Added option to save NGAP pcaps.

lib/include/srsran/common/ngap_pcap.h

@@ -0,0 +1,43 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSRAN_NGAP_PCAP_H
+#define SRSRAN_NGAP_PCAP_H
+
+#include "srsran/common/pcap.h"
+#include <string>
+
+namespace srsran {
+
+class ngap_pcap
+{
+public:
+  ngap_pcap();
+  ngap_pcap(const ngap_pcap& other) = delete;
+  ngap_pcap& operator=(const ngap_pcap& other) = delete;
+  ngap_pcap(ngap_pcap&& other)                 = delete;
+  ngap_pcap& operator=(ngap_pcap&& other) = delete;
+
+  void enable();
+  void open(const char* filename_);
+  void close();
+  void write_ngap(uint8_t* pdu, uint32_t pdu_len_bytes);
+
+private:
+  bool        enable_write = false;
+  std::string filename;
+  FILE*       pcap_file = nullptr;
+};
+
+} // namespace srsran
+
+#endif // SRSRAN_NAS_PCAP_H

lib/include/srsran/common/pcap.h

@@ -24,6 +24,7 @@
 #define UDP_DLT 149 // UDP needs to be selected as protocol
 #define S1AP_LTE_DLT 150
 #define NAS_5G_DLT 151
+#define NGAP_5G_DLT 152
 
 /* This structure gets written to the start of the file */
 typedef struct pcap_hdr_s {
@@ -180,6 +181,12 @@ typedef struct S1AP_Context_Info_s {
   unsigned char dummy;
 } S1AP_Context_Info_t;
 
+/* Context information for every S1AP PDU that will be logged */
+typedef struct NGAP_Context_Info_s {
+  // No Context yet
+  unsigned char dummy;
+} NGAP_Context_Info_t;
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -204,6 +211,9 @@ int LTE_PCAP_RLC_WritePDU(FILE* fd, RLC_Context_Info_t* context, const unsigned
 /* Write an individual S1AP PDU (PCAP packet header + s1ap-context + s1ap-pdu) */
 int LTE_PCAP_S1AP_WritePDU(FILE* fd, S1AP_Context_Info_t* context, const unsigned char* PDU, unsigned int length);
 
+/* Write an individual S1AP PDU (PCAP packet header + s1ap-context + s1ap-pdu) */
+int LTE_PCAP_NGAP_WritePDU(FILE* fd, NGAP_Context_Info_t* context, const unsigned char* PDU, unsigned int length);
+
 /* Write an individual NR MAC PDU (PCAP packet header + UDP header + nr-mac-context + mac-pdu) */
 int NR_PCAP_MAC_UDP_WritePDU(FILE* fd, mac_nr_context_info_t* context, const unsigned char* PDU, unsigned int length);
 int NR_PCAP_PACK_MAC_CONTEXT_TO_BUFFER(mac_nr_context_info_t* context, uint8_t* buffer, unsigned int length);

lib/src/common/CMakeLists.txt

@@ -27,6 +27,7 @@ set(SOURCES arch_select.cc
             rrc_common.cc
             rlc_pcap.cc
             s1ap_pcap.cc
+            ngap_pcap.cc
             security.cc
             standard_streams.cc
             thread_pool.cc

lib/src/common/ngap_pcap.cc

@@ -0,0 +1,61 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsran/common/ngap_pcap.h"
+#include "srsran/common/pcap.h"
+#include "srsran/srsran.h"
+#include "srsran/support/emergency_handlers.h"
+#include <stdint.h>
+
+namespace srsran {
+
+/// Try to flush the contents of the pcap class before the application is killed.
+static void emergency_cleanup_handler(void* data)
+{
+  reinterpret_cast<ngap_pcap*>(data)->close();
+}
+
+ngap_pcap::ngap_pcap()
+{
+  add_emergency_cleanup_handler(emergency_cleanup_handler, this);
+}
+
+void ngap_pcap::enable()
+{
+  enable_write = true;
+}
+void ngap_pcap::open(const char* filename_)
+{
+  filename     = filename_;
+  pcap_file    = DLT_PCAP_Open(NGAP_5G_DLT, filename.c_str());
+  enable_write = true;
+}
+void ngap_pcap::close()
+{
+  if (!enable_write) {
+    return;
+  }
+  fprintf(stdout, "Saving NGAP PCAP file (DLT=%d) to %s\n", NGAP_5G_DLT, filename.c_str());
+  DLT_PCAP_Close(pcap_file);
+}
+
+void ngap_pcap::write_ngap(uint8_t* pdu, uint32_t pdu_len_bytes)
+{
+  if (enable_write) {
+    NGAP_Context_Info_t context;
+    if (pdu) {
+      LTE_PCAP_NGAP_WritePDU(pcap_file, &context, pdu, pdu_len_bytes);
+    }
+  }
+}
+
+} // namespace srsran

lib/src/common/pcap.c

@@ -336,6 +336,34 @@ int LTE_PCAP_S1AP_WritePDU(FILE* fd, S1AP_Context_Info_t* context, const unsigne
   return 1;
 }
 
+/* Write an individual PDU (PCAP packet header + s1ap-context + s1ap-pdu) */
+int LTE_PCAP_NGAP_WritePDU(FILE* fd, NGAP_Context_Info_t* context, const unsigned char* PDU, unsigned int length)
+{
+  pcaprec_hdr_t packet_header;
+
+  /* Can't write if file wasn't successfully opened */
+  if (fd == NULL) {
+    printf("Error: Can't write to empty file handle\n");
+    return 0;
+  }
+
+  /****************************************************************/
+  /* PCAP Header                                                  */
+  struct timeval t;
+  gettimeofday(&t, NULL);
+  packet_header.ts_sec   = t.tv_sec;
+  packet_header.ts_usec  = t.tv_usec;
+  packet_header.incl_len = length;
+  packet_header.orig_len = length;
+
+  /***************************************************************/
+  /* Now write everything to the file                            */
+  fwrite(&packet_header, sizeof(pcaprec_hdr_t), 1, fd);
+  fwrite(PDU, 1, length, fd);
+
+  return 1;
+}
+
 /**************************************************************************
  * API functions for writing MAC-NR PCAP files                           *
  **************************************************************************/

srsenb/src/main.cc

@@ -137,6 +137,8 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("pcap.nr_filename",  bpo::value<string>(&args->nr_stack.mac.pcap.filename)->default_value("/tmp/enb_mac_nr.pcap"), "NR MAC layer capture filename")
     ("pcap.s1ap_enable",   bpo::value<bool>(&args->stack.s1ap_pcap.enable)->default_value(false),         "Enable S1AP packet captures for wireshark")
     ("pcap.s1ap_filename", bpo::value<string>(&args->stack.s1ap_pcap.filename)->default_value("/tmp/enb_s1ap.pcap"), "S1AP layer capture filename")
+    ("pcap.ngap_enable",   bpo::value<bool>(&args->nr_stack.ngap_pcap.enable)->default_value(false),         "Enable NGAP packet captures for wireshark")
+    ("pcap.ngap_filename", bpo::value<string>(&args->nr_stack.ngap_pcap.filename)->default_value("/tmp/enb_ngap.pcap"), "NGAP layer capture filename")
     ("pcap.mac_net_enable", bpo::value<bool>(&args->stack.mac_pcap_net.enable)->default_value(false),         "Enable MAC network captures")
     ("pcap.bind_ip", bpo::value<string>(&args->stack.mac_pcap_net.bind_ip)->default_value("0.0.0.0"),         "Bind IP address for MAC network trace")
     ("pcap.bind_port", bpo::value<uint16_t>(&args->stack.mac_pcap_net.bind_port)->default_value(5687),        "Bind port for MAC network trace")
@@ -260,6 +262,14 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("scheduler.nr_pusch_mcs", bpo::value<int>(&args->nr_stack.mac.sched_cfg.fixed_ul_mcs)->default_value(28), "Fixed NR UL MCS (-1 for dynamic).")
     ("expert.nr_pusch_max_its", bpo::value<uint32_t>(&args->phy.nr_pusch_max_its)->default_value(10),     "Maximum number of LDPC iterations for NR.")
 
