#!/bin/sh
#
# iSCSI OCF resource agent
# Description: manage iSCSI disks (add/remove) using open-iscsi
#
# Copyright Dejan Muhamedagic <dejan@suse.de>
# (C) 2007 Novell Inc. All Rights Reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# Further, this software is distributed without any warranty that it is
# free of the rightful claim of any third person regarding infringement
# or the like.  Any license provided herein, whether implied or
# otherwise, applies only to this software file.  Patent licenses, if
# any, provided herein do not apply to combinations of this program with
# other software, or any other product whatsoever.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
#
# See usage() and meta_data() below for more details...
#
# OCF instance parameters:
#	OCF_RESKEY_portal: the iSCSI portal address or host name (required)
#	OCF_RESKEY_target: the iSCSI target (required)
#	OCF_RESKEY_iscsiadm: iscsiadm program path (optional)
#	OCF_RESKEY_discovery_type: discovery type (optional; default: sendtargets)
#	OCF_RESKEY_try_recovery: wait for iSCSI recovery in monitor (optional; default: false)
#
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

# Defaults
OCF_RESKEY_udev_default="yes"
OCF_RESKEY_iscsiadm_default="iscsiadm"
OCF_RESKEY_discovery_type_default="sendtargets"
OCF_RESKEY_try_recovery_default="false"

: ${OCF_RESKEY_udev=${OCF_RESKEY_udev_default}}
: ${OCF_RESKEY_iscsiadm=${OCF_RESKEY_iscsiadm_default}}
: ${OCF_RESKEY_discovery_type=${OCF_RESKEY_discovery_type_default}}

usage() {
  methods=`iscsi_methods`
  methods=`echo $methods | tr ' ' '|'`
  cat <<EOF
	usage: $0 {$methods}

	$0 manages an iSCSI target

	The 'start' operation starts (adds) the iSCSI target.
	The 'stop' operation stops (removes) the iSCSI target.
	The 'status' operation reports whether the iSCSI target is connected
	The 'monitor' operation reports whether the iSCSI target is connected
	The 'validate-all' operation reports whether the parameters are valid
	The 'methods' operation reports on the methods $0 supports

EOF
}

meta_data() {
	cat <<EOF
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="iscsi" version="1.0">
<version>1.0</version>

<longdesc lang="en">
OCF Resource Agent for iSCSI. Add (start) or remove (stop) iSCSI
targets.
</longdesc>
<shortdesc lang="en">Manages a local iSCSI initiator and its connections to iSCSI targets</shortdesc>

<parameters>

<parameter name="portal" unique="0" required="1">
<longdesc lang="en">
The iSCSI portal address in the form: {ip_address|hostname}[":"port]
</longdesc>
<shortdesc lang="en">Portal address</shortdesc>
<content type="string" />
</parameter>

<parameter name="target" unique="1" required="1">
<longdesc lang="en">
The iSCSI target IQN.
</longdesc>
<shortdesc lang="en">Target IQN</shortdesc>
<content type="string" />
</parameter>

<parameter name="discovery_type" unique="0" required="0">
<longdesc lang="en">
Target discovery type. Check the open-iscsi documentation for
supported discovery types.
</longdesc>
<shortdesc lang="en">Target discovery type</shortdesc>
<content type="string" default="${OCF_RESKEY_discovery_type_default}" />
</parameter>

<parameter name="iscsiadm" unique="0" required="0">
<longdesc lang="en">
open-iscsi administration utility binary.
</longdesc>
<shortdesc lang="en">iscsiadm binary</shortdesc>
<content type="string" default="${OCF_RESKEY_iscsiadm_default}" />
</parameter>

<parameter name="udev" unique="0" required="0">
<longdesc lang="en">
If the next resource depends on the udev creating a device then
we wait until it is finished. On a normally loaded host this
should be done quickly, but you may be unlucky. If you are not
using udev set this to "no", otherwise we will spin in a loop
until a timeout occurs.
</longdesc>
<shortdesc lang="en">udev</shortdesc>
<content type="string" default="${OCF_RESKEY_udev_default}" />
</parameter>

