[MME] Add Purge-UE Capability (#1991)

* [MME] Add Purge-UE Capability

* Add OGS_GTP_..._PURGE_AND_REMOVE to split CLR case

lib/diameter/s6a/message.h

@@ -59,9 +59,6 @@ extern "C" {
 #define OGS_DIAM_S6A_ULR_INITIAL_ATTACH_IND             (1 << 5)
 #define OGS_DIAM_S6A_ULR_PS_LCS_SUPPORTED_BY_UE         (1 << 6)
 
-#define OGS_DIAM_S6A_PUA_FLAGS_FREEZE_MTMSI             (1)
-#define OGS_DIAM_S6A_PUA_FLAGS_FREEZE_PTMSI             (1 << 1)
-
 #define OGS_DIAM_S6A_UE_SRVCC_NOT_SUPPORTED             (0)
 #define OGS_DIAM_S6A_UE_SRVCC_SUPPORTED                 (1)
 
@@ -169,15 +166,21 @@ typedef struct ogs_diam_s6a_aia_message_s {
 } ogs_diam_s6a_aia_message_t;
 
 typedef struct ogs_diam_s6a_ula_message_s {
-#define OGS_DIAM_S6A_ULA_FLAGS_SEPARATION_INDICATION        (0)
+#define OGS_DIAM_S6A_ULA_FLAGS_SEPARATION_INDICATION       (0)
-#define OGS_DIAM_S6A_ULA_FLAGS_MME_REGISTERED_FOR_SMS       (1)
+#define OGS_DIAM_S6A_ULA_FLAGS_MME_REGISTERED_FOR_SMS      (1)
     uint32_t ula_flags;
     ogs_subscription_data_t subscription_data;
 } ogs_diam_s6a_ula_message_t;
 
+typedef struct ogs_diam_s6a_pua_message_s {
+#define OGS_DIAM_S6A_PUA_FLAGS_FREEZE_MTMSI                (1)
+#define OGS_DIAM_S6A_PUA_FLAGS_FREEZE_PTMSI                (1 << 1)
+    uint32_t pua_flags;
+} ogs_diam_s6a_pua_message_t;
+
 typedef struct ogs_diam_s6a_clr_message_s {
-#define OGS_DIAM_S6A_CLR_FLAGS_S6A_S6D_INDICATOR            (1)
+#define OGS_DIAM_S6A_CLR_FLAGS_S6A_S6D_INDICATOR           (1)
-#define OGS_DIAM_S6A_CLR_FLAGS_REATTACH_REQUIRED            (1 << 1)
+#define OGS_DIAM_S6A_CLR_FLAGS_REATTACH_REQUIRED           (1 << 1)
     uint32_t clr_flags;
     uint32_t cancellation_type;
 } ogs_diam_s6a_clr_message_t;
@@ -221,6 +224,7 @@ typedef struct ogs_diam_s6a_message_s {
     ogs_diam_s6a_clr_message_t      clr_message;
     ogs_diam_s6a_aia_message_t      aia_message;
     ogs_diam_s6a_ula_message_t      ula_message;
+    ogs_diam_s6a_pua_message_t      pua_message;
 } ogs_diam_s6a_message_t;
 
 int ogs_diam_s6a_init(void);

lib/gtp/xact.h

@@ -96,15 +96,16 @@ typedef struct ogs_gtp_xact_s {
 #define OGS_GTP_MODIFY_QOS_UPDATE ((uint64_t)1<<1)
     uint64_t        update_flags;
 
-#define OGS_GTP_DELETE_NO_ACTION                                1
+#define OGS_GTP_DELETE_NO_ACTION                                        1
-#define OGS_GTP_DELETE_SEND_AUTHENTICATION_REQUEST              2
+#define OGS_GTP_DELETE_SEND_AUTHENTICATION_REQUEST                      2
-#define OGS_GTP_DELETE_SEND_DETACH_ACCEPT                       3
+#define OGS_GTP_DELETE_SEND_DETACH_ACCEPT                               3
-#define OGS_GTP_DELETE_SEND_DEACTIVATE_BEARER_CONTEXT_REQUEST   4
+#define OGS_GTP_DELETE_SEND_DEACTIVATE_BEARER_CONTEXT_REQUEST           4
-#define OGS_GTP_DELETE_SEND_RELEASE_WITH_UE_CONTEXT_REMOVE      5
+#define OGS_GTP_DELETE_SEND_RELEASE_WITH_UE_CONTEXT_REMOVE              5
-#define OGS_GTP_DELETE_SEND_RELEASE_WITH_S1_REMOVE_AND_UNLINK   6
+#define OGS_GTP_DELETE_SEND_RELEASE_WITH_UE_CONTEXT_PURGE_AND_REMOVE    6
-#define OGS_GTP_DELETE_HANDLE_PDN_CONNECTIVITY_REQUEST          7
+#define OGS_GTP_DELETE_SEND_RELEASE_WITH_S1_REMOVE_AND_UNLINK           7
-#define OGS_GTP_DELETE_UE_CONTEXT_REMOVE_PARTIAL                8
+#define OGS_GTP_DELETE_HANDLE_PDN_CONNECTIVITY_REQUEST                  8
-#define OGS_GTP_DELETE_IN_PATH_SWITCH_REQUEST                   9
+#define OGS_GTP_DELETE_UE_CONTEXT_REMOVE_PARTIAL                        9
+#define OGS_GTP_DELETE_IN_PATH_SWITCH_REQUEST                           10
 
     int             delete_action;
 

src/mme/esm-sm.c

@@ -145,7 +145,7 @@ void esm_state_inactive(ogs_fsm_t *s, mme_event_t *e)
                 ogs_assert(OGS_OK ==
                     s1ap_send_ue_context_release_command(mme_ue->enb_ue,
                         S1AP_Cause_PR_nas, S1AP_CauseNas_normal_release,
-                        S1AP_UE_CTX_REL_UE_CONTEXT_REMOVE, 0));
+                        S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE, 0));
                 OGS_FSM_TRAN(s, &esm_state_exception);
                 break;
             }
@@ -160,7 +160,7 @@ void esm_state_inactive(ogs_fsm_t *s, mme_event_t *e)
                 ogs_assert(OGS_OK ==
                     s1ap_send_ue_context_release_command(mme_ue->enb_ue,
                         S1AP_Cause_PR_nas, S1AP_CauseNas_normal_release,
-                        S1AP_UE_CTX_REL_UE_CONTEXT_REMOVE, 0));
+                        S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE, 0));
                 OGS_FSM_TRAN(s, &esm_state_exception);
                 break;
             }

src/mme/mme-context.h

@@ -262,10 +262,11 @@ struct enb_ue_s {
 #define S1AP_UE_CTX_REL_S1_CONTEXT_REMOVE                   1
 #define S1AP_UE_CTX_REL_S1_REMOVE_AND_UNLINK                2
 #define S1AP_UE_CTX_REL_UE_CONTEXT_REMOVE                   3
-#define S1AP_UE_CTX_REL_S1_HANDOVER_COMPLETE                4
+#define S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE         4
-#define S1AP_UE_CTX_REL_S1_HANDOVER_CANCEL                  5
+#define S1AP_UE_CTX_REL_S1_HANDOVER_COMPLETE                5
-#define S1AP_UE_CTX_REL_S1_HANDOVER_FAILURE                 6
+#define S1AP_UE_CTX_REL_S1_HANDOVER_CANCEL                  6
-#define S1AP_UE_CTX_REL_S1_PAGING                           7
+#define S1AP_UE_CTX_REL_S1_HANDOVER_FAILURE                 7
+#define S1AP_UE_CTX_REL_S1_PAGING                           8
     uint8_t         ue_ctx_rel_action;
 
     bool            part_of_s1_reset_requested;

src/mme/mme-fd-path.c

@@ -40,6 +40,7 @@ struct sess_state {
 
 static void mme_s6a_aia_cb(void *data, struct msg **msg);
 static void mme_s6a_ula_cb(void *data, struct msg **msg);
+static void mme_s6a_pua_cb(void *data, struct msg **msg);
 
 static void state_cleanup(struct sess_state *sess_data, os0_t sid, void *opaque)
 {
@@ -1218,6 +1219,98 @@ void mme_s6a_send_ulr(mme_ue_t *mme_ue)
     ogs_assert(pthread_mutex_unlock(&ogs_diam_logger_self()->stats_lock) == 0);
 }
 
