80 lines
2.4 KiB
C
80 lines
2.4 KiB
C
/* SCTP kernel reference Implementation
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* Copyright (c) 1999-2001 Motorola, Inc.
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* Copyright (c) 2001-2003 International Business Machines, Corp.
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*
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* This file is part of the SCTP kernel reference Implementation
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*
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* SCTP Checksum functions
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*
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* The SCTP reference implementation is free software;
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* you can redistribute it and/or modify it under the terms of
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* the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* The SCTP reference implementation is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* ************************
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU CC; see the file COPYING. If not, see
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* <http://www.gnu.org/licenses/>.
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*
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* Please send any bug reports or fixes you make to the
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* email address(es):
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* lksctp developers <linux-sctp@vger.kernel.org>
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*
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* Written or modified by:
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* Dinakaran Joseph
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* Jon Grimm <jgrimm@us.ibm.com>
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* Sridhar Samudrala <sri@us.ibm.com>
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*
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* Rewritten to use libcrc32c by:
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* Vlad Yasevich <vladislav.yasevich@hp.com>
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*/
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#ifndef __sctp_checksum_h__
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#define __sctp_checksum_h__
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#include <linux/types.h>
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#include <net/sctp/sctp.h>
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#include <linux/crc32c.h>
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#include <linux/crc32.h>
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static inline __wsum sctp_csum_update(const void *buff, int len, __wsum sum)
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{
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/* This uses the crypto implementation of crc32c, which is either
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* implemented w/ hardware support or resolves to __crc32c_le().
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*/
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return (__force __wsum)crc32c((__force __u32)sum, buff, len);
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}
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static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2,
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int offset, int len)
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{
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return (__force __wsum)__crc32c_le_combine((__force __u32)csum,
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(__force __u32)csum2, len);
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}
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static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
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unsigned int offset)
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{
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struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
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const struct skb_checksum_ops ops = {
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.update = sctp_csum_update,
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.combine = sctp_csum_combine,
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};
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__le32 old = sh->checksum;
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__wsum new;
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sh->checksum = 0;
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new = ~__skb_checksum(skb, offset, skb->len - offset, ~(__wsum)0, &ops);
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sh->checksum = old;
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return cpu_to_le32((__force __u32)new);
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}
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#endif /* __sctp_checksum_h__ */
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