DU-level changes to handle F1 UE Context Setup in NSA/phy-test/do-ra

Co-authored-by: Francesco Mani <email@francescomani.it>
2025-05-04 09:34:41 +02:00
parent 6c5514d5c9
commit 7b9442f58d
3 changed files with 113 additions and 29 deletions
@@ -27,6 +27,7 @@
 #include "openair2/LAYER2/nr_rlc/nr_rlc_oai_api.h"
 #include "F1AP_CauseRadioNetwork.h"
 #include "NR_HandoverPreparationInformation.h"
+#include "NR_CG-ConfigInfo.h"
 #include "openair3/ocp-gtpu/gtp_itf.h"
 #include "openair2/LAYER2/nr_pdcp/nr_pdcp_oai_api.h"
 #include "lib/f1ap_interface_management.h"
@@ -342,6 +343,8 @@ static int handle_ue_context_drbs_setup(NR_UE_info_t *UE,
      resp_drb->up_dl_tnl[0].teid = resp_f1.gnb_NGu_teid[0];
    }

+    if (!cellGroupConfig->rlc_BearerToAddModList)
+      cellGroupConfig->rlc_BearerToAddModList = calloc_or_fail(1, sizeof(*cellGroupConfig->rlc_BearerToAddModList));
    int ret = ASN_SEQUENCE_ADD(&cellGroupConfig->rlc_BearerToAddModList->list, rlc_BearerConfig);
    DevAssert(ret == 0);
  }
@@ -461,6 +464,52 @@ static NR_UE_NR_Capability_t *get_ue_nr_cap_from_ho_prep_info(uint8_t *buf, uint
  return cap;
 }

+static NR_CG_ConfigInfo_t *get_cg_config_info(uint8_t *buf, uint32_t len)
+{
+  struct NR_CG_ConfigInfo *cg_configinfo = NULL;
+  asn_dec_rval_t dec_rval = uper_decode_complete(NULL, &asn_DEF_NR_CG_ConfigInfo, (void **)&cg_configinfo, buf, len);
+  if (dec_rval.code != RC_OK) {
+    LOG_W(NR_MAC, "cannot decode CG-ConfigInfo, ignoring it\n");
+    return NULL;
+  }
+  //xer_fprint(stdout, &asn_DEF_NR_CG_ConfigInfo, cg_configinfo);
+  return cg_configinfo;
+}
+
+static NR_UE_NR_Capability_t *get_ue_nr_cap_from_cg_config_info(const NR_CG_ConfigInfo_t *cgci)
+{
+  /* INTO DU handler */
+  if (cgci->criticalExtensions.present != NR_CG_ConfigInfo__criticalExtensions_PR_c1)
+    return NULL;
+  if (!cgci->criticalExtensions.choice.c1
+      || cgci->criticalExtensions.choice.c1->present != NR_CG_ConfigInfo__criticalExtensions__c1_PR_cg_ConfigInfo)
+    return NULL;
+
+  const NR_CG_ConfigInfo_IEs_t *cgci_ie = cgci->criticalExtensions.choice.c1->choice.cg_ConfigInfo;
+  if (!cgci_ie->ue_CapabilityInfo)
+    return NULL;
+
+  // Decode UE-CapabilityRAT-ContainerList
+  const OCTET_STRING_t *cap_buf = cgci_ie->ue_CapabilityInfo;
+  NR_UE_CapabilityRAT_ContainerList_t *clist = NULL;
+  asn_dec_rval_t dec_rval = uper_decode_complete(NULL,
+                                        &asn_DEF_NR_UE_CapabilityRAT_ContainerList,
+                                        (void **)&clist,
+                                        cap_buf->buf,
+                                        cap_buf->size);
+
+  if (dec_rval.code != RC_OK) {
+    LOG_W(NR_MAC,
+          "Failed to decode NR_UE_CapabilityRAT_ContainerList (%zu bits), size of OCTET_STRING %lu\n",
+          dec_rval.consumed,
+          cap_buf->size);
+    return NULL;
+  }
+  NR_UE_NR_Capability_t *cap = get_nr_cap(clist);
+  ASN_STRUCT_FREE(asn_DEF_NR_UE_CapabilityRAT_ContainerList, clist);
+  return cap;
+}
+
 NR_CellGroupConfig_t *clone_CellGroupConfig(const NR_CellGroupConfig_t *orig)
 {
  uint8_t buf[16636];
@@ -473,45 +522,75 @@ NR_CellGroupConfig_t *clone_CellGroupConfig(const NR_CellGroupConfig_t *orig)
  return cloned;
 }

