BSD 4.4 Lite Usr.bin Sources

1 files changed, 69 insertions, 0 deletions

diff --git a/usr.bin/cksum/sum1.c b/usr.bin/cksum/sum1.c
new file mode 100644
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--- /dev/null
+++ b/usr.bin/cksum/sum1.c
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+/*-
+ * 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
+static char sccsid[] = "@(#)sum1.c	8.1 (Berkeley) 6/6/93";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <unistd.h>
+
+int
+csum1(fd, cval, clen)
+	register int fd;
+	u_long *cval, *clen;
+{
+	register u_long total;
+	register int nr;
+	register u_int crc;
+	register u_char *p;
+	u_char buf[8192];
+
+	/*
+	 * 16-bit checksum, rotating right before each addition;
+	 * overflow is discarded.
+	 */
+	crc = total = 0;
+	while ((nr = read(fd, buf, sizeof(buf))) > 0)
+		for (total += nr, p = buf; nr--; ++p) {
+			if (crc & 1)
+				crc |= 0x10000;
+			crc = ((crc >> 1) + *p) & 0xffff;
+		}
+	if (nr < 0)
+		return(1);
+
+	*cval = crc;
+	*clen = total;
+	return(0);
+}