1 /** 2 * eCryptfs: Linux filesystem encryption layer 3 * 4 * Copyright (C) 1997-2003 Erez Zadok 5 * Copyright (C) 2001-2003 Stony Brook University 6 * Copyright (C) 2004-2007 International Business Machines Corp. 7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> 8 * Michael C. Thompson <mcthomps@us.ibm.com> 9 * Tyler Hicks <tyhicks@ou.edu> 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License as 13 * published by the Free Software Foundation; either version 2 of the 14 * License, or (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, but 17 * WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 * General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 24 * 02111-1307, USA. 25 */ 26 27 #include <linux/dcache.h> 28 #include <linux/file.h> 29 #include <linux/module.h> 30 #include <linux/namei.h> 31 #include <linux/skbuff.h> 32 #include <linux/crypto.h> 33 #include <linux/netlink.h> 34 #include <linux/mount.h> 35 #include <linux/pagemap.h> 36 #include <linux/key.h> 37 #include <linux/parser.h> 38 #include <linux/fs_stack.h> 39 #include "ecryptfs_kernel.h" 40 41 /** 42 * Module parameter that defines the ecryptfs_verbosity level. 43 */ 44 int ecryptfs_verbosity = 0; 45 46 module_param(ecryptfs_verbosity, int, 0); 47 MODULE_PARM_DESC(ecryptfs_verbosity, 48 "Initial verbosity level (0 or 1; defaults to " 49 "0, which is Quiet)"); 50 51 /** 52 * Module parameter that defines the number of netlink message buffer 53 * elements 54 */ 55 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; 56 57 module_param(ecryptfs_message_buf_len, uint, 0); 58 MODULE_PARM_DESC(ecryptfs_message_buf_len, 59 "Number of message buffer elements"); 60 61 /** 62 * Module parameter that defines the maximum guaranteed amount of time to wait 63 * for a response through netlink. The actual sleep time will be, more than 64 * likely, a small amount greater than this specified value, but only less if 65 * the netlink message successfully arrives. 66 */ 67 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; 68 69 module_param(ecryptfs_message_wait_timeout, long, 0); 70 MODULE_PARM_DESC(ecryptfs_message_wait_timeout, 71 "Maximum number of seconds that an operation will " 72 "sleep while waiting for a message response from " 73 "userspace"); 74 75 /** 76 * Module parameter that is an estimate of the maximum number of users 77 * that will be concurrently using eCryptfs. Set this to the right 78 * value to balance performance and memory use. 79 */ 80 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; 81 82 module_param(ecryptfs_number_of_users, uint, 0); 83 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " 84 "concurrent users of eCryptfs"); 85 86 unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT; 87 88 void __ecryptfs_printk(const char *fmt, ...) 89 { 90 va_list args; 91 va_start(args, fmt); 92 if (fmt[1] == '7') { /* KERN_DEBUG */ 93 if (ecryptfs_verbosity >= 1) 94 vprintk(fmt, args); 95 } else 96 vprintk(fmt, args); 97 va_end(args); 98 } 99 100 /** 101 * ecryptfs_init_persistent_file 102 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with 103 * the lower dentry and the lower mount set 104 * 105 * eCryptfs only ever keeps a single open file for every lower 106 * inode. All I/O operations to the lower inode occur through that 107 * file. When the first eCryptfs dentry that interposes with the first 108 * lower dentry for that inode is created, this function creates the 109 * persistent file struct and associates it with the eCryptfs 110 * inode. When the eCryptfs inode is destroyed, the file is closed. 