[PATCH net] stmmac: fix reception of 802.1ad Ethernet tagged frames

[PATCH net] stmmac: fix reception of 802.1ad Ethernet tagged frames

[Elad Nachman]

stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().

The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .

This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
(ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).

This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
instead of using the hard-coded value of ETH_P_8021Q.

Signed-off-by: Elad Nachman <eladn@gilat.com>

---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b65e2d1..ced2d34 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3293,17 +3293,19 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+	struct vlan_ethhdr *veth;
 	u16 vlanid;
+	__be16 vlan_proto;
 
 	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
 	    NETIF_F_HW_VLAN_CTAG_RX &&
 	    !__vlan_get_tag(skb, &vlanid)) {
 		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
+		veth = (struct vlan_ethhdr *)skb->data;
+		vlan_proto = veth->h_vlan_proto;
+		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
 		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
 	}
 }
 
-- 
2.7.4

Re: [PATCH net] stmmac: fix reception of 802.1ad Ethernet tagged frames

[Toshiaki Makita]

On 2018/05/08 15:01, Elad Nachman wrote:
> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
> and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .
> 
> This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
> 
> This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
> instead of using the hard-coded value of ETH_P_8021Q.
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>
> 
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index b65e2d1..ced2d34 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3293,17 +3293,19 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>  
>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>  {
> -	struct ethhdr *ehdr;
> +	struct vlan_ethhdr *veth;
>  	u16 vlanid;
> +	__be16 vlan_proto;
>  
>  	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
>  	    NETIF_F_HW_VLAN_CTAG_RX &&
>  	    !__vlan_get_tag(skb, &vlanid)) {
>  		/* pop the vlan tag */
> -		ehdr = (struct ethhdr *)skb->data;
> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
> +		veth = (struct vlan_ethhdr *)skb->data;
> +		vlan_proto = veth->h_vlan_proto;
> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>  		skb_pull(skb, VLAN_HLEN);
> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);

This is what devices with NETIF_F_HW_VLAN_STAG_RX are supposed to do,
not NETIF_F_HW_VLAN_CTAG_RX.

By the way this looks like doing the same thing as skb_vlan_untag in
__netif_receive_skb_core, so seems unnecessary to add HW_VLAN_STAG_RX.
Alternatively you can check if vlan_proto is 8021Q here.

-- 
Toshiaki Makita

Re: [PATCH net] stmmac: fix reception of 802.1ad Ethernet tagged frames

[Elad Nachman]

Currently running:
ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100

On eth0=stmmac succeeds, but the end result is that the vlan device gets proto 802.1q instead of proto 802.1ad and drops the received packet. Without the patch packets gets dropped for a seemingly "correct" 802.1ad ip link configuration.

If NETIF_F_HW_VLAN_STAG_RX is a requirement for the driver for supporting 802.1ad protocols then the Linux kernel should return error when user-space requests to create a vlan device with proto 802.1ad for physical devices which lacks NETIF_F_HW_VLAN_STAG_RX, which is not currently the case.

skb_vlan_untag() does nothing if __vlan_hwaccel_put_tag() was already called before (in the driver). The only possible alternative is to completely remove stmmac_rx_vlan() from the stmmac code and let skb_vlan_untag() handles things in a generic way.


On 08/05/18 09:43, Toshiaki Makita wrote:
> On 2018/05/08 15:01, Elad Nachman wrote:
>> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().
>>
>> The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
>> and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .
>>
>> This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
>> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
>>
>> This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
>> instead of using the hard-coded value of ETH_P_8021Q.
>>
>> Signed-off-by: Elad Nachman <eladn@gilat.com>
>>
>> ---
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 10 ++++++----
>>  1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> index b65e2d1..ced2d34 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> @@ -3293,17 +3293,19 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>>  
>>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>>  {
>> -	struct ethhdr *ehdr;
>> +	struct vlan_ethhdr *veth;
>>  	u16 vlanid;
>> +	__be16 vlan_proto;
>>  
>>  	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
>>  	    NETIF_F_HW_VLAN_CTAG_RX &&
>>  	    !__vlan_get_tag(skb, &vlanid)) {
>>  		/* pop the vlan tag */
>> -		ehdr = (struct ethhdr *)skb->data;
>> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
>> +		veth = (struct vlan_ethhdr *)skb->data;
>> +		vlan_proto = veth->h_vlan_proto;
>> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>>  		skb_pull(skb, VLAN_HLEN);
>> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
>> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
> 
> This is what devices with NETIF_F_HW_VLAN_STAG_RX are supposed to do,
> not NETIF_F_HW_VLAN_CTAG_RX.
> 
> By the way this looks like doing the same thing as skb_vlan_untag in
> __netif_receive_skb_core, so seems unnecessary to add HW_VLAN_STAG_RX.
> Alternatively you can check if vlan_proto is 8021Q here.
> 

Re: [PATCH net] stmmac: fix reception of 802.1ad Ethernet tagged frames

[Toshiaki Makita]

On 2018/05/08 16:11, Elad Nachman wrote:
> Currently running:
> ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100
> 
> On eth0=stmmac succeeds, but the end result is that the vlan device gets proto 802.1q instead of proto 802.1ad and drops the received packet. Without the patch packets gets dropped for a seemingly "correct" 802.1ad ip link configuration.
> 
> If NETIF_F_HW_VLAN_STAG_RX is a requirement for the driver for supporting 802.1ad protocols then the Linux kernel should return error when user-space requests to create a vlan device with proto 802.1ad for physical devices which lacks NETIF_F_HW_VLAN_STAG_RX, which is not currently the case.

