#!/bin/bash
#==============================================================================
# Copyright IBM Corp. 2007
#
# chchp
#
# Script to modify channel-path state.
#
# Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
#
# This file is part of s390-tools
#
# s390-tools is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# s390-tools 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 s390-tools; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#==============================================================================

SYSFS="/sys"
VERSION="%S390_TOOLS_VERSION%"
TOOLNAME=${0##*/}
MAX_CHPID_CSS=255
MAX_CHPID_ID=255

# Print help text
function print_help()
{
	cat <<EOF
Usage: ${TOOLNAME} COMMAND CHPID

Modify the state of channel-path CHPID. CHPID can be a single, hexadecimal
channel-path identifier, a comma-separated list or a range of identifiers.

COMMANDS:
-v, --vary VALUE           Logically vary channel-path to VALUE (1=on, 0=off)
-c, --configure VALUE      Configure channel-path to VALUE (1=on, 0=standby)
-a, --attribute KEY=VALUE  Set channel-path attribute KEY to VALUE
-h, --help                 Print this help, then exit
    --version              Print version information, then exit
EOF
}

# Print version information
function print_version()
{
	cat <<EOF
${TOOLNAME}: version ${VERSION}.
Copyright IBM Corp. 2007
EOF
}

# Print channel-path directory
function get_chp_dir()
{
	local DIR;

	DIR=$(printf "%s/devices/css%x/chp%x.%x" "$SYSFS" "$1" "$1" "$2")
	if [ ! -d $DIR ] ; then
		DIR=$(printf "%s/devices/css%x/chp%x.%02x" "$SYSFS" "$1" "$1" \
		      "$2")
	fi
	echo $DIR
}

# Write and check attribute value
function write_value()
{
	local DIR=$1
	local KEY=$2
	local VAL=$3
	local VAL2

	if [ ! -f $DIR/$KEY ] ; then
		echo "failed - no such attribute"
		exit 1
	fi
	if [ ! -w $DIR/$KEY ] ; then
		echo "failed - attribute not writable"
		exit 1
	fi
	if ! echo $VAL > $DIR/$KEY ; then
		echo "failed - write failed"
		exit 1
	fi
	if ! read < $DIR/$KEY VAL2 ; then
		echo "failed - could not determine new attribute value"
		exit 1
	fi
	# Skip value comparison for 'status' attribute because input
	# can be specified in different ways
	if [ "$KEY" != "status" ] ; then
		if [ "$VAL" != "$VAL2" ] ; then
			echo "failed - attribute value not as expected"
			exit 1
		fi
	fi
	echo done.
}

# Configure channel-path
function configure()
{
	local CSS=$1
	local NUM=$2
	local DIR=$3
	local VAL=$4

	if [ "$VAL" == "0" ] ; then
		OP="standby"
	else
		OP="online"
	fi

	printf "Configure %s %x.%02x... " $OP $CSS $NUM
	write_value $DIR "configure" $VAL
}

# Vary channel-path
function vary()
{
	local CSS=$1
	local NUM=$2
	local DIR=$3

	if [ "$4" == "0" ] ; then
		VAL="offline"
	else
		VAL="online"
	fi

	printf "Vary %s %x.%02x... " $VAL $CSS $NUM
	write_value $DIR "status" $VAL
}

# Modify channel-path attribute
function attribute()
{
	local CSS=$1
	local NUM=$2
	local DIR=$3
	local KEY=${4%%=*}
	local VAL=${4#*=}

	printf "Attribute %s=%s %x.%02x... " $KEY $VAL $CSS $NUM
	write_value $DIR $KEY $VAL
}

# Make sure only one command is specified
function check_and_set_command()
{
	if [ ! -z "$COMMAND" ] ; then
		echo "$TOOLNAME: Only one of --vary, --configure or " \
		     "--attribute allowed" >&2
		exit 1
	fi
	COMMAND=$1
}

# Make sure command argument was specified correctly
function check_and_set_value()
{
	if [ -z "$1" ] ; then
		echo "$TOOLNAME: --${COMMAND} requires an argument" >&2
		exit 1
	fi
	if [ "$COMMAND" == "attribute" ] ; then
		local KEY=${1%%=*}
		local VAL=${1#*=}

		if [ "$KEY" == "$1" ] || [ -z "$KEY" ] || [ -z "$VAL" ] ; then
			echo "$TOOLNAME: --attribute requires an argument " \
			     "KEY=VALUE" >&2
			exit 1
		fi
	fi
	VALUE=$1
}

# Extract css id from channel-path id string
function get_chpid_css()
{
	local VAR=$1
	local CHPID=$2
	local CSS
	local RESULT

	CSS=${CHPID%%.*}
	if [ "$CSS" == "$CHPID" ] ; then
		RESULT=0
	else
		let RESULT="0x$CSS" 2>/dev/null
		if [ -z "$RESULT" ] ; then
			echo "$TOOLNAME: Invalid channel-path identifier " \
			     "'$CHPID'" >&2
			exit 1
		fi
		if [ "$RESULT" -lt 0 ] || [ $RESULT -gt $MAX_CHPID_CSS ] ; then
			echo "$TOOLNAME: Invalid channel-path identifier " \
			     "'$CHPID'" >&2
			exit 1
		fi
	fi
	eval $VAR=$RESULT
}

