cipher_name_src, 373 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 374 mount_crypt_stat->global_default_fn_cipher_name[ 375 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; 376 fn_cipher_name_set = 1; 377 break; 378 case ecryptfs_opt_fn_cipher_key_bytes: 379 fn_cipher_key_bytes_src = args[0].from; 380 fn_cipher_key_bytes = 381 (int)simple_strtol(fn_cipher_key_bytes_src, 382 &fn_cipher_key_bytes_src, 0); 383 mount_crypt_stat->global_default_fn_cipher_key_bytes = 384 fn_cipher_key_bytes; 385 fn_cipher_key_bytes_set = 1; 386 break; 387 case ecryptfs_opt_unlink_sigs: 388 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 389 break; 390 case ecryptfs_opt_err: 391 default: 392 printk(KERN_WARNING 393 "%s: eCryptfs: unrecognized option [%s]\n", 394 __func__, p); 395 } 396 } 397 if (!sig_set) { 398 rc = -EINVAL; 399 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 400 "auth tok signature as a mount " 401 "parameter; see the eCryptfs README\n"); 402 goto out; 403 } 404 if (!cipher_name_set) { 405 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 406 407 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); 408 strcpy(mount_crypt_stat->global_default_cipher_name, 409 ECRYPTFS_DEFAULT_CIPHER); 410 } 411 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 412 && !fn_cipher_name_set) 413 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 414 mount_crypt_stat->global_default_cipher_name); 415 if (!cipher_key_bytes_set) 416 mount_crypt_stat->global_default_cipher_key_size = 0; 417 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 418 && !fn_cipher_key_bytes_set) 419 mount_crypt_stat->global_default_fn_cipher_key_bytes = 420 mount_crypt_stat->global_default_cipher_key_size; 421 mutex_lock(&key_tfm_list_mutex); 422 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 423 NULL)) { 424 rc = ecryptfs_add_new_key_tfm( 425 NULL, mount_crypt_stat->global_default_cipher_name, 426 mount_crypt_stat->global_default_cipher_key_size); 427 if (rc) { 428 printk(KERN_ERR "Error attempting to initialize " 429 "cipher with name = [%s] and key size = [%td]; " 430 "rc = [%d]\n", 431 mount_crypt_stat->global_default_cipher_name, 432 mount_crypt_stat->global_default_cipher_key_size, 433 rc); 434 rc = -EINVAL; 435 mutex_unlock(&key_tfm_list_mutex); 436 goto out; 437 } 438 } 439 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 440 && !ecryptfs_tfm_exists( 441 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 442 rc = ecryptfs_add_new_key_tfm( 443 NULL, mount_crypt_stat->global_default_fn_cipher_name, 444 mount_crypt_stat->global_default_fn_cipher_key_bytes); 445 if (rc) { 446 printk(KERN_ERR "Error attempting to initialize " 447 "cipher with name = [%s] and key size = [%td]; " 448 "rc = [%d]\n", 449 mount_crypt_stat->global_default_fn_cipher_name, 450 mount_crypt_stat->global_default_fn_cipher_key_bytes, 451 rc); 452 rc = -EINVAL; 453 mutex_unlock(&key_tfm_list_mutex); 454 goto out; 455 } 456 } 457 mutex_unlock(&key_tfm_list_mutex); 458 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 459 if (rc) 460 printk(KERN_WARNING "One or more global auth toks could not " 461 "properly register; rc = [%d]\n", rc); 462out: 463 return rc; 464} 465 466struct kmem_cache *ecryptfs_sb_info_cache; 467static struct file_system_type ecryptfs_fs_type; 468 469/** 470 * ecryptfs_read_super 471 * @sb: The ecryptfs super block 472 * @dev_name: The path to mount over 473 * 474 * Read the super block of the lower filesystem, and use 475 * ecryptfs_interpose to create our initial inode and super block 476 * struct. 