Network-initiated de-registration improvement

src/app/monitor.hpp

@@ -35,6 +35,7 @@ enum class StateType
     MM_SUB,
     RM,
     CM,
+    U5,
 };
 
 class INodeListener

src/ue/mm/base.cpp

@@ -25,6 +25,7 @@ NasMm::NasMm(TaskBase *base, UeTimers *timers) : m_base{base}, m_timers{timers},
     m_cmState = ECmState::CM_IDLE;
     m_mmState = EMmState::MM_DEREGISTERED;
     m_mmSubState = EMmSubState::MM_DEREGISTERED_NA;
+    m_uState = E5UState::U1_UPDATED;
     m_autoBehaviour = base->config->autoBehaviour;
     m_validSim = base->config->supi.has_value();
 }
@@ -165,6 +166,25 @@ void NasMm::switchCmState(ECmState state)
     triggerMmCycle();
 }
 
+void NasMm::switchUState(E5UState state)
+{
+    E5UState oldState = m_uState;
+    m_uState = state;
+
+    onSwitchUState(oldState, m_uState);
+
+    if (m_base->nodeListener)
+    {
+        m_base->nodeListener->onSwitch(app::NodeType::UE, m_base->config->getNodeName(), app::StateType::U5,
+                                       ToJson(oldState).str(), ToJson(m_uState).str());
+    }
+
+    if (state != oldState)
+        m_logger->info("UE switches to state: %s", ToJson(state).str().c_str());
+
+    triggerMmCycle();
+}
+
 void NasMm::onSwitchMmState(EMmState oldState, EMmState newState, EMmSubState oldSubState, EMmSubState newSubSate)
 {
     // The UE shall mark the 5G NAS security context on the USIM or in the non-volatile memory as invalid when the UE
@@ -210,6 +230,10 @@ void NasMm::onSwitchCmState(ECmState oldState, ECmState newState)
     }
 }
 
+void NasMm::onSwitchUState(E5UState oldState, E5UState newState)
+{
+}
+
 void NasMm::receivePlmnSearchResponse(const std::string &gnbName)
 {
     if (m_base->nodeListener)
@@ -284,4 +308,20 @@ void NasMm::onTimerExpire(nas::NasTimer &timer)
     }
 }
 
+void NasMm::invalidateAcquiredParams()
+{
+    m_storedGuti = {};
+    m_lastVisitedRegisteredTai = {};
+    m_taiList = {};
+    m_currentNsCtx = {};
+    m_nonCurrentNsCtx = {};
+}
+
+void NasMm::invalidateSim()
+{
+    m_logger->warn("USIM is removed or invalidated");
+    m_validSim = false;
+    invalidateAcquiredParams();
+}
+
 } // namespace nr::ue

src/ue/mm/dereg.cpp

@@ -7,6 +7,7 @@
 //
 
 #include "mm.hpp"
+#include <nas/utils.hpp>
 #include <ue/sm/sm.hpp>
 
 namespace nr::ue
@@ -20,6 +21,9 @@ void NasMm::sendDeregistration(nas::ESwitchOff switchOff, bool dueToDisable5g)
         return;
     }
 
+    m_logger->debug("Starting de-registration procedure. switch-off[%d] disable-5g[%d]",
+                    switchOff == nas::ESwitchOff::SWITCH_OFF ? 1 : 0, (int)dueToDisable5g);
+
     auto request = std::make_unique<nas::DeRegistrationRequestUeOriginating>();
     request->deRegistrationType.accessType = nas::EDeRegistrationAccessType::THREEGPP_ACCESS;
     request->deRegistrationType.reRegistrationRequired = nas::EReRegistrationRequired::NOT_REQUIRED;
@@ -57,6 +61,8 @@ void NasMm::sendDeregistration(nas::ESwitchOff switchOff, bool dueToDisable5g)
 
 void NasMm::receiveDeregistrationAccept(const nas::DeRegistrationAcceptUeOriginating &msg)
 {
+    m_logger->debug("De-registration accept received");
+
     if (m_mmSubState != EMmSubState::MM_DEREGISTERED_INITIATED_NA)
     {
         m_logger->warn("De-registration accept message ignored. UE is not in MM_DEREGISTERED_INITIATED");
@@ -84,7 +90,22 @@ void NasMm::receiveDeregistrationAccept(const nas::DeRegistrationAcceptUeOrigina
 
 void NasMm::receiveDeregistrationRequest(const nas::DeRegistrationRequestUeTerminated &msg)
 {
-    bool forceIgnoreReregistration = false; // todo use this
+    if (m_rmState != ERmState::RM_REGISTERED)
+    {
+        m_logger->warn("De-registration message ignored. UE is already de-registered");
+        return;
+    }
+
+    if (msg.deRegistrationType.accessType == nas::EDeRegistrationAccessType::NON_THREEGPP_ACCESS)
+    {
+        m_logger->warn("De-registration message ignored. Access type mismatch");
+        sendMmStatus(nas::EMmCause::SEMANTICALLY_INCORRECT_MESSAGE);
+        return;
+    }
+
+    m_logger->debug("Network initiated de-registration request received");
+
+    bool forceIgnoreReregistration = false;
 
