#!/bin/sh
#* reason                       -- why this script was called, one of: pre-init connect disconnect
#* VPNGATEWAY                   -- vpn gateway address (always present)
#* TUNDEV                       -- tunnel device (always present)
#* INTERNAL_IP4_ADDRESS         -- address (always present)
#* INTERNAL_IP4_NETMASK         -- netmask (often unset)
#* INTERNAL_IP4_DNS             -- list of dns serverss
#* INTERNAL_IP4_NBNS            -- list of wins servers
#* CISCO_DEF_DOMAIN             -- default domain name
#* CISCO_BANNER                 -- banner from server
#* CISCO_SPLIT_INC              -- number of networks in split-network-list
#* CISCO_SPLIT_INC_%d_ADDR      -- network address
#* CISCO_SPLIT_INC_%d_MASK      -- subnet mask (for example: 255.255.255.0)
#* CISCO_SPLIT_INC_%d_MASKLEN   -- subnet masklen (for example: 24)
#* CISCO_SPLIT_INC_%d_PROTOCOL  -- protocol (often just 0)
#* CISCO_SPLIT_INC_%d_SPORT     -- source port (often just 0)
#* CISCO_SPLIT_INC_%d_DPORT     -- destination port (often just 0)

#set -x

OS="`uname -s`"

VPNC_WIN_SCRIPT=/etc/vpnc/vpnc-script-win

case "$OS" in
	CYGWIN_NT*)
		# why does "--kernel-name" include "--kernel-release" on cygwin?!
		exec $VPNC_WIN_SCRIPT
		;;
	*)
		;;
esac

DEFAULT_ROUTE_FILE=/var/lib/vpnc/defaultroute

# Import Mandriva Linux configuration for resolv.conf update
. /etc/sysconfig/network-scripts/network-functions
DEVICE=$TUNDEV

# some systems, eg. Darwin & FreeBSD, prune /var/run on boot
if ! [ -d "/var/run/vpnc" ]; then
       mkdir -p /var/run/vpnc
fi

# stupid SunOS: no blubber in /usr/local/bin ... (on stdout)
IPROUTE="`which ip | grep '^/' 2> /dev/null`"

if [ "$OS" = "Linux" ]; then
	ifconfig_syntax_ptp="pointopoint"
	route_syntax_gw="gw"
	route_syntax_del="del"
	route_syntax_netmask="netmask"
else
	ifconfig_syntax_ptp=""
	route_syntax_gw=""
	route_syntax_del="delete"
	route_syntax_netmask="-netmask"
fi

####

kernel_is_2_6_or_above() {
	case `uname -r` in
		1.*|2.[012345]*)
			return 1
			;;
		*)
			return 0
			;;
	esac
}

do_pre_init() {
	if [ "$OS" = "Linux" ]; then
		if (exec 6<> /dev/net/tun) > /dev/null 2>&1 ; then
			:
		else # can't open /dev/net/tun
			test -e /proc/sys/kernel/modprobe && `cat /proc/sys/kernel/modprobe` tun 2>/dev/null
			# fix for broken devfs in kernel 2.6.x
			if [ "`readlink /dev/net/tun`" = misc/net/tun \
				-a ! -e /dev/net/misc/net/tun -a -e /dev/misc/net/tun ] ; then
				ln -sf /dev/misc/net/tun /dev/net/tun
			fi
			# make sure tun device exists
			if [ ! -e /dev/net/tun ]; then
				mkdir -p /dev/net
				mknod -m 0640 /dev/net/tun c 10 200
			fi
			# workaround for a possible latency caused by udev, sleep max. 10s
			if kernel_is_2_6_or_above ; then
				for x in `seq 100` ; do
					(exec 6<> /dev/net/tun) > /dev/null 2>&1 && break;
					sleep 0.1
				done
			fi
		fi
	elif [ "$OS" = "FreeBSD" ]; then
		if [ ! -e /dev/tun ]; then
			kldload if_tun
		fi
	elif [ "$OS" = "NetBSD" ]; then
		:
	elif [ "$OS" = "OpenBSD" ]; then
		:
	elif [ "$OS" = "SunOS" ]; then
		:
	elif [ "$OS" = "Darwin" ]; then
		:
	fi
}

do_ifconfig() {
	ifconfig "$TUNDEV" inet "$INTERNAL_IP4_ADDRESS" $ifconfig_syntax_ptp "$INTERNAL_IP4_ADDRESS" netmask 255.255.255.255 mtu 1000 up
}

destroy_tun_device() {
	case "$OS" in
	NetBSD) # and probably others...
		ifconfig "$TUNDEV" destroy
		;;
	esac
}

if [ -n "$IPROUTE" ]; then
	fix_ip_get_output () {
		sed 's/cache//;s/metric \?[0-9]\+ [0-9]\+//g;s/hoplimit [0-9]\+//g'
	}

	set_vpngateway_route() {
		$IPROUTE route add `$IPROUTE route get "$VPNGATEWAY" | fix_ip_get_output`
		$IPROUTE route flush cache
	}
	
	del_vpngateway_route() {
		$IPROUTE route $route_syntax_del "$VPNGATEWAY"
		$IPROUTE route flush cache
	}
	
	set_default_route() {
		$IPROUTE route | grep '^default' | fix_ip_get_output > "$DEFAULT_ROUTE_FILE"
		$IPROUTE route $route_syntax_del default
		$IPROUTE route add default dev "$TUNDEV"
		$IPROUTE route flush cache
	}
	
