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 const struct path *path = ecryptfs_dentry_to_lower_path(dentry); 110 int rc; 111 112 rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt, 113 cred); 114 if (rc) { 115 printk(KERN_ERR "Error opening lower file " 116 "for lower_dentry [0x%p] and lower_mnt [0x%p]; " 117 "rc = [%d]\n", path->dentry, path->mnt, rc); 118 (*lower_file) = NULL; 119 } 120 return rc; 121 } 122 123 int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) 124 { 125 struct ecryptfs_inode_info *inode_info; 126 int count, rc = 0; 127 128 inode_info = ecryptfs_inode_to_private(inode); 129 mutex_lock(&inode_info->lower_file_mutex); 130 count = atomic_inc_return(&inode_info->lower_file_count); 131 if (WARN_ON_ONCE(count < 1)) 132 rc = -EINVAL; 133 else if (count == 1) { 134 rc = ecryptfs_init_lower_file(dentry, 135 &inode_info->lower_file); 136 if (rc) 137 atomic_set(&inode_info->lower_file_count, 0); 138 } 139 mutex_unlock(&inode_info->lower_file_mutex); 140 return rc; 141 } 142 143 void ecryptfs_put_lower_file(struct inode *inode) 144 { 145 struct ecryptfs_inode_info *inode_info; 146 147 inode_info = ecryptfs_inode_to_private(inode); 148 if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, 149 &inode_info->lower_file_mutex)) { 150 filemap_write_and_wait(inode->i_mapping); 151 fput(inode_info->lower_file); 152 inode_info->lower_file = NULL; 153 mutex_unlock(&inode_info->lower_file_mutex); 154 } 155 } 156 157 enum { 158 Opt_sig, Opt_ecryptfs_sig, Opt_cipher, Opt_ecryptfs_cipher, 159 Opt_ecryptfs_key_bytes, Opt_passthrough, Opt_xattr_metadata, 160 Opt_encrypted_view, Opt_fnek_sig, Opt_fn_cipher, 161 Opt_fn_cipher_key_bytes, Opt_unlink_sigs, Opt_mount_auth_tok_only, 162 Opt_check_dev_ruid 163 }; 164 165 static const struct fs_parameter_spec ecryptfs_fs_param_spec[] = { 166 fsparam_string ("sig", Opt_sig), 167 fsparam_string ("ecryptfs_sig", Opt_ecryptfs_sig), 168 fsparam_string ("cipher", Opt_cipher), 169 fsparam_string ("ecryptfs_cipher", Opt_ecryptfs_cipher), 170 fsparam_u32 ("ecryptfs_key_bytes", Opt_ecryptfs_key_bytes), 171 fsparam_flag ("ecryptfs_passthrough", Opt_passthrough), 172 fsparam_flag ("ecryptfs_xattr_metadata", Opt_xattr_metadata), 173 fsparam_flag ("ecryptfs_encrypted_view", Opt_encrypted_view), 174 fsparam_string ("ecryptfs_fnek_sig", Opt_fnek_sig), 175 fsparam_string ("ecryptfs_fn_cipher", Opt_fn_cipher), 176 fsparam_u32 ("ecryptfs_fn_key_bytes", Opt_fn_cipher_key_bytes), 177 fsparam_flag ("ecryptfs_unlink_sigs", Opt_unlink_sigs), 178 fsparam_flag ("ecryptfs_mount_auth_tok_only", Opt_mount_auth_tok_only), 179 fsparam_flag ("ecryptfs_check_dev_ruid", Opt_check_dev_ruid), 180 {} 181 }; 182 183 static int ecryptfs_init_global_auth_toks( 184 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 185 { 186 struct ecryptfs_global_auth_tok *global_auth_tok; 187 struct ecryptfs_auth_tok *auth_tok; 188 int rc = 0; 189 190 list_for_each_entry(global_auth_tok, 191 &mount_crypt_stat->global_auth_tok_list, 192 mount_crypt_stat_list) { 193 rc = ecryptfs_keyring_auth_tok_for_sig( 194 &global_auth_tok->global_auth_tok_key, &auth_tok, 195 global_auth_tok->sig); 196 if (rc) { 197 printk(KERN_ERR "Could not find valid key in user " 198 "session keyring for sig specified in mount " 199 "option: [%s]\n", global_auth_tok->sig); 200 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 201 goto out; 202 } else { 203 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 204 up_write(&(global_auth_tok->global_auth_tok_key)->sem); 205 } 206 } 207 out: 208 return rc; 209 } 210 211 static void ecryptfs_init_mount_crypt_stat( 212 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 213 { 214 memset((void *)mount_crypt_stat, 0, 215 sizeof(struct ecryptfs_mount_crypt_stat)); 