[SCTP]: Fix sctp_cookie alignment in the packet.
On 64 bit architectures, sctp_cookie sent as part of INIT-ACK is not
aligned on a 64 bit boundry and thus causes unaligned access exceptions.
The layout of the cookie prameter is this:
|<----- Parameter Header --------------------|<--- Cookie DATA --------
-----------------------------------------------------------------------
| param type (16 bits) | param len (16 bits) | sig [32 bytes] | cookie..
-----------------------------------------------------------------------
The cookie data portion contains 64 bit values on 64 bit architechtures
(timeval) that fall on a 32 bit alignment boundry when used as part of
the on-wire format, but align correctly when used in internal
structures. This patch explicitely pads the on-wire format so that
it is properly aligned.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index f5c22d7..72aeae4 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -405,8 +405,9 @@
/* The format of our cookie that we send to our peer. */
struct sctp_signed_cookie {
__u8 signature[SCTP_SECRET_SIZE];
+ __u32 __pad; /* force sctp_cookie alignment to 64 bits */
struct sctp_cookie c;
-};
+} __attribute__((packed));
/* This is another convenience type to allocate memory for address
* params for the maximum size and pass such structures around