<parameter name="try_recovery" unique="0" required="0">
<longdesc lang="en">
If the iSCSI session exists but is currently inactive/broken,
which is most probably due to network problems, the iSCSI layer
will try to recover. If this parameter is set to true, we'll wait
for the recovery to succeed. In that case the monitor operation
can only time out so you should set the monitor op timeout
attribute appropriately.
</longdesc>
<shortdesc lang="en">On error wait for iSCSI recovery in monitor</shortdesc>
<content type="boolean" default="${OCF_RESKEY_try_recovery_default}" />
</parameter>

</parameters>

<actions>
<action name="start" timeout="120s" />
<action name="stop" timeout="120s" />
<action name="status" timeout="30s" />
<action name="monitor" depth="0" timeout="30s" interval="120s" />
<action name="validate-all" timeout="5s" />
<action name="methods" timeout="5s" />
<action name="meta-data" timeout="5s" />
</actions>
</resource-agent>
EOF
}

iscsi_methods() {
  cat <<EOF
	start
	stop
	status
	monitor
	validate-all
	methods
	meta-data
	usage
EOF
}

#
# open-iscsi interface
#

is_iscsid_running() {
	ps -e -o cmd | grep -qs '[i]scsid'
}
open_iscsi_setup() {
	discovery=open_iscsi_discovery
	add_disk=open_iscsi_add
	remove_disk=open_iscsi_remove
	disk_status=open_iscsi_monitor
	iscsiadm=${OCF_RESKEY_iscsiadm}

	have_binary ${iscsiadm} ||
		return 3
	if is_iscsid_running; then
		return 0
	elif grep -qs '^iscsid.startup' /etc/iscsi/iscsid.conf; then
		# apparently on RedHat (perhaps elsewhere?), there is a
		# kind of iscsid autostart once root invokes some
		# open_iscsi command; the iscsid.startup hook should take
		# care of it; reported by m.richardson@ed.ac.uk (see also
		# the discussion at the linux-ha-dev ML)
		return 1
	else
		ocf_exit_reason "iscsid not running; please start open-iscsi utilities"
		return 2
	fi
}

#
# discovery return codes:
#   0: ok (variable portal set)
#   1: target not found
#   2: target found but can't connect it unambigously
#   3: iscsiadm returned error
#
# open-iscsi >= "2.0-872" changed discovery semantics
# see http://www.mail-archive.com/open-iscsi@googlegroups.com/msg04883.html
# there's a new discoverydb command which should be used instead discovery
 
open_iscsi_discovery() {
	local output
	local discovery_variant="discovery"
	local options=""
	local cmd
	local version=`$iscsiadm --version | awk '{print $3}'`

	ocf_version_cmp "$version" "2.0-871"
	if [ $? -eq 2 ]; then # newer than 2.0-871?
		discovery_variant="discoverydb"
		[ "$discovery_type" = "sendtargets" ] &&
			options="-D"
	fi
	cmd="$iscsiadm -m $discovery_variant -p $OCF_RESKEY_portal -t $discovery_type $options"
	output=`$cmd`
	if [ $? -ne 0 -o x = "x$output" ]; then
		[ x != "x$output" ] && {
			ocf_exit_reason "$cmd FAILED"
			echo "$output"
		}
		return 3
	fi
	PORTAL=`echo "$output" |
		awk -v target="$OCF_RESKEY_target" '
		$NF==target{
			if( NF==3 ) portal=$2; # sles compat mode
			else portal=$1;
			sub(",.*","",portal);
			print portal;
		}'`

