linux/arch/mips/lib/csum_partial_copy.c

50 lines
1.2 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994, 1995 Waldorf Electronics GmbH
* Copyright (C) 1998, 1999 Ralf Baechle
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <asm/byteorder.h>
#include <asm/string.h>
#include <asm/uaccess.h>
#include <net/checksum.h>
/*
* copy while checksumming, otherwise like csum_partial
*/
unsigned int csum_partial_copy_nocheck(const unsigned char *src,
unsigned 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 unsigned char __user *src,
unsigned char *dst, int len, unsigned int sum, int *err_ptr)
{
int missing;
might_sleep();
missing = copy_from_user(dst, src, len);
if (missing) {
memset(dst + len - missing, 0, missing);
*err_ptr = -EFAULT;
}
return csum_partial(dst, len, sum);
}