add xdp_build_skb_from_frame utility routine

PATCH Superseded Lorenzo Bianconi 5 participants 9 messages Dec 16, 2020 – Jan 12, 2021

Subsystems (4)

Networking Network drivers BPF XDP

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Lorenzo Bianconi

author

2020-12-16 19:33 UTC #0 lore raw

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.

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 | 45 +---------------------------------
 net/core/xdp.c      | 59 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 59 deletions(-)

Signature · 1 line

2.29.2

Lorenzo Bianconi

author

2020-12-16 19:33 UTC #1 lore raw

PATCH 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.

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 include/net/xdp.h   |  3 +++
 kernel/bpf/cpumap.c | 45 +--------------------------------------------
 net/core/xdp.c      | 44 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 44 deletions(-)

include/net/xdp.h +3 -0

index 600acb307db6..da62fa20fa8a 100644
@@ -145,6 +145,9 @@ 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 +1 ~~-44~~

57 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

Jesper Dangaard Brouer

Acked-by on v1 1/2

2021-01-12 16:48 UTC #2 lore raw

Re: [PATCH bpf-next 1/2] net: xdp: introduce __xdp_build_skb_from_frame utility routine

Quoted 10 lines · On Wed, 16 Dec 2020 19:38:33 +0100 Lorenzo Bianconi <[email protected]> wrote:

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.
Signed-off-by Lorenzo Bianconi <[email protected]>
---
 include/net/xdp.h   |  3 +++
 kernel/bpf/cpumap.c | 45 +--------------------------------------------
 net/core/xdp.c      | 44 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 44 deletions(-)

Acked-by Jesper Dangaard Brouer <[email protected]>

Signature · 4 lines

Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer

Lorenzo Bianconi

author

2020-12-16 19:33 UTC #3 lore raw

PATCH 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.

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 02bfcdf50a7a..dbacf90df2b5 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 da62fa20fa8a..11ec93f827c0 100644
@@ -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)

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

Toshiaki Makita

Reviewed-by on v1 2/2

2020-12-17 13:13 UTC #4 lore raw

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

Quoted 6 lines · 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.
Signed-off-by Lorenzo Bianconi <[email protected]>

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 <[email protected]>

Jesper Dangaard Brouer

Acked-by on v1 2/2

2021-01-12 16:52 UTC #5 lore raw

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

In reply to Lorenzo Bianconi

Quoted 11 lines · On Wed, 16 Dec 2020 19:38:34 +0100 Lorenzo Bianconi <[email protected]> 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 <[email protected]>
---
 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 <[email protected]>

Signature · 4 lines

Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer

Lorenzo Bianconi

2021-01-12 16:10 UTC #6 lore raw

In reply to Lorenzo Bianconi

Quoted 5 lines

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.

Hi Daniel/Alexei,

since this series is marked as "archived" in patchwork, do I need to resubmit it?

Regards,
Lorenzo

Quoted 14 lines

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 | 45 +---------------------------------
 net/core/xdp.c      | 59 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 59 deletions(-)
Signature · 1 line
2.29.2

Daniel Borkmann

maintainer

2021-01-12 16:51 UTC #7 lore raw

Quoted 7 lines · Lorenzo Bianconi

Quoted 5 lines
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.
since this series is marked as "archived" in patchwork, do I need to resubmit it?

Yes please do, afaik there was some minor feedback from Toshiaki which was not yet addressed from your side.

Thanks,
Daniel

Lorenzo Bianconi

2021-01-12 16:55 UTC #8 lore raw

Quoted 11 lines · Lorenzo Bianconi

Quoted 7 lines
Quoted 5 lines
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.
since this series is marked as "archived" in patchwork, do I need to resubmit it?
Yes please do, afaik there was some minor feedback from Toshiaki which was not yet addressed from your side.

ack, will do.

Regards,
Lorenzo

Quoted 4 lines

Thanks,
Daniel