patch-2.1.101 linux/arch/mips/lib/checksum.c
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- Lines: 132
- Date:
Wed Dec 31 16:00:00 1969
- Orig file:
v2.1.100/linux/arch/mips/lib/checksum.c
- Orig date:
Wed Dec 10 10:31:10 1997
diff -u --recursive --new-file v2.1.100/linux/arch/mips/lib/checksum.c linux/arch/mips/lib/checksum.c
@@ -1,131 +0,0 @@
-/*
- * 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.
- *
- * MIPS specific IP/TCP/UDP checksumming routines
- *
- * Authors: Ralf Baechle, <ralf@gnu.ai.mit.edu>
- * Lots of code moved from tcp.c and ip.c; see those files
- * for more names.
- *
- * 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.
- *
- * $Id: checksum.c,v 1.2 1997/07/29 18:37:35 ralf Exp $
- */
-#include <net/checksum.h>
-#include <linux/types.h>
-#include <asm/byteorder.h>
-#include <asm/string.h>
-#include <asm/uaccess.h>
-
-static inline unsigned short from32to16(unsigned long x)
-{
- /* 32 bits --> 16 bits + carry */
- x = (x & 0xffff) + (x >> 16);
- /* 16 bits + carry --> 16 bits including carry */
- x = (x & 0xffff) + (x >> 16);
- return x;
-}
-
-static inline unsigned long do_csum(const unsigned char * buff, int len)
-{
- int odd, count;
- unsigned long result = 0;
-
- if (len <= 0)
- goto out;
- odd = 1 & (unsigned long) buff;
- if (odd) {
- result = be16_to_cpu(*buff);
- len--;
- buff++;
- }
- count = len >> 1; /* nr of 16-bit words.. */
- if (count) {
- if (2 & (unsigned long) buff) {
- result += *(unsigned short *) buff;
- count--;
- len -= 2;
- buff += 2;
- }
- count >>= 1; /* nr of 32-bit words.. */
- if (count) {
- unsigned long carry = 0;
- do {
- unsigned long w = *(unsigned long *) buff;
- count--;
- buff += 4;
- result += carry;
- result += w;
- carry = (w > result);
- } while (count);
- result += carry;
- result = (result & 0xffff) + (result >> 16);
- }
- if (len & 2) {
- result += *(unsigned short *) buff;
- buff += 2;
- }
- }
- if (len & 1)
- result += le16_to_cpu(*buff);
- result = from32to16(result);
- if (odd)
- result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
-out:
- return result;
-}
-
-/*
- * computes a partial checksum, e.g. for TCP/UDP fragments
- */
-unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum)
-{
- unsigned long result = do_csum(buff, len);
-
- /* add in old sum, and carry.. */
- result += sum;
- if(sum > result)
- result += 1;
- return result;
-}
-
-/*
- * copy while checksumming, otherwise like csum_partial
- */
-unsigned int csum_partial_copy(const char *src, char *dst,
- int len, unsigned int sum)
-{
- /*
- * It's 2:30 am and I don't feel like doing it real ...
- * This is lots slower than the real thing (tm)
- */
- sum = csum_partial(src, len, sum);
- memcpy(dst, src, len);
-
- return sum;
-}
-
-/*
- * Copy from userspace and compute checksum. If we catch an exception
- * then zero the rest of the buffer.
- */
-unsigned int csum_partial_copy_from_user (const char *src, char *dst,
- int len, unsigned int sum,
- int *err_ptr)
-{
- int *dst_err_ptr=NULL;
- int missing;
-
- missing = copy_from_user(dst, src, len);
- if (missing) {
- memset(dst + len - missing, 0, missing);
- *err_ptr = -EFAULT;
- }
-
- return csum_partial(dst, len, sum);
-}
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