diff options
| -rw-r--r-- | include/net/checksum.h | 5 | ||||
| -rw-r--r-- | net/core/filter.c | 6 |
2 files changed, 11 insertions, 0 deletions
diff --git a/include/net/checksum.h b/include/net/checksum.h index 10a16b5bd1c7..abffc64e7300 100644 --- a/include/net/checksum.h +++ b/include/net/checksum.h @@ -120,6 +120,11 @@ static inline __wsum csum_partial_ext(const void *buff, int len, __wsum sum) #define CSUM_MANGLED_0 ((__force __sum16)0xffff) +static inline void csum_replace_by_diff(__sum16 *sum, __wsum diff) +{ + *sum = csum_fold(csum_add(diff, ~csum_unfold(*sum))); +} + static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to) { __wsum tmp = csum_sub(~csum_unfold(*sum), (__force __wsum)from); diff --git a/net/core/filter.c b/net/core/filter.c index 69f4ffc0a282..356a251657a5 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1447,6 +1447,12 @@ static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) return -EFAULT; switch (flags & BPF_F_HDR_FIELD_MASK) { + case 0: + if (unlikely(from != 0)) + return -EINVAL; + + csum_replace_by_diff(ptr, to); + break; case 2: csum_replace2(ptr, from, to); break; |