| 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/mount.h> |
| 33 | #include <linux/pagemap.h> |
| 34 | #include <linux/key.h> |
| 35 | #include <linux/parser.h> |
| 36 | #include <linux/fs_stack.h> |
| 37 | #include <linux/slab.h> |
| 38 | #include <linux/magic.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 message buffer elements |
| 53 | */ |
| 54 | unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; |
| 55 | |
| 56 | module_param(ecryptfs_message_buf_len, uint, 0); |
| 57 | MODULE_PARM_DESC(ecryptfs_message_buf_len, |
| 58 | "Number of message buffer elements"); |
| 59 | |
| 60 | /** |
| 61 | * Module parameter that defines the maximum guaranteed amount of time to wait |
| 62 | * for a response from ecryptfsd. The actual sleep time will be, more than |
| 63 | * likely, a small amount greater than this specified value, but only less if |
| 64 | * the message successfully arrives. |
| 65 | */ |
| 66 | signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; |
| 67 | |
| 68 | module_param(ecryptfs_message_wait_timeout, long, 0); |
| 69 | MODULE_PARM_DESC(ecryptfs_message_wait_timeout, |
| 70 | "Maximum number of seconds that an operation will " |
| 71 | "sleep while waiting for a message response from " |
| 72 | "userspace"); |
| 73 | |
| 74 | /** |
| 75 | * Module parameter that is an estimate of the maximum number of users |
| 76 | * that will be concurrently using eCryptfs. Set this to the right |
| 77 | * value to balance performance and memory use. |
| 78 | */ |
| 79 | unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; |
| 80 | |
| 81 | module_param(ecryptfs_number_of_users, uint, 0); |
| 82 | MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " |
| 83 | "concurrent users of eCryptfs"); |
| 84 | |
| 85 | void __ecryptfs_printk(const char *fmt, ...) |
| 86 | { |
| 87 | va_list args; |
| 88 | va_start(args, fmt); |
| 89 | if (fmt[1] == '7') { /* KERN_DEBUG */ |
| 90 | if (ecryptfs_verbosity >= 1) |
| 91 | vprintk(fmt, args); |
| 92 | } else |
| 93 | vprintk(fmt, args); |
| 94 | va_end(args); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * ecryptfs_init_lower_file |
| 99 | * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with |
| 100 | * the lower dentry and the lower mount set |
| 101 | * |
| 102 | * eCryptfs only ever keeps a single open file for every lower |
| 103 | * inode. All I/O operations to the lower inode occur through that |
| 104 | * file. When the first eCryptfs dentry that interposes with the first |
| 105 | * lower dentry for that inode is created, this function creates the |
| 106 | * lower file struct and associates it with the eCryptfs |
| 107 | * inode. When all eCryptfs files associated with the inode are released, the |
| 108 | * file is closed. |
| 109 | * |
| 110 | * The lower file will be opened with read/write permissions, if |
| 111 | * possible. Otherwise, it is opened read-only. |
| 112 | * |
| 113 | * This function does nothing if a lower file is already |
| 114 | * associated with the eCryptfs inode. |
| 115 | * |
| 116 | * Returns zero on success; non-zero otherwise |
| 117 | */ |
| 118 | static int ecryptfs_init_lower_file(struct dentry *dentry, |
| 119 | struct file **lower_file) |
| 120 | { |
| 121 | const struct cred *cred = current_cred(); |
| 122 | struct path *path = ecryptfs_dentry_to_lower_path(dentry); |
| 123 | int rc; |
| 124 | |
| 125 | rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt, |
| 126 | cred); |
| 127 | if (rc) { |
| 128 | printk(KERN_ERR "Error opening lower file " |
| 129 | "for lower_dentry [0x%p] and lower_mnt [0x%p]; " |
| 130 | "rc = [%d]\n", path->dentry, path->mnt, rc); |
| 131 | (*lower_file) = NULL; |
| 132 | } |
| 133 | return rc; |
| 134 | } |
| 135 | |
| 136 | int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) |
| 137 | { |
| 138 | struct ecryptfs_inode_info *inode_info; |
| 139 | int count, rc = 0; |
| 140 | |
