IBM improvements to linuxrc.s390 (#475350)

IBM has reworked linuxrc.s390 to provide a better initial configuration
experience for users.

4 files changed, 3377 insertions, 486 deletions

diff --git a/loader/Makefile b/loader/Makefile
index def2badea..861604c3e 100644
--- a/loader/Makefile
+++ b/loader/Makefile
@@ -70,7 +70,7 @@ REALCC=gcc
 
 # linuxrc + shutdown on s390, init everywhere else
 ifneq (,$(filter s390 s390x,$(ARCH)))
-BINS += linuxrc.s390 shutdown
+BINS += linuxrc.s390 lsznet.raw shutdown
 SHUTDOWNOPTS = -DAS_SHUTDOWN=1
 else
 BINS += init
@@ -98,6 +98,9 @@ loader.po: $(wildcard *.c)
 linuxrc.s390:
 	@echo "Nothing to do for $@"
 
+lsznet.raw:
+	@echo "Nothing to do for $@"
+
 init: init.o undomounts.o shutdown.o copy.o
 	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^
 
diff --git a/loader/linuxrc.s390 b/loader/linuxrc.s390
index af2d43956..1db416771 100644
--- a/loader/linuxrc.s390
+++ b/loader/linuxrc.s390
@@ -1,5 +1,6 @@
-#! /bin/sh
-#
+#! /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>
@@ -8,6 +9,8 @@
 #        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
@@ -23,175 +26,2745 @@
 #    along with this program; if not, write to the Free Software
 #    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #
-VERSION=1.1
+
+# prerequisites of this script to run inside the RHEL5.3 installer initrd:
+# - copy udevsettle and udevd to initrd
+# - copy lsznet.raw to initrd as /sbin/lsznet
+# - create /etc/udev/udev.conf with at least one comment line as content
+
+VERSION=1.2
 
 export TEXTDOMAIN=s390installer
 export TEXTDOMAINDIR=/usr/lib/locale
 
-# check IP address format
-# param: IP string
-# return: 0 (valid IP) or 1 (invalid IP)
-checkip()
-{
-    checkipv6 $1
-    a=$?
-    checkipv4 $1
-    b=$?
+# helper function to execute command in arguments and print command on stdout
+function debug() {
+    # uncomment the following echo "$*" to enable debug output
+    #echo "$*"
+    $*
+}
 
-    if [ $a -eq 1 ] || [ $b -eq 1 ]; then
-        return 1
+# 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
 }
 
-checkipv6()
+# for checkipv6 / checkipv4 see also:
+# https://bugzilla.redhat.com/show_bug.cgi?id=234152#c11
+# https://enterprise.redhat.com/issue-tracker/?module=issues&action=view&tid=115847
+
+# see also RFC4291,sec.2.2
+# the following check is incomplete, but sufficient to distinguish from IPv4
+function checkipv6()
 {
-    ip=$1
-    echo $ip | awk -F':' 'BEGIN{ error = 0} { if (NF > 8) error=1;  i = 1; while (i++<=NF) {if (!match(toupper($i), "^[0-9A-F]*$")){ error=1}}exit error}'
-    return $?;
+    local ip=$1
+    [ -z "$ip" ] && return 1
+    echo $ip | awk -F':' '
+        BEGIN {
+          error = 0
+        }
+
+        {
+          if (NF > 8) {
+            error = 1
+            exit error
+          }
+          for (i = 1; i <= NF; i++) {
+            if ( ! match(toupper($i), "^[0-9A-F]{0,4}$") ) {
+              error = 1
+              break
+            }
+          }
+          exit error
+        }
+    '
+    return $?
 }
 
-checkipv4()
+function checkipv4()
 {
-    ip=$1
+    local ip=$1
     echo $ip | awk -F'.' '{ if (NF != 4) { exit 1 } i=1; while (i<=NF) { if ($i>255 || $i<0) { exit 1 }; i=i+1; } exit 0 }'
     return $?
 }
 
-doshutdown()
+function doshutdown()
 {
-    echo $"about to exec shutdown"
     exec /sbin/shutdown
     exit 0
 }
 
-doreboot()
+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
 }
 
-sysecho () {
-	file=$1
-	shift
-	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 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
 }
 
