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>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index e935a22..c01e043 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1931,7 +1931,7 @@
/* 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 @@
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 @@
}
(*dst_size) = dst_byte_offset;
out:
- return rc;
+ return;
}
/**
@@ -2208,16 +2222,8 @@
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 @@
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,