477 */ 478static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) 479{ 480 struct path path; 481 int rc; 482 483 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 484 if (rc) { 485 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); 486 goto out; 487 } 488 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 489 rc = -EINVAL; 490 printk(KERN_ERR "Mount on filesystem of type " 491 "eCryptfs explicitly disallowed due to " 492 "known incompatibilities\n"); 493 goto out_free; 494 } 495 ecryptfs_set_superblock_lower(sb, path.dentry->d_sb); 496 sb->s_maxbytes = path.dentry->d_sb->s_maxbytes; 497 sb->s_blocksize = path.dentry->d_sb->s_blocksize; 498 ecryptfs_set_dentry_lower(sb->s_root, path.dentry); 499 ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt); 500 rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0); 501 if (rc) 502 goto out_free; 503 rc = 0; 504 goto out; 505out_free: 506 path_put(&path); 507out: 508 return rc; 509} 510 511/** 512 * ecryptfs_get_sb 513 * @fs_type 514 * @flags 515 * @dev_name: The path to mount over 516 * @raw_data: The options passed into the kernel 517 * 518 * The whole ecryptfs_get_sb process is broken into 3 functions: 519 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any 520 * ecryptfs_read_super(): this accesses the lower filesystem and uses 521 * ecryptfs_interpose to perform most of the linking 522 * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c) 523 */ 524static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, 525 const char *dev_name, void *raw_data, 526 struct vfsmount *mnt) 527{ 528 struct super_block *s; 529 struct ecryptfs_sb_info *sbi; 530 struct ecryptfs_dentry_info *root_info; 531 const char *err = "Getting sb failed"; 532 int rc; 533 534 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 535 if (!sbi) { 536 rc = -ENOMEM; 537 goto out; 538 } 539 540 rc = ecryptfs_parse_options(sbi, raw_data); 541 if (rc) { 542 err = "Error parsing options"; 543 goto out; 544 } 545 546 s = sget(fs_type, NULL, set_anon_super, NULL); 547 if (IS_ERR(s)) { 548 rc = PTR_ERR(s); 549 goto out; 550 } 551 552 s->s_flags = flags; 553 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 554 if (rc) { 555 deactivate_locked_super(s); 556 goto out; 557 } 558 559 ecryptfs_set_superblock_private(s, sbi); 560 s->s_bdi = &sbi->bdi; 561 562 /* ->kill_sb() will take care of sbi after that point */ 563 sbi = NULL; 564 s->s_op = &ecryptfs_sops; 565 566 rc = -ENOMEM; 567 s->s_root = d_alloc(NULL, &(const struct qstr) { 568 .hash = 0,.name = "/",.len = 1}); 569 if (!s->s_root) { 570 deactivate_locked_super(s); 571 goto out; 572 } 573 s->s_root->d_op = &ecryptfs_dops; 574 s->s_root->d_sb = s; 575 s->s_root->d_parent = s->s_root; 576 577 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 578 if (!root_info) { 579 deactivate_locked_super(s); 580 goto out; 581 } 582 /* ->kill_sb() will take care of root_info */ 583 ecryptfs_set_dentry_private(s->s_root, root_info); 584 s->s_flags |= MS_ACTIVE; 585 rc = ecryptfs_read_super(s, dev_name); 586 if (rc) { 587 deactivate_locked_super(s); 588 err = "Reading sb failed"; 589 goto out; 590 } 591 simple_set_mnt(mnt, s); 592 return 0; 593 594out: 595 if (sbi) { 596 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 597 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 598 } 599 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 600 return rc; 601} 602 603/** 604 * ecryptfs_kill_block_super 605 * @sb: The ecryptfs super block 606 * 607 * Used to bring the superblock down and free the private data. 608 */ 609static void ecryptfs_kill_block_super(struct super_block *sb) 610{ 611 