Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 1 | /* 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 Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 49 | static inline __be32 sctp_crc32c(__be32 crc, u8 *buffer, u16 length) |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 50 | { |
Harvey Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 51 | return (__force __be32)crc32c((__force u32)crc, buffer, length); |
| 52 | } |
| 53 | |
| 54 | static inline __be32 sctp_start_cksum(__u8 *buffer, __u16 length) |
| 55 | { |
| 56 | __be32 crc = ~cpu_to_be32(0); |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 57 | __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 Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 64 | crc = sctp_crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32)); |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 65 | |
| 66 | /* Skip checksum field of the header. */ |
Harvey Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 67 | crc = sctp_crc32c(crc, zero, sizeof(__u32)); |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 68 | |
| 69 | /* Calculate the rest of the CRC. */ |
Harvey Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 70 | crc = sctp_crc32c(crc, &buffer[sizeof(struct sctphdr)], |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 71 | length - sizeof(struct sctphdr)); |
| 72 | return crc; |
| 73 | } |
| 74 | |
Harvey Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 75 | static inline __be32 sctp_update_cksum(__u8 *buffer, __u16 length, __be32 crc32) |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 76 | { |
Harvey Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 77 | return sctp_crc32c(crc32, buffer, length); |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 78 | } |
| 79 | |
Harvey Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 80 | static inline __be32 sctp_end_cksum(__be32 crc32) |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 81 | { |
Harvey Harrison | 336d326 | 2008-07-18 23:07:09 -0700 | [diff] [blame^] | 82 | return ~crc32; |
Vlad Yasevich | 9ad0977 | 2007-12-16 14:06:41 -0800 | [diff] [blame] | 83 | } |