]>
Commit | Line | Data |
---|---|---|
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 AV |
26 | __wsum csum_and_copy_from_user (const void __user *src, void *dst, |
27 | int len, __wsum sum, int *err_ptr) | |
1da177e4 | 28 | { |
96d4f267 | 29 | if (access_ok(src, len)) |
1da177e4 LT |
30 | return csum_partial_copy_from_user(src, dst, len, sum, err_ptr); |
31 | ||
32 | if (len) | |
33 | *err_ptr = -EFAULT; | |
34 | ||
35 | return sum; | |
36 | } | |
37 | #endif | |
38 | ||
39 | #ifndef HAVE_CSUM_COPY_USER | |
56649d5d AV |
40 | static __inline__ __wsum csum_and_copy_to_user |
41 | (const void *src, void __user *dst, int len, __wsum sum, int *err_ptr) | |
1da177e4 LT |
42 | { |
43 | sum = csum_partial(src, len, sum); | |
44 | ||
96d4f267 | 45 | if (access_ok(dst, len)) { |
1da177e4 LT |
46 | if (copy_to_user(dst, src, len) == 0) |
47 | return sum; | |
48 | } | |
49 | if (len) | |
50 | *err_ptr = -EFAULT; | |
51 | ||
56649d5d | 52 | return (__force __wsum)-1; /* invalid checksum */ |
1da177e4 LT |
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 | ||
56649d5d AV |
83 | static inline __wsum |
84 | csum_block_add(__wsum csum, __wsum csum2, int offset) | |
1da177e4 | 85 | { |
56649d5d | 86 | u32 sum = (__force u32)csum2; |
33803963 AD |
87 | |
88 | /* rotate sum to align it with a 16b boundary */ | |
89 | if (offset & 1) | |
90 | sum = ror32(sum, 8); | |
91 | ||
56649d5d | 92 | return csum_add(csum, (__force __wsum)sum); |
1da177e4 LT |
93 | } |
94 | ||
2817a336 DB |
95 | static inline __wsum |
96 | csum_block_add_ext(__wsum csum, __wsum csum2, int offset, int len) | |
97 | { | |
98 | return csum_block_add(csum, csum2, offset); | |
99 | } | |
100 | ||
56649d5d AV |
101 | static inline __wsum |
102 | csum_block_sub(__wsum csum, __wsum csum2, int offset) | |
1da177e4 | 103 | { |
33803963 | 104 | return csum_block_add(csum, ~csum2, offset); |
56649d5d AV |
105 | } |
106 | ||
107 | static inline __wsum csum_unfold(__sum16 n) | |
108 | { | |
109 | return (__force __wsum)n; | |
1da177e4 LT |
110 | } |
111 | ||
cea80ea8 DB |
112 | static inline __wsum csum_partial_ext(const void *buff, int len, __wsum sum) |
113 | { | |
114 | return csum_partial(buff, len, sum); | |
115 | } | |
116 | ||
f6ab0288 | 117 | #define CSUM_MANGLED_0 ((__force __sum16)0xffff) |
a99a00cf | 118 | |
8050c0f0 DB |
119 | static inline void csum_replace_by_diff(__sum16 *sum, __wsum diff) |
120 | { | |
121 | *sum = csum_fold(csum_add(diff, ~csum_unfold(*sum))); | |
122 | } | |
123 | ||
a99a00cf PM |
124 | static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to) |
125 | { | |
d53a2aa3 ED |
126 | __wsum tmp = csum_sub(~csum_unfold(*sum), (__force __wsum)from); |
127 | ||
128 | *sum = csum_fold(csum_add(tmp, (__force __wsum)to)); | |
a99a00cf PM |
129 | } |
130 | ||
99f0b958 ED |
131 | /* Implements RFC 1624 (Incremental Internet Checksum) |
132 | * 3. Discussion states : | |
133 | * HC' = ~(~HC + ~m + m') | |
134 | * m : old value of a 16bit field | |
135 | * m' : new value of a 16bit field | |
136 | */ | |
137 | static inline void csum_replace2(__sum16 *sum, __be16 old, __be16 new) | |
a99a00cf | 138 | { |
99f0b958 | 139 | *sum = ~csum16_add(csum16_sub(~(*sum), old), new); |
a99a00cf PM |
140 | } |
141 | ||
142 | struct sk_buff; | |
4fc70747 | 143 | void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, |
4b048d6d | 144 | __be32 from, __be32 to, bool pseudohdr); |
4fc70747 JP |
145 | void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, |
146 | const __be32 *from, const __be32 *to, | |
4b048d6d | 147 | bool pseudohdr); |
abc5d1ff TH |
148 | void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb, |
149 | __wsum diff, bool pseudohdr); | |
a99a00cf PM |
150 | |
151 | static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb, | |
152 | __be16 from, __be16 to, | |
4b048d6d | 153 | bool pseudohdr) |
a99a00cf PM |
154 | { |
155 | inet_proto_csum_replace4(sum, skb, (__force __be32)from, | |
156 | (__force __be32)to, pseudohdr); | |
157 | } | |
158 | ||
7c967b22 TH |
159 | static inline __wsum remcsum_adjust(void *ptr, __wsum csum, |
160 | int start, int offset) | |
161 | { | |
162 | __sum16 *psum = (__sum16 *)(ptr + offset); | |
163 | __wsum delta; | |
164 | ||
165 | /* Subtract out checksum up to start */ | |
166 | csum = csum_sub(csum, csum_partial(ptr, start, 0)); | |
167 | ||
168 | /* Set derived checksum in packet */ | |
369620a0 TH |
169 | delta = csum_sub((__force __wsum)csum_fold(csum), |
170 | (__force __wsum)*psum); | |
7c967b22 TH |
171 | *psum = csum_fold(csum); |
172 | ||
173 | return delta; | |
174 | } | |
175 | ||
26c4f7da TH |
176 | static inline void remcsum_unadjust(__sum16 *psum, __wsum delta) |
177 | { | |
22fbece1 | 178 | *psum = csum_fold(csum_sub(delta, (__force __wsum)*psum)); |
26c4f7da TH |
179 | } |
180 | ||
1da177e4 | 181 | #endif |