path: root/loader/linuxrc.s390

#! /bin/bash

# linuxrc.s390: init process of Red Hat's installer initrd for s390(x)
# Copyright (C) 2000-2004 by
#        Bernhard Rosenkraenzer <bero@redhat.com>
#        Oliver Paukstadt <opaukstadt@millenux.com>
#        Karsten Hopp <karsten@redhat.de>
#        Florian La Roche <laroche@redhat.com>
#        Nils Philippsen <nils@redhat.de>
#        Helge Deller <hdeller@redhat.de>
#        David Sainty <dsainty@redhat.com>
# Copyright (C) IBM Corp. 2008,2009
#        Author: Steffen Maier <maier@de.ibm.com>
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

# prerequisites of this script to run inside the installer initrd:
# - udevadm and udevd need to be there
# - have /etc/udev/udev.conf with at least one comment line as content
# - if necessary, have udev rules
# - copy lsznet.raw and controlunits.sh to initrd
# - pack kernel modules and module-init-tools (no longer use busybox for that)
# - "multi on" in /etc/host.conf [RH bugs 486457,486461,483244]

# TODOs:
# - make sure driver modules get loaded automatically
# - udev rule for lcs/ctcm vs. cu3088
# - make sure netiucv gets loaded even without udev events since on no bus

VERSION=1.2

export TEXTDOMAIN=s390installer
export TEXTDOMAINDIR=/usr/lib/locale

# helper function to execute command in arguments and print command on stdout
function debug() {
    # uncomment the following echo "$*" to enable debug output
    #echo "$*"
    $*
}

# FIXME: maybe change to "$$" for production use, in case it wouldn't be init
declare -r INITPID="1"

unset testing
[ "$$" != "$INITPID" ] && testing="1"
# uncomment the following test="1" to never execute sensitive commands
#testing="1"

# helper function to disable commands while running outside the initrd
function tv() {
    if [ -z "$testing" ]; then
        $*
    else
        return 0
    fi
}

function checkipv6()
{
    local ip=$1
    [ -z "$ip" ] && return 1
    /sbin/ipcalc -c -6 "$ip" >/dev/null 2>&1
    return $?
}

function checkipv4()
{
    local ip=$1
    [ -z "$ip" ] && return 1
    /sbin/ipcalc -c -4 "$ip" >/dev/null 2>&1
    return $?
}

function doshutdown()
{
    exec /sbin/shutdown
    exit 0
}

function doreboot()
{
    # find out the location of /boot and use it to re-ipl
    boot="$(cat /proc/mounts | grep " /mnt/sysimage/boot " | awk -F" " '{print $1}')"
    if [ -z $boot ]; then
        # use root if /boot not used
        boot="$(cat /proc/mounts | grep " /mnt/sysimage " | awk -F" " '{print $1}')"
    fi

    # lookup dasd disk
    echo $boot | grep "dasd" > /dev/null
    if [ $? -eq 0 ]; then
        type="ccw"
        boot="$(basename $boot)"
        # strip partition number from dasd device
        boot="$(echo ${boot%[0-9]})"
        id="$(basename $(readlink /sys/block/$boot/device))"
        echo $type > /sys/firmware/reipl/reipl_type
        echo $id > /sys/firmware/reipl/$type/device
    else
        # scsi re-ipl only supported on newer machines
        doshutdown
        exit 0
    fi

    echo $"about to exec shutdown -r"
    exec /sbin/shutdown -r
    exit 0
}

function sysecho () {
    file=$1
    shift
    local i=1
    while [ $i -le 10 ] ; do
        if [ ! -f "$file" ]; then
            sleep 1
            i=$((i+1))
        else
            break
        fi
    done
    [ -f "$file" ] && echo $* > $file
}

function startinetd()
{
    echo
    echo $"Starting sshd to allow login over the network."
    if [ -z "$testing" ]; then
        echo $"Welcome to the anaconda install environment $VERSION for $S390ARCH" > /etc/issue.net
        echo $"Welcome to the anaconda install environment $VERSION for $S390ARCH" > /etc/motd
        echo >> /etc/motd
    fi # testing

    /sbin/sshd
    if [ -z "$RUNKS" ]; then
        echo
        echo $"Connect now to $IPADDR and login as user root to start the installation."
        echo $"E.g. using: ssh -X root@$IPADDR"
        read
        while : ; do
            /bin/sh --login
            [ $? = 0 ] || break
        done
    fi
}

# read file from CMS and write it to /tmp
function readcmsfile() # $1=dasdport $2=filename
{
    local dev
    if [ $# -ne 2 ]; then return; fi
    # precondition: udevd created dasda block device node
    if ! sysecho /proc/cio_ignore "free $1"; then
        echo $"DASD $1 could not be cleared from device blacklist"
        return 1
    fi
    # /proc/cio_ignore won't block on freeing devices until resensing
    # has been completed, so wait until the udev event queue depletes
    # (without udevadm settle we could wait 2 seconds unconditionally)
    #debug ls -laF /dev/.udev
    udevadm settle
    # even though the device might now be online, some of its
    # sysfs attributes might not yet be available
    sleep 1
    # precondition: dasd_eckd_mod driver incl. dependencies loaded,
    #               dasd_mod must be loaded without setting any DASD online
    if [ ${#1} == 3 ]; then
        dev="0.0.0${1}"
    elif [ ${#1} == 4 ]; then
        dev="0.0.${1}"
    fi
    if ! sysecho /sys/bus/ccw/devices/$dev/online 1; then
        echo $"DASD $dev could not be set online"
        return 1
    fi
    if ! cmsfscat -d /dev/dasda -a $2 > /tmp/$2; then
        echo $"Could not read conf file $2 on CMS DASD $1."
    fi
    if ! sysecho /sys/bus/ccw/devices/$dev/online 0; then
        echo $"DASD $dev could not be set offline again"
        return 1
    fi
    # consequences of no more module unload: loader/anaconda can no longer
    # use DASD option to online DASDs and set other DASD parameters!
}

# adaption of the same function in init.c (udevd gets started later)
function createDevices()
{
    awk '{ printf("mknod /dev/%s %s %s %s\n", $1, $2, $3, $4);
      printf("chmod %s /dev/%s\n", $5, $1);
      printf("chown %s /dev/%s\n", $6, $1);
    }' <<EOF | sh
console c 5 1 600 root:root
null c 1 3 666 root:root
zero c 1 5 666 root:root
mem c 1 1 600 root:root
ptmx c 5 2 666 root:root
tty  c 5 0 666 root:root
tty0 c 4 0 600 root:tty
tty1 c 4 1 600 root:tty
random c 1 8 644 root:root
urandom c 1 9 644 root:root
rtc c 10 135 644 root:root
EOF
    # tty handling is different from init.c since s390 does not have all
    for i in 2 3 4 5 6 7 8 9 ; do
        ln -s console /dev/tty$i
    done
    mkdir /dev/pts
    ln -s /proc/self/fd /dev/fd
}

# approximately the main() function of init.c
function init_main() {
    S390ARCH=$(uname -m)
    if [ "$S390ARCH" = "s390" ]; then
        export S390ARCH="S/390"
    else
        export S390ARCH="zSeries"
    fi

    echo
    echo $"Starting the $S390ARCH initrd to configure networking. Version is $VERSION"

    # set up env vars as we do in init.c
    if [ $(uname -m) = "s390x" ]; then
        LD_LIBRARY_PATH=/lib64:/usr/lib64:/usr/X11R6/lib64:/usr/kerberos/lib64:/lib:/usr/lib:/usr/X11R6/lib:/usr/kerberos/lib
    else
        LD_LIBRARY_PATH=/lib:/usr/lib:/usr/X11R6/lib:/usr/kerberos/lib
    fi
    export LD_LIBRARY_PATH

    PATH="$PATH:/usr/bin:/bin:/sbin:/usr/sbin:/mnt/sysimage/bin:/mnt/sysimage/usr/bin:/mnt/sysimage/usr/sbin:/mnt/sysimage/sbin:/mnt/sysimage/usr/X11R6/bin"
    export PATH
    HOME=/
    export HOME
    PYTHONPATH=/tmp/updates
    export PYTHONPATH

    if [ -z "$testing" ]; then

        mount -t proc none /proc

        mount -t tmpfs none /dev
        createDevices
        # udevd req'd by udevadm settle (/dev/.udev/queue)
        # in readcmsfile, dialog_network_table, semantic_check_subchannels.
        # (important: start udevd at the right time, e.g. after setup of /dev)
        echo $"starting udev..."
        udevd --daemon

        mount -t devpts /dev/pts /dev/pts
        mount -t sysfs none /sys
        # remount root fs rw
        mount /dev/root /  -o remount,rw

        # limit output on 3270 console
        # (console_loglevel of 4 is just right to not get driver info,
        #  e.g. from qeth, since that would mix up with the user dialog)
        echo "4 4 1 7" > /proc/sys/kernel/printk

        # make /tmp/ramfs
        mount -t ramfs none /tmp

        ifconfig lo 127.0.0.1 netmask 255.0.0.0
        route add -host 127.0.0.1 dev lo

        echo -e "127.0.0.1\tlocalhost.localdomain localhost localhost4 localhost4.localdomain4" > /etc/hosts
        echo -e     "::1\t\tlocalhost.localdomain localhost localhost6 localhost6.localdomain6" >> /etc/hosts

        # init.c would also fork /sbin/dbus-uuidgen --ensure
        #                    and /sbin/dbus-daemon --system

    fi # testing
}

# from here on accesses to sysfs try to follow
# linux/Documentation/sysfs-rules.txt

### lsznet.raw integration

declare -a nettable

function read_lsznet_output() {
    #local lsznet_output=/tmp/lsznet.raw
    #lsznet.raw > $lsznet_output
    count=0
    local line
    while read line; do
        nettable[$count]="$line"
        count=$((count + 1))
    #done < $lsznet_output
    #rm -f $lsznet_output
    # using the more sophisticated process substitution instead of temp file
    # requires the symlink /dev/fd -> /proc/self/fd => createDevices
    done < <(lsznet)
}

function print_nettable() {
    local fmtstring="%3s %-14s %-7s %-5s %-4s %-6s %-7s %s\n"
    printf "$fmtstring" \
        "NUM" "CARD" "CU" "CHPID" "TYPE" "DRIVER" "IF" "DEVICES"
    local i
    for ((i=0; i < count; i++)); do
        local item cutype chp chpidtype devdrv devname chlist cardtype
        read item cutype chp chpidtype devdrv devname chlist cardtype <<< ${nettable[$i]}
        printf "$fmtstring" \
            $item "$cardtype" $cutype $chp "$chpidtype" $devdrv $devname $chlist
    done
}

function clear_screen() {
    # FIXME: find a way to clear screen despite 3215 line mode terminal
    echo
}

function dialog_network_table() {
    while : ; do
        echo $"Scanning for available network devices..."
        # This may take a long time so we show "progress":
        #( while true; do echo -n "."; sleep 1; done ) &
        #local childpid=$!
        read_lsznet_output
        #kill $childpid
        #echo
        echo $"Autodetection found ${count} devices."
        # count==0: there might still be a blacklist the user wants to clear.
        # do not flood user with long list if there are many devices
        if [ "$count" -le 15 ]; then
            # Show list
            answer=s
        else # [ $count -gt 15 ]
            echo
            while : ; do
                echo $"s) show all, m) manual config:"
                local answer
                read answer
                case $answer in
                    s|m) break ;;
                esac
            done
        fi
        [ "$answer" = "m" ] && break
        # show network table to select network hardware configuration from
        if [ "$count" -gt 0 ]; then
            clear_screen
            print_nettable
            echo
        fi
        # account for possibly ignored common I/O devices
        # cio_wc_bytes is NOT local so it can be re-used outside this function
        cio_wc_bytes=0
        local cio_wc_filename cio_wc_foo
        if [ -f /proc/cio_ignore ]; then
            local cio_wc=$(wc -c /proc/cio_ignore)
            read cio_wc_bytes cio_wc_filename cio_wc_foo <<< "$cio_wc"
            if [ "$cio_wc_bytes" != "0" ]; then
                echo $"Note: There is a device blacklist active! (Clearing might take long)"
                #cat /proc/cio_ignore | tr '\n' ','
                #echo
            else
                if [ "$count" -eq 0 ]; then
                    # count==0 AND no device blacklist => manual mode
                    echo $"Entering manual configuration mode."
                    break
                fi
            fi
        fi
        # selection dialog
        while : ; do
            [ "$count" -gt 0 ] && echo -n $"<num>) use config, "
            [ "$cio_wc_bytes" != "0" ] && echo -n $"c) clear blacklist, "
            echo $"m) manual config, r) rescan, s) shell:"
            local choice
            read choice
            [ -z "$choice" ] && continue
            if [ "$choice" = "s" ]; then
                echo $"Enter 'exit' at the shell prompt to get back to the installation dialog."
                /bin/bash
                continue 2
            fi
            [ "$choice" = "m" ] && break
            [ "$choice" = "r" ] && continue 2
            [ "$cio_wc_bytes" != "0" -a "$choice" = "c" ] && break
            [[ "$choice" =~ ^[[:digit:]]+$ ]]
            case $? in
                0)
                    # string matched the pattern
                    [ "$choice" -ge 1 -a "$choice" -le "$count"  ] && break
                    ;;
                1)
                    # string did not match the pattern
                    continue
                    ;;
                2)
                    echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
                    ;;
                *)
                    echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
                    ;;
            esac
        done
        if [ "$choice" = "c" ]; then
            echo $"Clearing device blacklist..."
            if sysecho /proc/cio_ignore "free all"; then
                cio_wc_bytes=0
                # /proc/cio_ignore won't block on freeing devices
                # until resensing has been completed, so wait until
                # the udev event queue depletes.
                # This may take a long time so we show "progress":
                #( while true; do echo -n "."; sleep 3; done ) &
                #local childpid=$!
                #debug ls -laF /dev/.udev
                udevadm settle
                # (virtual) CTC/A takes some more time to appear in sysfs
                # FIXME: how long to wait? 3 seconds seems to be enough.
                sleep 3
                #kill $childpid
                #echo
                continue
            else
                echo $"Device blacklist could not be cleared"
            fi
        fi
        [ "$choice" = "m" ] && break
        # finally extract config info from selected item
        # array nettable starts at index zero, user input starts at index one
        choice=$((choice - 1))
        local item cutype chp chpidtype devdrv devname chlist cardtype
        read item cutype chp chpidtype devdrv devname chlist cardtype <<< ${nettable[$choice]}
        # $NETTYPE happens to be exactly the network driver name
        if [ "$devdrv" = "ctcm" ]; then
            NETTYPE="ctc"
        else
            NETTYPE=$devdrv
        fi
        SUBCHANNELS=$chlist
        break
    done
    echo
}

