Added the ability to save S1AP pcaps at the eNB.

srsenb/enb.conf.example

@@ -76,9 +76,9 @@ rx_gain = 40
 
 
 #####################################################################
-# MAC-layer packet capture configuration
+# Packet capture configuration
 #
-# Packets are captured to file in the compact format decoded by 
+# MAC Packets are captured to file in the compact format decoded by 
 # the Wireshark mac-lte-framed dissector and with DLT 147. 
 # To use the dissector, edit the preferences for DLT_USER to 
 # add an entry with DLT=147, Payload Protocol=mac-lte-framed.
@@ -89,12 +89,22 @@ rx_gain = 40
 # WRITE_SIB_PCAP enabled in srsenb/src/stack/mac/mac.cc if you want
 # SIB to be part of the MAC pcap file.
 #
-# enable:   Enable MAC layer packet captures (true/false)
+# S1AP Packets are captured to file in the compact format decoded by 
-# filename: File path to use for packet captures
+# the Wireshark s1ap dissector and with DLT 150. 
+# To use the dissector, edit the preferences for DLT_USER to 
+# add an entry with DLT=150, Payload Protocol=s1ap.
+#
+# mac_enable:   Enable MAC layer packet captures (true/false)
+# mac_filename: File path to use for packet captures
+# s1ap_enable:   Enable or disable the PCAP.
+# s1ap_filename: File name where to save the PCAP.
+#
 #####################################################################
 [pcap]
-enable = false
+mac_enable = false
-filename = /tmp/enb.pcap
+mac_filename = /tmp/enb_mac.pcap
+s1ap_enable = false
+s1ap_filename = /tmp/enb_s1ap.pcap
 
 #####################################################################
 # Log configuration
@@ -268,4 +278,4 @@ nof_ctrl_symbols = 3
 #rrc_inactivity_timer = 60000
 #max_prach_offset_us  = 30
 #eea_pref_list = EEA0, EEA2, EEA1
-#eia_pref_list = EIA2, EIA1, EIA0
+#eia_pref_list = EIA2, EIA1, EIA0

srsenb/hdr/stack/enb_stack_base.h

@@ -56,7 +56,8 @@ typedef struct {
 typedef struct {
   mac_args_t       mac;
   s1ap_args_t      s1ap;
-  pcap_args_t      pcap;
+  pcap_args_t      mac_pcap;
+  pcap_args_t      s1ap_pcap;
   stack_log_args_t log;
   embms_args_t     embms;
 } stack_args_t;

srsenb/hdr/stack/enb_stack_lte.h

@@ -136,13 +136,14 @@ private:
   srslte::timer_handler                           timers;
   std::unique_ptr<srslte::rx_multisocket_handler> rx_sockets;
 
-  srsenb::mac      mac;
+  srsenb::mac       mac;
-  srslte::mac_pcap mac_pcap;
+  srslte::mac_pcap  mac_pcap;
-  srsenb::rlc      rlc;
+  srsenb::rlc       rlc;
-  srsenb::pdcp     pdcp;
+  srsenb::pdcp      pdcp;
-  srsenb::rrc      rrc;
+  srsenb::rrc       rrc;
-  srsenb::gtpu     gtpu;
+  srsenb::gtpu      gtpu;
-  srsenb::s1ap     s1ap;
+  srsenb::s1ap      s1ap;
+  srslte::s1ap_pcap s1ap_pcap;
 
   srslte::logger*           logger = nullptr;
   srslte::byte_buffer_pool* pool   = nullptr;

srsenb/hdr/stack/upper/s1ap.h

@@ -28,6 +28,7 @@
 #include "srslte/common/buffer_pool.h"
 #include "srslte/common/common.h"
 #include "srslte/common/logmap.h"
+#include "srslte/common/s1ap_pcap.h"
 #include "srslte/common/threads.h"
 #include "srslte/interfaces/enb_interfaces.h"
 
@@ -85,7 +86,8 @@ public:
 
   // Stack interface
   bool
-  handle_mme_rx_msg(srslte::unique_byte_buffer_t pdu, const sockaddr_in& from, const sctp_sndrcvinfo& sri, int flags);
+       handle_mme_rx_msg(srslte::unique_byte_buffer_t pdu, const sockaddr_in& from, const sctp_sndrcvinfo& sri, int flags);
+  void start_pcap(srslte::s1ap_pcap* pcap_);
 
 private:
   static const int MME_PORT        = 36412;
@@ -114,6 +116,9 @@ private:
   asn1::s1ap::tai_s        tai;
   asn1::s1ap::eutran_cgi_s eutran_cgi;
 
+  // PCAP
+  srslte::s1ap_pcap *pcap;
+
   asn1::s1ap::s1_setup_resp_s s1setupresponse;
 
   void build_tai_cgi();

srsenb/src/main.cc

@@ -90,11 +90,9 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("rf.device_args",       bpo::value<string>(&args->rf.device_args)->default_value("auto"),       "Front-end device arguments")
     ("rf.time_adv_nsamples", bpo::value<string>(&args->rf.time_adv_nsamples)->default_value("auto"), "Transmission time advance")
 