No. You can create 802.1ad devices without HW_VLAN_STAG_RX, but you
should not strip 802.1ad tag in driver without HW_VLAN_STAG_RX.
__netif_receive_skb_core should handle them if the device does not have
HW_VLAN_STAG_RX.

> skb_vlan_untag() does nothing if __vlan_hwaccel_put_tag() was already called before (in the driver). The only possible alternative is to completely remove stmmac_rx_vlan() from the stmmac code and let skb_vlan_untag() handles things in a generic way.

You cannot remove an already added feature in the driver.
Alternatively you can skip stripping vlan if vlan_proto is not 8021Q.
Something like this.

	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
	    NETIF_F_HW_VLAN_CTAG_RX &&
	    !__vlan_get_tag(skb, &vlanid)) {
		veth = (struct vlan_ethhdr *)skb->data;
		vlan_proto = veth->h_vlan_proto;
		if (vlan_proto == htons(ETH_P_8021Q)) {
			/* pop the vlan tag */
			memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
			skb_pull(skb, VLAN_HLEN);
			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
		}
 	}
 }

-- 
Toshiaki Makita

[PATCH v2 net] stmmac: strip vlan tag on reception only for 8021q tagged frames

[Elad Nachman]

stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().

The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() without checking the actual VLAN tag.

This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
(ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).

This fix only strips the VLAN tag for 802.1Q tagged protocols. 802.1AD frames will be handled later by skb_vlan_untag() .

Signed-off-by: Elad Nachman <eladn@gilat.com>

---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b65e2d1..b230ab5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3293,17 +3293,21 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+	struct vlan_ethhdr *veth;
 	u16 vlanid;
+	__be16 vlan_proto;
 
 	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
 	    NETIF_F_HW_VLAN_CTAG_RX &&
 	    !__vlan_get_tag(skb, &vlanid)) {
-		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
-		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		veth = (struct vlan_ethhdr *)skb->data;
+		vlan_proto = veth->h_vlan_proto;
+		if (likely(vlan_proto == htons(ETH_P_8021Q))) {
+			/* pop the vlan tag */
+			memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
+			skb_pull(skb, VLAN_HLEN);
+			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		}
 	}
 }
 
-- 
2.7.4

Re: [PATCH v2 net] stmmac: strip vlan tag on reception only for 8021q tagged frames

[David Miller]

From: Elad Nachman <eladv6@gmail.com>
Date: Fri, 11 May 2018 10:31:40 +0300

> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan
> before calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with
> 802.1Q protocol, and assigns ETH_P_8021Q to the skb by hard-coding
> the parameter on call to __vlan_hwaccel_put_tag() without checking
> the actual VLAN tag.
> 
> This causes packets not to be passed to the VLAN slave if it was
> created with 802.1AD protocol (ip link add link eth0 eth0.100 type
> vlan proto 802.1ad id 100).
> 
> This fix only strips the VLAN tag for 802.1Q tagged
> protocols. 802.1AD frames will be handled later by skb_vlan_untag().
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>

Giuseppe and Alexandre, please review this patch.

Re: [PATCH v2 net] stmmac: strip vlan tag on reception only for 8021q tagged frames

[David Miller]

From: David Miller <davem@davemloft.net>
Date: Thu, 17 May 2018 12:43:56 -0400 (EDT)

> Giuseppe and Alexandre, please review this patch.

If nobody thinks this patch is important enough to actually
review, I'm tossing it.

Sorry.

Re: [PATCH v2 net] stmmac: strip vlan tag on reception only for 8021q tagged frames

[Florian Fainelli]

On 05/21/2018 08:48 AM, David Miller wrote:
> From: David Miller <davem@davemloft.net>
> Date: Thu, 17 May 2018 12:43:56 -0400 (EDT)
> 
>> Giuseppe and Alexandre, please review this patch.
> 
> If nobody thinks this patch is important enough to actually
> review, I'm tossing it.
> 
> Sorry.
> 

How about looping in Jose?
-- 
Florian

Re: [PATCH v2 net] stmmac: strip vlan tag on reception only for 8021q tagged frames

[Jose Abreu]

On 21-05-2018 17:42, Florian Fainelli wrote:
> On 05/21/2018 08:48 AM, David Miller wrote:
>> From: David Miller <davem@davemloft.net>
>> Date: Thu, 17 May 2018 12:43:56 -0400 (EDT)
>>
>>> Giuseppe and Alexandre, please review this patch.
>> If nobody thinks this patch is important enough to actually
>> review, I'm tossing it.
>>
>> Sorry.
>>
> How about looping in Jose?

Thanks for the cc Florian!

Elad,

Looking at this patch I have a couple of questions and suggestions:

I see that most drivers use this pattern so, are they all broken?
or is this a special case?

You can also get the inner/outer vlan tag by reading desc0 of
receive descriptor. Which can make this completely agnostic of
VLAN tag.

Thanks and Best Regards,
Jose Miguel Abreu

Re: [PATCH v2 net] stmmac: strip vlan tag on reception only for 8021q tagged frames

[Elad Nachman]

Jose,

I am not sure which drivers you have checked. I guess most non-networking embedded drivers never use 802.1AD
so they stay broken unknowingly.
Specifically, I have tested Intel e1000e based card which works correctly versus stmmac which works incorrectly.

If you check netdev.c in e1000e then the vlan strip is conditional upon checking of 802.1Q bit in the descriptor,
which does not happen in stmmac_main.c - the vlan stripping happens based on any tag header check.
Once I applied my patch things started working - did not have to patch e1000e. The problem is that ip link allows to create 802.1ad devices which are not 0x8100 tagged but stmmac and probably other drivers handles the non 0x8100 tag incorrectly and the vlan slave discards the frame.