declare -r PREFIXFORMAT=[[:xdigit:]]*
declare -r SSIDFORMAT=[0-3]
declare -r BUSIDFORMAT=[[:xdigit:]][[:xdigit:]][[:xdigit:]][[:xdigit:]]
declare -r IDFORMAT=$PREFIXFORMAT.$SSIDFORMAT.$BUSIDFORMAT
declare -r SUBCHANNEL_TYPE_IO=0

. /sbin/controlunits

function cardtype2cleartext() {
    local cardtype=$1
    case $cardtype in
        OSD_10GIG)        echo "OSA card in OSD mode, 10 Gigabit Ethernet" ;;
        OSD_1000)         echo "OSA card in OSD mode, Gigabit Ethernet" ;;
        OSD_100)          echo "OSA card in OSD mode, Fast Ethernet" ;;
        OSD_GbE_LANE)     echo "OSA card in OSD mode, Gigabit Ethernet, LAN Emulation" ;;
        OSD_FE_LANE)      echo "OSA card in OSD mode, Fast Ethernet, LAN Emulation" ;;
        OSD_TR_LANE)      echo "OSA card in OSD mode, Token Ring, LAN Emulation" ;;
        OSD_ATM_LANE)     echo "OSA card in OSD mode, ATM, LAN Emulation" ;;
        OSD_Express)      echo "OSA card in OSD mode, unknown link type" ;;
        HSTR)             echo "OSA card in OSD mode, High Speed Token Ring" ;;
        OSN)              echo "OSA for NCP, ESCON/CDLC bridge" ;;
        HiperSockets)     echo "HiperSockets with CHPID type IQD" ;;
        "GuestLAN QDIO")  echo "GuestLAN based on OSA (QDIO)" ;;
        "GuestLAN Hiper") echo "GuestLAN based on HiperSockets" ;;
        unknown)          echo "other" ;;
        *) echo "unknown"
            echo "l.$LINENO: found unknown card_type, code needs to be fixed" 1>&2
            ;;
    esac
}

# returns true iff running under z/VM
function isVM() {
    local cpu_version=$(cat /proc/cpuinfo |grep "^processor " | head -n1 | sed 's/.*version = \([[:xdigit:]][[:xdigit:]]\).*/\1/' | tr '[:lower:]' '[:upper:]')
    if [ "$cpu_version" = "FF" ]; then
        return 0
    else
        return 1
    fi
}

# watch out: potential error message as side effect
function isLayer2Default() {
    # Read default from sysfs because according to device
    # drivers book there are differences in the default between
    # OSA (l2), hipersockets (l3).
    # This only works here in installer where nobody has overwritten
    # the default setting with another custom value already!
    if [ ! -f /sys/devices/${NETTYPE}/$SCH_R_DEVBUSID/layer2 ]; then
        echo $"Could not read layer mode from sysfs"
        return 1
    fi
    local layer2
    read layer2 < /sys/devices/${NETTYPE}/$SCH_R_DEVBUSID/layer2
    if [ "$layer2" = "1" ]; then
        return 0
    else
        return 1
    fi
}

# returns true iff either LAYER2 has been set to 1 or is the default
# watch out: potential error message as side effect
function isLayer2() {
    case "x$LAYER2" in
        x0) return 1 ;; # layer 3
        x1) return 0 ;; # layer 2
        x)  # LAYER2 is unset or empty => qeth driver default applies.
            isLayer2Default
            return $?
            ;;
        *) echo "l.$LINENO: unknown value \"$LAYER2\" for LAYER2, code needs to be fixed" 1>&2
            return 2 ;;
    esac
}

# returns true iff qeth device $SCH_R_DEVBUSID
# is capable of supporting IPv6
# watch out: potential error message as side effect
function ipv6_capable() {
    [ "$NETTYPE" = "qeth" ] || return 1
    case $cardtype in
        OSD_10GIG|OSD_1000|OSD_100|OSD_Express|HiperSockets|"GuestLAN QDIO")
            return 0 ;;
        OSD_GbE_LANE|OSD_FE_LANE|OSD_TR_LANE|OSD_ATM_LANE) return 1 ;;
        HSTR|OSN|unknown) return 1 ;;
        "GuestLAN Hiper") return 1 ;;
        *) echo $"Unknown card_type to determine IPv6 support"
            return 1 ;;
    esac
}

# sets device online _and_ retrieves DEVICE at the same time
# iucv cannot be set online since it's not based on ccw(group)
function set_device_online() {
    echo $"Activating network device..."
    local sysnettype
    case "${NETTYPE}" in
        qeth) sysnettype=${NETTYPE} ;;
        lcs|ctc) sysnettype=cu3088 ;;
    esac
    if ! [ -f /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/online ]; then
        echo $"Sysfs path to set device online does not exist."
        return 1
    fi
    if ! sysecho /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/online "1"; then
        echo $"Could not set device ($SUBCHANNELS) online"
        return 1
    fi
    local i=1
    while : ; do
        local online
        read online < /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/online
        [ "$online" == "1" ] && break
        sleep 1
        i=$((i+1))
        if [ "$i" -gt 10 ]; then
            echo $"Could not set device ($SUBCHANNELS) online within timeout"
            return 1
        fi
    done
    if [ "$NETTYPE" = "lcs" -o "$NETTYPE" = "ctc" ]; then
        # KH FIXME: Workaround for missing sysfs interface
        #   DEVICE=$(cat /sys/devices/lcs/${SUBCHANNELS//,*/}/if_name)
        # replaced with flexible solution:
        # https://bugzilla.redhat.com/show_bug.cgi?id=204803#c9
        # "sys/bus/ccwgroup/devices/${SUBCHANNEL}/net\:*
        # for lcs after setting online"
        if [ ! -h /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/net:* ]; then
            echo $"Device $SUBCHANNELS does not have required sysfs attribute 'net:*'"
            return 1
        fi
        DEVICE=$(echo /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/net:*)
        DEVICE=${DEVICE//*:/}
        if [ "$DEVICE" = "" ]; then
            echo $"Could not get device name for $SUBCHANNELS"
            return 1
        fi
    else # qeth
        if [ ! -f /sys/devices/qeth/$SCH_R_DEVBUSID/if_name ]; then
            echo $"Device $SUBCHANNELS does not have required sysfs attribute 'if_name'"
            return 1
        fi
        # (device needs to be online to read if_name from sysfs attribute!)
        read DEVICE < /sys/devices/qeth/$SCH_R_DEVBUSID/if_name
        if [ "$DEVICE" = "" ]; then
            echo $"Could not get device name for $SUBCHANNELS"
            return 1
        fi
        if [ -f /sys/devices/qeth/$SCH_R_DEVBUSID/card_type ]; then
            read cardtype < /sys/devices/qeth/$SCH_R_DEVBUSID/card_type
            #debug echo "$cardtype"
            # device is now online and link type will be known
            echo -n $"Detected: "
            cardtype2cleartext "$cardtype"
        else
            echo $"Could not read qeth network card type from sysfs."
        fi
    fi
}

# sets device up and blocks until device appears to be up
function set_device_up() {
    if [ -z "$DEVICE" ]; then
        echo $"Could not determine interface name to bring up device $SUBCHANNELS"
        return 1
    fi
    # Device does not come up fast enough to use "ip" to configure, so block.
    # While OSA come up themselves after setting online,
    # e.g. HiperSockets won't => set them up explicitly for the following check
    debug ip link set up $DEVICE
    local i=1
    while : ; do
        local tst=$(ip -o link show up dev $DEVICE)
        [ -n "$tst" ] && break
        sleep 1
        i=$((i+1))
        if [ "$i" -gt 10 ]; then
            echo $"Could not bring up device $DEVICE within timeout"
            return 1
        fi
    done
    return 0
}

function syntax_check_domainname() {
    # - match against regex adopted from RFC1035,sec.2.3.1 or RFC1034,sec.3.5
    #   (Internationalized Domain Names in Applications (IDNA) [RFC4690]
    #    have to be entered after encoding by punycode [RFC3492])
    [[ "$1" =~ ^[[:alpha:]]([[:alnum:]-]{0,61}[[:alnum:]])?(\\.[[:alpha:]]([[:alnum:]-]{0,61}[[:alnum:]])?)*$ ]]
    case $? in
        0)
            # string matched the pattern
            return 0
            ;;
        1)
            # string did not match the pattern
            echo "$2"
            ;;
        2)
            echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
            ;;
        *)
            echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
            ;;
    esac
    return 1
}

function modprobe_alias() {
    if [ ":$NETTYPE" = ":iucv" ]; then
        echo "alias $DEVICE netiucv" >> /tmp/modprobe.conf
    elif [ ":$NETTYPE" = ":ctc" ]; then
        echo "alias $DEVICE ctcm" >> /tmp/modprobe.conf
    else
        echo "alias $DEVICE $NETTYPE" >> /tmp/modprobe.conf
    fi
    if [ $? -ne 0 ]; then
        echo $"Could not append alias for network device $DEVICE to modprobe.conf"
        return 1
    fi
    return 0
}

function disable_ipv6_autoconf() {
    sysctl -w net.ipv6.conf.all.accept_ra=0 > /dev/null
    sysctl -w net.ipv6.conf.all.accept_redirects=0 > /dev/null
    sysctl -w net.ipv6.conf.all.autoconf=0 > /dev/null
    sysctl -w net.ipv6.conf.default.accept_ra=0 > /dev/null
    sysctl -w net.ipv6.conf.default.accept_redirects=0 > /dev/null
    sysctl -w net.ipv6.conf.default.autoconf=0 > /dev/null
}

function configure_ipv6_address() {
    # device needs to be online
    # arp flag needs to be on for ipv6 over osa because of ndisc.
    # happens automatically by the driver. do NOT mess with default setting.
    #NO#debug ip link set dev $DEVICE arp on
    if ! debug ip -6 address add $IPADDR/$NETMASK dev $DEVICE; then
        echo $"Could net set IPv6 address $IPADDR/$NETMASK for device $DEVICE"
        return 1
    fi
    # network route has been set by above "ip address add" already
    # take care of MTU, which is bundled with ifconfig in the other IPv4 cases
    if [ -n "$MMTU" ]; then
        if ! debug ip link set $DEVICE $MMTU; then
            echo $"Could net set maximum transfer unit ($MMTU) for device $DEVICE"
            return 1
        fi
    fi
    return 0
}

function configure_ipv4_address() {
    # it's IPv4 and we can make use of ipcalc for better usability
    if ipcalc -bmnp $ipcalc_arg > /tmp/ipcalc.$$.out 2> /dev/null; then
        . /tmp/ipcalc.$$.out
    else
        echo $"Could not calculate network address and broadcast address from"
        echo $" IPv4 address $IPADDR and netmask $NETMASK"
        return 1
    fi
    rm /tmp/ipcalc.$$.out
    # device needs to be online
    if ! debug ifconfig $DEVICE $IPADDR $MMTU netmask $NETMASK broadcast $BROADCAST; then
        echo $"Could not set IPv4 address $IPADDR for device $DEVICE"
        echo $" with network mask $NETMASK and broadcast address $BROADCAST"
        [ -n "$MMTU" ] && echo $" and maximum transfer unit: $MMTU"
        return 1
    fi
    # This network route is already there after ifconfig!
    #if ! debug route add -net $NETWORK netmask $NETMASK dev $DEVICE; then
    #    echo $"Could not add network route to $NETWORK/$NETMASK on device $DEVICE"
    #    return 1
    #fi
    return 0
}

function handle_mtu() {
    # don't ask for MTU, but use it if it has been set in the .parm file
    # don't overwrite MMTU if it has been set for CTC
    [ -n "$MTU" -a -z "$MMTU" ] && MMTU="mtu $MTU"
}

function rollback_config() {
    # each transaction to roll back may fail, if previous setup has not
    # made progress that far to reach a certain transation
    # => error output is misleading and should be avoided
    [ -n "$DEVICE" ] && tv ip -4 route flush default dev $DEVICE
    [ -n "$DEVICE" ] && tv ip -6 route flush default dev $DEVICE
    # address flush seems to be effective for all address families
    [ -n "$DEVICE" ] && ip address flush dev $DEVICE
    # iucv device needs to be down before removal
    [ -n "$DEVICE" ] && ip link set down $DEVICE &> /dev/null
    if [ -n "$NETTYPE" ]; then
        if [ "$NETTYPE" = "iucv" ]; then
            if [ -n "$DEVICE" ]; then
                sysecho /sys/bus/iucv/drivers/netiucv/remove $DEVICE
            fi
        else # "$NETTYPE" != "iucv"
            if [ -n "$SCH_R_DEVBUSID" ]; then
                local sysnettype
                case "${NETTYPE}" in
                    qeth) sysnettype=${NETTYPE} ;;
                    lcs|ctc) sysnettype=cu3088 ;;
                esac
                [ -f /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/online ] && \
                    sysecho /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/online "0"
                [ -f /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/ungroup ] && \
                    sysecho /sys/devices/${sysnettype}/$SCH_R_DEVBUSID/ungroup "1"
            fi
        fi
    fi
    [ -z "$mtu_was_set" ] && unset MTU
    [ -z "$mmtu_was_set" ] && unset MMTU
    [ -z "$vswitch_was_set" ] && unset VSWITCH
    # prevent possible reuse of an old DEVICE on restarting dialog
    unset DEVICE
}

