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eCryptfs: Filename Encryption: filldir, lookup, and readlink

Browse source 
Make the requisite modifications to ecryptfs_filldir(), ecryptfs_lookup(),
and ecryptfs_readlink() to call out to filename encryption functions.
Propagate filename encryption policy flags from mount-wide crypt_stat to
inode crypt_stat.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Halcrow 2009-01-06 14:42:00 -08:00 committed by Linus Torvalds
parent 51ca58dcc9
commit addd65ad8d
4 changed files with 195 additions and 242 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

107
fs/ecryptfs/crypto.c
View file

@ -924,6 +924,15 @@ static void ecryptfs_copy_mount_wide_flags_to_inode_flags(
crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED;
if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
crypt_stat->flags |= ECRYPTFS_ENCRYPT_FILENAMES;
if (mount_crypt_stat->flags
& ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK)
crypt_stat->flags |= ECRYPTFS_ENCFN_USE_MOUNT_FNEK;
else if (mount_crypt_stat->flags
& ECRYPTFS_GLOBAL_ENCFN_USE_FEK)
crypt_stat->flags |= ECRYPTFS_ENCFN_USE_FEK;
}
}
static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs(
@ -1060,7 +1069,8 @@ struct ecryptfs_flag_map_elem {
static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = {
{0x00000001, ECRYPTFS_ENABLE_HMAC},
{0x00000002, ECRYPTFS_ENCRYPTED},
{0x00000004, ECRYPTFS_METADATA_IN_XATTR}
{0x00000004, ECRYPTFS_METADATA_IN_XATTR},
{0x00000008, ECRYPTFS_ENCRYPT_FILENAMES}
};
/**
@ -1213,6 +1223,8 @@ int ecryptfs_read_and_validate_header_region(char *data,
&(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
int rc;
if (crypt_stat->extent_size == 0)
crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE;
rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size,
ecryptfs_inode);
if (rc) {
@ -1222,7 +1234,6 @@ int ecryptfs_read_and_validate_header_region(char *data,
}
if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) {
rc = -EINVAL;
ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n");
}
out:
return rc;
@ -1628,98 +1639,6 @@ out:
return rc;
}
/**
* ecryptfs_encode_filename - converts a plaintext file name to cipher text
* @crypt_stat: The crypt_stat struct associated with the file anem to encode
* @name: The plaintext name
* @length: The length of the plaintext
* @encoded_name: The encypted name
*
* Encrypts and encodes a filename into something that constitutes a
* valid filename for a filesystem, with printable characters.
*
* We assume that we have a properly initialized crypto context,
* pointed to by crypt_stat->tfm.
*
* TODO: Implement filename decoding and decryption here, in place of
* memcpy. We are keeping the framework around for now to (1)
* facilitate testing of the components needed to implement filename
* encryption and (2) to provide a code base from which other
* developers in the community can easily implement this feature.
*
* Returns the length of encoded filename; negative if error
*/
int
ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat,
const char *name, int length, char **encoded_name)
{
int error = 0;
(*encoded_name) = kmalloc(length + 2, GFP_KERNEL);
if (!(*encoded_name)) {
error = -ENOMEM;
goto out;
}
/* TODO: Filename encryption is a scheduled feature for a
* future version of eCryptfs. This function is here only for
* the purpose of providing a framework for other developers
* to easily implement filename encryption. Hint: Replace this
* memcpy() with a call to encrypt and encode the
* filename, the set the length accordingly. */
memcpy((void *)(*encoded_name), (void *)name, length);
(*encoded_name)[length] = '\0';
error = length + 1;
out:
return error;
}
/**
* ecryptfs_decode_filename - converts the cipher text name to plaintext
* @crypt_stat: The crypt_stat struct associated with the file
* @name: The filename in cipher text
* @length: The length of the cipher text name
* @decrypted_name: The plaintext name
*
* Decodes and decrypts the filename.
*
* We assume that we have a properly initialized crypto context,
* pointed to by crypt_stat->tfm.
*
* TODO: Implement filename decoding and decryption here, in place of
* memcpy. We are keeping the framework around for now to (1)
* facilitate testing of the components needed to implement filename
* encryption and (2) to provide a code base from which other
* developers in the community can easily implement this feature.
*
* Returns the length of decoded filename; negative if error
*/
int
ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat,
const char *name, int length, char **decrypted_name)
{
int error = 0;
(*decrypted_name) = kmalloc(length + 2, GFP_KERNEL);
if (!(*decrypted_name)) {
error = -ENOMEM;
goto out;
}
/* TODO: Filename encryption is a scheduled feature for a
* future version of eCryptfs. This function is here only for
* the purpose of providing a framework for other developers
* to easily implement filename encryption. Hint: Replace this
* memcpy() with a call to decode and decrypt the
* filename, the set the length accordingly. */
memcpy((void *)(*decrypted_name), (void *)name, length);
(*decrypted_name)[length + 1] = '\0'; /* Only for convenience
* in printing out the
* string in debug
* messages */
error = length;
out:
return error;
}
/**
* ecryptfs_encrypt_filename - encrypt filename
*

