eCryptfs: Replace miscdev read/write magic numbers

ecryptfs_miscdev_read() and ecryptfs_miscdev_write() contained many
magic numbers for specifying packet header field sizes and offsets. This
patch defines those values and replaces the magic values.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index ac1ad48c2376..8e3b943e330f 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -109,7 +109,7 @@ int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
                 (*size) += ((unsigned char)(data[1]) + 192);
                 (*length_size) = 2;
         } else if (data[0] == 255) {
-                /* Five-byte length; we're not supposed to see this */
+                /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
                 ecryptfs_printk(KERN_ERR, "Five-byte packet length not "
                                 "supported\n");
                 rc = -EINVAL;
@@ -126,7 +126,7 @@ out:
 /**
  * ecryptfs_write_packet_length
  * @dest: The byte array target into which to write the length. Must
- *        have at least 5 bytes allocated.
+ *        have at least ECRYPTFS_MAX_PKT_LEN_SIZE bytes allocated.
  * @size: The length to write.
  * @packet_size_length: The number of bytes used to encode the packet
  *                      length is written to this address.
@@ -146,6 +146,7 @@ int ecryptfs_write_packet_length(char *dest, size_t size,
                 dest[1] = ((size - 192) % 256);
                 (*packet_size_length) = 2;
         } else {
+                /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
                 rc = -EINVAL;
                 ecryptfs_printk(KERN_WARNING,
                                 "Unsupported packet size: [%zd]\n", size);