### workflow helper functions

# workflow ideas:
# - setting/applying single configuration steps right away save us explicit
#   syntactical & semantic checks PLUS we get direct feedback on error
# - check error level of forked external programs and react on errors

unset reenter
unset redoitem
unset interaction_happened

function reenter() {
    [ -z "$reenter" ] && return 1
    # reenter menu should only be shown if NOT redoing item
    if [ -n "$redoitem" ]; then
        # unset redoitem # wrong => do NOT do this here
        return 1
    fi
    return 0
}

function reenter_menu() {
    local oldvalue=$1
    interaction_happened="yes"
    # unsetting input here is not sufficient, since reenter_menu
    # is not called for predefined parameters
    # which then might get assigned a previous old input of another parameter!
    #unset input
    reenter || return 0
    # don't present reenter menu for empty parameters
    # (currently ignoring parameters that are allowed to be empty!)
    # this could be improved by checking if variable has been set/defined
    #[ -z "$1" ] && return 0
    while : ; do
        if [ -n "$helptext" ]; then
            echo $"0) default is previous \"$oldvalue\", 1) new value, ?) help"
        else
            echo $"0) default is previous \"$oldvalue\", 1) new value"
        fi
        # uncoded alternative: 2) skip parameter
        local answer
        read answer
        [ -z "$answer" ] && return 1
        case $answer in
            0) return 1 ;;
            1)  # Deciding to enter new value gets user out of reenter-mode
                # temporarily for this parameter.
                # To put it differently: redoing does NOT present old values.
                redoitem="yes"
                echo -n $"new value: "
                return 0
                ;;
            "?") input="?"
                return 1
                ;;
        esac
    done
}

function workflow_item_menu() {
    local noredo=$1
    # default is to continue if running kickstart to prevent interaction
    [ -n "$RUNKS" ] && return 0
    interaction_happened="yes"
    while : ; do
        unset redoitem
        if [ "$noredo" = "noredo" ]; then
            echo $"1) continue, 2) restart dialog, 3) halt, 4) shell"
        else
            echo $"0) redo this parameter, 1) continue, 2) restart dialog, 3) halt, 4) shell"
        fi
        local answer
        read answer
        case $answer in
            0) [ "$noredo" = "noredo" ] && continue
                redoitem="yes"
                continue 2
                ;;
            1) return 0 ;; # can be used to break at caller on ignore
            2) reenter="yes"
                rollback_config
                continue 3
                ;;
            3) tv doshutdown
                exit 0
                ;;
            4) echo $"Enter 'exit' at the shell prompt to get back to the installation dialog."
                /bin/bash
                if [ "$noredo" != "noredo" ] && [ -n "$question_prefix" ]; then
                    $question_prefix
                    echo
                fi
                ;; # stay in workflow item menu
        esac
    done
}

# input variables: PARMNAME, question_prefix, question_choices,
#                  "options" ...
# output variables: $question_prefix, $helptext
# modifies: the variable named $PARMNAME, $OPTIND
function ask() {
    [ $# -lt 3 ] && echo "l.$LINENO: too few arguments (<3), please fix calling code." 1>&2
    local PARMNAME=$1
    shift
    question_prefix=$1
    shift
    local question_choices=$1
    shift
    local exception
    local syntax_check
    unset helptext
    local handle
    local finish
    local optname
    OPTIND=1
    while getopts ":e:s:h:c:f:" optname; do
        case $optname in
            e) exception=$OPTARG ;;
            s) syntax_check=$OPTARG ;;
            h) helptext=$OPTARG ;;
            c) handle=$OPTARG ;;
            f) finish=$OPTARG ;;
            "?") ;; # ignore invalid option
            :) echo "l.$LINENO: Missing parameter to option -$OPTARG" 1>&2 ;;
        esac
    done
    while : ; do
        unset input
        local input
        # actually ask question if one of the following is true:
        # - $PARMNAME parameter has not been set yet, e.g. not in parm file
        # - on 2nd and further attempts, i.e. redoing the parameter
        # - on having restarted the whole dialog
        # describing the same from another viewpoint:
        # - if $PARMNAME has been set, try to check syntax and apply
        # - on redo, $PARMNAME has been set and reenter is false,
        #   but still ask question again
        # - on reenter, $PARMNAME might have been set, but still ask question
        if [ -z "${!PARMNAME}" -o -n "$redoitem" -o -n "$reenter" ]; then
            # one empty line to separate parameter questions from each other
            echo
            $question_prefix
            if reenter; then
                echo
            else
                $question_choices
            fi
            # on reenter, give choice between old value and entering new one
            reenter_menu ${!PARMNAME} && read input \
                && [ "$input" != "?" ] && eval ${PARMNAME}=\$input
            # escaping the $ in the RHS of the eval statement makes it safe
        fi
        if [ -n "$helptext" ] && [ "$input" = "?" ]; then
            $helptext
            continue
        fi
        # optional: default or exceptional handling
        [ -n "$exception" ] && $exception
        if [ -n "$syntax_check" -a -z "$handle" ]; then
            # some parameters have only syntax check (and deferred config):
            if $syntax_check; then
                break
            else
                workflow_item_menu && break
            fi
        elif [ -n "$syntax_check" -a -n "$handle" ]; then
            # most common parameters have syntax and configuration:
            # user might still continue on syntax error
            $syntax_check || workflow_item_menu
            # optional: actual configuration
            if $handle; then
                # parmname has been configured successfully
                break
            else
                # user might still continue on configuration failure
                workflow_item_menu && break
            fi
        elif [ -n "$finish" ]; then
            # few parameters need special handling done by their own function:
            $finish
        else
            echo $"Unsupported calling of ask function, please fix calling code"
        fi
    done # PARMNAME
    # disable potential temporary redoing-mode during reenter-mode
    unset redoitem
}

### NETTYPE

function syntax_check_nettype() {
    # - NETTYPE \in {qeth,lcs,ctc,iucv}
    [[ "$NETTYPE" =~ (^qeth$)|(^lcs$)|(^ctc$)|(^iucv$) ]]
    case $? in
        0)
            # string matched the pattern
            if [ "$NETTYPE" = "iucv" ] && ! isVM; then
                echo $"IUCV network type is only available under z/VM (NETTYPE)."
                return 1
            fi
            return 0
            ;;
        1)
            # string did not match the pattern
            ;;
        2)
            echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
            ;;
        *)
            echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
            ;;
    esac
    echo $"Incorrect format or value for network type (NETTYPE): $NETTYPE"
    return 1
}

function question_prefix_nettype() {
    echo -n $"Network type"
}

function question_choices_nettype() {
    if isVM; then
        echo $" (qeth, lcs, ctc, iucv, ? for help). Default is qeth:"
    else
        echo $" (qeth, lcs, ctc, ? for help). Default is qeth:"
    fi
}

function helptext_nettype() {
    echo $" Help text for network type:"
    echo $"  qeth: OSA-Express Fast Ethernet, Gigabit Ethernet (including 1000Base-T),"
    echo $"        High Speed Token Ring, and ATM (running Ethernet LAN emulation)"
    echo $"        features in QDIO mode."
    echo $"        [default]"
    echo $"  lcs:  OSA-2 Ethernet/Token Ring, OSA-Express Fast Ethernet in non-QDIO mode,"
    echo $"        OSA-Express High Speed Token Ring in non-QDIO mode and Gigabit Ethernet"
    echo $"        in non-QDIO mode."
    echo $"  ctc:  Deprecated, useful for migration."
    isVM && echo $"  iucv: Deprecated, useful for migration."
}

function exception_nettype() {
    # - default is qeth since it should be common
    if [ -z "$NETTYPE" ]; then
        NETTYPE=qeth
        break
    fi
}

function finish_nettype() {
    if syntax_check_nettype; then
        break
    else
        # necessary parts which would otherwise be done by workflow_item_menu
        interaction_happened="yes"
        redoitem="yes"
    fi
}

function do_nettype() {
    ask NETTYPE \
        question_prefix_nettype question_choices_nettype \
        -h helptext_nettype -e exception_nettype -f finish_nettype
}

### CHANDEV

function do_chandev() {
    echo
    echo $"The CHANDEV variable isn't used anymore, please update your "
    echo $".parm or the .conf file to use NETTYPE, SUBCHANNELS, etc. instead."
    echo
}

### SUBCHANNELS

function syntax_check_subchannels() {
    SUBCHANNELS=$(echo $SUBCHANNELS | tr ABCDEF abcdef)
    # - make subchannel question dependent on NETTYPE (2 vs. 3 subchannels)
    if [ "$NETTYPE" = "qeth" ]; then
        # - match against regex, depending on qeth
        [[ "$SUBCHANNELS" =~ ^[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4},[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4},[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4}$ ]]
    else
        # - match against regex, depending on lcs/ctc
        [[ "$SUBCHANNELS" =~ ^[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4},[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4}$ ]]
    fi
    case $? in
        0)
            # string matched the pattern
            return 0
            ;;
        1)
            # string did not match the pattern
            echo $"Incorrect format for channels (SUBCHANNELS): $SUBCHANNELS"
            ;;
        2)
            echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
            ;;
        *)
            echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
            ;;
    esac
    return 1
}

