#!/bin/bash
#
# Copyright (c) 2013 Red Hat, Inc. <http://www.redhat.com>
# This file is part of GlusterFS.
#
# This file is licensed to you under your choice of the GNU Lesser
# General Public License, version 3 or any later version (LGPLv3 or
# later), or the GNU General Public License, version 2 (GPLv2), in all
# cases as published by the Free Software Foundation.

_init ()
{
    # log level definitions
    LOG_NONE=NONE;
    LOG_CRITICAL=CRITICAL;
    LOG_ERROR=ERROR;
    LOG_WARNING=WARNING;
    LOG_INFO=INFO
    LOG_DEBUG=DEBUG;
    LOG_TRACE=TRACE;

    HOST_NAME_MAX=64;

    prefix="@prefix@";
    exec_prefix=@exec_prefix@;
    cmd_line=$(echo "@sbindir@/glusterfs");

    # check whether getfattr exists
    export PATH
    getfattr=$(which getfattr 2>/dev/null);
    if [ $? -ne 0 ]; then
        echo "WARNING: getfattr not found, certain checks will be skipped.."
    fi

    alias lsL='ls -L'
    mounttab=/proc/mounts
    uname_s=`uname -s`
    case ${uname_s} in
        NetBSD)
            getinode="stat -f %i"
            getdev="stat -f %d"
            lgetinode="${getinode} -L"
            lgetdev="${getdev} -L"
            ;;
        Linux)
            getinode="stat -c %i"
            getdev="stat -c %d"
            lgetinode="${getinode} -L"
            lgetdev="${getdev} -L"
            ;;
    esac

    UPDATEDBCONF=/etc/updatedb.conf
}

is_valid_hostname ()
{
    local server=$1

    length=$(echo $server | wc -c)
    if [ ${length} -gt ${HOST_NAME_MAX} ]; then
        return 1
    fi
}

parse_backup_volfile_servers ()
{
    local server_list=$1
    local servers=""
    local new_servers=""

    servers=$(echo ${server_list} | sed 's/\:/ /g')
    for server in ${servers}; do
        is_valid_hostname ${server}
        if [ $? -eq 1 ]; then
            continue
        fi
        new_servers=$(echo "${new_servers} ${server}")
    done

    echo ${new_servers}
}

parse_volfile_servers ()
{
    local server_list=$1
    local servers=""
    local new_servers=""

    servers=$(echo ${server_list} | sed 's/,/ /g')
    for server in ${servers}; do
        is_valid_hostname ${server}
        if [ $? -eq 1 ]; then
            continue
        fi
        new_servers=$(echo "${new_servers} ${server}")
    done

    echo ${new_servers}
}

start_glusterfs ()
{
    if [ -n "$log_level_str" ]; then
        case "$( echo $log_level_str | awk '{print toupper($0)}')" in
            "ERROR")
                log_level=$LOG_ERROR;
                ;;
            "INFO")
                log_level=$LOG_INFO;
                ;;
            "DEBUG")
                log_level=$LOG_DEBUG;
                ;;
            "CRITICAL")
                log_level=$LOG_CRITICAL;
                ;;
            "WARNING")
                log_level=$LOG_WARNING;
                ;;
            "TRACE")
                log_level=$LOG_TRACE;
                ;;
            "NONE")
                log_level=$LOG_NONE;
                ;;
            *)
                echo "invalid log level $log_level_str, using INFO";
                log_level=$LOG_INFO;
                ;;
        esac
    fi

    # options without values start here
    if [ -n "$read_only" ]; then
        cmd_line=$(echo "$cmd_line --read-only");
    fi

    if [ -n "$acl" ]; then
        cmd_line=$(echo "$cmd_line --acl");
    fi

    if [ -n "$selinux" ]; then
         cmd_line=$(echo "$cmd_line --selinux");
    fi

    if [ -n "$enable_ino32" ]; then
        cmd_line=$(echo "$cmd_line --enable-ino32");
    fi

    if [ -n "$worm" ]; then
        cmd_line=$(echo "$cmd_line --worm");
    fi

    if [ -n "$fopen_keep_cache" ]; then
        cmd_line=$(echo "$cmd_line --fopen-keep-cache");
    fi

    if [ -n "$volfile_check" ]; then
        cmd_line=$(echo "$cmd_line --volfile-check");
    fi

    if [ -n "$mem_accounting" ]; then
        cmd_line=$(echo "$cmd_line --mem-accounting");
    fi

    if [ -n "$aux_gfid_mount" ]; then
        cmd_line=$(echo "$cmd_line --aux-gfid-mount");
    fi

