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 */ 44 int ecryptfs_verbosity = 0; 45 46 module_param(ecryptfs_verbosity, int, 0); 47 MODULE_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 */ 54 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 55 56 module_param(ecryptfs_message_buf_len, uint, 0); 57 MODULE_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 */ 66 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 67 68 module_param(ecryptfs_message_wait_timeout, long, 0); 69 MODULE_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 */ 79 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 80 81 module_param(ecryptfs_number_of_users, uint, 0); 82 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 83 "concurrent users of eCryptfs"); 84 85 void __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 */ 117 int 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 */ 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); 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 ecryptfs_sb_info *sbi, 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 &sbi->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 static struct file_system_type ecryptfs_fs_type; 487 488 /** 489 * ecryptfs_read_super 490 * @sb: The ecryptfs super block 491 * @dev_name: The path to mount over 492 * 493 * Read the super block of the lower filesystem, and use 494 * ecryptfs_interpose to create our initial inode and super block 495 * struct. 496 */ 497 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) 498 { 499 struct path path; 500 int rc; 501 502 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 503 if (rc) { 504 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); 505 goto out; 506 } 507 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 508 rc = -EINVAL; 509 printk(KERN_ERR "Mount on filesystem of type " 510 "eCryptfs explicitly disallowed due to " 511 "known incompatibilities\n"); 512 goto out_free; 513 } 514 ecryptfs_set_superblock_lower(sb, path.dentry->d_sb); 515 sb->s_maxbytes = path.dentry->d_sb->s_maxbytes; 516 sb->s_blocksize = path.dentry->d_sb->s_blocksize; 517 ecryptfs_set_dentry_lower(sb->s_root, path.dentry); 518 ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt); 519 rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0); 520 if (rc) 521 goto out_free; 522 rc = 0; 523 goto out; 524 out_free: 525 path_put(&path); 526 out: 527 return rc; 528 } 529 530 /** 531 * ecryptfs_get_sb 532 * @fs_type 533 * @flags 534 * @dev_name: The path to mount over 535 * @raw_data: The options passed into the kernel 536 * 537 * The whole ecryptfs_get_sb process is broken into 3 functions: 538 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any 539 * ecryptfs_read_super(): this accesses the lower filesystem and uses 540 * ecryptfs_interpose to perform most of the linking 541 * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c) 542 */ 543 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, 544 const char *dev_name, void *raw_data, 545 struct vfsmount *mnt) 546 { 547 struct super_block *s; 548 struct ecryptfs_sb_info *sbi; 549 struct ecryptfs_dentry_info *root_info; 550 const char *err = "Getting sb failed"; 551 int rc; 552 553 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 554 if (!sbi) { 555 rc = -ENOMEM; 556 goto out; 557 } 558 559 rc = ecryptfs_parse_options(sbi, raw_data); 560 if (rc) { 561 err = "Error parsing options"; 562 goto out; 563 } 564 565 s = sget(fs_type, NULL, set_anon_super, NULL); 566 if (IS_ERR(s)) { 567 rc = PTR_ERR(s); 568 goto out; 569 } 570 571 s->s_flags = flags; 572 rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); 573 if (rc) { 574 deactivate_locked_super(s); 575 goto out; 576 } 577 578 ecryptfs_set_superblock_private(s, sbi); 579 s->s_bdi = &sbi->bdi; 580 581 /* ->kill_sb() will take care of sbi after that point */ 582 sbi = NULL; 583 s->s_op = &ecryptfs_sops; 584 585 rc = -ENOMEM; 586 s->s_root = d_alloc(NULL, &(const struct qstr) { 587 .hash = 0,.name = "/",.len = 1}); 588 if (!s->s_root) { 589 deactivate_locked_super(s); 590 goto out; 591 } 592 s->s_root->d_op = &ecryptfs_dops; 593 