| 141 | inode_info = ecryptfs_inode_to_private(inode); |
| 142 | mutex_lock(&inode_info->lower_file_mutex); |
| 143 | count = atomic_inc_return(&inode_info->lower_file_count); |
| 144 | if (WARN_ON_ONCE(count < 1)) |
| 145 | rc = -EINVAL; |
| 146 | else if (count == 1) { |
| 147 | rc = ecryptfs_init_lower_file(dentry, |
| 148 | &inode_info->lower_file); |
| 149 | if (rc) |
| 150 | atomic_set(&inode_info->lower_file_count, 0); |
| 151 | } |
| 152 | mutex_unlock(&inode_info->lower_file_mutex); |
| 153 | return rc; |
| 154 | } |
| 155 | |
| 156 | void ecryptfs_put_lower_file(struct inode *inode) |
| 157 | { |
| 158 | struct ecryptfs_inode_info *inode_info; |
| 159 | |
| 160 | inode_info = ecryptfs_inode_to_private(inode); |
| 161 | if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, |
| 162 | &inode_info->lower_file_mutex)) { |
| 163 | filemap_write_and_wait(inode->i_mapping); |
| 164 | fput(inode_info->lower_file); |
| 165 | inode_info->lower_file = NULL; |
| 166 | mutex_unlock(&inode_info->lower_file_mutex); |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, |
| 171 | ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, |
| 172 | ecryptfs_opt_ecryptfs_key_bytes, |
| 173 | ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, |
| 174 | ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, |
| 175 | ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, |
| 176 | ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, |
| 177 | ecryptfs_opt_check_dev_ruid, |
| 178 | ecryptfs_opt_err }; |
| 179 | |
| 180 | static const match_table_t tokens = { |
| 181 | {ecryptfs_opt_sig, "sig=%s"}, |
| 182 | {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, |
| 183 | {ecryptfs_opt_cipher, "cipher=%s"}, |
| 184 | {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, |
| 185 | {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, |
| 186 | {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, |
| 187 | {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, |
| 188 | {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, |
| 189 | {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, |
| 190 | {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, |
| 191 | {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, |
| 192 | {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, |
| 193 | {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, |
| 194 | {ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"}, |
| 195 | {ecryptfs_opt_err, NULL} |
| 196 | }; |
| 197 | |
| 198 | static int ecryptfs_init_global_auth_toks( |
| 199 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
| 200 | { |
| 201 | struct ecryptfs_global_auth_tok *global_auth_tok; |
| 202 | struct ecryptfs_auth_tok *auth_tok; |
| 203 | int rc = 0; |
| 204 | |
| 205 | list_for_each_entry(global_auth_tok, |
| 206 | &mount_crypt_stat->global_auth_tok_list, |
| 207 | mount_crypt_stat_list) { |
| 208 | rc = ecryptfs_keyring_auth_tok_for_sig( |
| 209 | &global_auth_tok->global_auth_tok_key, &auth_tok, |
| 210 | global_auth_tok->sig); |
| 211 | if (rc) { |
| 212 | printk(KERN_ERR "Could not find valid key in user " |
| 213 | "session keyring for sig specified in mount " |
| 214 | "option: [%s]\n", global_auth_tok->sig); |
| 215 | global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; |
| 216 | goto out; |
| 217 | } else { |
| 218 | global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; |
| 219 | up_write(&(global_auth_tok->global_auth_tok_key)->sem); |
| 220 | } |
| 221 | } |
| 222 | out: |
| 223 | return rc; |
| 224 | } |
| 225 | |
| 226 | static void ecryptfs_init_mount_crypt_stat( |
| 227 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
| 228 | { |
| 229 | memset((void *)mount_crypt_stat, 0, |
| 230 | sizeof(struct ecryptfs_mount_crypt_stat)); |
| 231 | INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); |
| 232 | mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); |