-
-startinetd()
+function startinetd()
 {
-	echo
-	echo $"Starting telnetd and sshd to allow login over the network."
-   echo $"Welcome to the anaconda install environment $VERSION for $S390ARCH" > /etc/issue.net
-   echo $"Welcome to the anaconda install environment $VERSION for $S390ARCH" > /etc/motd
-   echo >> /etc/motd
-
-	/sbin/xinetd -stayalive -reuse -pidfile /tmp/xinetd.pid
-	/sbin/sshd
-	if [ -z "$RUNKS" ]; then
-	  echo 
-	  echo $"Connect now to $IPADDR to start the installation."
-	  read
-  	  while : ; do
-			/bin/sh --login
-			[ $? = 0 ] || break
-	  done
-	fi
+    echo
+    echo $"Starting telnetd and sshd to allow login over the network."
+    if [ -z "$testing" ]; then
+        echo $"Welcome to the anaconda install environment $VERSION for $S390ARCH" > /etc/issue.net
+        echo $"Welcome to the anaconda install environment $VERSION for $S390ARCH" > /etc/motd
+        echo >> /etc/motd
+    fi # testing
+
+    /sbin/xinetd -stayalive -reuse -pidfile /tmp/xinetd.pid
+    /sbin/sshd
+    if [ -z "$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
-readcmsfile() # $1=dasdport $2=filename
+function readcmsfile() # $1=dasdport $2=filename
 {
-   local dev
-   if [ $# -ne 2 ]; then return; fi
-   mknod /dev/dasda b 94 0
-   insmod dasd_mod$LO dasd=$1
-   insmod dasd_eckd_mod$LO
-   cmsfscat -d /dev/dasda -a $2 > /tmp/$2
-   if [ ${#1} == 3 ]; then 
-      dev="0.0.0${1}"
-   elif [ ${#1} == 4 ]; then
-      dev="0.0.${1}"
-   fi
-   sysecho /sys/bus/ccw/drivers/dasd-eckd/$dev/online 0
-   rmmod dasd_eckd_mod
-   rmmod dasd_mod
-}
-
-setupdevice()
-{
-   if [ -z "$SUBCHANNELS" -o -z "$NETTYPE" ]; then
-      echo $"SUBCHANNELS or NETTYPE empty, cannot continue."
-      exit 1
-   fi
-   SYSDIR=${SUBCHANNELS//,*/}   # get first subchannel. This is where the device can be brought online
-   sysecho /sys/bus/ccwgroup/drivers/${NETTYPE}/group "$SUBCHANNELS"
-   if [ -n "$PORTNAME" ]; then
-		if [ "$NETTYPE" = "lcs" ]; then
-			sysecho /sys/bus/ccwgroup/drivers/${NETTYPE}/${SYSDIR}/portno "$PORTNAME"
-		else
-			sysecho /sys/bus/ccwgroup/drivers/${NETTYPE}/${SYSDIR}/portname "$PORTNAME"
-		fi
-	fi
-   if [ -n "$CTCPROT" -a "$NETTYPE" = "ctc" ]; then
-      sysecho /sys/bus/ccwgroup/drivers/ctc/${SYSDIR}/protocol "$CTCPROT"
-   fi
-   if [ -n "$LAYER2" -a "$NETTYPE" = "qeth" ]; then
-      sysecho /sys/bus/ccwgroup/drivers/qeth/${SYSDIR}/layer2 "$LAYER2"
-   fi
-   sysecho /sys/bus/ccwgroup/drivers/${NETTYPE}/${SYSDIR}/online 1
-}
-
-createDevices()
+    local dev
+    if [ $# -ne 2 ]; then return; fi
+    mknod /dev/dasda b 94 0
+    if ! sysecho /proc/cio_ignore "free $1"; then
+        echo $"DASD $1 could not be cleared from device blacklist"
+        return 1
+    fi
+    # /proc/cio_ignore won't block on freeing devices until resensing
+    # has been completed, so wait until the udev event queue depletes
+    # (without udevsettle we could wait 2 seconds unconditionally)
+    #debug ls -laF /dev/.udev
+    udevsettle
+    sleep 1
+    insmod dasd_mod$LO dasd=$1
+    insmod dasd_eckd_mod$LO
+    if ! cmsfscat -d /dev/dasda -a $2 > /tmp/$2; then
+        echo $"Could not read conf file $2 on CMS DASD $1."
+    fi
+    # maybe replace with a more robust: dev=$(printf "0.0.%04x" $((0x${1})))
+    if [ ${#1} == 3 ]; then
+        dev="0.0.0${1}"
+    elif [ ${#1} == 4 ]; then
+        dev="0.0.${1}"
+    fi
+    sysecho /sys/bus/ccw/drivers/dasd-eckd/$dev/online 0
+    rmmod dasd_eckd_mod
+    rmmod dasd_mod
+}
+
+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
+      printf("chmod %s /dev/%s\n", $5, $1);
+      printf("chown %s /dev/%s\n", $6, $1);
+    }' <<EOF | sh
+console c 5 1 600 root:root
+null c 1 3 666 root:root
+zero c 1 5 666 root:root
+mem c 1 1 600 root:root
+ptmx c 5 2 666 root:root
+tty  c 5 0 666 root:root
+tty0 c 4 0 600 root:tty
+tty1 c 4 1 600 root:tty
+random c 1 8 644 root:root
+urandom c 1 9 644 root:root
+rtc c 10 135 644 root:root
+EOF
+    for i in 2 3 4 5 6 7 8 9 ; do
+        ln -s console /dev/tty$i
+    done
+    mkdir /dev/pts
+    ln -s /proc/self/fd /dev/fd
+}
+
+# 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
+                udevsettle
+                # (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
+                # udevsettle only works if udevd is running (/dev/.udev/queue)!
+                # (without udevsettle we could wait 5-10 seconds uncond.)
+                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]}
+        # $NETTYPE happens to be exactly the network driver name
+        NETTYPE=$devdrv
+        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
+
+# The following combinations of control unit type and model were taken from the
+# Linux network device drivers for s390 on 2008-06-09 from Linux 2.6.25.4.
+# The list (among other things) should be adapted, if any of those device
+# drivers start supporting different CU types/models.
+# (Alternatively, the list could be generated by reading the modaliases
+#  directly out of the device driver modules:
+#  modinfo qeth/cu3088 | fgrep 'alias:'
+#  However, this would still require a list of device driver modules.)
+
+declare -r -a CU=(
+    1731/01
+    1731/05
+    3088/08
+    3088/1f
+    3088/1e
+    3088/01
+    3088/60
+)
+
+declare -r -a CU_DEVDRV=(
+    qeth
+    qeth
+    ctc
+    ctc
+    ctc
+    lcs
+    lcs
+)
+
+# Searches for a match of argument 1 on the array $CU and sets $cu_idx
+# to the matched array index on success.
+# Returns 0 on success, 1 on failure.
+function search_cu() {
+    local scu=$1
+    local i
+    for ((i=0; i < ${#CU[@]}; i++)); do
+        if [ "$scu" == "${CU[i]}" ]; then
+            cu_idx=$i
+            return 0
+        fi
+    done
+    return 1
+}
+
+function cardtype2cleartext() {
+    local cardtype=$1
+    case $cardtype in
+        OSD_10GIG)        echo "OSA card in OSD mode, 10 Gigabit Ethernet" ;;
+        OSD_1000)         echo "OSA card in OSD mode, Gigabit Ethernet" ;;
+        OSD_100)          echo "OSA card in OSD mode, Fast Ethernet" ;;
+        OSD_GbE_LANE)     echo "OSA card in OSD mode, Gigabit Ethernet, LAN Emulation" ;;
+        OSD_FE_LANE)      echo "OSA card in OSD mode, Fast Ethernet, LAN Emulation" ;;
+        OSD_TR_LANE)      echo "OSA card in OSD mode, Token Ring, LAN Emulation" ;;
+        OSD_ATM_LANE)     echo "OSA card in OSD mode, ATM, LAN Emulation" ;;
+        OSD_Express)      echo "OSA card in OSD mode, unknown link type" ;;
+        HSTR)             echo "OSA card in OSD mode, High Speed Token Ring" ;;
+        OSN)              echo "OSA for NCP, ESCON/CDLC bridge" ;;
+        HiperSockets)     echo "HiperSocket with CHPID type IQD" ;;
+        "GuestLAN QDIO")  echo "GuestLAN based on OSA (QDIO)" ;;
+        "GuestLAN Hiper") echo "GuestLAN based on HiperSocket" ;;
+        unknown)          echo "other" ;;
+        *) echo "unknown"
+            echo "l.$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
+}
+
+# echos one comparable integer built from 3 arguments in kernel version style
+function kernel_version() {
+    [ $# -eq 3 ] || return 1
+    local krn_ver=$1 krn_patch=$2 krn_sub=$3
+    local version=$(( (krn_ver << 16) + (krn_patch << 8) + krn_sub ))
+    # <<EOF convince syntax highlighter that above shifts are no here documents
+    echo $version
+    return 0
+}
+
+# echos one comparable integer built from actual running kernel version
+function linux_version() {
+    local krn_ver krn_patch krn_sub
+    local krn_foo krn_extra
+    IFS=.
+    read krn_ver krn_patch krn_foo < <(uname -r)
+    unset IFS
+    IFS=-
+    read krn_sub krn_extra <<< "$krn_foo"
+    unset IFS
+    kernel_version $krn_ver $krn_patch $krn_sub
+}
+
+# watch out: potential error message as side effect
+function isLayer2Default() {
+    # Read default from sysfs because according to device
+    # drivers book there are differences in the default between