function semantic_check_subchannels() {
    local subch_count
    if [ "$NETTYPE" = "qeth" ]; then
        subch_count=3
    else
        subch_count=2
    fi
    # done: make subchannel handling more robust by not relying on REMATCH
    local -a subch_array
    IFS=,
    read -a subch_array <<< "indexzero,$SUBCHANNELS"
    unset IFS
    local i
    local all_subch_good=0
    for ((i=1; i <= $subch_count; i++)); do
        local devbusid=${subch_array[$i]}
        # remember first subchannel for potential undo of ccwgroup
        # (via /sys/devices/qeth/$SCH_R_DEVBUSID/ungroup)
        [ "$i" -eq 1 ] && SCH_R_DEVBUSID=$devbusid
        local prefix ssid devno foo
        IFS=.
        read prefix ssid devno foo <<< "$devbusid"
        unset IFS
        local dev_p=$(echo /sys/devices/css$prefix/$IDFORMAT/$devbusid)
        # - check for existence of devnos in sysfs
        if [ ! -d "$dev_p" -a "$cio_wc_bytes" != "0" ]; then
            # - try to free from /proc/cio_ignore if they don't exist
            echo $"Device $devbusid not present, trying to clear from blacklist and resense..."
            if sysecho /proc/cio_ignore "free $devbusid"; then
                # /proc/cio_ignore won't block on freeing devices
                # until resensing has been completed, so wait until
                # the udev event queue depletes (without udevadm settle we
                # could wait 2 seconds unconditionally)
                #debug ls -laF /dev/.udev
                udevadm settle
                # even though the device might now be online, some of its
                # sysfs attributes (e.g. cutype) might not yet be available
                sleep 1
            else
                echo $"Device $devbusid could not be cleared from device blacklist"
            fi
        fi
        # reevaluate since globbing might not have worked before device existed
        dev_p=$(echo /sys/devices/css$prefix/$IDFORMAT/$devbusid)
        if [ ! -d "$dev_p" ]; then
            echo $"Device $devbusid does not exist"
            all_subch_good=1
            continue
        fi
        # devno does exist now
        local subch_p=${dev_p%/*}
        local subch=${subch_p##*/}
        # filter definitely unusable subchannels ...
        # - check for subchannel type I/O
        if [ -f $subch_p/type ]; then
            local type
            read type < $subch_p/type
            if [ "$type" != "$SUBCHANNEL_TYPE_IO" ]; then
                echo $"Channel $subch (device $devbusid) is not of type I/O"
                all_subch_good=1
                continue
            fi
        fi
        # - check for correct CU type/model, depending on qeth/lcs/ctc
        if [ ! -f $dev_p/cutype ]; then
            echo $"Device $devbusid does not have required sysfs attribute 'cutype'"
            all_subch_good=1
            continue
        fi
        local cutype
        read cutype < $dev_p/cutype
        if search_cu $cutype; then
            local driver
            if [ "$NETTYPE" = "ctc" ]; then
                driver="ctcm"
            else
                driver=$NETTYPE
            fi
            if [ "${CU_DEVDRV[$cu_idx]}" != "$driver" ]; then
                echo $"Device $devbusid has control unit type $cutype,"
                echo $" which does not match your selected network type $NETTYPE"
                all_subch_good=1
                continue
            fi
        else
            echo $"Device $devbusid has control unit type $cutype which is unknown"
            all_subch_good=1
            continue
        fi
        # read CHPIDs information about subchannels
        if [ ! -f $subch_p/chpids ]; then
            echo $"Channel $subch (device $devbusid) does not have required sysfs attribute 'chpids'"
            all_subch_good=1
            continue
        fi
        local chpid_list
        read chpid_list < $subch_p/chpids
        local -a chpids
        read -a chpids <<< "$chpid_list"
        if [ ${#chpids[@]} -ne 8 ]; then
            echo $"sysfs reported ${#chpids[@]} CHPIDs instead of expected 8, code needs fix"
        fi
        if [ ! -f $subch_p/pimpampom ]; then
            echo $"Channel $subch (device $devbusid) does not have required sysfs attribute 'pimpampom'"
            all_subch_good=1
            continue
        fi
        local pim pam pom foo
        read pim pam pom foo < $subch_p/pimpampom
        local pimchpidZ=""
        for ((chp=0; chp < 8; chp++)); do
            local mask=$((0x80 >> chp))
            if (( 0x$pim & $mask )); then
                pimchpidZ=${pimchpidZ}${chpids[chp]}
            else
                pimchpidZ=${pimchpidZ}"ZZ"
            fi
        done
        local pimchpids=${pimchpidZ//ZZ/}
        if [ "x$pimchpids" == "x" ]; then
            echo $"Channel $subch (device $devbusid) does not have any installed channel path"
            all_subch_good=1
            continue
        fi
        # compare parts of different subchannels for required matches
        if [ "$i" -eq 1 ]; then
            # remember parts of first subchannel for comparison
            local sch_r_prefix=$prefix
            local sch_r_ssid=$ssid
            local sch_r_devno=$devno
            local sch_r_pimchipidZ=$pimchpidZ
            local sch_r_cutype=$cutype
        else
            local comparison=0
            # $sch_r_... might be empty if first channel was wrong
            # => be sure to quote all variable accesses in test statements.
            # - all subchannels must be of same CU type/model
            if [ "$cutype" != "$sch_r_cutype" ]; then
                echo $"Device $devbusid does not have the same control unit type as device $SCH_R_DEVBUSID"
                comparison=1
            fi
            # - all subchannels must have same CHPIDs
            if [ "$pimchpidZ" != "$sch_r_pimchipidZ" ]; then
                echo $"Device $devbusid does not have the same CHPIDs as device $SCH_R_DEVBUSID"
                comparison=1
            fi
            # - all subchannels should have same prefix & ssid ?
            if [ "$prefix" != "$sch_r_prefix" \
                -o "$ssid" != "$sch_r_ssid" ]; then
                echo $"Device $devbusid does not have the same prefix and subchannel set ID as device $SCH_R_DEVBUSID"
                comparison=1
            fi
            if [ "$i" -eq 2 ]; then
                local sch_w_devbusid=$devbusid
                local sch_w_devno=$devno
                # TODO: not true for CTCM => relax
                # - write_devbusid == read_devbusid+1
                if [ $((0x$devno)) -ne $((0x$sch_r_devno + 1)) ]; then
                    echo $"Device bus ID of write channel (dev $devbusid) must be one larger than"
                    echo $" that of read channel (dev $SCH_R_DEVBUSID)"
                    comparison=1
                fi
            elif [ "$i" -eq 3 ]; then
                # check data subchannel unequal to read/write subchannel
                # (also seems to be handled by ccwgroup kernel subsystem)
                if [ "$devbusid" = "$sch_w_devbusid" \
                    -o "$devbusid" = "$SCH_R_DEVBUSID" ]; then
                    echo $"Device bus ID of data channel (dev $devbusid) must be different to that of"
                    echo $" read channel ($SCH_R_DEVBUSID) and write channel ($sch_w_devbusid)"
                    comparison=1
                fi
            fi
            if [ "$comparison" != 0 ]; then
                all_subch_good=1
                continue
            fi
        fi
        # filter potentially good subchannels ...
        if [ -h $dev_p/group_device ]; then
            echo $"Device $devbusid is already in a ccwgroup and thus unavailable"
            all_subch_good=1
            continue
        fi
        if [ ! -f $dev_p/online ]; then
            echo $"Device $devbusid does not have required sysfs attribute 'online'"
            all_subch_good=1
            continue
        fi
        local online
        read online < $dev_p/online
        if [ "$online" = "1" ]; then
            echo $"Device $devbusid is already in use and thus unavailable"
            all_subch_good=1
            continue
        fi
        # - check availability
        if [ ! -f $dev_p/availability ]; then
            echo $"Device $devbusid does not have required sysfs attribute 'availability'"
            all_subch_good=1
            continue
        fi
        local availability
        read availability < $dev_p/availability
        if [ "$availability" != "good" ]; then
            echo $"Device $devbusid is not available but '$availiability'"
            all_subch_good=1
            continue
        fi

    done # for ((i=1; i <= $subch_count; i++))
    if [ "$all_subch_good" = "0" ]; then
        return 0
    fi
    return 1
}

function handle_subchannels() {
    # - try to establish ccwgroup right here and fail out on error
    local driver
    if [ "$NETTYPE" = "ctc" ]; then
        driver="ctcm"
    else
        driver=$NETTYPE
    fi
    if sysecho /sys/bus/ccwgroup/drivers/${driver}/group "$SUBCHANNELS"; then
        case "$NETTYPE" in
            qeth)
                # Just preliminary card_type info until device goes online!
                # In fact it seems enough to separate OSA from HiperSockets.
                if [ -f /sys/devices/qeth/$SCH_R_DEVBUSID/card_type ]; then
                    read cardtype < /sys/devices/qeth/$SCH_R_DEVBUSID/card_type
                else
                    echo $"Could not read qeth network card type from sysfs."
                fi
                ;;
            ctc|lcs)
                if [ -f /sys/devices/cu3088/$SCH_R_DEVBUSID/type ]; then
                    local type
                    read type < /sys/devices/cu3088/$SCH_R_DEVBUSID/type
                    [ "$type" = "CTC/A" ] && \
                        type="channel-to-channel adapter (CTC/A)"
                    echo $"Detected: $type"
                else
                    echo $"Could not read ctc network card type from sysfs."
                fi
                ;;
        esac
        return 0
    else
        echo $"Channels $SUBCHANNELS could not be grouped"
    fi
    return 1
}

function question_prefix_subchannels() {
    if [ "$NETTYPE" = "qeth" ]; then
        echo -n $"Read,write,data channel"
    else
        echo -n $"Read,write channel"
    fi
}

function question_choices_subchannels() {
    if [ "$NETTYPE" = "qeth" ]; then
        echo $" (e.g. 0.0.0300,0.0.0301,0.0.0302 or ? for help)."
    else
        echo $" (e.g. 0.0.0600,0.0.0601 or ? for help)"
    fi
}

function helptext_subchannels() {
    if [ "$NETTYPE" = "qeth" ]; then
        echo $" Help text for qeth channels:"
        echo $"  Enter the device bus ID of your CCW devices."
        echo $"  QETH needs three channels for read, write, and data,"
        echo $"  e.g. 0.0.0300,0.0.0301,0.0.0302"
    else
        echo $" Help text for lcs/ctc channels:"
        echo $"  Enter the device bus ID of your CCW devices."
        echo $"  CTC/ESCON and LCS need two channels for read and write,"
        echo $"  e.g. 0.0.0600,0.0.0601 will configure the CTC or ESCON interface"
        echo $"  with the channels 0x600 and 0x601"
    fi
}

function finish_subchannels() {
    syntax_check_subchannels || workflow_item_menu
    # continuing on syntax error is doomed to fail,
    # since handle_subchannels relies on the regex-based strict parsing
    # in syntax_check_subchannels which does not match anything then
    # news: relaxed by splitting semantic check and actual handling
    semantic_check_subchannels || workflow_item_menu
    if handle_subchannels; then
        break
    else
        workflow_item_menu && break
    fi
}

function do_subchannels() {
    ask SUBCHANNELS \
        question_prefix_subchannels question_choices_subchannels \
        -h helptext_subchannels -f finish_subchannels
}

### PORTNAME (qeth)

function syntax_check_portname() {
    # - 1-8 characters, we convert it to upper case
    PORTNAME=$(echo $PORTNAME | tr '[:lower:]' '[:upper:]')
    local portname_len=${#PORTNAME}
    if [ "$portname_len" -ge 1 -a "$portname_len" -le 8 ]; then
        return 0
    fi
    echo $"Incorrect string length [1..8] for portname (PORTNAME): $PORTNAME"
    return 1
}

function handle_portname() {
    [ -n "$PORTNAME" ] || return 0
    # - try to set portname right here w/ error handling
    if sysecho /sys/devices/${NETTYPE}/$SCH_R_DEVBUSID/portname "$PORTNAME"; then
        return 0
    else
        echo $"Portname '$PORTNAME' could not be configured for $SUBCHANNELS"
    fi
    return 1
}

function hint_portname() {
    if [ -f /sys/devices/${NETTYPE}/$SCH_R_DEVBUSID/portname ]; then
        local pname_hint
        read pname_hint < /sys/devices/${NETTYPE}/$SCH_R_DEVBUSID/portname
        if [ "$pname_hint" = "no portname required" ]; then
            echo $"  * Your configuration does not require a portname. *"
        fi
    fi
}

function question_prefix_portname(){
    echo -n $"Portname"
}

function question_choices_portname(){
    echo $" (1..8 characters, or ? for help). Default is no portname:"
}

function helptext_portname(){
    echo $" Help text for portname:"
    # updated text describing when portname is obsolete;
    # taken from:
    # SA22-7935-09, Open Systems Adapter-Express Customer's
    #   Guide and Reference, 10th ed. May 2008, IBM, p.17f.
    # SC33-8411-00, Device Drivers, Features, and Commands,
    #   1st ed. May 2008, IBM, p.116.
    echo $"  Portname of the OSA-Express feature in QDIO mode and z/VM Guest LAN."
    echo $"  This parameter is optional with:"
    echo $"   - z/VM 4.4.0 or z/VM 4.3.0 with APARs VM63308 and PQ73878"
    echo $"   - z800, z900 with >= Driver 3G - EC stream J11204, MCL032 (OSA level 3.33)"
    echo $"   - z890, z990, z9, z10 mainframes"
    hint_portname
    echo $"  If portname is used, all operating systems sharing port must use same name."
    echo $"  Input empty string if you don't want to enter a portname. [default]"
}

function exception_portname(){
    [ -z "$PORTNAME" ] && break
}

function do_portname() {
    ask PORTNAME \
        question_prefix_portname question_choices_portname \
        -h helptext_portname \
        -e exception_portname -s syntax_check_portname -c handle_portname
}

### PORTNO (qeth)

function syntax_check_qeth_portno() {
    case $PORTNO in
        0|1)
            return 0
            ;;
    esac
    echo $"Incorrect format or value for relative port number (PORTNO): $PORTNO"
    return 1
}

function handle_qeth_portno() {
    if sysecho /sys/devices/qeth/$SCH_R_DEVBUSID/portno "$PORTNO"; then
        return 0
    fi
    echo $"Could not configure relative port number $PORTNO for $SUBCHANNELS"
    return 1
}

function question_prefix_portno() {
    echo -n $"Relative port number for OSA"
}

function question_choices_portno() {
    echo $" (0, 1, or ? for help). Default is 0:"
}

function helptext_portno() {
    echo $" Help text for relative port number for OSA with 2 ports per CHPID:"
    echo $"  This applies to:"
    echo $"   - OSA-Express3 Gigabit Ethernet on z10 systems"
    echo $"   - OSA-Express ATM on zSeries 800 and 900 systems"
    echo $"  0 for relative port number 0 [default]"
    echo $"  1 for relative port number 1"
    echo $"  Input empty string to not modify the default configuration."
}

function exception_portno() {
    # Writing portno of e.g. hipersockets device fails.
    # Therefore, do not configure on empty default value.
    [ -z "$PORTNO" ] && break
}

function do_portno() {
    ask PORTNO \
        question_prefix_portno question_choices_portno \
        -h helptext_portno -e exception_portno \
        -s syntax_check_qeth_portno -c handle_qeth_portno
}