216 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 217 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 218 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 219 } 220 221 struct ecryptfs_fs_context { 222 /* Mount option status trackers */ 223 bool check_ruid; 224 bool sig_set; 225 bool cipher_name_set; 226 bool cipher_key_bytes_set; 227 bool fn_cipher_name_set; 228 bool fn_cipher_key_bytes_set; 229 }; 230 231 /** 232 * ecryptfs_parse_param 233 * @fc: The ecryptfs filesystem context 234 * @param: The mount parameter to parse 235 * 236 * The signature of the key to use must be the description of a key 237 * already in the keyring. Mounting will fail if the key can not be 238 * found. 239 * 240 * Returns zero on success; non-zero on error 241 */ 242 static int ecryptfs_parse_param( 243 struct fs_context *fc, 244 struct fs_parameter *param) 245 { 246 int rc; 247 int opt; 248 struct fs_parse_result result; 249 struct ecryptfs_fs_context *ctx = fc->fs_private; 250 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 251 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 252 &sbi->mount_crypt_stat; 253 254 opt = fs_parse(fc, ecryptfs_fs_param_spec, param, &result); 255 if (opt < 0) 256 return opt; 257 258 switch (opt) { 259 case Opt_sig: 260 case Opt_ecryptfs_sig: 261 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 262 param->string, 0); 263 if (rc) { 264 printk(KERN_ERR "Error attempting to register " 265 "global sig; rc = [%d]\n", rc); 266 return rc; 267 } 268 ctx->sig_set = 1; 269 break; 270 case Opt_cipher: 271 case Opt_ecryptfs_cipher: 272 strscpy(mount_crypt_stat->global_default_cipher_name, 273 param->string); 274 ctx->cipher_name_set = 1; 275 break; 276 case Opt_ecryptfs_key_bytes: 277 mount_crypt_stat->global_default_cipher_key_size = 278 result.uint_32; 279 ctx->cipher_key_bytes_set = 1; 280 break; 281 case Opt_passthrough: 282 mount_crypt_stat->flags |= 283 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 284 break; 285 case Opt_xattr_metadata: 286 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; 287 break; 288 case Opt_encrypted_view: 289 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; 290 mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 291 break; 292 case Opt_fnek_sig: 293 strscpy(mount_crypt_stat->global_default_fnek_sig, 294 param->string); 295 rc = ecryptfs_add_global_auth_tok( 296 mount_crypt_stat, 297 mount_crypt_stat->global_default_fnek_sig, 298 ECRYPTFS_AUTH_TOK_FNEK); 299 if (rc) { 300 printk(KERN_ERR "Error attempting to register " 301 "global fnek sig [%s]; rc = [%d]\n", 302 mount_crypt_stat->global_default_fnek_sig, rc); 303 return rc; 304 } 305 mount_crypt_stat->flags |= 306 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 307 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); 308 break; 309 case Opt_fn_cipher: 310 strscpy(mount_crypt_stat->global_default_fn_cipher_name, 311 param->string); 312 ctx->fn_cipher_name_set = 1; 313 break; 314 case Opt_fn_cipher_key_bytes: 315 mount_crypt_stat->global_default_fn_cipher_key_bytes = 316 result.uint_32; 317 ctx->fn_cipher_key_bytes_set = 1; 318 break; 319 case Opt_unlink_sigs: 320 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; 321 break; 322 case Opt_mount_auth_tok_only: 323 mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; 324 break; 325 case Opt_check_dev_ruid: 326 ctx->check_ruid = 1; 327 break; 328 default: 329 return -EINVAL; 330 } 331 332 return 0; 333 } 334 335 static int ecryptfs_validate_options(struct fs_context *fc) 336 { 337 int rc = 0; 338 u8 cipher_code; 339 struct ecryptfs_fs_context *ctx = fc->fs_private; 340 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 341 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 