// Copyright 2023 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

#include "pw_bluetooth_sapphire/internal/host/common/byte_buffer.h"
#include "pw_bluetooth_sapphire/internal/host/hci-spec/protocol.h"
#include "pw_bluetooth_sapphire/internal/host/l2cap/basic_mode_rx_engine.h"
#include "pw_bluetooth_sapphire/internal/host/l2cap/fragmenter.h"

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
  constexpr bt::hci_spec::ConnectionHandle kTestHandle = 0x0001;
  constexpr bt::l2cap::ChannelId kTestChannelId = 0x0001;
  bt::l2cap::Fragmenter fragmenter(kTestHandle);
  bt::l2cap::internal::BasicModeRxEngine rx_engine;

  // The use of a fragmenter, to build a PDU for the receive engine, is
  // admittedly counterintuitive. (In actual operation, we use a Fragmenter on
  // the transmit path, and a Recombiner on the receive path.) Pragmatically,
  // however, the Fragmenter is the easiest way to build a PDU.
  //
  // Note that using a Fragmenter to build the PDU doesn't decrease the efficacy
  // of fuzzing, because the only guarantees provided by the Fragmenter are
  // those that are preconditions for RxEngine::ProcessPdu().
  auto pdu = fragmenter.BuildFrame(kTestChannelId,
                                   bt::BufferView(data, size),
                                   bt::l2cap::FrameCheckSequenceOption::kNoFcs);
  rx_engine.ProcessPdu(std::move(pdu));
  return 0;
}