--- /dev/null
+/**
+ * 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_alloc(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;
+ }
+ memset(file_info, 0, sizeof(*file_info));
+ 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;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff