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# network-functions-ipv6
#
# Taken from: network-functions-ipv6
# (P) & (C) 1997-2005 by Peter Bieringer <pb@bieringer.de>
#
#  You will find more information on the initscripts-ipv6 homepage at
#   http://www.deepspace6.net/projects/initscripts-ipv6.html
#
# Version: 2006-08-03
#
#






##### Logging function
#  $1: <message> : message string
#  $2: [stdout|stderr].[err|warn[ing]|inf[o]|notice] : log level with optional channel, default is "stdout.notice"
#      [syslog.[facility.].err|warn[ing]|inf[o]|notice : syslog channel, default is "syslog.user.notice"
#  $3: <function name> : name of function which calls this log function, can be empty using ""
# return code: 0=ok 1=argument error  3=major problem
ipv6_log() {
        local message="$1"
        local level="$2"
        local name="$3"

        if [ -z "$message" ]; then
                echo $"ERROR: [ipv6_log] Missing 'message' (arg 1)" >/dev/stderr
                return 1
        fi
        if [ -z "$level" ]; then
                local level="stdout.notice"
        fi


        # Map loglevel now
        local fn=1
        local fnawk="print \$$fn"
        local t="$(echo $level | awk -F. "{ $fnawk }")"

        # Check channel, if given
        case $t in
            'stdout'|'stderr'|'syslog')
                local channel="$t"
                local fn=$(($fn + 1))
                ;;
            *)
                local channel="stdout"
                ;;
        esac

        # Check syslog facilty, if given
        if [ "$channel" = "syslog" ]; then
                local fnawk="print \$$fn"
                local t="$(echo $level | awk -F. "{ $fnawk }")"
                case $t in
                    'local0'|'local1'|'local2'|'local3'|'local4'|'local5'|'local6'|'local7'|'daemon')
                        local facility="$t"
                        local fn=$(($fn + 1))
                        ;;
                    *)
                        local facility="user"
                        ;;
                esac
        fi

        local fnawk="print \$$fn"
        local t="$(echo $level | awk -F. "{ $fnawk }")"

        # Map priority
        [ "$t" = "inf"      ] && local t="info"
        [ "$t" = "deb"      ] && local t="debug"
        [ "$t" = "warning"  ] && local t="warn"
        [ "$t" = "error"    ] && local t="err"
        [ "$t" = "critical" ] && local t="crit"

        # Check priority, if given
        case $t in
            'info'|'debug'|'notice'|'warn'|'err'|'crit')
                        local priority="$t"
                        local fn=$(($fn + 1))
                        ;;
                    *)
                        local priority="notice"
                        ;;
        esac

        local fnawk="print \$$fn"
        local t="$(echo $level | awk -F. "{ $fnawk }")"
        if [ -n "$t" ]; then
                echo $"ERROR: [ipv6_log] Loglevel isn't valid '$level' (arg 2)" >/dev/stderr
                return 1
        fi

        # Generate function text
        if [ -z "$name" ]; then
                local txt_name=""
        else
                local txt_name="[$name]"
        fi

        # Log message
        case $channel in
            'stdout'|'stderr')
                # Generate level text
                case $priority in
                    'debug')
                        local txt_level=$"DEBUG    "
                        ;;
                    'err')
                        local txt_level=$"ERROR    "
                        ;;
                    'warn')
                        local txt_level=$"WARN     "
                        ;;
                    'crit')
                        local txt_level=$"CRITICAL "
                        ;;
                    'info')
                        local txt_level=$"INFO     "
                        ;;
                    'notice')
                        local txt_level=$"NOTICE   "
                        ;;
                esac

                [ -n "$txt_name" ] && local txt_name="$txt_name "

                if [ "$channel" = "stderr" ]; then
                        echo "$txt_level: ${txt_name}${message}" >/dev/stderr
                elif [ "$channel" = "stdout" ]; then
                        echo "$txt_level: ${txt_name}${message}"
                fi
                ;;
            'syslog')
                # note: logger resides in /usr/bin, but not used by default
                if ! [ -x /usr/bin/logger ]; then
                        echo $"ERROR: [ipv6_log] Syslog is chosen, but binary 'logger' doesn't exist or isn't executable" >/dev/stderr
                        return 3
                fi
                if [ -z "$txt_name" ]; then
                        /usr/bin/logger -p $facility.$priority $message
                else
                        /usr/bin/logger -p $facility.$priority -t "$txt_name" "$message"
                fi
                ;;
            *)
                echo $"ERROR: [ipv6_log] Cannot log to channel '$channel'" >/dev/stderr
                return 3
                ;;
        esac

