#!/bin/bash

KEXEC=/sbin/kexec

KDUMP_KERNELVER=""

KDUMP_COMMANDLINE=""

KEXEC_ARGS=""

KDUMP_CONFIG_FILE="/etc/kdump.conf"

MKDUMPRD="/sbin/mkdumprd -f"

DRACUT_MODULES_FILE="/usr/lib/dracut/modules.txt"

SAVE_PATH=/var/crash

SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa"

INITRD_CHECKSUM_LOCATION="/boot/.fadump_initrd_checksum"

DUMP_TARGET=""

DEFAULT_INITRD=""

DEFAULT_INITRD_BAK=""

TARGET_INITRD=""

FADUMP_ENABLED_SYS_NODE="/sys/kernel/fadump_enabled"

FADUMP_REGISTER_SYS_NODE="/sys/kernel/fadump_registered"

#kdump shall be the default dump mode

DEFAULT_DUMP_MODE="kdump"

image_time=0

. /lib/kdump/kdump-lib.sh

standard_kexec_args="-p"

# Some default values in case /etc/sysconfig/kdump doesn't include

KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug"

if [ -f /etc/sysconfig/kdump ]; then

	. /etc/sysconfig/kdump

fi

single_instance_lock()

{

	local rc timeout=5

	exec 9>/var/lock/kdump

	flock -n 9

	rc=$?

	while [ $rc -ne 0 ]; do

		echo "Another app is currently holding the kdump lock; waiting for it to exit..."

		flock -w $timeout 9

		rc=$?

	done

}

determine_dump_mode()

{

	# Check if firmware-assisted dump is enabled

	# if yes, set the dump mode as fadump

	if is_fadump_capable; then

		echo "Dump mode is fadump"

		DEFAULT_DUMP_MODE="fadump"

	fi

}

# remove_cmdline_param <kernel cmdline> <param1> [<param2>] ... [<paramN>]

# Remove a list of kernel parameters from a given kernel cmdline and print the result.

# For each "arg" in the removing params list, "arg" and "arg=xxx" will be removed if exists.

remove_cmdline_param()

{

	local cmdline=$1

	shift

	for arg in $@; do

		cmdline=`echo $cmdline | \

			 sed -e "s/\b$arg=[^ ]*\b//g" \

			     -e "s/\b$arg\b//g" \

			     -e "s/\s\+/ /g"`

	done

	echo $cmdline

}

#

# This function returns the "initial apicid" of the

# boot cpu (cpu 0) if present.

#

get_bootcpu_initial_apicid()

{

    awk '							\

	BEGIN { CPU = "-1"; }					\

	$1=="processor" && $2==":"	{ CPU = $NF; }		\

	CPU=="0" && /initial apicid/	{ print $NF; }		\

	'							\

	/proc/cpuinfo

}

#

# This function appends argument "$2=$3" to string ($1) if not already present.

#

append_cmdline()

{

	local cmdline=$1

	local newstr=${cmdline/$2/""}

	# unchanged str implies argument wasn't there

	if [ "$cmdline" == "$newstr" ]; then

		cmdline="${cmdline} ${2}=${3}"

	fi

	echo $cmdline

}

# This function performs a series of edits on the command line

prepare_cmdline()

{

	local cmdline;

	if [ -z "$KDUMP_COMMANDLINE" ]; then

		cmdline=`cat /proc/cmdline`

	else

		cmdline=${KDUMP_COMMANDLINE}

	fi

	# These params should always be removed

	cmdline=`remove_cmdline_param "$cmdline" crashkernel panic_on_warn`

	# These params can be removed configurably

	cmdline=`remove_cmdline_param "$cmdline" ${KDUMP_COMMANDLINE_REMOVE}`

	cmdline="${cmdline} ${KDUMP_COMMANDLINE_APPEND}"

	local id=`get_bootcpu_initial_apicid`

	if [ ! -z ${id} ] ; then

		cmdline=`append_cmdline "${cmdline}" disable_cpu_apicid ${id}`

	fi

	echo $cmdline

}

save_core()

