On Fri, 2026-10-16 at 05:43 -0400, Michael S. Tsirkin wrote:
>
> > > > > - virtio_net_hdr_to_skb(skb, vheader,
> > > > > virtio_legacy_is_little_endian());
> > > > > + if (virtio_net_hdr_to_skb(skb, vheader,
> > > > > + virtio_legacy_is_little_endian()) < 0)
> > > > > + return -1;
> > > > > return 0;
> > > > >
> > > >
> > > > Seems it'd be simpler to just
> > > >
> > > > return virtio_net_hdr_to_skb(...);
> > > >
> > > > As far as I can tell, the function only returns -EINVAL or 0 (never a
> > > > positive value), and the caller only cares about negative (error) or
> > > > positive (no checksum needed), so that'd be equivalent?
> > > >
> > > > johannes
> > >
> > > if raw_verify_header can safely return any errno - i did not want to
> > > audit it.
> >
> > You already used an LLM and still didn't want to? ;-)
> >
> > I checked briefly (by hand) and it seems fine, it's assigned to the
> > function pointer, which only has two callers on the _kern.c side.
> >
> > johannes
>
>
> header_check = vp->verify_header(
>
> mmsg_vector->msg_hdr.msg_iov->iov_base,
> skb,
> vp
> );
> if (header_check < 0) {
> /* Overlay header failed to verify - discard.
> * We can actually keep this skb and reuse it,
> * but that will make the prep logic too
> * complex.
> */
> dev_kfree_skb_irq(skb);
> vp->estats.rx_encaps_errors++;
> (*skbuff_vector) = NULL;
> mmsg_vector++;
> skbuff_vector++;
> continue;
> }
> if (header_check > 0) {
> vp->estats.rx_csum_offload_good++;
> skb->ip_summed = CHECKSUM_UNNECESSARY;
> }
>
>
>
> so any negative is fine, but if we return 1 then it will force to
> CHECKSUM_UNNECESSARY
> which I am not sure is what was intended?
>
Right, but virtio_net_hdr_to_skb() cannot return 1, only 0 on success
and -ERROR on failure?
johannes
