diff options
Diffstat (limited to 'fs/ecryptfs/main.c')
| -rw-r--r-- | fs/ecryptfs/main.c | 831 |
1 files changed, 831 insertions, 0 deletions
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c new file mode 100644 index 000000000000..7a11b8ae6644 --- /dev/null +++ b/fs/ecryptfs/main.c @@ -0,0 +1,831 @@ +/** + * eCryptfs: Linux filesystem encryption layer + * + * Copyright (C) 1997-2003 Erez Zadok + * Copyright (C) 2001-2003 Stony Brook University + * Copyright (C) 2004-2006 International Business Machines Corp. + * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> + * Michael C. Thompson <mcthomps@us.ibm.com> + * + * 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 <linux/dcache.h> +#include <linux/file.h> +#include <linux/module.h> +#include <linux/namei.h> +#include <linux/skbuff.h> +#include <linux/crypto.h> +#include <linux/netlink.h> +#include <linux/mount.h> +#include <linux/dcache.h> +#include <linux/pagemap.h> +#include <linux/key.h> +#include <linux/parser.h> +#include "ecryptfs_kernel.h" + +/** + * 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)"); + +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_interpose + * @lower_dentry: Existing dentry in the lower filesystem + * @dentry: ecryptfs' dentry + * @sb: ecryptfs's super_block + * @flag: If set to true, then d_add is called, else d_instantiate is called + * + * Interposes upper and lower dentries. + * + * Returns zero on success; non-zero otherwise + */ +int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, + struct super_block *sb, int flag) +{ + struct inode *lower_inode; + struct inode *inode; + int rc = 0; + + lower_inode = lower_dentry->d_inode; + if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { + rc = -EXDEV; + goto out; + } + if (!igrab(lower_inode)) { + rc = -ESTALE; + goto out; + } + inode = iget5_locked(sb, (unsigned long)lower_inode, + ecryptfs_inode_test, ecryptfs_inode_set, + lower_inode); + if (!inode) { + rc = -EACCES; + iput(lower_inode); + goto out; + } + if (inode->i_state & I_NEW) + unlock_new_inode(inode); + else + iput(lower_inode); + if (S_ISLNK(lower_inode->i_mode)) + inode->i_op = &ecryptfs_symlink_iops; + else if (S_ISDIR(lower_inode->i_mode)) + inode->i_op = &ecryptfs_dir_iops; + if (S_ISDIR(lower_inode->i_mode)) + inode->i_fop = &ecryptfs_dir_fops; + /* TODO: Is there a better way to identify if the inode is + * special? */ + if (S_ISBLK(lower_inode->i_mode) || S_ISCHR(lower_inode->i_mode) || + S_ISFIFO(lower_inode->i_mode) || S_ISSOCK(lower_inode->i_mode)) + init_special_inode(inode, lower_inode->i_mode, + lower_inode->i_rdev); + dentry->d_op = &ecryptfs_dops; + if (flag) + d_add(dentry, inode); + else + d_instantiate(dentry, inode); + ecryptfs_copy_attr_all(inode, lower_inode); + /* This size will be overwritten for real files w/ headers and + * other metadata */ + ecryptfs_copy_inode_size(inode, lower_inode); +out: + return rc; +} + +enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug, + ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher, + ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes, + ecryptfs_opt_passthrough, ecryptfs_opt_err }; + +static match_table_t tokens = { + {ecryptfs_opt_sig, "sig=%s"}, + {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, + {ecryptfs_opt_debug, "debug=%u"}, + {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"}, + {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_err, NULL} +}; + +/** + * ecryptfs_verify_version + * @version: The version number to confirm + * + * Returns zero on good version; non-zero otherwise + */ +static int ecryptfs_verify_version(u16 version) +{ + int rc = 0; + unsigned char major; + unsigned char minor; + + major = ((version >> 8) & 0xFF); + minor = (version & 0xFF); + if (major != ECRYPTFS_VERSION_MAJOR) { + ecryptfs_printk(KERN_ERR, "Major version number mismatch. " + "Expected [%d]; got [%d]\n", + ECRYPTFS_VERSION_MAJOR, major); + rc = -EINVAL; + goto out; + } + if (minor != ECRYPTFS_VERSION_MINOR) { + ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " + "Expected [%d]; got [%d]\n", + ECRYPTFS_VERSION_MINOR, minor); + rc = -EINVAL; + goto out; + } +out: + return rc; +} + +/** + * ecryptfs_parse_options + * @sb: The ecryptfs super block + * @options: The options pased to the kernel + * + * 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 super_block *sb, char *options) +{ + char *p; + int rc = 0; + int sig_set = 0; + int cipher_name_set = 0; + int cipher_key_bytes; + int cipher_key_bytes_set = 0; + struct key *auth_tok_key = NULL; + struct ecryptfs_auth_tok *auth_tok = NULL; + struct ecryptfs_mount_crypt_stat *mount_crypt_stat = + &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; + substring_t args[MAX_OPT_ARGS]; + int token; + char *sig_src; + char *sig_dst; + char *debug_src; + char *cipher_name_dst; + char *cipher_name_src; + char *cipher_key_bytes_src; + struct crypto_tfm *tmp_tfm; + int cipher_name_len; + + if (!options) { + rc = -EINVAL; + goto out; + } + 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; + sig_dst = + mount_crypt_stat->global_auth_tok_sig; + memcpy(sig_dst, sig_src, ECRYPTFS_SIG_SIZE_HEX); + sig_dst[ECRYPTFS_SIG_SIZE_HEX] = '\0'; + ecryptfs_printk(KERN_DEBUG, + "The mount_crypt_stat " + "global_auth_tok_sig set to: " + "[%s]\n", sig_dst); + sig_set = 1; + break; + case ecryptfs_opt_debug: + case ecryptfs_opt_ecryptfs_debug: + debug_src = args[0].from; + ecryptfs_verbosity = + (int)simple_strtol(debug_src, &debug_src, + 0); + ecryptfs_printk(KERN_DEBUG, + "Verbosity set to [%d]" "\n", + ecryptfs_verbosity); + 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); + ecryptfs_printk(KERN_DEBUG, + "The mount_crypt_stat " + "global_default_cipher_name set to: " + "[%s]\n", cipher_name_dst); + 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; + ecryptfs_printk(KERN_DEBUG, + "The mount_crypt_stat " + "global_default_cipher_key_size " + "set to: [%d]\n", mount_crypt_stat-> + global_default_cipher_key_size); + cipher_key_bytes_set = 1; + break; + case ecryptfs_opt_passthrough: + mount_crypt_stat->flags |= + ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; + break; + case ecryptfs_opt_err: + default: + ecryptfs_printk(KERN_WARNING, + "eCryptfs: unrecognized option '%s'\n", + p); + } + } + /* Do not support lack of mount-wide signature in 0.1 + * release */ + if (!sig_set) { + rc = -EINVAL; + ecryptfs_printk(KERN_ERR, "You must supply a valid " + "passphrase auth tok signature as a mount " + "parameter; see the eCryptfs README\n"); + goto out; + } + if (!cipher_name_set) { + cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); + if (unlikely(cipher_name_len + >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) { + rc = -EINVAL; + BUG(); + goto out; + } + memcpy(mount_crypt_stat->global_default_cipher_name, + ECRYPTFS_DEFAULT_CIPHER, cipher_name_len); + mount_crypt_stat->global_default_cipher_name[cipher_name_len] + = '\0'; + } + if (!cipher_key_bytes_set) { + mount_crypt_stat->global_default_cipher_key_size = + ECRYPTFS_DEFAULT_KEY_BYTES; + ecryptfs_printk(KERN_DEBUG, "Cipher key size was not " + "specified. Defaulting to [%d]\n", + mount_crypt_stat-> + global_default_cipher_key_size); + } + rc = ecryptfs_process_cipher( + &tmp_tfm, + &mount_crypt_stat->global_key_tfm, + mount_crypt_stat->global_default_cipher_name, + mount_crypt_stat->global_default_cipher_key_size); + if (tmp_tfm) + crypto_free_tfm(tmp_tfm); + if (rc) { + printk(KERN_ERR "Error attempting to initialize cipher [%s] " + "with key size [%Zd] bytes; rc = [%d]\n", + mount_crypt_stat->global_default_cipher_name, + mount_crypt_stat->global_default_cipher_key_size, rc); + rc = -EINVAL; + goto out; + } + mutex_init(&mount_crypt_stat->global_key_tfm_mutex); + ecryptfs_printk(KERN_DEBUG, "Requesting the key with description: " + "[%s]\n", mount_crypt_stat->global_auth_tok_sig); + /* The reference to this key is held until umount