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![Tyler Hicks](/assets/img/avatar_default.png)
eCryptfs has file encryption keys (FEK), file encryption key encryption keys (FEKEK), and filename encryption keys (FNEK). The per-file FEK is encrypted with one or more FEKEKs and stored in the header of the encrypted file. I noticed that the FEK is also being encrypted by the FNEK. This is a problem if a user wants to use a different FNEK than their FEKEK, as their file contents will still be accessible with the FNEK. This is a minimalistic patch which prevents the FNEKs signatures from being copied to the inode signatures list. Ultimately, it keeps the FEK from being encrypted with a FNEK. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Acked-by: Dustin Kirkland <kirkland@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
900 lines
26 KiB
C
900 lines
26 KiB
C
/**
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* eCryptfs: Linux filesystem encryption layer
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*
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* Copyright (C) 1997-2003 Erez Zadok
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* Copyright (C) 2001-2003 Stony Brook University
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* Copyright (C) 2004-2007 International Business Machines Corp.
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* Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
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* Michael C. Thompson <mcthomps@us.ibm.com>
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* Tyler Hicks <tyhicks@ou.edu>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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* 02111-1307, USA.
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*/
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#include <linux/dcache.h>
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#include <linux/file.h>
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#include <linux/module.h>
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#include <linux/namei.h>
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#include <linux/skbuff.h>
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#include <linux/crypto.h>
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#include <linux/mount.h>
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#include <linux/pagemap.h>
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#include <linux/key.h>
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#include <linux/parser.h>
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#include <linux/fs_stack.h>
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#include "ecryptfs_kernel.h"
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/**
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* Module parameter that defines the ecryptfs_verbosity level.
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*/
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int ecryptfs_verbosity = 0;
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module_param(ecryptfs_verbosity, int, 0);
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MODULE_PARM_DESC(ecryptfs_verbosity,
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"Initial verbosity level (0 or 1; defaults to "
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"0, which is Quiet)");
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/**
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* Module parameter that defines the number of message buffer elements
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*/
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unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
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module_param(ecryptfs_message_buf_len, uint, 0);
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MODULE_PARM_DESC(ecryptfs_message_buf_len,
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"Number of message buffer elements");
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/**
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* Module parameter that defines the maximum guaranteed amount of time to wait
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* for a response from ecryptfsd. The actual sleep time will be, more than
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* likely, a small amount greater than this specified value, but only less if
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* the message successfully arrives.
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*/
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signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
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module_param(ecryptfs_message_wait_timeout, long, 0);
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MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
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"Maximum number of seconds that an operation will "
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"sleep while waiting for a message response from "
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"userspace");
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/**
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* Module parameter that is an estimate of the maximum number of users
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* that will be concurrently using eCryptfs. Set this to the right
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* value to balance performance and memory use.
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*/
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unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
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module_param(ecryptfs_number_of_users, uint, 0);
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MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
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"concurrent users of eCryptfs");
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void __ecryptfs_printk(const char *fmt, ...)
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{
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va_list args;
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va_start(args, fmt);
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if (fmt[1] == '7') { /* KERN_DEBUG */
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if (ecryptfs_verbosity >= 1)
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vprintk(fmt, args);
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} else
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vprintk(fmt, args);
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va_end(args);
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}
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/**
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* ecryptfs_init_persistent_file
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* @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
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* the lower dentry and the lower mount set
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*
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* eCryptfs only ever keeps a single open file for every lower
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* inode. All I/O operations to the lower inode occur through that
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* file. When the first eCryptfs dentry that interposes with the first
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* lower dentry for that inode is created, this function creates the
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* persistent file struct and associates it with the eCryptfs
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* inode. When the eCryptfs inode is destroyed, the file is closed.
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*
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* The persistent file will be opened with read/write permissions, if
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* possible. Otherwise, it is opened read-only.
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*
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* This function does nothing if a lower persistent file is already
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* associated with the eCryptfs inode.
