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/fips.h> 16 #include <linux/module.h> 17 #include <linux/namei.h> 18 #include <linux/skbuff.h> 19 #include <linux/pagemap.h> 20 #include <linux/key.h> 21 #include <linux/fs_context.h> 22 #include <linux/fs_parser.h> 23 #include <linux/fs_stack.h> 24 #include <linux/sysfs.h> 25 #include <linux/slab.h> 26 #include <linux/string.h> 27 #include <linux/magic.h> 28 #include "ecryptfs_kernel.h" 29 30 /* 31 * Module parameter that defines the ecryptfs_verbosity level. 32 */ 33 int ecryptfs_verbosity = 0; 34 35 module_param(ecryptfs_verbosity, int, 0); 36 MODULE_PARM_DESC(ecryptfs_verbosity, 37 "Initial verbosity level (0 or 1; defaults to " 38 "0, which is Quiet)"); 39 40 /* 41 * Module parameter that defines the number of message buffer elements 42 */ 43 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 44 45 module_param(ecryptfs_message_buf_len, uint, 0); 46 MODULE_PARM_DESC(ecryptfs_message_buf_len, 47 "Number of message buffer elements"); 48 49 /* 50 * Module parameter that defines the maximum guaranteed amount of time to wait 51 * for a response from ecryptfsd. The actual sleep time will be, more than 52 * likely, a small amount greater than this specified value, but only less if 53 * the message successfully arrives. 54 */ 55 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 56 57 module_param(ecryptfs_message_wait_timeout, long, 0); 58 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 59 "Maximum number of seconds that an operation will " 60 "sleep while waiting for a message response from " 61 "userspace"); 62 63 /* 64 * Module parameter that is an estimate of the maximum number of users 65 * that will be concurrently using eCryptfs. Set this to the right 66 * value to balance performance and memory use. 67 */ 68 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 69 70 module_param(ecryptfs_number_of_users, uint, 0); 71 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 72 "concurrent users of eCryptfs"); 73 74 void __ecryptfs_printk(const char *fmt, ...) 75 { 76 va_list args; 77 va_start(args, fmt); 78 if (fmt[1] == '7') { /* KERN_DEBUG */ 79 if (ecryptfs_verbosity >= 1) 80 vprintk(fmt, args); 81 } else 82 vprintk(fmt, args); 83 va_end(args); 84 } 85 86 /* 87 * ecryptfs_init_lower_file 88 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 89 * the lower dentry and the lower mount set 90 * 91 * eCryptfs only ever keeps a single open file for every lower 92 * inode. All I/O operations to the lower inode occur through that 93 * file. When the first eCryptfs dentry that interposes with the first 94 * lower dentry for that inode is created, this function creates the 95 * lower file struct and associates it with the eCryptfs 96 * inode. When all eCryptfs files associated with the inode are released, the 97 * file is closed. 98 * 99 * The lower file will be opened with read/write permissions, if 100 * possible. Otherwise, it is opened read-only. 101 * 102 * This function does nothing if a lower file is already 103 * associated with the eCryptfs inode. 104 * 105 * Returns zero on success; non-zero otherwise 106 */ 107 static int ecryptfs_init_lower_file(struct dentry *dentry, 108 struct file **lower_file) 109 { 110 const struct cred *cred = current_cred(); 111 struct path path = ecryptfs_lower_path(dentry); 112 int rc; 113 114 rc = ecryptfs_privileged_open(lower_file, path.dentry, path.mnt, cred); 115 if (rc) { 116 printk(KERN_ERR "Error opening lower file " 117 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 118 "rc = [%d]\n", path.dentry, path.mnt, rc); 119 (*lower_file) = NULL; 120 } 121 return rc; 122 } 123 124 