    # options with values start here
    if [ -n "$log_level" ]; then
        cmd_line=$(echo "$cmd_line --log-level=$log_level");
    fi

    if [ -n "$log_file" ]; then
        cmd_line=$(echo "$cmd_line --log-file=$log_file");
    fi

    if [ -n "$direct_io_mode" ]; then
        cmd_line=$(echo "$cmd_line --direct-io-mode=$direct_io_mode");
    fi

    if [ -n "$use_readdirp" ]; then
        cmd_line=$(echo "$cmd_line --use-readdirp=$use_readdirp");
    fi

    if [ -n "$volume_name" ]; then
        cmd_line=$(echo "$cmd_line --volume-name=$volume_name");
    fi

    if [ -n "$attribute_timeout" ]; then
        cmd_line=$(echo "$cmd_line --attribute-timeout=$attribute_timeout");
    fi

    if [ -n "$entry_timeout" ]; then
        cmd_line=$(echo "$cmd_line --entry-timeout=$entry_timeout");
    fi

    if [ -n "$negative_timeout" ]; then
        cmd_line=$(echo "$cmd_line --negative-timeout=$negative_timeout");
    fi

    if [ -n "$gid_timeout" ]; then
        cmd_line=$(echo "$cmd_line --gid-timeout=$gid_timeout");
    fi

    if [ -n "$bg_qlen" ]; then
        cmd_line=$(echo "$cmd_line --background-qlen=$bg_qlen");
    fi

    if [ -n "$cong_threshold" ]; then
        cmd_line=$(echo "$cmd_line --congestion-threshold=$cong_threshold");
    fi

    if [ -n "$fuse_mountopts" ]; then
        cmd_line=$(echo "$cmd_line --fuse-mountopts=$fuse_mountopts");
    fi

    if [ -n "$xlator_option" ]; then
        cmd_line=$(echo "$cmd_line --xlator-option=$xlator_option");
    fi

    # for rdma volume, we have to fetch volfile with '.rdma' added
    # to volume name, so that it fetches the right client vol file
    volume_id_rdma="";

    if [ -z "$volfile_loc" ]; then
        if  [ -n "$server_ip" ]; then

            servers=$(parse_volfile_servers ${server_ip});
            if [ -n "$servers" ]; then
                for i in $(echo ${servers}); do
                    cmd_line=$(echo "$cmd_line --volfile-server=$i");
                done
            else
                echo "ERROR: No valid servers found on command line.. exiting"
                print_usage
                exit 1
            fi

            if [ -n "$backupvolfile_server" ]; then
                if [ -z "$backup_volfile_servers" ]; then
                    is_valid_hostname ${backupvolfile_server};
                    if [ $? -eq 1 ]; then
                        echo "ERROR: Invalid backup server specified.. exiting"
                        exit 1
                    fi
                    cmd_line=$(echo "$cmd_line --volfile-server=$backupvolfile_server");
                fi
            fi

            if [ -n "$backup_volfile_servers" ]; then
                backup_servers=$(parse_backup_volfile_servers ${backup_volfile_servers})
                for i in $(echo ${backup_servers}); do
                    cmd_line=$(echo "$cmd_line --volfile-server=$i");
                done
            fi

            if [ -n "$server_port" ]; then
                cmd_line=$(echo "$cmd_line --volfile-server-port=$server_port");
            fi

            if [ -n "$transport" ]; then
                cmd_line=$(echo "$cmd_line --volfile-server-transport=$transport");
                if [ "$transport" = "rdma" ]; then
                    volume_id_rdma=".rdma";
                fi
            fi

            if [ -n "$volume_id" ]; then
                if [ -n "$volume_id_rdma" ]; then
                    volume_id="$volume_id$volume_id_rdma";
                fi
                cmd_line=$(echo "$cmd_line --volfile-id=$volume_id");
            fi
        fi
    else
        cmd_line=$(echo "$cmd_line --volfile=$volfile_loc");
    fi

    if [ -n "$fuse_mountopts" ]; then
        cmd_line=$(echo "$cmd_line --fuse-mountopts=$fuse_mountopts");
    fi

    cmd_line=$(echo "$cmd_line $mount_point");

