move ether_crc32_le to if_ethersubr.c. Add ether_crc32_be

1 files changed, 75 insertions, 1 deletions

diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 417993e4dc3..ffffc70d106 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ethersubr.c,v 1.61 2002/02/07 23:20:57 art Exp $	*/
+/*	$OpenBSD: if_ethersubr.c,v 1.62 2002/05/07 19:28:58 nate Exp $	*/
 /*	$NetBSD: if_ethersubr.c,v 1.19 1996/05/07 02:40:30 thorpej Exp $	*/
 
 /*
@@ -1087,6 +1087,80 @@ ether_ifdetach(ifp)
 	}
 }
 
+#if 0
+/*
+ * This is for reference.  We have a table-driven version
+ * of the little-endian crc32 generator, which is faster
+ * than the double-loop.
+ */
+u_int32_t
+ether_crc32_le(const u_int8_t *buf, size_t len)
+{
+	u_int32_t c, crc, carry;
+	size_t i, j;
+
+	crc = 0xffffffffU;	/* initial value */
+
+	for (i = 0; i < len; i++) {
+		c = buf[i];
+		for (j = 0; j < 8; j++) {
+			carry = ((crc & 0x01) ? 1 : 0) ^ (c & 0x01);
+			crc >>= 1;
+			c >>= 1;
+			if (carry)
+				crc = (crc ^ ETHER_CRC_POLY_LE);
+		}
+	}
+
+	return (crc);
+}
+#else
+u_int32_t
+ether_crc32_le(const u_int8_t *buf, size_t len)
+{
+	static const u_int32_t crctab[] = {
+		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
+		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
+		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
+		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
+	};
+	u_int32_t crc;
+	int i;
+
+	crc = 0xffffffffU;	/* initial value */
+
+	for (i = 0; i < len; i++) {
+		crc ^= buf[i];
+		crc = (crc >> 4) ^ crctab[crc & 0xf];
+		crc = (crc >> 4) ^ crctab[crc & 0xf];
+	}
+
+	return (crc);
+}
+#endif
+
+u_int32_t
+ether_crc32_be(const u_int8_t *buf, size_t len)
+{
+	u_int32_t c, crc, carry;
+	size_t i, j;
+
+	crc = 0xffffffffU;	/* initial value */
+
+	for (i = 0; i < len; i++) {
+		c = buf[i];
+		for (j = 0; j < 8; j++) {
+			carry = ((crc & 0x80000000U) ? 1 : 0) ^ (c & 0x01);
+			crc <<= 1;
+			c >>= 1;
+			if (carry)
+				crc = (crc ^ ETHER_CRC_POLY_BE) | carry;
+		}
+	}
+
+	return (crc);
+}
+
 u_char	ether_ipmulticast_min[6] = { 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 };
 u_char	ether_ipmulticast_max[6] = { 0x01, 0x00, 0x5e, 0x7f, 0xff, 0xff };