Re: Network link detection

From: Chris Friesen
Date: Thu Mar 03 2011 - 18:55:06 EST


On 03/03/2011 04:01 PM, David Miller wrote:
> From: Chris Friesen <chris.friesen@xxxxxxxxxxx>
> Date: Thu, 03 Mar 2011 15:38:35 -0600
>
>> You might look at whether you could write a kernel module to register
>> for NETDEV_CHANGE notifications and pass that back to userspace.
>
> This is the kind of responses you get when you ask networking specific
> questions and don't CC: netdev :-/

My apologies for misleading the original poster. I can only claim a
brain fart since I've actually used rtnetlink for other things.

> There is this thing called netlink, you can listen for arbitrary
> network state change events on a socket, and get the link state
> notifications you are looking for. It's in use by many real
> applications like NetworkManager and co.

For future reference then, to listen for link state notifications you'd
use NETLINK_ROUTE with nl_groups set to RTMGRP_LINK, and the link state
will be signaled in the if_flags field of received messages?

Chris

--
Chris Friesen
Software Developer
GENBAND
chris.friesen@xxxxxxxxxxx
www.genband.com
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