/** * eCryptfs: Linux filesystem encryption layer * * Copyright (C) 1997-2003 Erez Zadok * Copyright (C) 2001-2003 Stony Brook University * Copyright (C) 2004-2007 International Business Machines Corp. * Author(s): Michael A. Halcrow * Michael C. Thompson * Tyler Hicks * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA * 02111-1307, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "ecryptfs_kernel.h" #ifdef CONFIG_WTL_ENCRYPTION_FILTER #include #endif /** * Module parameter that defines the ecryptfs_verbosity level. */ int ecryptfs_verbosity = 0; module_param(ecryptfs_verbosity, int, 0); MODULE_PARM_DESC(ecryptfs_verbosity, "Initial verbosity level (0 or 1; defaults to " "0, which is Quiet)"); /** * Module parameter that defines the number of message buffer elements */ unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; module_param(ecryptfs_message_buf_len, uint, 0); MODULE_PARM_DESC(ecryptfs_message_buf_len, "Number of message buffer elements"); /** * Module parameter that defines the maximum guaranteed amount of time to wait * for a response from ecryptfsd. The actual sleep time will be, more than * likely, a small amount greater than this specified value, but only less if * the message successfully arrives. */ signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; module_param(ecryptfs_message_wait_timeout, long, 0); MODULE_PARM_DESC(ecryptfs_message_wait_timeout, "Maximum number of seconds that an operation will " "sleep while waiting for a message response from " "userspace"); /** * Module parameter that is an estimate of the maximum number of users * that will be concurrently using eCryptfs. Set this to the right * value to balance performance and memory use. */ unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; module_param(ecryptfs_number_of_users, uint, 0); MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " "concurrent users of eCryptfs"); void __ecryptfs_printk(const char *fmt, ...) { va_list args; va_start(args, fmt); if (fmt[1] == '7') { /* KERN_DEBUG */ if (ecryptfs_verbosity >= 1) vprintk(fmt, args); } else vprintk(fmt, args); va_end(args); } /** * ecryptfs_init_lower_file * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with * the lower dentry and the lower mount set * * eCryptfs only ever keeps a single open file for every lower * inode. All I/O operations to the lower inode occur through that * file. When the first eCryptfs dentry that interposes with the first * lower dentry for that inode is created, this function creates the * lower file struct and associates it with the eCryptfs * inode. When all eCryptfs files associated with the inode are released, the * file is closed. * * The lower file will be opened with read/write permissions, if * possible. Otherwise, it is opened read-only. * * This function does nothing if a lower file is already * associated with the eCryptfs inode. * * Returns zero on success; non-zero otherwise */ static int ecryptfs_init_lower_file(struct dentry *dentry, struct file **lower_file) { const struct cred *cred = current_cred(); struct path *path = ecryptfs_dentry_to_lower_path(dentry); int rc; rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt, cred); if (rc) { printk(KERN_ERR "Error opening lower file " "for lower_dentry [0x%p] and lower_mnt [0x%p]; " "rc = [%d]\n", path->dentry, path->mnt, rc); (*lower_file) = NULL; } return rc; } int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) { struct ecryptfs_inode_info *inode_info; int count, rc = 0; inode_info = ecryptfs_inode_to_private(inode); mutex_lock(&inode_info->lower_file_mutex); count = atomic_inc_return(&inode_info->lower_file_count); if (WARN_ON_ONCE(count < 1)) rc = -EINVAL; else if (count == 1) { rc = ecryptfs_init_lower_file(dentry, &inode_info->lower_file); if (rc) atomic_set(&inode_info->lower_file_count, 0); } mutex_unlock(&inode_info->lower_file_mutex); return rc; } void ecryptfs_put_lower_file(struct inode *inode) { struct ecryptfs_inode_info *inode_info; inode_info = ecryptfs_inode_to_private(inode); if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, &inode_info->lower_file_mutex)) { filemap_write_and_wait(inode->i_mapping); fput(inode_info->lower_file); inode_info->lower_file = NULL; mutex_unlock(&inode_info->lower_file_mutex); } } enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes, ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, ecryptfs_opt_check_dev_ruid, #ifdef CONFIG_WTL_ENCRYPTION_FILTER ecryptfs_opt_enable_filtering, #endif ecryptfs_opt_enable_cc, ecryptfs_opt_base, ecryptfs_opt_type, ecryptfs_opt_label, ecryptfs_opt_err }; static const match_table_t tokens = { {ecryptfs_opt_sig, "sig=%s"}, {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, {ecryptfs_opt_cipher, "cipher=%s"}, {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, {ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"}, #ifdef CONFIG_WTL_ENCRYPTION_FILTER {ecryptfs_opt_enable_filtering, "ecryptfs_enable_filtering=%s"}, #endif {ecryptfs_opt_enable_cc, "ecryptfs_enable_cc"}, {ecryptfs_opt_base, "base=%s"}, {ecryptfs_opt_type, "type=%s"}, {ecryptfs_opt_label, "label=%s"}, {ecryptfs_opt_err, NULL} }; static int ecryptfs_init_global_auth_toks( struct ecryptfs_mount_crypt_stat *mount_crypt_stat) { struct ecryptfs_global_auth_tok *global_auth_tok; struct ecryptfs_auth_tok *auth_tok; int rc = 0; list_for_each_entry(global_auth_tok, &mount_crypt_stat->global_auth_tok_list, mount_crypt_stat_list) { rc = ecryptfs_keyring_auth_tok_for_sig( &global_auth_tok->global_auth_tok_key, &auth_tok, global_auth_tok->sig); if (rc) { printk(KERN_ERR "Could not find valid key in user " "session keyring for sig specified in mount " "option: [%s]\n", global_auth_tok->sig); global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; goto out; } else { global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; up_write(&(global_auth_tok->global_auth_tok_key)->sem); } } out: return rc; } static void ecryptfs_init_mount_crypt_stat( struct ecryptfs_mount_crypt_stat *mount_crypt_stat) { memset((void *)mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat)); INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; } static void ecryptfs_init_propagate_stat( struct ecryptfs_propagate_stat *propagate_stat) { memset((void *)propagate_stat, 0, sizeof(struct ecryptfs_propagate_stat)); propagate_stat->propagate_type = TYPE_E_NONE; } #ifdef CONFIG_WTL_ENCRYPTION_FILTER static int parse_enc_file_filter_parms( struct ecryptfs_mount_crypt_stat *mcs, char *str) { char *token = NULL; int count = 0; mcs->max_name_filter_len = 0; while ((token = strsep(&str, "|")) != NULL) { if (count >= ENC_NAME_FILTER_MAX_INSTANCE) return -1; strncpy(mcs->enc_filter_name[count++], token, ENC_NAME_FILTER_MAX_LEN); if (mcs->max_name_filter_len < strlen(token)) mcs->max_name_filter_len = strlen(token); } return 0; } static int parse_enc_ext_filter_parms( struct ecryptfs_mount_crypt_stat *mcs, char *str) { char *token = NULL; int count = 0; while ((token = strsep(&str, "|")) != NULL) { if (count >= ENC_EXT_FILTER_MAX_INSTANCE) return -1; strncpy(mcs->enc_filter_ext[count++], token, ENC_EXT_FILTER_MAX_LEN); } return 0; } static int parse_enc_filter_parms( struct ecryptfs_mount_crypt_stat *mcs, char *str) { char *token = NULL; if (!strcmp("*", str)) { mcs->flags |= ECRYPTFS_ENABLE_NEW_PASSTHROUGH; return 0; } token = strsep(&str, ":"); if (token != NULL) parse_enc_file_filter_parms(mcs, token); token = strsep(&str, ":"); if (token != NULL) parse_enc_ext_filter_parms(mcs, token); return 0; } #endif /** * ecryptfs_parse_options * @sb: The ecryptfs super block * @options: The options passed to the kernel * @check_ruid: set to 1 if device uid should be checked against the ruid * * Parse mount options: * debug=N - ecryptfs_verbosity level for debug output * sig=XXX - description(signature) of the key to use * * Returns the dentry object of the lower-level (lower/interposed) * directory; We want to mount our stackable file system on top of * that lower directory. * * The signature of the key to use must be the description of a key * already in the keyring. Mounting will fail if the key can not be * found. * * Returns zero on success; non-zero on error */ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, uid_t *check_ruid) { char *p; int rc = 0; int sig_set = 0; int cipher_name_set = 0; int fn_cipher_name_set = 0; int cipher_key_bytes; int cipher_key_bytes_set = 0; int fn_cipher_key_bytes; int fn_cipher_key_bytes_set = 0; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = &sbi->mount_crypt_stat; struct ecryptfs_propagate_stat *propagate_stat = &sbi->propagate_stat; substring_t args[MAX_OPT_ARGS]; int token; char *sig_src; char *cipher_name_dst; char *cipher_name_src; char *fn_cipher_name_dst; char *fn_cipher_name_src; char *fnek_dst; char *fnek_src; char *cipher_key_bytes_src; char *fn_cipher_key_bytes_src; char *base_path_src; char *base_path_dst; char *propagate_type; char *label_src; char *label_dst; u8 cipher_code; char cipher_mode[ECRYPTFS_MAX_CIPHER_MODE_SIZE+1] = ECRYPTFS_AES_ECB_MODE; *check_ruid = 0; if (!options) { rc = -EINVAL; goto out; } ecryptfs_init_mount_crypt_stat(mount_crypt_stat); ecryptfs_init_propagate_stat(propagate_stat); while ((p = strsep(&options, ",")) != NULL) { if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case ecryptfs_opt_sig: case ecryptfs_opt_ecryptfs_sig: sig_src = args[0].from; rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, sig_src, 0); if (rc) { printk(KERN_ERR "Error attempting to register " "global sig; rc = [%d]\n", rc); goto out; } sig_set = 1; break; case ecryptfs_opt_cipher: case ecryptfs_opt_ecryptfs_cipher: cipher_name_src = args[0].from; cipher_name_dst = mount_crypt_stat-> global_default_cipher_name; strncpy(cipher_name_dst, cipher_name_src, ECRYPTFS_MAX_CIPHER_NAME_SIZE); cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; cipher_name_set = 1; break; case ecryptfs_opt_ecryptfs_key_bytes: cipher_key_bytes_src = args[0].from; cipher_key_bytes = (int)simple_strtol(cipher_key_bytes_src, &cipher_key_bytes_src, 0); mount_crypt_stat->global_default_cipher_key_size = cipher_key_bytes; cipher_key_bytes_set = 1; break; case ecryptfs_opt_passthrough: mount_crypt_stat->flags |= ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; break; case ecryptfs_opt_xattr_metadata: mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; break; case ecryptfs_opt_encrypted_view: mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED; mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED; break; case ecryptfs_opt_fnek_sig: fnek_src = args[0].from; fnek_dst = mount_crypt_stat->global_default_fnek_sig; strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); mount_crypt_stat->global_default_fnek_sig[ ECRYPTFS_SIG_SIZE_HEX] = '\0'; rc = ecryptfs_add_global_auth_tok( mount_crypt_stat, mount_crypt_stat->global_default_fnek_sig, ECRYPTFS_AUTH_TOK_FNEK); if (rc) { printk(KERN_ERR "Error attempting to register " "global fnek sig [%s]; rc = [%d]\n", mount_crypt_stat->global_default_fnek_sig, rc); goto out; } mount_crypt_stat->flags |= (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); break; case ecryptfs_opt_fn_cipher: fn_cipher_name_src = args[0].from; fn_cipher_name_dst = mount_crypt_stat->global_default_fn_cipher_name; strncpy(fn_cipher_name_dst, fn_cipher_name_src, ECRYPTFS_MAX_CIPHER_NAME_SIZE); mount_crypt_stat->global_default_fn_cipher_name[ ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; fn_cipher_name_set = 1; break; case ecryptfs_opt_fn_cipher_key_bytes: fn_cipher_key_bytes_src = args[0].from; fn_cipher_key_bytes = (int)simple_strtol(fn_cipher_key_bytes_src, &fn_cipher_key_bytes_src, 0); mount_crypt_stat->global_default_fn_cipher_key_bytes = fn_cipher_key_bytes; fn_cipher_key_bytes_set = 1; break; case ecryptfs_opt_unlink_sigs: mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; break; case ecryptfs_opt_mount_auth_tok_only: mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; break; case ecryptfs_opt_check_dev_ruid: *check_ruid = 1; break; #ifdef CONFIG_WTL_ENCRYPTION_FILTER case ecryptfs_opt_enable_filtering: rc = parse_enc_filter_parms(mount_crypt_stat, args[0].from); if (rc) { printk(KERN_ERR "Error attempting to parse encryption " "filtering parameters.\n"); rc = -EINVAL; goto out; } mount_crypt_stat->flags |= ECRYPTFS_ENABLE_FILTERING; break; #endif case ecryptfs_opt_enable_cc: mount_crypt_stat->flags |= ECRYPTFS_ENABLE_CC; strncpy(cipher_mode, ECRYPTFS_AES_CBC_MODE, ECRYPTFS_MAX_CIPHER_MODE_SIZE+1); break; case ecryptfs_opt_base: base_path_src = args[0].from; base_path_dst = propagate_stat->base_path; strncpy(base_path_dst, base_path_src, ECRYPTFS_BASE_PATH_SIZE); break; case ecryptfs_opt_type: propagate_type = match_strdup(&args[0]); if (!propagate_type) return -ENOMEM; if (!strncmp(propagate_type, "default", strlen("default"))) propagate_stat->propagate_type = TYPE_E_DEFAULT; else if (!strncmp(propagate_type, "read", strlen("read"))) propagate_stat->propagate_type = TYPE_E_READ; else if (!strncmp(propagate_type, "write", strlen("write"))) propagate_stat->propagate_type = TYPE_E_WRITE; else { printk(KERN_WARNING "%s: eCryptfs: unrecognized option [type=%s]\n", __func__, propagate_type); propagate_stat->propagate_type = TYPE_E_NONE; } kfree(propagate_type); break; case ecryptfs_opt_label: label_src = args[0].from; label_dst = propagate_stat->label; if (!label_dst) { ecryptfs_printk(KERN_ERR, "label_dst is null\n"); return -ENOMEM; } strncpy(label_dst, label_src, ECRYPTFS_LABEL_SIZE); break; case ecryptfs_opt_err: default: printk(KERN_WARNING "%s: eCryptfs: unrecognized option [%s]\n", __func__, p); } } if (!sig_set) { rc = -EINVAL; ecryptfs_printk(KERN_ERR, "You must supply at least one valid " "auth tok signature as a mount " "parameter; see the eCryptfs README\n"); goto out; } if (!cipher_name_set) { int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE); strcpy(mount_crypt_stat->global_default_cipher_name, ECRYPTFS_DEFAULT_CIPHER); } if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) && !fn_cipher_name_set) strcpy(mount_crypt_stat->global_default_fn_cipher_name, mount_crypt_stat->global_default_cipher_name); if (!cipher_key_bytes_set) mount_crypt_stat->global_default_cipher_key_size = 0; if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) && !fn_cipher_key_bytes_set) mount_crypt_stat->global_default_fn_cipher_key_bytes = mount_crypt_stat->global_default_cipher_key_size; cipher_code = ecryptfs_code_for_cipher_string( mount_crypt_stat->global_default_cipher_name, mount_crypt_stat->global_default_cipher_key_size); if (!cipher_code) { ecryptfs_printk(KERN_ERR, "eCryptfs doesn't support cipher: %s\n", mount_crypt_stat->global_default_cipher_name); rc = -EINVAL; goto out; } mutex_lock(&key_tfm_list_mutex); if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, cipher_mode, NULL)) { rc = ecryptfs_add_new_key_tfm( NULL, mount_crypt_stat->global_default_cipher_name, mount_crypt_stat->global_default_cipher_key_size, mount_crypt_stat->flags); if (rc) { printk(KERN_ERR "Error attempting to initialize " "cipher with name = [%s] and key size = [%td]; " "rc = [%d]\n", mount_crypt_stat->global_default_cipher_name, mount_crypt_stat->global_default_cipher_key_size, rc); rc = -EINVAL; mutex_unlock(&key_tfm_list_mutex); goto out; } } if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) && !ecryptfs_tfm_exists( mount_crypt_stat->global_default_fn_cipher_name, cipher_mode, NULL)) { rc = ecryptfs_add_new_key_tfm( NULL, mount_crypt_stat->global_default_fn_cipher_name, mount_crypt_stat->global_default_fn_cipher_key_bytes, mount_crypt_stat->flags); if (rc) { printk(KERN_ERR "Error attempting to initialize " "cipher with name = [%s] and key size = [%td]; " "rc = [%d]\n", mount_crypt_stat->global_default_fn_cipher_name, mount_crypt_stat->global_default_fn_cipher_key_bytes, rc); rc = -EINVAL; mutex_unlock(&key_tfm_list_mutex); goto out; } } mutex_unlock(&key_tfm_list_mutex); rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); if (rc) printk(KERN_WARNING "One or more global auth toks could not " "properly register; rc = [%d]\n", rc); out: return rc; } struct kmem_cache *ecryptfs_sb_info_cache; static struct file_system_type ecryptfs_fs_type; /** * ecryptfs_get_sb * @fs_type * @flags * @dev_name: The path to mount over * @raw_data: The options passed into the kernel */ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data) { struct super_block *s, *lower_sb; struct ecryptfs_sb_info *sbi; struct ecryptfs_mount_crypt_stat *mount_crypt_stat; struct ecryptfs_dentry_info *root_info; const char *err = "Getting sb failed"; struct inode *inode; struct path path; uid_t check_ruid; int rc; sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); if (!sbi) { rc = -ENOMEM; goto out; } if (!dev_name) { rc = -EINVAL; err = "Device name cannot be null"; goto out; } rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid); if (rc) { err = "Error parsing options"; goto out; } mount_crypt_stat = &sbi->mount_crypt_stat; s = sget(fs_type, NULL, set_anon_super, flags, NULL); if (IS_ERR(s)) { rc = PTR_ERR(s); goto out; } rc = super_setup_bdi(s); if (rc) goto out1; ecryptfs_set_superblock_private(s, sbi); if (sbi->propagate_stat.propagate_type != TYPE_E_NONE) s->s_op = &ecryptfs_multimount_sops; else s->s_op = &ecryptfs_sops; /* ->kill_sb() will take care of sbi after that point */ sbi = NULL; s->s_op = &ecryptfs_sops; s->s_xattr = ecryptfs_xattr_handlers; s->s_d_op = &ecryptfs_dops; err = "Reading sb failed"; rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); if (rc) { ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); goto out1; } if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { rc = -EINVAL; printk(KERN_ERR "Mount on filesystem of type " "eCryptfs explicitly disallowed due to " "known incompatibilities\n"); goto out_free; } if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { rc = -EPERM; printk(KERN_ERR "Mount of device (uid: %d) not owned by " "requested user (uid: %d)\n", i_uid_read(d_inode(path.dentry)), from_kuid(&init_user_ns, current_uid())); goto out_free; } lower_sb = path.dentry->d_sb; atomic_inc(&lower_sb->s_active); ecryptfs_set_superblock_lower(s, path.dentry->d_sb); /** * Set the POSIX ACL flag based on whether they're enabled in the lower * mount. */ s->s_flags = flags & ~SB_POSIXACL; s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL; /** * Force a read-only eCryptfs mount when: * 1) The lower mount is ro * 2) The ecryptfs_encrypted_view mount