Commit daa5cdc3 authored by David Ahern's avatar David Ahern Committed by Daniel Borkmann
Browse files

net: Refactor xdp_convert_buff_to_frame 



Move the guts of xdp_convert_buff_to_frame to a new helper,
xdp_update_frame_from_buff so it can be reused removing code duplication

Suggested-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Co-developed-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarDavid Ahern <dsahern@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/90a68c283d7ebeb48924934c9b7ac79492300472.1594734381.git.lorenzo@kernel.org
parent 9b74ebb2

include/net/xdp.h

+22 −13
Original line number Diff line number Diff line
@@ -121,39 +121,48 @@ void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp) 
	xdp->frame_sz = frame->frame_sz;

}



/* Convert xdp_buff to xdp_frame */

static inline

struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp)

int xdp_update_frame_from_buff(struct xdp_buff *xdp,

			       struct xdp_frame *xdp_frame)

{

	struct xdp_frame *xdp_frame;

	int metasize;

	int headroom;



	if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL)

		return xdp_convert_zc_to_xdp_frame(xdp);

	int metasize, headroom;



	/* Assure headroom is available for storing info */

	headroom = xdp->data - xdp->data_hard_start;

	metasize = xdp->data - xdp->data_meta;

	metasize = metasize > 0 ? metasize : 0;

	if (unlikely((headroom - metasize) < sizeof(*xdp_frame)))

		return NULL;

		return -ENOSPC;



	/* Catch if driver didn't reserve tailroom for skb_shared_info */

	if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) {

		XDP_WARN("Driver BUG: missing reserved tailroom");

		return NULL;

		return -ENOSPC;

	}



	/* Store info in top of packet */

	xdp_frame = xdp->data_hard_start;



	xdp_frame->data = xdp->data;

	xdp_frame->len  = xdp->data_end - xdp->data;

	xdp_frame->headroom = headroom - sizeof(*xdp_frame);

	xdp_frame->metasize = metasize;

	xdp_frame->frame_sz = xdp->frame_sz;



	return 0;

}



/* Convert xdp_buff to xdp_frame */

static inline

struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp)

{

	struct xdp_frame *xdp_frame;



	if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL)

		return xdp_convert_zc_to_xdp_frame(xdp);



	/* Store info in top of packet */

	xdp_frame = xdp->data_hard_start;

	if (unlikely(xdp_update_frame_from_buff(xdp, xdp_frame) < 0))

		return NULL;



	/* rxq only valid until napi_schedule ends, convert to xdp_mem_info */

	xdp_frame->mem = xdp->rxq->mem;