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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
7 * Copyright (C) 1999 Silicon Graphics, Inc.
8 * Copyright (C) 2001 Thiemo Seufer.
9 * Copyright (C) 2002 Maciej W. Rozycki
10 * Copyright (C) 2014 Imagination Technologies Ltd.
11 */
12#ifndef _ASM_CHECKSUM_H
13#define _ASM_CHECKSUM_H
14
15#ifdef CONFIG_GENERIC_CSUM
16#include <asm-generic/checksum.h>
17#else
18
19#include <linux/in6.h>
20
21#include <linux/uaccess.h>
22
23/*
24 * computes the checksum of a memory block at buff, length len,
25 * and adds in "sum" (32-bit)
26 *
27 * returns a 32-bit number suitable for feeding into itself
28 * or csum_tcpudp_magic
29 *
30 * this function must be called with even lengths, except
31 * for the last fragment, which may be odd
32 *
33 * it's best to have buff aligned on a 32-bit boundary
34 */
35__wsum csum_partial(const void *buff, int len, __wsum sum);
36
37__wsum __csum_partial_copy_from_user(const void __user *src, void *dst, int len);
38__wsum __csum_partial_copy_to_user(const void *src, void __user *dst, int len);
39
40#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
41static inline
42__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
43{
44 might_fault();
45 if (!access_ok(src, len))
46 return 0;
47 return __csum_partial_copy_from_user(src, dst, len);
48}
49
50/*
51 * Copy and checksum to user
52 */
53#define HAVE_CSUM_COPY_USER
54static inline
55__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
56{
57 might_fault();
58 if (!access_ok(dst, len))
59 return 0;
60 return __csum_partial_copy_to_user(src, dst, len);
61}
62
63/*
64 * the same as csum_partial, but copies from user space (but on MIPS
65 * we have just one address space, so this is identical to the above)
66 */
67#define _HAVE_ARCH_CSUM_AND_COPY
68__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len);
69static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
70{
71 return __csum_partial_copy_nocheck(src, dst, len);
72}
73
74/*
75 * Fold a partial checksum without adding pseudo headers
76 */
77static inline __sum16 csum_fold(__wsum csum)
78{
79 u32 sum = (__force u32)csum;
80
81 sum += (sum << 16);
82 csum = (__force __wsum)(sum < (__force u32)csum);
83 sum >>= 16;
84 sum += (__force u32)csum;
85
86 return (__force __sum16)~sum;
87}
88#define csum_fold csum_fold
89
90/*
91 * This is a version of ip_compute_csum() optimized for IP headers,
92 * which always checksum on 4 octet boundaries.
93 *
94 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
95 * Arnt Gulbrandsen.
96 */
97static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
98{
99 const unsigned int *word = iph;
100 const unsigned int *stop = word + ihl;
101 unsigned int csum;
102 int carry;
103
104 csum = word[0];
105 csum += word[1];
106 carry = (csum < word[1]);
107 csum += carry;
108
109 csum += word[2];
110 carry = (csum < word[2]);
111 csum += carry;
112
113 csum += word[3];
114 carry = (csum < word[3]);
115 csum += carry;
116
117 word += 4;
118 do {
119 csum += *word;
120 carry = (csum < *word);
121 csum += carry;
122 word++;
123 } while (word != stop);
124
125 return csum_fold(csum);
126}
127#define ip_fast_csum ip_fast_csum
128
129static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
130 __u32 len, __u8 proto,
131 __wsum isum)
132{
133 const unsigned int sh32 = IS_ENABLED(CONFIG_64BIT) ? 32 : 0;
134 unsigned long sum = (__force unsigned long)daddr;
135 unsigned long tmp;
136 __u32 osum;
137
138 tmp = (__force unsigned long)saddr;
139 sum += tmp;
140
141 if (IS_ENABLED(CONFIG_32BIT))
142 sum += sum < tmp;
143
144 /*
145 * We know PROTO + LEN has the sign bit clear, so cast to a signed
146 * type to avoid an extraneous zero-extension where TMP is 64-bit.
