patch-pre2.0.8 linux/arch/ppc/lib/checksum.c

• Lines: 137
• Date: Mon May 27 12:00:58 1996
• Orig file: pre2.0.7/linux/arch/ppc/lib/checksum.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file pre2.0.7/linux/arch/ppc/lib/checksum.c linux/arch/ppc/lib/checksum.c
@@ -0,0 +1,136 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IP/TCP/UDP checksumming routines
+ *
+ * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Tom May, <ftom@netcom.com>
+ *		Lots of code moved from tcp.c and ip.c; see those files
+ *		for more names.
+ *
+ * Adapted for PowerPC by Gary Thomas <gdt@mc.com>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <net/checksum.h>
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
+{
+	unsigned long result = ~_csum_partial(buff, len, sum);
+#if 0	
+printk("Csum partial(%x, %d, %x) = %x\n", buff, len, sum, result);
+dump_buf(buff, len);
+#endif
+	return result;
+}
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums
+ *
+ * here even more important to align src and dst on a 32-bit boundary
+ */
+
+unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum)
+{
+	/*
+	 * The whole idea is to do the copy and the checksum at
+	 * the same time, but we do it the easy way now.
+	 *
+	 * At least csum on the source, not destination, for cache
+	 * reasons..
+	 */
+	sum = csum_partial(src, len, sum);
+	memcpy(dst, src, len);
+	return sum;
+}
+
+extern unsigned short _ip_fast_csum(unsigned char *buf);
+
+unsigned short
+ip_fast_csum(unsigned char *buf, unsigned int len)
+{
+	unsigned short _val;
+	_val = _ip_fast_csum(buf);
+#if 0
+	printk("IP CKSUM(%x, %d) = %x\n", buf, len, _val);
+	dump_buf(buf, len*4);
+#endif	
+	return (_val);
+}
+
+extern unsigned short _ip_compute_csum(unsigned char *buf, int len);
+
+unsigned short
+ip_compute_csum(unsigned char *buf, int len)
+{
+	unsigned short _val;
+	_val = _ip_compute_csum(buf, len);
+#if 0
+	printk("Compute IP CKSUM(%x, %d) = %x\n", buf, len, _val);
+	dump_buf(buf, len);
+#endif	
+	return (_val);
+}
+
+unsigned short
+_udp_check(unsigned char *buf, int len, int saddr, int daddr, int hdr);
+
+unsigned short
+udp_check(unsigned char *buf, int len, int saddr, int daddr)
+{
+	unsigned short _val;
+	int hdr;
+	hdr = (len << 16) + IPPROTO_UDP;
+	_val = _udp_check(buf, len, saddr, daddr, hdr);
+#if 0
+	printk("UDP CSUM(%x,%d,%x,%x) = %x\n", buf, len, saddr, daddr, _val);
+	dump_buf(buf, len);
+#endif	
+	return (_val);
+}
+
+unsigned short
+_tcp_check(unsigned char *buf, int len, int saddr, int daddr, int hdr);
+
+unsigned short
+csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum)
+{
+	unsigned short _val;
+	_val = _csum_tcpudp_magic(saddr, daddr, sum, (len<<16)+proto);
+#if 0
+	printk("TCP Magic(%x, %x, %x, %x) = %x\n", saddr, daddr, (len<<16)+proto, sum, _val);
+#endif
+	return (_val);
+}
+
+/*
+ *	Fold a partial checksum without adding pseudo headers
+ */
+
+unsigned short csum_fold(unsigned int sum)
+{
+	sum = (sum & 0xffff) + (sum >> 16);
+	sum = (sum & 0xffff) + (sum >> 16);
+	return ~sum;
+}
+