1 // Copyright 2023 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 
15 #pragma once
16 #include "pw_bluetooth_sapphire/internal/host/common/byte_buffer.h"
17 #include "pw_bluetooth_sapphire/internal/host/l2cap/pdu.h"
18 
19 namespace bt::l2cap::internal {
20 
21 // The interface between a Channel, and the module implementing the
22 // mode-specific receive logic. The primary purpose of an RxEngine is to
23 // transform PDUs into SDUs. See Bluetooth Core Spec v5.0, Volume 3, Part A,
24 // Sec 2.4, "Modes of Operation" for more information about the possible modes.
25 class RxEngine {
26  public:
27   RxEngine() = default;
28   virtual ~RxEngine() = default;
29 
30   // Consumes a PDU and returns a buffer containing the resulting SDU. Returns
31   // nullptr if no SDU was produced.
32   //
33   // Notes:
34   // * Callers should not interpret a nullptr as an error, as there are many
35   //   valid conditions under which a PDU does not yield an SDU.
36   // * The caller must ensure that |pdu.is_valid() == true|.
37   virtual ByteBufferPtr ProcessPdu(PDU pdu) = 0;
38 
39  private:
40   BT_DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(RxEngine);
41 };
42 
43 }  // namespace bt::l2cap::internal
44