147 */
148 tmp = (__s32)(proto + len);
149 tmp <<= IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? 8 : 0;
150 sum += tmp;
151 if (IS_ENABLED(CONFIG_32BIT))
152 sum += sum < tmp;
153
154 tmp = (__force unsigned long)isum;
155 sum += tmp;
156
157 if (IS_ENABLED(CONFIG_32BIT)) {
158 sum += sum < tmp;
159 osum = sum;
160 } else if (IS_ENABLED(CONFIG_64BIT)) {
161 tmp = sum << sh32;
162 sum += tmp;
163 osum = sum < tmp;
164 osum += sum >> sh32;
165 } else {
166 BUILD_BUG();
167 }
168
169 return (__force __wsum)osum;
170}
171#define csum_tcpudp_nofold csum_tcpudp_nofold
172
173/*
174 * this routine is used for miscellaneous IP-like checksums, mainly
175 * in icmp.c
176 */
177static inline __sum16 ip_compute_csum(const void *buff, int len)
178{
179 return csum_fold(csum_partial(buff, len, 0));
180}
181
182#define _HAVE_ARCH_IPV6_CSUM
183static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
184 const struct in6_addr *daddr,
185 __u32 len, __u8 proto,
186 __wsum sum)
187{
188 __wsum tmp;
189
190 __asm__(
191 " .set push # csum_ipv6_magic\n"
192 " .set noreorder \n"
193 " .set noat \n"
194 " addu %0, %5 # proto (long in network byte order)\n"
195 " sltu $1, %0, %5 \n"
196 " addu %0, $1 \n"
197
198 " addu %0, %6 # csum\n"
199 " sltu $1, %0, %6 \n"
200 " lw %1, 0(%2) # four words source address\n"
201 " addu %0, $1 \n"
202 " addu %0, %1 \n"
203 " sltu $1, %0, %1 \n"
204
205 " lw %1, 4(%2) \n"
206 " addu %0, $1 \n"
207 " addu %0, %1 \n"
208 " sltu $1, %0, %1 \n"
209
210 " lw %1, 8(%2) \n"
211 " addu %0, $1 \n"
212 " addu %0, %1 \n"
213 " sltu $1, %0, %1 \n"
214
215 " lw %1, 12(%2) \n"
216 " addu %0, $1 \n"
217 " addu %0, %1 \n"
218 " sltu $1, %0, %1 \n"
219
220 " lw %1, 0(%3) \n"
221 " addu %0, $1 \n"
222 " addu %0, %1 \n"
223 " sltu $1, %0, %1 \n"
224
225 " lw %1, 4(%3) \n"
226 " addu %0, $1 \n"
227 " addu %0, %1 \n"
228 " sltu $1, %0, %1 \n"
229
230 " lw %1, 8(%3) \n"
231 " addu %0, $1 \n"
232 " addu %0, %1 \n"
233 " sltu $1, %0, %1 \n"
234
235 " lw %1, 12(%3) \n"
236 " addu %0, $1 \n"
237 " addu %0, %1 \n"
238 " sltu $1, %0, %1 \n"
239
240 " addu %0, $1 # Add final carry\n"
241 " .set pop"
242 : "=&r" (sum), "=&r" (tmp)
243 : "r" (saddr), "r" (daddr),
244 "0" (htonl(len)), "r" (htonl(proto)), "r" (sum));
245
246 return csum_fold(sum);
247}
248
249#include <asm-generic/checksum.h>
250#endif /* CONFIG_GENERIC_CSUM */
251
252#endif /* _ASM_CHECKSUM_H */
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
7 * Copyright (C) 1999 Silicon Graphics, Inc.
8 * Copyright (C) 2001 Thiemo Seufer.
9 * Copyright (C) 2002 Maciej W. Rozycki
10 * Copyright (C) 2014 Imagination Technologies Ltd.
