#!/bin/bash --norc

# New mkdumprd

#

# Copyright 2011 Red Hat, Inc.

#

# Written by Cong Wang <amwang@redhat.com>

#

. /lib/kdump/kdump-lib.sh

export IN_KDUMP=1

conf_file="/etc/kdump.conf"

SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa"

SAVE_PATH=$(grep ^path $conf_file| cut -d' '  -f2)

[ -z "$SAVE_PATH" ] && SAVE_PATH="/var/crash"

extra_modules=""

dracut_args=("--hostonly" "--hostonly-cmdline" "-o" "plymouth dash")

OVERRIDE_RESETTABLE=0

perror_exit() {

    echo $@ >&2

    exit 1

}

perror() {

    echo $@ >&2

}

get_persistent_dev() {

    local i _tmp _dev

    _dev=$(udevadm info --query=name --name="$1" 2>/dev/null)

    [ -z "$_dev" ] && {

        perror_exit "Kernel dev name of $1 is not found."

    }

    for i in /dev/mapper/* /dev/disk/by-uuid/* /dev/disk/by-id/*; do

        _tmp=$(udevadm info --query=name --name="$i" 2>/dev/null)

        if [ "$_tmp" = "$_dev" ]; then

            echo $i

            return

        fi

    done

    perror "WARNING: Persistent device name of $1 not found. Using $1 as dump target name"

    echo $1

}

add_dracut_arg() {

    local arg qarg is_quoted=0

    while [ $# -gt 0 ];

    do

        arg="${1//\'/\"}"

        #Handle quoted substring properly for passing it to dracut_args array.

        if [ $is_quoted -eq 0 ]; then

            if [[ "$arg" == "\"" ]] || [[ $arg != ${arg#\"} ]]; then

                is_quoted=1

                arg=${arg#\"}

            fi

        fi

        if [ $is_quoted -eq 1 ]; then

            qarg="$qarg $arg"

            if [[ "$arg" == "\"" ]] || [[ $arg != ${arg%\"} ]]; then

                is_quoted=0

                arg=${qarg%\"}

                qarg=""

            else

                shift

                continue

            fi

        fi

        dracut_args+=("$arg")

        shift

    done

}

add_dracut_module() {

    add_dracut_arg "--add" "$1"

}

add_dracut_mount() {

    add_dracut_arg "--mount" "$1"

}

add_dracut_sshkey() {

    add_dracut_arg "--sshkey" "$1"

}

# Generic substring function.  If $2 is in $1, return 0.

strstr() { [[ $1 =~ $2 ]]; }

target_is_root() {

    local _t

    _t=$(findmnt -k -n -r -o TARGET $1|sort|head -1)

    [ "$_t" = "/" ]

}

# caller should ensure $1 is valid and mounted in 1st kernel

to_mount() {

    local _dev=$1 _s _t _o _mntopts _pdev

    _s=$(findmnt -k -f -n -r -o SOURCE $_dev)

    _t=$(findmnt -k -f -n -r -o TARGET,FSTYPE $_dev)

    _o=$(findmnt -k -f -n -r -o OPTIONS $_dev)

    _o=${_o/#ro/rw} #mount fs target as rw in 2nd kernel

    _o="${_o},nofail" #with nofail set, systemd won't block for mount failure

    _mntopts="$_t $_o"

    #for non-nfs _dev converting to use udev persistent name

    if [ -b "$_s" ]; then

        _pdev="$(get_persistent_dev $_s)"

        if [ $? -ne 0 ]; then

            return 1

        fi

    else

        _pdev=$_dev

    fi

    echo "$_pdev $_mntopts"

}

to_mount_point() {

    echo $(findmnt -k -f -n -r -o TARGET $1)

}

is_readonly_mount() {

    local _mnt

    _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)

    #fs/proc_namespace.c: show_mountinfo():

    #seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");

    [[ "$_mnt" =~ ^ro ]]

}

#Function: get_ssh_size

#$1=dump target

#called from while loop and shouldn't read from stdin, so we're using "ssh -n"

get_ssh_size() {

    local _opt _out _size

    _opt="-i $SSH_KEY_LOCATION -o BatchMode=yes -o StrictHostKeyChecking=yes"

    _out=$(ssh -q -n $_opt $1 "df -P $SAVE_PATH")

    [ $? -ne 0 ] && {

        perror_exit "checking remote ssh server available size failed."

