ladybird/Kernel/FileSystem/ProcFS.h
Andreas Kling 8e79bde2b7 Kernel: Move KBufferBuilder to the fallible KBuffer API
KBufferBuilder::build() now returns an OwnPtr<KBuffer> and can fail.
Clients of the API have been updated to handle that situation.
2020-12-18 19:22:26 +01:00

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6.5 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/HashMap.h>
#include <AK/Types.h>
#include <Kernel/FileSystem/FileSystem.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/KBuffer.h>
#include <Kernel/Lock.h>
namespace Kernel {
class Process;
class ProcFSInode;
class ProcFS final : public FS {
friend class ProcFSInode;
public:
virtual ~ProcFS() override;
static NonnullRefPtr<ProcFS> create();
virtual bool initialize() override;
virtual const char* class_name() const override;
virtual NonnullRefPtr<Inode> root_inode() const override;
static void add_sys_bool(String&&, Lockable<bool>&, Function<void()>&& notify_callback = nullptr);
static void add_sys_string(String&&, Lockable<String>&, Function<void()>&& notify_callback = nullptr);
private:
ProcFS();
struct ProcFSDirectoryEntry {
ProcFSDirectoryEntry() { }
ProcFSDirectoryEntry(const char* a_name, unsigned a_proc_file_type, bool a_supervisor_only, OwnPtr<KBuffer> (*read_callback)(InodeIdentifier) = nullptr, ssize_t (*write_callback)(InodeIdentifier, const UserOrKernelBuffer&, size_t) = nullptr, RefPtr<ProcFSInode>&& a_inode = nullptr)
: name(a_name)
, proc_file_type(a_proc_file_type)
, supervisor_only(a_supervisor_only)
, read_callback(read_callback)
, write_callback(write_callback)
, inode(move(a_inode))
{
}
const char* name { nullptr };
unsigned proc_file_type { 0 };
bool supervisor_only { false };
OwnPtr<KBuffer> (*read_callback)(InodeIdentifier);
ssize_t (*write_callback)(InodeIdentifier, const UserOrKernelBuffer&, size_t);
RefPtr<ProcFSInode> inode;
InodeIdentifier identifier(unsigned fsid) const;
};
RefPtr<Inode> get_inode(InodeIdentifier) const;
ProcFSDirectoryEntry* get_directory_entry(InodeIdentifier) const;
Vector<ProcFSDirectoryEntry> m_entries;
mutable Lock m_inodes_lock;
mutable HashMap<unsigned, ProcFSInode*> m_inodes;
RefPtr<ProcFSInode> m_root_inode;
};
class ProcFSInode final : public Inode {
friend class ProcFS;
public:
virtual ~ProcFSInode() override;
private:
// ^Inode
virtual ssize_t read_bytes(off_t, ssize_t, UserOrKernelBuffer& buffer, FileDescription*) const override;
virtual InodeMetadata metadata() const override;
virtual KResult traverse_as_directory(Function<bool(const FS::DirectoryEntryView&)>) const override;
virtual RefPtr<Inode> lookup(StringView name) override;
virtual void flush_metadata() override;
virtual ssize_t write_bytes(off_t, ssize_t, const UserOrKernelBuffer& buffer, FileDescription*) override;
virtual KResultOr<NonnullRefPtr<Inode>> create_child(const String& name, mode_t, dev_t, uid_t, gid_t) override;
virtual KResult add_child(Inode&, const StringView& name, mode_t) override;
virtual KResult remove_child(const StringView& name) override;
virtual KResultOr<size_t> directory_entry_count() const override;
virtual KResult chmod(mode_t) override;
virtual KResult chown(uid_t, gid_t) override;
virtual KResultOr<NonnullRefPtr<Custody>> resolve_as_link(Custody& base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0) const override;
ProcFS& fs() { return static_cast<ProcFS&>(Inode::fs()); }
const ProcFS& fs() const { return static_cast<const ProcFS&>(Inode::fs()); }
ProcFSInode(ProcFS&, unsigned index);
};
class ProcFSProxyInode final : public Inode {
friend class ProcFSInode;
public:
virtual ~ProcFSProxyInode() override;
private:
// ^Inode
virtual ssize_t read_bytes(off_t, ssize_t, UserOrKernelBuffer&, FileDescription*) const override { ASSERT_NOT_REACHED(); }
virtual InodeMetadata metadata() const override;
virtual KResult traverse_as_directory(Function<bool(const FS::DirectoryEntryView&)>) const override { ASSERT_NOT_REACHED(); }
virtual RefPtr<Inode> lookup(StringView name) override;
virtual void flush_metadata() override {};
virtual ssize_t write_bytes(off_t, ssize_t, const UserOrKernelBuffer&, FileDescription*) override { ASSERT_NOT_REACHED(); }
virtual KResultOr<NonnullRefPtr<Inode>> create_child(const String& name, mode_t, dev_t, uid_t, gid_t) override;
virtual KResult add_child(Inode&, const StringView& name, mode_t) override;
virtual KResult remove_child(const StringView& name) override;
virtual KResultOr<size_t> directory_entry_count() const override;
virtual KResult chmod(mode_t) override { return KResult(-EINVAL); }
virtual KResult chown(uid_t, gid_t) override { return KResult(-EINVAL); }
virtual KResultOr<NonnullRefPtr<Custody>> resolve_as_link(Custody&, RefPtr<Custody>*, int, int) const override { ASSERT_NOT_REACHED(); }
virtual FileDescription* preopen_fd() override { return m_fd; }
ProcFS& fs() { return static_cast<ProcFS&>(Inode::fs()); }
const ProcFS& fs() const { return static_cast<const ProcFS&>(Inode::fs()); }
ProcFSProxyInode(ProcFS&, FileDescription&);
static NonnullRefPtr<ProcFSProxyInode> create(ProcFS& fs, FileDescription& fd)
{
return adopt(*new ProcFSProxyInode(fs, fd));
}
NonnullRefPtr<FileDescription> m_fd;
};
}