# Extract id from channel-path id string
function get_chpid_id()
{
	local VAR=$1
	local CHPID=$2
	local ID
	local RESULT

	ID=${CHPID##*.}
	let RESULT="0x$ID" 2>/dev/null
	if [ -z "$RESULT" ] ; then
		echo "$TOOLNAME: Invalid channel-path identifier '$CHPID'" >&2
		exit 1
	fi
	if [ "$RESULT" -lt 0 ] || [ $RESULT -gt $MAX_CHPID_ID ] ; then
		echo "$TOOLNAME: Invalid channel-path identifier '$CHPID'" >&2
		exit 1
	fi
	eval $VAR=$RESULT
}

# Perform command specified by COMMAND and VALUE
function perform_command()
{
	local CSS=$1
	local ID=$2
	local DIR

	DIR=$(get_chp_dir "$CSS" "$ID")
	if [ ! -d "$DIR" ] ; then
		printf "Skipping unknown channel-path "
		printf "%x.%02x\n" $CSS $ID
		return
	fi
	case $COMMAND in
	vary)
		vary $CSS $ID $DIR $VALUE
		;;
	configure)
		configure $CSS $ID $DIR $VALUE
		;;
	attribute)
		attribute $CSS $ID $DIR $VALUE
		;;
	esac
}

# Calculate iterator steps for chpid loop
function get_iterator_step()
{
	local VAR=$1
	local CSS1=$2
	local ID1=$3
	local CSS2=$4
	local ID2=$5
	local RESULT

	if [ $CSS1 -eq $CSS2 ] ;then
		if [ $ID1 -le $ID2 ] ; then	
			RESULT=1
		else
			RESULT=-1
		fi
	elif [ $CSS1 -lt $CSS2 ] ; then
		RESULT=1
	else
		RESULT=-1
	fi

	eval $VAR=$RESULT
}

function loop_chpids()
{
	local CSS1=$1
	local ID1=$2
	local CSS2=$3
	local ID2=$4
	local FUNC=$5
	local STEP

	get_iterator_step STEP $1 $2 $3 $4
	# Loop
	while true ; do
		# Perform function
		eval $FUNC $CSS1 $ID1
		# Check for loop end
		if [ $CSS1 -eq $CSS2 ] && [ $ID1 -eq $ID2 ] ; then
			break
		fi
		# Advance iterator
		let ID1=$ID1+$STEP
		if [ $ID1 -lt 0 ] ; then
			let CSS1=$CSS1-1
			ID1=255
		elif [ $ID2 -gt 255 ] ; then
			let CSS1=$CSS1+1
			ID1=0
		fi
	done
}

# Parse command line parameters
COMMAND=""
VALUE=""
CHPID_LIST=""
while [ $# -gt 0 ]; do
	case $1 in
	-h|--help)
		print_help
		exit 0
		;;
	--version)
		print_version
		exit 0
		;;
	-v|--vary)
		check_and_set_command "vary"
		check_and_set_value "$2"
		shift
		;;
	-c|--configure)
		check_and_set_command "configure"
		check_and_set_value "$2"
		shift
		;;
	-a|--attribute)
		check_and_set_command "attribute"
		check_and_set_value "$2"
		shift
		;;
	-*|--*)
		echo "$TOOLNAME: Invalid option $1" >&2
		echo "Try '$TOOLNAME --help' for more information" >&2
		exit 1
		;;
	*)
		if [ -z "$CHPID_LIST" ] ; then
			CHPID_LIST="$1"
		else
			CHPID_LIST="$CHPID_LIST,$1"
		fi
		;;
	esac
	shift
done

if [ -z "$COMMAND" ] ; then
	echo "$TOOLNAME: One of --vary, --configure or --attribute required" >&2
	exit 1
fi

if [ -z "$CHPID_LIST" ] ; then
	echo "$TOOLNAME: Need to specify at least one channel-path ID" >&2
	exit 1
fi

if [ ! -e "$SYSFS" ] ; then
	echo "$TOOLNAME: $SYSFS does not exist" >&2
	exit 1
fi

if [ ! -d "$SYSFS" ] ; then
	echo "$TOOLNAME: $SYSFS is not a directory" >&2
	exit 1
fi

# Loop over comma-separated list
IFS=','
for CHPID in $CHPID_LIST ; do
	if [ -z "$CHPID" ] ; then
		continue
	fi
	CHPID_FROM=${CHPID%%-*}
	if [ "$CHPID" == "$CHPID_FROM" ] ; then
		CHPID_TO=$CHPID_FROM
	else
		CHPID_TO=${CHPID##*-}
		if [ -z "$CHPID_TO" ] ; then
			echo "$TOOLNAME: Invalid channel-path identifier " \
			     "range $CHPID" >&2
			exit 1
		fi
	fi
	get_chpid_css FROM_CSS $CHPID_FROM
	get_chpid_id FROM_ID $CHPID_FROM
	get_chpid_css TO_CSS $CHPID_TO
	get_chpid_id TO_ID $CHPID_TO
	loop_chpids $FROM_CSS $FROM_ID $TO_CSS $TO_ID perform_command
done