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971436030dc145d2a5c4900973e179641be927ab
openairinterface5g/openair2/RRC/NR/rrc_gNB.c
Guido Casati 971436030d E1AP: convert PDU session arrays to dynamic allocation 
Replace fixed-size PDU session arrays with dynamically allocated
pointers in E1AP bearer context request/response types to reduce
memory footprint and improve scalability.

Memory usage is now proportional to actual PDU session count
instead of always allocating for maximum capacity.

Impact:
- Callers must allocate and free PDU session arrays; E1AP decode/cp
  allocate, free_e1ap_context_setup_request/mod_request free them.

Major changes:
- Request/response types (e1ap_messages_types.h): pduSession, pduSessionMod,
  pduSessionRem as pointers in setup/mod request and setup/modif response structs.
- E1AP lib: decode allocates with bounds check; cp/eq/free handle pointer members;
  e1ap.c frees setup request after handling.
- CU-UP (cucp_cuup_handler): allocate resp.pduSession and modif.pduSessionMod.
- CU-CP side (cuup_cucp_direct, rrc_gNB, rrc_gNB_NGAP): allocate at E1 request
  build and call free after send where needed; rrc_gNB_NGAP includes E1AP free decls.
- Tests (e1ap_lib_test, nr-cuup-load-test): allocate PDU session arrays in helpers.

Signed-off-by: Guido Casati <guido.casati@openairinterface.org>
2026-05-04 12:03:27 +02:00

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/*
* SPDX-License-Identifier: LicenseRef-CSSL-1.0
*/
/*!
* \brief rrc procedures for gNB
*/
#include <netinet/in.h>
#include <netinet/sctp.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "5g_platform_types.h"
#include "openair2/RRC/NR/nr_rrc_proto.h"
#include "openair2/RRC/NR/rrc_gNB_UE_context.h"
#include "openair3/SECU/key_nas_deriver.h"
#include "openair3/ocp-gtpu/gtp_itf.h"
#include "BIT_STRING.h"
#include "F1AP_CauseProtocol.h"
#include "F1AP_CauseRadioNetwork.h"
#include "NGAP_CauseRadioNetwork.h"
#include "openair2/LAYER2/NR_MAC_COMMON/nr_mac.h"
#include "OCTET_STRING.h"
#include "RRC/NR/MESSAGES/asn1_msg.h"
#include "RRC/NR/mac_rrc_dl.h"
#include "RRC/NR/nr_rrc_common.h"
#include "SIMULATION/TOOLS/sim.h"
#include "T.h"
#include "asn_codecs.h"
#include "asn_internal.h"
#include "assertions.h"
#include "byte_array.h"
#include "common/ngran_types.h"
#include "common/openairinterface5g_limits.h"
#include "common/platform_constants.h"
#include "common/ran_context.h"
#include "common/utils/nr/nr_common.h"
#include "common_lib.h"
#include "constr_SEQUENCE.h"
#include "constr_TYPE.h"
#include "cucp_cuup_if.h"
#include "e1ap_messages_types.h"
#include "executables/softmodem-common.h"
#include "f1ap_messages_types.h"
#include "gtpv1_u_messages_types.h"
#include "intertask_interface.h"
#include "linear_alloc.h"
#include "ngap_messages_types.h"
#include "nr_pdcp/nr_pdcp_entity.h"
#include "nr_pdcp/nr_pdcp_oai_api.h"
#include "nr_rrc_defs.h"
#include "oai_asn1.h"
#include "openair2/F1AP/f1ap_common.h"
#include "openair2/F1AP/f1ap_ids.h"
#include "openair2/F1AP/lib/f1ap_rrc_message_transfer.h"
#include "openair2/F1AP/lib/f1ap_interface_management.h"
#include "openair2/F1AP/lib/f1ap_ue_context.h"
#include "rrc_gNB_NGAP.h"
#include "rrc_gNB_du.h"
#include "rrc_cell_management.h"
#include "rrc_gNB_mobility.h"
#include "rrc_gNB_radio_bearers.h"
#include "rrc_cell_management.h"
#include "rrc_messages_types.h"
#include "rrc_gNB_asn1.h"
#include "seq_arr.h"
#include "tree.h"
#include "uper_decoder.h"
#include "uper_encoder.h"
#include "utils.h"
#include "x2ap_messages_types.h"
#include "xer_encoder.h"
#include "E1AP/lib/e1ap_bearer_context_management.h"
#include "E1AP/lib/e1ap_interface_management.h"
#include "NR_DL-DCCH-Message.h"
#include "ds/byte_array.h"
#include "alg/find.h"
#include "NR_HandoverCommand.h"
#include "openair2/SDAP/nr_sdap/nr_sdap_configuration.h"
#ifdef E2_AGENT
#include "openair2/E2AP/RAN_FUNCTION/O-RAN/ran_func_rc_extern.h"
#define E2_AGENT_SIGNAL_DL_DCCH_RRC_MSG(BUF, LEN, ID) \
do { \
byte_array_t buffer_ba = {.len = LEN}; \
buffer_ba.buf = (uint8_t *)BUF; \
signal_rrc_msg(DL_DCCH_NR_RRC_CLASS, ID, buffer_ba); \
} while (0)
#endif
mui_t rrc_gNB_mui = 0;
/* Per-transaction max_delays counter to limit retry attempts */
#define MAX_DELAYS 100
/** @brief clone and re-enqueue an NGAP message after delaying
* delays the ongoing transaction (in msg_p) by setting a timer to wait
* 10ms; upon expiry, delivers to RRC, which sends the message to itself */
static void delay_transaction(MessageDef *msg_p, int wait_us)
{
MessagesIds id = ITTI_MSG_ID(msg_p);
AssertFatal(id == NGAP_PDUSESSION_SETUP_REQ || id == NGAP_PDUSESSION_RELEASE_COMMAND,
"delay_transaction(): unsupported message id %d\n",
id);
MessageDef *new = itti_alloc_new_message(TASK_RRC_GNB, 0, id);
// Copy only the specific message struct, not the entire union.
// The union (msg_t) contains all message types and is much larger than
// the allocated space (which is sized for the specific message type only).
if (id == NGAP_PDUSESSION_SETUP_REQ) {
NGAP_PDUSESSION_SETUP_REQ(new) = NGAP_PDUSESSION_SETUP_REQ(msg_p);
} else if (id == NGAP_PDUSESSION_RELEASE_COMMAND) {
NGAP_PDUSESSION_RELEASE_COMMAND(new) = NGAP_PDUSESSION_RELEASE_COMMAND(msg_p);
}
int instance = msg_p->ittiMsgHeader.originInstance;
long timer_id;
timer_setup(0, wait_us, TASK_RRC_GNB, instance, TIMER_ONE_SHOT, new, &timer_id);
}
static void reset_delayed_action(delayed_action_state_t *delayed_action)
{
delayed_action->ongoing_transaction = false;
delayed_action->max_delays = 0;
}
void init_delayed_action(delayed_action_state_t *delayed_action)
{
delayed_action->ongoing_transaction = true;
delayed_action->max_delays = MAX_DELAYS;
}
/* \brief checks if any transaction is ongoing for any xid of this UE */
static bool transaction_ongoing(const gNB_RRC_UE_t *UE)
{
for (int xid = 0; xid < NR_RRC_TRANSACTION_IDENTIFIER_NUMBER; ++xid) {
if (UE->xids[xid] != RRC_ACTION_NONE)
return true;
}
return false;
}
/** @brief delay control: returns true if delayed, false if should proceed
* This is a hack. We observed that with some UEs, PDU session requests might
* come in quick succession, faster than the RRC reconfiguration for the PDU
* session requests can be carried out (UE is doing reconfig, and second PDU
* session request arrives). We don't have currently the means to "queue up"
* these transactions, which would probably involve some rework of the RRC.
* To still allow these requests to come in and succeed, we below check and delay transactions
* for 10ms. However, to not accidentally end up in infinite loops, the
* maximum number is capped on a per-UE basis as indicated in variable
* max_delays_pdu_session. See commit 277f8da0 for more details. */
static bool rrc_delay_transaction(instance_t instance, MessageDef *msg_p)
{
uint32_t cu_ue_id = 0;
if (ITTI_MSG_ID(msg_p) == NGAP_PDUSESSION_SETUP_REQ) {
cu_ue_id = NGAP_PDUSESSION_SETUP_REQ(msg_p).gNB_ue_ngap_id;
} else if (ITTI_MSG_ID(msg_p) == NGAP_PDUSESSION_RELEASE_COMMAND) {
cu_ue_id = NGAP_PDUSESSION_RELEASE_COMMAND(msg_p).gNB_ue_ngap_id;
}
AssertFatal(cu_ue_id > 0, "cu_ue_id not found in message %s\n", ITTI_MSG_NAME(msg_p));
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(RC.nrrrc[instance], cu_ue_id);
if (!ue_context_p)
return false; // nothing to delay
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
bool delay = UE->delayed_action.ongoing_transaction && UE->delayed_action.max_delays > 0;
/* Check if any PDU session action is ongoing */
if (delay || transaction_ongoing(UE)) {
int wait_us = 10000;
LOG_I(NR_RRC,
"UE %d: ongoing transaction, delaying incoming transaction by %d us\n",
UE->rrc_ue_id,
wait_us);
delay_transaction(msg_p, wait_us);
UE->delayed_action.max_delays--;
return true; /* delayed */
}
LOG_D(NR_RRC, "UE %d: no delayed action ongoing, proceeding with incoming transaction\n", UE->rrc_ue_id);
return false; /* not delayed */
}
typedef struct {
gNB_RRC_INST *rrc;
f1ap_ue_context_rel_cmd_t *release_cmd;
sctp_assoc_t assoc_id;
} deliver_ue_ctxt_release_data_t;
const NR_RedCapParameters_r17_t *get_redcapparam_r17(NR_UE_NR_Capability_t *UE_Capability_nr)
{
if (UE_Capability_nr && UE_Capability_nr->nonCriticalExtension && UE_Capability_nr->nonCriticalExtension->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension
&& UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->redCapParameters_r17) {
return UE_Capability_nr->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension
->nonCriticalExtension->redCapParameters_r17;
} else
return NULL;
}
static void rrc_deliver_ue_ctxt_release_cmd(void *deliver_pdu_data, ue_id_t ue_id, int srb_id, char *buf, int size, int sdu_id)
{
UNUSED(ue_id);
UNUSED(srb_id);
UNUSED(sdu_id);
DevAssert(deliver_pdu_data != NULL);
deliver_ue_ctxt_release_data_t *data = deliver_pdu_data;
byte_array_t rrc_cont = {.buf = (uint8_t *)buf, .len = size};
data->release_cmd->rrc_container = &rrc_cont;
data->rrc->mac_rrc.ue_context_release_command(data->assoc_id, data->release_cmd);
}
static bool eq_cell_id(const void *vval, const void *vit)
{
const int *cell_id = (const int *)vval;
const neighbour_cell_configuration_t *cell = (const neighbour_cell_configuration_t *)vit;
return cell->nr_cell_id == *cell_id;
}
const neighbour_cell_configuration_t *get_neighbour_cell_config(const gNB_RRC_INST *rrc, int cell_id)
{
if (!rrc->neighbour_cell_configuration)
return NULL;
seq_arr_t *head = rrc->neighbour_cell_configuration;
LOG_D(NR_RRC, "Number of neighbour cell configurations: %ld\n", head->size);
elm_arr_t e = find_if(head, &cell_id, eq_cell_id);
if (e.found) {
const neighbour_cell_configuration_t *cell = (const neighbour_cell_configuration_t *)e.it;
LOG_D(NR_RRC, "Found matching neighbour cell with Cell ID %ld\n", cell->nr_cell_id);
return cell;
}
return NULL;
}
static bool eq_pci(const void *vval, const void *vit)
{
const int *pci = (const int *)vval;
const nr_neighbour_cell_t *neighbour = (const nr_neighbour_cell_t *)vit;
return neighbour->physicalCellId == *pci;
}
const nr_neighbour_cell_t *get_neighbour_cell_by_pci(const neighbour_cell_configuration_t *cell, int pci)
{
DevAssert(cell);
elm_arr_t e = find_if((seq_arr_t *)&cell->neighbour_cells, &pci, eq_pci);
if (e.found) {
const nr_neighbour_cell_t *neighbour = (const nr_neighbour_cell_t *)e.it;
LOG_D(NR_RRC, "Found matching neighbour cell with PCI %d and Cell ID %ld\n", neighbour->physicalCellId, neighbour->nrcell_id);
return neighbour;
}
LOG_E(NR_RRC, "No matching neighbour cell found for Physical Cell ID: %d\n", pci);
return NULL;
}
typedef struct deliver_dl_rrc_message_data_s {
const gNB_RRC_INST *rrc;
f1ap_dl_rrc_message_t *dl_rrc;
sctp_assoc_t assoc_id;
} deliver_dl_rrc_message_data_t;
static void rrc_deliver_dl_rrc_message(void *deliver_pdu_data, ue_id_t ue_id, int srb_id, char *buf, int size, int sdu_id)
{
UNUSED(ue_id);
UNUSED(sdu_id);
DevAssert(deliver_pdu_data != NULL);
deliver_dl_rrc_message_data_t *data = (deliver_dl_rrc_message_data_t *)deliver_pdu_data;
data->dl_rrc->rrc_container = (uint8_t *)buf;
data->dl_rrc->rrc_container_length = size;
DevAssert(data->dl_rrc->srb_id == srb_id);
data->rrc->mac_rrc.dl_rrc_message_transfer(data->assoc_id, data->dl_rrc);
}
static void nr_rrc_transfer_protected_rrc_message(const gNB_RRC_INST *rrc,
const gNB_RRC_UE_t *ue_p,
uint8_t srb_id,
const uint32_t message_id,
const uint8_t *buffer,
int size)
{
DevAssert(size > 0);
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
f1ap_dl_rrc_message_t dl_rrc = {.gNB_CU_ue_id = ue_p->rrc_ue_id, .gNB_DU_ue_id = ue_data.secondary_ue, .srb_id = srb_id};
deliver_dl_rrc_message_data_t data = {.rrc = rrc, .dl_rrc = &dl_rrc, .assoc_id = ue_data.du_assoc_id};
nr_pdcp_data_req_srb(ue_p->rrc_ue_id,
srb_id,
rrc_gNB_mui++,
size,
(unsigned char *const)buffer,
rrc_deliver_dl_rrc_message,
&data);
#ifdef E2_AGENT
E2_AGENT_SIGNAL_DL_DCCH_RRC_MSG(buffer, size, message_id);
#else
UNUSED(message_id);
#endif
}
static void rrc_gNB_CU_DU_init(gNB_RRC_INST *rrc)
{
switch (rrc->node_type) {
case ngran_gNB_CUCP:
mac_rrc_dl_f1ap_init(&rrc->mac_rrc);
cucp_cuup_message_transfer_e1ap_init(rrc);
break;
case ngran_gNB_CU:
mac_rrc_dl_f1ap_init(&rrc->mac_rrc);
cucp_cuup_message_transfer_direct_init(rrc);
break;
case ngran_gNB:
mac_rrc_dl_direct_init(&rrc->mac_rrc);
cucp_cuup_message_transfer_direct_init(rrc);
break;
case ngran_gNB_DU:
/* silently drop this, as we currently still need the RRC at the DU. As
* soon as this is not the case anymore, we can add the AssertFatal() */
//AssertFatal(1==0,"nothing to do for DU\n");
break;
default:
AssertFatal(0 == 1, "Unknown node type %d\n", rrc->node_type);
break;
}
cu_init_f1_ue_data();
}
void openair_rrc_gNB_configuration(gNB_RRC_INST *rrc, nr_rrc_config_t *configuration)
{
AssertFatal(rrc != NULL, "RC.nrrrc not initialized!");
AssertFatal(MAX_MOBILES_PER_GNB < (module_id_t)0xFFFFFFFFFFFFFFFF, " variable overflow");
AssertFatal(configuration!=NULL,"configuration input is null\n");
rrc->module_id = 0;
rrc_gNB_CU_DU_init(rrc);
uid_linear_allocator_init(&rrc->uid_allocator);
RB_INIT(&rrc->rrc_ue_head);
RB_INIT(&rrc->cuups);
RB_INIT(&rrc->dus);
RB_INIT(&rrc->cells);
rrc->configuration = *configuration;
}
static void rrc_gNB_process_AdditionRequestInformation(const module_id_t gnb_mod_idP, x2ap_ENDC_sgnb_addition_req_t *m)
{
gNB_RRC_INST *rrc = RC.nrrrc[gnb_mod_idP];
AssertFatal(NODE_IS_MONOLITHIC(rrc->node_type), "NSA, phy_test, and do_ra only work in monolithic\n");
sctp_assoc_t assoc_id = -1; // monolithic gNB
rrc_add_nsa_user(rrc, m, assoc_id);
}
//-----------------------------------------------------------------------------
unsigned int rrc_gNB_get_next_transaction_identifier(module_id_t gnb_mod_idP)
//-----------------------------------------------------------------------------
{
static unsigned int transaction_id[NUMBER_OF_gNB_MAX] = {0};
// used also in NGAP thread, so need thread safe operation
unsigned int tmp = __atomic_add_fetch(&transaction_id[gnb_mod_idP], 1, __ATOMIC_SEQ_CST);
tmp %= NR_RRC_TRANSACTION_IDENTIFIER_NUMBER;
LOG_T(NR_RRC, "generated xid is %d\n", tmp);
return tmp;
}
/** @brief Create srb-ToAddModList for RRCSetup and RRCReconfiguration messages
* @param reestablish bitmap to indicates whether PDCP should be re-established
* for the SRB1 and/or SRB2. For convenience the bitmap is 0-based, with index 1
* corresponding to SRB1, index 2 to SRB2. 3GPP TS 38.331 RadioBearerConfig
* specifies that PDCP shall be re-established whenever the security key used
* for the radio bearer changes, with some expections for SRB1 (i.e. when resuming
* an RRC connection, or at the first reconfiguration after RRC connection
* reestablishment in NR, do not re-establish PDCP) */
NR_SRB_ToAddModList_t *createSRBlist(gNB_RRC_UE_t *ue, uint8_t reestablish)
{
if (!ue->Srb[SRB1].Active) {
LOG_E(NR_RRC, "Call SRB list while SRB1 doesn't exist\n");
return NULL;
}
NR_SRB_ToAddModList_t *list = CALLOC(sizeof(*list), 1);
for (int i = 0; i < NR_NUM_SRB; i++)
if (ue->Srb[i].Active) {
asn1cSequenceAdd(list->list, NR_SRB_ToAddMod_t, srb);
srb->srb_Identity = i;
/* Based on the bitmap, set reestablishPDCP for SRB1 and SRB2 */
if ((i == SRB1 || i == SRB2) && (reestablish & (1 << i))) {
asn1cCallocOne(srb->reestablishPDCP, NR_SRB_ToAddMod__reestablishPDCP_true);
} else {
DevAssert(!(reestablish & (1 << i)));
}
}
return list;
}
static NR_SDAP_Config_t *nr_rrc_build_sdap_config_ie(const int pdusession_id,
uint8_t n_flows,
pdusession_level_qos_parameter_t *qos,
const nr_sdap_configuration_t *sdap_config)
{
DevAssert(n_flows < MAX_QOS_FLOWS);
// SDAP
NR_SDAP_Config_t *sc = calloc_or_fail(1, sizeof(*sc));
sc->defaultDRB = true;
sc->pdu_Session = pdusession_id;
sc->sdap_HeaderDL = sdap_config->header_dl_absent ? NR_SDAP_Config__sdap_HeaderDL_absent : NR_SDAP_Config__sdap_HeaderDL_present;
sc->sdap_HeaderUL = sdap_config->header_ul_absent ? NR_SDAP_Config__sdap_HeaderUL_absent : NR_SDAP_Config__sdap_HeaderUL_present;
// QoS
asn1cCalloc(sc->mappedQoS_FlowsToAdd, mappedQoS_FlowsToAdd);
for (uint8_t i = 0; i < n_flows; ++i) {
DevAssert(i < MAX_QOS_FLOWS);
NR_QFI_t *qfi = calloc_or_fail(1, sizeof(*qfi));
*qfi = qos[i].qfi;
LOG_D(NR_RRC, "Adding QFI %ld to PDU Session %d\n", *qfi, pdusession_id);
asn1cSeqAdd(&mappedQoS_FlowsToAdd->list, qfi);
}
return sc;
}
NR_DRB_ToAddModList_t *createDRBlist(gNB_RRC_UE_t *ue, bool reestablish, bool do_integrity, bool do_ciphering)
{
NR_DRB_ToAddModList_t *DRB_configList = CALLOC(sizeof(*DRB_configList), 1);
FOR_EACH_SEQ_ARR(drb_t *, drb, &ue->drbs) {
rrc_pdu_session_param_t *pduSession = find_pduSession(&ue->pduSessions, drb->pdusession_id);
if (!pduSession) {
LOG_D(NR_RRC, "PDU Session %d not found, skip\n", drb->pdusession_id);
continue;
}
if (pduSession->status > PDU_SESSION_STATUS_TOMODIFY) {
LOG_D(NR_RRC, "PDU Session %d is not to add/mod\n", drb->pdusession_id);
continue;
}
pdusession_t *session = &pduSession->param;
NR_DRB_ToAddMod_t *drb_ToAddMod = calloc_or_fail(1, sizeof(*drb_ToAddMod));
drb_ToAddMod->drb_Identity = drb->drb_id;
// PDCP config
drb_ToAddMod->pdcp_Config = nr_rrc_build_pdcp_config_ie(do_integrity, do_ciphering, &drb->pdcp_config);
if (reestablish) {
asn1cCallocOne(drb_ToAddMod->reestablishPDCP, NR_DRB_ToAddMod__reestablishPDCP_true);
}
// cn-association: SDAP config
// Get all QoS flows mapped to this DRB
pdusession_level_qos_parameter_t flows_to_add[MAX_QOS_FLOWS] = {0};
uint8_t n_flows = 0;
FOR_EACH_SEQ_ARR(nr_rrc_qos_t *, q, &session->qos)
{
if (q->drb_id == drb->drb_id) {
DevAssert(n_flows < MAX_QOS_FLOWS);
flows_to_add[n_flows++] = q->qos;
}
}
asn1cCalloc(drb_ToAddMod->cnAssociation, cn_association);
cn_association->present = NR_DRB_ToAddMod__cnAssociation_PR_sdap_Config;
cn_association->choice.sdap_Config = nr_rrc_build_sdap_config_ie(drb->pdusession_id, n_flows, flows_to_add, &session->sdap_config);
asn1cSeqAdd(&DRB_configList->list, drb_ToAddMod);
}
if (DRB_configList->list.count == 0) {
free(DRB_configList);
return NULL;
}
return DRB_configList;
}
void freeSRBlist(NR_SRB_ToAddModList_t *l)
{
ASN_STRUCT_FREE(asn_DEF_NR_SRB_ToAddModList, l);
}
void activate_srb(gNB_RRC_UE_t *UE, int srb_id)
{
AssertFatal(srb_id == 1 || srb_id == 2, "handling only SRB 1 or 2\n");
if (UE->Srb[srb_id].Active == 1) {
LOG_W(RRC, "UE %d SRB %d already activated\n", UE->rrc_ue_id, srb_id);
return;
}
LOG_I(RRC, "activate SRB %d of UE %d\n", srb_id, UE->rrc_ue_id);
UE->Srb[srb_id].Active = 1;
NR_SRB_ToAddModList_t *list = CALLOC(sizeof(*list), 1);
asn1cSequenceAdd(list->list, NR_SRB_ToAddMod_t, srb);
srb->srb_Identity = srb_id;
if (srb_id == 1) {
nr_pdcp_entity_security_keys_and_algos_t null_security_parameters = {0};
nr_pdcp_add_srbs(true, UE->rrc_ue_id, list, &null_security_parameters);
} else {
nr_pdcp_entity_security_keys_and_algos_t security_parameters;
security_parameters.ciphering_algorithm = UE->ciphering_algorithm;
security_parameters.integrity_algorithm = UE->integrity_algorithm;
nr_derive_key(RRC_ENC_ALG, UE->ciphering_algorithm, UE->kgnb, security_parameters.ciphering_key);
nr_derive_key(RRC_INT_ALG, UE->integrity_algorithm, UE->kgnb, security_parameters.integrity_key);
nr_pdcp_add_srbs(true,
UE->rrc_ue_id,
list,
&security_parameters);
}
freeSRBlist(list);
}
/** @brief Fill common fields of F1AP UE Context Setup Request
* This helper function initializes common fields that are shared between
* different UE context setup scenarios (serving DU, target DU).
