kexec-tools/mkdumprd

#!/bin/bash --norc
# New mkdumprd
#
# Copyright 2011 Red Hat, Inc.
#
# Written by Cong Wang <amwang@redhat.com>
#

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

[[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut
. $dracutbasedir/dracut-functions.sh
. /lib/kdump/kdump-lib.sh
. /lib/kdump/kdump-logger.sh
export IN_KDUMP=1

#initiate the kdump logger
dlog_init
if [[ $? -ne 0 ]]; then
	echo "failed to initiate the kdump logger."
	exit 1
fi

SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa"
SAVE_PATH=$(get_save_path)
OVERRIDE_RESETTABLE=0

extra_modules=""
dracut_args=( --add kdumpbase --quiet --hostonly --hostonly-cmdline --hostonly-i18n --hostonly-mode strict -o "plymouth dash resume ifcfg earlykdump" )

readonly MKDUMPRD_TMPDIR="$(mktemp -d -t mkdumprd.XXXXXX)"
[ -d "$MKDUMPRD_TMPDIR" ] || perror_exit "dracut: mktemp -p -d -t dracut.XXXXXX failed."
readonly MKDUMPRD_TMPMNT="$MKDUMPRD_TMPDIR/target"

trap '
    ret=$?;
    is_mounted $MKDUMPRD_TMPMNT && umount -f $MKDUMPRD_TMPMNT;
    [[ -d $MKDUMPRD_TMPDIR ]] && rm --one-file-system -rf -- "$MKDUMPRD_TMPDIR";
    exit $ret;
    ' EXIT

# clean up after ourselves no matter how we die.
trap 'exit 1;' SIGINT

add_dracut_arg() {
    dracut_args+=( "$@" )
}

add_dracut_mount() {
    add_dracut_arg "--mount" "$1"
}

add_dracut_sshkey() {
    add_dracut_arg "--sshkey" "$1"
}

# caller should ensure $1 is valid and mounted in 1st kernel
to_mount() {
    local _target=$1 _fstype=$2 _options=$3 _sed_cmd _new_mntpoint _pdev

    _new_mntpoint=$(get_kdump_mntpoint_from_target "$_target")
    _fstype="${_fstype:-$(get_fs_type_from_target "$_target")}"
    _options="${_options:-$(get_mntopt_from_target "$_target")}"
    _options="${_options:-defaults}"

    if [[ "$_fstype" == "nfs"* ]]; then
        _pdev=$_target
        _sed_cmd+='s/,addr=[^,]*//;'
        _sed_cmd+='s/,proto=[^,]*//;'
        _sed_cmd+='s/,clientaddr=[^,]*//;'
    else
        # for non-nfs _target converting to use udev persistent name
        _pdev="$(kdump_get_persistent_dev "$_target")"
        if [[ -z $_pdev ]]; then
            return 1
        fi
    fi

    # mount fs target as rw in 2nd kernel
    _sed_cmd+='s/\(^\|,\)ro\($\|,\)/\1rw\2/g;'
    # with 'noauto' in fstab nfs and non-root disk mount will fail in 2nd
    # kernel, filter it out here.
    _sed_cmd+='s/\(^\|,\)noauto\($\|,\)/\1/g;'
    # drop nofail or nobootwait
    _sed_cmd+='s/\(^\|,\)nofail\($\|,\)/\1/g;'
    _sed_cmd+='s/\(^\|,\)nobootwait\($\|,\)/\1/g;'

    _options=$(echo "$_options" | sed "$_sed_cmd")

    echo "$_pdev $_new_mntpoint $_fstype $_options"
}

#Function: get_ssh_size
#$1=dump target
#called from while loop and shouldn't read from stdin, so we're using "ssh -n"
get_ssh_size() {
    local _out
    local _opt=("-i" "$SSH_KEY_LOCATION" "-o" "BatchMode=yes" "-o" "StrictHostKeyChecking=yes")

    if ! _out=$(ssh -q -n "${_opt[@]}" "$1" "df" "--output=avail" "$SAVE_PATH"); then
        perror_exit "checking remote ssh server available size failed."
    fi

    echo -n "$_out" | tail -1
}

#mkdir if save path does not exist on ssh dump target
#$1=ssh dump target
#caller should ensure write permission on $1:$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 $1:$SAVE_PATH"
    fi