342 343 344 mount_crypt_stat = &sbi->mount_crypt_stat; 345 346 if (!ctx->sig_set) { 347 rc = -EINVAL; 348 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 349 "auth tok signature as a mount " 350 "parameter; see the eCryptfs README\n"); 351 goto out; 352 } 353 if (!ctx->cipher_name_set) { 354 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 355 356 BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE); 357 strcpy(mount_crypt_stat->global_default_cipher_name, 358 ECRYPTFS_DEFAULT_CIPHER); 359 } 360 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 361 && !ctx->fn_cipher_name_set) 362 strcpy(mount_crypt_stat->global_default_fn_cipher_name, 363 mount_crypt_stat->global_default_cipher_name); 364 if (!ctx->cipher_key_bytes_set) 365 mount_crypt_stat->global_default_cipher_key_size = 0; 366 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 367 && !ctx->fn_cipher_key_bytes_set) 368 mount_crypt_stat->global_default_fn_cipher_key_bytes = 369 mount_crypt_stat->global_default_cipher_key_size; 370 371 cipher_code = ecryptfs_code_for_cipher_string( 372 mount_crypt_stat->global_default_cipher_name, 373 mount_crypt_stat->global_default_cipher_key_size); 374 if (!cipher_code) { 375 ecryptfs_printk(KERN_ERR, 376 "eCryptfs doesn't support cipher: %s\n", 377 mount_crypt_stat->global_default_cipher_name); 378 rc = -EINVAL; 379 goto out; 380 } 381 382 mutex_lock(&key_tfm_list_mutex); 383 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, 384 NULL)) { 385 rc = ecryptfs_add_new_key_tfm( 386 NULL, mount_crypt_stat->global_default_cipher_name, 387 mount_crypt_stat->global_default_cipher_key_size); 388 if (rc) { 389 printk(KERN_ERR "Error attempting to initialize " 390 "cipher with name = [%s] and key size = [%td]; " 391 "rc = [%d]\n", 392 mount_crypt_stat->global_default_cipher_name, 393 mount_crypt_stat->global_default_cipher_key_size, 394 rc); 395 rc = -EINVAL; 396 mutex_unlock(&key_tfm_list_mutex); 397 goto out; 398 } 399 } 400 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) 401 && !ecryptfs_tfm_exists( 402 mount_crypt_stat->global_default_fn_cipher_name, NULL)) { 403 rc = ecryptfs_add_new_key_tfm( 404 NULL, mount_crypt_stat->global_default_fn_cipher_name, 405 mount_crypt_stat->global_default_fn_cipher_key_bytes); 406 if (rc) { 407 printk(KERN_ERR "Error attempting to initialize " 408 "cipher with name = [%s] and key size = [%td]; " 409 "rc = [%d]\n", 410 mount_crypt_stat->global_default_fn_cipher_name, 411 mount_crypt_stat->global_default_fn_cipher_key_bytes, 412 rc); 413 rc = -EINVAL; 414 mutex_unlock(&key_tfm_list_mutex); 415 goto out; 416 } 417 } 418 mutex_unlock(&key_tfm_list_mutex); 419 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 420 if (rc) 421 printk(KERN_WARNING "One or more global auth toks could not " 422 "properly register; rc = [%d]\n", rc); 423 out: 424 return rc; 425 } 426 427 struct kmem_cache *ecryptfs_sb_info_cache; 428 static struct file_system_type ecryptfs_fs_type; 429 430 /* 431 * ecryptfs_get_tree 432 * @fc: The filesystem context 433 */ 434 static int ecryptfs_get_tree(struct fs_context *fc) 435 { 436 struct super_block *s; 437 struct ecryptfs_fs_context *ctx = fc->fs_private; 438 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 439 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 440 struct ecryptfs_dentry_info *root_info; 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 s = sget_fc(fc, NULL, set_anon_super_fc); 460 if (IS_ERR(s)) { 461 rc = PTR_ERR(s); 462 goto out; 463 } 464 465 rc = super_setup_bdi(s); 466 if (rc) 467 goto out1; 468 469 ecryptfs_set_superblock_private(s, sbi); 470 471 /* ->kill_sb() will take care of sbi after that point */ 472 sbi = NULL; 473 s->s_op = &ecryptfs_sops; 474 s->s_xattr = ecryptfs_xattr_handlers; 