1 files changed, 97 insertions, 0 deletions
diff --git a/usr.sbin/pim6sd/crc.c b/usr.sbin/pim6sd/crc.c
new file mode 100644
index 0000000..917371e
--- /dev/null
+++ b/usr.sbin/pim6sd/crc.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 1999 LSIIT Laboratory.
+ * 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 project 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 PROJECT 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 PROJECT 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.
+ */
+/*
+ *  Questions concerning this software should be directed to
+ *  Mickael Hoerdt (hoerdt@clarinet.u-strasbg.fr) LSIIT Strasbourg.
+ *
+ */
+/*
+ * This program has been derived from pimd.
+ * The pimd program is covered by the license in the accompanying file
+ * named "LICENSE.pimd".
+ *
+ * $FreeBSD$
+ */
+/* CRC implantation : stolen from RFC 2083 section 15.*/
+
+/* Table of CRCs of all 8-bit messages. */
+	unsigned long crc_table[256];
+
+/* Flag: has the table been computed? Initially false. */
+	int crc_table_computed = 0;
+
+
+/* Make the table for a fast CRC. */
+
+void make_crc_table(void)
+{
+	unsigned long c;
+	int n, k;
+	for (n = 0; n < 256; n++)
+	{
+		c = (unsigned long) n;
+          	for (k = 0; k < 8; k++)
+		{
+            		if (c & 1)
+              			c = 0xedb88320L ^ (c >> 1);
+            		else
+              			c = c >> 1;
+          	}
+          crc_table[n] = c;
+        }
+        crc_table_computed = 1;
+}
+
+/* Update a running CRC with the bytes buf[0..len-1]--the CRC
+   should be initialized to all 1's, and the transmitted value
+   is the 1's complement of the final running CRC (see the
+   crc() routine below)). */
+
+unsigned long update_crc(unsigned long crc, unsigned char *buf,
+                               int len)
+{
+	unsigned long c = crc;
+	int n;
+
+	if (!crc_table_computed)
+		make_crc_table();
+	for (n = 0; n < len; n++)
+	{
+          	c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
+        }
+        return c;
+}
+
+
+/* Return the CRC of the bytes buf[0..len-1]. */
+
+unsigned long crc(unsigned char *buf, int len)
+{
+        return update_crc(0xffffffffL, buf, len) ^ 0xffffffffL;
+}