1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * eCryptfs: Linux filesystem encryption layer 4 * 5 * Copyright (C) 1997-2003 Erez Zadok 6 * Copyright (C) 2001-2003 Stony Brook University 7 * Copyright (C) 2004-2007 International Business Machines Corp. 8 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> 9 * Michael C. Thompson <mcthomps@us.ibm.com> 10 * Tyler Hicks <code@tyhicks.com> 11 */ 12 13 #include <linux/dcache.h> 14 #include <linux/file.h> 15 #include <linux/module.h> 16 #include <linux/namei.h> 17 #include <linux/skbuff.h> 18 #include <linux/pagemap.h> 19 #include <linux/key.h> 20 #include <linux/fs_context.h> 21 #include <linux/fs_parser.h> 22 #include <linux/fs_stack.h> 23 #include <linux/sysfs.h> 24 #include <linux/slab.h> 25 #include <linux/magic.h> 26 #include "ecryptfs_kernel.h" 27 28 /* 29 * Module parameter that defines the ecryptfs_verbosity level. 30 */ 31 int ecryptfs_verbosity = 0; 32 33 module_param(ecryptfs_verbosity, int, 0); 34 MODULE_PARM_DESC(ecryptfs_verbosity, 35 "Initial verbosity level (0 or 1; defaults to " 36 "0, which is Quiet)"); 37 38 /* 39 * Module parameter that defines the number of message buffer elements 40 */ 41 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 42 43 module_param(ecryptfs_message_buf_len, uint, 0); 44 MODULE_PARM_DESC(ecryptfs_message_buf_len, 45 "Number of message buffer elements"); 46 47 /* 48 * Module parameter that defines the maximum guaranteed amount of time to wait 49 * for a response from ecryptfsd. The actual sleep time will be, more than 50 * likely, a small amount greater than this specified value, but only less if 51 * the message successfully arrives. 52 */ 53 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 54 55 module_param(ecryptfs_message_wait_timeout, long, 0); 56 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 57 "Maximum number of seconds that an operation will " 58 "sleep while waiting for a message response from " 59 "userspace"); 60 61 /* 62 * Module parameter that is an estimate of the maximum number of users 63 * that will be concurrently using eCryptfs. Set this to the right 64 * value to balance performance and memory use. 65 */ 66 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 67 68 module_param(ecryptfs_number_of_users, uint, 0); 69 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 70 "concurrent users of eCryptfs"); 71 72 void __ecryptfs_printk(const char *fmt, ...) 73 { 74 va_list args; 75 va_start(args, fmt); 76 if (fmt[1] == '7') { /* KERN_DEBUG */ 77 if (ecryptfs_verbosity >= 1) 78 vprintk(fmt, args); 79 } else 80 vprintk(fmt, args); 81 va_end(args); 82 } 83 84 /* 85 * ecryptfs_init_lower_file 86 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 87 * the lower dentry and the lower mount set 88 * 89 * eCryptfs only ever keeps a single open file for every lower 90 * inode. All I/O operations to the lower inode occur through that 91 * file. When the first eCryptfs dentry that interposes with the first 92 * lower dentry for that inode is created, this function creates the 93 * lower file struct and associates it with the eCryptfs 94 * inode. When all eCryptfs files associated with the inode are released, the 95 * file is closed. 96 * 97 * The lower file will be opened with read/write permissions, if 98 * possible. Otherwise, it is opened read-only. 99 * 100 * This function does nothing if a lower file is already 101 * associated with the eCryptfs inode. 