bash script fails in squeeze

["Bonno Bloksma" <b.bloksma@tio.nl>]

Hi,

This script has been working flawlesly in Debian Etch and Lenny but after upgrading to Squeeze it no 
longer seems to work and I cannot find out why.

Below the full "defaultgw-test.sh" script which attempts to determin whethet the local internet 
gateway (ADLS, Cable, etc) is functioning. If not it will switch the default gateway over to the 
intranet connection where the internet traffic when then leave our WAN network. This way each site 
has a fast local consumer internet gateway but still has the reliability of a buisiness connection.

This bash script has been doing it's job for the past few years but suddenly stopped working in 
squeeze. Each part seems to work but the complete script does not. :-(
I have been doing some test runs to see where the problem is and I cannot find it. I hope someone 
can shed some light on this weird problem.

In the /etc/tiofirewall.conf file is a line
UPLINK_IP=192.168.178.1
which the script reads to determine what the default gateway for that site is supposed to be.

----------<defaultgw-test.sh>-----------------------------
#!/bin/bash

# v1.2
# 12-jul-2010
# 1.0 PINGHOST2 nu ook goed toegevoegd voor test defaultgw in de lucht
# pingtest() nu met count 2
# 1.1 ADSL_IP heet nu UPLINK_IP (change firewall 3.43)
# Debug info toegevoegd
# 1.2 IP nummer fw.tio.nl gewijzigd

DEBUGINFO=false
# PINGHOST is ping.xs4all.nl, de maatstaf of de DSL het nog doet
PINGHOST=194.109.21.51
# PINGHOST2 is ip van fw.tio.nl voor het geval de eerste even niet bereikbaar is
PINGHOST2=77.222.72.50
# DEFAULTGW moet de defaultgateway van deze machine zijn
DEFAULTGW=`grep UPLINK_IP= /etc/tiofirewall.conf | cut -d= -f2`

if [ $DEBUGINFO = true ] ; then
 echo "Default gateway is" $DEFAULTGW
fi

# hieronder hoeft niets gewijzigd te worden

function pingtest() {
 IPHOST=$1
 ping -c2 $IPHOST >/dev/null 2>&1
 VALUE=$?
 [ $VALUE == 0 ] && echo OK || echo NOK
}

function routezebra() {
 [ X"`ip route ls | grep ^default | grep zebra`" == X ] && \
   echo NO || echo YES
}

function nodefaultgw() {
 [ `routezebra` == NO ] && \
   echo "deleting default route via DSL, now learning default via OSPF!" && \
   ip route del default
}

function yesdefaultgw() {
 [ `routezebra` == YES ] && \
   echo "adding default route via DSL, ignoring default learnt via OSPF" && \
   ip route add default via $DEFAULTGW
}

# test of $PINGHOST pingt
# pingt hij niet, test dan nog een keer
# pingt hij dan nog niet, verwijder dan de defaultroute
[ `pingtest $PINGHOST` == NOK ] && \
[ `pingtest $PINGHOST2` == NOK ] && \
 sleep 2 && \
 [ `pingtest $PINGHOST` == NOK ] && \
 [ `pingtest $PINGHOST2` == NOK ] && \
 nodefaultgw

sleep 2

# test of $PINGHOST pingt
# pingt hij, test dan nog een keer
# pingt hij dan weer, voeg dan de defaultroute toe
([ `pingtest $PINGHOST` == OK ] || [ `pingtest $PINGHOST2` == OK ]) && \
 sleep 2 && \
 ([ `pingtest $PINGHOST` == OK ] || [ `pingtest $PINGHOST2` == OK ]) && \
 yesdefaultgw
----------<\defaultgw-test.sh>-----------------------------


Below some tests.
----------<callscript.sh>-----------------------------
echo pingonly.sh ----------
/root/test/pingonly.sh
echo status=$?

echo ping2.sh ----------
/root/test/ping2.sh
echo status=$?

echo ping3.sh ----------
/root/test/ping3.sh
echo status=$?

echo ping4.sh ----------
/root/test/ping4.sh
echo status=$?

echo no-yes-defaultgw.sh ----------
/root/test/no-yes-defaultgw.sh
echo status=$?
----------<\callscript.sh>-----------------------------

OUTPUT callscript
=================
linrtm:~/test# ./callscript.sh
pingonly.sh ----------
OK
OK
status=0
ping2.sh ----------
default gateway
status=0
ping3.sh ----------
default gateway
status=0
ping4.sh ----------
status=1
no-yes-defaultgw.sh ----------
deleting default route via DSL, now learning default via OSPF!
adding default route via DSL, ignoring default learnt via OSPF
status=0

SCRIPT INHOUD
=============

All scripts contain the same content as the defaultgw-test.sh script with the same procedures and 
definitions. Only the "action lines" at the end of the script are different.

pingonly.sh ----------
pingtest $PINGHOST
pingtest $PINGHOST2

ping2.sh ----------
# test of $PINGHOST pingt
# pingt hij niet, test dan nog een keer
# pingt hij dan nog niet, verwijder dan de defaultroute
[ `pingtest $PINGHOST` == NOK ] && \
[ `pingtest $PINGHOST2` == NOK ] && \
  echo no default gateway || echo default gateway

ping3.sh ----------
# test of $PINGHOST pingt
# pingt hij niet, test dan nog een keer
# pingt hij dan nog niet, verwijder dan de defaultroute
[ `pingtest $PINGHOST` == NOK ] && \
[ `pingtest $PINGHOST2` == NOK ] && \
 sleep 2 && \
 [ `pingtest $PINGHOST` == NOK ] && \
 [ `pingtest $PINGHOST2` == NOK ] && \
  echo no default gateway || echo default gateway

ping4.sh ----------
# test of $PINGHOST pingt
# pingt hij niet, test dan nog een keer
# pingt hij dan nog niet, verwijder dan de defaultroute
[ `pingtest $PINGHOST` == NOK ] && \
[ `pingtest $PINGHOST2` == NOK ] && \
 sleep 2 && \
 [ `pingtest $PINGHOST` == NOK ] && \
 [ `pingtest $PINGHOST2` == NOK ] && \
 nodefaultgw


no-yes-defaultgw.sh ----------
nodefaultgw
sleep 2
yesdefaultgw


I hope someone can find a reason why for instance ping4 fails and ping3 does not.

Met vriendelijke groet,
Bonno Bloksma
senior systeembeheerder