Hint to allow static IPv6 in LFS
Sun Dec  8 13:33:36 PST 2019
        
AUTHOR: Joel Bion <jpbipv6hints at gmail.com>

DATE: 2019-12-08

LICENSE:

GNU Free Documentation License Version 1.2, with the additional requirement
that the "WARRANTY DISCLAIMER" sections are strictly adhered to by all users of
this document and/or its contents.

SYNOPSIS: Using a static IPv6 address with LFS

DESCRIPTION:

This hint describes how a static IPv6 address can be added to a system built
with LFS.

WARRANTY DISCLAIMER:

1. DISCLAIMER OF WARRANTY

THERE IS NO WARRANTY FOR THIS DOCUMENT, TO THE EXTENT PERMITTED BY APPLICABLE
LAW. THE COPYRIGHT HOLDER, AUTHORS, AND/OR OTHER PARTIES PROVIDE THE DOCUMENT
AND/OR ITS INFORMATION "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE
QUALITY AND PERFORMANCE OF THE DOCUMENT AND/OR ITS INFORMATION IS WITH YOU.
SHOULD THE DOCUMENT AND/OR ITS INFORMATION PROVE DEFECTIVE, YOU ASSUME THE COST
OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

2. Limitation of Liability.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY
COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE DOCUMENT
AND/OR ITS INFORMATION AS PERMITTED IN ITS LICENSE, BE LIABLE TO YOU FOR
DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OR INABILITY TO USE THE DOCUMENT AND/OR ITS INFORMATION
(INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR
LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE DOCUMENT AND/OR
ITS INFORMATION TO ACHIEVE ITS INTENDED RESULT), EVEN IF SUCH HOLDER OR OTHER
PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

3. Interpretation of Sections 1 and 2.

If the disclaimer of warranty and limitation of liability provided above cannot
be given local legal effect according to their terms, reviewing courts shall
apply local law that most closely approximates an absolute waiver of all civil
liability in connection with the documentation and/or its contents.

ATTACHMENTS:

None

PREREQUISITES:

This hint requires you to have a working LFS system, with a static IPv4
address. The hint was built with LFS version 9.0, but is likely to work back to
version 7.0.

This hint requires that you have a good understanding of IPv6, including, but
not limited to, IPv6 address formats, the differences between things such as
link-local addresses vs. global addresses, what IPv6 Router Advertisements are,
and what they usually provide to a host, what prefix delegation is, etc.  In
other words, you should be fully IPv6 knowledgeable, and are just looking for
how to incorporate IPv6 into your LFS system.

Note: ISPs have not completely standardized on how they provide IPv6
connectivity. This hint works with ISPs that let you choose an IPv6 address
within the range of a prefix delegation you've been assigned, and do not filter
your choice of that address. Further, the default use of the system is one
where the default gateway is given to the system via IPv6-RD. It may also work
with ISPs who are similar to the above description, but require you to
configure a default gateway address.

SECURITY CONSIDERATIONS:

THERE ARE PLENTY OF SECURITY CONSIDERATIONS!

It is assumed that you have a deep understanding of the security implications
of adding IPv6 support to a network and/or hosts (server, client, etc.).  If
you do not have such an understanding, or/and have not configured and tested
your network and end systems to ensure they will be equally or better protected
with IPv6 enabled, you need to question whether or not you are properly ready,
from a security standpoint, to enable IPv6. Security and protection are 100%
your responsibility! For example, the original author of this hint does not
enable global IPv6 in his home network out of concern over IPv6 security.
You've been warned!

HINT:

Used in this hint:

   IPv6 address: 2001:DB8:1234::123:150
   IPv6 prefix: 112
   IPv4 address: 192.51.100.93
   IPv4 broadcast: 192.51.100.255
   IPv4 prefix: 24
   IPv4 gateway: 192.51.100.1
   Domain name: example.com
   Interface name: eth0

HINT STEP 1 - PREPARING FOR IPv6

How you exactly and completely do this is well beyond the scope of this hint.
It turns out simply enabling IPv6 is quite easy. But, preparing for it and
adjusting to its consequences can be difficult. This hint step describes the
various things you must consider before you introduce IPv6 to your system. As a
point of reference: the hint author spent perhaps a few hours figuring out how
to add IPv6 to his LFS system. But he spent multiple weekends preparing for it,
and the last repercussions (the creation of a PTR record by his ISP) took over
a week.