+    //NGAP section
+    ("gnb.enb_id",             bpo::value<uint32_t>(&args->nr_stack.ngap.gnb_id)->default_value(0),                       "gNodeB ID")
+    ("gnb.name",               bpo::value<string>(&args->nr_stack.ngap.gnb_name)->default_value("srsgnb01"), "gNodeB Name")
+    ("gnb.amf_addr",           bpo::value<string>(&args->nr_stack.ngap.amf_addr)->default_value("127.0.0.1"),"IP address of MME for S1 connection")
+    ("gnb.gtp_bind_addr",      bpo::value<string>(&args->nr_stack.ngap.gtp_bind_addr)->default_value("192.168.3.1"), "Local IP address to bind for GTP connection")
+    ("gnb.gtp_advertise_addr", bpo::value<string>(&args->nr_stack.ngap.gtp_advertise_addr)->default_value(""), "IP address of eNB to advertise for DL GTP-U Traffic")
+    ("gnb.ngc_bind_addr",      bpo::value<string>(&args->nr_stack.ngap.ngc_bind_addr)->default_value("192.168.3.1"), "Local IP address to bind for S1AP connection")
+
     // VNF params
     ("vnf.type", bpo::value<string>(&args->phy.vnf_args.type)->default_value("gnb"), "VNF instance type [gnb,ue].")
     ("vnf.addr", bpo::value<string>(&args->phy.vnf_args.bind_addr)->default_value("localhost"), "Address to bind VNF interface.")
@@ -336,6 +346,12 @@ void parse_args(all_args_t* args, int argc, char* argv[])
   if (!srsran::string_to_mnc(mnc, &args->stack.s1ap.mnc)) {
     cout << "Error parsing enb.mnc:" << mnc << " - must be a 2 or 3-digit string." << endl;
   }
+  if (!srsran::string_to_mcc(mcc, &args->nr_stack.ngap.mcc)) {
+    cout << "Error parsing enb.mcc:" << mcc << " - must be a 3-digit string." << endl;
+  }
+  if (!srsran::string_to_mnc(mnc, &args->nr_stack.ngap.mnc)) {
+    cout << "Error parsing enb.mnc:" << mnc << " - must be a 2 or 3-digit string." << endl;
+  }
 
   if (args->stack.embms.enable) {
     if (args->stack.mac.sched.max_nof_ctrl_symbols == 3) {

srsgnb/hdr/stack/gnb_stack_nr.h

@@ -27,6 +27,8 @@
 #include "srsenb/hdr/stack/enb_stack_base.h"
 #include "srsran/interfaces/gnb_interfaces.h"
 
+#include "srsran/common/ngap_pcap.h"
+
 namespace srsenb {
 
 class ngap;
@@ -36,6 +38,7 @@ struct gnb_stack_args_t {
   stack_log_args_t log;
   mac_nr_args_t    mac;
   ngap_args_t      ngap;
+  pcap_args_t      ngap_pcap;
 };
 
 class gnb_stack_nr final : public srsenb::enb_stack_base,
@@ -129,6 +132,8 @@ private:
   srslog::basic_logger& gtpu_logger;
   srslog::basic_logger& stack_logger;
 
+  srsran::ngap_pcap ngap_pcap;
+
   // task scheduling
   static const int                      STACK_MAIN_THREAD_PRIO = 4;
   srsran::task_scheduler                task_sched;

srsgnb/hdr/stack/ngap/ngap.h

@@ -22,6 +22,7 @@
 #include "srsran/common/buffer_pool.h"
 #include "srsran/common/common.h"
 #include "srsran/common/network_utils.h"
+#include "srsran/common/ngap_pcap.h"
 #include "srsran/common/stack_procedure.h"
 #include "srsran/common/standard_streams.h"
 #include "srsran/common/task_scheduler.h"
@@ -70,10 +71,13 @@ public:
 
   // Stack interface
   bool
-       handle_amf_rx_msg(srsran::unique_byte_buffer_t pdu, const sockaddr_in& from, const sctp_sndrcvinfo& sri, int flags);
+  handle_amf_rx_msg(srsran::unique_byte_buffer_t pdu, const sockaddr_in& from, const sctp_sndrcvinfo& sri, int flags);
   void get_metrics(ngap_metrics_t& m);
   void get_args(ngap_args_t& args_);
 
+  // PCAP
+  void start_pcap(srsran::ngap_pcap* pcap_);
+
 private:
   static const int AMF_PORT        = 38412;
   static const int ADDR_FAMILY     = AF_INET;
@@ -128,6 +132,9 @@ private:
   // TS 38.413 - Section 9.2.1.1 - PDU Session Resource Setup Request
   bool handle_ue_pdu_session_res_setup_request(const asn1::ngap_nr::pdu_session_res_setup_request_s& msg);
 
+  // PCAP
+  srsran::ngap_pcap* pcap = nullptr;
+
   class user_list
   {
   public:

srsgnb/src/stack/gnb_stack_nr.cc

@@ -104,6 +104,11 @@ int gnb_stack_nr::init(const gnb_stack_args_t& args_,
     gtpu_args.mme_addr      = args.ngap.amf_addr;
     gtpu_args.gtp_bind_addr = args.ngap.gtp_bind_addr;
     gtpu->init(gtpu_args, &pdcp);
+
+    if (args.ngap_pcap.enable) {
+      ngap_pcap.open(args.ngap_pcap.filename.c_str());
+      ngap->start_pcap(&ngap_pcap);
+    }
   }
 
   // TODO: add SDAP

srsgnb/src/stack/ngap/ngap.cc

@@ -371,11 +371,10 @@ bool ngap::handle_amf_rx_msg(srsran::unique_byte_buffer_t pdu,
 
 bool ngap::handle_ngap_rx_pdu(srsran::byte_buffer_t* pdu)
 {
-  // TODO:
   // Save message to PCAP
-  // if (pcap != nullptr) {
-  //   pcap->write_ngap(pdu->msg, pdu->N_bytes);
-  // }
+  if (pcap != nullptr) {
+    pcap->write_ngap(pdu->msg, pdu->N_bytes);
+  }
 
   ngap_pdu_c     rx_pdu;
   asn1::cbit_ref bref(pdu->msg, pdu->N_bytes);
@@ -696,6 +695,11 @@ bool ngap::sctp_send_ngap_pdu(const asn1::ngap_nr::ngap_pdu_c& tx_pdu, uint32_t
   }
   buf->N_bytes = bref.distance_bytes();
 
+  // Save message to PCAP
+  if (pcap != nullptr) {
+    pcap->write_ngap(buf->msg, buf->N_bytes);
+  }
+
   if (rnti != SRSRAN_INVALID_RNTI) {
     logger.info(buf->msg, buf->N_bytes, "Tx NGAP SDU, %s, rnti=0x%x", procedure_name, rnti);
   } else {
@@ -794,4 +798,11 @@ std::string ngap::get_cause(const cause_c& c)
   return cause;
 }
 
+/*
+ * PCAP
+ */
+void ngap::start_pcap(srsran::ngap_pcap* pcap_)
+{
+  pcap = pcap_;
+}
 } // namespace srsenb