    }

    #ssh output removed the line break, so print field NF-2

    _size=$(echo -n $_out| awk '{avail=NF-2; print $avail}')

    echo -n $_size

}

#mkdir if save path does not exist on ssh dump target

#$1=ssh dump target

#caller should ensure write permission on $DUMP_TARGET:$SAVE_PATH

#called from while loop and shouldn't read from stdin, so we're using "ssh -n"

mkdir_save_path_ssh()

{

    local _opt _dir

    _opt="-i $SSH_KEY_LOCATION -o BatchMode=yes -o StrictHostKeyChecking=yes"

    ssh -qn $_opt $1 mkdir -p $SAVE_PATH 2>&1 > /dev/null

    _ret=$?

    if [ $_ret -ne 0 ]; then

        perror_exit "mkdir failed on $DUMP_TARGET:$SAVE_PATH"

    fi

    #check whether user has write permission on $SAVE_PATH/$DUMP_TARGET

    _dir=$(ssh -qn $_opt $1 mktemp -dqp $SAVE_PATH 2>/dev/null)

    _ret=$?

    if [ $_ret -ne 0 ]; then

        perror_exit "Could not create temporary directory on $DUMP_TARGET:$SAVE_PATH. Make sure user has write permission on destination"

    fi

    ssh -qn $_opt $1 rmdir $_dir

    return 0

}

#mkdir if save path does not exist on dump target filesystem

#$1=dump target

#caller should ensure $1 is mounted

mkdir_save_path_fs() {

    local _mnt=$(to_mount_point $1)

    local _remount="no"

    local _ret

    [ ! -d ${_mnt}/$SAVE_PATH ] && {

        if is_readonly_mount $1; then

            echo "Mounting $1 as read-write for creating dump directory.."

            mount -o remount,rw $1 || {

                perror_exit "Mounting $1 as read-write failed."

            }

            _remount="yes"

        fi

        mkdir -p ${_mnt}/$SAVE_PATH

        _ret=$?

        [ "$_remount" = "yes" ] && {

            echo "Remounting $1 as read-only."

            mount -o remount,ro $1 || {

                perror_exit "Remounting $1 as read-only failed."

            }

        }

        [ $_ret -ne 0 ] && {

            perror_exit "Creating ${_mnt}/$SAVE_PATH failed."

        }

    }

}

#Function: get_fs_size

#$1=dump target

get_fs_size() {

    local _mnt=$(to_mount_point $1)

    echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print $4}')

}

#Function: get_raw_size

#$1=dump target

get_raw_size() {

        echo -n $(fdisk -s "$1")

}

#Function: check_size

#$1: dump type string ('raw', 'fs', 'ssh')

#$2: dump target

check_size() {

    local avail memtotal

    memtotal=$(awk '/MemTotal/{print $2}' /proc/meminfo)

    case "$1" in

        raw)

            avail=$(get_raw_size "$2")

            ;;

        ssh)

            avail=$(get_ssh_size "$2")

            ;;

        fs)

            avail=$(get_fs_size "$2")

            ;;

        *)

            return

    esac

    if [ $? -ne 0 ]; then

            perror_exit "Check dump target size failed"

    fi

    if [ $avail -lt $memtotal ]; then

        echo "Warning: There might not be enough space to save a vmcore."

        echo "         The size of $2 should be greater than $memtotal kilo bytes."

    fi

}

# $1: core_collector config value

verify_core_collector() {

    if grep -q "^raw" $conf_file && [ "${1%% *}" != "makedumpfile" ]; then

        echo "Warning: specifying a non-makedumpfile core collector, you will have to recover the vmcore manually."

    fi

    if is_ssh_dump_target || is_raw_dump_target; then

        if [ "${1%% *}" = "makedumpfile" ]; then

            ! strstr "$1" "-F" && {

                perror_exit "The specified dump target needs makedumpfile \"-F\" option."

