Wait until network is ready for remote authentication

Hi,

refer to this Bug #1039151 to see the background.

Lightdm should wait until we have Networking ready. If no network is available it should start immediately. This is necessary for all non local authentication methods like sssd etc.
If lightdm starts to early it may lead to failed login attempts until network is ready and for example M$-AD Server is available.

These are the scripts i used to prevent lightdm from starting to early:

Here are the skripts:

/etc/init/networkdelay.conf :

description "wait for IP to be there"

#emits networkdelay

start on (net-device-up IFACE!=lo
        and local-filesystems)

#start on (((starting lightdm or starting kdm) or starting xdm) or starting lxdm)
start on (starting lightdm
        or starting kdm
        or starting xdm
        or starting lxdm)

task

script
        exec /usr/sbin/network-ok
end script

/usr/sbin/network-ok:

#!/bin/sh
LOG=/tmp/network-diag
rm $LOG
#LOG=/dev/null
#touch $LOG
MAXWAIT=60
T0=`cut -f1 -d. /proc/uptime`

while (( test $(($T0+$MAXWAIT)) -gt $(cut -f1 -d. /proc/uptime) ))
do
 date >> $LOG
 pidof lightdm >> $LOG
 #GW=`ip ro list default |head -1 |cut -d " " -f 3`
 GW=`ip -4 ro list 0.0.0.0/0 | cut -d " " -f 3`
# ethtool eth0 >> $LOG
 test -n "$GW" && ping -c1 -w1 $GW >> $LOG 2>&1 && break
 sleep 1
done