* @param ue UE context
* @param cell (primary serving) cell container
* @param gNB_DU_ue_id Optional gNB-DU UE ID to include in the request (NULL if not provided)
* @return F1AP UE Context Setup Request */
static f1ap_ue_context_setup_req_t rrc_fill_f1_ue_context_setup(gNB_RRC_UE_t *ue,
const nr_rrc_cell_container_t *cell,
const uint32_t *gNB_DU_ue_id)
{
f1ap_ue_context_setup_req_t req = {
.gNB_CU_ue_id = ue->rrc_ue_id,
.servCellIndex = RRC_PCELL_INDEX,
.plmn = cell->info.plmn,
.nr_cellid = cell->info.cell_id,
};
/* UE Aggregate Maximum Bit Rate Uplink is C-ifDRBSetup: 1 Gbps */
req.gnb_du_ue_agg_mbr_ul = malloc_or_fail(sizeof(*req.gnb_du_ue_agg_mbr_ul));
*req.gnb_du_ue_agg_mbr_ul = 1000000000; /* bps */
/* Measurement timing configuration */
req.cu_to_du_rrc_info.meas_timing_config = get_meas_timing_config(cell->mtc, ue->measConfig);
/* UE capabilities */
if (ue->ue_cap_buffer.len > 0) {
req.cu_to_du_rrc_info.ue_cap = malloc_or_fail(sizeof(byte_array_t));
*req.cu_to_du_rrc_info.ue_cap = copy_byte_array(ue->ue_cap_buffer);
}
/* gNB-DU UE ID */
if (gNB_DU_ue_id) {
req.gNB_DU_ue_id = malloc_or_fail(sizeof(*req.gNB_DU_ue_id));
*req.gNB_DU_ue_id = *gNB_DU_ue_id;
}
return req;
}
//-----------------------------------------------------------------------------
static void rrc_gNB_generate_RRCSetup(instance_t instance,
rrc_gNB_ue_context_t *const ue_context_pP,
const uint8_t *masterCellGroup,
int masterCellGroup_len)
//-----------------------------------------------------------------------------
{
LOG_UE_DL_EVENT(&ue_context_pP->ue_context, "Send RRC Setup\n");
gNB_RRC_UE_t *ue_p = &ue_context_pP->ue_context;
gNB_RRC_INST *rrc = RC.nrrrc[instance];
unsigned char buf[1024];
uint8_t xid = rrc_gNB_get_next_transaction_identifier(instance);
ue_p->xids[xid] = RRC_SETUP;
NR_SRB_ToAddModList_t *SRBs = createSRBlist(ue_p, false);
int size = do_RRCSetup(buf, sizeof(buf), xid, masterCellGroup, masterCellGroup_len, SRBs);
AssertFatal(size > 0, "do_RRCSetup failed\n");
AssertFatal(size <= 1024, "memory corruption\n");
LOG_DUMPMSG(NR_RRC, DEBUG_RRC, (char *)buf, size, "[MSG] RRC Setup\n");
freeSRBlist(SRBs);
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
int srbid = 0;
f1ap_dl_rrc_message_t dl_rrc = {
.gNB_CU_ue_id = ue_p->rrc_ue_id,
.gNB_DU_ue_id = ue_data.secondary_ue,
.rrc_container = buf,
.rrc_container_length = size,
.srb_id = srbid
};
rrc->mac_rrc.dl_rrc_message_transfer(ue_data.du_assoc_id, &dl_rrc);
}
static void rrc_gNB_generate_RRCReject(gNB_RRC_INST *rrc, rrc_gNB_ue_context_t *const ue_context_pP)
//-----------------------------------------------------------------------------
{
gNB_RRC_UE_t *ue_p = &ue_context_pP->ue_context;
LOG_A(NR_RRC, "Send RRCReject to RNTI %04x\n", ue_p->rnti);
unsigned char buf[1024];
int size = do_RRCReject(buf);
AssertFatal(size > 0, "do_RRCReject failed\n");
AssertFatal(size <= 1024, "memory corruption\n");
LOG_DUMPMSG(NR_RRC, DEBUG_RRC,
(char *)buf,
size,
"[MSG] RRCReject \n");
LOG_I(NR_RRC, " [RAPROC] ue %04x Logical Channel DL-CCCH, Generating NR_RRCReject (bytes %d)\n", ue_p->rnti, size);
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
int srbid = 0;
f1ap_dl_rrc_message_t dl_rrc = {
.gNB_CU_ue_id = ue_p->rrc_ue_id,
.gNB_DU_ue_id = ue_data.secondary_ue,
.rrc_container = buf,
.rrc_container_length = size,
.srb_id = srbid,
};
rrc->mac_rrc.dl_rrc_message_transfer(ue_data.du_assoc_id, &dl_rrc);
/* release the created UE context, we rejected the UE */
rrc_remove_ue(rrc, ue_context_pP);
}
//-----------------------------------------------------------------------------
/*
* Process the rrc setup complete message from UE (SRB1 Active)
*/
static void rrc_gNB_process_RRCSetupComplete(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, NR_RRCSetupComplete_IEs_t *rrcSetupComplete)
//-----------------------------------------------------------------------------
{
UE->Srb[1].Active = 1;
UE->Srb[2].Active = 0;
rrc_gNB_send_NGAP_NAS_FIRST_REQ(rrc, UE, rrcSetupComplete);
}
static nr_a3_event_t *get_a3_configuration(gNB_RRC_INST *rrc, int pci)
{
nr_measurement_configuration_t *measurementConfiguration = &rrc->measurementConfiguration;
if (!measurementConfiguration->a3_event_list)
return NULL;
for (uint8_t i = 0; i < measurementConfiguration->a3_event_list->size; i++) {
nr_a3_event_t *a3_event = (nr_a3_event_t *)seq_arr_at(measurementConfiguration->a3_event_list, i);
if (a3_event->pci == pci)
return a3_event;
}
return NULL;
}
static NR_ReportConfigToAddMod_t *prepare_periodic_event_report(const nr_per_event_t *per_event)
{
NR_ReportConfigToAddMod_t *rc = calloc(1, sizeof(*rc));
rc->reportConfigId = 1;
rc->reportConfig.present = NR_ReportConfigToAddMod__reportConfig_PR_reportConfigNR;
NR_PeriodicalReportConfig_t *prc = calloc(1, sizeof(*prc));
prc->rsType = NR_NR_RS_Type_ssb;
prc->reportInterval = NR_ReportInterval_ms1024;
prc->reportAmount = NR_PeriodicalReportConfig__reportAmount_infinity;
prc->reportQuantityCell.rsrp = true;
prc->reportQuantityCell.rsrq = true;
prc->reportQuantityCell.sinr = true;
prc->reportQuantityRS_Indexes = calloc(1, sizeof(*prc->reportQuantityRS_Indexes));
prc->reportQuantityRS_Indexes->rsrp = true;
prc->reportQuantityRS_Indexes->rsrq = true;
prc->reportQuantityRS_Indexes->sinr = true;
asn1cCallocOne(prc->maxNrofRS_IndexesToReport, per_event->maxReportCells);
prc->maxReportCells = per_event->maxReportCells;
prc->includeBeamMeasurements = per_event->includeBeamMeasurements;
NR_ReportConfigNR_t *rcnr = calloc(1, sizeof(*rcnr));
rcnr->reportType.present = NR_ReportConfigNR__reportType_PR_periodical;
rcnr->reportType.choice.periodical = prc;
rc->reportConfig.choice.reportConfigNR = rcnr;
return rc;
}
static NR_ReportConfigToAddMod_t *prepare_a2_event_report(const nr_a2_event_t *a2_event)
{
NR_ReportConfigToAddMod_t *rc_A2 = calloc(1, sizeof(*rc_A2));
rc_A2->reportConfigId = 2;
rc_A2->reportConfig.present = NR_ReportConfigToAddMod__reportConfig_PR_reportConfigNR;
NR_EventTriggerConfig_t *etrc_A2 = calloc(1, sizeof(*etrc_A2));
etrc_A2->eventId.present = NR_EventTriggerConfig__eventId_PR_eventA2;
etrc_A2->eventId.choice.eventA2 = calloc(1, sizeof(*etrc_A2->eventId.choice.eventA2));
etrc_A2->eventId.choice.eventA2->a2_Threshold.present = NR_MeasTriggerQuantity_PR_rsrp;
etrc_A2->eventId.choice.eventA2->a2_Threshold.choice.rsrp = a2_event->threshold_RSRP;
etrc_A2->eventId.choice.eventA2->reportOnLeave = false;
etrc_A2->eventId.choice.eventA2->hysteresis = 0;
etrc_A2->eventId.choice.eventA2->timeToTrigger = a2_event->timeToTrigger;
etrc_A2->rsType = NR_NR_RS_Type_ssb;
etrc_A2->reportInterval = NR_ReportInterval_ms480;
etrc_A2->reportAmount = NR_EventTriggerConfig__reportAmount_r4;
etrc_A2->reportQuantityCell.rsrp = true;
etrc_A2->reportQuantityCell.rsrq = true;
etrc_A2->reportQuantityCell.sinr = true;
asn1cCallocOne(etrc_A2->maxNrofRS_IndexesToReport, 4);
etrc_A2->maxReportCells = 1;
etrc_A2->includeBeamMeasurements = false;
NR_ReportConfigNR_t *rcnr_A2 = calloc(1, sizeof(*rcnr_A2));
rcnr_A2->reportType.present = NR_ReportConfigNR__reportType_PR_eventTriggered;
rcnr_A2->reportType.choice.eventTriggered = etrc_A2;
rc_A2->reportConfig.choice.reportConfigNR = rcnr_A2;
return rc_A2;
}
static NR_ReportConfigToAddMod_t *prepare_a3_event_report(const nr_a3_event_t *a3_event, NR_ReportConfigId_t reportConfigId)
{
NR_ReportConfigToAddMod_t *rc_A3 = calloc(1, sizeof(*rc_A3));
// 3 is default A3 Report Config ID. So cellId(0) specific Report Config ID
// starts from 4
rc_A3->reportConfigId = reportConfigId;
rc_A3->reportConfig.present = NR_ReportConfigToAddMod__reportConfig_PR_reportConfigNR;
NR_EventTriggerConfig_t *etrc_A3 = calloc(1, sizeof(*etrc_A3));
etrc_A3->eventId.present = NR_EventTriggerConfig__eventId_PR_eventA3;
etrc_A3->eventId.choice.eventA3 = calloc(1, sizeof(*etrc_A3->eventId.choice.eventA3));
etrc_A3->eventId.choice.eventA3->a3_Offset.present = NR_MeasTriggerQuantityOffset_PR_rsrp;
etrc_A3->eventId.choice.eventA3->a3_Offset.choice.rsrp = a3_event->a3_offset;
etrc_A3->eventId.choice.eventA3->reportOnLeave = true;
etrc_A3->eventId.choice.eventA3->hysteresis = a3_event->hysteresis;
etrc_A3->eventId.choice.eventA3->timeToTrigger = a3_event->timeToTrigger;
etrc_A3->rsType = NR_NR_RS_Type_ssb;
etrc_A3->reportInterval = NR_ReportInterval_ms1024;
etrc_A3->reportAmount = NR_EventTriggerConfig__reportAmount_r4;
etrc_A3->reportQuantityCell.rsrp = true;
etrc_A3->reportQuantityCell.rsrq = true;
etrc_A3->reportQuantityCell.sinr = true;
asn1cCallocOne(etrc_A3->maxNrofRS_IndexesToReport, 4);
etrc_A3->maxReportCells = 4;
etrc_A3->includeBeamMeasurements = false;
NR_ReportConfigNR_t *rcnr_A3 = calloc(1, sizeof(*rcnr_A3));
rcnr_A3->reportType.present = NR_ReportConfigNR__reportType_PR_eventTriggered;
rcnr_A3->reportType.choice.eventTriggered = etrc_A3;
rc_A3->reportConfig.choice.reportConfigNR = rcnr_A3;
return rc_A3;
}
void free_RRCReconfiguration_params(nr_rrc_reconfig_param_t params)
{
ASN_STRUCT_FREE(asn_DEF_NR_DRB_ToAddModList, params.drb_config_list);
ASN_STRUCT_FREE(asn_DEF_NR_SRB_ToAddModList, params.srb_config_list);
ASN_STRUCT_FREE(asn_DEF_NR_SecurityConfig, params.security_config);
free(params.drb_rel);
for (int i = 0; i < params.num_nas_msg; i++)
FREE_AND_ZERO_BYTE_ARRAY(params.dedicated_NAS_msg_list[i]);
}
NR_MeasConfig_t *nr_rrc_get_measconfig(const gNB_RRC_INST *rrc, uint64_t nr_cellid)
{
nr_rrc_cell_container_t *cell = get_cell_by_cell_id(&((gNB_RRC_INST *)rrc)->cells, nr_cellid);
DevAssert(cell != NULL);
if (cell->mtc != NULL) {
NR_ReportConfigToAddMod_t *rc_PER = NULL;
NR_ReportConfigToAddMod_t *rc_A2 = NULL;
seq_arr_t rc_A3_seq = {0};
seq_arr_t neigh_seq = {0};
seq_arr_init(&rc_A3_seq, sizeof(NR_ReportConfigToAddMod_t));
seq_arr_init(&neigh_seq, sizeof(nr_neighbour_cell_t));
// Get cell info from the cell container
int band = cell->info.mode == NR_MODE_TDD ? cell->info.tdd.dlul.band : cell->info.fdd.dl.band;
const NR_MeasTimingList_t *mtlist = cell->mtc->criticalExtensions.choice.c1->choice.measTimingConf->measTiming;
const NR_MeasTiming_t *mt = mtlist->list.array[0];
const neighbour_cell_configuration_t *neighbour_config = get_neighbour_cell_config(rrc, cell->info.cell_id);
const seq_arr_t *neighbour_cells = neighbour_config ? &neighbour_config->neighbour_cells : NULL;
int *neigh_a3_id = NULL;
if (neighbour_cells && neighbour_cells->size)
neigh_a3_id = calloc_or_fail(neighbour_cells->size, sizeof(int));
const nr_measurement_configuration_t *meas_cfg = &rrc->measurementConfiguration;
const seq_arr_t *a3_event_list = meas_cfg->a3_event_list;
if (neighbour_cells && a3_event_list && a3_event_list->size > 0) {
/* Loop through neighbours and find related A3 configuration
If no related A3 but there is default add the default one.
If default one added once as a report, no need to add it again && duplication.
*/
LOG_D(NR_RRC, "Preparing A3 Event Measurement Configuration!\n");
bool default_a3_added = false; // To ensure that the default configuration is only added once
int i = 0;
FOR_EACH_SEQ_ARR(nr_neighbour_cell_t *, neighbourCell, neighbour_cells) {
seq_arr_push_back(&neigh_seq, neighbourCell, sizeof(nr_neighbour_cell_t));
const nr_a3_event_t *a3Event = get_a3_configuration((gNB_RRC_INST *)rrc, neighbourCell->physicalCellId);
if (!a3Event) {
/* no A3 event configured for this neighbour, let's try the default one, if it exists */
if (default_a3_added) {
/* default A3 exists and is already added, use it for this neighbour */
neigh_a3_id[i] = 3;
continue;
}
/* try to get the default A3 config */
a3Event = get_a3_configuration((gNB_RRC_INST *)rrc, -1);
if (!a3Event) {
/* no default A3 config found, so no A3 config for this neighbour */
neigh_a3_id[i] = -1;
continue;
}
default_a3_added = true;
/* default A3 report config ID is 3 */
neigh_a3_id[i] = 3;
} else {
/* specific A3 report config ID are 4, 5, ... */
neigh_a3_id[i] = i + 4;
}
NR_ReportConfigId_t reportConfigId = neigh_a3_id[i];
seq_arr_push_back(&rc_A3_seq, prepare_a3_event_report(a3Event, reportConfigId), sizeof(NR_ReportConfigToAddMod_t));
i++;
}
}
if (meas_cfg->per_event)
rc_PER = prepare_periodic_event_report(meas_cfg->per_event);
if (meas_cfg->a2_event)
rc_A2 = prepare_a2_event_report(meas_cfg->a2_event);
NR_MeasConfig_t *result = get_MeasConfig(mt, band, cell->info.pci, rc_PER, rc_A2, &rc_A3_seq, &neigh_seq, neigh_a3_id);
// Clean up sequence arrays
seq_arr_free(&rc_A3_seq, NULL);
seq_arr_free(&neigh_seq, NULL);
free(neigh_a3_id);
return result;
}
return NULL;
}
/** @brief Prepare the instance of RRCReconfigurationParams to be pass to RRC encoding */
nr_rrc_reconfig_param_t get_RRCReconfiguration_params(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, uint8_t srb_reest_bitmap, bool drb_reestablish)
{
uint8_t xid = rrc_gNB_get_next_transaction_identifier(rrc->module_id);
// Re-establish PDCP for SRB2 only
bool do_integrity = rrc->security.do_drb_integrity;
bool do_ciphering = rrc->security.do_drb_ciphering;
NR_SRB_ToAddModList_t *SRBs = createSRBlist(UE, srb_reest_bitmap);
NR_DRB_ToAddModList_t *DRBs = createDRBlist(UE, drb_reestablish, do_integrity, do_ciphering);
nr_rrc_reconfig_param_t params = {.cgc = &UE->mcg,
.transaction_id = xid,
.drb_config_list = DRBs,
.meas_config = UE->measConfig,
.srb_config_list = SRBs};
FOR_EACH_SEQ_ARR(rrc_pdu_session_param_t *, item, &UE->pduSessions) {
pdusession_t *session = &item->param;
// Collect NAS PDUs
if (session->nas_pdu.len > 0) {
params.dedicated_NAS_msg_list[params.num_nas_msg++] = session->nas_pdu;
session->nas_pdu.buf = NULL;
session->nas_pdu.len = 0;
LOG_D(NR_RRC, "Transfer NAS info with size %ld to RRCReconfiguration params\n", session->nas_pdu.len);
}
// Collect DRBs to release for PDU sessions marked for release
if (item->status == PDU_SESSION_STATUS_TORELEASE) {
if (!params.drb_rel)
params.drb_rel = calloc_or_fail(MAX_DRBS_PER_UE, sizeof(int));
FOR_EACH_SEQ_ARR (drb_t *, drb, &UE->drbs) {
if (drb->pdusession_id == session->pdusession_id) {
if (params.n_drb_rel >= MAX_DRBS_PER_UE) {
LOG_E(NR_RRC, "UE %d: Too many DRBs to release (max %d)\n", UE->rrc_ue_id, MAX_DRBS_PER_UE);
break;
}
params.drb_rel[params.n_drb_rel++] = drb->drb_id;
LOG_D(NR_RRC,
"UE %d: Added DRB %d to release list for PDU session %d\n",
UE->rrc_ue_id,
drb->drb_id,
session->pdusession_id);
}
}
}
}
if (UE->nas_pdu.len > 0) {
params.dedicated_NAS_msg_list[params.num_nas_msg++] = UE->nas_pdu;
UE->nas_pdu.buf = NULL;
UE->nas_pdu.len = 0;
LOG_D(NR_RRC, "Transfer NAS info with size %ld to RRCReconfiguration params\n", UE->nas_pdu.len);
}
return params;
}
byte_array_t rrc_gNB_encode_RRCReconfiguration(gNB_RRC_UE_t *UE, nr_rrc_reconfig_param_t params)
{
byte_array_t msg = do_RRCReconfiguration(&params);
if (msg.len <= 0) {
LOG_E(NR_RRC, "UE %d: Failed to generate RRCReconfiguration\n", UE->rrc_ue_id);
return msg;
}
LOG_DUMPMSG(NR_RRC, DEBUG_RRC, msg.buf, msg.len, "[MSG] RRC Reconfiguration\n");
return msg;
}
/* Forward declaration */
static void cuup_notify_reestablishment(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p);
#define ASSERT_PDU_ACTION_SINGLE(action, expected) \
do { \
DevAssert((action) != RRC_REESTABLISH_COMPLETE); \
DevAssert((action) == RRC_ACTION_NONE || (action) == (expected)); \
} while (0)
/** @brief Set xid for all PDU sessions and derive RRC transaction action from
* session statuses. At most one active status (NEW, TOMODIFY, TORELEASE) or reestablishment.
* Status vs procedures (F1AP UE Context Setup/Modification Response only):
* - NEW: Initial Context Setup or PDU Session Resource Setup Request;
* E1 then F1 Setup/Modification.
* - TORELEASE: NGAP PDU Session Release Command -> E1 Bearer Context
* Modification (release) -> F1 Modification (release DRBs).
* - ESTABLISHED: Bystander when adding/releasing others.
* - TOMODIFY: TODO
* - FAILED: Bystander. Cleaned up in modify response */
static rrc_action_t rrc_gNB_action_from_pdusession_status(gNB_RRC_UE_t *ue_p,
const nr_rrc_reconfig_param_t *params,
bool is_reestablishment)
{
rrc_action_t action = is_reestablishment ? RRC_REESTABLISH_COMPLETE : RRC_ACTION_NONE;
FOR_EACH_SEQ_ARR (rrc_pdu_session_param_t *, item, &ue_p->pduSessions) {
/* Only sessions that participate in this transaction get the current xid. */
if (item->status != PDU_SESSION_STATUS_FAILED && item->status != PDU_SESSION_STATUS_ESTABLISHED) {
item->xid = params->transaction_id;
}
if (item->status == PDU_SESSION_STATUS_TOMODIFY) {
ASSERT_PDU_ACTION_SINGLE(action, RRC_PDUSESSION_MODIFY);
LOG_I(NR_RRC, "PDU Session Modify: status to TOMODIFY for PDU Session %d \n", item->param.pdusession_id);
action = RRC_PDUSESSION_MODIFY;
} else if (item->status == PDU_SESSION_STATUS_NEW) {
ASSERT_PDU_ACTION_SINGLE(action, RRC_PDUSESSION_ESTABLISH);
LOG_I(NR_RRC, "PDU Session New: status to ESTABLISH for PDU Session %d \n", item->param.pdusession_id);
action = RRC_PDUSESSION_ESTABLISH;
} else if (item->status == PDU_SESSION_STATUS_TORELEASE) {
DevAssert(params->n_drb_rel > 0);
ASSERT_PDU_ACTION_SINGLE(action, RRC_PDUSESSION_RELEASE);
LOG_I(NR_RRC,
"PDU Session Release: setting PDU Session status to TORELEASE for PDU Session %d \n",
item->param.pdusession_id);
action = RRC_PDUSESSION_RELEASE;
}
/* ESTABLISHED and FAILED do not drive transaction action */
}
return action;
}
/** @brief Generate and send RRC Reconfiguration message.
* Handles both normal reconfiguration and first reconfiguration after re-establishment.
