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/slab.h> 24 #include <linux/magic.h> 25 #include "ecryptfs_kernel.h" 26 27 /* 28 * Module parameter that defines the ecryptfs_verbosity level. 29 */ 30 int ecryptfs_verbosity = 0; 31 32 module_param(ecryptfs_verbosity, int, 0); 33 MODULE_PARM_DESC(ecryptfs_verbosity, 34 "Initial verbosity level (0 or 1; defaults to " 35 "0, which is Quiet)"); 36 37 /* 38 * Module parameter that defines the number of message buffer elements 39 */ 40 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 41 42 module_param(ecryptfs_message_buf_len, uint, 0); 43 MODULE_PARM_DESC(ecryptfs_message_buf_len, 44 "Number of message buffer elements"); 45 46 /* 47 * Module parameter that defines the maximum guaranteed amount of time to wait 48 * for a response from ecryptfsd. The actual sleep time will be, more than 49 * likely, a small amount greater than this specified value, but only less if 50 * the message successfully arrives. 51 */ 52 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 53 54 module_param(ecryptfs_message_wait_timeout, long, 0); 55 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 56 "Maximum number of seconds that an operation will " 57 "sleep while waiting for a message response from " 58 "userspace"); 59 60 /* 61 * Module parameter that is an estimate of the maximum number of users 62 * that will be concurrently using eCryptfs. Set this to the right 63 * value to balance performance and memory use. 64 */ 65 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 66 67 module_param(ecryptfs_number_of_users, uint, 0); 68 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 69 "concurrent users of eCryptfs"); 70 71 void __ecryptfs_printk(const char *fmt, ...) 72 { 73 va_list args; 74 va_start(args, fmt); 75 if (fmt[1] == '7') { /* KERN_DEBUG */ 76 if (ecryptfs_verbosity >= 1) 77 vprintk(fmt, args); 78 } else 79 vprintk(fmt, args); 80 va_end(args); 81 } 82 83 /* 84 * ecryptfs_init_lower_file 85 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 86 * the lower dentry and the lower mount set 87 * 88 * eCryptfs only ever keeps a single open file for every lower 89 * inode. All I/O operations to the lower inode occur through that 90 * file. When the first eCryptfs dentry that interposes with the first 91 * lower dentry for that inode is created, this function creates the 92 * lower file struct and associates it with the eCryptfs 93 * inode. When all eCryptfs files associated with the inode are released, the 94 * file is closed. 95 * 96 * The lower file will be opened with read/write permissions, if 97 * possible. Otherwise, it is opened read-only. 98 * 99 * This function does nothing if a lower file is already 100 * associated with the eCryptfs inode. 101 * 102 * Returns zero on success; non-zero otherwise 103 */ 104 static int ecryptfs_init_lower_file(struct dentry *dentry, 105 struct file **lower_file) 106 { 107 const struct cred *cred = current_cred(); 108 const struct path *path = ecryptfs_dentry_to_lower_path(dentry); 109 int rc; 110 111 rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt, 112 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 struct ecryptfs_dentry_info *root_info; 440 const char *err = "Getting sb failed"; 441 struct inode *inode; 442 struct path path; 443 int rc; 444 445 if (!fc->source) { 446 rc = -EINVAL; 447 err = "Device name cannot be null"; 448 goto out; 449 } 450 451 mount_crypt_stat = &sbi->mount_crypt_stat; 452 rc = ecryptfs_validate_options(fc); 453 if (rc) { 454 err = "Error validating options"; 455 goto out; 456 } 457 458 s = sget_fc(fc, NULL, set_anon_super_fc); 459 if (IS_ERR(s)) { 460 rc = PTR_ERR(s); 461 goto out; 462 } 463 464 rc = super_setup_bdi(s); 465 if (rc) 466 goto out1; 467 468 ecryptfs_set_superblock_private(s, sbi); 