HINT STEP 1A - SECURITY

As said above, protecting your host and network with IPv6 enabled is different
than doing this in an IPv4 world. Some things are similar, but other things are
quite different. You cannot assume that a good knowledge of IPv4 security is
all you need to know to make the same network/server secure when running IPv6.
Study up on this, read a book or two about it, etc. Learn more than you know
about IPv4 security because IPv6 security is more complex, and introduces
concepts (such as global reach-ability of your systems) that you may never have
faced before. YOU are responsible for your system's security and to know the
risks that enabling ipv6 creates!

HINT STEP 1B - DNS CONSIDERATIONS

Depending on your needs, do you have all the proper IPv6-supporting records you
need in your domain's zone file? Depending on how you have previously set
things up, you may need to not just add a AAAA edit DMARC, MX, etc records set
up at your domain name provider? If you are sending email from your LFS system,
you may need to have a PTR record created by your ISP that provides 'reverse
DNS' support. This PTR record may take your ISP days or weeks to set up - so
plan ahead, and verify that all is set up property (even your ISP's PTR record)
rather than assuming it all will work!

HINT STEP 1C - COPING WITH IP ADDRESS OR IPv4 PROTOCOL-SPECIFIC CONFIGURATIONS

Most likely, you are familiar with IPv4 addresses in /etc/hosts, but a system
that has been using a static IPv4 address for some time may have its numeric
IPv4 address stored in many configurations. It may also have the network
portion of the IPv4 address stored in places, with the host portion of the
number zeroed out (for example: 192.51.100.0) or perhaps specify the broadcast
address explicitly (for example: 192.51.100.255.) You may also have
applications that need to have IPv6 support configured in, or may make new
decisions when they discover IPv6 is enabled that you need to configure around,
etc. You need to figure this out to get your system up and properly behaving
with both IPv4 and IPv6 configured.

HINT STEP 1D - OBTAINING ADDITIONAL PACKAGES REQUIRED TO SUPPORT IPv6.

There is the occasional package that needs to have an additional package added
to the system to support IPv6. This is particularly true of applications that
are written in languages that encourage the use of widely-available libraries
to perform much of the work (examples include Perl and Python.) So, for your
installed packages, check out which ones are directly utilizing the Internet in
any way, and see if they require any extra packages to support IPv6.

HINT STEP 1E - ENABLE IPv6 IN THE LINUX KERNEL

Rebuild the Linux kernel, as specified in the LFS documentation, but examine
your configuration file, and edit it to ensure the following lines are set.

    CONFIG_IPV6=y
      - Essential IPv6 support
    CONFIG_IPV6_SIT=y
      - Enables use of IPv6-in-IPv4 tunnels - one day you may need this
    CONFIG_IPV6_NDISC_NODETYPE=y
      - Enables certain checks on neighbor discovery
    CONFIG_IPV6_TUNNEL=y
      - Supports RFC2473 IPv6-in-IPv6 and IPv4-in-IPv6 tunnels- one day you
        may need this
    CONFIG_IPV6_MULTIPLE_TABLES=y
    CONFIG_IPV6_SUBTREES=y
      - Together, the above two enable support for multiple IPv6 routingi tables
        (such as source-addressed based routing)
    CONFIG_INET6_AH=y
    CONFIG_INET6_ESP=y
    CONFIG_INET6_IPCOMP=y
    CONFIG_INET6_XFRM_TUNNEL=y
    CONFIG_INET6_TUNNEL=y
      - Above needed for IPsec with IPv6. You may not use this; the hint author
        does.
    CONFIG_NF_SOCKET_IPV6=m
    CONFIG_NF_TPROXY_IPV6=m
    CONFIG_NF_TABLES_IPV6=y
    CONFIG_NFT_REJECT_IPV6=m
    CONFIG_NFT_FIB_IPV6=m
    CONFIG_NF_REJECT_IPV6=y
    CONFIG_NF_LOG_IPV6=m
    CONFIG_IP6_NF_MATCH_IPV6HEADER=y
    CONFIG_NF_DEFRAG_IPV6=y
     - Netfilter support for various commonly-referenced elements of IPv6
       packet filtering. Many host-based firewall tools need these to be
       enabled.