is done The + * call to key_put is done in ecryptfs_put_super() */ + auth_tok_key = request_key(&key_type_user, + mount_crypt_stat->global_auth_tok_sig, + NULL); + if (!auth_tok_key || IS_ERR(auth_tok_key)) { + ecryptfs_printk(KERN_ERR, "Could not find key with " + "description: [%s]\n", + mount_crypt_stat->global_auth_tok_sig); + process_request_key_err(PTR_ERR(auth_tok_key)); + rc = -EINVAL; + goto out; + } + auth_tok = ecryptfs_get_key_payload_data(auth_tok_key); + if (ecryptfs_verify_version(auth_tok->version)) { + ecryptfs_printk(KERN_ERR, "Data structure version mismatch. " + "Userspace tools must match eCryptfs kernel " + "module with major version [%d] and minor " + "version [%d]\n", ECRYPTFS_VERSION_MAJOR, + ECRYPTFS_VERSION_MINOR); + rc = -EINVAL; + goto out; + } + if (auth_tok->token_type != ECRYPTFS_PASSWORD) { + ecryptfs_printk(KERN_ERR, "Invalid auth_tok structure " + "returned from key\n"); + rc = -EINVAL; + goto out; + } + mount_crypt_stat->global_auth_tok_key = auth_tok_key; + mount_crypt_stat->global_auth_tok = auth_tok; +out: + return rc; +} + +struct kmem_cache *ecryptfs_sb_info_cache; + +/** + * ecryptfs_fill_super + * @sb: The ecryptfs super block + * @raw_data: The options passed to mount + * @silent: Not used but required by function prototype + * + * Sets up what we can of the sb, rest is done in ecryptfs_read_super + * + * Returns zero on success; non-zero otherwise + */ +static int +ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) +{ + int rc = 0; + + /* Released in ecryptfs_put_super() */ + ecryptfs_set_superblock_private(sb, + kmem_cache_alloc(ecryptfs_sb_info_cache, + SLAB_KERNEL)); + if (!ecryptfs_superblock_to_private(sb)) { + ecryptfs_printk(KERN_WARNING, "Out of memory\n"); + rc = -ENOMEM; + goto out; + } + memset(ecryptfs_superblock_to_private(sb), 0, + sizeof(struct ecryptfs_sb_info)); + sb->s_op = &ecryptfs_sops; + /* Released through deactivate_super(sb) from get_sb_nodev */ + sb->s_root = d_alloc(NULL, &(const struct qstr) { + .hash = 0,.name = "/",.len = 1}); + if (!sb->s_root) { + ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); + rc = -ENOMEM; + goto out; + } + sb->s_root->d_op = &ecryptfs_dops; + sb->s_root->d_sb = sb; + sb->s_root->d_parent = sb->s_root; + /* Released in d_release when dput(sb->s_root) is called */ + /* through deactivate_super(sb) from get_sb_nodev() */ + ecryptfs_set_dentry_private(sb->s_root, + kmem_cache_alloc(ecryptfs_dentry_info_cache, + SLAB_KERNEL)); + if (!ecryptfs_dentry_to_private(sb->s_root)) { + ecryptfs_printk(KERN_ERR, + "dentry_info_cache alloc failed\n"); + rc = -ENOMEM; + goto out; + } + memset(ecryptfs_dentry_to_private(sb->s_root), 0, + sizeof(struct ecryptfs_dentry_info)); + rc = 0; +out: + /* Should be able to rely on deactivate_super called from + * get_sb_nodev */ + return rc; +} + +/** + * ecryptfs_read_super + * @sb: The ecryptfs super block + * @dev_name: The path to mount over + * + * Read the super block of the lower filesystem, and use + * ecryptfs_interpose to create our initial inode and super block + * struct. + */ +static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) +{ + int rc; + struct nameidata nd; + struct dentry *lower_root; + struct vfsmount *lower_mnt; + + memset(&nd, 0, sizeof(struct nameidata)); + rc = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); + if (rc) { + ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); + goto out_free; + } + lower_root = nd.dentry; + if (!lower_root->d_inode) { + ecryptfs_printk(KERN_WARNING, + "No directory to interpose on\n"); + rc = -ENOENT; + goto out_free; + } + lower_mnt = nd.mnt; + ecryptfs_set_superblock_lower(sb, lower_root->d_sb); + sb->s_maxbytes = lower_root->d_sb->s_maxbytes; + ecryptfs_set_dentry_lower(sb->s_root, lower_root); + ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt); + if ((rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0))) + goto out_free; + rc = 0; + goto out; +out_free: + path_release(&nd); +out: + return rc; +} + +/** + * ecryptfs_get_sb + * @fs_type + * @flags + * @dev_name: The path to mount over + * @raw_data: The options passed into the kernel + * + * The whole ecryptfs_get_sb process is broken into 4 functions: + * ecryptfs_parse_options(): handle options passed to ecryptfs, if any + * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block + * with as much information as it can before needing + * the lower filesystem. + * ecryptfs_read_super(): this accesses the lower filesystem and uses + * ecryptfs_interpolate to perform most of the linking + * ecryptfs_interpolate(): links the lower filesystem into ecryptfs + */ +static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data, + struct vfsmount *mnt) +{ + int rc; + struct super_block *sb; + + rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); + if (rc < 0) { + printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); + goto out; + } + sb = mnt->mnt_sb; + rc = ecryptfs_parse_options(sb, raw_data); + if (rc) { + printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); + goto out_abort; + } + rc = ecryptfs_read_super(sb, dev_name); + if (rc) { + printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); + goto out_abort; + } + goto out; +out_abort: + dput(sb->s_root); + up_write(&sb->s_umount); + deactivate_super(sb); +out: + return rc; +} + +/** + * ecryptfs_kill_block_super + * @sb: The ecryptfs super block + * + * Used to bring the superblock down and free the private data. + * Private data is free'd in ecryptfs_put_super() + */ +static void ecryptfs_kill_block_super(struct super_block *sb) +{ + generic_shutdown_super(sb); +} + +static struct file_system_type ecryptfs_fs_type = { + .owner = THIS_MODULE, + .name = "ecryptfs", + .get_sb = ecryptfs_get_sb, + .kill_sb = ecryptfs_kill_block_super, + .fs_flags = 0 +}; + +/** + * inode_info_init_once + * + * Initializes the ecryptfs_inode_info_cache when it is created + */ +static void +inode_info_init_once(void *vptr, struct kmem_cache *cachep, unsigned long flags) +{ + struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; + + if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == + SLAB_CTOR_CONSTRUCTOR) + inode_init_once(&ei->vfs_inode); +} + +static struct ecryptfs_cache_info { + kmem_cache_t **cache; + const char *name; + size_t size; + void (*ctor)(void*, struct kmem_cache *, unsigned long); +} 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), + .ctor = inode_info_init_once, + }, + { + .cache = &ecryptfs_sb_info_cache, + .name = "ecryptfs_sb_cache", + .size = sizeof(struct ecryptfs_sb_info), + }, + { + .cache = &ecryptfs_header_cache_0, + .name = "ecryptfs_headers_0", + .size = PAGE_CACHE_SIZE, + }, + { + .cache = &ecryptfs_header_cache_1, + .name = "ecryptfs_headers_1", + .size = PAGE_CACHE_SIZE, + }, + { + .cache = &ecryptfs_header_cache_2, + .name = "ecryptfs_headers_2", + .size = PAGE_CACHE_SIZE, + }, + { + .cache = &ecryptfs_lower_page_cache, + .name = "ecryptfs_lower_page_cache", + .size = PAGE_CACHE_SIZE, + }, +}; + +static void ecryptfs_free_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]; + if (*(info->cache)) + 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->ctor, NULL); + if (!*(info->cache)) { + ecryptfs_free_kmem_caches(); + ecryptfs_printk(KERN_WARNING, "%s: " + "kmem_cache_create failed\n", + info->name); + return -ENOMEM; + } + } + return 0; +} + +struct ecryptfs_obj { + char *name; + struct list_head slot_list; + struct kobject kobj; +}; + +struct ecryptfs_attribute { + struct attribute attr; + ssize_t(*show) (struct ecryptfs_obj *, char *); + ssize_t(*store) (struct ecryptfs_obj *, const char *, size_t); +}; + +static ssize_t +ecryptfs_attr_store(struct kobject *kobj, + struct attribute *attr, const char *buf, size_t len) +{ + struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj, + kobj); + struct ecryptfs_attribute *attribute = + container_of(attr, struct