6
fs/ecryptfs/ecryptfs_kernel.h
View file

@ -627,12 +627,6 @@ int ecryptfs_decode_and_decrypt_filename(char **decrypted_name,
struct dentry *ecryptfs_dentry,
const char *name, size_t name_size);
int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
int ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat,
const char *name, int length,
char **decrypted_name);
int ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat,
const char *name, int length,
char **encoded_name);
int ecryptfs_encrypt_and_encode_filename(
char **encoded_name,
size_t *encoded_name_size,

30
fs/ecryptfs/file.c
View file

@ -77,27 +77,27 @@ struct ecryptfs_getdents_callback {
/* Inspired by generic filldir in fs/readdir.c */
static int
ecryptfs_filldir(void *dirent, const char *name, int namelen, loff_t offset,
u64 ino, unsigned int d_type)
ecryptfs_filldir(void *dirent, const char *lower_name, int lower_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 name_size;
char *name;
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;
rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
buf->dentry, lower_name,
lower_namelen);
if (rc) {
printk(KERN_ERR "%s: Error attempting to decode and decrypt "
"filename [%s]; rc = [%d]\n", __func__, lower_name,
rc);
goto out;
}
rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset,
ino, d_type);
kfree(decoded_name);
rc = buf->filldir(buf->dirent, name, name_size, offset, ino, d_type);
kfree(name);
if (rc >= 0)
buf->entries_written++;
out:
@ -106,8 +106,8 @@ out:
/**
* ecryptfs_readdir
* @file: The ecryptfs file struct
* @dirent: Directory entry
* @file: The eCryptfs directory file
* @dirent: Directory entry handle
* @filldir: The filldir callback function
*/
static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir)