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*
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* Returns zero on success; non-zero otherwise
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*/
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int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
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{
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const struct cred *cred = current_cred();
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struct ecryptfs_inode_info *inode_info =
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ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
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int rc = 0;
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mutex_lock(&inode_info->lower_file_mutex);
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if (!inode_info->lower_file) {
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struct dentry *lower_dentry;
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struct vfsmount *lower_mnt =
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ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
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lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
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rc = ecryptfs_privileged_open(&inode_info->lower_file,
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lower_dentry, lower_mnt, cred);
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if (rc || IS_ERR(inode_info->lower_file)) {
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printk(KERN_ERR "Error opening lower persistent file "
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"for lower_dentry [0x%p] and lower_mnt [0x%p]; "
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"rc = [%d]\n", lower_dentry, lower_mnt, rc);
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rc = PTR_ERR(inode_info->lower_file);
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inode_info->lower_file = NULL;
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}
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}
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mutex_unlock(&inode_info->lower_file_mutex);
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return rc;
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}
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/**
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* ecryptfs_interpose
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* @lower_dentry: Existing dentry in the lower filesystem
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* @dentry: ecryptfs' dentry
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* @sb: ecryptfs's super_block
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* @flags: flags to govern behavior of interpose procedure
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*
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* Interposes upper and lower dentries.
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*
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* Returns zero on success; non-zero otherwise
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*/
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int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
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struct super_block *sb, u32 flags)
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{
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struct inode *lower_inode;
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struct inode *inode;
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int rc = 0;
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lower_inode = lower_dentry->d_inode;
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if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
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rc = -EXDEV;
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goto out;
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}
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if (!igrab(lower_inode)) {
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rc = -ESTALE;
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goto out;
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}
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inode = iget5_locked(sb, (unsigned long)lower_inode,
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ecryptfs_inode_test, ecryptfs_inode_set,
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lower_inode);
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if (!inode) {
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rc = -EACCES;
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iput(lower_inode);
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goto out;
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}
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if (inode->i_state & I_NEW)
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unlock_new_inode(inode);
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else
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iput(lower_inode);
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if (S_ISLNK(lower_inode->i_mode))
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inode->i_op = &ecryptfs_symlink_iops;
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else if (S_ISDIR(lower_inode->i_mode))
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inode->i_op = &ecryptfs_dir_iops;
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if (S_ISDIR(lower_inode->i_mode))
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inode->i_fop = &ecryptfs_dir_fops;
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if (special_file(lower_inode->i_mode))
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init_special_inode(inode, lower_inode->i_mode,
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lower_inode->i_rdev);
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dentry->d_op = &ecryptfs_dops;
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if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
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d_add(dentry, inode);
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else
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d_instantiate(dentry, inode);
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fsstack_copy_attr_all(inode, lower_inode, NULL);
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/* This size will be overwritten for real files w/ headers and
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* other metadata */
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fsstack_copy_inode_size(inode, lower_inode);
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out:
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return rc;
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}
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enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
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ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
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ecryptfs_opt_ecryptfs_key_bytes,
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ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
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ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
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ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
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ecryptfs_opt_err };
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static const match_table_t tokens = {
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{ecryptfs_opt_sig, "sig=%s"},
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{ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
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{ecryptfs_opt_cipher, "cipher=%s"},
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{ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
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{ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
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{ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
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{ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
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{ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
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{ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
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{ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
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{ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
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{ecryptfs_opt_err, NULL}
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};
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static int ecryptfs_init_global_auth_toks(
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struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
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{
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struct ecryptfs_global_auth_tok *global_auth_tok;
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int rc = 0;
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list_for_each_entry(global_auth_tok,
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&mount_crypt_stat->global_auth_tok_list,
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mount_crypt_stat_list) {
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rc = ecryptfs_keyring_auth_tok_for_sig(
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&global_auth_tok->global_auth_tok_key,
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&global_auth_tok->global_auth_tok,
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global_auth_tok->sig);
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if (rc) {
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printk(KERN_ERR "Could not find valid key in user "
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"session keyring for sig specified in mount "
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"option: [%s]\n", global_auth_tok->sig);
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global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
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goto out;
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} else
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global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
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}
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out:
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return rc;
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}
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static void ecryptfs_init_mount_crypt_stat(
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struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
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{
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memset((void *)mount_crypt_stat, 0,
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sizeof(struct ecryptfs_mount_crypt_stat));
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INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
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mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
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mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
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}
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/**
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* ecryptfs_parse_options
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* @sb: The ecryptfs super block
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* @options: The options pased to the kernel
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*
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* Parse mount options:
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* debug=N - ecryptfs_verbosity level for debug output
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* sig=XXX - description(signature) of the key to use
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*
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* Returns the dentry object of the lower-level (lower/interposed)
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* directory; We want to mount our stackable file system on top of
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* that lower directory.
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*
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* The signature of the key to use must be the description of a key
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* already in the keyring. Mounting will fail if the key can not be
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* found.
