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authorKiyoshi Aman <kiyoshi.aman+adelie@gmail.com>2019-02-01 22:55:37 +0000
committerKiyoshi Aman <kiyoshi.aman+adelie@gmail.com>2019-02-03 18:22:05 -0600
commit5b57d28ffb6e1ef86b50f7d05d977826eae89bfe (patch)
tree154a22fe556b49e6927197336f8bf91b12eacd5e /usr.bin/cksum/sum2.c
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diff --git a/usr.bin/cksum/sum2.c b/usr.bin/cksum/sum2.c
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+/* $NetBSD: sum2.c,v 1.13 2005/02/05 00:13:34 simonb Exp $ */
+
+/*-
+ * 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. 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.
+ */
+
+#if HAVE_NBTOOL_CONFIG_H
+#include "nbtool_config.h"
+#endif
+
+#include <sys/cdefs.h>
+#if defined(__RCSID) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)sum2.c 8.1 (Berkeley) 6/6/93";
+#else
+__RCSID("$NetBSD: sum2.c,v 1.13 2005/02/05 00:13:34 simonb Exp $");
+#endif
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "extern.h"
+
+int
+csum2(int fd, u_int32_t *cval, off_t *clen)
+{
+ u_int32_t thecrc;
+ off_t 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
+ * thecrc = (r % 2^16) + r / 2^16
+ */
+ thecrc = 0;
+ total = 0;
+ while ((nr = read(fd, buf, sizeof(buf))) > 0)
+ for (total += nr, p = buf; nr--; ++p)
+ thecrc += *p;
+ if (nr < 0)
+ return 1;
+
+ thecrc = (thecrc & 0xffff) + (thecrc >> 16);
+ thecrc = (thecrc & 0xffff) + (thecrc >> 16);
+
+ *cval = thecrc;
+ *clen = total;
+ return 0;
+}