+/*******************************************************************
+ *
+ * @brief Process received Handover Request
+ *
+ * @details
+ *
+ * Function : XNAPProcHandoverReq
+ *
+ * Functionality:
+ * 1. Unpack Cell Id from msg and find DU to which it belongs
+ * 2. Create UE context for UE in handover and store in DU DB
+ * 3. Decode the F1AP UE context modification msg received in
+ * XNAP message buffer and extract UE configurations
+ * 4. Send UE context setup request to DU with these configs
+ *
+ * @params[in] Pointer to destination Id
+ * Pointer to message buffer
+ * @return void
+ *
+ ******************************************************************/
+void XNAPProcHandoverReq(uint32_t destId, Buffer *mBuf)
+{
+ uint8_t duIdx, cellIdx;
+ uint8_t cuUeF1apIdSrc;
+ uint32_t cellId;
+ DuDb *duDb;
+ CuCellCb *cellCb;
+
+ DU_LOG("\nINFO --> CU STUB : Received Handover Request");
+
+ /* Find DU Db and Cell Cb from cellId */
+ CMCHKUNPK(oduUnpackUInt32, &(cellId), mBuf);
+ for(duIdx = 0; duIdx < cuCb.numDu; duIdx++)
+ {
+ duDb = &cuCb.duInfo[duIdx];
+ SEARCH_CELL_DB(cellIdx, duDb, cellId, cellCb)
+ if(cellCb)
+ break;
+ }
+ if(!cellCb)
+ {
+ DU_LOG("\nERROR --> CU_STUB: Failed to find Cell Id [%d] received in HO Request", cellId);
+ return;
+ }
+
+ /* Fetch CU UE F1AP ID of UE in handover assigned by source CU */
+ CMCHKUNPK(oduUnpackUInt8, &(cuUeF1apIdSrc), mBuf);
+
+ /* Filling temporary UE context which will be used to create actual UE context at
+ * CU later */
+ CU_ALLOC(duDb->tempUeCtxtInHo, sizeof(CuUeCb));
+ if(!duDb->tempUeCtxtInHo)
+ {
+ DU_LOG("\nERROR --> XNAP : Failed to allocate memory to temporary UE context for UE in handover");
+ return;
+ }
+ memset(duDb->tempUeCtxtInHo, 0, sizeof(CuUeCb));
+ duDb->tempUeCtxtInHo->cellCb = cellCb;
+ duDb->tempUeCtxtInHo->gnbCuUeF1apId = ++cuCb.gnbCuUeF1apIdGenerator;
+ duDb->tempUeCtxtInHo->state = UE_HANDOVER_IN_PROGRESS;
+ duDb->tempUeCtxtInHo->hoInfo.HOType = Xn_Based_Inter_CU_HO;
+ duDb->tempUeCtxtInHo->hoInfo.srcNodeId = destId;
+ duDb->tempUeCtxtInHo->hoInfo.tgtNodeId = cuCb.cuCfgParams.cuId;
+ duDb->tempUeCtxtInHo->hoInfo.tgtCellId = cellId;
+ duDb->tempUeCtxtInHo->hoInfo.cuUeF1apIdSrc = cuUeF1apIdSrc;
+ duDb->tempUeCtxtInHo->hoInfo.cuUeF1apIdTgt = duDb->tempUeCtxtInHo->gnbCuUeF1apId;
+
+ /* Decode UE context modification response msg received in Xn Msg */
+ char *recvBuf;
+ MsgLen recvBufLen, copyLen;
+ F1AP_PDU_t *f1apMsg = NULLP;
+ F1AP_PDU_t f1apasnmsg ;
+
+ f1apMsg = &f1apasnmsg;
+ memset(f1apMsg, 0, sizeof(F1AP_PDU_t));
+ if(F1APDecodeMsg(f1apMsg, mBuf, &recvBuf, &recvBufLen) != ROK)
+ {
+ DU_LOG("\nERROR --> F1AP : F1AP PDU decode failed");
+ return;
+ }
+ CU_FREE(recvBuf, recvBufLen);
+ procUeContextModificationResponse(duDb->duId, f1apMsg, NULL, 0);
+}
+
+/*******************************************************************
+ *
+ * @brief Build And send dummy Handover request ack to Peer CU
+ *
+ * @details