ecryptfs_attribute, attr); + + return (attribute->store ? attribute->store(obj, buf, len) : 0); +} + +static ssize_t +ecryptfs_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj, + kobj); + struct ecryptfs_attribute *attribute = + container_of(attr, struct ecryptfs_attribute, attr); + + return (attribute->show ? attribute->show(obj, buf) : 0); +} + +static struct sysfs_ops ecryptfs_sysfs_ops = { + .show = ecryptfs_attr_show, + .store = ecryptfs_attr_store +}; + +static struct kobj_type ecryptfs_ktype = { + .sysfs_ops = &ecryptfs_sysfs_ops +}; + +static decl_subsys(ecryptfs, &ecryptfs_ktype, NULL); + +static ssize_t version_show(struct ecryptfs_obj *obj, char *buff) +{ + return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); +} + +static struct ecryptfs_attribute sysfs_attr_version = __ATTR_RO(version); + +struct ecryptfs_version_str_map_elem { + u32 flag; + char *str; +} ecryptfs_version_str_map[] = { + {ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"}, + {ECRYPTFS_VERSIONING_PUBKEY, "pubkey"}, + {ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"}, + {ECRYPTFS_VERSIONING_POLICY, "policy"} +}; + +static ssize_t version_str_show(struct ecryptfs_obj *obj, char *buff) +{ + int i; + int remaining = PAGE_SIZE; + int total_written = 0; + + buff[0] = '\0'; + for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) { + int entry_size; + + if (!(ECRYPTFS_VERSIONING_MASK + & ecryptfs_version_str_map[i].flag)) + continue; + entry_size = strlen(ecryptfs_version_str_map[i].str); + if ((entry_size + 2) > remaining) + goto out; + memcpy(buff, ecryptfs_version_str_map[i].str, entry_size); + buff[entry_size++] = '\n'; + buff[entry_size] = '\0'; + buff += entry_size; + total_written += entry_size; + remaining -= entry_size; + } +out: + return total_written; +} + +static struct ecryptfs_attribute sysfs_attr_version_str = __ATTR_RO(version_str); + +static int do_sysfs_registration(void) +{ + int rc; + + if ((rc = subsystem_register(&ecryptfs_subsys))) { + printk(KERN_ERR + "Unable to register ecryptfs sysfs subsystem\n"); + goto out; + } + rc = sysfs_create_file(&ecryptfs_subsys.kset.kobj, + &sysfs_attr_version.attr); + if (rc) { + printk(KERN_ERR + "Unable to create ecryptfs version attribute\n"); + subsystem_unregister(&ecryptfs_subsys); + goto out; + } + rc = sysfs_create_file(&ecryptfs_subsys.kset.kobj, + &sysfs_attr_version_str.attr); + if (rc) { + printk(KERN_ERR + "Unable to create ecryptfs version_str attribute\n"); + sysfs_remove_file(&ecryptfs_subsys.kset.kobj, + &sysfs_attr_version.attr); + subsystem_unregister(&ecryptfs_subsys); + goto out; + } +out: + return rc; +} + +static int __init ecryptfs_init(void) +{ + int rc; + + if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_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 [%d] bytes; " + "the page size is [%d] bytes.\n", + ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_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 = register_filesystem(&ecryptfs_fs_type); + if (rc) { + printk(KERN_ERR "Failed to register filesystem\n"); + ecryptfs_free_kmem_caches(); + goto out; + } + kset_set_kset_s(&ecryptfs_subsys, fs_subsys); + sysfs_attr_version.attr.owner = THIS_MODULE; + sysfs_attr_version_str.attr.owner = THIS_MODULE; + rc = do_sysfs_registration(); + if (rc) { + printk(KERN_ERR "sysfs registration failed\n"); + unregister_filesystem(&ecryptfs_fs_type); + ecryptfs_free_kmem_caches(); + goto out; + } +out: + return rc; +} + +static void __exit ecryptfs_exit(void) +{ + sysfs_remove_file(&ecryptfs_subsys.kset.kobj, + &sysfs_attr_version.attr); + sysfs_remove_file(&ecryptfs_subsys.kset.kobj, + &sysfs_attr_version_str.attr); + subsystem_unregister(&ecryptfs_subsys); + unregister_filesystem(&ecryptfs_fs_type); + ecryptfs_free_kmem_caches(); +} + +MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); +MODULE_DESCRIPTION("eCryptfs"); + +MODULE_LICENSE("GPL"); + +module_init(ecryptfs_init) +module_exit(ecryptfs_exit) |