102 * 103 * Returns zero on success; non-zero otherwise 104 */ 105 static int ecryptfs_init_lower_file(struct dentry *dentry, 106 struct file **lower_file) 107 { 108 const struct cred *cred = current_cred(); 109 struct path path = ecryptfs_lower_path(dentry); 110 int rc; 111 112 rc = ecryptfs_privileged_open(lower_file, path.dentry, path.mnt, cred); 113 if (rc) { 114 printk(KERN_ERR "Error opening lower file " 115 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 116 "rc = [%d]\n", path.dentry, path.mnt, rc); 117 (*lower_file) = NULL; 118 } 119 return rc; 120 } 121 122 int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) 123 { 124 struct ecryptfs_inode_info *inode_info; 125 int count, rc = 0; 126 127 inode_info = ecryptfs_inode_to_private(inode); 128 mutex_lock(&inode_info->lower_file_mutex); 129 count = atomic_inc_return(&inode_info->lower_file_count); 130 if (WARN_ON_ONCE(count < 1)) 131 rc = -EINVAL; 132 else if (count == 1) { 133 rc = ecryptfs_init_lower_file(dentry, 134 &inode_info->lower_file); 135 if (rc) 136 atomic_set(&inode_info->lower_file_count, 0); 137 } 138 mutex_unlock(&inode_info->lower_file_mutex); 139 return rc; 140 } 141 142 void ecryptfs_put_lower_file(struct inode *inode) 143 { 144 struct ecryptfs_inode_info *inode_info; 145 146 inode_info = ecryptfs_inode_to_private(inode); 147 if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, 148 &inode_info->lower_file_mutex)) { 149 filemap_write_and_wait(inode->i_mapping); 150 fput(inode_info->lower_file); 151 inode_info->lower_file = NULL; 152 mutex_unlock(&inode_info->lower_file_mutex); 153 } 154 } 155 156 enum { 157 Opt_sig, Opt_ecryptfs_sig, Opt_cipher, Opt_ecryptfs_cipher, 158 Opt_ecryptfs_key_bytes, Opt_passthrough, Opt_xattr_metadata, 159 Opt_encrypted_view, Opt_fnek_sig, Opt_fn_cipher, 160 Opt_fn_cipher_key_bytes, Opt_unlink_sigs, Opt_mount_auth_tok_only, 161 Opt_check_dev_ruid 162 }; 163 164 static const struct fs_parameter_spec ecryptfs_fs_param_spec[] = { 165 fsparam_string ("sig", Opt_sig), 166 fsparam_string ("ecryptfs_sig", Opt_ecryptfs_sig), 167 fsparam_string ("cipher", Opt_cipher), 168 fsparam_string ("ecryptfs_cipher", Opt_ecryptfs_cipher), 169 fsparam_u32 ("ecryptfs_key_bytes", Opt_ecryptfs_key_bytes), 170 fsparam_flag ("ecryptfs_passthrough", Opt_passthrough), 171 fsparam_flag ("ecryptfs_xattr_metadata", Opt_xattr_metadata), 172 fsparam_flag ("ecryptfs_encrypted_view", Opt_encrypted_view), 173 fsparam_string ("ecryptfs_fnek_sig", Opt_fnek_sig), 174 fsparam_string ("ecryptfs_fn_cipher", Opt_fn_cipher), 175 fsparam_u32 ("ecryptfs_fn_key_bytes", Opt_fn_cipher_key_bytes), 176 fsparam_flag ("ecryptfs_unlink_sigs", Opt_unlink_sigs), 177 fsparam_flag ("ecryptfs_mount_auth_tok_only", Opt_mount_auth_tok_only), 178 fsparam_flag ("ecryptfs_check_dev_ruid", Opt_check_dev_ruid), 179 {} 180 }; 181 182 static int ecryptfs_init_global_auth_toks( 183 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 184 { 185 struct ecryptfs_global_auth_tok *global_auth_tok; 186 struct ecryptfs_auth_tok *auth_tok; 187 int rc = 0; 188 189 list_for_each_entry(global_auth_tok, 190 &mount_crypt_stat->global_auth_tok_list, 191 mount_crypt_stat_list) { 192 rc = ecryptfs_keyring_auth_tok_for_sig( 193 &global_auth_tok->global_auth_tok_key, &auth_tok, 194 global_auth_tok->sig); 195 if (rc) { 196 printk(KERN_ERR "Could not find valid key in user " 197 "session keyring for sig specified in mount " 198 "option: [%s]\n", global_auth_tok->sig); 199 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 200 goto out; 201 } else { 202 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 203 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 204 } 205 } 206 out: 207 return rc; 208 } 209 210 static void ecryptfs_init_mount_crypt_stat( 211 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 212 { 213 memset((void *)mount_crypt_stat, 0, 214 sizeof(struct ecryptfs_mount_crypt_stat)); 215 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 216 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 