211 lines
6.4 KiB
C
211 lines
6.4 KiB
C
/**
|
|
* 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/fs.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/key.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/file.h>
|
|
#include <linux/crypto.h>
|
|
#include "ecryptfs_kernel.h"
|
|
|
|
struct kmem_cache *ecryptfs_inode_info_cache;
|
|
|
|
/**
|
|
* ecryptfs_alloc_inode - allocate an ecryptfs inode
|
|
* @sb: Pointer to the ecryptfs super block
|
|
*
|
|
* Called to bring an inode into existence.
|
|
*
|
|
* Only handle allocation, setting up structures should be done in
|
|
* ecryptfs_read_inode. This is because the kernel, between now and
|
|
* then, will 0 out the private data pointer.
|
|
*
|
|
* Returns a pointer to a newly allocated inode, NULL otherwise
|
|
*/
|
|
static struct inode *ecryptfs_alloc_inode(struct super_block *sb)
|
|
{
|
|
struct ecryptfs_inode_info *inode_info;
|
|
struct inode *inode = NULL;
|
|
|
|
inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);
|
|
if (unlikely(!inode_info))
|
|
goto out;
|
|
ecryptfs_init_crypt_stat(&inode_info->crypt_stat);
|
|
mutex_init(&inode_info->lower_file_mutex);
|
|
inode_info->lower_file = NULL;
|
|
inode = &inode_info->vfs_inode;
|
|
out:
|
|
return inode;
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_destroy_inode
|
|
* @inode: The ecryptfs inode
|
|
*
|
|
* This is used during the final destruction of the inode. All
|
|
* allocation of memory related to the inode, including allocated
|
|
* memory in the crypt_stat struct, will be released here. This
|
|
* function also fput()'s the persistent file for the lower inode.
|
|
* There should be no chance that this deallocation will be missed.
|
|
*/
|
|
static void ecryptfs_destroy_inode(struct inode *inode)
|
|
{
|
|
struct ecryptfs_inode_info *inode_info;
|
|
|
|
inode_info = ecryptfs_inode_to_private(inode);
|
|
if (inode_info->lower_file) {
|
|
struct dentry *lower_dentry =
|
|
inode_info->lower_file->f_dentry;
|
|
|
|
BUG_ON(!lower_dentry);
|
|
if (lower_dentry->d_inode) {
|
|
fput(inode_info->lower_file);
|
|
inode_info->lower_file = NULL;
|
|
d_drop(lower_dentry);
|
|
}
|
|
}
|
|
ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
|
|
kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_init_inode
|
|
* @inode: The ecryptfs inode
|
|
*
|
|
* Set up the ecryptfs inode.
|
|
*/
|
|
void ecryptfs_init_inode(struct inode *inode, struct inode *lower_inode)
|
|
{
|
|
ecryptfs_set_inode_lower(inode, lower_inode);
|
|
inode->i_ino = lower_inode->i_ino;
|
|
inode->i_version++;
|
|
inode->i_op = &ecryptfs_main_iops;
|
|
inode->i_fop = &ecryptfs_main_fops;
|
|
inode->i_mapping->a_ops = &ecryptfs_aops;
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_put_super
|
|
* @sb: Pointer to the ecryptfs super block
|
|
*
|
|
* Final actions when unmounting a file system.
|
|
* This will handle deallocation and release of our private data.
|
|
*/
|
|
static void ecryptfs_put_super(struct super_block *sb)
|
|
{
|
|
struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
|
|
|
|
lock_kernel();
|
|
|
|
ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
|
|
kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
|
|
ecryptfs_set_superblock_private(sb, NULL);
|
|
|
|
unlock_kernel();
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_statfs
|
|
* @sb: The ecryptfs super block
|
|
* @buf: The struct kstatfs to fill in with stats
|
|
*
|
|
* Get the filesystem statistics. Currently, we let this pass right through
|
|
* to the lower filesystem and take no action ourselves.
|
|
*/
|
|
static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf)
|
|
{
|
|
return vfs_statfs(ecryptfs_dentry_to_lower(dentry), buf);
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_clear_inode
|
|
* @inode - The ecryptfs inode
|
|
*
|
|
* Called by iput() when the inode reference count reached zero
|
|
* and the inode is not hashed anywhere. Used to clear anything
|
|
* that needs to be, before the inode is completely destroyed and put
|
|
* on the inode free list. We use this to drop out reference to the
|
|
* lower inode.
|
|
*/
|
|
static void ecryptfs_clear_inode(struct inode *inode)
|
|
{
|
|
iput(ecryptfs_inode_to_lower(inode));
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_show_options
|
|
*
|
|
* Prints the mount options for a given superblock.
|
|
* Returns zero; does not fail.
|
|
*/
|
|
static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt)
|
|
{
|
|
struct super_block *sb = mnt->mnt_sb;
|
|
struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
|
|
&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
|
|
struct ecryptfs_global_auth_tok *walker;
|
|
|
|
mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
|
|
list_for_each_entry(walker,
|
|
&mount_crypt_stat->global_auth_tok_list,
|
|
mount_crypt_stat_list) {
|
|
if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK)
|
|
seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig);
|
|
else
|
|
seq_printf(m, ",ecryptfs_sig=%s", walker->sig);
|
|
}
|
|
mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
|
|
|
|
seq_printf(m, ",ecryptfs_cipher=%s",
|
|
mount_crypt_stat->global_default_cipher_name);
|
|
|
|
if (mount_crypt_stat->global_default_cipher_key_size)
|
|
seq_printf(m, ",ecryptfs_key_bytes=%zd",
|
|
mount_crypt_stat->global_default_cipher_key_size);
|
|
if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)
|
|
seq_printf(m, ",ecryptfs_passthrough");
|
|
if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
|
|
seq_printf(m, ",ecryptfs_xattr_metadata");
|
|
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
|
|
seq_printf(m, ",ecryptfs_encrypted_view");
|
|
if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS)
|
|
seq_printf(m, ",ecryptfs_unlink_sigs");
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct super_operations ecryptfs_sops = {
|
|
.alloc_inode = ecryptfs_alloc_inode,
|
|
.destroy_inode = ecryptfs_destroy_inode,
|
|
.drop_inode = generic_delete_inode,
|
|
.put_super = ecryptfs_put_super,
|
|
.statfs = ecryptfs_statfs,
|
|
.remount_fs = NULL,
|
|
.clear_inode = ecryptfs_clear_inode,
|
|
.show_options = ecryptfs_show_options
|
|
};
|