| 233 | mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; |
| 234 | } |
| 235 | |
| 236 | /** |
| 237 | * ecryptfs_parse_options |
| 238 | * @sb: The ecryptfs super block |
| 239 | * @options: The options passed to the kernel |
| 240 | * @check_ruid: set to 1 if device uid should be checked against the ruid |
| 241 | * |
| 242 | * Parse mount options: |
| 243 | * debug=N - ecryptfs_verbosity level for debug output |
| 244 | * sig=XXX - description(signature) of the key to use |
| 245 | * |
| 246 | * Returns the dentry object of the lower-level (lower/interposed) |
| 247 | * directory; We want to mount our stackable file system on top of |
| 248 | * that lower directory. |
| 249 | * |
| 250 | * The signature of the key to use must be the description of a key |
| 251 | * already in the keyring. Mounting will fail if the key can not be |
| 252 | * found. |
| 253 | * |
| 254 | * Returns zero on success; non-zero on error |
| 255 | */ |
| 256 | static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, |
| 257 | uid_t *check_ruid) |
| 258 | { |
| 259 | char *p; |
| 260 | int rc = 0; |
| 261 | int sig_set = 0; |
| 262 | int cipher_name_set = 0; |
| 263 | int fn_cipher_name_set = 0; |
| 264 | int cipher_key_bytes; |
| 265 | int cipher_key_bytes_set = 0; |
| 266 | int fn_cipher_key_bytes; |
| 267 | int fn_cipher_key_bytes_set = 0; |
| 268 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
| 269 | &sbi->mount_crypt_stat; |
| 270 | substring_t args[MAX_OPT_ARGS]; |
| 271 | int token; |
| 272 | char *sig_src; |
| 273 | char *cipher_name_dst; |
| 274 | char *cipher_name_src; |
| 275 | char *fn_cipher_name_dst; |
| 276 | char *fn_cipher_name_src; |
| 277 | char *fnek_dst; |
| 278 | char *fnek_src; |
| 279 | char *cipher_key_bytes_src; |
| 280 | char *fn_cipher_key_bytes_src; |
| 281 | u8 cipher_code; |
| 282 | |
| 283 | *check_ruid = 0; |
| 284 | |
| 285 | if (!options) { |
| 286 | rc = -EINVAL; |
| 287 | goto out; |
| 288 | } |
| 289 | ecryptfs_init_mount_crypt_stat(mount_crypt_stat); |
| 290 | while ((p = strsep(&options, ",")) != NULL) { |
| 291 | if (!*p) |
| 292 | continue; |
| 293 | token = match_token(p, tokens, args); |
| 294 | switch (token) { |
| 295 | case ecryptfs_opt_sig: |
| 296 | case ecryptfs_opt_ecryptfs_sig: |
| 297 | sig_src = args[0].from; |
| 298 | rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, |
| 299 | sig_src, 0); |
| 300 | if (rc) { |
| 301 | printk(KERN_ERR "Error attempting to register " |
| 302 | "global sig; rc = [%d]\n", rc); |
| 303 | goto out; |
| 304 | } |
| 305 | sig_set = 1; |
| 306 | break; |
| 307 | case ecryptfs_opt_cipher: |
| 308 | case ecryptfs_opt_ecryptfs_cipher: |
| 309 | cipher_name_src = args[0].from; |
| 310 | cipher_name_dst = |
| 311 | mount_crypt_stat-> |
| 312 | global_default_cipher_name; |
| 313 | strncpy(cipher_name_dst, cipher_name_src, |
| 314 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); |
| 315 | cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
| 316 | cipher_name_set = 1; |
| 317 | break; |
| 318 | case ecryptfs_opt_ecryptfs_key_bytes: |
| 319 | cipher_key_bytes_src = args[0].from; |
| 320 | cipher_key_bytes = |
| 321 | (int)simple_strtol(cipher_key_bytes_src, |
| 322 | &cipher_key_bytes_src, 0); |
| 323 | mount_crypt_stat->global_default_cipher_key_size = |
| 324 | cipher_key_bytes; |
| 325 | cipher_key_bytes_set = 1; |
| 326 | break; |
| 327 | case ecryptfs_opt_passthrough: |
| 328 | mount_crypt_stat->flags |= |
| 329 | ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; |
| 330 | break; |
| 331 | case ecryptfs_opt_xattr_metadata: |
| 332 | mount_crypt_stat->flags |= |
| 333 | ECRYPTFS_XATTR_METADATA_ENABLED; |
| 334 | break; |
| 335 | case ecryptfs_opt_encrypted_view: |
| 336 | mount_crypt_stat->flags |= |
| 337 | ECRYPTFS_XATTR_METADATA_ENABLED; |
| 338 | mount_crypt_stat->flags |= |
| 339 | ECRYPTFS_ENCRYPTED_VIEW_ENABLED; |
| 340 | break; |
