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