* @param rrc RRC instance
* @param ue_p UE context
* @param is_reestablishment True if this is the first reconfiguration after re-establishment */
static void rrc_gNB_generate_dedicatedRRCReconfiguration(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p, bool is_reestablishment)
{
/** Get RRC Reconfiguration parameters
* For the first reconfiguration after a re-establishment: re-establish PDCP for SRB2
* (SRB1 already re-established in RRCReestablishment) and all DRBs,
* For the subsequent reconfigurations: do not re-establish PDCP for any bearer */
uint8_t srb_reest_bitmap = is_reestablishment ? (1 << SRB2) : 0;
bool drb_reestablish = is_reestablishment;
nr_rrc_reconfig_param_t params = get_RRCReconfiguration_params(rrc, ue_p, srb_reest_bitmap, drb_reestablish);
ue_p->xids[params.transaction_id] = rrc_gNB_action_from_pdusession_status(ue_p, &params, is_reestablishment);
byte_array_t msg = rrc_gNB_encode_RRCReconfiguration(ue_p, params);
if (msg.len <= 0) {
LOG_E(NR_RRC,
"UE %d: Failed to generate RRCReconfiguration%s\n",
ue_p->rrc_ue_id,
is_reestablishment ? " for re-establishment" : "");
free_RRCReconfiguration_params(params);
return;
}
/* Per TS 38.331 5.3.5.6.3, re-establish SRB2 PDCP when sending the first
* RRCReconfiguration after reestablishment */
if (is_reestablishment) {
if (ue_p->Srb[SRB2].Active) {
nr_pdcp_entity_security_keys_and_algos_t security_parameters = {0};
security_parameters.ciphering_algorithm = ue_p->ciphering_algorithm;
security_parameters.integrity_algorithm = ue_p->integrity_algorithm;
nr_derive_key(RRC_ENC_ALG, ue_p->ciphering_algorithm, ue_p->kgnb, security_parameters.ciphering_key);
nr_derive_key(RRC_INT_ALG, ue_p->integrity_algorithm, ue_p->kgnb, security_parameters.integrity_key);
nr_pdcp_reestablishment(ue_p->rrc_ue_id, SRB2, true, &security_parameters);
}
/* Per TS 38.331 5.3.5.6.5, re-establish PDCP for all DRBs when sending the first
* RRCReconfiguration after RRC connection re-establishment (over E1 to CU-UP) */
cuup_notify_reestablishment(rrc, ue_p);
}
LOG_UE_DL_EVENT(ue_p,
"Generate RRCReconfiguration%s (bytes %ld, xid %d)\n",
is_reestablishment ? " after re-establishment" : "",
msg.len,
params.transaction_id);
const uint32_t msg_id = NR_DL_DCCH_MessageType__c1_PR_rrcReconfiguration;
nr_rrc_transfer_protected_rrc_message(rrc, ue_p, DL_SCH_LCID_DCCH, msg_id, msg.buf, msg.len);
free_RRCReconfiguration_params(params);
free_byte_array(msg);
}
void rrc_gNB_modify_dedicatedRRCReconfiguration(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p)
{
int qos_flow_index = 0;
nr_rrc_reconfig_param_t params = get_RRCReconfiguration_params(rrc, ue_p, 0, false);
ue_p->xids[params.transaction_id] = RRC_PDUSESSION_MODIFY;
FOR_EACH_SEQ_ARR(rrc_pdu_session_param_t *, item, &ue_p->pduSessions) {
pdusession_t *session = &item->param;
item->xid = params.transaction_id;
// bypass the new and already configured pdu sessions
if (item->status != PDU_SESSION_STATUS_TOMODIFY) {
continue;
}
// Reference TS23501 Table 5.7.4-1: Standardized 5QI to QoS characteristics mapping
FOR_EACH_SEQ_ARR(nr_rrc_qos_t *, qos, &session->qos) {
switch (qos->qos.fiveQI) {
case 1: //100ms
case 2: //150ms
case 3: //50ms
case 4: //300ms
case 5: //100ms
case 6: //300ms
case 7: //100ms
case 8: //300ms
case 9: //300ms Video (Buffered Streaming)TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)
// TODO
break;
default:
LOG_E(NR_RRC, "not supported 5qi %lu\n", qos->qos.fiveQI);
ngap_cause_t cause = {.type = NGAP_CAUSE_RADIO_NETWORK, .value = NGAP_CauseRadioNetwork_not_supported_5QI_value};
item->status = PDU_SESSION_STATUS_FAILED;
item->xid = params.transaction_id;
item->cause = cause;
continue;
}
LOG_I(NR_RRC, "PDU Session ID %d, QOS flow %d, 5QI %ld \n", session->pdusession_id, qos_flow_index, qos->qos.fiveQI);
}
}
byte_array_t msg = do_RRCReconfiguration(&params);
if (msg.len <= 0) {
LOG_E(NR_RRC, "UE %d: Failed to generate RRCReconfiguration\n", ue_p->rrc_ue_id);
return;
}
LOG_DUMPMSG(NR_RRC, DEBUG_RRC, msg.buf, msg.len, "[MSG] RRC Reconfiguration\n");
LOG_I(NR_RRC, "UE %d: Generate RRCReconfiguration (bytes %ld, xid %d)\n", ue_p->rrc_ue_id, msg.len, params.transaction_id);
const uint32_t msg_id = NR_DL_DCCH_MessageType__c1_PR_rrcReconfiguration;
nr_rrc_transfer_protected_rrc_message(rrc, ue_p, DL_SCH_LCID_DCCH, msg_id, msg.buf, msg.len);
free_RRCReconfiguration_params(params);
free_byte_array(msg);
}
static void fill_security_info(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, security_information_t *secInfo)
{
secInfo->cipheringAlgorithm = rrc->security.do_drb_ciphering ? UE->ciphering_algorithm : 0;
secInfo->integrityProtectionAlgorithm = rrc->security.do_drb_integrity ? UE->integrity_algorithm : 0;
nr_derive_key(UP_ENC_ALG, secInfo->cipheringAlgorithm, UE->kgnb, (uint8_t *)secInfo->encryptionKey);
nr_derive_key(UP_INT_ALG, secInfo->integrityProtectionAlgorithm, UE->kgnb, (uint8_t *)secInfo->integrityProtectionKey);
}
/** @brief Add DRB modification to E1AP bearer modification request
* Finds PDU session by DRB ID, creates/updates PDU session modification entry
* and appends DRB modification
* @param req E1AP bearer modification request
* @param ue UE context
* @param drb_id DRB ID to find PDU session for
* @param drb_to_mod DRB modification data to append
* @return true if successful, false if PDU session not found */
static bool append_e1_drb_mod_req(e1ap_bearer_mod_req_t *req,
gNB_RRC_UE_t *ue,
const int drb_id,
const DRB_nGRAN_to_mod_t *drb_to_mod)
{
// Find PDU session by DRB ID
rrc_pdu_session_param_t *pdu = find_pduSession_from_drbId(ue, drb_id);
if (!pdu) {
LOG_E(NR_RRC, "UE %d: Failed to append E1 DRB mod, no PDU session found (DRB=%d)\n", ue->rrc_ue_id, drb_id);
return false;
}
int pdu_id = pdu->param.pdusession_id;
// Find existing PDU session modification entry or create new one
pdu_session_to_mod_t *pdu_mod = NULL;
for (int i = 0; i < req->numPDUSessionsMod; ++i) {
if (req->pduSessionMod[i].sessionId == pdu_id) {
pdu_mod = &req->pduSessionMod[i];
break;
}
}
// Create new PDU session modification entry if not found
if (!pdu_mod) {
DevAssert(req->numPDUSessionsMod < NR_MAX_NB_PDU_SESSIONS);
int new_index = req->numPDUSessionsMod++;
req->pduSessionMod[new_index].sessionId = pdu_id;
pdu_mod = &req->pduSessionMod[new_index];
}
// Append DRB modification
DevAssert(pdu_mod->numDRB2Modify < E1AP_MAX_NUM_DRBS);
pdu_mod->DRBnGRanModList[pdu_mod->numDRB2Modify++] = *drb_to_mod;
return true;
}
/** @brief Create DRB modification for reestablishment from existing DRB */
static DRB_nGRAN_to_mod_t get_e1_drb_mod_reestablishment(const drb_t *drb, const bearer_context_pdcp_config_t *pdcp_config)
{
DRB_nGRAN_to_mod_t drb_e1 = {0};
drb_e1.id = drb->drb_id;
drb_e1.numDlUpParam = 1;
memcpy(&drb_e1.DlUpParamList[0].tl_info.tlAddress, &drb->du_tunnel_config.addr.buffer, sizeof(uint8_t) * 4);
drb_e1.DlUpParamList[0].tl_info.teId = drb->du_tunnel_config.teid;
/* PDCP configuration */
drb_e1.pdcp_config = malloc_or_fail(sizeof(*drb_e1.pdcp_config));
*drb_e1.pdcp_config = *pdcp_config;
drb_e1.pdcp_config->pDCP_Reestablishment = true;
return drb_e1;
}
/**
* @brief Notify E1 re-establishment to CU-UP
*/
static void cuup_notify_reestablishment(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p)
{
// Quit if no CU-UP is associated
if (!is_cuup_associated(rrc) || !ue_associated_to_cuup(ue_p)) {
return;
}
e1ap_bearer_mod_req_t req = {
.gNB_cu_cp_ue_id = ue_p->rrc_ue_id,
.gNB_cu_up_ue_id = ue_p->rrc_ue_id,
};
uint16_t num_pdu_sessions = seq_arr_size(&ue_p->pduSessions);
DevAssert(num_pdu_sessions > 0);
req.pduSessionMod = calloc_or_fail(num_pdu_sessions, sizeof(*req.pduSessionMod));
bool um_on_default_drb = rrc->configuration.um_on_default_drb;
/* loop through active DRBs */
FOR_EACH_SEQ_ARR(drb_t *, drb, &ue_p->drbs) {
bearer_context_pdcp_config_t pdcp = set_bearer_context_pdcp_config(drb->pdcp_config, um_on_default_drb, ue_p->redcap_cap);
DRB_nGRAN_to_mod_t drb_e1 = get_e1_drb_mod_reestablishment(drb, &pdcp);
if (!append_e1_drb_mod_req(&req, ue_p, drb->drb_id, &drb_e1)) {
LOG_W(NR_RRC, "UE %d: Failed to append E1 DRB mod for reestablishment (DRB=%d)\n", ue_p->rrc_ue_id, drb->drb_id);
}
}
/* During reestablishment, for DRB integrity protection security keys change (KgNB* is derived),
* so security information MUST be sent to CU-UP to update DRB security keys. */
req.secInfo = malloc_or_fail(sizeof(*req.secInfo));
fill_security_info(rrc, ue_p, req.secInfo);
/* Send E1 Bearer Context Modification Request (3GPP TS 38.463) */
sctp_assoc_t assoc_id = get_existing_cuup_for_ue(ue_p);
rrc->cucp_cuup.bearer_context_mod(assoc_id, &req);
free_e1ap_context_mod_request(&req);
}
/** @brief Generate and send RRCReestablishment message to UE
* This function implements the gNB side of the RRC Connection Re-establishment procedure
* as specified in 3GPP TS 38.331 clause 5.3.7.4.
* @param ue_context_pP UE context pointer
* @param old_rnti Previous RNTI of the UE before re-establishment
* @param du DU container containing cell information for key derivation */
static void rrc_gNB_generate_RRCReestablishment(rrc_gNB_ue_context_t *ue_context_pP,
const rnti_t old_rnti,
const nr_rrc_cell_container_t *cell)
{
module_id_t module_id = 0;
gNB_RRC_INST *rrc = RC.nrrrc[module_id];
gNB_RRC_UE_t *ue_p = &ue_context_pP->ue_context;
uint8_t buffer[NR_RRC_BUF_SIZE] = {0};
uint8_t xid = rrc_gNB_get_next_transaction_identifier(module_id);
ue_p->xids[xid] = RRC_REESTABLISH;
nr_rrc_cell_container_t *pcell = rrc_get_pcell_for_ue(rrc, ue_p);
DevAssert(pcell != NULL);
DevAssert(pcell->info.cell_id == cell->info.cell_id);
uint32_t ssb_arfcn = get_ssb_arfcn(pcell);
LOG_I(NR_RRC, "Reestablishment update key pci=%d, earfcn_dl=%u\n", pcell->info.pci, ssb_arfcn);
/* Per TS 33.501 6.9.2.3.4: When sending RRCReestablishment with nextHopChainingCount,
* we're staying at the same NCC level (not advancing), so use horizontal derivation
* from the currently active KgNB. Vertical derivation (from NH) is only used when
* advancing to a new NCC level, which happens during handover or masterKeyUpdate. */
const uint8_t *base_key = ue_p->kgnb;
nr_derive_key_ng_ran_star(pcell->info.pci, ssb_arfcn, base_key, ue_p->kgnb);
int size = do_RRCReestablishment(ue_context_pP->ue_context.nh_ncc, buffer, NR_RRC_BUF_SIZE, xid);
LOG_A(NR_RRC, "Send RRCReestablishment [%d bytes] to RNTI %04x\n", size, ue_p->rnti);
/* Ciphering and Integrity according to TS 33.501 */
nr_pdcp_entity_security_keys_and_algos_t security_parameters = {0};
DevAssert(ue_p->ciphering_algorithm >= NR_CipheringAlgorithm_nea0 && ue_p->ciphering_algorithm <= NR_CipheringAlgorithm_nea2);
DevAssert(ue_p->integrity_algorithm >= NR_IntegrityProtAlgorithm_nia0 && ue_p->integrity_algorithm <= NR_IntegrityProtAlgorithm_nia2);
/* Derive the keys from kgnb */
nr_derive_key(RRC_ENC_ALG, ue_p->ciphering_algorithm, ue_p->kgnb, security_parameters.ciphering_key);
nr_derive_key(RRC_INT_ALG, ue_p->integrity_algorithm, ue_p->kgnb, security_parameters.integrity_key);
LOG_I(NR_RRC,
"Set PDCP security UE %d RNTI %04x nea %ld nia %d in RRCReestablishment\n",
ue_p->rrc_ue_id,
ue_p->rnti,
ue_p->ciphering_algorithm,
ue_p->integrity_algorithm);
/* RRCReestablishment is integrity protected but not ciphered,
* so let's configure only integrity protection right now.
* Ciphering is enabled below, after generating RRCReestablishment.
*/
security_parameters.integrity_algorithm = ue_p->integrity_algorithm;
security_parameters.ciphering_algorithm = 0;
/* Re-establish PDCP for SRB1, according to 5.3.7.4 of 3GPP TS 38.331,
* and configure security via set_security internally.
* Note: SRB2 is NOT re-established here. Per TS 38.331 5.3.5.6.3, SRB2
* should be re-established in the first RRCReconfiguration after
* RRCReestablishmentComplete */
ue_p->Srb[SRB1].Active = 1;
nr_pdcp_reestablishment(ue_p->rrc_ue_id, SRB1, true, &security_parameters);
/* F1AP DL RRC Message Transfer */
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
uint32_t old_gNB_DU_ue_id = old_rnti;
f1ap_dl_rrc_message_t dl_rrc = {.gNB_CU_ue_id = ue_p->rrc_ue_id,
.gNB_DU_ue_id = ue_data.secondary_ue,
.srb_id = DL_SCH_LCID_DCCH,
.old_gNB_DU_ue_id = &old_gNB_DU_ue_id};
deliver_dl_rrc_message_data_t data = {.rrc = rrc, .dl_rrc = &dl_rrc, .assoc_id = ue_data.du_assoc_id};
nr_pdcp_data_req_srb(ue_p->rrc_ue_id, DL_SCH_LCID_DCCH, rrc_gNB_mui++, size, (unsigned char *const)buffer, rrc_deliver_dl_rrc_message, &data);
#ifdef E2_AGENT
E2_AGENT_SIGNAL_DL_DCCH_RRC_MSG(buffer, size, NR_DL_DCCH_MessageType__c1_PR_rrcReestablishment);
#endif
/* RRCReestablishment has been generated, let's enable ciphering now. */
security_parameters.ciphering_algorithm = ue_p->ciphering_algorithm;
/* SRBs */
for (int srb_id = 1; srb_id < NR_NUM_SRB; srb_id++) {
if (ue_p->Srb[srb_id].Active)
nr_pdcp_config_set_security(ue_p->rrc_ue_id, srb_id, true, &security_parameters);
}
}
/// @brief Function tha processes RRCReestablishmentComplete message sent by the UE, after RRCReestasblishment request.
static void rrc_gNB_process_RRCReestablishmentComplete(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p, const uint8_t xid)
{
LOG_I(NR_RRC, "UE %d Processing NR_RRCReestablishmentComplete from UE\n", ue_p->rrc_ue_id);
ue_p->xids[xid] = RRC_ACTION_NONE;
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
bool different_du_detected = !ue_p->f1_ue_context_active;
if (different_du_detected) {
/** Handle UE access on a different DU than the original one
* Per 38.401 8.7: "If the UE accessed from a gNB-DU other than the original
* one, the gNB-CU should trigger the UE Context Setup procedure". */
nr_rrc_cell_container_t *cell = rrc_get_pcell_for_ue(rrc, ue_p);
// UE should have a PCell set at this point (set when RRCReestablishmentRequest was handled)
if (cell == NULL) {
LOG_E(NR_RRC, "UE %d: no PCell for reestablishment on different DU\n", ue_p->rrc_ue_id);
return;
}
rrc_f1_ue_context_setup_for_target_du(rrc, ue_p, cell, NULL);
} else {
// Request DU to provide CellGroupConfig with reestablishRLC flags for re-establishment
// According to TS 38.473 transparency requirements, CU should not construct or re-encode CellGroupConfig
f1ap_ue_context_mod_req_t ue_context_modif_req = {
.gNB_CU_ue_id = ue_p->rrc_ue_id,
.gNB_DU_ue_id = ue_data.secondary_ue,
};
// Request CellGroupConfig from DU in the response
ue_context_modif_req.gNB_DU_Configuration_Query = calloc_or_fail(1, sizeof(*ue_context_modif_req.gNB_DU_Configuration_Query));
*ue_context_modif_req.gNB_DU_Configuration_Query = true;
/** Send UE context modification request to DU, which will respond with CellGroupConfig
* containing reestablishRLC flags for re-establishment.
* The response will be handled in rrc_CU_process_ue_context_modification_response()
* which will store the encoded CellGroupConfig and trigger RRC Reconfiguration */
rrc->mac_rrc.ue_context_modification_request(ue_data.du_assoc_id, &ue_context_modif_req);
free_ue_context_mod_req(&ue_context_modif_req);
}
}
int nr_rrc_reconfiguration_req(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p)
{
uint8_t xid = rrc_gNB_get_next_transaction_identifier(rrc->module_id);
ue_p->xids[xid] = RRC_DEDICATED_RECONF;
ue_p->ongoing_reconfiguration = true;
nr_rrc_reconfig_param_t params = {.cgc = &ue_p->mcg, .transaction_id = xid};
byte_array_t msg = do_RRCReconfiguration(&params);
if (msg.len <= 0) {
LOG_E(NR_RRC, "UE %d: Failed to generate RRCReconfiguration\n", ue_p->rrc_ue_id);
return -1;
}
const uint32_t msg_id = NR_DL_DCCH_MessageType__c1_PR_rrcReconfiguration;
nr_rrc_transfer_protected_rrc_message(rrc, ue_p, DL_SCH_LCID_DCCH, msg_id, msg.buf, msg.len);
free_byte_array(msg);
free_RRCReconfiguration_params(params);
return 0;
}
/** @brief Store encoded CellGroupConfig for transparent forwarding (TS 38.473 requirement).
* CU must not decode/re-encode CellGroupConfig, only forward encoded bytes to UE. */
static void store_cgc(gNB_RRC_UE_t *UE, const byte_array_t *cgc)
{
LOG_D(RRC, "UE %04x storing CellGroupConfig encoded bytes for transparent forwarding (len=%ld)\n", UE->rnti, cgc->len);
free_byte_array(UE->mcg);
UE->mcg = copy_byte_array(*cgc);
if (LOG_DEBUGFLAG(DEBUG_ASN1))
dump_cgc(UE->mcg.buf, UE->mcg.len);
}
static void rrc_handle_RRCSetupRequest(gNB_RRC_INST *rrc,
sctp_assoc_t assoc_id,
const NR_RRCSetupRequest_IEs_t *rrcSetupRequest,
const f1ap_initial_ul_rrc_message_t *msg)
{
rrc_gNB_ue_context_t *ue_context_p = NULL;
if (NR_InitialUE_Identity_PR_randomValue == rrcSetupRequest->ue_Identity.present) {
/* randomValue BIT STRING (SIZE (39)) */
if (rrcSetupRequest->ue_Identity.choice.randomValue.size != 5) { // 39-bit random value
LOG_E(NR_RRC,
"wrong InitialUE-Identity randomValue size, expected 5, provided %lu",
(long unsigned int)rrcSetupRequest->ue_Identity.choice.randomValue.size);
return;
}
uint64_t random_value = 0;
memcpy(((uint8_t *)&random_value) + 3,
rrcSetupRequest->ue_Identity.choice.randomValue.buf,
rrcSetupRequest->ue_Identity.choice.randomValue.size);
ue_context_p = rrc_gNB_create_ue_context(assoc_id, msg->crnti, rrc, random_value, msg->gNB_DU_ue_id);
} else if (NR_InitialUE_Identity_PR_ng_5G_S_TMSI_Part1 == rrcSetupRequest->ue_Identity.present) {
/* <5G-S-TMSI> = <AMF Set ID><AMF Pointer><5G-TMSI> 48-bit */
/* ng-5G-S-TMSI-Part1 BIT STRING (SIZE (39)) */
if (rrcSetupRequest->ue_Identity.choice.ng_5G_S_TMSI_Part1.size != 5) {
LOG_E(NR_RRC,
"wrong ng_5G_S_TMSI_Part1 size, expected 5, provided %lu \n",
(long unsigned int)rrcSetupRequest->ue_Identity.choice.ng_5G_S_TMSI_Part1.size);
return;
}
uint64_t s_tmsi_part1 = BIT_STRING_to_uint64(&rrcSetupRequest->ue_Identity.choice.ng_5G_S_TMSI_Part1);
LOG_I(NR_RRC, "Received UE 5G-S-TMSI-Part1 %ld\n", s_tmsi_part1);
ue_context_p = rrc_gNB_create_ue_context(assoc_id, msg->crnti, rrc, s_tmsi_part1, msg->gNB_DU_ue_id);
AssertFatal(ue_context_p != NULL, "out of memory\n");
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
UE->Initialue_identity_5g_s_TMSI.presence = true;
UE->ng_5G_S_TMSI_Part1 = s_tmsi_part1;
} else {
uint64_t random_value = 0;
memcpy(((uint8_t *)&random_value) + 3,
rrcSetupRequest->ue_Identity.choice.randomValue.buf,
rrcSetupRequest->ue_Identity.choice.randomValue.size);
ue_context_p = rrc_gNB_create_ue_context(assoc_id, msg->crnti, rrc, random_value, msg->gNB_DU_ue_id);
LOG_E(NR_RRC, "RRCSetupRequest without random UE identity or S-TMSI not supported, let's reject the UE %04x\n", msg->crnti);
rrc_gNB_generate_RRCReject(rrc, ue_context_p);
return;
}
// If the DU to CU RRC Container IE is not included in the INITIAL UL RRC MESSAGE TRANSFER,
// the gNB-CU should reject the UE under the assumption that the gNB-DU is not able to serve such UE
if (msg->du2cu_rrc_container == NULL) {
// this will remove the UE context
rrc_gNB_generate_RRCReject(rrc, ue_context_p);
return;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
byte_array_t cgc = {.buf = msg->du2cu_rrc_container, .len = msg->du2cu_rrc_container_length};
store_cgc(UE, &cgc);
UE->establishment_cause = rrcSetupRequest->establishmentCause;
// Add PCell to serving_cells array
nr_rrc_cell_container_t *cell = get_cell_by_cell_id(&rrc->cells, msg->nr_cellid);
if (!cell) {
LOG_E(NR_RRC, "Cell %ld not found, rejecting UE\n", msg->nr_cellid);
rrc_gNB_generate_RRCReject(rrc, ue_context_p);
return;
}
/* Update PCell in serving_cells array */
ue_serving_cell_t *added = rrc_update_ue_pcell(UE, cell);
if (added == NULL) {
LOG_E(NR_RRC, "RRCSetup: failed to add PCell (cell %ld)\n", cell->info.cell_id);
rrc_gNB_generate_RRCReject(rrc, ue_context_p);
return;
}
UE->ongoing_reconfiguration = false;
UE->measConfig = nr_rrc_get_measconfig(rrc, msg->nr_cellid);
activate_srb(UE, 1);
rrc_gNB_generate_RRCSetup(0, ue_context_p, msg->du2cu_rrc_container, msg->du2cu_rrc_container_length);
}
static const char *get_reestab_cause(NR_ReestablishmentCause_t c)
{
switch (c) {
case NR_ReestablishmentCause_otherFailure:
return "Other Failure";
case NR_ReestablishmentCause_handoverFailure:
return "Handover Failure";
case NR_ReestablishmentCause_reconfigurationFailure:
return "Reconfiguration Failure";
default:
break;
}
return "UNKNOWN Failure (ASN.1 decoder error?)";
}
static rrc_gNB_ue_context_t *rrc_gNB_get_ue_context_source_cell(gNB_RRC_INST *rrc_instance_pP, long pci, rnti_t rntiP)
{
rrc_gNB_ue_context_t *ue_context_p;
RB_FOREACH(ue_context_p, rrc_nr_ue_tree_s, &rrc_instance_pP->rrc_ue_head) {
gNB_RRC_UE_t *ue = &ue_context_p->ue_context;
if (!ue->ho_context || !ue->ho_context->source)
continue;
nr_ho_source_cu_t *source_ctx = ue->ho_context->source;
const nr_rrc_cell_container_t *source_cell = source_ctx->cell;
if (source_cell && source_ctx->old_rnti == rntiP && source_cell->info.pci == pci)
return ue_context_p;
}
return NULL;
}
/**
* @brief Rollback F1-U DL TL and TEID in RRC
*/
static void f1u_dl_gtp_rollback(gNB_RRC_UE_t *UE)
{
DevAssert(UE != NULL);
DevAssert(UE->ho_context->source != NULL);
FOR_EACH_SEQ_ARR(drb_t *, drb, &UE->drbs) {
drb->du_tunnel_config = UE->ho_context->source->old_du_tunnel_config;
LOG_W(NR_RRC, "DRB id %d rollback to tunnel TEID %x\n", drb->drb_id, drb->du_tunnel_config.teid);
}
}
/** @brief Resolve previous/old cell (UE identity physCellId): same cell, else neighbor
* of current cell, else any cell with that PCI in this DU. */
static const nr_rrc_cell_container_t *get_previous_cell_by_pci_in_du(gNB_RRC_INST *rrc,
const nr_rrc_cell_container_t *current_cell,
const nr_rrc_du_container_t *du,
uint16_t pci)
{
if (current_cell->info.pci == pci)
return current_cell;
const neighbour_cell_configuration_t *neigh_config = get_neighbour_cell_config(rrc, current_cell->info.cell_id);
if (neigh_config != NULL) {
const nr_neighbour_cell_t *neighbour = get_neighbour_cell_by_pci(neigh_config, pci);
if (neighbour != NULL) {
nr_rrc_cell_container_t *c = get_cell_by_cell_id(&rrc->cells, neighbour->nrcell_id);
if (c != NULL && c->assoc_id == du->assoc_id)
return c;
}
}
return rrc_get_cell_by_pci_for_du(&du->cells, pci);
}
static void rrc_handle_RRCReestablishmentRequest(gNB_RRC_INST *rrc,
sctp_assoc_t assoc_id,
const NR_RRCReestablishmentRequest_IEs_t *req,
const f1ap_initial_ul_rrc_message_t *msg)
{
uint64_t random_value = 0;
const char *scause = get_reestab_cause(req->reestablishmentCause);
const long physCellId = req->ue_Identity.physCellId;
long ngap_cause = NGAP_CAUSE_RADIO_NETWORK_UNSPECIFIED; /* cause in case of NGAP release req */
const rnti_t old_rnti = req->ue_Identity.c_RNTI;
rrc_gNB_ue_context_t *ue_context_p = NULL;
ue_serving_cell_t *added = NULL;
LOG_I(NR_RRC,
"Reestablishment RNTI %04x req C-RNTI %04x physCellId %ld cause %s\n",
msg->crnti,
old_rnti,
physCellId,
scause);
const nr_rrc_du_container_t *du = get_du_by_assoc_id(rrc, assoc_id);
if (du == NULL) {
LOG_E(RRC, "received CCCH message, but no corresponding DU found\n");
return;
}
// Fetch current cell: where the reestablishment request was received
nr_rrc_cell_container_t *current_cell = get_cell_by_cell_id(&rrc->cells, msg->nr_cellid);
if (current_cell == NULL || current_cell->assoc_id != du->assoc_id) {
LOG_E(NR_RRC,
"received CCCH message, but no corresponding cell found for nr_cellid %ld in DU (assoc_id %d)\n",
msg->nr_cellid,
assoc_id);
return;
}
// Validate C-RNTI range (3GPP TS 38.321 version 15.13.0 Section 7.1 Table 7.1-1)
if (old_rnti < 0x1 || old_rnti > 0xffef) {
LOG_E(NR_RRC, "NR_RRCReestablishmentRequest c_RNTI %04x range error, fallback to RRC setup\n", old_rnti);
goto fallback_rrc_setup;
}
if (current_cell->mtc == NULL) {
// some UEs don't send MeasurementTimingConfiguration, so we don't know the
// SSB ARFCN and can't do reestablishment. handle it gracefully by doing
// RRC setup procedure instead
LOG_E(NR_RRC, "no MeasurementTimingConfiguration for this cell, cannot perform reestablishment\n");
ngap_cause = NGAP_CAUSE_RADIO_NETWORK_RELEASE_DUE_TO_NGRAN_GENERATED_REASON;
goto fallback_rrc_setup;
}
const nr_rrc_cell_container_t *cell = get_previous_cell_by_pci_in_du(rrc, current_cell, du, (uint16_t)physCellId);
if (cell == NULL) {
LOG_E(NR_RRC, "received CCCH message, but no corresponding cell found for PCI %ld in DU (assoc_id %d)\n", physCellId, assoc_id);
return;
}
ue_context_p = rrc_gNB_get_ue_context_by_rnti(rrc, assoc_id, old_rnti);
if (ue_context_p == NULL) {
// Fallback 1: Try to find UE by RNTI only (re-establishment on different DU scenario)
ue_context_p = rrc_gNB_get_ue_context_by_rnti_any_du(rrc, old_rnti);
if (ue_context_p == NULL) {
// Fallback 2: Try to find UE by source cell (handover scenario)
ue_context_p = rrc_gNB_get_ue_context_source_cell(rrc, physCellId, old_rnti);
if (ue_context_p == NULL) {
LOG_E(NR_RRC, "NR_RRCReestablishmentRequest without UE context, fallback to RRC setup\n");
goto fallback_rrc_setup;
}
}
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
if (!UE->as_security_active) {
/* no active security context, need to restart entire connection */
LOG_E(NR_RRC, "UE requested Reestablishment without activated AS security\n");
ngap_cause = NGAP_CAUSE_RADIO_NETWORK_RELEASE_DUE_TO_NGRAN_GENERATED_REASON;
goto fallback_rrc_setup;
}
f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
nr_ho_source_cu_t *source_ctx = UE->ho_context ? UE->ho_context->source : NULL;
DevAssert(!source_ctx || source_ctx->cell != NULL);
const nr_rrc_cell_container_t *source_cell = source_ctx ? source_ctx->cell : NULL;
bool ho_reestab_on_source = source_cell ? cell->info.cell_id == source_cell->info.cell_id : false;
if (ho_reestab_on_source) {
/* the UE came back on the source DU while doing handover, release at
* target DU and and update the association to the initial DU one */
LOG_W(NR_RRC, "handover for UE %d/RNTI %04x failed, rollback to original cell\n", UE->rrc_ue_id, UE->rnti);
// find the transaction of handover (the corresponding reconfig) and abort it
for (int i = 0; i < NR_RRC_TRANSACTION_IDENTIFIER_NUMBER; ++i) {
if (UE->xids[i] == RRC_DEDICATED_RECONF)
UE->xids[i] = RRC_ACTION_NONE;
}
source_ctx->ho_cancel(rrc, UE);
f1u_dl_gtp_rollback(UE);
/* we need the original CellGroupConfig */
store_cgc(UE, &source_ctx->old_cgc);
/* update to old DU assoc id -- RNTI + secondary DU UE ID further below */
ue_data.du_assoc_id = source_cell->assoc_id;
bool success = cu_update_f1_ue_data(UE->rrc_ue_id, &ue_data);
DevAssert(success);
nr_rrc_finalize_ho(UE);
} else if (physCellId != cell->info.pci) {
/* Check if this is a different DU scenario or "too fast movement" scenario */
if (assoc_id != ue_data.du_assoc_id) {
/* Different DU scenario - physCellId differs because UE is re-establishing on a different DU.