HINT STEP 2 - INSTALL NEW VERSIONS OF MULTIPLE LFS SCRIPTS

Script copies are given at the end of this hint. Put them in place in the
location specified, overwriting the files you have in some cases with these new
versions. You should save backup copies of any scripts you are about to replace
or modify. The modified scripts have been tested in the hint author's system to
still work even if IPv6 is NOT used.

NOTE: THESE VERSIONS OF THE SCRIPT ARE KNOWN TO WORK IN LFS 9.0, IN SYSTEMS
USING THE LFS-Bootscripts PACKAGE DATED 20191031. IF YOUR BOOTSCRIPTS ARE FROM
A DIFFERENT VERSION, YOU SHOULD CHECK TO SEE THESE STILL CAN BE USED BY CLOSELY
COMPARING THESE GIVEN VERSIONS TO THE ONES ON YOUR SYSTEM.  HINT STEP 3 -
MODIFY VARIOUS CONFIGURATION FILES

HINT STEP 3A - MODIFY /etc/sysconfig/ifconfig.eth0

In /etc/sysconfig/ifconfig.eth0, add in your IPv6 address and prefix, and
change the service pointer to ipv46-static, to create a resulting file that
looks something like this.  Obviously, edit to match your setup.

    ONBOOT=yes
    IFACE=eth0
    SERVICE=ipv46-static
    IP=192.51.100.93
    PREFIX=24
    GATEWAY=192.51.100.1
    BROADCAST=192.51.100.255
    IP6=2001:DB8:1234::123:150
    PREFIX6=112

HINT STEP 3B - MODIFY /etc/hosts

Add the following to /etc/hosts, if not already there. Obviously, edit to match
your setup.

   2001:DB8:1234::123:150 example.com
   2001:DB8:1234::123:150 www.example.com (maybe)
   ::1     localhost ip6-localhost ip6-loopback ourserver
   fe00::0 ip6-localnet
   ff00::0 ip6-mcastprefix
   ff02::1 ip6-allnodes
   ff02::2 ip6-allrouters
   ff02::3 ip6-allhosts

HINT STEP 3C - EDIT (OR POSSIBLE EVEN CREATE) /etc/sysctl.conf

Add the following lines to /etc/sysctl.conf. Obviously, edit to match your
setup.

       net.ipv6.conf.eth0.disable_ipv6=0
       net.ipv6.conf.eth0.autoconf=0

What they do:

       net.ipv6.conf.eth0.disable_ipv6=0
        - 'disables the disabling' (net result, enables) IPv6 on this interface
       net.ipv6.conf.eth0.autoconf=0
        - Disables receiving an IPv6 address from IPv6-RD packets sent by your
          gateway/router.

NOTE: If you plan to disable IPv6, you should change the sysctl.conf entries to
read as follows, as well as reverting your ifconfig.eth0 file.

Example of sysctl.conf entries to help revert from using IPv6:

       net.ipv6.conf.eth0.disable_ipv6=1
       net.ipv6.conf.eth0.autoconf=1

HINT STEP 3D (OPTIONAL) - create/edit /etc/sysconfig/network

   Add in the line shown below. There may still be a very small number of
   applications and/or packages that need to see this line in this file to
   'believe' that IPv6 is enabled on your system, and it is painful to discover
   and debug the ones that do. It's much easier to just add the following line
   to this file, even though it's pretty frustrating and clumsy to have to do
   this:

     NETWORKING_IPV6=yes

HINT STEP 4 - Reboot and check things out

    Upon reboot, issue these commands and see if they give sensible results:

      ip -4 address
      ip -4 route
      ip -6 address
      ip -6 route

    The 'address' variant should show you interface addresses. Ideally, you
    have only ONE global IPv6 address on your interface: the one you
    configured. But you should also have link-specific addresses as well.