### LAYER2

function syntax_check_layer2() {
    # - $LAYER2 \in {0,1}
    case $LAYER2 in
        0|1)
            return 0
            ;;
    esac
    echo $"Incorrect format or value for layer2 mode (LAYER2): $LAYER2"
    return 1
}

function handle_layer2() {
    [ "$NETTYPE" == "qeth" ] || return 0
    [ -n "$LAYER2" ] || return 0
    # - try to set layer2 mode right here w/ error handling
    if sysecho /sys/devices/${NETTYPE}/$SCH_R_DEVBUSID/layer2 "$LAYER2"; then
        return 0
    else
        echo $"Layer2 mode '$LAYER2' could not be configured for $SUBCHANNELS"
    fi
    return 1
}

function question_prefix_layer2() {
    echo -n $"Layer mode"
}

function question_choices_layer2() {
    echo -n $" (0 for layer3, 1 for layer2, or ? for help)."
    if [ "$isLayer2Default" = "yes" ]; then
        echo $" Default is 1:"
    else
        echo $" Default is 0:"
    fi
}

function helptext_layer2() {
    echo $" Help text for OSA mode of operation: layer 2 vs. layer 3"
    if [ "$isLayer2Default" = "yes" ]; then
        echo $"  0 for layer 3 mode (may not work with dhcp, tcpdump, etc.)"
        echo $"  1 for layer 2 mode [default]"
    else
        echo $"  0 for layer 3 mode [default] (may not work with dhcp, tcpdump, etc.)"
        echo $"  1 for layer 2 mode"
    fi
}

function exception_layer2() {
    if [ -z "$LAYER2" ]; then
        isLayer2Default && LAYER2=1 || LAYER2=0
        # do not break, always apply, default may differ from online layer mode
        #break
    fi
}

function do_layer2() {
    isLayer2Default && isLayer2Default=yes || isLayer2Default=no
    ask LAYER2 \
        question_prefix_layer2 question_choices_layer2 \
        -h helptext_layer2 -e exception_layer2 \
        -s syntax_check_layer2 -c handle_layer2
}

### MACADDR

function syntax_check_macaddr() {
    # - match against regex
    [[ "$MACADDR" =~ ^[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]$ ]]
    case $? in
        0)
            # string matched the pattern
            return 0
            ;;
        1)
            # string did not match the pattern
            echo $"Incorrect format for mac address (MACADDR): $MACADDR"
            ;;
        2)
            echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
            ;;
        *)
            echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
            ;;
    esac
    return 1
}

function handle_macaddr() {
    # - try to set macaddr right here w/ error handlg.
    # device needs to be online
    if debug ifconfig $DEVICE hw ether $MACADDR; then
        return 0
    fi
    echo $"MAC address $MACADDR could not be configured for"
    echo $" $SUBCHANNELS (network device $DEVICE)"
    return 1
}

function question_prefix_macaddr() {
    echo -n $"Unique MAC address"
}

function question_choices_macaddr() {
    macaddr_default=$(ifconfig $DEVICE | grep 'HWaddr' | sed 's/.*HWaddr \([[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]:[[:xdigit:]][[:xdigit:]]\).*/\1/')
    echo $" (e.g. 02:00:00:00:00:00, ? for help). Default is $macaddr_default:"
}

function helptext_macaddr() {
    echo $" Help text for MAC address:"
    if [ -z "${cardtype//OSD_*/}" ]; then
        echo $"  For real OSA in layer 2 mode, a random MAC address is automatically assigned."
    else
        echo $"  If connecting to a layer 2 VSWITCH, a MAC address is automatically assigned."
    fi
    echo $"  You may accept the automatic MAC address with an empty input. [default]"
    echo $"  If the automatic address is not unique, please provide a MAC address."
    [ -z "${cardtype//OSD_*/}" ] && \
        echo $"  For real OSA, the provided address must be different from that of the OSA."
    echo $"  You may override the automatic MAC address with non-empty input."
    echo $"  An example MAC address would be: 02:00:00:00:00:00"
}

function exception_macaddr() {
    if [ -z "$MACADDR" ]; then
        if [ -z "${cardtype//OSD_*/}" ]; then
            # keep random default MAC address of real OSA,
            # so the OSA comes up with the same MAC each time in the future
            MACADDR=$macaddr_default
        else
            # virtual OSA in layer2 is GuestLAN or VSWITCH
            VSWITCH=1
        fi
        break
    fi
}

function do_macaddr() {
    ask MACADDR \
        question_prefix_macaddr question_choices_macaddr \
        -h helptext_macaddr -e exception_macaddr \
        -s syntax_check_macaddr -c handle_macaddr
}

### CTCPROT

function syntax_check_ctcprot() {
    case "x$CTCPROT" in
        x|x0)
            unset CTCPROT
            return 0
            ;;
        x1|x3)
            return 0
            ;;
        x2)
            echo $"CTC tty's are not usable for this installation (CTCPROT)"
            ;;
        *)
            echo $"Incorrect format or value for CTC protocol (CTCPROT): $CTCPROT"
            ;;
    esac
    return 1
}

function handle_ctcprot() {
    [ -n "$CTCPROT" ] || return 0
    if sysecho /sys/devices/cu3088/${SCH_R_DEVBUSID}/protocol "$CTCPROT"; then
        return 0
    fi
    echo $"Could not configure CTC protocol $CTCPROT for $SUBCHANNELS"
    return 1
}

function question_prefix_ctcprot() {
    echo -n $"CTC protocol"
}

function question_choices_ctcprot() {
    echo $" (0, 1, 3, or ? for help). Default is 0:"
}

function helptext_ctcprot() {
    echo $" Help text for CTC protocol:"
    echo $"  Protocol which should be used for the CTC interface"
    echo $"  0 for compatibility with p.e. VM TCP service machine [default]"
    echo $"  1 for enhanced package checking for Linux peers"
    echo $"  3 for compatibility with OS/390 or z/OS peers"
}

function do_ctcprot() {
    ask CTCPROT \
        question_prefix_ctcprot question_choices_ctcprot \
        -h helptext_ctcprot -s syntax_check_ctcprot -c handle_ctcprot
}

### PORTNAME (LCS portno)

function syntax_check_lcs_portno() {
    [[ "$PORTNAME" =~ ^[[:digit:]]+$ ]]
    case $? in
        0)
            # string matched the pattern
            return 0
            ;;
        1)
            # string did not match the pattern
            ;;
        2)
            echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
            ;;
        *)
            echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
            ;;
    esac
    echo $"Incorrect format for LCS port number (PORTNAME): $PORTNAME"
    return 1
}

function handle_lcs_portno() {
    [ -n "$PORTNAME" ] || return 0
    if sysecho /sys/devices/cu3088/$SCH_R_DEVBUSID/portno "$PORTNAME"; then
        return 0
    fi
    echo $"Could not configure relative port number $PORTNAME for $SUBCHANNELS"
    return 1
}

function question_prefix_lcs_portno() {
    echo -n $"Relative port number of your LCS device"
}

function question_choices_lcs_portno() {
    echo $" (number or ? for help). Default is 0:"
}

function helptext_lcs_portno() {
    echo $" Help text for relative port number of LCS device:"
    echo $"  Required for OSA-Express ATM cards only."
}

function exception_lcs_portno() {
    [ -z "$PORTNAME" ] && break
}

function do_lcs_portno() {
    # LCS portno and QETH portname share the parameter variable PORTNAME.
    # For compatibility with existing parm files we keep this scheme.
    ask PORTNAME \
        question_prefix_lcs_portno question_choices_lcs_portno \
        -e exception_lcs_portno \
        -h helptext_lcs_portno -s syntax_check_lcs_portno -c handle_lcs_portno
}

### PEERID

function syntax_check_peerid() {
    if [ "${#PEERID}" -lt 0 -o "${#PEERID}" -gt 8 ]; then
        echo $"Incorrect string length [0..8] for IUCV connection to peer (PEERID): $PEERID"
        return 1
    fi
    PEERID=$(echo $PEERID | tr '[:lower:]' '[:upper:]')
    [[ "$PEERID" =~ ^[[:alnum:]$]{0,8}$ ]]
    case $? in
        0)
            # string matched the pattern
            return 0
            ;;
        1)
            # string did not match the pattern
            ;;
        2)
            echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
            ;;
        *)
            echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
            ;;
    esac
    echo $"Incorrect format for IUCV connection to peer (PEERID): $PEERID"
    return 1
}

function handle_peerid() {
    if ! sysecho /sys/bus/iucv/drivers/netiucv/connection "$PEERID"; then
        echo $"Could not create new IUCV connection to peer $PEERID"
        return 1
    fi
    # find netiucv with proper guest user ID in
    # /sys/bus/iucv/drivers/netiucv/netiucv[0-9]+/user
    local userpath
    while read userpath; do
        local user
        read user < $userpath
        [ "$user" = "$PEERID" ] && break
    done < <(ls -1 /sys/devices/iucv/netiucv[0-9]*/user 2> /dev/null)
    if [ "$user" != "$PEERID" ]; then
        echo $"Could not find configured connection to peer $PEERID"
        return 1
    fi
    local netiucv=${userpath%%/user}
    netiucv=${netiucv##*/}
    if [ "$netiucv" = "" ]; then
        echo $"Could not get netiucv instance for peer $PEERID"
        return 1
    fi
    if [ ! -h /sys/devices/iucv/${netiucv}/net:* ]; then
        echo $"Device $netiucv does not have required sysfs attribute 'net:*'"
        return 1
    fi
    DEVICE=$(echo /sys/devices/iucv/${netiucv}/net:*)
    DEVICE=${DEVICE//*:/}
    if [ "$DEVICE" = "" ]; then
        echo $"Could not get device name for $netiucv"
        return 1
    fi
    return 0
}

function question_prefix_peerid() {
    echo -n $"Peer ID of the VM guest to connect to"
}

function question_choices_peerid() {
    echo $" (0..8 characters or ? for help):"
}

function helptext_peerid() {
    echo $" Help text for the peer ID of the VM guest you want to connect to:"
    echo $"  User ID of a VM guest you want to connect to."
    echo $"  0..8 alphabetic/numeric characters or dollar-signs '$'."
    echo $"  Your input will be converted to uppercase."
}

function do_peerid() {
    ask PEERID \
        question_prefix_peerid question_choices_peerid \
        -h helptext_peerid -s syntax_check_peerid -c handle_peerid
}

### HOSTNAME

function syntax_check_hostname() {
    syntax_check_domainname "$HOSTNAME" "Incorrect format for hostname (HOSTNAME): $HOSTNAME"
}

function handle_hostname() {
    if ! hostname $HOSTNAME; then
        echo $"Could not configure hostname $HOSTNAME"
        return 1
    fi
    return 0
}

function question_prefix_hostname() {
    echo -n $"Hostname of your new Linux guest"
}

function question_choices_hostname() {
    echo $" (FQDN e.g. s390.redhat.com or ? for help):"
}

function helptext_hostname() {
    echo $" Help text for hostname:"
    echo $"  Enter the full qualified domain name of your host."
}

function do_hostname() {
    ask HOSTNAME \
        question_prefix_hostname question_choices_hostname \
        -h helptext_hostname -s syntax_check_hostname -c handle_hostname
}

### IPADDR

function syntax_check_ipaddr() {
    unset ipv4
    unset ipv6
    if checkipv4 $IPADDR; then
        ipv4="yes"
        return 0
    elif [ "$ipv6_capable" = "yes" ] && checkipv6 $IPADDR; then
        ipv6="yes"
        return 0
    fi
    echo $"Incorrect format for IP address (IPADDR): $IPADDR"
    return 1
}

function question_prefix_ipaddr() {
    echo -n $"IPv4 address"
    [ "$ipv6_capable" = "yes" ] && echo -n $" / IPv6 addr."
}

function question_choices_ipaddr() {
    echo -n $" (e.g. 10.0.0.2"
    [ "$ipv6_capable" = "yes" ] && echo -n $" / 2001:0DB8::"
    echo $" or ? for help)"
}

function helptext_ipaddr() {
    echo $" Help text for IP address:"
    echo $"  Enter a valid IPv4 address of your new Linux guest (e.g. 10.0.0.2)"
    if [ "$ipv6_capable" = "yes" ]; then
        echo $"  or alternatively a valid IPv6 address without CIDR prefix (e.g. 2001:0DB8::)"
        echo $"  IPv6 is supported on:"
        echo $"   - Ethernet interfaces of the OSA-Express adapter running in QDIO mode."
        echo $"   - HiperSockets interfaces"
        echo $"   - z/VM guest LAN interfaces running in QDIO mode."
        echo $"  IPv6 is not supported on HiperSockets guest LAN, OSA-Express Token Ring, ATM."
    fi
}

function do_ipaddr() {
    ipv6_capable && ipv6_capable=yes || ipv6_capable=no
    ask IPADDR \
        question_prefix_ipaddr question_choices_ipaddr \
        -h helptext_ipaddr -s syntax_check_ipaddr
    # no handling/configuring of IPADDR yet, since more parameters needed
}

