[PATCH v2] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[PATCH v2] 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: eafaa88b3eb7 ("net: hsr: Add support for redbox supervision frames")

Signed-off-by: Lukasz Majewski <lukma@denx.de>
---
Changes for v2:
- Update commit message to point to correct commit in "Fixes:"

---
 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 v2] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[Jiri Pirko]

Wed, Feb 28, 2024 at 09:56:44AM 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: eafaa88b3eb7 ("net: hsr: Add support for redbox supervision frames")
>

And yet the extra empty line is still here :/


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

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

Re: [PATCH v2] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[Paolo Abeni]

On Wed, 2024-02-28 at 13:31 +0100, Jiri Pirko wrote:
> Wed, Feb 28, 2024 at 09:56:44AM 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: eafaa88b3eb7 ("net: hsr: Add support for redbox supervision frames")
> > 
> 
> And yet the extra empty line is still here :/

To avoid more back & forth on otherwise correct patch, I'll fix this
while applying the patch. I hope it's clear to everybody this is an
exception and not the new normal :)

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

Please have a better look to the Documentation before the next post,
and use the checkpatch script before the submission.

Thanks,

Paolo

Re: [PATCH v2] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Wed, 28 Feb 2024 09:56:44 +0100 you 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
> 
> [...]

Here is the summary with links:
  - [v2] net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames
    https://git.kernel.org/netdev/net/c/51dd4ee03722

You are awesome, thank you!
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