patch-2.4.20 linux-2.4.20/net/bluetooth/bnep/crc32.c

• Lines: 60
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/net/bluetooth/bnep/crc32.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/net/bluetooth/bnep/crc32.c linux-2.4.20/net/bluetooth/bnep/crc32.c
@@ -0,0 +1,59 @@
+/* 
+ * Based on linux-2.5/lib/crc32 by Matt Domsch <Matt_Domsch@dell.com>
+ *
+ * FIXME: Remove in 2.5  
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <asm/atomic.h>
+
+#include "crc32.h"
+
+#define CRCPOLY_BE 0x04c11db7
+#define CRC_BE_BITS 8
+
+static u32 *bnep_crc32_table;
+
+/*
+ * This code is in the public domain; copyright abandoned.
+ * Liability for non-performance of this code is limited to the amount
+ * you paid for it.  Since it is distributed for free, your refund will
+ * be very very small.  If it breaks, you get to keep both pieces.
+ */
+u32 bnep_crc32(u32 crc, unsigned char const *p, size_t len)
+{
+	while (len--)
+		crc = (crc << 8) ^ bnep_crc32_table[(crc >> 24) ^ *p++];
+	
+	return crc;
+}
+
+int __init bnep_crc32_init(void)
+{
+	unsigned i, j;
+	u32 crc = 0x80000000;
+
+	bnep_crc32_table = kmalloc((1 << CRC_BE_BITS) * sizeof(u32), GFP_KERNEL);
+	if (!bnep_crc32_table)
+		return -ENOMEM;
+
+	bnep_crc32_table[0] = 0;
+
+	for (i = 1; i < 1 << CRC_BE_BITS; i <<= 1) {
+		crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0);
+		for (j = 0; j < i; j++)
+			bnep_crc32_table[i + j] = crc ^ bnep_crc32_table[j];
+	}
+	return 0;
+}
+
+void __exit bnep_crc32_cleanup(void)
+{
+	if (bnep_crc32_table)
+		kfree(bnep_crc32_table);
+	bnep_crc32_table = NULL;
+}