#!/bin/bash
declare -A WWIDMAP
declare -A NAMEMAP
declare -A TYPEMAP

WM_DEBUG=yes
WM_DEFAULT_USER="oracle"
WM_DEFAULT_GROUP="oracle"
WM_CONF_PATH="/etc/wwidmap"
WM_DEV_PATH="oracleasm/disks"
WM_MAP_PATH="${WM_CONF_PATH}/map"
WM_CONF="${WM_CONF_PATH}/conf"
WM_USER="$WM_DEFAULT_USER"
WM_GROUP="$WM_DEFAULT_GROUP"
WM_LOCK="/var/lock/wm.lock"
WM_SCSI_ID="/sbin/scsi_id"
WM_SCSI_ID_FLAGS="-g -u"

# load config
. $WM_CONF

error () {
    echo "ERROR: $@" 1>&2
}

warn () {
    echo "WARNING: $@" 1>&2
}

debug () {
    [ "$WM_DEBUG" == "yes" ] && echo "$@" 1>&2
}

# debug print
print_wwid_mapping() {
    local WWID=$1
    if [ "$WWID" == "" ]; then
        return
    fi
    debug "NNAME for WWID '$WWID' is: '${WWIDMAP[$WWID]}' (${TYPEMAP[$WWID]})"
}

# store the WWID map to disk
wm_store_wwid_map() {
    TMP_MAP=$(mktemp --tmpdir=$WM_CONF_DIR)
    if [ ! -f $TMP_MAP ]; then
        error "could not write temporary file"
        exit 1
    fi
    for WWID in ${!WWIDMAP[@]}; do
        echo "$WWID ${WWIDMAP[$WWID]} ${TYPEMAP[$WWID]}"
    done  >> $TMP_MAP
    mv $TMP_MAP $WM_MAP_PATH
}

# read the WWID map from disk
wm_load_wwid_map() {
    if [ ! -f $WM_MAP_PATH ] || [ ! -r $WM_MAP_PATH  ]; then
        error "$WM_MAP_PATH does not exist or is not readable"
        exit 1
    fi
    while read WWID NNAME TYPE; do
        if [[ $WWID == \#* ]]; then
            continue
        fi
        WWIDMAP[$WWID]="$NNAME"
        NAMEMAP[$NNAME]="$WWID"
        TYPEMAP[$WWID]="$TYPE"
    done < $WM_MAP_PATH
}

# add_wwid_mapping <wwid> <nickname> <sd|mpath>
add_wwid_mapping() {
    local WWID
    WWID="$1"
    NNAME="$2"
    if [ "$WWID" == "" ]; then
        warn "no wwid given"
        return
    fi
    if [ "$NNAME" == "" ]; then
        warn "no nickname given"
        return
    fi
    if [ "${NAMEMAP[$WWID]}" != "" ]; then
        warn "$WWID already mapped to name ${NAMEMAP[$WWID]}; replacing it."
    fi
    WWIDMAP[$WWID]="$NNAME"
    NAMEMAP[$NNAME]="$WWID"
    TYPEMAP[$WWID]="sd"
}

# del_wwid_mapping <wwid>
del_wwid_mapping() {
    local WWID NNAME
    WWID="$1"
    if [ "$WWID" == "" ]; then
        return 1
    fi
    if [ "${WWIDMAP[$WWID]}" == "" ]; then
        warn "WARNING: $WWID does not exist; doing nothing."
        return 1
    fi
    NNAME=${WWIDMAP[$WWID]}
    unset WWIDMAP[$WWID]
    unset NAMEMAP[$NNAME]
    unset TYPEMAP[$WWID]
}

wm_scsi_id () {
    $WM_SCSI_ID $WM_SCSI_ID_FLAGS $1
}

wm_configure () {
    cat <<EOF
Configuring the udev wwid map.

This will configure persistent mappings and permissions for storage
devices. The current values will be shown in brackets ('[]'). Hitting
<ENTER> without typing an answer will keep the current value. Ctrl-C
will abort.

