mirror of
https://github.com/SerenityOS/serenity
synced 2024-07-09 09:00:46 +00:00
743a9e9ebf
The networking subsystem currently assumes all adapters are Ethernet adapters, including the LoopbackAdapter, so all packets are pre-pended with an Ethernet Frame header. Since the MTU must not include any overhead added by the data-link (Ethernet in this case) or physical layers, we need to subtract it from the MTU. This fixes a kernel panic which occurs when sending a packet that is at least 65523 bytes long through the loopback adapter, which results in the kernel "receiving" a packet which is larger than the support MTU out the other end. (As the actual final size was increased by the addition of the ethernet frame header)
40 lines
1.2 KiB
C++
40 lines
1.2 KiB
C++
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/Singleton.h>
|
|
#include <Kernel/Net/LoopbackAdapter.h>
|
|
|
|
namespace Kernel {
|
|
|
|
static bool s_loopback_initialized = false;
|
|
|
|
ErrorOr<NonnullRefPtr<LoopbackAdapter>> LoopbackAdapter::try_create()
|
|
{
|
|
return TRY(adopt_nonnull_ref_or_enomem(new (nothrow) LoopbackAdapter("loop"sv)));
|
|
}
|
|
|
|
LoopbackAdapter::LoopbackAdapter(StringView interface_name)
|
|
: NetworkAdapter(interface_name)
|
|
{
|
|
VERIFY(!s_loopback_initialized);
|
|
s_loopback_initialized = true;
|
|
// The networking subsystem currently assumes all adapters are Ethernet adapters, including the LoopbackAdapter,
|
|
// so all packets are pre-pended with an Ethernet Frame header. Since the MTU must not include any overhead added
|
|
// by the data-link (Ethernet in this case) or physical layers, we need to subtract it from the MTU.
|
|
set_mtu(65536 - sizeof(EthernetFrameHeader));
|
|
set_mac_address({ 19, 85, 2, 9, 0x55, 0xaa });
|
|
}
|
|
|
|
LoopbackAdapter::~LoopbackAdapter() = default;
|
|
|
|
void LoopbackAdapter::send_raw(ReadonlyBytes payload)
|
|
{
|
|
dbgln_if(LOOPBACK_DEBUG, "LoopbackAdapter: Sending {} byte(s) to myself.", payload.size());
|
|
did_receive(payload);
|
|
}
|
|
|
|
}
|