{

	coredir="/var/crash/`date +"%Y-%m-%d-%H:%M"`"

	mkdir -p $coredir

	cp --sparse=always /proc/vmcore $coredir/vmcore-incomplete

	if [ $? == 0 ]; then

		mv $coredir/vmcore-incomplete $coredir/vmcore

		echo "saved a vmcore to $coredir"

	else

		echo "failed to save a vmcore to $coredir" >&2

	fi

	# pass the dmesg to Abrt tool if exists, in order

	# to collect the kernel oops message.

	# https://fedorahosted.org/abrt/

	if [ -x /usr/bin/dumpoops ]; then

		makedumpfile --dump-dmesg $coredir/vmcore $coredir/dmesg >/dev/null 2>&1

		dumpoops -d $coredir/dmesg >/dev/null 2>&1

		if [ $? == 0 ]; then

			echo "kernel oops has been collected by abrt tool"

		fi

	fi

}

rebuild_fadump_initrd()

{

	local target_initrd_tmp

	# this file tells the initrd is fadump enabled

	touch /tmp/fadump.initramfs

	target_initrd_tmp="$TARGET_INITRD.tmp"

	$MKDUMPRD $target_initrd_tmp --rebuild $TARGET_INITRD --kver $kdump_kver \

		-i /tmp/fadump.initramfs /etc/fadump.initramfs

	if [ $? != 0 ]; then

		echo "mkdumprd: failed to rebuild initrd with fadump support" >&2

		rm -f /tmp/fadump.initramfs

		return 1

	fi

	rm -f /tmp/fadump.initramfs

	# updating fadump initrd

	mv $target_initrd_tmp $TARGET_INITRD

	sync

	return 0

}

rebuild_kdump_initrd()

{

	$MKDUMPRD $TARGET_INITRD $kdump_kver

	if [ $? != 0 ]; then

		echo "mkdumprd: failed to make kdump initrd" >&2

		return 1

	fi

	return 0

}

rebuild_initrd()

{

	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then

		rebuild_fadump_initrd

	else

		rebuild_kdump_initrd

	fi

	return $?

}

#$1: the files to be checked with IFS=' '

check_exist()

{

	for file in $1; do

		if [ ! -f "$file" ]; then

			echo -n "Error: $file not found."; echo

			return 1

		fi

	done

}

#$1: the files to be checked with IFS=' '

check_executable()

{

	for file in $1; do

		if [ ! -x "$file" ]; then

			echo -n "Error: $file is not executable."; echo

			return 1

		fi

	done

}

backup_default_initrd()

{

	if [ ! -f "$DEFAULT_INITRD" ]; then

		return

	fi

	if [ ! -e $DEFAULT_INITRD_BAK ]; then

		echo "Backing up $DEFAULT_INITRD before rebuild."

		# save checksum to verify before restoring

		sha1sum $DEFAULT_INITRD > $INITRD_CHECKSUM_LOCATION

		cp $DEFAULT_INITRD $DEFAULT_INITRD_BAK

		if [ $? -ne 0 ]; then

			echo "WARNING: failed to backup $DEFAULT_INITRD."

			rm -f $DEFAULT_INITRD_BAK

		fi

	fi

}

restore_default_initrd()

{

	# If a backup initrd exists, we must be switching back from

	# fadump to kdump. Restore the original default initrd.

	if [ -f $DEFAULT_INITRD_BAK ] && [ -f $INITRD_CHECKSUM_LOCATION ]; then

		# verify checksum before restoring

		backup_checksum=`sha1sum $DEFAULT_INITRD_BAK | awk '{ print $1 }'`

		default_checksum=`cat $INITRD_CHECKSUM_LOCATION | awk '{ print $1 }'`

		if [ "$default_checksum" != "$backup_checksum" ]; then

			echo "WARNING: checksum mismatch! Can't restore original initrd.."

		else

			rm -f $INITRD_CHECKSUM_LOCATION

			mv $DEFAULT_INITRD_BAK $DEFAULT_INITRD

			if [[ $? -eq 0 ]]; then

				echo -n "Restoring original initrd as fadump mode "

				echo "is disabled."

				sync

			fi

		fi

	fi

}

check_config()

{

	local nr

	nr=$(awk 'BEGIN{cnt=0} /^raw|^ssh[[:blank:]]|^nfs|^ext[234]|^xfs|^btrfs|^minix|^dracut_args .*\-\-mount/{cnt++} END{print cnt}' $KDUMP_CONFIG_FILE)

	[ $nr -gt 1 ] && {

		echo "More than one dump targets specified."

		return 1

	}

	nr=$(grep "^dracut_args .*\-\-mount" $KDUMP_CONFIG_FILE | grep -o "\-\-mount" | wc -l)

	[ $nr -gt 1 ] && {

		echo "Multiple mount targets specified in one \"dracut_args\"."

		return 1

	}

	while read config_opt config_val; do

		case "$config_opt" in

		\#* | "")

			;;

		raw|ext2|ext3|ext4|minix|btrfs|xfs|nfs|ssh|sshkey|path|core_collector|kdump_post|kdump_pre|extra_bins|extra_modules|default|force_rebuild|force_no_rebuild|dracut_args|fence_kdump_args|fence_kdump_nodes)

			# remove inline comments after the end of a directive.

			config_val=$(strip_comments $config_val)

			[ -z "$config_val" ] && {

				echo "Invalid kdump config value for option $config_opt."

				return 1;

			}

			;;

		net|options|link_delay|disk_timeout|debug_mem_level|blacklist)

			echo "Deprecated kdump config option: $config_opt. Refer to kdump.conf manpage for alternatives."

			return 1

			;;

		*)

			echo "Invalid kdump config option $config_opt"

			return 1;

			;;

		esac

	done < $KDUMP_CONFIG_FILE

	check_default_config || return 1

	check_fence_kdump_config || return 1

	return 0

}

# get_pcs_cluster_modified_files <image timestamp>

# return list of modified file for fence_kdump modified in Pacemaker cluster

get_pcs_cluster_modified_files()

{

	local time_stamp

	local modified_files

	is_generic_fence_kdump && return 1

	is_pcs_fence_kdump || return 1

	time_stamp=`pcs cluster cib | xmllint --xpath 'string(/cib/@cib-last-written)' - | \

		xargs -0 date +%s --date`

	if [ -n $time_stamp -a $time_stamp -gt $image_time ]; then

		modified_files="cluster-cib"

	fi

	if [ -f $FENCE_KDUMP_CONFIG_FILE ]; then

		time_stamp=`stat -c "%Y" $FENCE_KDUMP_CONFIG_FILE`

		if [ "$time_stamp" -gt "$image_time" ]; then

			modified_files="$modified_files $FENCE_KDUMP_CONFIG_FILE"

		fi

	fi

	echo $modified_files

}

check_boot_dir()

{

	#If user specify a boot dir for kdump kernel, let's use it. Otherwise

	#check whether it's a atomic host. If yes parse the subdirectory under

	#/boot; If not just find it under /boot.

	[ -n "$KDUMP_BOOTDIR" ] && return

	if ! is_atomic || [ "$(uname -m)" = "s390x" ]; then

		KDUMP_BOOTDIR="/boot"

	else

		eval $(cat /proc/cmdline| grep "BOOT_IMAGE" | cut -d' ' -f1)

		KDUMP_BOOTDIR="/boot"$(dirname $BOOT_IMAGE)

	fi

}

setup_initrd()

{

	DEFAULT_INITRD="${KDUMP_BOOTDIR}/initramfs-`uname -r`.img"

	DEFAULT_INITRD_BAK="${KDUMP_BOOTDIR}/.initramfs-`uname -r`.img.default"

	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then

		TARGET_INITRD="$DEFAULT_INITRD"

		if [ ! -s "$TARGET_INITRD" ]; then

			echo "Error: No initrd found to rebuild!"

			return 1

		fi

	else

		TARGET_INITRD="${KDUMP_BOOTDIR}/initramfs-${kdump_kver}kdump.img"

	fi

}

check_files_modified()

{

	local modified_files=""

	#also rebuild when Pacemaker cluster conf is changed and fence kdump is enabled.

	modified_files=$(get_pcs_cluster_modified_files)

	EXTRA_BINS=`grep ^kdump_post $KDUMP_CONFIG_FILE | cut -d\  -f2`

	CHECK_FILES=`grep ^kdump_pre $KDUMP_CONFIG_FILE | cut -d\  -f2`

	EXTRA_BINS="$EXTRA_BINS $CHECK_FILES"

