Filling Xn structures- from CU configuration

Adding Config file

Review comments-changes

Config file changes

Parameter XN Enable related changes

Added XNAP section in config file

CMakeLists.txt

@@ -1446,7 +1446,7 @@ add_library(e1_if
 
 target_link_libraries(e1_if PRIVATE asn1_nr_rrc_hdrs asn1_lte_rrc_hdrs asn1_f1ap SECURITY ${OPENSSL_LIBRARIES} e1ap GTPV1U)
 
-target_link_libraries(L2_NR PRIVATE f1ap x2ap s1ap ngap nr_rrc e1ap nr_rlc nr_common)
+target_link_libraries(L2_NR PRIVATE f1ap x2ap s1ap ngap nr_rrc e1ap nr_rlc nr_common xnap)
 if(OAI_AERIAL)
     target_compile_definitions(L2_NR PRIVATE ENABLE_AERIAL)
 endif()

common/utils/LOG/log.h

@@ -161,6 +161,7 @@ extern "C" {
   COMP_DEF(M2AP, )              \
   COMP_DEF(M3AP, )              \
   COMP_DEF(NGAP, )              \
+  COMP_DEF(XNAP, )              \
   COMP_DEF(GNB_APP, log)        \
   COMP_DEF(NR_RRC, log)         \
   COMP_DEF(NR_MAC, log)         \

common/utils/T/T_messages.txt

@@ -1250,6 +1250,28 @@ ID = LEGACY_E1AP_ERROR
     GROUP = ALL:LEGACY_E1AP:LEGACY_GROUP_ERROR:LEGACY
     FORMAT = string,log
 
+ID = LEGACY_XNAP_TRACE
+    DESC = XNAP TRACE LEVEL
+    GROUP = ALL:LEGACY_XNAP:LEGACY_GROUP_TRACE:LEGACY
+    FORMAT = string,log
+ID = LEGACY_XNAP_DEBUG
+    DESC = XNAP DEBUG LEVEL
+    GROUP = ALL:LEGACY_XNAP:LEGACY_GROUP_DEBUG:LEGACY
+    FORMAT = string,log
+ID = LEGACY_XNAP_INFO
+    DESC = XNAP INFO LEVEL
+    GROUP = ALL:LEGACY_XNAP:LEGACY_GROUP_INFO:LEGACY
+    FORMAT = string,log
+ID = LEGACY_XNAP_WARNING
+    DESC = XNAP WARNING LEVEL
+    GROUP = ALL:LEGACY_XNAP:LEGACY_GROUP_WARNING:LEGACY
+    FORMAT = string,log
+ID = LEGACY_XNAP_ERROR
+    DESC = XNAP ERROR LEVEL
+    GROUP = ALL:LEGACY_XNAP:LEGACY_GROUP_ERROR:LEGACY
+    FORMAT = string,log
+
+
 #################
 #### UE LOGS ####
 #################

common/utils/ocp_itti/intertask_interface.h

@@ -321,6 +321,7 @@ typedef struct {
   TASK_DEF(TASK_DU_F1, 200)           \
   TASK_DEF(TASK_CUCP_E1, 200)         \
   TASK_DEF(TASK_CUUP_E1, 200)         \
+  TASK_DEF(TASK_XNAP, 200)            \
   TASK_DEF(TASK_RRC_UE_SIM, 200)      \
   TASK_DEF(TASK_RRC_GNB_SIM, 200)     \
   TASK_DEF(TASK_RRC_NSA_UE, 200)      \

