[mme] handle second s1ap setup as reset (#87)

althea-net · Mar 7, 2024 · d876379 · d876379
1 parent 1f418f2
commit d876379
Show file tree

Hide file tree

Showing 4 changed files with 17 additions and 3 deletions.
diff --git a/lib/gtp/xact.h b/lib/gtp/xact.h
@@ -112,6 +112,7 @@ typedef struct ogs_gtp_xact_s {
 #define OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_LO_CONNREFUSED 2
 #define OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_RESET_ALL      3
 #define OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_RESET_PARTIAL  4
+#define OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_S1_SETUPREQ    5
     int             release_action;
 
 #define OGS_GTP_DELETE_INDIRECT_HANDOVER_COMPLETE 1

diff --git a/src/mme/mme-gtp-path.c b/src/mme/mme-gtp-path.c
@@ -554,7 +554,8 @@ void mme_gtp_send_release_all_ue_in_enb(mme_enb_t *enb, int action)
         mme_ue = enb_ue->mme_ue;
 
         if (mme_ue) {
-            if (action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_LO_CONNREFUSED) {
+            if (action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_LO_CONNREFUSED ||
+                action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_S1_SETUPREQ) {
                 /*
                  * https://github.com/open5gs/open5gs/pull/1497
                  *
@@ -585,7 +586,8 @@ void mme_gtp_send_release_all_ue_in_enb(mme_enb_t *enb, int action)
                 enb_ue->enb_ue_s1ap_id, enb_ue->mme_ue_s1ap_id, action);
 
             if (action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_LO_CONNREFUSED ||
-                action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_RESET_ALL) {
+                action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_RESET_ALL ||
+                action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_S1_SETUPREQ) {
                 enb_ue_remove(enb_ue);
             } else {
                 /* At this point, it does not support other action */

diff --git a/src/mme/mme-s11-handler.c b/src/mme/mme-s11-handler.c
@@ -1330,7 +1330,8 @@ void mme_s11_handle_release_access_bearers_response(
         } else {
             ogs_error("ENB-S1 Context has already been removed");
         }
-    } else if (action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_LO_CONNREFUSED) {
+    } else if (action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_LO_CONNREFUSED ||
+               action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_S1_SETUPREQ) {
     /* enb_ue_unlink() and enb_ue_remove() has already been executed.
      * So, there is no `enb_ue` context */
 

diff --git a/src/mme/s1ap-handler.c b/src/mme/s1ap-handler.c
@@ -244,7 +244,17 @@ void s1ap_handle_s1_setup_request(mme_enb_t *enb, ogs_s1ap_message_t *message)
 
     stats_update_mme_enbs();
 
+    if (enb->state.s1_setup_success == true) {
+        // we have already associated with this eNB in the past, so
+        // something happened. Per 36.413.8.7.3.1 we need to clear
+        // all associated UE contexts similar to a Reset procedure.
+        ogs_warn("eNB was previously associated. Clearing all associated UE contexts.");
+
+        mme_gtp_send_release_all_ue_in_enb(
+                enb, OGS_GTP_RELEASE_S1_CONTEXT_REMOVE_BY_S1_SETUPREQ);
+    }
     enb->state.s1_setup_success = true;
+
     r = s1ap_send_s1_setup_response(enb);
     ogs_expect(r == OGS_OK);
     ogs_assert(r != OGS_ERROR);