217 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 218 } 219 220 struct ecryptfs_fs_context { 221 /* Mount option status trackers */ 222 bool check_ruid; 223 bool sig_set; 224 bool cipher_name_set; 225 bool cipher_key_bytes_set; 226 bool fn_cipher_name_set; 227 bool fn_cipher_key_bytes_set; 228 }; 229 230 /** 231 * ecryptfs_parse_param 232 * @fc: The ecryptfs filesystem context 233 * @param: The mount parameter to parse 234 * 235 * The signature of the key to use must be the description of a key 236 * already in the keyring. Mounting will fail if the key can not be 237 * found. 238 * 239 * Returns zero on success; non-zero on error 240 */ 241 static int ecryptfs_parse_param( 242 struct fs_context *fc, 243 struct fs_parameter *param) 244 { 245 int rc; 246 int opt; 247 struct fs_parse_result result; 248 struct ecryptfs_fs_context *ctx = fc->fs_private; 249 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 250 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 251 &sbi->mount_crypt_stat; 252 253 opt = fs_parse(fc, ecryptfs_fs_param_spec, param, &result); 254 if (opt < 0) 255 return opt; 256 257 switch (opt) { 258 case Opt_sig: 259 case Opt_ecryptfs_sig: 260 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 261 param->string, 0); 262 if (rc) { 263 printk(KERN_ERR "Error attempting to register " 264 "global sig; rc = [%d]\n", rc); 265 return rc; 266 } 267 ctx->sig_set = 1; 268 break; 269 case Opt_cipher: 270 case Opt_ecryptfs_cipher: 271 strscpy(mount_crypt_stat->global_default_cipher_name, 272 param->string); 273 ctx->cipher_name_set = 1; 274 break; 275 case Opt_ecryptfs_key_bytes: 276 mount_crypt_stat->global_default_cipher_key_size = 277 result.uint_32; 278 ctx->cipher_key_bytes_set = 1; 279 break; 280 case Opt_passthrough: 281 mount_crypt_stat->flags |= 282 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 283 break; 284 case Opt_xattr_metadata: 285 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; 286 break; 287 case Opt_encrypted_view: 288 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; 289 mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 290 break; 291 case Opt_fnek_sig: 292 strscpy(mount_crypt_stat->global_default_fnek_sig, 293 param->string); 294 rc = ecryptfs_add_global_auth_tok( 295 mount_crypt_stat, 296 mount_crypt_stat->global_default_fnek_sig, 297 ECRYPTFS_AUTH_TOK_FNEK); 298 if (rc) { 299 printk(KERN_ERR "Error attempting to register " 300 "global fnek sig [%s]; rc = [%d]\n", 301 mount_crypt_stat->global_default_fnek_sig, rc); 302 return rc; 303 } 304 mount_crypt_stat->flags |= 305 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 306 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 307 break; 308 case Opt_fn_cipher: 309 strscpy(mount_crypt_stat->global_default_fn_cipher_name, 310 param->string); 311 ctx->fn_cipher_name_set = 1; 312 break; 313 case Opt_fn_cipher_key_bytes: 314 mount_crypt_stat->global_default_fn_cipher_key_bytes = 315 result.uint_32; 316 ctx->fn_cipher_key_bytes_set = 1; 317 break; 318 case Opt_unlink_sigs: 319 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 320 break; 321 case Opt_mount_auth_tok_only: 322 mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 323 break; 324 case Opt_check_dev_ruid: 325 ctx->check_ruid = 1; 326 break; 327 default: 328 return -EINVAL; 329 } 330 331 return 0; 332 } 333 334 static int ecryptfs_validate_options(struct fs_context *fc) 335 { 336 int rc = 0; 337 u8 cipher_code; 338 struct ecryptfs_fs_context *ctx = fc->fs_private; 339 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 340 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 341 342 343 mount_crypt_stat = &sbi->mount_crypt_stat; 344 345 if (!ctx->sig_set) { 346 rc = -EINVAL; 