+    # OSA (l2), hipersockets (l3).
+    # This only works here in installer where nobody has overwritten
+    # the default setting with another custom value already!
+    if [ ! -f /sys/devices/${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 $SCH_R_DEVBUSID and kernel version
+# is capable of supporting IPv6
+# watch out: potential error message as side effect
+function ipv6_capable() {
+    [ "$NETTYPE" = "qeth" ] || return 1
+    case $cardtype in
+        OSD_10GIG|OSD_1000|OSD_100|OSD_Express|"GuestLAN QDIO") return 0 ;;
+        HiperSockets)
+            if isLayer2; then
+                return 0
+            elif [ $(linux_version) -ge $(kernel_version 2 6 26) ]; then
+                return 0
+            else
+                return 1
+            fi
+            ;;
+        OSD_GbE_LANE|OSD_FE_LANE|OSD_TR_LANE|OSD_ATM_LANE) return 1 ;;
+        HSTR|OSN|unknown) return 1 ;;
+        "GuestLAN Hiper") return 1 ;;
+        *) echo $"Unknown card_type to determine IPv6 support"
+            return 1 ;;
+    esac
+}
+
+function insert_module() {
+    local module=${1}
+    if grep "^${module%.ko} .*$" /proc/modules &> /dev/null ; then
+        # module has already been loaded => do not try to load again
+        return 0
+    fi
+    if ! insmod $module; then
+        echo $"Could not load kernel module $module"
+    fi
+}
+
+function load_kernel_modules() {
+    if [ ":$NETTYPE" = ":ctc" ]; then
+        insert_module ccwgroup$LO
+        insert_module cu3088$LO
+        insert_module fsm$LO
+        insert_module ctc$LO
+    elif [ ":$NETTYPE" = ":iucv" ]; then
+        insert_module fsm$LO
+        insert_module iucv$LO
+        insert_module netiucv$LO
+    elif [ "$NETTYPE" = "lcs" ]; then
+        insert_module ccwgroup$LO
+        insert_module cu3088$LO
+        insert_module lcs$LO
+    elif [ "$NETTYPE" = "qeth" ]; then
+        insert_module crypto_api$LO
+        insert_module xfrm_nalgo$LO
+        insert_module ipv6$LO
+        insert_module ccwgroup$LO
+        insert_module qdio$LO
+        insert_module qeth$LO
+    fi
+}
+
+function remove_module() {
+    if ! rmmod $1; then
+        #echo $"Could not remove kernel module $1"
+        :
+    fi
+}
+
+function remove_kernel_modules() {
+    if [ ":$NETTYPE" = ":ctc" ]; then
+        remove_module ctc
+        remove_module fsm
+        remove_module cu3088
+        remove_module ccwgroup
+    elif [ ":$NETTYPE" = ":iucv" ]; then
+        remove_module netiucv
+        remove_module iucv
+        remove_module fsm
+    elif [ "$NETTYPE" = "lcs" ]; then
+        remove_module lcs
+        remove_module cu3088
+        remove_module ccwgroup
+    elif [ "$NETTYPE" = "qeth" ]; then
+        remove_module qeth
+        remove_module qdio
+        remove_module ccwgroup
+        # The remaining 3 modules can hardly be unloaded
+        # since e.g. loopback holds an inet6 address and thus a reference.
+        # But that's no problem as long as the device drivers are removed.
+        remove_module ipv6
+        remove_module xfrm_nalgo
+        remove_module crypto_api
+    fi
+}
+
+# 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. HiperSocket won't, so 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
+    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
+    # Try to silently unload modules. We ignore failures since
+    # load_kernel_modules only tries to load missing modules.
+    tv remove_kernel_modules
+    # 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 udevsettle we
+                # could wait 2 seconds unconditionally)
+                #debug ls -laF /dev/.udev
+                udevsettle
+                # 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 $cutype; then
+            if [ "${CU_DEVDRV[$cu_idx]}" != "$NETTYPE" ]; 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
+                # - 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
+    if sysecho /sys/bus/ccwgroup/drivers/${NETTYPE}/group "$SUBCHANNELS"; then
+        case "$NETTYPE" in
+            qeth)
+                # Just preliminary card_type info until device goes online!
+                # In fact it seems enough to separate OSA from HiperSocket.
+                if [ -f /sys/devices/qeth/$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=$(cat /sys/devices/cu3088/$SCH_R_DEVBUSID/type)
+                    [ "$type" = "CTC/A" ] && type="channel-to-channel adapter"
+                    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 $"  Input empty string to not modify the default configuration."
+}
+
+function exception_portno() {
+    # Writing portno of e.g. hipersocket device fails.
+    # Therefore, do not configure on empty default value.
+    [ -z "$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 $"  1 for layer 2 mode"
+    fi
+}
+
+function exception_layer2() {
+    [ -z "$LAYER2" ] && break
+}
+
+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() {
+    echo -n $" (e.g. 02:00:00:00:00:00, ? for help)."
+    # for virtual OSAs macaddr is optional and defaults to not specifying one
+    if [ -z "${cardtype//OSD_*/}" ]; then
+        echo
+    else
+        echo $" Default is automatic:"
+    fi
+}
+
+function helptext_macaddr() {
+    echo $" Help text for MAC address:"
+    echo $"  This is required for real OSA in layer 2 mode."
+    echo $"  If connecting to a layer 2 VSWITCH, a MAC address is automatically assigned."
+    echo -n $"  You may accept the automatic MAC address with an empty input."
+    if [ -z "${cardtype//OSD_*/}" ]; then
+        echo
+    else
+        echo $" [default]"
+    fi
+    echo $"  You may override the automatic MAC address with non-empty input."
+    echo $"  An example MAC address would be: 02:00:00:00:00:00"
+}
+
+function exception_macaddr() {
+    # for real OSAs macaddr is required
+    if [ -n "${cardtype//OSD_*/}" ]; then
+        # for virtual OSAs macaddr is optional
+        if [ -z "$MACADDR" ]; then
+            VSWITCH=1
+            break
+        fi
+    fi
+}
+
+function do_macaddr() {
+    ask MACADDR \
+        question_prefix_macaddr question_choices_macaddr \
+        -h helptext_macaddr -e exception_macaddr \
+        -s syntax_check_macaddr -c handle_macaddr
+}
+
+### CTCPROT
+
+function syntax_check_ctcprot() {
+    case "x$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 layer 2 interfaces"
+        [ $(linux_version) -ge $(kernel_version 2 6 26) ] && \
+            echo $"   - HiperSockets layer 3 interfaces"
+        echo $"   - z/VM guest LAN interfaces running in QDIO mode."
+        echo $"  IPv6 is not supported on HiperSocket guest LAN, OSA-Express Token Ring, ATM."
+    fi
+}
+
+function do_ipaddr() {
+    ipv6_capable && ipv6_capable=yes || ipv6_capable=no
+    ask IPADDR \
+        question_prefix_ipaddr question_choices_ipaddr \
+        -h helptext_ipaddr -s syntax_check_ipaddr
+    # no handling/configuring of IPADDR yet, since more parameters needed
+}
+
+### NETMASK (IPv4)
+
+function syntax_check_netmask_v4() {
+    # also support CIDR prefix
+    if [[ "$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
+        udevsettle
+        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
-	for i in 2 3 4 5 6 7 8 9 ; do
-	    ln -s console /dev/tty$i
-	done
-	mkdir /dev/pts
+    [ "$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 $"Enter 'exit' at the shell prompt to get back to the installation dialog."
+                /bin/bash
+                ;;
+    esac
+    done
+    return 1
+}
+
+### MAIN ###
+
 S390ARCH=`uname -m`
 if [ "$S390ARCH" = "s390" ]; then
-   export S390ARCH="S/390"
+    export S390ARCH="S/390"
 else
-   export S390ARCH="zSeries"
+    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
+    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
+    LD_LIBRARY_PATH=/lib:/usr/lib:/usr/X11R6/lib:/usr/kerberos/lib
 fi
 export LD_LIBRARY_PATH
 
