Commit 97a0e1ea authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Alexei Starovoitov
Browse files

net, xdp: Introduce __xdp_build_skb_from_frame utility routine 



Introduce __xdp_build_skb_from_frame utility routine to build
the skb from xdp_frame. Rely on __xdp_build_skb_from_frame in
cpumap code.

Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/4f9f4c6b3dd3933770c617eb6689dbc0c6e25863.1610475660.git.lorenzo@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 09c02d55

include/net/xdp.h

+3 −0
Original line number Diff line number Diff line
@@ -164,6 +164,9 @@ void xdp_warn(const char *msg, const char *func, const int line); 
#define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__)



struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp);

struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,

					   struct sk_buff *skb,

					   struct net_device *dev);



static inline

void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)

kernel/bpf/cpumap.c

+2 −44
Original line number Diff line number Diff line
@@ -141,49 +141,6 @@ static void cpu_map_kthread_stop(struct work_struct *work) 
	kthread_stop(rcpu->kthread);

}



static struct sk_buff *cpu_map_build_skb(struct xdp_frame *xdpf,

					 struct sk_buff *skb)

{

	unsigned int hard_start_headroom;

	unsigned int frame_size;

	void *pkt_data_start;



	/* Part of headroom was reserved to xdpf */

	hard_start_headroom = sizeof(struct xdp_frame) +  xdpf->headroom;



	/* Memory size backing xdp_frame data already have reserved

	 * room for build_skb to place skb_shared_info in tailroom.

	 */

	frame_size = xdpf->frame_sz;



	pkt_data_start = xdpf->data - hard_start_headroom;

	skb = build_skb_around(skb, pkt_data_start, frame_size);

	if (unlikely(!skb))

		return NULL;



	skb_reserve(skb, hard_start_headroom);

	__skb_put(skb, xdpf->len);

	if (xdpf->metasize)

		skb_metadata_set(skb, xdpf->metasize);



	/* Essential SKB info: protocol and skb->dev */

	skb->protocol = eth_type_trans(skb, xdpf->dev_rx);



	/* Optional SKB info, currently missing:

	 * - HW checksum info		(skb->ip_summed)

	 * - HW RX hash			(skb_set_hash)

	 * - RX ring dev queue index	(skb_record_rx_queue)

	 */



	/* Until page_pool get SKB return path, release DMA here */

	xdp_release_frame(xdpf);



	/* Allow SKB to reuse area used by xdp_frame */

	xdp_scrub_frame(xdpf);



	return skb;

}



static void __cpu_map_ring_cleanup(struct ptr_ring *ring)

{

	/* The tear-down procedure should have made sure that queue is
@@ -350,7 +307,8 @@ static int cpu_map_kthread_run(void *data) 
			struct sk_buff *skb = skbs[i];

			int ret;



			skb = cpu_map_build_skb(xdpf, skb);

			skb = __xdp_build_skb_from_frame(xdpf, skb,

							 xdpf->dev_rx);

			if (!skb) {

				xdp_return_frame(xdpf);

				continue;

net/core/xdp.c

+44 −0
Original line number Diff line number Diff line
@@ -513,3 +513,47 @@ void xdp_warn(const char *msg, const char *func, const int line) 
	WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg);

};

EXPORT_SYMBOL_GPL(xdp_warn);



struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,

					   struct sk_buff *skb,

					   struct net_device *dev)

{

	unsigned int headroom, frame_size;

	void *hard_start;



	/* Part of headroom was reserved to xdpf */

	headroom = sizeof(*xdpf) + xdpf->headroom;



	/* Memory size backing xdp_frame data already have reserved

	 * room for build_skb to place skb_shared_info in tailroom.

	 */

	frame_size = xdpf->frame_sz;



	hard_start = xdpf->data - headroom;

	skb = build_skb_around(skb, hard_start, frame_size);

	if (unlikely(!skb))

		return NULL;



	skb_reserve(skb, headroom);

	__skb_put(skb, xdpf->len);

	if (xdpf->metasize)

		skb_metadata_set(skb, xdpf->metasize);



	/* Essential SKB info: protocol and skb->dev */

	skb->protocol = eth_type_trans(skb, dev);



	/* Optional SKB info, currently missing:

	 * - HW checksum info		(skb->ip_summed)

	 * - HW RX hash			(skb_set_hash)

	 * - RX ring dev queue index	(skb_record_rx_queue)

	 */



	/* Until page_pool get SKB return path, release DMA here */

	xdp_release_frame(xdpf);



	/* Allow SKB to reuse area used by xdp_frame */

	xdp_scrub_frame(xdpf);



	return skb;

}

EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame);