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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
|
/*
* 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) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
* Copyright (C) 1999 Silicon Graphics, Inc.
* Copyright (C) 2001 Thiemo Seufer.
* Copyright (C) 2002 Maciej W. Rozycki
* Copyright (C) 2014 Imagination Technologies Ltd.
*/
#ifndef _ASM_CHECKSUM_H
#define _ASM_CHECKSUM_H
#ifdef CONFIG_GENERIC_CSUM
#include <asm-generic/checksum.h>
#else
#include <linux/in6.h>
#include <linux/uaccess.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
*/
__wsum csum_partial(const void *buff, int len, __wsum sum);
__wsum __csum_partial_copy_kernel(const void *src, void *dst,
int len, __wsum sum, int *err_ptr);
__wsum __csum_partial_copy_from_user(const void *src, void *dst,
int len, __wsum sum, int *err_ptr);
__wsum __csum_partial_copy_to_user(const void *src, void *dst,
int len, __wsum sum, int *err_ptr);
/*
* this is a new version of the above that records errors it finds in *errp,
* but continues and zeros the rest of the buffer.
*/
static inline
__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
__wsum sum, int *err_ptr)
{
might_fault();
if (uaccess_kernel())
return __csum_partial_copy_kernel((__force void *)src, dst,
len, sum, err_ptr);
else
return __csum_partial_copy_from_user((__force void *)src, dst,
len, sum, err_ptr);
}
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
if (access_ok(VERIFY_READ, src, len))
return csum_partial_copy_from_user(src, dst, len, sum,
err_ptr);
if (len)
*err_ptr = -EFAULT;
return sum;
}
/*
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
static inline
__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
__wsum sum, int *err_ptr)
{
might_fault();
if (access_ok(VERIFY_WRITE, dst, len)) {
if (uaccess_kernel())
return __csum_partial_copy_kernel(src,
(__force void *)dst,
len, sum, err_ptr);
else
return __csum_partial_copy_to_user(src,
(__force void *)dst,
len, sum, err_ptr);
}
if (len)
*err_ptr = -EFAULT;
return (__force __wsum)-1; /* invalid checksum */
}
/*
* the same as csum_partial, but copies from user space (but on MIPS
* we have just one address space, so this is identical to the above)
*/
__wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum);
#define csum_partial_copy_nocheck csum_partial_copy_nocheck
/*
* Fold a partial checksum without adding pseudo headers
*/
static inline __sum16 csum_fold(__wsum csum)
{
u32 sum = (__force u32)csum;
sum += (sum << 16);
csum = (sum < csum);
sum >>= 16;
sum += csum;
return (__force __sum16)~sum;
}
#define csum_fold csum_fold
/*
* 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.
*/
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
const unsigned int *word = iph;
const unsigned int *stop = word + ihl;
unsigned int csum;
int carry;
csum = word[0];
csum += word[1];
carry = (csum < word[1]);
csum += carry;
csum += word[2];
carry = (csum < word[2]);
csum += carry;
csum += word[3];
carry = (csum < word[3]);
csum += carry;
word += 4;
do {
csum += *word;
carry = (csum < *word);
csum += carry;
word++;
} while (word != stop);
return csum_fold(csum);
}
#define ip_fast_csum ip_fast_csum
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
__asm__(
" .set push # csum_tcpudp_nofold\n"
" .set noat \n"
#ifdef CONFIG_32BIT
" addu %0, %2 \n"
" sltu $1, %0, %2 \n"
" addu %0, $1 \n"
" addu %0, %3 \n"
" sltu $1, %0, %3 \n"
" addu %0, $1 \n"
" addu %0, %4 \n"
" sltu $1, %0, %4 \n"
" addu %0, $1 \n"
#endif
#ifdef CONFIG_64BIT
" daddu %0, %2 \n"
" daddu %0, %3 \n"
" daddu %0, %4 \n"
" dsll32 $1, %0, 0 \n"
" daddu %0, $1 \n"
" sltu $1, %0, $1 \n"
" dsra32 %0, %0, 0 \n"
" addu %0, $1 \n"
#endif
" .set pop"
: "=r" (sum)
: "0" ((__force unsigned long)daddr),
"r" ((__force unsigned long)saddr),
#ifdef __MIPSEL__
"r" ((proto + len) << 8),
#else
"r" (proto + len),
#endif
"r" ((__force unsigned long)sum));
return sum;
}
#define csum_tcpudp_nofold csum_tcpudp_nofold
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static inline __sum16 ip_compute_csum(const void *buff, int len)
{
return csum_fold(csum_partial(buff, len, 0));
}
#define _HAVE_ARCH_IPV6_CSUM
static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
const struct in6_addr *daddr,
__u32 len, __u8 proto,
__wsum sum)
{
__wsum tmp;
__asm__(
" .set push # csum_ipv6_magic\n"
" .set noreorder \n"
" .set noat \n"
" addu %0, %5 # proto (long in network byte order)\n"
" sltu $1, %0, %5 \n"
" addu %0, $1 \n"
" addu %0, %6 # csum\n"
" sltu $1, %0, %6 \n"
" lw %1, 0(%2) # four words source address\n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 4(%2) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 8(%2) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 12(%2) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 0(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 4(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 8(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 12(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" addu %0, $1 # Add final carry\n"
" .set pop"
: "=&r" (sum), "=&r" (tmp)
: "r" (saddr), "r" (daddr),
"0" (htonl(len)), "r" (htonl(proto)), "r" (sum));
return csum_fold(sum);
}
#include <asm-generic/checksum.h>
#endif /* CONFIG_GENERIC_CSUM */
#endif /* _ASM_CHECKSUM_H */
|