475 set_default_d_op(s, &ecryptfs_dops); 476 477 err = "Reading sb failed"; 478 rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 479 if (rc) { 480 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 481 goto out1; 482 } 483 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 484 rc = -EINVAL; 485 printk(KERN_ERR "Mount on filesystem of type " 486 "eCryptfs explicitly disallowed due to " 487 "known incompatibilities\n"); 488 goto out_free; 489 } 490 491 if (is_idmapped_mnt(path.mnt)) { 492 rc = -EINVAL; 493 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n"); 494 goto out_free; 495 } 496 497 if (ctx->check_ruid && 498 !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { 499 rc = -EPERM; 500 printk(KERN_ERR "Mount of device (uid: %d) not owned by " 501 "requested user (uid: %d)\n", 502 i_uid_read(d_inode(path.dentry)), 503 from_kuid(&init_user_ns, current_uid())); 504 goto out_free; 505 } 506 507 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 508 509 /** 510 * Set the POSIX ACL flag based on whether they're enabled in the lower 511 * mount. 512 */ 513 s->s_flags = fc->sb_flags & ~SB_POSIXACL; 514 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL; 515 516 /** 517 * Force a read-only eCryptfs mount when: 518 * 1) The lower mount is ro 519 * 2) The ecryptfs_encrypted_view mount option is specified 520 */ 521 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) 522 s->s_flags |= SB_RDONLY; 523 524 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 525 s->s_blocksize = path.dentry->d_sb->s_blocksize; 526 s->s_magic = ECRYPTFS_SUPER_MAGIC; 527 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; 528 529 rc = -EINVAL; 530 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { 531 pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); 532 goto out_free; 533 } 534 535 inode = ecryptfs_get_inode(d_inode(path.dentry), s); 536 rc = PTR_ERR(inode); 537 if (IS_ERR(inode)) 538 goto out_free; 539 540 s->s_root = d_make_root(inode); 541 if (!s->s_root) { 542 rc = -ENOMEM; 543 goto out_free; 544 } 545 546 rc = -ENOMEM; 547 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 548 if (!root_info) 549 goto out_free; 550 551 /* ->kill_sb() will take care of root_info */ 552 ecryptfs_set_dentry_private(s->s_root, root_info); 553 root_info->lower_path = path; 554 555 s->s_flags |= SB_ACTIVE; 556 fc->root = dget(s->s_root); 557 return 0; 558 559 out_free: 560 path_put(&path); 561 out1: 562 deactivate_locked_super(s); 563 out: 564 if (sbi) 565 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 566 567 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 568 return rc; 569 } 570 571 /** 572 * ecryptfs_kill_block_super 573 * @sb: The ecryptfs super block 574 * 575 * Used to bring the superblock down and free the private data. 576 */ 577 static void ecryptfs_kill_block_super(struct super_block *sb) 578 { 579 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 580 kill_anon_super(sb); 581 if (!sb_info) 582 return; 583 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 584 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 585 } 586 587 static void ecryptfs_free_fc(struct fs_context *fc) 588 { 589 struct ecryptfs_fs_context *ctx = fc->fs_private; 590 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 591 592 kfree(ctx); 593 594 if (sbi) { 595 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 596 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 597 } 598 } 599 600 static const struct fs_context_operations ecryptfs_context_ops = { 601 .free = ecryptfs_free_fc, 602 .parse_param = ecryptfs_parse_param, 603 .get_tree = ecryptfs_get_tree, 604 .reconfigure = NULL, 605 }; 606 607 static int ecryptfs_init_fs_context(struct fs_context *fc) 608 { 609 struct