Fix P-GW crashed without PCRF (#402)

lib/diameter/common/base.h

@@ -69,6 +69,7 @@ int ogs_diam_init(int mode, const char *conffile, ogs_diam_config_t *fd_config);
 void ogs_diam_final(void);
 
 int ogs_diam_config_init(ogs_diam_config_t *fd_config);
+bool ogs_diam_peer_connected(void);
 
 int fd_avp_search_avp ( struct avp * groupedavp, 
         struct dict_object * what, struct avp ** avp );

lib/diameter/common/meson.build

@@ -27,6 +27,7 @@ libdiameter_common_sources = files('''
     message.c
     logger.c
     config.c
+    util.c
     init.c
 '''.split())
 

lib/diameter/common/util.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2019 by Sukchan Lee <acetcom@gmail.com>
+ *
+ * This file is part of Open5GS.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "ogs-diameter-common.h"
+
+bool ogs_diam_peer_connected(void)
+{
+    struct fd_list *li;
+    bool connected = false;
+
+	CHECK_POSIX( pthread_rwlock_rdlock(&fd_g_peers_rw) );
+    for (li = fd_g_peers.next; li != &fd_g_peers; li = li->next) {
+        struct peer_hdr *p = (struct peer_hdr *)li->o;
+        int state = fd_peer_get_state(p);
+
+        ogs_assert(p);
+        ogs_assert(p->info.pi_diamid);
+        ogs_assert(p->info.pi_diamidlen);
+
+        if (state == STATE_OPEN) {
+            ogs_debug("'%s' STATE is OPEN", p->info.pi_diamid);
+            connected = true;
+        } else {
+            ogs_debug("'%s' STATE[%d] is NOT open ", p->info.pi_diamid, state);
+        }
+    }
+	CHECK_POSIX( pthread_rwlock_unlock(&fd_g_peers_rw) );
+
+    return connected;
+}
+

src/mme/mme-s11-handler.c

@@ -122,6 +122,10 @@ void mme_s11_handle_create_session_response(
     }
 
     if (cause_value != OGS_GTP_CAUSE_REQUEST_ACCEPTED) {
+        if (OGS_FSM_CHECK(&mme_ue->sm, emm_state_initial_context_setup)) {
+            nas_send_attach_reject(mme_ue,
+                EMM_CAUSE_NETWORK_FAILURE, ESM_CAUSE_NETWORK_FAILURE);
+        }
         mme_send_delete_session_or_mme_ue_context_release(mme_ue);
         return;
     }

src/pgw/pgw-s5c-handler.c

@@ -95,6 +95,11 @@ void pgw_s5c_handle_create_session_request(
         cause_value = OGS_GTP_CAUSE_MANDATORY_IE_MISSING;
     }
 
+    if (!ogs_diam_peer_connected()) {
+        ogs_error("No Diameter Peer");
+        cause_value = OGS_GTP_CAUSE_REMOTE_PEER_NOT_RESPONDING;
+    }
+
     if (cause_value != OGS_GTP_CAUSE_REQUEST_ACCEPTED) {
         ogs_gtp_send_error_message(xact, sess ? sess->sgw_s5c_teid : 0,
                 OGS_GTP_CREATE_SESSION_RESPONSE_TYPE, cause_value);
@@ -177,7 +182,8 @@ void pgw_s5c_handle_create_session_request(
             sess->uli_type = OGS_DIAM_GX_3GPP_USER_LOCATION_INFO_TYPE_ECGI;
 
         if (uli.flags.tai) {
-            memcpy(&sess->tai.plmn_id, &uli.tai.plmn_id, sizeof(uli.tai.plmn_id));
+            memcpy(&sess->tai.plmn_id, &uli.tai.plmn_id,
+                    sizeof(uli.tai.plmn_id));
             sess->tai.tac = uli.tai.tac;
         }
         if (uli.flags.e_cgi) {
@@ -195,6 +201,8 @@ void pgw_s5c_handle_delete_session_request(
         pgw_sess_t *sess, ogs_gtp_xact_t *xact,
         ogs_pkbuf_t *gtpbuf, ogs_gtp_delete_session_request_t *req)
 {
+    uint8_t cause_value = 0;
+
     ogs_debug("[PGW] Delete Session Request");
 
     ogs_assert(xact);
@@ -202,9 +210,17 @@ void pgw_s5c_handle_delete_session_request(
 
     if (!sess) {
         ogs_warn("No Context");
+        cause_value = OGS_GTP_CAUSE_CONTEXT_NOT_FOUND;
+    }
+
+    if (!ogs_diam_peer_connected()) {
+        ogs_error("No Diameter Peer");
+        cause_value = OGS_GTP_CAUSE_REMOTE_PEER_NOT_RESPONDING;
+    }
+
+    if (cause_value != OGS_GTP_CAUSE_REQUEST_ACCEPTED) {
         ogs_gtp_send_error_message(xact, sess ? sess->sgw_s5c_teid : 0,
-                OGS_GTP_DELETE_SESSION_RESPONSE_TYPE,
-                OGS_GTP_CAUSE_CONTEXT_NOT_FOUND);
+                OGS_GTP_DELETE_SESSION_RESPONSE_TYPE, cause_value);
         ogs_pkbuf_free(gtpbuf);
         return;
     }

src/sgw/sgw-s5c-handler.c

@@ -92,6 +92,14 @@ void sgw_s5c_handle_create_session_response(ogs_gtp_xact_t *s5c_xact,
                 ogs_error("No Cause");
                 cause_value = OGS_GTP_CAUSE_MANDATORY_IE_MISSING;
             }
+        } else {
+            /* Deliver PGW cause value to the MME */
+            ogs_warn("Cause[%d] : No Accepted", cause_value);
+            ogs_gtp_send_error_message(
+                    s11_xact, sgw_ue ? sgw_ue->mme_s11_teid : 0,
+                    OGS_GTP_CREATE_SESSION_RESPONSE_TYPE,
+                    cause_value);
+            return;
         }
     } else {
         ogs_error("No Cause");
@@ -143,7 +151,8 @@ void sgw_s5c_handle_create_session_response(ogs_gtp_xact_t *s5c_xact,
 
     if (cause_value != OGS_GTP_CAUSE_REQUEST_ACCEPTED) {
         ogs_gtp_send_error_message(s11_xact, sgw_ue ? sgw_ue->mme_s11_teid : 0,
-                OGS_GTP_CREATE_SESSION_RESPONSE_TYPE, cause_value);
+                OGS_GTP_CREATE_SESSION_RESPONSE_TYPE,
+                cause_value);
         return;
     }