![Robert P. J. Day](/assets/img/avatar_default.png)
Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the corresponding "kmem_cache_zalloc()" call. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@muc.de> Cc: Roland McGrath <roland@redhat.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Greg KH <greg@kroah.com> Acked-by: Joel Becker <Joel.Becker@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Jan Kara <jack@ucw.cz> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
469 lines
14 KiB
C
469 lines
14 KiB
C
/**
|
|
* eCryptfs: Linux filesystem encryption layer
|
|
*
|
|
* Copyright (C) 1997-2004 Erez Zadok
|
|
* Copyright (C) 2001-2004 Stony Brook University
|
|
* Copyright (C) 2004-2006 International Business Machines Corp.
|
|
* Author(s): Michael A. Halcrow <mhalcrow@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/file.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/security.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/compat.h>
|
|
#include <linux/fs_stack.h>
|
|
#include "ecryptfs_kernel.h"
|
|
|
|
/**
|
|
* ecryptfs_llseek
|
|
* @file: File we are seeking in
|
|
* @offset: The offset to seek to
|
|
* @origin: 2 - offset from i_size; 1 - offset from f_pos
|
|
*
|
|
* Returns the position we have seeked to, or negative on error
|
|
*/
|
|
static loff_t ecryptfs_llseek(struct file *file, loff_t offset, int origin)
|
|
{
|
|
loff_t rv;
|
|
loff_t new_end_pos;
|
|
int rc;
|
|
int expanding_file = 0;
|
|
struct inode *inode = file->f_mapping->host;
|
|
|
|
/* If our offset is past the end of our file, we're going to
|
|
* need to grow it so we have a valid length of 0's */
|
|
new_end_pos = offset;
|
|
switch (origin) {
|
|
case 2:
|
|
new_end_pos += i_size_read(inode);
|
|
expanding_file = 1;
|
|
break;
|
|
case 1:
|
|
new_end_pos += file->f_pos;
|
|
if (new_end_pos > i_size_read(inode)) {
|
|
ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
|
|
"> i_size_read(inode)(=[0x%.16x])\n",
|
|
new_end_pos, i_size_read(inode));
|
|
expanding_file = 1;
|
|
}
|
|
break;
|
|
default:
|
|
if (new_end_pos > i_size_read(inode)) {
|
|
ecryptfs_printk(KERN_DEBUG, "new_end_pos(=[0x%.16x]) "
|
|
"> i_size_read(inode)(=[0x%.16x])\n",
|
|
new_end_pos, i_size_read(inode));
|
|
expanding_file = 1;
|
|
}
|
|
}
|
|
ecryptfs_printk(KERN_DEBUG, "new_end_pos = [0x%.16x]\n", new_end_pos);
|
|
if (expanding_file) {
|
|
rc = ecryptfs_truncate(file->f_path.dentry, new_end_pos);
|
|
if (rc) {
|
|
rv = rc;
|
|
ecryptfs_printk(KERN_ERR, "Error on attempt to "
|
|
"truncate to (higher) offset [0x%.16x];"
|
|
" rc = [%d]\n", new_end_pos, rc);
|
|
goto out;
|
|
}
|
|
}
|
|
rv = generic_file_llseek(file, offset, origin);
|
|
out:
|
|
return rv;
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_read_update_atime
|
|
*
|
|
* generic_file_read updates the atime of upper layer inode. But, it
|
|
* doesn't give us a chance to update the atime of the lower layer
|
|
* inode. This function is a wrapper to generic_file_read. It
|
|
* updates the atime of the lower level inode if generic_file_read
|
|
* returns without any errors. This is to be used only for file reads.
|
|
* The function to be used for directory reads is ecryptfs_read.
