Line data    Source code

       1              : /*
       2              :  *
       3              :  *    Copyright (c) 2020 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              : #include "ResourceRecord.h"
      19              : 
      20              : namespace mdns {
      21              : namespace Minimal {
      22              : 
      23          864 : bool ResourceRecord::Append(HeaderRef & hdr, ResourceType asType, RecordWriter & out) const
      24              : {
      25              :     // order is important based on resource type. First come answers, then authorityAnswers
      26              :     // and then additional:
      27          864 :     if ((asType == ResourceType::kAuthority) && (hdr.GetAdditionalCount() != 0))
      28              :     {
      29            1 :         return false;
      30              :     }
      31          863 :     if ((asType == ResourceType::kAnswer) && ((hdr.GetAdditionalCount() != 0) || (hdr.GetAuthorityCount() != 0)))
      32              :     {
      33            2 :         return false;
      34              :     }
      35              : 
      36          861 :     out.WriteQName(mQName);
      37              : 
      38          861 :     out.Writer()                                  //
      39          861 :         .Put16(static_cast<uint16_t>(GetType()))  //
      40          861 :         .Put16(static_cast<uint16_t>(GetClass())) //
      41          861 :         .Put32(static_cast<uint32_t>(GetTtl()))   //
      42              :         ;
      43              : 
      44          861 :     chip::Encoding::BigEndian::BufferWriter sizeOutput(out.Writer()); // copy to re-output size
      45          861 :     out.Put16(0);                                                     // dummy, will be replaced later
      46              : 
      47          861 :     if (!WriteData(out))
      48              :     {
      49           37 :         return false;
      50              :     }
      51          824 :     sizeOutput.Put16(static_cast<uint16_t>(out.Writer().Needed() - sizeOutput.Needed() - 2));
      52              : 
      53              :     // This MUST be final and separated out: record count is only updated on success.
      54          824 :     if (out.Fit())
      55              :     {
      56          824 :         switch (asType)
      57              :         {
      58           36 :         case ResourceType::kAdditional:
      59           36 :             hdr.SetAdditionalCount(static_cast<uint16_t>(hdr.GetAdditionalCount() + 1));
      60           36 :             break;
      61           12 :         case ResourceType::kAuthority:
      62           12 :             hdr.SetAuthorityCount(static_cast<uint16_t>(hdr.GetAuthorityCount() + 1));
      63           12 :             break;
      64          776 :         case ResourceType::kAnswer:
      65          776 :             hdr.SetAnswerCount(static_cast<uint16_t>(hdr.GetAnswerCount() + 1));
      66          776 :             break;
      67              :         }
      68              :     }
      69              : 
      70          824 :     return out.Fit();
      71              : }
      72              : 
      73              : } // namespace Minimal
      74              : } // namespace mdns