Regarding the getting the tag from the descriptor - this is of course a possibility. My original patch handled stripping of all tags but then I was told here that I cannot strip 802.1ad tags without the NETIF_F_HW_VLAN_STAG_RX feature, which is probably correct regardless of the source of the vlan tag - skb or descriptor.

I can also add the NETIF_F_HW_VLAN_STAG_RX feature plus the following original v1 patch:
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c	2018-04-11 17:04:00.586057300 +0300
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c	2018-04-11 17:05:33.601992400 +0300
@@ -3293,17 +3293,19 @@ dma_map_err:
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+	struct vlan_ethhdr *veth;
 	u16 vlanid;
+	__be16 vlan_proto;
 
 	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
 	    NETIF_F_HW_VLAN_CTAG_RX &&
 	    !__vlan_get_tag(skb, &vlanid)) {
 		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
+		veth = (struct vlan_ethhdr *)skb->data;
+		vlan_proto = veth->h_vlan_proto;
+		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
 		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
 	}
 }

There are three reasons why I prefer using this approach rather than the descriptor approach:

A. It is inline with the original driver code.
B. Using descriptor vlan will require to completely rewrite stmmac_rx_vlan and will result in at least 2-3 times line counts in the patch.
C. I have no idea if first silicon implementations of DWMAC IP had some kind of HW bug (for example AXI clock glitch) which caused sampling of the VLAN tag in the descriptors to be unstable, and since I have no access to such hardware for regression I risk breaking stmmac for such old SOCs in case they decide to jump kernel versions to the latest.

Thanks,

Elad.

On 22/05/18 11:56, Jose Abreu wrote:
> On 21-05-2018 17:42, Florian Fainelli wrote:
>> On 05/21/2018 08:48 AM, David Miller wrote:
>>> From: David Miller <davem@davemloft.net>
>>> Date: Thu, 17 May 2018 12:43:56 -0400 (EDT)
>>>
>>>> Giuseppe and Alexandre, please review this patch.
>>> If nobody thinks this patch is important enough to actually
>>> review, I'm tossing it.
>>>
>>> Sorry.
>>>
>> How about looping in Jose?
> 
> Thanks for the cc Florian!
> 
> Elad,
> 
> Looking at this patch I have a couple of questions and suggestions:
> 
> I see that most drivers use this pattern so, are they all broken?
> or is this a special case?
> 
> You can also get the inner/outer vlan tag by reading desc0 of
> receive descriptor. Which can make this completely agnostic of
> VLAN tag.
> 
> Thanks and Best Regards,
> Jose Miguel Abreu
> 

Re: [PATCH v2 net] stmmac: strip vlan tag on reception only for 8021q tagged frames

[Jose Abreu]

On 23-05-2018 16:00, Elad Nachman wrote:
> Jose,
>
> I am not sure which drivers you have checked. I guess most non-networking embedded drivers never use 802.1AD
> so they stay broken unknowingly.
> Specifically, I have tested Intel e1000e based card which works correctly versus stmmac which works incorrectly.
>
> If you check netdev.c in e1000e then the vlan strip is conditional upon checking of 802.1Q bit in the descriptor,
> which does not happen in stmmac_main.c - the vlan stripping happens based on any tag header check.
> Once I applied my patch things started working - did not have to patch e1000e. The problem is that ip link allows to create 802.1ad devices which are not 0x8100 tagged but stmmac and probably other drivers handles the non 0x8100 tag incorrectly and the vlan slave discards the frame.
>
> Regarding the getting the tag from the descriptor - this is of course a possibility. My original patch handled stripping of all tags but then I was told here that I cannot strip 802.1ad tags without the NETIF_F_HW_VLAN_STAG_RX feature, which is probably correct regardless of the source of the vlan tag - skb or descriptor.
>
> I can also add the NETIF_F_HW_VLAN_STAG_RX feature plus the following original v1 patch:
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c	2018-04-11 17:04:00.586057300 +0300
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c	2018-04-11 17:05:33.601992400 +0300
> @@ -3293,17 +3293,19 @@ dma_map_err:
>  
>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>  {
> -	struct ethhdr *ehdr;
> +	struct vlan_ethhdr *veth;
>  	u16 vlanid;
> +	__be16 vlan_proto;
>  
>  	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
>  	    NETIF_F_HW_VLAN_CTAG_RX &&
>  	    !__vlan_get_tag(skb, &vlanid)) {
>  		/* pop the vlan tag */
> -		ehdr = (struct ethhdr *)skb->data;
> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
> +		veth = (struct vlan_ethhdr *)skb->data;
> +		vlan_proto = veth->h_vlan_proto;
> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>  		skb_pull(skb, VLAN_HLEN);
> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
>  	}
>  }
>
> There are three reasons why I prefer using this approach rather than the descriptor approach:
>
> A. It is inline with the original driver code.
> B. Using descriptor vlan will require to completely rewrite stmmac_rx_vlan and will result in at least 2-3 times line counts in the patch.
> C. I have no idea if first silicon implementations of DWMAC IP had some kind of HW bug (for example AXI clock glitch) which caused sampling of the VLAN tag in the descriptors to be unstable, and since I have no access to such hardware for regression I risk breaking stmmac for such old SOCs in case they decide to jump kernel versions to the latest.

Your approach seems okay by me. Please submit a patch with this
to netdev for proper review.