| 341 | case ecryptfs_opt_fnek_sig: |
| 342 | fnek_src = args[0].from; |
| 343 | fnek_dst = |
| 344 | mount_crypt_stat->global_default_fnek_sig; |
| 345 | strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); |
| 346 | mount_crypt_stat->global_default_fnek_sig[ |
| 347 | ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
| 348 | rc = ecryptfs_add_global_auth_tok( |
| 349 | mount_crypt_stat, |
| 350 | mount_crypt_stat->global_default_fnek_sig, |
| 351 | ECRYPTFS_AUTH_TOK_FNEK); |
| 352 | if (rc) { |
| 353 | printk(KERN_ERR "Error attempting to register " |
| 354 | "global fnek sig [%s]; rc = [%d]\n", |
| 355 | mount_crypt_stat->global_default_fnek_sig, |
| 356 | rc); |
| 357 | goto out; |
| 358 | } |
| 359 | mount_crypt_stat->flags |= |
| 360 | (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES |
| 361 | | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); |
| 362 | break; |
| 363 | case ecryptfs_opt_fn_cipher: |
| 364 | fn_cipher_name_src = args[0].from; |
| 365 | fn_cipher_name_dst = |
| 366 | mount_crypt_stat->global_default_fn_cipher_name; |
| 367 | strncpy(fn_cipher_name_dst, fn_cipher_name_src, |
| 368 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); |
| 369 | mount_crypt_stat->global_default_fn_cipher_name[ |
| 370 | ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
| 371 | fn_cipher_name_set = 1; |
| 372 | break; |
| 373 | case ecryptfs_opt_fn_cipher_key_bytes: |
| 374 | fn_cipher_key_bytes_src = args[0].from; |
| 375 | fn_cipher_key_bytes = |
| 376 | (int)simple_strtol(fn_cipher_key_bytes_src, |
| 377 | &fn_cipher_key_bytes_src, 0); |
| 378 | mount_crypt_stat->global_default_fn_cipher_key_bytes = |
| 379 | fn_cipher_key_bytes; |
| 380 | fn_cipher_key_bytes_set = 1; |
| 381 | break; |
| 382 | case ecryptfs_opt_unlink_sigs: |
| 383 | mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; |
| 384 | break; |
| 385 | case ecryptfs_opt_mount_auth_tok_only: |
| 386 | mount_crypt_stat->flags |= |
| 387 | ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; |
| 388 | break; |
| 389 | case ecryptfs_opt_check_dev_ruid: |
| 390 | *check_ruid = 1; |
| 391 | break; |
| 392 | case ecryptfs_opt_err: |
| 393 | default: |
| 394 | printk(KERN_WARNING |
| 395 | "%s: eCryptfs: unrecognized option [%s]\n", |
| 396 | __func__, p); |
| 397 | } |
| 398 | } |
| 399 | if (!sig_set) { |
| 400 | rc = -EINVAL; |
| 401 | ecryptfs_printk(KERN_ERR, "You must supply at least one valid " |
| 402 | "auth tok signature as a mount " |
| 403 | "parameter; see the eCryptfs README\n"); |
| 404 | goto out; |
| 405 | } |
| 406 | if (!cipher_name_set) { |
| 407 | int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); |
| 408 | |
| 409 | BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE); |
| 410 | strcpy(mount_crypt_stat->global_default_cipher_name, |
| 411 | ECRYPTFS_DEFAULT_CIPHER); |
| 412 | } |
| 413 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
| 414 | && !fn_cipher_name_set) |
| 415 | strcpy(mount_crypt_stat->global_default_fn_cipher_name, |
| 416 | mount_crypt_stat->global_default_cipher_name); |
| 417 | if (!cipher_key_bytes_set) |
| 418 | mount_crypt_stat->global_default_cipher_key_size = 0; |
| 419 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
| 420 | && !fn_cipher_key_bytes_set) |
| 421 | mount_crypt_stat->global_default_fn_cipher_key_bytes = |
| 422 | mount_crypt_stat->global_default_cipher_key_size; |
| 423 | |
| 424 | cipher_code = ecryptfs_code_for_cipher_string( |
| 425 | mount_crypt_stat->global_default_cipher_name, |
| 426 | mount_crypt_stat->global_default_cipher_key_size); |
| 427 | if (!cipher_code) { |
| 428 | ecryptfs_printk(KERN_ERR, |
| 429 | "eCryptfs doesn't support cipher: %s", |
| 430 | mount_crypt_stat->global_default_cipher_name); |
| 431 | rc = -EINVAL; |
| 432 | goto out; |
| 433 | } |
| 434 | |
| 435 | mutex_lock(&key_tfm_list_mutex); |
| 436 | if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, |