@@ -202,358 +2775,281 @@ export HOME
 PYTHONPATH=/tmp/updates
 export PYTHONPATH
 
-mount -t proc none /proc
-mount -t tmpfs none /dev
-createDevices
-mount -t devpts /dev/pts /dev/pts
-mount -t sysfs none /sys
-# remount root fs rw
-mount /dev/root /  -o remount,rw
+if [ -z "$testing" ]; then
 
-# limit output on x3270 console (well, not really -- need debugging now)
-echo "8 4 1 1" > /proc/sys/kernel/printk
+    mount -t proc none /proc
+    mount -t tmpfs none /dev
+    createDevices
+    mount -t devpts /dev/pts /dev/pts
+    mount -t sysfs none /sys
+    # remount root fs rw
+    mount /dev/root /  -o remount,rw
 
-# make /tmp/ramfs
-mount -t ramfs none /tmp
+    # limit output on x3270 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
 
-ifconfig lo 127.0.0.1 netmask 255.0.0.0
-route add -host 127.0.0.1 dev lo 2>/dev/null
+    # make /tmp/ramfs
+    mount -t ramfs none /tmp
 
-echo -e "127.0.0.1\tlocalhost.localdomain localhost" > /etc/hosts
-echo -e "::1\t\tlocalhost6.localdomain6 localhost6" >> /etc/hosts
+    ifconfig lo 127.0.0.1 netmask 255.0.0.0
+    route add -host 127.0.0.1 dev lo
 
