Line data    Source code

       1             : /*
       2             :  *    Copyright (c) 2024 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             : #include "FabricScopedPreEncodedValue.h"
      19             : #include <lib/core/TLVReader.h>
      20             : #include <lib/support/CodeUtils.h>
      21             : 
      22             : #include <optional>
      23             : 
      24             : namespace chip {
      25             : namespace app {
      26             : namespace DataModel {
      27             : 
      28           4 : FabricScopedPreEncodedValue::FabricScopedPreEncodedValue(const ByteSpan & aData) : mData(aData) {}
      29             : 
      30           3 : CHIP_ERROR FabricScopedPreEncodedValue::EncodeForRead(TLV::TLVWriter & aWriter, TLV::Tag aTag, FabricIndex aFabricIndex) const
      31             : {
      32             :     TLV::TLVReader reader;
      33           3 :     reader.Init(mData);
      34             : 
      35           3 :     ReturnErrorOnFailure(reader.Next());
      36             : 
      37           3 :     return aWriter.CopyElement(aTag, reader);
      38             : }
      39             : 
      40           6 : FabricIndex FabricScopedPreEncodedValue::GetFabricIndex() const
      41             : {
      42             :     TLV::TLVReader reader;
      43           6 :     reader.Init(mData);
      44           6 :     CHIP_ERROR err = reader.Next();
      45           6 :     if (err != CHIP_NO_ERROR)
      46             :     {
      47           0 :         return kUndefinedFabricIndex;
      48             :     }
      49             : 
      50             :     // We must have a struct here.
      51           6 :     if (reader.GetType() != TLV::kTLVType_Structure)
      52             :     {
      53           0 :         return kUndefinedFabricIndex;
      54             :     }
      55             : 
      56             :     TLV::TLVType structType;
      57           6 :     err = reader.EnterContainer(structType);
      58           6 :     if (err != CHIP_NO_ERROR)
      59             :     {
      60           0 :         return kUndefinedFabricIndex;
      61             :     }
      62             : 
      63             :     // Now look for a single field with the right tag.
      64           6 :     std::optional<FabricIndex> foundFabricIndex;
      65           6 :     constexpr TLV::Tag kFabricIndexTag = TLV::ContextTag(254);
      66          18 :     while ((err = reader.Next()) == CHIP_NO_ERROR)
      67             :     {
      68          12 :         if (reader.GetTag() != kFabricIndexTag)
      69             :         {
      70           6 :             continue;
      71             :         }
      72             : 
      73           6 :         if (foundFabricIndex.has_value())
      74             :         {
      75             :             // Two fabric indices?  Just give up.  Note that this will lead to
      76             :             // errors encoding our value.
      77           0 :             return kUndefinedFabricIndex;
      78             :         }
      79             : 
      80           6 :         err = reader.Get(foundFabricIndex.emplace());
      81           6 :         if (err != CHIP_NO_ERROR)
      82             :         {
      83           0 :             return kUndefinedFabricIndex;
      84             :         }
      85             :     }
      86             : 
      87           6 :     if (err != CHIP_ERROR_END_OF_TLV)
      88             :     {
      89           0 :         return kUndefinedFabricIndex;
      90             :     }
      91             : 
      92           6 :     err = reader.ExitContainer(structType);
      93           6 :     if (err != CHIP_NO_ERROR)
      94             :     {
      95           0 :         return kUndefinedFabricIndex;
      96             :     }
      97             : 
      98           6 :     return foundFabricIndex.value_or(kUndefinedFabricIndex);
      99             : }
     100             : 
     101             : } // namespace DataModel
     102             : } // namespace app
     103             : } // namespace chip