+/* MME Sends Purge UE Request to HSS */
+void mme_s6a_send_pur(mme_ue_t *mme_ue)
+{
+    int ret;
+
+    struct msg *req = NULL;
+    struct avp *avp;
+    union avp_value val;
+    struct sess_state *sess_data = NULL, *svg;
+    struct session *session = NULL;
+
+    ogs_assert(mme_ue);
+
+    ogs_debug("[MME] Purge-UE-Request");
+
+    /* Create the random value to store with the session */
+    sess_data = ogs_calloc(1, sizeof(*sess_data));
+    ogs_assert(sess_data);
+    sess_data->mme_ue = mme_ue;
+
+    /* Create the request */
+    ret = fd_msg_new(ogs_diam_s6a_cmd_pur, MSGFL_ALLOC_ETEID, &req);
+    ogs_assert(ret == 0);
+
+    /* Create a new session */
+    #define OGS_DIAM_S6A_APP_SID_OPT  "app_s6a"
+    ret = fd_msg_new_session(req, (os0_t)OGS_DIAM_S6A_APP_SID_OPT, 
+            CONSTSTRLEN(OGS_DIAM_S6A_APP_SID_OPT));
+    ogs_assert(ret == 0);
+    ret = fd_msg_sess_get(fd_g_config->cnf_dict, req, &session, NULL);
+    ogs_assert(ret == 0);
+
+    /* Set the Auth-Session-State AVP */
+    ret = fd_msg_avp_new(ogs_diam_auth_session_state, 0, &avp);
+    ogs_assert(ret == 0);
+    val.i32 = OGS_DIAM_AUTH_SESSION_NO_STATE_MAINTAINED;
+    ret = fd_msg_avp_setvalue(avp, &val);
+    ogs_assert(ret == 0);
+    ret = fd_msg_avp_add(req, MSG_BRW_LAST_CHILD, avp);
+    ogs_assert(ret == 0);
+
+    /* Set Origin-Host & Origin-Realm */
+    ret = fd_msg_add_origin(req, 0);
+    ogs_assert(ret == 0);
+
+    /* Set the Destination-Realm AVP */
+    ret = fd_msg_avp_new(ogs_diam_destination_realm, 0, &avp);
+    ogs_assert(ret == 0);
+    val.os.data = (unsigned char *)(fd_g_config->cnf_diamrlm);
+    val.os.len  = strlen(fd_g_config->cnf_diamrlm);
+    ret = fd_msg_avp_setvalue(avp, &val);
+    ogs_assert(ret == 0);
+    ret = fd_msg_avp_add(req, MSG_BRW_LAST_CHILD, avp);
+    ogs_assert(ret == 0);
+
+    /* Set the User-Name AVP */
+    ret = fd_msg_avp_new(ogs_diam_user_name, 0, &avp);
+    ogs_assert(ret == 0);
+    val.os.data = (uint8_t *)mme_ue->imsi_bcd;
+    val.os.len  = strlen(mme_ue->imsi_bcd);
+    ret = fd_msg_avp_setvalue(avp, &val);
+    ogs_assert(ret == 0);
+    ret = fd_msg_avp_add(req, MSG_BRW_LAST_CHILD, avp);
+    ogs_assert(ret == 0);
+
+    /* Set Vendor-Specific-Application-Id AVP */
+    ret = ogs_diam_message_vendor_specific_appid_set(
+            req, OGS_DIAM_S6A_APPLICATION_ID);
+    ogs_assert(ret == 0);
+
+    ret = clock_gettime(CLOCK_REALTIME, &sess_data->ts);
+    ogs_assert(ret == 0);
+
+    /* Keep a pointer to the session data for debug purpose,
+     * in real life we would not need it */
+    svg = sess_data;
+
+    /* Store this value in the session */
+    ret = fd_sess_state_store(mme_s6a_reg, session, &sess_data);
+    ogs_assert(ret == 0);
+    ogs_assert(sess_data == 0);
+
+    /* Send the request */
+    ret = fd_msg_send(&req, mme_s6a_pua_cb, svg);
+    ogs_assert(ret == 0);
+
+    /* Increment the counter */
+    ogs_assert(pthread_mutex_lock(&ogs_diam_logger_self()->stats_lock) == 0);
+    ogs_diam_logger_self()->stats.nb_sent++;
+    ogs_assert(pthread_mutex_unlock(&ogs_diam_logger_self()->stats_lock) == 0);
+}
+
 /* MME received Update Location Answer from HSS */
 static void mme_s6a_ula_cb(void *data, struct msg **msg)
 {
@@ -1456,6 +1549,197 @@ static void mme_s6a_ula_cb(void *data, struct msg **msg)
     return;
 }
 
+/* MME received Purge UE Answer from HSS */
+static void mme_s6a_pua_cb(void *data, struct msg **msg)
+{
+    int ret;
+
+    struct sess_state *sess_data = NULL;
+    struct timespec ts;
+    struct session *session;
+    struct avp *avp, *avpch;
+    struct avp_hdr *hdr;
+    unsigned long dur;
+    int error = 0;
+    int new;
+
+    mme_event_t *e = NULL;
+    mme_ue_t *mme_ue = NULL;
+    ogs_diam_s6a_message_t *s6a_message = NULL;
+    ogs_diam_s6a_pua_message_t *pua_message = NULL;
+
+    ogs_debug("[MME] Purge-UE-Answer");
+
+    ret = clock_gettime(CLOCK_REALTIME, &ts);
+    ogs_assert(ret == 0);
+
+    /* Search the session, retrieve its data */
+    ret = fd_msg_sess_get(fd_g_config->cnf_dict, *msg, &session, &new);
+    ogs_expect_or_return(ret == 0);
+    ogs_expect_or_return(new == 0);
+
+    ret = fd_sess_state_retrieve(mme_s6a_reg, session, &sess_data);
+    ogs_expect_or_return(ret == 0);
+    ogs_expect_or_return(sess_data);
+    ogs_expect_or_return((void *)sess_data == data);
+
+    mme_ue = sess_data->mme_ue;
+    ogs_assert(mme_ue);
+
+    /* Set Purge-UE Command */
+    s6a_message = ogs_calloc(1, sizeof(ogs_diam_s6a_message_t));
+    ogs_assert(s6a_message);
+    s6a_message->cmd_code = OGS_DIAM_S6A_CMD_CODE_PURGE_UE;
+    pua_message = &s6a_message->pua_message;
+    ogs_assert(pua_message);
+
+    /* AVP: 'Result-Code'(268)
+     * The Result-Code AVP indicates whether a particular request was completed
+     * successfully or whether an error occurred. The Result-Code data field
+     * contains an IANA-managed 32-bit address space representing errors.
+     * Reference: RFC 6733
+     */
+    ret = fd_msg_search_avp(*msg, ogs_diam_result_code, &avp);
+    ogs_assert(ret == 0);
+    if (avp) {
+        ret = fd_msg_avp_hdr(avp, &hdr);
+        ogs_assert(ret == 0);
+        s6a_message->result_code = hdr->avp_value->i32;
+        s6a_message->err = &s6a_message->result_code;
+        ogs_debug("    Result Code: %d", hdr->avp_value->i32);
+    } else {
+        ret = fd_msg_search_avp(*msg, ogs_diam_experimental_result, &avp);
+        ogs_assert(ret == 0);
+        if (avp) {
+            ret = fd_avp_search_avp(avp,
+                    ogs_diam_experimental_result_code, &avpch);
+            ogs_assert(ret == 0);
+            if (avpch) {
+                ret = fd_msg_avp_hdr(avpch, &hdr);
+                ogs_assert(ret == 0);
+                s6a_message->result_code = hdr->avp_value->i32;
+                s6a_message->exp_err = &s6a_message->result_code;
+                ogs_debug("    Experimental Result Code: %d",
+                        s6a_message->result_code);
+            }
+        } else {
+            ogs_error("no Result-Code");
+            error++;
+        }
+    }
+
+    /* AVP: 'Origin-Host'(264)
+     * The Origin-Host AVP identifies the endpoint that originated the Diameter
+     * message. Relay agents MUST NOT modify this AVP. The value of the
+     * Origin-Host AVP is guaranteed to be unique within a single host.
+     * Reference: RFC 6733
+     */
+    ret = fd_msg_search_avp(*msg, ogs_diam_origin_host, &avp);
+    ogs_assert(ret == 0);
+    if (avp) {
+        ret = fd_msg_avp_hdr(avp, &hdr);
+        ogs_assert(ret == 0);
+        ogs_debug("    From '%.*s'",
+                (int)hdr->avp_value->os.len, hdr->avp_value->os.data);
+    } else {
+        ogs_error("no_Origin-Host");
+        error++;
+    }
+
+    /* AVP: 'Origin-Realm'(296)