        return 0
}


###### Beginning of main code here, always executed on "source|. network-functions-ipv6"



###### End of main code here


##### Test for IPv6 capabilites
# $1: (optional) testflag: currently supported: "testonly" (do not load a module)
# return code: 0=ok 2=IPv6 test fails
ipv6_test() {
        local fn="ipv6_test"

        local testflag=$1

        if ! [ -f /proc/net/if_inet6 ]; then
                if [ "$testflag" = "testonly" ]; then
                        return 2
                else
                        modprobe ipv6

                        if ! [ -f /proc/net/if_inet6 ]; then
                                #       ipv6_log $"Kernel is not compiled with IPv6 support" crit $fn
                                return 2
                        fi
                fi
        fi

        if ! [ -d /proc/sys/net/ipv6/conf/ ]; then
                return 2
        fi

        return 0
}

##### Static IPv6 route configuration

# Set static IPv6 route
#  $1: <IPv6 network> : to route
#  $2: <IPv6 gateway> : over which $1 should be routed (if "::", gw will be skipped)
#  $3: [<Interface>] : (optional)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem adding route
ipv6_add_route() {
        local fn="ipv6_add_route"

        local networkipv6=$1
        local gatewayipv6=$2
        local device=$3         # maybe empty

        if [ -z "$networkipv6" ]; then
                ipv6_log $"Missing parameter 'IPv6-network' (arg 1)" err $fn
                return 1
        fi

        if [ -z "$gatewayipv6" ]; then
                ipv6_log $"Missing parameter 'IPv6-gateway' (arg 2)" err $fn
                return 1
        fi

        ipv6_test || return 2

        ipv6_test_ipv6_addr_valid $networkipv6 || return 2
        ipv6_test_ipv6_addr_valid $gatewayipv6 || return 2

        if [ -z "$device" ]; then
                local returntxt="$(/sbin/ip -6 route add $networkipv6 via $gatewayipv6 metric 1 2>&1)"
        else
                if [ "$gatewayipv6" = "::" ]; then
                        local returntxt="$(/sbin/ip -6 route add $networkipv6 dev $device metric 1 2>&1)"
                else
                        local returntxt="$(/sbin/ip -6 route add $networkipv6 via $gatewayipv6 dev $device metric 1 2>&1)"
                fi
        fi

        if [ -n "$returntxt" ]; then
                if echo $returntxt | LC_ALL=C grep -q "File exists"; then
                        # Netlink: "File exists"
                        true
                elif echo $returntxt | LC_ALL=C grep -q "No route to host"; then
                        # Netlink: "No route to host"
                        ipv6_log $"'No route to host' adding route '$networkipv6' via gateway '$gatewayipv6' through device '$device'" warn $fn
                        return 3
                else
                        ipv6_log $"Unknown error" warn $fn
                        return 3
                fi
        fi

        return 0
}

##### automatic tunneling configuration

## Configure automatic tunneling up
# return code: 0=ok 2=IPv6 test fails 3=major problem
ipv6_enable_autotunnel() {
        local fn="ipv6_enable_autotunnel"

        ipv6_test || return 2

        # enable IPv6-over-IPv4 tunnels
        if ipv6_test_device_status sit0; then
                true
        else
                # bring up basic tunnel device
                /sbin/ip link set sit0 up

                        if ! ipv6_test_device_status sit0; then
                                ipv6_log $"Tunnel device 'sit0' enabling didn't work" err $fn
                                return 3
                        fi

                # Set sysctls proper (regardless "default")
                /sbin/sysctl -e -w net.ipv6.conf.sit0.forwarding=1 >/dev/null 2>&1
                /sbin/sysctl -e -w net.ipv6.conf.sit0.accept_ra=0 >/dev/null 2>&1
                /sbin/sysctl -e -w net.ipv6.conf.sit0.accept_redirects=0 >/dev/null 2>&1
        fi

        return 0
}

##### Interface configuration

## Add an IPv6 address for given interface
#  $1: <Interface>
#  $2: <IPv6 address[/prefix]>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_add_addr_on_device() {
        local fn="ipv6_add_addr_on_device"

        local device=$1
        local address=$2

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        if [ -z "$address" ]; then
                ipv6_log $"Missing parameter 'IPv6-address' (arg 2)" err $fn
                return 1
        fi

        ipv6_test || return 2

        ipv6_test_ipv6_addr_valid $address || return 1

        ipv6_test_device_status $device
        local result=$?