    The 'route' variant should show a default gateway. If you see it, try
    testing by using 'ping6' on a few well known sites. While this hint cannot
    'sponsor' any by listing it, just think of the major websites in the world.
    Some won't support IPv6, but some will, and you should see that you get
    successful 'ping6' packets sent to one or more of these. If none work, you
    need to examine and debug things. You may need to manually set up your IPv6
    gateway with the GATEWAY6=<ipv6-address-of-gateway> parameter in the
    ifconfig.<interface-name> file.

    NOTE: YOUR MACHINE IS NOW POTENTIALLY REACHABLE ON THE GLOBAL INTERNET WITH
    IPv6!

HINT STEP 5 - IF YOU HAVEN'T CONFIGURED PROPER SECURITY MEASURES FOR IPv6...

    ...then good-golly, please do so NOW! Your system could be vulnerable!

HINT STEP 6 - VERIFY YOU CAN BE REACHED VIA IPv6

    If your LFS machine is a server, meant for the public to reach, you have
    many additional steps to perform. Firewall setup, ensuring others can reach
    your device at its IPv6 address. Ensuring that all the packages you depend
    on are setup with either IPv6 in mind

HINT STEP 7 - A FEW MINOR OTHER THINGS

    There's always more to do. Here are a couple of things I happen to
    remember:

HINT STEP 7A - ADD IPv6 DNS SERVERS TO /etc/resolv.conf

    These aren't absolutely necessary, as resolving an IPv6 address can be done
    in a query to a DNS carried in IPv6, but these are nice to have. Your DNS
    provider will know what, if any, IPv6 addresses they have for their DNS
    resolvers.

HINT STEP 7B - MONITOR YOUR IPv6 SETUP

    Regular 'ipaddr' commands do not work. Use 'ip'. Examples:

     ip -4 address:  returns list of IPv4 interface addresses
     ip -4 route:    returns IPv4 routing table
     ip -6 address:  returns list of IPv6 interface addresses
     ip -6 route:    returns IPv6 routing table

HINT STEP 7C - A COMMON PROBLEM

    Sometimes firewalls from our ISP can be set to filter IPv6 altogether or be
    set with 'state' - allowing traffic not to be initiated from the outside.
    Either of these might be contrary to what you want to have happen
    (especially if your newly IPv6-capable machine is meant to be reached by
    other systems on the Internet as a web server or something else.) - so you
    may need to edit your ISP Gateway/Firewall/etc. settings.

HINT STEP 8 - MONITOR AND VERIFY, TRY USING EVERYTHING ON YOUR SYSTEM

    You'll just need to, as soon as possible, try everything to make sure it
    all works.

ACKNOWLEDGEMENTS:

   * The Internet at large for providing many examples of IPv6 security 
     and usage.
   * The app developers for adding IPv6 support to their applications The
   * providers of LFS - such a great base for a system!

CHANGELOG:

[2019-12-08] First version.

MODIFIED AND NEW SCRIPTS

Modifed script /sbin/ifup

#!/bin/sh
########################################################################
# Begin /sbin/ifup
#
# Description : Interface Up
#
# Authors     : Nathan Coulson - nathan at linuxfromscratch.org
#               Kevin P. Fleming - kpfleming at linuxfromscratch.org
# Update      : Bruce Dubbs - bdubbs at linuxfromscratch.org
#               DJ Lucas - dj at linuxfromscratch.org
#               Joel Bion - jpbipv6hint at gmail.com
#
# Version     : LFS 9.0
#
# Notes       : The IFCONFIG variable is passed to the SERVICE script
#               in the /lib/services directory, to indicate what file the
#               service should source to get interface specifications.
#
########################################################################

up()
{
   log_info_msg "Bringing up the ${1} interface..."