openair2/COMMON/xnap_messages_types.h

@@ -0,0 +1,120 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+/*! \file xnap_messages_types.h
+ * \author Sreeshma Shiv <sreeshmau@iisc.ac.in>
+ * \date August 2023
+ * \version 1.0
+ */
+#ifndef XNAP_MESSAGES_TYPES_H_
+#define XNAP_MESSAGES_TYPES_H_
+
+#define XNAP_MAX_NB_GNB_IP_ADDRESS 4
+#define XNAP_MAX_NB_CELLS 4 //can be changed
+
+typedef struct xnap_sctp_s {
+  uint16_t sctp_in_streams;
+  uint16_t sctp_out_streams;
+} xnap_sctp_t;
+
+typedef struct xnap_net_config_t {
+  uint8_t nb_xn;
+  char* gnb_xn_interface_ip_address;
+  char* target_gnb_xn_ip_address[XNAP_MAX_NB_GNB_IP_ADDRESS];
+  uint32_t gnb_port_for_XNC;
+  xnap_sctp_t sctp_streams;
+} xnap_net_config_t;
+
+typedef struct xnap_plmn_t {
+  uint16_t mcc;
+  uint16_t mnc;
+  uint8_t  mnc_digit_length;
+} xnap_plmn_t;
+
+typedef struct xnap_amf_regioninfo_s {
+  xnap_plmn_t plmn;
+  uint8_t amf_region_id;
+} xnap_amf_regioninfo_t;
+
+typedef enum xnap_mode_t { XNAP_MODE_TDD = 0, XNAP_MODE_FDD = 1 } xnap_mode_t;
+
+typedef struct xnap_nr_frequency_info_t {
+  uint32_t arfcn;
+  int band;
+} xnap_nr_frequency_info_t;
+
+typedef struct xnap_transmission_bandwidth_t {
+  uint8_t scs;
+  uint16_t nrb;
+} xnap_transmission_bandwidth_t;
+
+typedef struct xnap_fdd_info_t {
+  xnap_nr_frequency_info_t ul_freqinfo;
+  xnap_nr_frequency_info_t dl_freqinfo;
+  xnap_transmission_bandwidth_t ul_tbw;
+  xnap_transmission_bandwidth_t dl_tbw;
+} xnap_fdd_info_t;
+
+typedef struct xnap_tdd_info_t {
+  xnap_nr_frequency_info_t freqinfo;
+  xnap_transmission_bandwidth_t tbw;
+} xnap_tdd_info_t;
+
+typedef struct xnap_snssai_s {
+  uint8_t sst;
+  uint8_t sd;
+} xnap_snssai_t;
+
+typedef struct xnap_served_cell_info_t {
+  // NR CGI
+  xnap_plmn_t plmn;
+  uint64_t nr_cellid; // NR Global Cell Id
+  uint16_t nr_pci;// NR Physical Cell Ids
+
+  /* Tracking area code */
+  uint32_t tac;
+
+  xnap_mode_t mode;
+  union {
+    xnap_fdd_info_t fdd;
+    xnap_tdd_info_t tdd;
+  };
+
+  uint8_t *measurement_timing_information;
+} xnap_served_cell_info_t;
+
+typedef struct xnap_setup_req_s {
+  uint64_t gNB_id;
+  /* Tracking area code */
+  uint16_t num_tai;
+  uint32_t tai_support;
+  xnap_plmn_t plmn_support;
+  // Number of slide support items
+  uint16_t num_snssai;
+  xnap_snssai_t snssai[2];
+  xnap_amf_regioninfo_t amf_region_info;
+  uint8_t num_cells_available;
+  struct {
+    xnap_served_cell_info_t info;
+  } cell[XNAP_MAX_NB_CELLS];
+} xnap_setup_req_t;
+
+#endif /* XNAP_MESSAGES_TYPES_H_ */

openair2/GNB_APP/gnb_app.c

@@ -53,6 +53,8 @@
 #include "openair2/E1AP/e1ap.h"
 #include "gnb_config.h"
 #include "openair2/LAYER2/NR_MAC_gNB/mac_proto.h"
+#include "openair2/XNAP/xnap_task.h"
+#include "openair2/XNAP/xnap_inst_procedures_management.h"
 
 extern unsigned char NB_gNB_INST;
 
@@ -154,6 +156,19 @@ void *gNB_app_task(void *args_p)
       itti_send_msg_to_task(TASK_CUCP_E1, 0, msg);
     }
 
+    if (node_type == ngran_gNB_CUCP || node_type == ngran_gNB_CU || node_type == ngran_gNB) {
+      if (is_xnap_enabled()) {
+        if (itti_create_task(TASK_XNAP, xnap_task, NULL) < 0) {
+          LOG_E(XNAP, "Create task for XNAP failed\n");
+        }
+        xnap_net_config_t xn_net_config = Read_IPconfig_Xn();
+        createXninst(0, NULL, &xn_net_config);
+
+      } else {
+        LOG_I(XNAP, "XNAP is disabled.\n");
+      }
+    }
+
     if (node_type == ngran_gNB_CUUP) {
       AssertFatal(false, "To run CU-UP use executable nr-cuup\n");
     }

openair2/GNB_APP/gnb_config.c

@@ -2429,6 +2429,45 @@ int gNB_app_handle_f1ap_gnb_cu_configuration_update(f1ap_gnb_cu_configuration_up
   return(ret);
 }
 
