Telnet module to manually/release DRBs of UE

common/utils/telnetsrv/CMakeLists.txt

@@ -59,8 +59,13 @@ add_library(telnetsrv_ci MODULE telnetsrv_ci.c)
 target_link_libraries(telnetsrv_ci PRIVATE asn1_nr_rrc_hdrs asn1_lte_rrc_hdrs)
 add_dependencies(telnetsrv telnetsrv_ci)
 
+message(STATUS "Add bearer specific telnet functions in libtelnetsrv_bearer.so")
+add_library(telnetsrv_bearer MODULE telnetsrv_bearer.c)
+target_link_libraries(telnetsrv_bearer PRIVATE asn1_nr_rrc_hdrs asn1_lte_rrc_hdrs)
+add_dependencies(telnetsrv telnetsrv_bearer)
+
 # all libraries should be written to root build dir
-set_target_properties(telnetsrv telnetsrv_enb telnetsrv_5Gue telnetsrv_ci
+set_target_properties(telnetsrv telnetsrv_enb telnetsrv_5Gue telnetsrv_ci telnetsrv_bearer
                       PROPERTIES LIBRARY_OUTPUT_DIRECTORY ../../..
 )
 

common/utils/telnetsrv/telnetsrv_bearer.c

@@ -0,0 +1,121 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+
+#include "openair2/RRC/NR/rrc_gNB_UE_context.h"
+
+#define TELNETSERVERCODE
+#include "telnetsrv.h"
+
+#define ERROR_MSG_RET(mSG, aRGS...) do { prnt(mSG, ##aRGS); return 1; } while (0)
+
+static int get_single_ue_rnti(void)
+{
+  rrc_gNB_ue_context_t *ue_context_p = NULL;
+  RB_FOREACH(ue_context_p, rrc_nr_ue_tree_s, &(RC.nrrrc[0]->rrc_ue_head)) {
+    return ue_context_p->ue_context.rnti;
+  }
+  return -1;
+}
+
+int get_single_rnti(char *buf, int debug, telnet_printfunc_t prnt)
+{
+  if (buf)
+    ERROR_MSG_RET("no parameter allowed\n");
+
+  int rnti = get_single_ue_rnti();
+  if (rnti < 1)
+    ERROR_MSG_RET("different number of UEs\n");
+
+  prnt("single UE RNTI %04x\n", rnti);
+  return 0;
+}
+
+void rrc_gNB_trigger_new_bearer(int rnti);
+int add_bearer(char *buf, int debug, telnet_printfunc_t prnt)
+{
+  int rnti = -1;
+  if (!buf) {
+    rnti = get_single_ue_rnti();
+    if (rnti < 1)
+      ERROR_MSG_RET("no UE found\n");
+  } else {
+    rnti = strtol(buf, NULL, 16);
+    if (rnti < 1 || rnti >= 0xfffe)
+      ERROR_MSG_RET("RNTI needs to be [1,0xfffe]\n");
+  }
+
+  // verify it exists in RRC as well
+  rrc_gNB_ue_context_t *rrcue = rrc_gNB_get_ue_context_by_rnti(RC.nrrrc[0], rnti);
+  if (!rrcue)
+    ERROR_MSG_RET("could not find UE with RNTI %04x\n", rnti);
+
+  rrc_gNB_trigger_new_bearer(rnti);
+  prnt("called rrc_gNB_trigger_new_bearer(%04x)\n", rnti);
+  return 0;
+}
+
+void rrc_gNB_trigger_release_bearer(int rnti);
+int release_bearer(char *buf, int debug, telnet_printfunc_t prnt)
+{
+  int rnti = -1;
+  if (!buf) {
+    rnti = get_single_ue_rnti();
+    if (rnti < 1)
+      ERROR_MSG_RET("no UE found\n");
+  } else {
+    rnti = strtol(buf, NULL, 16);
+    if (rnti < 1 || rnti >= 0xfffe)
+      ERROR_MSG_RET("RNTI needs to be [1,0xfffe]\n");
+  }
+
+  // verify it exists in RRC as well
+  rrc_gNB_ue_context_t *rrcue = rrc_gNB_get_ue_context_by_rnti(RC.nrrrc[0], rnti);
+  if (!rrcue)
+    ERROR_MSG_RET("could not find UE with RNTI %04x\n", rnti);
+
+  rrc_gNB_trigger_release_bearer(rnti);
+  prnt("called rrc_gNB_trigger_release_bearer(%04x)\n", rnti);
+  return 0;
+}
+
+static telnetshell_cmddef_t bearercmds[] = {
+  {"get_single_rnti", "", get_single_rnti},
+  {"add_bearer", "[rnti(hex,opt)]", add_bearer},
+  {"release_bearer", "[rnti(hex,opt)]", release_bearer},
+  {"", "", NULL},
+};
+
+static telnetshell_vardef_t bearervars[] = {
+
+  {"", 0, 0, NULL}
+};
+
+void add_bearer_cmds(void) {
+  add_telnetcmd("bearer", bearervars, bearercmds);
+}

