[PATCH bpf-next V1 3/7] net: xdp: Add kfuncs to store hw metadata in xdp_buff

[Jesper Dangaard Brouer <hawk@xxxxxxxxxx>]

From: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>

Introduce the following kfuncs to store hw metadata provided by the NIC
into the xdp_buff struct:

- rx-hash: bpf_xdp_store_rx_hash
- rx-vlan: bpf_xdp_store_rx_vlan
- rx-hw-ts: bpf_xdp_store_rx_ts

Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
Signed-off-by: Jesper Dangaard Brouer <hawk@xxxxxxxxxx>
---
 include/net/xdp.h |    5 +++++
 net/core/xdp.c    |   45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 5dcdf634ae4a..ef73f0bcc441 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -153,6 +153,11 @@ static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp)
 	xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC;
 }
 
+static __always_inline bool xdp_buff_has_valid_meta_area(struct xdp_buff *xdp)
+{
+	return !!(xdp->flags & XDP_FLAGS_META_AREA);
+}
+
 static __always_inline void
 xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
 {
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 61edbd424494..7d59543d7916 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -957,12 +957,57 @@ __bpf_kfunc int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
 	return -EOPNOTSUPP;
 }
 
+__bpf_kfunc int bpf_xdp_store_rx_hash(struct xdp_md *ctx, u32 hash,
+				      enum xdp_rss_hash_type rss_type)
+{
+	struct xdp_buff *xdp = (struct xdp_buff *)ctx;
+
+	if (!xdp_buff_has_valid_meta_area(xdp))
+		return -ENOSPC;
+
+	xdp->rx_meta->hash.val = hash;
+	xdp->rx_meta->hash.type = rss_type;
+	xdp->flags |= XDP_FLAGS_META_RX_HASH;
+
+	return 0;
+}
+
+__bpf_kfunc int bpf_xdp_store_rx_vlan(struct xdp_md *ctx, __be16 vlan_proto,
+				      u16 vlan_tci)
+{
+	struct xdp_buff *xdp = (struct xdp_buff *)ctx;
+
+	if (!xdp_buff_has_valid_meta_area(xdp))
+		return -ENOSPC;
+
+	xdp->rx_meta->vlan.proto = vlan_proto;
+	xdp->rx_meta->vlan.tci = vlan_tci;
+	xdp->flags |= XDP_FLAGS_META_RX_VLAN;
+
+	return 0;
+}
+
+__bpf_kfunc int bpf_xdp_store_rx_ts(struct xdp_md *ctx, u64 ts)
+{
+	struct xdp_buff *xdp = (struct xdp_buff *)ctx;
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
+	struct skb_shared_hwtstamps *shwt = &sinfo->hwtstamps;
+
+	shwt->hwtstamp = ts;
+	xdp->flags |= XDP_FLAGS_META_RX_TS;
+
+	return 0;
+}
+
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(xdp_metadata_kfunc_ids)
 #define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
 XDP_METADATA_KFUNC_xxx
 #undef XDP_METADATA_KFUNC
+BTF_ID_FLAGS(func, bpf_xdp_store_rx_hash)
+BTF_ID_FLAGS(func, bpf_xdp_store_rx_vlan)
+BTF_ID_FLAGS(func, bpf_xdp_store_rx_ts)
 BTF_KFUNCS_END(xdp_metadata_kfunc_ids)
 
 static const struct btf_kfunc_id_set xdp_metadata_kfunc_set = {