git://bbs.cooldavid.org / net-next-2.6.git / blame
| Commit | Line | Data |
|---|---|---|
| 9ad0977f VY |
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 | ||
| 336d3262 | 49 | static inline __be32 sctp_crc32c(__be32 crc, u8 *buffer, u16 length) |
| 9ad0977f | 50 | { |
| 336d3262 HH |
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); | |
| 9ad0977f VY |
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. */ | |
| 336d3262 | 64 | crc = sctp_crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32)); |
| 9ad0977f VY |
65 | |
| 66 | /* Skip checksum field of the header. */ | |
| 336d3262 | 67 | crc = sctp_crc32c(crc, zero, sizeof(__u32)); |
| 9ad0977f VY |
68 | |
| 69 | /* Calculate the rest of the CRC. */ | |
| 336d3262 | 70 | crc = sctp_crc32c(crc, &buffer[sizeof(struct sctphdr)], |
| 9ad0977f VY |
71 | length - sizeof(struct sctphdr)); |
| 72 | return crc; | |
| 73 | } | |
| 74 | ||
| 336d3262 | 75 | static inline __be32 sctp_update_cksum(__u8 *buffer, __u16 length, __be32 crc32) |
| 9ad0977f | 76 | { |
| 336d3262 | 77 | return sctp_crc32c(crc32, buffer, length); |
| 9ad0977f VY |
78 | } |
| 79 | ||
| 336d3262 | 80 | static inline __be32 sctp_end_cksum(__be32 crc32) |
| 9ad0977f | 81 | { |
| 9c5ff5f7 | 82 | return (__force __be32)~cpu_to_le32((__force u32)crc32); |
| 9ad0977f | 83 | } |