     // 5.5.2.2.6 Abnormal cases in the UE (de-registration collision)
     if (m_mmState == EMmState::MM_DEREGISTERED_INITIATED)
@@ -111,9 +132,13 @@ void NasMm::receiveDeregistrationRequest(const nas::DeRegistrationRequestUeTermi
         return;
     }
 
-    // TODO: this function is not complete
+    bool reRegistrationRequired =
+        msg.deRegistrationType.reRegistrationRequired == nas::EReRegistrationRequired::REQUIRED &&
+        !forceIgnoreReregistration;
 
-    if (msg.deRegistrationType.reRegistrationRequired == nas::EReRegistrationRequired::REQUIRED)
+    // todo local release of pdu sessions
+
+    if (reRegistrationRequired)
     {
         m_timers->t3346.stop();
         m_timers->t3396.stop();
@@ -122,8 +147,63 @@ void NasMm::receiveDeregistrationRequest(const nas::DeRegistrationRequestUeTermi
     }
 
     sendNasMessage(nas::DeRegistrationAcceptUeTerminated{});
-    switchMmState(EMmState::MM_DEREGISTERED, EMmSubState::MM_DEREGISTERED_NA);
     switchRmState(ERmState::RM_DEREGISTERED);
+
+    // If the de-registration type indicates "re-registration not required", the UE shall take the actions depending on
+    // the received 5GMM cause value. Otherwise ignore the 5GMM cause value.
+    if (msg.deRegistrationType.reRegistrationRequired == nas::EReRegistrationRequired::NOT_REQUIRED)
+    {
+        if (msg.mmCause.has_value())
+        {
+            switch (msg.mmCause->value)
+            {
+            case nas::EMmCause::ILLEGAL_UE:
+            case nas::EMmCause::ILLEGAL_ME:
+            case nas::EMmCause::FIVEG_SERVICES_NOT_ALLOWED: {
+                switchUState(E5UState::U3_ROAMING_NOT_ALLOWED);
+                invalidateSim();
+                switchMmState(EMmState::MM_DEREGISTERED, EMmSubState::MM_DEREGISTERED_NA);
+                break;
+            }
+            // case nas::EMmCause::PLMN_NOT_ALLOWED: {
+            //    switchUState(E5UState::U3_ROAMING_NOT_ALLOWED);
+            //    invalidateAcquiredParams();
+            //    // TODO: add to forbidden plmn list, otherwise endless plmn search may occur.
+            //    switchMmState(EMmState::MM_DEREGISTERED, EMmSubState::MM_DEREGISTERED_PLMN_SEARCH);
+            //    break;
+            //}
+            case nas::EMmCause::TA_NOT_ALLOWED: {
+                switchUState(E5UState::U3_ROAMING_NOT_ALLOWED);
+                invalidateAcquiredParams();
+                switchMmState(EMmState::MM_DEREGISTERED, EMmSubState::MM_DEREGISTERED_LIMITED_SERVICE);
+                break;
+            }
+            case nas::EMmCause::N1_MODE_NOT_ALLOWED: {
+                switchUState(E5UState::U3_ROAMING_NOT_ALLOWED);
+                invalidateAcquiredParams();
+                switchMmState(EMmState::MM_NULL, EMmSubState::MM_NULL_NA);
+                break;
+            }
+            case nas::EMmCause::CONGESTION: {
+                switchUState(E5UState::U2_NOT_UPDATED);
+                m_timers->t3346.stop();
+                switchMmState(EMmState::MM_DEREGISTERED, EMmSubState::MM_DEREGISTERED_ATTEMPTING_REGISTRATION);
+                if (msg.t3346Value.has_value() && msg.t3346Value->value != 0)
+                    m_timers->t3346.start(*msg.t3346Value);
+                break;
+            }
+            default: {
+                m_logger->err("Unhandled network-initiated de-registration cause[%s]",
+                              nas::utils::EnumToString(msg.mmCause->value));
+
+                switchUState(E5UState::U3_ROAMING_NOT_ALLOWED);
+                invalidateSim();
+                switchMmState(EMmState::MM_DEREGISTERED, EMmSubState::MM_DEREGISTERED_NA);
+                break;
+            }
+            }
+        }
+    }
 }
 
