Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * Checksumming functions for IP, TCP, UDP and so on |
| 7 | * |
| 8 | * Authors: Jorge Cwik, <jorge@laser.satlink.net> |
| 9 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> |
| 10 | * Borrows very liberally from tcp.c and ip.c, see those |
| 11 | * files for more names. |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or |
| 14 | * modify it under the terms of the GNU General Public License |
| 15 | * as published by the Free Software Foundation; either version |
| 16 | * 2 of the License, or (at your option) any later version. |
| 17 | */ |
| 18 | |
| 19 | #ifndef _CHECKSUM_H |
| 20 | #define _CHECKSUM_H |
| 21 | |
| 22 | #include <linux/errno.h> |
| 23 | #include <asm/types.h> |
| 24 | #include <asm/byteorder.h> |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 25 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <asm/checksum.h> |
| 27 | |
| 28 | #ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER |
| 29 | static inline |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 30 | __wsum csum_and_copy_from_user (const void __user *src, void *dst, |
| 31 | int len, __wsum sum, int *err_ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | { |
| 33 | if (access_ok(VERIFY_READ, src, len)) |
| 34 | return csum_partial_copy_from_user(src, dst, len, sum, err_ptr); |
| 35 | |
| 36 | if (len) |
| 37 | *err_ptr = -EFAULT; |
| 38 | |
| 39 | return sum; |
| 40 | } |
| 41 | #endif |
| 42 | |
| 43 | #ifndef HAVE_CSUM_COPY_USER |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 44 | static __inline__ __wsum csum_and_copy_to_user |
| 45 | (const void *src, void __user *dst, int len, __wsum sum, int *err_ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | { |
| 47 | sum = csum_partial(src, len, sum); |
| 48 | |
| 49 | if (access_ok(VERIFY_WRITE, dst, len)) { |
| 50 | if (copy_to_user(dst, src, len) == 0) |
| 51 | return sum; |
| 52 | } |
| 53 | if (len) |
| 54 | *err_ptr = -EFAULT; |
| 55 | |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 56 | return (__force __wsum)-1; /* invalid checksum */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | } |
| 58 | #endif |
| 59 | |
Tom Herbert | 07064c6 | 2014-05-02 16:28:03 -0700 | [diff] [blame] | 60 | #ifndef HAVE_ARCH_CSUM_ADD |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 61 | static inline __wsum csum_add(__wsum csum, __wsum addend) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | { |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 63 | u32 res = (__force u32)csum; |
| 64 | res += (__force u32)addend; |
| 65 | return (__force __wsum)(res + (res < (__force u32)addend)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | } |
Tom Herbert | 07064c6 | 2014-05-02 16:28:03 -0700 | [diff] [blame] | 67 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 69 | static inline __wsum csum_sub(__wsum csum, __wsum addend) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | { |
| 71 | return csum_add(csum, ~addend); |
| 72 | } |
| 73 | |
Eric Dumazet | 99f0b95 | 2014-03-23 19:51:36 -0700 | [diff] [blame] | 74 | static inline __sum16 csum16_add(__sum16 csum, __be16 addend) |
| 75 | { |
| 76 | u16 res = (__force u16)csum; |
| 77 | |
| 78 | res += (__force u16)addend; |
| 79 | return (__force __sum16)(res + (res < (__force u16)addend)); |
| 80 | } |
| 81 | |
| 82 | static inline __sum16 csum16_sub(__sum16 csum, __be16 addend) |
| 83 | { |
| 84 | return csum16_add(csum, ~addend); |
| 85 | } |
| 86 | |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 87 | static inline __wsum |
| 88 | csum_block_add(__wsum csum, __wsum csum2, int offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | { |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 90 | u32 sum = (__force u32)csum2; |
Alexander Duyck | 3380396 | 2016-03-09 09:25:26 -0800 | [diff] [blame] | 91 | |
| 92 | /* rotate sum to align it with a 16b boundary */ |
| 93 | if (offset & 1) |
| 94 | sum = ror32(sum, 8); |
| 95 | |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 96 | return csum_add(csum, (__force __wsum)sum); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | } |
| 98 | |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 99 | static inline __wsum |
Daniel Borkmann | 2817a33 | 2013-10-30 11:50:51 +0100 | [diff] [blame] | 100 | csum_block_add_ext(__wsum csum, __wsum csum2, int offset, int len) |
| 101 | { |
| 102 | return csum_block_add(csum, csum2, offset); |
| 103 | } |
| 104 | |
| 105 | static inline __wsum |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 106 | csum_block_sub(__wsum csum, __wsum csum2, int offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | { |
Alexander Duyck | 3380396 | 2016-03-09 09:25:26 -0800 | [diff] [blame] | 108 | return csum_block_add(csum, ~csum2, offset); |
Al Viro | 56649d5 | 2006-11-14 21:23:59 -0800 | [diff] [blame] | 109 | } |
| 110 | |
| 111 | static inline __wsum csum_unfold(__sum16 n) |
| 112 | { |
| 113 | return (__force __wsum)n; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | } |
| 115 | |
Daniel Borkmann | cea80ea | 2013-11-04 17:10:25 +0100 | [diff] [blame] | 116 | static inline __wsum csum_partial_ext(const void *buff, int len, __wsum sum) |
| 117 | { |
| 118 | return csum_partial(buff, len, sum); |
| 119 | } |
| 120 | |
Al Viro | f6ab028 | 2006-11-16 02:36:50 -0800 | [diff] [blame] | 121 | #define CSUM_MANGLED_0 ((__force __sum16)0xffff) |
Patrick McHardy | a99a00c | 2007-11-30 01:14:30 +1100 | [diff] [blame] | 122 | |
Daniel Borkmann | 8050c0f | 2016-03-04 15:15:02 +0100 | [diff] [blame] | 123 | static inline void csum_replace_by_diff(__sum16 *sum, __wsum diff) |
| 124 | { |
| 125 | *sum = csum_fold(csum_add(diff, ~csum_unfold(*sum))); |
| 126 | } |
| 127 | |
Patrick McHardy | a99a00c | 2007-11-30 01:14:30 +1100 | [diff] [blame] | 128 | static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to) |
| 129 | { |
Eric Dumazet | d53a2aa | 2015-05-15 08:52:19 -0700 | [diff] [blame] | 130 | __wsum tmp = csum_sub(~csum_unfold(*sum), (__force __wsum)from); |
| 131 | |
| 132 | *sum = csum_fold(csum_add(tmp, (__force __wsum)to)); |
Patrick McHardy | a99a00c | 2007-11-30 01:14:30 +1100 | [diff] [blame] | 133 | } |
| 134 | |
Eric Dumazet | 99f0b95 | 2014-03-23 19:51:36 -0700 | [diff] [blame] | 135 | /* Implements RFC 1624 (Incremental Internet Checksum) |
| 136 | * 3. Discussion states : |
| 137 | * HC' = ~(~HC + ~m + m') |
| 138 | * m : old value of a 16bit field |
| 139 | * m' : new value of a 16bit field |
| 140 | */ |
| 141 | static inline void csum_replace2(__sum16 *sum, __be16 old, __be16 new) |
Patrick McHardy | a99a00c | 2007-11-30 01:14:30 +1100 | [diff] [blame] | 142 | { |
Eric Dumazet | 99f0b95 | 2014-03-23 19:51:36 -0700 | [diff] [blame] | 143 | *sum = ~csum16_add(csum16_sub(~(*sum), old), new); |
Patrick McHardy | a99a00c | 2007-11-30 01:14:30 +1100 | [diff] [blame] | 144 | } |
| 145 | |
| 146 | struct sk_buff; |
Joe Perches | 4fc7074 | 2013-07-31 17:31:38 -0700 | [diff] [blame] | 147 | void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, |
Tom Herbert | 4b048d6 | 2015-08-17 13:42:25 -0700 | [diff] [blame] | 148 | __be32 from, __be32 to, bool pseudohdr); |
Joe Perches | 4fc7074 | 2013-07-31 17:31:38 -0700 | [diff] [blame] | 149 | void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, |
| 150 | const __be32 *from, const __be32 *to, |
Tom Herbert | 4b048d6 | 2015-08-17 13:42:25 -0700 | [diff] [blame] | 151 | bool pseudohdr); |
Tom Herbert | abc5d1f | 2015-08-17 13:42:26 -0700 | [diff] [blame] | 152 | void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb, |
| 153 | __wsum diff, bool pseudohdr); |
Patrick McHardy | a99a00c | 2007-11-30 01:14:30 +1100 | [diff] [blame] | 154 | |
| 155 | static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb, |
| 156 | __be16 from, __be16 to, |
Tom Herbert | 4b048d6 | 2015-08-17 13:42:25 -0700 | [diff] [blame] | 157 | bool pseudohdr) |
Patrick McHardy | a99a00c | 2007-11-30 01:14:30 +1100 | [diff] [blame] | 158 | { |
| 159 | inet_proto_csum_replace4(sum, skb, (__force __be32)from, |
| 160 | (__force __be32)to, pseudohdr); |
| 161 | } |
| 162 | |
Tom Herbert | 7c967b2 | 2014-11-25 11:21:19 -0800 | [diff] [blame] | 163 | static inline __wsum remcsum_adjust(void *ptr, __wsum csum, |
| 164 | int start, int offset) |
| 165 | { |
| 166 | __sum16 *psum = (__sum16 *)(ptr + offset); |
| 167 | __wsum delta; |
| 168 | |
| 169 | /* Subtract out checksum up to start */ |
| 170 | csum = csum_sub(csum, csum_partial(ptr, start, 0)); |
| 171 | |
| 172 | /* Set derived checksum in packet */ |
Tom Herbert | 369620a | 2015-12-10 12:37:44 -0800 | [diff] [blame] | 173 | delta = csum_sub((__force __wsum)csum_fold(csum), |
| 174 | (__force __wsum)*psum); |
Tom Herbert | 7c967b2 | 2014-11-25 11:21:19 -0800 | [diff] [blame] | 175 | *psum = csum_fold(csum); |
| 176 | |
| 177 | return delta; |
| 178 | } |
| 179 | |
Tom Herbert | 26c4f7d | 2015-02-10 16:30:27 -0800 | [diff] [blame] | 180 | static inline void remcsum_unadjust(__sum16 *psum, __wsum delta) |
| 181 | { |
| 182 | *psum = csum_fold(csum_sub(delta, *psum)); |
| 183 | } |
| 184 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | #endif |