| | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| | 2 | #ifndef __ASM_GENERIC_CHECKSUM_H |
| | 3 | #define __ASM_GENERIC_CHECKSUM_H |
| | 4 | |
| | 5 | #include <linux/bitops.h> |
| | 6 | |
| | 7 | /* |
| | 8 | * computes the checksum of a memory block at buff, length len, |
| | 9 | * and adds in "sum" (32-bit) |
| | 10 | * |
| | 11 | * returns a 32-bit number suitable for feeding into itself |
| | 12 | * or csum_tcpudp_magic |
| | 13 | * |
| | 14 | * this function must be called with even lengths, except |
| | 15 | * for the last fragment, which may be odd |
| | 16 | * |
| | 17 | * it's best to have buff aligned on a 32-bit boundary |
| | 18 | */ |
| | 19 | extern __wsum csum_partial(const void *buff, int len, __wsum sum); |
| | 20 | |
| | 21 | #ifndef ip_fast_csum |
| | 22 | /* |
| | 23 | * This is a version of ip_compute_csum() optimized for IP headers, |
| | 24 | * which always checksum on 4 octet boundaries. |
| | 25 | */ |
| | 26 | extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); |
| | 27 | #endif |
| | 28 | |
| | 29 | #ifndef csum_fold |
| | 30 | /* |
| | 31 | * Fold a partial checksum |
| | 32 | */ |
| | 33 | static inline __sum16 csum_fold(__wsum csum) |
| | 34 | { |
| | 35 | u32 sum = (__force u32)csum; |
| | 36 | return (__force __sum16)((~sum - ror32(sum, 16)) >> 16); |
| | 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 */ |
projects / linux-2.6-block.git / blame_incremental