From 3073ab6822587166fc1dcaa04f3d61e3e89c37cc Mon Sep 17 00:00:00 2001
From: Pedro Alvarez <pedro.alvarez@softwareradiosystems.com>
Date: Tue, 21 Aug 2018 14:11:28 +0100
Subject: [PATCH] Changed dettach request to use downlink nas transport.

---
 srsepc/hdr/mme/nas.h                 |  2 +-
 srsepc/src/mme/nas.cc                | 43 ++++++++++++++--------------
 srsepc/src/mme/s1ap_nas_transport.cc |  4 +--
 3 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/srsepc/hdr/mme/nas.h b/srsepc/hdr/mme/nas.h
index ff118a859..7fc4dfb73 100644
--- a/srsepc/hdr/mme/nas.h
+++ b/srsepc/hdr/mme/nas.h
@@ -192,7 +192,7 @@ public:
   bool handle_identity_response(            srslte::byte_buffer_t *nas_msg, srslte::byte_buffer_t *reply_buffer, bool *reply_flag);
   bool handle_tracking_area_update_request( srslte::byte_buffer_t *nas_msg, srslte::byte_buffer_t *reply_buffer, bool *reply_flag);
   bool handle_authentication_failure(       srslte::byte_buffer_t *nas_msg, srslte::byte_buffer_t *reply_buffer, bool *reply_flag);
-  bool handle_nas_detach_request(           srslte::byte_buffer_t *nas_msg, srslte::byte_buffer_t *reply_buffer, bool *reply_flag);
+  bool handle_nas_detach_request(           srslte::byte_buffer_t *nas_msg);
 
   /* Downlink NAS messages packing */
   bool pack_authentication_request  (srslte::byte_buffer_t *reply_msg);
diff --git a/srsepc/src/mme/nas.cc b/srsepc/src/mme/nas.cc
index 032912f95..f6efa819e 100644
--- a/srsepc/src/mme/nas.cc
+++ b/srsepc/src/mme/nas.cc
@@ -482,27 +482,6 @@ nas::handle_guti_attach_request_unknown_ue( uint32_t enb_ue_s1ap_id,
  * Handle Uplink NAS Transport message
  *
  */
-bool
-nas::handle_nas_detach_request(srslte::byte_buffer_t *nas_msg, srslte::byte_buffer_t *reply_msg, bool *reply_flag)
-{
-
-  m_nas_log->console("Detach request -- IMSI %015lu\n", m_emm_ctx.imsi);
-  m_nas_log->info("Detach request -- IMSI %015lu\n", m_emm_ctx.imsi);
-  LIBLTE_MME_DETACH_REQUEST_MSG_STRUCT detach_req;
-
-  LIBLTE_ERROR_ENUM err = liblte_mme_unpack_detach_request_msg((LIBLTE_BYTE_MSG_STRUCT*) nas_msg, &detach_req);
-  if(err !=LIBLTE_SUCCESS) {
-      m_nas_log->error("Could not unpack detach request\n");
-      return false;
-  }
-
-  m_gtpc->send_delete_session_request(m_emm_ctx.imsi);
-  m_emm_ctx.state = EMM_STATE_DEREGISTERED;
-  if (m_ecm_ctx.mme_ue_s1ap_id!=0) {
-      m_s1ap->send_ue_context_release_command(m_ecm_ctx.mme_ue_s1ap_id);
-  }
-  return true;
-}
 
 bool
 nas::handle_nas_authentication_response(srslte::byte_buffer_t *nas_msg, srslte::byte_buffer_t *reply_buffer, bool* reply_flag)
@@ -830,6 +809,28 @@ nas::handle_authentication_failure(srslte::byte_buffer_t *nas_msg, srslte::byte_
   return true;
 }
 
+bool
+nas::handle_nas_detach_request(srslte::byte_buffer_t *nas_msg)
+{
+
+  m_nas_log->console("Detach request -- IMSI %015lu\n", m_emm_ctx.imsi);
+  m_nas_log->info("Detach request -- IMSI %015lu\n", m_emm_ctx.imsi);
+  LIBLTE_MME_DETACH_REQUEST_MSG_STRUCT detach_req;
+
+  LIBLTE_ERROR_ENUM err = liblte_mme_unpack_detach_request_msg((LIBLTE_BYTE_MSG_STRUCT*) nas_msg, &detach_req);
+  if(err !=LIBLTE_SUCCESS) {
+    m_nas_log->error("Could not unpack detach request\n");
+    return false;
+  }
+
+  m_gtpc->send_delete_session_request(m_emm_ctx.imsi);
+  m_emm_ctx.state = EMM_STATE_DEREGISTERED;
+  if (m_ecm_ctx.mme_ue_s1ap_id!=0) {
+    m_s1ap->send_ue_context_release_command(m_ecm_ctx.mme_ue_s1ap_id);
+  }
+  return true;
+}
+
 /*Packing/Unpacking helper functions*/
 bool
 nas::pack_authentication_request(srslte::byte_buffer_t *reply_msg)
diff --git a/srsepc/src/mme/s1ap_nas_transport.cc b/srsepc/src/mme/s1ap_nas_transport.cc
index 9a1a130a6..2b9776b58 100644
--- a/srsepc/src/mme/s1ap_nas_transport.cc
+++ b/srsepc/src/mme/s1ap_nas_transport.cc
@@ -235,7 +235,7 @@ s1ap_nas_transport::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRA
     case LIBLTE_MME_MSG_TYPE_DETACH_REQUEST:
       m_s1ap_log->info("Plain Protected UL NAS: Detach Request\n");
       m_s1ap_log->console("Plain Protected UL NAS: Detach Request\n");
-      nas_ctx->handle_nas_detach_request(nas_msg, reply_buffer, reply_flag);
+      nas_ctx->handle_nas_detach_request(nas_msg);
       break;
     default:
       m_s1ap_log->warning("Unhandled Plain NAS message 0x%x\n", msg_type );
@@ -302,7 +302,7 @@ s1ap_nas_transport::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRA
     case LIBLTE_MME_MSG_TYPE_DETACH_REQUEST:
       m_s1ap_log->info("Integrity Protected UL NAS: Detach Request\n");
       m_s1ap_log->console("Integrity Protected UL NAS: Detach Request\n");
-      nas_ctx->handle_nas_detach_request(nas_msg, reply_buffer, reply_flag);
+      nas_ctx->handle_nas_detach_request(nas_msg);
       break;
     default:
       m_s1ap_log->warning("Unhandled NAS integrity protected message %s\n", liblte_nas_msg_type_to_string(msg_type));