+xnap_net_config_t Read_IPconfig_Xn(void)
+{
+  xnap_net_config_t nc = {0};
+  paramdef_t XnParamsneighbour[] = Xn_NEIGHBOUR_PARAMS_DESC;
+  paramlist_def_t XnParamneighbourList = {GNB_CONFIG_STRING_TARGET_GNB_Xn_ADDRESS, NULL, 0};
+  paramdef_t SCTPParams[] = GNBSCTPPARAMS_DESC;
+  char aprefix[MAX_OPTNAME_SIZE * 2 + 8];
+  sprintf(aprefix, "%s.[%i].%s", GNB_CONFIG_STRING_GNB_LIST, 0, GNB_CONFIG_STRING_XNAP);
+  config_getlist(config_get_if(), &XnParamneighbourList, XnParamsneighbour, sizeofArray(XnParamsneighbour), aprefix);
+  AssertFatal(XnParamneighbourList.numelt <= XNAP_MAX_NB_GNB_IP_ADDRESS,
+              "value of XnParamList.numelt %d must be lower than XnAP_MAX_NB_GNB_IP_ADDRESS %d value: reconsider to increase "
+              "XNAP_MAX_NB_GNB_IP_ADDRESS\n",
+              XnParamneighbourList.numelt,
+              XNAP_MAX_NB_GNB_IP_ADDRESS);
+  LOG_I(XNAP, "Number of Target gNBs configured: %d\n", XnParamneighbourList.numelt);
+  for (int l = 0; l < XnParamneighbourList.numelt; l++) {
+    nc.nb_xn += 1;
+    nc.target_gnb_xn_ip_address[l] = strdup(*(XnParamneighbourList.paramarray[l][GNB_CONFIG_STRING_TARGET_GNB_Xn_IP_ADDRESS_IDX].strptr));
+    LOG_I(XNAP, "Target gNB %d: %s \n", l+1, nc.target_gnb_xn_ip_address[l]);
+  }
+
+  // NETWORK_INTERFACES
+  paramdef_t XnParams[] = XnPARAMS_DESC;
+  config_get(config_get_if(), XnParams, sizeofArray(XnParams), aprefix);
+  nc.gnb_port_for_XNC = (uint32_t) * (XnParams[GNB_CONFIG_STRING_GNB_PORT_FOR_XNC_IDX].uptr);
+  AssertFatal(((XnParams[GNB_CONFIG_STRING_GNB_IP_ADDR_FOR_XNC_IDX].strptr != NULL) && (nc.gnb_port_for_XNC != 0)), 
+              "gNB Interface IP/Port not added in the CU/gNB configuration file \n");
+  nc.gnb_xn_interface_ip_address = strdup(*(XnParams[GNB_CONFIG_STRING_GNB_IP_ADDR_FOR_XNC_IDX].strptr));
+
+  // SCTP SETTING
+  nc.sctp_streams.sctp_out_streams = SCTP_OUT_STREAMS;
+  nc.sctp_streams.sctp_in_streams = SCTP_IN_STREAMS;
+  sprintf(aprefix, "%s.[%i].%s", GNB_CONFIG_STRING_GNB_LIST, 0, GNB_CONFIG_STRING_SCTP_CONFIG);
+  config_get(config_get_if(), SCTPParams, sizeofArray(SCTPParams), aprefix);
+  nc.sctp_streams.sctp_in_streams = (uint16_t) * (SCTPParams[GNB_SCTP_INSTREAMS_IDX].uptr);
+  nc.sctp_streams.sctp_out_streams = (uint16_t) * (SCTPParams[GNB_SCTP_OUTSTREAMS_IDX].uptr);
+  return nc;
+}
+
 ngran_node_t get_node_type(void)
 {
   paramdef_t        MacRLC_Params[] = MACRLCPARAMS_DESC;

openair2/GNB_APP/gnb_config.h

@@ -43,6 +43,7 @@
 #include "f1ap_messages_types.h"
 #include "e1ap_messages_types.h"
 
+#include "xnap_messages_types.h"
 #include "rrc_messages_types.h"
 #include "intertask_interface.h"
 #include "RRC/NR/nr_rrc_defs.h"
@@ -107,6 +108,7 @@ int RCconfig_NR_X2(MessageDef *msg_p, uint32_t i);
 void wait_f1_setup_response(void);
 int gNB_app_handle_f1ap_gnb_cu_configuration_update(f1ap_gnb_cu_configuration_update_t *gnb_cu_cfg_update);
 MessageDef *RCconfig_NR_CU_E1(const E1_t *entity);
+xnap_net_config_t Read_IPconfig_Xn(void);
 ngran_node_t get_node_type(void);
 