-    ("pcap.enable",       bpo::value<bool>(&args->stack.pcap.enable)->default_value(false),         "Enable MAC packet captures for wireshark")
-    ("pcap.filename",     bpo::value<string>(&args->stack.pcap.filename)->default_value("ue.pcap"), "MAC layer capture filename")
-
     ("gui.enable",        bpo::value<bool>(&args->gui.enable)->default_value(false),          "Enable GUI plots")
 
+    /* Log section */
     ("log.rf_level",     bpo::value<string>(&args->rf.log_level),         "RF log level")
     ("log.phy_level",     bpo::value<string>(&args->phy.log.phy_level),   "PHY log level")
     ("log.phy_hex_limit", bpo::value<int>(&args->phy.log.phy_hex_limit),  "PHY log hex dump limit")
@@ -118,6 +116,12 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("log.filename",      bpo::value<string>(&args->log.filename)->default_value("/tmp/ue.log"),"Log filename")
     ("log.file_max_size", bpo::value<int>(&args->log.file_max_size)->default_value(-1), "Maximum file size (in kilobytes). When passed, multiple files are created. Default -1 (single file)")
 
+    /* PCAP */
+    ("pcap.mac_enable",    bpo::value<bool>(&args->stack.mac_pcap.enable)->default_value(false),         "Enable MAC packet captures for wireshark")
+    ("pcap.mac_filename",  bpo::value<string>(&args->stack.mac_pcap.filename)->default_value("enb_mac.pcap"), "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("enb_s1ap.pcap"), "S1AP layer capture filename")
+   
     /* MCS section */
     ("scheduler.pdsch_mcs", bpo::value<int>(&args->stack.mac.sched.pdsch_mcs)->default_value(-1), "Optional fixed PDSCH MCS (ignores reported CQIs if specified)")
     ("scheduler.pdsch_max_mcs", bpo::value<int>(&args->stack.mac.sched.pdsch_max_mcs)->default_value(-1), "Optional PDSCH MCS limit")

srsenb/src/stack/enb_stack_lte.cc

@@ -97,10 +97,14 @@ int enb_stack_lte::init(const stack_args_t& args_, const rrc_cfg_t& rrc_cfg_)
   stack_log.set_hex_limit(128);
 
   // Set up pcap and trace
-  if (args.pcap.enable) {
+  if (args.mac_pcap.enable) {
-    mac_pcap.open(args.pcap.filename.c_str());
+    mac_pcap.open(args.mac_pcap.filename.c_str());
     mac.start_pcap(&mac_pcap);
   }
+  if (args.s1ap_pcap.enable) {
+    s1ap_pcap.open(args.s1ap_pcap.filename.c_str());
+    s1ap.start_pcap(&s1ap_pcap);
+  }
 
   // Init Rx socket handler
   rx_sockets.reset(new srslte::rx_multisocket_handler("ENBSOCKETS", &stack_log));
@@ -156,9 +160,12 @@ void enb_stack_lte::stop_impl()
   pdcp.stop();
   rrc.stop();
 
-  if (args.pcap.enable) {
+  if (args.mac_pcap.enable) {
     mac_pcap.close();
   }
+  if (args.s1ap_pcap.enable) {
+    s1ap_pcap.close();
+  }
 
   // erasing the queues is the last thing, bc we need them to call stop_impl()
   pending_tasks.erase_queue(sync_queue_id);

srsenb/src/stack/upper/s1ap.cc

@@ -505,6 +505,11 @@ bool s1ap::handle_mme_rx_msg(srslte::unique_byte_buffer_t pdu,
 
 bool s1ap::handle_s1ap_rx_pdu(srslte::byte_buffer_t* pdu)
 {
+  // Save message to PCAP
+  if (pcap != nullptr) {
+    pcap->write_s1ap(pdu->msg, pdu->N_bytes);
+  }
+
   s1ap_pdu_c     rx_pdu;
   asn1::cbit_ref bref(pdu->msg, pdu->N_bytes);
 
@@ -1137,9 +1142,14 @@ bool s1ap::sctp_send_s1ap_pdu(const asn1::s1ap::s1ap_pdu_c& tx_pdu, uint32_t rnt
     return false;
   }
   asn1::bit_ref bref(buf->msg, buf->get_tailroom());
-
   tx_pdu.pack(bref);
   buf->N_bytes = bref.distance_bytes();
+
+  // Save message to PCAP
+  if (pcap != nullptr) {
+    pcap->write_s1ap(buf->msg, buf->N_bytes);
+  }
+
   if (rnti > 0) {
     s1ap_log->info_hex(buf->msg, buf->N_bytes, "Sending %s for rnti=0x%x", procedure_name, rnti);
   } else {
@@ -1216,6 +1226,10 @@ std::string s1ap::get_cause(const cause_c& c)
   return cause;
 }
 
+void s1ap::start_pcap(srslte::s1ap_pcap* pcap_)
+{
+  pcap = pcap_;
+}
 /*******************************************************************************
 /*               s1ap::ue Class
 ********************************************************************************/