|
|
*/
|
|
static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
|
|
const struct iovec *iov,
|
|
unsigned long nr_segs, loff_t pos)
|
|
{
|
|
int rc;
|
|
struct dentry *lower_dentry;
|
|
struct vfsmount *lower_vfsmount;
|
|
struct file *file = iocb->ki_filp;
|
|
|
|
rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
|
|
/*
|
|
* Even though this is a async interface, we need to wait
|
|
* for IO to finish to update atime
|
|
*/
|
|
if (-EIOCBQUEUED == rc)
|
|
rc = wait_on_sync_kiocb(iocb);
|
|
if (rc >= 0) {
|
|
lower_dentry = ecryptfs_dentry_to_lower(file->f_path.dentry);
|
|
lower_vfsmount = ecryptfs_dentry_to_lower_mnt(file->f_path.dentry);
|
|
touch_atime(lower_vfsmount, lower_dentry);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
struct ecryptfs_getdents_callback {
|
|
void *dirent;
|
|
struct dentry *dentry;
|
|
filldir_t filldir;
|
|
int err;
|
|
int filldir_called;
|
|
int entries_written;
|
|
};
|
|
|
|
/* Inspired by generic filldir in fs/readir.c */
|
|
static int
|
|
ecryptfs_filldir(void *dirent, const char *name, int namelen, loff_t offset,
|
|
u64 ino, unsigned int d_type)
|
|
{
|
|
struct ecryptfs_crypt_stat *crypt_stat;
|
|
struct ecryptfs_getdents_callback *buf =
|
|
(struct ecryptfs_getdents_callback *)dirent;
|
|
int rc;
|
|
int decoded_length;
|
|
char *decoded_name;
|
|
|
|
crypt_stat = ecryptfs_dentry_to_private(buf->dentry)->crypt_stat;
|
|
buf->filldir_called++;
|
|
decoded_length = ecryptfs_decode_filename(crypt_stat, name, namelen,
|
|
&decoded_name);
|
|
if (decoded_length < 0) {
|
|
rc = decoded_length;
|
|
goto out;
|
|
}
|
|
rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset,
|
|
ino, d_type);
|
|
kfree(decoded_name);
|
|
if (rc >= 0)
|
|
buf->entries_written++;
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_readdir
|
|
* @file: The ecryptfs file struct
|
|
* @dirent: Directory entry
|
|
* @filldir: The filldir callback function
|
|
*/
|
|
static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir)
|
|
{
|
|
int rc;
|
|
struct file *lower_file;
|
|
struct inode *inode;
|
|
struct ecryptfs_getdents_callback buf;
|
|
|
|
lower_file = ecryptfs_file_to_lower(file);
|
|
lower_file->f_pos = file->f_pos;
|
|
inode = file->f_path.dentry->d_inode;
|
|
memset(&buf, 0, sizeof(buf));
|
|
buf.dirent = dirent;
|
|
buf.dentry = file->f_path.dentry;
|
|
buf.filldir = filldir;
|
|
retry:
|
|
buf.filldir_called = 0;
|
|
buf.entries_written = 0;
|
|
buf.err = 0;
|
|
rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf);
|
|
if (buf.err)
|
|
rc = buf.err;
|
|
if (buf.filldir_called && !buf.entries_written)
|
|
goto retry;
|
|
file->f_pos = lower_file->f_pos;
|
|
if (rc >= 0)
|
|
fsstack_copy_attr_atime(inode, lower_file->f_path.dentry->d_inode);
|
|
return rc;
|
|
}
|
|
|
|
struct kmem_cache *ecryptfs_file_info_cache;
|
|
|
|
int ecryptfs_open_lower_file(struct file **lower_file,
|
|
struct dentry *lower_dentry,
|
|
struct vfsmount *lower_mnt, int flags)
|
|
{
|
|
int rc = 0;
|
|
|
|
dget(lower_dentry);
|
|
mntget(lower_mnt);
|
|
*lower_file = dentry_open(lower_dentry, lower_mnt, flags);
|
|
if (IS_ERR(*lower_file)) {
|
|
printk(KERN_ERR "Error opening lower file for lower_dentry "
|
|
"[0x%p], lower_mnt [0x%p], and flags [0x%x]\n",
|
|
lower_dentry, lower_mnt, flags);
|
|
rc = PTR_ERR(*lower_file);
|
|
*lower_file = NULL;
|
|
goto out;
|
|
}
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
int ecryptfs_close_lower_file(struct file *lower_file)
|
|
{
|
|
fput(lower_file);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_open
|
|
* @inode: inode speciying file to open
|
|
* @file: Structure to return filled in
|
|
*
|
|
* Opens the file specified by inode.