 #ifdef E2_AGENT

openair2/GNB_APP/gnb_paramdef.h

@@ -537,6 +537,36 @@ typedef enum {
 /*-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------*/
 /*-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------*/
 
+/* Xn configuration parameters section name */
+#define GNB_CONFIG_STRING_XNAP "XNAP"
+
+#define GNB_CONFIG_XNAP_ENABLE_IDX                                    0
+#define GNB_CONFIG_STRING_GNB_IP_ADDR_FOR_XNC_IDX                     1 
+#define GNB_CONFIG_STRING_GNB_PORT_FOR_XNC_IDX                        2
+
+#define GNB_CONFIG_STRING_XNAP_ENABLE  		  "ENABLE_XN"
+#define GNB_CONFIG_STRING_GNB_IP_ADDR_FOR_XNC     "GNB_IP_ADDRESS_FOR_XNC"
+#define GNB_CONFIG_STRING_GNB_PORT_FOR_XNC        "GNB_PORT_FOR_XNC"
+
+#define XnPARAMS_DESC { \
+  {GNB_CONFIG_STRING_XNAP_ENABLE, NULL , PARAMFLAG_BOOL , .iptr=NULL, .defintval=0, TYPE_INT, 0}, \
+  {GNB_CONFIG_STRING_GNB_IP_ADDR_FOR_XNC, "interface ip for xnc", 0, .strptr=NULL, .defstrval=NULL, TYPE_STRING, 0},\
+  {GNB_CONFIG_STRING_GNB_PORT_FOR_XNC, NULL, 0, .uptr=NULL, .defintval=0L, TYPE_UINT, 0}, \
+  }
+
+
+#define GNB_CONFIG_STRING_TARGET_GNB_Xn_ADDRESS    "Target_gNB_XN_address"
+#define GNB_CONFIG_STRING_TARGET_GNB_Xn_IP_ADDRESS  "ip"
+
+#define Xn_NEIGHBOUR_PARAMS_DESC \
+  {\
+        {GNB_CONFIG_STRING_TARGET_GNB_Xn_IP_ADDRESS, "target ip address", 0,.uptr=NULL, .defstrval=NULL, TYPE_STRING, 0}, \
+  }
+
+#define GNB_CONFIG_STRING_TARGET_GNB_Xn_IP_ADDRESS_IDX              0
+
+/*---------------------------------------------------------------------------------------------------------------------------------------*/
+
 /* E1 configuration section */
 #define GNB_CONFIG_STRING_E1_PARAMETERS                   "E1_INTERFACE"
 

openair2/XNAP/CMakeLists.txt

@@ -1,7 +1,9 @@
 add_subdirectory(MESSAGES)
-add_library(xnap xnap_common.c)
+add_library(xnap
+              xnap_common.c
+	      xnap_task.c
+              xnap_inst_procedures_management.c)
 target_link_libraries(xnap
                         PUBLIC asn1_xnap
                         PRIVATE nr_rrc)
 target_include_directories(xnap PUBLIC ${CMAKE_CURRENT_DIR})
-

openair2/XNAP/xnap_defs.h

@@ -0,0 +1,64 @@
+/* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#include <stdint.h>
+#include "queue.h"
+#include "tree.h"
+#include "sctp_eNB_defs.h"
+#include "xnap_messages_types.h"
+
+#ifndef XNAP_GNB_DEFS_H_
+#define XNAP_GNB_DEFS_H_
+
+/* This structure describes association of gNBs over Xn  */
+typedef struct xnap_gNB_data_t {
+  /* gNB descriptors tree, ordered by sctp assoc id */
+  RB_ENTRY(xnap_gNB_data_t) entry;
+  char *gNB_name;
+  long nci;
+  /*  target gNB ID */
+  uint64_t gNB_id;
+  /* Number of input/ouput streams */
+  uint16_t in_streams;
+  uint16_t out_streams;
+  /* SCTP association id */
+  sctp_assoc_t assoc_id;
+} xnap_gNB_data_t;
+
+typedef struct xnap_gNB_instance_s {
+  /* Number of target gNBs requested by gNB (tree size) */
+  uint32_t xn_target_gnb_nb;
+  /* Number of target gNBs for which association is pending */
+  uint32_t xn_target_gnb_pending_nb;
+  /* Number of target gNB successfully associated to gNB */
+  uint32_t xn_target_gnb_associated_nb;
+  /* Tree of XNAP gNB associations ordered by association ID */
+  RB_HEAD(xnap_gnb_tree, xnap_gNB_data_t) xnap_gnbs; // gNBs, indexed by assoc_id
+  size_t num_gnbs;
+  instance_t instance;
+  xnap_setup_req_t setup_req;
+  /* The gNB IP address to bind */
+  xnap_net_config_t net_config;
+  /* SCTP information */
+  xnap_sctp_t sctp_streams;
+  char *gNB_name;
+} xnap_gNB_instance_t;
+
+#endif /* XNAP_GNB_DEFS_H_ */

