From f5c90ead7e37fb618ae2624e41a534921ea0e0d7 Mon Sep 17 00:00:00 2001
From: Robert Schmidt <robert.schmidt@openairinterface.org>
Date: Mon, 21 Aug 2023 17:24:47 +0200
Subject: [PATCH] Free DU at CU on lost connection, store assoc ID
- store the assoc ID of a UE at the RRC
- if F1 receives an SCTP shutdown, it removes the endpoint
- F1 will also send an "F1 Lost Connection" message to the RRC
- it is not yet possible to reconnect a DU after it had already been
connected at the CU, since the CU F1AP task will try to rebind GTP,
which fails
---
openair2/COMMON/f1ap_messages_def.h | 3 +++
openair2/COMMON/f1ap_messages_types.h | 6 +++++
openair2/F1AP/f1ap_common.c | 10 ++++++++
openair2/F1AP/f1ap_common.h | 1 +
openair2/F1AP/f1ap_cu_interface_management.c | 1 +
openair2/F1AP/f1ap_cu_task.c | 12 +++++++++
openair2/RRC/NR/nr_rrc_defs.h | 1 +
openair2/RRC/NR/rrc_gNB.c | 26 +++++++++++++++++---
8 files changed, 57 insertions(+), 3 deletions(-)
diff --git a/openair2/COMMON/f1ap_messages_def.h b/openair2/COMMON/f1ap_messages_def.h
index 9cb63a0a06b..0689dd52ac3 100644
--- a/openair2/COMMON/f1ap_messages_def.h
+++ b/openair2/COMMON/f1ap_messages_def.h
@@ -32,6 +32,9 @@ MESSAGE_DEF(F1AP_SETUP_RESP , MESSAGE_PRIORITY_MED, f1ap_setup_resp_t
MESSAGE_DEF(F1AP_SETUP_FAILURE , MESSAGE_PRIORITY_MED, f1ap_setup_failure_t , f1ap_setup_failure)
MESSAGE_DEF(F1AP_GNB_CU_CONFIGURATION_UPDATE , MESSAGE_PRIORITY_MED, f1ap_gnb_cu_configuration_update_t , f1ap_gnb_cu_configuration_update)
+/* F1AP -> RRC to inform about lost connection */
+MESSAGE_DEF(F1AP_LOST_CONNECTION, MESSAGE_PRIORITY_MED, f1ap_lost_connection_t, f1ap_lost_connection)
+
/* MAC -> F1AP messages */
MESSAGE_DEF(F1AP_INITIAL_UL_RRC_MESSAGE , MESSAGE_PRIORITY_MED, f1ap_initial_ul_rrc_message_t , f1ap_initial_ul_rrc_message)
MESSAGE_DEF(F1AP_UL_RRC_MESSAGE , MESSAGE_PRIORITY_MED, f1ap_ul_rrc_message_t , f1ap_ul_rrc_message)
diff --git a/openair2/COMMON/f1ap_messages_types.h b/openair2/COMMON/f1ap_messages_types.h
index b3875c01bff..b0ec1e1e356 100644
--- a/openair2/COMMON/f1ap_messages_types.h
+++ b/openair2/COMMON/f1ap_messages_types.h
@@ -39,6 +39,8 @@
#define F1AP_GNB_CU_CONFIGURATION_UPDATE_FAILURE(mSGpTR) (mSGpTR)->ittiMsg.f1ap_gnb_cu_configuration_update_failure
#define F1AP_SETUP_FAILURE(mSGpTR) (mSGpTR)->ittiMsg.f1ap_setup_failure
+#define F1AP_LOST_CONNECTION(mSGpTR) (mSGpTR)->ittiMsg.f1ap_lost_connection
+
#define F1AP_INITIAL_UL_RRC_MESSAGE(mSGpTR) (mSGpTR)->ittiMsg.f1ap_initial_ul_rrc_message
#define F1AP_UL_RRC_MESSAGE(mSGpTR) (mSGpTR)->ittiMsg.f1ap_ul_rrc_message
#define F1AP_UE_CONTEXT_SETUP_REQ(mSGpTR) (mSGpTR)->ittiMsg.f1ap_ue_context_setup_req
@@ -405,4 +407,8 @@ typedef struct f1ap_paging_ind_s {
uint8_t paging_drx;
} f1ap_paging_ind_t;
+typedef struct f1ap_lost_connection_t {
+ int dummy;
+} f1ap_lost_connection_t;
+
#endif /* F1AP_MESSAGES_TYPES_H_ */
diff --git a/openair2/F1AP/f1ap_common.c b/openair2/F1AP/f1ap_common.c
index 91e7d85efed..3491adc48a0 100644
--- a/openair2/F1AP/f1ap_common.c
+++ b/openair2/F1AP/f1ap_common.c
@@ -63,3 +63,13 @@ void createF1inst(instance_t instanceP, f1ap_setup_req_t *req, f1ap_net_config_t
