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add xdp_build_skb_from_frame utility routine

PATCH Applied Lorenzo Bianconi 2 participants 4 messages Jan 12, 2021 – Jan 18, 2021

Subsystems (4)
Networking Network drivers BPF XDP
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Lorenzo Bianconi

author
#0 lore raw

v2 cover add xdp_build_skb_from_frame utility routine

Introduce __xdp_build_skb_from_frame and xdp_build_skb_from_frame routines to build the skb from a 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/xdp_build_skb_from_frame in cpumap and veth code.

Changes since v1:
- fix a checkpatch warning
- improve commit log in patch 2/2

Lorenzo Bianconi (2):
net: xdp: introduce __xdp_build_skb_from_frame utility routine
net: xdp: introduce xdp_build_skb_from_frame utility routine

 drivers/net/veth.c  | 18 +++-----------
 include/net/xdp.h   |  5 ++++
 kernel/bpf/cpumap.c | 46 ++---------------------------------
 net/core/xdp.c      | 59 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 69 insertions(+), 59 deletions(-)
Signature · 1 line
2.29.2
author
#1 lore raw

PATCH v2 1/2 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.

Acked-by Jesper Dangaard Brouer <[email protected]>
Signed-off-by Lorenzo Bianconi <[email protected]>
---
 include/net/xdp.h   |  3 +++
 kernel/bpf/cpumap.c | 46 ++-------------------------------------------
 net/core/xdp.c      | 44 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 44 deletions(-)
include/net/xdp.h +3 -0
index 0cf3976ce77c..689206dee6de 100644
@@ -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

58 lines not on this page · raw message

net/core/xdp.c +44 -0

47 lines not on this page · raw message

Signature · 1 line
2.29.2
author
#2 lore raw

PATCH v2 2/2 net: xdp: introduce xdp_build_skb_from_frame utility routine

In reply to Lorenzo Bianconi

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.
Introduce missing xdp metadata support in veth_xdp_rcv_one routine. Add missing metadata support in veth_xdp_rcv_one().

Reviewed-by Toshiaki Makita <[email protected]>
Acked-by Jesper Dangaard Brouer <[email protected]>
Signed-off-by Lorenzo Bianconi <[email protected]>
---
 drivers/net/veth.c | 18 +++---------------
 include/net/xdp.h  |  2 ++
 net/core/xdp.c     | 15 +++++++++++++++
 3 files changed, 20 insertions(+), 15 deletions(-)
drivers/net/veth.c +3 -15
index 99caae7d1641..6e03b619c93c 100644
@@ -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();
include/net/xdp.h +2 -0
index 689206dee6de..c4bfdc9a8b79 100644
@@ -167,6 +167,8 @@ 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)
net/core/xdp.c +15 -0
index aeb09ed0704c..0d2630a35c3e 100644
@@ -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);
Signature · 1 line
2.29.2
CI Applied
#3 lore raw
In reply to Lorenzo Bianconi
This series was applied to bpf/bpf-next.git (refs/heads/master):

Hello:

This series was applied to bpf/bpf-next.git (refs/heads/master):

Quoted 11 lines · On Tue, 12 Jan 2021 19:26:11 +0100 you wrote:

Introduce __xdp_build_skb_from_frame and xdp_build_skb_from_frame routines to build the skb from a 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/xdp_build_skb_from_frame in cpumap and veth code.

Changes since v1:
- fix a checkpatch warning
- improve commit log in patch 2/2

[...]

Here is the summary with links:
- [v2,bpf-next,1/2] net: xdp: introduce __xdp_build_skb_from_frame utility routine

    https://git.kernel.org/bpf/bpf-next/c/e753e92bbf33
  - [v2,bpf-next,2/2] net: xdp: introduce xdp_build_skb_from_frame utility routine
    https://git.kernel.org/bpf/bpf-next/c/a2c2998d5c6b

You are awesome, thank you!
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