 } // namespace nr::ue

src/ue/mm/mm.hpp

@@ -33,6 +33,7 @@ class NasMm
     ECmState m_cmState;
     EMmState m_mmState;
     EMmSubState m_mmSubState;
+    E5UState m_uState;
 
     nas::IE5gsMobileIdentity m_storedSuci{};
     nas::IE5gsMobileIdentity m_storedGuti{};
@@ -78,9 +79,13 @@ class NasMm
     void switchMmState(EMmState state, EMmSubState subState);
     void switchRmState(ERmState state);
     void switchCmState(ECmState state);
+    void switchUState(E5UState state);
     void onSwitchMmState(EMmState oldState, EMmState newState, EMmSubState oldSubState, EMmSubState newSubSate);
     void onSwitchRmState(ERmState oldState, ERmState newState);
     void onSwitchCmState(ECmState oldState, ECmState newState);
+    void onSwitchUState(E5UState oldState, E5UState newState);
+    void invalidateAcquiredParams();
+    void invalidateSim();
 
     /* Transport */
     void sendMmStatus(nas::EMmCause cause);

src/ue/types.cpp

@@ -134,14 +134,28 @@ Json ToJson(const UeConfig &v)
 Json ToJson(const UeTimers &v)
 {
     return Json::Obj({
-        {"T3346", ToJson(v.t3346)}, {"T3396", ToJson(v.t3396)}, {"T3444", ToJson(v.t3444)},
-        {"T3445", ToJson(v.t3445)}, {"T3502", ToJson(v.t3502)}, {"T3510", ToJson(v.t3510)},
-        {"T3511", ToJson(v.t3511)}, {"T3512", ToJson(v.t3512)}, {"T3516", ToJson(v.t3516)},
-        {"T3517", ToJson(v.t3517)}, {"T3519", ToJson(v.t3519)}, {"T3520", ToJson(v.t3520)},
-        {"T3521", ToJson(v.t3521)}, {"T3525", ToJson(v.t3525)}, {"T3540", ToJson(v.t3540)},
-        {"T3580", ToJson(v.t3580)}, {"T3581", ToJson(v.t3581)}, {"T3582", ToJson(v.t3582)},
-        {"T3583", ToJson(v.t3583)}, {"T3584", ToJson(v.t3584)}, {"T3585", ToJson(v.t3585)},
+        {"T3346", ToJson(v.t3346)}, {"T3396", ToJson(v.t3396)}, {"T3444", ToJson(v.t3444)}, {"T3445", ToJson(v.t3445)},
+        {"T3502", ToJson(v.t3502)}, {"T3510", ToJson(v.t3510)}, {"T3511", ToJson(v.t3511)}, {"T3512", ToJson(v.t3512)},
+        {"T3516", ToJson(v.t3516)}, {"T3517", ToJson(v.t3517)}, {"T3519", ToJson(v.t3519)}, {"T3520", ToJson(v.t3520)},
+        {"T3521", ToJson(v.t3521)}, {"T3525", ToJson(v.t3525)}, {"T3540", ToJson(v.t3540)}, {"T3580", ToJson(v.t3580)},
+        {"T3581", ToJson(v.t3581)}, {"T3582", ToJson(v.t3582)}, {"T3583", ToJson(v.t3583)}, {"T3584", ToJson(v.t3584)},
+        {"T3585", ToJson(v.t3585)},
     });
 }
 
+Json ToJson(const E5UState &state)
+{
+    switch (state)
+    {
+    case E5UState::U1_UPDATED:
+        return "5U1-UPDATED";
+    case E5UState::U2_NOT_UPDATED:
+        return "5U2-NOT-UPDATED";
+    case E5UState::U3_ROAMING_NOT_ALLOWED:
+        return "5U3-ROAMING-NOT-ALLOWED";
+    default:
+        return "?";
+    }
+}
+
 } // namespace nr::ue

src/ue/types.hpp

@@ -363,6 +363,7 @@ Json ToJson(const ECmState &state);
 Json ToJson(const ERmState &state);
 Json ToJson(const EMmState &state);
 Json ToJson(const EMmSubState &state);
+Json ToJson(const E5UState &state);
 Json ToJson(const UeConfig &v);
 Json ToJson(const UeTimers &v);