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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - include/asm-generic/checksum.h
1 #ifndef __ASM_GENERIC_CHECKSUM_H
2 #define __ASM_GENERIC_CHECKSUM_H
5 * computes the checksum of a memory block at buff, length len,
6 * and adds in "sum" (32-bit)
8 * returns a 32-bit number suitable for feeding into itself
11 * this function must be called with even lengths, except
12 * for the last fragment, which may be odd
14 * it's best to have buff aligned on a 32-bit boundary
16 extern __wsum
csum_partial(const void *buff
, int len
, __wsum sum
);
19 * the same as csum_partial, but copies from src while it
22 * here even more important to align src and dst on a 32-bit (or even
23 * better 64-bit) boundary
25 extern __wsum
csum_partial_copy(const void *src
, void *dst
, int len
, __wsum sum
);
28 * the same as csum_partial_copy, but copies from user space.
30 * here even more important to align src and dst on a 32-bit (or even
31 * better 64-bit) boundary
33 extern __wsum
csum_partial_copy_from_user(const void __user
*src
, void *dst
,
34 int len
, __wsum sum
, int *csum_err
);
36 #define csum_partial_copy_nocheck(src, dst, len, sum) \
37 csum_partial_copy((src), (dst), (len), (sum))
40 * This is a version of ip_compute_csum() optimized for IP headers,
41 * which always checksum on 4 octet boundaries.
43 extern __sum16
ip_fast_csum(const void *iph
, unsigned int ihl
);
46 * Fold a partial checksum
48 static inline __sum16
csum_fold(__wsum csum
)
50 u32 sum
= (__force u32
)csum
;
51 sum
= (sum
& 0xffff) + (sum
>> 16);
52 sum
= (sum
& 0xffff) + (sum
>> 16);
53 return (__force __sum16
)~sum
;
56 #ifndef csum_tcpudp_nofold
58 * computes the checksum of the TCP/UDP pseudo-header
59 * returns a 16-bit checksum, already complemented
62 csum_tcpudp_nofold(__be32 saddr
, __be32 daddr
, unsigned short len
,
63 unsigned short proto
, __wsum sum
);
67 csum_tcpudp_magic(__be32 saddr
, __be32 daddr
, unsigned short len
,
68 unsigned short proto
, __wsum sum
)
70 return csum_fold(csum_tcpudp_nofold(saddr
, daddr
, len
, proto
, sum
));
74 * this routine is used for miscellaneous IP-like checksums, mainly
77 extern __sum16
ip_compute_csum(const void *buff
, int len
);
79 #endif /* __ASM_GENERIC_CHECKSUM_H */