From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Friesen Subject: Re: Network link detection Date: Thu, 03 Mar 2011 17:54:12 -0600 Message-ID: <4D702A24.70805@genband.com> References: <20110303193006.GA29129@svh.nico22.de> <4D700A5B.2000807@genband.com> <20110303.140106.191399853.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: dev@nico22.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: David Miller Return-path: In-Reply-To: <20110303.140106.191399853.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 03/03/2011 04:01 PM, David Miller wrote: > From: Chris Friesen > 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@genband.com www.genband.com