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*
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* Returns zero on success; non-zero on error
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*/
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static int ecryptfs_parse_options(struct super_block *sb, char *options)
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{
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char *p;
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int rc = 0;
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int sig_set = 0;
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int cipher_name_set = 0;
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int fn_cipher_name_set = 0;
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int cipher_key_bytes;
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int cipher_key_bytes_set = 0;
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int fn_cipher_key_bytes;
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int fn_cipher_key_bytes_set = 0;
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struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
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&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
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substring_t args[MAX_OPT_ARGS];
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int token;
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char *sig_src;
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char *cipher_name_dst;
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char *cipher_name_src;
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char *fn_cipher_name_dst;
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char *fn_cipher_name_src;
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char *fnek_dst;
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char *fnek_src;
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char *cipher_key_bytes_src;
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char *fn_cipher_key_bytes_src;
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if (!options) {
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rc = -EINVAL;
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goto out;
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}
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ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
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while ((p = strsep(&options, ",")) != NULL) {
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if (!*p)
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continue;
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token = match_token(p, tokens, args);
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switch (token) {
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case ecryptfs_opt_sig:
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case ecryptfs_opt_ecryptfs_sig:
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sig_src = args[0].from;
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rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
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sig_src, 0);
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if (rc) {
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printk(KERN_ERR "Error attempting to register "
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"global sig; rc = [%d]\n", rc);
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goto out;
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}
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sig_set = 1;
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break;
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case ecryptfs_opt_cipher:
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case ecryptfs_opt_ecryptfs_cipher:
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cipher_name_src = args[0].from;
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cipher_name_dst =
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mount_crypt_stat->
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global_default_cipher_name;
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strncpy(cipher_name_dst, cipher_name_src,
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ECRYPTFS_MAX_CIPHER_NAME_SIZE);
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cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
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cipher_name_set = 1;
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break;
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case ecryptfs_opt_ecryptfs_key_bytes:
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cipher_key_bytes_src = args[0].from;
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cipher_key_bytes =
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(int)simple_strtol(cipher_key_bytes_src,
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&cipher_key_bytes_src, 0);
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mount_crypt_stat->global_default_cipher_key_size =
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cipher_key_bytes;
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cipher_key_bytes_set = 1;
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break;
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case ecryptfs_opt_passthrough:
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mount_crypt_stat->flags |=
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ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
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break;
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case ecryptfs_opt_xattr_metadata:
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mount_crypt_stat->flags |=
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ECRYPTFS_XATTR_METADATA_ENABLED;
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break;
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case ecryptfs_opt_encrypted_view:
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mount_crypt_stat->flags |=
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ECRYPTFS_XATTR_METADATA_ENABLED;
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mount_crypt_stat->flags |=
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ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
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break;
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case ecryptfs_opt_fnek_sig:
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fnek_src = args[0].from;
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fnek_dst =
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mount_crypt_stat->global_default_fnek_sig;
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strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
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mount_crypt_stat->global_default_fnek_sig[
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ECRYPTFS_SIG_SIZE_HEX] = '\0';
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rc = ecryptfs_add_global_auth_tok(
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mount_crypt_stat,
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mount_crypt_stat->global_default_fnek_sig,
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ECRYPTFS_AUTH_TOK_FNEK);
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if (rc) {
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printk(KERN_ERR "Error attempting to register "
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"global fnek sig [%s]; rc = [%d]\n",
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mount_crypt_stat->global_default_fnek_sig,
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rc);
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goto out;
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}