111 * 112 * The persistent file will be opened with read/write permissions, if 113 * possible. Otherwise, it is opened read-only. 114 * 115 * This function does nothing if a lower persistent file is already 116 * associated with the eCryptfs inode. 117 * 118 * Returns zero on success; non-zero otherwise 119 */ 120 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) 121 { 122 struct ecryptfs_inode_info *inode_info = 123 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); 124 int rc = 0; 125 126 mutex_lock(&inode_info->lower_file_mutex); 127 if (!inode_info->lower_file) { 128 struct dentry *lower_dentry; 129 struct vfsmount *lower_mnt = 130 ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); 131 132 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 133 /* Corresponding dput() and mntput() are done when the 134 * persistent file is fput() when the eCryptfs inode 135 * is destroyed. */ 136 dget(lower_dentry); 137 mntget(lower_mnt); 138 inode_info->lower_file = dentry_open(lower_dentry, 139 lower_mnt, 140 (O_RDWR | O_LARGEFILE)); 141 if (IS_ERR(inode_info->lower_file)) 142 inode_info->lower_file = dentry_open(lower_dentry, 143 lower_mnt, 144 (O_RDONLY 145 | O_LARGEFILE)); 146 if (IS_ERR(inode_info->lower_file)) { 147 printk(KERN_ERR "Error opening lower persistent file " 148 "for lower_dentry [0x%p] and lower_mnt [0x%p]\n", 149 lower_dentry, lower_mnt); 150 rc = PTR_ERR(inode_info->lower_file); 151 inode_info->lower_file = NULL; 152 } 153 } 154 mutex_unlock(&inode_info->lower_file_mutex); 155 return rc; 156 } 157 158 /** 159 * ecryptfs_interpose 160 * @lower_dentry: Existing dentry in the lower filesystem 161 * @dentry: ecryptfs' dentry 162 * @sb: ecryptfs's super_block 163 * @flag: If set to true, then d_add is called, else d_instantiate is called 164 * 165 * Interposes upper and lower dentries. 166 * 167 * Returns zero on success; non-zero otherwise 168 */ 169 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, 170 struct super_block *sb, int flag) 171 { 172 struct inode *lower_inode; 173 struct inode *inode; 174 int rc = 0; 175 176 lower_inode = lower_dentry->d_inode; 177 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { 178 rc = -EXDEV; 179 goto out; 180 } 181 if (!igrab(lower_inode)) { 182 rc = -ESTALE; 183 goto out; 184 } 185 inode = iget5_locked(sb, (unsigned long)lower_inode, 186 ecryptfs_inode_test, ecryptfs_inode_set, 187 lower_inode); 188 if (!inode) { 189 rc = -EACCES; 190 iput(lower_inode); 191 goto out; 192 } 193 if (inode->i_state & I_NEW) 194 unlock_new_inode(inode); 195 else 196 iput(lower_inode); 197 if (S_ISLNK(lower_inode->i_mode)) 198 inode->i_op = &ecryptfs_symlink_iops; 199 else if (S_ISDIR(lower_inode->i_mode)) 200 inode->i_op = &ecryptfs_dir_iops; 201 if (S_ISDIR(lower_inode->i_mode)) 202 inode->i_fop = &ecryptfs_dir_fops; 203 if (special_file(lower_inode->i_mode)) 204 init_special_inode(inode, lower_inode->i_mode, 205 lower_inode->i_rdev); 206 dentry->d_op = &ecryptfs_dops; 207 if (flag) 208 d_add(dentry, inode); 209 else 210 d_instantiate(dentry, inode); 211 fsstack_copy_attr_all(inode, lower_inode, NULL); 212 /* This size will be overwritten for real files w/ headers and 213 * other metadata */ 214 fsstack_copy_inode_size(inode, lower_inode); 215 rc = ecryptfs_init_persistent_file(dentry); 216 if (rc) { 217 printk(KERN_ERR "%s: Error attempting to initialize the " 218 "persistent file for the dentry with name [%s]; " 219 "rc = [%d]\n", __FUNCTION__, dentry->d_name.name, rc); 