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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <Kernel/Devices/CharacterDevice.h>
10
11namespace Kernel {
12
13class NullDevice final : public CharacterDevice {
14 friend class DeviceManagement;
15
16public:
17 virtual ~NullDevice() override;
18
19 static NonnullLockRefPtr<NullDevice> must_initialize();
20
21private:
22 NullDevice();
23
24 // ^Device
25 virtual bool is_openable_by_jailed_processes() const override { return true; }
26
27 // ^CharacterDevice
28 virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
29 virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override;
30 virtual bool can_write(OpenFileDescription const&, u64) const override { return true; }
31 virtual bool can_read(OpenFileDescription const&, u64) const override;
32 virtual StringView class_name() const override { return "NullDevice"sv; }
33 virtual bool is_seekable() const override { return true; }
34};
35
36}