294
fs/ecryptfs/inode.c
View file

@ -228,8 +228,7 @@ ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
{
int rc;
/* ecryptfs_do_create() calls ecryptfs_interpose(), which opens
* the crypt_stat->lower_file (persistent file) */
/* ecryptfs_do_create() calls ecryptfs_interpose() */
rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
if (unlikely(rc)) {
ecryptfs_printk(KERN_WARNING, "Failed to create file in"
@ -244,141 +243,91 @@ out:
}
/**
* 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.
* ecryptfs_lookup_and_interpose_lower - Perform a lookup
*/
static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
struct dentry *lower_dentry,
struct ecryptfs_crypt_stat *crypt_stat,
struct inode *ecryptfs_dir_inode,
struct nameidata *ecryptfs_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 inode *lower_inode;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
char *page_virt = NULL;
struct inode *lower_inode;
u64 file_size;
int rc = 0;
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_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(dir, lower_dir_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(dentry,
ecryptfs_set_dentry_private(ecryptfs_dentry,
kmem_cache_alloc(ecryptfs_dentry_info_cache,
GFP_KERNEL));
if (!ecryptfs_dentry_to_private(dentry)) {
if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting "
"to allocate ecryptfs_dentry_info struct\n");
printk(KERN_ERR "%s: Out of memory whilst attempting "
"to allocate ecryptfs_dentry_info struct\n",
__func__);
goto out_dput;
}
ecryptfs_set_dentry_lower(dentry, lower_dentry);
ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
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(dentry, NULL);
d_add(ecryptfs_dentry, NULL);
goto out;
}
rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb,
ECRYPTFS_INTERPOSE_FLAG_D_ADD);
rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
ecryptfs_dir_inode->i_sb, 1);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error interposing\n");
printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
__func__, rc);
goto out;
}
if (S_ISDIR(lower_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n");
if (S_ISDIR(lower_inode->i_mode))
goto out;
}
if (S_ISLNK(lower_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n");
if (S_ISLNK(lower_inode->i_mode))
goto out;
}
if (special_file(lower_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n");
if (special_file(lower_inode->i_mode))
goto out;
}
if (!nd) {
ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave"
"as we *think* we are about to unlink\n");
if (!ecryptfs_nd)
goto out;
}
/* Released in this function */
page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2,
GFP_USER);
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;
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 (!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__,
dentry->d_name.name, rc);
goto out;
ecryptfs_dentry->d_name.name, rc);
goto out_free_kmem;
}
}
rc = ecryptfs_read_and_validate_header_region(page_virt,
dentry->d_inode);
ecryptfs_dentry->d_inode);
if (rc) {
rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry);
rc = ecryptfs_read_and_validate_xattr_region(page_virt,
ecryptfs_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;
goto out_free_kmem;
}
crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
}
mount_crypt_stat = &ecryptfs_superblock_to_private(
dentry->d_sb)->mount_crypt_stat;
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
@ -388,14 +337,103 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
} else {
file_size = get_unaligned_be64(page_virt);
}
i_size_write(dentry->d_inode, (loff_t)file_size);
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_dput:
dput(lower_dentry);
d_drop(dentry);
d_drop(ecryptfs_dentry);
out:
return rc;
}
/**
* ecryptfs_lookup
* @ecryptfs_dir_inode: The eCryptfs directory inode
* @ecryptfs_dentry: The eCryptfs dentry that we are looking up
* @ecryptfs_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 *ecryptfs_dir_inode,
struct dentry *ecryptfs_dentry,
struct nameidata *ecryptfs_nd)
{
char *encrypted_and_encoded_name = NULL;
int encrypted_and_encoded_name_size;
struct ecryptfs_crypt_stat *crypt_stat = NULL;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
struct ecryptfs_inode_info *inode_info;
struct dentry *lower_dir_dentry, *lower_dentry;
int rc = 0;
ecryptfs_dentry->d_op = &ecryptfs_dops;
if ((ecryptfs_dentry->d_name.len == 1
&& !strcmp(ecryptfs_dentry->d_name.name, "."))
|| (ecryptfs_dentry->d_name.len == 2
&& !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
goto out_d_drop;
}
lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
lower_dir_dentry,
