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         920 : 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         920 :     if ((asType == ResourceType::kAuthority) && (hdr.GetAdditionalCount() != 0))
      28             :     {
      29           1 :         return false;
      30             :     }
      31         919 :     if ((asType == ResourceType::kAnswer) && ((hdr.GetAdditionalCount() != 0) || (hdr.GetAuthorityCount() != 0)))
      32             :     {
      33           2 :         return false;
      34             :     }
      35             : 
      36         917 :     out.WriteQName(mQName);
      37             : 
      38         917 :     out.Writer()                                  //
      39         917 :         .Put16(static_cast<uint16_t>(GetType()))  //
      40         917 :         .Put16(static_cast<uint16_t>(GetClass())) //
      41         917 :         .Put32(static_cast<uint32_t>(GetTtl()))   //
      42             :         ;
      43             : 
      44         917 :     chip::Encoding::BigEndian::BufferWriter sizeOutput(out.Writer()); // copy to re-output size
      45         917 :     out.Put16(0);                                                     // dummy, will be replaced later
      46             : 
      47         917 :     if (!WriteData(out))
      48             :     {
      49          37 :         return false;
      50             :     }
      51         880 :     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         880 :     if (out.Fit())
      55             :     {
      56         880 :         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         832 :         case ResourceType::kAnswer:
      65         832 :             hdr.SetAnswerCount(static_cast<uint16_t>(hdr.GetAnswerCount() + 1));
      66         832 :             break;
      67             :         }
      68             :     }
      69             : 
      70         880 :     return out.Fit();
      71             : }
      72             : 
      73             : } // namespace Minimal
      74             : } // namespace mdns