ecryptfs_fs_context *ctx; 610 struct ecryptfs_sb_info *sbi = NULL; 611 612 ctx = kzalloc(sizeof(struct ecryptfs_fs_context), GFP_KERNEL); 613 if (!ctx) 614 return -ENOMEM; 615 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 616 if (!sbi) { 617 kfree(ctx); 618 ctx = NULL; 619 return -ENOMEM; 620 } 621 622 ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat); 623 624 fc->fs_private = ctx; 625 fc->s_fs_info = sbi; 626 fc->ops = &ecryptfs_context_ops; 627 return 0; 628 } 629 630 static struct file_system_type ecryptfs_fs_type = { 631 .owner = THIS_MODULE, 632 .name = "ecryptfs", 633 .init_fs_context = ecryptfs_init_fs_context, 634 .parameters = ecryptfs_fs_param_spec, 635 .kill_sb = ecryptfs_kill_block_super, 636 .fs_flags = 0 637 }; 638 MODULE_ALIAS_FS("ecryptfs"); 639 640 /* 641 * inode_info_init_once 642 * 643 * Initializes the ecryptfs_inode_info_cache when it is created 644 */ 645 static void 646 inode_info_init_once(void *vptr) 647 { 648 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 649 650 inode_init_once(&ei->vfs_inode); 651 } 652 653 static struct ecryptfs_cache_info { 654 struct kmem_cache **cache; 655 const char *name; 656 size_t size; 657 slab_flags_t flags; 658 void (*ctor)(void *obj); 659 } ecryptfs_cache_infos[] = { 660 { 661 .cache = &ecryptfs_auth_tok_list_item_cache, 662 .name = "ecryptfs_auth_tok_list_item", 663 .size = sizeof(struct ecryptfs_auth_tok_list_item), 664 }, 665 { 666 .cache = &ecryptfs_file_info_cache, 667 .name = "ecryptfs_file_cache", 668 .size = sizeof(struct ecryptfs_file_info), 669 }, 670 { 671 .cache = &ecryptfs_dentry_info_cache, 672 .name = "ecryptfs_dentry_info_cache", 673 .size = sizeof(struct ecryptfs_dentry_info), 674 }, 675 { 676 .cache = &ecryptfs_inode_info_cache, 677 .name = "ecryptfs_inode_cache", 678 .size = sizeof(struct ecryptfs_inode_info), 679 .flags = SLAB_ACCOUNT, 680 .ctor = inode_info_init_once, 681 }, 682 { 683 .cache = &ecryptfs_sb_info_cache, 684 .name = "ecryptfs_sb_cache", 685 .size = sizeof(struct ecryptfs_sb_info), 686 }, 687 { 688 .cache = &ecryptfs_header_cache, 689 .name = "ecryptfs_headers", 690 .size = PAGE_SIZE, 691 }, 692 { 693 .cache = &ecryptfs_xattr_cache, 694 .name = "ecryptfs_xattr_cache", 695 .size = PAGE_SIZE, 696 }, 697 { 698 .cache = &ecryptfs_key_record_cache, 699 .name = "ecryptfs_key_record_cache", 700 .size = sizeof(struct ecryptfs_key_record), 701 }, 702 { 703 .cache = &ecryptfs_key_sig_cache, 704 .name = "ecryptfs_key_sig_cache", 705 .size = sizeof(struct ecryptfs_key_sig), 706 }, 707 { 708 .cache = &ecryptfs_global_auth_tok_cache, 709 .name = "ecryptfs_global_auth_tok_cache", 710 .size = sizeof(struct ecryptfs_global_auth_tok), 711 }, 712 { 713 .cache = &ecryptfs_key_tfm_cache, 714 .name = "ecryptfs_key_tfm_cache", 715 .size = sizeof(struct ecryptfs_key_tfm), 716 }, 717 }; 718 719 static void ecryptfs_free_kmem_caches(void) 720 { 721 int i; 722 723 /* 724 * Make sure all delayed rcu free inodes are flushed before we 725 * destroy cache. 726 */ 727 rcu_barrier(); 728 729 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 730 struct ecryptfs_cache_info *info; 731 732 info = &ecryptfs_cache_infos[i]; 733 kmem_cache_destroy(*(info->cache)); 734 } 735 } 736 737 /** 738 * ecryptfs_init_kmem_caches 739 * 740 * Returns zero on success; non-zero otherwise 741 */ 742 static int ecryptfs_init_kmem_caches(void) 743 { 744 int i; 745 746 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 747 struct ecryptfs_cache_info *info; 748 749 info = &ecryptfs_cache_infos[i]; 750 *(info->cache) = kmem_cache_create(info->name, info->size, 0, 751 SLAB_HWCACHE_ALIGN | info->flags, info->ctor); 752 if (!*(info->cache)) { 753 ecryptfs_free_kmem_caches(); 754 ecryptfs_printk(KERN_WARNING, "%s: " 755 "kmem_cache_create failed\n", 756 info->name); 757 return -ENOMEM; 758 } 759 } 760 return 0; 761 } 762 763 static struct kobject *ecryptfs_kobj; 764 765 static ssize_t version_show(struct kobject *kobj, 766 struct kobj_attribute *attr, char *buff) 767 { 768 return sysfs_emit(buff, "%d\n", ECRYPTFS_VERSIONING_MASK); 769 } 770 771 static struct kobj_attribute version_attr = __ATTR_RO(version); 772 773 static struct attribute *attributes[] = { 774 &version_attr.attr, 775 NULL, 776 }; 777 778 static const struct attribute_group attr_group = { 779 .attrs = attributes, 780 }; 781 782 static int do_sysfs_registration(void) 783 { 784 int rc; 785 786 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 787 if (!ecryptfs_kobj) { 788 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 789 rc = -ENOMEM; 790 goto out; 791 } 792 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 793 if (rc) { 794 printk(KERN_ERR 795 "Unable to create ecryptfs version attributes\n"); 796 kobject_put(ecryptfs_kobj); 797 } 798 out: 799 return rc; 800 } 801 802 static void do_sysfs_unregistration(void) 803 { 804 sysfs_remove_group(ecryptfs_kobj, &attr_group); 805 kobject_put(ecryptfs_kobj); 806 } 807 808 static int __init ecryptfs_init(void) 809 { 810 int rc; 811 812 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) { 813 rc = -EINVAL; 814 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 815 "larger than the host's page size, and so " 816 "eCryptfs cannot run on this system. The " 817 "default eCryptfs extent size is [%u] bytes; " 818 "the page size is [%lu] bytes.\n", 819 ECRYPTFS_DEFAULT_EXTENT_SIZE, 820 (unsigned long)PAGE_SIZE); 821 goto out; 822 } 823 rc = ecryptfs_init_kmem_caches(); 824 if (rc) { 825 printk(KERN_ERR 826 "Failed to allocate one or more kmem_cache objects\n"); 827 goto out; 828 } 829 rc = do_sysfs_registration(); 830 if (rc) { 831 printk(KERN_ERR "sysfs registration failed\n"); 832 goto out_free_kmem_caches; 833 } 834 rc = ecryptfs_init_kthread(); 835 if (rc) { 836 printk(KERN_ERR "%s: kthread initialization failed; " 837 "rc = [%d]\n", __func__, rc); 838 goto out_do_sysfs_unregistration; 839 } 840 rc = ecryptfs_init_messaging(); 841 if (rc) { 842 printk(KERN_ERR "Failure occurred while attempting to " 843 "initialize the communications channel to " 844 "ecryptfsd\n"); 845 goto out_destroy_kthread; 846 } 847 rc = ecryptfs_init_crypto(); 848 if (rc) { 849 printk(KERN_ERR "Failure whilst attempting to init crypto; " 850 "rc = [%d]\n", rc); 851 goto out_release_messaging; 852 } 853 rc = register_filesystem(&ecryptfs_fs_type); 854 if (rc) { 855 printk(KERN_ERR "Failed to register filesystem\n"); 856 goto out_destroy_crypto; 857 } 858 if (ecryptfs_verbosity > 0) 859 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 860 "will be written to the syslog!\n", ecryptfs_verbosity); 861 862 goto out; 863 out_destroy_crypto: 864 ecryptfs_destroy_crypto(); 865 out_release_messaging: 866 ecryptfs_release_messaging(); 867 out_destroy_kthread: 868 ecryptfs_destroy_kthread(); 869 out_do_sysfs_unregistration: 870 do_sysfs_unregistration(); 871 out_free_kmem_caches: 872 ecryptfs_free_kmem_caches(); 873 out: 874 return rc; 875 } 876 877 static void __exit ecryptfs_exit(void) 878 { 879 int rc; 880 881 rc = ecryptfs_destroy_crypto(); 882 if (rc) 883 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 884 "rc = [%d]\n", rc); 885 ecryptfs_release_messaging(); 886 ecryptfs_destroy_kthread(); 887 do_sysfs_unregistration(); 888 unregister_filesystem(&ecryptfs_fs_type); 889 ecryptfs_free_kmem_caches(); 890 } 891 892 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 893 MODULE_DESCRIPTION("eCryptfs"); 894 895 MODULE_LICENSE("GPL"); 896 897 module_init(ecryptfs_init) 898 module_exit(ecryptfs_exit) 899