	set_network_route() {
		NETWORK="$1"
		NETMASK="$2"
		NETMASKLEN="$3"
		$IPROUTE route add "$NETWORK/$NETMASKLEN" dev "$TUNDEV"
		$IPROUTE route flush cache
	}
	
	reset_default_route() {
		$IPROUTE route $route_syntax_del default > /dev/null 2>&1
		$IPROUTE route add `cat "$DEFAULT_ROUTE_FILE"`
		$IPROUTE route flush cache
	}
	
	del_network_route() {
		# linux deletes routes automatically if the device is shut down
		return
		#NETWORK="$1"
		#NETMASK="$2"
		#NETMASKLEN="$3"
		#$IPROUTE route $route_syntax_del "$NETWORK/$NETMASKLEN" dev "$TUNDEV" 
		#$IPROUTE route flush cache
	}
else
	get_default_gw() {
		# isn't -n supposed to give --numeric output?
		# apperently not...
		netstat -r -n | sed 's/default/0.0.0.0/' | grep '^0.0.0.0' | awk '{print $2}'
	}
	
	set_vpngateway_route() {
		route add -host "$VPNGATEWAY" $route_syntax_gw "`get_default_gw`"
	}

	del_vpngateway_route() {
		route $route_syntax_del -host "$VPNGATEWAY"
	}
	
	set_default_route() {
		DEFAULTGW="`get_default_gw`"
		echo "$DEFAULTGW" > "$DEFAULT_ROUTE_FILE"
		route $route_syntax_del default "$DEFAULTGW"
		route add default $route_syntax_gw "$INTERNAL_IP4_ADDRESS"
	}
	
	set_network_route() {
		NETWORK="$1"
		NETMASK="$2"
		NETMASKLEN="$3"
		route add -net "$NETWORK" $route_syntax_netmask "$NETMASK" $route_syntax_gw "$INTERNAL_IP4_ADDRESS"
	}
	
	reset_default_route() {
		route $route_syntax_del default
		route add default $route_syntax_gw `cat "$DEFAULT_ROUTE_FILE"`
	}
	
	del_network_route() {
		case "$OS" in
		Linux|NetBSD) # and probably others...
			# routes are deleted automatically on device shutdown
			return
			;;
		esac
		NETWORK="$1"
		NETMASK="$2"
		NETMASKLEN="$3"
		route $route_syntax_del -net "$NETWORK" $route_syntax_netmask "$NETMASK" $route_syntax_gw "$INTERNAL_IP4_ADDRESS"
	}
fi

write_resolvconf() {
	local d
	local ns
	if [ -n "$CISCO_DEF_DOMAIN" ]; then
		d="search $CISCO_DEF_DOMAIN"
	fi

	if [ -n "$INTERNAL_IP4_DNS" ]; then
		for nameserver in "$INTERNAL_IP4_DNS"; do
			ns="$ns"$'\n'"nameserver $nameserver"
		done
	fi

	if [ -n "$d" -o -n "$ns" ]; then
		change_resolv_conf "$d" "$ns"
	fi
}

reset_resolvconf() {
	clear_resolv_conf
}

do_connect() {
	if [ -n "$CISCO_BANNER" ]; then
		echo "Connect Banner:"
		echo "$CISCO_BANNER" | while read LINE ; do echo "|" "$LINE" ; done
		echo
	fi
	
	do_ifconfig
	set_vpngateway_route
	if [ -n "$CISCO_SPLIT_INC" ]; then
		i=0
		while [ $i -lt $CISCO_SPLIT_INC ] ; do
			eval NETWORK="\${CISCO_SPLIT_INC_${i}_ADDR}"
			eval NETMASK="\${CISCO_SPLIT_INC_${i}_MASK}"
			eval NETMASKLEN="\${CISCO_SPLIT_INC_${i}_MASKLEN}"
			set_network_route "$NETWORK" "$NETMASK" "$NETMASKLEN"
			i=`expr $i + 1`
		done
		for i in $INTERNAL_IP4_DNS ; do
			set_network_route "$i" "255.255.255.255" "32"
		done
	else
		set_default_route
	fi
	
	if [ -n "$INTERNAL_IP4_DNS" ]; then
		write_resolvconf
	fi
}

do_disconnect() {
	destroy_tun_device
	if [ -n "$CISCO_SPLIT_INC" ]; then
		i=0
		while [ $i -lt $CISCO_SPLIT_INC ] ; do
			eval NETWORK="\${CISCO_SPLIT_INC_${i}_ADDR}"
			eval NETMASK="\${CISCO_SPLIT_INC_${i}_MASK}"
			eval NETMASKLEN="\${CISCO_SPLIT_INC_${i}_MASKLEN}"
			del_network_route "$NETWORK" "$NETMASK" "$NETMASKLEN"
			i=`expr $i + 1`
		done
		for i in $INTERNAL_IP4_DNS ; do
			del_network_route "$i" "255.255.255.255" "32"
		done
	else
		if [ -s "$DEFAULT_ROUTE_FILE" ]; then
			reset_default_route
			rm -f -- "$DEFAULT_ROUTE_FILE"
		fi
	fi
	
	del_vpngateway_route
	
	if [ -n "$INTERNAL_IP4_DNS" ]; then
		reset_resolvconf
	fi
}

####

if [ -z "$reason" ]; then
	echo "this script must be called from vpnc" 1>&2
	exit 1
fi

case "$reason" in
	pre-init)
		do_pre_init
		;;
	connect)
		do_connect
		;;
	disconnect)
		do_disconnect
		;;
	*)
		echo "unknown reason '$reason'. Maybe vpnc-script is out of date" 1>&2
		exit 1
		;;
esac

exit 0
