#!/bin/sh

PPPMON_LOCK=/var/run/ppmon.lock
PPP_ON_BOOT=/etc/ppp/ppp_on_boot
CALL_LIST=$@
LOG_DIR=/tmp

PING_CHECK_TIMEOUT=120          #Ping check frequency (s)
PING_CONFIRM_CHECK_TIMEOUT=20	#Ping timeout before confirming ping
PMON_LOOP_TIMEOUT=1		#E1 check

#Restart wanrouter if all mlppp  
#go down to indicate to other side
#that all ports went down and
#IPCP will be restarted
#Options: 0: disable
#         1: enable
WANROUTER_RESTART_ON_ALL_DOWN=1	


#Wanrouter restart timeout
#before starting up the wanpipe ports
#This option works in conjunction with
#above option.
WANROUTER_DOWN_TIMEOUT=10


pidcnt=0
unset WANPIPE_STATUS
unset PPPD_ISP_NAME
ping_was_ok=0

function pmon_log
{
	logger -p daemon.info "pppmon[$$]: $1";
	echo "pppmon[$$]: $1";
}

function load_ppp_modules
{
	eval "modprobe ppp_generic 2> /dev/null"
	eval "modprobe ppp_synctty 2> /dev/null"

	eval "cat /proc/ksyms | grep ppp_register_channel 2> /dev/null > /dev/null"
	if [ $? -ne 0 ]; then
		pmon_log "Error: Kernel has no PPP support"
		return 1
	fi

	return 0;
}

function stop_all_pppd
{
	timeout=15;
	pppdown=0;

	pmon_log "Stopping all PPPD Services"
	eval "killall pppd 2> /dev/null"

	while [ $timeout -gt 0 ]; 
	do
		timeout=$((timeout -1))
		eval "killall pppd 2> /dev/null"
		if [ $? -eq 0 ]; then
			pmon_log "Waiting for pppd to go down"
			sleep 1
		else
			pppdown=1;
			break;
		fi
	done
	
	if [ $pppdown -eq 0 ]; then
		pmon_log "Forcing PPPD Kill"
		eval "killall -9 pppd 2> /dev/null"
		sleep 1
	else
		pmon_log "PPPD is down"
	fi 
}


function pmon_hangup_pppd
{
        isp_dev=$1

        pidtmp=$(ps fax  | grep "[p]ppd.*$isp_dev")
        pid2=${pidtmp/# /}
        pid=$(echo $pid2 | cut -d" " -f 1)

        eval "kill -s HUP $pid"
        if [ $? -ne 0 ]; then
                pmon_log "Error: Failed to hangup on $isp_dev"
                return 1
        fi
        return 0
}


function pmon_find_call_idx
{
	local callname=$1
	
	for ((i=1;i<=$pidcnt;i+=1)); do
		if [ "${PPPD_ISP_NAME[$i]}" = "$callname" ]; then
			return $i
		fi
	done

	return 255
}


function pmon_check_wanpipe_ports
{
	local idx
	local calllist=$1	

        for call in $calllist
        do
                wanpipe_dev=${call#isp_}
                rstatus=$(cat /proc/net/wanrouter/status | grep $wanpipe_dev | cut -d'|' -f 4)
                status=${rstatus// /}
                #pmon_log "Dev $wanpipe_dev New  Status -$status-"

		pmon_find_call_idx $call
		idx=$?			

		#pmon_log "IDX of $call is $idx Old Status ${WANPIPE_STATUS[$idx]} "
		
		if [ ${WANPIPE_STATUS[$idx]} != $status ]; then

			if [ $status != "Connected" ]; then
				if [ ${WANPIPE_STATUS[$idx]} == "Connected" ]; then
					pmon_log "Error: Device $wanpipe_dev is $status - Hanging up $call"	
					pmon_hangup_pppd $call
				fi
			fi
			WANPIPE_STATUS[$idx]=$status;	
		fi

		
        done
}

function pmon_ping_check
{
        local rip=$(cat /etc/ppp/peers/isp_wanpipe1 | grep "^\w.*:" |cut -f2 -d :)

	#if ppp interface is not up no point of pinging
	eval "ifconfig | grep "$rip" 2> /dev/null > /dev/null"
	if [ $? -ne 0 ]; then
		if [ $ping_was_ok -eq 1 ]; then
        		pmon_log "Error: Failed MLPPP ppp interface is down... restarting" 
			ping_was_ok=0;
			return 1
		fi