f1_inst[0]->net_config = *nc;
pthread_mutex_unlock(&f1_inst_mtx);
}
+
+void destroyF1inst(instance_t instance)
+{
+ DevAssert(instance == 0);
+ pthread_mutex_lock(&f1_inst_mtx);
+ AssertFatal(f1_inst[0] != NULL, "Attempted to free uninitialized F1 instances\n");
+ free(f1_inst[instance]);
+ f1_inst[instance] = NULL;
+ pthread_mutex_unlock(&f1_inst_mtx);
+}
diff --git a/openair2/F1AP/f1ap_common.h b/openair2/F1AP/f1ap_common.h
index 1329ebdfce0..3e0cbb4c8a4 100644
--- a/openair2/F1AP/f1ap_common.h
+++ b/openair2/F1AP/f1ap_common.h
@@ -418,6 +418,7 @@ uint8_t F1AP_get_next_transaction_identifier(instance_t mod_idP, instance_t cu_m
f1ap_cudu_inst_t *getCxt(instance_t instanceP);
void createF1inst(instance_t instanceP, f1ap_setup_req_t *req, f1ap_net_config_t *nc);
+void destroyF1inst(instance_t instance);
//lts: C struct type is not homogeneous, so we need macros instead of functions
#define addnRCGI(nRCGi, servedCelL) \
diff --git a/openair2/F1AP/f1ap_cu_interface_management.c b/openair2/F1AP/f1ap_cu_interface_management.c
index ad3880c71ba..3ee88c33b50 100644
--- a/openair2/F1AP/f1ap_cu_interface_management.c
+++ b/openair2/F1AP/f1ap_cu_interface_management.c
@@ -94,6 +94,7 @@ int CU_handle_F1_SETUP_REQUEST(instance_t instance,
}
MessageDef *message_p = itti_alloc_new_message(TASK_CU_F1, 0, F1AP_SETUP_REQ);
+ message_p->ittiMsgHeader.originInstance = assoc_id;
f1ap_setup_req_t *req = &F1AP_SETUP_REQ(message_p);
/* gNB_DU_id */
// this function exits if the ie is mandatory
diff --git a/openair2/F1AP/f1ap_cu_task.c b/openair2/F1AP/f1ap_cu_task.c
index 330d4f5422a..2d47398d51b 100644
--- a/openair2/F1AP/f1ap_cu_task.c
+++ b/openair2/F1AP/f1ap_cu_task.c
@@ -71,6 +71,18 @@ static void cu_task_handle_sctp_association_ind(instance_t instance,
static void cu_task_handle_sctp_association_resp(instance_t instance, sctp_new_association_resp_t *sctp_new_association_resp) {
DevAssert(sctp_new_association_resp != NULL);
+ if (sctp_new_association_resp->sctp_state == SCTP_STATE_SHUTDOWN) {
+ f1ap_cudu_inst_t *f1ap_cu_data = getCxt(instance);
+ AssertFatal(f1ap_cu_data != NULL, "illegal state: SCTP shutdown for non-existing F1AP endpoint\n");
+ LOG_I(F1AP, "Received SCTP shutdown for assoc_id %d, removing endpoint\n", sctp_new_association_resp->assoc_id);
+ destroyF1inst(instance);
+ /* inform RRC that the DU is gone */
+ MessageDef *message_p = itti_alloc_new_message(TASK_CU_F1, 0, F1AP_LOST_CONNECTION);
+ message_p->ittiMsgHeader.originInstance = sctp_new_association_resp->assoc_id;
+ itti_send_msg_to_task(TASK_RRC_GNB, instance, message_p);
+ return;
+ }
+
if (sctp_new_association_resp->sctp_state != SCTP_STATE_ESTABLISHED) {
LOG_W(F1AP, "Received unsuccessful result for SCTP association (%u), instance %ld, cnx_id %u\n",
sctp_new_association_resp->sctp_state,
diff --git a/openair2/RRC/NR/nr_rrc_defs.h b/openair2/RRC/NR/nr_rrc_defs.h
index 465f968a4d1..362d2bcee5f 100644
--- a/openair2/RRC/NR/nr_rrc_defs.h
+++ b/openair2/RRC/NR/nr_rrc_defs.h
@@ -369,6 +369,7 @@ typedef struct cucp_cuup_if_s {
} cucp_cuup_if_t;