11 */
12#ifndef _ASM_CHECKSUM_H
13#define _ASM_CHECKSUM_H
14
15#include <linux/in6.h>
16
17#include <asm/uaccess.h>
18
19/*
20 * computes the checksum of a memory block at buff, length len,
21 * and adds in "sum" (32-bit)
22 *
23 * returns a 32-bit number suitable for feeding into itself
24 * or csum_tcpudp_magic
25 *
26 * this function must be called with even lengths, except
27 * for the last fragment, which may be odd
28 *
29 * it's best to have buff aligned on a 32-bit boundary
30 */
31__wsum csum_partial(const void *buff, int len, __wsum sum);
32
33__wsum __csum_partial_copy_kernel(const void *src, void *dst,
34 int len, __wsum sum, int *err_ptr);
35
36__wsum __csum_partial_copy_from_user(const void *src, void *dst,
37 int len, __wsum sum, int *err_ptr);
38__wsum __csum_partial_copy_to_user(const void *src, void *dst,
39 int len, __wsum sum, int *err_ptr);
40/*
41 * this is a new version of the above that records errors it finds in *errp,
42 * but continues and zeros the rest of the buffer.
43 */
44static inline
45__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
46 __wsum sum, int *err_ptr)
47{
48 might_fault();
49 if (segment_eq(get_fs(), get_ds()))
50 return __csum_partial_copy_kernel((__force void *)src, dst,
51 len, sum, err_ptr);
52 else
53 return __csum_partial_copy_from_user((__force void *)src, dst,
54 len, sum, err_ptr);
55}
56
57#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
58static inline
59__wsum csum_and_copy_from_user(const void __user *src, void *dst,
60 int len, __wsum sum, int *err_ptr)
61{
62 if (access_ok(VERIFY_READ, src, len))
63 return csum_partial_copy_from_user(src, dst, len, sum,
64 err_ptr);
65 if (len)
66 *err_ptr = -EFAULT;
67
68 return sum;
69}
70
71/*
72 * Copy and checksum to user
73 */
74#define HAVE_CSUM_COPY_USER
75static inline
76__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
77 __wsum sum, int *err_ptr)
78{
79 might_fault();
80 if (access_ok(VERIFY_WRITE, dst, len)) {
81 if (segment_eq(get_fs(), get_ds()))
82 return __csum_partial_copy_kernel(src,
83 (__force void *)dst,
84 len, sum, err_ptr);
85 else
86 return __csum_partial_copy_to_user(src,
87 (__force void *)dst,
88 len, sum, err_ptr);
89 }
90 if (len)
91 *err_ptr = -EFAULT;
92
93 return (__force __wsum)-1; /* invalid checksum */
94}
95
96/*
97 * the same as csum_partial, but copies from user space (but on MIPS
98 * we have just one address space, so this is identical to the above)
99 */
100__wsum csum_partial_copy_nocheck(const void *src, void *dst,
101 int len, __wsum sum);
102
103/*
104 * Fold a partial checksum without adding pseudo headers
105 */
106static inline __sum16 csum_fold(__wsum sum)
107{
108 __asm__(
109 " .set push # csum_fold\n"
110 " .set noat \n"
111 " sll $1, %0, 16 \n"
112 " addu %0, $1 \n"
113 " sltu $1, %0, $1 \n"
114 " srl %0, %0, 16 \n"
115 " addu %0, $1 \n"
116 " xori %0, 0xffff \n"
117 " .set pop"
118 : "=r" (sum)
119 : "0" (sum));
120
121 return (__force __sum16)sum;
122}
123
124/*
125 * This is a version of ip_compute_csum() optimized for IP headers,
126 * which always checksum on 4 octet boundaries.
127 *
128 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
129 * Arnt Gulbrandsen.