220 goto out; 221 } 222 out: 223 return rc; 224 } 225 226 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug, 227 ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher, 228 ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes, 229 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, 230 ecryptfs_opt_encrypted_view, ecryptfs_opt_err }; 231 232 static match_table_t tokens = { 233 {ecryptfs_opt_sig, "sig=%s"}, 234 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, 235 {ecryptfs_opt_debug, "debug=%u"}, 236 {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"}, 237 {ecryptfs_opt_cipher, "cipher=%s"}, 238 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, 239 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, 240 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, 241 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, 242 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, 243 {ecryptfs_opt_err, NULL} 244 }; 245 246 static int ecryptfs_init_global_auth_toks( 247 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 248 { 249 struct ecryptfs_global_auth_tok *global_auth_tok; 250 int rc = 0; 251 252 list_for_each_entry(global_auth_tok, 253 &mount_crypt_stat->global_auth_tok_list, 254 mount_crypt_stat_list) { 255 rc = ecryptfs_keyring_auth_tok_for_sig( 256 &global_auth_tok->global_auth_tok_key, 257 &global_auth_tok->global_auth_tok, 258 global_auth_tok->sig); 259 if (rc) { 260 printk(KERN_ERR "Could not find valid key in user " 261 "session keyring for sig specified in mount " 262 "option: [%s]\n", global_auth_tok->sig); 263 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; 264 rc = 0; 265 } else 266 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; 267 } 268 return rc; 269 } 270 271 static void ecryptfs_init_mount_crypt_stat( 272 struct ecryptfs_mount_crypt_stat *mount_crypt_stat) 273 { 274 memset((void *)mount_crypt_stat, 0, 275 sizeof(struct ecryptfs_mount_crypt_stat)); 276 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); 277 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); 278 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; 279 } 280 281 /** 282 * ecryptfs_parse_options 283 * @sb: The ecryptfs super block 284 * @options: The options pased to the kernel 285 * 286 * Parse mount options: 287 * debug=N - ecryptfs_verbosity level for debug output 288 * sig=XXX - description(signature) of the key to use 289 * 290 * Returns the dentry object of the lower-level (lower/interposed) 291 * directory; We want to mount our stackable file system on top of 292 * that lower directory. 293 * 294 * The signature of the key to use must be the description of a key 295 * already in the keyring. Mounting will fail if the key can not be 296 * found. 297 * 298 * Returns zero on success; non-zero on error 299 */ 300 static int ecryptfs_parse_options(struct super_block *sb, char *options) 301 { 302 char *p; 303 int rc = 0; 304 int sig_set = 0; 305 int cipher_name_set = 0; 306 int cipher_key_bytes; 307 int cipher_key_bytes_set = 0; 308 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 309 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; 310 substring_t args[MAX_OPT_ARGS]; 311 int token; 312 char *sig_src; 313 char *debug_src; 314 char *cipher_name_dst; 315 char *cipher_name_src; 316 char *cipher_key_bytes_src; 317 int cipher_name_len; 318 319 if (!options) { 320 rc = -EINVAL; 321 goto out; 322 } 323 ecryptfs_init_mount_crypt_stat(mount_crypt_stat); 324 while ((p = strsep(&options, ",")) != NULL) { 325 if (!