#!/bin/sh
#
# network-functions-ipv6
#
# Taken from:
# (P) & (C) 1997-2001 by Peter Bieringer <pb@bieringer.de>
#
# Version: 2001-03-03b
#
# Extended address detection is enabled, if 'ipv6calc' is installed
#  Available here: http://www.bieringer.de/linux/IPv6/tools/index.html#ipv6calc
#
# Known bugs:
#  sit0 will not be shutdowned, if an additional IPv6 address was manually added to this device
#

# Filter tags (for stripping, empty lines following here if all is stripped)




# Return values
#  0 = ok
#  1 = error occurs
#  2 = not enabled, i.e. no IPv6 kernel support or switched off by configuration

##### Test for "ipv6calc" (can be used for better duplicate address detection)
EXISTS_ipv6calc=no	
	if which ipv6calc >/dev/null 2>&1; then
		EXISTS_ipv6calc=yes
	else
		true
	fi


##### Test for IPv6 capabilites

function test_ipv6()
{

	# Test for IPv6 enabled kernel

	if ! [ -f /proc/net/if_inet6 ]; then
		modprobe ipv6
	
		if ! [ -f /proc/net/if_inet6 ]; then
				echo $"Kernel is not compiled with IPv6 support"
			return 2
		fi
	fi



	return 0
}

##### Control IPv6 forwarding
# Display usage
function forwarding_ipv6_usage() {
	echo $"Usage: $0 yes|no [device]"
}


# Control IPv6 forwarding
#  $1: control [yes|no|on|off]
#  $2: network device (if not given, global IPv6 forwarding is set)
function forwarding_ipv6() {
	fw_control=$1
	fw_device=$2		# maybe empty

	if [ -z "$fw_control" ]; then
		echo $"Missing parameter 'forwarding control'"
		forwarding_ipv6_usage
		return 1
	fi

	if ! [ "$fw_control" = "yes" -o "$fw_control" = "no" -o "$fw_control" = "on" -o "$fw_control" = "off" ]; then
		echo $"Don't understand forwarding control parameter '$fw_control'"
		forwarding_ipv6_usage
		return 1
	fi
	
	# Device "lo" need no IPv6 configuration
	if [ "$fw_device" = "lo" ]; then
		return 0;
	fi

	# Run IPv6 test
	test_ipv6 || return    


	if [ "$fw_control" = "yes" -o "$fw_control" = "on" ]; then
		status=1
	else
		status=0
	fi

	# Global control? (if no device is given)
	if [ -z "$fw_device" ]; then
			sysctl -w net.ipv6.conf.all.forwarding=$status >/dev/null 2>&1
	fi
	
	# Per device control
	if [ ! -z "$fw_device" ]; then
			sysctl -w net.ipv6.conf.$fw_device.forwarding=$status >/dev/null 2>&1
	fi
	
}


##### Static IPv6 route configuration

# Display usage
function ifupdown_ipv6_route_usage() {
	echo $"Usage: $0 IPv6-network IPv6-gateway [device]"
}

# Set static IPv6 route
#  $1: IPv6 network to route
#  $2: IPv6 gateway over which $1 should be routed
#  $3: Interface (optional)
function ifup_ipv6_route() {
	networkipv6=$1
	gatewayipv6=$2
	device=$3		# maybe empty

	if [ -z "$networkipv6" ]; then
		echo $"Missing parameter 'IPv6-network'"
		ifupdown_ipv6_route_usage
		return 1
	fi

	if [ -z "$gatewayipv6" ]; then
		echo $"Missing parameter 'IPv6-gateway'"
		ifupdown_ipv6_route_usage
		return 1
	fi

	# Device "lo" need no IPv6 configuration
	if [ "$device" = "lo" ]; then
		return 0;
	fi
	
	# Run IPv6 test
	test_ipv6 || return    

	
	if [ -z "$device" ]; then
			output="`LC_ALL=C route -A inet6 add $networkipv6 gw $gatewayipv6 2>&1`"
			if [ $? -ne 0 ]; then
				if echo $output | grep -i -q 'SIOCADDRT: File exists';  then
					true
				else
					echo $output
				fi
			fi
	else
			output="`LC_ALL=C route -A inet6 add $networkipv6 gw $gatewayipv6 dev $device 2>&1`"
			if [ $? -ne 0 ]; then
				if echo $output | grep -i -q 'SIOCADDRT: File exists';  then
					true
				else
					echo $output
				fi
			fi
	fi

