eCryptfs: Clean up ecryptfs_decode_from_filename()

Flesh out the comments for ecryptfs_decode_from_filename(). Remove the
return condition, since it is always 0.

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 14:42:05 -08:00 committed by Linus Torvalds
parent 7d8bc2be51
commit 71c11c378f

View file

@ -1931,7 +1931,7 @@ static unsigned char *portable_filename_chars = ("-.0123456789ABCD"
/* We could either offset on every reverse map or just pad some 0x00's
* at the front here */
static unsigned char filename_rev_map[] = {
static const unsigned char filename_rev_map[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 7 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 15 */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 23 */
@ -2012,16 +2012,30 @@ void ecryptfs_encode_for_filename(unsigned char *dst, size_t *dst_size,
return;
}
int ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size,
const unsigned char *src, size_t src_size)
/**
* ecryptfs_decode_from_filename
* @dst: If NULL, this function only sets @dst_size and returns. If
* non-NULL, this function decodes the encoded octets in @src
* into the memory that @dst points to.
* @dst_size: Set to the size of the decoded string.
* @src: The encoded set of octets to decode.
* @src_size: The size of the encoded set of octets to decode.
*/
static void
ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size,
const unsigned char *src, size_t src_size)
{
u8 current_bit_offset = 0;
size_t src_byte_offset = 0;
size_t dst_byte_offset = 0;
int rc = 0;
if (dst == NULL) {
/* Not exact; conservatively long */
/* Not exact; conservatively long. Every block of 4
* encoded characters decodes into a block of 3
* decoded characters. This segment of code provides
* the caller with the maximum amount of allocated
* space that @dst will need to point to in a
* subsequent call. */
(*dst_size) = (((src_size + 1) * 3) / 4);
goto out;
}
@ -2055,7 +2069,7 @@ int ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size,
}
(*dst_size) = dst_byte_offset;
out:
return rc;
return;
}
/**
@ -2208,16 +2222,8 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name,
name += ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE;
name_size -= ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE;
rc = ecryptfs_decode_from_filename(NULL, &decoded_name_size,
name, name_size);
if (rc) {
printk(KERN_ERR "%s: Error attempting to decode "
"filename; rc = [%d]\n", __func__, rc);
rc = ecryptfs_copy_filename(plaintext_name,
plaintext_name_size,
orig_name, orig_name_size);
goto out;
}
ecryptfs_decode_from_filename(NULL, &decoded_name_size,
name, name_size);
decoded_name = kmalloc(decoded_name_size, GFP_KERNEL);
if (!decoded_name) {
printk(KERN_ERR "%s: Out of memory whilst attempting "
@ -2226,17 +2232,8 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name,
rc = -ENOMEM;
goto out;
}
rc = ecryptfs_decode_from_filename(decoded_name,
&decoded_name_size,
name, name_size);
if (rc) {
printk(KERN_ERR "%s: Error attempting to decode "
"filename; rc = [%d]\n", __func__, rc);
rc = ecryptfs_copy_filename(plaintext_name,
plaintext_name_size,
orig_name, orig_name_size);
goto out_free;
}
ecryptfs_decode_from_filename(decoded_name, &decoded_name_size,
name, name_size);
rc = ecryptfs_parse_tag_70_packet(plaintext_name,
plaintext_name_size,
&packet_size,