        if [ "$result" = "0" ]; then
                true
        elif [ "$result" != "11" ]; then
                ipv6_log $"Device '$device' doesn't exist" err $fn
                return 3
        else
                /sbin/ip link set $device up

                        if ! ipv6_test_device_status $device; then
                                ipv6_log $"Device '$device' enabling didn't work" err $fn
                                return 3
                        fi
        fi

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

        # Check prefix length and using '64' as default
        if [ -z "$prefixlength_implicit" ]; then
                local prefixlength_implicit="64"
                local address="$address_implicit/$prefixlength_implicit"
        fi

        /sbin/ip -6 addr replace $address dev $device
        local result=$?

        if [ $result -eq 2 ]; then
                return 0
        elif [ $result -ne 0 ]; then
                ipv6_log $"Cannot add IPv6 address '$address' on dev '$device'" err $fn
                return 3
        fi

        return 0
}


## Remove all IPv6 routes and addresses on given interface (cleanup to prevent kernel crashes)
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_cleanup_device() {
        local fn="ipv6_cleanup_device"

        local device=$1

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        ipv6_test testonly || return 2

        # Remove all IPv6 routes through this device (but not "lo")
        if [ "$device" != "lo" ]; then
                /sbin/ip -6 route flush dev $device scope global >/dev/null 2>&1
                /sbin/ip -6 route flush dev $device scope site   >/dev/null 2>&1
        fi

        # Remove all IPv6 addresses on this interface
        /sbin/ip -6 addr flush dev $device scope global >/dev/null 2>&1
        /sbin/ip -6 addr flush dev $device scope site   >/dev/null 2>&1

        return 0
}


## Remove all IPv6 6to4 related routes and addresses on given interface
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_cleanup_6to4_device() {
        local fn="ipv6_cleanup_6to4_device"

        local device=$1

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        ipv6_test testonly || return 2

        # Cleanup 6to4 addresses on this device
        /sbin/ip -6 addr show dev $dev scope global permanent | LC_ALL=C grep -w inet6 | awk '{ print $2}' | LC_ALL=C grep "^2002:" | while read addr; do
                /sbin/ip -6 addr del ${addr} dev ${dev}
        done

        # Get all IPv6 routes through given interface related to 6to4 and remove them
        /sbin/ip -6 route show dev $device | LC_ALL=C grep "^2002:" | while read ipv6net dummy; do
                /sbin/ip -6 route del $ipv6net dev $device
        done

        return 0
}


##### Some address test functions

## Test a given IPv6 address for validity
#  $1: <IPv6 address>
# return code: 0=ok 1=not valid
ipv6_test_ipv6_addr_valid() {
        ipcalc -cs6 $1
}


## Test a given IPv4 address for validity
#  $1: <IPv4 address>
# return code: 0=ok 1=not valid
ipv6_test_ipv4_addr_valid() {
        ipcalc -cs4 $1
}


## Test a given IPv4 address for not a private but unicast one
#  $1: <IPv4 address>
# return code: 0=ok 1=argument error 10=private or not unicast
ipv6_test_ipv4_addr_global_usable() {
        local fn="ipv6_test_ipv4_addr_global_usable"