+ *
+ * Function : BuildAndSendHOReqAck
+ *
+ * Functionality:
+ * Build And send dummy Handover request ack to Peer CU
+ *
+ * @params[in] Pointer to UE Cb
+ * Message to be sent
+ * Message Length
+ * @return void
+ *
+ ******************************************************************/
+void BuildAndSendHOReqAck(CuUeCb *ueCb, char *xnMsg, MsgLen xnMsgLen)
+{
+ Buffer *mBuf = NULLP;
+
+ if(ODU_GET_MSG_BUF(1, 1, &mBuf) == ROK)
+ {
+ if(ODU_ADD_POST_MSG_MULT((Data *)xnMsg, xnMsgLen, mBuf) == ROK)
+ {
+ CMCHKPK(oduPackUInt8, ueCb->gnbCuUeF1apId, mBuf);
+ CMCHKPK(oduPackUInt8, ueCb->hoInfo.cuUeF1apIdSrc, mBuf);
+ CMCHKPK(oduPackUInt8, HO_REQ_ACK, mBuf);
+ if(sctpSend(XN_INTERFACE, ueCb->hoInfo.srcNodeId, mBuf) != ROK)
+ {
+ DU_LOG("\nERROR --> CU_STUB: Failed to send handover request ack to peer CU");
+ }
+ }
+ }
+}
+
+/*******************************************************************
+ *
+ * @brief Process received Handover Request Ack
+ *
+ * @details
+ *
+ * Function : XNAPProcHandoverReqAck
+ *
+ * Functionality:
+ * 1. Unpack CU UE F1AP ID (by SCU) and fetch UE CB and
+ * the corresponding DU DB (SDU)
+ * 2. Unpack CU UE F1AP ID (by TCU) and fill in UEcb->hoInfo
+ * 3. Decode DU to CU RRC Container received in XNAP message
+ * buffer and extract UE configurations.
+ * 4. Send UE Context modification response to SDU conatining
+ * RRC Reconfig Message and command to stop transmission
+ * to UE in handover.
+ *
+ * @params[in] Destination Id
+ * Pointer to message buffer
+ * @return void
+ *
+ ******************************************************************/
+void XNAPProcHandoverReqAck(uint32_t destId, Buffer *mBuf)
+{
+ uint8_t duIdx, duId, ueIdx;
+ uint8_t cuUeF1apIdSrc;
+ uint8_t cuUeF1apIdTgt;
+ DuDb *duDb;
+ CuUeCb *ueCb;
+
+ DU_LOG("\nINFO --> CU STUB : Received Handover Request Acknowledgement");
+
+ /* Fetch UE CB and DU DB in Source CU for UE under Inter-CU Handover */
+ CMCHKUNPK(oduUnpackUInt8, &(cuUeF1apIdSrc), mBuf);
+ for(duIdx = 0; duIdx < cuCb.numDu; duIdx++)
+ {
+ for(ueIdx = 0; ueIdx < MAX_NUM_CELL * MAX_NUM_UE; ueIdx++)
+ {
+ if(cuCb.duInfo[duIdx].ueCb[ueIdx].gnbCuUeF1apId == cuUeF1apIdSrc)
+ {
+ duDb = &cuCb.duInfo[duIdx];
+ ueCb = &cuCb.duInfo[duIdx].ueCb[ueIdx];
+ break;
+ }
+ }
+ if(duDb && ueCb)
+ break;
+ }
+ if(!duDb || !ueCb)
+ {
+ DU_LOG("\nERROR --> CU STUB : UE CB not found for CU UE F1AP ID [%d]", cuUeF1apIdSrc);
+ return;
+ }
+
+ /* Decode CU UE F1AP ID assigned by Target CU to UE in handover and store
+ * this in hoInfo block for use during future message exchange between the
+ * two CUs */
+ CMCHKUNPK(oduUnpackUInt8, &(cuUeF1apIdTgt), mBuf);
+ ueCb->hoInfo.cuUeF1apIdTgt = cuUeF1apIdTgt;
+
+ /* Decode DU to CU RRC Container received in Xn Msg */
+ OCTET_STRING_t rrcCont;
+ MsgLen copyCnt;
+
+ /* Copy mBuf into char array to decode it */
+ memset(&rrcCont, 0, sizeof(OCTET_STRING_t));
+ ODU_GET_MSG_LEN(mBuf, &rrcCont.size);
+ CU_ALLOC(rrcCont.buf, rrcCont.size);
+ if(rrcCont.buf == NULLP)
+ {
+ DU_LOG("\nERROR --> XNAP : Memory allocation failed");
+ return;
+ }
+ if(ODU_COPY_MSG_TO_FIX_BUF(mBuf, 0, rrcCont.size, (Data *)rrcCont.buf, ©Cnt) != ROK)
+ {
+ DU_LOG("\nERROR --> F1AP : Failed while copying %d", copyCnt);
+ return;
+ }
+
+ /* Extract DU to CU RRC container information and store in UE CB */
+ extractDuToCuRrcCont(ueCb, rrcCont);
+
+ CU_FREE(rrcCont.buf, rrcCont.size);
+
+ /* Send UE Context Modification request after filling it using the information received in
+ * Xn Handover Request Ack */
+ if(BuildAndSendUeContextModificationReq(duDb->duId, ueCb, STOP_DATA_TX) != ROK)
+ {
+ DU_LOG("\nERROR -> F1AP : Failed at BuildAndSendUeContextModificationReq()");
+ return;
+ }
+}
+
+/*******************************************************************
+ *
+ * @brief Build And send dummy UE Context Release to Peer CU
+ *
+ * @details
+ *
+ * Function : BuildAndSendUeContextRelease
+ *
+ * Functionality:
+ * Build And send dummy UE Context Release to Peer CU
+ *
+ * @params[in] Pointer to UE Cb
+ * @return void
+ *
+ ******************************************************************/
+void BuildAndSendUeContextRelease(CuUeCb *ueCb)
+{
+ Buffer *mBuf = NULLP;
+
+ if(ODU_GET_MSG_BUF(1, 1, &mBuf) == ROK)
+ {
+ CMCHKPK(oduPackUInt8, ueCb->hoInfo.cuUeF1apIdSrc, mBuf);
+ CMCHKPK(oduPackUInt8, UE_CTXT_REL, mBuf);
+ if(sctpSend(XN_INTERFACE, ueCb->hoInfo.srcNodeId, mBuf) != ROK)
+ {
+ DU_LOG("\nERROR --> CU_STUB: Failed to send UE context release to peer CU");
+ }
+ }
+
+ return;
+}
+
+/*******************************************************************
+ * @brief Process received UE Context Release
+ *
+ * @details
+ *
+ * Function : XNAPProcUeContextRel
+ *
+ * Functionality:
+ * 1. Unpack CU UE F1AP ID (by SCU) and fetch UE CB and
+ * the corresponding DU DB (SDU)
+ * 2. Send UE Context release command to SDU
+ *
+ * @params[in] Destination Id
+ * Pointer to message buffer
+ * @return void
+ *
+ ******************************************************************/
+void XNAPProcUeContextRel(uint32_t destId, Buffer *mBuf)
+{
+ uint8_t duIdx, duId, ueIdx;
+ uint8_t cuUeF1apIdSrc;
+ DuDb *duDb;
+ CuUeCb *ueCb;
+
+ DU_LOG("\nINFO --> CU STUB : Received UE Context Release");
+
+ /* Fetch UE CB and DU DB in Source CU for UE under Inter-CU Handover */
+ CMCHKUNPK(oduUnpackUInt8, &(cuUeF1apIdSrc), mBuf);
+ for(duIdx = 0; duIdx < cuCb.numDu; duIdx++)
+ {
+ for(ueIdx = 0; ueIdx < MAX_NUM_CELL * MAX_NUM_UE; ueIdx++)
+ {
+ if(cuCb.duInfo[duIdx].ueCb[ueIdx].gnbCuUeF1apId == cuUeF1apIdSrc)
+ {
+ duDb = &cuCb.duInfo[duIdx];
+ ueCb = &duDb->ueCb[ueIdx];
+ break;
+ }
+ }
+ if(duDb && ueCb)
+ break;
+ }
+ if(!duDb || !ueCb)
+ {
+ DU_LOG("\nERROR --> CU STUB : UE CB not found for CU UE F1AP ID [%d]", cuUeF1apIdSrc);
+ return;
+ }
+
+ BuildAndSendUeContextReleaseCommand(duDb->duId, ueCb->gnbCuUeF1apId, ueCb->gnbDuUeF1apId);
+}
+