add support for IMEISV when requesting UE idendity

srsue/hdr/stack/upper/nas.h

@@ -136,6 +136,11 @@ private:
   const uint32_t t3410_duration_ms = 15 * 1000; // 15s according to TS 24.301 Sec 10.2
   const uint32_t t3411_duration_ms = 10 * 1000; // 10s according to TS 24.301 Sec 10.2
 
+  // TS 23.003 Sec. 6.2.2 IMEISV's last two octets are Software Version Number (SVN)
+  // which identifies the software version number of the mobile equipment
+  const uint8_t ue_svn_oct1 = 0x5;
+  const uint8_t ue_svn_oct2 = 0x3;
+
   // Security
   bool    eia_caps[8]   = {};
   bool    eea_caps[8]   = {};

srsue/src/stack/upper/nas.cc

@@ -1280,8 +1280,8 @@ void nas::parse_security_mode_command(uint32_t lcid, unique_byte_buffer_t pdu)
     sec_mode_comp.imeisv_present    = true;
     sec_mode_comp.imeisv.type_of_id = LIBLTE_MME_MOBILE_ID_TYPE_IMEISV;
     usim->get_imei_vec(sec_mode_comp.imeisv.imeisv, 15);
-    sec_mode_comp.imeisv.imeisv[14] = 5;
-    sec_mode_comp.imeisv.imeisv[15] = 3;
+    sec_mode_comp.imeisv.imeisv[14] = ue_svn_oct1;
+    sec_mode_comp.imeisv.imeisv[15] = ue_svn_oct2;
   } else {
     sec_mode_comp.imeisv_present = false;
   }
@@ -1927,6 +1927,12 @@ void nas::send_identity_response(const uint8 id_type, const uint8_t sec_hdr_type
       id_resp.mobile_id.type_of_id = LIBLTE_MME_MOBILE_ID_TYPE_IMEI;
       usim->get_imei_vec(id_resp.mobile_id.imei, 15);
       break;
+    case LIBLTE_MME_MOBILE_ID_TYPE_IMEISV:
+      id_resp.mobile_id.type_of_id = LIBLTE_MME_MOBILE_ID_TYPE_IMEISV;
+      usim->get_imei_vec(id_resp.mobile_id.imeisv, 15);
+      id_resp.mobile_id.imeisv[14] = ue_svn_oct1;
+      id_resp.mobile_id.imeisv[15] = ue_svn_oct2;
+      break;
     default:
       nas_log->error("Unhandled ID type: %d\n", id_type);
       return;