            }

        fi

    fi

}

add_mount() {

    if ! target_is_root "$1"; then

        local _mnt=$(to_mount "$1")

        if [ $? -ne 0 ]; then

            exit 1

        fi

        add_dracut_mount "$_mnt"

    fi

}

# get_maj_min <device>

# Prints the major and minor of a device node.

# Example:

# $ get_maj_min /dev/sda2

# 8:2

get_maj_min() {

    local _dev

    _dev=$(stat -L -c '$((0x%t)):$((0x%T))' "$1" 2>/dev/null)

    _dev=$(eval "echo $_dev")

    echo $_dev

}

# ugly workaround for the lvm design

# There is no volume group device,

# so, there are no slave devices for volume groups.

# Logical volumes only have the slave devices they really live on,

# but you cannot create the logical volume without the volume group.

# And the volume group might be bigger than the devices the LV needs.

check_vol_slaves() {

    local _lv _vg _pv

    for i in /dev/mapper/*; do

        _lv=$(get_maj_min $i)

        if [[ $_lv = $2 ]]; then

            _vg=$(lvm lvs --noheadings -o vg_name $i 2>/dev/null)

            # strip space

            _vg=$(echo $_vg)

            if [[ $_vg ]]; then

                for _pv in $(lvm vgs --noheadings -o pv_name "$_vg" 2>/dev/null)

                do

                    check_block_and_slaves $1 $(get_maj_min $_pv) && return 0

                done

            fi

        fi

    done

    return 1

}

# Walk all the slave relationships for a given block device.

# Stop when our helper function returns success

# $1 = function to call on every found block device

# $2 = block device in major:minor format

check_block_and_slaves() {

    local _x

    [[ -b /dev/block/$2 ]] || return 1 # Not a block device? So sorry.

    "$1" $2 && return

    check_vol_slaves "$@" && return 0

    if [[ -f /sys/dev/block/$2/../dev ]]; then

        check_block_and_slaves $1 $(cat "/sys/dev/block/$2/../dev") && return 0

    fi

    [[ -d /sys/dev/block/$2/slaves ]] || return 1

    for _x in /sys/dev/block/$2/slaves/*/dev; do

        [[ -f $_x ]] || continue

        check_block_and_slaves $1 $(cat "$_x") && return 0

    done

    return 1

}

to_dev_name() {

    local dev="${1//\"/}"

    case "$dev" in

    UUID=*)

        dev=`blkid -U "${dev#UUID=}"`

        ;;

    LABEL=*)

        dev=`blkid -L "${dev#LABEL=}"`

        ;;

    esac

    echo $dev

}

get_block_dump_target()

{

    local _target

    _target=$(get_user_configured_dump_disk)

    [ -n "$_target" ] && echo $(to_dev_name $_target) && return

    #get rootfs device name

    _target=$(get_root_fs_device)

    [ -b "$_target" ] && echo $(to_dev_name $_target)

}

# If no dump disk is specified make sure /var/crash is not mounted on a

# separate disk.

check_block_dump_target()

{

    local _target

    local _mntpoint

    is_user_configured_dump_target && return

    _target=$(get_root_fs_device)

    if [ -b "$_target" ]; then

        mkdir -p $SAVE_PATH

        _mntpoint=`df $SAVE_PATH | tail -1 |  awk '{print $NF}'`

        if [ "$_mntpoint" != "/" ]; then

            perror "No dump target specified. Default dump target is rootfs block device."

            perror "But dump path $SAVE_PATH is not backed by rootfs block device. "

            perror_exit "Either explicitly specify a dump target or specify a dump path backed by rootfs block device"

        fi

    fi

}

get_default_action_target()

{

    local _target

    local _action=$(grep "^default" /etc/kdump.conf 2>/dev/null | awk '{print $2}')

    if [ -n "$_action" ] && [ "$_action" = "dump_to_rootfs" ]; then

        #get rootfs device name

        _target=$(findmnt -k -f -n -o SOURCE /)

        [ -b "$_target" ] && echo $(to_dev_name $_target)

    fi

    return

}

get_override_resettable()

{

    local override_resettable

    override_resettable=$(grep "^override_resettable" $conf_file)

    if [ -n "$override_resettable" ]; then

        OVERRIDE_RESETTABLE=$(echo $override_resettable | cut -d' '  -f2)

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

            perror_exit "override_resettable value $OVERRIDE_RESETTABLE is invalid"

        fi

    fi

}

# $1: function name

for_each_block_target()

{

    local dev majmin

    #check dump target

    dev=$(get_block_dump_target)

    if [ -n "$dev" ]; then

        majmin=$(get_maj_min $dev)

        check_block_and_slaves $1 $majmin && return 1

    fi

    #check rootfs when default action dump_to_rootfs is set

    dev=$(get_default_action_target)

    if [ -n "$dev" ]; then

        majmin=$(get_maj_min $dev)

        check_block_and_slaves $1 $majmin && return 2

    fi

    return 0

}

#judge if a specific device with $1 is unresettable

#return false if unresettable.