   if ip link show $1 > /dev/null 2>&1; then
      link_status=`ip link show $1`

      if [ -n "${link_status}" ]; then
         if ! echo "${link_status}" | grep -q UP; then
            ip link set $1 up
         fi
      fi

   else
      log_failure_msg "Interface ${IFACE} doesn't exist."
      exit 1
   fi

   evaluate_retval
}

RELEASE="9.0"

USAGE="Usage: $0 [ -hV ] [--help] [--version] interface"
VERSTR="LFS ifup, version ${RELEASE}"

while [ $# -gt 0 ]; do
    case "$1" in
       --help | -h)     help="y"; break ;;

       --version | -V)  echo "${VERSTR}"; exit 0 ;;

       -*)              echo "ifup: ${1}: invalid option" >&2
                        echo "${USAGE}" >& 2
                        exit 2 ;;

       *)               break ;;
    esac
done

if [ -n "$help" ]; then
    echo "${VERSTR}"
    echo "${USAGE}"
    echo
    cat << HERE_EOF
ifup is used to bring up a network interface.  The interface
parameter, e.g. eth0 or eth0:2, must match the trailing part of the
interface specifications file, e.g. /etc/sysconfig/ifconfig.eth0:2.

HERE_EOF
    exit 0
fi

file=/etc/sysconfig/ifconfig.${1}

# Skip backup files
[ "${file}" = "${file%""~""}" ] || exit 0

. /lib/lsb/init-functions

if [ ! -r "${file}" ]; then
    log_failure_msg "Unable to bring up ${1} interface! ${file} is missing or cannot be accessed."
    exit 1
fi

.  $file

if [ "$IFACE" = "" ]; then
    log_failure_msg "Unable to bring up ${1} interface! ${file} does not define an interface [IFACE]."
    exit 1
fi

# Do not process this service if started by boot, and ONBOOT
# is not set to yes
if [ "${IN_BOOT}" = "1" -a "${ONBOOT}" != "yes" ]; then
    exit 0
fi

# Bring up the interface
if [ "$VIRTINT" != "yes" ]; then
    up ${IFACE}
fi

for S in ${SERVICE}; do
   if [ ! -x "/lib/services/${S}" ]; then
     MSG="\nUnable to process ${file}.  Either "
     MSG="${MSG}the SERVICE '${S} was not present "
     MSG="${MSG}or cannot be executed."
     log_failure_msg "$MSG"
     exit 1
   fi
done

if [ "${SERVICE}" = "wpa" ]; then log_success_msg; fi

# Create/configure the interface
for S in ${SERVICE}; do
   IFCONFIG=${file} /lib/services/${S} ${IFACE} up
done

# Set link up virtual interfaces
if [ "${VIRTINT}" == "yes" ]; then
    up ${IFACE}
fi

# Bring up any additional interface components
for I in $INTERFACE_COMPONENTS; do up $I; done

# Set MTU if requested. Check if MTU has a "good" value.
if test -n "${MTU}"; then
    if [[ ${MTU} =~ ^[0-9]+$ ]] &amp;&amp; [[ $MTU -ge 68 ]] ; then
       for I in $IFACE $INTERFACE_COMPONENTS; do
          ip link set dev $I mtu $MTU;
       done
    else
       log_info_msg2 "Invalid MTU $MTU"
    fi
fi

# Set the IPv4 default gateway if requested
if [ -n "${GATEWAY}" ]; then
    if ip -4 route | grep -q default; then
       log_warning_msg "IPv4 Gateway already set up; skipping."
    else
       log_info_msg "Adding default IPv4 gateway ${GATEWAY} to the ${IFACE} interface..."
       ip route add default via ${GATEWAY} dev ${IFACE}
       evaluate_retval
    fi
fi

# Set the IPv6 default gateway if requested (but only if an IPv6 address was
# given)
if [ "${IP6}" ]; then
    if [ -n "${GATEWAY6}" ]; then
       if ip -6 route | grep -q default; then
          log_warning_msg "IPv6 gateway already set up; skipping."
       else
          log_info_msg "Adding default IPv6 gateway ${GATEWAY} to the ${IFACE} interface..."
          ip -6 route add default via ${GATEWAY6} dev ${IFACE}
          evaluate_retval
       fi
    fi
fi