EOF

    echo -n "Default user to own device nodes [$WM_USER]: "
    read _WM_USER
    if [ "$_WM_USER" != "" ]; then
        WM_USER=$_WM_USER;
    fi
    echo -n "Default group to own device nodes [$WM_GROUP]: "
    read _WM_GROUP
    if [ "$_WM_GROUP" != "" ]; then
        WM_GROUP=$_WM_GROUP;
    fi
    echo -n "Default device directory [$WM_DEV_PATH]: "
    read _WM_DEV_PATH
    if [ "$_WM_DEV_PATH" != "" ]; then
        WM_DEV_PATH=$_WM_DEV_PATH;
    fi
    debug "WM_DEV_PATH=\"$WM_DEV_PATH\""
    debug "WM_USER=\"$WM_USER\""
    debug "WM_GROUP=\"$WM_GROUP\""
    echo -n "Writing wwid map configuration: "
    TMP_CONF=$(mktemp --tmpdir=$WM_CONF_PATH)
    if [ ! -f $TMP_CONF ]; then
        echo
        error "could not write temporary file"
        exit 1
    fi
    echo "WM_DEV_PATH=\"$WM_DEV_PATH\"" >> $TMP_CONF
    echo "WM_USER=\"$WM_USER\"" >> $TMP_CONF
    echo "WM_GROUP=\"$WM_GROUP\"" >> $TMP_CONF
    mv $TMP_CONF $WM_CONF
    if [ "$?" != 0 ]; then
        error "could not create configuration file $WM_CONF"
        exit
    fi
    echo "done"
}

# createdisk <nickname> <device>
wm_createdisk () {
    local WWID DEV NNAME
    NNAME="$1"
    DEV="$2"
    if [ "$DEV" == "" ] || [ "$NNAME" == "" ]; then
        echo "Usage: $0 createdisk <nickname> <device>"
        exit 2
    fi
    WWID=$(wm_scsi_id $DEV)
    add_wwid_mapping $WWID $NNAME "sd"
    wm_store_wwid_map
}

wm_deletedisk () {
    local WWID NNAME
    NNAME=$1
    if [ "$NNAME" == "" ]; then
        echo "Usage: $0 deletedisk <nickname>"
        exit 2
    fi
    WWID=${NAMEMAP[$NNAME]}
    if [ "$WWID" == "" ]; then
        error "\"$NNAME\" does not exist"
        echo "Usage: $0 deletedisk <nickname>"
        exit 2
    fi
    echo -n "Removing wwid map disk \"$NNAME\":"
    del_wwid_mapping $WWID \
    && echo "                                  [  OK  ]"
    wm_store_wwid_map
}

wm_list_disks () {
    for D in ${WWIDMAP[@]}; do
        echo $D
    done | sort -V
}

wm_querydisk () {
    warn "(unimplemented)"
}

wm_scandisks () {
    warn "(unimplemented)"
}

wm_map () {
    local WWID
    WWID="$1"
    if [ "$WWID" == "" ] || [ "${WWIDMAP[$WWID]}" == "" ]; then
        echo "Usage: $0 map <wwid>" 1>&2
        exit 2
    fi
    echo "WM_WWID=$WWID"
    echo "WM_NAME=$WM_DEV_PATH/${WWIDMAP[$WWID]}"
    echo "WM_TYPE=${TYPEMAP[$WWID]}"
    echo "WM_USER=$WM_USER"
    echo "WM_GROUP=$WM_GROUP"
}

case "$1" in
    configure)
        wm_configure
        ;;
    createdisk)
        wm_load_wwid_map
        wm_createdisk $2 $3
        ;;
    deletedisk)
        wm_load_wwid_map
        wm_deletedisk $2
        ;;
    listdisks)
        wm_load_wwid_map
        wm_list_disks
        ;;
    querydisk)
        wm_querydisk
        ;;
    scandisks)
        wm_scandisks
        ;;
    map)
        wm_load_wwid_map
        wm_map $2
        ;;
    *)
        echo -n "Usage: $0 "
        echo "{configure|createdisk|deletedisk|scandisks|querydisk|map}"
        exit 2
esac