[PATCH] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[PATCH] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[Lukasz Majewski]

Current HSR implementation uses following supervisory frame (even for
HSRv1 the HSR tag is not is not present):

00000000: 01 15 4e 00 01 2d XX YY ZZ 94 77 10 88 fb 00 01
00000010: 7e 1c 17 06 XX YY ZZ 94 77 10 1e 06 XX YY ZZ 94
00000020: 77 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 00 00 00 00 00 00 00 00

The current code adds extra two bytes (i.e. sizeof(struct hsr_sup_tlv))
when offset for skb_pull() is calculated.
This is wrong, as both 'struct hsrv1_ethhdr_sp' and 'hsrv0_ethhdr_sp'
already have 'struct hsr_sup_tag' defined in them, so there is no need
for adding extra two bytes.

This code was working correctly as with no RedBox support, the check for
HSR_TLV_EOT (0x00) was off by two bytes, which were corresponding to
zeroed padded bytes for minimal packet size.

Fixes: f43200a2c98b ("net: hsr: Provide RedBox support")

Signed-off-by: Lukasz Majewski <lukma@denx.de>
---
 net/hsr/hsr_forward.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
index 2afe28712a7a..5d68cb181695 100644
--- a/net/hsr/hsr_forward.c
+++ b/net/hsr/hsr_forward.c
@@ -83,7 +83,7 @@ static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
 		return false;
 
 	/* Get next tlv */
-	total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tag->tlv.HSR_TLV_length;
+	total_length += hsr_sup_tag->tlv.HSR_TLV_length;
 	if (!pskb_may_pull(skb, total_length))
 		return false;
 	skb_pull(skb, total_length);
-- 
2.20.1

Re: [PATCH] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[Jiri Pirko]

Mon, Feb 26, 2024 at 04:24:47PM CET, lukma@denx.de wrote:
>Current HSR implementation uses following supervisory frame (even for
>HSRv1 the HSR tag is not is not present):
>
>00000000: 01 15 4e 00 01 2d XX YY ZZ 94 77 10 88 fb 00 01
>00000010: 7e 1c 17 06 XX YY ZZ 94 77 10 1e 06 XX YY ZZ 94
>00000020: 77 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>00000030: 00 00 00 00 00 00 00 00 00 00 00 00
>
>The current code adds extra two bytes (i.e. sizeof(struct hsr_sup_tlv))
>when offset for skb_pull() is calculated.
>This is wrong, as both 'struct hsrv1_ethhdr_sp' and 'hsrv0_ethhdr_sp'
>already have 'struct hsr_sup_tag' defined in them, so there is no need
>for adding extra two bytes.
>
>This code was working correctly as with no RedBox support, the check for
>HSR_TLV_EOT (0x00) was off by two bytes, which were corresponding to
>zeroed padded bytes for minimal packet size.
>
>Fixes: f43200a2c98b ("net: hsr: Provide RedBox support")
>

No need for this empty line.

>Signed-off-by: Lukasz Majewski <lukma@denx.de>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Re: [PATCH] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[Simon Horman]

On Mon, Feb 26, 2024 at 04:24:47PM +0100, Lukasz Majewski wrote:
> Current HSR implementation uses following supervisory frame (even for
> HSRv1 the HSR tag is not is not present):
> 
> 00000000: 01 15 4e 00 01 2d XX YY ZZ 94 77 10 88 fb 00 01
> 00000010: 7e 1c 17 06 XX YY ZZ 94 77 10 1e 06 XX YY ZZ 94
> 00000020: 77 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00000030: 00 00 00 00 00 00 00 00 00 00 00 00
> 
> The current code adds extra two bytes (i.e. sizeof(struct hsr_sup_tlv))
> when offset for skb_pull() is calculated.
> This is wrong, as both 'struct hsrv1_ethhdr_sp' and 'hsrv0_ethhdr_sp'
> already have 'struct hsr_sup_tag' defined in them, so there is no need
> for adding extra two bytes.
> 
> This code was working correctly as with no RedBox support, the check for
> HSR_TLV_EOT (0x00) was off by two bytes, which were corresponding to
> zeroed padded bytes for minimal packet size.
> 
> Fixes: f43200a2c98b ("net: hsr: Provide RedBox support")

Hi Lukasz,

The commit cited above does seem to be present in net or net-next.
Perhaps the tag should be:

   Fixes: eafaa88b3eb7 ("net: hsr: Add support for redbox supervision frames")

> 
> Signed-off-by: Lukasz Majewski <lukma@denx.de>

...

Re: [PATCH] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[Lukasz Majewski]

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Hi Simon,

> On Mon, Feb 26, 2024 at 04:24:47PM +0100, Lukasz Majewski wrote:
> > Current HSR implementation uses following supervisory frame (even
> > for HSRv1 the HSR tag is not is not present):
> > 
> > 00000000: 01 15 4e 00 01 2d XX YY ZZ 94 77 10 88 fb 00 01
> > 00000010: 7e 1c 17 06 XX YY ZZ 94 77 10 1e 06 XX YY ZZ 94
> > 00000020: 77 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00000030: 00 00 00 00 00 00 00 00 00 00 00 00
> > 
> > The current code adds extra two bytes (i.e. sizeof(struct
> > hsr_sup_tlv)) when offset for skb_pull() is calculated.
> > This is wrong, as both 'struct hsrv1_ethhdr_sp' and
> > 'hsrv0_ethhdr_sp' already have 'struct hsr_sup_tag' defined in
> > them, so there is no need for adding extra two bytes.
> > 
> > This code was working correctly as with no RedBox support, the
> > check for HSR_TLV_EOT (0x00) was off by two bytes, which were
> > corresponding to zeroed padded bytes for minimal packet size.
> > 
> > Fixes: f43200a2c98b ("net: hsr: Provide RedBox support")  
> 
> Hi Lukasz,
> 
> The commit cited above does seem to be present in net or net-next.
> Perhaps the tag should be:
> 
>    Fixes: eafaa88b3eb7 ("net: hsr: Add support for redbox supervision
> frames")

Thanks for spotting it - I must have overlook it when preparing the
commit message.

> 
> > 
> > Signed-off-by: Lukasz Majewski <lukma@denx.de>  
> 
> ...




Best regards,

Lukasz Majewski

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