        local testipv4addr_globalusable=$1


        if [ -z "$testipv4addr_globalusable" ]; then
                return 1
        fi

        # Test for a globally usable IPv4 address now
                # test 0.0.0.0/8
                /bin/ipcalc --network $testipv4addr_globalusable 255.0.0.0   | LC_ALL=C grep -q "NETWORK=0\.0\.0\.0"     && return 10
                # test 10.0.0.0/8     (RFC 1918 / private)
                /bin/ipcalc --network $testipv4addr_globalusable 255.0.0.0   | LC_ALL=C grep -q "NETWORK=10\.0\.0\.0"    && return 10
                # test 127.0.0.0/8    (loopback)
                /bin/ipcalc --network $testipv4addr_globalusable 255.0.0.0   | LC_ALL=C grep -q "NETWORK=127\.0\.0\.0"   && return 10
                # test 169.254.0.0/16 (APIPA / DHCP link local)
                /bin/ipcalc --network $testipv4addr_globalusable 255.255.0.0 | LC_ALL=C grep -q "NETWORK=169\.254\.0\.0" && return 10
                # test 172.16.0.0/12  (RFC 1918 / private)
                /bin/ipcalc --network $testipv4addr_globalusable 255.240.0.0 | LC_ALL=C grep -q "NETWORK=172\.16\.0\.0"  && return 10
                # test 192.168.0.0/16 (RFC 1918 / private)
                /bin/ipcalc --network $testipv4addr_globalusable 255.255.0.0 | LC_ALL=C grep -q "NETWORK=192\.168\.0\.0" && return 10
                # test 224.0.0.0/3    (multicast and reserved, broadcast)
                /bin/ipcalc --network $testipv4addr_globalusable 224.0.0.0   | LC_ALL=C grep -q "NETWORK=224\.0\.0\.0"   && return 10

        return 0
}


## Test a given device for status
#  $1: <Interface>
# return code: 0=ok 1=argument error 10=not exists 11=down
ipv6_test_device_status() {
        local fn="ipv6_test_device_status"

        local device=$1

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        # Test if device exists
        if [ ! -d "/sys/class/net/${device}" ]; then
                # not exists
                return 10
        fi

        # Test if device is up
        if /sbin/ip link show dev $device 2>/dev/null | LC_ALL=C grep -q "UP"; then
                # up
                return 0
        else
                # down
                return 11
        fi
}


## Create 6to4 prefix
#  $1: <IPv4 address>
# stdout: <6to4address>
# return code: 0=ok 1=argument error
ipv6_create_6to4_prefix() {
        local fn="ipv6_create_6to4_prefix"

        local ipv4addr=$1

        if [ -z "$ipv4addr" ]; then
                ipv6_log $"Missing parameter 'IPv4 address' (arg 1)" stderr.err $fn
        fi

        local major1="$(echo $ipv4addr | awk -F. '{ print $1 }')"
        local minor1="$(echo $ipv4addr | awk -F. '{ print $2 }')"
        local major2="$(echo $ipv4addr | awk -F. '{ print $3 }')"
        local minor2="$(echo $ipv4addr | awk -F. '{ print $4 }')"

        if [ -z "$major1" -o -z "$minor1" -o -z "$major2" -o -z "$minor2" ]; then
                return 1
        fi

        if [ $major1 -eq 0 ]; then
                local block1="$(printf "%x" $minor1)"
        else
                local block1="$(printf "%x%02x" $major1 $minor1)"
        fi
        if [ $major2 -eq 0 ]; then
                local block2="$(printf "%x" $minor2)"
        else
                local block2="$(printf "%x%02x" $major2 $minor2)"
        fi

        local prefix6to4="2002:$block1:$block2"

        echo "$prefix6to4"
        return 0
}


## Check and create 6to4 tunnel relay address
#  $1: <IPv4 address|IPv6to4 address>
# stdout: <tunnel relay address>
# return code: 0=ok 1=argument error
ipv6_create_6to4_relay_address() {
        local fn="ipv6_create_6to4_relay_address"

        local addr=$1

        if [ -z "$addr" ]; then
                ipv6_log $"Missing parameter 'address' (arg 1)" stderr.err $fn
                return 1
        fi

        # Check
        if ipv6_test_ipv4_addr_valid $addr ; then
                # ok, a IPv4 one
                if ipv6_test_ipv4_addr_global_usable $addr; then
                        # IPv4 globally usable
                        local ipv6to4_relay="::$addr"
                else
                        ipv6_log $"Given address '$addr' is not a global IPv4 one (arg 1)" stderr.err $fn
                        return 1
                fi
        else
                ipv6_log $"Given address '$addr' is not a valid IPv4 one (arg 1)" stderr.err $fn
                return 1
        fi

        echo "$ipv6to4_relay"

        return 0
}


##### 6to4 tunneling setup

## Configure 6to4 tunneling up
#  $1: <Interface> : only "tun6to4" is supported
#  $2: <IPv4 address> : global IPv4 address of interface (will be used to generate 6to4 prefix)
#  $3: [<IPv6 suffix>] : for 6to4 prefix (optional, default is "::1")
#  $4: [<MTU>] : MTU of tunnel device (optional, default is automatic)
#  $5: [<IPv4 address>] : local IPv4 address of tunnel interface (required in case of 6to4 behind NAT)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_add_6to4_tunnel() {
        local fn="ipv6_add_6to4_tunnel"

        local device=$1
        local globalipv4=$2
        local globalipv6to4suffix=$3
        local mtu=$4
        local localipv4=$5