|
|
*
|
|
* Returns zero on success; non-zero otherwise
|
|
*/
|
|
static int ecryptfs_open(struct inode *inode, struct file *file)
|
|
{
|
|
int rc = 0;
|
|
struct ecryptfs_crypt_stat *crypt_stat = NULL;
|
|
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
|
|
struct dentry *ecryptfs_dentry = file->f_path.dentry;
|
|
/* Private value of ecryptfs_dentry allocated in
|
|
* ecryptfs_lookup() */
|
|
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
|
|
struct inode *lower_inode = NULL;
|
|
struct file *lower_file = NULL;
|
|
struct vfsmount *lower_mnt;
|
|
struct ecryptfs_file_info *file_info;
|
|
int lower_flags;
|
|
|
|
/* Released in ecryptfs_release or end of function if failure */
|
|
file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
|
|
ecryptfs_set_file_private(file, file_info);
|
|
if (!file_info) {
|
|
ecryptfs_printk(KERN_ERR,
|
|
"Error attempting to allocate memory\n");
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
|
|
crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
|
|
mount_crypt_stat = &ecryptfs_superblock_to_private(
|
|
ecryptfs_dentry->d_sb)->mount_crypt_stat;
|
|
mutex_lock(&crypt_stat->cs_mutex);
|
|
if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED)) {
|
|
ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
|
|
/* Policy code enabled in future release */
|
|
ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED);
|
|
ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
|
|
}
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
lower_flags = file->f_flags;
|
|
if ((lower_flags & O_ACCMODE) == O_WRONLY)
|
|
lower_flags = (lower_flags & O_ACCMODE) | O_RDWR;
|
|
if (file->f_flags & O_APPEND)
|
|
lower_flags &= ~O_APPEND;
|
|
lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
|
|
/* Corresponding fput() in ecryptfs_release() */
|
|
if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
|
|
lower_flags))) {
|
|
ecryptfs_printk(KERN_ERR, "Error opening lower file\n");
|
|
goto out_puts;
|
|
}
|
|
ecryptfs_set_file_lower(file, lower_file);
|
|
/* Isn't this check the same as the one in lookup? */
|
|
lower_inode = lower_dentry->d_inode;
|
|
if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
|
|
ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
|
|
ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
|
|
rc = 0;
|
|
goto out;
|
|
}
|
|
mutex_lock(&crypt_stat->cs_mutex);
|
|
if (i_size_read(lower_inode) < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) {
|
|
if (!(mount_crypt_stat->flags
|
|
& ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
|
|
rc = -EIO;
|
|
printk(KERN_WARNING "Attempt to read file that is "
|
|
"not in a valid eCryptfs format, and plaintext "
|
|
"passthrough mode is not enabled; returning "
|
|
"-EIO\n");
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
goto out_puts;
|
|
}
|
|
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
|
|
rc = 0;
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
goto out;
|
|
} else if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
|
|
ECRYPTFS_POLICY_APPLIED)
|
|
|| !ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
|
|
ECRYPTFS_KEY_VALID)) {
|
|
rc = ecryptfs_read_headers(ecryptfs_dentry, lower_file);
|
|
if (rc) {
|
|
ecryptfs_printk(KERN_DEBUG,
|
|
"Valid headers not found\n");
|
|
if (!(mount_crypt_stat->flags
|
|
& ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
|
|
rc = -EIO;
|
|
printk(KERN_WARNING "Attempt to read file that "
|
|
"is not in a valid eCryptfs format, "
|
|
"and plaintext passthrough mode is not "
|
|
"enabled; returning -EIO\n");
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
goto out_puts;
|
|
}
|
|
ECRYPTFS_CLEAR_FLAG(crypt_stat->flags,
|
|
ECRYPTFS_ENCRYPTED);
|
|
rc = 0;
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
goto out;
|
|
}
|
|
}
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
