diff options
| author | Paul Chaignon <paul.chaignon@gmail.com> | 2025-04-08 11:00:04 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-04-09 20:07:31 -0700 |
| commit | b412fd6bcc4c1696b0674434f56b198950c0e2bf (patch) | |
| tree | db209981bf4fde9f58bab36b8df13fd343eaf452 /tools/include | |
| parent | 690d43d3b36b154d39eb7b0283f5f65582a49d90 (diff) | |
bpf: Clarify role of BPF_F_RECOMPUTE_CSUM
BPF_F_RECOMPUTE_CSUM doesn't update the actual L3 and L4 checksums in
the packet, but simply updates skb->csum (according to skb->ip_summed).
This patch clarifies that to avoid confusions.
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/ff6895d42936f03dbb82334d8bcfd50e00c79086.1744102490.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 07ee73cdf97b..14ef3db844fa 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1995,11 +1995,15 @@ union bpf_attr { * long bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags) * Description * Store *len* bytes from address *from* into the packet - * associated to *skb*, at *offset*. *flags* are a combination of - * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the - * checksum for the packet after storing the bytes) and - * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\ - * **->swhash** and *skb*\ **->l4hash** to 0). + * associated to *skb*, at *offset*. The *flags* are a combination + * of the following values: + * + * **BPF_F_RECOMPUTE_CSUM** + * Automatically update *skb*\ **->csum** after storing the + * bytes. + * **BPF_F_INVALIDATE_HASH** + * Set *skb*\ **->hash**, *skb*\ **->swhash** and *skb*\ + * **->l4hash** to 0. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers |