kernel-ark/include/net/sctp/checksum.h
Vlad Yasevich 4458f04c02 sctp: Clean up sctp checksumming code
The sctp crc32c checksum is always generated in little endian.
So, we clean up the code to treat it as little endian and remove
all the __force casts.

Suggested by Herbert Xu.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-16 00:03:10 -08:00

84 lines
2.6 KiB
C

/* SCTP kernel reference Implementation
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001-2003 International Business Machines, Corp.
*
* This file is part of the SCTP kernel reference Implementation
*
* SCTP Checksum functions
*
* The SCTP reference implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* The SCTP reference implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, write to
* the Free Software Foundation, 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <lksctp-developers@lists.sourceforge.net>
*
* Or submit a bug report through the following website:
* http://www.sf.net/projects/lksctp
*
* Written or modified by:
* Dinakaran Joseph
* Jon Grimm <jgrimm@us.ibm.com>
* Sridhar Samudrala <sri@us.ibm.com>
*
* Rewritten to use libcrc32c by:
* Vlad Yasevich <vladislav.yasevich@hp.com>
*
* Any bugs reported given to us we will try to fix... any fixes shared will
* be incorporated into the next SCTP release.
*/
#include <linux/types.h>
#include <net/sctp/sctp.h>
#include <linux/crc32c.h>
static inline __u32 sctp_crc32c(__u32 crc, u8 *buffer, u16 length)
{
return crc32c(crc, buffer, length);
}
static inline __u32 sctp_start_cksum(__u8 *buffer, __u16 length)
{
__u32 crc = ~(__u32)0;
__u8 zero[sizeof(__u32)] = {0};
/* Optimize this routine to be SCTP specific, knowing how
* to skip the checksum field of the SCTP header.
*/
/* Calculate CRC up to the checksum. */
crc = sctp_crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32));
/* Skip checksum field of the header. */
crc = sctp_crc32c(crc, zero, sizeof(__u32));
/* Calculate the rest of the CRC. */
crc = sctp_crc32c(crc, &buffer[sizeof(struct sctphdr)],
length - sizeof(struct sctphdr));
return crc;
}
static inline __u32 sctp_update_cksum(__u8 *buffer, __u16 length, __u32 crc32)
{
return sctp_crc32c(crc32, buffer, length);
}
static inline __le32 sctp_end_cksum(__be32 crc32)
{
return cpu_to_le32(~crc32);
}