[PATCH v9 bpf-next 07/14] net: xdp: add multi-buff support to xdp_build_skb_from_frame

Lorenzo Bianconi
2021-06-14T12:51:08Z

Introduce xdp multi-buff support to
__xdp_build_skb_from_frame/xdp_build_skb_from_frame
utility routines.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
net/core/xdp.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/net/core/xdp.c b/net/core/xdp.c
index f61c63115c95..71bedf6049a1 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -582,9 +582,15 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
struct sk_buff *skb,
struct net_device *dev)
{
+ struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
unsigned int headroom, frame_size;
+ int i, num_frags = 0;
void *hard_start;

+ /* xdp multi-buff frame */
+ if (unlikely(xdp_frame_is_mb(xdpf)))
+ num_frags = sinfo->nr_frags;
+
/* Part of headroom was reserved to xdpf */
headroom = sizeof(*xdpf) + xdpf->headroom;

@@ -603,6 +609,13 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
if (xdpf->metasize)
skb_metadata_set(skb, xdpf->metasize);

+ for (i = 0; i < num_frags; i++)
+ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+ skb_frag_page(&sinfo->frags[i]),
+ skb_frag_off(&sinfo->frags[i]),
+ skb_frag_size(&sinfo->frags[i]),
+ xdpf->frame_sz);
+
/* Essential SKB info: protocol and skb->dev */
skb->protocol = eth_type_trans(skb, dev);

--
2.31.1