347 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 348 "auth tok signature as a mount " 349 "parameter; see the eCryptfs README\n"); 350 goto out; 351 } 352 if (!ctx->cipher_name_set) { 353 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 354 355 BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE); 356 strcpy(mount_crypt_stat->global_default_cipher_name, 357 ECRYPTFS_DEFAULT_CIPHER); 358 } 359 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 360 && !ctx->fn_cipher_name_set) 361 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 362 mount_crypt_stat->global_default_cipher_name); 363 if (!ctx->cipher_key_bytes_set) 364 mount_crypt_stat->global_default_cipher_key_size = 0; 365 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 366 && !ctx->fn_cipher_key_bytes_set) 367 mount_crypt_stat->global_default_fn_cipher_key_bytes = 368 mount_crypt_stat->global_default_cipher_key_size; 369 370 cipher_code = ecryptfs_code_for_cipher_string( 371 mount_crypt_stat->global_default_cipher_name, 372 mount_crypt_stat->global_default_cipher_key_size); 373 if (!cipher_code) { 374 ecryptfs_printk(KERN_ERR, 375 "eCryptfs doesn't support cipher: %s\n", 376 mount_crypt_stat->global_default_cipher_name); 377 rc = -EINVAL; 378 goto out; 379 } 380 381 mutex_lock(&key_tfm_list_mutex); 382 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 383 NULL)) { 384 rc = ecryptfs_add_new_key_tfm( 385 NULL, mount_crypt_stat->global_default_cipher_name, 386 mount_crypt_stat->global_default_cipher_key_size); 387 if (rc) { 388 printk(KERN_ERR "Error attempting to initialize " 389 "cipher with name = [%s] and key size = [%td]; " 390 "rc = [%d]\n", 391 mount_crypt_stat->global_default_cipher_name, 392 mount_crypt_stat->global_default_cipher_key_size, 393 rc); 394 rc = -EINVAL; 395 mutex_unlock(&key_tfm_list_mutex); 396 goto out; 397 } 398 } 399 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 400 && !ecryptfs_tfm_exists( 401 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 402 rc = ecryptfs_add_new_key_tfm( 403 NULL, mount_crypt_stat->global_default_fn_cipher_name, 404 mount_crypt_stat->global_default_fn_cipher_key_bytes); 405 if (rc) { 406 printk(KERN_ERR "Error attempting to initialize " 407 "cipher with name = [%s] and key size = [%td]; " 408 "rc = [%d]\n", 409 mount_crypt_stat->global_default_fn_cipher_name, 410 mount_crypt_stat->global_default_fn_cipher_key_bytes, 411 rc); 412 rc = -EINVAL; 413 mutex_unlock(&key_tfm_list_mutex); 414 goto out; 415 } 416 } 417 mutex_unlock(&key_tfm_list_mutex); 418 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 419 if (rc) 420 printk(KERN_WARNING "One or more global auth toks could not " 421 "properly register; rc = [%d]\n", rc); 422 out: 423 return rc; 424 } 425 426 struct kmem_cache *ecryptfs_sb_info_cache; 427 static struct file_system_type ecryptfs_fs_type; 428 429 /* 430 * ecryptfs_get_tree 431 * @fc: The filesystem context 432 */ 433 static int ecryptfs_get_tree(struct fs_context *fc) 434 { 435 struct super_block *s; 436 struct ecryptfs_fs_context *ctx = fc->fs_private; 437 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 438 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 439 const char *err = "Getting sb failed"; 440 struct inode *inode; 441 struct path path; 442 int rc; 443 444 if (!fc->source) { 445 rc = -EINVAL; 446 err = "Device name cannot be null"; 447 goto out; 448 } 449 450 mount_crypt_stat = &sbi->mount_crypt_stat; 451 rc = ecryptfs_validate_options(fc); 452 if (rc) { 453 err = "Error validating options"; 454 goto out; 455 } 456 457 s = sget_fc(fc, NULL, set_anon_super_fc); 458 if (IS_ERR(s)) { 459 rc = PTR_ERR(s); 460 goto out; 461 } 462 463 rc = super_setup_bdi(s); 464 if (rc) 465 goto out1; 466 