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 612 kill_anon_super(sb); 613 if (!sb_info) 614 return; 615 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 616 bdi_destroy(&sb_info->bdi); 617 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 618} 619 620static struct file_system_type ecryptfs_fs_type = { 621 .owner = THIS_MODULE, 622 .name = "ecryptfs", 623 .get_sb = ecryptfs_get_sb, 624 .kill_sb = ecryptfs_kill_block_super, 625 .fs_flags = 0 626}; 627 628/** 629 * inode_info_init_once 630 * 631 * Initializes the ecryptfs_inode_info_cache when it is created 632 */ 633static void 634inode_info_init_once(void *vptr) 635{ 636 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 637 638 inode_init_once(&ei->vfs_inode); 639} 640 641static struct ecryptfs_cache_info { 642 struct kmem_cache **cache; 643 const char *name; 644 size_t size; 645 void (*ctor)(void *obj); 646} ecryptfs_cache_infos[] = { 647 { 648 .cache = &ecryptfs_auth_tok_list_item_cache, 649 .name = "ecryptfs_auth_tok_list_item", 650 .size = sizeof(struct ecryptfs_auth_tok_list_item), 651 }, 652 { 653 .cache = &ecryptfs_file_info_cache, 654 .name = "ecryptfs_file_cache", 655 .size = sizeof(struct ecryptfs_file_info), 656 }, 657 { 658 .cache = &ecryptfs_dentry_info_cache, 659 .name = "ecryptfs_dentry_info_cache", 660 .size = sizeof(struct ecryptfs_dentry_info), 661 }, 662 { 663 .cache = &ecryptfs_inode_info_cache, 664 .name = "ecryptfs_inode_cache", 665 .size = sizeof(struct ecryptfs_inode_info), 666 .ctor = inode_info_init_once, 667 }, 668 { 669 .cache = &ecryptfs_sb_info_cache, 670 .name = "ecryptfs_sb_cache", 671 .size = sizeof(struct ecryptfs_sb_info), 672 }, 673 { 674 .cache = &ecryptfs_header_cache_1, 675 .name = "ecryptfs_headers_1", 676 .size = PAGE_CACHE_SIZE, 677 }, 678 { 679 .cache = &ecryptfs_header_cache_2, 680 .name = "ecryptfs_headers_2", 681 .size = PAGE_CACHE_SIZE, 682 }, 683 { 684 .cache = &ecryptfs_xattr_cache, 685 .name = "ecryptfs_xattr_cache", 686 .size = PAGE_CACHE_SIZE, 687 }, 688 { 689 .cache = &ecryptfs_key_record_cache, 690 .name = "ecryptfs_key_record_cache", 691 .size = sizeof(struct ecryptfs_key_record), 692 }, 693 { 694 .cache = &ecryptfs_key_sig_cache, 695 .name = "ecryptfs_key_sig_cache", 696 .size = sizeof(struct ecryptfs_key_sig), 697 }, 698 { 699 .cache = &ecryptfs_global_auth_tok_cache, 700 .name = "ecryptfs_global_auth_tok_cache", 701 .size = sizeof(struct ecryptfs_global_auth_tok), 702 }, 703 { 704 .cache = &ecryptfs_key_tfm_cache, 705 .name = "ecryptfs_key_tfm_cache", 706 .size = sizeof(struct ecryptfs_key_tfm), 707 }, 708 { 709 .cache = &ecryptfs_open_req_cache, 710 .name = "ecryptfs_open_req_cache", 711 .size = sizeof(struct ecryptfs_open_req), 712 }, 713}; 714 715static void ecryptfs_free_kmem_caches(void) 716{ 717 int i; 718 719 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 720 struct ecryptfs_cache_info *info; 721 722 info = &ecryptfs_cache_infos[i]; 723 if (*(info->cache)) 724 kmem_cache_destroy(*(info->cache)); 725 } 726} 727 728/** 729 * ecryptfs_init_kmem_caches 730 * 731 * Returns zero on success; non-zero otherwise 732 */ 733static int ecryptfs_init_kmem_caches(void) 734{ 735 int i; 736 737 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 738 struct ecryptfs_cache_info *info; 739 740 info = &ecryptfs_cache_infos[i]; 741 *(info->cache) = kmem_cache_create(info->name, info->size, 742 0, SLAB_HWCACHE_ALIGN, info->ctor); 743 if (!