Line data    Source code

       1             : /*
       2             :  *
       3             :  *    Copyright (c) 2020-2021 Project CHIP Authors
       4             :  *    All rights reserved.
       5             :  *
       6             :  *    Licensed under the Apache License, Version 2.0 (the "License");
       7             :  *    you may not use this file except in compliance with the License.
       8             :  *    You may obtain a copy of the License at
       9             :  *
      10             :  *        http://www.apache.org/licenses/LICENSE-2.0
      11             :  *
      12             :  *    Unless required by applicable law or agreed to in writing, software
      13             :  *    distributed under the License is distributed on an "AS IS" BASIS,
      14             :  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      15             :  *    See the License for the specific language governing permissions and
      16             :  *    limitations under the License.
      17             :  */
      18             : 
      19             : /**
      20             :  *    @file
      21             :  *      This file implements an object for a CHIP Echo unsolicited
      22             :  *      responder (server).
      23             :  *
      24             :  */
      25             : 
      26             : #include "Echo.h"
      27             : 
      28             : namespace chip {
      29             : namespace Protocols {
      30             : namespace Echo {
      31             : 
      32           2 : CHIP_ERROR EchoServer::Init(Messaging::ExchangeManager * exchangeMgr)
      33             : {
      34             :     // Error if already initialized.
      35           2 :     VerifyOrReturnError(mExchangeMgr == nullptr, CHIP_ERROR_INCORRECT_STATE);
      36             : 
      37           2 :     mExchangeMgr          = exchangeMgr;
      38           2 :     OnEchoRequestReceived = nullptr;
      39             : 
      40             :     // Register to receive unsolicited Echo Request messages from the exchange manager.
      41           2 :     mExchangeMgr->RegisterUnsolicitedMessageHandlerForType(MsgType::EchoRequest, this);
      42             : 
      43           2 :     return CHIP_NO_ERROR;
      44             : }
      45             : 
      46           0 : void EchoServer::Shutdown()
      47             : {
      48           0 :     if (mExchangeMgr != nullptr)
      49             :     {
      50           0 :         mExchangeMgr->UnregisterUnsolicitedMessageHandlerForType(MsgType::EchoRequest);
      51           0 :         mExchangeMgr = nullptr;
      52             :     }
      53           0 : }
      54             : 
      55           2 : CHIP_ERROR EchoServer::OnUnsolicitedMessageReceived(const PayloadHeader & payloadHeader, ExchangeDelegate *& newDelegate)
      56             : {
      57             :     // Handle messages by myself
      58           2 :     newDelegate = this;
      59           2 :     return CHIP_NO_ERROR;
      60             : }
      61             : 
      62           2 : CHIP_ERROR EchoServer::OnMessageReceived(Messaging::ExchangeContext * ec, const PayloadHeader & payloadHeader,
      63             :                                          System::PacketBufferHandle && payload)
      64             : {
      65             :     // NOTE: we already know this is an Echo Request message because we explicitly registered with the
      66             :     // Exchange Manager for unsolicited Echo Requests.
      67             : 
      68             :     // Call the registered OnEchoRequestReceived handler, if any.
      69           2 :     if (OnEchoRequestReceived != nullptr)
      70             :     {
      71           0 :         OnEchoRequestReceived(ec, payload.Retain());
      72             :     }
      73             : 
      74           2 :     System::PacketBufferHandle response;
      75             : 
      76             :     // Since we are re-using the inbound EchoRequest buffer to send the EchoResponse, if necessary,
      77             :     // adjust the position of the payload within the buffer to ensure there is enough room for the
      78             :     // outgoing network headers.  This is necessary because in some network stack configurations,
      79             :     // the incoming header size may be smaller than the outgoing size.
      80           2 :     if (payload->EnsureReservedSize(CHIP_SYSTEM_CONFIG_HEADER_RESERVE_SIZE) && MessagePacketBuffer::HasFooterSpace(payload))
      81             :     {
      82           2 :         response = std::move(payload);
      83             :     }
      84             :     else
      85             :     {
      86           0 :         response = MessagePacketBuffer::NewWithData(payload->Start(), payload->DataLength());
      87           0 :         VerifyOrReturnError(!response.IsNull(), CHIP_ERROR_NO_MEMORY);
      88             :     }
      89             : 
      90             :     // Send an Echo Response back to the sender.
      91           2 :     return ec->SendMessage(MsgType::EchoResponse, std::move(response));
      92           2 : }
      93             : 
      94             : } // namespace Echo
      95             : } // namespace Protocols
      96             : } // namespace chip