#!/bin/sh
#
#	crypt/LUKS OCF RA. Manages cryptsetup devices.
#
# Copyright (c) 2020 Red Hat GmbH, Heinz Mauelshagen
#                    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.
#

#######################################################################
# Initialization:

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

# Parameter defaults
OCF_RESKEY_encrypted_dev_default=""
OCF_RESKEY_crypt_dev_default=""
OCF_RESKEY_key_file_default=""
OCF_RESKEY_crypt_type_default=""
OCF_RESKEY_force_stop_default="false"

: ${OCF_RESKEY_encrypted_dev=${OCF_RESKEY_encrypted_dev_default}}
: ${OCF_RESKEY_crypt_dev=${OCF_RESKEY_crypt_dev_default}}
: ${OCF_RESKEY_key_file=${OCF_RESKEY_key_file_default}}
: ${OCF_RESKEY_crypt_type=${OCF_RESKEY_crypt_type_default}}
: ${OCF_RESKEY_force_stop=${OCF_RESKEY_force_stop_default}}

#######################################################################

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

<longdesc lang="en">
This is a LUKS/crypt Resource Agent managing encrypted devices via cryptsetup(8).
The agent imposes limitations on device types supported: luks, luks[1..N].
</longdesc>
<shortdesc lang="en">LUKS/crypt resource agent</shortdesc>

<parameters>

<parameter name="encrypted_dev" unique="1" required="1">
<longdesc lang="en">
Encrypted backing device, which should be defined by UUID,
36 characters including '-'s as reported by blkid(8).

Although it can be defined as a block device path (e.g. /dev/sdh),
the UUID should be preferred over the block device path to allow for the
unique discovery of the crypt backing device given the volatile nature of
/dev entries (e.g. /dev/sdh on one node may be /dev/sdg on another).

Only define as block device path if you know what you are doing.
</longdesc>
<shortdesc lang="en">Encrypted device</shortdesc>
<content type="string" default="${OCF_RESKEY_encrypted_dev_default}" />
</parameter>

<parameter name="crypt_dev" unique="1" required="1">
<longdesc lang="en">
Encrypted device name, no path.  I.e. the one given in "cryptsetup open name ...".
The resulting block device path is /dev/mapper/name.
</longdesc>
<shortdesc lang="en">Encrypted device</shortdesc>
<content type="string" default="${OCF_RESKEY_crypt_dev_default}" />
</parameter>

<parameter name="key_file" unique="0" required="1">
<longdesc lang="en">
Key file path containing the encryption passphrase
(aka key; see cryptsetup(8)).  For LUKS, the passphrase as of the key_file
parameter is used to decrypt a randomly selected key when the device was created.
</longdesc>
<shortdesc lang="en">Key file</shortdesc>
<content type="string" default="${OCF_RESKEY_key_file_default}" />
</parameter>

<parameter name="crypt_type" unique="0" required="1">
<longdesc lang="en">
Encryption (device) type (e.g. "luks" or "luks2").

This parameter affirms the encryption format as of the crypt metadata
thus allowing for safety measures when starting the encrypted resource.
</longdesc>
<shortdesc lang="en">Encryption type</shortdesc>
<content type="string" default="${OCF_RESKEY_crypt_type_default}" />
</parameter>

<parameter name="force_stop" unique="0" required="0">
<longdesc lang="en">
If processes or kernel threads are using the crypt device, it cannot
be stopped. We will try to stop processes, first by sending TERM and
then, if that doesn't help in $PROC_CLEANUP_TIME seconds, using KILL.
The lsof(8) program is required to get the list of array users.
Of course, the kernel threads cannot be stopped this way.
If the processes are critical for data integrity, then set this
parameter to false. Note that in that case the stop operation
will fail and the node will be fenced.
</longdesc>
<shortdesc lang="en">force stop processes using the crpyt device</shortdesc>
<content type="boolean" default="${OCF_RESKEY_force_stop_default}" />
</parameter>

</parameters>

<actions>
<action name="start"        timeout="20s" />
<action name="stop"         timeout="20s" />
<action name="monitor"      timeout="20s" interval="10s" depth="0" />
<action name="meta-data"    timeout="5s" />
<action name="validate-all" timeout="10s" />
</actions>
</resource-agent>
END
}

# Disable cryptsetup auto-recovery if cloned.
disable_locks=""
ocf_is_clone && disable_locks="--disable-locks"

crypt_usage() {
	cat <<END
usage: $0 {start|stop|monitor|usage|meta-data|validate-all}

Expects to have a fully populated OCF RA-compliant environment set.
END
}

encrypted_dev="${OCF_RESKEY_encrypted_dev}"
crypt_dev="${OCF_RESKEY_crypt_dev}"
crypt_dev_path="/dev/mapper/$crypt_dev"
key_file="${OCF_RESKEY_key_file}"
crypt_type="${OCF_RESKEY_crypt_type}"
force_stop="${OCF_RESKEY_force_stop}"

crypt_validate_all() {
	if ! have_binary cryptsetup; then
		ocf_exit_reason "Please install cryptsetup(8)"
		return $OCF_ERR_INSTALLED
	fi
	if [ -z "$encrypted_dev" ]; then
		ocf_exit_reason "Undefined OCF_RESKEY_encrypted_dev"
		return $OCF_ERR_CONFIGURED
	fi
	if [ -n "$encrypted_dev" ]; then
		case "$encrypted_dev" in
		*-*-*-*) if [ `echo "$encrypted_dev" | wc -c` -ne 37 ]; then
				ocf_exit_reason "Bogus encrypted device UUID \"$encrypted_dev\""
				return $OCF_ERR_ARGS
			 fi
			 encrypted_dev=/dev/disk/by-uuid/"$encrypted_dev";;
		*)	 case "$encrypted_dev" in
			 /dev/*) ;;
			 *)	ocf_exit_reason "Bogus encrypted device path"
				return $OCF_ERR_ARGS;;
			 esac
		esac
	fi

