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| author | Paul Chaignon <paul.chaignon@gmail.com> | 2025-04-08 11:00:51 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-19 15:40:39 +0200 |
| commit | 3904dfba2913835cf4ac1ba6b5dd44ce89171aa7 (patch) | |
| tree | 48384028232a9b5b8984c9086cacf9a0be1757d0 /include/uapi | |
| parent | 4649767d62afed95981328c2fea2198b1146e784 (diff) | |
bpf: Clarify the meaning of BPF_F_PSEUDO_HDR
[ Upstream commit 5a15a050df714959f0d5a57ac3201bd1c6594984 ]
In the bpf_l4_csum_replace helper, the BPF_F_PSEUDO_HDR flag should only
be set if the modified header field is part of the pseudo-header.
If you modify for example the UDP ports and pass BPF_F_PSEUDO_HDR,
inet_proto_csum_replace4 will update skb->csum even though it shouldn't
(the port and the UDP checksum updates null each other).
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/5126ef84ba75425b689482cbc98bffe75e5d8ab0.1744102490.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: ead7f9b8de65 ("bpf: Fix L4 csum update on IPv6 in CHECKSUM_COMPLETE")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/bpf.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index fd404729b115..bceb1950ec20 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2051,7 +2051,7 @@ union bpf_attr { * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and * for updates resulting in a null checksum the value is set to * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates - * the checksum is to be computed against a pseudo-header. + * that the modified header field is part of the pseudo-header. * * This helper works in combination with **bpf_csum_diff**\ (), * which does not update the checksum in-place, but offers more |