#!/bin/sh

#

# Function and variables used in initramfs environment, POSIX compatible

#

DEFAULT_PATH="/var/crash/"

KDUMP_CONFIG_FILE="/etc/kdump.conf"

# Read kdump config in well formated style

kdump_read_conf()

{

    # Following steps are applied in order: strip trailing comment, strip trailing space,

    # strip heading space, match non-empty line, remove duplicated spaces between conf name and value

    [ -f "$KDUMP_CONFIG_FILE" ] && sed -n -e "s/#.*//;s/\s*$//;s/^\s*//;s/\(\S\+\)\s*\(.*\)/\1 \2/p" $KDUMP_CONFIG_FILE

}

# Retrieves config value defined in kdump.conf

# $1: config name, sed regexp compatible

kdump_get_conf_val() {

    # For lines matching "^\s*$1\s+", remove matched part (config name including space),

    # remove tailing comment, space, then store in hold space. Print out the hold buffer on last line.

    [ -f "$KDUMP_CONFIG_FILE" ] && \

        sed -n -e "/^\s*\($1\)\s\+/{s/^\s*\($1\)\s\+//;s/#.*//;s/\s*$//;h};\${x;p}" $KDUMP_CONFIG_FILE

}

is_mounted()

{

    findmnt -k -n $1 &>/dev/null

}

get_mount_info()

{

    local _info_type=$1 _src_type=$2 _src=$3; shift 3

    local _info=$(findmnt -k -n -r -o $_info_type --$_src_type $_src $@)

    [ -z "$_info" ] && [ -e "/etc/fstab" ] && _info=$(findmnt -s -n -r -o $_info_type --$_src_type $_src $@)

    echo $_info

}

is_ipv6_address()

{

    echo $1 | grep -q ":"

}

is_fs_type_nfs()

{

    [ "$1" = "nfs" ] || [ "$1" = "nfs4" ]

}

# If $1 contains dracut_args "--mount", return <filesystem type>

get_dracut_args_fstype()

{

    echo $1 | grep "\-\-mount" | sed "s/.*--mount .\(.*\)/\1/" | cut -d' ' -f3

}

# If $1 contains dracut_args "--mount", return <device>

get_dracut_args_target()

{

    echo $1 | grep "\-\-mount" | sed "s/.*--mount .\(.*\)/\1/" | cut -d' ' -f1

}

get_save_path()

{

    local _save_path=$(kdump_get_conf_val path)

    [ -z "$_save_path" ] && _save_path=$DEFAULT_PATH

    # strip the duplicated "/"

    echo $_save_path | tr -s /

}

get_root_fs_device()

{

    findmnt -k -f -n -o SOURCE /

}

# Return the current underlying device of a path, ignore bind mounts

get_target_from_path()

{

    local _target

    _target=$(df $1 2>/dev/null | tail -1 |  awk '{print $1}')

    [[ "$_target" == "/dev/root" ]] && [[ ! -e /dev/root ]] && _target=$(get_root_fs_device)

    echo $_target

}

get_fs_type_from_target()

{

    get_mount_info FSTYPE source $1 -f

}

get_mntpoint_from_target()

{

    # --source is applied to ensure non-bind mount is returned

    get_mount_info TARGET source $1 -f

}

is_ssh_dump_target()

{

    [[ $(kdump_get_conf_val ssh) == *@* ]]

}

is_raw_dump_target()

{

    [[ $(kdump_get_conf_val raw) ]]

}

is_nfs_dump_target()

{

    if [[ $(kdump_get_conf_val nfs) ]]; then

        return 0;

    fi

    if is_fs_type_nfs $(get_dracut_args_fstype "$(kdump_get_conf_val dracut_args)"); then

        return 0

    fi

    local _save_path=$(get_save_path)

    local _target=$(get_target_from_path $_save_path)

    local _fstype=$(get_fs_type_from_target $_target)

    if is_fs_type_nfs $_fstype; then

        return 0

    fi

    return 1

}

is_fs_dump_target()

{

    [[ $(kdump_get_conf_val "ext[234]\|xfs\|btrfs\|minix") ]]

}