1 files changed, 74 insertions, 0 deletions
diff --git a/usr.bin/cksum/sum2.c b/usr.bin/cksum/sum2.c
new file mode 100644
index 0000000..540d9e5
--- /dev/null
+++ b/usr.bin/cksum/sum2.c
@@ -0,0 +1,74 @@
+/*-
+ * 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.
+ * 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
+#endif /* not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+
+#include <unistd.h>
+#include <stdint.h>
+
+#include "extern.h"
+
+int
+csum2(int fd, uint32_t *cval, off_t *clen)
+{
+	uint32_t lcrc;
+	int nr;
+	off_t total;
+	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);
+}