/*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint #if 0 static char sccsid[] = "@(#)sum2.c 8.1 (Berkeley) 6/6/93"; #endif static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ #include <sys/types.h> #include <unistd.h> #include "extern.h" int csum2(fd, cval, clen) int fd; u_int32_t *cval, *clen; { u_int32_t lcrc, total; int nr; u_char *p; u_char buf[8192]; /* * Draft 8 POSIX 1003.2: * * s = sum of all bytes * r = s % 2^16 + (s % 2^32) / 2^16 * lcrc = (r % 2^16) + r / 2^16 */ lcrc = total = 0; while ((nr = read(fd, buf, sizeof(buf))) > 0) for (total += nr, p = buf; nr--; ++p) lcrc += *p; if (nr < 0) return(1); lcrc = (lcrc & 0xffff) + (lcrc >> 16); lcrc = (lcrc & 0xffff) + (lcrc >> 16); *cval = lcrc; *clen = total; return(0); }