int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) 125 { 126 struct ecryptfs_inode_info *inode_info; 127 int count, rc = 0; 128 129 inode_info = ecryptfs_inode_to_private(inode); 130 mutex_lock(&inode_info->lower_file_mutex); 131 count = atomic_inc_return(&inode_info->lower_file_count); 132 if (WARN_ON_ONCE(count < 1)) 133 rc = -EINVAL; 134 else if (count == 1) { 135 rc = ecryptfs_init_lower_file(dentry, 136 &inode_info->lower_file); 137 if (rc) 138 atomic_set(&inode_info->lower_file_count, 0); 139 } 140 mutex_unlock(&inode_info->lower_file_mutex); 141 return rc; 142 } 143 144 void ecryptfs_put_lower_file(struct inode *inode) 145 { 146 struct ecryptfs_inode_info *inode_info; 147 148 inode_info = ecryptfs_inode_to_private(inode); 149 if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, 150 &inode_info->lower_file_mutex)) { 151 filemap_write_and_wait(inode->i_mapping); 152 fput(inode_info->lower_file); 153 inode_info->lower_file = NULL; 154 mutex_unlock(&inode_info->lower_file_mutex); 155 } 156 } 157 158 enum { 159 Opt_sig, Opt_ecryptfs_sig, Opt_cipher, Opt_ecryptfs_cipher, 160 Opt_ecryptfs_key_bytes, Opt_passthrough, Opt_xattr_metadata, 161 Opt_encrypted_view, Opt_fnek_sig, Opt_fn_cipher, 162 Opt_fn_cipher_key_bytes, Opt_unlink_sigs, Opt_mount_auth_tok_only, 163 Opt_check_dev_ruid 164 }; 165 166 static const struct fs_parameter_spec ecryptfs_fs_param_spec[] = { 167 fsparam_string ("sig", Opt_sig), 168 fsparam_string ("ecryptfs_sig", Opt_ecryptfs_sig), 169 fsparam_string ("cipher", Opt_cipher), 170 fsparam_string ("ecryptfs_cipher", Opt_ecryptfs_cipher), 171 fsparam_u32 ("ecryptfs_key_bytes", Opt_ecryptfs_key_bytes), 172 fsparam_flag ("ecryptfs_passthrough", Opt_passthrough), 173 fsparam_flag ("ecryptfs_xattr_metadata", Opt_xattr_metadata), 174 fsparam_flag ("ecryptfs_encrypted_view", Opt_encrypted_view), 175 fsparam_string ("ecryptfs_fnek_sig", Opt_fnek_sig), 176 fsparam_string ("ecryptfs_fn_cipher", Opt_fn_cipher), 177 fsparam_u32 ("ecryptfs_fn_key_bytes", Opt_fn_cipher_key_bytes), 178 fsparam_flag ("ecryptfs_unlink_sigs", Opt_unlink_sigs), 179 fsparam_flag ("ecryptfs_mount_auth_tok_only", Opt_mount_auth_tok_only), 180 fsparam_flag ("ecryptfs_check_dev_ruid", Opt_check_dev_ruid), 181 {} 182 }; 183 184 static int ecryptfs_init_global_auth_toks( 185 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 186 { 187 struct ecryptfs_global_auth_tok *global_auth_tok; 188 struct ecryptfs_auth_tok *auth_tok; 189 int rc = 0; 190 191 list_for_each_entry(global_auth_tok, 192 &mount_crypt_stat->global_auth_tok_list, 193 mount_crypt_stat_list) { 194 rc = ecryptfs_keyring_auth_tok_for_sig( 195 &global_auth_tok->global_auth_tok_key, &auth_tok, 196 global_auth_tok->sig); 197 if (rc) { 198 printk(KERN_ERR "Could not find valid key in user " 199 "session keyring for sig specified in mount " 200 "option: [%s]\n", global_auth_tok->sig); 201 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 202 goto out; 203 } else { 204 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 205 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 206 } 207 } 208 out: 209 return rc; 210 } 211 212 static void ecryptfs_init_mount_crypt_stat( 213 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 214 { 215 memset((void *)mount_crypt_stat, 0, 216 sizeof(struct ecryptfs_mount_crypt_stat)); 217 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 218 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 219 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 220 } 221 222 struct ecryptfs_fs_context { 223 /* Mount option status trackers */ 224 bool check_ruid; 225 bool sig_set; 226 bool cipher_name_set; 227 bool cipher_key_bytes_set; 228 bool fn_cipher_name_set; 229 bool fn_cipher_key_bytes_set; 230 }; 231 232 /** 233 * ecryptfs_parse_param 234 * @fc: The ecryptfs filesystem context 235 * @param: The mount parameter to parse 236 * 237 * The signature of the key to use must be the description of a key 238 * already in the keyring. Mounting will fail if the key can not be 239 * found. 