469 470 /* ->kill_sb() will take care of sbi after that point */ 471 sbi = NULL; 472 s->s_op = &ecryptfs_sops; 473 s->s_xattr = ecryptfs_xattr_handlers; 474 s->s_d_op = &ecryptfs_dops; 475 476 err = "Reading sb failed"; 477 rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); 478 if (rc) { 479 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); 480 goto out1; 481 } 482 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { 483 rc = -EINVAL; 484 printk(KERN_ERR "Mount on filesystem of type " 485 "eCryptfs explicitly disallowed due to " 486 "known incompatibilities\n"); 487 goto out_free; 488 } 489 490 if (is_idmapped_mnt(path.mnt)) { 491 rc = -EINVAL; 492 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n"); 493 goto out_free; 494 } 495 496 if (ctx->check_ruid && 497 !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { 498 rc = -EPERM; 499 printk(KERN_ERR "Mount of device (uid: %d) not owned by " 500 "requested user (uid: %d)\n", 501 i_uid_read(d_inode(path.dentry)), 502 from_kuid(&init_user_ns, current_uid())); 503 goto out_free; 504 } 505 506 ecryptfs_set_superblock_lower(s, path.dentry->d_sb); 507 508 /** 509 * Set the POSIX ACL flag based on whether they're enabled in the lower 510 * mount. 511 */ 512 s->s_flags = fc->sb_flags & ~SB_POSIXACL; 513 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL; 514 515 /** 516 * Force a read-only eCryptfs mount when: 517 * 1) The lower mount is ro 518 * 2) The ecryptfs_encrypted_view mount option is specified 519 */ 520 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) 521 s->s_flags |= SB_RDONLY; 522 523 s->s_maxbytes = path.dentry->d_sb->s_maxbytes; 524 s->s_blocksize = path.dentry->d_sb->s_blocksize; 525 s->s_magic = ECRYPTFS_SUPER_MAGIC; 526 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; 527 528 rc = -EINVAL; 529 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { 530 pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); 531 goto out_free; 532 } 533 534 inode = ecryptfs_get_inode(d_inode(path.dentry), s); 535 rc = PTR_ERR(inode); 536 if (IS_ERR(inode)) 537 goto out_free; 538 539 s->s_root = d_make_root(inode); 540 if (!s->s_root) { 541 rc = -ENOMEM; 542 goto out_free; 543 } 544 545 rc = -ENOMEM; 546 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); 547 if (!root_info) 548 goto out_free; 549 550 /* ->kill_sb() will take care of root_info */ 551 ecryptfs_set_dentry_private(s->s_root, root_info); 552 root_info->lower_path = path; 553 554 s->s_flags |= SB_ACTIVE; 555 fc->root = dget(s->s_root); 556 return 0; 557 558 out_free: 559 path_put(&path); 560 out1: 561 deactivate_locked_super(s); 562 out: 563 if (sbi) 564 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 565 566 printk(KERN_ERR "%s; rc = [%d]\n", err, rc); 567 return rc; 568 } 569 570 /** 571 * ecryptfs_kill_block_super 572 * @sb: The ecryptfs super block 573 * 574 * Used to bring the superblock down and free the private data. 575 */ 576 static void ecryptfs_kill_block_super(struct super_block *sb) 577 { 578 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 579 kill_anon_super(sb); 580 if (!sb_info) 581 return; 582 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); 583 kmem_cache_free(ecryptfs_sb_info_cache, sb_info); 584 } 585 586 static void ecryptfs_free_fc(struct fs_context *fc) 587 { 588 struct ecryptfs_fs_context *ctx = fc->fs_private; 589 struct ecryptfs_sb_info *sbi = fc->s_fs_info; 590 591 kfree(ctx); 592 593 if (sbi) { 594 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); 595 kmem_cache_free(ecryptfs_sb_info_cache, sbi); 596 } 597 } 598 599 static const struct fs_context_operations ecryptfs_context_ops = { 600 .free = ecryptfs_free_fc, 601 .parse_param = ecryptfs_parse_param, 602 .get_tree = ecryptfs_get_tree, 603 .reconfigure = NULL, 604 }; 