    $cmd_line;

    inode=$( ${getinode} $mount_point 2>/dev/null);
    # this is required if the stat returns error
    if [ $? -ne 0 ]; then
        echo "Mount failed. Please check the log file for more details."
        umount $mount_point > /dev/null 2>&1;
        exit 1;
    fi
}

print_usage ()
{
cat << EOF
Usage: $0 <volumeserver>:<volumeid/volumeport> -o<options> <mountpoint>
Options:
man 8 $0
To display the version number of the mount helper: $0 -V
EOF
}

# check for recursive mounts. i.e, mounting over an existing brick
check_recursive_mount ()
{
    if [ $1 = "/" ]; then
        echo "Cannot mount over root";
        exit 2;
    fi

    # GFID check first
    # remove trailing / from mount point
    mnt_dir=${1%/};

    if [ -n ${getfattr} ]; then
        ${getfattr} -n trusted.gfid $mnt_dir 2>/dev/null | grep -iq "trusted.gfid=";
        if [ $? -eq 0 ]; then
            echo "ERROR: $mnt_dir is in use as a brick of a gluster volume";
            exit 2;
        fi
    fi

    # check if the mount point is a brick's parent directory
    GLUSTERD_WORKDIR="/var/lib/glusterd";

    lsL "$GLUSTERD_WORKDIR"/vols/*/bricks/* > /dev/null 2>&1;
    if [ $? -ne 0 ]; then
        return;
    fi

    brick_path=`grep ^path "$GLUSTERD_WORKDIR"/vols/*/bricks/* 2>/dev/null | cut -d "=" -f 2`;
    root_inode=`${lgetinode} /`;
    root_dev=`${lgetdev} /`;
    mnt_inode=`${lgetinode} $mnt_dir`;
    mnt_dev=`${lgetdev} $mnt_dir`;
    for brick in "$brick_path"; do
        # evaluate brick path to see if this is local, if non-local, skip iteration
        ls $brick > /dev/null 2>&1;
        if [ $? -ne 0 ]; then
            continue;
        fi

        if [ -n ${getfattr} ]; then
            ${getfattr} -n trusted.gfid "$brick" 2>/dev/null | grep -iq "trusted.gfid=";
            if [ $? -eq 0 ]; then
                # brick is local
                while [ 1 ]; do
                    tmp_brick="$brick";
                    brick="$brick"/..;
                    brick_dev=`${lgetdev} $brick`;
                    brick_inode=`${lgetinode} $brick`;
                    if [ "$mnt_inode" -eq "$brick_inode" \
                        -a "$mnt_dev" -eq "$brick_dev" ]; then
                        echo "ERROR: ${mnt_dir} is a parent of the brick ${tmp_brick}";
                        exit 2;
                    fi
                    [ "$root_inode" -ne "$brick_inode" \
                        -o "$root_dev" -ne "$brick_dev" ] || break;
                done;
            else
                continue;
            fi
        else
            continue;
        fi
    done;
}

with_options()
{
    local key=$1
    local value=$2

    # Handle options with values.
    case "$key" in
        "log-level")
            log_level_str=$value
            ;;
        "log-file")
            log_file=$value
            ;;
        "transport")
            transport=$value
            ;;
        "direct-io-mode")
            direct_io_mode=$value
            ;;
        "volume-name")
            volume_name=$value
            ;;
        "volume-id")
            volume_id=$value
            ;;
        "volfile-check")
            volfile_check=$value
            ;;
        "server-port")
            server_port=$value
            ;;
        "attribute-timeout")
            attribute_timeout=$value
            ;;
        "entry-timeout")
            entry_timeout=$value
            ;;
        "negative-timeout")
            negative_timeout=$value
            ;;
        "gid-timeout")
            gid_timeout=$value
            ;;
        "background-qlen")
            bg_qlen=$value
            ;;
        "backup-volfile-servers")
            backup_volfile_servers=$value
            ;;
        "backupvolfile-server")
            backupvolfile_server=$value
            ;;
        "congestion-threshold")
            cong_threshold=$value
            ;;
        "xlator-option")
            xlator_option=$value
            ;;
        "fuse-mountopts")
            fuse_mountopts=$value
            ;;
        "use-readdirp")
            use_readdirp=$value
            ;;
        *)
            echo "Invalid option: $key"
            exit 0
            ;;
    esac
}

