[PATCH] mac80211: drop non-auth 3-addr data frames when running as a 4-addr station

[PATCH] mac80211: drop non-auth 3-addr data frames when running as a 4-addr station

[Felix Fietkau]

When running as a 4-addr station against an AP that has the 4-addr VLAN
interface and the main 3-addr AP interface bridged together, sometimes
frames originating from the station were looping back from the 3-addr AP
interface, causing the bridge code to emit warnings about receiving frames
with its own source address.
I'm not sure why this is happening yet, but I think it's a good idea to
drop all frames (except 802.1x/EAP frames) that do not match the configured
addressing mode, including 4-address frames sent to a 3-address station.
User test reports indicate that the problem goes away with this patch.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
 net/mac80211/rx.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index a6701ed..54e3108 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1561,9 +1561,13 @@ __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
 		return -1;
 
+	if (!ieee80211_802_1x_port_control(rx) &&
+	    sdata->vif.type == NL80211_IFTYPE_STATION &&
+	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control))
+		return -1;
+
 	if (is_multicast_ether_addr(hdr->addr1) &&
-	    ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
-	     (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
+	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
 		return -1;
 
 	return ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
-- 
1.7.3.2

Re: [PATCH] mac80211: drop non-auth 3-addr data frames when running as a 4-addr station

[Johannes Berg]

On Sat, 2011-01-15 at 14:38 +0100, Felix Fietkau wrote:
> When running as a 4-addr station against an AP that has the 4-addr VLAN
> interface and the main 3-addr AP interface bridged together, sometimes
> frames originating from the station were looping back from the 3-addr AP
> interface, causing the bridge code to emit warnings about receiving frames
> with its own source address.
> I'm not sure why this is happening yet, but I think it's a good idea to
> drop all frames (except 802.1x/EAP frames) that do not match the configured
> addressing mode, including 4-address frames sent to a 3-address station.
> User test reports indicate that the problem goes away with this patch.
> 
> Signed-off-by: Felix Fietkau <nbd@openwrt.org>
> ---
>  net/mac80211/rx.c |    8 ++++++--
>  1 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index a6701ed..54e3108 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -1561,9 +1561,13 @@ __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
>  	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
>  		return -1;
>  
> +	if (!ieee80211_802_1x_port_control(rx) &&

I think you need a different check there. This just checks the STA is
authorized.

johannes

Re: [PATCH] mac80211: drop non-auth 3-addr data frames when running as a 4-addr station

[Felix Fietkau]

On 2011-01-17 3:20 PM, Johannes Berg wrote:
> On Sat, 2011-01-15 at 14:38 +0100, Felix Fietkau wrote:
>>  When running as a 4-addr station against an AP that has the 4-addr VLAN
>>  interface and the main 3-addr AP interface bridged together, sometimes
>>  frames originating from the station were looping back from the 3-addr AP
>>  interface, causing the bridge code to emit warnings about receiving frames
>>  with its own source address.
>>  I'm not sure why this is happening yet, but I think it's a good idea to
>>  drop all frames (except 802.1x/EAP frames) that do not match the configured
>>  addressing mode, including 4-address frames sent to a 3-address station.
>>  User test reports indicate that the problem goes away with this patch.
>>
>>  Signed-off-by: Felix Fietkau<nbd@openwrt.org>
>>  ---
>>   net/mac80211/rx.c |    8 ++++++--
>>   1 files changed, 6 insertions(+), 2 deletions(-)
>>
>>  diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
>>  index a6701ed..54e3108 100644
>>  --- a/net/mac80211/rx.c
>>  +++ b/net/mac80211/rx.c
>>  @@ -1561,9 +1561,13 @@ __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
>>   	sdata->vif.type == NL80211_IFTYPE_AP_VLAN&&  !sdata->u.vlan.sta)
>>   		return -1;
>>
>>  +	if (!ieee80211_802_1x_port_control(rx)&&
>
> I think you need a different check there. This just checks the STA is
> authorized.
You're right. I'll fix and resend.

- Felix