    #check whether user has write permission on $1:$SAVE_PATH
    _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 $1:$SAVE_PATH. Make sure user has write permission on destination"
    fi
    ssh -qn "${_opt[@]}" "$1" rmdir "$_dir"

    return 0
}

#Function: get_fs_size
#$1=dump target
get_fs_size() {
    df --output=avail "$(get_mntpoint_from_target "$1")/$SAVE_PATH" | tail -1
}

#Function: get_raw_size
#$1=dump target
get_raw_size() {
    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
        dwarn "Warning: There might not be enough space to save a vmcore."
        dwarn "         The size of $2 should be greater than $memtotal kilo bytes."
    fi
}

check_save_path_fs()
{
    local _path=$1

    if [[ ! -d $_path ]]; then
        perror_exit "Dump path $_path does not exist."
    fi
}

mount_failure()
{
    local _target=$1
    local _mnt=$2
    local _fstype=$3
    local msg="Failed to mount $_target"

    if [[ -n "$_mnt" ]]; then
        msg="$msg on $_mnt"
    fi

    msg="$msg for kdump preflight check."

    if [[ $_fstype = "nfs" ]]; then
        msg="$msg Please make sure nfs-utils has been installed."
    fi

    perror_exit "$msg"
}

check_user_configured_target()
{
    local _target=$1 _cfg_fs_type=$2 _mounted
    local _mnt=$(get_mntpoint_from_target "$_target")
    local _opt=$(get_mntopt_from_target "$_target")
    local _fstype=$(get_fs_type_from_target "$_target")

    if [[ -n "$_fstype" ]]; then
        # In case of nfs4, nfs should be used instead, nfs* options is deprecated in kdump.conf
        [[ $_fstype = "nfs"* ]] && _fstype=nfs

        if [[ -n "$_cfg_fs_type" ]] && [[ "$_fstype" != "$_cfg_fs_type" ]]; then
            perror_exit "\"$_target\" have a wrong type config \"$_cfg_fs_type\", expected \"$_fstype\""
        fi
    else
        _fstype="$_cfg_fs_type"
        _fstype="$_cfg_fs_type"
    fi

    # For noauto mount, mount it inplace with default value.
    # Else use the temporary target directory
    if [[ -n "$_mnt" ]]; then
        if ! is_mounted "$_mnt"; then
            if [[ $_opt  = *",noauto"* ]]; then
                mount "$_mnt"
                [[ $? -ne 0 ]] && mount_failure "$_target" "$_mnt" "$_fstype"
                _mounted=$_mnt
            else
                perror_exit "Dump target \"$_target\" is neither mounted nor configured as \"noauto\""
            fi
        fi
    else
        _mnt=$MKDUMPRD_TMPMNT
        mkdir -p "$_mnt"
        mount "$_target" "$_mnt" -t "$_fstype" -o defaults
        [[ $? -ne 0 ]] && mount_failure "$_target" "" "$_fstype"
        _mounted=$_mnt
    fi

    # For user configured target, use $SAVE_PATH as the dump path within the target
    if [[ ! -d "$_mnt/$SAVE_PATH" ]]; then
        perror_exit "Dump path \"$_mnt/$SAVE_PATH\" does not exist in dump target \"$_target\""
    fi

    check_size fs "$_target"

    # Unmount it early, if function is interrupted and didn't reach here, the shell trap will clear it up anyway
    if [[ -n "$_mounted" ]]; then
        umount -f -- "$_mounted"
    fi
}

# $1: core_collector config value
verify_core_collector() {
    local _cmd="${1%% *}"
    local _params="${1#* }"

    if [[ "$_cmd" != "makedumpfile" ]]; then
        if is_raw_dump_target; then
            dwarn "Warning: specifying a non-makedumpfile core collector, you will have to recover the vmcore manually."
        fi
        return
    fi

    if is_ssh_dump_target || is_raw_dump_target; then
        if ! strstr "$_params" "-F"; then
            perror_exit "The specified dump target needs makedumpfile \"-F\" option."
        fi
        _params="$_params vmcore"
    else
        _params="$_params vmcore dumpfile"
    fi

    # shellcheck disable=SC2086
    if ! $_cmd --check-params $_params; then
        perror_exit "makedumpfile parameter check failed."
    fi
}

add_mount() {
    local _mnt=$(to_mount "$@")

    if [[ $? -ne 0 ]]; then
        exit 1
    fi

    add_dracut_mount "$_mnt"
}

#handle the case user does not specify the dump target explicitly
handle_default_dump_target()
{
    local _target
    local _mntpoint

    is_user_configured_dump_target && return

    check_save_path_fs "$SAVE_PATH"

