diff options
| author | Paul Chaignon <paul.chaignon@gmail.com> | 2025-04-08 11:00:51 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-04-09 20:07:31 -0700 |
| commit | 5a15a050df714959f0d5a57ac3201bd1c6594984 (patch) | |
| tree | 1d4e09bcdc57f7354bfaf0930eb9a8a00aee7332 | |
| parent | b412fd6bcc4c1696b0674434f56b198950c0e2bf (diff) | |
bpf: Clarify the meaning of BPF_F_PSEUDO_HDR
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>
| -rw-r--r-- | include/uapi/linux/bpf.h | 2 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 14ef3db844fa..71d5ac83cf5d 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2055,7 +2055,7 @@ 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 diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 14ef3db844fa..71d5ac83cf5d 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2055,7 +2055,7 @@ 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 |