openair2/XNAP/xnap_inst_procedures_management.c

@@ -0,0 +1,55 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include "intertask_interface.h"
+#include "assertions.h"
+#include "conversions.h"
+#include "xnap_defs.h"
+
+static xnap_gNB_instance_t *xn_inst[NUMBER_OF_gNB_MAX] = {0};
+
+static int xnap_gNB_compare_assoc_id(const xnap_gNB_data_t *p1, const xnap_gNB_data_t *p2)
+{
+  if (p1->assoc_id > p2->assoc_id)
+    return 1;
+  if (p1->assoc_id == p2->assoc_id)
+    return 0;
+  return -1; /* p1->assoc_id < p1->assoc_id */
+}
+
+RB_GENERATE(xnap_gnb_tree, xnap_gNB_data_t, entry, xnap_gNB_compare_assoc_id);
+
+static pthread_mutex_t xn_inst_mtx = PTHREAD_MUTEX_INITIALIZER;
+void createXninst(instance_t instanceP, xnap_setup_req_t *req, xnap_net_config_t *nc)
+{
+  DevAssert(instanceP == 0);
+  pthread_mutex_lock(&xn_inst_mtx);
+  AssertFatal(xn_inst[0] == NULL, "Attempted to initialize multiple Xn instances\n");
+  xn_inst[0] = calloc(1, sizeof(xnap_gNB_instance_t));
+  AssertFatal(xn_inst[0] != NULL, "out of memory\n");
+  if (req)
+    xn_inst[0]->setup_req = *req;
+  if (nc)
+    xn_inst[0]->net_config = *nc;
+  pthread_mutex_unlock(&xn_inst_mtx);
+}

openair2/XNAP/xnap_inst_procedures_management.h

@@ -0,0 +1,27 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#ifndef __XNAP_GNB_MANAGEMENT_PROCEDURES__H__
+#define __XNAP_GNB_MANAGEMENT_PROCEDURES__H__
+
+void createXninst(instance_t instanceP, xnap_setup_req_t *req, xnap_net_config_t *nc);
+
+#endif /* __XNAP_GNB_MANAGEMENT_PROCEDURES__H__ */

openair2/XNAP/xnap_task.c

@@ -0,0 +1,79 @@
+/* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+/*! \file XNAP/xnap_gNB_task.c
+ * \brief XNAP tasks and functions definitions
+ * \author Sreeshma Shiv
+ * \date Aug 2023
+ * \version 1.0
+ * \email: sreeshmau@iisc.ac.in
+ */
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <arpa/inet.h>
+#include "intertask_interface.h"
+#include <openair3/ocp-gtpu/gtp_itf.h>
+#include "xnap_task.h"
+#include "gnb_paramdef.h"
+#include "common/config/config_userapi.h"
+
+void *xnap_task(void *arg)
+{
+  LOG_D(XNAP, "Starting XNAP layer\n");
+  itti_mark_task_ready(TASK_XNAP);
+
+  while (1) {
+    MessageDef *received_msg = NULL;
+    itti_receive_msg(TASK_XNAP, &received_msg);
+    LOG_D(XNAP, "Received message %d:%s\n", ITTI_MSG_ID(received_msg), ITTI_MSG_NAME(received_msg));
+    switch (ITTI_MSG_ID(received_msg)) {
+      case TERMINATE_MESSAGE:
+        LOG_W(XNAP, "Exiting XNAP thread\n");
+        itti_exit_task();
+        break;
+
+      default:
+        LOG_E(XNAP, "Received unhandled message: %d:%s\n", ITTI_MSG_ID(received_msg), ITTI_MSG_NAME(received_msg));
+        break;
+    }
+
+    int result = itti_free(ITTI_MSG_ORIGIN_ID(received_msg), received_msg);
+    AssertFatal(result == EXIT_SUCCESS, "Failed to free memory (%d)!\n", result);
+    received_msg = NULL;
+  }
+  return NULL;
+}
+
+
+int is_xnap_enabled(void)
+{
+  int xn_enabled; 
+  char xn_path[MAX_OPTNAME_SIZE*2 + 8];
+  sprintf(xn_path, "%s.[%i].%s", GNB_CONFIG_STRING_GNB_LIST, 0, GNB_CONFIG_STRING_XNAP);
+  paramdef_t Xn_Params[] = XnPARAMS_DESC;
+  config_get(config_get_if(), Xn_Params, sizeofArray(Xn_Params), xn_path);   
+  xn_enabled = *(Xn_Params[GNB_CONFIG_XNAP_ENABLE_IDX].iptr);
+  if (xn_enabled) {
+    LOG_I(XNAP, "XNAP enabled\n");
+  }
+  return xn_enabled;
+}

