273160ffc6
sctp_hdr(skb) only works when skb->transport_header is set properly.
But in Netfilter, skb->transport_header for ipv6 is not guaranteed
to be right value for sctphdr. It would cause to fail to check the
checksum for sctp packets.
So fix it by using offset, which is always right in all places.
v1->v2:
- Fix the changelog.
Fixes: e6d8b64b34 ("net: sctp: fix and consolidate SCTP checksumming code")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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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