From f0f2052ca32012dba4a81cd579d4ab83b056402c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= <sebastien.deronne@gmail.com>
Date: Tue, 5 Sep 2023 22:07:25 +0200
Subject: [PATCH] wifi: Send groupcast MPDUs using GCR service in A-MSDUs made
 of single A-MSDU subframes

---
 src/wifi/model/block-ack-manager.cc           |  3 +-
 .../model/ht/ht-frame-exchange-manager.cc     |  2 +-
 src/wifi/model/msdu-aggregator.cc             | 36 ++++++++++++++-----
 3 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/src/wifi/model/block-ack-manager.cc b/src/wifi/model/block-ack-manager.cc
index 53143325b..aded941cc 100644
--- a/src/wifi/model/block-ack-manager.cc
+++ b/src/wifi/model/block-ack-manager.cc
@@ -796,7 +796,8 @@ BlockAckManager::NotifyGotMpdu(Ptr<const WifiMpdu> mpdu)
     std::optional<Mac48Address> groupAddress;
     if (const auto addr1 = mpdu->GetOriginal()->GetHeader().GetAddr1(); addr1.IsGroup())
     {
-        groupAddress = mpdu->begin()->second.GetDestinationAddr();
+        groupAddress =
+            mpdu->GetHeader().IsQosAmsdu() ? mpdu->begin()->second.GetDestinationAddr() : addr1;
     }
     if (auto it = GetRecipientBaAgreement(originator, tid, groupAddress);
         it != m_recipientAgreements.end())
diff --git a/src/wifi/model/ht/ht-frame-exchange-manager.cc b/src/wifi/model/ht/ht-frame-exchange-manager.cc
index 297c3cd24..ec2cb9206 100644
--- a/src/wifi/model/ht/ht-frame-exchange-manager.cc
+++ b/src/wifi/model/ht/ht-frame-exchange-manager.cc
@@ -456,7 +456,7 @@ HtFrameExchangeManager::StartFrameExchange(Ptr<QosTxop> edca, Time availableTime
     }
 
     // Use SendDataFrame if we can try aggregation
-    if (hdr.IsQosData() && !hdr.GetAddr1().IsGroup() && !peekedItem->IsFragment() &&
+    if (hdr.IsQosData() && !hdr.GetAddr1().IsBroadcast() && !peekedItem->IsFragment() &&
         !GetWifiRemoteStationManager()->NeedFragmentation(peekedItem =
                                                               CreateAliasIfNeeded(peekedItem)))
     {
diff --git a/src/wifi/model/msdu-aggregator.cc b/src/wifi/model/msdu-aggregator.cc
index e215f60bc..1e439e5d3 100644
--- a/src/wifi/model/msdu-aggregator.cc
+++ b/src/wifi/model/msdu-aggregator.cc
@@ -9,10 +9,11 @@
 
 #include "msdu-aggregator.h"
 
+#include "ap-wifi-mac.h"
+#include "gcr-manager.h"
 #include "qos-txop.h"
 #include "wifi-mac-queue.h"
 #include "wifi-mac-trailer.h"
-#include "wifi-mac.h"
 #include "wifi-remote-station-manager.h"
 #include "wifi-tx-parameters.h"
 
@@ -83,15 +84,12 @@ MsduAggregator::GetNextAmsdu(Ptr<WifiMpdu> peekedItem,
 {
     NS_LOG_FUNCTION(this << *peekedItem << &txParams << availableTime);
 
-    Ptr<WifiMacQueue> queue = m_mac->GetTxopQueue(peekedItem->GetQueueAc());
-
-    uint8_t tid = peekedItem->GetHeader().GetQosTid();
-    auto recipient = peekedItem->GetOriginal()->GetHeader().GetAddr1();
-
     /* "The Address 1 field of an MPDU carrying an A-MSDU shall be set to an
      * individual address or to the GCR concealment address" (Section 10.12
      * of 802.11-2016)
      */
+    const auto& header = peekedItem->GetOriginal()->GetHeader();
+    const auto recipient = GetIndividuallyAddressedRecipient(m_mac, header);
     NS_ABORT_MSG_IF(recipient.IsBroadcast(), "Recipient address is broadcast");
 
     /* "A STA shall not transmit an A-MSDU within a QoS Data frame under a block
@@ -106,14 +104,34 @@ MsduAggregator::GetNextAmsdu(Ptr<WifiMpdu> peekedItem,
 
     NS_ASSERT(m_htFem);
 
+    auto queue = m_mac->GetTxopQueue(peekedItem->GetQueueAc());
+
+    // if GCR, A-MSDU is always used with a single A-MSDU subframe
+    if (IsGcr(m_mac, header))
+    {
+        auto msdu = peekedItem->GetOriginal();
+        auto gcrAmsdu =
+            Create<WifiMpdu>(msdu->GetPacket(), msdu->GetHeader(), msdu->GetTimestamp());
+        gcrAmsdu->Aggregate(nullptr);
+        queue->Replace(msdu, gcrAmsdu);
+        return m_htFem->CreateAliasIfNeeded(gcrAmsdu);
+    }
+    else if (IsGroupcast(recipient))
+    {
+        NS_LOG_DEBUG("No A-MSDU aggregation for groupcast frames without GCR service");
+        return nullptr;
+    }
+
+    const auto tid = header.GetQosTid();
     if (GetMaxAmsduSize(recipient, tid, txParams.m_txVector.GetModulationClass()) == 0)
     {
         NS_LOG_DEBUG("A-MSDU aggregation disabled");
         return nullptr;
     }
 
-    Ptr<WifiMpdu> amsdu = queue->GetOriginal(peekedItem);
-    uint8_t nMsdu = 1;
+    // perform A-MSDU aggregation
+    auto amsdu = queue->GetOriginal(peekedItem);
+    std::size_t nMsdu = 1;
     peekedItem = queue->PeekByTidAndAddress(tid, recipient, peekedItem->GetOriginal());
 
     // stop aggregation if we find an A-MSDU in the queue. This likely happens when an A-MSDU is
@@ -127,7 +145,7 @@ MsduAggregator::GetNextAmsdu(Ptr<WifiMpdu> peekedItem,
                       "Found item with sequence number assignment after one without: perhaps "
                       "sequence numbers were not released correctly?");
         // find the next MPDU before dequeuing the current one
-        Ptr<const WifiMpdu> msdu = peekedItem->GetOriginal();
+        auto msdu = peekedItem->GetOriginal();
         peekedItem = queue->PeekByTidAndAddress(tid, recipient, msdu);
         queue->DequeueIfQueued({amsdu});
         // perform A-MSDU aggregation