1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/staging/vt6655/tether.c b/drivers/staging/vt6655/tether.c
new file mode 100644
index 00000000000..1e7d3e2115a
--- /dev/null
+++ b/drivers/staging/vt6655/tether.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2003 VIA Networking, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *
+ * File: tether.c
+ *
+ * Purpose:
+ *
+ * Author: Tevin Chen
+ *
+ * Date: May 21, 1996
+ *
+ * Functions:
+ *      ETHbyGetHashIndexByCrc32 - Calculate multicast hash value by CRC32
+ *      ETHbIsBufferCrc32Ok - Check CRC value of the buffer if Ok or not
+ *
+ * Revision History:
+ *
+ */
+
+#include "device.h"
+#include "tmacro.h"
+#include "tcrc.h"
+#include "tether.h"
+
+/*---------------------  Static Definitions -------------------------*/
+
+/*---------------------  Static Classes  ----------------------------*/
+
+/*---------------------  Static Variables  --------------------------*/
+
+/*---------------------  Static Functions  --------------------------*/
+
+/*---------------------  Export Variables  --------------------------*/
+
+/*
+ * Description: Calculate multicast hash value by CRC32
+ *
+ * Parameters:
+ *  In:
+ *		pbyMultiAddr    - Multicast Address
+ *  Out:
+ *      none
+ *
+ * Return Value: Hash value
+ *
+ */
+unsigned char ETHbyGetHashIndexByCrc32(unsigned char *pbyMultiAddr)
+{
+	int     ii;
+	unsigned char byTmpHash;
+	unsigned char byHash = 0;
+
+	// get the least 6-bits from CRC generator
+	byTmpHash = (unsigned char)(CRCdwCrc32(pbyMultiAddr, ETH_ALEN,
+					       0xFFFFFFFFL) & 0x3F);
+	// reverse most bit to least bit
+	for (ii = 0; ii < (sizeof(byTmpHash) * 8); ii++) {
+		byHash <<= 1;
+		if (byTmpHash & 0x01)
+			byHash |= 1;
+		byTmpHash >>= 1;
+	}
+
+	// adjust 6-bits to the right most
+	return byHash >> 2;
+}
+
+/*
+ * Description: Check CRC value of the buffer if Ok or not
+ *
+ * Parameters:
+ *  In:
+ *		pbyBuffer	    - pointer of buffer (normally is rx buffer)
+ *		cbFrameLength	- length of buffer, including CRC portion
+ *  Out:
+ *      none
+ *
+ * Return Value: true if ok; false if error.
+ *
+ */
+bool ETHbIsBufferCrc32Ok(unsigned char *pbyBuffer, unsigned int cbFrameLength)
+{
+	unsigned long dwCRC;
+
+	dwCRC = CRCdwGetCrc32(pbyBuffer, cbFrameLength - 4);
+	if (cpu_to_le32(*((unsigned long *)(pbyBuffer + cbFrameLength - 4))) != dwCRC)
+		return false;
+
+	return true;
+}