240 * 241 * Returns zero on success; non-zero on error 242 */ 243 static int ecryptfs_parse_param( 244 struct fs_context *fc, 245 struct fs_parameter *param) 246 { 247 int rc; 248 int opt; 249 struct fs_parse_result result; 250 struct ecryptfs_fs_context *ctx = fc->fs_private; 251 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 252 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 253 &sbi->mount_crypt_stat; 254 255 opt = fs_parse(fc, ecryptfs_fs_param_spec, param, &result); 256 if (opt < 0) 257 return opt; 258 259 switch (opt) { 260 case Opt_sig: 261 case Opt_ecryptfs_sig: 262 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 263 param->string, 0); 264 if (rc) { 265 printk(KERN_ERR "Error attempting to register " 266 "global sig; rc = [%d]\n", rc); 267 return rc; 268 } 269 ctx->sig_set = 1; 270 break; 271 case Opt_cipher: 272 case Opt_ecryptfs_cipher: 273 strscpy(mount_crypt_stat->global_default_cipher_name, 274 param->string); 275 ctx->cipher_name_set = 1; 276 break; 277 case Opt_ecryptfs_key_bytes: 278 mount_crypt_stat->global_default_cipher_key_size = 279 result.uint_32; 280 ctx->cipher_key_bytes_set = 1; 281 break; 282 case Opt_passthrough: 283 mount_crypt_stat->flags |= 284 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 285 break; 286 case Opt_xattr_metadata: 287 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; 288 break; 289 case Opt_encrypted_view: 290 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; 291 mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 292 break; 293 case Opt_fnek_sig: 294 strscpy(mount_crypt_stat->global_default_fnek_sig, 295 param->string); 296 rc = ecryptfs_add_global_auth_tok( 297 mount_crypt_stat, 298 mount_crypt_stat->global_default_fnek_sig, 299 ECRYPTFS_AUTH_TOK_FNEK); 300 if (rc) { 301 printk(KERN_ERR "Error attempting to register " 302 "global fnek sig [%s]; rc = [%d]\n", 303 mount_crypt_stat->global_default_fnek_sig, rc); 304 return rc; 305 } 306 mount_crypt_stat->flags |= 307 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 308 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 309 break; 310 case Opt_fn_cipher: 311 strscpy(mount_crypt_stat->global_default_fn_cipher_name, 312 param->string); 313 ctx->fn_cipher_name_set = 1; 314 break; 315 case Opt_fn_cipher_key_bytes: 316 mount_crypt_stat->global_default_fn_cipher_key_bytes = 317 result.uint_32; 318 ctx->fn_cipher_key_bytes_set = 1; 319 break; 320 case Opt_unlink_sigs: 321 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 322 break; 323 case Opt_mount_auth_tok_only: 324 mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 325 break; 326 case Opt_check_dev_ruid: 327 ctx->check_ruid = 1; 328 break; 329 default: 330 return -EINVAL; 331 } 332 333 return 0; 334 } 335 336 static int ecryptfs_validate_options(struct fs_context *fc) 337 { 338 int rc = 0; 339 u8 cipher_code; 340 struct ecryptfs_fs_context *ctx = fc->fs_private; 341 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 342 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 343 344 345 mount_crypt_stat = &sbi->mount_crypt_stat; 346 347 if (!ctx->sig_set) { 348 rc = -EINVAL; 349 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 350 "auth tok signature as a mount " 351 "parameter; see the eCryptfs README\n"); 352 goto out; 353 } 354 if (!ctx->cipher_name_set) { 355 