}

# Delete static IPv6 route
#  $1: IPv6 network to route
#  $2: IPv6 gateway over which $1 should be routed
#  $3: Interface (optional)
function ifdown_ipv6_route() {
	networkipv6=$1
	gatewayipv6=$2
	device=$3		# maybe empty

	if [ -z "$networkipv6" ]; then
		echo $"Missing parameter 'IPv6-network'"
		ifup_ipv6_route_usage
		return 1
	fi

	if [ -z "$gatewayipv6" ]; then
		echo $"Missing parameter 'IPv6-gateway'"
		ifup_ipv6_route_usage
		return 1
	fi

	# Device "lo" need no IPv6 configuration
	if [ "$device" = "lo" ]; then
		return 0;
	fi

	# Run IPv6 test
	test_ipv6 || return    

	
	if [ -z "$device" ]; then
			output="`LC_ALL=C route -A inet6 del $networkipv6 gw $gatewayipv6 2>&1`"
			if [ $? -ne 0 ]; then
				if echo $output | grep -i -q 'SIOCDELRT: No such process'; then
					true
				else
					echo $output
				fi
			fi
	else
			output="`LC_ALL=C route -A inet6 del $networkipv6 gw $gatewayipv6 dev $device 2>&1`"
			if [ $? -ne 0 ]; then
				if echo $output | grep -i -q 'SIOCDELRT: No such process'; then
					true
				else
					echo $output
				fi
			fi
	fi

}


##### automatic tunneling configuration

## Configure automatic tunneling up
function ifup_ipv6_autotunnel() {
	
	# Run IPv6 test
	test_ipv6 || return    


	# enable IPv6-over-IPv4 tunnels
	if LC_ALL=C ifconfig sit0 | grep -q "UP "; then
		# already up, do nothing
		true
	else
		# basic tunnel device to up
			ifconfig sit0 up

			# Switch on forwarding
			forwarding_ipv6 on sit0
	fi
	
}


## Configure automatic tunneling down
function ifdown_ipv6_autotunnel() {

	# Run IPv6 test
	test_ipv6 || return    


	if LC_ALL=C ifconfig sit0 | grep -q "UP "; then
		# still up?

		# disable IPv6-over-IPv4 tunnels (if a tunnel is no longer up)
		if LC_ALL=C route -n -A inet6 -n | grep sit0 | awk '{ print $2 }' | grep -v -q "^::$"; then
			# still existing routes, skip shutdown of sit0
			true
		elif LC_ALL=C ifconfig sit0 | grep 'inet6 addr:' | awk '{ print $3 }' | grep -v -q '^::'; then
			# still existing IPv6 addresses, skip shutdown of sit0
			true
		else
			# basic tunnel device to down
				# Switch off forwarding 
				forwarding_ipv6 off sit0
			
				ifconfig sit0 down
		fi
	fi

}	


##### static tunneling configuration

function ifupdown_ipv6_tunnel_usage() {
	echo $"Usage: $0 interfacename IPv4-tunneladdress IPv6-route"
}


## Configure static tunnels up
#  $1: Interface (not needed - dummy)
#  $2: IPv4 address of foreign tunnel
#  $3: IPv6 route through this tunnel
function ifup_ipv6_tunnel() {
	device=$1
	addressipv4tunnel=$2
	routeipv6=$3

	if [ -z "$device" ]; then
		echo $"Missing parameter 'device'"
		ifupdown_ipv6_tunnel_usage
		return 1
	fi

	if [ -z "$addressipv4tunnel" ]; then
		echo $"Missing parameter 'IPv4-tunneladdress'"
		ifupdown_ipv6_tunnel_usage
		return 1
	fi

	if [ -z "$routeipv6" ]; then
		echo $"Missing parameter 'IPv6-route'"
		ifupdown_ipv6_tunnel_usage
		return 1
	fi
	
	# Run IPv6 test
	test_ipv6 || return    


	# enable general IPv6-over-IPv4 tunneling
	ifup_ipv6_autotunnel
	
    	# Set up a tunnel
		output="`LC_ALL=C route -A inet6 add $routeipv6 gw ::$addressipv4tunnel dev sit0 2>&1`"
		if [ $? -ne 0 ]; then
			if echo $output | grep -i -q 'SIOCADDRT: File exists';  then
				true
			else
				echo $output
			fi
		fi