| 437 | NULL)) { |
| 438 | rc = ecryptfs_add_new_key_tfm( |
| 439 | NULL, mount_crypt_stat->global_default_cipher_name, |
| 440 | mount_crypt_stat->global_default_cipher_key_size); |
| 441 | if (rc) { |
| 442 | printk(KERN_ERR "Error attempting to initialize " |
| 443 | "cipher with name = [%s] and key size = [%td]; " |
| 444 | "rc = [%d]\n", |
| 445 | mount_crypt_stat->global_default_cipher_name, |
| 446 | mount_crypt_stat->global_default_cipher_key_size, |
| 447 | rc); |
| 448 | rc = -EINVAL; |
| 449 | mutex_unlock(&key_tfm_list_mutex); |
| 450 | goto out; |
| 451 | } |
| 452 | } |
| 453 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
| 454 | && !ecryptfs_tfm_exists( |
| 455 | mount_crypt_stat->global_default_fn_cipher_name, NULL)) { |
| 456 | rc = ecryptfs_add_new_key_tfm( |
| 457 | NULL, mount_crypt_stat->global_default_fn_cipher_name, |
| 458 | mount_crypt_stat->global_default_fn_cipher_key_bytes); |
| 459 | if (rc) { |
| 460 | printk(KERN_ERR "Error attempting to initialize " |
| 461 | "cipher with name = [%s] and key size = [%td]; " |
| 462 | "rc = [%d]\n", |
| 463 | mount_crypt_stat->global_default_fn_cipher_name, |
| 464 | mount_crypt_stat->global_default_fn_cipher_key_bytes, |
| 465 | rc); |
| 466 | rc = -EINVAL; |
| 467 | mutex_unlock(&key_tfm_list_mutex); |
| 468 | goto out; |
| 469 | } |
| 470 | } |
| 471 | mutex_unlock(&key_tfm_list_mutex); |
| 472 | rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); |
| 473 | if (rc) |
| 474 | printk(KERN_WARNING "One or more global auth toks could not " |
| 475 | "properly register; rc = [%d]\n", rc); |
| 476 | out: |
| 477 | return rc; |
| 478 | } |
| 479 | |
| 480 | struct kmem_cache *ecryptfs_sb_info_cache; |
| 481 | static struct file_system_type ecryptfs_fs_type; |
| 482 | |
| 483 | /** |
| 484 | * ecryptfs_get_sb |
| 485 | * @fs_type |
| 486 | * @flags |
| 487 | * @dev_name: The path to mount over |
| 488 | * @raw_data: The options passed into the kernel |
| 489 | */ |
| 490 | static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, |
| 491 | const char *dev_name, void *raw_data) |
| 492 | { |
| 493 | struct super_block *s; |
| 494 | struct ecryptfs_sb_info *sbi; |
| 495 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; |
| 496 | struct ecryptfs_dentry_info *root_info; |
| 497 | const char *err = "Getting sb failed"; |
| 498 | struct inode *inode; |
| 499 | struct path path; |
| 500 | uid_t check_ruid; |
| 501 | int rc; |
| 502 | |
| 503 | sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); |
| 504 | if (!sbi) { |
| 505 | rc = -ENOMEM; |
| 506 | goto out; |
| 507 | } |
| 508 | |
| 509 | rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid); |
| 510 | if (rc) { |
| 511 | err = "Error parsing options"; |
| 512 | goto out; |
| 513 | } |
| 514 | mount_crypt_stat = &sbi->mount_crypt_stat; |
| 515 | |
| 516 | s = sget(fs_type, NULL, set_anon_super, flags, NULL); |
| 517 | if (IS_ERR(s)) { |
| 518 | rc = PTR_ERR(s); |
| 519 | goto out; |
| 520 | } |
| 521 | |
| 522 | rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs"); |
| 523 | if (rc) |
| 524 | goto out1; |
| 525 | |
| 526 | ecryptfs_set_superblock_private(s, sbi); |
| 527 | s->s_bdi = &sbi->bdi; |
| 528 | |
| 529 | /* ->kill_sb() will take care of sbi after that point */ |
| 530 | sbi = NULL; |
| 531 | s->s_op = &ecryptfs_sops; |
| 532 | s->s_d_op = &ecryptfs_dops; |
| 533 | |
| 534 | err = "Reading sb failed"; |
| 535 | rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); |
| 536 | if (rc) { |
| 537 | ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); |
| 538 | goto out1; |
| 539 | } |
| 540 | if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { |
| 541 | rc = -EINVAL; |
| 542 | printk(KERN_ERR "Mount on filesystem of type " |
| 543 | "eCryptfs explicitly disallowed due to " |
| 544 | "known incompatibilities\n"); |
| 545 | goto out_free; |
| 546 | } |
| 547 | |
