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2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
1da177e4 LT |
2 | /* |
3 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
4 | * operating system. INET is implemented using the BSD Socket | |
5 | * interface as the means of communication with the user level. | |
6 | * | |
7 | * Checksumming functions for IP, TCP, UDP and so on | |
8 | * | |
9 | * Authors: Jorge Cwik, <jorge@laser.satlink.net> | |
10 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | |
11 | * Borrows very liberally from tcp.c and ip.c, see those | |
12 | * files for more names. | |
1da177e4 LT |
13 | */ |
14 | ||
15 | #ifndef _CHECKSUM_H | |
16 | #define _CHECKSUM_H | |
17 | ||
18 | #include <linux/errno.h> | |
19 | #include <asm/types.h> | |
20 | #include <asm/byteorder.h> | |
7c0f6ba6 | 21 | #include <linux/uaccess.h> |
1da177e4 LT |
22 | #include <asm/checksum.h> |
23 | ||
24 | #ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER | |
25 | static inline | |
56649d5d | 26 | __wsum csum_and_copy_from_user (const void __user *src, void *dst, |
c693cc46 | 27 | int len) |
1da177e4 | 28 | { |
5904122c | 29 | if (copy_from_user(dst, src, len)) |
c693cc46 AV |
30 | return 0; |
31 | return csum_partial(dst, len, ~0U); | |
1da177e4 LT |
32 | } |
33 | #endif | |
34 | ||
35 | #ifndef HAVE_CSUM_COPY_USER | |
56649d5d | 36 | static __inline__ __wsum csum_and_copy_to_user |
c693cc46 | 37 | (const void *src, void __user *dst, int len) |
1da177e4 | 38 | { |
c693cc46 | 39 | __wsum sum = csum_partial(src, len, ~0U); |
1da177e4 | 40 | |
001c1a65 AV |
41 | if (copy_to_user(dst, src, len) == 0) |
42 | return sum; | |
c693cc46 | 43 | return 0; |
1da177e4 LT |
44 | } |
45 | #endif | |
46 | ||
6e41c585 AV |
47 | #ifndef _HAVE_ARCH_CSUM_AND_COPY |
48 | static inline __wsum | |
cc44c17b | 49 | csum_partial_copy_nocheck(const void *src, void *dst, int len) |
6e41c585 AV |
50 | { |
51 | memcpy(dst, src, len); | |
cc44c17b | 52 | return csum_partial(dst, len, 0); |
6e41c585 AV |
53 | } |
54 | #endif | |
55 | ||
07064c6e | 56 | #ifndef HAVE_ARCH_CSUM_ADD |
56649d5d | 57 | static inline __wsum csum_add(__wsum csum, __wsum addend) |
1da177e4 | 58 | { |
56649d5d AV |
59 | u32 res = (__force u32)csum; |
60 | res += (__force u32)addend; | |
61 | return (__force __wsum)(res + (res < (__force u32)addend)); | |
1da177e4 | 62 | } |
07064c6e | 63 | #endif |
1da177e4 | 64 | |
56649d5d | 65 | static inline __wsum csum_sub(__wsum csum, __wsum addend) |
1da177e4 LT |
66 | { |
67 | return csum_add(csum, ~addend); | |
68 | } | |
69 | ||
99f0b958 ED |
70 | static inline __sum16 csum16_add(__sum16 csum, __be16 addend) |
71 | { | |
72 | u16 res = (__force u16)csum; | |
73 | ||
74 | res += (__force u16)addend; | |
75 | return (__force __sum16)(res + (res < (__force u16)addend)); | |
76 | } | |
77 | ||
78 | static inline __sum16 csum16_sub(__sum16 csum, __be16 addend) | |
79 | { | |
80 | return csum16_add(csum, ~addend); | |
81 | } | |
82 | ||
594e450b | 83 | static inline __wsum csum_shift(__wsum sum, int offset) |
1da177e4 | 84 | { |
33803963 AD |
85 | /* rotate sum to align it with a 16b boundary */ |
86 | if (offset & 1) | |
594e450b AV |
87 | return (__force __wsum)ror32((__force u32)sum, 8); |
88 | return sum; | |
89 | } | |
33803963 | 90 | |
594e450b AV |
91 | static inline __wsum |
92 | csum_block_add(__wsum csum, __wsum csum2, int offset) | |
93 | { | |