* Re-establishment is allowed, UE Context Setup will be triggered at RRCReestablishmentComplete. */
// Store original du_assoc_id and du_ue_id for immediate release
const sctp_assoc_t old_du_assoc_id = ue_data.du_assoc_id;
const uint32_t old_du_ue_id = ue_data.secondary_ue;
LOG_I(NR_RRC,
"UE %d: Re-establishment on different DU (physCellId %ld from old cell != %d from new DU, du_assoc_id %d -> %d)\n",
UE->rrc_ue_id,
physCellId,
cell->info.pci,
ue_data.du_assoc_id,
assoc_id);
// Update to new DU
ue_data.du_assoc_id = assoc_id;
/* Release old DU context immediately per 3GPP TS 38.473 §8.3.3.2:
* "Interactions with UE Context Setup procedure:
* The UE Context Release procedure may be performed before the UE Context Setup
* procedure to release an existing UE-associated logical F1-connection and related
* resources in the gNB-DU" */
DevAssert(old_du_ue_id != 0);
RETURN_IF_INVALID_ASSOC_ID(old_du_assoc_id);
f1ap_ue_context_rel_cmd_t cmd = {
.gNB_CU_ue_id = UE->rrc_ue_id,
.gNB_DU_ue_id = old_du_ue_id,
.cause = F1AP_CAUSE_RADIO_NETWORK,
.cause_value = F1AP_CauseRadioNetwork_normal_release,
};
rrc->mac_rrc.ue_context_release_command(old_du_assoc_id, &cmd);
LOG_I(NR_RRC,
"UE %d: Re-establishment on different DU - releasing old DU immediately (assoc_id %d, DU UE ID %u)\n",
UE->rrc_ue_id,
old_du_assoc_id,
old_du_ue_id);
// on a new DU: we will have to send f1_ue_context again
UE->f1_ue_context_active = false;
// Update f1_ue_data after release
bool success = cu_update_f1_ue_data(UE->rrc_ue_id, &ue_data);
DevAssert(success);
} else {
/* Same DU but different physCellId - "too fast movement" scenario:
* UE was moving from previous cell so quickly that RRCReestablishment for previous cell was received in this cell */
LOG_I(NR_RRC,
"RRC Reestablishment Request from different physCellId (%ld) than current physCellId (%d), fallback to RRC setup\n",
physCellId,
cell->info.pci);
ngap_cause = NGAP_CAUSE_RADIO_NETWORK_RELEASE_DUE_TO_NGRAN_GENERATED_REASON;
goto fallback_rrc_setup;
}
}
/* TODO: start timer in ITTI and drop UE if it does not come back */
// update with new RNTI, and update secondary UE association
UE->rnti = msg->crnti;
/* Update PCell in serving_cells array */
DevAssert(cell->info.cell_id == msg->nr_cellid);
added = rrc_update_ue_pcell(UE, cell);
if (added == NULL) {
LOG_E(NR_RRC, "Reestablishment: failed to add PCell (cell %ld)\n", cell->info.cell_id);
return;
}
ue_data.secondary_ue = msg->gNB_DU_ue_id;
bool success = cu_update_f1_ue_data(UE->rrc_ue_id, &ue_data);
DevAssert(success);
rrc_gNB_generate_RRCReestablishment(ue_context_p, old_rnti, cell);
return;
fallback_rrc_setup:
fill_random(&random_value, sizeof(random_value));
random_value = random_value & 0x7fffffffff; /* random value is 39 bits */
ngap_cause_t cause = {.type = NGAP_CAUSE_RADIO_NETWORK, .value = ngap_cause};
/* request release of the "old" UE in case it exists */
if (ue_context_p != NULL)
rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_REQ(0, ue_context_p, cause);
rrc_gNB_ue_context_t *new = rrc_gNB_create_ue_context(assoc_id, msg->crnti, rrc, random_value, msg->gNB_DU_ue_id);
activate_srb(&new->ue_context, 1);
added = rrc_update_ue_pcell(&new->ue_context, current_cell);
DevAssert(added);
rrc_gNB_generate_RRCSetup(0, new, msg->du2cu_rrc_container, msg->du2cu_rrc_container_length);
return;
}
static void process_Periodical_Measurement_Report(gNB_RRC_UE_t *ue_ctxt, NR_MeasurementReport_t *measurementReport)
{
ASN_STRUCT_FREE(asn_DEF_NR_MeasResults, ue_ctxt->measResults);
ue_ctxt->measResults = NULL;
const NR_MeasId_t id = measurementReport->criticalExtensions.choice.measurementReport->measResults.measId;
AssertFatal(id, "unexpected MeasResult for MeasurementId %ld received\n", id);
asn1cCallocOne(ue_ctxt->measResults, measurementReport->criticalExtensions.choice.measurementReport->measResults);
/* we "keep" the measurement report, so set to 0 */
free(measurementReport->criticalExtensions.choice.measurementReport);
measurementReport->criticalExtensions.choice.measurementReport = NULL;
}
static void process_Event_Based_Measurement_Report(gNB_RRC_INST *rrc,
gNB_RRC_UE_t *ue,
NR_ReportConfigNR_t *report,
NR_MeasurementReport_t *measurementReport)
{
NR_EventTriggerConfig_t *event_triggered = report->reportType.choice.eventTriggered;
int servingCellRSRP = 0;
int neighbourCellRSRP = 0;
int scell_pci = -1;
int best_rsrp = -10000;
switch (event_triggered->eventId.present) {
case NR_EventTriggerConfig__eventId_PR_eventA2:
LOG_I(NR_RRC, "HO LOG: Event A2 (Serving becomes worse than threshold)\n");
break;
case NR_EventTriggerConfig__eventId_PR_eventA3: {
LOG_W(NR_RRC, "HO LOG: Event A3 Report for UE %d - Neighbour Becomes Better than Serving!\n", ue->rrc_ue_id);
if (!measurementReport->criticalExtensions.choice.measurementReport) {
LOG_E(NR_RRC, "HO LOG: Event A3 Report: measurementReport is null\n");
break;
}
const NR_MeasResults_t *measResults = &measurementReport->criticalExtensions.choice.measurementReport->measResults;
for (int serving_cell_idx = 0; serving_cell_idx < measResults->measResultServingMOList.list.count; serving_cell_idx++) {
const NR_MeasResultServMO_t *meas_result_serv_MO = measResults->measResultServingMOList.list.array[serving_cell_idx];
scell_pci = *(meas_result_serv_MO->measResultServingCell.physCellId);
if (meas_result_serv_MO->measResultServingCell.measResult.cellResults.resultsSSB_Cell) {
servingCellRSRP = *(meas_result_serv_MO->measResultServingCell.measResult.cellResults.resultsSSB_Cell->rsrp) - 157;
} else {
servingCellRSRP = *(meas_result_serv_MO->measResultServingCell.measResult.cellResults.resultsCSI_RS_Cell->rsrp) - 157;
}
LOG_D(NR_RRC, "Serving Cell RSRP: %d\n", servingCellRSRP);
}
if (measResults->measResultNeighCells == NULL ||
measResults->measResultNeighCells->present != NR_MeasResults__measResultNeighCells_PR_measResultListNR) {
LOG_D(NR_RRC, "HO LOG: No neighbor cell measurements available\n");
break;
}
const NR_MeasResultListNR_t *measResultListNR = measResults->measResultNeighCells->choice.measResultListNR;
for (int neigh_meas_idx = 0; neigh_meas_idx < measResultListNR->list.count; neigh_meas_idx++) {
const NR_MeasResultNR_t *meas_result_neigh_cell = (measResultListNR->list.array[neigh_meas_idx]);
const int neighbour_pci = *(meas_result_neigh_cell->physCellId);
// TS 138 133 Table 10.1.6.1-1: SS-RSRP and CSI-RSRP measurement report mapping
const struct NR_MeasResultNR__measResult__cellResults *cellResults = &(meas_result_neigh_cell->measResult.cellResults);
if (cellResults->resultsSSB_Cell) {
neighbourCellRSRP = *(cellResults->resultsSSB_Cell->rsrp) - 157;
} else {
neighbourCellRSRP = *(cellResults->resultsCSI_RS_Cell->rsrp) - 157;
}
LOG_I(NR_RRC,
"HO LOG: Measurement Report for the neighbour %d with RSRP: %d\n",
neighbour_pci,
neighbourCellRSRP);
// Resolve source cell by PCI from UE's serving cells
const nr_rrc_cell_container_t *source_cell = NULL;
FOR_EACH_SEQ_ARR (ue_serving_cell_t *, scell, &ue->serving_cells) {
nr_rrc_cell_container_t *cell_by_id = get_cell_by_cell_id(&rrc->cells, scell->nci);
if (cell_by_id != NULL && cell_by_id->info.pci == scell_pci) {
source_cell = cell_by_id;
break;
}
}
if (source_cell == NULL) {
LOG_W(NR_RRC,
"UE %d: received measurement report but source cell with PCI %d not found in UE's serving cells, skipping\n",
ue->rrc_ue_id,
scell_pci);
continue;
}
// Resolve target cell via neighbour configuration
const neighbour_cell_configuration_t *cell = get_neighbour_cell_config(rrc, source_cell->info.cell_id);
const nr_neighbour_cell_t *neighbour = get_neighbour_cell_by_pci(cell, neighbour_pci);
const nr_rrc_cell_container_t *target_cell = NULL;
if (neighbour != NULL) {
// Resolve target cell by cell_id from neighbour config (may be NULL if no F1 connection)
target_cell = get_cell_by_cell_id(&rrc->cells, neighbour->nrcell_id);
}
// CU does not have f1 connection with neighbour cell context. So check does serving cell has this phyCellId as a
// neighbour.
if (!target_cell && neighbour) {
// No F1 connection but static neighbour configuration is available
const nr_a3_event_t *a3_event_configuration = get_a3_configuration(rrc, neighbour->physicalCellId);
/* if no A3 event configured for this physical cell ID, try to get the default one */
if (!a3_event_configuration)
a3_event_configuration = get_a3_configuration(rrc, -1);
// Additional check - This part can be modified according to additional cell specific Handover Margin
// a3-Offset: The actual value is field value * 0.5 dB.
if (a3_event_configuration
&& ((a3_event_configuration->a3_offset * 0.5 + a3_event_configuration->hysteresis)
< (neighbourCellRSRP - servingCellRSRP))) {
if (neighbourCellRSRP > best_rsrp) {
// UE can send multiple neighbour cells A3 event report in 1 Meas Report. So, we need to find the best neighbour
best_rsrp = neighbourCellRSRP;
LOG_I(NR_RRC, "HO LOG: Serving Cell RSRP: %d - Best Neighbor RSRP: %d ! Trigger N2 HO\n", servingCellRSRP, best_rsrp);
nr_rrc_trigger_n2_ho(rrc, ue, neighbour);
}
LOG_D(NR_RRC, "HO LOG: Trigger N2 HO for the neighbour gnb: %u cell: %lu\n", neighbour->gNB_ID, neighbour->nrcell_id);
}
} else if (target_cell && neighbour) {
/* we know the cell and are connected to the DU! */
nr_rrc_trigger_f1_ho(rrc, ue, source_cell, target_cell);
} else {
LOG_W(NR_RRC, "UE %d: received A3 event for stronger neighbor PCI %d, but no such neighbour in configuration\n", ue->rrc_ue_id, neighbour_pci);
}
}
} break;
default:
LOG_D(NR_RRC, "NR_EventTriggerConfig__eventId_PR_NOTHING or Other event report\n");
break;
}
}
static void rrc_gNB_process_MeasurementReport(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, NR_MeasurementReport_t *measurementReport)
{
NR_MeasurementReport__criticalExtensions_PR p = measurementReport->criticalExtensions.present;
if (p != NR_MeasurementReport__criticalExtensions_PR_measurementReport
|| measurementReport->criticalExtensions.choice.measurementReport == NULL) {
LOG_E(NR_RRC, "UE %d: expected presence of MeasurementReport, but has %d (%p)\n", UE->rrc_ue_id, p, measurementReport->criticalExtensions.choice.measurementReport);
return;
}
if (LOG_DEBUGFLAG(DEBUG_ASN1))
xer_fprint(stdout, &asn_DEF_NR_MeasurementReport, (void *)measurementReport);
NR_MeasConfig_t *meas_config = UE->measConfig;
if (meas_config == NULL) {
LOG_I(NR_RRC, "Unexpected Measurement Report from UE with id: %d\n", UE->rrc_ue_id);
return;
}
NR_MeasurementReport_IEs_t *measurementReport_IEs = measurementReport->criticalExtensions.choice.measurementReport;
const NR_MeasId_t measId = measurementReport_IEs->measResults.measId;
NR_MeasIdToAddMod_t *meas_id_s = NULL;
for (int meas_idx = 0; meas_idx < meas_config->measIdToAddModList->list.count; meas_idx++) {
if (measId == meas_config->measIdToAddModList->list.array[meas_idx]->measId) {
meas_id_s = meas_config->measIdToAddModList->list.array[meas_idx];
break;
}
}
if (meas_id_s == NULL) {
LOG_E(NR_RRC, "Incoming Meas ID with id: %d Can not Found!\n", (int)measId);
return;
}
LOG_D(NR_RRC, "HO LOG: Meas Id is found: %d\n", (int)meas_id_s->measId);
struct NR_ReportConfigToAddMod__reportConfig *report_config = NULL;
for (int rep_id = 0; rep_id < meas_config->reportConfigToAddModList->list.count; rep_id++) {
if (meas_id_s->reportConfigId == meas_config->reportConfigToAddModList->list.array[rep_id]->reportConfigId) {
report_config = &meas_config->reportConfigToAddModList->list.array[rep_id]->reportConfig;
}
}
if (report_config == NULL || report_config->choice.reportConfigNR == NULL) {
LOG_E(NR_RRC, "There is no related report configuration for this measId!\n");
return;
}
if (report_config->choice.reportConfigNR->reportType.present == NR_ReportConfigNR__reportType_PR_periodical)
return process_Periodical_Measurement_Report(UE, measurementReport);
if (report_config->choice.reportConfigNR->reportType.present == NR_ReportConfigNR__reportType_PR_eventTriggered)
return process_Event_Based_Measurement_Report(rrc, UE, report_config->choice.reportConfigNR, measurementReport);
LOG_E(NR_RRC, "Incoming Report Type: %d is not supported! \n", report_config->choice.reportConfigNR->reportType.present);
}
static void handle_rrcReestablishmentComplete(gNB_RRC_INST *rrc,
gNB_RRC_UE_t *UE,
const NR_RRCReestablishmentComplete_t *cplt)
{
NR_RRCReestablishmentComplete__criticalExtensions_PR p = cplt->criticalExtensions.present;
if (p != NR_RRCReestablishmentComplete__criticalExtensions_PR_rrcReestablishmentComplete) {
LOG_E(NR_RRC, "UE %d: expected presence of rrcReestablishmentComplete, but message has %d\n", UE->rrc_ue_id, p);
return;
}
rrc_gNB_process_RRCReestablishmentComplete(rrc, UE, cplt->rrc_TransactionIdentifier);
UE->ue_reestablishment_counter++;
}
/**
* @brief Forward stored NAS PDU to UE (3GPP TS 38.413)
* - 8.2.1.2: If the NAS-PDU IE is included in the PDU SESSION RESOURCE SETUP REQUEST message,
* the NG-RAN node shall pass it to the UE.
* - 8.3.1.2: If the NAS-PDU IE is included in the INITIAL CONTEXT SETUP REQUEST message,
* the NG-RAN node shall pass it transparently towards the UE.
* - 8.6.2: The NAS-PDU IE contains an AMF–UE message that is transferred without interpretation in the NG-RAN node.
