[pkg-wpa-devel] Bug#737109: Bug#737109: hostapd: Bridged interface dropped from bridge

[Stefan Lippers-Hollmann]

Hi

On Thursday 30 January 2014, Mark Hindley wrote:
[...]
> I am using hostapd in a bridged wlan/eth setup. The wifi card is 
> 
>  00:08.0 Ethernet controller: Atheros Communications Inc. AR5212/AR5213 Wireless Network Adapter (rev 01)
[...]
> When using hostapd/stable, clients using the wlan are sometimes suddenly 
> unable to communicate through the bridge and wlan0 is no longer present 
> in the output of brctl show br0. 
> 
> At the same time syslog shows:
> 
> /var/log/syslog.2.gz:Jan 19 11:31:07 titan kernel: device wlan0.sta1 entered promiscuous mode
> /var/log/syslog.2.gz:Jan 19 11:31:07 titan kernel: br0: port 3(wlan0.sta1) entering forwarding state
> /var/log/syslog.2.gz:Jan 19 11:31:07 titan kernel: br0: port 3(wlan0.sta1) entering forwarding state
> /var/log/syslog.2.gz:Jan 19 11:31:11 titan ntpd[3468]: Listen normally on 19 wlan0.sta1 fe80::20f:3dff:feaa:96f0 UDP 123
> /var/log/syslog.2.gz:Jan 19 11:31:18 titan kernel: wlan0.sta1: no IPv6 routers present
> /var/log/syslog.2.gz:Jan 19 11:31:22 titan kernel: br0: port 3(wlan0.sta1) entering forwarding state
> /var/log/syslog.2.gz:Jan 19 11:31:22 titan kernel: device wlan0.sta1 left promiscuous mode
> /var/log/syslog.2.gz:Jan 19 11:31:22 titan kernel: br0: port 3(wlan0.sta1) entering disabled state
> /var/log/syslog.2.gz:Jan 19 11:31:24 titan ntpd[3468]: Deleting interface #19 wlan0.sta1, fe80::20f:3dff:feaa:96f0#123, interface stats: received=0, sent=0, dropped=0, active_time=13 secs
> 
> Wireless traffic across the bridge can be restored by adding wlan0 back 
> to the bridge with brctl addif br0 wlan0
> 
> There is a similar ticket in the OpenWRT lists at 
> https://dev.openwrt.org/ticket/9257
> 
> Their fix is https://dev.openwrt.org/changeset/26724
> 
> I have rebuilt hostapd with an updated version of the same patch and it 
> also seems to fix the problem for me. Perhaps you would consider including it?
> 
> My patch below. The only change I made to the OpenWRT version was to 
> reflect the move of drv->ioctl_sock to drv->global->ioctl_sock and to 
> refresh the line numbers.
[...]

Thanks a lot for investigating this so well and providing a patch, 
which seems to have gotten decent testing and looks to be pretty 
straight forward. However I'm concerned that this particular patch
appears to be around three years old, without having been merged into
hostapd upstream, despite the patch author usually being quite active
in upstream development[1] of these wireless needs...

Given that the old bugtracker at w1.fi no longer exists, I can't 
confirm at the moment if this patch had been submitted upstream and/ or
if it has been rejected for any reasons, which makes me a bit reluctant
to apply it to Debian. So far I haven't come to a conclusion yet and
while this patch might not be part of the very next wpa upload, I'll 
keep it in mind.

Regards
	Stefan Lippers-Hollmann

[1]	I'm aware that OpenWrt is probably the only party actively working
	on 4addr support
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