
#!/bin/sh

# PROVIDE: zfskeys
# REQUIRE: zpool
# BEFORE: zfs zvol

. /etc/rc.subr

name="zfskeys"
desc="Load dataset keys"
rcvar="zfskeys_enable"
extra_commands="status"
start_cmd="load_zfs_keys"
stop_cmd="unload_zfs_keys"
status_cmd="status_zfs_keys"
required_modules="zfs"

# Note that zfskeys_datasets must have any character found in IFS escaped.
# Forcibly unmounting/unloading only applies to filesystems; ignored for zvols.
: ${zfskeys_datasets:=''}
: ${zfskeys_timeout:=10}
: ${zfskeys_unload_force:='NO'}

encode_args()
{
    shift && [ $# -gt 0 ] && printf "%s\0" "$@" | b64encode -r -
}

list_datasets()
{
    if [ "$zfskeys_args" ]; then
        echo "$zfskeys_args" | b64decode -r |
            xargs -0 zfs get -H -s local -o value,name keylocation
    elif [ ! "$zfskeys_datasets" ]; then
        zfs get -H -t filesystem,volume -s local -o value,name keylocation
    else
        echo "$zfskeys_datasets" | xargs -n 1 zfs get -H -s local \
            -o value,name keylocation
    fi
}

unlock_fs()
{
    local fs="$1"
    local kl="$2"
    local k="${kl##file://}"

    if [ "$k" ] && [ -f "$k" ] && [ -s "$k" ] && [ -r "$k" ]; then
        if [ "$(zfs get -Ho value keystatus "$fs")" = 'available' ]; then
            echo "Key already loaded for $fs."
        elif keytest=$(zfs load-key -n -L "$kl" "$fs" 2>&1); then
            echo "Loading key for $fs from $kl.."
            if ! keyload=$(timeout $zfskeys_timeout zfs load-key -L "$kl" "$fs" 2>&1) ; then
                if [ $? -eq 124 ]; then
                    echo "Timed out loading key from $kl for $fs"
                else
                    echo "Failed to load key from $kl for $fs:"
                    echo "$keyload"
                fi
            fi
        else
            echo "Could not verify key from $kl for $fs:"
            echo "$keytest"
        fi
    else
        echo "Key file $k not found, empty or unreadable. Skipping $fs.."
    fi
}

lock_fs()
{
    local fs=$1

    if [ "$(zfs get -Ho value mounted "$fs")" = 'yes' ]; then
        if checkyesno zfskeys_unload_force ; then
            zfs unmount -f "$fs" && echo "Forcibly unmounted $fs."
        else
            zfs unmount "$fs" && echo "Unmounted $fs."
        fi
    fi
    if [ "$?" -ne 0 ]; then
        echo "Unmount failed for $fs"
    elif [ "$(zfs get -Ho value keystatus "$fs")" = 'available' ]; then
        zfs unload-key "$fs" && echo "Unloaded key for $fs."
    else
        echo "No key loaded for $fs."
    fi
}

status_zfs_keys()
{
    local IFS=$(printf "\t")

    list_datasets | while read kl fs ; do
        echo "$fs: $(zfs get -Ho value keystatus "$fs")"
    done
}

load_zfs_keys()
{
    local IFS=$(printf "\t")

    list_datasets | while read kl fs ; do
        unlock_fs "$fs" "$kl"
    done
}

unload_zfs_keys()
{
    local IFS=$(printf "\t")

    list_datasets | while read kl fs ; do
        lock_fs "$fs"
    done
}

zfskeys_args=$(encode_args "$@")
load_rc_config $name
run_rc_command "$1"