*/
void rrc_forward_ue_nas_message(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE)
{
if (UE->nas_pdu.buf == NULL || UE->nas_pdu.len == 0)
return; // no problem: the UE will re-request a NAS PDU
LOG_UE_DL_EVENT(UE, "Send DL Information Transfer [%ld bytes]\n", UE->nas_pdu.len);
uint8_t buffer[4096];
unsigned int xid = rrc_gNB_get_next_transaction_identifier(rrc->module_id);
uint32_t length = do_NR_DLInformationTransfer(buffer, sizeof(buffer), xid, UE->nas_pdu.len, UE->nas_pdu.buf);
LOG_DUMPMSG(NR_RRC, DEBUG_RRC, buffer, length, "[MSG] RRC DL Information Transfer\n");
rb_id_t srb_id = UE->Srb[2].Active ? DL_SCH_LCID_DCCH1 : DL_SCH_LCID_DCCH;
const uint32_t msg_id = NR_DL_DCCH_MessageType__c1_PR_dlInformationTransfer;
nr_rrc_transfer_protected_rrc_message(rrc, UE, srb_id, msg_id, buffer, length);
// no need to free UE->nas_pdu.buf, do_NR_DLInformationTransfer() did that
UE->nas_pdu.buf = NULL;
UE->nas_pdu.len = 0;
}
static void handle_ueCapabilityInformation(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, const NR_UECapabilityInformation_t *ue_cap_info)
{
int xid = ue_cap_info->rrc_TransactionIdentifier;
rrc_action_t a = UE->xids[xid];
UE->xids[xid] = RRC_ACTION_NONE;
if (a != RRC_UECAPABILITY_ENQUIRY) {
LOG_E(NR_RRC, "UE %d: received unsolicited UE Capability Information, aborting procedure\n", UE->rrc_ue_id);
return;
}
int eutra_index = -1;
if (ue_cap_info->criticalExtensions.present == NR_UECapabilityInformation__criticalExtensions_PR_ueCapabilityInformation) {
const NR_UE_CapabilityRAT_ContainerList_t *ue_CapabilityRAT_ContainerList =
ue_cap_info->criticalExtensions.choice.ueCapabilityInformation->ue_CapabilityRAT_ContainerList;
/* Encode UE-CapabilityRAT-ContainerList for sending to the DU */
FREE_AND_ZERO_BYTE_ARRAY(UE->ue_cap_buffer);
UE->ue_cap_buffer.len = uper_encode_to_new_buffer(&asn_DEF_NR_UE_CapabilityRAT_ContainerList,
NULL,
ue_CapabilityRAT_ContainerList,
(void **)&UE->ue_cap_buffer.buf);
if (UE->ue_cap_buffer.len <= 0) {
LOG_E(RRC, "could not encode UE-CapabilityRAT-ContainerList, abort handling capabilities\n");
return;
}
LOG_UE_UL_EVENT(UE, "Received UE capabilities\n");
for (int i = 0; i < ue_CapabilityRAT_ContainerList->list.count; i++) {
const NR_UE_CapabilityRAT_Container_t *ue_cap_container = ue_CapabilityRAT_ContainerList->list.array[i];
if (ue_cap_container->rat_Type == NR_RAT_Type_nr) {
if (UE->UE_Capability_nr) {
ASN_STRUCT_FREE(asn_DEF_NR_UE_NR_Capability, UE->UE_Capability_nr);
UE->UE_Capability_nr = 0;
}
UE->UE_Capability_nr = decode_nr_ue_capability(UE->rnti, ue_CapabilityRAT_ContainerList);
if (!UE->UE_Capability_nr) {
LOG_E(NR_RRC, "UE %d: NR capability decoding failed\n", UE->rrc_ue_id);
return;
}
if (LOG_DEBUGFLAG(DEBUG_ASN1)) {
xer_fprint(stdout, &asn_DEF_NR_UE_NR_Capability, UE->UE_Capability_nr);
}
const NR_RedCapParameters_r17_t *redcap_p = get_redcapparam_r17(UE->UE_Capability_nr);
if (redcap_p) {
UE->redcap_cap = calloc_or_fail(1, sizeof(*UE->redcap_cap));
UE->redcap_cap->support_of_redcap_r17 = redcap_p->supportOfRedCap_r17 != NULL;
UE->redcap_cap->support_of_16drb_redcap_r17 = redcap_p->supportOf16DRB_RedCap_r17 != NULL;
if (UE->UE_Capability_nr->pdcp_Parameters.ext2)
UE->redcap_cap->pdcp_drb_long_sn_redcap_r17 = UE->UE_Capability_nr->pdcp_Parameters.ext2->longSN_RedCap_r17 != NULL;
if (UE->UE_Capability_nr->rlc_Parameters && UE->UE_Capability_nr->rlc_Parameters->ext2)
UE->redcap_cap->rlc_am_drb_long_sn_redcap_r17 =
UE->UE_Capability_nr->rlc_Parameters->ext2->am_WithLongSN_RedCap_r17 != NULL;
}
UE->UE_Capability_size = ue_cap_container->ue_CapabilityRAT_Container.size;
if (eutra_index != -1) {
LOG_E(NR_RRC, "fatal: more than 1 eutra capability\n");
return;
}
eutra_index = i;
}
if (ue_cap_container->rat_Type == NR_RAT_Type_eutra_nr) {
if (UE->UE_Capability_MRDC) {
ASN_STRUCT_FREE(asn_DEF_NR_UE_MRDC_Capability, UE->UE_Capability_MRDC);
UE->UE_Capability_MRDC = 0;
}
asn_dec_rval_t dec_rval = uper_decode(NULL,
&asn_DEF_NR_UE_MRDC_Capability,
(void **)&UE->UE_Capability_MRDC,
ue_cap_container->ue_CapabilityRAT_Container.buf,
ue_cap_container->ue_CapabilityRAT_Container.size,
0,
0);
if (LOG_DEBUGFLAG(DEBUG_ASN1)) {
xer_fprint(stdout, &asn_DEF_NR_UE_MRDC_Capability, UE->UE_Capability_MRDC);
}
if ((dec_rval.code != RC_OK) && (dec_rval.consumed == 0)) {
LOG_E(NR_RRC, "UE %d: Failed to decode nr UE capabilities (%zu bytes)\n", UE->rrc_ue_id, dec_rval.consumed);
ASN_STRUCT_FREE(asn_DEF_NR_UE_MRDC_Capability, UE->UE_Capability_MRDC);
UE->UE_Capability_MRDC = 0;
}
UE->UE_MRDC_Capability_size = ue_cap_container->ue_CapabilityRAT_Container.size;
}
if (ue_cap_container->rat_Type == NR_RAT_Type_eutra) {
// TODO
}
}
if (eutra_index == -1)
return;
}
rrc_gNB_send_NGAP_UE_CAPABILITIES_IND(rrc, UE, ue_cap_info);
if (UE->n_initial_pdu > 0) {
/* there were PDU sessions with the NG UE Context setup, but we had to set
* up security and request capabilities, so trigger PDU sessions now. The
* UE NAS message will be forwarded in the corresponding reconfiguration,
* the Initial context setup response after reconfiguration complete. */
if (!is_cuup_associated(rrc)) {
LOG_W(NR_RRC, "Failed to setup bearers for UE %d: send Initial Context Setup Response\n", UE->rrc_ue_id);
rrc_gNB_send_NGAP_INITIAL_CONTEXT_SETUP_RESP(rrc, UE);
rrc_forward_ue_nas_message(rrc, UE);
return;
}
// Add to UE context lists
nr_rrc_add_bearers(rrc, UE, UE->n_initial_pdu, UE->initial_pdus);
// Trigger bearer setup
trigger_bearer_setup(rrc, UE, UE->ambr.dl_br);
} else {
rrc_gNB_send_NGAP_INITIAL_CONTEXT_SETUP_RESP(rrc, UE);
rrc_forward_ue_nas_message(rrc, UE);
}
return;
}
static void handle_rrcSetupComplete(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, const NR_RRCSetupComplete_t *setup_complete)
{
uint8_t xid = setup_complete->rrc_TransactionIdentifier;
UE->xids[xid] = RRC_ACTION_NONE;
if (setup_complete->criticalExtensions.present != NR_RRCSetupComplete__criticalExtensions_PR_rrcSetupComplete) {
LOG_E(NR_RRC, "malformed RRCSetupComplete received from UE %d\n", UE->rrc_ue_id);
return;
}
NR_RRCSetupComplete_IEs_t *setup_complete_ies = setup_complete->criticalExtensions.choice.rrcSetupComplete;
if (setup_complete_ies->ng_5G_S_TMSI_Value != NULL) {
uint64_t fiveg_s_TMSI = 0;
if (setup_complete_ies->ng_5G_S_TMSI_Value->present == NR_RRCSetupComplete_IEs__ng_5G_S_TMSI_Value_PR_ng_5G_S_TMSI_Part2) {
const BIT_STRING_t *part2 = &setup_complete_ies->ng_5G_S_TMSI_Value->choice.ng_5G_S_TMSI_Part2;
if (part2->size != 2) {
LOG_E(NR_RRC, "wrong ng_5G_S_TMSI_Part2 size, expected 2, provided %lu", part2->size);
return;
}
if (UE->Initialue_identity_5g_s_TMSI.presence) {
uint16_t stmsi_part2 = BIT_STRING_to_uint16(part2);
LOG_I(RRC, "s_tmsi part2 %d (%02x %02x)\n", stmsi_part2, part2->buf[0], part2->buf[1]);
// Part2 is leftmost 9, Part1 is rightmost 39 bits of 5G-S-TMSI
fiveg_s_TMSI = nr_build_full_5g_s_tmsi(UE->ng_5G_S_TMSI_Part1, stmsi_part2);
} else {
LOG_W(RRC, "UE %d received 5G-S-TMSI-Part2, but no 5G-S-TMSI-Part1 present, won't send 5G-S-TMSI to core\n", UE->rrc_ue_id);
UE->Initialue_identity_5g_s_TMSI.presence = false;
}
} else if (setup_complete_ies->ng_5G_S_TMSI_Value->present == NR_RRCSetupComplete_IEs__ng_5G_S_TMSI_Value_PR_ng_5G_S_TMSI) {
const NR_NG_5G_S_TMSI_t *bs_stmsi = &setup_complete_ies->ng_5G_S_TMSI_Value->choice.ng_5G_S_TMSI;
if (bs_stmsi->size != 6) {
LOG_E(NR_RRC, "wrong ng_5G_S_TMSI size, expected 6, provided %lu", bs_stmsi->size);
return;
}
fiveg_s_TMSI = BIT_STRING_to_uint64(bs_stmsi);
UE->Initialue_identity_5g_s_TMSI.presence = true;
}
if (UE->Initialue_identity_5g_s_TMSI.presence) {
uint16_t amf_set_id;
uint8_t amf_pointer;
uint32_t fiveg_tmsi;
nr_deconstruct_5g_s_tmsi(fiveg_s_TMSI, &amf_set_id, &amf_pointer, &fiveg_tmsi);
LOG_I(NR_RRC,
"5g_s_TMSI: 0x%lX, amf_set_id: 0x%X (%d), amf_pointer: 0x%X (%d), 5g TMSI: 0x%X \n",
fiveg_s_TMSI,
amf_set_id,
amf_set_id,
amf_pointer,
amf_pointer,
fiveg_tmsi);
UE->Initialue_identity_5g_s_TMSI.amf_set_id = amf_set_id;
UE->Initialue_identity_5g_s_TMSI.amf_pointer = amf_pointer;
UE->Initialue_identity_5g_s_TMSI.fiveg_tmsi = fiveg_tmsi;
// update random identity with 5G-S-TMSI, which only contained Part1 of it
UE->random_ue_identity = fiveg_s_TMSI;
}
}
#ifdef E2_AGENT
const uint32_t msg_id = NR_UL_DCCH_MessageType__c1_PR_rrcSetupComplete;
signal_ue_id(UE, UL_DCCH_NR_RRC_CLASS, msg_id);
#endif
rrc_gNB_process_RRCSetupComplete(rrc, UE, setup_complete->criticalExtensions.choice.rrcSetupComplete);
return;
}
static void handle_rrcReconfigurationComplete(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, const NR_RRCReconfigurationComplete_t *reconfig_complete)
{
uint8_t xid = reconfig_complete->rrc_TransactionIdentifier;
UE->ue_reconfiguration_counter++;
UE->ongoing_reconfiguration = false;
switch (UE->xids[xid]) {
case RRC_PDUSESSION_RELEASE: {
rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE(rrc, UE, xid);
reset_delayed_action(&UE->delayed_action);
} break;
case RRC_PDUSESSION_ESTABLISH:
if (UE->n_initial_pdu > 0) {
/* PDU sessions through initial UE context setup */
rrc_gNB_send_NGAP_INITIAL_CONTEXT_SETUP_RESP(rrc, UE);
UE->n_initial_pdu = 0;
free(UE->initial_pdus);
UE->initial_pdus = NULL;
} else if (seq_arr_size(&UE->pduSessions) > 0)
rrc_gNB_send_NGAP_PDUSESSION_SETUP_RESP(rrc, UE);
else
LOG_W(NR_RRC,
"UE %d: RRC Reconfiguration Complete for PDU session establishment, but no PDU sessions were setup\n",
UE->rrc_ue_id);
reset_delayed_action(&UE->delayed_action);
break;
case RRC_PDUSESSION_MODIFY:
rrc_gNB_send_NGAP_PDUSESSION_MODIFY_RESP(rrc, UE, xid);
break;
case RRC_REESTABLISH_COMPLETE:
case RRC_DEDICATED_RECONF:
/* do nothing */
break;
case RRC_ACTION_NONE:
LOG_E(RRC, "UE %d: Received RRC Reconfiguration Complete with xid %d while no transaction is ongoing\n", UE->rrc_ue_id, xid);
break;
default:
LOG_E(RRC, "UE %d: Received unexpected transaction type %d for xid %d\n", UE->rrc_ue_id, UE->xids[xid], xid);
break;
}
UE->xids[xid] = RRC_ACTION_NONE;
for (int i = 0; i < NR_RRC_TRANSACTION_IDENTIFIER_NUMBER; ++i) {
if (UE->xids[i] != RRC_ACTION_NONE) {
LOG_I(RRC, "UE %d: transaction %d still ongoing for action %d\n", UE->rrc_ue_id, i, UE->xids[i]);
}
}
if (UE->ho_context != NULL) {
LOG_A(NR_RRC, "handover for UE %d/RNTI %04x complete!\n", UE->rrc_ue_id, UE->rnti);
DevAssert(UE->ho_context->target != NULL);
UE->ho_context->target->ho_success(rrc, UE);
nr_rrc_finalize_ho(UE);
}
f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
ReconfigurationCompl_t rc = RRCreconf_success;
f1ap_ue_context_mod_req_t req = {
.gNB_CU_ue_id = UE->rrc_ue_id,
.gNB_DU_ue_id = ue_data.secondary_ue,
.reconfig_compl = &rc,
};
rrc->mac_rrc.ue_context_modification_request(ue_data.du_assoc_id, &req);
/* nothing to be freed */
}
static void rrc_gNB_generate_UECapabilityEnquiry(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue)
{
uint8_t buffer[100];
T(T_ENB_RRC_UE_CAPABILITY_ENQUIRY, T_INT(rrc->module_id), T_INT(0), T_INT(0), T_INT(ue->rrc_ue_id));
uint8_t xid = rrc_gNB_get_next_transaction_identifier(rrc->module_id);
ue->xids[xid] = RRC_UECAPABILITY_ENQUIRY;
int size = do_NR_SA_UECapabilityEnquiry(buffer, xid);
LOG_I(NR_RRC, "UE %d: Logical Channel DL-DCCH, Generate NR UECapabilityEnquiry (bytes %d, xid %d)\n", ue->rrc_ue_id, size, xid);
AssertFatal(!NODE_IS_DU(rrc->node_type), "illegal node type DU!\n");
const uint32_t msg_id = NR_DL_DCCH_MessageType__c1_PR_ueCapabilityEnquiry;
nr_rrc_transfer_protected_rrc_message(rrc, ue, DL_SCH_LCID_DCCH, msg_id, buffer, size);
}
static int rrc_gNB_decode_dcch(gNB_RRC_INST *rrc, const f1ap_ul_rrc_message_t *msg)
{
/* we look up by CU UE ID! Do NOT change back to RNTI! */
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, msg->gNB_CU_ue_id);
if (!ue_context_p) {
LOG_E(RRC, "could not find UE context for CU UE ID %u, aborting transaction\n", msg->gNB_CU_ue_id);
return -1;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
if (msg->srb_id < 1 || msg->srb_id > 2) {
LOG_E(NR_RRC, "Received message on SRB %d, discarding message\n", msg->srb_id);
return -1;
}
LOG_D(NR_RRC, "UE %d: Decoding DCCH %d size %d\n", UE->rrc_ue_id, msg->srb_id, msg->rrc_container_length);
LOG_DUMPMSG(RRC, DEBUG_RRC, (char *)msg->rrc_container, msg->rrc_container_length, "[MSG] RRC UL Information Transfer \n");
NR_UL_DCCH_Message_t *ul_dcch_msg = NULL;
asn_dec_rval_t dec_rval =
uper_decode(NULL, &asn_DEF_NR_UL_DCCH_Message, (void **)&ul_dcch_msg, msg->rrc_container, msg->rrc_container_length, 0, 0);
if ((dec_rval.code != RC_OK) && (dec_rval.consumed == 0)) {
LOG_E(NR_RRC, "UE %d: Failed to decode UL-DCCH (%zu bytes)\n", UE->rrc_ue_id, dec_rval.consumed);
return -1;
}
if (LOG_DEBUGFLAG(DEBUG_ASN1)) {
xer_fprint(stdout, &asn_DEF_NR_UL_DCCH_Message, (void *)ul_dcch_msg);
}
if (ul_dcch_msg->message.present == NR_UL_DCCH_MessageType_PR_c1) {
#ifdef E2_AGENT
// 38.331 Sec 6.2.1: message index of UL-DCCH-Message
const uint32_t rrc_msg_id = ul_dcch_msg->message.choice.c1->present;
byte_array_t buffer_ba = {.len = msg->rrc_container_length};
buffer_ba.buf = msg->rrc_container;
signal_rrc_msg(UL_DCCH_NR_RRC_CLASS, rrc_msg_id, buffer_ba);
#endif
switch (ul_dcch_msg->message.choice.c1->present) {
case NR_UL_DCCH_MessageType__c1_PR_NOTHING:
LOG_I(NR_RRC, "Received PR_NOTHING on UL-DCCH-Message\n");
break;
case NR_UL_DCCH_MessageType__c1_PR_rrcReconfigurationComplete:
LOG_UE_UL_EVENT(UE, "Received RRCReconfigurationComplete\n");
handle_rrcReconfigurationComplete(rrc, UE, ul_dcch_msg->message.choice.c1->choice.rrcReconfigurationComplete);
break;
case NR_UL_DCCH_MessageType__c1_PR_rrcSetupComplete:
LOG_UE_UL_EVENT(UE, "Received RRCSetupComplete (RRC_CONNECTED reached)\n");
handle_rrcSetupComplete(rrc, UE, ul_dcch_msg->message.choice.c1->choice.rrcSetupComplete);
break;
case NR_UL_DCCH_MessageType__c1_PR_measurementReport:
if (ul_dcch_msg->message.choice.c1->choice.measurementReport != NULL) {
rrc_gNB_process_MeasurementReport(rrc, UE, ul_dcch_msg->message.choice.c1->choice.measurementReport);
} else {
LOG_E(NR_RRC, "UE %d: No measurementReport CHOICE is given\n", ue_context_p->ue_context.rrc_ue_id);
}
break;
case NR_UL_DCCH_MessageType__c1_PR_ulInformationTransfer:
LOG_UE_UL_EVENT(UE, "Received RRC UL Information Transfer [%d bytes]\n", msg->rrc_container_length);
rrc_gNB_send_NGAP_UPLINK_NAS(rrc, UE, ul_dcch_msg);
break;
case NR_UL_DCCH_MessageType__c1_PR_securityModeComplete:
LOG_UE_UL_EVENT(UE, "Received Security Mode Complete\n");
/* configure ciphering */
nr_rrc_pdcp_config_security(UE, true);
UE->as_security_active = true;
/* trigger UE capability enquiry if we don't have them yet */
if (UE->ue_cap_buffer.len == 0) {
rrc_gNB_generate_UECapabilityEnquiry(rrc, UE);
/* else blocks are executed after receiving UE capability info */
} else if (UE->n_initial_pdu > 0) {
/* there were PDU sessions with the NG UE Context setup, but we had
* to set up security, so trigger PDU sessions now. The UE NAS
* message will be forwarded in the corresponding reconfiguration,
* the Initial context setup response after reconfiguration complete. */
if (!is_cuup_associated(rrc)) {
LOG_W(NR_RRC, "Failed to setup bearers for UE %d: send Initial Context Setup Response\n", UE->rrc_ue_id);
rrc_gNB_send_NGAP_INITIAL_CONTEXT_SETUP_RESP(rrc, UE);
rrc_forward_ue_nas_message(rrc, UE);
return -1;
}
// Add to UE context lists
nr_rrc_add_bearers(rrc, UE, UE->n_initial_pdu, UE->initial_pdus);
// Trigger bearer setup
trigger_bearer_setup(rrc, UE, UE->ambr.dl_br);
} else {
/* we already have capabilities, and no PDU sessions to setup, ack
* this UE */
rrc_gNB_send_NGAP_INITIAL_CONTEXT_SETUP_RESP(rrc, UE);
rrc_forward_ue_nas_message(rrc, UE);
}
break;
case NR_UL_DCCH_MessageType__c1_PR_securityModeFailure:
LOG_E(NR_RRC, "UE %d: received securityModeFailure\n", ue_context_p->ue_context.rrc_ue_id);
LOG_W(NR_RRC, "Cannot continue as no AS security is activated (implementation missing)\n");
break;
case NR_UL_DCCH_MessageType__c1_PR_ueCapabilityInformation:
handle_ueCapabilityInformation(rrc, UE, ul_dcch_msg->message.choice.c1->choice.ueCapabilityInformation);
break;
case NR_UL_DCCH_MessageType__c1_PR_rrcReestablishmentComplete:
LOG_UE_UL_EVENT(UE, "Received RRCReestablishmentComplete\n");
const NR_RRCReestablishmentComplete_t *rc = ul_dcch_msg->message.choice.c1->choice.rrcReestablishmentComplete;
handle_rrcReestablishmentComplete(rrc, UE, rc);
break;
default:
break;
}
}
ASN_STRUCT_FREE(asn_DEF_NR_UL_DCCH_Message, ul_dcch_msg);
return 0;
}
void rrc_gNB_process_initial_ul_rrc_message(sctp_assoc_t assoc_id, const f1ap_initial_ul_rrc_message_t *ul_rrc)
{
AssertFatal(assoc_id != 0, "illegal assoc_id == 0: should be -1 (monolithic) or >0 (split)\n");
gNB_RRC_INST *rrc = RC.nrrrc[0];
LOG_I(NR_RRC, "Decoding CCCH: RNTI %04x, payload_size %d\n", ul_rrc->crnti, ul_rrc->rrc_container_length);
NR_UL_CCCH_Message_t *ul_ccch_msg = NULL;
asn_dec_rval_t dec_rval = uper_decode(NULL,
&asn_DEF_NR_UL_CCCH_Message,
(void **)&ul_ccch_msg,
ul_rrc->rrc_container,
ul_rrc->rrc_container_length,
0,
0);
if (dec_rval.code != RC_OK || dec_rval.consumed == 0) {
LOG_E(NR_RRC, " FATAL Error in receiving CCCH\n");
return;
}
if (ul_ccch_msg->message.present == NR_UL_CCCH_MessageType_PR_c1) {
switch (ul_ccch_msg->message.choice.c1->present) {
case NR_UL_CCCH_MessageType__c1_PR_NOTHING:
LOG_W(NR_RRC, "Received PR_NOTHING on UL-CCCH-Message, ignoring message\n");
break;
case NR_UL_CCCH_MessageType__c1_PR_rrcSetupRequest:
LOG_D(NR_RRC, "Received RRCSetupRequest on UL-CCCH-Message (UE rnti %04x)\n", ul_rrc->crnti);
rrc_handle_RRCSetupRequest(rrc, assoc_id, &ul_ccch_msg->message.choice.c1->choice.rrcSetupRequest->rrcSetupRequest, ul_rrc);
break;
case NR_UL_CCCH_MessageType__c1_PR_rrcResumeRequest:
LOG_E(NR_RRC, "Received rrcResumeRequest message, but handling is not implemented\n");
break;
case NR_UL_CCCH_MessageType__c1_PR_rrcReestablishmentRequest: {
LOG_D(NR_RRC, "Received RRCReestablishmentRequest on UL-CCCH-Message (UE RNTI %04x)\n", ul_rrc->crnti);
rrc_handle_RRCReestablishmentRequest(
rrc,
assoc_id,
&ul_ccch_msg->message.choice.c1->choice.rrcReestablishmentRequest->rrcReestablishmentRequest,
ul_rrc);
} break;
case NR_UL_CCCH_MessageType__c1_PR_rrcSystemInfoRequest:
LOG_I(NR_RRC, "UE %04x receive rrcSystemInfoRequest message \n", ul_rrc->crnti);
/* TODO */
break;
default:
LOG_E(NR_RRC, "UE %04x Unknown message\n", ul_rrc->crnti);
break;
}
}
ASN_STRUCT_FREE(asn_DEF_NR_UL_CCCH_Message, ul_ccch_msg);
}
static void rrc_gNB_trigger_nsa_release(module_id_t mod_id, int ue_id)
{
gNB_RRC_INST *rrc = RC.nrrrc[mod_id];
rrc_gNB_ue_context_t *ue_context = rrc_gNB_get_ue_context(rrc, ue_id);
if (!ue_context) {
LOG_E(NR_RRC, "could not find UE for ID %d\n", ue_id);
return;
}
rrc_release_nsa_user(rrc, ue_context);
}
void rrc_gNB_process_release_request(const module_id_t gnb_mod_idP, x2ap_ENDC_sgnb_release_request_t *m)
{
/* it's not the RNTI, it's the UE ID ... */
rrc_gNB_trigger_nsa_release(gnb_mod_idP, m->rnti);
}
void rrc_gNB_process_dc_overall_timeout(const module_id_t gnb_mod_idP, x2ap_ENDC_dc_overall_timeout_t *m)
{
/* it's not the RNTI, it's the UE ID ... */
rrc_gNB_trigger_nsa_release(gnb_mod_idP, m->rnti);
}
/* \brief fill E1 bearer modification's DRB from F1 DRB
* \param drb_e1 pointer to a DRB inside an E1 bearer modification message
* \param drb_f1 pointer to a DRB inside an F1 UE Ctxt modification Response */
static DRB_nGRAN_to_mod_t fill_e1_bearer_modif_from_f1(const f1ap_drb_setup_t *drb_f1)
{
DRB_nGRAN_to_mod_t drb_e1 = {0};
drb_e1.id = drb_f1->id;
drb_e1.numDlUpParam = drb_f1->up_dl_tnl_len;
drb_e1.DlUpParamList[0].tl_info.tlAddress = drb_f1->up_dl_tnl[0].tl_address;
drb_e1.DlUpParamList[0].tl_info.teId = drb_f1->up_dl_tnl[0].teid;
return drb_e1;
}
static gtpu_tunnel_t f1u_gtp_update(uint32_t teid, const in_addr_t addr)
{
gtpu_tunnel_t out = {0};
out.teid = teid;
memcpy(&out.addr.buffer, &addr, 4);
out.addr.length = sizeof(addr);
return out;
}
/**
* @brief Update DRB TEID information in RRC storage from received DRB list
*/
static void store_du_f1u_tunnel(const f1ap_drb_setup_t *drbs, int n, gNB_RRC_UE_t *ue)
{
for (int i = 0; i < n; i++) {
const f1ap_drb_setup_t *drb_f1 = &drbs[i];
AssertFatal(drb_f1->up_dl_tnl_len == 1, "can handle only one UP param\n");
AssertFatal(drb_f1->id < MAX_DRBS_PER_UE, "illegal DRB ID %d\n", drb_f1->id);
drb_t *drb = get_drb(&ue->drbs, drb_f1->id);
DevAssert(drb);
drb->du_tunnel_config = f1u_gtp_update(drb_f1->up_dl_tnl[0].teid, drb_f1->up_dl_tnl[0].tl_address);
}
}
static DRB_nGRAN_to_mod_t get_e1_drb_mod_pdcp_status(const drb_t *drb,
bearer_context_pdcp_config_t *pdcp_config,
const ngap_drb_status_t *drb_status)
{
DevAssert(drb_status);
DevAssert(pdcp_config);
DevAssert(drb);
DRB_nGRAN_to_mod_t drb_to_mod = {0};
drb_to_mod.id = drb->drb_id;
drb_to_mod.pdcp_sn_status_requested = false;
// PDCP SN Status Information
drb_to_mod.pdcp_config = calloc_or_fail(1, sizeof(*drb_to_mod.pdcp_config));
*drb_to_mod.pdcp_config = *pdcp_config;
drb_to_mod.pdcp_status = calloc_or_fail(1, sizeof(*drb_to_mod.pdcp_status));
drb_to_mod.pdcp_status->dl_count.hfn = drb_status->dl_count.hfn;
drb_to_mod.pdcp_status->dl_count.sn = drb_status->dl_count.pdcp_sn;
drb_to_mod.pdcp_status->ul_count.hfn = drb_status->ul_count.hfn;
drb_to_mod.pdcp_status->ul_count.sn = drb_status->ul_count.pdcp_sn;
return drb_to_mod;
}
/** @brief Send E1 bearer context modification request to CU-UP */
static void e1_send_bearer_modification_request(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, e1ap_bearer_mod_req_t *req)
{
if (req->numPDUSessionsMod == 0) {
LOG_W(NR_RRC, "UE %d: No PDU sessions to modify in E1 bearer update\n", UE->rrc_ue_id);
return;
}
DevAssert(req->numPDUSessions == 0);
req->secInfo = malloc_or_fail(sizeof(*req->secInfo));
fill_security_info(rrc, UE, req->secInfo);
sctp_assoc_t assoc_id = get_existing_cuup_for_ue(UE);
rrc->cucp_cuup.bearer_context_mod(assoc_id, req);
}
/** @brief Send E1 bearer updates for DRBs to setup from F1 UE Context Modification Response */
static void e1_send_bearer_updates(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, int n, f1ap_drb_setup_t *drbs)
{
if (!is_cuup_associated(rrc) || n <= 0)
return;
e1ap_bearer_mod_req_t req = {
.gNB_cu_cp_ue_id = UE->rrc_ue_id,
.gNB_cu_up_ue_id = UE->rrc_ue_id,
};
uint16_t num_pdu_sessions = seq_arr_size(&UE->pduSessions);
DevAssert(num_pdu_sessions > 0);
req.pduSessionMod = calloc_or_fail(num_pdu_sessions, sizeof(*req.pduSessionMod));
for (int i = 0; i < n; i++) {
const f1ap_drb_setup_t *drb_f1 = &drbs[i];
int drb_id = drb_f1->id;
rrc_pdu_session_param_t *pdu = find_pduSession_from_drbId(UE, drb_id);
if (!pdu)
continue;
DRB_nGRAN_to_mod_t drb_to_mod = fill_e1_bearer_modif_from_f1(drb_f1);
if (!append_e1_drb_mod_req(&req, UE, drb_id, &drb_to_mod)) {
LOG_W(NR_RRC, "UE %d: Failed to append E1 DRB mod from F1 (DRB=%d)\n", UE->rrc_ue_id, drb_id);
}
}
e1_send_bearer_modification_request(rrc, UE, &req);
free_e1ap_context_mod_request(&req);
}
/** @brief Request PDCP status from CU-UP during inter-CU handover */
static void e1_request_pdcp_status(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE)
{
if (!is_cuup_associated(rrc))
return;
e1ap_bearer_mod_req_t req = {
.gNB_cu_cp_ue_id = UE->rrc_ue_id,
.gNB_cu_up_ue_id = UE->rrc_ue_id,
};
uint16_t num_pdu_sessions = seq_arr_size(&UE->pduSessions);
DevAssert(num_pdu_sessions > 0);
req.pduSessionMod = calloc_or_fail(num_pdu_sessions, sizeof(*req.pduSessionMod));
FOR_EACH_SEQ_ARR(drb_t *, drb, &UE->drbs) {
DRB_nGRAN_to_mod_t drb_to_mod = {.id = drb->drb_id, .pdcp_sn_status_requested = true};
LOG_D(NR_RRC, "PDCP Status requested (drb_id=%d)\n", drb->drb_id);
if (!append_e1_drb_mod_req(&req, UE, drb->drb_id, &drb_to_mod)) {
LOG_W(NR_RRC, "UE %d: Failed to append E1 DRB mod for PDCP status request (DRB=%d)\n", UE->rrc_ue_id, drb->drb_id);
}
}
e1_send_bearer_modification_request(rrc, UE, &req);
free_e1ap_context_mod_request(&req);
}
/** @brief Notify CU-UP with PDCP status during handover */
void e1_notify_pdcp_status(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, const ngap_drb_status_t *drb_status)
{
if (!is_cuup_associated(rrc) || !drb_status)
return;
e1ap_bearer_mod_req_t req = {
.gNB_cu_cp_ue_id = UE->rrc_ue_id,
.gNB_cu_up_ue_id = UE->rrc_ue_id,
};
uint16_t num_pdu_sessions = seq_arr_size(&UE->pduSessions);
DevAssert(num_pdu_sessions > 0);
req.pduSessionMod = calloc_or_fail(num_pdu_sessions, sizeof(*req.pduSessionMod));
FOR_EACH_SEQ_ARR(drb_t *, drb, &UE->drbs) {
LOG_I(NR_RRC, "Forward PDCP Status to CU-UP (drb_id=%d)\n", drb->drb_id);
bearer_context_pdcp_config_t pdcp_config = set_bearer_context_pdcp_config(drb->pdcp_config, rrc->configuration.um_on_default_drb, UE->redcap_cap);
DRB_nGRAN_to_mod_t drb_to_mod = get_e1_drb_mod_pdcp_status(drb, &pdcp_config, drb_status);
append_e1_drb_mod_req(&req, UE, drb->drb_id, &drb_to_mod);
}
e1_send_bearer_modification_request(rrc, UE, &req);
free_e1ap_context_mod_request(&req);
}
static NR_MeasGapConfig_t *get_meas_gap_config(const f1ap_du_to_cu_rrc_info_t *du_to_cu_rrc_info)
{
if (!du_to_cu_rrc_info->meas_gap_config) {
return NULL;
}
NR_MeasGapConfig_t *measGapConfig = NULL;
asn_dec_rval_t dec_rval = uper_decode_complete(NULL,
&asn_DEF_NR_MeasGapConfig,
(void **)&measGapConfig,
(uint8_t *)du_to_cu_rrc_info->meas_gap_config->buf,
du_to_cu_rrc_info->meas_gap_config->len);
AssertFatal(dec_rval.code == RC_OK && dec_rval.consumed > 0, "measGapConfig decode error\n");
return measGapConfig;
}
/** @brief Detect re-establishment by checking reestablishRLC flags in CellGroupConfig.
* Temporary decode only for detection (not for modification, to preserve transparency).
* DU sets reestablishRLC=true for bearers needing RLC re-establishment (except SRB1).
* @param cgc Encoded CellGroupConfig from DU to CU transfer IE
* @return True if re-establishment is detected, false otherwise */
static bool rrc_detect_reestablishment(const byte_array_t *cgc)
{
if (!cgc || !cgc->buf || cgc->len == 0) {
return false;
}
NR_CellGroupConfig_t *temp_cellGroupConfig = NULL;
asn_dec_rval_t dec_rval =
uper_decode_complete(NULL, &asn_DEF_NR_CellGroupConfig, (void **)&temp_cellGroupConfig, cgc->buf, cgc->len);
if (dec_rval.code != RC_OK || dec_rval.consumed == 0) {
LOG_W(NR_RRC,
"Failed to decode CellGroupConfig for re-establishment detection (code=%d, consumed=%zu)\n",
dec_rval.code,
dec_rval.consumed);
return false;
}
bool is_reestablishment = false;
// Check if any RLC bearer has reestablishRLC flag set
if (temp_cellGroupConfig->rlc_BearerToAddModList && temp_cellGroupConfig->rlc_BearerToAddModList->list.count > 0) {
for (int i = 0; i < temp_cellGroupConfig->rlc_BearerToAddModList->list.count; i++) {
if (temp_cellGroupConfig->rlc_BearerToAddModList->list.array[i]->reestablishRLC
&& *temp_cellGroupConfig->rlc_BearerToAddModList->list.array[i]->reestablishRLC
== NR_RLC_BearerConfig__reestablishRLC_true) {
is_reestablishment = true;
break;
}
}
}
ASN_STRUCT_FREE(asn_DEF_NR_CellGroupConfig, temp_cellGroupConfig);
return is_reestablishment;
}
static void rrc_CU_process_ue_context_setup_response(MessageDef *msg_p, instance_t instance)
{
f1ap_ue_context_setup_resp_t *resp = &F1AP_UE_CONTEXT_SETUP_RESP(msg_p);
gNB_RRC_INST *rrc = RC.nrrrc[instance];
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, resp->gNB_CU_ue_id);
if (!ue_context_p) {
LOG_E(RRC, "could not find UE context for CU UE ID %u, aborting transaction\n", resp->gNB_CU_ue_id);
return;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
UE->f1_ue_context_active = true;
// Store the encoded CellGroupConfig for transparent forwarding
byte_array_t *cgc = &resp->du_to_cu_rrc_info.cell_group_config;
store_cgc(UE, cgc);
// Process measurement gap config if present
NR_MeasGapConfig_t *measGapConfig = get_meas_gap_config(&resp->du_to_cu_rrc_info);
if (measGapConfig) {
UE->measConfig->measGapConfig = measGapConfig;
}
if (!IS_SA_MODE(get_softmodem_params())) {
rrc_add_nsa_user_resp(UE, resp);
return;
}
if (resp->drbs_len > 0) {
int num_drb = seq_arr_size(&UE->drbs);
DevAssert(num_drb == 0 || num_drb == resp->drbs_len);
/* Note: we would ideally check that SRB2 is acked, but at least LiteOn DU
* seems buggy and does not ack, so simply check that locally we activated */
AssertFatal(UE->Srb[1].Active && UE->Srb[2].Active, "SRBs 1 and 2 must be active during DRB Establishment");
store_du_f1u_tunnel(resp->drbs, resp->drbs_len, UE);
if (num_drb == 0)
e1_send_bearer_updates(rrc, UE, resp->drbs_len, resp->drbs);
else
cuup_notify_reestablishment(rrc, UE);
}
if (UE->ho_context == NULL) {
// Check if this is a re-establishment scenario by examining the CellGroupConfig
bool is_reestablishment = rrc_detect_reestablishment(cgc);
rrc_gNB_generate_dedicatedRRCReconfiguration(rrc, UE, is_reestablishment);
} else {
// case of handover
// handling of "target CU" information
DevAssert(UE->ho_context->target != NULL);
DevAssert(resp->crnti != NULL);
UE->ho_context->target->du_ue_id = resp->gNB_DU_ue_id;
UE->ho_context->target->new_rnti = *resp->crnti;
UE->ho_context->target->ho_req_ack(rrc, UE);
}
}
static void rrc_CU_process_ue_context_release_request(MessageDef *msg_p, sctp_assoc_t assoc_id)
{
const int instance = 0;
f1ap_ue_context_rel_req_t *req = &F1AP_UE_CONTEXT_RELEASE_REQ(msg_p);
gNB_RRC_INST *rrc = RC.nrrrc[instance];
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, req->gNB_CU_ue_id);
int srbid = 1;
if (!ue_context_p) {
LOG_W(RRC, "could not find UE context for CU UE ID %u: auto-generate release command\n", req->gNB_CU_ue_id);
uint8_t buffer[NR_RRC_BUF_SIZE] = {0};
int size = do_NR_RRCRelease(buffer, NR_RRC_BUF_SIZE, rrc_gNB_get_next_transaction_identifier(0));
RETURN_IF_INVALID_ASSOC_ID(assoc_id);
f1ap_ue_context_rel_cmd_t ue_context_release_cmd = {
.gNB_CU_ue_id = req->gNB_CU_ue_id,
.gNB_DU_ue_id = req->gNB_DU_ue_id,
.cause = F1AP_CAUSE_RADIO_NETWORK,
.cause_value = 10, // 10 = F1AP_CauseRadioNetwork_normal_release
.srb_id = &srbid, // C-ifRRCContainer => is added below
};
deliver_ue_ctxt_release_data_t data = {.rrc = rrc, .release_cmd = &ue_context_release_cmd, .assoc_id = assoc_id};
nr_pdcp_data_req_srb(req->gNB_CU_ue_id, srbid, rrc_gNB_mui++, size, buffer, rrc_deliver_ue_ctxt_release_cmd, &data);
return;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
if (UE->ho_context != NULL) {
nr_ho_source_cu_t *source_ctx = UE->ho_context->source;
bool from_source_du = source_ctx && source_ctx->cell->assoc_id == assoc_id;
if (from_source_du) {
// we received release request from the source DU, but HO is still
// ongoing; free the UE, and remove the HO context.
LOG_W(NR_RRC,
"UE %d: release request from source cell PCI %d during HO, marking HO as complete\n",
UE->rrc_ue_id,
source_ctx->cell->info.pci);
RETURN_IF_INVALID_ASSOC_ID(source_ctx->cell->assoc_id);
f1ap_ue_context_rel_cmd_t cmd = {
.gNB_CU_ue_id = UE->rrc_ue_id,
.gNB_DU_ue_id = source_ctx->du_ue_id,
.cause = F1AP_CAUSE_RADIO_NETWORK,
.cause_value = 5, // 5 = F1AP_CauseRadioNetwork_interaction_with_other_procedure
};
rrc->mac_rrc.ue_context_release_command(assoc_id, &cmd);
nr_rrc_finalize_ho(UE);
return;
}
// if we receive the release request from the target DU (regardless if
// successful), we assume it is "genuine" and ask the AMF to release
nr_rrc_finalize_ho(UE);
} else {
f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
if (ue_data.du_assoc_id != assoc_id) {
LOG_W(NR_RRC,
"UE context release request from unexpected DU with assoc_id %d for rrc_ue_id %d with du_assoc_id %d\n",
assoc_id,
UE->rrc_ue_id,
ue_data.du_assoc_id);
return;
}
}
/* TODO: marshall types correctly */
LOG_I(NR_RRC, "received UE Context Release Request for UE %u, forwarding to AMF\n", req->gNB_CU_ue_id);
ngap_cause_t cause = {.type = NGAP_CAUSE_RADIO_NETWORK, .value = NGAP_CAUSE_RADIO_NETWORK_RADIO_CONNECTION_WITH_UE_LOST};
rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_REQ(instance, ue_context_p, cause);
}
static void rrc_delete_ue_data(gNB_RRC_UE_t *UE)
{
/* Clean up handover context if it exists */
if (UE->ho_context)
nr_rrc_finalize_ho(UE);
ASN_STRUCT_FREE(asn_DEF_NR_UE_NR_Capability, UE->UE_Capability_nr);
free_byte_array(UE->mcg);
ASN_STRUCT_FREE(asn_DEF_NR_MeasResults, UE->measResults);
FREE_AND_ZERO_BYTE_ARRAY(UE->ue_cap_buffer);
free_MeasConfig(UE->measConfig);
free(UE->redcap_cap);
UE->redcap_cap = NULL;
seq_arr_free(&UE->pduSessions, free_pdusession);
seq_arr_free(&UE->drbs, free_drb);
seq_arr_free(&UE->serving_cells, NULL);
}
void rrc_remove_ue(gNB_RRC_INST *rrc, rrc_gNB_ue_context_t *ue_context_p)
{
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
/* we call nr_pdcp_remove_UE() in the handler of E1 bearer release, but if we
* are in E1, we also need to free the UE in the CU-CP, so call it twice to
* cover all cases */
nr_pdcp_remove_UE(UE->rrc_ue_id);
LOG_I(NR_RRC, "removed UE CU UE ID %u/RNTI %04x \n", UE->rrc_ue_id, UE->rnti);
rrc_delete_ue_data(UE);
rrc_gNB_remove_ue_context(rrc, ue_context_p);
}
static void rrc_CU_process_ue_context_release_complete(MessageDef *msg_p)
{
const int instance = 0;
f1ap_ue_context_rel_cplt_t *complete = &F1AP_UE_CONTEXT_RELEASE_COMPLETE(msg_p);
gNB_RRC_INST *rrc = RC.nrrrc[instance];
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, complete->gNB_CU_ue_id);
if (!ue_context_p) {
LOG_E(RRC, "could not find UE context for CU UE ID %u, aborting transaction\n", complete->gNB_CU_ue_id);
return;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
if (UE->an_release) {
/* only trigger release if it has been requested by core
* otherwise, it might be CU that requested release on a DU during normal
* operation (i.e, handover) */
rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_COMPLETE(0, UE->rrc_ue_id, &UE->pduSessions);
rrc_remove_ue(RC.nrrrc[0], ue_context_p);
}
}
static void rrc_CU_process_ue_context_modification_response(MessageDef *msg_p, instance_t instance)
{
f1ap_ue_context_mod_resp_t *resp = &F1AP_UE_CONTEXT_MODIFICATION_RESP(msg_p);
gNB_RRC_INST *rrc = RC.nrrrc[instance];
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, resp->gNB_CU_ue_id);
if (!ue_context_p) {
LOG_E(RRC, "could not find UE context for CU UE ID %u, aborting transaction\n", resp->gNB_CU_ue_id);
return;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
bool is_inter_cu_ho = UE->ho_context && UE->ho_context->source && !UE->ho_context->target;
if (resp->drbs_len > 0) { // DRB to setup
store_du_f1u_tunnel(resp->drbs, resp->drbs_len, UE);
e1_send_bearer_updates(rrc, UE, resp->drbs_len, resp->drbs);
} else if (is_inter_cu_ho) { // PDCP status request
e1_request_pdcp_status(rrc, UE);
}
if (resp->du_to_cu_rrc_info) {
byte_array_t *cgc = &resp->du_to_cu_rrc_info->cell_group_config;
/* hack for interoperability with srsRAN: ignore cell group config if empty */
/* cell group config is empty if buffer length is 2 and content is all 0 */
bool cgc_is_empty = cgc->len == 2 && cgc->buf[0] == 0 && cgc->buf[1] == 0;
if (!cgc_is_empty) {
// Store the encoded CellGroupConfig for transparent forwarding
store_cgc(UE, cgc);
// Check if this is a re-establishment scenario by examining the CellGroupConfig
bool is_reestablishment = rrc_detect_reestablishment(cgc);
rrc_gNB_generate_dedicatedRRCReconfiguration(rrc, UE, is_reestablishment);
} else {
LOG_W(NR_RRC, "hack: UE %d: ignore empty CellGroupConfig in UEContextModificationResponse\n", UE->rrc_ue_id);
}
}
// Reconfiguration should have been sent to the UE, so it will attempt the
// handover. In the F1 case, update with new RNTI, and update secondary UE
// association, so we can receive the new UE from the target DU (in N2/Xn,
// nothing is to be done, we wait for confirmation to release the UE in the
// CU/DU)
if (UE->ho_context && UE->ho_context->target && UE->ho_context->source) {
nr_ho_source_cu_t *source_ctx = UE->ho_context->source;
DevAssert(source_ctx->old_rnti == UE->rnti);
nr_rrc_apply_target_context(UE);
/* Update cell association after handover */
if (!nr_rrc_update_cell_assoc_after_ho(UE)) {
return;
}
}
}
static void rrc_CU_process_ue_modification_required(MessageDef *msg_p, instance_t instance, sctp_assoc_t assoc_id)
{
gNB_RRC_INST *rrc = RC.nrrrc[instance];
f1ap_ue_context_modif_required_t *required = &F1AP_UE_CONTEXT_MODIFICATION_REQUIRED(msg_p);
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, required->gNB_CU_ue_id);
if (ue_context_p == NULL) {
LOG_E(RRC, "Could not find UE context for CU UE ID %d, cannot handle UE context modification request\n", required->gNB_CU_ue_id);
f1ap_ue_context_modif_refuse_t refuse = {
.gNB_CU_ue_id = required->gNB_CU_ue_id,
.gNB_DU_ue_id = required->gNB_DU_ue_id,
.cause = F1AP_CAUSE_RADIO_NETWORK,
.cause_value = F1AP_CauseRadioNetwork_unknown_or_already_allocated_gnb_cu_ue_f1ap_id,
};
rrc->mac_rrc.ue_context_modification_refuse(msg_p->ittiMsgHeader.originInstance, &refuse);
return;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
bool on_source_du = UE->ho_context && UE->ho_context->source && UE->ho_context->source->cell
&& UE->ho_context->source->cell->assoc_id == assoc_id;
if (on_source_du) {
LOG_W(NR_RRC, "UE %d: UE Context Modification Required during handover, ignoring message\n", UE->rrc_ue_id);
return;
}
/* Check if UE is accessing a different DU than its current one */
f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
/** Refuse UE Context Modification Required from any DU if:
* UE Context Setup Request was sent but Setup Response hasn't arrived yet.
* This includes the case where UE is re-establishing on a different DU. The CU has
* already triggered UE Context Setup on the new DU (per TS 38.401 §8.7), and Setup Response
* is pending. Modification Required from any DU during this transition should be refused
* to avoid conflicts with the ongoing Setup procedure.
*
* Note: according to TS 38.401 §8.7 "it is assumed that the UE accessed the original gNB-DU
* where the UE context is available for that UE, and either steps 9-10 or steps 9’-10’
* may be executed or both could be skipped."