	CHECK_FILES=`grep ^extra_bins $KDUMP_CONFIG_FILE | cut -d\  -f2-`

	EXTRA_BINS="$EXTRA_BINS $CHECK_FILES"

	files="$KDUMP_CONFIG_FILE $kdump_kernel $EXTRA_BINS"

	[[ -e /etc/fstab ]] && files="$files /etc/fstab"

	check_exist "$files" && check_executable "$EXTRA_BINS"

	[ $? -ne 0 ] && return 2

	for file in $files; do

		time_stamp=`stat -c "%Y" $file`

		if [ "$time_stamp" -gt "$image_time" ]; then

			modified_files="$modified_files $file"

		fi

	done

	if [ -n "$modified_files" ]; then

		echo "Detected change(s) in the following file(s):"

		echo -n "  "; echo "$modified_files" | sed 's/\s/\n  /g'

		return 1

	fi

	return 0

}

check_dump_fs_modified()

{

	local _old_dev _old_mntpoint _old_fstype

	local _new_dev _new_mntpoint _new_fstype

	local _target _path _dracut_args

	# No need to check in case of mount target specified via "dracut_args".

	if is_mount_in_dracut_args; then

		return 0

	fi

	# No need to check in case of raw target.

	# Currently we do not check also if ssh/nfs target is specified

	if is_ssh_dump_target || is_nfs_dump_target || is_raw_dump_target; then

		return 0

	fi

	_target=$(get_user_configured_dump_disk)

	if [[ -n "$_target" ]]; then

		_target=$(to_dev_name $_target)

		_new_fstype=$(blkid $_target | awk -F"TYPE=" '{print $2}' | cut -d '"' -f 2)

	else

		_path=$(get_save_path)

		set -- $(df -T $_path 2>/dev/null | tail -1 | awk '{ print $1, $2}')

		_target=$(to_dev_name $1)

		_new_fstype=$2

		if [[ -z "$_target" || -z "$_new_fstype" ]];then

			echo "Dump path $_path does not exist"

			return 2

		fi

	fi

	if [[ $(expr substr $_new_fstype 1 3) = "nfs" ]];then

		_new_dev=$_target

	else

		_new_dev=$(kdump_get_persistent_dev $_target $_new_fstype)

	fi

	if ! findmnt $_target >/dev/null; then

            echo "Dump target $_target is probably not mounted."

	    return 2

        fi

	_new_mntpoint="/kdumproot/$(get_mntpoint_from_target $_target)"

	_dracut_args=$(lsinitrd $TARGET_INITRD -f usr/lib/dracut/build-parameter.txt)

	if [[ -z "$_dracut_args" ]];then

		echo "Warning: No dracut arguments found in initrd"

		return 0

	fi

	# if --mount argument present then match old and new target, mount

	# point and file system. If any of them mismatches then rebuild

	echo $_dracut_args | grep "\-\-mount" &> /dev/null

	if [[ $? -eq 0 ]];then

		set -- $(echo $_dracut_args | awk -F "--mount '" '{print $2}' | cut -d' ' -f1,2,3)

		_old_dev=$1

		_old_mntpoint=$2

		_old_fstype=$3

		[[ $_new_dev = $_old_dev && $_new_mntpoint = $_old_mntpoint && $_new_fstype = $_old_fstype ]] && return 0

	# otherwise rebuild if target device is not a root device

	else

		[[ "$_target" = "$(get_root_fs_device)" ]] && return 0

	fi

	echo "Detected change in File System"

	return 1

}

check_wdt_modified()

{

	local -A _drivers

	local _alldrivers _active _wdtdrv _wdtppath _dir

	local wd_old wd_new

	is_wdt_mod_omitted

	[[ $? -eq 0 ]] && return 0

	[[ -d /sys/class/watchdog/ ]] || return 0

	# Copied logic from dracut 04watchdog/module-setup.sh::installkernel()

	for _dir in /sys/class/watchdog/*; do

		[[ -d "$_dir" ]] || continue

		[[ -f "$_dir/state" ]] || continue

		_active=$(< "$_dir/state")