# End /sbin/ifup


+++++++++++++++++++++++++++++++++++++++++++++++++++

Modified script /sbin/ifdown

#!/bin/bash
########################################################################
# Begin /sbin/ifdown
#
# Description : Interface Down
#
# Authors     : Nathan Coulson - nathan at linuxfromscratch.org
#               Kevin P. Fleming - kpfleming at linuxfromscratch.org
# Update      : Bruce Dubbs - bdubbs at linuxfromscratch.org
#               Joel Bion - jpbipv6hint at gmail.com
#
# Version     : LFS 9.0
#
# Notes       : the IFCONFIG variable is passed to the scripts found
#               in the /lib/services directory, to indicate what file the
#               service should source to get interface specifications.
#
########################################################################

RELEASE="9.0"

USAGE="Usage: $0 [ -hV ] [--help] [--version] interface"
VERSTR="LFS ifdown, version ${RELEASE}"

while [ $# -gt 0 ]; do
    case "$1" in
       --help | -h)     help="y"; break ;;

       --version | -V)  echo "${VERSTR}"; exit 0 ;;

       -*)              echo "ifdown: ${1}: invalid option" >&2
                        echo "${USAGE}" >& 2
                        exit 2 ;;

       *)               break ;;
    esac
done

if [ -n "$help" ]; then
    echo "${VERSTR}"
    echo "${USAGE}"
    echo
    cat << HERE_EOF
ifdown is used to bring down a network interface.  The interface
parameter, e.g. eth0 or eth0:2, must match the trailing part of the
interface specifications file, e.g. /etc/sysconfig/ifconfig.eth0:2.

HERE_EOF
    exit 0
fi

file=/etc/sysconfig/ifconfig.${1}

# Skip backup files
[ "${file}" = "${file%""~""}" ] || exit 0

. /lib/lsb/init-functions

if [ ! -r "${file}" ]; then
    log_warning_msg "${file} is missing or cannot be accessed."
    exit 1
fi

. ${file}

if [ "$IFACE" = "" ]; then
    log_failure_msg "${file} does not define an interface [IFACE]."
    exit 1
fi

# We only need to first service to bring down the interface
S=`echo ${SERVICE} | cut -f1 -d" "`

if ip link show ${IFACE} > /dev/null 2<&1; then
    if [ -n "${S}" -a -x "/lib/services/${S}" ]; then
      IFCONFIG=${file} /lib/services/${S} ${IFACE} down
    else
      MSG="Unable to process ${file}.  Either "
      MSG="${MSG}the SERVICE variable was not set "
      MSG="${MSG}or the specified service cannot be executed."
      log_failure_msg "$MSG"
      exit 1
   fi
else
    log_warning_msg "Interface ${1} doesn't exist."
fi

# Leave the interface up if there are additional interfaces in the device
# However, for IPv6, we insist those adddresses must be global in scope,
# and not just one of the very many link-scope addresses IPv6 provides us.

link_status=`ip link show ${IFACE} 2>/dev/null`

if [ -n "${link_status}" ]; then
    if [ "$(echo "${link_status}" | grep UP)" != "" ]; then
       if [ "$(ip addr show ${IFACE} | grep 'inet ')" == "" -a 
            "$(ip addr show ${IFACE} | grep 'inet6 ' | 
            grep 'scope global')" == "" ]; then
          log_info_msg "Bringing down the ${IFACE} interface..."
          ip link set ${IFACE} down
          evaluate_retval
       fi
    fi
fi

# End /sbin/ifdown

New script /lib/services/ipv46-static, based off of ipv4-static

#!/bin/sh
########################################################################
# Begin /lib/services/ipv46-static
#
# Description : IPV4 Static Boot Script
#
# Authors     : Nathan Coulson - nathan at linuxfromscratch.org
#               Kevin P. Fleming - kpfleming at linuxfromscratch.org
# Update      : Bruce Dubbs - bdubbs at linuxfromscratch.org
#             : Joel Bion - jpbipv6hint at gmail.com
#
# Version     : LFS 9.0
#
########################################################################

