#!/bin/bash

#

# 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

#

# Author: Dan Bar Dov <danb@voltaire.com>

# iscsi_discovery:

#    * does a send-targets discovery to the given IP

#    * set the transport type to the preferred transport (or tcp is -t flag is not used)

#    * tries to login

#    * if succeeds,

#          o logout,

#          o mark record autmatic (unless -m flag is used)

#    * else

#          o reset transport type to TCP

#          o try to login

#          o if succeeded

#                + logout

#                + mark record automatic (unless -m flag is used)

#

usage()

{

	echo "Usage: $0 <IP> [-p <port>] [-d] [-t <tcp|iser> [-f]] [-m] [-l]"

	echo "Options:"

	echo  "-p		set the port number (default is 3260)."

	echo  "-d		print debugging information"

	echo  "-t		set transport (default is tcp)."

	echo  "-f		force specific transport -disable the fallback to tcp (default is fallback enabled)."

	echo  "			force the transport specified by the argument of the -t flag."

	echo  "-m		manual startup - will set manual startup (default is automatic startup)."

	echo  "-l		login to the new discovered nodes (default is false)."

}

dbg()

{

	$debug && echo $@

}

initialize()

{

	trap "exit" 2

	debug=false

	force="0"

	log_out="1"

	startup_manual="0"

	#set default transport to tcp

	transport=tcp

	#set default port to 3260

	port=3260;

}

parse_cmdline()

{

	if [ $# -lt 1 ]; then

		usage

		exit 1

	fi

	# check if the IP address is valid

	ip=`echo $1 | awk -F'.' '$1 != "" && $1 <=255 && $2 != "" && $2 <= 255 && $3 != "" && $3 <= 255 && $4 != "" && $4 <= 255 {print $0}'`

	if [ -z "$ip" ]; then

		echo "$1 is not a vaild IP address!"

		exit 1

	fi

	shift

	while getopts "dfmlt:p:" options; do

	 case $options in

		d ) debug=true;;

		f ) force="1";;

		t ) transport=$OPTARG;;

		p ) port=$OPTARG;;

		m ) startup_manual="1";;

		l ) log_out=0;;

		\? ) usage

			exit 1;;

		* )  usage

			exit 1;;

	 esac

	done

}

discover()

{

	# If open-iscsi is already logged in to the portal, exit

	if [ $(iscsiadm -m session | grep -c ${ip}:${port}) -ne 0 ]; then

		echo "Please logout from all targets on ${ip}:${port} before trying to run discovery on that portal"

		exit 2

	fi

	connected=0

	discovered=0

	dbg "starting discovery to $ip"

	disc="$(iscsiadm -m discovery --type sendtargets --portal ${ip}:${port})"

	echo "${disc}" | while read portal target

	do

		portal=${portal%,*}

		select_transport

	done

	discovered=$(echo "${disc}" | wc -l)

	if [ ${discovered} = 0 ]; then

		echo "failed to discover targets at ${ip}"

		exit 2

	else

		echo "discovered ${discovered} targets at ${ip}"

	fi

}

try_login()

{

	if [ "$startup_manual" != "1" ]; then

		iscsiadm -m node --targetname ${target} --portal ${portal} --op update -n node.conn[0].startup -v automatic

	fi

	iscsiadm -m node --targetname ${target} --portal ${portal} --login >/dev/null 2>&1

	ret=$?

	if [ ${ret} = 0 ]; then

		echo "Set target ${target} to automatic login over ${transport} to portal ${portal}"

		((connected++))

		if [ "$log_out" = "1" ]; then

			iscsiadm -m node --targetname ${target} --portal ${portal} --logout

		fi

	else

		echo "Cannot login over ${transport} to portal ${portal}"

		iscsiadm -m node --targetname ${target} --portal ${portal} --op update -n node.conn[0].startup -v manual

	fi

	return ${ret}

}

set_transport()

{

	transport=$1

	case "$transport" in

	iser)

		# iSER does not use digest

		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.conn[0].iscsi.DataDigest -v None

		;;

	cxgb3i)

		# cxgb3i supports <= 16K packet (BHS + AHS + pdu payload + digests)

		iscsiadm -m node --targetname ${target} --portal ${portal} \

			--op update -n node.conn[0].iscsi.MaxRecvDataSegmentLength \

			-v 8192

		;;

	esac

	transport_name=`iscsiadm  -m node -p ${portal} -T ${target} |awk '/transport_name/ {print $1}'`

	iscsiadm -m node --targetname ${target} --portal ${portal} \

			--op update -n ${transport_name} -v ${transport}

}

select_transport()

{

	set_transport $transport

	dbg "Testing $transport-login to target ${target} portal ${portal}"

	try_login;

	if [ $? != 0 -a  "$force" = "0" ]; then

		set_transport tcp

		dbg "starting to test tcp-login to target ${target} portal ${portal}"

		try_login;

	fi

}

check_iscsid()

{

	#check if iscsid is running

	pidof iscsid &>/dev/null

	ret=$?

	if [ $ret -ne 0 ]; then

		echo "iscsid is not running"

		echo "Exiting..."

		exit 1

	fi

}

check_iscsid

initialize

parse_cmdline "$@"

discover