s->s_root->d_sb = s; 594 s->s_root->d_parent = s->s_root; 595 596 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 597 if (!root_info) { 598 deactivate_locked_super(s); 599 goto out; 600 } 601 /* ->kill_sb() will take care of root_info */ 602 ecryptfs_set_dentry_private(s->s_root, root_info); 603 s->s_flags |= MS_ACTIVE; 604 rc = ecryptfs_read_super(s, dev_name); 605 if (rc) { 606 deactivate_locked_super(s); 607 err = "Reading sb failed"; 608 goto out; 609 } 610 simple_set_mnt(mnt, s); 611 return 0; 612 613 out: 614 if (sbi) { 615 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 616 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 617 } 618 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 619 return rc; 620 } 621 622 /** 623 * ecryptfs_kill_block_super 624 * @sb: The ecryptfs super block 625 * 626 * Used to bring the superblock down and free the private data. 627 */ 628 static void ecryptfs_kill_block_super(struct super_block *sb) 629 { 630 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 631 kill_anon_super(sb); 632 if (!sb_info) 633 return; 634 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 635 bdi_destroy(&sb_info->bdi); 636 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 637 } 638 639 static struct file_system_type ecryptfs_fs_type = { 640 .owner = THIS_MODULE, 641 .name = "ecryptfs", 642 .get_sb = ecryptfs_get_sb, 643 .kill_sb = ecryptfs_kill_block_super, 644 .fs_flags = 0 645 }; 646 647 /** 648 * inode_info_init_once 649 * 650 * Initializes the ecryptfs_inode_info_cache when it is created 651 */ 652 static void 653 inode_info_init_once(void *vptr) 654 { 655 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 656 657 inode_init_once(&ei->vfs_inode); 658 } 659 660 static struct ecryptfs_cache_info { 661 struct kmem_cache **cache; 662 const char *name; 663 size_t size; 664 void (*ctor)(void *obj); 665 } ecryptfs_cache_infos[] = { 666 { 667 .cache = &ecryptfs_auth_tok_list_item_cache, 668 .name = "ecryptfs_auth_tok_list_item", 669 .size = sizeof(struct ecryptfs_auth_tok_list_item), 670 }, 671 { 672 .cache = &ecryptfs_file_info_cache, 673 .name = "ecryptfs_file_cache", 674 .size = sizeof(struct ecryptfs_file_info), 675 }, 676 { 677 .cache = &ecryptfs_dentry_info_cache, 678 .name = "ecryptfs_dentry_info_cache", 679 .size = sizeof(struct ecryptfs_dentry_info), 680 }, 681 { 682 .cache = &ecryptfs_inode_info_cache, 683 .name = "ecryptfs_inode_cache", 684 .size = sizeof(struct ecryptfs_inode_info), 685 .ctor = inode_info_init_once, 686 }, 687 { 688 .cache = &ecryptfs_sb_info_cache, 689 .name = "ecryptfs_sb_cache", 690 .size = sizeof(struct ecryptfs_sb_info), 691 }, 692 { 693 .cache = &ecryptfs_header_cache_1, 694 .name = "ecryptfs_headers_1", 695 .size = PAGE_CACHE_SIZE, 696 }, 697 { 698 .cache = &ecryptfs_header_cache_2, 699 .name = "ecryptfs_headers_2", 700 .size = PAGE_CACHE_SIZE, 701 }, 702 { 703 .cache = &ecryptfs_xattr_cache, 704 .name = "ecryptfs_xattr_cache", 705 .size = PAGE_CACHE_SIZE, 706 }, 707 { 708 .cache = &ecryptfs_key_record_cache, 709 .name = "ecryptfs_key_record_cache", 710 .size = sizeof(struct ecryptfs_key_record), 711 }, 712 { 713 .cache = &ecryptfs_key_sig_cache, 714 .name = "ecryptfs_key_sig_cache", 715 .size = sizeof(struct ecryptfs_key_sig), 716 }, 717 { 718 .cache = &ecryptfs_global_auth_tok_cache, 719 .name = "ecryptfs_global_auth_tok_cache", 720 .size = sizeof(struct ecryptfs_global_auth_tok), 721 }, 722 { 723 .cache = &ecryptfs_key_tfm_cache, 724 .name = "ecryptfs_key_tfm_cache", 725 .size = sizeof(struct ecryptfs_key_tfm), 726 }, 727 { 728 .cache = &ecryptfs_open_req_cache, 729 .name = "ecryptfs_open_req_cache", 730 .size = sizeof(struct ecryptfs_open_req), 731 }, 732 }; 733 734 static void ecryptfs_free_kmem_caches(void) 735 { 736 int i; 737 738 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 739 struct ecryptfs_cache_info *info; 740 741 info = &ecryptfs_cache_infos[i]; 742 if (*(info->cache)) 743 kmem_cache_destroy(*(info->cache)); 744 } 745 } 746 747 /** 748 * ecryptfs_init_kmem_caches 749 * 750 * Returns zero on success; non-zero otherwise 751 */ 752 static int ecryptfs_init_kmem_caches(void) 753 { 754 int i; 755 756 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 757 struct ecryptfs_cache_info *info; 758 759 info = &ecryptfs_cache_infos[i]; 760 *(info->cache) = kmem_cache_create(info->name, info->size, 761 0, SLAB_HWCACHE_ALIGN, info->ctor); 762 if (!