-LO=""
+    echo -e "127.0.0.1\tlocalhost.localdomain localhost" > /etc/hosts
+    echo -e "::1\t\tlocalhost6.localdomain6 localhost6" >> /etc/hosts
 
-[ -L /sbin/insmod ] && LO=".ko"
+    LO=""
 
-# Parse configuration
-if [ -n "$CMSDASD" -a -n "$CMSCONFFILE" ]; then
-   readcmsfile $CMSDASD $CMSCONFFILE
-   source /tmp/$CMSCONFFILE #2>/dev/null
-fi
+    [ -L /sbin/insmod ] && LO=".ko"
+
+    # udevd req'd by udevsettle in readcmsfile, dialog_network_table, and
+    # semantic_check_subchannels.
+    # (important to start udevd at the right time, e.g. after setup of /dev)
+    udevd --daemon
+
+    # Parse configuration
+    if [ -n "$CMSDASD" -a -n "$CMSCONFFILE" ]; then
+        readcmsfile $CMSDASD $CMSCONFFILE
+        source /tmp/$CMSCONFFILE #2>/dev/null
+    fi
+
+fi # testing
+
+### MAIN (continuation) ###
 
 if [ -r /sys/firmware/ipl/ipl_type ]; then
-	if [ "`cat /sys/firmware/ipl/ipl_type`" = "fcp" ]; then
-		while [ 1 ]; do
-			echo $"Your IPL device is set to FCP."
-			echo $"Would you like to perform a CD-ROM/DVD-ROM installation? (y/n)"
-			read do_cd_install
-			case $do_cd_install in
-				y|Y|[Yy][Ee][Ss])
-					# set up FCP cdrom here
-					insmod qdio$LO
-					insmod scsi_mod$LO
-					insmod scsi_transport_fc$LO
-					insmod zfcp$LO
-					CD_DEVICE="`cat /sys/firmware/ipl/device`"
-					WWPN="`cat /sys/firmware/ipl/wwpn`"
-					LUN="`cat /sys/firmware/ipl/lun`"
-					echo 1 > /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/online
-					echo $WWPN > /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/port_add
-					echo $LUN > /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/$WWPN/unit_add
-					break
-					;;
-				n|N|[Nn][Oo])
-					break
-					;;
-				*)
-					echo
-					echo $"*** INVALID ANSWER: $do_cd_install"
-					echo
-					unset do_cd_install
-					;;
-			esac
-		done
-	fi
+    if [ "`cat /sys/firmware/ipl/ipl_type`" = "fcp" ]; then
+        while [ 1 ]; do
+            echo $"Your IPL device is set to FCP."
+            echo $"Would you like to perform a CD-ROM/DVD-ROM installation? (y/n)"
+            read do_cd_install
+            case $do_cd_install in
+                y|Y|[Yy][Ee][Ss])
+                    insert_module qdio$LO
+                    insert_module scsi_mod$LO
+                    insert_module scsi_transport_fc$LO
+                    insert_module zfcp$LO
+                    CD_DEVICE="`cat /sys/firmware/ipl/device`"
+                    WWPN="`cat /sys/firmware/ipl/wwpn`"
+                    LUN="`cat /sys/firmware/ipl/lun`"
+                    if sysecho /proc/cio_ignore "free $CD_DEVICE"; then
+                        udevsettle
+                        sleep 1
+                    else
+                        echo $"Device $CD_DEVICE could not be cleared from device blacklist"
+                    fi
+                    echo 1 > /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/online
+                    [ $? == 0 ] || echo $"Could not set FCP device $CD_DEVICE online"
+                    echo $WWPN > /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/port_add
+                    [ $? == 0 ] || echo $"Could not add WWPN $WWPN on FCP device $CD_DEVICE"
+                    echo $LUN > /sys/bus/ccw/drivers/zfcp/$CD_DEVICE/$WWPN/unit_add
+                    [ $? == 0 ] || 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 "${cardtype//OSD_*/}" ] can be used to check for real OSA
+
+# Parse configuration
 # Check for missing parameters, prompt for them if necessary
-while [ -z "$NETTYPE" ]; do
-   echo $"Which kind of network device do you intend to use"
-   echo $"  (e.g. ctc, iucv, qeth, lcs)."
-   echo $"Enter 'qeth' for OSA-Express Fast Ethernet, Gigabit Ethernet"
-   echo $"  (including 1000Base-T), High Speed Token Ring, and ATM "
-   echo $"  (running Ethernet LAN emulation) features in QDIO mode."
-   echo $"Enter 'lcs' for OSA­2 Ethernet/Token Ring, OSA-Express Fast Ethernet in"
-   echo $"  non-QDIO mode, OSA-Express High Speed Token Ring in non-QDIO mode and"
-   echo $"  Gigabit Ethernet in non-QDIO mode."
-	read NETTYPE
-done
-if [ "$NETTYPE" != "iucv" ]; then   # iucv is the only interface without ccw config
-   if [ -n "$CHANDEV" ]; then
-		echo
-		echo $"The CHANDEV variable isn't used anymore, please update your "
-		echo $".parm or the .conf file"
-		echo
-	fi
-   while [ -z "$SUBCHANNELS" ]; do
-		echo $"Enter the bus ID and the device number of your CCW devices."
-		echo $"CTC/ESCON and LCS need two subchannels:"
-		echo $"(e.g. \"0.0.0600,0.0.0601\" will configure the CTC or ESCON interface"
-		echo $"with the subchannels 0x600 and 0x601)"
-		echo $"QETH needs three subchannels p.e. 0.0.0300,0.0.0301,0.0.0302"
-		read SUBCHANNELS
-   done
-	SUBCHANNELS=`echo $SUBCHANNELS | /sbin/busybox tr ABCDEF abcdef`
-	if [ "$NETTYPE" = "qeth" ]; then
-		if [ -z "$PORTNAME" ]; then
-			echo $"Portname of the OSA-Express feature in QDIO mode and z/VM Guest LAN"
-			echo $"This parameter is optional with z/VM 4.4.0 or z/VM 4.3.0 with"
-			echo $"APARs VM63308 and PQ73878"
-			echo $"Press enter if you don't want to enter a portname"
-			read PORTNAME
-		fi
-		if [ -z "$LAYER2" ]; then
-			echo $"Enter the mode of operation for the OSA device"
-			echo $"0 for layer 3 mode (default)"
-			echo $"1 for layer 2 mode"
-			read LAYER2
-		fi
-		if [ "$LAYER2" == 1 ]; then
-		   if [ -z "$VSWITCH" -o "$VSWITCH" == 0 ]; then
-		      if [ -z "$MACADDR" ]; then
-			   echo $"Enter a unique MAC address (eg. 02:00:00:00:00:00)."
-			   echo $"Leave this blank and press enter if connecting to a"
-			   echo $"Layer 2 VSWITCH, as this is automatically assigned"
-			   read MACADDR
-		      fi
-		   fi
-		fi
-   fi
-fi
+while : ; do
 