Thanks and Best Regards,
Jose Miguel Abreu

>
> Thanks,
>
> Elad.
>
> On 22/05/18 11:56, Jose Abreu wrote:
>> On 21-05-2018 17:42, Florian Fainelli wrote:
>>> On 05/21/2018 08:48 AM, David Miller wrote:
>>>> From: David Miller <davem@davemloft.net>
>>>> Date: Thu, 17 May 2018 12:43:56 -0400 (EDT)
>>>>
>>>>> Giuseppe and Alexandre, please review this patch.
>>>> If nobody thinks this patch is important enough to actually
>>>> review, I'm tossing it.
>>>>
>>>> Sorry.
>>>>
>>> How about looping in Jose?
>> Thanks for the cc Florian!
>>
>> Elad,
>>
>> Looking at this patch I have a couple of questions and suggestions:
>>
>> I see that most drivers use this pattern so, are they all broken?
>> or is this a special case?
>>
>> You can also get the inner/outer vlan tag by reading desc0 of
>> receive descriptor. Which can make this completely agnostic of
>> VLAN tag.
>>
>> Thanks and Best Regards,
>> Jose Miguel Abreu
>>

[PATCH v3 net] stmmac: Added support for 802.1ad S-TAG stripping

[Elad Nachman]

stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().

The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .

This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
(ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).

This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
instead of using the hard-coded value of ETH_P_8021Q.
NETIF_F_HW_VLAN_STAG_RX was added to the net device features to reflect this new support.

Signed-off-by: Elad Nachman <eladn@gilat.com>

---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b65e2d1..2d2f37f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3293,17 +3293,19 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+	struct vlan_ethhdr *veth;
 	u16 vlanid;
+	__be16 vlan_proto;
 
-	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
-	    NETIF_F_HW_VLAN_CTAG_RX &&
+	if ((dev->features & (NETIF_F_HW_VLAN_CTAG_RX|NETIF_F_HW_VLAN_STAG_RX)) ==
+	    (NETIF_F_HW_VLAN_CTAG_RX|NETIF_F_HW_VLAN_STAG_RX) &&
 	    !__vlan_get_tag(skb, &vlanid)) {
 		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
+		veth = (struct vlan_ethhdr *)skb->data;
+		vlan_proto = veth->h_vlan_proto;
+		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
 		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
 	}
 }
 
@@ -4344,7 +4346,7 @@ int stmmac_dvr_probe(struct device *device,
 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
 #ifdef STMMAC_VLAN_TAG_USED
 	/* Both mac100 and gmac support receive VLAN tag detection */
-	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
+	ndev->features |= (NETIF_F_HW_VLAN_CTAG_RX|NETIF_F_HW_VLAN_STAG_RX);
 #endif
 	priv->msg_enable = netif_msg_init(debug, default_msg_level);
 
-- 
2.7.4

Re: [PATCH v3 net] stmmac: Added support for 802.1ad S-TAG stripping

[Toshiaki Makita]

On 2018/05/25 1:56, Elad Nachman wrote:
> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
> and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .
> 
> This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
> 
> This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
> instead of using the hard-coded value of ETH_P_8021Q.
> NETIF_F_HW_VLAN_STAG_RX was added to the net device features to reflect this new support.
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>
> 
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index b65e2d1..2d2f37f 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3293,17 +3293,19 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>  
>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>  {
> -	struct ethhdr *ehdr;
> +	struct vlan_ethhdr *veth;
>  	u16 vlanid;
> +	__be16 vlan_proto;
>  
> -	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
> -	    NETIF_F_HW_VLAN_CTAG_RX &&
> +	if ((dev->features & (NETIF_F_HW_VLAN_CTAG_RX|NETIF_F_HW_VLAN_STAG_RX)) ==
> +	    (NETIF_F_HW_VLAN_CTAG_RX|NETIF_F_HW_VLAN_STAG_RX) &&

This is basically not a correct condition since you cannot strip CTAG if
HW_VLAN_STAG_RX is disabled even when HW_VLAN_CTAG_RX is enabled.

The correct behavior is stripping CTAG when CTAG_RX is enabled and
stripping STAG when STAG_RX is enabled, so this code cannot be
protocol-agnostic. I suggested handling only CTAG in this driver because
I thought adding STAG support will make this unnecessarily complicated.

But I now actually noticed that this driver seems not able to toggle
CTAG_RX nor STAG_RX because hw_features does not include them. So this
code should work even if the condition is wrong, but in the first place
why we need to check if dev->features includes CTAG_RX here... it's
always included. It seems removing this check will be sufficient.

>  	    !__vlan_get_tag(skb, &vlanid)) {
>  		/* pop the vlan tag */
> -		ehdr = (struct ethhdr *)skb->data;
> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
> +		veth = (struct vlan_ethhdr *)skb->data;
> +		vlan_proto = veth->h_vlan_proto;
> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>  		skb_pull(skb, VLAN_HLEN);
> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
>  	}
>  }
>  
> @@ -4344,7 +4346,7 @@ int stmmac_dvr_probe(struct device *device,
>  	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
>  #ifdef STMMAC_VLAN_TAG_USED
>  	/* Both mac100 and gmac support receive VLAN tag detection */
> -	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
> +	ndev->features |= (NETIF_F_HW_VLAN_CTAG_RX|NETIF_F_HW_VLAN_STAG_RX);
>  #endif
>  	priv->msg_enable = netif_msg_init(debug, default_msg_level);
>  
> 

-- 
Toshiaki Makita

[PATCH v4 net] stmmac: 802.1ad tag stripping support fix

[Elad Nachman]

stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().

The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .

This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
(ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).

This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
instead of using the hard-coded value of ETH_P_8021Q.
NETIF_F_HW_VLAN_CTAG_RX check was removed to be in line with the driver actual abilities.