}	


## Configure static tunnels down
#  $1: Interface (not used - dummy)
#  $2: IPv4 address of foreign tunnel
#  $3: IPv6 route through this tunnel
function ifdown_ipv6_tunnel() {
	device=$1
	addressipv4tunnel=$2
	routeipv6=$3

	if [ -z "$device" ]; then
		echo $"Missing parameter 'device'"
		ifupdown_ipv6_tunnel_usage
		return 1
	fi

	if [ -z "$addressipv4tunnel" ]; then
		echo $"Missing parameter 'IPv4-tunneladdress'"
		ifupdown_ipv6_tunnel_usage
		return 1
	fi

	if [ -z "$routeipv6" ]; then
		echo $"Missing parameter 'IPv6-route'"
		ifupdown_ipv6_tunnel_usage
		return 1
	fi

	# Run IPv6 test
	test_ipv6 || return    


		# Set up a tunnel
		output="`route -A inet6 del $routeipv6 gw ::$addressipv4tunnel dev sit0 2>&1`"
		if [ $? -ne 0 ]; then
			if echo $output | grep -i -q 'SIOCDELRT: No such process'; then
				true
			else
				echo $output
			fi
		fi

	# disable IPv6-over-IPv4 tunneling (if no longer a tunnel is up)
	ifdown_ipv6_autotunnel

}	


## Remove all IPv6 tunnels for a given tunnel endpoint
#  $1: Interface (not used - dummy)
#  $2: IPv4-tunneladdress 
function ifdown_ipv6_tunnel_all() {
	idtuall_device=$1
	idtuall_tunnel=$2

	if [ -z "$idtuall_device" ]; then
		echo $"Missing parameter 'device'"
		echo $"Usage: ifdown_ipv6_tunnel_all interfacename IPv4-tunneladdress"
		return 1
	fi

	if [ -z "$idtuall_tunnel" ]; then
		echo $"Missing parameter 'IPv4-tunneladdress'"
		echo $"Usage: ifdown_ipv6_tunnel_all interfacename IPv4-tunneladdress"
		return 1
	fi
	# Get all IPv6 routes through given interface and remove them
	LC_ALL=C route -n -A inet6 | grep "::$idtuall_tunnel" | while read ipv6net nexthop flags metric ref use iface args; do
		if [ "::$idtuall_tunnel" = "$nexthop" ]; then
			if echo $flags | grep -v -q "A"; then
				# Only non addrconf (automatic installed) routes should be removed
				ifdown_ipv6_tunnel $idtuall_device $idtuall_tunnel $ipv6net
			fi
		fi
	done
}


##### Test, whether an IPv6 address exists on an interface
# $1: Device for testing
# $2: Address to test (without prefix)
# $3: Prefix of address $1
# return values: 1:problem, 10:not exists, 11:exits
function test_ipv6_addrs_exists () {
	testdevice=$1
	testaddr=$2
	testprefix=$3

	if [ -z "$testaddr" ]; then
		echo $"Missing parameter 'IPv6AddrToTest'"
		return 1
	fi


	if [ "$EXISTS_ipv6calc" = "yes" ]; then
		# Using ipv6calc and compare against /proc/net/if_inet6

		convertresult="`ipv6calc --addr2if_inet6 $testaddr/$testprefix`"
		# Split in address, scope and prefix length
		test_addr="`echo $convertresult | awk '{ print $1 }'`"
		test_scope="`echo $convertresult | awk '{ print $2 }'`"
		test_prefixlength="`echo $convertresult | awk '{ print $3 }'`"

		if [ -z "$test_prefixlength" ]; then
			testresult="`grep "$test_addr .. .. $test_scope .." /proc/net/if_inet6 | grep $testdevice$`"
		else
			testresult="`grep "$test_addr .. $test_prefixlength $test_scope .." /proc/net/if_inet6 | grep $testdevice$`"
		fi
		if [ ! -z "$testresult" ]; then
			return 11
		else
			return 10
		fi
	else
		# low budget version, only works if given address is in equal form like ifconfig displays
		testresult="`LC_ALL=C ifconfig $testdevice | grep "inet6 addr:" | grep -i ": $testaddr/$testprefix" | awk '{ print $3 }'`"
		if [ ! -z "$testresult" ]; then
			return 11
		else
			return 10
		fi
	fi
}

##### Interface configuration
function ifupdown_ipv6_usage() {
	echo $"Usage: $0 interfacename IPv6-address/IPv6-prefixlength"
}

## Add an IPv6 address for given interface
#  $1: Interface 
#  $2: IPv6 address
function ifup_ipv6_real() {
	device=$1
	address=$2

	if [ -z "$device" ]; then
		echo $"Missing parameter 'device'"
		ifupdown_ipv6_usage
		return 1
	fi

   	# Device "lo" need no IPv6 configuration
   	if [ "$device" = "lo" ]; then
		return 0;
	fi

	if [ -z "$address" ]; then
		echo $"Missing parameter 'IPv6-address'"
		ifupdown_ipv6_usage
		return 1
	fi