		[[ "$_active" =  "active" ]] || continue

		# device/modalias will return driver of this device

		_wdtdrv=$(< "$_dir/device/modalias")

		# There can be more than one module represented by same

		# modalias. Currently load all of them.

		# TODO: Need to find a way to avoid any unwanted module

		# represented by modalias

		_wdtdrv=$(modprobe --set-version "$kdump_kver" -R $_wdtdrv 2>/dev/null)

		if [[ $_wdtdrv ]]; then

			for i in $_wdtdrv; do

				_drivers[$i]=1

			done

		fi

		# however in some cases, we also need to check that if there is

		# a specific driver for the parent bus/device.  In such cases

		# we also need to enable driver for parent bus/device.

		_wdtppath=$(readlink -f "$_dir/device")

		while [[ -d "$_wdtppath" ]] && [[ "$_wdtppath" != "/sys" ]]; do

			_wdtppath=$(readlink -f "$_wdtppath/..")

			[[ -f "$_wdtppath/modalias" ]] || continue

			_wdtdrv=$(< "$_wdtppath/modalias")

			_wdtdrv=$(modprobe --set-version "$kdump_kver" -R $_wdtdrv 2>/dev/null)

			if [[ $_wdtdrv ]]; then

				for i in $_wdtdrv; do

					_drivers[$i]=1

				done

			fi

		done

	done

	# ensure that watchdog module is loaded as early as possible

	_alldrivers="${!_drivers[*]}"

	[[ $_alldrivers ]] && wd_new="rd.driver.pre=${_alldrivers// /,}"

	wd_old=$(lsinitrd $TARGET_INITRD -f etc/cmdline.d/00-watchdog.conf)

	[[ "$wd_old" = "$wd_new" ]] && return 0

	return 1

}

# returns 0 if system is not modified

# returns 1 if system is modified

# returns 2 if system modification is invalid

check_system_modified()

{

	local ret

	[[ -f $TARGET_INITRD ]] || return 1

	check_files_modified

	ret=$?

	if [ $ret -ne 0 ]; then

		return $ret

	fi

	check_dump_fs_modified

	ret=$?

	if [ $ret -ne 0 ]; then

		return $ret

	fi

	check_wdt_modified

	if [ $? -ne 0 ]; then

		echo "Detected change in watchdog state"

		return 1

	fi

	return 0

}

check_rebuild()

{

	local extra_modules

	local capture_capable_initrd="1"

	local _force_rebuild force_rebuild="0"

	local _force_no_rebuild force_no_rebuild="0"

	local ret system_modified="0"

	check_boot_dir

	if [ -z "$KDUMP_KERNELVER" ]; then

		kdump_kver=`uname -r`

	else

		kdump_kver=$KDUMP_KERNELVER

	fi

	kdump_kernel="${KDUMP_BOOTDIR}/${KDUMP_IMG}-${kdump_kver}${KDUMP_IMG_EXT}"

	setup_initrd

	if [ $? -ne 0 ]; then

		return 1

	fi

	_force_no_rebuild=`grep ^force_no_rebuild $KDUMP_CONFIG_FILE 2>/dev/null`

	if [ $? -eq 0 ]; then

		force_no_rebuild=`echo $_force_no_rebuild | cut -d' '  -f2`

		if [ "$force_no_rebuild" != "0" ] && [ "$force_no_rebuild" != "1" ];then

			echo "Error: force_no_rebuild value is invalid"

			return 1

		fi

	fi

	_force_rebuild=`grep ^force_rebuild $KDUMP_CONFIG_FILE 2>/dev/null`

	if [ $? -eq 0 ]; then

		force_rebuild=`echo $_force_rebuild | cut -d' '  -f2`

		if [ "$force_rebuild" != "0" ] && [ "$force_rebuild" != "1" ];then

			echo "Error: force_rebuild value is invalid"

			return 1

		fi

	fi

	if [[ "$force_no_rebuild" == "1" && "$force_rebuild" == "1" ]]; then

		echo "Error: force_rebuild and force_no_rebuild are enabled simultaneously in kdump.conf"

		return 1

	fi

	# Will not rebuild kdump initrd

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

		return 0

	fi

	#will rebuild every time if extra_modules are specified

	extra_modules=`grep ^extra_modules $KDUMP_CONFIG_FILE`

	[ -n "$extra_modules" ] && force_rebuild="1"

