1 files changed, 166 insertions, 0 deletions
diff --git a/Kernel/FileSystem/OpenFileDescription.h b/Kernel/FileSystem/OpenFileDescription.h
new file mode 100644
index 0000000000..04c3c08e61
--- /dev/null
+++ b/Kernel/FileSystem/OpenFileDescription.h
@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Badge.h>
+#include <AK/ByteBuffer.h>
+#include <AK/RefCounted.h>
+#include <Kernel/FileSystem/FIFO.h>
+#include <Kernel/FileSystem/Inode.h>
+#include <Kernel/FileSystem/InodeMetadata.h>
+#include <Kernel/FileSystem/VirtualFileSystem.h>
+#include <Kernel/KBuffer.h>
+#include <Kernel/VirtualAddress.h>
+
+namespace Kernel {
+
+class OpenFileDescriptionData {
+public:
+    virtual ~OpenFileDescriptionData() = default;
+};
+
+class OpenFileDescription : public RefCounted<OpenFileDescription> {
+    MAKE_SLAB_ALLOCATED(OpenFileDescription)
+public:
+    static KResultOr<NonnullRefPtr<OpenFileDescription>> try_create(Custody&);
+    static KResultOr<NonnullRefPtr<OpenFileDescription>> try_create(File&);
+    ~OpenFileDescription();
+
+    Thread::FileBlocker::BlockFlags should_unblock(Thread::FileBlocker::BlockFlags) const;
+
+    bool is_readable() const { return m_readable; }
+    bool is_writable() const { return m_writable; }
+
+    void set_readable(bool b) { m_readable = b; }
+    void set_writable(bool b) { m_writable = b; }
+
+    void set_rw_mode(int options)
+    {
+        set_readable(options & O_RDONLY);
+        set_writable(options & O_WRONLY);
+    }
+
+    KResult close();
+
+    KResultOr<off_t> seek(off_t, int whence);
+    KResultOr<size_t> read(UserOrKernelBuffer&, size_t);
+    KResultOr<size_t> write(const UserOrKernelBuffer& data, size_t);
+    KResult stat(::stat&);
+
+    // NOTE: These ignore the current offset of this file description.
+    KResultOr<size_t> read(UserOrKernelBuffer&, u64 offset, size_t);
+    KResultOr<size_t> write(u64 offset, UserOrKernelBuffer const&, size_t);
+
+    KResult chmod(mode_t);
+
+    bool can_read() const;
+    bool can_write() const;
+
+    KResultOr<size_t> get_dir_entries(UserOrKernelBuffer& buffer, size_t);
+
+    KResultOr<NonnullOwnPtr<KBuffer>> read_entire_file();
+
+    KResultOr<NonnullOwnPtr<KString>> try_serialize_absolute_path();
+    String absolute_path() const;
+
+    bool is_direct() const { return m_direct; }
+
+    bool is_directory() const { return m_is_directory; }
+
+    File& file() { return *m_file; }
+    const File& file() const { return *m_file; }
+
+    bool is_device() const;
+    const Device* device() const;
+    Device* device();
+
+    bool is_tty() const;
+    const TTY* tty() const;
+    TTY* tty();
+
+    bool is_inode_watcher() const;
+    const InodeWatcher* inode_watcher() const;
+    InodeWatcher* inode_watcher();
+
+    bool is_master_pty() const;
+    const MasterPTY* master_pty() const;
+    MasterPTY* master_pty();
+
+    InodeMetadata metadata() const;
+    Inode* inode() { return m_inode.ptr(); }
+    const Inode* inode() const { return m_inode.ptr(); }
+
+    Custody* custody() { return m_custody.ptr(); }
+    const Custody* custody() const { return m_custody.ptr(); }
+
+    KResultOr<Memory::Region*> mmap(Process&, Memory::VirtualRange const&, u64 offset, int prot, bool shared);
+
+    bool is_blocking() const { return m_is_blocking; }
+    void set_blocking(bool b) { m_is_blocking = b; }
+    bool should_append() const { return m_should_append; }
+    void set_should_append(bool s) { m_should_append = s; }
+
+    u32 file_flags() const { return m_file_flags; }
+    void set_file_flags(u32);
+
+    bool is_socket() const;
+    Socket* socket();
+    const Socket* socket() const;
+
+    bool is_fifo() const;
+    FIFO* fifo();
+    FIFO::Direction fifo_direction() const { return m_fifo_direction; }
+    void set_fifo_direction(Badge<FIFO>, FIFO::Direction direction) { m_fifo_direction = direction; }
+
+    OwnPtr<OpenFileDescriptionData>& data() { return m_data; }
+
+    void set_original_inode(Badge<VirtualFileSystem>, NonnullRefPtr<Inode>&& inode) { m_inode = move(inode); }
+
+    KResult truncate(u64);
+
+    off_t offset() const { return m_current_offset; }
+
+    KResult chown(UserID, GroupID);
+
+    FileBlockerSet& blocker_set();
+
+    KResult apply_flock(Process const&, Userspace<flock const*>);
+    KResult get_flock(Userspace<flock*>) const;
+
+private:
+    friend class VirtualFileSystem;
+    explicit OpenFileDescription(File&);
+
+    KResult attach();
+
+    void evaluate_block_conditions()
+    {
+        blocker_set().unblock_all_blockers_whose_conditions_are_met();
+    }
+
+    RefPtr<Custody> m_custody;
+    RefPtr<Inode> m_inode;
+    NonnullRefPtr<File> m_file;
+
+    off_t m_current_offset { 0 };
+
+    OwnPtr<OpenFileDescriptionData> m_data;
+
+    u32 m_file_flags { 0 };
+
+    bool m_readable : 1 { false };
+    bool m_writable : 1 { false };
+    bool m_is_blocking : 1 { true };
+    bool m_is_directory : 1 { false };
+    bool m_should_append : 1 { false };
+    bool m_direct : 1 { false };
+    FIFO::Direction m_fifo_direction { FIFO::Direction::Neither };
+
+    Mutex m_lock { "OpenFileDescription" };
+};
+
+}