#!/bin/sh
#
# Copyright (C) Voltaire Ltd. 2006.  ALL RIGHTS RESERVED.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 59 Temple
# Place, Suite 330, Boston, MA 02111-1307 USA
#
# Author: Dan Bar Dov <danb@voltaire.com>

# iscsi_discovery:
#    * does a send-targets discovery to the given IP
#    * set the transport type to ISER
#    * tries to login
#    * if succeeds,
#          o logout,
#          o mark record autmatic 
#    * else
#          o reset transport type to TCP
#          o try to login
#          o if succeeded
#                + logout
#                + mark record automatic 
#

dbg()
{
	$debug || echo $@
}

initialize()
{
	trap "exit" 2
	usage="Usage: $0 [-d] <IP> [<port>]"
	debug=false
}

parse_cmdline()
{
	if [ "$1" = "-d" ]; then
		debug=true
		shift
	fi
	if [ $# -lt 1 ]; then
		echo ${usage}
		exit 1
	fi

	ip=$1
	port=${2:-3260}
}


discover()
{
	connected=0
	discovered=0
	df=/tmp/discovered.$$

	dbg "starting discovery to $ip"
	iscsiadm -m discovery --type sendtargets --portal ${ip}:${port} > ${df}
	while read portal target
	do
		portal=${portal%,*}
		select_transport
	done < ${df}

	discovered=$(cat ${df} | wc -l)
	if [ ${discovered} = 0 ]; then
		echo "failed to discover targets at ${ip}"
		exit 2
	else 
		echo "discovered ${discovered} targets at ${ip}, connected to ${connected}"
	fi
	/bin/rm -f ${df}
}

set_auto_if_login()
{
	iscsiadm -m node --targetname ${target} --portal ${portal} --login >/dev/null 2>&1
	ret=$?
	if [ ${ret} = 0 ]; then
        	iscsiadm -m node --targetname ${target} --portal ${portal} --logout
		iscsiadm -m node --targetname ${target} --portal ${portal} --op update -n node.conn[0].startup -v automatic
		echo "Set target ${target} to automatic login over ${transport} to portal ${portal}"
		connected=$(($connected + 1))
	fi
	return ${ret}
}

set_transport()
{
	transport=$1
	iscsiadm -m node --targetname ${target} --portal ${portal} \
			 --op update -n node.conn[0].iscsi.HeaderDigest -v None
	iscsiadm -m node --targetname ${target} --portal ${portal} \
			 --op update -n node.transport_name -v ${transport}
}

select_transport()
{
	set_transport iser
	dbg "Testing iser-login to target ${target} portal ${portal}"
	set_auto_if_login
	if [ $? != 0 ]; then
		set_transport tcp
		dbg "starting to test tcp-login to target ${target} portal ${portal}"
		set_auto_if_login
	fi
}

initialize
parse_cmdline "$@"
discover