-static NR_UE_info_t *create_new_UE(gNB_MAC_INST *mac, uint32_t cu_id)
+static NR_UE_info_t *create_new_UE(gNB_MAC_INST *mac, uint32_t cu_id, const NR_CG_ConfigInfo_t *cgci)
 {
+  const bool is_SA = IS_SA_MODE(get_softmodem_params());
  int CC_id = 0;
  rnti_t rnti;
-  bool found = nr_mac_get_new_rnti(&mac->UE_info, &rnti);
-  if (!found)
-    return NULL;
-
-  NR_UE_info_t *UE = get_new_nr_ue_inst(&mac->UE_info.uid_allocator, rnti, NULL);
-  AssertFatal(UE != NULL, "cannot create UE context, UE context setup failure not implemented\n");
-  if (!add_new_UE_RA(mac, UE)) {
-    delete_nr_ue_data(UE, /*not used*/ NULL, &mac->UE_info.uid_allocator);
-    LOG_E(NR_MAC, "UE list full while creating new UE\n");
-    return NULL;
+  if (get_softmodem_params()->phy_test) {
+    AssertFatal(mac->UE_info.connected_ue_list[0] == NULL, "phytest: UE already present\n");
+    rnti = 0x1234;
+  } else {
+    bool found = nr_mac_get_new_rnti(&mac->UE_info, &rnti);
+    if (!found)
+      return NULL;
  }

  f1_ue_data_t new_ue_data = {.secondary_ue = cu_id};
  bool success = du_add_f1_ue_data(rnti, &new_ue_data);
  DevAssert(success);

-  const NR_ServingCellConfigCommon_t *scc = mac->common_channels[CC_id].ServingCellConfigCommon;
-  const NR_ServingCellConfig_t *sccd = mac->common_channels[CC_id].pre_ServingCellConfig;
-  NR_CellGroupConfig_t *cellGroupConfig = get_initial_cellGroupConfig(UE->uid, scc, sccd, &mac->radio_config);
-  cellGroupConfig->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(UE->rnti, UE->uid, scc);
+  NR_UE_info_t *UE = get_new_nr_ue_inst(&mac->UE_info.uid_allocator, rnti, NULL);
+  AssertFatal(UE != NULL, "cannot create UE context, UE context setup failure not implemented\n");
+
+  NR_CellGroupConfig_t *cellGroupConfig = NULL;
+  NR_COMMON_channels_t *cc = &mac->common_channels[CC_id];
+  const NR_ServingCellConfigCommon_t *scc = cc->ServingCellConfigCommon;
+  const NR_ServingCellConfig_t *sccd = cc->pre_ServingCellConfig;
+  const nr_mac_config_t *configuration = &mac->radio_config;
+  if (is_SA) {
+    cellGroupConfig = get_initial_cellGroupConfig(UE->uid, scc, sccd, &mac->radio_config);
+    cellGroupConfig->spCellConfig->reconfigurationWithSync = get_reconfiguration_with_sync(UE->rnti, UE->uid, scc);
+  } else {
+    NR_UE_NR_Capability_t *cap = get_ue_nr_cap_from_cg_config_info(cgci);
+    cellGroupConfig = get_default_secondaryCellGroup(scc, sccd, cap, 1, 1, configuration, UE->uid);
+    // TODO: fixme: gives a new random RNTI
+    UE->rnti = cellGroupConfig->spCellConfig->reconfigurationWithSync->newUE_Identity;
+    // TODO: in NSA we assign capabilities here, otherwise outside => not logic
+    UE->capability = cap;
+  }
  // note: we don't pass the cellGroupConfig to add_new_nr_ue() because we need
  // the uid to create the CellGroupConfig (which is in the UE context created
  // by add_new_nr_ue(); it's a kind of chicken-and-egg problem), so below we
  // complete the UE context with the information that add_new_nr_ue() would
  // have added
+  AssertFatal(cellGroupConfig != NULL, "out of memory\n");
  UE->CellGroup = cellGroupConfig;

