diff options
Diffstat (limited to 'include/net/checksum.h')
| -rw-r--r-- | include/net/checksum.h | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/include/net/checksum.h b/include/net/checksum.h index 87cb1903640d..e339a9513e29 100644 --- a/include/net/checksum.h +++ b/include/net/checksum.h @@ -122,9 +122,7 @@ static inline __wsum csum_partial_ext(const void *buff, int len, __wsum sum) static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to) { - __be32 diff[] = { ~from, to }; - - *sum = csum_fold(csum_partial(diff, sizeof(diff), ~csum_unfold(*sum))); + *sum = csum_fold(csum_add(csum_sub(~csum_unfold(*sum), from), to)); } /* Implements RFC 1624 (Incremental Internet Checksum) @@ -153,4 +151,20 @@ static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb, (__force __be32)to, pseudohdr); } +static inline __wsum remcsum_adjust(void *ptr, __wsum csum, + int start, int offset) +{ + __sum16 *psum = (__sum16 *)(ptr + offset); + __wsum delta; + + /* Subtract out checksum up to start */ + csum = csum_sub(csum, csum_partial(ptr, start, 0)); + + /* Set derived checksum in packet */ + delta = csum_sub(csum_fold(csum), *psum); + *psum = csum_fold(csum); + + return delta; +} + #endif |