-while [ -z "$HOSTNAME" -o "$HOSTNAME" = "(none)" ]; do
-	echo $"Enter the FQDN of your new Linux guest (e.g. s390.redhat.com):"
-	read HOSTNAME
-done
-while [ -z "$IPADDR" ]; do
-  echo $"Enter a valid IP address of your new Linux guest:"
-  read IPADDR
-  checkip $IPADDR
-  ret=$?
-  if [ $ret -eq 1 ]; then
-    echo -n "Invalid IP address format. "
-    unset IPADDR
-  fi
-done
-while [ -z "$NETWORK" ]; do
-  echo $"Enter a valid network address of the new Linux guest:"
-  read NETWORK
-  checkip $NETWORK
-  ret=$?
-  if [ $ret -eq 1 ]; then
-    echo -n "Invalid network address format. "
-    unset NETWORK
-  fi
-done
-if [ "$NETTYPE" = "qeth" ] || [ "$NETTYPE" = "lcs" ]; then
-	 while [ -z "$NETMASK" ]; do
-		  echo $"Enter the netmask for the new Linux guest (e.g. 255.255.255.0):"
-		  read NETMASK
-		  checkip $NETMASK
-		  ret=$?
-		  if [ $ret -eq 1 ]; then
-		    echo -n "Invalid netmask format. "
-		    unset NETMASK
-		  fi
-	 done
-	 while [ -z "$BROADCAST" ]; do
-		  echo $"Enter the broadcast address for the new Linux guest:"
-		  read BROADCAST
-		  checkip $BROADCAST
-		  ret=$?
-		  if [ $ret -eq 1 ]; then
-		    echo -n "Invalid broadcast address format. "
-		    unset BROADCAST
-		  fi
-	 done
-	 while [ -z "$GATEWAY" ]; do
-		  echo $"Enter your default gateway:"
-		  read GATEWAY
-		  checkip $GATEWAY
-		  ret=$?
-		  if [ $ret -eq 1 ]; then
-		    echo -n "Invalid gateway address format. "
-		    unset GATEWAY
-		  fi
-	 done
-    if [ ":$NETTYPE" = ":lcs" ]; then
-        if [ -n "$RUNKS" -a -z "$PORTNAME" ]; then
-           PORTNAME=0
-        fi
-        while [ -z "$PORTNAME" ]; do
-           echo $"Enter the relative port number of your LCS device"
-           echo $"(required for OSA-Express ATM cards only):"
-           read PORTNAME
-        done
+    # do not show list of possible network device configurations, if:
+    # - running unattended install with kickstart
+    # - relevant parameters have already been specified in parm file
+    #   (a possible optimization would be matching those parms to table entry)
+    # - dialog has not been restarted
+    [ -n "$reenter" \
+        -o -z "$RUNKS" -a \( -z "$NETTYPE" -o -z "$SUBCHANNELS" \) ] && \
+        dialog_network_table
+    if isVM; then
+        echo $"* NOTE: To enter default or empty values press enter twice. *"
+    fi
+    do_nettype
+    tv load_kernel_modules
+    # only works, if ipv6 kernel module has been loaded before:
+    [ "$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/HiperSocket/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 "$PORTNAME" ] && PORTNAME=0
+            do_lcs_portno
+            set_device_online || workflow_item_menu noredo
+        fi
+    else # iucv
+        do_peerid
     fi
-else  # ctc0, iucv0
-    if [ -z "$NETMASK" ]; then
-        # If the user did not supply netmask, we add the right one.
-        NETMASK="255.255.255.255"
-    fi
-	 while [ -z "$GATEWAY" ]; do
-		  echo $"Enter the IP of your CTC / ESCON / IUCV point-to-point partner:"
-		  read GATEWAY
-	 done
-
-	 if [ "$NETTYPE" = "ctc" ]; then
-        if [ -z "$MTU" ]; then
-		      MTU="1500"
-        fi
-        if [ -z "$RUNKS" ]; then
-           if [ -n "$CTCPROT" ]; then
-              validprot=1
-           else
-              validprot=0
-           fi
-           while [ "$validprot" = "0" ]; do
-              echo $"Select which protocol 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 $"3 for compatibility with OS/390 or z/OS peers"
-              read CTCPROT
-              case "x$CTCPROT" in
-              x|x0)
-                 validprot=1
-                 unset CTCPROT
-                 ;;
-              x1|x3)
-                 validprot=1
-                 ;;
-              x2)
-                 echo $"CTC tty's are not usable for this installation"
-                 ;;
-              *)
-                 echo $"Invalid selection"
-                 ;;
-              esac
-           done
-	    fi
-	 fi
-	 if [ ":$NETTYPE" = ":iucv" ]; then
-		  while [ -z "$PEERID" ]; do
-			   echo $"Enter the peer id of the VM guest you want to"
-				echo $"connect to (in capital letters)."
-			   read PEERID
-		  done
-	 fi
-fi
-# don't ask for MTU, but use it if it has been set in the .parm file
-# don't overwrite MMTU if it has been set for CTC
-if [ -n "$MTU" -a -z "$MMTU" ]; then
-	 MMTU="mtu $MTU"
-fi
 
-# configure network-interface
-if [ ":$NETTYPE" = ":ctc" ]; then
-   insmod ccwgroup$LO
-	insmod cu3088$LO
-	insmod fsm$LO
-	insmod ctc$LO
-   setupdevice
-   DEVICE=${NETTYPE}0
-	ifconfig $DEVICE $IPADDR $MMTU pointopoint $GATEWAY
-   echo "alias $DEVICE ctc" >> /tmp/modprobe.conf
-elif [ ":$NETTYPE" = ":iucv" ]; then
-	insmod fsm$LO
-	insmod iucv$LO
-	insmod netiucv$LO
-	sysecho /sys/bus/iucv/drivers/netiucv/connection $PEERID
-   DEVICE=${NETTYPE}0
-	ifconfig $DEVICE $IPADDR $MMTU pointopoint $GATEWAY
-   echo "alias $DEVICE netiucv" >> /tmp/modprobe.conf
-elif [ "$NETTYPE" = "lcs" ]; then
-   insmod ccwgroup$LO
-	insmod cu3088$LO
-	insmod lcs$LO
-   setupdevice
-# KH FIXME: Workaround for missing sysfs interface
-#   DEVICE=`cat /sys/devices/lcs/${SUBCHANNELS//,*/}/if_name`
-   DEVICE=eth0
-	ifconfig $DEVICE $IPADDR $MMTU netmask $NETMASK broadcast $BROADCAST
-	route add -net $NETWORK netmask $NETMASK dev $DEVICE 2>/dev/null
-   echo "alias $DEVICE lcs" >> /tmp/modprobe.conf
-elif [ "$NETTYPE" = "qeth" ]; then
-	insmod ccwgroup$LO
-	insmod crypto_api$LO
-	insmod xfrm_nalgo$LO
-	insmod qdio$LO
-	insmod ipv6$LO
-	insmod qeth$LO
-   setupdevice
-   DEVICE=`cat /sys/devices/qeth/${SUBCHANNELS//,*/}/if_name`
-   if [ -n "$LAYER2" -a -n "$MACADDR" ]; then
-       ifconfig $DEVICE hw ether $MACADDR
-   fi
-	ifconfig $DEVICE $IPADDR $MMTU netmask $NETMASK broadcast $BROADCAST
-	route add -net $NETWORK netmask $NETMASK dev $DEVICE 2>/dev/null
-	echo "alias $DEVICE qeth" >> /tmp/modprobe.conf
-else
-   echo $"Unknown network device, aborting installation"
-   exit 1
-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
 
-route add default gw $GATEWAY dev $DEVICE 2>/dev/null
-# BH FIXME: Workaround for manual MACADDR, need ping to update arp table
-ping -c 1 $GATEWAY > /dev/null
+    [ "$HOSTNAME" = "(none)" ] && unset HOSTNAME
+    do_hostname
 
-if [ -z "$DNS" ]; then
-	echo $"Enter your DNS server(s), separated by colons (:):"
-	read DNS
-fi
-if [ -z "$DNS" ]; then
-	echo $"You might encounter problems without a nameserver, especially"
-	echo $"with FTP installs"
-fi
+    # Note: The workflow_item_menu does a rollback_config on restart
+    # dialog, i.e. hardware config has been reset and it is impossible to
+    # only restart halfway at IPADDR.
+    do_ipaddr
+    if [ "$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
 
-if [ -n "$DNS" -a -z "$SEARCHDNS" ]; then
-	echo $"Enter your DNS search domain(s) (if any), separated by colons (:):"
-	read SEARCHDNS
-fi
+    modprobe_alias
+    do_dns
+    [ -n "$DNS" ] && do_searchdns
 