ecryptfs_dentry->d_name.len);
if (IS_ERR(lower_dentry)) {
rc = PTR_ERR(lower_dentry);
printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
"lower_dentry = [%s]\n", __func__, rc,
ecryptfs_dentry->d_name.name);
goto out_d_drop;
}
if (lower_dentry->d_inode)
goto lookup_and_interpose;
inode_info = ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
if (inode_info) {
crypt_stat = &inode_info->crypt_stat;
/* TODO: lock for crypt_stat comparison */
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
ecryptfs_set_default_sizes(crypt_stat);
}
if (crypt_stat)
mount_crypt_stat = crypt_stat->mount_crypt_stat;
else
mount_crypt_stat = &ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
if (!(crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCRYPT_FILENAMES))
&& !(mount_crypt_stat && (mount_crypt_stat->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
goto lookup_and_interpose;
dput(lower_dentry);
rc = ecryptfs_encrypt_and_encode_filename(
&encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
crypt_stat, mount_crypt_stat, ecryptfs_dentry->d_name.name,
ecryptfs_dentry->d_name.len);
if (rc) {
printk(KERN_ERR "%s: Error attempting to encrypt and encode "
"filename; rc = [%d]\n", __func__, rc);
goto out_d_drop;
}
lower_dentry = lookup_one_len(encrypted_and_encoded_name,
lower_dir_dentry,
encrypted_and_encoded_name_size - 1);
if (IS_ERR(lower_dentry)) {
rc = PTR_ERR(lower_dentry);
printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
"lower_dentry = [%s]\n", __func__, rc,
encrypted_and_encoded_name);
goto out_d_drop;
}
lookup_and_interpose:
rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
crypt_stat, ecryptfs_dir_inode,
ecryptfs_nd);
goto out;
out_d_drop:
d_drop(ecryptfs_dentry);
out:
kfree(encrypted_and_encoded_name);
return ERR_PTR(rc);
}
@ -466,19 +504,21 @@ static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
char *encoded_symname;
int encoded_symlen;
struct ecryptfs_crypt_stat *crypt_stat = NULL;
size_t encoded_symlen;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname,
strlen(symname),
&encoded_symname);
if (encoded_symlen < 0) {
rc = encoded_symlen;
mount_crypt_stat = &ecryptfs_superblock_to_private(
dir->i_sb)->mount_crypt_stat;
rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
&encoded_symlen,
NULL,
mount_crypt_stat, symname,
strlen(symname));
if (rc)
goto out_lock;
}
rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
encoded_symname);
kfree(encoded_symname);
@ -602,52 +642,54 @@ out_lock:
}
static int
ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
{
int rc;
struct dentry *lower_dentry;
char *decoded_name;
char *lower_buf;
mm_segment_t old_fs;
struct dentry *lower_dentry;
struct ecryptfs_crypt_stat *crypt_stat;
char *plaintext_name;
size_t plaintext_name_size;
mm_segment_t old_fs;
int rc;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
if (!lower_dentry->d_inode->i_op->readlink) {
rc = -EINVAL;
goto out;
}
crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
/* Released in this function */
lower_buf = kmalloc(bufsiz, GFP_KERNEL);
if (lower_buf == NULL) {
ecryptfs_printk(KERN_ERR, "Out of memory\n");
printk(KERN_ERR "%s: Out of memory whilst attempting to "
"kmalloc [%d] bytes\n", __func__, bufsiz);
rc = -ENOMEM;
goto out;
}
old_fs = get_fs();
set_fs(get_ds());
ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
"lower_dentry->d_name.name = [%s]\n",
lower_dentry->d_name.name);
rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
(char __user *)lower_buf,
bufsiz);
set_fs(old_fs);
if (rc >= 0) {
crypt_stat = NULL;
rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc,
&decoded_name);
if (rc == -ENOMEM)
rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
&plaintext_name_size,
dentry, lower_buf,
rc);
if (rc) {
printk(KERN_ERR "%s: Error attempting to decode and "
"decrypt filename; rc = [%d]\n", __func__,
rc);
goto out_free_lower_buf;
if (rc > 0) {
ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes "
"to userspace: [%*s]\n", rc,
decoded_name);
if (copy_to_user(buf, decoded_name, rc))
rc = -EFAULT;
}
kfree(decoded_name);
fsstack_copy_attr_atime(dentry->d_inode,
lower_dentry->d_inode);
rc = copy_to_user(buf, plaintext_name, plaintext_name_size);
if (rc)
rc = -EFAULT;
else
rc = plaintext_name_size;
kfree(plaintext_name);
fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
}
out_free_lower_buf:
kfree(lower_buf);
@ -669,8 +711,6 @@ static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
}
old_fs = get_fs();
set_fs(get_ds());
ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
"dentry->d_name.name = [%s]\n", dentry->d_name.name);
rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
set_fs(old_fs);
if (rc < 0)