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1da177e4 LT |
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 | */ | |
11 | #ifndef _ASM_CHECKSUM_H | |
12 | #define _ASM_CHECKSUM_H | |
13 | ||
1da177e4 LT |
14 | #include <linux/in6.h> |
15 | ||
16 | #include <asm/uaccess.h> | |
17 | ||
18 | /* | |
19 | * computes the checksum of a memory block at buff, length len, | |
20 | * and adds in "sum" (32-bit) | |
21 | * | |
22 | * returns a 32-bit number suitable for feeding into itself | |
23 | * or csum_tcpudp_magic | |
24 | * | |
25 | * this function must be called with even lengths, except | |
26 | * for the last fragment, which may be odd | |
27 | * | |
28 | * it's best to have buff aligned on a 32-bit boundary | |
29 | */ | |
8e3d8433 | 30 | __wsum csum_partial(const void *buff, int len, __wsum sum); |
1da177e4 | 31 | |
f860c90b AN |
32 | __wsum __csum_partial_copy_user(const void *src, void *dst, |
33 | int len, __wsum sum, int *err_ptr); | |
34 | ||
1da177e4 LT |
35 | /* |
36 | * this is a new version of the above that records errors it finds in *errp, | |
37 | * but continues and zeros the rest of the buffer. | |
38 | */ | |
f860c90b AN |
39 | static inline |
40 | __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, | |
41 | __wsum sum, int *err_ptr) | |
42 | { | |
ef41f460 | 43 | might_fault(); |
f860c90b AN |
44 | return __csum_partial_copy_user((__force void *)src, dst, |
45 | len, sum, err_ptr); | |
46 | } | |
1da177e4 LT |
47 | |
48 | /* | |
49 | * Copy and checksum to user | |
50 | */ | |
51 | #define HAVE_CSUM_COPY_USER | |
f860c90b AN |
52 | static inline |
53 | __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len, | |
54 | __wsum sum, int *err_ptr) | |
1da177e4 | 55 | { |
ef41f460 | 56 | might_fault(); |
f860c90b AN |
57 | if (access_ok(VERIFY_WRITE, dst, len)) |
58 | return __csum_partial_copy_user(src, (__force void *)dst, | |
59 | len, sum, err_ptr); | |
60 | if (len) | |
1da177e4 | 61 | *err_ptr = -EFAULT; |
1da177e4 | 62 | |
f860c90b | 63 | return (__force __wsum)-1; /* invalid checksum */ |
1da177e4 LT |
64 | } |
65 | ||
66 | /* | |
67 | * the same as csum_partial, but copies from user space (but on MIPS | |
68 | * we have just one address space, so this is identical to the above) | |
69 | */ | |
8e3d8433 AV |
70 | __wsum csum_partial_copy_nocheck(const void *src, void *dst, |
71 | int len, __wsum sum); | |
1da177e4 LT |
72 | |
73 | /* | |
74 | * Fold a partial checksum without adding pseudo headers | |
75 | */ | |
8e3d8433 | 76 | static inline __sum16 csum_fold(__wsum sum) |
1da177e4 LT |
77 | { |
78 | __asm__( | |
04988d6f TS |
79 | " .set push # csum_fold\n" |
80 | " .set noat \n" | |
81 | " sll $1, %0, 16 \n" | |
82 | " addu %0, $1 \n" | |
83 | " sltu $1, %0, $1 \n" | |
84 | " srl %0, %0, 16 \n" | |
85 | " addu %0, $1 \n" | |
86 | " xori %0, 0xffff \n" | |
87 | " .set pop" | |
1da177e4 LT |
88 | : "=r" (sum) |
89 | : "0" (sum)); | |
90 | ||
8e3d8433 | 91 | return (__force __sum16)sum; |
1da177e4 LT |
92 | } |
93 | ||
94 | /* | |
95 | * This is a version of ip_compute_csum() optimized for IP headers, | |
96 | * which always checksum on 4 octet boundaries. | |
97 | * | |
98 | * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by | |
99 | * Arnt Gulbrandsen. | |
100 | */ | |
8e3d8433 | 101 | static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) |
1da177e4 | 102 | { |
8e3d8433 AV |
103 | const unsigned int *word = iph; |
104 | const unsigned int *stop = word + ihl; | |
1da177e4 LT |
105 | unsigned int csum; |
106 | int carry; | |
107 | ||
108 | csum = word[0]; | |
109 | csum += word[1]; | |
110 | carry = (csum < word[1]); | |
111 | csum += carry; | |
112 | ||
113 | csum += word[2]; | |
114 | carry = (csum < word[2]); | |
115 | csum += carry; | |
116 | ||
117 | csum += word[3]; | |
118 | carry = (csum < word[3]); | |
119 | csum += carry; | |
120 | ||
121 | word += 4; | |
122 | do { | |
123 | csum += *word; | |
124 | carry = (csum < *word); | |
125 | csum += carry; | |
126 | word++; | |
127 | } while (word != stop); | |
128 | ||
129 | return csum_fold(csum); | |
130 | } | |
131 | ||