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        if [ -z "$globalipv4" ]; then
                ipv6_log $"Missing parameter 'global IPv4 address' (arg 2)" err $fn
                return 1
        fi

        # Check device
        if [ "$device" != "tun6to4" ]; then
                ipv6_log $"Given device '$device' is not supported (arg 1)" err $fn
                return 1
        fi

        # Copy global IPv4 address to local if last one is not given
        if [ -z "$localipv4" ]; then
                localipv4="$globalipv4"
        fi

        ipv6_test || return 2

        # Generate 6to4 address
        local prefix6to4="$(ipv6_create_6to4_prefix $globalipv4)"
        if [ $? -ne 0 -o -z "$prefix6to4" ]; then
                return 3
        fi

        if [ -z "$globalipv6to4suffix" ]; then
                local address6to4="${prefix6to4}::1/16"
        else
                local address6to4="${prefix6to4}::${globalipv6to4suffix}/16"
        fi

                ipv6_add_tunnel_device tun6to4 0.0.0.0 $address6to4 $localipv4
                if [ $? -ne 0 ]; then
                        local retval=3
                else
                        local retval=0
                fi

                # Add unspecific unreachable route for local 6to4 address space
                /sbin/ip route add unreach ${prefix6to4}::/48

        # Set MTU, if given
        if [ -n "$mtu" ]; then
                ipv6_set_mtu $device $mtu
        fi

        return $retval
}


## Configure all 6to4 tunneling down
#  $1: <Interface> : only "tun6to4" is supported
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_cleanup_6to4_tunnels() {
        local fn="ipv6_cleanup_6to4_tunnels"

        local device=$1

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        # Check device
        if [ "$device" != "tun6to4" ]; then
                ipv6_log $"Given device '$device' is not supported (arg 1)" err $fn
                return 1
        fi

        ipv6_test testonly || return 2

                ipv6_del_tunnel_device tun6to4

                # Remove all unspecific unreachable routes for local 6to4 address space
                /sbin/ip -6 route | LC_ALL=C grep "^unreachable 2002:" | LC_ALL=C grep "/48 dev lo" | while read token net rest; do
                        /sbin/ip route del unreach $net
                done

        return 0
}


## Configure 6to4 tunneling down
#  $1: <Interface> : only "tun6to4" is supported
#  $2: <IPv4 address> : global address of local interface
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_del_6to4_tunnel() {
        local fn="ipv6_del_6to4_tunnel"

        local device=$1
        local localipv4=$2

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        if [ -z "$localipv4" ]; then
                ipv6_log $"Missing parameter 'local IPv4 address' (arg 2)" err $fn
                return 1
        fi

        # Check device
        if [ "$device" != "tun6to4" ]; then
                ipv6_log $"Given device '$device' is not supported (arg 1)" err $fn
                return 1
        fi

        ipv6_test || return 2

                ipv6_del_tunnel_device tun6to4
                local retval=$?

                # Remove unspecific unreachable route for local 6to4 address space
                /sbin/ip route del unreach ${prefix6to4}::/48

        return $retval
}


## Configure a static tunnel device up
#  $1: <Interface>
#  $2: <IPv4 address> : of foreign tunnel
#  $3: [<IPv6 address>] : local one of a P-t-P tunnel (optional)
#  $4: [<IPv4 address>] : local one of tunnel (optional)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_add_tunnel_device() {
        local fn="ipv6_add_tunnel_device"

        local device=$1
        local addressipv4tunnel=$2
        local addressipv6local=$3
        local addressipv4tunnellocal=$4

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        if [ -z "$addressipv4tunnel" ]; then
                ipv6_log $"Missing parameter 'IPv4-tunnel address' (arg 2)" err $fn
                return 1
        fi

        if [ -z "$addressipv4tunnellocal" ]; then
                local addressipv4tunnellocal="any"
        fi

        ipv6_test || return 2

        if ! ipv6_test_device_status $device; then
                local ttldefault="$(/sbin/sysctl -e net.ipv4.ip_default_ttl | awk '{ print $3 }')"
                if [ -z "$ttldefault" ]; then
                        local ttldefault=64
                fi