467 ecryptfs_set_superblock_private(s, sbi); 468 469 /* ->kill_sb() will take care of sbi after that point */ 470 sbi = NULL; 471 s->s_op = &ecryptfs_sops; 472 s->s_xattr = ecryptfs_xattr_handlers; 473 set_default_d_op(s, &ecryptfs_dops); 474 475 err = "Reading sb failed"; 476 rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 477 if (rc) { 478 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 479 goto out1; 480 } 481 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 482 rc = -EINVAL; 483 printk(KERN_ERR "Mount on filesystem of type " 484 "eCryptfs explicitly disallowed due to " 485 "known incompatibilities\n"); 486 goto out_free; 487 } 488 489 if (is_idmapped_mnt(path.mnt)) { 490 rc = -EINVAL; 491 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n"); 492 goto out_free; 493 } 494 495 if (ctx->check_ruid && 496 !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { 497 rc = -EPERM; 498 printk(KERN_ERR "Mount of device (uid: %d) not owned by " 499 "requested user (uid: %d)\n", 500 i_uid_read(d_inode(path.dentry)), 501 from_kuid(&init_user_ns, current_uid())); 502 goto out_free; 503 } 504 505 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 506 507 /** 508 * Set the POSIX ACL flag based on whether they're enabled in the lower 509 * mount. 510 */ 511 s->s_flags = fc->sb_flags & ~SB_POSIXACL; 512 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL; 513 514 /** 515 * Force a read-only eCryptfs mount when: 516 * 1) The lower mount is ro 517 * 2) The ecryptfs_encrypted_view mount option is specified 518 */ 519 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) 520 s->s_flags |= SB_RDONLY; 521 522 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 523 s->s_blocksize = path.dentry->d_sb->s_blocksize; 524 s->s_magic = ECRYPTFS_SUPER_MAGIC; 525 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; 526 527 rc = -EINVAL; 528 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { 529 pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); 530 goto out_free; 531 } 532 533 inode = ecryptfs_get_inode(d_inode(path.dentry), s); 534 rc = PTR_ERR(inode); 535 if (IS_ERR(inode)) 536 goto out_free; 537 538 s->s_root = d_make_root(inode); 539 if (!s->s_root) { 540 rc = -ENOMEM; 541 goto out_free; 542 } 543 544 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 545 ecryptfs_superblock_to_private(s)->lower_mnt = path.mnt; 546 547 s->s_flags |= SB_ACTIVE; 548 fc->root = dget(s->s_root); 549 return 0; 550 551 out_free: 552 path_put(&path); 553 out1: 554 deactivate_locked_super(s); 555 out: 556 if (sbi) 557 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 558 559 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 560 return rc; 561 } 562 563 /** 564 * ecryptfs_kill_block_super 565 * @sb: The ecryptfs super block 566 * 567 * Used to bring the superblock down and free the private data. 568 */ 569 static void ecryptfs_kill_block_super(struct super_block *sb) 570 { 571 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 572 kill_anon_super(sb); 573 if (!sb_info) 574 return; 575 mntput(sb_info->lower_mnt); 576 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 577 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 578 } 579 580 static void ecryptfs_free_fc(struct fs_context *fc) 581 { 582 struct ecryptfs_fs_context *ctx = fc->fs_private; 583 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 584 585 kfree(ctx); 586 587 if (sbi) { 588 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 589 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 590 } 591 } 592 593 static const struct fs_context_operations ecryptfs_context_ops = { 594 .free = ecryptfs_free_fc, 595 .parse_param = ecryptfs_parse_param, 596 .get_tree = ecryptfs_get_tree, 597 .reconfigure = NULL, 598 }; 599 600 static int ecryptfs_init_fs_context(struct fs_context *fc) 601 { 602 struct ecryptfs_fs_context *ctx; 603 struct ecryptfs_sb_info *sbi = NULL; 604 605 ctx = kzalloc(sizeof(struct ecryptfs_fs_context), GFP_KERNEL); 606 if (!ctx) 607 return -ENOMEM; 608 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 609 if (!sbi) { 610 kfree(ctx); 611 ctx = NULL; 612 return -ENOMEM; 613 } 614 615 ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat); 616 617 fc->fs_private = ctx; 618 fc->s_fs_info = sbi; 619 fc->ops = &ecryptfs_context_ops; 620 return 0; 621 } 622 623 static struct file_system_type ecryptfs_fs_type = { 624 .owner = THIS_MODULE, 625 .name = "ecryptfs", 626 .init_fs_context = ecryptfs_init_fs_context, 627 .parameters = ecryptfs_fs_param_spec, 628 .kill_sb = ecryptfs_kill_block_super, 629 .fs_flags = 0 630 }; 631 MODULE_ALIAS_FS("ecryptfs"); 632 633 /* 634 * inode_info_init_once 635 * 636 * Initializes the ecryptfs_inode_info_cache when it is created 637 */ 638 static void 639 inode_info_init_once(void *vptr) 640 { 641 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 642 643 inode_init_once(&ei->vfs_inode); 644 } 645 646 static struct ecryptfs_cache_info { 647 struct kmem_cache **cache; 648 const char *name; 649 size_t size; 650 slab_flags_t flags; 651 void (*ctor)(void *obj); 652 } ecryptfs_cache_infos[] = { 653 { 654 .cache = &ecryptfs_auth_tok_list_item_cache, 655 .name = "ecryptfs_auth_tok_list_item", 656 .size = sizeof(struct ecryptfs_auth_tok_list_item), 657 }, 658 { 659 .cache = &ecryptfs_file_info_cache, 660 .name = "ecryptfs_file_cache", 661 .size = sizeof(struct ecryptfs_file_info), 662 }, 663 { 664 .cache = &ecryptfs_inode_info_cache, 665 .name = "ecryptfs_inode_cache", 666 .size = sizeof(struct ecryptfs_inode_info), 667 .flags = SLAB_ACCOUNT, 668 .ctor = inode_info_init_once, 669 }, 670 { 671 .cache = &ecryptfs_sb_info_cache, 672 .name = "ecryptfs_sb_cache", 673 .size = sizeof(struct ecryptfs_sb_info), 674 }, 675 { 676 .cache = &ecryptfs_header_cache, 677 .name = "ecryptfs_headers", 678 .size = PAGE_SIZE, 679 }, 680 { 681 .cache = &ecryptfs_xattr_cache, 682 .name = "ecryptfs_xattr_cache", 683 .size = PAGE_SIZE, 684 }, 685 { 686 .cache = &ecryptfs_key_record_cache, 687 .name = "ecryptfs_key_record_cache", 688 .size = sizeof(struct ecryptfs_key_record), 689 }, 690 { 691 .cache = &ecryptfs_key_sig_cache, 692 .name = "ecryptfs_key_sig_cache", 693 .size = sizeof(struct ecryptfs_key_sig), 694 }, 695 { 696 .cache = &ecryptfs_global_auth_tok_cache, 697 .name = "ecryptfs_global_auth_tok_cache", 698 .size = sizeof(struct ecryptfs_global_auth_tok), 699 }, 700 { 701 .cache = &ecryptfs_key_tfm_cache, 702 .name = "ecryptfs_key_tfm_cache", 703 .size = sizeof(struct ecryptfs_key_tfm), 704 }, 705 }; 706 707 static void ecryptfs_free_kmem_caches(void) 708 { 709 int i; 710 711 /* 712 * Make sure all delayed rcu free inodes are flushed before we 713 * destroy cache. 714 */ 715 rcu_barrier(); 716 717 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 718 struct ecryptfs_cache_info *info; 719 720 info = &ecryptfs_cache_infos[i]; 721 kmem_cache_destroy(*(info->cache)); 722 } 723 } 724 725 /** 726 * ecryptfs_init_kmem_caches 727 * 728 * Returns zero on success; non-zero otherwise 729 */ 730 static int ecryptfs_init_kmem_caches(void) 731 { 732 int i; 733 734 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 735 struct ecryptfs_cache_info *info; 736 737 info = &ecryptfs_cache_infos[i]; 738 *(info->cache) = kmem_cache_create(info->name, info->size, 0, 739 SLAB_HWCACHE_ALIGN | info->flags, info->ctor); 740 if (!