From 4e76f3b7e6987b56495ab7da4ea44f624c4f462a Mon Sep 17 00:00:00 2001
From: Stefano Avallone <stavallo@gmail.com>
Date: Tue, 4 Feb 2025 09:08:20 +0100
Subject: [PATCH] wifi: MAC retrieves time to end MAC RX event from PHY

---
 src/wifi/model/phy-entity.cc | 21 +++++++++++++++++++++
 src/wifi/model/phy-entity.h  |  9 +++++++++
 src/wifi/model/wifi-phy.cc   | 13 +++++++++++++
 src/wifi/model/wifi-phy.h    |  9 +++++++++
 4 files changed, 52 insertions(+)

diff --git a/src/wifi/model/phy-entity.cc b/src/wifi/model/phy-entity.cc
index a68326ab2..6e22407b6 100644
--- a/src/wifi/model/phy-entity.cc
+++ b/src/wifi/model/phy-entity.cc
@@ -844,6 +844,27 @@ PhyEntity::GetReceptionStatus(Ptr<WifiMpdu> mpdu,
     }
 }
 
+std::optional<Time>
+PhyEntity::GetTimeToMacHdrEnd(uint16_t staId) const
+{
+    const auto it = m_endOfMacHdrEvents.find(staId);
+
+    if (it == m_endOfMacHdrEvents.cend())
+    {
+        return std::nullopt;
+    }
+
+    for (const auto& endOfMacHdrEvent : it->second)
+    {
+        if (endOfMacHdrEvent.IsPending())
+        {
+            return Simulator::GetDelayLeft(endOfMacHdrEvent);
+        }
+    }
+
+    return std::nullopt;
+}
+
 std::pair<MHz_u, WifiSpectrumBandInfo>
 PhyEntity::GetChannelWidthAndBand(const WifiTxVector& txVector, uint16_t /* staId */) const
 {
diff --git a/src/wifi/model/phy-entity.h b/src/wifi/model/phy-entity.h
index 6bb570a7e..6c4f7254b 100644
--- a/src/wifi/model/phy-entity.h
+++ b/src/wifi/model/phy-entity.h
@@ -409,6 +409,15 @@ class PhyEntity : public SimpleRefCount<PhyEntity>
      */
     void CancelRunningEndPreambleDetectionEvents();
 
+    /**
+     * Get the remaining time to the end of the MAC header reception of the next MPDU being
+     * received from the given STA, if any.
+     *
+     * @param staId the STA-ID of the transmitter; equals SU_STA_ID for SU PPDUs
+     * @return the remaining time to the end of the MAC header reception of the next MPDU, if any
+     */
+    virtual std::optional<Time> GetTimeToMacHdrEnd(uint16_t staId) const;
+
     /**
      * Return the STA ID that has been assigned to the station this PHY belongs to.
      * This is typically called for MU PPDUs, in order to pick the correct PSDU.
diff --git a/src/wifi/model/wifi-phy.cc b/src/wifi/model/wifi-phy.cc
index 22f6ade71..882d070ba 100644
--- a/src/wifi/model/wifi-phy.cc
+++ b/src/wifi/model/wifi-phy.cc
@@ -1797,6 +1797,19 @@ WifiPhy::NotifyMonitorSniffTx(Ptr<const WifiPsdu> psdu,
     }
 }
 
+std::optional<Time>
+WifiPhy::GetTimeToMacHdrEnd(uint16_t staId) const
+{
+    for (auto& [modClass, phyEntity] : m_phyEntities)
+    {
+        if (auto remTime = phyEntity->GetTimeToMacHdrEnd(staId))
+        {
+            return remTime;
+        }
+    }
+    return std::nullopt;
+}
+
 WifiConstPsduMap
 WifiPhy::GetWifiConstPsduMap(Ptr<const WifiPsdu> psdu, const WifiTxVector& txVector)
 {
diff --git a/src/wifi/model/wifi-phy.h b/src/wifi/model/wifi-phy.h
index 36029bc65..741c04222 100644
--- a/src/wifi/model/wifi-phy.h
+++ b/src/wifi/model/wifi-phy.h
@@ -894,6 +894,15 @@ class WifiPhy : public Object
      */
     dB_u GetRxGain() const;
 
+    /**
+     * Get the remaining time to the end of the MAC header reception of the next MPDU being
+     * received from the given STA, if any.
+     *
+     * @param staId the STA-ID of the transmitter; equals SU_STA_ID for SU PPDUs
+     * @return the remaining time to the end of the MAC header reception of the next MPDU, if any
+     */
+    std::optional<Time> GetTimeToMacHdrEnd(uint16_t staId) const;
+
     /**
      * Sets the device this PHY is associated with.
      *