| 548 | if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { |
| 549 | rc = -EPERM; |
| 550 | printk(KERN_ERR "Mount of device (uid: %d) not owned by " |
| 551 | "requested user (uid: %d)\n", |
| 552 | i_uid_read(d_inode(path.dentry)), |
| 553 | from_kuid(&init_user_ns, current_uid())); |
| 554 | goto out_free; |
| 555 | } |
| 556 | |
| 557 | ecryptfs_set_superblock_lower(s, path.dentry->d_sb); |
| 558 | |
| 559 | /** |
| 560 | * Set the POSIX ACL flag based on whether they're enabled in the lower |
| 561 | * mount. |
| 562 | */ |
| 563 | s->s_flags = flags & ~MS_POSIXACL; |
| 564 | s->s_flags |= path.dentry->d_sb->s_flags & MS_POSIXACL; |
| 565 | |
| 566 | /** |
| 567 | * Force a read-only eCryptfs mount when: |
| 568 | * 1) The lower mount is ro |
| 569 | * 2) The ecryptfs_encrypted_view mount option is specified |
| 570 | */ |
| 571 | if (path.dentry->d_sb->s_flags & MS_RDONLY || |
| 572 | mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) |
| 573 | s->s_flags |= MS_RDONLY; |
| 574 | |
| 575 | s->s_maxbytes = path.dentry->d_sb->s_maxbytes; |
| 576 | s->s_blocksize = path.dentry->d_sb->s_blocksize; |
| 577 | s->s_magic = ECRYPTFS_SUPER_MAGIC; |
| 578 | s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; |
| 579 | |
| 580 | rc = -EINVAL; |
| 581 | if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { |
| 582 | pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); |
| 583 | goto out_free; |
| 584 | } |
| 585 | |
| 586 | inode = ecryptfs_get_inode(d_inode(path.dentry), s); |
| 587 | rc = PTR_ERR(inode); |
| 588 | if (IS_ERR(inode)) |
| 589 | goto out_free; |
| 590 | |
| 591 | s->s_root = d_make_root(inode); |
| 592 | if (!s->s_root) { |
| 593 | rc = -ENOMEM; |
| 594 | goto out_free; |
| 595 | } |
| 596 | |
| 597 | rc = -ENOMEM; |
| 598 | root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); |
| 599 | if (!root_info) |
| 600 | goto out_free; |
| 601 | |
| 602 | /* ->kill_sb() will take care of root_info */ |
| 603 | ecryptfs_set_dentry_private(s->s_root, root_info); |
| 604 | root_info->lower_path = path; |
| 605 | |
| 606 | s->s_flags |= MS_ACTIVE; |
| 607 | return dget(s->s_root); |
| 608 | |
| 609 | out_free: |
| 610 | path_put(&path); |
| 611 | out1: |
| 612 | deactivate_locked_super(s); |
| 613 | out: |
| 614 | if (sbi) { |
| 615 | ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); |
| 616 | kmem_cache_free(ecryptfs_sb_info_cache, sbi); |
| 617 | } |
| 618 | printk(KERN_ERR "%s; rc = [%d]\n", err, rc); |
| 619 | return ERR_PTR(rc); |
| 620 | } |
| 621 | |
| 622 | /** |
| 623 | * ecryptfs_kill_block_super |
| 624 | * @sb: The ecryptfs super block |
| 625 | * |
| 626 | * Used to bring the superblock down and free the private data. |
| 627 | */ |
| 628 | static void ecryptfs_kill_block_super(struct super_block *sb) |
| 629 | { |
| 630 | struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); |
| 631 | kill_anon_super(sb); |
| 632 | if (!sb_info) |
| 633 | return; |
| 634 | ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); |
| 635 | bdi_destroy(&sb_info->bdi); |
| 636 | kmem_cache_free(ecryptfs_sb_info_cache, sb_info); |
| 637 | } |
| 638 | |
| 639 | static struct file_system_type ecryptfs_fs_type = { |
| 640 | .owner = THIS_MODULE, |
| 641 | .name = "ecryptfs", |
| 642 | .mount = ecryptfs_mount, |
| 643 | .kill_sb = ecryptfs_kill_block_super, |
| 644 | .fs_flags = 0 |
| 645 | }; |
| 646 | MODULE_ALIAS_FS("ecryptfs"); |
| 647 | |
| 648 | /** |
| 649 | * inode_info_init_once |
| 650 | * |
| 651 | * Initializes the ecryptfs_inode_info_cache when it is created |
| 652 | */ |
| 653 | static void |
| 654 | inode_info_init_once(void *vptr) |
| 655 | { |
| 656 | struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; |
| 657 | |
| 658 | inode_init_once(&ei->vfs_inode); |
| 659 | } |
| 660 | |
| 661 | static struct ecryptfs_cache_info { |
| 662 | struct kmem_cache **cache; |
| 663 | const char *name; |
| 664 | size_t size; |
