ladybird/Kernel/Syscalls/fcntl.cpp

61 lines
1.9 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Tasks/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$fcntl(int fd, int cmd, uintptr_t arg)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::stdio));
dbgln_if(IO_DEBUG, "sys$fcntl: fd={}, cmd={}, arg={}", fd, cmd, arg);
auto description = TRY(open_file_description(fd));
// NOTE: The FD flags are not shared between OpenFileDescription objects.
// This means that dup() doesn't copy the FD_CLOEXEC flag!
switch (cmd) {
case F_DUPFD_CLOEXEC:
case F_DUPFD: {
int arg_fd = (int)arg;
if (arg_fd < 0)
return EINVAL;
return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
auto fd_allocation = TRY(fds.allocate(arg_fd));
fds[fd_allocation.fd].set(*description, (cmd == F_DUPFD_CLOEXEC) ? FD_CLOEXEC : 0);
return fd_allocation.fd;
});
}
case F_GETFD:
return m_fds.with_exclusive([fd](auto& fds) { return fds[fd].flags(); });
case F_SETFD:
m_fds.with_exclusive([fd, arg](auto& fds) { fds[fd].set_flags(arg); });
break;
case F_GETFL:
return description->file_flags();
case F_SETFL:
description->set_file_flags(arg);
break;
case F_ISTTY:
return description->is_tty();
case F_GETLK:
TRY(description->get_flock(Userspace<flock*>(arg)));
return 0;
case F_SETLK:
TRY(description->apply_flock(Process::current(), Userspace<flock const*>(arg), ShouldBlock::No));
return 0;
case F_SETLKW:
TRY(description->apply_flock(Process::current(), Userspace<flock const*>(arg), ShouldBlock::Yes));
return 0;
default:
return EINVAL;
}
return 0;
}
}