On Fri, Jul 28, 2023 at 07:39:14PM +0200, Larysa Zaremba wrote:
>
> +union xdp_csum_info {
> + /* Checksum referred to by ``csum_start + csum_offset`` is considered
> + * valid, but was never calculated, TX device has to do this,
> + * starting from csum_start packet byte.
> + * Any preceding checksums are also considered valid.
> + * Available, if ``status == XDP_CHECKSUM_PARTIAL``.
> + */
> + struct {
> + u16 csum_start;
> + u16 csum_offset;
> + };
> +
CHECKSUM_PARTIAL makes sense on TX, but this RX. I don't see in the above.
> + /* Checksum, calculated over the whole packet.
> + * Available, if ``status & XDP_CHECKSUM_COMPLETE``.
> + */
> + u32 checksum;
imo XDP RX should only support XDP_CHECKSUM_COMPLETE with u32 checksum
or XDP_CHECKSUM_UNNECESSARY.
> +};
> +
> +enum xdp_csum_status {
> + /* HW had parsed several transport headers and validated their
> + * checksums, same as ``CHECKSUM_UNNECESSARY`` in ``sk_buff``.
> + * 3 least significant bytes contain number of consecutive checksums,
> + * starting with the outermost, reported by hardware as valid.
> + * ``sk_buff`` checksum level (``csum_level``) notation is provided
> + * for driver developers.
> + */
> + XDP_CHECKSUM_VALID_LVL0 = 1, /* 1 outermost checksum */
> + XDP_CHECKSUM_VALID_LVL1 = 2, /* 2 outermost checksums */
> + XDP_CHECKSUM_VALID_LVL2 = 3, /* 3 outermost checksums */
> + XDP_CHECKSUM_VALID_LVL3 = 4, /* 4 outermost checksums */
> + XDP_CHECKSUM_VALID_NUM_MASK = GENMASK(2, 0),
> + XDP_CHECKSUM_VALID = XDP_CHECKSUM_VALID_NUM_MASK,
I don't see what bpf prog suppose to do with these levels.
The driver should pick between 3:
XDP_CHECKSUM_UNNECESSARY, XDP_CHECKSUM_COMPLETE, XDP_CHECKSUM_NONE.
No levels and no anything partial. please.
