jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <Kernel/Process.h>
8#include <Kernel/Random.h>
9#include <Kernel/UserOrKernelBuffer.h>
10
11namespace Kernel {
12
13// We don't use the flag yet, but we could use it for distinguishing
14// random source like Linux, unlike the OpenBSD equivalent. However, if we
15// do, we should be able of the caveats that Linux has dealt with.
16ErrorOr<FlatPtr> Process::sys$getrandom(Userspace<void*> buffer, size_t buffer_size, [[maybe_unused]] unsigned flags)
17{
18 VERIFY_NO_PROCESS_BIG_LOCK(this);
19 TRY(require_promise(Pledge::stdio));
20 if (buffer_size > NumericLimits<ssize_t>::max())
21 return EINVAL;
22
23 auto data_buffer = TRY(UserOrKernelBuffer::for_user_buffer(buffer, buffer_size));
24
25 return TRY(data_buffer.write_buffered<1024>(buffer_size, [&](Bytes bytes) {
26 get_good_random_bytes(bytes);
27 return bytes.size();
28 }));
29}
30
31}