                # Test whether remote IPv4 address was already applied to another tunnel
                if [ "$addressipv4tunnel" != "0.0.0.0" -a "$addressipv4tunnel" != "any" ]; then
                        /sbin/ip tunnel show remote $addressipv4tunnel 2>/dev/null | LC_ALL=C grep -w "ipv6/ip" | while IFS=":" read devnew rest; do
                                if [ "$devnew" != "$device" ]; then
                                        ipv6_log $"Given remote address '$addressipv4tunnel' on tunnel device '$device' is already configured on device '$devnew'" err $fn
                                        return 3
                                fi
                        done
                fi

                /sbin/ip tunnel add $device mode sit ttl $ttldefault remote $addressipv4tunnel local $addressipv4tunnellocal
                if [ $? -ne 0 ]; then
                        return 3
                fi

                # Test, whether "ip tunnel show" reports valid content
                if ! /sbin/ip tunnel show $device 2>/dev/null | LC_ALL=C grep -q -w "remote"; then
                        ipv6_log $"Tunnel device '$device' creation didn't work" err $fn
                        return 3
                fi

                /sbin/ip link set $device up

                if ! ipv6_test_device_status $device; then
                        ipv6_log $"Tunnel device '$device' bringing up didn't work" err $fn
                        return 3
                fi

                # Set sysctls proper (regardless "default")
                /sbin/sysctl -e -w net.ipv6.conf.$SYSCTLDEVICE.forwarding=1 >/dev/null 2>&1
                /sbin/sysctl -e -w net.ipv6.conf.$SYSCTLDEVICE.accept_ra=0 >/dev/null 2>&1
                /sbin/sysctl -e -w net.ipv6.conf.$SYSCTLDEVICE.accept_redirects=0 >/dev/null 2>&1

                if [ -n "$addressipv6local" ]; then
                        # Setup P-t-P address
                        ipv6_add_addr_on_device $device $addressipv6local
                        if [ $? -ne 0 ]; then
                                return 3
                        fi
                fi
        else
                false
        fi

        return 0
}


## Configure a static tunnel device down
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_del_tunnel_device() {
        local fn="ipv6_del_tunnel_device"

        local device=$1

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        ipv6_test testonly || return 2

        if ipv6_test_device_status $device; then
                ipv6_cleanup_device $device
        else
                if [ "$device" != "sit0" ]; then
                        false
                fi
        fi

        if [ "$device" != "sit0" ]; then
                if /sbin/ip tunnel show $device 2>/dev/null | LC_ALL=C grep -q -w "ipv6/ip"; then
                        /sbin/ip tunnel del $device

                                if ipv6_test_device_status $device; then
                                        return 3
                                fi
                else
                        false
                fi
        fi

        return 0
}


## Cleanup all dedicated tunnel devices
ipv6_cleanup_tunnel_devices() {
        local fn="ipv6_cleanup_tunnel_devices"

        ipv6_test testonly || return 2

        # Find still existing tunnel devices and shutdown and delete them

        /sbin/ip tunnel show | LC_ALL=C grep -w "ipv6/ip" | awk -F: '{ print $1 }' | while read device; do
                ipv6_del_tunnel_device $device
        done

        return 0
}


## Get address of a dedicated tunnel
#  $1: <Interface>
#  $2: local|remote : local or remote address
# stdout: <IPv4 address> if available
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_get_ipv4addr_of_tunnel() {
        local fn="ipv6_get_local_ipv4_of_tunnel"

        local device=$1
        local selection=$2

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" stderr.err $fn
                return 1
        fi

        if [ -z "$selection" ]; then
                ipv6_log $"Missing parameter 'selection' (arg 2)" stderr.err $fn
                return 1
        fi
        if [ "$selection" != "local" -a "$selection" != "remote" ]; then
                ipv6_log $"Unsupported selection '$selection' specified (arg 2)" stderr.err $fn
                return 1
        fi

        ipv6_test testonly || return 2

        ipv6_test_device_status $device

        if [ $? != 0 -a $? != 11 ]; then
                # Device doesn't exist
                return 3
        fi