130 */
131static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
132{
133 const unsigned int *word = iph;
134 const unsigned int *stop = word + ihl;
135 unsigned int csum;
136 int carry;
137
138 csum = word[0];
139 csum += word[1];
140 carry = (csum < word[1]);
141 csum += carry;
142
143 csum += word[2];
144 carry = (csum < word[2]);
145 csum += carry;
146
147 csum += word[3];
148 carry = (csum < word[3]);
149 csum += carry;
150
151 word += 4;
152 do {
153 csum += *word;
154 carry = (csum < *word);
155 csum += carry;
156 word++;
157 } while (word != stop);
158
159 return csum_fold(csum);
160}
161
162static inline __wsum csum_tcpudp_nofold(__be32 saddr,
163 __be32 daddr, unsigned short len, unsigned short proto,
164 __wsum sum)
165{
166 __asm__(
167 " .set push # csum_tcpudp_nofold\n"
168 " .set noat \n"
169#ifdef CONFIG_32BIT
170 " addu %0, %2 \n"
171 " sltu $1, %0, %2 \n"
172 " addu %0, $1 \n"
173
174 " addu %0, %3 \n"
175 " sltu $1, %0, %3 \n"
176 " addu %0, $1 \n"
177
178 " addu %0, %4 \n"
179 " sltu $1, %0, %4 \n"
180 " addu %0, $1 \n"
181#endif
182#ifdef CONFIG_64BIT
183 " daddu %0, %2 \n"
184 " daddu %0, %3 \n"
185 " daddu %0, %4 \n"
186 " dsll32 $1, %0, 0 \n"
187 " daddu %0, $1 \n"
188 " dsra32 %0, %0, 0 \n"
189#endif
190 " .set pop"
191 : "=r" (sum)
192 : "0" ((__force unsigned long)daddr),
193 "r" ((__force unsigned long)saddr),
194#ifdef __MIPSEL__
195 "r" ((proto + len) << 8),
196#else
197 "r" (proto + len),
198#endif
199 "r" ((__force unsigned long)sum));
200
201 return sum;
202}
203
204/*
205 * computes the checksum of the TCP/UDP pseudo-header
206 * returns a 16-bit checksum, already complemented
207 */
208static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
209 unsigned short len,
210 unsigned short proto,
211 __wsum sum)
212{
213 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
214}
215
216/*
217 * this routine is used for miscellaneous IP-like checksums, mainly
218 * in icmp.c
219 */
220static inline __sum16 ip_compute_csum(const void *buff, int len)
221{
222 return csum_fold(csum_partial(buff, len, 0));
223}
224
225#define _HAVE_ARCH_IPV6_CSUM
226static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
227 const struct in6_addr *daddr,
228 __u32 len, unsigned short proto,
229 __wsum sum)
230{
231 __asm__(
232 " .set push # csum_ipv6_magic\n"
233 " .set noreorder \n"
234 " .set noat \n"
235 " addu %0, %5 # proto (long in network byte order)\n"
236 " sltu $1, %0, %5 \n"
237 " addu %0, $1 \n"
238
239 " addu %0, %6 # csum\n"
240 " sltu $1, %0, %6 \n"
241 " lw %1, 0(%2) # four words source address\n"
242 " addu %0, $1 \n"
243 " addu %0, %1 \n"
244 " sltu $1, %0, %1 \n"
245
246 " lw %1, 4(%2) \n"
247 " addu %0, $1 \n"
248 " addu %0, %1 \n"
249 " sltu $1, %0, %1 \n"
250
251 " lw %1, 8(%2) \n"
252 " addu %0, $1 \n"
253 " addu %0, %1 \n"
254 " sltu $1, %0, %1 \n"
255
256 " lw %1, 12(%2) \n"
257 " addu %0, $1 \n"
258 " addu %0, %1 \n"
259 " sltu $1, %0, %1 \n"
260
261 " lw %1, 0(%3) \n"
262 " addu %0, $1 \n"
263 " addu %0, %1 \n"
264 " sltu $1, %0, %1 \n"
265
266 " lw %1, 4(%3) \n"
267 " addu %0, $1 \n"
268 " addu %0, %1 \n"
269 " sltu $1, %0, %1 \n"
270
271 " lw %1, 8(%3) \n"
272 " addu %0, $1 \n"
273 " addu %0, %1 \n"
274 " sltu $1, %0, %1 \n"
275
276 " lw %1, 12(%3) \n"
277 " addu %0, $1 \n"
278 " addu %0, %1 \n"
279 " sltu $1, %0, %1 \n"
280
281 " addu %0, $1 # Add final carry\n"
282 " .set pop"
283 : "=r" (sum), "=r" (proto)
284 : "r" (saddr), "r" (daddr),
285 "0" (htonl(len)), "1" (htonl(proto)), "r" (sum));
286
287 return csum_fold(sum);
288}
289
290#endif /* _ASM_CHECKSUM_H */