605 606 static int ecryptfs_init_fs_context(struct fs_context *fc) 607 { 608 struct ecryptfs_fs_context *ctx; 609 struct ecryptfs_sb_info *sbi = NULL; 610 611 ctx = kzalloc(sizeof(struct ecryptfs_fs_context), GFP_KERNEL); 612 if (!ctx) 613 return -ENOMEM; 614 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 615 if (!sbi) { 616 kfree(ctx); 617 ctx = NULL; 618 return -ENOMEM; 619 } 620 621 ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat); 622 623 fc->fs_private = ctx; 624 fc->s_fs_info = sbi; 625 fc->ops = &ecryptfs_context_ops; 626 return 0; 627 } 628 629 static struct file_system_type ecryptfs_fs_type = { 630 .owner = THIS_MODULE, 631 .name = "ecryptfs", 632 .init_fs_context = ecryptfs_init_fs_context, 633 .parameters = ecryptfs_fs_param_spec, 634 .kill_sb = ecryptfs_kill_block_super, 635 .fs_flags = 0 636 }; 637 MODULE_ALIAS_FS("ecryptfs"); 638 639 /* 640 * inode_info_init_once 641 * 642 * Initializes the ecryptfs_inode_info_cache when it is created 643 */ 644 static void 645 inode_info_init_once(void *vptr) 646 { 647 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 648 649 inode_init_once(&ei->vfs_inode); 650 } 651 652 static struct ecryptfs_cache_info { 653 struct kmem_cache **cache; 654 const char *name; 655 size_t size; 656 slab_flags_t flags; 657 void (*ctor)(void *obj); 658 } ecryptfs_cache_infos[] = { 659 { 660 .cache = &ecryptfs_auth_tok_list_item_cache, 661 .name = "ecryptfs_auth_tok_list_item", 662 .size = sizeof(struct ecryptfs_auth_tok_list_item), 663 }, 664 { 665 .cache = &ecryptfs_file_info_cache, 666 .name = "ecryptfs_file_cache", 667 .size = sizeof(struct ecryptfs_file_info), 668 }, 669 { 670 .cache = &ecryptfs_dentry_info_cache, 671 .name = "ecryptfs_dentry_info_cache", 672 .size = sizeof(struct ecryptfs_dentry_info), 673 }, 674 { 675 .cache = &ecryptfs_inode_info_cache, 676 .name = "ecryptfs_inode_cache", 677 .size = sizeof(struct ecryptfs_inode_info), 678 .flags = SLAB_ACCOUNT, 679 .ctor = inode_info_init_once, 680 }, 681 { 682 .cache = &ecryptfs_sb_info_cache, 683 .name = "ecryptfs_sb_cache", 684 .size = sizeof(struct ecryptfs_sb_info), 685 }, 686 { 687 .cache = &ecryptfs_header_cache, 688 .name = "ecryptfs_headers", 689 .size = PAGE_SIZE, 690 }, 691 { 692 .cache = &ecryptfs_xattr_cache, 693 .name = "ecryptfs_xattr_cache", 694 .size = PAGE_SIZE, 695 }, 696 { 697 .cache = &ecryptfs_key_record_cache, 698 .name = "ecryptfs_key_record_cache", 699 .size = sizeof(struct ecryptfs_key_record), 700 }, 701 { 702 .cache = &ecryptfs_key_sig_cache, 703 .name = "ecryptfs_key_sig_cache", 704 .size = sizeof(struct ecryptfs_key_sig), 705 }, 706 { 707 .cache = &ecryptfs_global_auth_tok_cache, 708 .name = "ecryptfs_global_auth_tok_cache", 709 .size = sizeof(struct ecryptfs_global_auth_tok), 710 }, 711 { 712 .cache = &ecryptfs_key_tfm_cache, 713 .name = "ecryptfs_key_tfm_cache", 714 .size = sizeof(struct ecryptfs_key_tfm), 715 }, 716 }; 717 718 static void ecryptfs_free_kmem_caches(void) 719 { 720 int i; 721 722 /* 723 * Make sure all delayed rcu free inodes are flushed before we 724 * destroy cache. 725 */ 726 rcu_barrier(); 727 728 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 729 struct ecryptfs_cache_info *info; 730 731 info = &ecryptfs_cache_infos[i]; 732 kmem_cache_destroy(*(info->cache)); 733 } 734 } 735 736 /** 737 * ecryptfs_init_kmem_caches 738 * 739 * Returns zero on success; non-zero otherwise 740 */ 741 static int ecryptfs_init_kmem_caches(void) 742 { 743 int i; 744 745 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 746 struct ecryptfs_cache_info *info; 747 748 info = &ecryptfs_cache_infos[i]; 749 *(info->cache) = kmem_cache_create(info->name, info->size, 0, 750 SLAB_HWCACHE_ALIGN | info->flags, info->ctor); 751 if (!