From af07cc75ec0d1b245d4620c69d3a20ea01f57cf2 Mon Sep 17 00:00:00 2001
From: Flander Bojan <flander@iskratel.si>
Date: Wed, 1 Feb 2023 08:28:57 +0000
Subject: [PATCH] Support for UPF HA - release/establish new PDU session

---
 src/amf/namf-handler.c |  5 +----
 src/smf/context.h      |  1 +
 src/smf/gsm-sm.c       | 33 ++++++++++++++++++++++++++++++---
 src/smf/pfcp-sm.c      | 25 +++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/src/amf/namf-handler.c b/src/amf/namf-handler.c
index 36ed9089a..1b062e48d 100644
--- a/src/amf/namf-handler.c
+++ b/src/amf/namf-handler.c
@@ -377,9 +377,6 @@ int amf_namf_comm_handle_n1_n2_message_transfer(
             return OGS_ERROR;
         }
 
-        if (n1buf)
-            ogs_pkbuf_free(n1buf);
-
         if (CM_IDLE(amf_ue)) {
             if (n2buf)
                 ogs_pkbuf_free(n2buf);
@@ -394,7 +391,7 @@ int amf_namf_comm_handle_n1_n2_message_transfer(
             }
 
         } else if (CM_CONNECTED(amf_ue)) {
-            r = nas_send_pdu_session_release_command(sess, NULL, n2buf);
+            r = nas_send_pdu_session_release_command(sess, n1buf, n2buf);
             ogs_expect(r == OGS_OK);
             ogs_assert(r != OGS_ERROR);
         } else {
diff --git a/src/smf/context.h b/src/smf/context.h
index 95143c519..9fbd98b8e 100644
--- a/src/smf/context.h
+++ b/src/smf/context.h
@@ -371,6 +371,7 @@ typedef struct smf_sess_s {
 #define SMF_NGAP_STATE_DELETE_TRIGGER_UE_REQUESTED              1
 #define SMF_NGAP_STATE_DELETE_TRIGGER_PCF_INITIATED             2
 #define SMF_NGAP_STATE_ERROR_INDICATION_RECEIVED_FROM_5G_AN     3
+#define SMF_NGAP_STATE_DELETE_TRIGGER_SMF_INITIATED             4
     struct {
         int pdu_session_resource_release;
     } ngap_state;
diff --git a/src/smf/gsm-sm.c b/src/smf/gsm-sm.c
index 3fee8d941..73993910d 100644
--- a/src/smf/gsm-sm.c
+++ b/src/smf/gsm-sm.c
@@ -749,6 +749,8 @@ void smf_gsm_state_operational(ogs_fsm_t *s, smf_event_t *e)
     uint8_t gtp1_cause, gtp2_cause;
     bool release;
 
+    int state = 0;
+
     ogs_assert(s);
     ogs_assert(e);
 
@@ -861,6 +863,7 @@ void smf_gsm_state_operational(ogs_fsm_t *s, smf_event_t *e)
         SWITCH(sbi_message->h.service.name)
         CASE(OGS_SBI_SERVICE_NAME_NPCF_SMPOLICYCONTROL)
             stream = e->h.sbi.data;
+            state = e->h.sbi.state;
 
             SWITCH(sbi_message->h.resource.component[0])
             CASE(OGS_SBI_RESOURCE_NAME_SM_POLICIES)
@@ -897,8 +900,31 @@ void smf_gsm_state_operational(ogs_fsm_t *s, smf_event_t *e)
                             break;
                         }
 
-                        OGS_FSM_TRAN(&sess->sm,
-                                &smf_gsm_state_wait_pfcp_deletion);
+                        if (state == OGS_PFCP_DELETE_TRIGGER_SMF_INITIATED) {
+                            OGS_FSM_TRAN(&sess->sm, smf_gsm_state_wait_5gc_n1_n2_release);
+
+                            smf_n1_n2_message_transfer_param_t param;
+
+                            memset(&param, 0, sizeof(param));
+                            param.state = SMF_NETWORK_REQUESTED_PDU_SESSION_RELEASE;
+                            sess->pti = OGS_NAS_PROCEDURE_TRANSACTION_IDENTITY_UNASSIGNED;
+                            param.n1smbuf = gsm_build_pdu_session_release_command(
+                                sess, OGS_5GSM_CAUSE_REACTIVATION_REQUESTED);
+                            ogs_assert(param.n1smbuf);
+
+                            param.n2smbuf =
+                                ngap_build_pdu_session_resource_release_command_transfer(
+                                    sess, SMF_NGAP_STATE_DELETE_TRIGGER_SMF_INITIATED,
+                                    NGAP_Cause_PR_nas, NGAP_CauseNas_normal_release);
+                            ogs_assert(param.n2smbuf);
+
+                            param.skip_ind = false;
+
+                            smf_namf_comm_send_n1_n2_message_transfer(sess, &param);
+                        } else {
+                            OGS_FSM_TRAN(&sess->sm,
+                                    &smf_gsm_state_wait_pfcp_deletion);
+                        }
                         break;
 
                     DEFAULT
@@ -1517,7 +1543,8 @@ void smf_gsm_state_wait_5gc_n1_n2_release(ogs_fsm_t *s, smf_event_t *e)
 
             } else if (
                 ngap_state == SMF_NGAP_STATE_DELETE_TRIGGER_UE_REQUESTED ||
-                ngap_state == SMF_NGAP_STATE_DELETE_TRIGGER_PCF_INITIATED) {
+                ngap_state == SMF_NGAP_STATE_DELETE_TRIGGER_PCF_INITIATED ||
+                ngap_state == SMF_NGAP_STATE_DELETE_TRIGGER_SMF_INITIATED) {
 
                 ogs_assert(true == ogs_sbi_send_http_status_no_content(stream));
 
diff --git a/src/smf/pfcp-sm.c b/src/smf/pfcp-sm.c
index 643bafff6..59a2421fc 100644
--- a/src/smf/pfcp-sm.c
+++ b/src/smf/pfcp-sm.c
@@ -315,6 +315,31 @@ void smf_pfcp_state_associated(ogs_fsm_t *s, smf_event_t *e)
         }
         break;
     case SMF_EVT_N4_NO_HEARTBEAT:
+        node = e->pfcp_node;
+        ogs_assert(node);
+
+        smf_ue_t *smf_ue = NULL, *next = NULL;;
+
+        ogs_list_for_each_safe(&smf_self()->smf_ue_list, next, smf_ue) {
+            smf_sess_t *sess = NULL, *next = NULL;;
+            ogs_assert(smf_ue);
+
+            ogs_list_for_each_safe(&smf_ue->sess_list, next, sess) {
+                ogs_assert(sess);
+
+                if (node == sess->pfcp_node) {
+                    smf_npcf_smpolicycontrol_param_t param;
+
+                    memset(&param, 0, sizeof(param));
+                    ogs_assert(true ==
+                        smf_sbi_discover_and_send(
+                            OGS_SBI_SERVICE_TYPE_NPCF_SMPOLICYCONTROL, NULL,
+                            smf_npcf_smpolicycontrol_build_delete,
+                            sess, NULL, OGS_PFCP_DELETE_TRIGGER_SMF_INITIATED, &param));
+                }
+            }
+        }
+
         ogs_warn("No Heartbeat from UPF [%s]:%d",
                     OGS_ADDR(addr, buf), OGS_PORT(addr));
         OGS_FSM_TRAN(s, smf_pfcp_state_will_associate);