        # Device exists, retrieve address
        if [ "$selection" = "local" ]; then
                local tunnel_local_ipv4addr="$(/sbin/ip tunnel show $device | awk '{ print $6 }')"
        elif [ "$selection" = "remote" ]; then
                local tunnel_local_ipv4addr="$(/sbin/ip tunnel show $device | awk '{ print $4 }')"
        fi

        if [ $? != 0 ]; then
                return 3
        fi

        if [ "$tunnel_local_ipv4addr" = "any" ]; then
                local tunnel_local_ipv4addr="0.0.0.0"
        fi

        echo "$tunnel_local_ipv4addr"

        return 0
}


## Get IPv4 address of a device
#  $1: <Interface>
# stdout: <IPv4 address> if available
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem (more than one IPv4 address applied)
ipv6_get_ipv4addr_of_device() {
        local fn="ipv6_get_ipv4addr_of_device"

        local device=$1

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" stderr.err $fn
                return 1
        fi

        ipv6_test_device_status $device

        if [ $? != 0 -a $? != 11 ]; then
                # Device doesn't exist
                return 3
        fi

        # Device exists, retrieve the first address only
        local ipv4addr="$(/sbin/ip -o -4 addr show dev $device | awk '{ print $4 }' | awk -F/ '{ print $1; exit }')"

        if [ $? != 0 ]; then
                return 3
        fi

        if [ "$ipv4addr" = "any" ]; then
                local ipv4addr="0.0.0.0"
        fi

        echo "$ipv4addr"

        return 0
}


## Set IPv6 MTU for a device
#  $1: <Interface>
#  $2: <IPv6 MTU>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_set_mtu() {
        local fn="ipv6_set_mtu"

        local device=$1
        local ipv6_mtu=$2

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        if [ -z "$ipv6_mtu" ]; then
                ipv6_log $"Missing parameter 'IPv6 MTU' (arg 2)" err $fn
                return 1
        fi

        # Check range
        if [ $ipv6_mtu -lt 1280 -o $ipv6_mtu -gt 65535 ]; then
                ipv6_log $"Given IPv6 MTU '$ipv6_mtu' is out of range" err $fn
                return 1
        fi

        ipv6_test testonly || return 2

        # Set value
        /sbin/ip link set dev $device mtu $ipv6_mtu

        return 0
}


## Set a default route
#  $1: <IPv6 address> : gateway, can also contain scope suffix (device name), cause a warning if not matching with $2 (but will have precedence)
#  $2: <gateway device>: gateway device (optional in case of $1 is a global address or $1 contains scope suffix)
#  $3: <check device>: (optional) device to check scope and gateway device against (setup is skipped, if not matching)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_set_default_route() {
        local fn="ipv6_set_default_route"

        local address=$1
        local device=$2
        local device_check=$3

        ipv6_test testonly || return 2

        # Map the unspecified address to nothing
        if [ "$address" = "::" ]; then
                local address=""
        fi

        if [ -n "$address" ]; then
                local addressgw=$(echo $address | awk -F% '{ print $1 }')
                local device_scope=$(echo $address | awk -F% '{ print $2 }')

                if [ -z "$addressgw" ]; then
                        ipv6_log $"Given IPv6 default gateway '$address' is not in proper format" err $fn
                        return 3
                fi

                # Scope device has precedence
                if [ -n "$device_scope" -a -n "$device" -a "$device_scope" != "$device" ]; then
                        ipv6_log $"Given IPv6 default gateway '$address' has scope '$device_scope' defined, given default gateway device '$device' will be not used" inf $fn
                        local device=""
                fi

                # Link local addresses require a device
                if echo $addressgw | LC_ALL=C grep -qi "^fe80:"; then
                        if [ -z "$device_scope" ]; then
                                if [ -z "$device" ]; then
                                        ipv6_log $"Given IPv6 default gateway '$address' is link-local, but no scope or gateway device is specified" err $fn
                                        return 3
                                fi
                        fi
                fi

                # Check whether the route belongs to the specific given interface
                if [ -n "$device_check" ]; then
                        # Check whether scope device matches given check device
                        if [ -n "$device_scope" -a "$device_check" != "$device_scope" ]; then
                                # scope device != specific given -> skip
                                return 0
                        elif [ -n "$device" -a "$device_check" != "$device" ]; then
                                # gateway device != specific given -> skip
                                return 0
                        fi
                fi