-[ -n "$HOSTNAME" ] && hostname $HOSTNAME
+    do_dasd
 
-# show interfaces and routing table
-ifconfig -a
-route -n
+    echo $"Initial configuration completed."
+    final_check && break
+    rollback_config
+    reenter="yes"
 
-# 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
-	RESOLVDNS=`echo $DNS |sed -e 's/:/ /g'`
-	for i in $RESOLVDNS; do echo "nameserver $i"; done >> /etc/resolv.conf
-fi
+done # outer dialog loop
 
-# make sure we have an /etc/hosts file (required for telnetd)
-if [ ! -z "$HOSTNAME" -a ! -z "$IPADDR" ]; then
-    echo -e "$IPADDR\t$HOSTNAME `echo $HOSTNAME | cut -d '.' -f 1`" >> /etc/hosts
-fi
+#echo $"Starting portmap."
+#portmap
+
+if [ -z "$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 $i"; done >> /etc/resolv.conf
+    fi
+
+    # make sure we have an /etc/hosts file (required for telnetd)
+    if [ ! -z "$HOSTNAME" -a ! -z "$IPADDR" ]; then
+        echo -e "$IPADDR\t$HOSTNAME `echo $HOSTNAME | cut -d '.' -f 1`" >> /etc/hosts
+    fi
+
+fi # testing
+
+if [ -z "$testing" ]; then
+    # undo startup of udevd, only needed it for possible calls of udevsettle
+    killall udevd
+fi # testing
 
-if [ -z "$DASD" ]; then
-   echo
-   echo $"Enter DASD range (e.g. 200-203   or  200,201,202,203)"
-   echo $"Press <Enter> for autoprobing (not recommended):"
-   echo
-   read DASD
-fi
 if [ -n "$DASD" ]; then
-   echo "DASD=$DASD" > /tmp/dasd_ports
+    echo "DASD=$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
+    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()
 
-grep -q ext3 /proc/filesystems
-if [ "$?" != "0" ]; then
-  insmod jbd$LO
-  insmod ext3$LO
-fi
+if [ -z "$testing" ]; then
+
+    grep -q ext3 /proc/filesystems
+    if [ "$?" != "0" ]; then
+        insmod jbd$LO
+        insmod ext3$LO
+    fi
+
+fi # testing
+
+# TODO/FIXME: also need to pass IPv6 decision to loader/anaconda
+#    [ "$ipv6" ] && echo "IPV6=yes"
 
 # transfer options into install environment
 cat > /tmp/install.cfg << EOF
@@ -571,12 +3067,18 @@ MTU="$MTU"
 NETWORK="$NETWORK"
 NETMASK="$NETMASK"
 BROADCAST="$BROADCAST"
-DNS="`echo $DNS | cut -d ':' -f 1`"
 SEARCHDNS="$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 $DNS | cut -d ':' -f 1`\" >> /tmp/install.cfg
+fi
+cat >> /tmp/install.cfg << EOF
 export LANG PORTNAME S390ARCH TEXTDOMAIN TEXTDOMAINDIR
 export HOSTNAME DEVICE NETTYPE IPADDR GATEWAY MTU
 export NETWORK NETMASK BROADCAST DNS SEARCHDNS
@@ -584,44 +3086,61 @@ export PEERID ONBOOT SUBCHANNELS CTCPROT
 EOF
 # immediately read it in again to export these into the shell below
 . /tmp/install.cfg
-cat /tmp/install.cfg >> /etc/profile
-
-NETSCRIPTS="/etc/sysconfig/network-scripts"
-IFCFGFILE="$NETSCRIPTS/ifcfg-$DEVICE"
-if [ ! -d "$NETSCRIPTS" ]; then
-    mkdir -p $NETSCRIPTS
-fi
-
-cat > $IFCFGFILE << EOF
+if [ -z "$testing" ]; then
+    cat /tmp/install.cfg >> /etc/profile
+fi # testing
+cat > /tmp/netinfo << EOF
 DEVICE=$DEVICE
 ONBOOT=yes
 BOOTPROTO=static
-IPADDR=$IPADDR
-NETMASK=$NETMASK
 GATEWAY=$GATEWAY
 BROADCAST=$BROADCAST
 HOSTNAME=$HOSTNAME
 MTU=$MTU
 SUBCHANNELS=$SUBCHANNELS
 EOF
-[ "$DNS" != "" ] && echo "DNS=`echo $DNS | cut -d ':' -f 1`" >> $IFCFGFILE
-[ "$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" >> $IFCFGFILE
-
-# so that the vars get propagated into the sshd shells
-mkdir /.ssh
-cat >> /.ssh/environment <<EOF
+if [ "$ipv6" ]; then
+    [ "$DNS" != "" ] && echo "DNS=`echo $DNS | cut -d ',' -f 1`" >> /tmp/netinfo
+else
+    [ "$DNS" != "" ] && echo "DNS=`echo $DNS | cut -d ':' -f 1`" >> /tmp/netinfo
+fi
+[ "$NETTYPE" != "" ] && echo "NETTYPE=$NETTYPE" >> /tmp/netinfo
+[ "$PEERID" != "" ] && echo "PEERID=$PEERID" >> /tmp/netinfo
+[ "$PORTNAME" != "" ] && echo "PORTNAME=$PORTNAME" >> /tmp/netinfo
+[ "$CTCPROT" != "" ] && echo "CTCPROT=$CTCPROT" >> /tmp/netinfo
+[ "$LAYER2" != "" ] && echo "LAYER2=$LAYER2" >> /tmp/netinfo
+[ "$MACADDR" != "" ] && echo "MACADDR=$MACADDR" >> /tmp/netinfo
+[ "$PORTNO" != "" ] && echo "PORTNO=$PORTNO" >> /tmp/netinfo
+# also needs support in stage2 to make PORTNO persistent,
+# i.e. OPTION="portno=1" in /etc/sysconfig/network-scripts/ifcfg-<netdevname>
+# this is done by the loader starting with RHEL 5.3
+if [ "$ipv6" ]; then
+    cat >> /tmp/netinfo << EOF
+IPV6INIT=yes
+IPV6_AUTOCONF=no
+IPV6ADDR=$IPADDR/$NETMASK
+EOF
+    # FIXME: /etc/sysconfig/network:IPV6_DEFAULTGW=$GATEWAY
+    #        /etc/sysconfig/network:NETWORKING_IPV6=yes
+else
+    cat >> /tmp/netinfo << EOF
+IPADDR=$IPADDR
+NETMASK=$NETMASK
+EOF
+fi
+
+if [ -z "$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
+    cat >> /etc/profile <<EOF
 LD_LIBRARY_PATH=$LD_LIBRARY_PATH
 PATH=$PATH
 HOME=$HOME
@@ -629,31 +3148,30 @@ PYTHONPATH=$PYTHONPATH
 export LD_LIBRARY_PATH PATH HOME PYTHONPATH
 EOF
 
-if [ -n "$DISPLAY" ]; then
-	 echo "export DISPLAY=$DISPLAY" >> /etc/profile
-fi
+    if [ -n "$DISPLAY" ]; then
+        echo "export DISPLAY=$DISPLAY" >> /etc/profile
+    fi
 
-# I'm tired of typing this out...
-echo "loader" >> /.bash_history
+    # I'm tired of typing this out...
+    echo "loader" >> /.bash_history
 
-echo -n $$ > /var/run/init.pid
-# shutdown (halt) on SIGUSR1
-trap doshutdown SIGUSR1
-# reboot on SIGUSR2
-trap doreboot SIGUSR2
+    echo -n $$ > /var/run/init.pid
 