Signed-off-by: Elad Nachman <eladn@gilat.com>

---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b65e2d1..284e6a7 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3293,17 +3293,17 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+	struct vlan_ethhdr *veth;
 	u16 vlanid;
+	__be16 vlan_proto;
 
-	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
-	    NETIF_F_HW_VLAN_CTAG_RX &&
-	    !__vlan_get_tag(skb, &vlanid)) {
+	if (!__vlan_get_tag(skb, &vlanid)) {
 		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
+		veth = (struct vlan_ethhdr *)skb->data;
+		vlan_proto = veth->h_vlan_proto;
+		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
 		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
 	}
 }
 
-- 
2.7.4

Re: [PATCH v4 net] stmmac: 802.1ad tag stripping support fix

[Toshiaki Makita]

On 2018/05/27 4:24, Elad Nachman wrote:
> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
> and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .
> 
> This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
> 
> This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
> instead of using the hard-coded value of ETH_P_8021Q.
> NETIF_F_HW_VLAN_CTAG_RX check was removed to be in line with the driver actual abilities.
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>
> 

I might have not been clear enough but you still need this hunk with
this change.

> -	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
> +	ndev->features |= (NETIF_F_HW_VLAN_CTAG_RX|NETIF_F_HW_VLAN_STAG_RX);

Also I guess spaces are preferred around '|'. Would you check it by
checkpatch.pl?

-- 
Toshiaki Makita

[PATCH v5 net] stmmac: 802.1ad tag stripping fix

[Elad Nachman]

stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().

The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .

This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
(ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).

This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
instead of using the hard-coded value of ETH_P_8021Q.
NETIF_F_HW_VLAN_CTAG_RX check was removed and NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver actual abilities.

Signed-off-by: Elad Nachman <eladn@gilat.com>

---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b65e2d1..f680bcf 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3293,17 +3293,17 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+	struct vlan_ethhdr *veth;
 	u16 vlanid;
+	__be16 vlan_proto;
 
-	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
-	    NETIF_F_HW_VLAN_CTAG_RX &&
-	    !__vlan_get_tag(skb, &vlanid)) {
+	if (!__vlan_get_tag(skb, &vlanid)) {
 		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
+		veth = (struct vlan_ethhdr *)skb->data;
+		vlan_proto = veth->h_vlan_proto;
+		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
 		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
 	}
 }
 
@@ -4344,7 +4344,7 @@ int stmmac_dvr_probe(struct device *device,
 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
 #ifdef STMMAC_VLAN_TAG_USED
 	/* Both mac100 and gmac support receive VLAN tag detection */
-	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
+	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
 #endif
 	priv->msg_enable = netif_msg_init(debug, default_msg_level);
 
-- 
2.7.4

Re: [PATCH v5 net] stmmac: 802.1ad tag stripping fix

[Toshiaki Makita]

On 2018/05/30 14:48, Elad Nachman wrote:
> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
> and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .
> 
> This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
> 
> This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
> instead of using the hard-coded value of ETH_P_8021Q.
> NETIF_F_HW_VLAN_CTAG_RX check was removed and NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver actual abilities.
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>
> 
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index b65e2d1..f680bcf 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3293,17 +3293,17 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>  
>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>  {
> -	struct ethhdr *ehdr;
> +	struct vlan_ethhdr *veth;
>  	u16 vlanid;
> +	__be16 vlan_proto;
>  
> -	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
> -	    NETIF_F_HW_VLAN_CTAG_RX &&
> -	    !__vlan_get_tag(skb, &vlanid)) {
> +	if (!__vlan_get_tag(skb, &vlanid)) {
>  		/* pop the vlan tag */
> -		ehdr = (struct ethhdr *)skb->data;
> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
> +		veth = (struct vlan_ethhdr *)skb->data;
> +		vlan_proto = veth->h_vlan_proto;
> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>  		skb_pull(skb, VLAN_HLEN);
> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
>  	}

Should this function contents be surrounded by
#ifdef STMMAC_VLAN_TAG_USED, since the features is enabled only when it
is defined?
Otherwise looks good to me from the perspective of vlan features.

>  }
>  
> @@ -4344,7 +4344,7 @@ int stmmac_dvr_probe(struct device *device,
>  	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
>  #ifdef STMMAC_VLAN_TAG_USED
>  	/* Both mac100 and gmac support receive VLAN tag detection */
> -	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
> +	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
>  #endif
>  	priv->msg_enable = netif_msg_init(debug, default_msg_level);
>  
> 

-- 
Toshiaki Makita

Re: [PATCH v5 net] stmmac: 802.1ad tag stripping fix

[Elad Nachman]

Interesting question. That's the way the driver was originally written and I tried to minimize the changes in the patch.
Anyway, common.h (included by stmmac_main.c) contains the following:

#if IS_ENABLED(CONFIG_VLAN_8021Q)
#define STMMAC_VLAN_TAG_USED
#include <linux/if_vlan.h>
#endif

So the define in question kicks in only once you enable 802.1Q support in the kernel .config .

Thanks,

Elad.

