> diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> --- a/drivers/net/veth.c
> +++ b/drivers/net/veth.c
> @@ -1693,6 +1693,25 @@ static int veth_xdp_rx_vlan_tag(const struct xdp_md
> *ctx, __be16 *vlan_proto,
> return err;
> }
>
> +static int veth_xdp_rx_checksum(const struct xdp_md *ctx,
> + enum xdp_checksum *ip_summed,
> + u32 *cksum_meta)
> +{
> + const struct veth_xdp_buff *_ctx = (void *)ctx;
> + const struct sk_buff *skb = _ctx->skb;
> +
> + if (!skb)
> + return -ENODATA;
> +
> + /* For locally generated packets ip_summed is set to
> + * CHECKSUM_PARTIAL.
> + */
> + *ip_summed = skb->ip_summed;
> + *cksum_meta = 0;
Should cksum_meta return different values based on ip_summed?
The API documentation in net/core/xdp.c states that cksum_meta should contain:
- the hw computed checksum value for XDP_CHECKSUM_COMPLETE
- the csum_level for XDP_CHECKSUM_UNNECESSARY
- 0 for XDP_CHECKSUM_NONE and XDP_CHECKSUM_PARTIAL
The ice driver implementation in this same series handles these cases:
switch (ip_summed) {
case XDP_CHECKSUM_COMPLETE:
*cksum_meta = csum_unfold(...); /* hw computed checksum */
break;
case XDP_CHECKSUM_UNNECESSARY:
if (tunnel)
*cksum_meta = 1; /* csum_level */
break;
default:
*cksum_meta = 0;
break;
}
While veth typically handles locally generated packets (CHECKSUM_PARTIAL) or
packets with CHECKSUM_NONE, packets forwarded from other interfaces could have
CHECKSUM_COMPLETE or CHECKSUM_UNNECESSARY with csum_level > 0.
Would something like the following be more consistent with the API:
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
*cksum_meta = skb->csum;
break;
case CHECKSUM_UNNECESSARY:
*cksum_meta = skb->csum_level;
break;
default:
*cksum_meta = 0;
break;
}
> +
> + return 0;
> +}
[ ... ]
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/21875603263
AI-authorship-score: low
AI-authorship-explanation: The commit follows established kernel patterns, has
a concise commit message, and is authored by a known kernel contributor with
extensive networking experience.
issues-found: 1
issue-severity-score: low
issue-severity-explanation: API inconsistency where cksum_meta always returns 0
instead of returning skb->csum for CHECKSUM_COMPLETE or skb->csum_level for
CHECKSUM_UNNECESSARY as documented.
