2023-06-29 14:30:18

by Vladimir Oltean

Subject: [PATCH net 1/2] net: dsa: tag_sja1105: fix MAC DA patching from meta frames

The SJA1105 manual says that at offset 4 into the meta frame payload we
have "MAC destination byte 2" and at offset 5 we have "MAC destination
byte 1". These are counted from the LSB, so byte 1 is h_dest[ETH_HLEN-2]
aka h_dest[4] and byte 2 is h_dest[ETH_HLEN-3] aka h_dest[3].

The sja1105_meta_unpack() function decodes these the other way around,
so a frame with MAC DA 01:80:c2:11:22:33 is received by the network
stack as having 01:80:c2:22:11:33.

Fixes: e53e18a6fe4d ("net: dsa: sja1105: Receive and decode meta frames")
Signed-off-by: Vladimir Oltean <[email protected]>
---
net/dsa/tag_sja1105.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
index 92a626a05e82..226191ec654b 100644
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c
@@ -118,8 +118,8 @@ static void sja1105_meta_unpack(const struct sk_buff *skb,
* a unified unpacking command for both device series.
*/
packing(buf, &meta->tstamp, 31, 0, 4, UNPACK, 0);
- packing(buf + 4, &meta->dmac_byte_4, 7, 0, 1, UNPACK, 0);
- packing(buf + 5, &meta->dmac_byte_3, 7, 0, 1, UNPACK, 0);
+ packing(buf + 4, &meta->dmac_byte_3, 7, 0, 1, UNPACK, 0);
+ packing(buf + 5, &meta->dmac_byte_4, 7, 0, 1, UNPACK, 0);
packing(buf + 6, &meta->source_port, 7, 0, 1, UNPACK, 0);
packing(buf + 7, &meta->switch_id, 7, 0, 1, UNPACK, 0);
}
--
2.34.1

2023-06-30 14:10:56

by Simon Horman

Subject: Re: [PATCH net 1/2] net: dsa: tag_sja1105: fix MAC DA patching from meta frames

On Thu, Jun 29, 2023 at 05:14:52PM +0300, Vladimir Oltean wrote:
> The SJA1105 manual says that at offset 4 into the meta frame payload we
> have "MAC destination byte 2" and at offset 5 we have "MAC destination
> byte 1". These are counted from the LSB, so byte 1 is h_dest[ETH_HLEN-2]
> aka h_dest[4] and byte 2 is h_dest[ETH_HLEN-3] aka h_dest[3].
>
> The sja1105_meta_unpack() function decodes these the other way around,
> so a frame with MAC DA 01:80:c2:11:22:33 is received by the network
> stack as having 01:80:c2:22:11:33.
>
> Fixes: e53e18a6fe4d ("net: dsa: sja1105: Receive and decode meta frames")
> Signed-off-by: Vladimir Oltean <[email protected]>

Reviewed-by: Simon Horman <[email protected]>

2023-07-02 14:47:53

by Florian Fainelli

Subject: Re: [PATCH net 1/2] net: dsa: tag_sja1105: fix MAC DA patching from meta frames

On 6/29/2023 4:14 PM, Vladimir Oltean wrote:
> The SJA1105 manual says that at offset 4 into the meta frame payload we
> have "MAC destination byte 2" and at offset 5 we have "MAC destination
> byte 1". These are counted from the LSB, so byte 1 is h_dest[ETH_HLEN-2]
> aka h_dest[4] and byte 2 is h_dest[ETH_HLEN-3] aka h_dest[3].
>
> The sja1105_meta_unpack() function decodes these the other way around,
> so a frame with MAC DA 01:80:c2:11:22:33 is received by the network
> stack as having 01:80:c2:22:11:33.
>
> Fixes: e53e18a6fe4d ("net: dsa: sja1105: Receive and decode meta frames")
> Signed-off-by: Vladimir Oltean <[email protected]>

Reviewed-by: Florian Fainelli <[email protected]>
--
Florian