1 files changed, 58 insertions, 0 deletions
diff --git a/sys/ufs/lfs/lfs_cksum.c b/sys/ufs/lfs/lfs_cksum.c
new file mode 100644
index 0000000..77b011a
--- /dev/null
+++ b/sys/ufs/lfs/lfs_cksum.c
@@ -0,0 +1,58 @@
+/*-
+ * 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.
+ *
+ *	@(#)lfs_cksum.c	8.1 (Berkeley) 6/11/93
+ */
+
+#include <sys/types.h>
+
+/*
+ * Simple, general purpose, fast checksum.  Data must be short-aligned.
+ * Returns a u_long in case we ever want to do something more rigorous.
+ *
+ * XXX
+ * Use the TCP/IP checksum instead.
+ */
+u_long
+cksum(str, len)
+	register void *str;
+	register size_t len;
+{
+	register u_long sum;
+	
+	len &= ~(sizeof(u_short) - 1);
+	for (sum = 0; len; len -= sizeof(u_short)) {
+		sum ^= *(u_short *)str;
+		++(u_short *)str;
+	}
+	return (sum);
+}