ladybird/Kernel/ProcessProcFSTraits.cpp
Daniel Bertalan 8dd11ae717 Kernel+SystemServer: Add /dev/tty
This file refers to the controlling terminal associated with the current
process. It's specified by POSIX, and is used by ports like openssh to
interface with the terminal even if the standard input/output is
redirected to somewhere else.

Our implementation leverages ProcFS's existing facilities to create
process-specific symbolic links. In our setup, `/dev/tty` is a symbolic
link to `/proc/self/tty`, which itself is a symlink to the appropriate
`/dev/pts` entry. If no TTY is attached, `/dev/tty` is left dangling.
2021-12-12 22:32:35 +01:00

70 lines
3.5 KiB
C++

/*
* Copyright (c) 2021, sin-ack <sin-ack@protonmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/ProcFS.h>
#include <Kernel/Process.h>
namespace Kernel {
UserID Process::ProcessProcFSTraits::owner_user() const
{
auto process = m_process.strong_ref();
if (!process)
return 0;
return process->uid();
}
GroupID Process::ProcessProcFSTraits::owner_group() const
{
auto process = m_process.strong_ref();
if (!process)
return 0;
return process->gid();
}
InodeIndex Process::ProcessProcFSTraits::component_index() const
{
auto process = m_process.strong_ref();
if (!process)
return {};
return SegmentedProcFSIndex::build_segmented_index_for_pid_directory(process->pid());
}
ErrorOr<NonnullRefPtr<Inode>> Process::ProcessProcFSTraits::to_inode(const ProcFS& procfs_instance) const
{
auto process = m_process.strong_ref();
if (!process)
return ESRCH;
return TRY(ProcFSProcessDirectoryInode::try_create(procfs_instance, process->pid()));
}
ErrorOr<void> Process::ProcessProcFSTraits::traverse_as_directory(FileSystemID fsid, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)> callback) const
{
auto process = m_process.strong_ref();
if (!process)
return ESRCH;
TRY(callback({ ".", { fsid, SegmentedProcFSIndex::build_segmented_index_for_pid_directory(process->pid()) }, DT_DIR }));
TRY(callback({ "..", { fsid, ProcFSComponentRegistry::the().root_directory().component_index() }, DT_DIR }));
TRY(callback({ "fd", { fsid, SegmentedProcFSIndex::build_segmented_index_for_sub_directory(process->pid(), SegmentedProcFSIndex::ProcessSubDirectory::OpenFileDescriptions) }, DT_DIR }));
TRY(callback({ "stacks", { fsid, SegmentedProcFSIndex::build_segmented_index_for_sub_directory(process->pid(), SegmentedProcFSIndex::ProcessSubDirectory::Stacks) }, DT_DIR }));
TRY(callback({ "unveil", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::Unveil) }, DT_REG }));
TRY(callback({ "pledge", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::Pledge) }, DT_REG }));
TRY(callback({ "fds", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::OpenFileDescriptions) }, DT_DIR }));
TRY(callback({ "exe", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::BinaryLink) }, DT_LNK }));
TRY(callback({ "cwd", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::CurrentWorkDirectoryLink) }, DT_LNK }));
TRY(callback({ "perf_events", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::PerformanceEvents) }, DT_REG }));
TRY(callback({ "vm", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::VirtualMemoryStats) }, DT_REG }));
TRY(callback({ "tty", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property_in_pid_directory(process->pid(), SegmentedProcFSIndex::MainProcessProperty::TTYLink) }, DT_LNK }));
return {};
}
}