fs/ecryptfs/main.c

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