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 356 357 BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE); 358 strscpy(mount_crypt_stat->global_default_cipher_name, 359 ECRYPTFS_DEFAULT_CIPHER); 360 } 361 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 362 && !ctx->fn_cipher_name_set) 363 strscpy(mount_crypt_stat->global_default_fn_cipher_name, 364 mount_crypt_stat->global_default_cipher_name); 365 if (!ctx->cipher_key_bytes_set) 366 mount_crypt_stat->global_default_cipher_key_size = 0; 367 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 368 && !ctx->fn_cipher_key_bytes_set) 369 mount_crypt_stat->global_default_fn_cipher_key_bytes = 370 mount_crypt_stat->global_default_cipher_key_size; 371 372 cipher_code = ecryptfs_code_for_cipher_string( 373 mount_crypt_stat->global_default_cipher_name, 374 mount_crypt_stat->global_default_cipher_key_size); 375 if (!cipher_code) { 376 ecryptfs_printk(KERN_ERR, 377 "eCryptfs doesn't support cipher: %s\n", 378 mount_crypt_stat->global_default_cipher_name); 379 rc = -EINVAL; 380 goto out; 381 } 382 383 mutex_lock(&key_tfm_list_mutex); 384 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 385 NULL)) { 386 rc = ecryptfs_add_new_key_tfm( 387 NULL, mount_crypt_stat->global_default_cipher_name, 388 mount_crypt_stat->global_default_cipher_key_size); 389 if (rc) { 390 printk(KERN_ERR "Error attempting to initialize " 391 "cipher with name = [%s] and key size = [%td]; " 392 "rc = [%d]\n", 393 mount_crypt_stat->global_default_cipher_name, 394 mount_crypt_stat->global_default_cipher_key_size, 395 rc); 396 rc = -EINVAL; 397 mutex_unlock(&key_tfm_list_mutex); 398 goto out; 399 } 400 } 401 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 402 && !ecryptfs_tfm_exists( 403 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 404 rc = ecryptfs_add_new_key_tfm( 405 NULL, mount_crypt_stat->global_default_fn_cipher_name, 406 mount_crypt_stat->global_default_fn_cipher_key_bytes); 407 if (rc) { 408 printk(KERN_ERR "Error attempting to initialize " 409 "cipher with name = [%s] and key size = [%td]; " 410 "rc = [%d]\n", 411 mount_crypt_stat->global_default_fn_cipher_name, 412 mount_crypt_stat->global_default_fn_cipher_key_bytes, 413 rc); 414 rc = -EINVAL; 415 mutex_unlock(&key_tfm_list_mutex); 416 goto out; 417 } 418 } 419 mutex_unlock(&key_tfm_list_mutex); 420 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 421 if (rc) 422 printk(KERN_WARNING "One or more global auth toks could not " 423 "properly register; rc = [%d]\n", rc); 424 out: 425 return rc; 426 } 427 428 struct kmem_cache *ecryptfs_sb_info_cache; 429 static struct file_system_type ecryptfs_fs_type; 430 431 /* 432 * ecryptfs_get_tree 433 * @fc: The filesystem context 434 */ 435 static int ecryptfs_get_tree(struct fs_context *fc) 436 { 437 struct super_block *s; 438 struct ecryptfs_fs_context *ctx = fc->fs_private; 439 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 440 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 441 const char *err = "Getting sb failed"; 442 struct inode *inode; 443 struct path path; 444 int rc; 445 446 if (!fc->source) { 447 rc = -EINVAL; 448 err = "Device name cannot be null"; 449 goto out; 450 } 451 452 mount_crypt_stat = &sbi->mount_crypt_stat; 453 rc = ecryptfs_validate_options(fc); 454 if (rc) { 455 err = "Error validating options"; 456 goto out; 457 } 458 459 if (fips_enabled) { 460 rc = -EINVAL; 461 err = "eCryptfs support is disabled due to FIPS"; 462 goto out; 463 } 464 465 s = sget_fc(fc, NULL, set_anon_super_fc); 466 if (IS_ERR(s)) { 467 rc = PTR_ERR(s); 468 goto out; 469 } 470 471 rc = super_setup_bdi(s); 472 if (rc) 473 goto out1; 474 475 ecryptfs_set_superblock_private(s, sbi); 