openair2/RRC/NR/rrc_gNB.c

@@ -46,6 +46,7 @@
 #include "LAYER2/NR_MAC_gNB/mac_proto.h"
 #include "common/utils/LOG/log.h"
 #include "RRC/NR/MESSAGES/asn1_msg.h"
+#include "openair2/E1AP/e1ap_asnc.h"
 
 #include "NR_BCCH-BCH-Message.h"
 #include "NR_UL-DCCH-Message.h"
@@ -2858,6 +2859,147 @@ rrc_gNB_generate_RRCRelease(
   /* UE will be freed after UE context release complete */
 }
 
+void rrc_gNB_trigger_new_bearer(int rnti)
+{
+  /* get RRC and UE */
+  gNB_RRC_INST *rrc = RC.nrrrc[0];
+  rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context_by_rnti(rrc, rnti);
+  if (ue_context_p == NULL) {
+    LOG_E(RRC, "unknown UE RNTI %04x\n", rnti);
+    return;
+  }
+  gNB_RRC_UE_t *ue = &ue_context_p->ue_context;
+
+  /* get the existing PDU sessoin */
+  if (ue->nb_of_pdusessions < 1) {
+    LOG_E(RRC, "no PDU session set up yet, cannot create additional bearer\n");
+    return;
+  }
+
+  if (ue->established_drbs[0].status != DRB_INACTIVE
+      && ue->established_drbs[1].status != DRB_INACTIVE) {
+    LOG_E(RRC, "already have two established bearers, aborting\n");
+    return;
+  }
+
+  e1ap_bearer_setup_req_t bearer_req = {0};
+  bearer_req.gNB_cu_cp_ue_id = ue->rrc_ue_id;
+  bearer_req.cipheringAlgorithm = ue->ciphering_algorithm;
+  memcpy(bearer_req.encryptionKey, ue->kgnb, sizeof(ue->kgnb));
+  bearer_req.integrityProtectionAlgorithm = ue->integrity_algorithm;
+  memcpy(bearer_req.integrityProtectionKey, ue->kgnb, sizeof(ue->kgnb));
+  bearer_req.ueDlAggMaxBitRate = 10000; /* probably does not matter */
+
+  pdu_session_to_setup_t *pdu = &bearer_req.pduSession[0];
+  //bearer_req.numPDUSessions++;
+  bearer_req.numPDUSessions = 1;
+  //pdu->sessionId = session->pdusession_id;
+  //pdu->sst = msg->allowed_nssai[i].sST;
+  //pdu->integrityProtectionIndication = rrc->security.do_drb_integrity ? E1AP_IntegrityProtectionIndication_required : E1AP_IntegrityProtectionIndication_not_needed;
+
+  //pdu->confidentialityProtectionIndication = rrc->security.do_drb_ciphering ? E1AP_ConfidentialityProtectionIndication_required : E1AP_ConfidentialityProtectionIndication_not_needed;
+  //pdu->teId = session->gtp_teid;
+  pdu->numDRB2Setup = 1; // One DRB per PDU Session. TODO: Remove hardcoding
+  DRB_nGRAN_to_setup_t *drb = &pdu->DRBnGRanList[0];
+  int drb_id = 2;
+  drb->id = drb_id;
+
+  drb->defaultDRB = E1AP_DefaultDRB_false;
+  drb->sDAP_Header_UL = !(rrc->configuration.enable_sdap);
+  drb->sDAP_Header_DL = !(rrc->configuration.enable_sdap);
+
+  drb->pDCP_SN_Size_UL = E1AP_PDCP_SN_Size_s_18;
+  drb->pDCP_SN_Size_DL = E1AP_PDCP_SN_Size_s_18;
+
+  drb->discardTimer = E1AP_DiscardTimer_infinity;
+  drb->reorderingTimer = E1AP_T_Reordering_ms0;
+
+  drb->rLC_Mode = E1AP_RLC_Mode_rlc_am;
+
+  drb->numCellGroups = 1; // assume one cell group associated with a DRB
+
+  for (int k=0; k < drb->numCellGroups; k++) {
+    cell_group_t *cellGroup = drb->cellGroupList + k;
+    cellGroup->id = 0; // MCG
+  }
+
+  int xid = rrc_gNB_get_next_transaction_identifier(0);
