Commit | Line | Data |
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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> | |
1da177e4 | 21 | #include <asm/checksum.h> |
68f4eae7 JK |
22 | #if !defined(_HAVE_ARCH_COPY_AND_CSUM_FROM_USER) || !defined(HAVE_CSUM_COPY_USER) |
23 | #include <linux/uaccess.h> | |
24 | #endif | |
1da177e4 LT |
25 | |
26 | #ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER | |
5486f5bf | 27 | static __always_inline |
56649d5d | 28 | __wsum csum_and_copy_from_user (const void __user *src, void *dst, |
c693cc46 | 29 | int len) |
1da177e4 | 30 | { |
5904122c | 31 | if (copy_from_user(dst, src, len)) |
c693cc46 AV |
32 | return 0; |
33 | return csum_partial(dst, len, ~0U); | |
1da177e4 LT |
34 | } |
35 | #endif | |
36 | ||
37 | #ifndef HAVE_CSUM_COPY_USER | |
5486f5bf | 38 | static __always_inline __wsum csum_and_copy_to_user |
c693cc46 | 39 | (const void *src, void __user *dst, int len) |
1da177e4 | 40 | { |
c693cc46 | 41 | __wsum sum = csum_partial(src, len, ~0U); |
1da177e4 | 42 | |
001c1a65 AV |
43 | if (copy_to_user(dst, src, len) == 0) |
44 | return sum; | |
c693cc46 | 45 | return 0; |
1da177e4 LT |
46 | } |
47 | #endif | |
48 | ||
6e41c585 | 49 | #ifndef _HAVE_ARCH_CSUM_AND_COPY |
5486f5bf | 50 | static __always_inline __wsum |
cc44c17b | 51 | csum_partial_copy_nocheck(const void *src, void *dst, int len) |
6e41c585 AV |
52 | { |
53 | memcpy(dst, src, len); | |
cc44c17b | 54 | return csum_partial(dst, len, 0); |
6e41c585 AV |
55 | } |
56 | #endif | |
57 | ||
07064c6e | 58 | #ifndef HAVE_ARCH_CSUM_ADD |
5486f5bf | 59 | static __always_inline __wsum csum_add(__wsum csum, __wsum addend) |
1da177e4 | 60 | { |
56649d5d AV |
61 | u32 res = (__force u32)csum; |
62 | res += (__force u32)addend; | |
63 | return (__force __wsum)(res + (res < (__force u32)addend)); | |
1da177e4 | 64 | } |
07064c6e | 65 | #endif |
1da177e4 | 66 | |
5486f5bf | 67 | static __always_inline __wsum csum_sub(__wsum csum, __wsum addend) |
1da177e4 LT |
68 | { |
69 | return csum_add(csum, ~addend); | |
70 | } | |
71 | ||
5486f5bf | 72 | static __always_inline __sum16 csum16_add(__sum16 csum, __be16 addend) |
99f0b958 ED |
73 | { |
74 | u16 res = (__force u16)csum; | |
75 | ||
76 | res += (__force u16)addend; | |
77 | return (__force __sum16)(res + (res < (__force u16)addend)); | |
78 | } | |
79 | ||
5486f5bf | 80 | static __always_inline __sum16 csum16_sub(__sum16 csum, __be16 addend) |
99f0b958 ED |
81 | { |
82 | return csum16_add(csum, ~addend); | |
83 | } | |
84 | ||
3af722cb | 85 | #ifndef HAVE_ARCH_CSUM_SHIFT |
5486f5bf | 86 | static __always_inline __wsum csum_shift(__wsum sum, int offset) |
1da177e4 | 87 | { |
33803963 AD |
88 | /* rotate sum to align it with a 16b boundary */ |
89 | if (offset & 1) | |
594e450b AV |
90 | return (__force __wsum)ror32((__force u32)sum, 8); |
91 | return sum; | |
92 | } | |
3af722cb | 93 | #endif |
33803963 | 94 | |
5486f5bf | 95 | static __always_inline __wsum |
594e450b AV |
96 | csum_block_add(__wsum csum, __wsum csum2, int offset) |
97 | { | |
98 | return csum_add(csum, csum_shift(csum2, offset)); | |
1da177e4 LT |
99 | } |
100 | ||
5486f5bf | 101 | static __always_inline __wsum |
2817a336 DB |
102 | csum_block_add_ext(__wsum csum, __wsum csum2, int offset, int len) |
103 | { | |
104 | return csum_block_add(csum, csum2, offset); | |
105 | } | |
106 | ||
5486f5bf | 107 | static __always_inline __wsum |
56649d5d | 108 | csum_block_sub(__wsum csum, __wsum csum2, int offset) |
1da177e4 | 109 | { |
