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
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_CHECKSUM_64_H
#define _ASM_X86_CHECKSUM_64_H
/*
* Checksums for x86-64
* Copyright 2002 by Andi Kleen, SuSE Labs
* with some code from asm-x86/checksum.h
*/
#include <linux/compiler.h>
#include <linux/uaccess.h>
#include <asm/byteorder.h>
/**
* csum_fold - Fold and invert a 32bit checksum.
* sum: 32bit unfolded sum
*
* Fold a 32bit running checksum to 16bit and invert it. This is usually
* the last step before putting a checksum into a packet.
* Make sure not to mix with 64bit checksums.
*/
static inline __sum16 csum_fold(__wsum sum)
{
asm(" addl %1,%0\n"
" adcl $0xffff,%0"
: "=r" (sum)
: "r" ((__force u32)sum << 16),
"0" ((__force u32)sum & 0xffff0000));
return (__force __sum16)(~(__force u32)sum >> 16);
}
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*
* By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
* Arnt Gulbrandsen.
*/
/**
* ip_fast_csum - Compute the IPv4 header checksum efficiently.
* iph: ipv4 header
* ihl: length of header / 4
*/
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
unsigned int sum;
asm(" movl (%1), %0\n"
" subl $4, %2\n"
" jbe 2f\n"
" addl 4(%1), %0\n"
" adcl 8(%1), %0\n"
" adcl 12(%1), %0\n"
"1: adcl 16(%1), %0\n"
" lea 4(%1), %1\n"
" decl %2\n"
" jne 1b\n"
" adcl $0, %0\n"
" movl %0, %2\n"
" shrl $16, %0\n"
" addw %w2, %w0\n"
" adcl $0, %0\n"
" notl %0\n"
"2:"
/* Since the input registers which are loaded with iph and ihl
are modified, we must also specify them as outputs, or gcc
will assume they contain their original values. */
: "=r" (sum), "=r" (iph), "=r" (ihl)
: "1" (iph), "2" (ihl)
: "memory");
return (__force __sum16)sum;
}
/**
* csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
* @saddr: source address
* @daddr: destination address
* @len: length of packet
* @proto: ip protocol of packet
* @sum: initial sum to be added in (32bit unfolded)
*
* Returns the pseudo header checksum the input data. Result is
* 32bit unfolded.
*/
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
__u8 proto, __wsum sum)
{
asm(" addl %1, %0\n"
" adcl %2, %0\n"
" adcl %3, %0\n"
" adcl $0, %0\n"
: "=r" (sum)
: "g" (daddr), "g" (saddr),
"g" ((len + proto)<<8), "0" (sum));
return sum;
}
/**
* csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
* @saddr: source address
* @daddr: destination address
* @len: length of packet
* @proto: ip protocol of packet
* @sum: initial sum to be added in (32bit unfolded)
*
* Returns the 16bit pseudo header checksum the input data already
* complemented and ready to be filled in.
*/
static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
/**
* csum_partial - Compute an internet checksum.
* @buff: buffer to be checksummed
* @len: length of buffer.
* @sum: initial sum to be added in (32bit unfolded)
*
* Returns the 32bit unfolded internet checksum of the buffer.
* Before filling it in it needs to be csum_fold()'ed.
* buff should be aligned to a 64bit boundary if possible.
*/
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
/* Do not call this directly. Use the wrappers below */
extern __visible __wsum csum_partial_copy_generic(const void *src, const void *dst,
int len, __wsum sum,
int *src_err_ptr, int *dst_err_ptr);
extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum isum, int *errp);
extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
int len, __wsum isum, int *errp);
extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum);
/**
* ip_compute_csum - Compute an 16bit IP checksum.
* @buff: buffer address.
* @len: length of buffer.
*
* Returns the 16bit folded/inverted checksum of the passed buffer.
* Ready to fill in.
*/
extern __sum16 ip_compute_csum(const void *buff, int len);
/**
* csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
* @saddr: source address
* @daddr: destination address
* @len: length of packet
* @proto: protocol of packet
* @sum: initial sum (32bit unfolded) to be added in
*
* Computes an IPv6 pseudo header checksum. This sum is added the checksum
* into UDP/TCP packets and contains some link layer information.
* Returns the unfolded 32bit checksum.
*/
struct in6_addr;
#define _HAVE_ARCH_IPV6_CSUM 1
extern __sum16
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
__u32 len, __u8 proto, __wsum sum);
static inline unsigned add32_with_carry(unsigned a, unsigned b)
{
asm("addl %2,%0\n\t"
"adcl $0,%0"
: "=r" (a)
: "0" (a), "rm" (b));
return a;
}
#define HAVE_ARCH_CSUM_ADD
static inline __wsum csum_add(__wsum csum, __wsum addend)
{
return (__force __wsum)add32_with_carry((__force unsigned)csum,
(__force unsigned)addend);
}
#endif /* _ASM_X86_CHECKSUM_64_H */
|
