From 65cb21ce05b0a449861a6432c4616bbf8d754047 Mon Sep 17 00:00:00 2001
From: Sukchan Lee <acetcom@gmail.com>
Date: Sat, 6 Jul 2019 23:30:05 +0900
Subject: [PATCH] [SGsAP] clarify P_TMSI availablity

---
 src/mme/emm-build.c   | 8 +++++---
 src/mme/emm-sm.c      | 4 ++--
 src/mme/mme-context.h | 6 ++++++
 src/mme/s1ap-build.c  | 4 +++-
 4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/mme/emm-build.c b/src/mme/emm-build.c
index 5461f7a06e..3fa62fc97e 100644
--- a/src/mme/emm-build.c
+++ b/src/mme/emm-build.c
@@ -22,6 +22,7 @@
 #include "nas-security.h"
 #include "mme-kdf.h"
 #include "emm-build.h"
+#include "mme-sm.h"
 
 #undef OGS_LOG_DOMAIN
 #define OGS_LOG_DOMAIN __emm_log_domain
@@ -111,16 +112,17 @@ int emm_build_attach_accept(
     eps_network_feature_support->length = 1;
     eps_network_feature_support->ims_vops = 1;
 
-    if (mme_ue->vlr) {
+    if (MME_P_TMSI_IS_AVAILABLE(mme_ue)) {
+        ogs_assert(mme_ue->vlr);
+        ogs_assert(mme_ue->p_tmsi);
+
         attach_accept->presencemask |=
             NAS_ATTACH_ACCEPT_LOCATION_AREA_IDENTIFICATION_PRESENT;
         lai->nas_plmn_id = mme_ue->vlr->lai.nas_plmn_id;
         lai->lac = mme_ue->vlr->lai.lac;
         ogs_debug("    LAI[PLMN_ID:%06x,LAC:%d]",
                 plmn_id_hexdump(&lai->nas_plmn_id), lai->lac);
-    }
 
-    if (mme_ue->p_tmsi) {
         attach_accept->presencemask |= NAS_ATTACH_ACCEPT_MS_IDENTITY_PRESENT;
         ms_identity->length = 5;
         tmsi->spare = 0xf;
diff --git a/src/mme/emm-sm.c b/src/mme/emm-sm.c
index c109d06254..ac1fc15cff 100644
--- a/src/mme/emm-sm.c
+++ b/src/mme/emm-sm.c
@@ -227,7 +227,7 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
                 return;
             }
 
-            if (mme_ue->p_tmsi) {
+            if (MME_P_TMSI_IS_AVAILABLE(mme_ue)) {
                 rv = sgsap_send_detach_indication(mme_ue);
             } else {
                 rv = mme_send_delete_session_or_detach(mme_ue);
@@ -650,7 +650,7 @@ void emm_state_initial_context_setup(ogs_fsm_t *s, mme_event_t *e)
                 OGS_FSM_TRAN(s, emm_state_exception);
                 break;
             }
-            if (mme_ue->p_tmsi)
+            if (MME_P_TMSI_IS_AVAILABLE(mme_ue))
                 sgsap_send_tmsi_reallocation_complete(mme_ue);
 
             OGS_FSM_TRAN(s, &emm_state_registered);
diff --git a/src/mme/mme-context.h b/src/mme/mme-context.h
index 1b069eda09..b3a32c2024 100644
--- a/src/mme/mme-context.h
+++ b/src/mme/mme-context.h
@@ -189,6 +189,12 @@ typedef struct mme_pgw_s {
     const char      *apn;
 } mme_pgw_t;
 
+#define MME_SGSAP_IS_CONNECTED(__mME) \
+    ((__mME) && ((__mME)->vlr) && \
+     (OGS_FSM_CHECK(&(__mME)->vlr->sm, sgsap_state_connected)))
+#define MME_P_TMSI_IS_AVAILABLE(__mME) \
+    (MME_SGSAP_IS_CONNECTED(__mME) && (__mME)->p_tmsi)
+
 typedef struct mme_vlr_s {
     ogs_lnode_t     lnode;
 
diff --git a/src/mme/s1ap-build.c b/src/mme/s1ap-build.c
index f3fd38c255..e088dad7b2 100644
--- a/src/mme/s1ap-build.c
+++ b/src/mme/s1ap-build.c
@@ -21,6 +21,7 @@
 #include "mme-context.h"
 
 #include "mme-kdf.h"
+#include "mme-sm.h"
 #include "s1ap-build.h"
 #include "s1ap-conv.h"
 
@@ -491,7 +492,8 @@ int s1ap_build_initial_context_setup_request(
     memcpy(SecurityKey->buf, mme_ue->kenb, SecurityKey->size);
 
     /* Set CS-Fallback */
-    if (mme_ue->nas_eps.type == MME_EPS_TYPE_EXTENDED_SERVICE_REQUEST) {
+    if (mme_ue->nas_eps.type == MME_EPS_TYPE_EXTENDED_SERVICE_REQUEST &&
+        MME_P_TMSI_IS_AVAILABLE(mme_ue)) {
         S1AP_CSFallbackIndicator_t *CSFallbackIndicator = NULL;
         S1AP_LAI_t *LAI = NULL;