sdk/fidl/fuchsia.device.fs/exporter.fidl

// Copyright 2021 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.device.fs;

using fuchsia.io;

using zx;

/// A protocol that lets a client connect to another protocol.
protocol Connector {
    /// Connect to the underlying protocol.
    Connect(resource struct {
        server zx.handle:CHANNEL;
    });
};

type ExportOptions = strict bits : uint32 {
    /// If present, the exported service will be invisible.
    INVISIBLE = 0x00000001;
};

/// Protocol through which a driver can export services to devfs.
@discoverable
protocol Exporter {
    /// Export `service_path` from `service_dir` to `devfs_path`. If `protocol_id`
    /// matches a known protocol, `service_path` will also be accessible through
    /// a class path.
    Export(resource struct {
        service_dir client_end:fuchsia.io.Directory;
        service_path string:fuchsia.io.MAX_PATH;
        devfs_path string:fuchsia.io.MAX_PATH;
        protocol_id uint32;
    }) -> () error zx.status;

    /// Export `service_path` from `service_dir` to `devfs_path`. If `protocol_id`
    /// matches a known protocol, `service_path` will also be accessible through
    /// a class path.
    ExportOptions(resource struct {
        service_dir client_end:fuchsia.io.Directory;
        service_path string:fuchsia.io.MAX_PATH;
        devfs_path string:fuchsia.io.MAX_PATH;
        protocol_id uint32;
        options ExportOptions;
    }) -> () error zx.status;

    /// Export a device in devfs.
    ///
    /// * error `ZX_ERR_ALREADY_EXISTS` if `topological_path` already exists.
    /// * error `ZX_ERR_NOT_FOUND` if `class_name` doesn't match a valid class name.
    ExportV2(resource struct {
        /// This is the connector that will have Connect called on it when a client opens the
        /// device. If the server end of this connection is dropped the export will automatically be
        /// cleaned up.
        open_client client_end:Connector;

        /// If this is present, then the device will be exported at this topological path.
        topological_path string:<fuchsia.io.MAX_PATH, optional>;

        /// If this is present, then the device will be exported into "/dev/class/{class_name}/".
        class_name string:<fuchsia.io.MAX_NAME_LENGTH, optional>;

        /// The options for the device being exported.
        options ExportOptions;
    }) -> () error zx.status;

    /// Make a `devfs_path` visible. Will return ZX_ERR_NOT_FOUND if the path
    /// does not exist or ZX_ERR_BAD_STATE if the path is not invisible.
    MakeVisible(struct {
        devfs_path string:fuchsia.io.MAX_PATH;
    }) -> () error zx.status;
};