-  nr_rlc_activate_srb0(UE->rnti, UE, NULL);
-  nr_mac_prepare_ra_ue(mac, UE);
-  /* SRB1 is added to RLC and MAC in the handler later */
+  if (get_softmodem_params()->phy_test) {
+    // phytest mode: we don't set up RA, etc
+    free_and_zero(UE->ra); // test-mode: UE will not do RA
+    bool res = add_connected_nr_ue(mac, UE);
+    DevAssert(res);
+  } else {
+    if (!add_new_UE_RA(mac, UE)) {
+      delete_nr_ue_data(UE, /*not used*/ NULL, &mac->UE_info.uid_allocator);
+      LOG_E(NR_MAC, "UE list full while creating new UE\n");
+      return NULL;
+    }
+    nr_mac_prepare_ra_ue(mac, UE);
+
+    if (is_SA) {
+      /* SRB1 is added to RLC and MAC in the handler later */
+      nr_rlc_activate_srb0(UE->rnti, UE, NULL);
+    }
+  }
  return UE;
 }

 void ue_context_setup_request(const f1ap_ue_context_setup_t *req)
 {
+  const bool is_SA = IS_SA_MODE(get_softmodem_params());
  gNB_MAC_INST *mac = RC.nrmac[0];
  /* response has same type as request... */
  f1ap_ue_context_setup_t resp = {
@@ -525,9 +604,11 @@ void ue_context_setup_request(const f1ap_ue_context_setup_t *req)
  bool ue_id_provided = resp.gNB_DU_ue_id > 0 && resp.gNB_DU_ue_id < 0xffff;

  NR_UE_NR_Capability_t *ue_cap = NULL;
+  NR_CG_ConfigInfo_t *cg_configinfo = NULL;
  if (req->cu_to_du_rrc_information != NULL) {
    const cu_to_du_rrc_information_t *cu2du = req->cu_to_du_rrc_information;
-    AssertFatal(cu2du->cG_ConfigInfo == NULL, "CG-ConfigInfo not handled\n");
+    if (cu2du->cG_ConfigInfo != NULL)
+      cg_configinfo = get_cg_config_info(cu2du->cG_ConfigInfo, cu2du->cG_ConfigInfo_length);
    if (cu2du->handoverPreparationInfo != NULL) {
      ue_cap = get_ue_nr_cap_from_ho_prep_info(cu2du->handoverPreparationInfo, cu2du->handoverPreparationInfo_length);
    } else if (cu2du->uE_CapabilityRAT_ContainerList != NULL) {
@@ -535,15 +616,21 @@ void ue_context_setup_request(const f1ap_ue_context_setup_t *req)
    }
    AssertFatal(cu2du->measConfig == NULL, "MeasConfig not handled\n");
  }
+  /* 38.473: "For DC operation, the CG-ConfigInfo IE shall be included in the CU
+   * to DU RRC Information IE at the gNB acting as secondary node" As of now,
+   * we only handle NSA => we check we have CG-ConfigInfo if not SA or have SA
+   * and no CG-ConfigInfo */
+  AssertFatal(is_SA ^ (cg_configinfo != NULL), "cannot have SA and CG-ConfigInfo: NR-DC not supported xor need CG-ConfigInfo for NSA/phy-test/do-ra\n");

  NR_SCHED_LOCK(&mac->sched_lock);