*p) 326 continue; 327 token = match_token(p, tokens, args); 328 switch (token) { 329 case ecryptfs_opt_sig: 330 case ecryptfs_opt_ecryptfs_sig: 331 sig_src = args[0].from; 332 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, 333 sig_src); 334 if (rc) { 335 printk(KERN_ERR "Error attempting to register " 336 "global sig; rc = [%d]\n", rc); 337 goto out; 338 } 339 sig_set = 1; 340 break; 341 case ecryptfs_opt_debug: 342 case ecryptfs_opt_ecryptfs_debug: 343 debug_src = args[0].from; 344 ecryptfs_verbosity = 345 (int)simple_strtol(debug_src, &debug_src, 346 0); 347 ecryptfs_printk(KERN_DEBUG, 348 "Verbosity set to [%d]" "\n", 349 ecryptfs_verbosity); 350 break; 351 case ecryptfs_opt_cipher: 352 case ecryptfs_opt_ecryptfs_cipher: 353 cipher_name_src = args[0].from; 354 cipher_name_dst = 355 mount_crypt_stat-> 356 global_default_cipher_name; 357 strncpy(cipher_name_dst, cipher_name_src, 358 ECRYPTFS_MAX_CIPHER_NAME_SIZE); 359 ecryptfs_printk(KERN_DEBUG, 360 "The mount_crypt_stat " 361 "global_default_cipher_name set to: " 362 "[%s]\n", cipher_name_dst); 363 cipher_name_set = 1; 364 break; 365 case ecryptfs_opt_ecryptfs_key_bytes: 366 cipher_key_bytes_src = args[0].from; 367 cipher_key_bytes = 368 (int)simple_strtol(cipher_key_bytes_src, 369 &cipher_key_bytes_src, 0); 370 mount_crypt_stat->global_default_cipher_key_size = 371 cipher_key_bytes; 372 ecryptfs_printk(KERN_DEBUG, 373 "The mount_crypt_stat " 374 "global_default_cipher_key_size " 375 "set to: [%d]\n", mount_crypt_stat-> 376 global_default_cipher_key_size); 377 cipher_key_bytes_set = 1; 378 break; 379 case ecryptfs_opt_passthrough: 380 mount_crypt_stat->flags |= 381 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; 382 break; 383 case ecryptfs_opt_xattr_metadata: 384 mount_crypt_stat->flags |= 385 ECRYPTFS_XATTR_METADATA_ENABLED; 386 break; 387 case ecryptfs_opt_encrypted_view: 388 mount_crypt_stat->flags |= 389 ECRYPTFS_XATTR_METADATA_ENABLED; 390 mount_crypt_stat->flags |= 391 ECRYPTFS_ENCRYPTED_VIEW_ENABLED; 392 break; 393 case ecryptfs_opt_err: 394 default: 395 ecryptfs_printk(KERN_WARNING, 396 "eCryptfs: unrecognized option '%s'\n", 397 p); 398 } 399 } 400 if (!sig_set) { 401 rc = -EINVAL; 402 ecryptfs_printk(KERN_ERR, "You must supply at least one valid " 403 "auth tok signature as a mount " 404 "parameter; see the eCryptfs README\n"); 405 goto out; 406 } 407 if (!cipher_name_set) { 408 cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); 409 if (unlikely(cipher_name_len 410 >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) { 411 rc = -EINVAL; 412 BUG(); 413 goto out; 414 } 415 memcpy(mount_crypt_stat->global_default_cipher_name, 416 ECRYPTFS_DEFAULT_CIPHER, cipher_name_len); 417 mount_crypt_stat->global_default_cipher_name[cipher_name_len] 418 = '\0'; 419 } 420 if (!cipher_key_bytes_set) { 421 mount_crypt_stat->global_default_cipher_key_size = 0; 422 } 423 rc = ecryptfs_add_new_key_tfm( 424 NULL, mount_crypt_stat->global_default_cipher_name, 425 mount_crypt_stat->global_default_cipher_key_size); 426 if (rc) { 427 printk(KERN_ERR "Error attempting to initialize cipher with " 428 "name = [%s] and key size = [%td]; rc = [%d]\n", 429 mount_crypt_stat->global_default_cipher_name, 430 mount_crypt_stat->global_default_cipher_key_size, rc); 431 rc = -EINVAL; 432 goto out; 433 } 434 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); 435 if (rc) { 436 printk(KERN_WARNING "One or more global auth toks could not " 437 "properly register; rc = [%d]\n", rc); 438 } 439 rc = 0; 440 out: 441 return rc; 