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Vlad Yasevich9ad09772007-12-16 14:06:41 -08001/* SCTP kernel reference Implementation
2 * Copyright (c) 1999-2001 Motorola, Inc.
3 * Copyright (c) 2001-2003 International Business Machines, Corp.
4 *
5 * This file is part of the SCTP kernel reference Implementation
6 *
7 * SCTP Checksum functions
8 *
9 * The SCTP reference implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
13 * any later version.
14 *
15 * The SCTP reference implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 * ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING. If not, write to
23 * the Free Software Foundation, 59 Temple Place - Suite 330,
24 * Boston, MA 02111-1307, USA.
25 *
26 * Please send any bug reports or fixes you make to the
27 * email address(es):
28 * lksctp developers <lksctp-developers@lists.sourceforge.net>
29 *
30 * Or submit a bug report through the following website:
31 * http://www.sf.net/projects/lksctp
32 *
33 * Written or modified by:
34 * Dinakaran Joseph
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Sridhar Samudrala <sri@us.ibm.com>
37 *
38 * Rewritten to use libcrc32c by:
39 * Vlad Yasevich <vladislav.yasevich@hp.com>
40 *
41 * Any bugs reported given to us we will try to fix... any fixes shared will
42 * be incorporated into the next SCTP release.
43 */
44
45#include <linux/types.h>
46#include <net/sctp/sctp.h>
47#include <linux/crc32c.h>
48
Harvey Harrison336d3262008-07-18 23:07:09 -070049static inline __be32 sctp_crc32c(__be32 crc, u8 *buffer, u16 length)
Vlad Yasevich9ad09772007-12-16 14:06:41 -080050{
Harvey Harrison336d3262008-07-18 23:07:09 -070051 return (__force __be32)crc32c((__force u32)crc, buffer, length);
52}
53
54static inline __be32 sctp_start_cksum(__u8 *buffer, __u16 length)
55{
56 __be32 crc = ~cpu_to_be32(0);
Vlad Yasevich9ad09772007-12-16 14:06:41 -080057 __u8 zero[sizeof(__u32)] = {0};
58
59 /* Optimize this routine to be SCTP specific, knowing how
60 * to skip the checksum field of the SCTP header.
61 */
62
63 /* Calculate CRC up to the checksum. */
Harvey Harrison336d3262008-07-18 23:07:09 -070064 crc = sctp_crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32));
Vlad Yasevich9ad09772007-12-16 14:06:41 -080065
66 /* Skip checksum field of the header. */
Harvey Harrison336d3262008-07-18 23:07:09 -070067 crc = sctp_crc32c(crc, zero, sizeof(__u32));
Vlad Yasevich9ad09772007-12-16 14:06:41 -080068
69 /* Calculate the rest of the CRC. */
Harvey Harrison336d3262008-07-18 23:07:09 -070070 crc = sctp_crc32c(crc, &buffer[sizeof(struct sctphdr)],
Vlad Yasevich9ad09772007-12-16 14:06:41 -080071 length - sizeof(struct sctphdr));
72 return crc;
73}
74
Harvey Harrison336d3262008-07-18 23:07:09 -070075static inline __be32 sctp_update_cksum(__u8 *buffer, __u16 length, __be32 crc32)
Vlad Yasevich9ad09772007-12-16 14:06:41 -080076{
Harvey Harrison336d3262008-07-18 23:07:09 -070077 return sctp_crc32c(crc32, buffer, length);
Vlad Yasevich9ad09772007-12-16 14:06:41 -080078}
79
Harvey Harrison336d3262008-07-18 23:07:09 -070080static inline __be32 sctp_end_cksum(__be32 crc32)
Vlad Yasevich9ad09772007-12-16 14:06:41 -080081{
Harvey Harrison336d3262008-07-18 23:07:09 -070082 return ~crc32;
Vlad Yasevich9ad09772007-12-16 14:06:41 -080083}