L3 RRC/NAS developments

src/gnb/rrc/connection.cpp

+//
+// This file is a part of UERANSIM open source project.
+// Copyright (c) 2021 ALİ GÜNGÖR.
+//
+// The software and all associated files are licensed under GPL-3.0
+// and subject to the terms and conditions defined in LICENSE file.
+//
+
+#include "task.hpp"
+
+#include <gnb/ngap/task.hpp>
+#include <lib/rrc/encode.hpp>
+
+#include <asn/ngap/ASN_NGAP_FiveG-S-TMSI.h>
+#include <asn/rrc/ASN_RRC_BCCH-BCH-Message.h>
+#include <asn/rrc/ASN_RRC_BCCH-DL-SCH-Message.h>
+#include <asn/rrc/ASN_RRC_CellGroupConfig.h>
+#include <asn/rrc/ASN_RRC_DL-CCCH-Message.h>
+#include <asn/rrc/ASN_RRC_DL-DCCH-Message.h>
+#include <asn/rrc/ASN_RRC_DLInformationTransfer-IEs.h>
+#include <asn/rrc/ASN_RRC_DLInformationTransfer.h>
+#include <asn/rrc/ASN_RRC_PCCH-Message.h>
+#include <asn/rrc/ASN_RRC_Paging.h>
+#include <asn/rrc/ASN_RRC_PagingRecord.h>
+#include <asn/rrc/ASN_RRC_PagingRecordList.h>
+#include <asn/rrc/ASN_RRC_RRCRelease-IEs.h>
+#include <asn/rrc/ASN_RRC_RRCRelease.h>
+#include <asn/rrc/ASN_RRC_RRCSetup-IEs.h>
+#include <asn/rrc/ASN_RRC_RRCSetup.h>
+#include <asn/rrc/ASN_RRC_RRCSetupComplete-IEs.h>
+#include <asn/rrc/ASN_RRC_RRCSetupComplete.h>
+#include <asn/rrc/ASN_RRC_RRCSetupRequest.h>
+#include <asn/rrc/ASN_RRC_UL-CCCH-Message.h>
+#include <asn/rrc/ASN_RRC_UL-CCCH1-Message.h>
+#include <asn/rrc/ASN_RRC_UL-DCCH-Message.h>
+#include <asn/rrc/ASN_RRC_ULInformationTransfer-IEs.h>
+#include <asn/rrc/ASN_RRC_ULInformationTransfer.h>
+
+namespace nr::gnb
+{
+
+void GnbRrcTask::receiveRrcSetupRequest(int ueId, const ASN_RRC_RRCSetupRequest &msg)
+{
+    auto *ue = tryFindUe(ueId);
+    if (ue)
+    {
+        // TODO: handle this more properly
+        m_logger->warn("Discarding RRC Setup Request, UE context already exists");
+        return;
+    }
+
+    if (msg.rrcSetupRequest.ue_Identity.present == ASN_RRC_InitialUE_Identity_PR_ng_5G_S_TMSI_Part1)
+    {
+        m_logger->err("RRC Setup Request with TMSI not implemented yet");
+        return;
+    }
+
+    if (msg.rrcSetupRequest.ue_Identity.present != ASN_RRC_InitialUE_Identity_PR_randomValue)
+    {
+        m_logger->err("Bad constructed RRC message ignored");
+        return;
+    }
+
+    int64_t initialRandomId = asn::GetBitStringLong<39>(msg.rrcSetupRequest.ue_Identity.choice.randomValue);
+    if (tryFindByInitialRandomId(initialRandomId) != nullptr)
+    {
+        m_logger->err("Initial random ID conflict [%ld], discarding RRC Setup Request", initialRandomId);
+        return;
+    }
+
+    ue = createUe(ueId);
+    ue->initialRandomId = initialRandomId;
+    ue->establishmentCause = msg.rrcSetupRequest.establishmentCause;
+
+    // Prepare RRC Setup
+    auto *pdu = asn::New<ASN_RRC_DL_CCCH_Message>();
+    pdu->message.present = ASN_RRC_DL_CCCH_MessageType_PR_c1;
+    pdu->message.choice.c1 = asn::NewFor(pdu->message.choice.c1);
+    pdu->message.choice.c1->present = ASN_RRC_DL_CCCH_MessageType__c1_PR_rrcSetup;
+    auto &rrcSetup = pdu->message.choice.c1->choice.rrcSetup = asn::New<ASN_RRC_RRCSetup>();
+    rrcSetup->rrc_TransactionIdentifier = getNextTid();
+    rrcSetup->criticalExtensions.present = ASN_RRC_RRCSetup__criticalExtensions_PR_rrcSetup;
+    auto &rrcSetupIEs = rrcSetup->criticalExtensions.choice.rrcSetup = asn::New<ASN_RRC_RRCSetup_IEs>();
+
+    ASN_RRC_CellGroupConfig masterCellGroup{};
+    masterCellGroup.cellGroupId = 0;
+
+    asn::SetOctetString(rrcSetupIEs->masterCellGroup,
+                        rrc::encode::EncodeS(asn_DEF_ASN_RRC_CellGroupConfig, &masterCellGroup));
+
+    m_logger->info("RRC Setup for UE[%d]", ueId);
+    sendRrcMessage(ueId, pdu);
+}
+
+void GnbRrcTask::receiveRrcSetupComplete(int ueId, const ASN_RRC_RRCSetupComplete &msg)
+{
+    auto *ue = findUe(ueId);
+    if (!ue)
+        return;
+
+    auto setupComplete = msg.criticalExtensions.choice.rrcSetupComplete;
+
+    auto *w = new NwGnbRrcToNgap(NwGnbRrcToNgap::INITIAL_NAS_DELIVERY);
+    w->ueId = ueId;
+    w->pdu = asn::GetOctetString(setupComplete->dedicatedNAS_Message);
+    w->rrcEstablishmentCause = ue->establishmentCause;
+    m_base->ngapTask->push(w);
+}
+
+} // namespace nr::gnb