442 } 443 444 struct kmem_cache *ecryptfs_sb_info_cache; 445 446 /** 447 * ecryptfs_fill_super 448 * @sb: The ecryptfs super block 449 * @raw_data: The options passed to mount 450 * @silent: Not used but required by function prototype 451 * 452 * Sets up what we can of the sb, rest is done in ecryptfs_read_super 453 * 454 * Returns zero on success; non-zero otherwise 455 */ 456 static int 457 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) 458 { 459 int rc = 0; 460 461 /* Released in ecryptfs_put_super() */ 462 ecryptfs_set_superblock_private(sb, 463 kmem_cache_zalloc(ecryptfs_sb_info_cache, 464 GFP_KERNEL)); 465 if (!ecryptfs_superblock_to_private(sb)) { 466 ecryptfs_printk(KERN_WARNING, "Out of memory\n"); 467 rc = -ENOMEM; 468 goto out; 469 } 470 sb->s_op = &ecryptfs_sops; 471 /* Released through deactivate_super(sb) from get_sb_nodev */ 472 sb->s_root = d_alloc(NULL, &(const struct qstr) { 473 .hash = 0,.name = "/",.len = 1}); 474 if (!sb->s_root) { 475 ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); 476 rc = -ENOMEM; 477 goto out; 478 } 479 sb->s_root->d_op = &ecryptfs_dops; 480 sb->s_root->d_sb = sb; 481 sb->s_root->d_parent = sb->s_root; 482 /* Released in d_release when dput(sb->s_root) is called */ 483 /* through deactivate_super(sb) from get_sb_nodev() */ 484 ecryptfs_set_dentry_private(sb->s_root, 485 kmem_cache_zalloc(ecryptfs_dentry_info_cache, 486 GFP_KERNEL)); 487 if (!ecryptfs_dentry_to_private(sb->s_root)) { 488 ecryptfs_printk(KERN_ERR, 489 "dentry_info_cache alloc failed\n"); 490 rc = -ENOMEM; 491 goto out; 492 } 493 rc = 0; 494 out: 495 /* Should be able to rely on deactivate_super called from 496 * get_sb_nodev */ 497 return rc; 498 } 499 500 /** 501 * ecryptfs_read_super 502 * @sb: The ecryptfs super block 503 * @dev_name: The path to mount over 504 * 505 * Read the super block of the lower filesystem, and use 506 * ecryptfs_interpose to create our initial inode and super block 507 * struct. 508 */ 509 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) 510 { 511 int rc; 512 struct nameidata nd; 513 struct dentry *lower_root; 514 struct vfsmount *lower_mnt; 515 516 memset(&nd, 0, sizeof(struct nameidata)); 517 rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd); 518 if (rc) { 519 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); 520 goto out; 521 } 522 lower_root = nd.dentry; 523 lower_mnt = nd.mnt; 524 ecryptfs_set_superblock_lower(sb, lower_root->d_sb); 525 sb->s_maxbytes = lower_root->d_sb->s_maxbytes; 526 ecryptfs_set_dentry_lower(sb->s_root, lower_root); 527 ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt); 528 rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0); 529 if (rc) 530 goto out_free; 531 rc = 0; 532 goto out; 533 out_free: 534 path_release(&nd); 535 out: 536 return rc; 537 } 538 539 /** 540 * ecryptfs_get_sb 541 * @fs_type 542 * @flags 543 * @dev_name: The path to mount over 544 * @raw_data: The options passed into the kernel 545 * 546 * The whole ecryptfs_get_sb process is broken into 4 functions: 547 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any 548 * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block 549 * with as much information as it can before needing 550 * the lower filesystem. 