	case `echo "$PORTAL" | wc -w` in
	0) #target not found
		echo "$output"
		ocf_exit_reason "target $OCF_RESKEY_target not found at portal $OCF_RESKEY_portal"
		return 1
	;;
	1) #we're ok
		return 0
	;;
	*) # handle multihome hosts reporting multiple portals
		for p in $PORTAL; do
			if [ "$OCF_RESKEY_portal" = "$p" ]; then
				PORTAL="$OCF_RESKEY_portal"
				return 0
			fi
		done
		echo "$output"
		ocf_exit_reason "sorry, can't handle multihomed hosts unless you specify the portal exactly"
		return 2
	;;
	esac
}
open_iscsi_add() {
	$iscsiadm -m node -p $1 -T $2 -l
}
open_iscsi_get_session_id() {
	local target="$1"
	local portal="$2"
	$iscsiadm -m session 2>/dev/null |
		grep -E "$target($|[[:space:]])" |
		grep -E "] $portal" |
		awk '{print $2}' | tr -d '[]'
}
open_iscsi_remove() {
	local target="$1"
	local session_id
	session_id=`open_iscsi_get_session_id "$target" "$OCF_RESKEY_portal"`
	if [ "$session_id" ]; then
		$iscsiadm -m session -r $session_id -u
	else
		ocf_exit_reason "cannot find session id for target $target"
		return 1
	fi
}
# open_iscsi_monitor return codes:
#   0: target running (logged in)
#   1: target not running and target record exists
#   2: iscsiadm -m session error (unexpected)
#   3: target record does not exist (discovery necessary)
#
open_iscsi_monitor() {
	local target="$1"
	local session_id conn_state outp
	local prev_state
	local recov

	recov=${2:-$OCF_RESKEY_try_recovery}
	session_id=`open_iscsi_get_session_id "$target" "$OCF_RESKEY_portal"`
	prev_state=""
	if [ -z "$session_id" ]; then
		if $iscsiadm -m node -p $OCF_RESKEY_portal -T $target >/dev/null 2>&1; then
			return 1 # record found
		else
			return 3
		fi
	fi
	while :; do
		outp=`$iscsiadm -m session -r $session_id -P 1` ||
			return 2
		conn_state=`echo "$outp" | sed -n '/Connection State/s/.*: //p'`
		# some drivers don't return connection state, in that case
		# we'll assume that we're still connected
		case "$conn_state" in
			"LOGGED IN")
				[ -n "$msg_logged" ] &&
					ocf_log info "connection state $conn_state. Session restored."
				return 0;;
			"Unknown"|"") # this is also probably OK
				[ -n "$msg_logged" ] &&
					ocf_log info "connection state $conn_state. Session restored."
				return 0;;
			*) # failed
				if [ "$__OCF_ACTION" != stop ] && ! ocf_is_probe && ocf_is_true $recov; then
					if [ "$conn_state" != "$prev_state" ]; then
						ocf_log warning "connection state $conn_state, waiting for recovery..."
						prev_state="$conn_state"
					fi
					sleep 1
				else
					ocf_exit_reason "iscsiadm output: $outp"
					return 2
				fi
			;;
		esac
	done
}

disk_discovery() {
	discovery_type=${OCF_RESKEY_discovery_type}
	$discovery  # discover and setup the real portal string (address)
	case $? in
	0) ;;
	1|2) exit $OCF_ERR_GENERIC ;;
	3) if ! is_iscsid_running; then
			[ $setup_rc -eq 1 ] &&
				ocf_log warning "iscsid.startup probably not correctly set in /etc/iscsi/iscsid.conf"
			exit $OCF_ERR_INSTALLED
	   fi
	   exit $OCF_ERR_GENERIC
	;;
	esac
}

