unicast probe response bssid changed by "wifi: mac80211: do link->MLD address translation on RX"

unicast probe response bssid changed by "wifi: mac80211: do link->MLD address translation on RX"

[Wen Gong]

Hi Johannes,

The mac addr of unicast rx packet all changed to the MLD address by 
below patch.
Now the probe presponse which is unicast packet is also changed mac 
address here.
I found bssid which is the MLD address of my test AP in cfg80211_get_bss().
For example, if the AP has 2 mlo links, link 1 is 5 GHz band, link 2 is 
2.4 GHz band,
then the 2 probe reponse will be changed to a same one.
seems we should skip probe presponse for the mac address change here, right?

https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?id=42fb9148c078004d07b4c39bd7b1086b6165780c
wifi: mac80211: do link->MLD address translation on RX

Re: unicast probe response bssid changed by "wifi: mac80211: do link->MLD address translation on RX"

[Wen Gong]

Hi Johannes,

May I get your comment about this?

On 9/14/2022 11:13 AM, Wen Gong wrote:
> Hi Johannes,
>
> The mac addr of unicast rx packet all changed to the MLD address by 
> below patch.
> Now the probe presponse which is unicast packet is also changed mac 
> address here.
> I found bssid which is the MLD address of my test AP in 
> cfg80211_get_bss().
> For example, if the AP has 2 mlo links, link 1 is 5 GHz band, link 2 
> is 2.4 GHz band,
> then the 2 probe reponse will be changed to a same one.
> seems we should skip probe presponse for the mac address change here, 
> right?
>
> https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?id=42fb9148c078004d07b4c39bd7b1086b6165780c 
>
> wifi: mac80211: do link->MLD address translation on RX
>

wifi: mac80211: Re: unicast probe response bssid changed by "wifi: mac80211: do link->MLD address translation on RX"

[Wen Gong]

On 9/14/2022 11:13 AM, Wen Gong wrote:
> Hi Johannes,
>
> The mac addr of unicast rx packet all changed to the MLD address by 
> below patch.
> Now the probe presponse which is unicast packet is also changed mac 
> address here.
> I found bssid which is the MLD address of my test AP in 
> cfg80211_get_bss().
> For example, if the AP has 2 mlo links, link 1 is 5 GHz band, link 2 
> is 2.4 GHz band,
> then the 2 probe reponse will be changed to a same one.
> seems we should skip probe presponse for the mac address change here, 
> right?
>
> https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?id=42fb9148c078004d07b4c39bd7b1086b6165780c 
>
> wifi: mac80211: do link->MLD address translation on RX
>
Hi Johannes,

May I get your comment about this?

I did below change in my local test to workaround the issue.

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index a57811372027..eaff5353520a 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4858,7 +4858,8 @@ static bool ieee80211_prepare_and_rx_handle(struct 
ieee80211_rx_data *rx,
          shwt->hwtstamp = skb_hwtstamps(skb)->hwtstamp;
      }

-    if (unlikely(link_sta)) {
+    if (unlikely(link_sta) &&
+        !(ieee80211_is_probe_resp(hdr->frame_control))) {
          /* translate to MLD addresses */
          if (ether_addr_equal(link->conf->addr, hdr->addr1))
              ether_addr_copy(hdr->addr1, rx->sdata->vif.addr);

Re: wifi: mac80211: Re: unicast probe response bssid changed by "wifi: mac80211: do link->MLD address translation on RX"

[Johannes Berg]

On Wed, 2022-10-19 at 17:35 +0800, Wen Gong wrote:
> On 9/14/2022 11:13 AM, Wen Gong wrote:
> > Hi Johannes,
> > 
> > The mac addr of unicast rx packet all changed to the MLD address by 
> > below patch.
> > Now the probe presponse which is unicast packet is also changed mac 
> > address here.
> > I found bssid which is the MLD address of my test AP in 
> > cfg80211_get_bss().
> > For example, if the AP has 2 mlo links, link 1 is 5 GHz band, link 2 
> > is 2.4 GHz band,
> > then the 2 probe reponse will be changed to a same one.
> > seems we should skip probe presponse for the mac address change here, 
> > right?
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?id=42fb9148c078004d07b4c39bd7b1086b6165780c 
> > 
> > wifi: mac80211: do link->MLD address translation on RX
> > 
> Hi Johannes,
> 
> May I get your comment about this?

Yes I've actually seen this issue as well.

> I did below change in my local test to workaround the issue.
> 
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index a57811372027..eaff5353520a 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -4858,7 +4858,8 @@ static bool ieee80211_prepare_and_rx_handle(struct 
> ieee80211_rx_data *rx,
>           shwt->hwtstamp = skb_hwtstamps(skb)->hwtstamp;
>       }
> 
> -    if (unlikely(link_sta)) {
> +    if (unlikely(link_sta) &&
> +        !(ieee80211_is_probe_resp(hdr->frame_control))) {
>           /* translate to MLD addresses */
> 

Maybe it should also be for beacons or so?

johannes

Re: wifi: mac80211: Re: unicast probe response bssid changed by "wifi: mac80211: do link->MLD address translation on RX"

[Wen Gong]

On 10/19/2022 5:38 PM, Johannes Berg wrote:
> On Wed, 2022-10-19 at 17:35 +0800, Wen Gong wrote:
>> On 9/14/2022 11:13 AM, Wen Gong wrote:
>>> Hi Johannes,
>>>
>>> The mac addr of unicast rx packet all changed to the MLD address by
>>> below patch.
>>> Now the probe presponse which is unicast packet is also changed mac
>>> address here.
>>> I found bssid which is the MLD address of my test AP in
>>> cfg80211_get_bss().
>>> For example, if the AP has 2 mlo links, link 1 is 5 GHz band, link 2
>>> is 2.4 GHz band,
>>> then the 2 probe reponse will be changed to a same one.
>>> seems we should skip probe presponse for the mac address change here,
>>> right?
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?id=42fb9148c078004d07b4c39bd7b1086b6165780c
>>>
>>> wifi: mac80211: do link->MLD address translation on RX
>>>
>> Hi Johannes,
>>
>> May I get your comment about this?
> Yes I've actually seen this issue as well.
>
>> I did below change in my local test to workaround the issue.
>>
>> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
>> index a57811372027..eaff5353520a 100644
>> --- a/net/mac80211/rx.c
>> +++ b/net/mac80211/rx.c
>> @@ -4858,7 +4858,8 @@ static bool ieee80211_prepare_and_rx_handle(struct
>> ieee80211_rx_data *rx,
>>            shwt->hwtstamp = skb_hwtstamps(skb)->hwtstamp;
>>        }
>>
>> -    if (unlikely(link_sta)) {
>> +    if (unlikely(link_sta) &&
>> +        !(ieee80211_is_probe_resp(hdr->frame_control))) {
>>            /* translate to MLD addresses */
>>
> Maybe it should also be for beacons or so?
>
> johannes
Yes, it should also for beacons.