551 * ecryptfs_read_super(): this accesses the lower filesystem and uses 552 * ecryptfs_interpolate to perform most of the linking 553 * ecryptfs_interpolate(): links the lower filesystem into ecryptfs 554 */ 555 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, 556 const char *dev_name, void *raw_data, 557 struct vfsmount *mnt) 558 { 559 int rc; 560 struct super_block *sb; 561 562 rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); 563 if (rc < 0) { 564 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); 565 goto out; 566 } 567 sb = mnt->mnt_sb; 568 rc = ecryptfs_parse_options(sb, raw_data); 569 if (rc) { 570 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); 571 goto out_abort; 572 } 573 rc = ecryptfs_read_super(sb, dev_name); 574 if (rc) { 575 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); 576 goto out_abort; 577 } 578 goto out; 579 out_abort: 580 dput(sb->s_root); 581 up_write(&sb->s_umount); 582 deactivate_super(sb); 583 out: 584 return rc; 585 } 586 587 /** 588 * ecryptfs_kill_block_super 589 * @sb: The ecryptfs super block 590 * 591 * Used to bring the superblock down and free the private data. 592 * Private data is free'd in ecryptfs_put_super() 593 */ 594 static void ecryptfs_kill_block_super(struct super_block *sb) 595 { 596 generic_shutdown_super(sb); 597 } 598 599 static struct file_system_type ecryptfs_fs_type = { 600 .owner = THIS_MODULE, 601 .name = "ecryptfs", 602 .get_sb = ecryptfs_get_sb, 603 .kill_sb = ecryptfs_kill_block_super, 604 .fs_flags = 0 605 }; 606 607 /** 608 * inode_info_init_once 609 * 610 * Initializes the ecryptfs_inode_info_cache when it is created 611 */ 612 static void 613 inode_info_init_once(struct kmem_cache *cachep, void *vptr) 614 { 615 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; 616 617 inode_init_once(&ei->vfs_inode); 618 } 619 620 static struct ecryptfs_cache_info { 621 struct kmem_cache **cache; 622 const char *name; 623 size_t size; 624 void (*ctor)(struct kmem_cache *cache, void *obj); 625 } ecryptfs_cache_infos[] = { 626 { 627 .cache = &ecryptfs_auth_tok_list_item_cache, 628 .name = "ecryptfs_auth_tok_list_item", 629 .size = sizeof(struct ecryptfs_auth_tok_list_item), 630 }, 631 { 632 .cache = &ecryptfs_file_info_cache, 633 .name = "ecryptfs_file_cache", 634 .size = sizeof(struct ecryptfs_file_info), 635 }, 636 { 637 .cache = &ecryptfs_dentry_info_cache, 638 .name = "ecryptfs_dentry_info_cache", 639 .size = sizeof(struct ecryptfs_dentry_info), 640 }, 641 { 642 .cache = &ecryptfs_inode_info_cache, 643 .name = "ecryptfs_inode_cache", 644 .size = sizeof(struct ecryptfs_inode_info), 645 .ctor = inode_info_init_once, 646 }, 647 { 648 .cache = &ecryptfs_sb_info_cache, 649 .name = "ecryptfs_sb_cache", 650 .size = sizeof(struct ecryptfs_sb_info), 651 }, 652 { 653 .cache = &ecryptfs_header_cache_0, 654 .name = "ecryptfs_headers_0", 655 .size = PAGE_CACHE_SIZE, 656 }, 657 { 658 .cache = &ecryptfs_header_cache_1, 659 .name = "ecryptfs_headers_1", 660 .size = PAGE_CACHE_SIZE, 661 }, 662 { 663 .cache = &ecryptfs_header_cache_2, 664 .name = "ecryptfs_headers_2", 665 .size = PAGE_CACHE_SIZE, 666 }, 667 { 668 .cache = &ecryptfs_xattr_cache, 669 .name = "ecryptfs_xattr_cache", 670 .size = PAGE_CACHE_SIZE, 671 }, 672 { 673 .cache = &ecryptfs_key_record_cache, 674 .name = "ecryptfs_key_record_cache", 675 .size = sizeof(struct ecryptfs_key_record), 676 }, 677 { 678 .cache = &ecryptfs_key_sig_cache, 679 .name = "ecryptfs_key_sig_cache", 680 .size = sizeof(struct ecryptfs_key_sig), 681 }, 682 { 683 .cache = &ecryptfs_global_auth_tok_cache, 684 .name = "ecryptfs_global_auth_tok_cache", 685 .size = sizeof(struct ecryptfs_global_auth_tok), 686 }, 687 { 688 .cache = &ecryptfs_key_tfm_cache, 689 .name = "ecryptfs_key_tfm_cache", 690 .size = sizeof(struct ecryptfs_key_tfm), 691 }, 692 }; 693 