### NETMASK (IPv4)

function syntax_check_netmask_v4() {
    # also support CIDR prefix
    if [[ "$NETMASK" =~ ^[[:digit:]]+$ ]]; then
        if [ "$NETMASK" -ge 1 -a "$NETMASK" -le 32 ]; then
            ipcalc_arg="$IPADDR/$NETMASK"
            return 0
        fi
        echo $"Incorrect value for network prefix [1..32] (NETMASK): $NETMASK"
        return 1
    elif checkipv4 $NETMASK; then
        ipcalc_arg="$IPADDR $NETMASK"
        return 0
    fi
    echo $"Incorrect format or value for network mask (NETMASK): $NETMASK"
    return 1
}

function question_prefix_netmask() {
    echo -n $"IPv4 netmask or CIDR prefix"
}

function hint_netmask_v4() {
    # default based on class a/b/c address
    local a b c d
    IFS=.
    read a b c d <<< "$IPADDR"
    unset IFS
    local ip=$(( ( a << 24 ) + ( b << 16 ) + ( c << 8 ) + ( d ) ))
    # <<EOF convince syntax highlighter that above shifts are no here documents
    if   [ $(( ip & 0x80000000 )) -eq $(( 0x00000000 )) ]; then
        # class a
        echo "255.0.0.0"
    elif [ $(( ip & 0xC0000000 )) -eq $(( 0x80000000 )) ]; then
        # class b
        echo "255.255.0.0"
    elif [ $(( ip & 0xE0000000 )) -eq $(( 0xC0000000 )) ]; then
        # class c
        echo "255.255.255.0"
    else
        # some other class that should not be used as host address
        return 1
    fi
    return 0
}

function question_choices_netmask() {
    echo -n $" (e.g. 255.255.255.0 or 1..32 or ? for help)"
    local default=$(hint_netmask_v4)
    if [ -n "$default" ]; then
        echo $". Default is $default:"
    else
        echo $":"
        echo $"The IP address you entered previously should probably not be used for a host."
    fi
}

function helptext_netmask() {
    echo $" Help text for IPv4 netmask or CIDR prefix:"
    echo $"  Enter a valid IPv4 netmask or CIDR prefix (e.g. 255.255.255.0 or 1..32)"
    local default=$(hint_netmask_v4)
    if [ -n "$default" ]; then
        echo $"  Default is $default"
    else
        echo $"The IP address you entered previously should probably not be used for a host."
    fi
}

function exception_netmask() {
    if [ -z "$NETMASK" ]; then
        NETMASK=$(hint_netmask_v4)
    fi
}

function do_netmask() {
    ask NETMASK \
        question_prefix_netmask question_choices_netmask \
        -h helptext_netmask \
        -s syntax_check_netmask_v4 -e exception_netmask
    # no handling/configuring of NETMASK yet, since more parameters needed
}

### NETMASK (IPv6)

function syntax_check_prefix_v6() {
    if [[ "$NETMASK" =~ ^[[:digit:]]+$ ]]; then
        if [ "$NETMASK" -ge 1 -a "$NETMASK" -le 128 ]; then
            return 0
        fi
    fi
    echo $"Incorrect value for network prefix [1..128] (NETMASK): $NETMASK"
    return 1
}

function question_prefix_netmask_v6() {
    echo -n $"CIDR prefix for the IPv6 address"
}

function question_choices_netmask_v6() {
    echo $" (1..128):"
}

function do_netmask_v6() {
    ask NETMASK \
        question_prefix_netmask_v6 question_choices_netmask_v6 \
        -s syntax_check_prefix_v6
    # no handling/configuring of NETMASK yet, since more parameters needed
}

### GATEWAY (IPv4)

function configure_ipv4_gateway() {
    # FIXME:
    # - Strictly speaking we should first check reachability of gateway
    #   and then configure the gateway route.
    #   This would require a new intermediate workflow_item step
    #   so that the user might continue despite unreachable gateway.
    # done: Only adding default route might add multiple undesired default
    # routes on redoing the parameter item, so delete default route
    # before adding a new one.
    ip -4 route del default dev $DEVICE >& /dev/null
    [ -z "$GATEWAY" ] && return 0
    if ! tv route add default gw $GATEWAY dev $DEVICE; then
        echo $"Could net set default route on device $DEVICE via gateway $GATEWAY"
        return 1
    fi
    # BH FIXME: Workaround for manual MACADDR, need ping to update arp table
    echo $"Trying to reach gateway $GATEWAY..."
    if [ "$NETTYPE" = "ctc" ]; then
        # (virtual) CTC(/A) seems to need some time to get functional
        local i=1
        while : ; do
            ping -c 1 $GATEWAY >& /dev/null && break
            i=$((i+1))
            if [ "$i" -gt 3 ]; then
                echo $"Could not reach gateway $GATEWAY within timeout"
                return 1
            fi
        done
    else
        if ! ping -c 1 $GATEWAY >& /dev/null; then
            echo $"Could not reach your default gateway $GATEWAY"
            return 1
        fi
    fi
    return 0
}

function hint_ipv4_gateway() {
    # - provide default suggestion based on network,
    #   for a class C network this would be either .1 or .254 at the end
    local a b c d
    IFS=.
    read a b c d <<< "$NETWORK"
    unset IFS
    local ip=$(( ( a << 24 ) + ( b << 16 ) + ( c << 8 ) + ( d ) ))
    # <<EOF convince syntax highlighter that above shifts are no here documents
    local lo=$(( ip | 1 ))
    local lo_a=$(( (lo & 0xFF000000) >> 24 ))
    local lo_b=$(( (lo & 0x00FF0000) >> 16 ))
    local lo_c=$(( (lo & 0x0000FF00) >> 8 ))
    local lo_d=$(( (lo & 0x000000FF) ))
    local hi=$(( ip | ( (2**(32 - PREFIX)) - 1 ) ))
    local hi_a=$(( (hi & 0xFF000000) >> 24 ))
    local hi_b=$(( (hi & 0x00FF0000) >> 16 ))
    local hi_c=$(( (hi & 0x0000FF00) >> 8 ))
    local hi_d=$(( (hi & 0x000000FE) ))
    echo $"  Depending on your network design patterns, the default gateway"
    echo $"   might be $lo_a.$lo_b.$lo_c.$lo_d or $hi_a.$hi_b.$hi_c.$hi_d"
}

function question_prefix_gateway() {
    echo -n $"IPv4 address of your default gateway"
}

function question_choices_gateway() {
    echo $" or ? for help:"
}

function helptext_gateway() {
    echo $" Help text for IPv4 default gateway:"
    echo $"  For HiperSockets with internal traffic only you may want to leave this empty"
    echo $"  and choose continue afterwards to go on without gateway."
    hint_ipv4_gateway
}

function finish_gateway() {
    if ! checkipv4 $GATEWAY; then
        # above checkipv4 is silent, so make up for syntax error
        echo $"Incorrect format for IPv4 address of gateway (GATEWAY): $GATEWAY"
        workflow_item_menu
    fi
    if configure_ipv4_gateway; then
        break
    else
        workflow_item_menu && break
    fi
}

# FIXME: allow empty/no gateway?

function do_gateway() {
    ask GATEWAY \
        question_prefix_gateway question_choices_gateway \
        -h helptext_gateway -f finish_gateway
}

### GATEWAY (IPv6)

function configure_ipv6_gateway() {
    # FIXME:
    # - Strictly speaking we should first check reachability of gateway
    #   and then configure the gateway route.
    #   This would require a new intermediate workflow_item step
    #   so that the user might continue despite unreachable gateway.
    # done: Only adding default route might add multiple undesired default
    # routes on redoing the parameter item, so delete default route
    # before adding a new one.
    ip -6 route del default dev $DEVICE >& /dev/null
    [ -z "$GATEWAY" ] && return 0
    # IPv6 http://www.ibiblio.org/pub/Linux/docs/HOWTO/other-formats/html_single/Linux+IPv6-HOWTO.html#AEN1147
    #       ip -6 route add ::/0 dev $DEVICE via $GATEWAY
    # (Could also be learned by autoconfiguration on the link:
    #  after IP address setup and device up,
    #   see if default route has been learned
    #   ip -6 route show | grep ^default
    #  However, we currently use manual IPv6 configuration only.)
    if ! debug ip -6 route add ::/0 dev $DEVICE via $GATEWAY; then
        echo $"Could net set default route on device $DEVICE"
        echo $" via gateway $GATEWAY"
        return 1
    fi
    # BH FIXME: Workaround for manual MACADDR, need ping to update arp table
    echo $"Trying to reach gateway $GATEWAY..."
    if ! ping6 -c 1 $GATEWAY >& /dev/null; then
        echo $"Could not reach your default gateway $GATEWAY"
        return 1
    fi
    return 0
}

function question_prefix_gateway_v6() {
    echo -n $"IPv6 address of your default gateway"
}

function question_choices_gateway_v6() {
    echo $":"
}

function helptext_gateway_v6() {
    echo $" Help text for IPv6 default gateway:"
    echo $"  For HiperSockets with internal traffic only you may want to leave this empty"
    echo $"  and choose continue afterwards to go on without gateway."
}

function finish_gateway_v6() {
    if ! checkipv6 $GATEWAY; then
        # above checkipv6 is silent, so make up for syntax error
        echo $"Incorrect format for IPv6 address of gateway (GATEWAY): $GATEWAY"
        workflow_item_menu
    fi
    if configure_ipv6_gateway; then
        break
    else
        workflow_item_menu && break
    fi
}

# FIXME: allow empty/no gateway?

function do_gateway_v6() {
    ask GATEWAY \
        question_prefix_gateway_v6 question_choices_gateway_v6 \
        -h helptext_gateway_v6 -f finish_gateway_v6
}

### GATEWAY (IPv4, point-to-point)

function configure_ipv4_ptp() {
    # device needs to be online
    if debug ifconfig $DEVICE $IPADDR $MMTU pointopoint $GATEWAY; then
        configure_ipv4_gateway
        return $?
    fi
    echo $"Could not set IPv4 address $IPADDR for device $DEVICE"
    echo $" to peer $GATEWAY"
    [ -n "$MMTU" ] && echo $" and maximum transfer unit: $MMTU"
    return 1
}

function question_prefix_ptp_gateway() {
    echo -n $"IPv4 address of your point-to-point partner"
}

function question_choices_ptp_gateway() {
    echo $" or ? for help:"
    # no hinting possible here
}

function helptext_ptp_gateway() {
    echo $" Help text for point-to-point partner:"
    echo $"  IPv4 address of your CTC / ESCON / IUCV point-to-point partner."
}

function finish_ptp_gateway() {
    if checkipv4 $GATEWAY; then
        if [ "$GATEWAY" = "$IPADDR" ]; then
            echo $"IPv4 address of partner should probably be different from the guest's address"
            workflow_item_menu && break
        else
            break
        fi
    else
        # above checkipv4 is silent, so make up for syntax error
        echo $"Incorrect format for IPv4 address of partner (GATEWAY): $GATEWAY"
        workflow_item_menu && break
    fi
    # too early to actually configure gateway
}

function do_ptp_gateway() {
    ask GATEWAY \
        question_prefix_ptp_gateway question_choices_ptp_gateway \
        -h helptext_ptp_gateway -f finish_ptp_gateway
}

### DNS

function syntax_check_dns() {
    if [ -z "$DNS" ]; then
        echo $"You might encounter problems without a nameserver, especially with FTP installs"
        return 1
    fi
    local dnsitem
    local allgood="yes"
    if [ "$ipv6" ]; then
        while read dnsitem; do
            if ! checkipv6 $dnsitem; then
                echo $"Not a valid IPv6 address for DNS server: $dnsitem"
                allgood="no"
            fi
        done < <(echo $DNS | sed 's/,/\n/g')
    else
         while read dnsitem; do
           if ! checkipv4 $dnsitem; then
                echo $"Not a valid IPv4 address for DNS server: $dnsitem"
                allgood="no"
            fi
         done < <(echo $DNS | sed 's/:/\n/g')
    fi
    if [ "$allgood" = "yes" ]; then
        return 0
    else
        return 1
    fi
}

function handle_dns() {
    # - foreach DNS try if server is reachable by one ping
    [ -z "$DNS" ] && return 0
    local dnsitem
    local allgood="yes"
    echo $"Trying to reach DNS servers..."
    if [ "$ipv6" ]; then
        while read dnsitem; do
            if ! ping6 -c 1 $dnsitem >& /dev/null; then
                echo $"Could not ping DNS server (might still serve DNS requests): $dnsitem"
                allgood="no"
                # this should not be a hard failure since some network
                # environments may prevent pings to DNS servers
                # => prevent workflow_item_menu in kickstart mode
            fi
        done < <(echo $DNS | sed 's/,/\n/g')
    else
        while read dnsitem; do
            # Some network environment may prevent a DNS server from being
            # reachable by ping, so it would make sense to use nslookup.
            # However, nslookup fails with "Resolver Error 0 (no error)"
            # at this stage of the setup progress => not useful
            if ! ping -c 1 $dnsitem >& /dev/null; then
                echo $"Could not ping DNS server: $dnsitem"
#                if nslookup $dnsitem $dnsitem >& /dev/null; then
#                    echo $" but could resolve DNS server with itself: $dnsitem"
#                else
#                    echo $"Could not resolve DNS server with itself: $dnsitem"
#                    allgood="no"
#                fi
#            elif ! nslookup $dnsitem $dnsitem >& /dev/null; then
#                echo $"Could not resolve DNS server with itself: $dnsitem"
                allgood="no"
            fi
        done < <(echo $DNS | sed 's/:/\n/g')
    fi
    if [ "$allgood" = "yes" ]; then
        return 0
    else
        return 1
    fi
}

function question_prefix_dns() {
    if [ "$ipv6" ]; then
        echo -n $"IPv6 addresses of DNS servers"
    else
        echo -n $"IPv4 addresses of DNS servers"
    fi
}

function question_choices_dns() {
    if [ "$ipv6" ]; then
        echo $" (separated by commas ',' or ? for help):"
    else
        echo $" (separated by colons ':' or ? for help):"
    fi
}

function helptext_dns() {
    echo $" Help text for DNS servers:"
    if [ "$ipv6" ]; then
        echo $"  Enter IPv6 addresses of DNS servers separated by commas ','"
    else
        echo $"  Enter IPv4 addresses of DNS servers separated by colons ':'"
    fi
    echo $"  Default are no DNS servers at all."
    echo $"  However, you might encounter problems without a nameserver,"
    echo $"   especially with FTP installs."
    if [ "$ipv6" ]; then
        echo $"  An example with 2 servers would be: 2001:0DB8::42,2001:0DB8::BE:AF"
    else
        echo $"  An example with 2 servers would be: 10.0.0.250:10.1.1.1"
    fi
}

function do_dns() {
    ask DNS \
        question_prefix_dns question_choices_dns \
        -h helptext_dns -s syntax_check_dns -c handle_dns
}