is_unresettable()

{

    local path="/sys/$(udevadm info --query=all --path=/sys/dev/block/$1 | awk '/^P:/ {print $2}' | sed -e 's/\(cciss[0-9]\+\/\).*/\1/g' -e 's/\/block\/.*$//')/resettable"

    local resettable=1

    if [ -f "$path" ]

    then

        resettable="$(cat $path)"

        [ $resettable -eq 0 -a "$OVERRIDE_RESETTABLE" -eq 0 ] && {

            local device=$(udevadm info --query=all --path=/sys/dev/block/$1 | awk -F= '/DEVNAME/{print $2}')

            echo "Device $device is unresettable"

            return 0

        }

    fi

    return 1

}

#check if machine is resettable.

#return true if resettable

check_resettable()

{

    local _ret _target

    get_override_resettable

    for_each_block_target is_unresettable

    _ret=$?

    [ $_ret -eq 0 ] && return

    if [ $_ret -eq 1 ]; then

        _target=$(get_block_dump_target)

        perror "Can not save vmcore to target device $_target . This device can not be initialized in kdump kernel as it is not resettable"

    elif [ $_ret -eq 2 ]; then

        _target=$(get_default_action_target)

        perror "Rootfs device $_target is not resettable, can not be used as the default target, please specify a default action"

    fi

    return 1

}

# $1: maj:min

is_crypt()

{

    local majmin=$1 dev line ID_FS_TYPE=""

    line=$(udevadm info --query=property --path=/sys/dev/block/$majmin \

            | grep "^ID_FS_TYPE")

    eval "$line"

    [[ "$ID_FS_TYPE" = "crypto_LUKS" ]] && {

        dev=$(udevadm info --query=all --path=/sys/dev/block/$majmin | awk -F= '/DEVNAME/{print $2}')

        echo "Device $dev is encrypted."

        return 0

    }

    return 1

}

check_crypt()

{

    local _ret _target

    for_each_block_target is_crypt

    _ret=$?

    [ $_ret -eq 0 ] && return

    return 1

}

check_block_dump_target

if ! check_resettable; then

    exit 1

fi

if ! check_crypt; then

    echo "Warning: Encrypted device is in dump path. User will prompted for password during second kernel boot."

fi

# firstly get right SSH_KEY_LOCATION

keyfile=$(awk '/^sshkey/ {print $2}' $conf_file)

if [ -f "$keyfile" ]; then

    # canonicalize the path

    SSH_KEY_LOCATION=$(/usr/bin/readlink -m $keyfile)

fi

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

    add_dracut_module "znet"

fi

while read config_opt config_val;

do

    # remove inline comments after the end of a directive.

    config_val=$(strip_comments $config_val)

    case "$config_opt" in

    extra_modules)

        extra_modules="$extra_modules $config_val"

        ;;

    ext[234]|xfs|btrfs|minix|nfs)

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

            perror_exit "Dump target $config_val is probably not mounted."

        fi

        if [ "$config_opt" = "nfs" ]; then

            add_dracut_module "nfs"

        fi

        add_mount "$config_val"

        mkdir_save_path_fs $config_val

        check_size fs $config_val

        ;;

    raw)

        #checking raw disk writable

        dd if=$config_val count=1 of=/dev/null > /dev/null 2>&1 || {

            perror_exit "Bad raw disk $config_val"

        }

        _praw=$(get_persistent_dev $config_val)

        if [ $? -ne 0 ]; then

            exit 1

        fi

        add_dracut_arg "--device" "$_praw"

        check_size raw $config_val

        ;;

    ssh)

        if strstr "$config_val" "@";

        then

            check_size ssh $config_val

            mkdir_save_path_ssh $config_val

            add_dracut_module "ssh-client"

		add_dracut_sshkey "$SSH_KEY_LOCATION"

        else

            perror_exit "Bad ssh dump target $config_val"

        fi

        ;;

    core_collector)

        verify_core_collector "$config_val"

        ;;

    dracut_args)

        add_dracut_arg $config_val

        ;;

    *)

        if [ -n $(echo $config_opt | grep "^#.*$") ]

        then

            continue

        fi

        ;;

    esac

done < $conf_file

if [ -n "$extra_modules" ]

then

    add_dracut_arg "--add-drivers" "$extra_modules"

fi

dracut "${dracut_args[@]}" "$@"

_rc=$?

sync

exit $_rc