without_options()
{
    local option=$1
    # Handle options without values.
    case "$option" in
        "ro")
            read_only=1
            ;;
        "acl")
            acl=1
            ;;
        "selinux")
            selinux=1
            ;;
        "worm")
            worm=1
            ;;
        "fopen-keep-cache")
            fopen_keep_cache=1
            ;;
        "enable-ino32")
            enable_ino32=1
            ;;
        "mem-accounting")
            mem_accounting=1
            ;;
        "aux-gfid-mount")
            if [ ${uname_s} = "Linux" ]; then
                aux_gfid_mount=1
            fi
            ;;
         # "mount -t glusterfs" sends this, but it's useless.
        "rw")
            ;;
         # these ones are interpreted during system initialization
        "noauto")
            ;;
        "_netdev")
            ;;
        *)
            echo "Invalid option $option";
            exit 0
            ;;
    esac
}

parse_options()
{
    local optarg=${1}
    for pair in $(echo ${optarg//,/ }); do
        key=$(echo "$pair" | cut -f1 -d'=');
        value=$(echo "$pair" | cut -f2- -d'=');
        if [ "$key" = "$value" ]; then
            without_options $pair;
        else
            with_options $key $value;
        fi
    done
}

update_updatedb()
{
    # Append fuse.glusterfs to PRUNEFS variable in updatedb.conf(5).
    # updatedb(8) should not index files under GlusterFS, indexing
    # GlusterFS is not necessary and should be avoided.
    # Following code disables updatedb crawl on 'glusterfs'
    test -f $UPDATEDBCONF && {
        if ! grep -q 'glusterfs' $UPDATEDBCONF; then
            sed 's/\(PRUNEFS.*\)"/\1 fuse.glusterfs"/' $UPDATEDBCONF \
                > ${UPDATEDBCONF}.bak
            mv -f ${UPDATEDBCONF}.bak $UPDATEDBCONF
        fi
    }
}

main ()
{

    volfile_loc=$1
    mount_point=$2

    ## `mount` specifies options as a last argument
    shift 2;
    while getopts "Vo:h" opt; do
        case "${opt}" in
            o)
                parse_options ${OPTARG};
                ;;
            V)
                ${cmd_line} -V;
                exit 0;
                ;;
            h)
                print_usage;
                exit 0;
                ;;
            ?)
                print_usage;
                exit 0;
                ;;
        esac
    done

    [ -r "$volfile_loc" ] || {
        server_ip=$(echo "$volfile_loc" | sed -n 's/\([a-zA-Z0-9:.\-]*\):.*/\1/p');
        volume_str=$(echo "$volfile_loc" | sed -n 's/.*:\([^ ]*\).*/\1/p');
        [ -n "$volume_str" ] && {
            volume_id="$volume_str";
        }
        volfile_loc="";
    }

    [ -z "$volume_id" -o -z "$server_ip" ] && {
        cat <<EOF
ERROR: Server name/volume name unspecified cannot proceed further..
Please specify correct format
Usage:
man 8 $0
EOF
        exit 0;
    }

    grep_ret=$(echo ${mount_point} | grep '^\-o');
    [ "x" != "x${grep_ret}" ] && {
        cat <<EOF
ERROR: -o options cannot be specified in either first two arguments..
Please specify correct style
Usage:
man 8 $0
EOF
        exit 0;
    }

    # No need to do a ! -d test, it is taken care while initializing the
    # variable mount_point
    [ -z "$mount_point" -o ! -d "$mount_point" ] && {
        cat <<EOF
ERROR: Mount point does not exist
Please specify a mount point
Usage:
man 8 $0
EOF
        exit 0;
    }

    # Simple check to avoid multiple identical mounts
    if grep -q "[[:space:]+]${mount_point}[[:space:]+]fuse" $mounttab; then
        echo -n "$0: according to mtab, GlusterFS is already mounted on "
        echo "$mount_point"
        exit 0;
    fi

    check_recursive_mount "$mount_point";

    update_updatedb;

    start_glusterfs;
}

_init "$@" && main "$@";