### SEARCHDNS

function syntax_check_searchdns() {
    [ -z "$SEARCHDNS" ] && return 0
    local dnsitem
    local allgood="yes"
    while read dnsitem; do
        syntax_check_domainname "$dnsitem" $"Not a valid DNS search domain: $dnsitem" || allgood="no"
    done < <(echo $SEARCHDNS | sed 's/:/\n/g')
    if [ "$allgood" = "yes" ]; then
        return 0
    else
        return 1
    fi
}

function question_prefix_searchdns() {
    echo -n $"DNS search domains"
}

function question_choices_searchdns() {
    echo $" (separated by colons ':' or ? for help):"
}

function helptext_searchdns() {
    echo $" Help text for DNS search domains:"
    echo $"  Enter search domains according to hostname syntax separated by colons."
    echo $"  Default are no DNS search domains at all."
    echo $"  An example would be: subdomain.domain.com:domain.com"
}

function do_searchdns() {
    ask SEARCHDNS \
        question_prefix_searchdns question_choices_searchdns \
        -h helptext_searchdns -s syntax_check_searchdns
}

### DASD

function parse_dasd() {
    local handle
    [ "$1" = "-h" ] && handle=yes || unset handle
    local dasditem
    local allgood="yes"
    while read dasditem; do
        case $dasditem in
            autodetect|probeonly|nopav) continue ;;
            "") continue ;; # empty range
            *)  local range features
                IFS='('
                read range features <<< "$dasditem"
                unset IFS
                # parse: dev OR dev'-'dev
                local lo=${range%%-*}
                [[ "$lo" =~ (^[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4}$)|(^[[:xdigit:]]{3,4}$) ]]
                case $? in
                    0)  ;; # string matched the pattern
                    1)  # string did not match the pattern
                        if [ -z "$handle" ]; then
                            echo $"Incorrect format for lower bound of DASD range $range: $lo"
                            allgood="no"
                        fi
                        ;;
                    2)  echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2 ;;
                    *)  echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2 ;;
                esac
                if [ "${range//*-*/}" = "" ]; then
                    local hi=${range##*-}
                    [[ "$hi" =~ (^[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4}$)|(^[[:xdigit:]]{3,4}$) ]]
                    case $? in
                        0)  ;; # string matched the pattern
                        1)  # string did not match the pattern
                            if [ -z "$handle" ]; then
                                echo $"Incorrect format for upper bound of DASD range $range: $hi"
                                allgood="no"
                            fi
                            ;;
                        2)  echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2 ;;
                        *)  echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2 ;;
                    esac
                fi
                if [ "$handle" = "yes" ]; then
                    if ! sysecho /proc/cio_ignore "free $range"; then
                        echo $"Could not free DASD device $range from device blacklist"
                        allgood="no"
                    fi
                fi
                if [ "${features//*)/}" != "" ]; then
                    if [ -z "$handle" ]; then
                        echo $"Missing closing parenthesis at features of DASD range $range: ($features"
                        allgood="no"
                    fi
                fi
                [ -z "$features" ] && continue
                features="${features%)}"
                while read feature; do
                    case $feature in
                        ro|diag|erplog) continue ;;
                        *)  if [ -z "$handle" ]; then
                                echo $"Unknown DASD feature for device range $range: $feature"
                                allgood="no"
                            fi
                            ;;
                    esac
                done < <(echo $features | sed 's/:/\n/g')
                ;;
        esac
    done < <(echo $DASD | sed 's/,/\n/g')
    if [ "$handle" = "yes" ]; then
        udevadm settle
        # even though the device might now be online, some of its
        # sysfs attributes might not yet be available
        sleep 1
    fi
    if [ "$allgood" = "yes" ]; then
        return 0
    else
        return 1
    fi
}

function syntax_check_dasd() {
    parse_dasd
    return $?
}

function handle_dasd() {
    parse_dasd -h
    return $?
}

function question_prefix_dasd() {
    echo -n $"DASD range"
}

function question_choices_dasd() {
    echo $" (e.g. 200-203,205 or ? for help). Default is autoprobing:"
}

function helptext_dasd() {
    echo $" Help text for DASD range:"
    echo $"  Comma separated list of ranges of device bus IDs."
    echo $"  Default is autoprobing (not recommended)."
    echo $"  Examples would be: 200-203 or 200,201,202,203 or 0.0.0200-0.0.0203,0.0.0205"
}

function exception_dasd() {
    [ -z "$DASD" ] && break
}

function do_dasd() {
    ask DASD \
        question_prefix_dasd question_choices_dasd \
        -h helptext_dasd -e exception_dasd -s syntax_check_dasd -c handle_dasd
}

### FCP

function syntax_check_fcp() {
    local allgood="yes"
    local i
    for i in ${!FCP_*}; do
        local -a fcp
        local devno wwpn lun
        read -a fcp <<< "${!i}"
        case ${#fcp[@]} in
            3)
                devno=${fcp[0]}
                wwpn=${fcp[1]}
                lun=${fcp[2]}
                ;;
            5)
                devno=${fcp[0]}
                wwpn=${fcp[2]}
                lun=${fcp[4]}
                echo $"Deprecated number of FCP arguments (5 instead of 3): "
                echo $" $i=\"${!i}\""
                echo $" should instead be: "
                echo $" $i=\"$devno $wwpn $lun\""
                ;;
            *)
                echo $"Unsupported number of FCP arguments (${#fcp[@]} instead of 3) in:"
                echo $" $i=\"${!i}\""
                allgood="no"
                continue
                ;;
        esac
        [[ "$devno" =~ (^[[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4}$)|(^[[:xdigit:]]{3,4}$) ]]
        case $? in
            0)  ;; # string matched the pattern
            1)  # string did not match the pattern
                echo $"Incorrect format for FCP device $devno in:"
                echo $" $i=\"${!i}\""
                allgood="no"
                ;;
            2)
                echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
                ;;
            *)
                echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
                ;;
        esac
        # zfcp.py:class ZFCPDevice would also accept WWPN without leading 0x
        [[ "$wwpn" =~ ^0x[[:xdigit:]]{16}$ ]]
        case $? in
            0)  ;; # string matched the pattern
            1)  # string did not match the pattern
                echo $"Incorrect format for FCP WWPN $wwpn in:"
                echo $" $i=\"${!i}\""
                allgood="no"
                ;;
            2)  echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2 ;;
            *)  echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2 ;;
        esac
        # zfcp.py:class ZFCPDevice would also accept LUN without leading 0x
        # zfcp.py:class ZFCPDevice would also accept 16 bit LUN and pads with 0
        [[ "$lun" =~ ^0x[[:xdigit:]]{8}0{8}$ ]]
        case $? in
            0)  ;; # string matched the pattern
            1)  # string did not match the pattern
                echo $"Incorrect format for FCP LUN $lun in:"
                echo $" $i=\"${!i}\""
                allgood="no"
                ;;
            2)
                echo "l.$LINENO: syntax error in regex of match operator =~, code needs to be fixed" 1>&2
                ;;
            *)
                echo "l.$LINENO: unexpected return code of regex match operator =~, code needs to be fixed" 1>&2
                ;;
        esac
    done
    if [ "$allgood" = "yes" ]; then
        return 0
    else
        return 1
    fi
}

###

function show_parms() {
    # The only issue with this stateless approach to showing parameters based
    # on their content being non-empty is, that parameters with defaults
    # such as LAYER2, (PORTNAME,) CTCPROT, PORTNO (,MACADDR) won't be shown
    # if the user just hit enter, so the parm file would be "incomplete".
    # However this is not easy to fix in here, since it would require the
    # inter-parameter dependenies coded below in the main part, e.g. an
    # empty LAYER2 should only be printed with default value if $NETTYPE=qeth.
    # For the time being, at least the parameters LAYER2, PORTNAME, and CTCPROT
    # only get asked on being empty if not running in kickstart mode.
    cat << EOF
NETTYPE=$NETTYPE
IPADDR=$IPADDR
NETMASK=$NETMASK
GATEWAY=$GATEWAY
HOSTNAME=$HOSTNAME
EOF
    [ "$SUBCHANNELS" ] && echo "SUBCHANNELS=$SUBCHANNELS"
    [ "$LAYER2" ] && echo "LAYER2=$LAYER2"
    [ "$VSWITCH" ] && echo "VSWITCH=$VSWITCH"
    [ "$MACADDR" ] && echo "MACADDR=$MACADDR"
    [ "$PORTNAME" ] && echo "PORTNAME=$PORTNAME"
    [ "$PORTNO" ] && echo "PORTNO=$PORTNO"
    [ "$PEERID" ] && echo "PEERID=$PEERID"
    [ "$CTCPROT" ] && echo "CTCPROT=$CTCPROT"
    if [ -n "$mmtu_was_set" ]; then
        echo "MMTU=\"$MMTU\""
    elif [ -n "$mtu_was_set" ]; then
        echo "MTU=$MTU"
    fi
    [ "$DNS" ] && echo "DNS=$DNS"
    [ "$SEARCHDNS" ] && echo "SEARCHDNS=$SEARCHDNS"
    [ "$DASD" ] && echo "DASD=$DASD"
}

function final_check() {
    # final check && break
    if [ -z "$interaction_happened" ]; then
        # if parm file was good enough just continue without interaction
        break
        return 0
    fi
    while : ; do
        # optionally consider "continue" as default
        # but then again the user may inadvertently continue
        echo
        echo $"c) continue, p) parm file/configuration, n) network state, r) restart, s) shell"
        local answer
        read answer
        case $answer in
            c) return 0 ;;
            p) echo
                show_parms ;;
            n) # show interfaces and routing table
                ifconfig -a
                if [ "$ipv6" ]; then
                    #route -n -A inet6
                    # the following produces more compact output for 80 columns
                    ip -6 route show | grep -v "^unreachable "
                else
                    route -n
                fi
                ;;
            r) break ;;
            s) echo $"Enter 'exit' at the shell prompt to get back to the installation dialog."
                /bin/bash
                ;;
    esac
    done
    return 1
}

### MAIN ###

init_main

# Parse configuration
if [ -n "$CMSDASD" -a -n "$CMSCONFFILE" ]; then
    readcmsfile $CMSDASD $CMSCONFFILE
    source /tmp/$CMSCONFFILE #2>/dev/null
fi

if [ -r /sys/firmware/ipl/ipl_type ]; then
    #local ipl_type
    read ipl_type < /sys/firmware/ipl/ipl_type
    if [ "$ipl_type" = "fcp" ]; then
        while : ; do
            echo $"Your IPL device is set to FCP."
            echo $"Would you like to perform a CD-ROM/DVD-ROM installation? (y/n)"
            #local do_cd_install
            read do_cd_install
            case $do_cd_install in
                y|Y|[Yy][Ee][Ss])
                    # precondition: zfcp driver incl. dependencies loaded
                    #local CD_DEVICE WWPN LUN
                    read CD_DEVICE < /sys/firmware/ipl/device
                    read WWPN < /sys/firmware/ipl/wwpn
                    read LUN < /sys/firmware/ipl/lun
                    if sysecho /proc/cio_ignore "free $CD_DEVICE"; then
                        udevadm settle
                        # even though device might now be online, some of its
                        # sysfs attributes might not yet be available
                        sleep 1
                    else
                        echo $"Device $CD_DEVICE could not be cleared from device blacklist"
                    fi
                    sysecho /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/online 1 \
                        || echo $"Could not set FCP device $CD_DEVICE online"
                    # port (WWPN) appears automatically
                    sysecho /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/$WWPN/unit_add $LUN \
                        || echo $"Could not add LUN $LUN at WWPN $WWPN on FCP device $CD_DEVICE"
                    break
                    ;;
                n|N|[Nn][Oo])
                    break
                    ;;
                *)
                    echo
                    echo $"*** INVALID ANSWER: $do_cd_install"
                    echo
                    unset do_cd_install
                    ;;
            esac
        done
    fi
fi