		#No point of pinging interface never came up
		return 0
	fi

        #pmon_log "Starting MLPPP Ping Check on $rip"
        eval "ping -c5 $rip 2> /dev/null > /dev/null" 
        if [ $? -ne 0 ]; then
		#Very first time do not try to timeout
                #because link was never up
		if [ $ping_was_ok -eq 1 ]; then

        		pmon_log "Error: Failed MLPPP ping check on $rip... confirming" 

			#Confirm that this failure is not due to heavy traffic
			for ((i=0;i<$PING_CONFIRM_CHECK_TIMEOUT;i++))
			do
				eval "ifconfig | grep "$rip" 2> /dev/null > /dev/null"
				if [ $? -ne 0 ]; then
        				pmon_log "Error: Failed MLPPP ppp interface is down... restarting" 
					return 1;
				fi
	
				pmon_check_wanpipe_ports "$CALL_LIST"
				
				sleep 1
			done

        		eval "ping -c5 $rip 2> /dev/null > /dev/null" 
			if [ $? -ne 0 ]; then	
        			pmon_log "Error: Failed MLPPP ping check on $rip... restarting" 
				ping_was_ok=0;
				return 1
			else
        			pmon_log "Note: Passed MLPPP ping check on $rip... continuing" 
			fi
		fi
	else
		ping_was_ok=1;
        fi

	return 0
}


#ps ax  | grep "pppmon" 
#pppmoncnt=$(ps aux | grep [p]ppmon  | grep [p]ppmon -c)
#pmon_log "PSMONCNT $pppmoncnt Rc=$? $$"
#if [ $pppmoncnt -gt 3 ]; then
#	pmon_log "Error: PPPMON is alread running: $pppmoncnt"
#	exit 1
#fi	
#exit 1


case "$1" in
  -*) echo "
Usage: pppmon  <list of call files>

If pppmon is invoked without arguments, $PPP_ON_BOOT file will be
run, presuming it exists and is executable. Otherwise, a PPP connection
will be started using settings from /etc/ppp/peers/provider.
If you specify one argument, a PPP connection will be started using
settings from the appropriate file in the /etc/ppp/peers/ directory, and
any additional arguments supplied will be passed as extra arguments to
pppd.
"
      exit 0
      ;;
esac


if [ -z "$1" -a -x "$PPP_ON_BOOT" ]; then
  exec "$PPP_ON_BOOT"
fi

load_ppp_modules
if [ $? -ne 0 ]; then
	exit 1;
fi
 
stop_all_pppd

while true
do

  rm -f /tmp/PPPD_STOPPED 2> /dev/null > /dev/null
  pidcnt=0

  for callfile in $CALL_LIST
  do
	pmon_log "Starting MLPPP on $callfile"

	if [ ! -f "/etc/ppp/peers/$callfile" ]; then
		pmon_log "Error: Call file /etc/ppp/peers/$callfile does not exist!"
		exit 1
	fi

  	eval "pppd call $callfile >> "$LOG_DIR/"$callfile".log" 2>> "$LOG_DIR/"$callfile".log" &"
	if [ $? -ne 0 ]; then
		pmon_log "Failed to start PPPD for $callfile! (err=$?)"
		pmon_log "Exiting...."
		sleep 5
		exit 1
	fi

	pidcnt=$((pidcnt+1))

	#pmon_log "ISP Name = $callfile  IDX=$pidcnt";
	PPPD_ISP_NAME[$pidcnt]=$callfile
	WANPIPE_STATUS[$pidcnt]="Disconnected"
	
  done

  lcnt=0;
  while true
  do
	runcnt=$(ps -C pppd | grep pppd -c)
	if [ $runcnt -ne $pidcnt ]; then
		stop_all_pppd
		if [ $WANROUTER_RESTART_ON_ALL_DOWN -gt 0 ]; then
			pmon_log "All MLPPP links down! Restarting wanpipe...."
			eval "wanrouter stop 2> /dev/null > /dev/null"	
			sleep $WANROUTER_DOWN_TIMEOUT
			eval "wanrouter start 2> /dev/null > /dev/null"
			pmon_log "All MLPPP links down! Wanpipe Restarted"
		
		fi
		break;
	fi

	pmon_check_wanpipe_ports "$CALL_LIST"
	
	lcnt=$((lcnt+1))
	if [ $lcnt -gt $PING_CHECK_TIMEOUT ]; then
		lcnt=0;
		pmon_ping_check
		if [ $? -ne 0 ]; then 
			stop_all_pppd
               		break;
		fi
	fi

	sleep $PMON_LOOP_TIMEOUT
	
  done

done&


exit 0