| 665 | unsigned long flags; |
| 666 | void (*ctor)(void *obj); |
| 667 | } ecryptfs_cache_infos[] = { |
| 668 | { |
| 669 | .cache = &ecryptfs_auth_tok_list_item_cache, |
| 670 | .name = "ecryptfs_auth_tok_list_item", |
| 671 | .size = sizeof(struct ecryptfs_auth_tok_list_item), |
| 672 | }, |
| 673 | { |
| 674 | .cache = &ecryptfs_file_info_cache, |
| 675 | .name = "ecryptfs_file_cache", |
| 676 | .size = sizeof(struct ecryptfs_file_info), |
| 677 | }, |
| 678 | { |
| 679 | .cache = &ecryptfs_dentry_info_cache, |
| 680 | .name = "ecryptfs_dentry_info_cache", |
| 681 | .size = sizeof(struct ecryptfs_dentry_info), |
| 682 | }, |
| 683 | { |
| 684 | .cache = &ecryptfs_inode_info_cache, |
| 685 | .name = "ecryptfs_inode_cache", |
| 686 | .size = sizeof(struct ecryptfs_inode_info), |
| 687 | .flags = SLAB_ACCOUNT, |
| 688 | .ctor = inode_info_init_once, |
| 689 | }, |
| 690 | { |
| 691 | .cache = &ecryptfs_sb_info_cache, |
| 692 | .name = "ecryptfs_sb_cache", |
| 693 | .size = sizeof(struct ecryptfs_sb_info), |
| 694 | }, |
| 695 | { |
| 696 | .cache = &ecryptfs_header_cache, |
| 697 | .name = "ecryptfs_headers", |
| 698 | .size = PAGE_CACHE_SIZE, |
| 699 | }, |
| 700 | { |
| 701 | .cache = &ecryptfs_xattr_cache, |
| 702 | .name = "ecryptfs_xattr_cache", |
| 703 | .size = PAGE_CACHE_SIZE, |
| 704 | }, |
| 705 | { |
| 706 | .cache = &ecryptfs_key_record_cache, |
| 707 | .name = "ecryptfs_key_record_cache", |
| 708 | .size = sizeof(struct ecryptfs_key_record), |
| 709 | }, |
| 710 | { |
| 711 | .cache = &ecryptfs_key_sig_cache, |
| 712 | .name = "ecryptfs_key_sig_cache", |
| 713 | .size = sizeof(struct ecryptfs_key_sig), |
| 714 | }, |
| 715 | { |
| 716 | .cache = &ecryptfs_global_auth_tok_cache, |
| 717 | .name = "ecryptfs_global_auth_tok_cache", |
| 718 | .size = sizeof(struct ecryptfs_global_auth_tok), |
| 719 | }, |
| 720 | { |
| 721 | .cache = &ecryptfs_key_tfm_cache, |
| 722 | .name = "ecryptfs_key_tfm_cache", |
| 723 | .size = sizeof(struct ecryptfs_key_tfm), |
| 724 | }, |
| 725 | }; |
| 726 | |
| 727 | static void ecryptfs_free_kmem_caches(void) |
| 728 | { |
| 729 | int i; |
| 730 | |
| 731 | /* |
| 732 | * Make sure all delayed rcu free inodes are flushed before we |
| 733 | * destroy cache. |
| 734 | */ |
| 735 | rcu_barrier(); |
| 736 | |
| 737 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { |
| 738 | struct ecryptfs_cache_info *info; |
| 739 | |
| 740 | info = &ecryptfs_cache_infos[i]; |
| 741 | if (*(info->cache)) |
| 742 | kmem_cache_destroy(*(info->cache)); |
| 743 | } |
| 744 | } |
| 745 | |
| 746 | /** |
| 747 | * ecryptfs_init_kmem_caches |
| 748 | * |
| 749 | * Returns zero on success; non-zero otherwise |
| 750 | */ |
| 751 | static int ecryptfs_init_kmem_caches(void) |
| 752 | { |
| 753 | int i; |
| 754 | |
| 755 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { |
| 756 | struct ecryptfs_cache_info *info; |
| 757 | |
| 758 | info = &ecryptfs_cache_infos[i]; |
| 759 | *(info->cache) = kmem_cache_create(info->name, info->size, 0, |
| 760 | SLAB_HWCACHE_ALIGN | info->flags, info->ctor); |
| 761 | if (!*(info->cache)) { |
| 762 | ecryptfs_free_kmem_caches(); |
| 763 | ecryptfs_printk(KERN_WARNING, "%s: " |
| 764 | "kmem_cache_create failed\n", |
| 765 | info->name); |
| 766 | return -ENOMEM; |
| 767 | } |
| 768 | } |
| 769 | return 0; |
| 770 | } |
| 771 | |
| 772 | static struct kobject *ecryptfs_kobj; |
| 773 | |
| 774 | static ssize_t version_show(struct kobject *kobj, |
| 775 | struct kobj_attribute *attr, char *buff) |
| 776 | { |
| 777 | return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); |
| 778 | } |
| 779 | |
| 780 | static struct kobj_attribute version_attr = __ATTR_RO(version); |
| 781 | |
| 782 | static struct attribute *attributes[] = { |
| 783 | &version_attr.attr, |
| 784 | NULL, |
| 785 | }; |
| 786 | |
| 787 | static struct attribute_group attr_group = { |
| 788 | .attrs = attributes, |
