[PATCH 4/5] eCryptfs: Filename Encryption: filldir, lookup, andreadlink

From: Michael Halcrow
Date: Tue Nov 04 2008 - 16:42:42 EST

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@xxxxxxxxxx>
---
fs/ecryptfs/crypto.c | 107 ++-------------
fs/ecryptfs/ecryptfs_kernel.h | 6 -
fs/ecryptfs/file.c | 30 ++--
fs/ecryptfs/inode.c | 294 +++++++++++++++++++++++------------------
4 files changed, 195 insertions(+), 242 deletions(-)

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 18c78ab..ea2afd2 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -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;
@@ -1629,98 +1640,6 @@ out:
}

/**
- * 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
*
* CBC-encrypts the filename. We do not want to encrypt the same
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index b648175..c11fc95 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -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,
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index eb3dc4c..6b0a99d 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -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)
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 89209f0..cf50729 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -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);
@@ -602,14 +642,15 @@ 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 ||
@@ -617,38 +658,39 @@ ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
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);
@@ -670,8 +712,6 @@ 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);
buf[rc] = '\0';
set_fs(old_fs);
--
1.5.3.6

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