patch-2.4.19 linux-2.4.19/include/linux/crc32.h

• Lines: 50
• Date: Fri Aug 2 17:39:45 2002
• Orig file: linux-2.4.18/include/linux/crc32.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/include/linux/crc32.h linux-2.4.19/include/linux/crc32.h
@@ -0,0 +1,49 @@
+/*
+ * crc32.h for early Linux 2.4.19pre kernel inclusion
+ * This defines ether_crc_le() and ether_crc() as inline functions
+ * This is slated to change to using the library crc32 functions
+ * as kernel 2.5.2 included at some future date.
+ */
+#ifndef _LINUX_CRC32_H
+#define _LINUX_CRC32_H
+
+#include <linux/types.h>
+
+/* The little-endian AUTODIN II ethernet CRC calculation.
+   N.B. Do not use for bulk data, use a table-based routine instead.
+   This is common code and should be moved to net/core/crc.c */
+static unsigned const ethernet_polynomial_le = 0xedb88320U;
+static inline unsigned ether_crc_le(int length, unsigned char *data)
+{
+	unsigned int crc = 0xffffffff;	/* Initial value. */
+	while(--length >= 0) {
+		unsigned char current_octet = *data++;
+		int bit;
+		for (bit = 8; --bit >= 0; current_octet >>= 1) {
+			if ((crc ^ current_octet) & 1) {
+				crc >>= 1;
+				crc ^= ethernet_polynomial_le;
+			} else
+				crc >>= 1;
+		}
+	}
+	return crc;
+}
+
+static unsigned const ethernet_polynomial = 0x04c11db7U;
+static inline u32 ether_crc(int length, unsigned char *data)
+{
+	int crc = -1;
+	while (--length >= 0) {
+		unsigned char current_octet = *data++;
+		int bit;
+		for (bit = 0; bit < 8; bit++, current_octet >>= 1) {
+			crc = (crc << 1) ^
+				((crc < 0) ^ (current_octet & 1) ?
+				 ethernet_polynomial : 0);
+		}
+	}
+	return crc;
+}
+
+#endif /* _LINUX_CRC32_H */