                # Set device now, if not given
                if [ -z "$device" ]; then
                        local device="$device_scope"
                fi

                if [ -z "$device" ]; then
                        # Note: this can cause a warning and a not installed route, if given address is not reachable on the link
                        ipv6_add_route ::/0 $addressgw
                else
                        ipv6_add_route ::/0 $addressgw $device
                fi
        elif [ -n "$device" ]; then
                # Check whether the route belongs to the specific given interface
                if [ -n "$device_check" -a "$device_check" != "$device" ]; then
                        # gateway device != specific given -> skip
                        return 0
                fi

                ipv6_test_route_requires_next_hop $device
                local result=$?

                if [ $result = 0 ]; then
                        ipv6_log $"Given IPv6 default device '$device' requires an explicit nexthop" err $fn
                        return 3
                elif [ $result != 10 ]; then
                        ipv6_log $"Given IPv6 default device '$device' doesn't exist or isn't up" err $fn
                        return 3
                fi

                ipv6_add_route ::/0 :: $device
        else
                ipv6_log $"No parameters given to setup a default route" err $fn
                return 3
        fi

        return 0
}


## Resolve need of explicit next hop for an interface
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem 10=needs no explicit hop
ipv6_test_route_requires_next_hop() {
        local fn="ipv6_test_route_requires_next_hop"

        local device=$1

        if [ -z "$device" ]; then
                ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
                return 1
        fi

        ipv6_test testonly || return 2

        ipv6_test_device_status $device

        if [ $? != 0 ]; then
                return 3
        fi

        if [ "$device" = "sit0" ]; then
                return 10
        fi

        if /sbin/ip -o link show $device 2>/dev/null |  LC_ALL=C grep -q "POINTOPOINT"; then
                return 10
        fi

        return 0
}


## Trigger radvd
#  $1: up|down : device reason for triggering (coming up or going down)
#  $2: [startstop|restart|reload|SIGHUP] : triger mechanism (default is "SIGHUP")
#        "startstop" : reason=up -> start, reason=down -> stop
#  $3: [<filename>] : alternative pid file  [optional]
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_trigger_radvd() {
        local fn="ipv6_trigger_radvd"

        local reason=$1
        local mechanism=$2
        local pidfile=$3

        if [ -z "$reason" ]; then
                ipv6_log $"No reason given for sending trigger to radvd" err $fn
                return 1
        fi

        if [ "$reason" != "up" -a "$reason" != "down" ]; then
                ipv6_log $"Unsupported reason '$reason' for sending trigger to radvd" err $fn
                return 1
        fi

        if [ -z "$mechanism" ]; then
                # Take default
                local mechanism="SIGHUP"
        fi

        if [ -z "$pidfile" ]; then
                local pidfile="/var/run/radvd/radvd.pid"
        fi

        # Print message and select action
        case $mechanism in
            'startstop')
                case $reason in
                    up)
                        local action="start"
                        ;;
                    down)
                        local action="stop"
                        ;;
                esac
                ;;
            'reload'|'restart'|'SIGHUP')
                local action="$mechanism"
                ;;
            *)
                ipv6_log $"Unsupported mechanism '$mechanism' for sending trigger to radvd" err $fn
                return 3
                ;;
        esac

        # PID file needed?
        if [ "$action" = "SIGHUP" ]; then
                if ! [ -f "$pidfile" ]; then
                        if [ "$reason" = "down" ]; then
                                # be quiet because triggering may have been disabled
                                true
                        else
                                ipv6_log $"Given pidfile '$pidfile' doesn't exist, cannot send trigger to radvd" err $fn
                        fi
                        return 3
                fi

                # Get PID
                local pid="$(cat $pidfile)"
                if [ -z "$pid" ]; then
                        # pidfile empty - strange
                        ipv6_log $"Pidfile '$pidfile' is empty, cannot send trigger to radvd" err $fn
                        return 3
                fi
        fi


        # Do action
        case $action in
            'SIGHUP')
                kill -HUP $pid
                ;;
            'reload'|'restart'|'stop'|'start')
                        if ! /sbin/chkconfig --list radvd >/dev/null 2>&1; then
                                if [ "$reason" = "down" ]; then
                                        # be quiet because triggering may have been disabled
                                        true
                                else
                                        ipv6_log $"radvd not (properly) installed, triggering failed" err $fn
                                fi
                                return 3
                        else
                                /sbin/service radvd $action >/dev/null 2>&1
                        fi
                ;;
            *)
                # Normally not reached, "action" is set above to proper value
                ;;
        esac

        return 0
}