19ad0977fSVlad Yasevich /* SCTP kernel reference Implementation 29ad0977fSVlad Yasevich * Copyright (c) 1999-2001 Motorola, Inc. 39ad0977fSVlad Yasevich * Copyright (c) 2001-2003 International Business Machines, Corp. 49ad0977fSVlad Yasevich * 59ad0977fSVlad Yasevich * This file is part of the SCTP kernel reference Implementation 69ad0977fSVlad Yasevich * 79ad0977fSVlad Yasevich * SCTP Checksum functions 89ad0977fSVlad Yasevich * 99ad0977fSVlad Yasevich * The SCTP reference implementation is free software; 109ad0977fSVlad Yasevich * you can redistribute it and/or modify it under the terms of 119ad0977fSVlad Yasevich * the GNU General Public License as published by 129ad0977fSVlad Yasevich * the Free Software Foundation; either version 2, or (at your option) 139ad0977fSVlad Yasevich * any later version. 149ad0977fSVlad Yasevich * 159ad0977fSVlad Yasevich * The SCTP reference implementation is distributed in the hope that it 169ad0977fSVlad Yasevich * will be useful, but WITHOUT ANY WARRANTY; without even the implied 179ad0977fSVlad Yasevich * ************************ 189ad0977fSVlad Yasevich * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 199ad0977fSVlad Yasevich * See the GNU General Public License for more details. 209ad0977fSVlad Yasevich * 219ad0977fSVlad Yasevich * You should have received a copy of the GNU General Public License 22a6227e26SJeff Kirsher * along with GNU CC; see the file COPYING. If not, see 23a6227e26SJeff Kirsher * <http://www.gnu.org/licenses/>. 249ad0977fSVlad Yasevich * 259ad0977fSVlad Yasevich * Please send any bug reports or fixes you make to the 269ad0977fSVlad Yasevich * email address(es): 2791705c61SDaniel Borkmann * lksctp developers <linux-sctp@vger.kernel.org> 289ad0977fSVlad Yasevich * 299ad0977fSVlad Yasevich * Written or modified by: 309ad0977fSVlad Yasevich * Dinakaran Joseph 319ad0977fSVlad Yasevich * Jon Grimm <jgrimm@us.ibm.com> 329ad0977fSVlad Yasevich * Sridhar Samudrala <sri@us.ibm.com> 339ad0977fSVlad Yasevich * 349ad0977fSVlad Yasevich * Rewritten to use libcrc32c by: 359ad0977fSVlad Yasevich * Vlad Yasevich <vladislav.yasevich@hp.com> 369ad0977fSVlad Yasevich */ 379ad0977fSVlad Yasevich 38a05b1019SDaniel Borkmann #ifndef __sctp_checksum_h__ 39a05b1019SDaniel Borkmann #define __sctp_checksum_h__ 40a05b1019SDaniel Borkmann 419ad0977fSVlad Yasevich #include <linux/types.h> 429ad0977fSVlad Yasevich #include <net/sctp/sctp.h> 439ad0977fSVlad Yasevich #include <linux/crc32c.h> 44e6d8b64bSDaniel Borkmann #include <linux/crc32.h> 459ad0977fSVlad Yasevich 46e6d8b64bSDaniel Borkmann static inline __wsum sctp_csum_update(const void *buff, int len, __wsum sum) 479ad0977fSVlad Yasevich { 48e6d8b64bSDaniel Borkmann /* This uses the crypto implementation of crc32c, which is either 49e6d8b64bSDaniel Borkmann * implemented w/ hardware support or resolves to __crc32c_le(). 509ad0977fSVlad Yasevich */ 51af2697a0SXin Long return (__force __wsum)crc32c((__force __u32)sum, buff, len); 529ad0977fSVlad Yasevich } 539ad0977fSVlad Yasevich 54e6d8b64bSDaniel Borkmann static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2, 55e6d8b64bSDaniel Borkmann int offset, int len) 569ad0977fSVlad Yasevich { 57af2697a0SXin Long return (__force __wsum)__crc32c_le_combine((__force __u32)csum, 58af2697a0SXin Long (__force __u32)csum2, len); 599ad0977fSVlad Yasevich } 609ad0977fSVlad Yasevich 61c3e933a5SMatteo Croce static const struct skb_checksum_ops sctp_csum_ops = { 62c3e933a5SMatteo Croce .update = sctp_csum_update, 63c3e933a5SMatteo Croce .combine = sctp_csum_combine, 64c3e933a5SMatteo Croce }; 65c3e933a5SMatteo Croce 66024ec3deSJoe Stringer static inline __le32 sctp_compute_cksum(const struct sk_buff *skb, 67024ec3deSJoe Stringer unsigned int offset) 68024ec3deSJoe Stringer { 69273160ffSXin Long struct sctphdr *sh = (struct sctphdr *)(skb->data + offset); 70af2697a0SXin Long __le32 old = sh->checksum; 71af2697a0SXin Long __wsum new; 72024ec3deSJoe Stringer 73e6d8b64bSDaniel Borkmann sh->checksum = 0; 74c3e933a5SMatteo Croce new = ~__skb_checksum(skb, offset, skb->len - offset, ~(__wsum)0, 75c3e933a5SMatteo Croce &sctp_csum_ops); 76e6d8b64bSDaniel Borkmann sh->checksum = old; 77024ec3deSJoe Stringer 78af2697a0SXin Long return cpu_to_le32((__force __u32)new); 79024ec3deSJoe Stringer } 80024ec3deSJoe Stringer 81a05b1019SDaniel Borkmann #endif /* __sctp_checksum_h__ */ 82