+     * This AVP contains the Realm of the originator of any Diameter message
+     * and MUST be present in all messages. This AVP SHOULD be placed as close
+     * to the Diameter header as possible.
+     * Reference: RFC 6733
+     */
+    ret = fd_msg_search_avp(*msg, ogs_diam_origin_realm, &avp);
+    ogs_assert(ret == 0);
+    if (avp) {
+        ret = fd_msg_avp_hdr(avp, &hdr);
+        ogs_assert(ret == 0);
+        ogs_debug("         ('%.*s')",
+                (int)hdr->avp_value->os.len, hdr->avp_value->os.data);
+    } else {
+        ogs_error("no_Origin-Realm");
+        error++;
+    }
+
+    /* AVP: 'PUA-Flags'(1406)
+     * The PUA-Flags AVP contains a bit mask, whose meanings are defined in
+     * table in 29.272 7.3.8/1.
+     * Reference: 3GPP TS 29.272-f70
+     */
+    ret = fd_msg_search_avp(*msg, ogs_diam_s6a_pua_flags, &avp);
+    ogs_assert(ret == 0);
+    if (avp) {
+        ret = fd_msg_avp_hdr(avp, &hdr);
+        ogs_assert(ret == 0);
+        pua_message->pua_flags = hdr->avp_value->i32;
+    }
+
+    if (!error) {
+        int rv;
+        e = mme_event_new(MME_EVENT_S6A_MESSAGE);
+        ogs_assert(e);
+        e->mme_ue = mme_ue;
+        e->s6a_message = s6a_message;
+        rv = ogs_queue_push(ogs_app()->queue, e);
+        if (rv != OGS_OK) {
+            ogs_error("ogs_queue_push() failed:%d", (int)rv);
+            ogs_free(s6a_message);
+            mme_event_free(e);
+        } else {
+            ogs_pollset_notify(ogs_app()->pollset);
+        }
+    } else {
+        ogs_free(s6a_message);
+    }
+
+    /* Free the message */
+    ogs_assert(pthread_mutex_lock(&ogs_diam_logger_self()->stats_lock) == 0);
+    dur = ((ts.tv_sec - sess_data->ts.tv_sec) * 1000000) +
+        ((ts.tv_nsec - sess_data->ts.tv_nsec) / 1000);
+    if (ogs_diam_logger_self()->stats.nb_recv) {
+        /* Ponderate in the avg */
+        ogs_diam_logger_self()->stats.avg =
+            (ogs_diam_logger_self()->stats.avg *
+            ogs_diam_logger_self()->stats.nb_recv + dur) /
+            (ogs_diam_logger_self()->stats.nb_recv + 1);
+        /* Min, max */
+        if (dur < ogs_diam_logger_self()->stats.shortest)
+            ogs_diam_logger_self()->stats.shortest = dur;
+        if (dur > ogs_diam_logger_self()->stats.longest)
+            ogs_diam_logger_self()->stats.longest = dur;
+    } else {
+        ogs_diam_logger_self()->stats.shortest = dur;
+        ogs_diam_logger_self()->stats.longest = dur;
+        ogs_diam_logger_self()->stats.avg = dur;
+    }
+    if (error)
+        ogs_diam_logger_self()->stats.nb_errs++;
+    else
+        ogs_diam_logger_self()->stats.nb_recv++;
+
+    ogs_assert(pthread_mutex_unlock(&ogs_diam_logger_self()->stats_lock) == 0);
+
+    /* Display how long it took */
+    if (ts.tv_nsec > sess_data->ts.tv_nsec)
+        ogs_trace("in %d.%06ld sec",
+                (int)(ts.tv_sec - sess_data->ts.tv_sec),
+                (long)(ts.tv_nsec - sess_data->ts.tv_nsec) / 1000);
+    else
+        ogs_trace("in %d.%06ld sec",
+                (int)(ts.tv_sec + 1 - sess_data->ts.tv_sec),
+                (long)(1000000000 + ts.tv_nsec - sess_data->ts.tv_nsec) / 1000);
+
+    ret = fd_msg_free(*msg);
+    ogs_assert(ret == 0);
+    *msg = NULL;
+
+    state_cleanup(sess_data, NULL, NULL);
+    return;
+}
+
 /* Callback for incoming Cancel-Location-Request messages */
 static int mme_ogs_diam_s6a_clr_cb( struct msg **msg, struct avp *avp,
         struct session *session, void *opaque, enum disp_action *act)