694 static void ecryptfs_free_kmem_caches(void) 695 { 696 int i; 697 698 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 699 struct ecryptfs_cache_info *info; 700 701 info = &ecryptfs_cache_infos[i]; 702 if (*(info->cache)) 703 kmem_cache_destroy(*(info->cache)); 704 } 705 } 706 707 /** 708 * ecryptfs_init_kmem_caches 709 * 710 * Returns zero on success; non-zero otherwise 711 */ 712 static int ecryptfs_init_kmem_caches(void) 713 { 714 int i; 715 716 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { 717 struct ecryptfs_cache_info *info; 718 719 info = &ecryptfs_cache_infos[i]; 720 *(info->cache) = kmem_cache_create(info->name, info->size, 721 0, SLAB_HWCACHE_ALIGN, info->ctor); 722 if (!*(info->cache)) { 723 ecryptfs_free_kmem_caches(); 724 ecryptfs_printk(KERN_WARNING, "%s: " 725 "kmem_cache_create failed\n", 726 info->name); 727 return -ENOMEM; 728 } 729 } 730 return 0; 731 } 732 733 struct ecryptfs_obj { 734 char *name; 735 struct list_head slot_list; 736 struct kobject kobj; 737 }; 738 739 struct ecryptfs_attribute { 740 struct attribute attr; 741 ssize_t(*show) (struct ecryptfs_obj *, char *); 742 ssize_t(*store) (struct ecryptfs_obj *, const char *, size_t); 743 }; 744 745 static ssize_t 746 ecryptfs_attr_store(struct kobject *kobj, 747 struct attribute *attr, const char *buf, size_t len) 748 { 749 struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj, 750 kobj); 751 struct ecryptfs_attribute *attribute = 752 container_of(attr, struct ecryptfs_attribute, attr); 753 754 return (attribute->store ? attribute->store(obj, buf, len) : 0); 755 } 756 757 static ssize_t 758 ecryptfs_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) 759 { 760 struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj, 761 kobj); 762 struct ecryptfs_attribute *attribute = 763 container_of(attr, struct ecryptfs_attribute, attr); 764 765 return (attribute->show ? attribute->show(obj, buf) : 0); 766 } 767 768 static struct sysfs_ops ecryptfs_sysfs_ops = { 769 .show = ecryptfs_attr_show, 770 .store = ecryptfs_attr_store 771 }; 772 773 static struct kobj_type ecryptfs_ktype = { 774 .sysfs_ops = &ecryptfs_sysfs_ops 775 }; 776 777 static decl_subsys(ecryptfs, &ecryptfs_ktype, NULL); 778 779 static ssize_t version_show(struct ecryptfs_obj *obj, char *buff) 780 { 781 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); 782 } 783 784 static struct ecryptfs_attribute sysfs_attr_version = __ATTR_RO(version); 785 786 static struct ecryptfs_version_str_map_elem { 787 u32 flag; 788 char *str; 789 } ecryptfs_version_str_map[] = { 790 {ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"}, 791 {ECRYPTFS_VERSIONING_PUBKEY, "pubkey"}, 792 {ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"}, 793 {ECRYPTFS_VERSIONING_POLICY, "policy"}, 794 {ECRYPTFS_VERSIONING_XATTR, "metadata in extended attribute"}, 795 {ECRYPTFS_VERSIONING_MULTKEY, "multiple keys per file"} 796 }; 797 798 static ssize_t version_str_show(struct ecryptfs_obj *obj, char *buff) 799 { 800 int i; 801 int remaining = PAGE_SIZE; 802 int total_written = 0; 803 804 buff[0] = '\0'; 805 for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) { 806 int entry_size; 807 808 if (!