diff mbox series

[bpf-next,2/2] net: xdp: introduce xdp_build_skb_from_frame utility routine

Message ID 9d24e4c90c91aa2d9de413ee38adc4e8e44fc81a.1608142960.git.lorenzo@kernel.org (mailing list archive)
State New, archived
Delegated to: BPF
Headers show
Series add xdp_build_skb_from_frame utility routine | expand

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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 7522 this patch: 7522
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 71 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 7612 this patch: 7612
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Lorenzo Bianconi Dec. 16, 2020, 6:38 p.m. UTC
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(-)

Comments

Toshiaki Makita Dec. 17, 2020, 1:12 p.m. UTC | #1
On 2020/12/17 3:38, Lorenzo Bianconi wrote:
> 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>

Thanks.
It seems you added missing metadata support in veth_xdp_rcv_one()?
It might be better to note that in the commitlog.

The code looks fine to me.

Reviewed-by: Toshiaki Makita <toshiaki.makita1@gmail.com>
Jesper Dangaard Brouer Jan. 12, 2021, 4:50 p.m. UTC | #2
On Wed, 16 Dec 2020 19:38:34 +0100
Lorenzo Bianconi <lorenzo@kernel.org> wrote:

> 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(-)

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
diff mbox series

Patch

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);