On 30/05/18 09:08, Toshiaki Makita wrote:
> On 2018/05/30 14:48, Elad Nachman wrote:
>> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before calling napi_gro_receive().
>>
>> The function assumes VLAN tagged frames are always tagged with 802.1Q protocol,
>> and assigns ETH_P_8021Q to the skb by hard-coding the parameter on call to __vlan_hwaccel_put_tag() .
>>
>> This causes packets not to be passed to the VLAN slave if it was created with 802.1AD protocol
>> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
>>
>> This fix passes the protocol from the VLAN header into __vlan_hwaccel_put_tag()
>> instead of using the hard-coded value of ETH_P_8021Q.
>> NETIF_F_HW_VLAN_CTAG_RX check was removed and NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver actual abilities.
>>
>> Signed-off-by: Elad Nachman <eladn@gilat.com>
>>
>> ---
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 16 ++++++++--------
>>  1 file changed, 8 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> index b65e2d1..f680bcf 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> @@ -3293,17 +3293,17 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>>  
>>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>>  {
>> -	struct ethhdr *ehdr;
>> +	struct vlan_ethhdr *veth;
>>  	u16 vlanid;
>> +	__be16 vlan_proto;
>>  
>> -	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
>> -	    NETIF_F_HW_VLAN_CTAG_RX &&
>> -	    !__vlan_get_tag(skb, &vlanid)) {
>> +	if (!__vlan_get_tag(skb, &vlanid)) {
>>  		/* pop the vlan tag */
>> -		ehdr = (struct ethhdr *)skb->data;
>> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
>> +		veth = (struct vlan_ethhdr *)skb->data;
>> +		vlan_proto = veth->h_vlan_proto;
>> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>>  		skb_pull(skb, VLAN_HLEN);
>> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
>> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
>>  	}
> 
> Should this function contents be surrounded by
> #ifdef STMMAC_VLAN_TAG_USED, since the features is enabled only when it
> is defined?
> Otherwise looks good to me from the perspective of vlan features.
> 
>>  }
>>  
>> @@ -4344,7 +4344,7 @@ int stmmac_dvr_probe(struct device *device,
>>  	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
>>  #ifdef STMMAC_VLAN_TAG_USED
>>  	/* Both mac100 and gmac support receive VLAN tag detection */
>> -	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
>> +	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
>>  #endif
>>  	priv->msg_enable = netif_msg_init(debug, default_msg_level);
>>  
>>
> 

Re: [PATCH v5 net] stmmac: 802.1ad tag stripping fix

[Toshiaki Makita]

On 2018/05/30 15:16, Elad Nachman wrote:
> Interesting question. That's the way the driver was originally written and I tried to minimize the changes in the patch.
> Anyway, common.h (included by stmmac_main.c) contains the following:
> 
> #if IS_ENABLED(CONFIG_VLAN_8021Q)
> #define STMMAC_VLAN_TAG_USED
> #include <linux/if_vlan.h>
> #endif
> 
> So the define in question kicks in only once you enable 802.1Q support in the kernel .config .

So, we end up with stripping vlan even though the device does not have
HW_VLAN_CTAG/STAG_RX when CONFIG_VLAN_8021Q is disabled, since the patch
anyway removed the original condition...

-- 
Toshiaki Makita

Re: [PATCH v5 net] stmmac: 802.1ad tag stripping fix

[David Miller]

From: Elad Nachman <eladv6@gmail.com>
Date: Wed, 30 May 2018 08:48:25 +0300

>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>  {
> -	struct ethhdr *ehdr;
> +	struct vlan_ethhdr *veth;
>  	u16 vlanid;
> +	__be16 vlan_proto;

Please order local variables from longest to shortest line.

>  
> -	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
> -	    NETIF_F_HW_VLAN_CTAG_RX &&
> -	    !__vlan_get_tag(skb, &vlanid)) {
> +	if (!__vlan_get_tag(skb, &vlanid)) {
>  		/* pop the vlan tag */
> -		ehdr = (struct ethhdr *)skb->data;
> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
> +		veth = (struct vlan_ethhdr *)skb->data;
> +		vlan_proto = veth->h_vlan_proto;
> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>  		skb_pull(skb, VLAN_HLEN);
> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
>  	}
>  }

I can't see how it is valid to do an unconditional software VLAN
untagging even when VLAN is disabled in the kernel config or the
NETIF_F_* feature bits are not set.

At a minimum that feature test has to stay there, and when it's clear
we let the generic VLAN code untag the packet.

Re: [PATCH v5 net] stmmac: 802.1ad tag stripping fix

[Toshiaki Makita]

On 2018/06/03 23:33, David Miller wrote:
> From: Elad Nachman <eladv6@gmail.com>
> Date: Wed, 30 May 2018 08:48:25 +0300
> 
>>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>>  {
>> -	struct ethhdr *ehdr;
>> +	struct vlan_ethhdr *veth;
>>  	u16 vlanid;
>> +	__be16 vlan_proto;
> 
> Please order local variables from longest to shortest line.
> 
>>  
>> -	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
>> -	    NETIF_F_HW_VLAN_CTAG_RX &&
>> -	    !__vlan_get_tag(skb, &vlanid)) {
>> +	if (!__vlan_get_tag(skb, &vlanid)) {
>>  		/* pop the vlan tag */
>> -		ehdr = (struct ethhdr *)skb->data;
>> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
>> +		veth = (struct vlan_ethhdr *)skb->data;
>> +		vlan_proto = veth->h_vlan_proto;
>> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>>  		skb_pull(skb, VLAN_HLEN);
>> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
>> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
>>  	}
>>  }
> 
> I can't see how it is valid to do an unconditional software VLAN
> untagging even when VLAN is disabled in the kernel config or the
> NETIF_F_* feature bits are not set.

Right. It is not valid.

> 
> At a minimum that feature test has to stay there, and when it's clear
> we let the generic VLAN code untag the packet.

Since NETIF_F_HW_VLAN_*_RX are not protocol agnostic, we need two kind
of similar checking here.

veth = (struct vlan_ethhdr *)skb->data;
vlan_proto = veth->h_vlan_proto;
if ((vlan_proto == htons(ETH_P_8021Q) &&
     dev->features & NETIF_F_HW_VLAN_CTAG_RX) ||
    (vlan_proto == htons(ETH_P_8021AD) &&
     dev->features & NETIF_F_HW_VLAN_STAG_RX) {
	vlanid = ntohs(veth->h_vlan_TCI);
	memmove(...);
	skb_pull(...);
	__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
}

An alternative way is not to check vlan_proto or features here but
compile this code only when VLAN is enabled in the kernel config. This
can be valid only because this driver does not have NETIF_F_HW_VLAN_*_RX
in hw_features and they can not be toggled for now.

static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
{
#ifdef STMMAC_VLAN_TAG_USED
	...
	if (!__vlan_get_tag(skb, &vlanid)) {
		...
		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
	}
#endif
}

-- 
Toshiaki Makita

[PATCH v6 net] stmmac: strip all VLAN tag types when kernel 802.1Q support is selected

[Elad Nachman]

stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before 
calling napi_gro_receive().

