2020-03-22 21:10:58

by Florian Fainelli

Subject: [PATCH net-next] net: dsa: Implement flow dissection for tag_brcm.c

Provide a flow_dissect callback which returns the network offset and
where to find the skb protocol, given the tags structure a common
function works for both tagging formats that are supported.

Signed-off-by: Florian Fainelli <[email protected]>
---
net/dsa/tag_brcm.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
index 9c3114179690..0d3f796d14a3 100644
--- a/net/dsa/tag_brcm.c
+++ b/net/dsa/tag_brcm.c
@@ -142,6 +142,27 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb,

return skb;
}
+
+static int brcm_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
+ int *offset)
+{
+ /* We have been called on the DSA master network device after
+ * eth_type_trans() which pulled the Ethernet header already.
+ * Frames have one of these two layouts:
+ * -----------------------------------
+ * | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM
+ * -----------------------------------
+ * -----------------------------------
+ * | 4b tag | MAC DA | MAC SA | Type | DSA_TAG_PROTO_BRCM_PREPEND
+ * -----------------------------------
+ * skb->data points 2 bytes before the actual Ethernet type field and
+ * we have an offset of 4bytes between where skb->data and where the
+ * payload starts.
+ */
+ *offset = BRCM_TAG_LEN;
+ *proto = ((__be16 *)skb->data)[1];
+ return 0;
+}
#endif

#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM)
@@ -177,6 +198,7 @@ static const struct dsa_device_ops brcm_netdev_ops = {
.xmit = brcm_tag_xmit,
.rcv = brcm_tag_rcv,
.overhead = BRCM_TAG_LEN,
+ .flow_dissect = brcm_tag_flow_dissect,
};

DSA_TAG_DRIVER(brcm_netdev_ops);
@@ -205,6 +227,7 @@ static const struct dsa_device_ops brcm_prepend_netdev_ops = {
.xmit = brcm_tag_xmit_prepend,
.rcv = brcm_tag_rcv_prepend,
.overhead = BRCM_TAG_LEN,
+ .flow_dissect = brcm_tag_flow_dissect,
};

DSA_TAG_DRIVER(brcm_prepend_netdev_ops);
--
2.19.1

2020-03-22 23:58:41

by Vladimir Oltean

Subject: Re: [PATCH net-next] net: dsa: Implement flow dissection for tag_brcm.c

On Sun, 22 Mar 2020 at 23:10, Florian Fainelli <[email protected]> wrote:
>
> Provide a flow_dissect callback which returns the network offset and
> where to find the skb protocol, given the tags structure a common
> function works for both tagging formats that are supported.
>
> Signed-off-by: Florian Fainelli <[email protected]>
> ---

Looks good to me.

> net/dsa/tag_brcm.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
> index 9c3114179690..0d3f796d14a3 100644
> --- a/net/dsa/tag_brcm.c
> +++ b/net/dsa/tag_brcm.c
> @@ -142,6 +142,27 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb,
>
> return skb;
> }
> +
> +static int brcm_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
> + int *offset)
> +{
> + /* We have been called on the DSA master network device after
> + * eth_type_trans() which pulled the Ethernet header already.
> + * Frames have one of these two layouts:
> + * -----------------------------------
> + * | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM
> + * -----------------------------------
> + * -----------------------------------
> + * | 4b tag | MAC DA | MAC SA | Type | DSA_TAG_PROTO_BRCM_PREPEND
> + * -----------------------------------
> + * skb->data points 2 bytes before the actual Ethernet type field and
> + * we have an offset of 4bytes between where skb->data and where the
> + * payload starts.
> + */
> + *offset = BRCM_TAG_LEN;
> + *proto = ((__be16 *)skb->data)[1];
> + return 0;
> +}
> #endif
>
> #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM)
> @@ -177,6 +198,7 @@ static const struct dsa_device_ops brcm_netdev_ops = {
> .xmit = brcm_tag_xmit,
> .rcv = brcm_tag_rcv,
> .overhead = BRCM_TAG_LEN,
> + .flow_dissect = brcm_tag_flow_dissect,
> };
>
> DSA_TAG_DRIVER(brcm_netdev_ops);
> @@ -205,6 +227,7 @@ static const struct dsa_device_ops brcm_prepend_netdev_ops = {
> .xmit = brcm_tag_xmit_prepend,
> .rcv = brcm_tag_rcv_prepend,
> .overhead = BRCM_TAG_LEN,
> + .flow_dissect = brcm_tag_flow_dissect,
> };
>
> DSA_TAG_DRIVER(brcm_prepend_netdev_ops);
> --
> 2.19.1
>

Regards,
-Vladimir

2020-03-23 18:28:35

by Vivien Didelot

Subject: Re: [PATCH net-next] net: dsa: Implement flow dissection for tag_brcm.c

On Sun, 22 Mar 2020 14:09:57 -0700, Florian Fainelli <[email protected]> wrote:
> Provide a flow_dissect callback which returns the network offset and
> where to find the skb protocol, given the tags structure a common
> function works for both tagging formats that are supported.
>
> Signed-off-by: Florian Fainelli <[email protected]>

Reviewed-by: Vivien Didelot <[email protected]>

2020-03-24 04:49:48

by David Miller

Subject: Re: [PATCH net-next] net: dsa: Implement flow dissection for tag_brcm.c

From: Florian Fainelli <[email protected]>
Date: Sun, 22 Mar 2020 14:09:57 -0700

> Provide a flow_dissect callback which returns the network offset and
> where to find the skb protocol, given the tags structure a common
> function works for both tagging formats that are supported.
>
> Signed-off-by: Florian Fainelli <[email protected]>

Applied, thanks Florian.