1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* SCTP kernel reference Implementation
3 * Copyright (c) 1999-2001 Motorola, Inc.
4 * Copyright (c) 2001-2003 International Business Machines, Corp.
5 *
6 * This file is part of the SCTP kernel reference Implementation
7 *
8 * SCTP Checksum functions
9 *
10 * Please send any bug reports or fixes you make to the
11 * email address(es):
12 * lksctp developers <linux-sctp@vger.kernel.org>
13 *
14 * Written or modified by:
15 * Dinakaran Joseph
16 * Jon Grimm <jgrimm@us.ibm.com>
17 * Sridhar Samudrala <sri@us.ibm.com>
18 * Vlad Yasevich <vladislav.yasevich@hp.com>
19 */
20
21#ifndef __sctp_checksum_h__
22#define __sctp_checksum_h__
23
24#include <linux/types.h>
25#include <linux/sctp.h>
26
27static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
28 unsigned int offset)
29{
30 struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
31 __le32 old = sh->checksum;
32 u32 new;
33
34 sh->checksum = 0;
35 new = ~skb_crc32c(skb, offset, len: skb->len - offset, crc: ~0);
36 sh->checksum = old;
37 return cpu_to_le32(new);
38}
39
40#endif /* __sctp_checksum_h__ */
41