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mount_crypt_stat->flags |=
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(ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
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| ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
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break;
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case ecryptfs_opt_fn_cipher:
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fn_cipher_name_src = args[0].from;
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fn_cipher_name_dst =
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mount_crypt_stat->global_default_fn_cipher_name;
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strncpy(fn_cipher_name_dst, fn_cipher_name_src,
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ECRYPTFS_MAX_CIPHER_NAME_SIZE);
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mount_crypt_stat->global_default_fn_cipher_name[
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ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
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fn_cipher_name_set = 1;
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break;
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case ecryptfs_opt_fn_cipher_key_bytes:
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fn_cipher_key_bytes_src = args[0].from;
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fn_cipher_key_bytes =
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(int)simple_strtol(fn_cipher_key_bytes_src,
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&fn_cipher_key_bytes_src, 0);
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mount_crypt_stat->global_default_fn_cipher_key_bytes =
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fn_cipher_key_bytes;
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fn_cipher_key_bytes_set = 1;
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break;
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case ecryptfs_opt_err:
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default:
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printk(KERN_WARNING
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"%s: eCryptfs: unrecognized option [%s]\n",
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__func__, p);
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}
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}
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if (!sig_set) {
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rc = -EINVAL;
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ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
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"auth tok signature as a mount "
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"parameter; see the eCryptfs README\n");
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goto out;
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}
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if (!cipher_name_set) {
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int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
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BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
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strcpy(mount_crypt_stat->global_default_cipher_name,
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ECRYPTFS_DEFAULT_CIPHER);
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}
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if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
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&& !fn_cipher_name_set)
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strcpy(mount_crypt_stat->global_default_fn_cipher_name,
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mount_crypt_stat->global_default_cipher_name);
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if (!cipher_key_bytes_set)
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mount_crypt_stat->global_default_cipher_key_size = 0;
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if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
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&& !fn_cipher_key_bytes_set)
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mount_crypt_stat->global_default_fn_cipher_key_bytes =
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mount_crypt_stat->global_default_cipher_key_size;
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mutex_lock(&key_tfm_list_mutex);
|
|
if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
|
|
NULL)) {
|
|
rc = ecryptfs_add_new_key_tfm(
|
|
NULL, mount_crypt_stat->global_default_cipher_name,
|
|
mount_crypt_stat->global_default_cipher_key_size);
|
|
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, 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);
|
|
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;
|
|
|
|
/**
|
|
* 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_zalloc(ecryptfs_sb_info_cache,
|
|
GFP_KERNEL));
|
|
if (!ecryptfs_superblock_to_private(sb)) {
|
|
ecryptfs_printk(KERN_WARNING, "Out of memory\n");
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
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_zalloc(ecryptfs_dentry_info_cache,
|
|
GFP_KERNEL));
|
|
if (!ecryptfs_dentry_to_private(sb->s_root)) {
|
|
ecryptfs_printk(KERN_ERR,
|
|
"dentry_info_cache alloc failed\n");
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
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)
|
|
{
|
|
struct path path;
|
|
int rc;
|
|
|
|
rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
|
|
if (rc) {
|
|
ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
|
|
goto out;
|
|
}
|
|
ecryptfs_set_superblock_lower(sb, path.dentry->d_sb);
|
|
sb->s_maxbytes = path.dentry->d_sb->s_maxbytes;
|
|
sb->s_blocksize = path.dentry->d_sb->s_blocksize;
|
|
ecryptfs_set_dentry_lower(sb->s_root, path.dentry);
|
|
ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt);
|
|
rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0);
|
|
if (rc)
|
|
goto out_free;
|
|
rc = 0;
|
|
goto out;
|
|
out_free:
|
|
path_put(&path);
|
|
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 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;
|
|
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),
|
|
.ctor = inode_info_init_once,
|
|
},
|
|
{
|
|
.cache = &ecryptfs_sb_info_cache,
|
|
.name = "ecryptfs_sb_cache",
|
|
.size = sizeof(struct ecryptfs_sb_info),
|
|
},
|
|
{
|
|
.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_xattr_cache,
|
|
.name = "ecryptfs_xattr_cache",
|
|
.size = PAGE_CACHE_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),
|
|
},
|
|
{
|
|
.cache = &ecryptfs_open_req_cache,
|
|
.name = "ecryptfs_open_req_cache",
|
|
.size = sizeof(struct ecryptfs_open_req),
|
|
},
|
|
};
|
|
|
|
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);
|
|
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 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_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");
|
|
goto out_free_kmem_caches;
|
|
}
|
|
rc = do_sysfs_registration();
|
|
if (rc) {
|
|
printk(KERN_ERR "sysfs registration failed\n");
|
|
goto out_unregister_filesystem;
|
|
}
|
|
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 occured 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;
|
|
}
|
|
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_release_messaging:
|
|
ecryptfs_release_messaging();
|
|
out_destroy_kthread:
|
|
ecryptfs_destroy_kthread();
|
|
out_do_sysfs_unregistration:
|
|
do_sysfs_unregistration();
|
|
out_unregister_filesystem:
|
|
unregister_filesystem(&ecryptfs_fs_type);
|
|
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 <mhalcrow@us.ibm.com>");
|
|
MODULE_DESCRIPTION("eCryptfs");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(ecryptfs_init)
|
|
module_exit(ecryptfs_exit)
|