*(info->cache)) { 763 ecryptfs_free_kmem_caches(); 764 ecryptfs_printk(KERN_WARNING, "%s: " 765 "kmem_cache_create failed\n", 766 info->name); 767 return -ENOMEM; 768 } 769 } 770 return 0; 771 } 772 773 static struct kobject *ecryptfs_kobj; 774 775 static ssize_t version_show(struct kobject *kobj, 776 struct kobj_attribute *attr, char *buff) 777 { 778 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 779 } 780 781 static struct kobj_attribute version_attr = __ATTR_RO(version); 782 783 static struct attribute *attributes[] = { 784 &version_attr.attr, 785 NULL, 786 }; 787 788 static struct attribute_group attr_group = { 789 .attrs = attributes, 790 }; 791 792 static int do_sysfs_registration(void) 793 { 794 int rc; 795 796 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 797 if (!ecryptfs_kobj) { 798 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 799 rc = -ENOMEM; 800 goto out; 801 } 802 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 803 if (rc) { 804 printk(KERN_ERR 805 "Unable to create ecryptfs version attributes\n"); 806 kobject_put(ecryptfs_kobj); 807 } 808 out: 809 return rc; 810 } 811 812 static void do_sysfs_unregistration(void) 813 { 814 sysfs_remove_group(ecryptfs_kobj, &attr_group); 815 kobject_put(ecryptfs_kobj); 816 } 817 818 static int __init ecryptfs_init(void) 819 { 820 int rc; 821 822 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 823 rc = -EINVAL; 824 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 825 "larger than the host's page size, and so " 826 "eCryptfs cannot run on this system. The " 827 "default eCryptfs extent size is [%d] bytes; " 828 "the page size is [%d] bytes.\n", 829 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); 830 goto out; 831 } 832 rc = ecryptfs_init_kmem_caches(); 833 if (rc) { 834 printk(KERN_ERR 835 "Failed to allocate one or more kmem_cache objects\n"); 836 goto out; 837 } 838 rc = register_filesystem(&ecryptfs_fs_type); 839 if (rc) { 840 printk(KERN_ERR "Failed to register filesystem\n"); 841 goto out_free_kmem_caches; 842 } 843 rc = do_sysfs_registration(); 844 if (rc) { 845 printk(KERN_ERR "sysfs registration failed\n"); 846 goto out_unregister_filesystem; 847 } 848 rc = ecryptfs_init_kthread(); 849 if (rc) { 850 printk(KERN_ERR "%s: kthread initialization failed; " 851 "rc = [%d]\n", __func__, rc); 852 goto out_do_sysfs_unregistration; 853 } 854 rc = ecryptfs_init_messaging(); 855 if (rc) { 856 printk(KERN_ERR "Failure occured while attempting to " 857 "initialize the communications channel to " 858 "ecryptfsd\n"); 859 goto out_destroy_kthread; 860 } 861 rc = ecryptfs_init_crypto(); 862 if (rc) { 863 printk(KERN_ERR "Failure whilst attempting to init crypto; " 864 "rc = [%d]\n", rc); 865 goto out_release_messaging; 866 } 867 if (ecryptfs_verbosity > 0) 868 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 869 "will be written to the syslog!\n", ecryptfs_verbosity); 870 871 goto out; 872 out_release_messaging: 873 ecryptfs_release_messaging(); 874 out_destroy_kthread: 875 ecryptfs_destroy_kthread(); 876 out_do_sysfs_unregistration: 877 do_sysfs_unregistration(); 878 out_unregister_filesystem: 879 unregister_filesystem(&ecryptfs_fs_type); 880 out_free_kmem_caches: 881 ecryptfs_free_kmem_caches(); 882 out: 883 return rc; 884 } 885 886 static void __exit ecryptfs_exit(void) 887 { 888 int rc; 889 890 rc = ecryptfs_destroy_crypto(); 891 if (rc) 892 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 893 "rc = [%d]\n", rc); 894 ecryptfs_release_messaging(); 895 ecryptfs_destroy_kthread(); 896 do_sysfs_unregistration(); 897 unregister_filesystem(&ecryptfs_fs_type); 898 ecryptfs_free_kmem_caches(); 899 } 900 901 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 902 MODULE_DESCRIPTION("eCryptfs"); 903 904 MODULE_LICENSE("GPL"); 905 906 module_init(ecryptfs_init) 907 module_exit(ecryptfs_exit) 908