From 345a3ec95fedd75ebc6248b42e99455fee013150 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= <sebastien.deronne@gmail.com>
Date: Sun, 3 Dec 2023 14:34:02 +0100
Subject: [PATCH] wifi: First group addressed frame might be transmitted using
 No-Ack/No-Retry policy before retransmitting it to the concealment address

---
 src/wifi/model/frame-exchange-manager.cc       |  7 +++++--
 src/wifi/model/ht/ht-frame-exchange-manager.cc | 10 +++++++---
 src/wifi/model/msdu-aggregator.cc              |  7 +++++++
 src/wifi/model/qos-txop.cc                     | 13 +++++++++----
 4 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/src/wifi/model/frame-exchange-manager.cc b/src/wifi/model/frame-exchange-manager.cc
index b78f412a0..6b3b7383f 100644
--- a/src/wifi/model/frame-exchange-manager.cc
+++ b/src/wifi/model/frame-exchange-manager.cc
@@ -532,9 +532,12 @@ FrameExchangeManager::SendMpdu()
                 Simulator::Schedule(txDuration + m_phy->GetSifs(), [=, this, mpdu = m_mpdu]() {
                     NS_LOG_DEBUG("Prepare groupcast MPDU for retry");
                     mpdu->ResetInFlight(m_linkId);
-                    mpdu->GetHeader().SetRetry();
                     // restore addr1 to the group address instead of the concealment address
-                    mpdu->GetHeader().SetAddr1(mpdu->begin()->second.GetDestinationAddr());
+                    if (m_apMac->GetGcrManager()->UseConcealment(mpdu->GetHeader()))
+                    {
+                        mpdu->GetHeader().SetAddr1(mpdu->begin()->second.GetDestinationAddr());
+                    }
+                    mpdu->GetHeader().SetRetry();
                 });
             }
             else
diff --git a/src/wifi/model/ht/ht-frame-exchange-manager.cc b/src/wifi/model/ht/ht-frame-exchange-manager.cc
index 8db969a2d..ac94638a1 100644
--- a/src/wifi/model/ht/ht-frame-exchange-manager.cc
+++ b/src/wifi/model/ht/ht-frame-exchange-manager.cc
@@ -1137,9 +1137,12 @@ HtFrameExchangeManager::SendPsdu()
                     for (const auto& mpdu : *PeekPointer(psdu))
                     {
                         mpdu->ResetInFlight(m_linkId);
-                        mpdu->GetHeader().SetRetry();
                         // restore addr1 to the group address instead of the concealment address
-                        mpdu->GetHeader().SetAddr1(mpdu->begin()->second.GetDestinationAddr());
+                        if (m_apMac->GetGcrManager()->UseConcealment(mpdu->GetHeader()))
+                        {
+                            mpdu->GetHeader().SetAddr1(mpdu->begin()->second.GetDestinationAddr());
+                        }
+                        mpdu->GetHeader().SetRetry();
                     }
                 });
             }
@@ -1278,7 +1281,8 @@ HtFrameExchangeManager::FinalizeMacHeader(Ptr<const WifiPsdu> psdu)
                 hdr.SetQosQueueSize(queueSizeForTid[tid].value());
             }
 
-            if (m_mac->GetTypeOfStation() == AP && m_apMac->UseGcr(hdr))
+            if (m_mac->GetTypeOfStation() == AP && m_apMac->UseGcr(hdr) &&
+                m_apMac->GetGcrManager()->UseConcealment(mpdu->GetHeader()))
             {
                 const auto& gcrConcealmentAddress =
                     m_apMac->GetGcrManager()->GetGcrConcealmentAddress();
diff --git a/src/wifi/model/msdu-aggregator.cc b/src/wifi/model/msdu-aggregator.cc
index 9e5ae4f01..545e0d468 100644
--- a/src/wifi/model/msdu-aggregator.cc
+++ b/src/wifi/model/msdu-aggregator.cc
@@ -109,6 +109,13 @@ MsduAggregator::GetNextAmsdu(Ptr<WifiMpdu> peekedItem,
     // if GCR, A-MSDU is always used with a single A-MSDU subframe
     if (IsGcr(m_mac, header))
     {
+        auto apMac = DynamicCast<ApWifiMac>(m_mac);
+        NS_ASSERT(apMac);
+        auto gcrManager = apMac->GetGcrManager();
+        if (!gcrManager->UseConcealment(peekedItem->GetHeader()))
+        {
+            return nullptr;
+        }
         auto msdu = peekedItem->GetOriginal();
         auto gcrAmsdu =
             Create<WifiMpdu>(msdu->GetPacket(), msdu->GetHeader(), msdu->GetTimestamp());
diff --git a/src/wifi/model/qos-txop.cc b/src/wifi/model/qos-txop.cc
index 8e83bed79..429d5b4d1 100644
--- a/src/wifi/model/qos-txop.cc
+++ b/src/wifi/model/qos-txop.cc
@@ -14,6 +14,7 @@
 #include "ap-wifi-mac.h"
 #include "channel-access-manager.h"
 #include "ctrl-headers.h"
+#include "gcr-manager.h"
 #include "mac-tx-middle.h"
 #include "mgt-action-headers.h"
 #include "mpdu-aggregator.h"
@@ -556,10 +557,14 @@ QosTxop::GetNextMpdu(uint8_t linkId,
                       GetBaBufferSize(peekedItem->GetOriginal()->GetHeader().GetAddr1(), tid)));
 
         // try A-MSDU aggregation if the MPDU does not contain an A-MSDU and does not already
-        // have a sequence number assigned (may be a retransmission)
-        if (m_mac->GetHtConfiguration() && !recipient.IsBroadcast() &&
-            !peekedItem->GetHeader().IsQosAmsdu() && !peekedItem->HasSeqNoAssigned() &&
-            !peekedItem->IsFragment())
+        // have a sequence number assigned (may be a retransmission) unless it is a concealed GCR
+        // MPDU:
+        if (auto apMac = DynamicCast<ApWifiMac>(m_mac);
+            m_mac->GetHtConfiguration() && !recipient.IsBroadcast() &&
+            !peekedItem->GetHeader().IsQosAmsdu() && !peekedItem->IsFragment() &&
+            (!peekedItem->HasSeqNoAssigned() ||
+             (IsGcr(m_mac, peekedItem->GetHeader()) &&
+              (apMac->GetGcrManager()->UseConcealment(peekedItem->GetHeader())))))
         {
             auto htFem = StaticCast<HtFrameExchangeManager>(qosFem);
             mpdu = htFem->GetMsduAggregator()->GetNextAmsdu(peekedItem, txParams, availableTime);