1 1.14 cheusov /* $NetBSD: sum1.c,v 1.14 2021/03/18 18:12:35 cheusov Exp $ */ 2 1.4 glass 3 1.1 cgd /*- 4 1.3 cgd * Copyright (c) 1991, 1993 5 1.3 cgd * The Regents of the University of California. All rights reserved. 6 1.1 cgd * 7 1.1 cgd * Redistribution and use in source and binary forms, with or without 8 1.1 cgd * modification, are permitted provided that the following conditions 9 1.1 cgd * are met: 10 1.1 cgd * 1. Redistributions of source code must retain the above copyright 11 1.1 cgd * notice, this list of conditions and the following disclaimer. 12 1.1 cgd * 2. Redistributions in binary form must reproduce the above copyright 13 1.1 cgd * notice, this list of conditions and the following disclaimer in the 14 1.1 cgd * documentation and/or other materials provided with the distribution. 15 1.9 agc * 3. Neither the name of the University nor the names of its contributors 16 1.1 cgd * may be used to endorse or promote products derived from this software 17 1.1 cgd * without specific prior written permission. 18 1.1 cgd * 19 1.1 cgd * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 1.1 cgd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 1.1 cgd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 1.1 cgd * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 1.1 cgd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 1.1 cgd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 1.1 cgd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 1.1 cgd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 1.1 cgd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 1.1 cgd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 1.1 cgd * SUCH DAMAGE. 30 1.1 cgd */ 31 1.1 cgd 32 1.11 jmc #if HAVE_NBTOOL_CONFIG_H 33 1.11 jmc #include "nbtool_config.h" 34 1.11 jmc #endif 35 1.11 jmc 36 1.6 lukem #include <sys/cdefs.h> 37 1.8 bjh21 #if defined(__RCSID) && !defined(lint) 38 1.4 glass #if 0 39 1.4 glass static char sccsid[] = "@(#)sum1.c 8.1 (Berkeley) 6/6/93"; 40 1.4 glass #else 41 1.14 cheusov __RCSID("$NetBSD: sum1.c,v 1.14 2021/03/18 18:12:35 cheusov Exp $"); 42 1.4 glass #endif 43 1.1 cgd #endif /* not lint */ 44 1.1 cgd 45 1.1 cgd #include <sys/types.h> 46 1.1 cgd #include <unistd.h> 47 1.1 cgd 48 1.5 cgd #include "extern.h" 49 1.5 cgd 50 1.3 cgd int 51 1.14 cheusov csum1(int fd, uint32_t *cval, off_t *clen) 52 1.1 cgd { 53 1.13 simonb off_t total; 54 1.13 simonb int nr; 55 1.13 simonb u_int thecrc; 56 1.13 simonb u_char *p; 57 1.1 cgd u_char buf[8192]; 58 1.1 cgd 59 1.1 cgd /* 60 1.1 cgd * 16-bit checksum, rotating right before each addition; 61 1.1 cgd * overflow is discarded. 62 1.1 cgd */ 63 1.7 atatat thecrc = total = 0; 64 1.1 cgd while ((nr = read(fd, buf, sizeof(buf))) > 0) 65 1.1 cgd for (total += nr, p = buf; nr--; ++p) { 66 1.7 atatat if (thecrc & 1) 67 1.7 atatat thecrc |= 0x10000; 68 1.7 atatat thecrc = ((thecrc >> 1) + *p) & 0xffff; 69 1.1 cgd } 70 1.1 cgd if (nr < 0) 71 1.12 xtraeme return 1; 72 1.1 cgd 73 1.7 atatat *cval = thecrc; 74 1.1 cgd *clen = total; 75 1.12 xtraeme return 0; 76 1.1 cgd } 77
Indexes created Sat Sep 20 22:09:52 GMT 2025