. /lib/lsb/init-functions
. ${IFCONFIG}

args6=""

if [ -z "${IP}" ]; then
    log_failure_msg "\nIP variable missing from ${IFCONFIG}, cannot continue."
    exit 1
fi

if [ -z "${PREFIX}" -a -z "${PEER}" ]; then
    log_warning_msg "\nPREFIX variable missing from ${IFCONFIG}, assuming 24."
    PREFIX=24
    args="${args} ${IP}/${PREFIX}"

elif [ -n "${PREFIX}" -a -n "${PEER}" ]; then
    log_failure_msg "\nPREFIX and PEER both specified in ${IFCONFIG}, cannot continue."
    exit 1

elif [ -n "${PREFIX}" ]; then
    args="${args} ${IP}/${PREFIX}"

elif [ -n "${PEER}" ]; then
    args="${args} ${IP} peer ${PEER}"
fi

if [ -n "${LABEL}" ]; then
    args="${args} label ${LABEL}"
fi

if [ -n "${BROADCAST}" ]; then
    args="${args} broadcast ${BROADCAST}"
fi

if [ -n "${IP6}" ]; then
     if [ -z "${PREFIX6}" ]; then
         log_warning_msg = "\nPREFIX6 variable missing from {$IFCONFIG}, assuming 64."
         PREFIX6=64
     fi
     args6="${args6} ${IP6}/${PREFIX6}"
fi

case "${2}" in
    up)
       if [ "$(ip addr show ${1} 2>/dev/null | grep ${IP}/)" = "" ]; then

          # Cosmetic output
          if ! $(echo ${SERVICE} | grep -q " "); then
            log_info_msg2 "\n" # Terminate the previous message
          fi

          log_info_msg "Adding IPv4 address ${IP} to the ${1} interface..."
          ip addr add ${args} dev ${1}
          evaluate_retval
       else
          log_warning_msg "Cannot add IPv4 address ${IP} to ${1}.  Already present."
       fi

       if [ -n "${IP6}" ]; then
           if [ "$(ip -6 addr show ${1} 2>/dev/null | grep ${IP6}/)" = "" ]; then

              # Cosmetic output
              if ! $(echo ${SERVICE} | grep -q " "); then
                  log_info_msg2 "\n" # Terminate the previous message
              fi

              log_info_msg "Adding IPv6 address ${IP6} to the ${1} interface..."
              ip -6 addr add ${args6} dev ${1}
              evaluate_retval
           else
              log_warning_msg "Cannot add IPv6 address ${IP6} to ${1}.  Already present."
           fi
        fi
    ;;

    down)
       if [ -n "${IP6}" ]; then
           if [ "$(ip -6 addr show ${1} 2>/dev/null | grep ${IP6}/)" != "" ]; then
              log_info_msg "Removing IPv6 address ${IP6} from the ${1} interface..."
              ip -6 addr del ${args6} dev ${1}
              evaluate_retval
           fi
       fi
       if [ "$(ip addr show ${1} 2>/dev/null | grep ${IP}/)" != "" ]; then
          log_info_msg "Removing IPv4 address ${IP} from the ${1} interface..."
          ip addr del ${args} dev ${1}
          evaluate_retval
       fi

       # This code is removed because removing the last address REMOVES the
       # default route from the routing table ALREADY
       # if [ -n "${GATEWAY}" ]; then
       #   # Only remove the gateway if there are no remaining ipv4 addresses
       #   if [ "$(ip addr show ${1} 2>/dev/null | grep 'inet ')" == "" ]; then
       #      log_info_msg "Removing IPv4 default gateway..."
       #      ip route del default
       #      evaluate_retval
       #   fi
       # fi
    ;;

    *)
       echo "Usage: ${0} [interface] {up|down}"
       exit 1
    ;;
esac

# End /lib/services/ip46-static