#!/bin/bash

PPPD_PIDFILE=/var/run/umts_pppd.pid

PPPD=pppd

STROK="remote IP address"

PPP_INT=ppp0

GCOM=""

LOGF="/tmp/umtslogs"

DESTS_FILE="/tmp/umts_dest_file"

FILE_TEMP_NID="/tmp/umts_temp_nid"

FILE_UMTS_INT="/tmp/umts_dev"


function set_umts_dev(){
	echo $1 > $FILE_UMTS_INT
}

function get_umts_dev(){
	cat $FILE_UMTS_INT
}


function start_gcom(){
    if ! $GCOM -d `get_umts_dev`; then
	return 1;
    fi

    return 0
}

function init(){
	local found=1

	modprobe nozomi
	modprobe serial_cs

	if [ -f /usr/bin/gcom ]; then 
		GCOM=/usr/bin/gcom
    	elif [ -f /usr/bin/comgt ]; then
		GCOM=/usr/bin/comgt
    	else
		echo "I couldn't find gcom"
    		return 1;
    	fi

	for i in /dev/umts_modem /dev/umts_modem1; do	
		echo "Testing if the umts interface is present on the device $i..."
		if $GCOM -d $i; then
			found=0
			set_umts_dev $i 
			break
		fi	
	done 
	
	if ! [  $found == 0 ]; then
		echo "I couldn't find the umts device; make a symlink from it to /dev/umts_modem"
		return 1
	fi

	if ! grep umts_table /etc/iproute2/rt_tables > /dev/null 2>&1; then
		echo "20 umts_table" >> /etc/iproute2/rt_tables
	fi

	return 0

}


function get_temp_nid(){
	cat $FILE_TEMP_NID
}


#called when the connection is started
function conn_on(){
	local sliver=$1
	#local sliver_nid=$2

	#DESTS_FILE contains added destinations
	rm -f $DESTS_FILE 
	touch $DESTS_FILE > /dev/null 2>&1

	set_temp_nid $sliver_nid

	set_routes $sliver

	cat $LOGF | grep "local"
	return 0

}

#called when the connection is terminated
function conn_off(){
	local sliver=$1
	#local sliver_nid=$2

	unset_routes $sliver

	for i in `cat $DESTS_FILE`; do
		del_destination $i $sliver > /dev/null 2>&1
	done

	rm $DESTS_FILE >/dev/null 2>&1
}

function start_umts(){
    local sliver=$1
    local sliver_nid=`get_nid $sliver`
   
    
    if status_umts; then
	 echo "Already connected"
	 return 0; 
    fi

    if ! [ -c `get_umts_dev` ]; then
	echo "Umts interface not present"
	return 1
    fi

    rm -f $LOGF

    exec /usr/sbin/pppd nodetach `get_umts_dev` 460800 \
        	0.0.0.0:0.0.0.0 \
        	connect "/usr/sbin/chat -v                     \
        	TIMEOUT         6                              \
        	ABORT           '\nBUSY\r'                     \
        	ABORT           '\nNO ANSWER\r'                \
        	ABORT           '\nRINGING\r\n\r\nRINGING\r'   \
        	''              ATZ     OK 'ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0' OK  \
        	ATD*99***1#    CONNECT ''" > $LOGF &

    echo $! > $PPPD_PIDFILE

    	
    sleep 5s;  #waiting for the interface to establish the link
    if grep "$STROK" $LOGF >/dev/null 2>&1; then
	
	conn_on $sliver $sliver_nid
    else
	#second try
	sleep 4s;
	if grep "$STROK" $LOGF >/dev/null 2>&1; then
	    conn_on $sliver $sliver_nid
	else
	    stop_umts $sliver
	    return 1
	fi
    fi
}




function stop_umts(){
    local sliver=$1

    if ! [ -e $PPPD_PIDFILE ]; then 
	echo "Disconnected"
	return 0;
    fi

    PID=`cat $PPPD_PIDFILE`;

    if [ -d /proc/$PID ] &&  grep $PPPD /proc/$PID/cmdline >/dev/null 2>&1; then 	
	#del_interface $1;
	conn_off $sliver `get_nid $sliver`
	kill $PID;
	sleep 5;
    fi

    if status_umts; then
	return 1;
    else
	cat $LOGF | grep "time"
	rm $PPPD_PIDFILE
	return 0
    fi
}


function status_umts(){

    if ! [ -e $PPPD_PIDFILE ]; then return 1; fi

    PID=`cat $PPPD_PIDFILE`

    if [ -d /proc/$PID ] &&  grep $PPPD /proc/$PID/cmdline >/dev/null 2>&1; then
	return 0;
    else 
	return 1;
    fi
}