| 789 | }; |
| 790 | |
| 791 | static int do_sysfs_registration(void) |
| 792 | { |
| 793 | int rc; |
| 794 | |
| 795 | ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); |
| 796 | if (!ecryptfs_kobj) { |
| 797 | printk(KERN_ERR "Unable to create ecryptfs kset\n"); |
| 798 | rc = -ENOMEM; |
| 799 | goto out; |
| 800 | } |
| 801 | rc = sysfs_create_group(ecryptfs_kobj, &attr_group); |
| 802 | if (rc) { |
| 803 | printk(KERN_ERR |
| 804 | "Unable to create ecryptfs version attributes\n"); |
| 805 | kobject_put(ecryptfs_kobj); |
| 806 | } |
| 807 | out: |
| 808 | return rc; |
| 809 | } |
| 810 | |
| 811 | static void do_sysfs_unregistration(void) |
| 812 | { |
| 813 | sysfs_remove_group(ecryptfs_kobj, &attr_group); |
| 814 | kobject_put(ecryptfs_kobj); |
| 815 | } |
| 816 | |
| 817 | static int __init ecryptfs_init(void) |
| 818 | { |
| 819 | int rc; |
| 820 | |
| 821 | if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { |
| 822 | rc = -EINVAL; |
| 823 | ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " |
| 824 | "larger than the host's page size, and so " |
| 825 | "eCryptfs cannot run on this system. The " |
| 826 | "default eCryptfs extent size is [%u] bytes; " |
| 827 | "the page size is [%lu] bytes.\n", |
| 828 | ECRYPTFS_DEFAULT_EXTENT_SIZE, |
| 829 | (unsigned long)PAGE_CACHE_SIZE); |
| 830 | goto out; |
| 831 | } |
| 832 | rc = ecryptfs_init_kmem_caches(); |
| 833 | if (rc) { |
| 834 | printk(KERN_ERR |
| 835 | "Failed to allocate one or more kmem_cache objects\n"); |
| 836 | goto out; |
| 837 | } |
| 838 | rc = do_sysfs_registration(); |
| 839 | if (rc) { |
| 840 | printk(KERN_ERR "sysfs registration failed\n"); |
| 841 | goto out_free_kmem_caches; |
| 842 | } |
| 843 | rc = ecryptfs_init_kthread(); |
| 844 | if (rc) { |
| 845 | printk(KERN_ERR "%s: kthread initialization failed; " |
| 846 | "rc = [%d]\n", __func__, rc); |
| 847 | goto out_do_sysfs_unregistration; |
| 848 | } |
| 849 | rc = ecryptfs_init_messaging(); |
| 850 | if (rc) { |
| 851 | printk(KERN_ERR "Failure occurred while attempting to " |
| 852 | "initialize the communications channel to " |
| 853 | "ecryptfsd\n"); |
| 854 | goto out_destroy_kthread; |
| 855 | } |
| 856 | rc = ecryptfs_init_crypto(); |
| 857 | if (rc) { |
| 858 | printk(KERN_ERR "Failure whilst attempting to init crypto; " |
| 859 | "rc = [%d]\n", rc); |
| 860 | goto out_release_messaging; |
| 861 | } |
| 862 | rc = register_filesystem(&ecryptfs_fs_type); |
| 863 | if (rc) { |
| 864 | printk(KERN_ERR "Failed to register filesystem\n"); |
| 865 | goto out_destroy_crypto; |
| 866 | } |
| 867 | if (ecryptfs_verbosity > 0) |
| 868 | printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " |
| 869 | "will be written to the syslog!\n", ecryptfs_verbosity); |
| 870 | |
| 871 | goto out; |
| 872 | out_destroy_crypto: |
| 873 | ecryptfs_destroy_crypto(); |
| 874 | out_release_messaging: |
| 875 | ecryptfs_release_messaging(); |
| 876 | out_destroy_kthread: |
| 877 | ecryptfs_destroy_kthread(); |
| 878 | out_do_sysfs_unregistration: |
| 879 | do_sysfs_unregistration(); |
| 880 | out_free_kmem_caches: |
| 881 | ecryptfs_free_kmem_caches(); |
| 882 | out: |
| 883 | return rc; |
| 884 | } |
| 885 | |
| 886 | static void __exit ecryptfs_exit(void) |
| 887 | { |
| 888 | int rc; |
| 889 | |
| 890 | rc = ecryptfs_destroy_crypto(); |
| 891 | if (rc) |
| 892 | printk(KERN_ERR "Failure whilst attempting to destroy crypto; " |
| 893 | "rc = [%d]\n", rc); |
| 894 | ecryptfs_release_messaging(); |
| 895 | ecryptfs_destroy_kthread(); |
| 896 | do_sysfs_unregistration(); |
| 897 | unregister_filesystem(&ecryptfs_fs_type); |
| 898 | ecryptfs_free_kmem_caches(); |
| 899 | } |
| 900 | |
| 901 | MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); |
| 902 | MODULE_DESCRIPTION("eCryptfs"); |
| 903 | |
| 904 | MODULE_LICENSE("GPL"); |
| 905 | |
| 906 | module_init(ecryptfs_init) |
| 907 | module_exit(ecryptfs_exit) |