8e3d8433 AV |
132 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, |
133 | __be32 daddr, unsigned short len, unsigned short proto, | |
134 | __wsum sum) | |
1da177e4 LT |
135 | { |
136 | __asm__( | |
04988d6f TS |
137 | " .set push # csum_tcpudp_nofold\n" |
138 | " .set noat \n" | |
875d43e7 | 139 | #ifdef CONFIG_32BIT |
04988d6f TS |
140 | " addu %0, %2 \n" |
141 | " sltu $1, %0, %2 \n" | |
142 | " addu %0, $1 \n" | |
1da177e4 | 143 | |
04988d6f TS |
144 | " addu %0, %3 \n" |
145 | " sltu $1, %0, %3 \n" | |
146 | " addu %0, $1 \n" | |
1da177e4 | 147 | |
04988d6f TS |
148 | " addu %0, %4 \n" |
149 | " sltu $1, %0, %4 \n" | |
150 | " addu %0, $1 \n" | |
1da177e4 | 151 | #endif |
875d43e7 | 152 | #ifdef CONFIG_64BIT |
04988d6f TS |
153 | " daddu %0, %2 \n" |
154 | " daddu %0, %3 \n" | |
155 | " daddu %0, %4 \n" | |
156 | " dsll32 $1, %0, 0 \n" | |
157 | " daddu %0, $1 \n" | |
e9728838 | 158 | " dsra32 %0, %0, 0 \n" |
1da177e4 | 159 | #endif |
04988d6f | 160 | " .set pop" |
1da177e4 | 161 | : "=r" (sum) |
66218da2 AN |
162 | : "0" ((__force unsigned long)daddr), |
163 | "r" ((__force unsigned long)saddr), | |
1da177e4 | 164 | #ifdef __MIPSEL__ |
8e3d8433 | 165 | "r" ((proto + len) << 8), |
1da177e4 | 166 | #else |
8e3d8433 | 167 | "r" (proto + len), |
1da177e4 | 168 | #endif |
1d464c26 | 169 | "r" ((__force unsigned long)sum)); |
1da177e4 LT |
170 | |
171 | return sum; | |
172 | } | |
173 | ||
174 | /* | |
175 | * computes the checksum of the TCP/UDP pseudo-header | |
176 | * returns a 16-bit checksum, already complemented | |
177 | */ | |
8e3d8433 | 178 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, |
1da177e4 LT |
179 | unsigned short len, |
180 | unsigned short proto, | |
8e3d8433 | 181 | __wsum sum) |
1da177e4 LT |
182 | { |
183 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); | |
184 | } | |
185 | ||
186 | /* | |
187 | * this routine is used for miscellaneous IP-like checksums, mainly | |
188 | * in icmp.c | |
189 | */ | |
8e3d8433 | 190 | static inline __sum16 ip_compute_csum(const void *buff, int len) |
1da177e4 LT |
191 | { |
192 | return csum_fold(csum_partial(buff, len, 0)); | |
193 | } | |
194 | ||
195 | #define _HAVE_ARCH_IPV6_CSUM | |
8e3d8433 AV |
196 | static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, |
197 | const struct in6_addr *daddr, | |
198 | __u32 len, unsigned short proto, | |
199 | __wsum sum) | |
1da177e4 LT |
200 | { |
201 | __asm__( | |
04988d6f TS |
202 | " .set push # csum_ipv6_magic\n" |
203 | " .set noreorder \n" | |
204 | " .set noat \n" | |
205 | " addu %0, %5 # proto (long in network byte order)\n" | |
206 | " sltu $1, %0, %5 \n" | |
207 | " addu %0, $1 \n" | |
208 | ||
209 | " addu %0, %6 # csum\n" | |
210 | " sltu $1, %0, %6 \n" | |
211 | " lw %1, 0(%2) # four words source address\n" | |
212 | " addu %0, $1 \n" | |
213 | " addu %0, %1 \n" | |
214 | " sltu $1, %0, %1 \n" | |
215 | ||
216 | " lw %1, 4(%2) \n" | |
217 | " addu %0, $1 \n" | |
218 | " addu %0, %1 \n" | |
219 | " sltu $1, %0, %1 \n" | |
220 | ||
221 | " lw %1, 8(%2) \n" | |
222 | " addu %0, $1 \n" | |
223 | " addu %0, %1 \n" | |
224 | " sltu $1, %0, %1 \n" | |
225 | ||
226 | " lw %1, 12(%2) \n" | |
227 | " addu %0, $1 \n" | |
228 | " addu %0, %1 \n" | |
229 | " sltu $1, %0, %1 \n" | |
230 | ||
231 | " lw %1, 0(%3) \n" | |
232 | " addu %0, $1 \n" | |
233 | " addu %0, %1 \n" | |
234 | " sltu $1, %0, %1 \n" | |
235 | ||
236 | " lw %1, 4(%3) \n" | |
237 | " addu %0, $1 \n" | |
238 | " addu %0, %1 \n" | |
239 | " sltu $1, %0, %1 \n" | |
240 | ||
241 | " lw %1, 8(%3) \n" | |
242 | " addu %0, $1 \n" | |
243 | " addu %0, %1 \n" | |
244 | " sltu $1, %0, %1 \n" | |
245 | ||
246 | " lw %1, 12(%3) \n" | |
247 | " addu %0, $1 \n" | |
248 | " addu %0, %1 \n" | |
249 | " sltu $1, %0, %1 \n" | |
250 | ||
251 | " addu %0, $1 # Add final carry\n" | |
252 | " .set pop" | |
1da177e4 LT |
253 | : "=r" (sum), "=r" (proto) |
254 | : "r" (saddr), "r" (daddr), | |
255 | "0" (htonl(len)), "1" (htonl(proto)), "r" (sum)); | |
256 | ||
257 | return csum_fold(sum); | |
258 | } | |
259 | ||
260 | #endif /* _ASM_CHECKSUM_H */ |