src/mme/mme-fd-path.h

@@ -35,6 +35,8 @@ void mme_s6a_send_air(mme_ue_t *mme_ue,
         *authentication_failure_parameter);
 /* MME Sends Update Location Request to HSS */
 void mme_s6a_send_ulr(mme_ue_t *mme_ue);
+/* MME Sends Purge UE Request to HSS */
+void mme_s6a_send_pur(mme_ue_t *mme_ue);
 
 #ifdef __cplusplus
 }

src/mme/mme-gtp-path.c

@@ -134,7 +134,7 @@ static void timeout(ogs_gtp_xact_t *xact, void *data)
             ogs_assert(OGS_OK ==
                 s1ap_send_ue_context_release_command(enb_ue,
                     S1AP_Cause_PR_nas, S1AP_CauseNas_normal_release,
-                    S1AP_UE_CTX_REL_UE_CONTEXT_REMOVE, 0));
+                    S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE, 0));
         } else {
             ogs_warn("No S1 Context");
         }

src/mme/mme-path.c

@@ -98,7 +98,7 @@ void mme_send_delete_session_or_mme_ue_context_release(mme_ue_t *mme_ue)
 
     if (SESSION_CONTEXT_IS_AVAILABLE(mme_ue)) {
         mme_gtp_send_delete_all_sessions(mme_ue,
-                OGS_GTP_DELETE_SEND_RELEASE_WITH_UE_CONTEXT_REMOVE);
+                OGS_GTP_DELETE_SEND_RELEASE_WITH_UE_CONTEXT_PURGE_AND_REMOVE);
     } else {
         enb_ue_t *enb_ue = enb_ue_cycle(mme_ue->enb_ue);
         if (enb_ue) {

src/mme/mme-s11-handler.c

@@ -634,6 +634,20 @@ void mme_s11_handle_delete_session_response(
             }
         }
 
+    } else if (action == 
+            OGS_GTP_DELETE_SEND_RELEASE_WITH_UE_CONTEXT_PURGE_AND_REMOVE) {
+        if (mme_sess_count(mme_ue) == 1) /* Last Session */ {
+            if (ECM_IDLE(mme_ue)) {
+                mme_s6a_send_pur(mme_ue);
+            } else {
+                ogs_assert(mme_ue->enb_ue);
+                ogs_assert(OGS_OK ==
+                    s1ap_send_ue_context_release_command(mme_ue->enb_ue,
+                    S1AP_Cause_PR_nas, S1AP_CauseNas_normal_release,
+                    S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE, 0));
+            }
+        }
+
     } else if (action ==
             OGS_GTP_DELETE_SEND_RELEASE_WITH_S1_REMOVE_AND_UNLINK) {
         if (mme_sess_count(mme_ue) == 1) /* Last Session */ {

src/mme/mme-s6a-handler.c

@@ -126,6 +126,33 @@ uint8_t mme_s6a_handle_ula(
     return OGS_NAS_EMM_CAUSE_REQUEST_ACCEPTED;
 }
 