|
|
"size: [0x%.16x]\n", inode, inode->i_ino,
|
|
i_size_read(inode));
|
|
ecryptfs_set_file_lower(file, lower_file);
|
|
goto out;
|
|
out_puts:
|
|
mntput(lower_mnt);
|
|
dput(lower_dentry);
|
|
kmem_cache_free(ecryptfs_file_info_cache,
|
|
ecryptfs_file_to_private(file));
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static int ecryptfs_flush(struct file *file, fl_owner_t td)
|
|
{
|
|
int rc = 0;
|
|
struct file *lower_file = NULL;
|
|
|
|
lower_file = ecryptfs_file_to_lower(file);
|
|
if (lower_file->f_op && lower_file->f_op->flush)
|
|
rc = lower_file->f_op->flush(lower_file, td);
|
|
return rc;
|
|
}
|
|
|
|
static int ecryptfs_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct file *lower_file = ecryptfs_file_to_lower(file);
|
|
struct ecryptfs_file_info *file_info = ecryptfs_file_to_private(file);
|
|
struct inode *lower_inode = ecryptfs_inode_to_lower(inode);
|
|
int rc;
|
|
|
|
if ((rc = ecryptfs_close_lower_file(lower_file))) {
|
|
printk(KERN_ERR "Error closing lower_file\n");
|
|
goto out;
|
|
}
|
|
inode->i_blocks = lower_inode->i_blocks;
|
|
kmem_cache_free(ecryptfs_file_info_cache, file_info);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static int
|
|
ecryptfs_fsync(struct file *file, struct dentry *dentry, int datasync)
|
|
{
|
|
struct file *lower_file = ecryptfs_file_to_lower(file);
|
|
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
|
|
struct inode *lower_inode = lower_dentry->d_inode;
|
|
int rc = -EINVAL;
|
|
|
|
if (lower_inode->i_fop->fsync) {
|
|
mutex_lock(&lower_inode->i_mutex);
|
|
rc = lower_inode->i_fop->fsync(lower_file, lower_dentry,
|
|
datasync);
|
|
mutex_unlock(&lower_inode->i_mutex);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static int ecryptfs_fasync(int fd, struct file *file, int flag)
|
|
{
|
|
int rc = 0;
|
|
struct file *lower_file = NULL;
|
|
|
|
lower_file = ecryptfs_file_to_lower(file);
|
|
if (lower_file->f_op && lower_file->f_op->fasync)
|
|
rc = lower_file->f_op->fasync(fd, lower_file, flag);
|
|
return rc;
|
|
}
|
|
|
|
static ssize_t ecryptfs_sendfile(struct file *file, loff_t * ppos,
|
|
size_t count, read_actor_t actor, void *target)
|
|
{
|
|
struct file *lower_file = NULL;
|
|
int rc = -EINVAL;
|
|
|
|
lower_file = ecryptfs_file_to_lower(file);
|
|
if (lower_file->f_op && lower_file->f_op->sendfile)
|
|
rc = lower_file->f_op->sendfile(lower_file, ppos, count,
|
|
actor, target);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int ecryptfs_ioctl(struct inode *inode, struct file *file,
|
|
unsigned int cmd, unsigned long arg);
|
|
|
|
const struct file_operations ecryptfs_dir_fops = {
|
|
.readdir = ecryptfs_readdir,
|
|
.ioctl = ecryptfs_ioctl,
|
|
.mmap = generic_file_mmap,
|
|
.open = ecryptfs_open,
|
|
.flush = ecryptfs_flush,
|
|
.release = ecryptfs_release,
|
|
.fsync = ecryptfs_fsync,
|
|
.fasync = ecryptfs_fasync,
|
|
.sendfile = ecryptfs_sendfile,
|
|
};
|
|
|
|
const struct file_operations ecryptfs_main_fops = {
|
|
.llseek = ecryptfs_llseek,
|
|
.read = do_sync_read,
|
|
.aio_read = ecryptfs_read_update_atime,
|
|
.write = do_sync_write,
|
|
.aio_write = generic_file_aio_write,
|
|
.readdir = ecryptfs_readdir,
|
|
.ioctl = ecryptfs_ioctl,
|
|
.mmap = generic_file_mmap,
|
|
.open = ecryptfs_open,
|
|
.flush = ecryptfs_flush,
|
|
.release = ecryptfs_release,
|
|
.fsync = ecryptfs_fsync,
|
|
.fasync = ecryptfs_fasync,
|
|
.sendfile = ecryptfs_sendfile,
|
|
};
|
|
|
|
static int
|
|
ecryptfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int rc = 0;
|
|
struct file *lower_file = NULL;
|
|
|
|
if (ecryptfs_file_to_private(file))
|
|
lower_file = ecryptfs_file_to_lower(file);
|
|
if (lower_file && lower_file->f_op && lower_file->f_op->ioctl)
|
|
rc = lower_file->f_op->ioctl(ecryptfs_inode_to_lower(inode),
|
|
lower_file, cmd, arg);
|
|
else
|
|
rc = -ENOTTY;
|
|
return rc;
|
|
}
|