+  /* generate a new bearer, it will be put into internal RRC state and picked
+   * up later */
+  generateDRB(ue,
+              drb_id,
+              &ue->pduSession[0],
+              rrc->configuration.enable_sdap,
+              rrc->security.do_drb_integrity,
+              rrc->security.do_drb_ciphering);
+
+  /* associate the new bearer to it */
+  ue->xids[xid] = RRC_PDUSESSION_MODIFY;
+  ue->pduSession[0].xid = xid; // hack: fake xid for ongoing PDU session
+  LOG_W(RRC, "trigger new bearer %ld for UE %04x xid %d\n", drb->id, ue->rnti, xid);
+  rrc->cucp_cuup.bearer_context_setup(&bearer_req, 0);
+}
+
+void rrc_gNB_trigger_release_bearer(int rnti)
+{
+  /* get RRC and UE */
+  gNB_RRC_INST *rrc = RC.nrrrc[0];
+  rrc_gNB_ue_context_t *ue_context_p = rrc_gNB_get_ue_context_by_rnti(rrc, rnti);
+  if (ue_context_p == NULL) {
+    LOG_E(RRC, "unknown UE RNTI %04x\n", rnti);
+    return;
+  }
+  gNB_RRC_UE_t *ue = &ue_context_p->ue_context;
+
+  if (ue->established_drbs[1].status == DRB_INACTIVE) {
+    LOG_E(RRC, "no second bearer, aborting\n");
+    return;
+  }
+
+  // don't use E1: bearer release is not implemented, call directly
+  // into PDCP/SDAP and then send corresponding message via F1
+
+  int drb_id = 2;
+  ue->established_drbs[1].status = DRB_INACTIVE;
+  ue->DRB_ReleaseList = calloc(1, sizeof(*ue->DRB_ReleaseList));
+  AssertFatal(ue->DRB_ReleaseList != NULL, "out of memory\n");
+  NR_DRB_Identity_t *asn1_drb = malloc(sizeof(*asn1_drb));
+  AssertFatal(asn1_drb != NULL, "out of memory\n");
+  int idx = 0;
+  NR_DRB_ToAddModList_t *drb_list = createDRBlist(ue, false);
+  while (idx < drb_list->list.count) {
+    const NR_DRB_ToAddMod_t *drbc = drb_list->list.array[idx];
+    if (drbc->drb_Identity == drb_id)
+      break;
+    ++idx;
+  }
+  if (idx < drb_list->list.count) {
+    nr_pdcp_release_drb(rnti, drb_id);
+    asn_sequence_del(&drb_list->list, idx, 1);
+  }
+  *asn1_drb = drb_id;
+  asn1cSeqAdd(&ue->DRB_ReleaseList->list, asn1_drb);
+
+  f1ap_drb_to_be_released_t drbs_to_be_released[1] = {{.rb_id = drb_id}};
+  f1_ue_data_t ue_data = cu_get_f1_ue_data(ue->rrc_ue_id);
+  f1ap_ue_context_modif_req_t ue_context_modif_req = {
+    .gNB_CU_ue_id = ue->rrc_ue_id,
+    .gNB_DU_ue_id = ue_data.secondary_ue,
+    .plmn.mcc = rrc->configuration.mcc[0],
+    .plmn.mnc = rrc->configuration.mnc[0],
+    .plmn.mnc_digit_length = rrc->configuration.mnc_digit_length[0],
+    .nr_cellid = rrc->nr_cellid,
+    .servCellId = 0, /* TODO: correct value? */
+    .srbs_to_be_setup_length = 0,
+    .srbs_to_be_setup = NULL,
+    .drbs_to_be_setup_length = 0,
+    .drbs_to_be_setup = NULL,
+    .drbs_to_be_released_length = 1,
+    .drbs_to_be_released = drbs_to_be_released,
+  };
+  rrc->mac_rrc.ue_context_modification_request(&ue_context_modif_req);
+}
+
 int rrc_gNB_generate_pcch_msg(uint32_t tmsi, uint8_t paging_drx, instance_t instance, uint8_t CC_id){
   const unsigned int Ttab[4] = {32,64,128,256};
   uint8_t Tc;