Re: SOCK_RAW does not receive broadcast (with VLAN unless PROMISC)

[Gil Beniamini <gil.beniamini@gmail.com>]

Patrick,
On the specific NIC (eth1) no vlan is defined, and in the new Linux
the application receive NOTHING at all. In order to debug, I start
"wireshark as root" and "wireshark" set PROMISC on, and the
application start receive the raw packets as expected. Later I started
setting PROMISC by my application, and it can receive the packets even
when "wireshark" is not running.
The problem that I have with PROMISC mode, is that I need to do the
irelevant  unicast filtering in software rather than get it from the
hardware (as it works in old kernel 2.6.20).
Thanks a lot, Gil

On Tue, Jun 9, 2009 at 2:40 PM, Patrick McHardy<kaber@trash.net> wrote:
> Gil Beniamini wrote:
>>
>> 9Jun09, The problem was seen with eth1 using driver e1000e, but also
>> was reproduced on 3c59x, to me it seems that the problem is not
>> related to a specific nic driver.
>> VLAN is running for other NICs, but on the application specific nic
>> (eth1) I use PF_PACKET (SOCK_RAW) , in order to get  the raw-packet
>> from the underlying device, and this start working again (like in
>> older kernel) as soon as the application set the socket to PROMISC
>> mode.
>
> OK, that might explain it. e1000e performs VLAN filtering in hardware
> and unless there are VLANs configured locally, all VLANs are filtered
> out. Are you seeing seeing only unicast VLAN traffic or no VLAN traffic
> at all? Please post a dump of the packets with and without promiscous
> mode.
>
>