* By design, CU-CP will trigger UE Context Setup Modification Request and DU does not send
* Modification Required during re-establishment. */
if (!UE->f1_ue_context_active) {
LOG_W(NR_RRC,
"UE %d: UE Context Modification Required received while UE Context Setup is pending (CU UE ID %d), refusing\n",
UE->rrc_ue_id,
required->gNB_CU_ue_id);
f1ap_ue_context_modif_refuse_t refuse = {
.gNB_CU_ue_id = required->gNB_CU_ue_id,
.gNB_DU_ue_id = required->gNB_DU_ue_id,
.cause = F1AP_CAUSE_RADIO_NETWORK,
.cause_value = F1AP_CauseRadioNetwork_interaction_with_other_procedure,
};
rrc->mac_rrc.ue_context_modification_refuse(msg_p->ittiMsgHeader.originInstance, &refuse);
return;
}
if (required->du_to_cu_rrc_information && required->du_to_cu_rrc_information->cellGroupConfig) {
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
LOG_I(RRC,
"UE Context Modification Required: new CellGroupConfig for UE ID %d/RNTI %04x, triggering reconfiguration\n",
UE->rrc_ue_id,
UE->rnti);
// Store the encoded CellGroupConfig for transparent forwarding
uint8_t *cgc_buf = required->du_to_cu_rrc_information->cellGroupConfig;
size_t cgc_len = required->du_to_cu_rrc_information->cellGroupConfig_length;
byte_array_t temp_cgc = {.buf = cgc_buf, .len = cgc_len};
store_cgc(UE, &temp_cgc);
/* trigger reconfiguration */
if (!UE->ongoing_reconfiguration)
nr_rrc_reconfiguration_req(rrc, UE);
return;
}
LOG_W(RRC,
"nothing to be done after UE Context Modification Required for UE ID %d/RNTI %04x\n",
required->gNB_CU_ue_id,
required->gNB_DU_ue_id);
}
unsigned int mask_flip(unsigned int x) {
return((((x>>8) + (x<<8))&0xffff)>>6);
}
/* \bref return F1AP QoS characteristics based on Qos flow parameters */
f1ap_qos_flow_param_t get_qos_char_from_qos_flow_param(const pdusession_level_qos_parameter_t *qos_param)
{
f1ap_qos_flow_param_t qos_char = {0};
if (qos_param->fiveQI_type == DYNAMIC) {
qos_char.qos_type = DYNAMIC;
qos_char.dyn.prio = qos_param->qos_priority;
qos_char.dyn.pdb = 100; // TODO
qos_char.dyn.per.scalar = 10; // TODO
qos_char.dyn.per.exponent = 100; // TODO
} else {
qos_char.qos_type = NON_DYNAMIC;
qos_char.nondyn.fiveQI = qos_param->fiveQI;
}
const qos_arp_t *a = &qos_param->arp;
qos_char.arp.prio = a->priority_level;
qos_char.arp.preempt_cap =
a->pre_emp_capability == PEC_MAY_TRIGGER_PREEMPTION ? MAY_TRIGGER_PREEMPTION : SHALL_NOT_TRIGGER_PREEMPTION;
qos_char.arp.preempt_vuln = a->pre_emp_vulnerability == PEV_PREEMPTABLE ? PREEMPTABLE : NOT_PREEMPTABLE;
return qos_char;
}
static f1ap_drb_info_nr_t fill_f1_drb_info_nr(pdusession_t *pdu, const uint8_t *qfis, const int num_qfis)
{
f1ap_drb_info_nr_t drb_info = {0};
drb_info.nssai = pdu->nssai;
drb_info.flows_len = num_qfis;
drb_info.flows = calloc_or_fail(num_qfis, sizeof(*drb_info.flows));
for (int i = 0; i < num_qfis; i++) {
int qfi = qfis[i];
/* find the stored QoS flow parameters for this QFI */
nr_rrc_qos_t *qos_param = find_qos(&pdu->qos, qfi);
DevAssert(qos_param);
/* QoS flows Flows Mapped to DRB Item */
f1ap_drb_flows_mapped_t *flow = &drb_info.flows[i];
flow->qfi = qfi;
flow->param = get_qos_char_from_qos_flow_param(&qos_param->qos);
}
/* DRB QoS IE: we just reuse the ones from the first flow */
drb_info.drb_qos = drb_info.flows[0].param;
return drb_info;
}
/** @brief Fill F1 DRB to Be Setup List (UE Context Setup Request)
* @param rrc RRC instance
* @param rrc_drb RRC DRB structure
* @param pdu PDU session parameters
* @param qfis List of QFIs
* @param num_qfis Number of QFIs in list
* @return Filled F1 DRB to setup structure */
static f1ap_drb_to_setup_t fill_f1_drb_to_be_setup(const gNB_RRC_INST *rrc,
const drb_t *rrc_drb,
rrc_pdu_session_param_t *pdu,
const uint8_t *qfis,
int num_qfis)
{
DevAssert(rrc);
DevAssert(rrc_drb);
DevAssert(pdu);
DevAssert(qfis);
DevAssert(num_qfis > 0);
DevAssert(num_qfis <= MAX_QOS_FLOWS);
f1ap_drb_to_setup_t drb = {0};
drb.id = rrc_drb->drb_id;
drb.qos_choice = F1AP_QOS_CHOICE_NR;
/* DRB Info (including QoS flows) */
drb.nr = fill_f1_drb_info_nr(&pdu->param, qfis, num_qfis);
memcpy(&drb.up_ul_tnl[0].tl_address, rrc_drb->cuup_tunnel_config.addr.buffer, sizeof(in_addr_t));
drb.up_ul_tnl[0].teid = rrc_drb->cuup_tunnel_config.teid;
drb.up_ul_tnl_len = 1;
/* RLC mode */
drb.rlc_mode = rrc->configuration.um_on_default_drb ? F1AP_RLC_MODE_UM_BIDIR : F1AP_RLC_MODE_AM;
/* PDCP SN length */
const nr_pdcp_configuration_t *pdcp = &rrc_drb->pdcp_config;
DevAssert(pdcp->drb.sn_size == 18 || pdcp->drb.sn_size == 12);
drb.dl_pdcp_sn_len = malloc_or_fail(sizeof(*drb.dl_pdcp_sn_len));
*drb.dl_pdcp_sn_len = pdcp->drb.sn_size == 18 ? F1AP_PDCP_SN_18B : F1AP_PDCP_SN_12B;
drb.ul_pdcp_sn_len = malloc_or_fail(sizeof(*drb.ul_pdcp_sn_len));
*drb.ul_pdcp_sn_len = pdcp->drb.sn_size == 18 ? F1AP_PDCP_SN_18B : F1AP_PDCP_SN_12B;
return drb;
}
/** @brief Helper function to process DRBs from a PDU session's DRB setup list */
static int fill_f1_drbs_from_e1(const gNB_RRC_INST *rrc,
gNB_RRC_UE_t *UE,
rrc_pdu_session_param_t *pdu,
const DRB_nGRAN_setup_t *drb_list,
const int drb_list_len,
f1ap_drb_to_setup_t drbs[32])
{
int nb_drb = 0;
for (int i = 0; i < drb_list_len; i++) {
const DRB_nGRAN_setup_t *drb_config = &drb_list[i];
drb_t *rrc_drb = get_drb(&UE->drbs, drb_config->id);
DevAssert(rrc_drb);
int nb_qos_flows = drb_config->numQosFlowSetup;
DevAssert(nb_qos_flows <= MAX_QOS_FLOWS);
AssertFatal(nb_qos_flows > 0, "must map at least one flow to a DRB\n");
uint8_t qfis[MAX_QOS_FLOWS] = {0};
for (int j = 0; j < nb_qos_flows; j++)
qfis[j] = drb_config->qosFlows[j].qfi;
drbs[nb_drb++] = fill_f1_drb_to_be_setup(rrc, rrc_drb, pdu, qfis, nb_qos_flows);
}
DevAssert(nb_drb < MAX_DRBS_PER_UE);
return nb_drb;
}
/* \brief fills a list of DRBs to be setup from a number of PDU sessions in E1
* bearer setup response */
static int fill_drb_to_be_setup_from_e1_resp(const gNB_RRC_INST *rrc,
gNB_RRC_UE_t *UE,
const pdu_session_setup_t *pduSession,
int numPduSession,
f1ap_drb_to_setup_t drbs[32])
{
int nb_drb = 0;
for (int p = 0; p < numPduSession; ++p) {
const pdu_session_setup_t *session = &pduSession[p];
rrc_pdu_session_param_t *pdu = find_pduSession(&UE->pduSessions, session->id);
DevAssert(pdu);
nb_drb += fill_f1_drbs_from_e1(rrc, UE, pdu, session->DRBnGRanList, session->numDRBSetup, &drbs[nb_drb]);
}
DevAssert(nb_drb < MAX_DRBS_PER_UE);
return nb_drb;
}
/** @brief Common helper to send F1 UE Context Modification Request with DRBs to setup
* This function handles the common logic for both setup and modify flows */
static void rrc_send_f1_ue_context_modification_request(const gNB_RRC_INST *rrc,
gNB_RRC_UE_t *ue_p,
int n_drbs,
f1ap_drb_to_setup_t *drbs,
int n_rel_drbs,
f1ap_drb_to_release_t *rel_drbs)
{
DevAssert(rrc);
DevAssert(ue_p);
DevAssert(n_drbs > 0 || n_rel_drbs > 0);
AssertFatal(ue_p->f1_ue_context_active, "logic error: calling ue context modification when context not established\n");
AssertFatal(ue_p->Srb[1].Active && ue_p->Srb[2].Active, "SRBs should already be active\n");
AssertFatal(!NODE_IS_DU(rrc->node_type), "illegal node type DU!\n");
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
f1ap_ue_context_mod_req_t req = {
.gNB_CU_ue_id = ue_p->rrc_ue_id,
.gNB_DU_ue_id = ue_data.secondary_ue,
.servCellIndex = RRC_PCELL_INDEX,
};
if (n_drbs > 0) {
req.drbs = calloc_or_fail(n_drbs, sizeof(*req.drbs));
memcpy(req.drbs, drbs, n_drbs * sizeof(*req.drbs));
req.drbs_len = n_drbs;
if (ue_p->ue_cap_buffer.len > 0) {
req.cu_to_du_rrc_info = calloc_or_fail(1, sizeof(*req.cu_to_du_rrc_info));
req.cu_to_du_rrc_info->ue_cap = calloc_or_fail(1, sizeof(*req.cu_to_du_rrc_info->ue_cap));
*req.cu_to_du_rrc_info->ue_cap = copy_byte_array(ue_p->ue_cap_buffer);
}
}
if (n_rel_drbs > 0) {
req.drbs_rel = calloc_or_fail(n_rel_drbs, sizeof(*req.drbs_rel));
memcpy(req.drbs_rel, rel_drbs, n_rel_drbs * sizeof(*req.drbs_rel));
req.drbs_rel_len = n_rel_drbs;
}
req.plmn = malloc_or_fail(sizeof(*req.plmn));
*req.plmn = rrc->configuration.plmn[0];
nr_rrc_cell_container_t *cell = rrc_get_pcell_for_ue((gNB_RRC_INST *)rrc, ue_p);
DevAssert(cell != NULL);
req.nr_cellid = malloc_or_fail(sizeof(*req.nr_cellid));
*req.nr_cellid = cell->info.cell_id;
// Request CellGroupConfig from DU in the response
req.gNB_DU_Configuration_Query = calloc_or_fail(1, sizeof(*req.gNB_DU_Configuration_Query));
*req.gNB_DU_Configuration_Query = true;
rrc->mac_rrc.ue_context_modification_request(ue_data.du_assoc_id, &req);
free_ue_context_mod_req(&req);
LOG_I(NR_RRC,
"UE %d trigger UE Context Modification Request (DRBs to setup: %d, DRBs to release: %d)\n",
ue_p->rrc_ue_id,
n_drbs,
n_rel_drbs);
}
/**
* @brief E1AP Bearer Context Setup Response processing on CU-CP
*/
static void rrc_gNB_process_e1_bearer_context_setup_resp(e1ap_bearer_setup_resp_t *resp)
{
gNB_RRC_INST *rrc = RC.nrrrc[0];
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, resp->gNB_cu_cp_ue_id);
if (ue_context_p == NULL) {
LOG_E(NR_RRC, "no UE with CU-CP UE ID %d found\n", resp->gNB_cu_cp_ue_id);
return;
}
gNB_RRC_UE_t *UE = &ue_context_p->ue_context;
// currently: we don't have "infrastructure" to save the CU-UP UE ID, so we
// assume (and below check) that CU-UP UE ID == CU-CP UE ID
AssertFatal(resp->gNB_cu_cp_ue_id == resp->gNB_cu_up_ue_id,
"cannot handle CU-UP UE ID different from CU-CP UE ID (%d vs %d)\n",
resp->gNB_cu_cp_ue_id,
resp->gNB_cu_up_ue_id);
// save the tunnel address for the PDU sessions
for (int i = 0; i < resp->numPDUSessions; i++) {
pdu_session_setup_t *e1_pdu = &resp->pduSession[i];
rrc_pdu_session_param_t *rrc_pdu = find_pduSession(&UE->pduSessions, e1_pdu->id);
if (rrc_pdu == NULL) {
LOG_W(RRC, "E1: received setup for PDU session %ld, but has not been requested\n", e1_pdu->id);
continue;
}
rrc_pdu->param.n3_outgoing = f1u_gtp_update(e1_pdu->tl_info.teId, e1_pdu->tl_info.tlAddress);
// save the tunnel address for the DRBs
for (int j = 0; j < e1_pdu->numDRBSetup; j++) {
DRB_nGRAN_setup_t *drb_config = &e1_pdu->DRBnGRanList[j];
// numUpParam only relevant in F1, but not monolithic
AssertFatal(drb_config->numUpParam <= 1, "can only up to one UP param\n");
drb_t *drb = get_drb(&UE->drbs, drb_config->id);
if (!drb) {
LOG_E(RRC, "E1: DRB %ld not found for PDU session %ld\n", drb_config->id, e1_pdu->id);
continue;
}
UP_TL_information_t *tl_info = &drb_config->UpParamList[0].tl_info;
drb->cuup_tunnel_config = f1u_gtp_update(tl_info->teId, tl_info->tlAddress);
}
}
// If HO Preparation Info is stored, N2 handover is ongoing
if (UE->ho_context) {
LOG_I(NR_RRC, "Received Bearer Context Setup Response for UE %d with valid HO Context\n", UE->rrc_ue_id);
UE->ho_context->target->ho_trigger(rrc, UE);
return;
}
if (!UE->f1_ue_context_active)
rrc_f1_ue_context_setup_from_e1_response(rrc, ue_context_p, resp);
else {
/* Instruction towards the DU for DRB configuration and tunnel creation */
f1ap_drb_to_setup_t *drbs = calloc_or_fail(E1AP_MAX_NUM_DRBS, sizeof(*drbs));
int n_drbs = fill_drb_to_be_setup_from_e1_resp(rrc, UE, resp->pduSession, resp->numPDUSessions, drbs);
rrc_send_f1_ue_context_modification_request(rrc, UE, n_drbs, drbs, 0 /* no DRBs to release */, NULL);
}
}
/** @brief E1AP Bearer Context Setup Failure processing on CU-CP */
void rrc_gNB_process_e1_bearer_context_setup_failure(e1ap_bearer_context_setup_failure_t *msg)
{
LOG_E(RRC,
"Received E1AP Bearer Context Setup Failure for UE CU-CP ID %d with cause (%d, %d)\n",
msg->gNB_cu_cp_ue_id,
msg->cause.type,
msg->cause.value);
}
/**
* @brief E1AP Bearer Context Modification Response processing on CU-CP
*/
void rrc_gNB_process_e1_bearer_context_modif_resp(const e1ap_bearer_modif_resp_t *resp)
{
LOG_I(NR_RRC, "Received E1AP Bearer Context Modification Response for UE CU-CP ID %d\n", resp->gNB_cu_cp_ue_id);
gNB_RRC_INST *rrc = RC.nrrrc[0];
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, resp->gNB_cu_cp_ue_id);
if (ue_context_p == NULL) {
LOG_E(RRC, "no UE with CU-CP UE ID %d found\n", resp->gNB_cu_cp_ue_id);
return;
}
gNB_RRC_UE_t *ue = &ue_context_p->ue_context;
int n_drb_mod = 0;
int drb_ids[MAX_DRBS_PER_UE] = {0};
f1ap_drb_to_release_t f1_drbs_rel[MAX_DRBS_PER_UE] = {0};
int n_f1_drbs_rel = 0;
e1_pdcp_status_info_t pdcp_status[MAX_DRBS_PER_UE] = {0};
for (int i = 0; i < resp->numPDUSessionsMod; ++i) {
const pdu_session_modif_t *pdu = &resp->pduSessionMod[i];
LOG_I(RRC, "UE %d: PDU session ID %ld modified %d bearers\n", resp->gNB_cu_cp_ue_id, pdu->id, pdu->numDRBModified);
for (int j = 0; j < pdu->numDRBModified; j++) {
// Trigger UL RAN Status Transfer
if (pdu->DRBnGRanModList[j].pdcp_status) {
DevAssert(n_drb_mod < MAX_DRBS_PER_UE);
drb_ids[n_drb_mod] = pdu->DRBnGRanModList[j].id;
pdcp_status[n_drb_mod++] = *pdu->DRBnGRanModList[j].pdcp_status;
}
}
// Collect DRBs to release for PDU sessions marked for release
rrc_pdu_session_param_t *pdu_session = find_pduSession(&ue->pduSessions, pdu->id);
if (pdu_session && pdu_session->status == PDU_SESSION_STATUS_TORELEASE) {
FOR_EACH_SEQ_ARR(drb_t *, drb, &ue->drbs) {
if (drb->pdusession_id == pdu->id) {
DevAssert(n_f1_drbs_rel < MAX_DRBS_PER_UE);
f1_drbs_rel[n_f1_drbs_rel++].id = drb->drb_id;
}
}
if (n_f1_drbs_rel == 0) {
LOG_E(NR_RRC, "UE %d: no DRBs to release for PDU session %ld\n", ue->rrc_ue_id, pdu->id);
}
}
}
if (n_drb_mod) {
LOG_I(NR_RRC, "UE %d: received PDU Status Info - send UL RAN Status Transfer\n", resp->gNB_cu_cp_ue_id);
if (ue->ho_context && ue->ho_context->source)
ue->ho_context->source->ho_status_transfer(rrc, ue, n_drb_mod, drb_ids, pdcp_status);
}
// F1 UE Context Modification Request (in case of new DRBs or DRBs to release)
if (n_f1_drbs_rel > 0) {
if (ue->f1_ue_context_active) {
// Send F1 UE Context Modification Request with DRBs to release
rrc_send_f1_ue_context_modification_request(rrc, ue, 0 /* no DRBs to setup */, NULL, n_f1_drbs_rel, f1_drbs_rel);
} else {
LOG_W(NR_RRC, "UE %d has DRB(s) to be set up or released but F1 UE context is not active\n", ue->rrc_ue_id);
}
}
}
/** @brief E1AP Bearer Context Modification Failure processing on CU-CP */
static void rrc_gNB_process_e1_bearer_context_modif_fail(const e1ap_bearer_context_mod_failure_t *fail)
{
gNB_RRC_INST *rrc = RC.nrrrc[0];
rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, fail->gNB_cu_cp_ue_id);
if (ue_context_p == NULL) {
LOG_E(NR_RRC, "No UE with CU-CP UE ID %d found (Bearer Context Modification Failure)\n", fail->gNB_cu_cp_ue_id);
return;
}
LOG_W(NR_RRC,
"Bearer Context Modification Failure received for UE ID %d (CU-UP ID %d), cause: %d\n",
fail->gNB_cu_cp_ue_id,
fail->gNB_cu_up_ue_id,
fail->cause.value);
}
/**
* @brief E1AP Bearer Context Release processing
*/
void rrc_gNB_process_e1_bearer_context_release_cplt(const e1ap_bearer_release_cplt_t *cplt)
{
// there is not really anything to do here as of now
// note that we don't check for the UE: it does not exist anymore if the F1
// UE context release complete arrived from the DU first, after which we free
// the UE context
LOG_I(RRC, "UE %d: received bearer release complete\n", cplt->gNB_cu_cp_ue_id);
}
static void print_meas_result_quantity(FILE *f, const NR_MeasQuantityResults_t *mqr)
{
fprintf(f, " resultSSB:");
if (!mqr) {
fprintf(f, " NOT PROVIDED\n");
return;
}
if (mqr->rsrp) {
const long rrsrp = *mqr->rsrp - 156;
fprintf(f, " RSRP %ld dBm", rrsrp);
} else {
fprintf(f, " RSRP not provided");
}
if (mqr->rsrq) {
const float rrsrq = (float) (*mqr->rsrq - 87) / 2.0f;
fprintf(f, " RSRQ %.1f dB", rrsrq);
} else {
fprintf(f, " RSRQ not provided");
}
if (mqr->sinr) {
const float rsinr = (float) (*mqr->sinr - 46) / 2.0f;
fprintf(f, " SINR %.1f dB", rsinr);
} else {
fprintf(f, " SINR not provided");
}
fprintf(f, "\n");
}
static void print_rrc_meas(FILE *f, const NR_MeasResults_t *measresults)
{
DevAssert(measresults->measResultServingMOList.list.count >= 1);
if (measresults->measResultServingMOList.list.count > 1)
LOG_W(RRC, "Received %d MeasResultServMO, but handling only 1!\n", measresults->measResultServingMOList.list.count);
NR_MeasResultServMO_t *measresultservmo = measresults->measResultServingMOList.list.array[0];
NR_MeasResultNR_t *measresultnr = &measresultservmo->measResultServingCell;
if (measresultnr->physCellId)
fprintf(f,
" servingCellId %ld MeasResultNR for phyCellId %ld:\n",
measresultservmo->servCellId,
*measresultnr->physCellId);
print_meas_result_quantity(f, measresultnr->measResult.cellResults.resultsSSB_Cell);
if (measresults->measResultNeighCells
&& measresults->measResultNeighCells->present == NR_MeasResults__measResultNeighCells_PR_measResultListNR) {
NR_MeasResultListNR_t *meas_neigh = measresults->measResultNeighCells->choice.measResultListNR;
for (int i = 0; i < meas_neigh->list.count; ++i) {
NR_MeasResultNR_t *measresultneigh = meas_neigh->list.array[i];
if (measresultneigh->physCellId)
fprintf(f, " neighboring cell for phyCellId %ld:\n", *measresultneigh->physCellId);
print_meas_result_quantity(f, measresultneigh->measResult.cellResults.resultsSSB_Cell);
}
}
}
static const char *get_pdusession_status_text(pdu_session_status_t status)
{
switch (status) {
case PDU_SESSION_STATUS_NEW: return "new";
case PDU_SESSION_STATUS_ESTABLISHED: return "established";
case PDU_SESSION_STATUS_TOMODIFY: return "to-modify";
case PDU_SESSION_STATUS_FAILED: return "failed";
case PDU_SESSION_STATUS_TORELEASE: return "to-release";
default: AssertFatal(false, "illegal PDU status code %d\n", status); return "illegal";
}
return "illegal";
}
static bool write_rrc_stats(const gNB_RRC_INST *rrc)
{
const char *filename = "nrRRC_stats.log";
FILE *f = fopen(filename, "w");
if (f == NULL) {
LOG_W(NR_RRC, "cannot open %s for writing: %d, %s\n", filename, errno, strerror(errno));
return false;
}
time_t now = time(NULL);
int i = 0;
rrc_gNB_ue_context_t *ue_context_p = NULL;
/* cast is necessary to eliminate warning "discards ‘const’ qualifier" */
RB_FOREACH(ue_context_p, rrc_nr_ue_tree_s, &((gNB_RRC_INST *)rrc)->rrc_ue_head)
{
const gNB_RRC_UE_t *ue_ctxt = &ue_context_p->ue_context;
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_ctxt->rrc_ue_id);
fprintf(f,
"UE %d CU UE ID %u DU UE ID %d RNTI %04x random identity %016lx",
i,
ue_ctxt->rrc_ue_id,
ue_data.secondary_ue,
ue_ctxt->rnti,
ue_ctxt->random_ue_identity);
if (ue_ctxt->Initialue_identity_5g_s_TMSI.presence)
fprintf(f, " S-TMSI %x", ue_ctxt->Initialue_identity_5g_s_TMSI.fiveg_tmsi);
fprintf(f, ":\n");
time_t last_seen = now - ue_ctxt->last_seen;
fprintf(f, " last RRC activity: %ld seconds ago\n", last_seen);
FOR_EACH_SEQ_ARR(rrc_pdu_session_param_t *, pdu, &ue_ctxt->pduSessions) {
fprintf(f, " PDU session ID %d status %s\n", pdu->param.pdusession_id, get_pdusession_status_text(pdu->status));
}
fprintf(f, " associated DU: ");
if (ue_data.du_assoc_id == -1)
fprintf(f, " (local/integrated CU-DU)");
else if (ue_data.du_assoc_id == 0)
fprintf(f, " DU offline/unavailable");
else