	#check to see if dependent files has been modified

	#since last build of the image file

	if [ -f $TARGET_INITRD ]; then

		image_time=`stat -c "%Y" $TARGET_INITRD 2>/dev/null`

		#in case of fadump mode, check whether the default/target

		#initrd is already built with dump capture capability

		if [ "$DEFAULT_DUMP_MODE" == "fadump" ]; then

			capture_capable_initrd=$(lsinitrd -f $DRACUT_MODULES_FILE $TARGET_INITRD | grep ^kdumpbase$ | wc -l)

		fi

	fi

	check_system_modified

	ret=$?

	if [ $ret -eq 2 ]; then

		return 1

	elif [ $ret -eq 1 ];then

		system_modified="1"

	fi

	handle_mode_switch

	if [ $image_time -eq 0 ]; then

		echo  -n "No kdump initial ramdisk found."; echo

	elif [ "$capture_capable_initrd" == "0" ]; then

		echo -n "Rebuild $TARGET_INITRD with dump capture support"; echo

	elif [ "$force_rebuild" != "0" ]; then

		echo -n "Force rebuild $TARGET_INITRD"; echo

	elif [ "$system_modified" != "0" ]; then

		:

	else

		return 0

	fi

	if [[ ! -w "$KDUMP_BOOTDIR" ]];then

		echo "$KDUMP_BOOTDIR does not have write permission. Can not rebuild $TARGET_INITRD"

		return 1

	fi

	echo "Rebuilding $TARGET_INITRD"

	rebuild_initrd

	return $?

}

# This function check iomem and determines if we have more than

# 4GB of ram available. Returns 1 if we do, 0 if we dont

need_64bit_headers()

{

	return `tail -n 1 /proc/iomem | awk '{ split ($1, r, "-"); \

	print (strtonum("0x" r[2]) > strtonum("0xffffffff")); }'`

}

# Load the kdump kernel specified in /etc/sysconfig/kdump

# If none is specified, try to load a kdump kernel with the same version

# as the currently running kernel.

load_kdump()

{

	ARCH=`uname -m`

	if [ "$ARCH" == "i686" -o "$ARCH" == "i386" ]

	then

		need_64bit_headers

		if [ $? == 1 ]

		then

			FOUND_ELF_ARGS=`echo $KEXEC_ARGS | grep elf32-core-headers`

			if [ -n "$FOUND_ELF_ARGS" ]

			then

				echo -n "Warning: elf32-core-headers overrides correct elf64 setting"

				echo

			else	

				KEXEC_ARGS="$KEXEC_ARGS --elf64-core-headers"

			fi

		else

			FOUND_ELF_ARGS=`echo $KEXEC_ARGS | grep elf64-core-headers`

			if [ -z "$FOUND_ELF_ARGS" ]

			then

				KEXEC_ARGS="$KEXEC_ARGS --elf32-core-headers"

			fi

		fi

	fi

	KDUMP_COMMANDLINE=`prepare_cmdline`

	# For secureboot enabled machines, use new kexec file based syscall.

	# Old syscall will always fail as it does not have capability to

	# to kernel signature verification.

	if is_secure_boot_enforced; then

		echo "Secure Boot is enabled. Using kexec file based syscall."

		KEXEC_ARGS="$KEXEC_ARGS -s"

	elif is_secure_mode_enforced; then

		echo "securelevel is set to 1 (Secure Mode). Using kexec file based syscall."

		KEXEC_ARGS="$KEXEC_ARGS -s"

	fi

	$KEXEC $KEXEC_ARGS $standard_kexec_args \

		--command-line="$KDUMP_COMMANDLINE" \

		--initrd=$TARGET_INITRD $kdump_kernel

	if [ $? == 0 ]; then

		echo "kexec: loaded kdump kernel"

		return 0

	else

		echo "kexec: failed to load kdump kernel" >&2

		return 1

	fi

}

check_ssh_config()

{

	while read config_opt config_val; do

		case "$config_opt" in

		sshkey)