-startinetd
+    # shutdown (halt) on SIGUSR1
+    trap doshutdown SIGUSR1
+    # reboot on SIGUSR2
+    trap doreboot SIGUSR2
 
-if [ -n "$RUNKS" ]; then
-	 /sbin/loader
-fi
+    startinetd
+
+    if [ -n "$RUNKS" ]; then
+        /sbin/loader
+    fi
+
+    doreboot
 
-# A shutdown needs to be performed here to avoid a loop booting back into the installer
-echo $"Finishing up with doshutdown"
-doshutdown
+fi # testing
 
 # ;;; Local Variables: ***
 # ;;; mode: sh ***
-# ;;; tab-width:3 ***
 # ;;; end: ***
-# vim:ts=3:sw=3
diff --git a/loader/lsznet.raw b/loader/lsznet.raw
new file mode 100644
index 000000000..5b3df91e2
--- /dev/null
+++ b/loader/lsznet.raw
@@ -0,0 +1,368 @@
+#! /bin/bash
+
+# lsznet.raw: list sensible network device hardware setups for Linux on s390(x)
+# 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; version 2 of the License only.
+#
+# 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
+
+readonly SYSFS=/sys
+# DEBUG=0 turns off debugging. >=1 means increasing debugging.
+readonly DEBUG=0
+
+# nothing to be changed below here
+
+export TEXTDOMAIN=lsznet.raw
+
+readonly CMD=${0##*/}
+
+function error() {
+    echo $"$CMD: ERROR: $*" 1>&2
+    exit 1;
+}
+
+# currently requires bash version 3.0 or later
+# (this seems reasonable since bash-3.0 has been shipped with
+#  RHEL 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7;
+#  bash-3.1 with RHEL 5.0, 5.1; and bash-3.2 with RHEL 5.2)
+if [ ${BASH_VERSINFO[0]} -lt 3 -o \
+    ${BASH_VERSINFO[1]} -lt 0 ]; then
+    error $"only works with BASH version 3.0 or later (current version used is ${BASH_VERSION})"
+fi
+
+# the script was designed for Linux kernel 2.6 and might work with newer ones
+kernel_version=$(uname -r)
+IFS=.
+read krn_ver krn_patch krn_foo <<< "$kernel_version"
+unset IFS
+if [ $krn_ver -lt 2 -o $krn_patch -lt 6 ]; then
+    error $"only works for kernel versions 2.6 or probably later"
+fi
+
+# The following combinations of control unit type and model were taken from the
+# Linux network device drivers for s390 on 2008-06-09 from Linux 2.6.25.4.
+# The list (among other things) should be adapted, if any of those device
+# drivers start supporting different CU types/models.
+# (Alternatively, the list could be generated by reading the modaliases
+#  directly out of the device driver modules:
+#  modinfo qeth/cu3088 | fgrep 'alias:'
+#  However, this would still require a list of device driver modules.)
+readonly -a CU=(
+    1731/01
+    1731/05
+    3088/08
+    3088/1f
+    3088/1e
+    3088/01
+    3088/60
+    3088/61
+)
+
+# $CU_CARDTYPE array is the only one which may contain entries with spaces
+readonly -a CU_CARDTYPE=(
+    "OSA (QDIO)"
+    "HiperSocket"
+    "CTC adapter"
+    "escon channel"
+    "ficon channel"
+    "LCS p390"
+    "LCS OSA"
+    "LCS CLAW"
+)
+
+readonly -a CU_DEVDRV=(
+    qeth
+    qeth
+    ctc
+    ctc
+    ctc
+    lcs
+    lcs
+    lcs
+)
+
+readonly -a CU_DEVNAME=(
+    eth
+    hsi
+    ctc
+    ctc
+    ctc
+    eth
+    eth
+    eth
+)
+
+readonly -a CU_GROUPCHANNELS=(
+    3
+    3
+    2
+    2
+    2
+    2
+    2
+    2
+)
+readonly -a CHPIDTYPES=(
+    [10]=OSE
+    [11]=OSD
+    [24]=IQD
+)
+
+readonly PREFIXFORMAT=[[:xdigit:]]*
+readonly SSIDFORMAT=[0-3]
+readonly BUSIDFORMAT=[[:xdigit:]][[:xdigit:]][[:xdigit:]][[:xdigit:]]
+readonly IDFORMAT=$PREFIXFORMAT.$SSIDFORMAT.$BUSIDFORMAT
+readonly SUBCHANNEL_TYPE_IO=0
+
+function debug() {
+    level=$1
+    shift
+    [ $DEBUG -ge $level ] && echo "$*" 1>&2
+}
+
+# Searches for a match of argument 1 on the array $CU and sets $cu_idx
+# to the matched array index on success.
+# Returns 0 on success, 1 on failure.
+function search_cu() {
+    local scu=$1
+    local i
+    for ((i=0; i < ${#CU[@]}; i++)); do
+        if [ $scu == ${CU[i]} ]; then
+            cu_idx=$i
+            return 0
+        fi
+    done
+    return 1
+}
+
+# Returns symbolic name of CHPID type in $chpidtype_symbolic,
+# if an entry in the array $CHPIDTYPES has been found at index of argument 1.
+# Returns "?" otherwise.
+# Always succeeds and returns 0.
+function search_chpt() {
+    local chpidtype_number=$1
+    chpidtype_symbolic=${CHPIDTYPES[$chpidtype_number]}
+    if [ "$chpidtype_symbolic" == "" ]; then
+        chpidtype_symbolic="?"
+    fi
+    return 0
+}
+
+# build_list:
+#
+# Prints list on standard output consisting of all subchannels and
+# ccwdevices whose control unit type/model match supported network
+# device types on s390.  Each matching entry is accompanied with
+# (almost all) corresponding attributes.
+#
+function build_list() {
+    # use /sys/devices/css*/ for startpath
+    readonly STARTPATH=$SYSFS/devices
+    # change to base directory so path globbing length with find is minimal
+    cd $STARTPATH
+    # fail out gracefully, if there is not expected sysfs environment
+    # (could even fail out near the top, if $(uname -m) != s390x)
+    csses=css$PREFIXFORMAT
+    for d in $csses; do
+        [ -d $d ] || exit
+    done
+    find $csses -name "$IDFORMAT" |
+    while read dir; do
+        debug 6 " examining sysfs directory $dir"
+        # must not use $...FORMAT (file globs) here since this is a regex:
+        [[ "$dir" =~ ^css\([[:xdigit:]]+\)/\([[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4}\)/\([[:xdigit:]]+\\.[0-3]\\.[[:xdigit:]]{4}\)$ ]]
+        case $? in
+            0)
+                # string matched the pattern
+                debug 6 " ${BASH_REMATCH[@]}"
+                prefix=${BASH_REMATCH[1]}
+                subch=${BASH_REMATCH[2]}
+                devbusid=${BASH_REMATCH[3]}
+                subch_p=css$prefix/$subch
+                dev_p=$subch_p/$devbusid
+                debug 6 " $subch_p $dev_p"
+                ;;
+            1)
+                # string did not match the pattern
+                continue
+                ;;
+            2)
+                error $"syntax error in regex of match operator =~, code needs to be fixed"
+                ;;
+            *)
+                error $"unexpected return code of regex match operator =~, code needs to be fixed"
+                ;;
+        esac
+        debug 5 " sysfs directory matched regex $dir"
+        # skip non-I/O-subchannels, i.e. chsc and message subchannels
+	if [ -f $subch_p/type ]; then
+	    read type < $subch_p/type
+            if [ $type != $SUBCHANNEL_TYPE_IO ]; then
+                debug 3 " skip non-I/O subchannel"
+                continue
+            fi
+	fi
+        # get subchannel information...
+        # ATTENTION: hex values from sysfs are WITHOUT leading 0x prefix!
+        read chpid_list < $subch_p/chpids
+        read -a chpids <<< "$chpid_list"
+        if [ ${#chpids[@]} -ne 8 ]; then
+            error $"sysfs reported ${#chpids[@]} CHPIDs instead of expected 8"
+        fi
+        read pim pam pom foo < $subch_p/pimpampom
+        pimchpidZ=""
+        local chp
+        for ((chp=0; chp < 8; chp++)); do
+            mask=$((0x80 >> chp))
+            if (( 0x$pim & $mask )); then
+                pimchpidZ=${pimchpidZ}${chpids[chp]}
+            else
+                pimchpidZ=${pimchpidZ}"ZZ"
+            fi
+        done
+        # get device information...
+        read cutype < $dev_p/cutype
+        read active < $dev_p/online
+        # skip already active subchannels and those that are already in a
+        # ccwgroup and thus not available any more:
+        [ $active == "1" ] && continue
+        [ -h $dev_p/group_device ] && continue
+        # get chpid information...
+        pimchpids=${pimchpidZ//ZZ/}
+        [ $pimchpids == "" ] && continue
+        # Taking the first 2 hex digits as CHPID relies somewhat on the fact
+        # that network adaptors don't use multipathing and only have one CHP.
+        # Anyway it's OK since we're only interested in CHPID type and I guess
+        # this should be equal for all possible multipaths to the same device.
+        chpid=${pimchpids:0:2}
+        chpid_p=css$prefix/chp$prefix.$chpid
+        read chptype < $chpid_p/type
+        # filter and output...
+        if search_cu $cutype; then
+            if [ "${CU_DEVDRV[$cu_idx]}" == "ctc" ]; then
+                # assume CTC are mostly virtual and ignore chpid from sysfs
+                chpidtype_symbolic="-"
+            else
+                search_chpt $chptype
+            fi
+            echo $pimchpids $devbusid $STARTPATH/$dev_p $cutype $chpidtype_symbolic $chptype ${CU_DEVDRV[$cu_idx]} ${CU_DEVNAME[$cu_idx]} ${CU_GROUPCHANNELS[$cu_idx]} $cu_idx ${CU_CARDTYPE[$cu_idx]}
+        else
+            debug 5 " skip non-network device $devbusid CU $cutype"
+        fi
+    done
+}
+
+# search_groups:
+#
+# Prints enumeration list on standard output consisting of possible
+# hardware configurations (ccwgroups) for network devices on s390.
+# Each configuration suggestion includes corresponding attributes
+# that are of potential interest for the user and fit in a fixed column
+# table on an 80 column screen.
+#
+# PRECONDITION: Standard input has to be stably sorted by device bus IDs and
+# then by CHPIDs, i.e. grouped by CHPIDs.
+#
+function search_groups() {
+    local w_prefix w_ssid w_devno
+    local d_prefix d_ssid d_devno
+    local prefix ssid devno x
+    local chp devbusid dev_p cutype chpidtypename chptype devdrv devname groupchs cu_idx cardtype
+    # remembered last state variables for possible ccwgroup:
+    local r_prefix="Z"
+    local r_ssid="Z"
+    local r_devno="ZZZZ"
+    local r_chp="ZZ"
+    local r_cutype="ZZZZ/ZZ"
+    local count=0
+    local item=1
+    local skipped=0
+    # currently unused are: dev_p,chptype, cu_idx.
+    while read chp devbusid dev_p cutype chpidtypename chptype devdrv devname groupchs cu_idx cardtype; do
+        debug 1 " # $chp $devbusid $dev_p $cutype $chpidtypename $chptype $devdrv $devname $groupchs $cu_idx $cardtype"
+        IFS=.
+        read prefix ssid devno x <<< "$devbusid"
+        unset IFS
+        if [ $r_chp != $chp \
+            -o $r_prefix != $prefix \
+            -o $r_ssid != $ssid \
+            -o $r_cutype != $cutype ]; then
+            # restart with new read channel info and remember it
+            r_prefix=$prefix
+            r_ssid=$ssid
+            r_devno=$devno
+            r_chp=$chp
+            r_cutype=$cutype
+            count=1
+            debug 2 " INFO: restart on different CHPID or prefix or CUtype/model"
+            continue
+        fi
+        count=$((count + 1))
+        if [ $count -eq 2 ]; then
+            # about to check if write channel is one above read channel
+            if [ $((0x$devno)) -ne $((0x$r_devno + 1)) ]; then
+                # start with new read channel info
+                r_prefix=$prefix
+                r_ssid=$ssid
+                r_devno=$devno
+                r_chp=$chp
+                r_cutype=$cutype
+                count=1
+                skipped=$((skipped + 1))
+                # unimplemented possible packed channel usage option:
+                # remember unused channels for later use as data channel
+                debug 2 " INFO: restart on unmatching read channel"
+                continue
+            fi
+            w_prefix=$prefix
+            w_ssid=$ssid
+            w_devno=$devno
+        elif [ $count -eq 3 ]; then
+            # remember data channel info
+            d_prefix=$prefix
+            d_ssid=$ssid
+            d_devno=$devno
+        fi
+        debug 2 " INFO: groupchs=$groupchs count=$count"
+        if [ $count -ne $groupchs ]; then
+            debug 2 " INFO: skip"
+            continue
+        fi
+        # found possible ccwgroup
+        case $count in
+            2)
+                chlist=$r_prefix.$r_ssid.$r_devno,$w_prefix.$w_ssid.$w_devno
+                ;;
+            3)
+                chlist=$r_prefix.$r_ssid.$r_devno,$w_prefix.$w_ssid.$w_devno,$d_prefix.$d_ssid.$d_devno
+                ;;
+            *)
+                error $"unknown number of channels for group, code needs to be fixed"
+                ;;
+        esac
+        echo $item $cutype $chp $chpidtypename $devdrv $devname $chlist "$cardtype"
+        item=$((item + 1))
+        # restart after successful detection
+        r_prefix="Z"
+        count=0
+    done
+    debug 1 " STATISTIC: skipped $skipped devnos because of unmatching read channel"
+}
+
+build_list |
+# stable sort by device bus IDs and then by CHPIDs => grouped by CHPIDs
+# (sorting only works since keys are fixed no. of digits with leading zeros!)
+sort -s -k 1,1 -k 2,2 |
+#cat ; exit # move at desired line and uncomment to see intermediate output
+search_groups
diff --git a/scripts/mk-images b/scripts/mk-images
index 523800efe..d42bc4ccc 100755
--- a/scripts/mk-images
+++ b/scripts/mk-images
@@ -603,6 +603,7 @@ makeinitrd() {
     else
         instbin $IMGPATH ${LOADERBINDIR##IMGPATH}/shutdown $MBD_DIR /sbin/shutdown
         instbin $IMGPATH /usr/lib/anaconda-runtime/loader/linuxrc.s390 $MBD_DIR /sbin/init
+        instbin $IMGPATH /usr/lib/anaconda-runtime/loader/lsznet.raw $MBD_DIR /sbin/lsznet
         instbin $IMGPATH /usr/sbin/dasdfmt $MBD_DIR /sbin/dasdfmt
     fi
 
@@ -631,6 +632,7 @@ makeinitrd() {
     instbin $IMGPATH /usr/sbin/udevd $MBD_DIR /sbin/udevd
     instbin $IMGPATH /usr/sbin/udevadm $MBD_DIR /sbin/udevadm
     instbin $IMGPATH /usr/bin/udevinfo $MBD_DIR /sbin/udevinfo
+    instbin $IMGPATH /usr/sbin/udevsettle $MBD_DIR /sbin/udevsettle
 
     instbin $IMGPATH /usr/bin/bash $MBD_DIR /sbin/bash
     ( cd $MBD_DIR/sbin ; ln -sf bash sh )