#
# NB: this is udev specific!
#
wait_for_udev() {
	dev=/dev/disk/by-path/ip-$PORTAL-iscsi-$OCF_RESKEY_target
	while :; do
		ls $dev* >/dev/null 2>&1 && break
		ocf_log warning "waiting for udev to create $dev" 
		sleep 1
	done
}
iscsi_monitor() {
	$disk_status $OCF_RESKEY_target $*
	case $? in
		0) return $OCF_SUCCESS;;
		1|3) return $OCF_NOT_RUNNING;;
		2) return $OCF_ERR_GENERIC;;
	esac
}
iscsi_start() {
	local rc
	$disk_status $OCF_RESKEY_target
	rc=$?
	if [ $rc -eq 3 ]; then
		disk_discovery
		$disk_status $OCF_RESKEY_target
		rc=$?
	fi
	case $rc in
	0)
		ocf_log info "iscsi $PORTAL $OCF_RESKEY_target already running"
		return $OCF_SUCCESS
	;;
	1)
		$add_disk $PORTAL $OCF_RESKEY_target ||
			return $OCF_ERR_GENERIC
		case "$OCF_RESKEY_udev" in
		[Yy]es) wait_for_udev ||
			return $OCF_ERR_GENERIC
		;;
		*) ;;
		esac
	;;
	*) # the session exists, but it's broken
		ocf_log warning "iscsi $PORTAL $OCF_RESKEY_target in failed state"
	;;
	esac
	iscsi_monitor 1 # enforce wait
	if [ $? -eq $OCF_SUCCESS ]; then
		return $OCF_SUCCESS
	else
		return $OCF_ERR_GENERIC
	fi
}
iscsi_stop() {
	iscsi_monitor
	if [ $? -ne $OCF_NOT_RUNNING ] ; then
		$remove_disk $OCF_RESKEY_target ||
			return $OCF_ERR_GENERIC
		iscsi_monitor
		if [ $? -ne $OCF_NOT_RUNNING ] ; then
			return $OCF_ERR_GENERIC
		else
			return $OCF_SUCCESS
		fi
	else
		ocf_log info "iscsi $OCF_RESKEY_target already stopped"
		return $OCF_SUCCESS
	fi
}

#
#	'main' starts here...
#

if [ $# -ne 1 ]; then
	usage
	exit $OCF_ERR_ARGS
fi

# These operations don't require OCF instance parameters to be set
case "$1" in
	meta-data)	meta_data
		exit $OCF_SUCCESS;;
	usage) usage
		exit $OCF_SUCCESS;;
	methods) iscsi_methods
		exit $OCF_SUCCESS;;
esac

if [ x = "x$OCF_RESKEY_target" ]; then
	ocf_exit_reason "target parameter not set"
	exit $OCF_ERR_CONFIGURED
fi

if [ x = "x$OCF_RESKEY_portal" ]; then
	ocf_exit_reason "portal parameter not set"
	exit $OCF_ERR_CONFIGURED
fi

case `uname` in
Linux) setup=open_iscsi_setup
;;
*) ocf_log info "platform `uname` may not be supported"
	setup=open_iscsi_setup
;;
esac

PORTAL="$OCF_RESKEY_portal" # updated by discovery
LSB_STATUS_STOPPED=3
$setup
setup_rc=$?
if [ $setup_rc -gt 1 ]; then
	ocf_exit_reason "iscsi initiator utilities not installed or not setup"
	case "$1" in
		stop) exit $OCF_SUCCESS;;
		monitor) exit $OCF_NOT_RUNNING;;
		status) exit $LSB_STATUS_STOPPED;;
		*) exit $OCF_ERR_INSTALLED;;
	esac
fi

if [ `id -u` != 0 ]; then
	ocf_exit_reason "$0 must be run as root"
	exit $OCF_ERR_PERM
fi

# which method was invoked?
case "$1" in
	start)
		iscsi_start
	;;
	stop)	iscsi_stop
	;;
	status)	iscsi_monitor
		rc=$?
		case $rc in
		$OCF_SUCCESS)
		  echo iscsi target $OCF_RESKEY_target running
		;;
		$OCF_NOT_RUNNING)
		  echo iscsi target $OCF_RESKEY_target stopped
		;;
		*)
		  echo iscsi target $OCF_RESKEY_target failed
		;;
		esac
		exit $rc
		;;
	monitor)	iscsi_monitor
	;;
	validate-all)	# everything already validated
		# just exit successfully here.
		exit $OCF_SUCCESS;;
	*)		iscsi_methods
		exit $OCF_ERR_UNIMPLEMENTED;;
esac

#
# vim:tabstop=4:shiftwidth=4:textwidth=0:wrapmargin=0