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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
26a28fa4 AB |
2 | #ifndef __ASM_GENERIC_CHECKSUM_H |
3 | #define __ASM_GENERIC_CHECKSUM_H | |
4 | ||
5 | /* | |
6 | * computes the checksum of a memory block at buff, length len, | |
7 | * and adds in "sum" (32-bit) | |
8 | * | |
9 | * returns a 32-bit number suitable for feeding into itself | |
10 | * or csum_tcpudp_magic | |
11 | * | |
12 | * this function must be called with even lengths, except | |
13 | * for the last fragment, which may be odd | |
14 | * | |
15 | * it's best to have buff aligned on a 32-bit boundary | |
16 | */ | |
17 | extern __wsum csum_partial(const void *buff, int len, __wsum sum); | |
18 | ||
64e69073 | 19 | #ifndef ip_fast_csum |
26a28fa4 AB |
20 | /* |
21 | * This is a version of ip_compute_csum() optimized for IP headers, | |
22 | * which always checksum on 4 octet boundaries. | |
23 | */ | |
24 | extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); | |
64e69073 | 25 | #endif |
26a28fa4 | 26 | |
64e69073 | 27 | #ifndef csum_fold |
26a28fa4 AB |
28 | /* |
29 | * Fold a partial checksum | |
30 | */ | |
31 | static inline __sum16 csum_fold(__wsum csum) | |
32 | { | |
33 | u32 sum = (__force u32)csum; | |
34 | sum = (sum & 0xffff) + (sum >> 16); | |
35 | sum = (sum & 0xffff) + (sum >> 16); | |
36 | return (__force __sum16)~sum; | |
37 | } | |
64e69073 | 38 | #endif |
26a28fa4 AB |
39 | |
40 | #ifndef csum_tcpudp_nofold | |
41 | /* | |
42 | * computes the checksum of the TCP/UDP pseudo-header | |
43 | * returns a 16-bit checksum, already complemented | |
44 | */ | |
45 | extern __wsum | |
01cfbad7 AD |
46 | csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, |
47 | __u8 proto, __wsum sum); | |
26a28fa4 AB |
48 | #endif |
49 | ||
4e29198e | 50 | #ifndef csum_tcpudp_magic |
26a28fa4 | 51 | static inline __sum16 |
01cfbad7 AD |
52 | csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, |
53 | __u8 proto, __wsum sum) | |
26a28fa4 AB |
54 | { |
55 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); | |
56 | } | |
4e29198e | 57 | #endif |
26a28fa4 AB |
58 | |
59 | /* | |
60 | * this routine is used for miscellaneous IP-like checksums, mainly | |
61 | * in icmp.c | |
62 | */ | |
63 | extern __sum16 ip_compute_csum(const void *buff, int len); | |
64 | ||
65 | #endif /* __ASM_GENERIC_CHECKSUM_H */ |