#add the ppp interface from the slice - not used at the moment
function add_interface(){
    local nid=`get_nid $1`
    $NADDRESS --add --nid $nid --ip $PPP_INT >>$LOGFILE 2>&1;
}

#remove the ppp interface from the slice - not used at the moment
function del_interface(){
    local nid=`get_nid $1`
    #$NADDRESS --remove --nid $NID --ip $PPP_INT >>$LOGFILE 2>&1;
}

#get slice network id
function get_nid(){
    id -u ${1}
}

function set_routes(){
	local sliver=$1
	local sliver_nid=`get_nid $sliver`
	local temp_nid=`get_temp_nid`
	local ppp_addr=`get_ppp_address`

	#remarking of packets to trigger rerouting and SNAT
	iptables -t mangle -A OUTPUT -j MARK --copy-xid 0x00
	iptables -t mangle -A OUTPUT -m mark --mark $sliver_nid -j MARK --set-mark $temp_nid
	iptables -t nat -A POSTROUTING -o $PPP_INT -j SNAT --to-source `get_ppp_address`
	iptables -t mangle -I POSTROUTING 1 -m mark --mark $temp_nid -j MARK --set-mark $sliver_nid
	
	#enable the explicit bind to the ppp interface
	ip route flush table umts_table >/dev/null 2>&1 
	ip rule add from $ppp_addr fwmark `get_temp_nid` table umts_table >/dev/null 2>&1
	ip route add default dev $PPP_INT src `get_ppp_address` table umts_table >/dev/null 2>&1
	ip route flush cache  >/dev/null 2>&1
}

function unset_routes(){
	local sliver=$1
	local sliver_nid=`get_nid $sliver`
	local temp_nid=`get_temp_nid`
	local ppp_addr=`get_ppp_address`

	#remarking and SNAT removed 
	iptables -t mangle -D OUTPUT -j MARK --copy-xid 0x00
	iptables -t mangle -D OUTPUT -m mark --mark $sliver_nid -j MARK --set-mark $temp_nid
	iptables -t nat -D POSTROUTING -o $PPP_INT -j SNAT --to-source `get_ppp_address`
	iptables -t mangle -D POSTROUTING -m mark --mark $temp_nid -j MARK --set-mark $sliver_nid

	#disable the explicit bind to the ppp interface
	ip rule del from $ppp_addr fwmark `get_temp_nid` table umts_table  >/dev/null 2>&1
	ip route del default dev $PPP_INT  src `get_ppp_address` table umts_table >/dev/null 2>&1
	ip route flush cache  >/dev/null 2>&1

}

function add_destination(){
	local dest="$1"
	local sliver=$2
	
	local sliver_nid=`get_nid $sliver`

	local temp_nid=`get_temp_nid`

	if [[ ! $dest ]]; then return 1; fi

	if ! status_umts; then
		return 1;
	fi
	
	if ip rule add to "$dest" fwmark $temp_nid table umts_table >/dev/null 2>&1; then
		echo "$dest" >> $DESTS_FILE
		return 0
	else 
		return 1	
	fi
	ip route flush cache  >/dev/null 2>&1
}

function del_destination(){
	local dest="$1"
	local sliver=$2

	local sliver_nid=`get_nid $sliver`

	local temp_nid=`get_temp_nid`

	if [[ ! $dest ]]; then return 1; fi
	#old - if ip route del to "$dest" dev $PPP_INT >/dev/null 2>&1; then
	if ip rule del to "$dest" fwmark $temp_nid table umts_table >/dev/null 2>&1; then
		return 0;
	else 
		return 1;
	fi
	ip route flush cache  >/dev/null 2>&1
}


function get_ppp_address(){
	ifconfig $PPP_INT | grep inet\ addr | cut -d ":" -f 2 | cut -d " " -f 1
}

function set_temp_nid(){
	local sliver_nid=$1
	local temp_nid=$((0x20000+$sliver_nid))

	#k=0
	#temp_nid=$sliver_nid
	
	#while grep :$temp_nid: /etc/passwd; do
	#	temp_nid=$((temp_nid+1))
	#	k=$((k+1))
	#	if [[ $k == 1000 ]]; then
	#		logger "Fatal error: I couldn't find a temp_nid"
	#		stop_umts
	#		exit 1
	#	fi
	#done

	echo $temp_nid > $FILE_TEMP_NID


}


function valid_dotted_quad(){
    oldIFS=$IFS
    IFS=.
    set -f
    set -- $1
    if [ $# -eq 4 ]
    then
      for seg
      do
        case $seg in
            ""|*[!0-9]*) return 1; break ;; ## Segment empty or non-numeric char
            *) [ $seg -gt 255 ] && return 2 ;;
        esac
      done
    else
      return 3 ## Not 4 segments
    fi
    IFS=$oldIFS
    set +f
    return 0;
}