(ECRYPTFS_VERSIONING_MASK 809 & ecryptfs_version_str_map[i].flag)) 810 continue; 811 entry_size = strlen(ecryptfs_version_str_map[i].str); 812 if ((entry_size + 2) > remaining) 813 goto out; 814 memcpy(buff, ecryptfs_version_str_map[i].str, entry_size); 815 buff[entry_size++] = '\n'; 816 buff[entry_size] = '\0'; 817 buff += entry_size; 818 total_written += entry_size; 819 remaining -= entry_size; 820 } 821 out: 822 return total_written; 823 } 824 825 static struct ecryptfs_attribute sysfs_attr_version_str = __ATTR_RO(version_str); 826 827 static int do_sysfs_registration(void) 828 { 829 int rc; 830 831 rc = subsystem_register(&ecryptfs_subsys); 832 if (rc) { 833 printk(KERN_ERR 834 "Unable to register ecryptfs sysfs subsystem\n"); 835 goto out; 836 } 837 rc = sysfs_create_file(&ecryptfs_subsys.kobj, 838 &sysfs_attr_version.attr); 839 if (rc) { 840 printk(KERN_ERR 841 "Unable to create ecryptfs version attribute\n"); 842 subsystem_unregister(&ecryptfs_subsys); 843 goto out; 844 } 845 rc = sysfs_create_file(&ecryptfs_subsys.kobj, 846 &sysfs_attr_version_str.attr); 847 if (rc) { 848 printk(KERN_ERR 849 "Unable to create ecryptfs version_str attribute\n"); 850 sysfs_remove_file(&ecryptfs_subsys.kobj, 851 &sysfs_attr_version.attr); 852 subsystem_unregister(&ecryptfs_subsys); 853 goto out; 854 } 855 out: 856 return rc; 857 } 858 859 static void do_sysfs_unregistration(void) 860 { 861 sysfs_remove_file(&ecryptfs_subsys.kobj, 862 &sysfs_attr_version.attr); 863 sysfs_remove_file(&ecryptfs_subsys.kobj, 864 &sysfs_attr_version_str.attr); 865 subsystem_unregister(&ecryptfs_subsys); 866 } 867 868 static int __init ecryptfs_init(void) 869 { 870 int rc; 871 872 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { 873 rc = -EINVAL; 874 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " 875 "larger than the host's page size, and so " 876 "eCryptfs cannot run on this system. The " 877 "default eCryptfs extent size is [%d] bytes; " 878 "the page size is [%d] bytes.\n", 879 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); 880 goto out; 881 } 882 rc = ecryptfs_init_kmem_caches(); 883 if (rc) { 884 printk(KERN_ERR 885 "Failed to allocate one or more kmem_cache objects\n"); 886 goto out; 887 } 888 rc = register_filesystem(&ecryptfs_fs_type); 889 if (rc) { 890 printk(KERN_ERR "Failed to register filesystem\n"); 891 goto out_free_kmem_caches; 892 } 893 kobj_set_kset_s(&ecryptfs_subsys, fs_subsys); 894 rc = do_sysfs_registration(); 895 if (rc) { 896 printk(KERN_ERR "sysfs registration failed\n"); 897 goto out_unregister_filesystem; 898 } 899 rc = ecryptfs_init_messaging(ecryptfs_transport); 900 if (rc) { 901 ecryptfs_printk(KERN_ERR, "Failure occured while attempting to " 902 "initialize the eCryptfs netlink socket\n"); 903 goto out_do_sysfs_unregistration; 904 } 905 rc = ecryptfs_init_crypto(); 906 if (rc) { 907 printk(KERN_ERR "Failure whilst attempting to init crypto; " 908 "rc = [%d]\n", rc); 909 goto out_release_messaging; 910 } 911 goto out; 912 out_release_messaging: 913 ecryptfs_release_messaging(ecryptfs_transport); 914 out_do_sysfs_unregistration: 915 do_sysfs_unregistration(); 916 out_unregister_filesystem: 917 unregister_filesystem(&ecryptfs_fs_type); 918 out_free_kmem_caches: 919 ecryptfs_free_kmem_caches(); 920 out: 921 return rc; 922 } 923 924 static void __exit ecryptfs_exit(void) 925 { 926 int rc; 927 928 rc = ecryptfs_destroy_crypto(); 929 if (rc) 930 printk(KERN_ERR "Failure whilst attempting to destroy crypto; " 931 "rc = [%d]\n", rc); 932 ecryptfs_release_messaging(ecryptfs_transport); 933 do_sysfs_unregistration(); 934 unregister_filesystem(&ecryptfs_fs_type); 935 ecryptfs_free_kmem_caches(); 936 } 937 938 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); 939 MODULE_DESCRIPTION("eCryptfs"); 940 941 MODULE_LICENSE("GPL"); 942 943 module_init(ecryptfs_init) 944 module_exit(ecryptfs_exit) 945