From 9c454937cbc25458219961503137127a631088d8 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@dragonflybsd.org>
Date: Thu, 10 Jul 2008 17:42:18 +0000
Subject: [PATCH] Add crc32_ext() - allows continuation of a 32 bit crc.

---
 sys/libkern/crc32.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/sys/libkern/crc32.c b/sys/libkern/crc32.c
index 9b6d41c560..9d5df6e05d 100644
--- a/sys/libkern/crc32.c
+++ b/sys/libkern/crc32.c
@@ -39,7 +39,7 @@
  * CRC32 code derived from work by Gary S. Brown.
  *
  * $FreeBSD: src/sys/libkern/crc32.c,v 1.1.2.1 2002/07/31 09:08:34 imp Exp $
- * $DragonFly: src/sys/libkern/crc32.c,v 1.4 2008/02/05 20:50:31 dillon Exp $
+ * $DragonFly: src/sys/libkern/crc32.c,v 1.5 2008/07/10 17:42:18 dillon Exp $
  */
 
 /*
@@ -118,3 +118,18 @@ crc32(const void *buf, size_t size)
 	return crc ^ ~0U;
 }
 
+uint32_t
+crc32_ext(const void *buf, size_t size, uint32_t ocrc)
+{
+	const uint8_t *p;
+	uint32_t crc;
+
+	p = buf;
+	crc = ~ocrc;
+
+	while (size--)
+		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
+
+	return crc ^ ~0U;
+}
+
-- 
2.11.4.GIT