#!/bin/sh
#
# tinc		tincd VPN setup script
#
# chkconfig: 	2345 15 85
#
# author:	Lubomir Bulej <pallas@kadan.cz>
#               Modified for RPM by Mads Kiilerich <mads@kiilerich.com>
# version:	1.0.3
#
# description:	this script takes care of starting and setting up of VPNs \
#		provided by tincd daemon. It parses the configuration files \
#		in all VPN directories and sets up the interfaces and routing
#
# processname:	tincd

# Source function library.
. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0

#############################################################################
# configuration

TINCD=/usr/sbin/tincd
TCONF=/etc/tinc
TPIDS=/var/run
#DEBUG_OPT=-dddd

# Check if ip-route is installed
if [ ! -f /sbin/ip ]; then
    echo "**tinc: ip-route utilities not installed!"
    exit
fi
		 

##############################################################################
# vpn_load ()		Loads VPN configuration
# 
# $1 ... VPN to load

vpn_load () {
    CFG="$TCONF/$1/tincd.conf"
    [ -f $CFG ] || { echo "Error: $CFG does not exist" >&2 ; return 1 }
    
    # load TINCD config
    DEV=`grep -i -e '^TapDevice' $CFG | sed 's/[[:space:]]//g;s/^.*=//g'`
    VPN=`grep -i -e '^(MyOwnVPNIP|MyVirtualIP)' -E $CFG | head -1 | sed 's/[[:space:]]//g;s/^.*=//g'`
    
    # discourage empty and multiple entries
    [ -z "$DEV" ] && \
		{ echo "Error: TapDevice needed" >&2 ; return 2 }
    echo $DEV | grep -q '^/dev/tap' ||
		{ echo "Error: TapDevice needs /dev/tapX" >&2 ; return 2 }
    [ `echo $DEV | wc -l` -gt 1 ] && \
		{ echo "Error in TapDevice" >&2 ; return 3 }
    [ -z "$VPN" ] && \
		{ echo "Error: MyOwnVPNIP/MyVirtualIP needed" >&2 ; return 2 }
    [ `echo $VPN | wc -l` -gt 1 ] && \
		{ echo "Error in MyOwnVPNIP/MyVirtualIP" >&2 ; return 3 }
    echo $VPN | grep -q -x  \
	'\([[:digit:]]\{1,3\}\.\)\{3\}[[:digit:]]\{1,3\}/[[:digit:]]\{1,2\}' ||
		{ echo "Error in MyOwnVPNIP/MyVirtualIP address $VPN" ; 
			return 3 }
    
    # network device
    TAP=`echo $DEV | cut -d"/" -f3`
    NUM=`echo $TAP | sed 's/tap//'`

    # IP address, netmask length
    ADR=`echo $VPN | cut -d"/" -f1`
    LEN=`echo $VPN | cut -d"/" -f2`

    # Expand bitlength to netmask    
    MSK=""; len=$LEN
    for cnt in 1 1 1 0; do
	if [ $len -ge 8 ]; then
	    msk=8
	else
	    msk=$len
	fi
	    
	MSK="$MSK$((255 & (255 << (8 - msk))))"
	[ $cnt -ne 0 ] && MSK="$MSK."
	len=$((len-msk))
    done

    # Network & broadcast
    BRD=`ipcalc --broadcast $ADR $MSK | cut -d"=" -f2`
    NET=`ipcalc --network $ADR $MSK | cut -d"=" -f2`
        
    # MAC address
    MAC=`printf "fe:fd:%0.2x:%0.2x:%0.2x:%0.2x" $(echo $ADR | sed 's/\./ /g')`
    # echo "TAP $TAP NUM $NUM ADR $ADR LEN $LEN MSK $MSK BRD $BRD NET $NET MAC $MAC" >&2
    return 0
}


##############################################################################
# vpn_start ()		starts specified VPN
# 
# $1 ... VPN to start

vpn_start () {    

    vpn_load $1 || { echo "Error: Could not vpn_load $1" >&2 ; return 1 }
            
    # create device file
    if [ ! -c $DEV ]; then
	[ -e $DEV ] && rm -f $DEV
	mknod --mode=0600 $DEV c 36 $((16 + NUM))
    fi
    
    # load device module
    { insmod ethertap --name="ethertap$NUM" unit="$NUM" 2>&1  || \
		{ echo "Error: cannot insmod ethertap$NUM" >&2 ; return 2 }
    } | grep -v '^Us'
    
    # configure the interface
    ip link set $TAP address $MAC #&> /dev/null
    ip link set $TAP up #&> /dev/null
    ip addr flush dev $TAP 2>&1 | grep -v -x '^Nothing to flush.' #&> /dev/null
    ip addr add $VPN brd $BRD dev $TAP #&> /dev/null
    
    # start tincd
    $TINCD --net="$1" $DEBUG_OPT || { echo "Error: Cannot start $TINCD" >&2; 
		return 3 }

    # default interface route
    ip route add $NET/$LEN dev $TAP #&> /dev/null

    # setup routes
    /etc/sysconfig/network-scripts/ifup-routes $TAP

    return 0
} # vpn_start


##############################################################################
# vpn_stop ()		Stops specified VPN
#
# $1 ... VPN to stop

vpn_stop () {

    vpn_load $1 || return 1
    
    # flush the routing table
    ip route flush dev $TAP &> /dev/null
    
    # kill the tincd daemon
    PID="$TPIDS/tincd.$1.pid"
    if [ -f $PID ]; then
        $TINCD --net="$1" --kill &> /dev/null
        RET=$?
    
        if [ $RET -eq 0 ]; then
	    dly=0
	    while [ $dly -le 5 ]; do
		[ -f $PID ] || break
	        sleep 1; dly=$((dly+1))
	    done
	else
	    rm -f $PID &> /dev/null
	fi
    fi
    
    # bring the interface down
    ip link set $TAP down &> /dev/null
    
    # remove kernel module
    rmmod "ethertap$NUM" &> /dev/null
    
    return 0
} # vpn_stop


# See how we were called.
case "$1" in
    start)
        echo -n "Bringing up VPNs: "
	for vpn in `ls -1 $TCONF`; do
	    vpn_start $vpn && echo -n "$vpn "
	done
	
	touch /var/lock/subsys/tinc
        action "" /bin/true
        ;;
	
    stop)
        echo -n "Shutting down VPNs: "
	for vpn in `ls -1 $TCONF`; do
	    vpn_stop $vpn && echo -n "$vpn "
	done
	
	rm -f /var/lock/susbsys/tinc
        action "" /bin/true
	;;
	
    status)
	echo -n "Currently running VPNs: "
	for vpn in `ls -1 $TCONF`; do
	    PID="$TPIDS/tincd.$vpn.pid"
	    echo -n "$vpn "
	    if [ -f $PID -a `ps ax | grep "^ *$(cat $PID)" | wc -l` -eq 1 ] 
	    then
		echo -n "OK "
	    else
		echo -n "Dead "
	    fi
	done
	echo	         
	;;	
	
    restart)
        $0 stop
	$0 start
	;;
		
    *)
        echo "Usage: tinc {start|stop|status|restart}"
        exit 1
esac

exit 0