    _save_path=$(get_bind_mount_source "$SAVE_PATH")
    _target=$(get_target_from_path "$_save_path")
    _mntpoint=$(get_mntpoint_from_target "$_target")

    SAVE_PATH=${_save_path##"$_mntpoint"}
    add_mount "$_target"
    check_size fs "$_target"
}

# $1: function name
for_each_block_target()
{
    local dev majmin

    for dev in $(get_kdump_targets); do
        [[ -b "$dev" ]] || continue
        majmin=$(get_maj_min "$dev")
        check_block_and_slaves "$1" "$majmin" && return 1
    done

    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 "$path" ]]
    then
        resettable="$(<"$path")"
        [[ $resettable -eq 0 ]] && [[ "$OVERRIDE_RESETTABLE" -eq 0 ]] && {
            local device=$(udevadm info --query=all --path="/sys/dev/block/$1" | awk -F= '/DEVNAME/{print $2}')
            derror "Error: Can not save vmcore because device $device is unresettable"
            return 0
        }
    fi

    return 1
}

#check if machine is resettable.
#return true if resettable
check_resettable()
{
    local _ret _target _override_resettable

    _override_resettable=$(kdump_get_conf_val override_resettable)
    OVERRIDE_RESETTABLE=${_override_resettable:-$OVERRIDE_RESETTABLE}
    if [ "$OVERRIDE_RESETTABLE" != "0" ] && [ "$OVERRIDE_RESETTABLE" != "1" ];then
        perror_exit "override_resettable value '$OVERRIDE_RESETTABLE' is invalid"
    fi

    for_each_block_target is_unresettable
    _ret=$?

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

    return 1
}

check_crypt()
{
    local _dev

    for _dev in $(get_kdump_targets); do
        if [[ -n $(get_luks_crypt_dev "$(get_maj_min "$_dev")") ]]; then
            derror "Device $_dev is encrypted." && return 1
        fi
    done
}

if ! check_resettable; then
    exit 1
fi

if ! check_crypt; then
    dwarn "Warning: Encrypted device is in dump path, which is not recommended, see kexec-kdump-howto.txt for more details."
fi

# firstly get right SSH_KEY_LOCATION
keyfile=$(kdump_get_conf_val sshkey)
if [[ -f "$keyfile" ]]; then
    # canonicalize the path
    SSH_KEY_LOCATION=$(/usr/bin/readlink -m "$keyfile")
fi

while read -r config_opt config_val;
do
    # remove inline comments after the end of a directive.
    case "$config_opt" in
    extra_modules)
        extra_modules="$extra_modules $config_val"
        ;;
    ext[234]|xfs|btrfs|minix|nfs)
        check_user_configured_target "$config_val" "$config_opt"
        add_mount "$config_val" "$config_opt"
        ;;
    raw)
        # checking raw disk writable
        dd if="$config_val" count=1 of=/dev/null > /dev/null 2>&1 || {
            perror_exit "Bad raw disk $config_val"
        }
        _praw=$(persistent_policy="by-id" kdump_get_persistent_dev "$config_val")
        if [[ -z $_praw ]]; then
            exit 1
        fi
        add_dracut_arg "--device" "$_praw"
        check_size raw "$config_val"
        ;;
    ssh)
        if strstr "$config_val" "@";
        then
            mkdir_save_path_ssh "$config_val"
            check_size ssh "$config_val"
            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)
        while read -r dracut_arg; do
            add_dracut_arg "$dracut_arg"
        done <<< "$(echo "$config_val" | xargs -n 1 echo)"
        ;;
    *)
        ;;
    esac
done <<< "$(kdump_read_conf)"

handle_default_dump_target

if [[ -n "$extra_modules" ]]
then
    add_dracut_arg "--add-drivers" "$extra_modules"
fi

# TODO: The below check is not needed anymore with the introduction of
#       'zz-fadumpinit' module, that isolates fadump's capture kernel initrd,
#       but still sysroot.mount unit gets generated based on 'root=' kernel
#       parameter available in fadump case. So, find a way to fix that first
#       before removing this check.
if ! is_fadump_capable; then
    # The 2nd rootfs mount stays behind the normal dump target mount,
    # so it doesn't affect the logic of check_dump_fs_modified().
    is_dump_to_rootfs && add_mount "$(to_dev_name "$(get_root_fs_device)")"

    add_dracut_arg "--no-hostonly-default-device"
fi

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

_rc=$?
sync
exit $_rc