[bpf-next V1 PATCH 05/15] xdp: introduce a new xdp_frame type
From: Jesper Dangaard Brouer <hidden>
Date: 2018-03-06 21:48:13
Subsystem:
networking [general], the rest, xdp (express data path) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Alexei Starovoitov, Daniel Borkmann, David S. Miller, Jesper Dangaard Brouer, John Fastabend
This is needed to convert drivers tuntap and virtio_net. This is a generalization of what is done inside cpumap, which will be converted later. Signed-off-by: Jesper Dangaard Brouer <redacted> --- include/net/xdp.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)
diff --git a/include/net/xdp.h b/include/net/xdp.h
index f6cbbbad412f..c5e7e2d27dd8 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h@@ -63,6 +63,46 @@ struct xdp_buff { struct xdp_rxq_info *rxq; }; +struct xdp_frame { + void *data; + u16 len; + u16 headroom; + u16 metasize; + /* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time, + * while mem info is valid on remote CPU. + */ + struct xdp_mem_info mem; +}; + +/* Convert xdp_buff to xdp_frame */ +static inline +struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp) +{ + struct xdp_frame *xdp_frame; + int metasize; + int 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; + + /* 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; + + /* rxq only valid until napi_schedule ends, convert to xdp_mem_info */ + xdp_frame->mem = xdp->rxq->mem; + + return xdp_frame; +} + static inline void xdp_return_frame(void *data, struct xdp_mem_info *mem) {