*(info->cache)) { 752 ecryptfs_free_kmem_caches(); 753 ecryptfs_printk(KERN_WARNING, "%s: " 754 "kmem_cache_create failed\n", 755 info->name); 756 return -ENOMEM; 757 } 758 } 759 return 0; 760 } 761 762 static struct kobject *ecryptfs_kobj; 763 764 static ssize_t version_show(struct kobject *kobj, 765 struct kobj_attribute *attr, char *buff) 766 { 767 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 768 } 769 770 static struct kobj_attribute version_attr = __ATTR_RO(version); 771 772 static struct attribute *attributes[] = { 773 &version_attr.attr, 774 NULL, 775 }; 776 777 static const struct attribute_group attr_group = { 778 .attrs = attributes, 779 }; 780 781 static int do_sysfs_registration(void) 782 { 783 int rc; 784 785 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); 786 if (!ecryptfs_kobj) { 787 printk(KERN_ERR "Unable to create ecryptfs kset\n"); 788 rc = -ENOMEM; 789 goto out; 790 } 791 rc = sysfs_create_group(ecryptfs_kobj, &attr_group); 792 if (rc) { 793 printk(KERN_ERR 794 "Unable to create ecryptfs version attributes\n"); 795 kobject_put(ecryptfs_kobj); 796 } 797 out: 798 return rc; 799 } 800 801 static void do_sysfs_unregistration(void) 802 { 803 sysfs_remove_group(ecryptfs_kobj, &attr_group); 804 kobject_put(ecryptfs_kobj); 805 } 806 807 static int __init ecryptfs_init(void) 808 { 809 int rc; 810 811 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) { 812 rc = -EINVAL; 813 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 814 "larger than the host's page size, and so " 815 "eCryptfs cannot run on this system. The " 816 "default eCryptfs extent size is [%u] bytes; " 817 "the page size is [%lu] bytes.\n", 818 ECRYPTFS_DEFAULT_EXTENT_SIZE, 819 (unsigned long)PAGE_SIZE); 820 goto out; 821 } 822 rc = ecryptfs_init_kmem_caches(); 823 if (rc) { 824 printk(KERN_ERR 825 "Failed to allocate one or more kmem_cache objects\n"); 826 goto out; 827 } 828 rc = do_sysfs_registration(); 829 if (rc) { 830 printk(KERN_ERR "sysfs registration failed\n"); 831 goto out_free_kmem_caches; 832 } 833 rc = ecryptfs_init_kthread(); 834 if (rc) { 835 printk(KERN_ERR "%s: kthread initialization failed; " 836 "rc = [%d]\n", __func__, rc); 837 goto out_do_sysfs_unregistration; 838 } 839 rc = ecryptfs_init_messaging(); 840 if (rc) { 841 printk(KERN_ERR "Failure occurred while attempting to " 842 "initialize the communications channel to " 843 "ecryptfsd\n"); 844 goto out_destroy_kthread; 845 } 846 rc = ecryptfs_init_crypto(); 847 if (rc) { 848 printk(KERN_ERR "Failure whilst attempting to init crypto; " 849 "rc = [%d]\n", rc); 850 goto out_release_messaging; 851 } 852 rc = register_filesystem(&ecryptfs_fs_type); 853 if (rc) { 854 printk(KERN_ERR "Failed to register filesystem\n"); 855 goto out_destroy_crypto; 856 } 857 if (ecryptfs_verbosity > 0) 858 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " 859 "will be written to the syslog!\n", ecryptfs_verbosity); 860 861 goto out; 862 out_destroy_crypto: 863 ecryptfs_destroy_crypto(); 864 out_release_messaging: 865 ecryptfs_release_messaging(); 866 out_destroy_kthread: 867 ecryptfs_destroy_kthread(); 868 out_do_sysfs_unregistration: 869 do_sysfs_unregistration(); 870 out_free_kmem_caches: 871 ecryptfs_free_kmem_caches(); 872 out: 873 return rc; 874 } 875 876 static void __exit ecryptfs_exit(void) 877 { 878 int rc; 879 880 rc = ecryptfs_destroy_crypto(); 881 if (rc) 882 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 883 "rc = [%d]\n", rc); 884 ecryptfs_release_messaging(); 885 ecryptfs_destroy_kthread(); 886 do_sysfs_unregistration(); 887 unregister_filesystem(&ecryptfs_fs_type); 888 ecryptfs_free_kmem_caches(); 889 } 890 891 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 892 MODULE_DESCRIPTION("eCryptfs"); 893 894 MODULE_LICENSE("GPL"); 895 896 module_init(ecryptfs_init) 897 module_exit(ecryptfs_exit) 898