The function assumes VLAN tagged frames are always tagged with 
802.1Q protocol, and assigns ETH_P_8021Q to the skb by hard-coding
the parameter on call to __vlan_hwaccel_put_tag() .

This causes packets not to be passed to the VLAN slave if it was created 
with 802.1AD protocol
(ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).

This fix passes the protocol from the VLAN header into 
__vlan_hwaccel_put_tag() instead of using the hard-coded value of
ETH_P_8021Q.

NETIF_F_HW_VLAN_CTAG_RX check was removed and instead the strip action 
is dependent upon a preprocessor define which is defined when 802.1Q 
support is selected in the kernel config. 

NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver 
actual abilities.

Signed-off-by: Elad Nachman <eladn@gilat.com>


---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b65e2d1..707917d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3293,18 +3293,20 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+#ifdef STMMAC_VLAN_TAG_USED
+	struct vlan_ethhdr *veth;
+	__be16 vlan_proto;
 	u16 vlanid;
 
-	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
-	    NETIF_F_HW_VLAN_CTAG_RX &&
-	    !__vlan_get_tag(skb, &vlanid)) {
+	if (!__vlan_get_tag(skb, &vlanid)) {
 		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
+		veth = (struct vlan_ethhdr *)skb->data;
+		vlan_proto = veth->h_vlan_proto;
+		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
 		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
 	}
+#endif
 }
 
 
@@ -4344,7 +4346,7 @@ int stmmac_dvr_probe(struct device *device,
 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
 #ifdef STMMAC_VLAN_TAG_USED
 	/* Both mac100 and gmac support receive VLAN tag detection */
-	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
+	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
 #endif
 	priv->msg_enable = netif_msg_init(debug, default_msg_level);
 
-- 
2.7.4

Re: [PATCH v6 net] stmmac: strip all VLAN tag types when kernel 802.1Q support is selected

[David Miller]

From: Elad Nachman <eladv6@gmail.com>
Date: Fri, 8 Jun 2018 12:19:29 +0300

> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before 
> calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with 
> 802.1Q protocol, and assigns ETH_P_8021Q to the skb by hard-coding
> the parameter on call to __vlan_hwaccel_put_tag() .
> 
> This causes packets not to be passed to the VLAN slave if it was created 
> with 802.1AD protocol
> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
> 
> This fix passes the protocol from the VLAN header into 
> __vlan_hwaccel_put_tag() instead of using the hard-coded value of
> ETH_P_8021Q.
> 
> NETIF_F_HW_VLAN_CTAG_RX check was removed and instead the strip action 
> is dependent upon a preprocessor define which is defined when 802.1Q 
> support is selected in the kernel config. 
> 
> NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver 
> actual abilities.
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>

You can't remove the NETIF_F_* checks.

If the user doesn't have VLAN offloading enabled, the VLAN tags should
be left in the packet as-is.

It can't be controlled by a CPP check.

Re: [PATCH v6 net] stmmac: strip all VLAN tag types when kernel 802.1Q support is selected

[Toshiaki Makita]

On 2018/06/11 4:29, David Miller wrote:
> From: Elad Nachman <eladv6@gmail.com>
> Date: Fri, 8 Jun 2018 12:19:29 +0300
> 
>> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before 
>> calling napi_gro_receive().
>>
>> The function assumes VLAN tagged frames are always tagged with 
>> 802.1Q protocol, and assigns ETH_P_8021Q to the skb by hard-coding
>> the parameter on call to __vlan_hwaccel_put_tag() .
>>
>> This causes packets not to be passed to the VLAN slave if it was created 
>> with 802.1AD protocol
>> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
>>
>> This fix passes the protocol from the VLAN header into 
>> __vlan_hwaccel_put_tag() instead of using the hard-coded value of
>> ETH_P_8021Q.
>>
>> NETIF_F_HW_VLAN_CTAG_RX check was removed and instead the strip action 
>> is dependent upon a preprocessor define which is defined when 802.1Q 
>> support is selected in the kernel config. 
>>
>> NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver 
>> actual abilities.
>>
>> Signed-off-by: Elad Nachman <eladn@gilat.com>
> 
> You can't remove the NETIF_F_* checks.
> 
> If the user doesn't have VLAN offloading enabled, the VLAN tags should
> be left in the packet as-is.
> 
> It can't be controlled by a CPP check.

David, NETIF_F_HW_VALN_*_RX is not user-controllable in this driver
because hw_features does not include them.

But this can break when those features are added to hw_features so if
David does not like this situation I think we need the condition anyway.

-- 
Toshiaki Makita

[PATCH v7 net] stmmac: added support for 802.1ad vlan stripping

[Elad Nachman]

stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before 
calling napi_gro_receive().

The function assumes VLAN tagged frames are always tagged with 
802.1Q protocol, and assigns ETH_P_8021Q to the skb by hard-coding
the parameter on call to __vlan_hwaccel_put_tag() .

This causes packets not to be passed to the VLAN slave if it was created 
with 802.1AD protocol
(ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).

This fix passes the protocol from the VLAN header into 
__vlan_hwaccel_put_tag() instead of using the hard-coded value of
ETH_P_8021Q.

