[PATCH bpf-next 2/2] net: xdp: introduce xdp_build_skb_from_frame utility routine
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: 2020-12-16 19:33:05
Also in:
bpf
Subsystem:
networking drivers, networking [general], the rest, xdp (express data path) · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer, John Fastabend
Introduce xdp_build_skb_from_frame utility routine to build the skb from xdp_frame. Respect to __xdp_build_skb_from_frame, xdp_build_skb_from_frame will allocate the skb object. Rely on xdp_build_skb_from_frame in veth driver. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- drivers/net/veth.c | 18 +++--------------- include/net/xdp.h | 2 ++ net/core/xdp.c | 15 +++++++++++++++ 3 files changed, 20 insertions(+), 15 deletions(-)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 02bfcdf50a7a..dbacf90df2b5 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c@@ -567,16 +567,10 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, struct veth_xdp_tx_bq *bq, struct veth_stats *stats) { - void *hard_start = frame->data - frame->headroom; - int len = frame->len, delta = 0; struct xdp_frame orig_frame; struct bpf_prog *xdp_prog; - unsigned int headroom; struct sk_buff *skb; - /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */ - hard_start -= sizeof(struct xdp_frame); - rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (likely(xdp_prog)) {
@@ -590,8 +584,8 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, switch (act) { case XDP_PASS: - delta = frame->data - xdp.data; - len = xdp.data_end - xdp.data; + if (xdp_update_frame_from_buff(&xdp, frame)) + goto err_xdp; break; case XDP_TX: orig_frame = *frame;
@@ -629,18 +623,12 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, } rcu_read_unlock(); - headroom = sizeof(struct xdp_frame) + frame->headroom - delta; - skb = veth_build_skb(hard_start, headroom, len, frame->frame_sz); + skb = xdp_build_skb_from_frame(frame, rq->dev); if (!skb) { xdp_return_frame(frame); stats->rx_drops++; - goto err; } - xdp_release_frame(frame); - xdp_scrub_frame(frame); - skb->protocol = eth_type_trans(skb, rq->dev); -err: return skb; err_xdp: rcu_read_unlock();
diff --git a/include/net/xdp.h b/include/net/xdp.h
index da62fa20fa8a..11ec93f827c0 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h@@ -148,6 +148,8 @@ 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); +struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct net_device *dev); static inline void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
diff --git a/net/core/xdp.c b/net/core/xdp.c
index aeb09ed0704c..0d2630a35c3e 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c@@ -557,3 +557,18 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, return skb; } EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame); + +struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct net_device *dev) +{ + struct sk_buff *skb; + + skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); + if (unlikely(!skb)) + return NULL; + + memset(skb, 0, offsetof(struct sk_buff, tail)); + + return __xdp_build_skb_from_frame(xdpf, skb, dev); +} +EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame);
--
2.29.2