From fb5ed767bee902e367b51bb78ed030308a341eff Mon Sep 17 00:00:00 2001
From: Sharan Naribole <sharan.naribole@gmail.com>
Date: Tue, 3 Sep 2024 16:30:43 +0200
Subject: [PATCH] wifi: Add Per-STA Profile BSS Params Change count
 (de)serialization

---
 src/wifi/model/eht/multi-link-element.cc | 39 +++++++++++++++++++++++-
 src/wifi/model/eht/multi-link-element.h  | 24 +++++++++++++--
 2 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/src/wifi/model/eht/multi-link-element.cc b/src/wifi/model/eht/multi-link-element.cc
index 1dcbc409a..0f28aee8e 100644
--- a/src/wifi/model/eht/multi-link-element.cc
+++ b/src/wifi/model/eht/multi-link-element.cc
@@ -274,7 +274,8 @@ MultiLinkElement::PerStaProfileSubelement::PerStaProfileSubelement(
     const PerStaProfileSubelement& perStaProfile)
     : m_variant(perStaProfile.m_variant),
       m_staControl(perStaProfile.m_staControl),
-      m_staMacAddress(perStaProfile.m_staMacAddress)
+      m_staMacAddress(perStaProfile.m_staMacAddress),
+      m_bssParamsChgCnt(perStaProfile.m_bssParamsChgCnt)
 {
     // deep copy of the STA Profile field
     auto staProfileCopy = [&](auto&& frame) {
@@ -304,6 +305,7 @@ MultiLinkElement::PerStaProfileSubelement::operator=(const PerStaProfileSubeleme
     m_variant = perStaProfile.m_variant;
     m_staControl = perStaProfile.m_staControl;
     m_staMacAddress = perStaProfile.m_staMacAddress;
+    m_bssParamsChgCnt = perStaProfile.m_bssParamsChgCnt;
 
     // deep copy of the STA Profile field
     auto staProfileCopy = [&](auto&& frame) {
@@ -369,6 +371,29 @@ MultiLinkElement::PerStaProfileSubelement::GetStaMacAddress() const
     return m_staMacAddress;
 }
 
+void
+MultiLinkElement::PerStaProfileSubelement::SetBssParamsChgCnt(uint8_t count)
+{
+    NS_ABORT_MSG_IF(m_variant != BASIC_VARIANT,
+                    "Expected Basic Variant, variant:" << +static_cast<uint8_t>(m_variant));
+    m_bssParamsChgCnt = count;
+    m_staControl |= 0x0800;
+}
+
+bool
+MultiLinkElement::PerStaProfileSubelement::HasBssParamsChgCnt() const
+{
+    return (m_staControl & 0x0800) != 0;
+}
+
+uint8_t
+MultiLinkElement::PerStaProfileSubelement::GetBssParamsChgCnt() const
+{
+    NS_ASSERT_MSG(m_bssParamsChgCnt.has_value(), "No value set for m_bssParamsChgCnt");
+    NS_ASSERT_MSG(HasBssParamsChgCnt(), "BSS Parameters Change count bit not set");
+    return m_bssParamsChgCnt.value();
+}
+
 void
 MultiLinkElement::PerStaProfileSubelement::SetAssocRequest(
     const std::variant<MgtAssocRequestHeader, MgtReassocRequestHeader>& assoc)
@@ -479,6 +504,10 @@ MultiLinkElement::PerStaProfileSubelement::GetStaInfoLength() const
     {
         ret += 6;
     }
+    if (HasBssParamsChgCnt())
+    {
+        ret += 1;
+    }
     // TODO add other subfields of the STA Info field
     return ret;
 }
@@ -536,6 +565,10 @@ MultiLinkElement::PerStaProfileSubelement::SerializeInformationField(Buffer::Ite
     {
         WriteTo(start, m_staMacAddress);
     }
+    if (HasBssParamsChgCnt())
+    {
+        start.WriteU8(GetBssParamsChgCnt());
+    }
     // TODO add other subfields of the STA Info field
     auto staProfileSerialize = [&](auto&& frame) {
         using T = std::decay_t<decltype(frame)>;
@@ -576,6 +609,10 @@ MultiLinkElement::PerStaProfileSubelement::DeserializeInformationField(Buffer::I
     {
         ReadFrom(i, m_staMacAddress);
     }
+    if (HasBssParamsChgCnt())
+    {
+        m_bssParamsChgCnt = i.ReadU8();
+    }
 
     // TODO add other subfields of the STA Info field
     uint16_t count = i.GetDistanceFrom(start);
diff --git a/src/wifi/model/eht/multi-link-element.h b/src/wifi/model/eht/multi-link-element.h
index 651888aa3..e3dca61c6 100644
--- a/src/wifi/model/eht/multi-link-element.h
+++ b/src/wifi/model/eht/multi-link-element.h
@@ -348,6 +348,23 @@ class MultiLinkElement : public WifiInformationElement
          */
         Mac48Address GetStaMacAddress() const;
 
+        /**
+         * Set the BSS Parameters Change Count subfield in the STA Info field.
+         *
+         * @param count BSS Parameters Change Count
+         */
+        void SetBssParamsChgCnt(uint8_t count);
+
+        /// @return whether the BSS Parameters Change Count subfield in STA Info field is present
+        bool HasBssParamsChgCnt() const;
+
+        /**
+         * Get BSS Parameters Change Count subfield in the STA Info field.
+         *
+         * @return count value
+         */
+        uint8_t GetBssParamsChgCnt() const;
+
         /**
          * Include the given (Re)Association Request frame body in the STA Profile field
          * of this Per-STA Profile subelement
@@ -457,9 +474,10 @@ class MultiLinkElement : public WifiInformationElement
          */
         uint16_t DeserProbeReqMlePerSta(ns3::Buffer::Iterator start, uint16_t length);
 
-        Variant m_variant;            //!< Multi-Link element variant
-        uint16_t m_staControl;        //!< STA Control field
-        Mac48Address m_staMacAddress; //!< STA MAC address
+        Variant m_variant;                        //!< Multi-Link element variant
+        uint16_t m_staControl;                    //!< STA Control field
+        Mac48Address m_staMacAddress;             //!< STA MAC address
+        std::optional<uint8_t> m_bssParamsChgCnt; //!< BSS Params Change Count (Basic MLE)
         std::variant<std::monostate,
                      std::unique_ptr<MgtAssocRequestHeader>,
                      std::unique_ptr<MgtReassocRequestHeader>,