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| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
|---|---|
| 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 | |
| 19 | #ifndef ip_fast_csum |
| 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); |
| 25 | #endif |
| 26 | |
| 27 | #ifndef csum_fold |
| 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 | } |
| 38 | #endif |
| 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 |
| 46 | csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, |
| 47 | __u8 proto, __wsum sum); |
| 48 | #endif |
| 49 | |
| 50 | #ifndef csum_tcpudp_magic |
| 51 | static inline __sum16 |
| 52 | csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, |
| 53 | __u8 proto, __wsum sum) |
| 54 | { |
| 55 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
| 56 | } |
| 57 | #endif |
| 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 */ |
| 66 |
Warning: This file is not a C or C++ file. It does not have highlighting.