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/* SPDX-License-Identifier: GPL-2.0-or-later */
/* 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
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* 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>
*/
#ifndef __sctp_checksum_h__
#define __sctp_checksum_h__
#include <linux/types.h>
#include <linux/sctp.h>
#include <linux/crc32c.h>
#include <linux/crc32.h>
static inline __wsum sctp_csum_update(const void *buff, int len, __wsum sum)
{
/* This uses the crypto implementation of crc32c, which is either
* implemented w/ hardware support or resolves to __crc32c_le().
*/
return (__force __wsum)crc32c((__force __u32)sum, buff, len);
}
static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2,
int offset, int len)
{
return (__force __wsum)__crc32c_le_combine((__force __u32)csum,
(__force __u32)csum2, len);
}
static const struct skb_checksum_ops sctp_csum_ops = {
.update = sctp_csum_update,
.combine = sctp_csum_combine,
};
static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
unsigned int offset)
{
struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
__le32 old = sh->checksum;
__wsum new;
sh->checksum = 0;
new = ~__skb_checksum(skb, offset, skb->len - offset, ~(__wsum)0,
&sctp_csum_ops);
sh->checksum = old;
return cpu_to_le32((__force __u32)new);
}
#endif /* __sctp_checksum_h__ */
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