Mapping between TMSI and GUTI

src/amf-app/amf_app.cpp

@@ -406,14 +406,16 @@ void amf_app::handle_itti_message(
     uc->isUeContextRequest = false;
   else
     uc->isUeContextRequest = true;
+
   uc->ran_ue_ngap_id = itti_msg.ran_ue_ngap_id;
   uc->amf_ue_ngap_id = amf_ue_ngap_id;
 
   std::string guti   = {};
   bool is_guti_valid = false;
   if (itti_msg.is_5g_s_tmsi_present) {
-    guti = itti_msg.tai.mcc + itti_msg.tai.mnc + amf_cfg.guami.regionID +
-           itti_msg._5g_s_tmsi;
+    guti = conv::tmsi_to_guti(
+        itti_msg.tai.mcc, itti_msg.tai.mnc, amf_cfg.guami.regionID,
+        itti_msg._5g_s_tmsi);
     is_guti_valid = true;
     Logger::amf_app().debug("Receiving GUTI %s", guti.c_str());
   }
@@ -821,6 +823,7 @@ uint32_t amf_app::get_number_registered_ues() const {
   std::shared_lock lock(m_amf_ue_ngap_id2ue_ctx);
   return amf_ue_ngap_id2ue_ctx.size();
 }
+
 //---------------------------------------------------------------------------------------------
 void amf_app::add_n1n2_message_subscription(
     const std::string& ue_ctx_id, const n1n2sub_id_t& sub_id,

src/amf-app/amf_n1.cpp

@@ -828,9 +828,9 @@ void amf_n1::service_request_handle(
     uint8_t amf_pointer = {};
     string tmsi         = {};
     if (service_request->Get5gSTmsi(amf_set_id, amf_pointer, tmsi)) {
-      std::string guti = uc->tai.mcc + uc->tai.mnc + amf_cfg.guami.regionID +
-                         std::to_string(amf_set_id) +
-                         std::to_string(amf_pointer) + tmsi;
+      std::string guti = conv::tmsi_to_guti(
+          uc->tai.mcc, uc->tai.mnc, amf_cfg.guami.regionID, amf_set_id,
+          amf_pointer, tmsi);
 
       Logger::amf_app().debug(
           "GUTI %s, 5G-TMSI %s", guti.c_str(), tmsi.c_str());
@@ -1121,7 +1121,7 @@ void amf_n1::registration_request_handle(
         }
 
         nc->is_imsi_present = true;
-        nc->imsi            = imsi.mcc + imsi.mnc + imsi.msin;
+        nc->imsi            = conv::get_imsi(imsi.mcc, imsi.mnc, imsi.msin);
         Logger::amf_n1().debug("Received IMSI %s", nc->imsi.c_str());
 
         // Trigger UE Reachability Status Notify
@@ -1146,7 +1146,7 @@ void amf_n1::registration_request_handle(
 
         set_supi_2_nas_context(supi, nc);
         Logger::amf_n1().info(
-            "Associating IMSI (%s) with nas_context (%p)", supi.c_str(), nc);
+            "Associating SUPI (%s) with nas_context (%p)", supi.c_str(), nc);
         if (!nc->is_stacs_available) {
           ue_info_t ueItem;
           ueItem.connStatus = "5GMM-CONNECTED";  //"CM-CONNECTED";
@@ -2585,9 +2585,9 @@ void amf_n1::security_mode_complete_handle(
       mcc, mnc, amf_cfg.guami.regionID, amf_cfg.guami.AmfSetID,
       amf_cfg.guami.AmfPointer, tmsi);
 
-  std::string guti = mcc + mnc + amf_cfg.guami.regionID +
-                     amf_cfg.guami.AmfSetID + amf_cfg.guami.AmfPointer +
-                     conv::tmsi_to_string(tmsi);
+  std::string guti = conv::tmsi_to_guti(
+      mcc, mnc, amf_cfg.guami.regionID, amf_cfg.guami.AmfSetID,
+      amf_cfg.guami.AmfPointer, conv::tmsi_to_string(tmsi));
   Logger::amf_n1().debug("Allocated GUTI %s", guti.c_str());
 