option is specified */ if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) s->s_flags |= SB_RDONLY; s->s_maxbytes = path.dentry->d_sb->s_maxbytes; s->s_blocksize = path.dentry->d_sb->s_blocksize; s->s_magic = ECRYPTFS_SUPER_MAGIC; s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; rc = -EINVAL; if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); goto out_free; } inode = ecryptfs_get_inode(d_inode(path.dentry), s); rc = PTR_ERR(inode); if (IS_ERR(inode)) goto out_sput; s->s_root = d_make_root(inode); if (!s->s_root) { rc = -ENOMEM; goto out_sput; } rc = -ENOMEM; root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); if (!root_info) goto out_sput; /* ->kill_sb() will take care of root_info */ ecryptfs_set_dentry_private(s->s_root, root_info); root_info->lower_path = path; s->s_flags |= SB_ACTIVE; return dget(s->s_root); out_sput: atomic_dec(&lower_sb->s_active); out_free: path_put(&path); out1: deactivate_locked_super(s); out: if (sbi) { ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); kmem_cache_free(ecryptfs_sb_info_cache, sbi); } printk(KERN_ERR "%s; rc = [%d]\n", err, rc); return ERR_PTR(rc); } /** * ecryptfs_kill_block_super * @sb: The ecryptfs super block * * Used to bring the superblock down and free the private data. */ static void ecryptfs_kill_block_super(struct super_block *sb) { struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); kill_anon_super(sb); if (!sb_info) return; if (sb_info->wsi_sb) atomic_dec(&sb_info->wsi_sb->s_active); ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); kmem_cache_free(ecryptfs_sb_info_cache, sb_info); } static struct file_system_type ecryptfs_fs_type = { .owner = THIS_MODULE, .name = "ecryptfs", .mount = ecryptfs_mount, .kill_sb = ecryptfs_kill_block_super, .fs_flags = 0 }; MODULE_ALIAS_FS("ecryptfs"); /** * inode_info_init_once * * Initializes the ecryptfs_inode_info_cache when it is created */ static void inode_info_init_once(void *vptr) { struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; inode_init_once(&ei->vfs_inode); } static struct ecryptfs_cache_info { struct kmem_cache **cache; const char *name; size_t size; slab_flags_t flags; void (*ctor)(void *obj); } ecryptfs_cache_infos[] = { { .cache = &ecryptfs_auth_tok_list_item_cache, .name = "ecryptfs_auth_tok_list_item", .size = sizeof(struct ecryptfs_auth_tok_list_item), }, { .cache = &ecryptfs_file_info_cache, .name = "ecryptfs_file_cache", .size = sizeof(struct ecryptfs_file_info), }, { .cache = &ecryptfs_dentry_info_cache, .name = "ecryptfs_dentry_info_cache", .size = sizeof(struct ecryptfs_dentry_info), }, { .cache = &ecryptfs_inode_info_cache, .name = "ecryptfs_inode_cache", .size = sizeof(struct ecryptfs_inode_info), .flags = SLAB_ACCOUNT, .ctor = inode_info_init_once, }, { .cache = &ecryptfs_sb_info_cache, .name = "ecryptfs_sb_cache", .size = sizeof(struct ecryptfs_sb_info), }, { .cache = &ecryptfs_header_cache, .name = "ecryptfs_headers", .size = PAGE_SIZE, }, { .cache = &ecryptfs_xattr_cache, .name = "ecryptfs_xattr_cache", .size = PAGE_SIZE, }, { .cache = &ecryptfs_key_record_cache, .name = "ecryptfs_key_record_cache", .size = sizeof(struct ecryptfs_key_record), }, { .cache = &ecryptfs_key_sig_cache, .name = "ecryptfs_key_sig_cache", .size = sizeof(struct ecryptfs_key_sig), }, { .cache = &ecryptfs_global_auth_tok_cache, .name = "ecryptfs_global_auth_tok_cache", .size = sizeof(struct ecryptfs_global_auth_tok), }, { .cache = &ecryptfs_key_tfm_cache, .name = "ecryptfs_key_tfm_cache", .size = sizeof(struct ecryptfs_key_tfm), }, }; static void ecryptfs_free_kmem_caches(void) { int i; /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { struct ecryptfs_cache_info *info; info = &ecryptfs_cache_infos[i]; kmem_cache_destroy(*(info->cache)); } } /** * ecryptfs_init_kmem_caches * * Returns zero on success; non-zero otherwise */ static int ecryptfs_init_kmem_caches(void) { int i; for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { struct ecryptfs_cache_info *info; info = &ecryptfs_cache_infos[i]; *(info->cache) = kmem_cache_create(info->name, info->size, 0, SLAB_HWCACHE_ALIGN | info->flags, info->ctor); if (!