#!/bin/bash

# USAGE: linkcheck.sh X Y  -- if X not responding to ping for Y minutes then reboot (wakes up after every Y minutes)
# MUST BE RUN ONLY ONCE (IT WILL MODIFY ROOTS CRONTAB)

# FOR MANDRAKE 10 (SysV style)
#CRONPATH=/var/spool/cron/root
#cmSTOP_CROND="/etc/init.d/crond stop"
#cmSTART_CROND="/etc/init.d/crond start"

# FOR SLACKWARE (router)
cmSTART_CROND="/usr/sbin/crond -l10 >>/var/adm/cron 2>&1"
CRONPATH="/var/spool/cron/crontabs/root"
cmSTOP_CROND="/bin/killall crond"

IFACE="/etc/orionet/iface_external"
LOCKFILE="/var/lock/nolink.now"
cmPING="/bin/ping -qc 3"
cmREBOOT="/sbin/ifconfig $IFACE down; /sbin/ifconfig $IFACE up; /etc/rc.d/rc.inet1"
ADDR=$1
DELAY=$2

if [ $# = 0 ]; then
    echo "USAGE: linkcheck.sh X Y  -- if X not responding to ping for Y minutes then reboot (wakes up after every Y minutes)
    MUST BE RUN ONLY ONCE (IT WILL MODIFY ROOTS CRONTAB)"
    /usr/bin/logger -p syslog.info -t linkcheck.sh Started without paramenters. Exiting
           exit 0
fi

#if started with 2 parameters then rewrite crontab else just check link with X and reboot if lockfile present
if [ $# = 2  ]; then
rm -f $LOCKFILE
echo  Setting new parameters: ping $ADDR every $DELAY minutes
/usr/bin/logger -p syslog.info -t linkcheck.sh Setting new parameters: ping $ADDR every $DELAY minutes
if [ -f $CRONPATH ];
  then sed -e '/linkcheck/d' $CRONPATH > /tmp/tmp.cron
       mv -f /tmp/tmp.cron $CRONPATH
  else echo "No crontab found at specified location... Exiting"
       exit 99
fi    
echo "Linkcheck: Removing previous startup line from root's crontab."
# stopping crond
$cmSTOP_CROND >> /var/log/syslog
if [ $? -eq 0 ]; then
  echo "Stopping crond successful"
# adding new line to crontab
  echo "*/$DELAY * * * *  "/usr/local/openbill/router/bin/linkcheck.sh ${ADDR}"" >> $CRONPATH
# try to start crontab
$cmSTART_CROND >> /var/log/syslog
  if [ $? -eq 0 ]; then
      echo "Linkcheck: Starting crond successful."
   else echo "Linkcheck: Starting crond failed."
   exit 99
  fi
  else echo "Linkcheck: Killing crond failed."
  exit 99
fi
exit 0
fi

# checking exit code of ping command...(if one argument given)
if [ $# = 1 ]; then
$cmPING $ADDR >> /dev/null
if [ $? -ne 0 ]; then
    if [ -f $LOCKFILE ];
       then
# link failed lockfile exist - restarting.          
    /usr/local/openbill/router/bin/mailsignal.sh No link to $ADDR. Restaring $IFACE by linkcheck.sh.      
        /usr/bin/logger -p syslog.error -t linkcheck.sh No link to $ADDR. Restaring interface $IFACE.
        $cmREBOOT
    if [ $? -ne 0 ]; then
        /usr/bin/logger -p syslog.error -t linkcheck.sh Failed restarting $IFACE...
        /usr/local/openbill/router/bin/mailsignal.sh Failed restaring $IFACE by linkcheck.sh.
    fi    
# link failed - create lock
       else touch $LOCKFILE
         /usr/bin/logger -p syslog.warning -t linkcheck.sh No link to host $ADDR.  Restart of $IFACE will be forced next check.
     exit 99
    fi
# if lockfile exist and link is ok - removing lock.
else if [ -f $LOCKFILE ]; then
           rm -fr $LOCKFILE
     fi
fi
fi