From a4ab293c8688b8ccb21d58a3c5e9df5f2e96ffee Mon Sep 17 00:00:00 2001
From: Stefano Avallone <stavallo@unina.it>
Date: Mon, 22 Aug 2022 17:18:38 +0200
Subject: [PATCH] wifi: Fix deserialization of RNR elements

... with multiple TBTT Information fields per Neighbor AP Information field.
---
 src/wifi/model/reduced-neighbor-report.cc | 18 +++++++++++++-----
 src/wifi/model/reduced-neighbor-report.h  | 16 ++++++++++++++--
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/wifi/model/reduced-neighbor-report.cc b/src/wifi/model/reduced-neighbor-report.cc
index 239f3e574..7761dcad0 100644
--- a/src/wifi/model/reduced-neighbor-report.cc
+++ b/src/wifi/model/reduced-neighbor-report.cc
@@ -347,9 +347,6 @@ ReducedNeighborReport::AddTbttInformationField (std::size_t nbrApInfoId)
 {
   NS_ASSERT (nbrApInfoId < m_nbrApInfoFields.size ());
   m_nbrApInfoFields.at (nbrApInfoId).tbttInformationSet.push_back (TbttInformation ());
-
-  // set the TBTT Information Count field
-  m_nbrApInfoFields.at (nbrApInfoId).tbttInfoHdr.tbttInfoCount = m_nbrApInfoFields.at (nbrApInfoId).tbttInformationSet.size () - 1;
 }
 
 void
@@ -568,8 +565,18 @@ ReducedNeighborReport::GetLinkId (std::size_t nbrApInfoId, std::size_t index) co
   return m_nbrApInfoFields.at (nbrApInfoId).tbttInformationSet.at (index).mldParameters.linkId & 0x0f;
 }
 
+void
+ReducedNeighborReport::WriteTbttInformationCount (std::size_t nbrApInfoId) const
+{
+  NS_ASSERT (nbrApInfoId < m_nbrApInfoFields.size ());
+  NS_ASSERT (!m_nbrApInfoFields.at (nbrApInfoId).tbttInformationSet.empty ());
+
+  // set the TBTT Information Count field
+  m_nbrApInfoFields.at (nbrApInfoId).tbttInfoHdr.tbttInfoCount = m_nbrApInfoFields.at (nbrApInfoId).tbttInformationSet.size () - 1;
+}
+
 uint8_t
-ReducedNeighborReport::GetTbttInformationCount (std::size_t nbrApInfoId) const
+ReducedNeighborReport::ReadTbttInformationCount (std::size_t nbrApInfoId) const
 {
   NS_ASSERT (nbrApInfoId < m_nbrApInfoFields.size ());
 
@@ -617,6 +624,7 @@ ReducedNeighborReport::SerializeInformationField (Buffer::Iterator start) const
 {
   for (std::size_t id = 0; id < m_nbrApInfoFields.size (); ++ id)
     {
+      WriteTbttInformationCount (id);
       WriteTbttInformationLength (id);
     }
 
@@ -688,7 +696,7 @@ ReducedNeighborReport::DeserializeInformationField (Buffer::Iterator start, uint
       std::size_t neighborId = m_nbrApInfoFields.size () - 1;
       ReadTbttInformationLength (neighborId);
 
-      for (uint8_t j = 0; j < GetTbttInformationCount (neighborId); j++)
+      for (uint8_t j = 0; j < ReadTbttInformationCount (neighborId); j++)
         {
           AddTbttInformationField (neighborId);
 
diff --git a/src/wifi/model/reduced-neighbor-report.h b/src/wifi/model/reduced-neighbor-report.h
index fd8dd70cd..227d931d7 100644
--- a/src/wifi/model/reduced-neighbor-report.h
+++ b/src/wifi/model/reduced-neighbor-report.h
@@ -291,15 +291,27 @@ public:
    */
   uint8_t GetLinkId (std::size_t nbrApInfoId, std::size_t index) const;
 
+private:
+  /**
+   * Set the TBTT Information Count field of the given Neighbor AP Information field
+   * based on the size of the tbttInformationSet field.
+   *
+   * This method is marked as const because it needs to be called within the
+   * SerializeInformationField method. In fact, only when serializing this object
+   * we can set the TBTT Information Count field based on the number of TBTT Information
+   * fields included in the given Neighbor AP Information field.
+   *
+   * \param nbrApInfoId identifier of the given Neighbor AP Information field
+   */
+  void WriteTbttInformationCount (std::size_t nbrApInfoId) const;
   /**
    * Get the TBTT Information Count field of the given Neighbor AP Information field.
    *
    * \param nbrApInfoId identifier of the given Neighbor AP Information field
    * \return the TBTT Information Count
    */
-  uint8_t GetTbttInformationCount (std::size_t nbrApInfoId) const;
+  uint8_t ReadTbttInformationCount (std::size_t nbrApInfoId) const;
 
-private:
   /**
    * Set the TBTT Information Length field of the given Neighbor AP Information field
    * based on the xxxPresent flags of the NeighborApInformation struct