# Perform a network installation

[ -n "$MTU" ] && mtu_was_set=$MTU
[ -n "$MMTU" ] && mmtu_was_set=$MMTU
[ -n "$VSWITCH" ] && vswitch_was_set=$VSWITCH

# [ -z "${cardtype//OSD_*/}" ] can be used to check for real OSA

# Check for missing parameters, prompt for them if necessary
while : ; do

    # do not show list of possible network device configurations, if:
    # - running unattended install with kickstart
    # - relevant parameters have already been specified in parm file
    #   (a possible optimization would be matching those parms to table entry)
    # - dialog has not been restarted
    [ -n "$reenter" \
        -o -z "$RUNKS" -a \( -z "$NETTYPE" -o -z "$SUBCHANNELS" \) ] && \
        dialog_network_table
    if isVM; then
        echo $"* NOTE: To enter default or empty values press enter twice. *"
    fi
    do_nettype
    # precondition: driver (qeth/lcs/ctcm/netiucv) loaded incl. dependencies
    # only works, if ipv6 kernel module has been loaded before:
    [ "$NETTYPE" = "qeth" ] && tv disable_ipv6_autoconf
    if [ "$NETTYPE" != "iucv" ]; then
        # all interface types except for iucv have ccw config
        [ -n "$CHANDEV" ] && do_chandev
        do_subchannels
        if [ "$NETTYPE" = "qeth" ]; then
            [ -z "$reenter" -a -n "$RUNKS" -a -z "$PORTNAME" ] || \
                [ -n "${cardtype//OSD_*/}" ] || do_portname
            # See also https://bugzilla.redhat.com/show_bug.cgi?id=439461
            #
            # If running in kickstart mode (unattended), we assume no
            # interaction and the user won't get asked for PORTNO.
            # Otherwise the user will be asked for PORTNO.
            # If the user specified PORTNO in parm/conf file, PORTNO gets
            # respected (or the user will be asked if it was wrong).
            if [ -f /sys/devices/qeth/$SCH_R_DEVBUSID/portno ]; then
                # driver support exists since RHEL5.2
                [ -z "$reenter" -a -n "$RUNKS" -a -z "$PORTNO" ] || \
                    [ -n "${cardtype//OSD_*/}" ] || do_portno
            fi
            do_layer2
            # set device online to know the device name
            # and to know if it's OSD/HiperSockets/GuestLAN BUT do not
            # try to ifconfig the device up since that requires
            # setting the mac address before (if applicable).
            set_device_online || workflow_item_menu noredo
            # MAC address handling is not part of
            # https://bugzilla.redhat.com/show_bug.cgi?id=233376
            # Instead the additions come from
            # https://bugzilla.redhat.com/show_bug.cgi?id=248049
            # The new parms VSWITCH and MACADDR are described in
            # the RHEL 5.1 release notes.
            if isLayer2; then
                if [ -z "$VSWITCH" -o "$VSWITCH" == 0 ]; then
                    do_macaddr
                fi
            fi
        elif [ "$NETTYPE" = "ctc" ]; then
            [ -z "$reenter" -a -n "$RUNKS" -a -z "$CTCPROT" ] || do_ctcprot
            set_device_online || workflow_item_menu noredo
        elif [ "$NETTYPE" = "lcs" ]; then
            [ -n "$RUNKS" -a -z "$PORTNAME" ] && PORTNAME=0
            do_lcs_portno
            set_device_online || workflow_item_menu noredo
        fi
    else # iucv
        do_peerid
    fi

    # device needs to be up before configuring with ifconfig/ip in
    # configure_ipv6_address/configure_ipv4_address/configure_ipv4_address
    set_device_up || workflow_item_menu noredo

    [ "$HOSTNAME" = "(none)" ] && unset HOSTNAME
    do_hostname

    # Note: The workflow_item_menu does a rollback_config on restart
    # dialog, i.e. hardware config has been reset and it is impossible to
    # only restart halfway at IPADDR.
    do_ipaddr
    if [ "$ipv6" ]; then
        # this branch is all IPv6 and at the same time also NETTYPE==qeth
        do_netmask_v6
        handle_mtu
        configure_ipv6_address || workflow_item_menu noredo
        do_gateway_v6
    else
        # Consider IPv4 as default, even for unknown IP versions
        # due to invalid input for IPADDR ignored by the user previously
        # (neither ipv6 nor ipv4 is set).
        # Otherwise we would skip things like NETMASK or GATEWAY
        # and jump forward to DNS which is probably not what we want.
        if [ "$NETTYPE" = "qeth" ] || [ "$NETTYPE" = "lcs" ]; then
            do_netmask
            handle_mtu
            configure_ipv4_address || workflow_item_menu noredo
            do_gateway
        else  # ctc0, iucv0
            if [ -z "$NETMASK" ]; then
                # If the user did not supply netmask, we add the right one.
                # Netmask MUST be present,
                # or pumpSetupInterface() blows routes.
                NETMASK="255.255.255.255"
            fi
            # don't ask for MTU, but use it if set in the parm file
            # don't overwrite MMTU if it has been set for CTC
            [ "$NETTYPE" = "ctc" -a -z "$MTU" -a -z "$MMTU" ] && \
                MMTU="mtu 1500"
            do_ptp_gateway
            configure_ipv4_ptp || workflow_item_menu noredo
        fi
    fi

    modprobe_alias
    do_dns
    [ -n "$DNS" ] && do_searchdns

    do_dasd

    echo $"Initial configuration completed."
    final_check && break
    rollback_config
    reenter="yes"

done # outer dialog loop

if [ -z "$testing" ]; then

    # convert to space-separated lists
    if [ -n "$SEARCHDNS" ]; then
        SEARCHDNS=$(echo $SEARCHDNS |sed -e 's/:/ /g')
        for i in "$SEARCHDNS"; do echo "search $i"; done >> /etc/resolv.conf
    fi
    if [ -n "$DNS" ]; then
        if [ "$ipv6" ]; then
            RESOLVDNS=$(echo $DNS |sed -e 's/,/ /g')
        else
            RESOLVDNS=$(echo $DNS |sed -e 's/:/ /g')
        fi
        for i in $RESOLVDNS; do echo "nameserver $i"; done >> /etc/resolv.conf
    fi

    # make sure we have an /etc/hosts file (originally required for telnetd)
    if [ ! -z "$HOSTNAME" -a ! -z "$IPADDR" ]; then
        echo -e "$IPADDR\t$HOSTNAME $(echo $HOSTNAME | cut -d '.' -f 1)" >> /etc/hosts
    fi

fi # testing

if [ -n "$DASD" ]; then
    echo "DASD=$DASD" > /tmp/dasd_ports
fi

# syntax check to give user early feedback on parameters provided in parm file
# (he probably won't notice the logs written by anaconda later on)
syntax_check_fcp
# currently we ignore failed syntax checks since FCP parms are non-interactive
for i in ${!FCP_*}; do
    echo "${!i}" >> /tmp/fcpconfig
done
# cio_ignore handling for FCP should happen when the content of /tmp/fcpconfig
# will actually be processed which is in anaconda's zfcp.py ZFCP::readConfig()

# TODO/FIXME: also need to pass IPv6 decision to loader/anaconda
#    [ "$ipv6" ] && echo "IPV6=yes"

# transfer options into install environment
cat > /tmp/install.cfg << EOF
LANG="$LANG"
S390ARCH="$S390ARCH"
TEXTDOMAIN="$TEXTDOMAIN"
TEXTDOMAINDIR="$TEXTDOMAINDIR"
PORTNAME="$PORTNAME"
HOSTNAME="$HOSTNAME"
DEVICE="$DEVICE"
NETTYPE="$NETTYPE"
IPADDR="$IPADDR"
GATEWAY="$GATEWAY"
MTU="$MTU"
NETWORK="$NETWORK"
NETMASK="$NETMASK"
BROADCAST="$BROADCAST"
SEARCHDNS="$SEARCHDNS"
PEERID="$PEERID"
SUBCHANNELS="$SUBCHANNELS"
ONBOOT="yes"
CTCPROT="$CTCPROT"
EOF
if [ "$ipv6" ]; then
    echo DNS=\"$(echo $DNS | cut -d ',' -f 1)\" >> /tmp/install.cfg
else
    echo DNS=\"$(echo $DNS | cut -d ':' -f 1)\" >> /tmp/install.cfg
fi
cat >> /tmp/install.cfg << EOF
export LANG PORTNAME S390ARCH TEXTDOMAIN TEXTDOMAINDIR
export HOSTNAME DEVICE NETTYPE IPADDR GATEWAY MTU
export NETWORK NETMASK BROADCAST DNS SEARCHDNS
export PEERID ONBOOT SUBCHANNELS CTCPROT
EOF
# immediately read it in again to export these into the shell below
. /tmp/install.cfg
if [ -z "$testing" ]; then
    cat /tmp/install.cfg >> /etc/profile
fi # testing

NETSCRIPTS="/etc/sysconfig/network-scripts"
IFCFGFILE="$NETSCRIPTS/ifcfg-$DEVICE"
if [ ! -d "$NETSCRIPTS" ]; then
    mkdir -p $NETSCRIPTS
fi

cat > $IFCFGFILE << EOF
DEVICE=$DEVICE
ONBOOT=yes
BOOTPROTO=static
GATEWAY=$GATEWAY
BROADCAST=$BROADCAST
HOSTNAME=$HOSTNAME
MTU=$MTU
SUBCHANNELS=$SUBCHANNELS
EOF
if [ "$ipv6" ]; then
    cat >> $IFCFGFILE << EOF
IPV6INIT=yes
IPV6_AUTOCONF=no
IPV6ADDR=$IPADDR/$NETMASK
IPV6_DEFAULTGW=$GATEWAY
EOF
    # FIXME: /etc/sysconfig/network:IPV6_DEFAULTGW=$GATEWAY
    #        /etc/sysconfig/network:NETWORKING_IPV6=yes
else
    cat >> $IFCFGFILE << EOF
IPADDR=$IPADDR
NETMASK=$NETMASK
EOF
fi
if [ "$ipv6" ]; then
    [ "$DNS" != "" ] && echo "DNS=$(echo $DNS | cut -d ',' -f 1)" >> $IFCFGFILE
else
    [ "$DNS" != "" ] && echo "DNS=$(echo $DNS | cut -d ':' -f 1)" >> $IFCFGFILE
fi
[ "$NETTYPE" != "" ] && echo "NETTYPE=$NETTYPE" >> $IFCFGFILE
[ "$PEERID" != "" ] && echo "PEERID=$PEERID" >> $IFCFGFILE
[ "$PORTNAME" != "" ] && echo "PORTNAME=$PORTNAME" >> $IFCFGFILE
[ "$CTCPROT" != "" ] && echo "CTCPROT=$CTCPROT" >> $IFCFGFILE
[ "$LAYER2" != "" ] && echo "LAYER2=$LAYER2" >> $IFCFGFILE
[ "$MACADDR" != "" ] && echo "MACADDR=$MACADDR" >> $IFCFGFILE
[ "$PORTNO" != "" ] && echo "PORTNO=$PORTNO" >> $IFCFGFILE
# also needs support in stage2 (loader.c,(net.c)) to make PORTNO persistent,
# i.e. OPTION="portno=1" in /etc/sysconfig/network-scripts/ifcfg-<netdevname>
# (see loader of RHEL 5.3)

if [ -z "$testing" ]; then

    # so that the vars get propagated into the sshd shells
    mkdir /.ssh
    cat >> /.ssh/environment <<EOF
LD_LIBRARY_PATH=$LD_LIBRARY_PATH
PATH=$PATH
HOME=$HOME
PYTHONPATH=$PYTHONPATH
EOF

    cat >> /etc/profile <<EOF
LD_LIBRARY_PATH=$LD_LIBRARY_PATH
PATH=$PATH
HOME=$HOME
PYTHONPATH=$PYTHONPATH
export LD_LIBRARY_PATH PATH HOME PYTHONPATH
EOF

    if [ -n "$DISPLAY" ]; then
        echo "export DISPLAY=$DISPLAY" >> /etc/profile
    fi

    # I'm tired of typing this out...
    echo "loader" >> /.bash_history

    echo -n $$ > /var/run/init.pid

    # shutdown (halt) on SIGUSR1
    trap doshutdown SIGUSR1
    # reboot on SIGUSR2
    trap doreboot SIGUSR2

    startinetd

    if [ -n "$RUNKS" ]; then
        /sbin/loader
    fi

    doreboot

fi # testing

# ;;; Local Variables: ***
# ;;; mode: sh ***
# ;;; end: ***