NETIF_F_HW_VLAN_STAG_RX check was added and the strip action is now
dependent on the correct combination of features and the detected vlan tag.

NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver 
actual abilities.

Signed-off-by: Elad Nachman <eladn@gilat.com>



---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 11fb7c7..c4ffbfb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3182,17 +3182,22 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
 {
-	struct ethhdr *ehdr;
+	struct vlan_ethhdr *veth;
+	__be16 vlan_proto;
 	u16 vlanid;
 
-	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
-	    NETIF_F_HW_VLAN_CTAG_RX &&
-	    !__vlan_get_tag(skb, &vlanid)) {
+	veth = (struct vlan_ethhdr *)skb->data;
+	vlan_proto = veth->h_vlan_proto;
+
+	if ((vlan_proto == htons(ETH_P_8021Q) &&
+	     dev->features & NETIF_F_HW_VLAN_CTAG_RX) ||
+	    (vlan_proto == htons(ETH_P_8021AD) &&
+	     dev->features & NETIF_F_HW_VLAN_STAG_RX)) {
 		/* pop the vlan tag */
-		ehdr = (struct ethhdr *)skb->data;
-		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
+		vlanid = ntohs(veth->h_vlan_TCI);
+		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
 		skb_pull(skb, VLAN_HLEN);
-		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
+		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
 	}
 }
 
@@ -4235,7 +4240,7 @@ int stmmac_dvr_probe(struct device *device,
 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
 #ifdef STMMAC_VLAN_TAG_USED
 	/* Both mac100 and gmac support receive VLAN tag detection */
-	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
+	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
 #endif
 	priv->msg_enable = netif_msg_init(debug, default_msg_level);
 
-- 
2.7.4

Re: [PATCH v7 net] stmmac: added support for 802.1ad vlan stripping

[Toshiaki Makita]

On 2018/06/15 15:57, Elad Nachman wrote:
> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before 
> calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with 
> 802.1Q protocol, and assigns ETH_P_8021Q to the skb by hard-coding
> the parameter on call to __vlan_hwaccel_put_tag() .
> 
> This causes packets not to be passed to the VLAN slave if it was created 
> with 802.1AD protocol
> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
> 
> This fix passes the protocol from the VLAN header into 
> __vlan_hwaccel_put_tag() instead of using the hard-coded value of
> ETH_P_8021Q.
> 
> NETIF_F_HW_VLAN_STAG_RX check was added and the strip action is now
> dependent on the correct combination of features and the detected vlan tag.
> 
> NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver 
> actual abilities.
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>

Reviewed-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>

> 
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 11fb7c7..c4ffbfb 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3182,17 +3182,22 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>  
>  static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
>  {
> -	struct ethhdr *ehdr;
> +	struct vlan_ethhdr *veth;
> +	__be16 vlan_proto;
>  	u16 vlanid;
>  
> -	if ((dev->features & NETIF_F_HW_VLAN_CTAG_RX) ==
> -	    NETIF_F_HW_VLAN_CTAG_RX &&
> -	    !__vlan_get_tag(skb, &vlanid)) {
> +	veth = (struct vlan_ethhdr *)skb->data;
> +	vlan_proto = veth->h_vlan_proto;
> +
> +	if ((vlan_proto == htons(ETH_P_8021Q) &&
> +	     dev->features & NETIF_F_HW_VLAN_CTAG_RX) ||
> +	    (vlan_proto == htons(ETH_P_8021AD) &&
> +	     dev->features & NETIF_F_HW_VLAN_STAG_RX)) {
>  		/* pop the vlan tag */
> -		ehdr = (struct ethhdr *)skb->data;
> -		memmove(skb->data + VLAN_HLEN, ehdr, ETH_ALEN * 2);
> +		vlanid = ntohs(veth->h_vlan_TCI);
> +		memmove(skb->data + VLAN_HLEN, veth, ETH_ALEN * 2);
>  		skb_pull(skb, VLAN_HLEN);
> -		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlanid);
> +		__vlan_hwaccel_put_tag(skb, vlan_proto, vlanid);
>  	}
>  }
>  
> @@ -4235,7 +4240,7 @@ int stmmac_dvr_probe(struct device *device,
>  	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
>  #ifdef STMMAC_VLAN_TAG_USED
>  	/* Both mac100 and gmac support receive VLAN tag detection */
> -	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
> +	ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
>  #endif
>  	priv->msg_enable = netif_msg_init(debug, default_msg_level);
>  
> 

-- 
Toshiaki Makita

Re: [PATCH v7 net] stmmac: added support for 802.1ad vlan stripping

[David Miller]

From: Elad Nachman <eladv6@gmail.com>
Date: Fri, 15 Jun 2018 09:57:39 +0300

> stmmac reception handler calls stmmac_rx_vlan() to strip the vlan before 
> calling napi_gro_receive().
> 
> The function assumes VLAN tagged frames are always tagged with 
> 802.1Q protocol, and assigns ETH_P_8021Q to the skb by hard-coding
> the parameter on call to __vlan_hwaccel_put_tag() .
> 
> This causes packets not to be passed to the VLAN slave if it was created 
> with 802.1AD protocol
> (ip link add link eth0 eth0.100 type vlan proto 802.1ad id 100).
> 
> This fix passes the protocol from the VLAN header into 
> __vlan_hwaccel_put_tag() instead of using the hard-coded value of
> ETH_P_8021Q.
> 
> NETIF_F_HW_VLAN_STAG_RX check was added and the strip action is now
> dependent on the correct combination of features and the detected vlan tag.
> 
> NETIF_F_HW_VLAN_STAG_RX feature was added to be in line with the driver 
> actual abilities.
> 
> Signed-off-by: Elad Nachman <eladn@gilat.com>

Applied, thank you.