+uint8_t mme_s6a_handle_pua(
+        mme_ue_t *mme_ue, ogs_diam_s6a_message_t *s6a_message)
+{
+    ogs_diam_s6a_pua_message_t *pua_message = NULL;
+
+    ogs_assert(mme_ue);
+    ogs_assert(s6a_message);
+    pua_message = &s6a_message->pua_message;
+    ogs_assert(pua_message);
+
+    if (s6a_message->result_code != ER_DIAMETER_SUCCESS) {
+        ogs_error("Purge UE failed for IMSI[%s] [%d]", mme_ue->imsi_bcd,
+            s6a_message->result_code);
+        mme_ue_hash_remove(mme_ue);
+        mme_ue_remove(mme_ue);
+        return OGS_ERROR;
+    }
+
+    if (pua_message->pua_flags & OGS_DIAM_S6A_PUA_FLAGS_FREEZE_MTMSI)
+        ogs_debug("Freeze M-TMSI requested but not implemented.");
+
+    mme_ue_hash_remove(mme_ue);
+    mme_ue_remove(mme_ue);
+
+    return OGS_OK;
+}
+
 uint8_t mme_s6a_handle_idr(
         mme_ue_t *mme_ue, ogs_diam_s6a_message_t *s6a_message)
 {

src/mme/mme-s6a-handler.h

@@ -30,6 +30,8 @@ uint8_t mme_s6a_handle_aia(
         mme_ue_t *mme_ue, ogs_diam_s6a_message_t *s6a_message);
 uint8_t mme_s6a_handle_ula(
         mme_ue_t *mme_ue, ogs_diam_s6a_message_t *s6a_message);
+uint8_t mme_s6a_handle_pua(
+        mme_ue_t *mme_ue, ogs_diam_s6a_message_t *s6a_message);
 uint8_t mme_s6a_handle_idr(
         mme_ue_t *mme_ue, ogs_diam_s6a_message_t *s6a_message);
 void mme_s6a_handle_clr(

src/mme/mme-sm.c

@@ -436,9 +436,12 @@ void mme_state_operational(ogs_fsm_t *s, mme_event_t *e)
                 ogs_assert(OGS_OK ==
                     s1ap_send_ue_context_release_command(enb_ue,
                         S1AP_Cause_PR_nas, S1AP_CauseNas_normal_release,
-                        S1AP_UE_CTX_REL_UE_CONTEXT_REMOVE, 0));
+                        S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE, 0));
             }
             break;
+        case OGS_DIAM_S6A_CMD_CODE_PURGE_UE:
+            mme_s6a_handle_pua(mme_ue, s6a_message);
+            break;
         case OGS_DIAM_S6A_CMD_CODE_CANCEL_LOCATION:
             mme_s6a_handle_clr(mme_ue, s6a_message);
             break;

src/mme/nas-path.c

@@ -346,7 +346,7 @@ int nas_eps_send_pdn_connectivity_reject(
             ogs_assert(OGS_OK ==
                 s1ap_send_ue_context_release_command(mme_ue->enb_ue,
                 S1AP_Cause_PR_nas, S1AP_CauseNas_normal_release,
-                S1AP_UE_CTX_REL_UE_CONTEXT_REMOVE, 0));
+                S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE, 0));
         }
     } else {
         esmbuf = esm_build_pdn_connectivity_reject(

src/mme/s1ap-handler.c

@@ -22,6 +22,7 @@
 
 #include "s1ap-path.h"
 #include "nas-path.h"
+#include "mme-fd-path.h"
 #include "mme-gtp-path.h"
 #include "sgsap-types.h"
 #include "sgsap-path.h"
@@ -1487,6 +1488,13 @@ void s1ap_handle_ue_context_release_action(enb_ue_t *enb_ue)
         mme_ue_hash_remove(mme_ue);
         mme_ue_remove(mme_ue);
         break;
+    case S1AP_UE_CTX_REL_UE_CONTEXT_PURGE_AND_REMOVE:
+        ogs_debug("    Action: UE context remove");
+        enb_ue_remove(enb_ue);
+        ogs_expect_or_return(mme_ue);
+
+        mme_s6a_send_pur(mme_ue);
+        break;
     case S1AP_UE_CTX_REL_S1_HANDOVER_COMPLETE:
         ogs_debug("    Action: S1 handover complete");