	# return early for probes where device might not be available yet
	# e.g. LVM exclusive volumes
	if ocf_is_probe; then
		return $OCF_SUCCESS
	fi

	if [ ! -b "$encrypted_dev" ] && [ ! -L "$encrypted_dev" ]; then
		ocf_exit_reason "Encrypted device $encrypted_dev not accessible"
		return $OCF_ERR_ARGS
	fi
	echo "$crypt_dev" | grep "/" >/dev/null
	if [ $? -eq 0 ] &&  [ -z "$crypt_dev" ]; then
		ocf_exit_reason "Crypt device \"$crypt_dev\" name has to at least 1 character long and without path"
		return $OCF_ERR_ARGS
	fi
	if [ ! -r "$key_file" ]; then
		ocf_exit_reason "Hash key file $key_file not accessible"
		return $OCF_ERR_ARGS
	fi
	if ocf_is_true "$force_stop" && ! have_binary lsof; then
		ocf_exit_reason "Force stop requested, please install lsof(8)"
		return $OCF_ERR_INSTALLED
	fi
	cryptsetup isLuks $encrypted_dev 2>/dev/null
	if [ $? -ne 0 ]; then
		ocf_exit_reason "$encrypted_dev is not a Luks formatted device"
		return $OCF_ERR_CONFIGURED
	fi

	return $OCF_SUCCESS
}

get_users_pids() {
	ocf_log debug "running lsof to list \"$crypt_dev\" users..."
	ocf_run -warn 'lsof $crypt_dev_path | tail -n +2 | awk "{print $2}" | sort -u'
}

stop_crypt_users() {
	local pids=`get_users_pids`

	if [ -z "$pids" ]; then
		ocf_log warn "lsof reported no users holding arrays"
		return 2
	fi

	ocf_stop_processes TERM $PROC_CLEANUP_TIME $pids
}

show_users() {
	local dm_dev

	ocf_log info "running lsof to list \"$crypt_dev\" users..."
	ocf_run -warn lsof $crypt_dev_path

	dm_dev=$(basename $(realpath $crypt_dev_path))
	if [ -d /sys/block/$dm_dev/holders ]; then
		ocf_log debug "ls -l /sys/block/$dm_dev/holders"
		ocf_run -warn ls -l /sys/block/$dm_dev/holders
	fi
}

crypt_stop_one() {
	cryptsetup close $crypt_dev $disable_locks
}

#######################################################################
#
# Action: START an encrypted resource
#
crypt_start() {
	local rc

	cryptsetup open $encrypted_dev $crypt_dev --type $crypt_type $disable_locks --key-file=$key_file
	rc=$?
	if [ $rc -eq 0 ];then
		crypt_monitor
		rc=$?
	else
		rc=$OCF_ERR_GERNERIC
	fi
	[ $rc -ne $OCF_SUCCESS ] && ocf_exit_reason "Failed to start encrypted device \"$crypt_dev\""

	return $rc
}

#
# Action: STOP an encrypted resource
#
crypt_stop() {
	local rc

	crypt_monitor
	rc=$?
	if [ $rc -ne $OCF_NOT_RUNNING ]; then
		crypt_stop_one
		crypt_monitor
		rc=$?
	fi
	if [ $rc -ne $OCF_NOT_RUNNING ] && ocf_is_true $force_stop; then
		stop_crypt_users
		case $? in
		2) rc=$OCF_SUCCESS;;
		*) crypt_stop_one
		   crypt_monitor
		   rc=$?;;
		esac
	fi
	if [ $rc -ne $OCF_NOT_RUNNING ]; then
		ocf_log warn "Couldn't stop crypt device \"$crypt_dev\" (rc=$rc)"
		show_users
		ocf_exit_reason "Failed to stop crypt device \"$crypt_dev\"!"
		return $OCF_ERR_GENERIC
	fi

	return $OCF_SUCCESS
}

#
# Action: MONITOR an encrypted resource
#
crypt_monitor() {
	cryptsetup status $crypt_dev $disable_locks >/dev/null 2>&1
	if [ $? -eq 0 ]; then
		if [ -b "$encrypted_dev" ] || [ -L $crypt_dev_path ]; then
			return $OCF_SUCCESS
		fi
		return $OCF_ERR_GENERIC
	fi

	[ "$__OCF_ACTION" = "monitor" ] && ! ocf_is_probe && ocf_exit_reason "Crypt resource not running"
	return $OCF_NOT_RUNNING
}

# Check for stange argument count.
if [ $# -ne 1 ]; then
	usage
	exit $OCF_ERR_ARGS
fi

case "$__OCF_ACTION" in
meta-data)	meta_data
		exit $OCF_SUCCESS;;
usage|help)	crypt_usage
		exit $OCF_SUCCESS;;
esac

# XME: remove once pacemaker is fixed and calls this action
crypt_validate_all
rc=$?
[ $rc -ne $OCF_SUCCESS ] && exit $rc

case "$__OCF_ACTION" in
start)		crypt_start; rc=$?;;
stop)		crypt_stop; rc=$?;;
monitor)	crypt_monitor; rc=$?;;
validate-all)	rc=$OCF_SUCCESS;; # crypt_validate_all would have errored out above already.
*)		crypt_usage
		exit $OCF_ERR_UNIMPLEMENTED;;
esac

ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION : $rc"
exit $rc