*(info->cache)) { 744 ecryptfs_free_kmem_caches(); 745 ecryptfs_printk(KERN_WARNING, "%s: " 746 "kmem_cache_create failed\n", 747 info->name); 748 return -ENOMEM; 749 } 750 } 751 return 0; 752} 753 754static struct kobject *ecryptfs_kobj; 755 756static ssize_t version_show(struct kobject *kobj, 757 struct kobj_attribute *attr, char *buff) 758{ 759 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 760} 761 762static struct kobj_attribute version_attr = __ATTR_RO(version); 763 764static struct attribute *attributes[] = { 765 &version_attr.attr, 766 NULL, 767}; 768 769static struct attribute_group attr_group = { 770 .attrs = attributes, 771}; 772 773static int do_sysfs_registration(void) 774{ 775 int rc; 776 777 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 778 if (!ecryptfs_kobj) { 779 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 780 rc = -ENOMEM; 781 goto out; 782 } 783 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 784 if (rc) { 785 printk(KERN_ERR 786 "Unable to create ecryptfs version attributes\n"); 787 kobject_put(ecryptfs_kobj); 788 } 789out: 790 return rc; 791} 792 793static void do_sysfs_unregistration(void) 794{ 795 sysfs_remove_group(ecryptfs_kobj, &attr_group); 796 kobject_put(ecryptfs_kobj); 797} 798 799static int __init ecryptfs_init(void) 800{ 801 int rc; 802 803 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 804 rc = -EINVAL; 805 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 806 "larger than the host's page size, and so " 807 "eCryptfs cannot run on this system. The " 808 "default eCryptfs extent size is [%d] bytes; " 809 "the page size is [%d] bytes.\n", 810 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); 811 goto out; 812 } 813 rc = ecryptfs_init_kmem_caches(); 814 if (rc) { 815 printk(KERN_ERR 816 "Failed to allocate one or more kmem_cache objects\n"); 817 goto out; 818 } 819 rc = register_filesystem(&ecryptfs_fs_type); 820 if (rc) { 821 printk(KERN_ERR "Failed to register filesystem\n"); 822 goto out_free_kmem_caches; 823 } 824 rc = do_sysfs_registration(); 825 if (rc) { 826 printk(KERN_ERR "sysfs registration failed\n"); 827 goto out_unregister_filesystem; 828 } 829 rc = ecryptfs_init_kthread(); 830 if (rc) { 831 printk(KERN_ERR "%s: kthread initialization failed; " 832 "rc = [%d]\n", __func__, rc); 833 goto out_do_sysfs_unregistration; 834 } 835 rc = ecryptfs_init_messaging(); 836 if (rc) { 837 printk(KERN_ERR "Failure occured while attempting to " 838 "initialize the communications channel to " 839 "ecryptfsd\n"); 840 goto out_destroy_kthread; 841 } 842 rc = ecryptfs_init_crypto(); 843 if (rc) { 844 printk(KERN_ERR "Failure whilst attempting to init crypto; " 845 "rc = [%d]\n", rc); 846 goto out_release_messaging; 847 } 848 if (ecryptfs_verbosity > 0) 849 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 850 "will be written to the syslog!\n", ecryptfs_verbosity); 851 852 goto out; 853out_release_messaging: 854 ecryptfs_release_messaging(); 855out_destroy_kthread: 856 ecryptfs_destroy_kthread(); 857out_do_sysfs_unregistration: 858 do_sysfs_unregistration(); 859out_unregister_filesystem: 860 unregister_filesystem(&ecryptfs_fs_type); 861out_free_kmem_caches: 862 ecryptfs_free_kmem_caches(); 863out: 864 return rc; 865} 866 867static void __exit ecryptfs_exit(void) 868{ 869 int rc; 870 871 rc = ecryptfs_destroy_crypto(); 872 if (rc) 873 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 874 "rc = [%d]\n", rc); 875 ecryptfs_release_messaging(); 876 ecryptfs_destroy_kthread(); 877 do_sysfs_unregistration(); 878 unregister_filesystem(&ecryptfs_fs_type); 879 ecryptfs_free_kmem_caches(); 880} 881 882MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 883MODULE_DESCRIPTION("eCryptfs"); 884 885MODULE_LICENSE("GPL"); 886 887module_init(ecryptfs_init) 888module_exit(ecryptfs_exit) 889