openair2/XNAP/xnap_task.h

@@ -0,0 +1,30 @@
+/* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+#ifndef XNAP_H_
+#define XNAP_H_
+
+void *xnap_task(void *arg);
+int is_xnap_enabled(void);
+
+#endif /* XNAP_H_ */

targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb-cu.sa.f1.xn.conf

@@ -0,0 +1,87 @@
+Active_gNBs = ( "gNB-CU-Xn");
+# Asn1_verbosity, choice in: none, info, annoying
+Asn1_verbosity = "none";
+Num_Threads_PUSCH = 8;
+
+gNBs =
+(
+ {
+    ////////// Identification parameters:
+    gNB_ID = 0xe00;
+
+#     cell_type =  "CELL_MACRO_GNB";
+
+    gNB_name  =  "gNB-CU-Xn";
+
+    // Tracking area code, 0x0000 and 0xfffe are reserved values
+    tracking_area_code  =  1;
+    plmn_list = ({ mcc = 001; mnc = 11; mnc_length = 2; snssaiList = ({ sst = 1, sd = 0xffffff }) });
+
+
+    nr_cellid = 12345670L;
+
+    tr_s_preference = "f1";
+
+    local_s_address = "127.0.0.4";
+    remote_s_address = "127.0.0.3";
+    local_s_portc   = 501;
+    local_s_portd   = 2153;
+    remote_s_portc  = 500;
+    remote_s_portd  = 2153;
+
+    # ------- SCTP definitions
+    SCTP :
+    {
+        # Number of streams to use in input/output
+        SCTP_INSTREAMS  = 2;
+        SCTP_OUTSTREAMS = 2;
+    };
+
+
+    ////////// AMF parameters:
+    amf_ip_address = ({ ipv4 = "192.168.70.132"; });
+
+    ////////// XnAP parameters:
+    XNAP :
+    {
+         ENABLE_XN = 1;
+         GNB_PORT_FOR_XNC            = 38422;
+         GNB_IP_ADDRESS_FOR_XNC      = "10.33.42.21";
+         Target_gNB_XN_address       = ({ ip = "10.33.42.22";});
+    };    
+    
+
+    NETWORK_INTERFACES :
+    {
+
+        GNB_IPV4_ADDRESS_FOR_NG_AMF              = "10.33.42.21";
+        GNB_IPV4_ADDRESS_FOR_NGU                 = "10.33.42.21";
+        GNB_PORT_FOR_S1U                         = 2152; # Spec 2152
+    };
+  }
+);
+
+security = {
+  # preferred ciphering algorithms
+  # the first one of the list that an UE supports in chosen
+  # valid values: nea0, nea1, nea2, nea3
+  ciphering_algorithms = ( "nea0" );
+
+  # preferred integrity algorithms
+  # the first one of the list that an UE supports in chosen
+  # valid values: nia0, nia1, nia2, nia3
+  integrity_algorithms = ( "nia2", "nia0" );
+
+  # setting 'drb_ciphering' to "no" disables ciphering for DRBs, no matter
+  # what 'ciphering_algorithms' configures; same thing for 'drb_integrity'
+  drb_ciphering = "yes";
+  drb_integrity = "no";
+};
+log_config :
+{
+  global_log_level = "info";
+  pdcp_log_level = "info";
+  rrc_log_level = "info";
+  f1ap_log_level = "info";
+  ngap_log_level = "info";
+};