94 | return csum_add(csum, csum_shift(csum2, offset)); | |
1da177e4 LT |
95 | } |
96 | ||
2817a336 DB |
97 | static inline __wsum |
98 | csum_block_add_ext(__wsum csum, __wsum csum2, int offset, int len) | |
99 | { | |
100 | return csum_block_add(csum, csum2, offset); | |
101 | } | |
102 | ||
56649d5d AV |
103 | static inline __wsum |
104 | csum_block_sub(__wsum csum, __wsum csum2, int offset) | |
1da177e4 | 105 | { |
33803963 | 106 | return csum_block_add(csum, ~csum2, offset); |
56649d5d AV |
107 | } |
108 | ||
109 | static inline __wsum csum_unfold(__sum16 n) | |
110 | { | |
111 | return (__force __wsum)n; | |
1da177e4 LT |
112 | } |
113 | ||
cea80ea8 DB |
114 | static inline __wsum csum_partial_ext(const void *buff, int len, __wsum sum) |
115 | { | |
116 | return csum_partial(buff, len, sum); | |
117 | } | |
118 | ||
f6ab0288 | 119 | #define CSUM_MANGLED_0 ((__force __sum16)0xffff) |
a99a00cf | 120 | |
8050c0f0 DB |
121 | static inline void csum_replace_by_diff(__sum16 *sum, __wsum diff) |
122 | { | |
123 | *sum = csum_fold(csum_add(diff, ~csum_unfold(*sum))); | |
124 | } | |
125 | ||
a99a00cf PM |
126 | static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to) |
127 | { | |
d53a2aa3 ED |
128 | __wsum tmp = csum_sub(~csum_unfold(*sum), (__force __wsum)from); |
129 | ||
130 | *sum = csum_fold(csum_add(tmp, (__force __wsum)to)); | |
a99a00cf PM |
131 | } |
132 | ||
99f0b958 ED |
133 | /* Implements RFC 1624 (Incremental Internet Checksum) |
134 | * 3. Discussion states : | |
135 | * HC' = ~(~HC + ~m + m') | |
136 | * m : old value of a 16bit field | |
137 | * m' : new value of a 16bit field | |
138 | */ | |
139 | static inline void csum_replace2(__sum16 *sum, __be16 old, __be16 new) | |
a99a00cf | 140 | { |
99f0b958 | 141 | *sum = ~csum16_add(csum16_sub(~(*sum), old), new); |
a99a00cf PM |
142 | } |
143 | ||
144 | struct sk_buff; | |
4fc70747 | 145 | void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, |
4b048d6d | 146 | __be32 from, __be32 to, bool pseudohdr); |
4fc70747 JP |
147 | void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, |
148 | const __be32 *from, const __be32 *to, | |
4b048d6d | 149 | bool pseudohdr); |
abc5d1ff TH |
150 | void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb, |
151 | __wsum diff, bool pseudohdr); | |
a99a00cf PM |
152 | |
153 | static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb, | |
154 | __be16 from, __be16 to, | |
4b048d6d | 155 | bool pseudohdr) |
a99a00cf PM |
156 | { |
157 | inet_proto_csum_replace4(sum, skb, (__force __be32)from, | |
158 | (__force __be32)to, pseudohdr); | |
159 | } | |
160 | ||
7c967b22 TH |
161 | static inline __wsum remcsum_adjust(void *ptr, __wsum csum, |
162 | int start, int offset) | |
163 | { | |
164 | __sum16 *psum = (__sum16 *)(ptr + offset); | |
165 | __wsum delta; | |
166 | ||
167 | /* Subtract out checksum up to start */ | |
168 | csum = csum_sub(csum, csum_partial(ptr, start, 0)); | |
169 | ||
170 | /* Set derived checksum in packet */ | |
369620a0 TH |
171 | delta = csum_sub((__force __wsum)csum_fold(csum), |
172 | (__force __wsum)*psum); | |
7c967b22 TH |
173 | *psum = csum_fold(csum); |
174 | ||
175 | return delta; | |
176 | } | |
177 | ||
26c4f7da TH |
178 | static inline void remcsum_unadjust(__sum16 *psum, __wsum delta) |
179 | { | |
22fbece1 | 180 | *psum = csum_fold(csum_sub(delta, (__force __wsum)*psum)); |
26c4f7da TH |
181 | } |
182 | ||
1da177e4 | 183 | #endif |