*(info->cache)) { 741 ecryptfs_free_kmem_caches(); 742 ecryptfs_printk(KERN_WARNING, "%s: " 743 "kmem_cache_create failed\n", 744 info->name); 745 return -ENOMEM; 746 } 747 } 748 return 0; 749 } 750 751 static struct kobject *ecryptfs_kobj; 752 753 static ssize_t version_show(struct kobject *kobj, 754 struct kobj_attribute *attr, char *buff) 755 { 756 return sysfs_emit(buff, "%d\n", ECRYPTFS_VERSIONING_MASK); 757 } 758 759 static struct kobj_attribute version_attr = __ATTR_RO(version); 760 761 static struct attribute *attributes[] = { 762 &version_attr.attr, 763 NULL, 764 }; 765 766 static const struct attribute_group attr_group = { 767 .attrs = attributes, 768 }; 769 770 static int do_sysfs_registration(void) 771 { 772 int rc; 773 774 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 775 if (!ecryptfs_kobj) { 776 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 777 rc = -ENOMEM; 778 goto out; 779 } 780 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 781 if (rc) { 782 printk(KERN_ERR 783 "Unable to create ecryptfs version attributes\n"); 784 kobject_put(ecryptfs_kobj); 785 } 786 out: 787 return rc; 788 } 789 790 static void do_sysfs_unregistration(void) 791 { 792 sysfs_remove_group(ecryptfs_kobj, &attr_group); 793 kobject_put(ecryptfs_kobj); 794 } 795 796 static int __init ecryptfs_init(void) 797 { 798 int rc; 799 800 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) { 801 rc = -EINVAL; 802 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 803 "larger than the host's page size, and so " 804 "eCryptfs cannot run on this system. The " 805 "default eCryptfs extent size is [%u] bytes; " 806 "the page size is [%lu] bytes.\n", 807 ECRYPTFS_DEFAULT_EXTENT_SIZE, 808 (unsigned long)PAGE_SIZE); 809 goto out; 810 } 811 rc = ecryptfs_init_kmem_caches(); 812 if (rc) { 813 printk(KERN_ERR 814 "Failed to allocate one or more kmem_cache objects\n"); 815 goto out; 816 } 817 rc = do_sysfs_registration(); 818 if (rc) { 819 printk(KERN_ERR "sysfs registration failed\n"); 820 goto out_free_kmem_caches; 821 } 822 rc = ecryptfs_init_kthread(); 823 if (rc) { 824 printk(KERN_ERR "%s: kthread initialization failed; " 825 "rc = [%d]\n", __func__, rc); 826 goto out_do_sysfs_unregistration; 827 } 828 rc = ecryptfs_init_messaging(); 829 if (rc) { 830 printk(KERN_ERR "Failure occurred while attempting to " 831 "initialize the communications channel to " 832 "ecryptfsd\n"); 833 goto out_destroy_kthread; 834 } 835 rc = ecryptfs_init_crypto(); 836 if (rc) { 837 printk(KERN_ERR "Failure whilst attempting to init crypto; " 838 "rc = [%d]\n", rc); 839 goto out_release_messaging; 840 } 841 rc = register_filesystem(&ecryptfs_fs_type); 842 if (rc) { 843 printk(KERN_ERR "Failed to register filesystem\n"); 844 goto out_destroy_crypto; 845 } 846 if (ecryptfs_verbosity > 0) 847 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 848 "will be written to the syslog!\n", ecryptfs_verbosity); 849 850 goto out; 851 out_destroy_crypto: 852 ecryptfs_destroy_crypto(); 853 out_release_messaging: 854 ecryptfs_release_messaging(); 855 out_destroy_kthread: 856 ecryptfs_destroy_kthread(); 857 out_do_sysfs_unregistration: 858 do_sysfs_unregistration(); 859 out_free_kmem_caches: 860 ecryptfs_free_kmem_caches(); 861 out: 862 return rc; 863 } 864 865 static void __exit ecryptfs_exit(void) 866 { 867 int rc; 868 869 rc = ecryptfs_destroy_crypto(); 870 if (rc) 871 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 872 "rc = [%d]\n", rc); 873 ecryptfs_release_messaging(); 874 ecryptfs_destroy_kthread(); 875 do_sysfs_unregistration(); 876 unregister_filesystem(&ecryptfs_fs_type); 877 ecryptfs_free_kmem_caches(); 878 } 879 880 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 881 MODULE_DESCRIPTION("eCryptfs"); 882 883 MODULE_LICENSE("GPL"); 884 885 module_init(ecryptfs_init) 886 module_exit(ecryptfs_exit) 887