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

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" "--add" "kdumpbase" "--add" "fstab-sys" "--add" "kernel-modules" "-c" "/dev/null" "-I" "/sbin/makedumpfile" "-o" "plymouth")

add_dracut_arg() {
    while [ $# -gt 0 ];
    do
        dracut_args+=("$1")
        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 ]]; }

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_rootdev() {
    mount | grep 'on / ' | grep -v rootfs | awk '{print $1}'
}

to_mount() {
    local _dev=$(to_dev_name $1)
    echo "$(grep "$_dev" /proc/mounts | cut -d' ' -f1-4)"
}

to_mount_point() {
    local _dev=$(to_dev_name $1)
    echo "$(grep "$_dev" /proc/mounts | cut -d' ' -f2)"
}

#Function: get_ssh_size
#$1=dump target
get_ssh_size() {
    local _opt _out _size
    _opt="-i $SSH_KEY_LOCATION -o BatchMode=yes -o StrictHostKeyChecking=yes"
    _out=$(ssh -q $_opt $1 "df -P $SAVE_PATH")
    if [ $? -ne 0 ]; then
        echo "checking remote ssh server available size failed."
        exit 1
    fi
    #ssh output removed the line break, so print $11 instead of $4
    _size=$(echo -n $_out|tail -1 | awk '{print $11}')
    echo -n $_size
}

#Function: get_fs_size
#$1=dump target
get_fs_size() {
    local _mnt=$(to_mount_point $1)
    [ ! -d ${_mnt}/$SAVE_PATH ] && {
        mkdir -p ${_mnt}/$SAVE_PATH
        [ $? -ne 0 ] && {
            echo "Creating ${_mnt}/$SAVE_PATH failed."
            exit 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 [ $avail -lt $memtotal ]; then
        echo "Warning: There is not enough space to save a vmcore."
        echo "         The size of $2 should be much greater than $memtotal kilo bytes."
    fi
}

is_ssh_dump_target()
{
    grep -q "^net.*@" $conf_file
}

is_raw_dump_target()
{
    grep -q "^raw" $conf_file
}

# $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" && {
                echo "The specified dump target needs makedumpfile \"-F\" option."
                exit 1
            }
        fi
    fi
}

add_mount() {
    local _dev=$(to_dev_name "$1")
    local _mnt=$(to_mount "$1")
    if [ "$_dev" = "$(get_rootdev)" ]; then
        :
    elif [ -n "$_mnt" ]; then
        add_dracut_mount "$_mnt"
    else
	return 1
    fi
    return 0
}

add_dracut_mount "$(to_mount "$(get_rootdev)")"

# 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
    case "$config_opt" in
    extra_modules)
        extra_modules="$extra_modules $config_val"
        ;;
    ext[234]|xfs|btrfs|minix)
        add_mount "$config_val"
        if [ $? -ne 0 ]; then
            echo "Dump target $config_val is probably not mounted."
            exit 1
        fi
        check_size fs $config_val
        ;;
    raw)
        #checking raw disk writable
        dd if=$config_val count=1 of=/dev/null > /dev/null 2>&1 || {
            echo "Bad raw disk $config_val"
            exit 1
        }
        check_size raw $config_val
        ;;
    net)
        if strstr "$config_val" "@";
        then
            check_size ssh $config_val
            add_dracut_module "ssh-client"
		add_dracut_sshkey "$SSH_KEY_LOCATION"
        else
            add_dracut_module "nfs"
            add_mount "$config_val"
            if [ $? -ne 0 ]; then
                echo "Dump target $config_val is probably not mounted."
                exit 1
            fi
            check_size fs $config_val
        fi
        ;;
    core_collector)
        verify_core_collector "$config_val"
        add_dracut_arg "-I" "${config_val%% *}"
        ;;
    extra_bins)
        add_dracut_arg "-I" "$config_val"
        ;;
    blacklist)
        add_dracut_arg "--omit-drivers" "$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 "${dracut_args[@]}" -M "$@"
_rc=$?
sync
exit $_rc