Re: [PATCH RESEND bpf-next 09/15] xdp: Add VLAN tag hint

Stanislav Fomichev
2023-05-12T18:30:13Z

On 05/12, Larysa Zaremba wrote:
> Implement functionality that enables drivers to expose VLAN tag
> to XDP code.
>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>

Acked-by: Stanislav Fomichev <sdf@google.com>

> ---
> Documentation/networking/xdp-rx-metadata.rst | 11 ++++++++-
> include/linux/netdevice.h | 2 ++
> include/net/xdp.h | 4 ++++
> kernel/bpf/offload.c | 4 ++++
> net/core/xdp.c | 24 ++++++++++++++++++++
> 5 files changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst
> index 25ce72af81c2..73a78029c596 100644
> --- a/Documentation/networking/xdp-rx-metadata.rst
> +++ b/Documentation/networking/xdp-rx-metadata.rst
> @@ -18,7 +18,16 @@ Currently, the following kfuncs are supported. In the future, as more
> metadata is supported, this set will grow:
>
> .. kernel-doc:: net/core/xdp.c
> - :identifiers: bpf_xdp_metadata_rx_timestamp bpf_xdp_metadata_rx_hash
> + :identifiers: bpf_xdp_metadata_rx_timestamp
> +
> +.. kernel-doc:: net/core/xdp.c
> + :identifiers: bpf_xdp_metadata_rx_hash
> +
> +.. kernel-doc:: net/core/xdp.c
> + :identifiers: bpf_xdp_metadata_rx_ctag
> +
> +.. kernel-doc:: net/core/xdp.c
> + :identifiers: bpf_xdp_metadata_rx_stag
>
> An XDP program can use these kfuncs to read the metadata into stack
> variables for its own consumption. Or, to pass the metadata on to other
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 08fbd4622ccf..fdae37fe11f5 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1655,6 +1655,8 @@ struct xdp_metadata_ops {
> int (*xmo_rx_timestamp)(const struct xdp_md *ctx, u64 *timestamp);
> int (*xmo_rx_hash)(const struct xdp_md *ctx, u32 *hash,
> enum xdp_rss_hash_type *rss_type);
> + int (*xmo_rx_ctag)(const struct xdp_md *ctx, u16 *vlan_tag);
> + int (*xmo_rx_stag)(const struct xdp_md *ctx, u16 *vlan_tag);
> };
>
> /**
> diff --git a/include/net/xdp.h b/include/net/xdp.h
> index 6381560efae2..2db7439fc60f 100644
> --- a/include/net/xdp.h
> +++ b/include/net/xdp.h
> @@ -389,6 +389,10 @@ void xdp_attachment_setup(struct xdp_attachment_info *info,
> bpf_xdp_metadata_rx_timestamp) \
> XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \
> bpf_xdp_metadata_rx_hash) \
> + XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_CTAG, \
> + bpf_xdp_metadata_rx_ctag) \
> + XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_STAG, \
> + bpf_xdp_metadata_rx_stag) \
>
> enum {
> #define XDP_METADATA_KFUNC(name, _) name,
> diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
> index d9c9f45e3529..2c6b6e82cfac 100644
> --- a/kernel/bpf/offload.c
> +++ b/kernel/bpf/offload.c
> @@ -848,6 +848,10 @@ void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
> p = ops->xmo_rx_timestamp;
> else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_HASH))
> p = ops->xmo_rx_hash;
> + else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_CTAG))
> + p = ops->xmo_rx_ctag;
> + else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_STAG))
> + p = ops->xmo_rx_stag;
> out:
> up_read(&bpf_devs_lock);
>
> diff --git a/net/core/xdp.c b/net/core/xdp.c
> index 41e5ca8643ec..eff21501609f 100644
> --- a/net/core/xdp.c
> +++ b/net/core/xdp.c
> @@ -738,6 +738,30 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
> return -EOPNOTSUPP;
> }
>
> +/**
> + * bpf_xdp_metadata_rx_ctag - Read XDP packet inner vlan tag.
> + * @ctx: XDP context pointer.
> + * @vlan_tag: Return value pointer.
> + *
> + * Returns 0 on success or ``-errno`` on error.
> + */
> +__bpf_kfunc int bpf_xdp_metadata_rx_ctag(const struct xdp_md *ctx, u16 *vlan_tag)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +/**
> + * bpf_xdp_metadata_rx_stag - Read XDP packet outer vlan tag.
> + * @ctx: XDP context pointer.
> + * @vlan_tag: Return value pointer.
> + *
> + * Returns 0 on success or ``-errno`` on error.
> + */
> +__bpf_kfunc int bpf_xdp_metadata_rx_stag(const struct xdp_md *ctx, u16 *vlan_tag)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> __diag_pop();
>
> BTF_SET8_START(xdp_metadata_kfunc_ids)
> --
> 2.35.3
>