typedef struct nr_rrc_du_container_t {
+ int assoc_id;
f1ap_setup_req_t *setup_req;
NR_MIB_t *mib;
NR_SIB1_t *sib1;
diff --git a/openair2/RRC/NR/rrc_gNB.c b/openair2/RRC/NR/rrc_gNB.c
index 505b22ab501..23fcbffe503 100644
--- a/openair2/RRC/NR/rrc_gNB.c
+++ b/openair2/RRC/NR/rrc_gNB.c
@@ -1801,12 +1801,12 @@ static bool rrc_gNB_plmn_matches(const gNB_RRC_INST *rrc, const f1ap_served_cell
&& rrc->nr_cellid == info->nr_cellid;
}
-static void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req)
+static void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, int assoc_id)
{
gNB_RRC_INST *rrc = RC.nrrrc[0];
DevAssert(rrc);
- LOG_I(NR_RRC, "Received F1 Setup Request from gNB_DU %lu (%s)\n", req->gNB_DU_id, req->gNB_DU_name);
+ LOG_I(NR_RRC, "Received F1 Setup Request from gNB_DU %lu (%s) on assoc_id %d\n", req->gNB_DU_id, req->gNB_DU_name, assoc_id);
// check:
// - it is the first DU
@@ -1876,6 +1876,7 @@ static void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req)
// we accept the DU
rrc->du = calloc(1, sizeof(*rrc->du));
AssertFatal(rrc->du != NULL, "out of memory\n");
+ rrc->du->assoc_id = assoc_id;
/* ITTI will free the setup request message via free(). So the memory
* "inside" of the message will remain, but the "outside" container no, so
@@ -2423,6 +2424,21 @@ void rrc_gNB_process_e1_bearer_context_setup_resp(e1ap_bearer_setup_resp_t *resp
prepare_and_send_ue_context_modification_f1(ue_context_p, resp);
}
+static void rrc_CU_process_f1_lost_connection(gNB_RRC_INST *rrc, f1ap_lost_connection_t *lc, int assoc_id)
+{
+ AssertFatal(rrc->du != NULL, "no DU connected, cannot received F1 lost connection\n");
+ AssertFatal(rrc->du->assoc_id == assoc_id,
+ "previously connected DU (%d) does not match DU for which connection has been lost (%d)\n",
+ rrc->du->assoc_id,
+ assoc_id);
+ (void) lc; // unused for the moment
+ ASN_STRUCT_FREE(asn_DEF_NR_MIB, rrc->du->mib);
+ ASN_STRUCT_FREE(asn_DEF_NR_SIB1, rrc->du->sib1);
+ free(rrc->du);
+ rrc->du = NULL;
+ LOG_I(RRC, "dropping DU with assoc_id %d (UE connections remain, if any)\n", assoc_id);
+}
+
static void print_rrc_meas(FILE *f, const NR_MeasResults_t *measresults)
{
DevAssert(measresults->measResultServingMOList.list.count >= 1);
@@ -2621,7 +2637,7 @@ void *rrc_gnb_task(void *args_p) {
/* Messages from F1AP task */
case F1AP_SETUP_REQ:
AssertFatal(!NODE_IS_DU(RC.nrrrc[instance]->node_type), "should not receive F1AP_SETUP_REQUEST in DU!\n");
- rrc_gNB_process_f1_setup_req(&F1AP_SETUP_REQ(msg_p));
+ rrc_gNB_process_f1_setup_req(&F1AP_SETUP_REQ(msg_p), msg_p->ittiMsgHeader.originInstance);
break;
case F1AP_UE_CONTEXT_SETUP_RESP:
@@ -2644,6 +2660,10 @@ void *rrc_gnb_task(void *args_p) {
rrc_CU_process_ue_context_release_complete(msg_p);
break;
+ case F1AP_LOST_CONNECTION:
+ rrc_CU_process_f1_lost_connection(RC.nrrrc[0], &F1AP_LOST_CONNECTION(msg_p), msg_p->ittiMsgHeader.originInstance);
+ break;
+
/* Messages from X2AP */
case X2AP_ENDC_SGNB_ADDITION_REQ:
LOG_I(NR_RRC, "Received ENDC sgNB addition request from X2AP \n");
--
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