Introduce NGAP emulator that connects to the AMF to perform NGAP enc/dec

- Performs NGAP setup request and handles NGAP setup response
 - This is introduced to test NGAP enc/dec of the NRPPa messages

To compile:

openairinterface5g$ mkdir build
openairinterface5g$ cd build
openairinterface5g/build$ cmake .. -GNinja
openairinterface5g/build$ ninja nr-cu-nrppa-test

To run:
openairinterface5g/build$ LD_LIBRARY_PATH=. ./tests/nr-cu-nrppa/nr-cu-nrppa-test -O ../tests/nr-cu-nrppa/nr-nrppa-test.conf

tests/CMakeLists.txt

@@ -1 +1,2 @@
 add_subdirectory(nr-cuup)
+add_subdirectory(nr-cu-nrppa)

tests/nr-cu-nrppa/CMakeLists.txt

@@ -0,0 +1,10 @@
+add_executable(nr-cu-nrppa-test nr-cu-nrppa.c
+               ${OPENAIR2_DIR}/GNB_APP/gnb_config_common.c
+               ${OPENAIR2_DIR}/GNB_APP/gnb_config_ng.c)
+  
+target_link_libraries(nr-cu-nrppa-test PRIVATE
+                      CONFIG_LIB ITTI SCTP_CLIENT
+                      f1ap ngap SECURITY
+                      UTIL softmodem_common)
+target_link_libraries(nr-cu-nrppa-test PRIVATE asn1_lte_rrc_hdrs asn1_nr_rrc_hdrs)
+add_dependencies(nr-cu-nrppa-test params_libconfig)

tests/nr-cu-nrppa/nr-cu-nrppa.c

@@ -0,0 +1,99 @@
+/*
+ * 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 "executables/softmodem-common.h"
+#include "common/utils/ocp_itti/intertask_interface.h"
+#include "common/ran_context.h"
+#include "nfapi/oai_integration/vendor_ext.h"
+#include "openair2/GNB_APP/gnb_config_common.h"
+#include "openair2/GNB_APP/gnb_config_ng.h"
+#include "openair2/GNB_APP/gnb_paramdef.h"
+#include "openair3/SCTP/sctp_default_values.h"
+
+RAN_CONTEXT_t RC;
+THREAD_STRUCT thread_struct;
+uint64_t downlink_frequency[MAX_NUM_CCs][4];
+int32_t uplink_frequency_offset[MAX_NUM_CCs][4];
+int oai_exit = 0;
+int gnb_id;
+
+void exit_function(const char *file, const char *function, const int line, const char *s, const int assert)
+{
+  if (assert) {
+    abort();
+  } else {
+    sleep(1); // allow other threads to exit first
+    exit(EXIT_SUCCESS);
+  }
+}
+
+nfapi_mode_t nfapi_mod = -1;
+void nfapi_setmode(nfapi_mode_t nfapi_mode)
+{
+  nfapi_mod = nfapi_mode;
+}
+nfapi_mode_t nfapi_getmode(void)
+{
+  return nfapi_mod;
+}
+
+ngran_node_t get_node_type()
+{
+  return ngran_gNB_CUUP;
+}
+
+configmodule_interface_t *uniqCfg = NULL;
+
+int main(int argc, char **argv)
+{
+  // load the config file
+  if ((uniqCfg = load_configmodule(argc, argv, CONFIG_ENABLECMDLINEONLY)) == NULL) {
+    exit_fun("[SOFTMODEM] Error, configuration module init failed\n");
+  }
+  logInit();
+
+  set_softmodem_sighandler();
+
+  // Initialize ITTI tasks
+  itti_init(TASK_MAX, tasks_info);
+
+  int rc;
+  rc = itti_create_task(TASK_SCTP, sctp_eNB_task, NULL);
+  AssertFatal(rc >= 0, "Create task for SCTP failed\n");
+
+  rc = itti_create_task(TASK_NGAP, ngap_gNB_task, NULL);
+  AssertFatal(rc >= 0, "Create task for NGAP failed\n");
+
+  MessageDef *msg_p;
+  msg_p = itti_alloc_new_message(TASK_GNB_APP, 0, NGAP_REGISTER_GNB_REQ);
+  RCconfig_NR_NG(msg_p, 0);
+  gnb_id = NGAP_REGISTER_GNB_REQ(msg_p).gNB_id;
+
+  LOG_I(GNB_APP, "Sending NGAP_REGISTER_GNB_REQ to TASK_NGAP\n");
+  itti_send_msg_to_task(TASK_NGAP, 0, msg_p);
+
+  printf("TYPE <CTRL-C> TO TERMINATE\n");
+  itti_wait_tasks_end(NULL);
+
+  logClean();
+  printf("Bye.\n");
+  return 0;
+}

tests/nr-cu-nrppa/nr-nrppa-test.conf

@@ -0,0 +1,52 @@
+Active_gNBs = ( "gNB-OAI");
+# Asn1_verbosity, choice in: none, info, annoying
+Asn1_verbosity = "none";
+
+gNBs =
+(
+ {
+    ////////// Identification parameters:
+    gNB_ID    =  0xe00;
+    gNB_name  =  "gNB-OAI";
+
+    // Tracking area code, 0x0000 and 0xfffe are reserved values
+    tracking_area_code  =  1;
+    plmn_list = ({ mcc = 001; mnc = 01; mnc_length = 2; snssaiList = ({ sst = 1; }) });
+
+    nr_cellid = 12345678L;
+
+    # ------- 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"; });
+
+
+    NETWORK_INTERFACES :
+    {
+        GNB_IPV4_ADDRESS_FOR_NG_AMF              = "192.168.70.129/24";
+        GNB_IPV4_ADDRESS_FOR_NGU                 = "192.168.70.129/24";
+        GNB_PORT_FOR_S1U                         = 2152; # Spec 2152
+    };
+
+  }
+);
+
+log_config :
+{
+  global_log_level                      ="info";
+  hw_log_level                          ="info";
+  phy_log_level                         ="info";
+  mac_log_level                         ="info";
+  rlc_log_level                         ="info";
+  pdcp_log_level                        ="info";
+  rrc_log_level                         ="info";
+  ngap_log_level                        ="debug";
+  f1ap_log_level                        ="debug";
+};