*(info->cache)) { ecryptfs_free_kmem_caches(); ecryptfs_printk(KERN_WARNING, "%s: " "kmem_cache_create failed\n", info->name); return -ENOMEM; } } return 0; } static struct kobject *ecryptfs_kobj; static ssize_t version_show(struct kobject *kobj, struct kobj_attribute *attr, char *buff) { return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); } static struct kobj_attribute version_attr = __ATTR_RO(version); static struct attribute *attributes[] = { &version_attr.attr, NULL, }; static const struct attribute_group attr_group = { .attrs = attributes, }; static int do_sysfs_registration(void) { int rc; ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); if (!ecryptfs_kobj) { printk(KERN_ERR "Unable to create ecryptfs kset\n"); rc = -ENOMEM; goto out; } rc = sysfs_create_group(ecryptfs_kobj, &attr_group); if (rc) { printk(KERN_ERR "Unable to create ecryptfs version attributes\n"); kobject_put(ecryptfs_kobj); } out: return rc; } static void do_sysfs_unregistration(void) { sysfs_remove_group(ecryptfs_kobj, &attr_group); kobject_put(ecryptfs_kobj); } static int __init ecryptfs_init(void) { int rc; if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) { rc = -EINVAL; ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " "larger than the host's page size, and so " "eCryptfs cannot run on this system. The " "default eCryptfs extent size is [%u] bytes; " "the page size is [%lu] bytes.\n", ECRYPTFS_DEFAULT_EXTENT_SIZE, (unsigned long)PAGE_SIZE); goto out; } rc = ecryptfs_init_kmem_caches(); if (rc) { printk(KERN_ERR "Failed to allocate one or more kmem_cache objects\n"); goto out; } rc = do_sysfs_registration(); if (rc) { printk(KERN_ERR "sysfs registration failed\n"); goto out_free_kmem_caches; } rc = ecryptfs_init_kthread(); if (rc) { printk(KERN_ERR "%s: kthread initialization failed; " "rc = [%d]\n", __func__, rc); goto out_do_sysfs_unregistration; } rc = ecryptfs_init_messaging(); if (rc) { printk(KERN_ERR "Failure occurred while attempting to " "initialize the communications channel to " "ecryptfsd\n"); goto out_destroy_kthread; } rc = ecryptfs_init_crypto(); if (rc) { printk(KERN_ERR "Failure whilst attempting to init crypto; " "rc = [%d]\n", rc); goto out_release_messaging; } rc = register_filesystem(&ecryptfs_fs_type); if (rc) { printk(KERN_ERR "Failed to register filesystem\n"); goto out_destroy_crypto; } if (ecryptfs_verbosity > 0) printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " "will be written to the syslog!\n", ecryptfs_verbosity); goto out; out_destroy_crypto: ecryptfs_destroy_crypto(); out_release_messaging: ecryptfs_release_messaging(); out_destroy_kthread: ecryptfs_destroy_kthread(); out_do_sysfs_unregistration: do_sysfs_unregistration(); out_free_kmem_caches: ecryptfs_free_kmem_caches(); out: return rc; } static void __exit ecryptfs_exit(void) { int rc; rc = ecryptfs_destroy_crypto(); if (rc) printk(KERN_ERR "Failure whilst attempting to destroy crypto; " "rc = [%d]\n", rc); ecryptfs_release_messaging(); ecryptfs_destroy_kthread(); do_sysfs_unregistration(); unregister_filesystem(&ecryptfs_fs_type); ecryptfs_free_kmem_caches(); } MODULE_AUTHOR("Michael A. Halcrow "); MODULE_DESCRIPTION("eCryptfs"); MODULE_LICENSE("GPL"); module_init(ecryptfs_init) module_exit(ecryptfs_exit)