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[SCTP]: Fix sctp_cookie alignment in the packet.

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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>
This commit is contained in:
Vlad Yasevich 2006-01-17 11:52:12 -08:00 committed by Sridhar Samudrala
parent 7a48f923b8
commit 9834a2bb49
2 changed files with 14 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
include/net/sctp/structs.h
View file

@ -405,8 +405,9 @@ struct sctp_cookie {
/* 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

14
net/sctp/sm_make_chunk.c
View file

@ -1275,7 +1275,12 @@ static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
unsigned int keylen;
char *key;
headersize = sizeof(sctp_paramhdr_t) + SCTP_SECRET_SIZE;
/* Header size is static data prior to the actual cookie, including
* any padding.
*/
headersize = sizeof(sctp_paramhdr_t) +
(sizeof(struct sctp_signed_cookie) -
sizeof(struct sctp_cookie));
bodysize = sizeof(struct sctp_cookie)
+ ntohs(init_chunk->chunk_hdr->length) + addrs_len;
@ -1362,7 +1367,12 @@ struct sctp_association *sctp_unpack_cookie(
struct sk_buff *skb = chunk->skb;
struct timeval tv;
headersize = sizeof(sctp_chunkhdr_t) + SCTP_SECRET_SIZE;
/* Header size is static data prior to the actual cookie, including
* any padding.
*/
headersize = sizeof(sctp_chunkhdr_t) +
(sizeof(struct sctp_signed_cookie) -
sizeof(struct sctp_cookie));
bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
fixed_size = headersize + sizeof(struct sctp_cookie);