   // registration_accept->SetT3512Value(0x5, T3512_TIMER_VALUE_MIN);

src/common/conversions.cpp

@@ -33,6 +33,9 @@
 #include "amf.hpp"
 #include "logger.hpp"
 
+constexpr uint8_t kTmsiIELength =
+    8;  // 4 bytes  -8 characters representation in hex
+
 static const char hex_to_ascii_table[16] = {
     '0', '1', '2', '3', '4', '5', '6', '7',
     '8', '9', 'a', 'b', 'c', 'd', 'e', 'f',
@@ -110,8 +113,8 @@ std::string conv::mncToString(
 //------------------------------------------------------------------------------
 std::string conv::tmsi_to_string(const uint32_t tmsi) {
   std::string s        = {};
-  std::string tmsi_str = std::to_string(tmsi);
-  uint8_t length       = 4 - tmsi_str.size();
+  std::string tmsi_str = uint32_to_hex_string(tmsi);
+  uint8_t length       = kTmsiIELength - tmsi_str.size();
   for (uint8_t i = 0; i < length; i++) {
     s.append("0");
   }
@@ -494,19 +497,43 @@ std::string conv::get_serving_network_name(
 
 //------------------------------------------------------------------------------
 std::string conv::uint32_to_hex_string(uint32_t value) {
-  char hex_str[8];
+  char hex_str[kTmsiIELength + 1];
   sprintf(hex_str, "%X", value);
+  Logger::amf_app().error(
+      "uint32_to_hex_string: %s", std::string(hex_str).c_str());
   return std::string(hex_str);
 }
 
 //------------------------------------------------------------------------------
 std::string conv::tmsi_to_guti(
     const std::string& mcc, const std::string& mnc,
-    const std::string& region_id, const std::string& tmsi) {
-  return {mcc + mnc + region_id + tmsi};
+    const std::string& region_id, const std::string& _5g_s_tmsi) {
+  return {mcc + mnc + region_id + _5g_s_tmsi};
 }
 
+//------------------------------------------------------------------------------
+std::string conv::tmsi_to_guti(
+    const std::string& mcc, const std::string& mnc,
+    const std::string& region_id, uint16_t amf_set_id, uint8_t amf_pointer,
+    const std::string& tmsi) {
+  return {mcc + mnc + region_id + std::to_string(amf_set_id) +
+          std::to_string(amf_pointer) + tmsi};
+}
+
+//------------------------------------------------------------------------------
+std::string conv::tmsi_to_guti(
+    const std::string& mcc, const std::string& mnc,
+    const std::string& region_id, const std::string& amf_set_id,
+    const std::string& amf_pointer, const std::string& tmsi) {
+  return {mcc + mnc + region_id + amf_set_id + amf_pointer + tmsi};
+}
 //------------------------------------------------------------------------------
 std::string conv::imsi_to_supi(const std::string& imsi) {
   return {"imsi-" + imsi};
 }
+
+//------------------------------------------------------------------------------
+std::string conv::get_imsi(
+    const std::string& mcc, const std::string& mnc, const std::string& msin) {
+  return {mcc + mnc + msin};
+}

src/common/conversions.hpp

@@ -102,8 +102,19 @@ class conv {
   static std::string uint32_to_hex_string(uint32_t value);
   static std::string tmsi_to_guti(
       const std::string& mcc, const std::string& mnc,
-      const std::string& region_id, const std::string& tmsi);
+      const std::string& region_id, const std::string& _5g_s_tmsi);
+  static std::string tmsi_to_guti(
+      const std::string& mcc, const std::string& mnc,
+      const std::string& region_id, uint16_t amf_set_id, uint8_t amf_pointer,
+      const std::string& tmsi);
+
+  static std::string tmsi_to_guti(
+      const std::string& mcc, const std::string& mnc,
+      const std::string& region_id, const std::string& amf_set_id,
+      const std::string& amf_pointer, const std::string& tmsi);
 
   static std::string imsi_to_supi(const std::string& imsi);
+  static std::string get_imsi(
+      const std::string& mcc, const std::string& mnc, const std::string& msin);
 };
 #endif /* FILE_CONVERSIONS_HPP_SEEN */