summaryrefslogtreecommitdiffstats
path: root/arch/mips64/lib/csum_partial_copy.c
blob: 9f08f405a843367ceffc31e99f872c06173267b6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
/* $Id: csum_partial_copy.c,v 1.1 1999/08/21 21:43:00 ralf Exp $
 *
 * 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.
 *
 * MIPS64 specific IP/TCP/UDP checksumming routines
 *
 * Copyright (C) 1998, 1999 Ralf Baechle
 */
#include <net/checksum.h>
#include <linux/types.h>
#include <asm/byteorder.h>
#include <asm/string.h>
#include <asm/uaccess.h>

/*
 * 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 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);
}

/*
 * Copy to userspace and compute checksum.
 */
unsigned int csum_partial_copy_to_user (const char *src, char *dst,
                                        int len, unsigned int sum,
                                        int *err_ptr)
{
	sum = csum_partial(src, len, sum);

	if (copy_to_user(dst, src, len)) {
		*err_ptr = -EFAULT;
		return sum;
	}

	return sum;
}