--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/qemu-symbian-svp/slirp/cksum.c	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 1988, 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)in_cksum.c	8.1 (Berkeley) 6/10/93
+ * in_cksum.c,v 1.2 1994/08/02 07:48:16 davidg Exp
+ */
+
+#include <slirp.h>
+
+/*
+ * Checksum routine for Internet Protocol family headers (Portable Version).
+ *
+ * This routine is very heavily used in the network
+ * code and should be modified for each CPU to be as fast as possible.
+ *
+ * XXX Since we will never span more than 1 mbuf, we can optimise this
+ */
+
+#define ADDCARRY(x)  (x > 65535 ? x -= 65535 : x)
+#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}
+
+int cksum(struct mbuf *m, int len)
+{
+	register u_int16_t *w;
+	register int sum = 0;
+	register int mlen = 0;
+	int byte_swapped = 0;
+
+	union {
+		u_int8_t	c[2];
+		u_int16_t	s;
+	} s_util;
+	union {
+		u_int16_t s[2];
+		u_int32_t l;
+	} l_util;
+
+	if (m->m_len == 0)
+	   goto cont;
+	w = mtod(m, u_int16_t *);
+
+	mlen = m->m_len;
+
+	if (len < mlen)
+	   mlen = len;
+	len -= mlen;
+	/*
+	 * Force to even boundary.
+	 */
+	if ((1 & (long) w) && (mlen > 0)) {
+		REDUCE;
+		sum <<= 8;
+		s_util.c[0] = *(u_int8_t *)w;
+		w = (u_int16_t *)((int8_t *)w + 1);
+		mlen--;
+		byte_swapped = 1;
+	}
+	/*
+	 * Unroll the loop to make overhead from
+	 * branches &c small.
+	 */
+	while ((mlen -= 32) >= 0) {
+		sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
+		sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
+		sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
+		sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
+		w += 16;
+	}
+	mlen += 32;
+	while ((mlen -= 8) >= 0) {
+		sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
+		w += 4;
+	}
+	mlen += 8;
+	if (mlen == 0 && byte_swapped == 0)
+	   goto cont;
+	REDUCE;
+	while ((mlen -= 2) >= 0) {
+		sum += *w++;
+	}
+
+	if (byte_swapped) {
+		REDUCE;
+		sum <<= 8;
+		byte_swapped = 0;
+		if (mlen == -1) {
+			s_util.c[1] = *(u_int8_t *)w;
+			sum += s_util.s;
+			mlen = 0;
+		} else
+
+		   mlen = -1;
+	} else if (mlen == -1)
+	   s_util.c[0] = *(u_int8_t *)w;
+
+cont:
+#ifdef DEBUG
+	if (len) {
+		DEBUG_ERROR((dfd, "cksum: out of data\n"));
+		DEBUG_ERROR((dfd, " len = %d\n", len));
+	}
+#endif
+	if (mlen == -1) {
+		/* The last mbuf has odd # of bytes. Follow the
+		 standard (the odd byte may be shifted left by 8 bits
+			   or not as determined by endian-ness of the machine) */
+		s_util.c[1] = 0;
+		sum += s_util.s;
+	}
+	REDUCE;
+	return (~sum & 0xffff);
+}