ladybird/Kernel/Syscalls/open.cpp

84 lines
2.6 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/RefPtr.h>
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Library/KLexicalPath.h>
#include <Kernel/Net/LocalSocket.h>
#include <Kernel/Tasks/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::open_impl(Userspace<Syscall::SC_open_params const*> user_params)
{
VERIFY_NO_PROCESS_BIG_LOCK(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;
auto path = TRY(get_syscall_path_argument(params.path));
// Disable checking open pledges when building userspace with coverage
// so that all processes can write out coverage data even with pledges
bool skip_pledge_verification = false;
#ifdef SKIP_PATH_VALIDATION_FOR_COVERAGE_INSTRUMENTATION
if (KLexicalPath::basename(path->view()).ends_with(".profraw"sv))
skip_pledge_verification = true;
#endif
if (!skip_pledge_verification) {
if (options & O_WRONLY)
TRY(require_promise(Pledge::wpath));
else if (options & O_RDONLY)
TRY(require_promise(Pledge::rpath));
if (options & O_CREAT)
TRY(require_promise(Pledge::cpath));
}
// Ignore everything except permission bits.
mode &= 0777;
dbgln_if(IO_DEBUG, "sys$open(dirfd={}, path='{}', options={}, mode={})", dirfd, path->view(), options, mode);
auto fd_allocation = TRY(allocate_fd());
auto base = TRY(custody_for_dirfd(dirfd));
auto description = TRY(VirtualFileSystem::the().open(credentials(), path->view(), options, mode & ~umask(), *base));
if (description->inode() && description->inode()->bound_socket())
return ENXIO;
return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
u32 fd_flags = (options & O_CLOEXEC) ? FD_CLOEXEC : 0;
fds[fd_allocation.fd].set(move(description), fd_flags);
return fd_allocation.fd;
});
}
ErrorOr<FlatPtr> Process::close_impl(int fd)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::stdio));
auto description = TRY(open_file_description(fd));
auto result = description->close();
m_fds.with_exclusive([fd](auto& fds) { fds[fd] = {}; });
if (result.is_error())
return result.release_error();
return 0;
}
}