33803963 | 110 | return csum_block_add(csum, ~csum2, offset); |
56649d5d AV |
111 | } |
112 | ||
5486f5bf | 113 | static __always_inline __wsum csum_unfold(__sum16 n) |
56649d5d AV |
114 | { |
115 | return (__force __wsum)n; | |
1da177e4 LT |
116 | } |
117 | ||
5486f5bf CL |
118 | static __always_inline |
119 | __wsum csum_partial_ext(const void *buff, int len, __wsum sum) | |
cea80ea8 DB |
120 | { |
121 | return csum_partial(buff, len, sum); | |
122 | } | |
123 | ||
f6ab0288 | 124 | #define CSUM_MANGLED_0 ((__force __sum16)0xffff) |
a99a00cf | 125 | |
5486f5bf | 126 | static __always_inline void csum_replace_by_diff(__sum16 *sum, __wsum diff) |
8050c0f0 DB |
127 | { |
128 | *sum = csum_fold(csum_add(diff, ~csum_unfold(*sum))); | |
129 | } | |
130 | ||
5486f5bf | 131 | static __always_inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to) |
a99a00cf | 132 | { |
d53a2aa3 ED |
133 | __wsum tmp = csum_sub(~csum_unfold(*sum), (__force __wsum)from); |
134 | ||
135 | *sum = csum_fold(csum_add(tmp, (__force __wsum)to)); | |
a99a00cf PM |
136 | } |
137 | ||
99f0b958 ED |
138 | /* Implements RFC 1624 (Incremental Internet Checksum) |
139 | * 3. Discussion states : | |
140 | * HC' = ~(~HC + ~m + m') | |
141 | * m : old value of a 16bit field | |
142 | * m' : new value of a 16bit field | |
143 | */ | |
5486f5bf | 144 | static __always_inline void csum_replace2(__sum16 *sum, __be16 old, __be16 new) |
a99a00cf | 145 | { |
99f0b958 | 146 | *sum = ~csum16_add(csum16_sub(~(*sum), old), new); |
a99a00cf PM |
147 | } |
148 | ||
d9b5ae5c PB |
149 | static inline void csum_replace(__wsum *csum, __wsum old, __wsum new) |
150 | { | |
151 | *csum = csum_add(csum_sub(*csum, old), new); | |
152 | } | |
153 | ||
a99a00cf | 154 | struct sk_buff; |
4fc70747 | 155 | void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, |
4b048d6d | 156 | __be32 from, __be32 to, bool pseudohdr); |
4fc70747 JP |
157 | void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, |
158 | const __be32 *from, const __be32 *to, | |
4b048d6d | 159 | bool pseudohdr); |
abc5d1ff TH |
160 | void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb, |
161 | __wsum diff, bool pseudohdr); | |
a99a00cf | 162 | |
5486f5bf CL |
163 | static __always_inline |
164 | void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb, | |
165 | __be16 from, __be16 to, bool pseudohdr) | |
a99a00cf PM |
166 | { |
167 | inet_proto_csum_replace4(sum, skb, (__force __be32)from, | |
168 | (__force __be32)to, pseudohdr); | |
169 | } | |
170 | ||
5486f5bf CL |
171 | static __always_inline __wsum remcsum_adjust(void *ptr, __wsum csum, |
172 | int start, int offset) | |
7c967b22 TH |
173 | { |
174 | __sum16 *psum = (__sum16 *)(ptr + offset); | |
175 | __wsum delta; | |
176 | ||
177 | /* Subtract out checksum up to start */ | |
178 | csum = csum_sub(csum, csum_partial(ptr, start, 0)); | |
179 | ||
180 | /* Set derived checksum in packet */ | |
369620a0 TH |
181 | delta = csum_sub((__force __wsum)csum_fold(csum), |
182 | (__force __wsum)*psum); | |
7c967b22 TH |
183 | *psum = csum_fold(csum); |
184 | ||
185 | return delta; | |
186 | } | |
187 | ||
5486f5bf | 188 | static __always_inline void remcsum_unadjust(__sum16 *psum, __wsum delta) |
26c4f7da | 189 | { |
22fbece1 | 190 | *psum = csum_fold(csum_sub(delta, (__force __wsum)*psum)); |
26c4f7da TH |
191 | } |
192 | ||
5486f5bf | 193 | static __always_inline __wsum wsum_negate(__wsum val) |
45cac675 ED |
194 | { |
195 | return (__force __wsum)-((__force u32)val); | |
196 | } | |
1da177e4 | 197 | #endif |