From 3cfe2e265ae1617766306abb4528e5741aa043d0 Mon Sep 17 00:00:00 2001 From: Guido Casati Date: Tue, 17 Jun 2025 13:32:21 +0200 Subject: [PATCH] RRC PDU Session Release: DRBs and PDU session teardown in NGAP PDU Session Release Response callback We need to keep PDU sessions and DRBs in list until the NGAP PDU Session Release Response is sent. * Introduced find_drb() and remove_drbs_by_pdu_session() helpers to locate and clean up DRBs linked to a specific PDU session * Targeted per-session DRB removal in rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE() * Ensures DRBs for unaffected PDU sessions remain intact * Remove unused PDU_SESSION_STATUS_RELEASED status: keeping this status is no longer relevant since the PDU sessions are effectively removed from the RRC lists Closes #867 Also, refactor rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND 3GPP TS 38.413 8.2.2 PDU Session Resource Release says: > upon reception the NG-RAN node shall execute the release of the requested PDU sessions. > For each PDU session to be released the NG-RAN node shall release the corresponding > resources over Uu and over NG, if any. Therefore, any PDU session in the pdusession_release_params list that is also present in the RRC list can be set to release, regardless of its status. The function signature was also updated along with other minor changes. --- openair2/RRC/NR/nr_rrc_defs.h | 1 - openair2/RRC/NR/rrc_gNB.c | 3 +- openair2/RRC/NR/rrc_gNB_NGAP.c | 40 +++++++++--------- openair2/RRC/NR/rrc_gNB_NGAP.h | 2 +- openair2/RRC/NR/rrc_gNB_radio_bearers.c | 56 +++++++++++++++++++++++++ openair2/RRC/NR/rrc_gNB_radio_bearers.h | 4 ++ 6 files changed, 83 insertions(+), 23 deletions(-) diff --git a/openair2/RRC/NR/nr_rrc_defs.h b/openair2/RRC/NR/nr_rrc_defs.h index e8820bcc76..e850ce373a 100644 --- a/openair2/RRC/NR/nr_rrc_defs.h +++ b/openair2/RRC/NR/nr_rrc_defs.h @@ -97,7 +97,6 @@ typedef enum pdu_session_satus_e { PDU_SESSION_STATUS_TOMODIFY, // ENDC NSA PDU_SESSION_STATUS_FAILED, PDU_SESSION_STATUS_TORELEASE, // to release DRB between eNB and UE - PDU_SESSION_STATUS_RELEASED } pdu_session_status_t; typedef struct pdusession_s { diff --git a/openair2/RRC/NR/rrc_gNB.c b/openair2/RRC/NR/rrc_gNB.c index 1e08c9cf25..a6c24fc579 100644 --- a/openair2/RRC/NR/rrc_gNB.c +++ b/openair2/RRC/NR/rrc_gNB.c @@ -2880,7 +2880,6 @@ static const char *get_pdusession_status_text(pdu_session_status_t status) case PDU_SESSION_STATUS_TOMODIFY: return "to-modify"; case PDU_SESSION_STATUS_FAILED: return "failed"; case PDU_SESSION_STATUS_TORELEASE: return "to-release"; - case PDU_SESSION_STATUS_RELEASED: return "released"; default: AssertFatal(false, "illegal PDU status code %d\n", status); return "illegal"; } return "illegal"; @@ -3014,7 +3013,7 @@ void *rrc_gnb_task(void *args_p) { break; case NGAP_PDUSESSION_RELEASE_COMMAND: - rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(msg_p, instance); + rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(&NGAP_PDUSESSION_RELEASE_COMMAND(msg_p), RC.nrrrc[instance]); break; case NGAP_DL_RAN_STATUS_TRANSFER: diff --git a/openair2/RRC/NR/rrc_gNB_NGAP.c b/openair2/RRC/NR/rrc_gNB_NGAP.c index 570e3912fa..7bcecb2533 100644 --- a/openair2/RRC/NR/rrc_gNB_NGAP.c +++ b/openair2/RRC/NR/rrc_gNB_NGAP.c @@ -1562,31 +1562,33 @@ void rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE(gNB_RRC_INST *rrc, gNB_RRC_UE DevAssert(resp->nb_of_pdusessions_released < NGAP_MAX_PDU_SESSION); resp->pdusession_release[resp->nb_of_pdusessions_released++].pdusession_id = pdusession->pdusession_id; } - session->status = PDU_SESSION_STATUS_RELEASED; } } + for (int i = 0; i < resp->nb_of_pdusessions_released; ++i) { + rm_pduSession(&UE->pduSessions, &UE->drbs, resp->pdusession_release[i].pdusession_id); + } + LOG_I(NR_RRC, "NGAP PDUSESSION RELEASE RESPONSE: rrc_ue_id %u release_pdu_sessions %d\n", resp->gNB_ue_ngap_id, resp->nb_of_pdusessions_released); itti_send_msg_to_task (TASK_NGAP, rrc->module_id, msg_p); } -//------------------------------------------------------------------------------ -int rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(MessageDef *msg_p, instance_t instance) -//------------------------------------------------------------------------------ +/** @brief Process NG PDU Session Resource Release command (8.2.2 of 3GPP TS 38.413) + * upon reception the NG-RAN node shall execute the release of the requested PDU sessions. + * For each PDU session to be released the NG-RAN node shall release the corresponding + * resources over Uu and over NG, if any. */ +int rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(ngap_pdusession_release_command_t *cmd, gNB_RRC_INST *rrc) { - uint32_t gNB_ue_ngap_id; - ngap_pdusession_release_command_t *cmd = &NGAP_PDUSESSION_RELEASE_COMMAND(msg_p); - gNB_ue_ngap_id = cmd->gNB_ue_ngap_id; - gNB_RRC_INST *rrc = RC.nrrrc[instance]; + uint32_t gNB_ue_ngap_id = cmd->gNB_ue_ngap_id; rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context(rrc, gNB_ue_ngap_id); if (!ue_context_p) { - LOG_E(NR_RRC, "[gNB %ld] not found ue context gNB_ue_ngap_id %u \n", instance, gNB_ue_ngap_id); + LOG_E(NR_RRC, "[gNB %d] UE context not found for gNB_ue_ngap_id %u \n", rrc->module_id, gNB_ue_ngap_id); return -1; } gNB_RRC_UE_t *UE = &ue_context_p->ue_context; - LOG_I(NR_RRC, "PDU Session Release: AMF_UE_NGAP_ID %lu rrc_ue_id %u release_pdusessions %d \n", + LOG_I(NR_RRC, "NG PDU Session Release command: AMF_UE_NGAP_ID=%lu, rrc_ue_id=%u, nb_pdusessions_torelease=%d \n", cmd->amf_ue_ngap_id, gNB_ue_ngap_id, cmd->nb_pdusessions_torelease); @@ -1597,17 +1599,17 @@ int rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(MessageDef *msg_p, instance_ LOG_E(NR_RRC, "Failed to release non-existing PDU Session %d\n", cmd->pdusession_release_params[pdusession].pdusession_id); continue; } - if (pduSession->status == PDU_SESSION_STATUS_FAILED) { + if (pduSession->status == PDU_SESSION_STATUS_TORELEASE) { + LOG_W(NR_RRC, "PDU Session %d already set to be released\n", pduSession->param.pdusession_id); continue; } - if (pduSession->status == PDU_SESSION_STATUS_ESTABLISHED) { - LOG_I(NR_RRC, "NG Release PDU Session %d \n", pduSession->param.pdusession_id); - pdu_session_to_remove_t *release = &req.pduSessionRem[req.numPDUSessionsRem++]; - release->sessionId = pduSession->param.pdusession_id; - release->cause.type = E1AP_CAUSE_RADIO_NETWORK; - release->cause.value = E1AP_RADIO_CAUSE_NORMAL_RELEASE; - pduSession->status = PDU_SESSION_STATUS_TORELEASE; - } + // Set PDU session to release, regardless of the status + LOG_I(NR_RRC, "Set PDU Session %d to release\n", pduSession->param.pdusession_id); + pdu_session_to_remove_t *release = &req.pduSessionRem[req.numPDUSessionsRem++]; + release->sessionId = pduSession->param.pdusession_id; + release->cause.type = E1AP_CAUSE_RADIO_NETWORK; + release->cause.value = E1AP_RADIO_CAUSE_NORMAL_RELEASE; + pduSession->status = PDU_SESSION_STATUS_TORELEASE; } if (req.numPDUSessionsRem == 0) { diff --git a/openair2/RRC/NR/rrc_gNB_NGAP.h b/openair2/RRC/NR/rrc_gNB_NGAP.h index 91c7722c52..c3f692ff5f 100644 --- a/openair2/RRC/NR/rrc_gNB_NGAP.h +++ b/openair2/RRC/NR/rrc_gNB_NGAP.h @@ -78,7 +78,7 @@ void rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_COMPLETE(instance_t instance, uint32_t