From: Phillip Hellewell eCryptfs file operations. Includes code to read header information from the underyling file when needed. Signed-off-by: Phillip Hellewell Signed-off-by: Michael Halcrow DESC ecryptfs: Remove ``NULL =='' syntax EDESC From: Mike Halcrow Remove ``NULL =='' syntax; easier on the eyes. Signed-off-by: Michael Halcrow DESC ecryptfs: Remove extraneous read of inode size from header EDESC From: Mike Halcrow Christoph Hellwig pointed out that the inode is not live at this point in ecryptfs_open(), and so this entire function is pointless. Signed-off-by: Michael Halcrow DESC ecryptfs fix EDESC From: Michael Halcrow Signed-off-by: Michael Halcrow DESC ecryptfs: fix premature release of file_info memory EDESC From: Michael Halcrow The file_info struct is being released, and then one of its members is referenced from the released memory. This patch cleans up the function and moves the release so that it occurs after the reference. Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton --- fs/ecryptfs/file.c | 572 +++++++++++++++++++++++++++++++++++++++++++ fs/ecryptfs/main.c | 2 2 files changed, 573 insertions(+), 1 deletion(-) diff -puN /dev/null fs/ecryptfs/file.c --- /dev/null +++ a/fs/ecryptfs/file.c @@ -0,0 +1,572 @@ +/** + * 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 + * Michael C. Thompson + * + * 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 +#include +#include +#include +#include +#include +#include +#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_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 file *file, char __user * buf, + size_t count, loff_t * ppos) +{ + int rc; + struct dentry *lower_dentry; + struct vfsmount *lower_vfsmount; + + rc = generic_file_read(file, buf, count, ppos); + if (rc >= 0) { + lower_dentry = ecryptfs_dentry_to_lower(file->f_dentry); + lower_vfsmount = ecryptfs_superblock_to_private( + file->f_dentry->d_inode->i_sb)->lower_mnt; + 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, + ino_t 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); + inode = file->f_dentry->d_inode; + memset(&buf, 0, sizeof(buf)); + buf.dirent = dirent; + buf.dentry = file->f_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) + ecryptfs_copy_attr_atime(inode, lower_file->f_dentry->d_inode); + return rc; +} + +struct kmem_cache *ecryptfs_file_info_cache; + +/** + * 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 dentry *ecryptfs_dentry = file->f_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; + int lower_flags; + + /* Released in ecryptfs_release or end of function if failure */ + ecryptfs_set_file_private(file, + kmem_cache_alloc(ecryptfs_file_info_cache, + SLAB_KERNEL)); + if (!ecryptfs_file_to_private(file)) { + 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; + 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); + } + /* This mntget & dget is undone via fput when the file is released */ + dget(lower_dentry); + 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_superblock_to_private(inode->i_sb)->lower_mnt; + mntget(lower_mnt); + /* Corresponding fput() in ecryptfs_release() */ + lower_file = dentry_open(lower_dentry, lower_mnt, lower_flags); + if (IS_ERR(lower_file)) { + rc = PTR_ERR(lower_file); + 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; + } + if (i_size_read(lower_inode) == 0) { + ecryptfs_printk(KERN_EMERG, "Zero-length lower file; " + "ecryptfs_create() had a problem?\n"); + rc = -ENOENT; + goto out_puts; + } 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"); + ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, + ECRYPTFS_ENCRYPTED); + /* At this point, we could just move on and + * have the encrypted data passed through + * as-is to userspace. For release 0.1, we are + * going to default to -EIO. */ + rc = -EIO; + goto out_puts; + } + } + 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); + + fput(lower_file); + inode->i_blocks = lower_inode->i_blocks; + kmem_cache_free(ecryptfs_file_info_cache, file_info); + return 0; +} + +static int +ecryptfs_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + int rc = -EINVAL; + struct file *lower_file = NULL; + struct dentry *lower_dentry; + + if (!file) { + lower_dentry = ecryptfs_dentry_to_lower(dentry); + if (lower_dentry->d_inode->i_fop + && lower_dentry->d_inode->i_fop->fsync) { + mutex_lock(&lower_dentry->d_inode->i_mutex); + rc = lower_dentry->d_inode->i_fop->fsync(lower_file, + lower_dentry, + datasync); + mutex_unlock(&lower_dentry->d_inode->i_mutex); + } + } else { + if (!ecryptfs_file_to_private(file)) { + rc = -EINVAL; + ecryptfs_printk(KERN_ERR, "ecryptfs_file_to_private" + "(file=[%p]) is NULL\n", file); + goto out; + } + lower_file = ecryptfs_file_to_lower(file); + lower_dentry = ecryptfs_dentry_to_lower(dentry); + if (lower_file->f_op && lower_file->f_op->fsync) { + mutex_lock(&lower_dentry->d_inode->i_mutex); + rc = lower_file->f_op->fsync(lower_file, lower_dentry, + datasync); + mutex_unlock(&lower_dentry->d_inode->i_mutex); + } + } +out: + return rc; +} + +static void locks_delete_block(struct file_lock *waiter) +{ + lock_kernel(); + list_del_init(&waiter->fl_block); + list_del_init(&waiter->fl_link); + waiter->fl_next = NULL; + unlock_kernel(); +} + +static int ecryptfs_posix_lock(struct file *file, struct file_lock *fl, int cmd) +{ + int rc; + +lock_file: + rc = posix_lock_file(file, fl); + if ((rc != -EAGAIN) || (cmd == F_SETLK)) + goto out; + rc = wait_event_interruptible(fl->fl_wait, !fl->fl_next); + if (!rc) + goto lock_file; + locks_delete_block(fl); +out: + return rc; +} + +static int ecryptfs_setlk(struct file *file, int cmd, struct file_lock *fl) +{ + int rc = -EINVAL; + struct inode *inode, *lower_inode; + struct file *lower_file = NULL; + + lower_file = ecryptfs_file_to_lower(file); + inode = file->f_dentry->d_inode; + lower_inode = lower_file->f_dentry->d_inode; + /* Don't allow mandatory locks on files that may be memory mapped + * and shared. */ + if (IS_MANDLOCK(lower_inode) && + (lower_inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID && + mapping_writably_mapped(lower_file->f_mapping)) { + rc = -EAGAIN; + goto out; + } + if (cmd == F_SETLKW) + fl->fl_flags |= FL_SLEEP; + rc = -EBADF; + switch (fl->fl_type) { + case F_RDLCK: + if (!(lower_file->f_mode & FMODE_READ)) + goto out; + break; + case F_WRLCK: + if (!(lower_file->f_mode & FMODE_WRITE)) + goto out; + break; + case F_UNLCK: + break; + default: + rc = -EINVAL; + goto out; + } + fl->fl_file = lower_file; + rc = security_file_lock(lower_file, fl->fl_type); + if (rc) + goto out; + if (lower_file->f_op && lower_file->f_op->lock) { + rc = lower_file->f_op->lock(lower_file, cmd, fl); + if (rc) + goto out; + goto upper_lock; + } + rc = ecryptfs_posix_lock(lower_file, fl, cmd); + if (rc) + goto out; +upper_lock: + fl->fl_file = file; + rc = ecryptfs_posix_lock(file, fl, cmd); + if (rc) { + fl->fl_type = F_UNLCK; + fl->fl_file = lower_file; + ecryptfs_posix_lock(lower_file, fl, cmd); + } +out: + return rc; +} + +static int ecryptfs_getlk(struct file *file, struct file_lock *fl) +{ + struct file_lock cfl; + struct file_lock *tempfl = NULL; + int rc = 0; + + if (file->f_op && file->f_op->lock) { + rc = file->f_op->lock(file, F_GETLK, fl); + if (rc < 0) + goto out; + } else + tempfl = (posix_test_lock(file, fl, &cfl) ? &cfl : NULL); + if (!tempfl) + fl->fl_type = F_UNLCK; + else + memcpy(fl, tempfl, sizeof(struct file_lock)); +out: + return rc; +} + +static int ecryptfs_fasync(int fd, struct file *file, int flag) +{ + int rc = 0; + struct file *lower_file = NULL; + + if (NULL != ecryptfs_file_to_private(file)) + lower_file = ecryptfs_file_to_lower(file); + else { + rc = -EINVAL; + goto out; + } + if (lower_file->f_op && lower_file->f_op->fasync) + rc = lower_file->f_op->fasync(fd, lower_file, flag); +out: + return rc; +} + +static int ecryptfs_lock(struct file *file, int cmd, struct file_lock *fl) +{ + int rc = 0; + struct file *lower_file = NULL; + + if (ecryptfs_file_to_private(file)) + lower_file = ecryptfs_file_to_lower(file); + ASSERT(lower_file); + rc = -EINVAL; + if (!fl) + goto out; + fl->fl_file = lower_file; + switch (cmd) { + case F_GETLK: + case F_GETLK64: + rc = ecryptfs_getlk(lower_file, fl); + break; + case F_SETLK: + case F_SETLKW: + case F_SETLK64: + case F_SETLKW64: + fl->fl_file = file; + rc = ecryptfs_setlk(file, cmd, fl); + break; + default: + rc = -EINVAL; + } + fl->fl_file = file; +out: + 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; + + if (ecryptfs_file_to_private(file)) + lower_file = ecryptfs_file_to_lower(file); + ASSERT(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, + .lock = ecryptfs_lock, + .sendfile = ecryptfs_sendfile, +}; + +const struct file_operations ecryptfs_main_fops = { + .llseek = ecryptfs_llseek, + .read = ecryptfs_read_update_atime, + .write = generic_file_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, + .lock = ecryptfs_lock, + .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; +} diff -puN fs/ecryptfs/main.c~ecryptfs-file-operations fs/ecryptfs/main.c --- a/fs/ecryptfs/main.c~ecryptfs-file-operations +++ a/fs/ecryptfs/main.c @@ -98,7 +98,7 @@ int ecryptfs_interpose(struct dentry *lo rc = -ENOMEM; goto out; } - if (NULL == ecryptfs_inode_to_lower(inode)) + if (!ecryptfs_inode_to_lower(inode)) ecryptfs_set_inode_lower(inode, igrab(lower_inode)); if (S_ISLNK(lower_inode->i_mode)) inode->i_op = &ecryptfs_symlink_iops; _