	# Test status of interface
	if LC_ALL=C ifconfig $device | grep -q "UP "; then
		# Interface is up
			true
	else
		# no IPv4 for this interface, interface is still down, do up ...
		ifconfig $device up
	fi

	# Extract address parts
	prefixlength_implicit="`echo $address | awk -F/ '{ print $2 }'`"
	address_implicit="`echo $address | awk -F/ '{ print $1 }'`"

	# Test for prefix length
	if [ -z "$prefixlength_implicit" ]; then
		echo $"Missing 'prefix length' for given address"
		ifupdown_ipv6_usage
		return 1
	elif [ $prefixlength_implicit -lt 0 -o $prefixlength_implicit -gt 128 ]; then
		echo $"'prefix length' on given address is out of range (0-128)"
		ifupdown_ipv6_usage
		return 1
	fi

	# Run IPv6 test
	test_ipv6 || return    


	# Only add, if address do not already exist
	test_ipv6_addrs_exists $device $address_implicit $prefixlength_implicit
	retval=$?
	if [ $retval -lt 10 ]; then
		return 2
	fi

	if [ $retval -eq 11 ]; then
		true
	else
			ifconfig $device add $address || return 2
	fi

}


## Remove all IPv6 routes and addresses for given interface
#   cleanup to prevent kernel crashes
#  $1: Interface 
function ifdown_ipv6_real_all() {
	idall_device=$1

	if [ -z "$idall_device" ]; then
		echo $"Missing parameter 'device'"
		echo $"Usage: ifdown_ipv6_real_all interfacename"
		return 1
	fi

	# Get all IPv6 routes through given interface and remove them
	LC_ALL=C route -n -A inet6 | grep $idall_device | while read ipv6net nexthop flags metric ref use iface args; do
		if [ "$idall_device" = "$iface" ]; then
			if echo $flags | grep -v -q "A"; then
				# Only non addrconf (automatic installed) routes should be removed
				ifdown_ipv6_route $ipv6net $nexthop $iface
			fi
		fi
	done
	
	# Get all IPv6 addresses assigned to given interface and remove them
	if [ "$EXISTS_ipv6calc" = "yes" ]; then
		grep $idall_device$ /proc/net/if_inet6 | while read hexaddr dummy1 hexprefixlenth hexscope device args; do
			if [ "$hexscope" != "20" ]; then
				ipv6addr="`ipv6calc --if_inet62addr $hexaddr $hexprefixlenth`"
				ifdown_ipv6_real $idall_device $ipv6addr
			fi
		done
	else
		LC_ALL=C ifconfig $idall_device | grep "inet6 addr:" | while read dummy1 dummy2 ipv6addr scope args; do
			if [ "$scope" != "Scope:Link" ]; then
				ifdown_ipv6_real $idall_device $ipv6addr
			fi
		done
	fi
}

## Remove an IPv6 address on given interface
#  $1: Interface 
#  $2: IPv6 address
function ifdown_ipv6_real() {
	device=$1
	address=$2

	if [ -z "$device" ]; then
		echo $"Missing parameter 'device'"
		ifupdown_ipv6_usage
		return 1
	fi

	# Device "lo" need no IPv6 configuration
	if [ "$device" = "lo" ]; then
		return 0;
	fi

	if [ -z "$address" ]; then
		echo $"Missing parameter 'IPv6-address'"
		ifupdown_ipv6_usage
		return 1
	fi

	# Extract address parts
	prefixlength_implicit="`echo $address | awk -F/ '{ print $2 }'`"
	address_implicit="`echo $address | awk -F/ '{ print $1 }'`"

	# Test for prefix length
	if [ -z "$prefixlength_implicit" ]; then
		echo $"Missing 'prefix length' for given address"
		ifupdown_ipv6_usage
		return 1
	elif [ $prefixlength_implicit -lt 0 -o $prefixlength_implicit -gt 128 ]; then
		echo $"'prefix length' on given address is out of range (0-128)"
		ifupdown_ipv6_usage
		return 1
	fi

	# Run IPv6 test
	test_ipv6 || return    


	# Only remove, if address exists and is not link-local (prevents from kernel crashing)
	test_ipv6_addrs_exists $device $address_implicit $prefixlength_implicit
	retval=$?
	if [ $retval -lt 10 ]; then
		return 2
	fi

	if [ $retval -eq 11 ]; then
			ifconfig $device del $address || return 2
	else
		true
	fi
    
}