  NR_UE_info_t *UE = NULL;
  if (!ue_id_provided) {
-    UE = create_new_UE(mac, req->gNB_CU_ue_id);
+    UE = create_new_UE(mac, req->gNB_CU_ue_id, cg_configinfo);
    resp.gNB_DU_ue_id = UE->rnti;
    resp.crnti = &UE->rnti;
  } else {
+    DevAssert(is_SA);
    UE = find_nr_UE(&mac->UE_info, req->gNB_DU_ue_id);
  }
  AssertFatal(UE, "no UE found or could not be created, but UE Context Setup Failed not implemented\n");
@@ -573,12 +660,13 @@ void ue_context_setup_request(const f1ap_ue_context_setup_t *req)

  NR_ServingCellConfigCommon_t *scc = mac->common_channels[0].ServingCellConfigCommon;
  UE->capability = ue_cap;
-  if (ue_cap != NULL) {
+  if (ue_cap != NULL && cg_configinfo == NULL) {
    // store the new UE capabilities, and update the cellGroupConfig
+    // only to be done if we did not already update through the cg_configinfo
    update_cellGroupConfig(new_CellGroup, UE->uid, UE->capability, &mac->radio_config, scc);
  }

-  if (!ue_id_provided) {
+  if (!ue_id_provided && cg_configinfo == NULL) {
    /* new UE: tell the UE to reestablish RLC */
    struct NR_CellGroupConfig__rlc_BearerToAddModList *addmod = new_CellGroup->rlc_BearerToAddModList;
    for (int i = 0; i < addmod->list.count; ++i) {
@@ -601,7 +689,8 @@ void ue_context_setup_request(const f1ap_ue_context_setup_t *req)

  ASN_STRUCT_FREE(asn_DEF_NR_CellGroupConfig, UE->CellGroup);
  UE->CellGroup = new_CellGroup;
-  configure_UE_BWP(mac, scc, UE, false, NR_SearchSpace__searchSpaceType_PR_common, -1, -1);
+  int ss_type = cg_configinfo ? NR_SearchSpace__searchSpaceType_PR_ue_Specific: NR_SearchSpace__searchSpaceType_PR_common;
+  configure_UE_BWP(mac, scc, UE, false, ss_type, -1, -1);

  NR_SCHED_UNLOCK(&mac->sched_lock);

@@ -329,7 +329,6 @@ void mac_top_init_gNB(ngran_node_t node_type,
      // setup PDCP, RLC
      nr_pdcp_entity_security_keys_and_algos_t null_security_parameters = {0};
      nr_pdcp_add_drbs(ENB_FLAG_NO, 0x1234, rbconfig->drb_ToAddModList, &null_security_parameters);
-      nr_rlc_add_drb(0x1234, rbconfig->drb_ToAddModList->list.array[0]->drb_Identity, rlc_rbconfig);

      // free memory
      free_nr_noS1_bearer_config(&rbconfig, &rlc_rbconfig);
@@ -3559,12 +3559,8 @@ NR_CellGroupConfig_t *get_default_secondaryCellGroup(const NR_ServingCellConfigC

  NR_CellGroupConfig_t *secondaryCellGroup = calloc(1, sizeof(*secondaryCellGroup));
  secondaryCellGroup->cellGroupId = scg_id;
-  /* LCID is 4 because the RLC layer requires it to be 3+rb_id; the rb_id is 1
-   * for first RB. We pre-configure RLC UM Bi-directional, priority is 1 */
-  NR_RLC_BearerConfig_t *RLC_BearerConfig = get_DRB_RLC_BearerConfig(4, 1, NR_RLC_Config_PR_um_Bi_Directional, 1);

-  secondaryCellGroup->rlc_BearerToAddModList = calloc(1, sizeof(*secondaryCellGroup->rlc_BearerToAddModList));
-  asn1cSeqAdd(&secondaryCellGroup->rlc_BearerToAddModList->list, RLC_BearerConfig);
+  /* rlc_BearerToAddModList is handled outside */

  secondaryCellGroup->mac_CellGroupConfig = configure_mac_cellgroup(&configuration->timer_config);
  secondaryCellGroup->physicalCellGroupConfig = configure_phy_cellgroup();