ladybird/Kernel/Devices/RandomDevice.cpp
Gunnar Beutner 1ce32ef675 Kernel: Let the user read/write more than one page from/to dev files
Previously reads and writes to /dev/zero, /dev/full, /dev/null and
/dev/random were limited to 4096 bytes.

This removes that restriction so that users can enjoy more zero bytes
in their buffers.
2021-05-27 09:30:19 +02:00

40 lines
891 B
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Devices/RandomDevice.h>
#include <Kernel/Random.h>
namespace Kernel {
UNMAP_AFTER_INIT RandomDevice::RandomDevice()
: CharacterDevice(1, 8)
{
}
UNMAP_AFTER_INIT RandomDevice::~RandomDevice()
{
}
bool RandomDevice::can_read(const FileDescription&, size_t) const
{
return true;
}
KResultOr<size_t> RandomDevice::read(FileDescription&, u64, UserOrKernelBuffer& buffer, size_t size)
{
return buffer.write_buffered<256>(size, [&](u8* data, size_t data_size) {
get_good_random_bytes(data, data_size);
return data_size;
});
}
KResultOr<size_t> RandomDevice::write(FileDescription&, u64, const UserOrKernelBuffer&, size_t size)
{
// FIXME: Use input for entropy? I guess that could be a neat feature?
return size;
}
}