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

conf_file="/etc/kdump.conf"
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 --hostonly-nics '' -o \"plymouth dash resume ifcfg earlykdump\" --compress=xz"

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="$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 _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
        _options=$(echo $_options | sed 's/,\(mount\)\?addr=[^,]*//g')
        _options=$(echo $_options | sed 's/,\(mount\)\?proto=[^,]*//g')
        _options=$(echo $_options | sed 's/,clientaddr=[^,]*//')
    else
        # for non-nfs _target converting to use udev persistent name
        _pdev="$(kdump_get_persistent_dev $_target)"
        if [ -z "$_pdev" ]; then
            return 1
        fi
    fi

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

    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 _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 $1:$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
#$1=dump target
get_fs_size() {
    local _mnt=$(get_mntpoint_from_target $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
        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
}

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 ] && perror_exit "Failed to mount $_target on $_mnt for kdump preflight check."
                _mounted=$_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 ] && perror_exit "Failed to mount $_target for kdump preflight check."
        _mounted=$_mnt
    fi

    # For user configured target, use $SAVE_PATH as the dump path within the target
    if [ ! -d "$_mnt/$SAVE_PATH" ]; then
        perror_exit "Dump path \"$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

    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
}

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

    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 "$path" ]
    then
        resettable="$(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}')
            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

    get_override_resettable

    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. 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

while read 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)
        add_dracut_arg $config_val
        ;;
    *)
        ;;
    esac
done <<< "$(read_strip_comments $conf_file)"

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

echo "$dracut_args $@" | xargs dracut