476 477 /* ->kill_sb() will take care of sbi after that point */ 478 sbi = NULL; 479 s->s_op = &ecryptfs_sops; 480 s->s_xattr = ecryptfs_xattr_handlers; 481 set_default_d_op(s, &ecryptfs_dops); 482 483 err = "Reading sb failed"; 484 rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 485 if (rc) { 486 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 487 goto out1; 488 } 489 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 490 rc = -EINVAL; 491 printk(KERN_ERR "Mount on filesystem of type " 492 "eCryptfs explicitly disallowed due to " 493 "known incompatibilities\n"); 494 goto out_free; 495 } 496 497 if (is_idmapped_mnt(path.mnt)) { 498 rc = -EINVAL; 499 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n"); 500 goto out_free; 501 } 502 503 if (ctx->check_ruid && 504 !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { 505 rc = -EPERM; 506 printk(KERN_ERR "Mount of device (uid: %d) not owned by " 507 "requested user (uid: %d)\n", 508 i_uid_read(d_inode(path.dentry)), 509 from_kuid(&init_user_ns, current_uid())); 510 goto out_free; 511 } 512 513 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 514 515 /** 516 * Set the POSIX ACL flag based on whether they're enabled in the lower 517 * mount. 518 */ 519 s->s_flags = fc->sb_flags & ~SB_POSIXACL; 520 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL; 521 522 /** 523 * Force a read-only eCryptfs mount when: 524 * 1) The lower mount is ro 525 * 2) The ecryptfs_encrypted_view mount option is specified 526 */ 527 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) 528 s->s_flags |= SB_RDONLY; 529 530 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 531 s->s_blocksize = path.dentry->d_sb->s_blocksize; 532 s->s_magic = ECRYPTFS_SUPER_MAGIC; 533 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; 534 s->s_time_gran = path.dentry->d_sb->s_time_gran; 535 536 rc = -EINVAL; 537 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { 538 pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); 539 goto out_free; 540 } 541 542 inode = ecryptfs_get_inode(d_inode(path.dentry), s); 543 rc = PTR_ERR(inode); 544 if (IS_ERR(inode)) 545 goto out_free; 546 547 s->s_root = d_make_root(inode); 548 if (!s->s_root) { 549 rc = -ENOMEM; 550 goto out_free; 551 } 552 553 ecryptfs_set_dentry_lower(s->s_root, path.dentry); 554 ecryptfs_superblock_to_private(s)->lower_mnt = path.mnt; 555 556 s->s_flags |= SB_ACTIVE; 557 fc->root = dget(s->s_root); 558 return 0; 559 560 out_free: 561 path_put(&path); 562 out1: 563 deactivate_locked_super(s); 564 out: 565 if (sbi) 566 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 567 568 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 569 return rc; 570 } 571 572 /** 573 * ecryptfs_kill_block_super 574 * @sb: The ecryptfs super block 575 * 576 * Used to bring the superblock down and free the private data. 577 */ 578 static void ecryptfs_kill_block_super(struct super_block *sb) 579 { 580 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 581 kill_anon_super(sb); 582 if (!sb_info) 583 return; 584 mntput(sb_info->lower_mnt); 585 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 586 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 587 } 588 589 static void ecryptfs_free_fc(struct fs_context *fc) 590 { 591 struct ecryptfs_fs_context *ctx = fc->fs_private; 592 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 593 594 kfree(ctx); 595 596 if (sbi) { 597 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 598 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 599 } 600 } 601 602 static const struct fs_context_operations ecryptfs_context_ops = { 603 .free = ecryptfs_free_fc, 604 .parse_param = ecryptfs_parse_param, 605 .get_tree = ecryptfs_get_tree, 606 .reconfigure = NULL, 607 }; 608 609 static int ecryptfs_init_fs_context(struct fs_context *fc) 610 { 611 struct ecryptfs_fs_context *ctx; 612 struct ecryptfs_sb_info *sbi = NULL; 613 614 ctx = kzalloc_obj(struct ecryptfs_fs_context); 615 if (!ctx) 616 return -ENOMEM; 617 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 618 if (!sbi) { 619 kfree(ctx); 620 ctx = NULL; 621 return -ENOMEM; 622 } 623 624 ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat); 625 626 fc->fs_private = ctx; 627 fc->s_fs_info = sbi; 628 fc->ops = &ecryptfs_context_ops; 629 return 0; 630 } 631 632 static struct file_system_type ecryptfs_fs_type = { 633 .owner = THIS_MODULE, 634 .name = "ecryptfs", 635 .init_fs_context = ecryptfs_init_fs_context, 636 .parameters = ecryptfs_fs_param_spec, 637 .kill_sb = ecryptfs_kill_block_super, 638 .fs_flags = 0 639 }; 640 MODULE_ALIAS_FS("ecryptfs"); 641 642 /* 643 * inode_info_init_once 644 * 645 * Initializes the ecryptfs_inode_info_cache when it is created 646 */ 647 static void 648 inode_info_init_once(void *vptr) 649 { 650 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 651 652 inode_init_once(&ei->vfs_inode); 653 } 654 655 static struct ecryptfs_cache_info { 656 struct kmem_cache **cache; 657 const char *name; 658 size_t size; 659 slab_flags_t flags; 660 void (*ctor)(void *obj); 661 } ecryptfs_cache_infos[] = { 662 { 663 .cache = &ecryptfs_auth_tok_list_item_cache, 664 .name = "ecryptfs_auth_tok_list_item", 665 .size = sizeof(struct ecryptfs_auth_tok_list_item), 666 }, 667 { 668 .cache = &ecryptfs_file_info_cache, 669 .name = "ecryptfs_file_cache", 670 .size = sizeof(struct ecryptfs_file_info), 671 }, 672 { 673 .cache = &ecryptfs_inode_info_cache, 674 .name = "ecryptfs_inode_cache", 675 .size = sizeof(struct ecryptfs_inode_info), 676 .flags = SLAB_ACCOUNT, 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, 686 .name = "ecryptfs_headers", 687 .size = PAGE_SIZE, 688 }, 689 { 690 .cache = &ecryptfs_xattr_cache, 691 .name = "ecryptfs_xattr_cache", 692 .size = PAGE_SIZE, 693 }, 694 { 695 .cache = &ecryptfs_key_record_cache, 696 .name = "ecryptfs_key_record_cache", 697 .size = sizeof(struct ecryptfs_key_record), 698 }, 699 { 700 .cache = &ecryptfs_key_sig_cache, 701 .name = "ecryptfs_key_sig_cache", 702 .size = sizeof(struct ecryptfs_key_sig), 703 }, 704 { 705 .cache = &ecryptfs_global_auth_tok_cache, 706 .name = "ecryptfs_global_auth_tok_cache", 707 .size = sizeof(struct ecryptfs_global_auth_tok), 708 }, 709 { 710 .cache = &ecryptfs_key_tfm_cache, 711 .name = "ecryptfs_key_tfm_cache", 712 .size = sizeof(struct ecryptfs_key_tfm), 713 }, 714 }; 715 716 static void ecryptfs_free_kmem_caches(void) 717 { 718 int i; 719 720 /* 721 * Make sure all delayed rcu free inodes are flushed before we 722 * destroy cache. 723 */ 724 rcu_barrier(); 725 726 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 727 struct ecryptfs_cache_info *info; 728 729 info = &ecryptfs_cache_infos[i]; 730 kmem_cache_destroy(*(info->cache)); 731 } 732 } 733 734 /** 735 * ecryptfs_init_kmem_caches 736 * 737 * Returns zero on success; non-zero otherwise 738 */ 739 static int ecryptfs_init_kmem_caches(void) 740 { 741 int i; 742 743 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 744 struct ecryptfs_cache_info *info; 745 746 info = &ecryptfs_cache_infos[i]; 747 *(info->cache) = kmem_cache_create(info->name, info->size, 0, 748 SLAB_HWCACHE_ALIGN | info->flags, info->ctor); 749 if (!