ladybird/Kernel/Syscalls/open.cpp
Andreas Kling a9204510a4 Kernel: Make file description lookup return KResultOr
Instead of checking it at every call site (to generate EBADF), we make
file_description(fd) return a KResultOr<NonnullRefPtr<FileDescription>>.

This allows us to wrap all the calls in TRY(). :^)

The only place that got a little bit messier from this is sys$mount(),
and there's a whole bunch of things there in need of cleanup.
2021-09-05 18:36:13 +02:00

77 lines
2.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$open(Userspace<const Syscall::SC_open_params*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto params = TRY(copy_typed_from_user(user_params));
int dirfd = params.dirfd;
int options = params.options;
u16 mode = params.mode;
if (options & O_NOFOLLOW_NOERROR)
return EINVAL;
if (options & O_UNLINK_INTERNAL)
return EINVAL;
if (options & O_WRONLY)
REQUIRE_PROMISE(wpath);
else if (options & O_RDONLY)
REQUIRE_PROMISE(rpath);
if (options & O_CREAT)
REQUIRE_PROMISE(cpath);
// Ignore everything except permission bits.
mode &= 0777;
auto path = TRY(get_syscall_path_argument(params.path));
dbgln_if(IO_DEBUG, "sys$open(dirfd={}, path='{}', options={}, mode={})", dirfd, path->view(), options, mode);
auto fd_allocation = TRY(m_fds.allocate());
RefPtr<Custody> base;
if (dirfd == AT_FDCWD) {
base = current_directory();
} else {
auto base_description = TRY(fds().file_description(dirfd));
if (!base_description->is_directory())
return ENOTDIR;
if (!base_description->custody())
return EINVAL;
base = base_description->custody();
}
auto description = TRY(VirtualFileSystem::the().open(path->view(), options, mode & ~umask(), *base));
if (description->inode() && description->inode()->socket())
return ENXIO;
u32 fd_flags = (options & O_CLOEXEC) ? FD_CLOEXEC : 0;
m_fds[fd_allocation.fd].set(move(description), fd_flags);
return fd_allocation.fd;
}
KResultOr<FlatPtr> Process::sys$close(int fd)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_PROMISE(stdio);
auto description = TRY(fds().file_description(fd));
auto result = description->close();
m_fds[fd] = {};
return result;
}
}