Line data    Source code

       1              : /*
       2              :  *    Copyright (c) 2022 Project CHIP Authors
       3              :  *    All rights reserved.
       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              : #pragma once
      19              : 
      20              : #include <inet/IPPacketInfo.h>
      21              : #include <system/SystemPacketBuffer.h>
      22              : 
      23              : namespace chip {
      24              : namespace Inet {
      25              : 
      26              : /**
      27              :  * @brief Filter for UDP Packets going into and out of UDPEndPoint queue.
      28              :  *
      29              :  * NOTE: This is only used by some low-level implementations of UDPEndPoint
      30              :  */
      31              : class EndpointQueueFilter
      32              : {
      33              : public:
      34              :     enum FilterOutcome
      35              :     {
      36              :         kAllowPacket = 0,
      37              :         kDropPacket  = 1,
      38              :     };
      39              : 
      40            1 :     virtual ~EndpointQueueFilter() {}
      41              : 
      42              :     /**
      43              :      * @brief Run filter prior to inserting in queue.
      44              :      *
      45              :      * If filter returns `kAllowPacket`, packet will be enqueued, and `FilterAfterDequeue` will
      46              :      * be called when it gets dequeued. If filter returns `kDropPacket`, packet will be dropped
      47              :      * rather than enqueued and `FilterAfterDequeue` method will not be called.
      48              :      *
      49              :      * WARNING: This is likely called from non-Matter-eventloop context, from network layer code.
      50              :      *          Be extremely careful about accessing any system data which may belong to Matter
      51              :      *          stack from this method.
      52              :      *
      53              :      * @param endpoint - pointer to endpoint instance (platform-dependent, which is why it's void)
      54              :      * @param pktInfo - info about source/dest of packet
      55              :      * @param pktPayload - payload content of packet
      56              :      *
      57              :      * @return kAllowPacket to allow packet to enqueue or kDropPacket to drop the packet
      58              :      */
      59            0 :     virtual FilterOutcome FilterBeforeEnqueue(const void * endpoint, const IPPacketInfo & pktInfo,
      60              :                                               const chip::System::PacketBufferHandle & pktPayload)
      61              :     {
      62            0 :         return FilterOutcome::kAllowPacket;
      63              :     }
      64              : 
      65              :     /**
      66              :      * @brief Run filter after dequeuing, prior to processing.
      67              :      *
      68              :      * If filter returns `kAllowPacket`, packet will be processed after dequeuing. If filter returns
      69              :      * `kDropPacket`, packet will be dropped and not processed, even though it was dequeued.
      70              :      *
      71              :      * WARNING: This is called from Matter thread context. Be extremely careful about accessing any
      72              :      *          data which may belong to different threads from this method.
      73              :      *
      74              :      * @param endpoint - pointer to endpoint instance (platform-dependent, which is why it's void)
      75              :      * @param pktInfo - info about source/dest of packet
      76              :      * @param pktPayload - payload content of packet
      77              :      *
      78              :      * @return kAllowPacket to allow packet to be processed or kDropPacket to drop the packet
      79              :      */
      80            0 :     virtual FilterOutcome FilterAfterDequeue(const void * endpoint, const IPPacketInfo & pktInfo,
      81              :                                              const chip::System::PacketBufferHandle & pktPayload)
      82              :     {
      83            0 :         return FilterOutcome::kAllowPacket;
      84              :     }
      85              : };
      86              : 
      87              : } // namespace Inet
      88              : } // namespace chip