1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #ifndef lint 33 #if 0 34 static char sccsid[] = "@(#)sum2.c 8.1 (Berkeley) 6/6/93"; 35 #endif 36 #endif /* not lint */ 37 #include <sys/cdefs.h> 38 #include <sys/types.h> 39 40 #include <unistd.h> 41 #include <stdint.h> 42 43 #include "extern.h" 44 45 int 46 csum2(int fd, uint32_t *cval, off_t *clen) 47 { 48 uint32_t lcrc; 49 int nr; 50 off_t total; 51 u_char *p; 52 u_char buf[8192]; 53 54 /* 55 * Draft 8 POSIX 1003.2: 56 * 57 * s = sum of all bytes 58 * r = s % 2^16 + (s % 2^32) / 2^16 59 * lcrc = (r % 2^16) + r / 2^16 60 */ 61 lcrc = total = 0; 62 while ((nr = read(fd, buf, sizeof(buf))) > 0) 63 for (total += nr, p = buf; nr--; ++p) 64 lcrc += *p; 65 if (nr < 0) 66 return (1); 67 68 lcrc = (lcrc & 0xffff) + (lcrc >> 16); 69 lcrc = (lcrc & 0xffff) + (lcrc >> 16); 70 71 *cval = lcrc; 72 *clen = total; 73 return (0); 74 } 75