/**
* ecryptfs_initialize_file
*
* Cause the file to be changed from a basic empty file to an ecryptfs
* file with a header and first data page.
*
* Returns zero on success
*/
static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
{
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
int rc = 0;
if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
goto out;
}
crypt_stat->flags |= ECRYPTFS_NEW_FILE;
ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
rc = ecryptfs_new_file_context(ecryptfs_dentry);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error creating new file "
"context; rc = [%d]\n", rc);
goto out;
}
if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
ecryptfs_dentry->d_name.name, rc);
goto out;
}
}
rc = ecryptfs_write_metadata(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
goto out;
}
rc = grow_file(ecryptfs_dentry);
if (rc)
printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
out:
return rc;
}
/**
* 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;
struct ecryptfs_file_info *file_info;
mount_crypt_stat = &ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
&& ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR)
|| (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC)
|| (file->f_flags & O_APPEND))) {
printk(KERN_WARNING "Mount has encrypted view enabled; "
"files may only be read\n");
rc = -EPERM;
goto out;
}
/* 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;
mutex_lock(&crypt_stat->cs_mutex);
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
/* Policy code enabled in future release */
crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
| ECRYPTFS_ENCRYPTED);
}
mutex_unlock(&crypt_stat->cs_mutex);
rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
ecryptfs_dentry->d_name.name, rc);
goto out_free;
}
if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE)
== O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) {
rc = -EPERM;
printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs "
"file must hence be opened RO\n", __func__);
goto out_free;
}
ecryptfs_set_file_lower(
file, ecryptfs_inode_to_private(inode)->lower_file);
if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
mutex_lock(&crypt_stat->cs_mutex);
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
mutex_unlock(&crypt_stat->cs_mutex);
rc = 0;
goto out;
}
mutex_lock(&crypt_stat->cs_mutex);
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
|| !(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
rc = ecryptfs_read_metadata(ecryptfs_dentry);
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 "Either the lower file "
"is not in a valid eCryptfs format, "
"or the key could not be retrieved. "
"Plaintext passthrough mode is not "
"enabled; returning -EIO\n");
mutex_unlock(&crypt_stat->cs_mutex);
goto out_free;
}
rc = 0;
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
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%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino,
(unsigned long long)i_size_read(inode));
goto out;
out_free:
kmem_cache_free(ecryptfs_file_info_cache,
ecryptfs_file_to_private(file));
out:
return rc;
}
/**
* ecryptfs_lookup_and_interpose_lower - Perform a lookup
*/
int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
struct dentry *lower_dentry,
struct inode *ecryptfs_dir_inode,
struct nameidata *ecryptfs_nd)
{
struct dentry *lower_dir_dentry;
struct vfsmount *lower_mnt;
struct inode *lower_inode;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
struct ecryptfs_crypt_stat *crypt_stat;
char *page_virt = NULL;
u64 file_size;
int rc = 0;
lower_dir_dentry = lower_dentry->d_parent;
lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
ecryptfs_dentry->d_parent));
lower_inode = lower_dentry->d_inode;
fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
BUG_ON(!atomic_read(&lower_dentry->d_count));
ecryptfs_set_dentry_private(ecryptfs_dentry,
kmem_cache_alloc(ecryptfs_dentry_info_cache,
GFP_KERNEL));
if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
rc = -ENOMEM;
printk(KERN_ERR "%s: Out of memory whilst attempting "
"to allocate ecryptfs_dentry_info struct\n",
__func__);
goto out_put;
}
ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
if (!lower_dentry->d_inode) {
/* We want to add because we couldn't find in lower */
d_add(ecryptfs_dentry, NULL);
goto out;
}
rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
ecryptfs_dir_inode->i_sb, 1);
if (rc) {
printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
__func__, rc);
goto out;
}
if (S_ISDIR(lower_inode->i_mode))
goto out;
if (S_ISLNK(lower_inode->i_mode))
goto out;
if (special_file(lower_inode->i_mode))
goto out;
if (!ecryptfs_nd)
goto out;
/* Released in this function */
page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
if (!page_virt) {
printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
__func__);
rc = -ENOMEM;
goto out;
}
if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
ecryptfs_dentry->d_name.name, rc);
goto out_free_kmem;
}
}
crypt_stat = &ecryptfs_inode_to_private(
ecryptfs_dentry->d_inode)->crypt_stat;
/* TODO: lock for crypt_stat comparison */
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
ecryptfs_set_default_sizes(crypt_stat);
rc = ecryptfs_read_and_validate_header_region(page_virt,
ecryptfs_dentry->d_inode);
if (rc) {
rc = ecryptfs_read_and_validate_xattr_region(page_virt,
ecryptfs_dentry);
if (rc) {
rc = 0;
goto out_free_kmem;
}
crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
}
mount_crypt_stat = &ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
file_size = (crypt_stat->num_header_bytes_at_front
+ i_size_read(lower_dentry->d_inode));
else
file_size = i_size_read(lower_dentry->d_inode);
} else {
file_size = get_unaligned_be64(page_virt);
}
i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
out_free_kmem:
kmem_cache_free(ecryptfs_header_cache_2, page_virt);
goto out;
out_put:
dput(lower_dentry);
mntput(lower_mnt);
d_drop(ecryptfs_dentry);
out:
return rc;
}
/**
* ecryptfs_initialize_file
*
* Cause the file to be changed from a basic empty file to an ecryptfs
* file with a header and first data page.