*(info->cache)) { 750 ecryptfs_free_kmem_caches(); 751 ecryptfs_printk(KERN_WARNING, "%s: " 752 "kmem_cache_create failed\n", 753 info->name); 754 return -ENOMEM; 755 } 756 } 757 return 0; 758 } 759 760 static struct kobject *ecryptfs_kobj; 761 762 static ssize_t version_show(struct kobject *kobj, 763 struct kobj_attribute *attr, char *buff) 764 { 765 return sysfs_emit(buff, "%d\n", ECRYPTFS_VERSIONING_MASK); 766 } 767 768 static struct kobj_attribute version_attr = __ATTR_RO(version); 769 770 static struct attribute *attributes[] = { 771 &version_attr.attr, 772 NULL, 773 }; 774 775 static const struct attribute_group attr_group = { 776 .attrs = attributes, 777 }; 778 779 static int do_sysfs_registration(void) 780 { 781 int rc; 782 783 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 784 if (!ecryptfs_kobj) { 785 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 786 rc = -ENOMEM; 787 goto out; 788 } 789 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 790 if (rc) { 791 printk(KERN_ERR 792 "Unable to create ecryptfs version attributes\n"); 793 kobject_put(ecryptfs_kobj); 794 } 795 out: 796 return rc; 797 } 798 799 static void do_sysfs_unregistration(void) 800 { 801 sysfs_remove_group(ecryptfs_kobj, &attr_group); 802 kobject_put(ecryptfs_kobj); 803 } 804 805 static int __init ecryptfs_init(void) 806 { 807 int rc; 808 809 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) { 810 rc = -EINVAL; 811 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 812 "larger than the host's page size, and so " 813 "eCryptfs cannot run on this system. The " 814 "default eCryptfs extent size is [%u] bytes; " 815 "the page size is [%lu] bytes.\n", 816 ECRYPTFS_DEFAULT_EXTENT_SIZE, 817 (unsigned long)PAGE_SIZE); 818 goto out; 819 } 820 rc = ecryptfs_init_kmem_caches(); 821 if (rc) { 822 printk(KERN_ERR 823 "Failed to allocate one or more kmem_cache objects\n"); 824 goto out; 825 } 826 rc = do_sysfs_registration(); 827 if (rc) { 828 printk(KERN_ERR "sysfs registration failed\n"); 829 goto out_free_kmem_caches; 830 } 831 rc = ecryptfs_init_kthread(); 832 if (rc) { 833 printk(KERN_ERR "%s: kthread initialization failed; " 834 "rc = [%d]\n", __func__, rc); 835 goto out_do_sysfs_unregistration; 836 } 837 rc = ecryptfs_init_messaging(); 838 if (rc) { 839 printk(KERN_ERR "Failure occurred while attempting to " 840 "initialize the communications channel to " 841 "ecryptfsd\n"); 842 goto out_destroy_kthread; 843 } 844 rc = ecryptfs_init_crypto(); 845 if (rc) { 846 printk(KERN_ERR "Failure whilst attempting to init crypto; " 847 "rc = [%d]\n", rc); 848 goto out_release_messaging; 849 } 850 rc = register_filesystem(&ecryptfs_fs_type); 851 if (rc) { 852 printk(KERN_ERR "Failed to register filesystem\n"); 853 goto out_destroy_crypto; 854 } 855 if (ecryptfs_verbosity > 0) 856 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 857 "will be written to the syslog!\n", ecryptfs_verbosity); 858 859 goto out; 860 out_destroy_crypto: 861 ecryptfs_destroy_crypto(); 862 out_release_messaging: 863 ecryptfs_release_messaging(); 864 out_destroy_kthread: 865 ecryptfs_destroy_kthread(); 866 out_do_sysfs_unregistration: 867 do_sysfs_unregistration(); 868 out_free_kmem_caches: 869 ecryptfs_free_kmem_caches(); 870 out: 871 return rc; 872 } 873 874 static void __exit ecryptfs_exit(void) 875 { 876 int rc; 877 878 rc = ecryptfs_destroy_crypto(); 879 if (rc) 880 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 881 "rc = [%d]\n", rc); 882 ecryptfs_release_messaging(); 883 ecryptfs_destroy_kthread(); 884 do_sysfs_unregistration(); 885 unregister_filesystem(&ecryptfs_fs_type); 886 ecryptfs_free_kmem_caches(); 887 } 888 889 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 890 MODULE_DESCRIPTION("eCryptfs"); 891 892 MODULE_LICENSE("GPL"); 893 894 module_init(ecryptfs_init) 895 module_exit(ecryptfs_exit) 896