fprintf(f, " DU assoc ID %d", ue_data.du_assoc_id);
fprintf(f, "\n");
if (ue_ctxt->measResults)
print_rrc_meas(f, ue_ctxt->measResults);
++i;
}
fprintf(f, "\n");
dump_du_info(rrc, f);
fclose(f);
return true;
}
void *rrc_gnb_task(void *args_p)
{
UNUSED(args_p);
MessageDef *msg_p;
instance_t instance;
int result;
long stats_timer_id = 1;
if (!IS_SOFTMODEM_NOSTATS) {
/* timer to write stats to file */
timer_setup(1, 0, TASK_RRC_GNB, 0, TIMER_PERIODIC, NULL, &stats_timer_id);
}
itti_mark_task_ready(TASK_RRC_GNB);
LOG_I(NR_RRC,"Entering main loop of NR_RRC message task\n");
while (1) {
// Wait for a message
itti_receive_msg(TASK_RRC_GNB, &msg_p);
const char *msg_name_p = ITTI_MSG_NAME(msg_p);
instance = ITTI_MSG_DESTINATION_INSTANCE(msg_p);
LOG_D(NR_RRC,
"RRC GNB Task Received %s for instance %ld from task %s\n",
ITTI_MSG_NAME(msg_p),
ITTI_MSG_DESTINATION_INSTANCE(msg_p),
ITTI_MSG_ORIGIN_NAME(msg_p));
switch (ITTI_MSG_ID(msg_p)) {
case TERMINATE_MESSAGE:
LOG_W(NR_RRC, " *** Exiting NR_RRC thread\n");
timer_remove(stats_timer_id);
itti_exit_task();
break;
case MESSAGE_TEST:
LOG_I(NR_RRC, "[gNB %ld] Received %s\n", instance, msg_name_p);
break;
case TIMER_HAS_EXPIRED:
if (TIMER_HAS_EXPIRED(msg_p).timer_id == stats_timer_id) {
if (!write_rrc_stats(RC.nrrrc[0]))
timer_remove(stats_timer_id);
} else {
itti_send_msg_to_task(TASK_RRC_GNB, 0, TIMER_HAS_EXPIRED(msg_p).arg); /* see rrc_gNB_process_NGAP_PDUSESSION_SETUP_REQ() */
}
break;
case F1AP_INITIAL_UL_RRC_MESSAGE:
AssertFatal(NODE_IS_CU(RC.nrrrc[instance]->node_type) || NODE_IS_MONOLITHIC(RC.nrrrc[instance]->node_type),
"should not receive F1AP_INITIAL_UL_RRC_MESSAGE, need call by CU!\n");
rrc_gNB_process_initial_ul_rrc_message(msg_p->ittiMsgHeader.originInstance, &F1AP_INITIAL_UL_RRC_MESSAGE(msg_p));
free_initial_ul_rrc_message_transfer(&F1AP_INITIAL_UL_RRC_MESSAGE(msg_p));
break;
/* Messages from PDCP */
/* From DU -> CU */
case F1AP_UL_RRC_MESSAGE:
rrc_gNB_decode_dcch(RC.nrrrc[instance], &F1AP_UL_RRC_MESSAGE(msg_p));
free_ul_rrc_message_transfer(&F1AP_UL_RRC_MESSAGE(msg_p));
break;
case NGAP_DOWNLINK_NAS:
rrc_gNB_process_NGAP_DOWNLINK_NAS(msg_p, instance);
break;
case NGAP_PDUSESSION_SETUP_REQ:
if (!rrc_delay_transaction(instance, msg_p))
rrc_gNB_process_NGAP_PDUSESSION_SETUP_REQ(msg_p, instance);
break;
case NGAP_PDUSESSION_MODIFY_REQ:
rrc_gNB_process_NGAP_PDUSESSION_MODIFY_REQ(&NGAP_PDUSESSION_MODIFY_REQ(msg_p), instance);
break;
case NGAP_PDUSESSION_RELEASE_COMMAND:
if (!rrc_delay_transaction(instance, msg_p))
rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(&NGAP_PDUSESSION_RELEASE_COMMAND(msg_p), RC.nrrrc[instance]);
break;
case NGAP_DL_RAN_STATUS_TRANSFER:
rrc_gNB_process_NGAP_DL_RAN_STATUS_TRANSFER(msg_p, instance);
break;
/* 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), msg_p->ittiMsgHeader.originInstance);
free_f1ap_setup_request(&F1AP_SETUP_REQ(msg_p));
break;
case F1AP_UE_CONTEXT_SETUP_RESP:
rrc_CU_process_ue_context_setup_response(msg_p, instance);
free_ue_context_setup_resp(&F1AP_UE_CONTEXT_SETUP_RESP(msg_p));
break;
case F1AP_UE_CONTEXT_MODIFICATION_RESP:
rrc_CU_process_ue_context_modification_response(msg_p, instance);
free_ue_context_mod_resp(&F1AP_UE_CONTEXT_MODIFICATION_RESP(msg_p));
break;
case F1AP_UE_CONTEXT_MODIFICATION_REQUIRED:
rrc_CU_process_ue_modification_required(msg_p, instance, msg_p->ittiMsgHeader.originInstance);
break;
case F1AP_UE_CONTEXT_RELEASE_REQ:
rrc_CU_process_ue_context_release_request(msg_p, msg_p->ittiMsgHeader.originInstance);
free_ue_context_rel_req(&F1AP_UE_CONTEXT_RELEASE_REQ(msg_p));
break;
case F1AP_UE_CONTEXT_RELEASE_COMPLETE:
rrc_CU_process_ue_context_release_complete(msg_p);
free_ue_context_rel_cplt(&F1AP_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;
case F1AP_GNB_DU_CONFIGURATION_UPDATE:
AssertFatal(!NODE_IS_DU(RC.nrrrc[instance]->node_type), "should not receive F1AP_SETUP_REQUEST in DU!\n");
rrc_gNB_process_f1_du_configuration_update(&F1AP_GNB_DU_CONFIGURATION_UPDATE(msg_p), msg_p->ittiMsgHeader.originInstance);
free_f1ap_du_configuration_update(&F1AP_GNB_DU_CONFIGURATION_UPDATE(msg_p));
break;
case F1AP_GNB_CU_CONFIGURATION_UPDATE_ACKNOWLEDGE:
AssertFatal(!NODE_IS_DU(RC.nrrrc[instance]->node_type),
"should not receive F1AP_GNB_CU_CONFIGURATION_UPDATE_ACKNOWLEDGE in DU!\n");
LOG_E(NR_RRC, "Handling of F1AP_GNB_CU_CONFIGURATION_UPDATE_ACKNOWLEDGE not implemented\n");
break;
case F1AP_RESET_ACK:
LOG_I(NR_RRC, "received F1AP reset acknowledgement\n");
free_f1ap_reset_ack(&F1AP_RESET_ACK(msg_p));
break;
/* Messages from X2AP */
case X2AP_ENDC_SGNB_ADDITION_REQ:
LOG_I(NR_RRC, "Received ENDC sgNB addition request from X2AP \n");
rrc_gNB_process_AdditionRequestInformation(instance, &X2AP_ENDC_SGNB_ADDITION_REQ(msg_p));
break;
case X2AP_ENDC_SGNB_RECONF_COMPLETE:
LOG_A(NR_RRC, "Handling of reconfiguration complete message at RRC gNB is pending \n");
break;
case NGAP_INITIAL_CONTEXT_SETUP_REQ:
rrc_gNB_process_NGAP_INITIAL_CONTEXT_SETUP_REQ(msg_p, instance);
break;
case X2AP_ENDC_SGNB_RELEASE_REQUEST:
LOG_I(NR_RRC, "Received ENDC sgNB release request from X2AP \n");
rrc_gNB_process_release_request(instance, &X2AP_ENDC_SGNB_RELEASE_REQUEST(msg_p));
break;
case X2AP_ENDC_DC_OVERALL_TIMEOUT:
rrc_gNB_process_dc_overall_timeout(instance, &X2AP_ENDC_DC_OVERALL_TIMEOUT(msg_p));
break;
case NGAP_UE_CONTEXT_RELEASE_COMMAND:
rrc_gNB_process_NGAP_UE_CONTEXT_RELEASE_COMMAND(msg_p, instance);
break;
case E1AP_SETUP_REQ:
rrc_gNB_process_e1_setup_req(msg_p->ittiMsgHeader.originInstance, &E1AP_SETUP_REQ(msg_p));
free_e1ap_cuup_setup_request(&E1AP_SETUP_REQ(msg_p));
break;
case E1AP_BEARER_CONTEXT_SETUP_RESP:
rrc_gNB_process_e1_bearer_context_setup_resp(&E1AP_BEARER_CONTEXT_SETUP_RESP(msg_p));
free_e1ap_context_setup_response(&E1AP_BEARER_CONTEXT_SETUP_RESP(msg_p));
break;
case E1AP_BEARER_CONTEXT_SETUP_FAILURE:
rrc_gNB_process_e1_bearer_context_setup_failure(&E1AP_BEARER_CONTEXT_SETUP_FAILURE(msg_p));
free_e1_bearer_context_setup_failure(&E1AP_BEARER_CONTEXT_SETUP_FAILURE(msg_p));
break;
case E1AP_BEARER_CONTEXT_MODIFICATION_RESP:
rrc_gNB_process_e1_bearer_context_modif_resp(&E1AP_BEARER_CONTEXT_MODIFICATION_RESP(msg_p));
free_e1ap_context_mod_response(&E1AP_BEARER_CONTEXT_MODIFICATION_RESP(msg_p));
break;
case E1AP_BEARER_CONTEXT_MODIFICATION_FAIL:
rrc_gNB_process_e1_bearer_context_modif_fail(&E1AP_BEARER_CONTEXT_MODIFICATION_FAIL(msg_p));
break;
case E1AP_BEARER_CONTEXT_RELEASE_CPLT:
rrc_gNB_process_e1_bearer_context_release_cplt(&E1AP_BEARER_CONTEXT_RELEASE_CPLT(msg_p));
break;
case E1AP_LOST_CONNECTION: /* CUCP */
rrc_gNB_process_e1_lost_connection(RC.nrrrc[0], msg_p->ittiMsgHeader.originInstance);
break;
case NGAP_PAGING_IND:
rrc_gNB_process_PAGING_IND(RC.nrrrc[instance], instance, &NGAP_PAGING_IND(msg_p));
break;
case NGAP_HANDOVER_REQUEST:
rrc_gNB_process_Handover_Request(RC.nrrrc[instance], &NGAP_HANDOVER_REQUEST(msg_p));
rrc_gNB_free_Handover_Request(&NGAP_HANDOVER_REQUEST(msg_p)); // Free transfered NG message
break;
case NGAP_HANDOVER_COMMAND:
rrc_gNB_process_HandoverCommand(RC.nrrrc[instance], &NGAP_HANDOVER_COMMAND(msg_p));
rrc_gNB_free_Handover_Command(&NGAP_HANDOVER_COMMAND(msg_p)); // Free transfered NG message
break;
default:
LOG_E(NR_RRC, "[gNB %ld] Received unexpected message %s\n", instance, msg_name_p);
break;
}
result = itti_free(ITTI_MSG_ORIGIN_ID(msg_p), msg_p);
AssertFatal(result == EXIT_SUCCESS, "Failed to free memory (%d)!\n", result);
msg_p = NULL;
}
}
//-----------------------------------------------------------------------------
void rrc_gNB_generate_SecurityModeCommand(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue_p)
//-----------------------------------------------------------------------------
{
uint8_t buffer[100];
AssertFatal(!ue_p->as_security_active, "logic error: security already active\n");
T(T_ENB_RRC_SECURITY_MODE_COMMAND, T_INT(0), T_INT(0), T_INT(0), T_INT(ue_p->rrc_ue_id));
NR_IntegrityProtAlgorithm_t integrity_algorithm = (NR_IntegrityProtAlgorithm_t)ue_p->integrity_algorithm;
int size = do_NR_SecurityModeCommand(buffer,
rrc_gNB_get_next_transaction_identifier(rrc->module_id),
ue_p->ciphering_algorithm,
integrity_algorithm);
LOG_DUMPMSG(NR_RRC, DEBUG_RRC, (char *)buffer, size, "[MSG] RRC Security Mode Command\n");
LOG_I(NR_RRC, "UE %u Logical Channel DL-DCCH, Generate SecurityModeCommand (bytes %d)\n", ue_p->rrc_ue_id, size);
const uint32_t msg_id = NR_DL_DCCH_MessageType__c1_PR_securityModeCommand;
nr_rrc_transfer_protected_rrc_message(rrc, ue_p, DL_SCH_LCID_DCCH, msg_id, buffer, size);
}
//-----------------------------------------------------------------------------
/*
* Generate the RRC Connection Release to UE.
* If received, UE should switch to RRC_IDLE mode.
*/
void rrc_gNB_generate_RRCRelease(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE)
{
uint8_t buffer[NR_RRC_BUF_SIZE] = {0};
int size = do_NR_RRCRelease(buffer, NR_RRC_BUF_SIZE, rrc_gNB_get_next_transaction_identifier(rrc->module_id));
LOG_UE_DL_EVENT(UE, "Send RRC Release\n");
f1_ue_data_t ue_data = cu_get_f1_ue_data(UE->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
int srbid = 1;
f1ap_ue_context_rel_cmd_t ue_context_release_cmd = {
.gNB_CU_ue_id = UE->rrc_ue_id,
.gNB_DU_ue_id = ue_data.secondary_ue,
.cause = F1AP_CAUSE_RADIO_NETWORK,
.cause_value = 10, // 10 = F1AP_CauseRadioNetwork_normal_release
.srb_id = &srbid, // C-ifRRCContainer => is added below
};
deliver_ue_ctxt_release_data_t data = {.rrc = rrc, .release_cmd = &ue_context_release_cmd, .assoc_id = ue_data.du_assoc_id};
nr_pdcp_data_req_srb(UE->rrc_ue_id, DL_SCH_LCID_DCCH, rrc_gNB_mui++, size, buffer, rrc_deliver_ue_ctxt_release_cmd, &data);
#ifdef E2_AGENT
E2_AGENT_SIGNAL_DL_DCCH_RRC_MSG(buffer, size, NR_DL_DCCH_MessageType__c1_PR_rrcRelease);
#endif
}
int rrc_gNB_generate_pcch_msg(sctp_assoc_t assoc_id, const NR_SIB1_t *sib1, uint32_t tmsi, uint8_t paging_drx)
{
instance_t instance = 0;
const unsigned int Ttab[4] = {32,64,128,256};
uint8_t Tc;
uint8_t Tue;
uint32_t pfoffset;
uint32_t N; /* N: min(T,nB). total count of PF in one DRX cycle */
uint32_t Ns = 0; /* Ns: max(1,nB/T) */
uint32_t T; /* DRX cycle */
uint8_t buffer[NR_RRC_BUF_SIZE];
/* get default DRX cycle from configuration */
Tc = sib1->servingCellConfigCommon->downlinkConfigCommon.pcch_Config.defaultPagingCycle;
Tue = paging_drx;
/* set T = min(Tc,Tue) */
T = Tc < Tue ? Ttab[Tc] : Ttab[Tue];
/* set N = PCCH-Config->nAndPagingFrameOffset */
switch (sib1->servingCellConfigCommon->downlinkConfigCommon.pcch_Config.nAndPagingFrameOffset.present) {
case NR_PCCH_Config__nAndPagingFrameOffset_PR_oneT:
N = T;
pfoffset = 0;
break;
case NR_PCCH_Config__nAndPagingFrameOffset_PR_halfT:
N = T/2;
pfoffset = 1;
break;
case NR_PCCH_Config__nAndPagingFrameOffset_PR_quarterT:
N = T/4;
pfoffset = 3;
break;
case NR_PCCH_Config__nAndPagingFrameOffset_PR_oneEighthT:
N = T/8;
pfoffset = 7;
break;
case NR_PCCH_Config__nAndPagingFrameOffset_PR_oneSixteenthT:
N = T/16;
pfoffset = 15;
break;
default:
LOG_E(RRC, "[gNB %ld] In rrc_gNB_generate_pcch_msg: pfoffset error (pfoffset %d)\n",
instance, sib1->servingCellConfigCommon->downlinkConfigCommon.pcch_Config.nAndPagingFrameOffset.present);
return (-1);
}
switch (sib1->servingCellConfigCommon->downlinkConfigCommon.pcch_Config.ns) {
case NR_PCCH_Config__ns_four:
if(*sib1->servingCellConfigCommon->downlinkConfigCommon.initialDownlinkBWP.pdcch_ConfigCommon->choice.setup->pagingSearchSpace == 0){
LOG_E(RRC, "[gNB %ld] In rrc_gNB_generate_pcch_msg: ns error only 1 or 2 is allowed when pagingSearchSpace is 0\n",
instance);
return (-1);
} else {
Ns = 4;
}
break;
case NR_PCCH_Config__ns_two:
Ns = 2;
break;
case NR_PCCH_Config__ns_one:
Ns = 1;
break;
default:
LOG_E(RRC, "[gNB %ld] In rrc_gNB_generate_pcch_msg: ns error (ns %ld)\n",
instance, sib1->servingCellConfigCommon->downlinkConfigCommon.pcch_Config.ns);
return (-1);
}
(void) N; /* not used, suppress warning */
(void) Ns; /* not used, suppress warning */
(void) pfoffset; /* not used, suppress warning */
/* Create message for PDCP (DLInformationTransfer_t) */
int length = do_NR_Paging(instance, buffer, tmsi);
if (length == -1) {
LOG_I(NR_RRC, "do_Paging error\n");
return -1;
}
// TODO, send message to pdcp
(void) assoc_id;
return 0;
}
/* F1AP UE Context Management Procedures */
/** @brief Fill DRB to Be Setup List for F1 UE Context Setup Request
* Returns number of DRBs filled, 0 if none */
static int rrc_fill_f1_drb_to_setup(const gNB_RRC_INST *rrc, const gNB_RRC_UE_t *ue, f1ap_drb_to_setup_t drbs[MAX_DRBS_PER_UE])
{
int nb_drb = 0;
FOR_EACH_SEQ_ARR(drb_t *, rrc_drb, &ue->drbs) {
DevAssert(nb_drb < MAX_DRBS_PER_UE);
/* fetch an existing PDU session for this DRB */
rrc_pdu_session_param_t *pdu = find_pduSession_from_drbId((gNB_RRC_UE_t *)ue, rrc_drb->drb_id);
AssertFatal(pdu != NULL, "no PDU session for DRB ID %d\n", rrc_drb->drb_id);
/* Collect all QFIs mapped to this DRB */
uint8_t qfis[MAX_QOS_FLOWS] = {0};
int num_qfis = 0;
FOR_EACH_SEQ_ARR (nr_rrc_qos_t *, qos, &pdu->param.qos) {
if (qos->drb_id == rrc_drb->drb_id) {
DevAssert(num_qfis < MAX_QOS_FLOWS);
qfis[num_qfis++] = qos->qos.qfi;
}
}
AssertFatal(num_qfis > 0, "no QoS flows mapped to DRB ID %d\n", rrc_drb->drb_id);
/* Use the common function to fill DRB setup */
drbs[nb_drb++] = fill_f1_drb_to_be_setup(rrc, rrc_drb, pdu, qfis, num_qfis);
}
return nb_drb;
}
/** @brief Prepare and send F1AP UE Context Setup Request for a target DU
* This function prepares and sends an F1AP UE Context Setup Request for
* a target DU in handover/mobility or reestablishment scenarios.
* It configures:
* - SRB1 and SRB2 for signaling
* - All existing DRBs from the UE context
* - Measurement configuration updated for the target DU's cell
* - PLMN and cell information from the target DU
* - UE aggregate maximum bit rate
* - Handover preparation information (if provided)
* @param rrc RRC instance
* @param ue UE context
* @param cell Target cell container containing cell information
* @param ho_prep_info Optional handover preparation information */
void rrc_f1_ue_context_setup_for_target_du(const gNB_RRC_INST *rrc,
gNB_RRC_UE_t *ue,
const nr_rrc_cell_container_t *cell,
const byte_array_t *ho_prep_info)
{
DevAssert(cell != NULL);
/* Handle two scenarios:
* 1. Handover (ho_prep_info provided): Prepare and copy handover preparation information
* for the target DU. The target DU will assign a new gNB-DU UE ID in the response.
* 2. Reestablishment on different DU (ho_prep_info NULL): The UE is accessing a different
* DU than the original one. Use secondary_ue (the new DU's RNTI) as gNB-DU UE ID because
* the UE context already exists in MAC layer from when RRCReestablishmentRequest was
* received on the new DU. The MAC layer will find the existing UE context using this RNTI. */
byte_array_t *hpi = NULL;
uint32_t du_ue_id = 0;
uint32_t *opt_du_ue_id = NULL;
if (ho_prep_info) {
/* Handover scenario: copy handover preparation information */
hpi = malloc_or_fail(sizeof(*hpi));
*hpi = copy_byte_array(*ho_prep_info);
} else {
/* Reestablishment scenario: use secondary_ue from existing UE context */
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
du_ue_id = ue_data.secondary_ue;
opt_du_ue_id = &du_ue_id;
}
LOG_I(NR_RRC, "Triggering UE Context Setup for UE %d on DU %d\n", ue->rrc_ue_id, cell->assoc_id);
int nb_srb = 2;
f1ap_srb_to_setup_t *srbs = calloc_or_fail(nb_srb, sizeof(*srbs));
f1ap_drb_to_setup_t *drbs = calloc_or_fail(MAX_DRBS_PER_UE, sizeof(*drbs));
/* Fill DRBs */
int nb_drb = rrc_fill_f1_drb_to_setup(rrc, ue, drbs);
/* Prepare SRBs */
srbs[0].id = SRB1;
srbs[1].id = SRB2;
/* Update measurement config for target DU */
free_MeasConfig(ue->measConfig);
ue->measConfig = nr_rrc_get_measconfig(rrc, cell->info.cell_id);
byte_array_t *meas_config = calloc_or_fail(1, sizeof(*meas_config));
meas_config->buf = calloc_or_fail(1, NR_RRC_BUF_SIZE);
meas_config->len = do_NR_MeasConfig(ue->measConfig, meas_config->buf, NR_RRC_BUF_SIZE);
/* Fill common fields */
f1ap_ue_context_setup_req_t req = rrc_fill_f1_ue_context_setup(ue, cell, opt_du_ue_id);
/* Fill target DU specific fields */
req.srbs_len = 2;
req.srbs = srbs;
req.drbs_len = nb_drb;
req.drbs = drbs;
req.cu_to_du_rrc_info.meas_config = meas_config;
req.cu_to_du_rrc_info.ho_prep_info = hpi;
RETURN_IF_INVALID_ASSOC_ID(cell->assoc_id);
rrc->mac_rrc.ue_context_setup_request(cell->assoc_id, &req);
free_ue_context_setup_req(&req);
}
/** @brief Prepare and send F1AP UE Context Setup Request to serving DU after E1AP bearer setup
* This function is called when the CU-CP receives an E1AP Bearer Context Setup Response
* and the UE context is not yet active on the F1 interface. It prepares a complete F1AP
* UE Context Setup Request containing:
* - SRB configuration (SRB2)
* - DRB configuration derived from the E1AP bearer setup response
* - UE capabilities and measurement timing configuration
* - PLMN and cell information from the serving DU
* The request is sent to the serving DU.
* @param rrc RRC instance
* @param ue_context_pP UE context
* @param resp E1AP bearer setup response containing PDU session and DRB information */
void rrc_f1_ue_context_setup_from_e1_response(const gNB_RRC_INST *rrc,
rrc_gNB_ue_context_t *const ue_context_pP,
const e1ap_bearer_setup_resp_t *resp)
{
gNB_RRC_UE_t *ue_p = &ue_context_pP->ue_context;
AssertFatal(!ue_p->f1_ue_context_active, "logic error: ue context already active\n");
AssertFatal(!NODE_IS_DU(rrc->node_type), "illegal node type DU!\n");
nr_rrc_cell_container_t *cell = rrc_get_pcell_for_ue((gNB_RRC_INST *)rrc, ue_p);
DevAssert(cell != NULL);
int nb_srb = 1;
f1ap_srb_to_setup_t *srbs = calloc_or_fail(nb_srb, sizeof(*srbs));
srbs[0].id = 2;
activate_srb(ue_p, srbs[0].id);
/* Instruction towards the DU for DRB configuration and tunnel creation */
f1ap_drb_to_setup_t *drbs = calloc_or_fail(E1AP_MAX_NUM_DRBS, sizeof(*drbs));
int n_drbs = fill_drb_to_be_setup_from_e1_resp(rrc, ue_p, resp->pduSession, resp->numPDUSessions, drbs);
/* Get gNB DU UE ID */
f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
RETURN_IF_INVALID_ASSOC_ID(ue_data.du_assoc_id);
const uint32_t du_ue_id = ue_data.secondary_ue;
/* Fill common fields */
f1ap_ue_context_setup_req_t ue_context_setup_req = rrc_fill_f1_ue_context_setup(ue_p, cell, &du_ue_id);
/* Fill bearers information for serving DU */
ue_context_setup_req.srbs_len = nb_srb;
ue_context_setup_req.srbs = srbs;
ue_context_setup_req.drbs_len = n_drbs;
ue_context_setup_req.drbs = drbs;
rrc->mac_rrc.ue_context_setup_request(ue_data.du_assoc_id, &ue_context_setup_req);
free_ue_context_setup_req(&ue_context_setup_req);
LOG_I(RRC, "UE %d trigger UE context setup request with %d DRBs\n", ue_p->rrc_ue_id, n_drbs);
}
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