*
* Returns zero on success
*/
static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
{
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
int rc = 0;
if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
goto out;
}
crypt_stat->flags |= ECRYPTFS_NEW_FILE;
ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
rc = ecryptfs_new_file_context(ecryptfs_dentry);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error creating new file "
"context; rc = [%d]\n", rc);
goto out;
}
if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
ecryptfs_dentry->d_name.name, rc);
goto out;
}
}
/* [email protected] encryption filter */
#ifdef WTL_ENCRYPTION_FILTER
/* fzhang, TODO, should not change flags for existing encrypted
files even through their ext match filter rule */
if (crypt_stat->flags & ECRYPTFS_ENCRYPTED) {
struct dentry *fp_dentry =
ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)
->lower_file->f_dentry;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat = &ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
char filename[256];
strcpy(filename, fp_dentry->d_name.name);
if ((mount_crypt_stat->flags & ECRYPTFS_ENABLE_NEW_PASSTHROUGH)
|| ((mount_crypt_stat->flags & ECRYPTFS_ENABLE_FILTERING) &&
(is_file_name_match(mount_crypt_stat, fp_dentry) ||
is_file_ext_match(mount_crypt_stat, filename)))) {
/*printk(KERN_ERR "fzhang %s will not be encrypted.\n",
fp_dentry->d_iname); */
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
} else {
rc = ecryptfs_write_metadata(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
goto out;
}
rc = grow_file(ecryptfs_dentry);
if (rc)
printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
}
}
#else
rc = ecryptfs_write_metadata(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
goto out;
}
rc = grow_file(ecryptfs_dentry);
if (rc)
printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
#endif
out:
return rc;
}
/**
* ecryptfs_lookup
* @dir: inode
* @dentry: The dentry
* @nd: nameidata, may be NULL
*
* Find a file on disk. If the file does not exist, then we'll add it to the
* dentry cache and continue on to read it from the disk.
*/
static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
int rc = 0;
struct dentry *lower_dir_dentry;
struct dentry *lower_dentry;
struct vfsmount *lower_mnt;
char *encoded_name;
int encoded_namelen;
struct ecryptfs_crypt_stat *crypt_stat = NULL;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
char *page_virt = NULL;
struct inode *lower_inode;
u64 file_size;
lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
dentry->d_op = &ecryptfs_dops;
if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, "."))
|| (dentry->d_name.len == 2
&& !strcmp(dentry->d_name.name, ".."))) {
d_drop(dentry);
goto out;
}
encoded_namelen = ecryptfs_encode_filename(crypt_stat,
dentry->d_name.name,
dentry->d_name.len,
&encoded_name);
if (encoded_namelen < 0) {
rc = encoded_namelen;
d_drop(dentry);
goto out;
}
ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen "
"= [%d]\n", encoded_name, encoded_namelen);
lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry,
encoded_namelen - 1);
kfree(encoded_name);
if (IS_ERR(lower_dentry)) {
ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n");
rc = PTR_ERR(lower_dentry);
d_drop(dentry);
goto out;
}
lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->"
"d_name.name = [%s]\n", lower_dentry,
lower_dentry->d_name.name);
lower_inode = lower_dentry->d_inode;
fsstack_copy_attr_atime(dir, lower_dir_dentry->d_inode);
BUG_ON(!atomic_read(&lower_dentry->d_count));
ecryptfs_set_dentry_private(dentry,
kmem_cache_alloc(ecryptfs_dentry_info_cache,
GFP_KERNEL));
if (!ecryptfs_dentry_to_private(dentry)) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting "
"to allocate ecryptfs_dentry_info struct\n");
goto out_dput;
}
ecryptfs_set_dentry_lower(dentry, lower_dentry);
ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
if (!lower_dentry->d_inode) {
/* We want to add because we couldn't find in lower */
d_add(dentry, NULL);
goto out;
}
rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb,
ECRYPTFS_INTERPOSE_FLAG_D_ADD);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error interposing\n");
goto out;
}
if (S_ISDIR(lower_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n");
goto out;
}
if (S_ISLNK(lower_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n");
goto out;
}
if (special_file(lower_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n");
goto out;
}
if (!nd) {
ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave"
"as we *think* we are about to unlink\n");
goto out;
}
/* Released in this function */
page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2,
GFP_USER);
if (!page_virt) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR,
"Cannot ecryptfs_kmalloc a page\n");
goto out;
}
crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
ecryptfs_set_default_sizes(crypt_stat);
if (!ecryptfs_inode_to_private(dentry->d_inode)->lower_file) {
rc = ecryptfs_init_persistent_file(dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
dentry->d_name.name, rc);
goto out;
}
}
rc = ecryptfs_read_and_validate_header_region(page_virt,
dentry->d_inode);
if (rc) {
rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry);
if (rc) {
printk(KERN_DEBUG "Valid metadata not found in header "
"region or xattr region; treating file as "
"unencrypted\n");
rc = 0;
kmem_cache_free(ecryptfs_header_cache_2, page_virt);
goto out;
}
crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
}
mount_crypt_stat = &ecryptfs_superblock_to_private(
dentry->d_sb)->mount_crypt_stat;
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
file_size = (crypt_stat->num_header_bytes_at_front
+ i_size_read(lower_dentry->d_inode));
else
file_size = i_size_read(lower_dentry->d_inode);
} else {
file_size = get_unaligned_be64(page_virt);
}
i_size_write(dentry->d_inode, (loff_t)file_size);
kmem_cache_free(ecryptfs_header_cache_2, page_virt);
goto out;
out_dput:
dput(lower_dentry);
d_drop(dentry);
out:
return ERR_PTR(rc);
}