void rrc_gNB_send_NGAP_UE_CAPABILITIES_IND(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, const NR_UECapabilityInformation_t *const ue_cap_info); -int rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(MessageDef *msg_p, instance_t instance); +int rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND(ngap_pdusession_release_command_t *cmd, gNB_RRC_INST *rrc); void rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, uint8_t xid); diff --git a/openair2/RRC/NR/rrc_gNB_radio_bearers.c b/openair2/RRC/NR/rrc_gNB_radio_bearers.c index 5af84f0399..c636e9e639 100644 --- a/openair2/RRC/NR/rrc_gNB_radio_bearers.c +++ b/openair2/RRC/NR/rrc_gNB_radio_bearers.c @@ -141,6 +141,62 @@ rrc_pdu_session_param_t *add_pduSession(seq_arr_t *sessions_ptr, const pdusessio return added; } +static bool eq_drb_pdu_session_id(const void *vval, const void *vit) +{ + const int *id = (const int *)vval; + const drb_t *elem = (const drb_t *)vit; + return elem->pdusession_id == *id; +} + +/** @brief Finds the first DRB with the given PDU session ID. + * @return Pointer to matching drb_t or NULL if not found. */ +static drb_t *find_drb_by_pdusession_id(seq_arr_t *seq, int pdusession_id) +{ + DevAssert(seq); + DevAssert(pdusession_id > 0 && pdusession_id <= NGAP_MAX_PDU_SESSION); + elm_arr_t elm = find_if(seq, &pdusession_id, eq_drb_pdu_session_id); + if (elm.found) + return (drb_t *)elm.it; + return NULL; +} + +/** @brief Removes a DRB from the list + * @param drbs The DRB list + * @param drb Pointer to the DRB to remove */ +static void nr_rrc_rm_drb(seq_arr_t *drbs, drb_t *drb) +{ + DevAssert(drbs); + DevAssert(drb); + LOG_I(NR_RRC, "Removing DRB ID %d (PDU Session ID=%d)\n", drb->drb_id, drb->pdusession_id); + seq_arr_erase_deep(drbs, drb, free_drb); +} + +/** @brief Removes a PDU Session from the list by ID + * Also removes all associated DRBs for this PDU session. + * @return true if successfully removed, false if not found */ +bool rm_pduSession(seq_arr_t *sessions, seq_arr_t *drbs, int pdusession_id) +{ + DevAssert(sessions); + DevAssert(drbs); + + rrc_pdu_session_param_t *session = find_pduSession(sessions, pdusession_id); + + if (session) { + LOG_I(NR_RRC, "Removing PDU Session %d from RRC setup list\n", pdusession_id); + // Remove all associated DRBs first + drb_t *drb; + while ((drb = find_drb_by_pdusession_id(drbs, pdusession_id))) { + nr_rrc_rm_drb(drbs, drb); + } + // Then remove the PDU session + seq_arr_erase_deep(sessions, session, free_pdusession); + return true; + } + + LOG_W(NR_RRC, "pdusession_id=%d not found to remove\n", pdusession_id); + return false; +} + /** @brief Add drb_t item in the UE context list for @param pdusession_id */ drb_t *nr_rrc_add_drb(seq_arr_t *drb_ptr, int pdusession_id, nr_pdcp_configuration_t *pdcp) { diff --git a/openair2/RRC/NR/rrc_gNB_radio_bearers.h b/openair2/RRC/NR/rrc_gNB_radio_bearers.h index f6821e314b..a1b09a5b02 100644 --- a/openair2/RRC/NR/rrc_gNB_radio_bearers.h +++ b/openair2/RRC/NR/rrc_gNB_radio_bearers.h @@ -39,6 +39,10 @@ rrc_pdu_session_param_t *add_pduSession(seq_arr_t *sessions_ptr, const pdusessio /// @brief get PDU session of UE ue through the DRB drb_id rrc_pdu_session_param_t *find_pduSession_from_drbId(gNB_RRC_UE_t *ue, int drb_id); +/// @brief Remove PDU Session from RRC list +/// Also removes all associated DRBs for this PDU session. +bool rm_pduSession(seq_arr_t *sessions, seq_arr_t *drbs, int pdusession_id); + /// @brief set PDCP configuration in E1 Bearer Context Management message bearer_context_pdcp_config_t set_bearer_context_pdcp_config(const nr_pdcp_configuration_t pdcp, bool um_on_default_drb,