[CSFB] Add MO-CSFB-Indication

lib/nas/nas-types.h

@@ -729,9 +729,9 @@ ED4(uint8_t type:4;,
  * M V 1/2 
  * 9.9.3.21 NAS key set identifier 
  * M V 1/2 */
-#define NAS_SERVICE_TYPE_CS_FALLBACK_OR_1XCS_FALLBACK_FROM_UE 0
-#define NAS_SERVICE_TYPE_CS_FALLBACK_OR_1XCS_FALLBACK_TO_UE 1
-#define NAS_SERVICE_TYPE_CS_FALLBACK_EMERGENCY_CALL_OR_1XCS_FALLBACK_EMERGENCY_CALL_FROM_UE 2
+#define NAS_SERVICE_TYPE_CS_FALLBACK_FROM_UE 0
+#define NAS_SERVICE_TYPE_CS_FALLBACK_TO_UE 1
+#define NAS_SERVICE_TYPE_CS_FALLBACK_EMERGENCY_CALL_FROM_UE 2
 typedef struct nas_service_type_s {
 ED3(uint8_t tsc:1;,
     uint8_t nas_key_set_identifier:3;,

src/mme/emm-sm.c

@@ -318,6 +318,15 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
     case MME_EPS_TYPE_EXTENDED_SERVICE_REQUEST:
         procedureCode = e->s1ap_code;
 
+        if (!MME_P_TMSI_IS_AVAILABLE(mme_ue)) {
+            ogs_warn("No P-TMSI : UE[%s]", mme_ue->imsi_bcd);
+            rv = nas_send_service_reject(mme_ue,
+                EMM_CAUSE_UE_IDENTITY_CANNOT_BE_DERIVED_BY_THE_NETWORK);
+            ogs_assert(rv == OGS_OK);
+            OGS_FSM_TRAN(s, emm_state_exception);
+            break;
+        }
+
         if (!SESSION_CONTEXT_IS_AVAILABLE(mme_ue)) {
             ogs_warn("No PDN Connection : UE[%s]", mme_ue->imsi_bcd);
             rv = nas_send_service_reject(mme_ue,
@@ -337,6 +346,14 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
         }
 
         if (procedureCode == S1AP_ProcedureCode_id_initialUEMessage) {
+            if (mme_ue->nas_eps.service.service_type ==
+                    NAS_SERVICE_TYPE_CS_FALLBACK_FROM_UE ||
+                mme_ue->nas_eps.service.service_type ==
+                    NAS_SERVICE_TYPE_CS_FALLBACK_EMERGENCY_CALL_FROM_UE) {
+                ogs_debug("    MO-CSFB-INDICATION[%d]",
+                        mme_ue->nas_eps.service.service_type);
+                sgsap_send_mo_csfb_indication(mme_ue);
+            }
             ogs_debug("    Iniital UE Message");
             rv = s1ap_send_initial_context_setup_request(mme_ue);
             ogs_assert(rv == OGS_OK);

src/mme/sgsap-build.c

@@ -170,5 +170,25 @@ ogs_pkbuf_t *sgsap_build_service_request(mme_ue_t *mme_ue)
 
 ogs_pkbuf_t *sgsap_build_mo_csfb_indication(mme_ue_t *mme_ue)
 {
-    return NULL;
+    mme_vlr_t *vlr = NULL;
+    ogs_tlv_t *root = NULL;
+    ogs_pkbuf_t *pkbuf = NULL;
+
+    ogs_assert(mme_ue);
+    vlr = mme_ue->vlr;
+    ogs_assert(vlr);
+
+    root = ogs_tlv_add(NULL, SGSAP_IE_IMSI_TYPE, SGSAP_IE_IMSI_LEN, 0,
+            &mme_ue->nas_mobile_identity_imsi);
+
+    pkbuf = ogs_pkbuf_alloc(NULL, MAX_SDU_LEN);
+    ogs_pkbuf_put_u8(pkbuf, SGSAP_MO_CSFB_INDICIATION);
+    ogs_pkbuf_put(pkbuf, MAX_SDU_LEN-1);
+
+    ogs_pkbuf_trim(pkbuf, 1+ogs_tlv_render(root,
+            pkbuf->data+1, MAX_SDU_LEN-1, OGS_TLV_MODE_T1_L1));
+
+    ogs_tlv_free_all(root);
+
+    return pkbuf;
 }

src/mme/sgsap-path.c

@@ -161,3 +161,19 @@ int sgsap_send_detach_indication(mme_ue_t *mme_ue)
 
     return OGS_OK;
 }
+
+int sgsap_send_mo_csfb_indication(mme_ue_t *mme_ue)
+{
+    int rv;
+    ogs_pkbuf_t *pkbuf = NULL;
+    ogs_assert(mme_ue);
+
+    ogs_debug("[SGSAP] MO-CSFB-INDICATION");
+    ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
+
+    pkbuf = sgsap_build_mo_csfb_indication(mme_ue);
+    rv = sgsap_send_to_vlr(mme_ue, pkbuf);
+    ogs_assert(rv == OGS_OK);
+
+    return OGS_OK;
+}

src/mme/sgsap-path.h

@@ -45,6 +45,7 @@ int sgsap_send_to_vlr(mme_ue_t *mme_ue, ogs_pkbuf_t *pkbuf);
 int sgsap_send_location_update_request(mme_ue_t *mme_ue);
 int sgsap_send_tmsi_reallocation_complete(mme_ue_t *mme_ue);
 int sgsap_send_detach_indication(mme_ue_t *mme_ue);
+int sgsap_send_mo_csfb_indication(mme_ue_t *mme_ue);
 
 #ifdef __cplusplus
 }

src/mme/sgsap-types.h

@@ -34,6 +34,8 @@ extern "C" {
 #define SGSAP_EPS_DETACH_ACK                            18
 #define SGSAP_IMSI_DETACH_INDICATION                    19
 #define SGSAP_IMSI_DETACH_ACK                           20
+#define SGSAP_RESET_INDICATION                          21
+#define SGSAP_RESET_ACK                                 22
 #define SGSAP_MO_CSFB_INDICIATION                       24
 
 #define SGSAP_IE_IMSI_TYPE                              1
@@ -56,6 +58,10 @@ extern "C" {
 #define SGSAP_IE_IMSI_DETACH_INDICATION_LEN             1
 #define SGSAP_IE_SERVICE_INDICATOR_TYPE                 32
 #define SGSAP_IE_SERVICE_INDICATOR_LEN                  1
+#define SGSAP_IE_TAI_TYPE                               35
+#define SGSAP_IE_TAI_LEN                                7
+#define SGSAP_IE_E_CGI_TYPE                             36
+#define SGSAP_IE_E_CGI_LEN                              9
 #define SGSAP_IE_UE_EMM_MODE_TYPE                       37
 #define SGSAP_IE_UE_EMM_MODE_LEN                        1
 

tests/csfb/csfb-test.c

@@ -750,6 +750,11 @@ static void test3_func(abts_case *tc, void *data)
     rv = testenb_s1ap_send(s1ap, sendbuf);
     ABTS_INT_EQUAL(tc, OGS_OK, rv);
 
+    /* Receive SGsAP-MO-CSFB-Indication */
+    recvbuf = testvlr_sgsap_read(sgsap);
+    ABTS_PTR_NOTNULL(tc, recvbuf);
+    ogs_pkbuf_free(recvbuf);
+
     /* Initial Context Setup Request */
     recvbuf = testenb_s1ap_read(s1ap);
     ABTS_PTR_NOTNULL(tc, recvbuf);