Line data    Source code

       1             : /*
       2             :  *
       3             :  *    Copyright (c) 2021 Project CHIP Authors
       4             :  *
       5             :  *    Licensed under the Apache License, Version 2.0 (the "License");
       6             :  *    you may not use this file except in compliance with the License.
       7             :  *    You may obtain a copy of the License at
       8             :  *
       9             :  *        http://www.apache.org/licenses/LICENSE-2.0
      10             :  *
      11             :  *    Unless required by applicable law or agreed to in writing, software
      12             :  *    distributed under the License is distributed on an "AS IS" BASIS,
      13             :  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      14             :  *    See the License for the specific language governing permissions and
      15             :  *    limitations under the License.
      16             :  */
      17             : /**
      18             :  *    @file
      19             :  *      This file defines types and objects for CHIP message counter messages in secure channel protocol.
      20             :  *
      21             :  */
      22             : 
      23             : #pragma once
      24             : 
      25             : #include <messaging/ExchangeDelegate.h>
      26             : #include <messaging/ExchangeMgr.h>
      27             : #include <protocols/Protocols.h>
      28             : #include <system/SystemPacketBuffer.h>
      29             : #include <transport/MessageCounterManagerInterface.h>
      30             : 
      31             : namespace chip {
      32             : namespace secure_channel {
      33             : 
      34             : class MessageCounterManager : public Messaging::UnsolicitedMessageHandler,
      35             :                               public Messaging::ExchangeDelegate,
      36             :                               public Transport::MessageCounterManagerInterface
      37             : {
      38             : public:
      39             :     static constexpr uint16_t kChallengeSize             = Transport::PeerMessageCounter::kChallengeSize;
      40             :     static constexpr uint16_t kCounterSize               = 4;
      41             :     static constexpr uint16_t kSyncRespMsgSize           = kChallengeSize + kCounterSize;
      42             :     static constexpr System::Clock::Timeout kSyncTimeout = System::Clock::Milliseconds32(500);
      43             : 
      44           0 :     MessageCounterManager() : mExchangeMgr(nullptr) {}
      45           0 :     ~MessageCounterManager() override {}
      46             : 
      47             :     CHIP_ERROR Init(Messaging::ExchangeManager * exchangeMgr);
      48             :     void Shutdown();
      49             : 
      50             :     // Implement MessageCounterManagerInterface
      51             :     CHIP_ERROR StartSync(const SessionHandle & session, Transport::SecureSession * state) override;
      52             :     CHIP_ERROR QueueReceivedMessageAndStartSync(const PacketHeader & packetHeader, const SessionHandle & session,
      53             :                                                 Transport::SecureSession * state, const Transport::PeerAddress & peerAddress,
      54             :                                                 System::PacketBufferHandle && msgBuf) override;
      55             : 
      56             :     /**
      57             :      * Send peer message counter synchronization request.
      58             :      * This function is called while processing a message encrypted with an application key from a peer whose message counter is not
      59             :      * synchronized. This message is sent on a newly created exchange, which is closed immediately after.
      60             :      *
      61             :      * @param[in]  session  The secure session handle of the received message.
      62             :      *
      63             :      * @retval  #CHIP_ERROR_NO_MEMORY         If memory could not be allocated for the new
      64             :      *                                         exchange context or new message buffer.
      65             :      * @retval  #CHIP_NO_ERROR                On success.
      66             :      *
      67             :      */
      68             :     CHIP_ERROR SendMsgCounterSyncReq(const SessionHandle & session, Transport::SecureSession * state);
      69             : 
      70             :     /**
      71             :      *  Add a CHIP message into the cache table to queue the incoming messages that trigger message counter synchronization
      72             :      * protocol for re-processing.
      73             :      *
      74             :      *  @param[in]    msgBuf           A handle to the packet buffer holding the received message.
      75             :      *
      76             :      *  @retval  #CHIP_ERROR_NO_MEMORY If there is no empty slot left in the table for addition.
      77             :      *  @retval  #CHIP_NO_ERROR On success.
      78             :      */
      79             :     CHIP_ERROR AddToReceiveTable(const PacketHeader & packetHeader, const Transport::PeerAddress & peerAddress,
      80             :                                  System::PacketBufferHandle && msgBuf);
      81             : 
      82             : private:
      83             :     /**
      84             :      *  @class ReceiveTableEntry
      85             :      *
      86             :      *  @brief
      87             :      *    This class is part of the CHIP Message Counter Synchronization Protocol and is used
      88             :      *    to keep track of a CHIP messages to be reprocessed whose source's
      89             :      *    message counter is unknown. The message is reprocessed after message
      90             :      *    counter synchronization is completed.
      91             :      *
      92             :      */
      93             :     struct ReceiveTableEntry
      94             :     {
      95             :         Transport::PeerAddress peerAddress; /**< The peer address for the message*/
      96             :         System::PacketBufferHandle msgBuf;  /**< A handle to the PacketBuffer object holding the message data. */
      97             :     };
      98             : 
      99             :     Messaging::ExchangeManager * mExchangeMgr; // [READ ONLY] Associated Exchange Manager object.
     100             : 
     101             :     // MessageCounterManager cache table to queue the incoming messages that trigger message counter synchronization protocol.
     102             :     ReceiveTableEntry mReceiveTable[CHIP_CONFIG_MCSP_RECEIVE_TABLE_SIZE];
     103             : 
     104             :     void ProcessPendingMessages(NodeId peerNodeId);
     105             : 
     106             :     CHIP_ERROR SendMsgCounterSyncResp(Messaging::ExchangeContext * exchangeContext, FixedByteSpan<kChallengeSize> challenge);
     107             :     CHIP_ERROR HandleMsgCounterSyncReq(Messaging::ExchangeContext * exchangeContext, System::PacketBufferHandle && msgBuf);
     108             :     CHIP_ERROR HandleMsgCounterSyncResp(Messaging::ExchangeContext * exchangeContext, System::PacketBufferHandle && msgBuf);
     109             : 
     110             :     CHIP_ERROR OnUnsolicitedMessageReceived(const PayloadHeader & payloadHeader, ExchangeDelegate *& newDelegate) override;
     111             :     CHIP_ERROR OnMessageReceived(Messaging::ExchangeContext * exchangeContext, const PayloadHeader & payloadHeader,
     112             :                                  System::PacketBufferHandle && payload) override;
     113             : 
     114             :     void OnResponseTimeout(Messaging::ExchangeContext * exchangeContext) override;
     115             : };
     116             : 
     117             : } // namespace secure_channel
     118             : } // namespace chip